Anesthetic propofol overdose causes endothelial cytotoxicity in vitro and endothelial barrier dysfunction in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Ming-Chung; Department of Anesthesiology, Chi Mei Medical Center, Liouying, Tainan, Taiwan; Chen, Chia-Ling

An overdose and a prolonged treatment of propofol may cause cellular cytotoxicity in multiple organs and tissues such as brain, heart, kidney, skeletal muscle, and immune cells; however, the underlying mechanism remains undocumented, particularly in vascular endothelial cells. Our previous studies showed that the activation of glycogen synthase kinase (GSK)-3 is pro-apoptotic in phagocytes during overdose of propofol treatment. Regarding the intravascular administration of propofol, we therefore hypothesized that propofol overdose also induces endothelial cytotoxicity via GSK-3. Propofol overdose (100 μg/ml) inhibited growth in human arterial and microvascular endothelial cells. After treatment, most of the endothelial cells experienced caspase-independent necrosis-likemore » cell death. The activation of cathepsin D following lysosomal membrane permeabilization (LMP) determined necrosis-like cell death. Furthermore, propofol overdose also induced caspase-dependent apoptosis, at least in part. Caspase-3 was activated and acted downstream of mitochondrial transmembrane potential (MTP) loss; however, lysosomal cathepsins were not required for endothelial cell apoptosis. Notably, activation of GSK-3 was essential for propofol overdose-induced mitochondrial damage and apoptosis, but not necrosis-like cell death. Intraperitoneal administration of a propofol overdose in BALB/c mice caused an increase in peritoneal vascular permeability. These results demonstrate the cytotoxic effects of propofol overdose, including cathepsin D-regulated necrosis-like cell death and GSK-3-regulated mitochondrial apoptosis, on endothelial cells in vitro and the endothelial barrier dysfunction by propofol in vivo. Highlights: ► Propofol overdose causes apoptosis and necrosis in endothelial cells. ► Propofol overdose triggers lysosomal dysfunction independent of autophagy. ► Glycogen synthase kinase-3 facilitates propofol overdose-induced apoptosis. ► Propofol overdose causes an increase in peritoneal vascular permeability.« less

Lipopolysaccharide-induced pulmonary endothelial barrier disruption and lung edema: critical role for bicarbonate stimulation of AC10.

PubMed

Nickols, Jordan; Obiako, Boniface; Ramila, K C; Putinta, Kevin; Schilling, Sarah; Sayner, Sarah L

2015-12-15

Bacteria-induced sepsis is a common cause of pulmonary endothelial barrier dysfunction and can progress toward acute respiratory distress syndrome. Elevations in intracellular cAMP tightly regulate pulmonary endothelial barrier integrity; however, cAMP signals are highly compartmentalized: whether cAMP is barrier-protective or -disruptive depends on the compartment (plasma membrane or cytosol, respectively) in which the signal is generated. The mammalian soluble adenylyl cyclase isoform 10 (AC10) is uniquely stimulated by bicarbonate and is expressed in pulmonary microvascular endothelial cells (PMVECs). Elevated extracellular bicarbonate increases cAMP in PMVECs to disrupt the endothelial barrier and increase the filtration coefficient (Kf) in the isolated lung. We tested the hypothesis that sepsis-induced endothelial barrier disruption and increased permeability are dependent on extracellular bicarbonate and activation of AC10. Our findings reveal that LPS-induced endothelial barrier disruption is dependent on extracellular bicarbonate: LPS-induced barrier failure and increased permeability are exacerbated in elevated bicarbonate compared with low extracellular bicarbonate. The AC10 inhibitor KH7 attenuated the bicarbonate-dependent LPS-induced barrier disruption. In the isolated lung, LPS failed to increase Kf in the presence of minimal perfusate bicarbonate. An increase in perfusate bicarbonate to the physiological range (24 mM) revealed the LPS-induced increase in Kf, which was attenuated by KH7. Furthermore, in PMVECs treated with LPS for 6 h, there was a dose-dependent increase in AC10 expression. Thus these findings reveal that LPS-induced pulmonary endothelial barrier failure requires bicarbonate activation of AC10. Copyright © 2015 the American Physiological Society.

Lipopolysaccharide-induced pulmonary endothelial barrier disruption and lung edema: critical role for bicarbonate stimulation of AC10

PubMed Central

Nickols, Jordan; Obiako, Boniface; Ramila, K. C.; Putinta, Kevin; Schilling, Sarah

2015-01-01

Bacteria-induced sepsis is a common cause of pulmonary endothelial barrier dysfunction and can progress toward acute respiratory distress syndrome. Elevations in intracellular cAMP tightly regulate pulmonary endothelial barrier integrity; however, cAMP signals are highly compartmentalized: whether cAMP is barrier-protective or -disruptive depends on the compartment (plasma membrane or cytosol, respectively) in which the signal is generated. The mammalian soluble adenylyl cyclase isoform 10 (AC10) is uniquely stimulated by bicarbonate and is expressed in pulmonary microvascular endothelial cells (PMVECs). Elevated extracellular bicarbonate increases cAMP in PMVECs to disrupt the endothelial barrier and increase the filtration coefficient (Kf) in the isolated lung. We tested the hypothesis that sepsis-induced endothelial barrier disruption and increased permeability are dependent on extracellular bicarbonate and activation of AC10. Our findings reveal that LPS-induced endothelial barrier disruption is dependent on extracellular bicarbonate: LPS-induced barrier failure and increased permeability are exacerbated in elevated bicarbonate compared with low extracellular bicarbonate. The AC10 inhibitor KH7 attenuated the bicarbonate-dependent LPS-induced barrier disruption. In the isolated lung, LPS failed to increase Kf in the presence of minimal perfusate bicarbonate. An increase in perfusate bicarbonate to the physiological range (24 mM) revealed the LPS-induced increase in Kf, which was attenuated by KH7. Furthermore, in PMVECs treated with LPS for 6 h, there was a dose-dependent increase in AC10 expression. Thus these findings reveal that LPS-induced pulmonary endothelial barrier failure requires bicarbonate activation of AC10. PMID:26475732

[Epithelial dysfunction associated with pyo-inflammatory diseases of the ENT organs].

PubMed

Petukhova, N A

The modern concept of epithelial-endothelial dysfunction and epithelial-endothelial distress-syndrome associated with pyo-inflammatory ENT diseases is presented. It has provided a basis for the analysis of the initial stages of etiopathogenesis of acute and chronic inflammation in the ENT system including the mucous and associated lymphoid tissues as well as the Pirogov-Waldeyer limphopharyngeal ring making up the first protective barrier. The leading role of dysbiosis of synanthropic microflora and endotoxins of the Gram-negative bacteria in the mechanisms of regional responsiveness of the organism to the infection and chronic endotoxic aggression is demonstrated. The regional and synthetic mechanisms underlying the interaction between the external and internal media of the organism are subjected to the analysis with special reference to those operating in epithelium. The possible variants of the outcome of these processes are considered including both the recovery and the development of chronic inflammation. It has been proved that the exhaustion of the internal reserves for the stabilization of the epithelium-associated lymphoid tissue system including the Pirogov-Waldeyer limphopharyngeal ring leads to the formation of epithelial dysfunction as the initial stage of epithelial-endothelial dysfunction and epithelial-endothelial distress-syndrome. It is concluded that the modern concept of epithelial-endothelial dysfunction and epithelial-endothelial distress-syndrome is a fundamental interdisciplinary phenomenon.

Endothelial dysfunction in dengue virus pathology.

PubMed

Vervaeke, Peter; Vermeire, Kurt; Liekens, Sandra

2015-01-01

Dengue virus (DENV) is a leading cause of illness and death, mainly in the (sub)tropics, where it causes dengue fever and/or the more serious diseases dengue hemorrhagic fever and dengue shock syndrome that are associated with changes in vascular permeability. Despite extensive research, the pathogenesis of DENV is still poorly understood and, although endothelial cells represent the primary fluid barrier of the blood vessels, the extent to which these cells contribute to DENV pathology is still under debate. The primary target cells for DENV are dendritic cells and monocytes/macrophages that release various chemokines and cytokines upon infection, which can activate the endothelium and are thought to play a major role in DENV-induced vascular permeability. However, recent studies indicate that DENV also replicates in endothelial cells and that DENV-infected endothelial cells may directly contribute to viremia, immune activation, vascular permeability and immune targeting of the endothelium. Also, the viral non-structural protein-1 and antibodies directed against this secreted protein have been reported to be involved in endothelial cell dysfunction. This review provides an extensive overview of the effects of DENV infection on endothelial cell physiology and barrier function. Copyright © 2014 John Wiley & Sons, Ltd.

Hypoxia/Aglycemia-Induced Endothelial Barrier Dysfunction and Tight Junction Protein Downregulation Can Be Ameliorated by Citicoline

PubMed Central

Pan, Qunwen; Zhao, Yuhui; Chen, Ji; Zhao, Bin; Chen, Yanfang

2013-01-01

This study explores the effect of citicoline on the permeability and expression of tight junction proteins (TJPs) in endothelial cells under hypoxia/aglycemia conditions. Hypoxia or oxygen and glucose deprivation (OGD) was utilized to induce endothelial barrier breakdown model on human umbilical vein endothelial cells (HUVECs) and mouse brain microvascular endothelial cells (bEnd.3s). The effect of citicoline on endothelial barrier breakdown models was determined at either low or high concentrations. FITC-Dextran flux was used to examine the endothelial permeability. The expression of TJPs was measured by immunofluorescence, Real-time PCR and Western Blot methods. Results showed that hypoxia or OGD increased the permeability of HUVECs accompanied with down-regulation of occludens-1 (ZO-1) and occludin at both mRNA and protein levels. Similarly in bEnd.3s, hypoxia increased the permeability and decreased the expression of ZO-1 and claudin-5. Citicoline treatment dose-dependently decreased the permeability in these two models, which paralleled with elevated expression of TJPs. The data demonstrate that citicoline restores the barrier function of endothelial cells compromised by hypoxia/aglycemia probably via up-regulating the expression of TJPs. PMID:24358213

Pericyte Derived Sphinogosine 1-Phosphate Induces the Expression of Adhesion Proteins and Modulates the Retinal Endothelial Cell Barrier

PubMed Central

McGuire, P.G.; Rangasamy, S.; Maestas, J.; Das, A.

2011-01-01

Objective The mechanisms that regulate the physical interaction of pericytes and endothelial cells and the effects of these interactions on interendothelial cell junctions are not well understood. We determined the extent to which vascular pericytes could regulate pericyte-endothelial adhesion and the consequences that this disruption might have on the function of the endothelial barrier. Methods and Results Human retinal microvascular endothelial cells were co-cultured with pericytes, and the effect on the monolayer resistance of endothelial cells and expression of the cell junction molecules N-cadherin and VE-cadherin were measured. The molecules responsible for the effect of pericytes or pericyte conditioned media on the endothelial resistance and cell junction molecules were further analyzed. Our results indicate that pericytes increase the barrier properties of endothelial cell monolayers. This barrier function is maintained through the secretion of pericyte-derived sphingosine 1-phosphate (S1P). S1P aids in maintenance of microvascular stability by up-regulating the expression of N-cadherin and VE-cadherin, and down-regulating the expression of angiopoietin 2. Conclusion Under normal circumstances, the retinal vascular pericytes maintain pericyte-endothelial contacts and vascular barrier function through the secretion of S1P. Alteration of pericyte-derived S1P production may be an important mechanism in the development of diseases characterized by vascular dysfunction and increased permeability. PMID:21940944

Sinomenine alleviates high glucose-induced renal glomerular endothelial hyperpermeability by inhibiting the activation of RhoA/ROCK signaling pathway.

PubMed

Yin, Qingqiao; Xia, Yuanyu; Wang, Guan

2016-09-02

As an early sign of diabetic cardiovascular disease, endothelial dysfunction may contribute to progressive diabetic nephropathy (DN). Endothelial hyperpermeability induced by hyperglycemia (HG) is a central pathogenesis for DN. Sinomenine (SIN) has strong anti-inflammatory and renal protective effects, following an unknown protective mechanism against HG-induced hyperpermeability. We herein explored the role of SIN in vitro in an HG-induced barrier dysfunction model in human renal glomerular endothelial cells (HRGECs). The cells were exposed to SIN and/or HG for 24 h, the permeability of which was significantly increased by HG. Moreover, junction protein occludin in the cell-cell junction area and its total expression in HRGECs were significantly decreased by HG. However, the dysfunction of tight junction and hyperpermeability of HRGECs were significantly reversed by SIN. Furthermore, SIN prevented HG-increased reactive oxygen species (ROS) by activating nuclear factor-E2-related factor 2 (Nrf2). Interestingly, activation of RhoA/ROCK induced by HG was reversed by SIN or ROCK inhibitor. HG-induced hyperpermeability was prevented by SIN. High ROS level, tight junction dysfunction and RhoA/ROCK activation were significantly attenuated with knockdown of Nrf2. Mediated by activation of Nrf2, SIN managed to significantly prevent HG-disrupted renal endothelial barrier function by suppressing the RhoA/ROCK signaling pathway through reducing ROS. We successfully identified a novel pathway via which SIN exerted antioxidative and renal protective functions, and provided a molecular basis for potential SIN applications in treating DN vascular disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

Acute alcohol intoxication-induced microvascular leakage.

PubMed

Doggett, Travis M; Breslin, Jerome W

2014-09-01

Alcohol intoxication can increase inflammation and worsen injury, yet the mechanisms involved are not clear. We investigated whether acute alcohol intoxication increases microvascular permeability and investigated potential signaling mechanisms in endothelial cells that may be involved. Conscious rats received a 2.5 g/kg alcohol bolus via gastric catheters to produce acute intoxication. Microvascular leakage of intravenously administered fluorescein isothiocyanate (FITC)-conjugated albumin (FITC-albumin) from the mesenteric microcirculation was assessed by intravital microscopy. Endothelial-specific mechanisms were studied using cultured endothelial cell monolayers. Transendothelial electrical resistance (TER) served as an index of barrier function, before and after treatment with alcohol or its metabolite acetaldehyde. Pharmacologic agents were used to test the roles of alcohol metabolism, oxidative stress, p38 mitogen-activated protein kinase (MAPK), myosin light-chain kinase (MLCK), rho kinase (ROCK), and exchange protein activated by cAMP (Epac). VE-cadherin localization was investigated to assess junctional integrity. Rac1 and RhoA activation was assessed by ELISA assays. Alcohol significantly increased FITC-albumin extravasation from the mesenteric microcirculation. Alcohol also significantly decreased TER and disrupted VE-cadherin organization at junctions. Acetaldehyde significantly decreased TER, but inhibition of alcohol dehydrogenase or application of a superoxide dismutase mimetic failed to prevent alcohol-induced decreases in TER. Inhibition of p38 MAPK, but not MLCK or ROCK, significantly attenuated the alcohol-induced barrier dysfunction. Alcohol rapidly decreased GTP-bound Rac1 but not RhoA during the drop in TER. Activation of Epac increased TER, but did not prevent alcohol from decreasing TER. However, activation of Epac after initiation of alcohol-induced barrier dysfunction quickly resolved TER to baseline levels. Our results suggest that alcohol intoxication increases microvascular permeability to plasma proteins. The data also suggest the endothelial-specific mechanism involves the p38 MAPK, Rac1, and reorganization of VE-cadherin at junctions. Last, activation of Epac can quickly resolve alcohol-induced endothelial barrier dysfunction. Copyright © 2014 by the Research Society on Alcoholism.

Neurovascular unit dysfunction with blood-brain barrier hyperpermeability contributes to major depressive disorder: a review of clinical and experimental evidence

PubMed Central

2013-01-01

About one-third of people with major depressive disorder (MDD) fail at least two antidepressant drug trials at 1 year. Together with clinical and experimental evidence indicating that the pathophysiology of MDD is multifactorial, this observation underscores the importance of elucidating mechanisms beyond monoaminergic dysregulation that can contribute to the genesis and persistence of MDD. Oxidative stress and neuroinflammation are mechanistically linked to the presence of neurovascular dysfunction with blood-brain barrier (BBB) hyperpermeability in selected neurological disorders, such as stroke, epilepsy, multiple sclerosis, traumatic brain injury, and Alzheimer’s disease. In contrast to other major psychiatric disorders, MDD is frequently comorbid with such neurological disorders and constitutes an independent risk factor for morbidity and mortality in disorders characterized by vascular endothelial dysfunction (cardiovascular disease and diabetes mellitus). Oxidative stress and neuroinflammation are implicated in the neurobiology of MDD. More recent evidence links neurovascular dysfunction with BBB hyperpermeability to MDD without neurological comorbidity. We review this emerging literature and present a theoretical integration between these abnormalities to those involving oxidative stress and neuroinflammation in MDD. We discuss our hypothesis that alterations in endothelial nitric oxide levels and endothelial nitric oxide synthase uncoupling are central mechanistic links in this regard. Understanding the contribution of neurovascular dysfunction with BBB hyperpermeability to the pathophysiology of MDD may help to identify novel therapeutic and preventative approaches. PMID:24289502

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, Qingqiao; Xia, Yuanyu, E-mail: xiayuanyu.wh@gmail.com; Wang, Guan

As an early sign of diabetic cardiovascular disease, endothelial dysfunction may contribute to progressive diabetic nephropathy (DN). Endothelial hyperpermeability induced by hyperglycemia (HG) is a central pathogenesis for DN. Sinomenine (SIN) has strong anti-inflammatory and renal protective effects, following an unknown protective mechanism against HG-induced hyperpermeability. We herein explored the role of SIN in vitro in an HG-induced barrier dysfunction model in human renal glomerular endothelial cells (HRGECs). The cells were exposed to SIN and/or HG for 24 h, the permeability of which was significantly increased by HG. Moreover, junction protein occludin in the cell-cell junction area and its total expression inmore » HRGECs were significantly decreased by HG. However, the dysfunction of tight junction and hyperpermeability of HRGECs were significantly reversed by SIN. Furthermore, SIN prevented HG-increased reactive oxygen species (ROS) by activating nuclear factor-E2-related factor 2 (Nrf2). Interestingly, activation of RhoA/ROCK induced by HG was reversed by SIN or ROCK inhibitor. HG-induced hyperpermeability was prevented by SIN. High ROS level, tight junction dysfunction and RhoA/ROCK activation were significantly attenuated with knockdown of Nrf2. Mediated by activation of Nrf2, SIN managed to significantly prevent HG-disrupted renal endothelial barrier function by suppressing the RhoA/ROCK signaling pathway through reducing ROS. We successfully identified a novel pathway via which SIN exerted antioxidative and renal protective functions, and provided a molecular basis for potential SIN applications in treating DN vascular disorders.« less

Induced Pluripotent Stem Cell-Derived Endothelial Cells in Insulin Resistance and Metabolic Syndrome.

PubMed

Carcamo-Orive, Ivan; Huang, Ngan F; Quertermous, Thomas; Knowles, Joshua W

2017-11-01

Insulin resistance leads to a number of metabolic and cellular abnormalities including endothelial dysfunction that increase the risk of vascular disease. Although it has been particularly challenging to study the genetic determinants that predispose to abnormal function of the endothelium in insulin-resistant states, the possibility of deriving endothelial cells from induced pluripotent stem cells generated from individuals with detailed clinical phenotyping, including accurate measurements of insulin resistance accompanied by multilevel omic data (eg, genetic and genomic characterization), has opened new avenues to study this relationship. Unfortunately, several technical barriers have hampered these efforts. In the present review, we summarize the current status of induced pluripotent stem cell-derived endothelial cells for modeling endothelial dysfunction associated with insulin resistance and discuss the challenges to overcoming these limitations. © 2017 American Heart Association, Inc.

Tight junctions and the modulation of barrier function in disease

PubMed Central

2008-01-01

Tight junctions create a paracellular barrier in epithelial and endothelial cells protecting them from the external environment. Two different classes of integral membrane proteins constitute the tight junction strands in epithelial cells and endothelial cells, occludin and members of the claudin protein family. In addition, cytoplasmic scaffolding molecules associated with these junctions regulate diverse physiological processes like proliferation, cell polarity and regulated diffusion. In many diseases, disruption of this regulated barrier occurs. This review will briefly describe the molecular composition of the tight junctions and then present evidence of the link between tight junction dysfunction and disease. PMID:18415116

Direct visualization of the arterial wall water permeability barrier using CARS microscopy

PubMed Central

Lucotte, Bertrand M.; Powell, Chloe; Knutson, Jay R.; Combs, Christian A.; Malide, Daniela; Yu, Zu-Xi; Knepper, Mark; Patel, Keval D.; Pielach, Anna; Johnson, Errin; Borysova, Lyudmyla; Balaban, Robert S.

2017-01-01

The artery wall is equipped with a water permeation barrier that allows blood to flow at high pressure without significant water leak. The precise location of this barrier is unknown despite its importance in vascular function and its contribution to many vascular complications when it is compromised. Herein we map the water permeability in intact arteries, using coherent anti-Stokes Raman scattering (CARS) microscopy and isotopic perfusion experiments. Generation of the CARS signal is optimized for water imaging with broadband excitation. We identify the water permeation barrier as the endothelial basolateral membrane and show that the apical membrane is highly permeable. This is confirmed by the distribution of the AQP1 water channel within endothelial membranes. These results indicate that arterial pressure equilibrates within the endothelium and is transmitted to the supporting basement membrane and internal elastic lamina macromolecules with minimal deformation of the sensitive endothelial cell. Disruption of this pressure transmission could contribute to endothelial cell dysfunction in various pathologies. PMID:28373558

Neuroprotective effect of selective DPP-4 inhibitor in experimental vascular dementia.

PubMed

Jain, Swati; Sharma, Bhupesh

2015-12-01

Vascular risk factors are associated with a higher incidence of dementia. Diabetes mellitus is considered as a main risk factor for Alzheimer's disease and vascular dementia. Both forms of dementia are posing greater risk to the world population and are increasing at a faster rate. In the past we have reported the induction of vascular dementia by experimental diabetes. This study investigates the role of vildagliptin, a dipeptidyl peptidase-4 inhibitor in the pharmacological interdiction of pancreatectomy diabetes induced vascular endothelial dysfunction and subsequent vascular dementia in rats. Attentional set shifting and Morris water-maze test were used for assessment of learning and memory. Vascular endothelial function, blood brain barrier permeability, serum glucose, serum nitrite/nitrate, oxidative stress (viz. aortic superoxide anion, brain thiobarbituric acid reactive species and brain glutathione), brain calcium and inflammation (myeloperoxidase) were also estimated. Pancreatectomy diabetes rats have shown impairment of endothelial function, blood brain barrier permeability, learning and memory along with increase in brain inflammation, oxidative stress and calcium. Administration of vildagliptin has significantly attenuated pancreatectomy induced impairment of learning, memory, endothelial function, blood brain barrier permeability and biochemical parameters. It may be concluded that vildagliptin, a dipeptidyl peptidase-4 inhibitor may be considered as potential pharmacological agents for the management of pancreatectomy induced endothelial dysfunction and subsequent vascular dementia. The selective modulators of dipeptidyl peptidase-4 may further be explored for their possible benefits in vascular dementia. Copyright © 2015 Elsevier Inc. All rights reserved.

Alda-1 Protects Against Acrolein-Induced Acute Lung Injury and Endothelial Barrier Dysfunction.

PubMed

Lu, Qing; Mundy, Miles; Chambers, Eboni; Lange, Thilo; Newton, Julie; Borgas, Diana; Yao, Hongwei; Choudhary, Gaurav; Basak, Rajshekhar; Oldham, Mahogany; Rounds, Sharon

2017-12-01

Inhalation of acrolein, a highly reactive aldehyde, causes lung edema. The underlying mechanism is poorly understood and there is no effective treatment. In this study, we demonstrated that acrolein not only dose-dependently induced lung edema but also promoted LPS-induced acute lung injury. Importantly, acrolein-induced lung injury was prevented and rescued by Alda-1, an activator of mitochondrial aldehyde dehydrogenase 2. Acrolein also dose-dependently increased monolayer permeability, disrupted adherens junctions and focal adhesion complexes, and caused intercellular gap formation in primary cultured lung microvascular endothelial cells (LMVECs). These effects were attenuated by Alda-1 and the antioxidant N-acetylcysteine, but not by the NADPH inhibitor apocynin. Furthermore, acrolein inhibited AMP-activated protein kinase (AMPK) and increased mitochondrial reactive oxygen species levels in LMVECs-effects that were associated with impaired mitochondrial respiration. AMPK total protein levels were also reduced in lung tissue of mice and LMVECs exposed to acrolein. Activation of AMPK with 5-aminoimidazole-4-carboxamide-1-β-4-ribofuranoside blunted an acrolein-induced increase in endothelial monolayer permeability, but not mitochondrial oxidative stress or inhibition of mitochondrial respiration. Our results suggest that acrolein-induced mitochondrial dysfunction may not contribute to endothelial barrier dysfunction. We speculate that detoxification of acrolein by Alda-1 and activation of AMPK may be novel approaches to prevent and treat acrolein-associated acute lung injury, which may occur after smoke inhalation.

Protective effect of Growth Hormone-Releasing Hormone agonist in bacterial toxin-induced pulmonary barrier dysfunction.

PubMed

Czikora, Istvan; Sridhar, Supriya; Gorshkov, Boris; Alieva, Irina B; Kasa, Anita; Gonzales, Joyce; Potapenko, Olena; Umapathy, Nagavedi S; Pillich, Helena; Rick, Ferenc G; Block, Norman L; Verin, Alexander D; Chakraborty, Trinad; Matthay, Michael A; Schally, Andrew V; Lucas, Rudolf

2014-01-01

Antibiotic treatment of patients infected with G(-) or G(+) bacteria promotes release of the toxins lipopolysaccharide (LPS) and pneumolysin (PLY) in their lungs. Growth Hormone-releasing Hormone (GHRH) agonist JI-34 protects human lung microvascular endothelial cells (HL-MVEC), expressing splice variant 1 (SV-1) of the receptor, from PLY-induced barrier dysfunction. We investigated whether JI-34 also blunts LPS-induced hyperpermeability. Since GHRH receptor (GHRH-R) signaling can potentially stimulate both cAMP-dependent barrier-protective pathways as well as barrier-disruptive protein kinase C pathways, we studied their interaction in GHRH agonist-treated HL-MVEC, in the presence of PLY, by means of siRNA-mediated protein kinase A (PKA) depletion. Barrier function measurements were done in HL-MVEC monolayers using Electrical Cell substrate Impedance Sensing (ECIS) and VE-cadherin expression by Western blotting. Capillary leak was assessed by Evans Blue dye (EBD) incorporation. Cytokine generation in broncho-alveolar lavage fluid (BALF) was measured by multiplex analysis. PKA and PKC-α activity were assessed by Western blotting. GHRH agonist JI-34 significantly blunts LPS-induced barrier dysfunction, at least in part by preserving VE-cadherin expression, while not affecting inflammation. In addition to activating PKA, GHRH agonist also increases PKC-α activity in PLY-treated HL-MVEC. Treatment with PLY significantly decreases resistance in control siRNA-treated HL-MVEC, but does so even more in PKA-depleted monolayers. Pretreatment with GHRH agonist blunts PLY-induced permeability in control siRNA-treated HL-MVEC, but fails to improve barrier function in PKA-depleted PLY-treated monolayers. GHRH signaling in HL-MVEC protects from both LPS and PLY-mediated endothelial barrier dysfunction and concurrently induces a barrier-protective PKA-mediated and a barrier-disruptive PKC-α-induced pathway in the presence of PLY, the former of which dominates the latter.

2-Chlorohexadecanoic acid induces ER stress and mitochondrial dysfunction in brain microvascular endothelial cells.

PubMed

Bernhart, Eva; Kogelnik, Nora; Prasch, Jürgen; Gottschalk, Benjamin; Goeritzer, Madeleine; Depaoli, Maria Rosa; Reicher, Helga; Nusshold, Christoph; Plastira, Ioanna; Hammer, Astrid; Fauler, Günter; Malli, Roland; Graier, Wolfgang F; Malle, Ernst; Sattler, Wolfgang

2018-05-01

Peripheral leukocytes induce blood-brain barrier (BBB) dysfunction through the release of cytotoxic mediators. These include hypochlorous acid (HOCl) that is formed via the myeloperoxidase-H 2 O 2 -chloride system of activated phagocytes. HOCl targets the endogenous pool of ether phospholipids (plasmalogens) generating chlorinated inflammatory mediators like e.g. 2-chlorohexadecanal and its conversion product 2-chlorohexadecanoic acid (2-ClHA). In the cerebrovasculature these compounds inflict damage to brain microvascular endothelial cells (BMVEC) that form the morphological basis of the BBB. To follow subcellular trafficking of 2-ClHA we synthesized a 'clickable' alkyne derivative (2-ClHyA) that phenocopied the biological activity of the parent compound. Confocal and superresolution structured illumination microscopy revealed accumulation of 2-ClHyA in the endoplasmic reticulum (ER) and mitochondria of human BMVEC (hCMEC/D3 cell line). 2-ClHA and its alkyne analogue interfered with protein palmitoylation, induced ER-stress markers, reduced the ER ATP content, and activated transcription and secretion of interleukin (IL)-6 as well as IL-8. 2-ClHA disrupted the mitochondrial membrane potential and induced procaspase-3 and PARP cleavage. The protein kinase R-like ER kinase (PERK) inhibitor GSK2606414 suppressed 2-ClHA-mediated activating transcription factor 4 synthesis and IL-6/8 secretion, but showed no effect on endothelial barrier dysfunction and cleavage of procaspase-3. Our data indicate that 2-ClHA induces potent lipotoxic responses in brain endothelial cells and could have implications in inflammation-induced BBB dysfunction. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Biosensor Technology Reveals the Disruption of the Endothelial Barrier Function and the Subsequent Death of Blood Brain Barrier Endothelial Cells to Sodium Azide and Its Gaseous Products.

PubMed

Kho, Dan T; Johnson, Rebecca H; O'Carroll, Simon J; Angel, Catherine E; Graham, E Scott

2017-09-21

Herein we demonstrate the sensitive nature of human blood-brain barrier (BBB) endothelial cells to sodium azide and its gaseous product. Sodium azide is known to be acutely cytotoxic at low millimolar concentrations, hence its use as a biological preservative (e.g., in antibodies). Loss of barrier integrity was noticed in experiments using Electric Cell-substrate Impedance Sensing (ECIS) biosensor technology, to measure endothelial barrier integrity continuously in real-time. Initially the effect of sodium azide was observed as an artefact where it was present in antibodies being employed in neutralisation experiments. This was confirmed where antibody clones that were azide-free did not mediate loss of barrier function. A delayed loss of barrier function in neighbouring wells implied the influence of a liberated gaseous product. ECIS technology demonstrated that the BBB endothelial cells had a lower level of direct sensitivity to sodium azide of ~3 µM. Evidence of gaseous toxicity was consistently observed at 30 µM and above, with disrupted barrier function and cell death in neighbouring wells. We highlight the ability of this cellular biosensor technology to reveal both the direct and gaseous toxicity mediated by sodium azide. The sensitivity and temporal dimension of ECIS technology was instrumental in these observations. These findings have substantial implications for the wide use of sodium azide in biological reagents, raising issues of their application in live-cell assays and with regard to the protection of the user. This research also has wider relevance highlighting the sensitivity of brain endothelial cells to a known mitochondrial disruptor. It is logical to hypothesise that BBB endothelial dysfunction due to mitochondrial dys-regulation could have an important but underappreciated role in a range of neurological diseases.

Force control of endothelium permeability in mechanically stressed pulmonary micro-vascular endothelial cells.

PubMed

Wang, Bin; Caluch, Adam; Fodil, Redouane; Féréol, Sophie; Zadigue, Patricia; Pelle, Gabriel; Louis, Bruno; Isabey, Daniel

2012-01-01

Mechanical factors play a key role in the pathogenesis of Acute Respiratory Distress Syndrome (ARDS) and Ventilator-Induced Lung Injury (VILI) as contributing to alveolo-capillary barrier dysfunction. This study aims at elucidating the role of the cytoskeleton (CSK) and cell-matrix adhesion system in the stressed endothelium and more precisely in the loss of integrity of the endothelial barrier. We purposely develop a cellular model made of a monolayer of confluent Human Pulmonary Microvascular Endothelial Cells (HPMVECs) whose cytoskeleton (CSK) is directly exposed to sustained cyclic mechanical stress for 1 and 2 h. We used RGD-coated ferromagnetic beads and measured permeability before and after stress application. We find that endothelial permeability increases in the stressed endothelium, hence reflecting a loss of integrity. Structural and mechanical results suggest that this endothelial barrier alteration would be due to physically-founded discrepancies in latero-basal reinforcement of adhesion sites in response to the global increase in CSK stiffness or centripetal intracellular forces. Basal reinforcement of adhesion is presently evidenced by the marked redistribution of αvβ3 integrin with cluster formation in the stressed endothelium.

High glucose, glucose fluctuation and carbonyl stress enhance brain microvascular endothelial barrier dysfunction: Implications for diabetic cerebral microvasculature.

PubMed

Li, Wei; Maloney, Ronald E; Aw, Tak Yee

2015-08-01

We previously demonstrated that in normal glucose (5mM), methylglyoxal (MG, a model of carbonyl stress) induced brain microvascular endothelial cell (IHEC) dysfunction that was associated with occludin glycation and prevented by N-acetylcysteine (NAC). Herein, we investigated the impact of high glucose and low GSH, conditions that mimicked the diabetic state, on MG-induced IHEC dysfunction. MG-induced loss of transendothelial electrical resistance (TEER) was potentiated in IHECs cultured for 7 or 12 days in 25 mM glucose (hyperglycemia); moreover, barrier function remained disrupted 6h after cell transfer to normal glucose media (acute glycemic fluctuation). Notably, basal occludin glycation was elevated under these glycemic states. TEER loss was exaggerated by inhibition of glutathione (GSH) synthesis and abrogated by NAC, which corresponded to GSH decreases and increases, respectively. Significantly, glyoxalase II activity was attenuated in hyperglycemic cells. Moreover, hyperglycemia and GSH inhibition increased MG accumulation, consistent with a compromised capacity for MG elimination. α-Oxoaldehydes (MG plus glyoxal) levels were elevated in streptozotocin-induced diabetic rat plasma. Immunohistochemistry revealed a prevalence of MG-positive, but fewer occludin-positive microvessels in the diabetic brain in vivo, and Western analysis confirmed an increase in MG-occludin adducts. These results provide the first evidence that hyperglycemia and acute glucose fluctuation promote MG-occludin formation and exacerbate brain microvascular endothelial dysfunction. Low occludin expression and high glycated-occludin contents in diabetic brain in vivo are factors that would contribute to the dysfunction of the cerebral microvasculature during diabetes. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

High glucose, glucose fluctuation and carbonyl stress enhance brain microvascular endothelial barrier dysfunction: Implications for diabetic cerebral microvasculature

PubMed Central

Li, Wei; Maloney, Ronald E.; Aw, Tak Yee

2015-01-01

We previously demonstrated that in normal glucose (5 mM), methylglyoxal (MG, a model of carbonyl stress) induced brain microvascular endothelial cell (IHEC) dysfunction that was associated with occludin glycation and prevented by N-acetylcysteine (NAC). Herein, we investigated the impact of high glucose and low GSH, conditions that mimicked the diabetic state, on MG-induced IHEC dysfunction. MG-induced loss of transendothelial electrical resistance (TEER) was potentiated in IHECs cultured for 7 or 12 days in 25 mM glucose (hyperglycemia); moreover, barrier function remained disrupted 6 h after cell transfer to normal glucose media (acute glycemic fluctuation). Notably, basal occludin glycation was elevated under these glycemic states. TEER loss was exaggerated by inhibition of glutathione (GSH) synthesis and abrogated by NAC, which corresponded to GSH decreases and increases, respectively. Significantly, glyoxalase II activity was attenuated in hyperglycemic cells. Moreover, hyperglycemia and GSH inhibition increased MG accumulation, consistent with a compromised capacity for MG elimination. α-Oxoaldehydes (MG plus glyoxal) levels were elevated in streptozotocin-induced diabetic rat plasma. Immunohistochemistry revealed a prevalence of MG-positive, but fewer occludin-positive microvessels in the diabetic brain in vivo, and Western analysis confirmed an increase in MG–occludin adducts. These results provide the first evidence that hyperglycemia and acute glucose fluctuation promote MG–occludin formation and exacerbate brain microvascular endothelial dysfunction. Low occludin expression and high glycated-occludin contents in diabetic brain in vivo are factors that would contribute to the dysfunction of the cerebral microvasculature during diabetes. PMID:25867911

Endothelial glycocalyx dysfunction in disease: albuminuria and increased microvascular permeability.

PubMed

Salmon, Andrew H J; Satchell, Simon C

2012-03-01

Appreciation of the glomerular microcirculation as a specialized microcirculatory bed, rather than as an entirely separate entity, affords important insights into both glomerular and systemic microvascular pathophysiology. In this review we compare regulation of permeability in systemic and glomerular microcirculations, focusing particularly on the role of the endothelial glycocalyx, and consider the implications for disease processes. The luminal surface of vascular endothelium throughout the body is covered with endothelial glycocalyx, comprising surface-anchored proteoglycans, supplemented with adsorbed soluble proteoglycans, glycosaminoglycans and plasma constituents. In both continuous and fenestrated microvessels, this endothelial glycocalyx provides resistance to the transcapillary escape of water and macromolecules, acting as an integral component of the multilayered barrier provided by the walls of these microvessels (ie acting in concert with clefts or fenestrae across endothelial cell layers, basement membranes and pericytes). Dysfunction of any of these capillary wall components, including the endothelial glycocalyx, can disrupt normal microvascular permeability. Because of its ubiquitous nature, damage to the endothelial glycocalyx alters the permeability of multiple capillary beds: in the glomerulus this is clinically apparent as albuminuria. Generalized damage to the endothelial glycocalyx can therefore manifest as both albuminuria and increased systemic microvascular permeability. This triad of altered endothelial glycocalyx, albuminuria and increased systemic microvascular permeability occurs in a number of important diseases, such as diabetes, with accumulating evidence for a similar phenomenon in ischaemia-reperfusion injury and infectious disease. The detection of albuminuria therefore has implications for the function of the microcirculation as a whole. The importance of the endothelial glycocalyx for other aspects of vascular function/dysfunction, such as mechanotransduction, leukocyte-endothelial interactions and the development of atherosclerosis, indicate that alterations in the endothelial glycocalyx may also be playing a role in the dysfunction of other organs observed in these disease states. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

PAR-2 triggers placenta-derived protease-induced altered VE-cadherin reorganization at endothelial junctions in preeclampsia.

PubMed

Gu, Y; Groome, L J; Alexander, J S; Wang, Y

2012-10-01

PAR-2 is a G-protein coupled protease receptor whose activation in endothelial cells (ECs) is associated with increased solute permeability. VE-cadherin is an endothelial-specific junction protein, which exhibits a disorganized distribution at cell junction during inflammation and is a useful indicator of endothelial barrier dysfunction. In the present study, we tested the hypothesis that PAR-2 activation mediates placenta-derived chymotrypsin-like protease (CLP)-induced endothelial junction disturbance and permeability in preeclampsia (PE). PAR-2 and VE-cadherin were examined by immunofluorescent staining. Specific CLP induced PAR-2 activation and altered VE-cadherin distribution was assessed following depletion of protease chymotrypsin in the placental conditioned medium and after PAR-2 siRNA. VE-cadherin assembly was determined by treating cells with protease chymotrypsin and/or the specific PAR-2 agonist SLIGKV-NH2. Our results showed: 1) placental conditioned medium not only disturbed VE-cadherin distribution at cell junctions but also activated PAR-2 in ECs; 2) PAR-2 siRNA blocked the placental conditioned medium induced PAR-2 upregulation and disorganization of VE-cadherin at cell junctions; 3) PAR-2 agonist induced PAR-2 activation and VE-cadherin reorganization were dose-dependent; and 4) PAR-2 agonist could stimulate ERK1/2 activation. These results strongly suggest that proteases produced by the placenta elicit endothelial barrier dysfunction via a PAR-2 signaling regulatory mechanism in PE. Copyright © 2012 Elsevier Ltd. All rights reserved.

PAR-2 triggers placenta-derived protease-induced altered VE-cadherin reorganization at endothelial junctions in preeclampsia

PubMed Central

Gu, Yang; Groome, Lynn J.; Alexander, J. Steven; Wang, Yuping

2014-01-01

PAR-2 is a G-protein coupled protease receptor whose activation in endothelial cells (ECs) is associated with increased solute permeability. VE-cadherin is an endothelial specific junction protein, which exhibits a disorganized distribution at cell junction during inflammation and is a useful indicator of endothelial barrier dysfunction. In the present study, we tested the hypothesis that PAR-2 activation mediates placenta-derived chymotrypsin-like protease (CLP)-induced endothelial junction disturbance and permeability in preeclampsia (PE). PAR-2 and VE-cadherin were examined by immunofluorescent staining. Specific CLP-induced PAR-2 activation and altered VE-cadherin distribution was assessed following depletion of protease chymotrypsin in the placental conditioned medium and after PAR-2 siRNA. VE-cadherin assembly was determined by treating cells with protease chymotrypsin and/or the specific PAR-2 agonist SLIGKV-NH2. Our results showed: 1) placental conditioned medium not only disturbed VE-cadherin distribution at cell junctions but also activated PAR-2 in ECs; 2) PAR-2 siRNA blocked the placental conditioned medium induced PAR-2 upregulation and disorganization of VE-cadherin at cell junctions; 3) PAR-2 agonist induced PAR-2 activation and VE-cadherin reorganization were dose-dependent; and 4) PAR-2 agonist could stimulate ERK1/2 activation. These results strongly suggest that proteases produced by the placenta elicit endothelial barrier dysfunction via a PAR-2 signaling regulatory mechanism in PE. PMID:22840244

Regulation of human cerebro-microvascular endothelial baso-lateral adhesion and barrier function by S1P through dual involvement of S1P1 and S1P2 receptors.

PubMed

Wiltshire, Rachael; Nelson, Vicky; Kho, Dan Ting; Angel, Catherine E; O'Carroll, Simon J; Graham, E Scott

2016-01-27

Herein we show that S1P rapidly and acutely reduces the focal adhesion strength and barrier tightness of brain endothelial cells. xCELLigence biosensor technology was used to measure focal adhesion, which was reduced by S1P acutely and this response was mediated through both S1P1 and S1P2 receptors. S1P increased secretion of several pro-inflammatory mediators from brain endothelial cells. However, the magnitude of this response was small in comparison to that mediated by TNFα or IL-1β. Furthermore, S1P did not significantly increase cell-surface expression of any key cell adhesion molecules involved in leukocyte recruitment, included ICAM-1 and VCAM-1. Finally, we reveal that S1P acutely and dynamically regulates microvascular endothelial barrier tightness in a manner consistent with regulated rapid opening followed by closing and strengthening of the barrier. We hypothesise that the role of the S1P receptors in this process is not to cause barrier dysfunction, but is related to controlled opening of the endothelial junctions. This was revealed using real-time measurement of barrier integrity using ECIS ZΘ TEER technology and endothelial viability using xCELLigence technology. Finally, we show that these responses do not occur simply though the pharmacology of a single S1P receptor but involves coordinated action of S1P1 and S1P2 receptors.

Ascorbate protects endothelial barrier function during septic insult: Role of protein phosphatase type 2A.

PubMed

Han, Min; Pendem, Suresh; Teh, Suet Ling; Sukumaran, Dinesh K; Wu, Feng; Wilson, John X

2010-01-01

Endothelial barrier dysfunction contributes to morbidity in sepsis. We tested the hypothesis that raising the intracellular ascorbate concentration protects the endothelial barrier from septic insult by inhibiting protein phosphatase type 2A. Monolayer cultures of microvascular endothelial cells were incubated with ascorbate, dehydroascorbic acid (DHAA), the NADPH oxidase inhibitors apocynin and diphenyliodonium, or the PP2A inhibitor okadaic acid and then were exposed to septic insult (lipopolysaccharide and interferon-gamma). Under standard culture conditions that depleted intracellular ascorbate, septic insult stimulated oxidant production and PP2A activity, dephosphorylated phosphoserine and phosphothreonine residues in the tight junction-associated protein occludin, decreased the abundance of occludin at cell borders, and increased monolayer permeability to albumin. NADPH oxidase inhibitors prevented PP2A activation and monolayer leak, showing that these changes required reactive oxygen species. Okadaic acid, at a concentration that inhibited PP2A activity and monolayer leak, prevented occludin dephosphorylation and redistribution, implicating PP2A in the response of occludin to septic insult. Incubation with ascorbate or DHAA raised intracellular ascorbate concentrations and mitigated the effects of septic insult. In conclusion, ascorbate acts within microvascular endothelial cells to inhibit septic stimulation of oxidant production by NADPH oxidase and thereby prevents PP2A activation, PP2A-dependent dephosphorylation and redistribution of occludin, and disruption of the endothelial barrier. Copyright 2009 Elsevier Inc. All rights reserved.

Poly(I:C) Induces Human Lung Endothelial Barrier Dysfunction by Disrupting Tight Junction Expression of Claudin-5

DOE PAGES

Huang, Li -Yun; Stuart, Christine; Takeda, Kazuyo; ...

2016-08-09

Viral infections are often accompanied by pulmonary microvascular leakage and vascular endothelial dysfunction via mechanisms that are not completely defined. Here, we investigated the effect of the Toll-like receptor 3 (TLR3) ligand polyinosinic-polycytidylic acid [Poly(I:C)], a synthetic analog of viral double-stranded RNA (dsRNA) commonly used to simulate viral infections, on the barrier function and tight junction integrity of primary human lung microvascular endothelial cells. Poly(I:C) stimulated IL-6, IL-8, TNFα, and IFNβ production in conjunction with the activation of NF-κB and IRF3 confirming the Poly(I:C)-responsiveness of these cells. Poly(I:C) increased endothelialmonolayer permeability with a corresponding dose- and time-dependent decrease in themore » expression of claudin-5, a transmembrane tight junction protein and reduction of CLDN5 mRNA levels. Immunofluorescence experiments revealed disappearance of membrane-associated claudin-5 and co-localization of cytoplasmic claudin-5 with lysosomal-associated membrane protein 1. Chloroquine and Bay11-7082, inhibitors of TLR3 and NF-κB signaling, respectively, protected against the loss of claudin-5. Altogether, these findings provide new insight on how dsRNA-activated signaling pathways may disrupt vascular endothelial function and contribute to vascular leakage pathologies.« less

Protection of cultured brain endothelial cells from cytokine-induced damage by α-melanocyte stimulating hormone.

PubMed

Harazin, András; Bocsik, Alexandra; Barna, Lilla; Kincses, András; Váradi, Judit; Fenyvesi, Ferenc; Tubak, Vilmos; Deli, Maria A; Vecsernyés, Miklós

2018-01-01

The blood-brain barrier (BBB), an interface between the systemic circulation and the nervous system, can be a target of cytokines in inflammatory conditions. Pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) induce damage in brain endothelial cells and BBB dysfunction which contribute to neuronal injury. The neuroprotective effects of α-melanocyte stimulating hormone (α-MSH) were investigated in experimental models, but there are no data related to the BBB. Based on our recent study, in which α-MSH reduced barrier dysfunction in human intestinal epithelial cells induced by TNF-α and IL-1β, we hypothesized a protective effect of α-MSH on brain endothelial cells. We examined the effect of these two pro-inflammatory cytokines, and the neuropeptide α-MSH on a culture model of the BBB, primary rat brain endothelial cells co-cultured with rat brain pericytes and glial cells. We demonstrated the expression of melanocortin-1 receptor in isolated rat brain microvessels and cultured brain endothelial cells by RT-PCR and immunohistochemistry. TNF-α and IL-1β induced cell damage, measured by impedance and MTT assay, which was attenuated by α-MSH (1 and 10 pM). The peptide inhibited the cytokine-induced increase in brain endothelial permeability, and restored the morphological changes in cellular junctions visualized by immunostaining for claudin-5 and β-catenin. Elevated production of reactive oxygen species and the nuclear translocation of NF-κB were also reduced by α-MSH in brain endothelial cells stimulated by cytokines. We demonstrated for the first time the direct beneficial effect of α-MSH on cultured brain endothelial cells, indicating that this neurohormone may be protective at the BBB.

Protection of cultured brain endothelial cells from cytokine-induced damage by α-melanocyte stimulating hormone

PubMed Central

Barna, Lilla; Kincses, András; Váradi, Judit; Fenyvesi, Ferenc; Tubak, Vilmos

2018-01-01

The blood–brain barrier (BBB), an interface between the systemic circulation and the nervous system, can be a target of cytokines in inflammatory conditions. Pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) induce damage in brain endothelial cells and BBB dysfunction which contribute to neuronal injury. The neuroprotective effects of α-melanocyte stimulating hormone (α-MSH) were investigated in experimental models, but there are no data related to the BBB. Based on our recent study, in which α-MSH reduced barrier dysfunction in human intestinal epithelial cells induced by TNF-α and IL-1β, we hypothesized a protective effect of α-MSH on brain endothelial cells. We examined the effect of these two pro-inflammatory cytokines, and the neuropeptide α-MSH on a culture model of the BBB, primary rat brain endothelial cells co-cultured with rat brain pericytes and glial cells. We demonstrated the expression of melanocortin-1 receptor in isolated rat brain microvessels and cultured brain endothelial cells by RT-PCR and immunohistochemistry. TNF-α and IL-1β induced cell damage, measured by impedance and MTT assay, which was attenuated by α-MSH (1 and 10 pM). The peptide inhibited the cytokine-induced increase in brain endothelial permeability, and restored the morphological changes in cellular junctions visualized by immunostaining for claudin-5 and β-catenin. Elevated production of reactive oxygen species and the nuclear translocation of NF-κB were also reduced by α-MSH in brain endothelial cells stimulated by cytokines. We demonstrated for the first time the direct beneficial effect of α-MSH on cultured brain endothelial cells, indicating that this neurohormone may be protective at the BBB. PMID:29780671

Intravital imaging of a pulmonary endothelial surface layer in a murine sepsis model.

PubMed

Park, Inwon; Choe, Kibaek; Seo, Howon; Hwang, Yoonha; Song, Eunjoo; Ahn, Jinhyo; Hwan Jo, You; Kim, Pilhan

2018-05-01

Direct intravital imaging of an endothelial surface layer (ESL) in pulmonary microcirculation could be a valuable approach to investigate the role of a vascular endothelial barrier in various pathological conditions. Despite its importance as a marker of endothelial cell damage and impairment of the vascular system, in vivo visualization of ESL has remained a challenging technical issue. In this work, we implemented a pulmonary microcirculation imaging system integrated to a custom-design video-rate laser scanning confocal microscopy platform. Using the system, a real-time cellular-level microscopic imaging of the lung was successfully performed, which facilitated a clear identification of individual flowing erythrocytes in pulmonary capillaries. Subcellular level pulmonary ESL was identified in vivo by fluorescence angiography using a dextran conjugated fluorophore to label blood plasma and the red blood cell (RBC) exclusion imaging analysis. Degradation of ESL width was directly evaluated in a murine sepsis model in vivo , suggesting an impairment of pulmonary vascular endothelium and endothelial barrier dysfunction.

Intravital imaging of a pulmonary endothelial surface layer in a murine sepsis model

PubMed Central

Park, Inwon; Choe, Kibaek; Seo, Howon; Hwang, Yoonha; Song, Eunjoo; Ahn, Jinhyo; Hwan Jo, You; Kim, Pilhan

2018-01-01

Direct intravital imaging of an endothelial surface layer (ESL) in pulmonary microcirculation could be a valuable approach to investigate the role of a vascular endothelial barrier in various pathological conditions. Despite its importance as a marker of endothelial cell damage and impairment of the vascular system, in vivo visualization of ESL has remained a challenging technical issue. In this work, we implemented a pulmonary microcirculation imaging system integrated to a custom-design video-rate laser scanning confocal microscopy platform. Using the system, a real-time cellular-level microscopic imaging of the lung was successfully performed, which facilitated a clear identification of individual flowing erythrocytes in pulmonary capillaries. Subcellular level pulmonary ESL was identified in vivo by fluorescence angiography using a dextran conjugated fluorophore to label blood plasma and the red blood cell (RBC) exclusion imaging analysis. Degradation of ESL width was directly evaluated in a murine sepsis model in vivo, suggesting an impairment of pulmonary vascular endothelium and endothelial barrier dysfunction. PMID:29760995

Phloretin ameliorates 2-chlorohexadecanal-mediated brain microvascular endothelial cell dysfunction in vitro

PubMed Central

Üllen, Andreas; Fauler, Günter; Bernhart, Eva; Nusshold, Christoph; Reicher, Helga; Leis, Hans-Jörg; Malle, Ernst; Sattler, Wolfgang

2012-01-01

2-Chlorohexadecanal (2-ClHDA), a chlorinated fatty aldehyde, is formed via attack on ether-phospholipids by hypochlorous acid (HOCl) that is generated by the myeloperoxidase–hydrogen peroxide–chloride system of activated leukocytes. 2-ClHDA levels are elevated in atherosclerotic lesions, myocardial infarction, and neuroinflammation. Neuroinflammatory conditions are accompanied by accumulation of neutrophils (an ample source of myeloperoxidase) in the brain. Microvessel damage by inflammatory mediators and/or reactive oxidants can induce blood–brain barrier (BBB) dysfunction, a pathological condition leading to cerebral edema, brain hemorrhage, and neuronal death. In this in vitro study we investigated the impact of 2-ClHDA on brain microvascular endothelial cells (BMVEC), which constitute the morphological basis of the BBB. We show that exogenously added 2-ClHDA is subject to rapid uptake and metabolism by BMVEC. Using C16 structural analogues of 2-ClHDA we found that the cytotoxic potential decreases in the following order: 2-ClHDA>hexadecanal>palmitic acid>2-ClHDA-dimethylacetal. 2-ClHDA induces loss of barrier function, mitochondrial dysfunction, apoptosis via activation of caspase 3, and altered intracellular redox balance. Finally we investigated potential protective effects of several natural polyphenols on in vitro BBB function. Of the compounds tested, phloretin almost completely abrogated 2-ClHDA-induced BMVEC barrier dysfunction and cell death. These data suggest that 2-ClHDA has the potential to induce BBB breakdown under inflammatory conditions and that phloretin confers protection in this experimental setting. PMID:22982051

A novel approach to prevent endothelial hyperpermeability: the Crataegus extract WS® 1442 targets the cAMP/Rap1 pathway.

PubMed

Bubik, Martin F; Willer, Elisabeth A; Bihari, Peter; Jürgenliemk, Guido; Ammer, Hermann; Krombach, Fritz; Zahler, Stefan; Vollmar, Angelika M; Fürst, Robert

2012-01-01

Endothelial hyperpermeability followed by edema formation is a hallmark of many severe disorders. Effective drugs directly targeting endothelial barrier function are widely lacking. We hypothesized that the hawthorn (Crataegus spp.) extract WS® 1442, a proven multi-component drug against moderate forms of heart failure, would prevent vascular leakage by affecting endothelial barrier-regulating systems. In vivo, WS® 1442 inhibited the histamine-evoked extravasation of FITC-dextran from mouse cremaster muscle venules. In cultured human endothelial cells, WS® 1442 blocked the thrombin-induced FITC-dextran permeability. By applying biochemical and microscopic techniques, we revealed that WS® 1442 abrogates detrimental effects of thrombin on adherens junctions (vascular endothelial-cadherin), the F-actin cytoskeleton, and the contractile apparatus (myosin light chain). Mechanistically, WS® 1442 inhibited the thrombin-induced rise of intracellular calcium (ratiometric measurement), followed by an inactivation of PKC and RhoA (pulldown assay). Moreover, WS® 1442 increased endothelial cAMP levels (ELISA), which consequently activated PKA and Rap1 (pulldown assay). Utilizing pharmacological inhibitors or siRNA, we found that PKA is not involved in barrier protection, whereas Epac1, Rap1, and Rac1 play a crucial role in the WS® 1442-induced activation of cortactin, which triggers a strong cortical actin rearrangement. In summary, WS® 1442 effectively protects against endothelial barrier dysfunction in vitro and in vivo. It specifically interacts with endothelial permeability-regulating systems by blocking the Ca(2+)/PKC/RhoA and activating the cAMP/Epac1/Rap1 pathway. As a proven safe herbal drug, WS® 1442 opens a novel pharmacological approach to treat hyperpermeability-associated diseases. This in-depth mechanistic work contributes to a better acceptance of this herbal remedy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Protein kinase C-α and arginase I mediate pneumolysin-induced pulmonary endothelial hyperpermeability.

PubMed

Lucas, Rudolf; Yang, Guang; Gorshkov, Boris A; Zemskov, Evgeny A; Sridhar, Supriya; Umapathy, Nagavedi S; Jezierska-Drutel, Agnieszka; Alieva, Irina B; Leustik, Martin; Hossain, Hamid; Fischer, Bernhard; Catravas, John D; Verin, Alexander D; Pittet, Jean-François; Caldwell, Ruth B; Mitchell, Timothy J; Cederbaum, Stephen D; Fulton, David J; Matthay, Michael A; Caldwell, Robert W; Romero, Maritza J; Chakraborty, Trinad

2012-10-01

Antibiotics-induced release of the pore-forming virulence factor pneumolysin (PLY) in patients with pneumococcal pneumonia results in its presence days after lungs are sterile and is a major factor responsible for the induction of permeability edema. Here we sought to identify major mechanisms mediating PLY-induced endothelial dysfunction. We evaluated PLY-induced endothelial hyperpermeability in human lung microvascular endothelial cells (HL-MVECs) and human lung pulmonary artery endothelial cells in vitro and in mice instilled intratracheally with PLY. PLY increases permeability in endothelial monolayers by reducing stable and dynamic microtubule content and modulating VE-cadherin expression. These events, dependent upon an increased calcium influx, are preceded by protein kinase C (PKC)-α activation, perturbation of the RhoA/Rac1 balance, and an increase in myosin light chain phosphorylation. At later time points, PLY treatment increases the expression and activity of arginase in HL-MVECs. Arginase inhibition abrogates and suppresses PLY-induced endothelial barrier dysfunction by restoring NO generation. Consequently, a specific PKC-α inhibitor and the TNF-derived tonoplast intrinsic protein peptide, which blunts PLY-induced PKC-α activation, are able to prevent activation of arginase in HL-MVECs and to reduce PLY-induced endothelial hyperpermeability in mice. Arginase I (AI)(+/-)/arginase II (AII)(-/-) C57BL/6 mice, displaying a significantly reduced arginase I expression in the lungs, are significantly less sensitive to PLY-induced capillary leak than their wild-type or AI(+/+)/AII(-/-) counterparts, indicating an important role for arginase I in PLY-induced endothelial hyperpermeability. These results identify PKC-α and arginase I as potential upstream and downstream therapeutic targets in PLY-induced pulmonary endothelial dysfunction.

Protein Kinase C-α and Arginase I Mediate Pneumolysin-Induced Pulmonary Endothelial Hyperpermeability

PubMed Central

Yang, Guang; Gorshkov, Boris A.; Zemskov, Evgeny A.; Sridhar, Supriya; Umapathy, Nagavedi S.; Jezierska-Drutel, Agnieszka; Alieva, Irina B.; Leustik, Martin; Hossain, Hamid; Fischer, Bernhard; Catravas, John D.; Verin, Alexander D.; Pittet, Jean-François; Caldwell, Ruth B.; Mitchell, Timothy J.; Cederbaum, Stephen D.; Fulton, David J.; Matthay, Michael A.; Caldwell, Robert W.; Romero, Maritza J.; Chakraborty, Trinad

2012-01-01

Antibiotics-induced release of the pore-forming virulence factor pneumolysin (PLY) in patients with pneumococcal pneumonia results in its presence days after lungs are sterile and is a major factor responsible for the induction of permeability edema. Here we sought to identify major mechanisms mediating PLY-induced endothelial dysfunction. We evaluated PLY-induced endothelial hyperpermeability in human lung microvascular endothelial cells (HL-MVECs) and human lung pulmonary artery endothelial cells in vitro and in mice instilled intratracheally with PLY. PLY increases permeability in endothelial monolayers by reducing stable and dynamic microtubule content and modulating VE-cadherin expression. These events, dependent upon an increased calcium influx, are preceded by protein kinase C (PKC)-α activation, perturbation of the RhoA/Rac1 balance, and an increase in myosin light chain phosphorylation. At later time points, PLY treatment increases the expression and activity of arginase in HL-MVECs. Arginase inhibition abrogates and suppresses PLY-induced endothelial barrier dysfunction by restoring NO generation. Consequently, a specific PKC-α inhibitor and the TNF-derived tonoplast intrinsic protein peptide, which blunts PLY-induced PKC-α activation, are able to prevent activation of arginase in HL-MVECs and to reduce PLY-induced endothelial hyperpermeability in mice. Arginase I (AI)+/−/arginase II (AII)−/− C57BL/6 mice, displaying a significantly reduced arginase I expression in the lungs, are significantly less sensitive to PLY-induced capillary leak than their wild-type or AI+/+/AII−/− counterparts, indicating an important role for arginase I in PLY-induced endothelial hyperpermeability. These results identify PKC-α and arginase I as potential upstream and downstream therapeutic targets in PLY-induced pulmonary endothelial dysfunction. PMID:22582175

Edaravone Protects against Methylglyoxal-Induced Barrier Damage in Human Brain Endothelial Cells

PubMed Central

Tóth, Andrea E.; Walter, Fruzsina R.; Bocsik, Alexandra; Sántha, Petra; Veszelka, Szilvia; Nagy, Lajos; Puskás, László G.; Couraud, Pierre-Olivier; Takata, Fuyuko; Dohgu, Shinya; Kataoka, Yasufumi; Deli, Mária A.

2014-01-01

Background Elevated level of reactive carbonyl species, such as methylglyoxal, triggers carbonyl stress and activates a series of inflammatory responses leading to accelerated vascular damage. Edaravone is the active substance of a Japanese medicine, which aids neurological recovery following acute brain ischemia and subsequent cerebral infarction. Our aim was to test whether edaravone can exert a protective effect on the barrier properties of human brain endothelial cells (hCMEC/D3 cell line) treated with methylglyoxal. Methodology Cell viability was monitored in real-time by impedance-based cell electronic sensing. The barrier function of the monolayer was characterized by measurement of resistance and flux of permeability markers, and visualized by immunohistochemistry for claudin-5 and β-catenin. Cell morphology was also examined by holographic phase imaging. Principal Findings Methylglyoxal exerted a time- and dose-dependent toxicity on cultured human brain endothelial cells: a concentration of 600 µM resulted in about 50% toxicity, significantly reduced the integrity and increased the permeability of the barrier. The cell morphology also changed dramatically: the area of cells decreased, their optical height significantly increased. Edaravone (3 mM) provided a complete protection against the toxic effect of methylglyoxal. Co-administration of edaravone restored cell viability, barrier integrity and functions of brain endothelial cells. Similar protection was obtained by the well-known antiglycating molecule, aminoguanidine, our reference compound. Conclusion These results indicate for the first time that edaravone is protective in carbonyl stress induced barrier damage. Our data may contribute to the development of compounds to treat brain endothelial dysfunction in carbonyl stress related diseases. PMID:25033388

Two barriers for sodium in vascular endothelium?

PubMed Central

Oberleithner, Hans

2012-01-01

Vascular endothelium plays a key role in blood pressure regulation. Recently, it has been shown that a 5% increase of plasma sodium concentration (sodium excess) stiffens endothelial cells by about 25%, leading to cellular dysfunction. Surface measurements demonstrated that the endothelial glycocalyx (eGC), an anionic biopolymer, deteriorates when sodium is elevated. In view of these results, a two-barrier model for sodium exiting the circulation across the endothelium is suggested. The first sodium barrier is the eGC which selectively buffers sodium ions with its negatively charged prote-oglycans.The second sodium barrier is the endothelial plasma membrane which contains sodium channels. Sodium excess, in the presence of aldosterone, leads to eGC break-down and, in parallel, to an up-regulation of plasma membrane sodium channels. The following hypothesis is postulated: Sodium excess increases vascular sodium permeability. Under such con-ditions (e.g. high-sodium diet), day-by-day ingested sodium, instead of being readily buffered by the eGC and then rapidly excreted by the kidneys, is distributed in the whole body before being finally excreted. Gradually, the sodium overload damages the organism. PMID:22471931

In vitro model of cerebral ischemia by using brain microvascular endothelial cells derived from human induced pluripotent stem cells.

PubMed

Kokubu, Yasuhiro; Yamaguchi, Tomoko; Kawabata, Kenji

2017-04-29

Brain-derived microvascular endothelial cells (BMECs), which play a central role in blood brain barrier (BBB), can be used for the evaluation of drug transport into the brain. Although human BMEC cell lines have already been reported, they lack original properties such as barrier integrity. Pluripotent stem cells (PSCs) can be used for various applications such as regenerative therapy, drug screening, and pathological study. In the recent study, an induction method of BMECs from PSCs has been established, making it possible to more precisely study the in vitro human BBB function. Here, using induced pluripotent stem (iPS) cell-derived BMECs, we examined the effects of oxygen-glucose deprivation (OGD) and OGD/reoxygenation (OGD/R) on BBB permeability. OGD disrupted the barrier function, and the dysfunction was rapidly restored by re-supply of the oxygen and glucose. Interestingly, TNF-α, which is known to be secreted from astrocytes and microglia in the cerebral ischemia, prevented the restoration of OGD-induced barrier dysfunction in an apoptosis-independent manner. Thus, we could establish the in vitro BBB disease model that mimics the cerebral ischemia by using iPS cell-derived BMECs. Copyright © 2017 Elsevier Inc. All rights reserved.

Phloretin ameliorates 2-chlorohexadecanal-mediated brain microvascular endothelial cell dysfunction in vitro.

PubMed

Ullen, Andreas; Fauler, Günter; Bernhart, Eva; Nusshold, Christoph; Reicher, Helga; Leis, Hans-Jörg; Malle, Ernst; Sattler, Wolfgang

2012-11-01

2-Chlorohexadecanal (2-ClHDA), a chlorinated fatty aldehyde, is formed via attack on ether-phospholipids by hypochlorous acid (HOCl) that is generated by the myeloperoxidase-hydrogen peroxide-chloride system of activated leukocytes. 2-ClHDA levels are elevated in atherosclerotic lesions, myocardial infarction, and neuroinflammation. Neuroinflammatory conditions are accompanied by accumulation of neutrophils (an ample source of myeloperoxidase) in the brain. Microvessel damage by inflammatory mediators and/or reactive oxidants can induce blood-brain barrier (BBB) dysfunction, a pathological condition leading to cerebral edema, brain hemorrhage, and neuronal death. In this in vitro study we investigated the impact of 2-ClHDA on brain microvascular endothelial cells (BMVEC), which constitute the morphological basis of the BBB. We show that exogenously added 2-ClHDA is subject to rapid uptake and metabolism by BMVEC. Using C16 structural analogues of 2-ClHDA we found that the cytotoxic potential decreases in the following order: 2-ClHDA>hexadecanal>palmitic acid>2-ClHDA-dimethylacetal. 2-ClHDA induces loss of barrier function, mitochondrial dysfunction, apoptosis via activation of caspase 3, and altered intracellular redox balance. Finally we investigated potential protective effects of several natural polyphenols on in vitro BBB function. Of the compounds tested, phloretin almost completely abrogated 2-ClHDA-induced BMVEC barrier dysfunction and cell death. These data suggest that 2-ClHDA has the potential to induce BBB breakdown under inflammatory conditions and that phloretin confers protection in this experimental setting. Copyright © 2012 Elsevier Inc. All rights reserved.

Brain endothelial dysfunction in cerebral adrenoleukodystrophy.

PubMed

Musolino, Patricia L; Gong, Yi; Snyder, Juliet M T; Jimenez, Sandra; Lok, Josephine; Lo, Eng H; Moser, Ann B; Grabowski, Eric F; Frosch, Matthew P; Eichler, Florian S

2015-11-01

See Aubourg (doi:10.1093/awv271) for a scientific commentary on this article.X-linked adrenoleukodystrophy is caused by mutations in the ABCD1 gene leading to accumulation of very long chain fatty acids. Its most severe neurological manifestation is cerebral adrenoleukodystrophy. Here we demonstrate that progressive inflammatory demyelination in cerebral adrenoleukodystrophy coincides with blood-brain barrier dysfunction, increased MMP9 expression, and changes in endothelial tight junction proteins as well as adhesion molecules. ABCD1, but not its closest homologue ABCD2, is highly expressed in human brain microvascular endothelial cells, far exceeding its expression in the systemic vasculature. Silencing of ABCD1 in human brain microvascular endothelial cells causes accumulation of very long chain fatty acids, but much later than the immediate upregulation of adhesion molecules and decrease in tight junction proteins. This results in greater adhesion and transmigration of monocytes across the endothelium. PCR-array screening of human brain microvascular endothelial cells after ABCD1 silencing revealed downregulation of both mRNA and protein levels of the transcription factor c-MYC (encoded by MYC). Interestingly, MYC silencing mimicked the effects of ABCD1 silencing on CLDN5 and ICAM1 without decreasing the levels of ABCD1 protein itself. Together, these data demonstrate that ABCD1 deficiency induces significant alterations in brain endothelium via c-MYC and may thereby contribute to the increased trafficking of leucocytes across the blood-brain barrier as seen in cerebral adrenouleukodystrophy. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Endothelium and Its Alterations in Cardiovascular Diseases: Life Style Intervention

PubMed Central

Paganelli, Corrado; Buffoli, Barbara; Rodella, Luigi Fabrizio; Rezzani, Rita

2014-01-01

The endothelium, which forms the inner cellular lining of blood vessels and lymphatics, is a highly metabolically active organ that is involved in many physiopathological processes, including the control of vasomotor tone, barrier function, leukocyte adhesion, and trafficking and inflammation. In this review, we summarized and described the following: (i) endothelial cell function in physiological conditions and (ii) endothelial cell activation and dysfunction in the main cardiovascular diseases (such as atherosclerosis, and hypertension) and to diabetes, cigarette smoking, and aging physiological process. Finally, we presented the currently available evidence that supports the beneficial effects of physical activity and various dietary compounds on endothelial functions. PMID:24719887

Endothelial β-Catenin Signaling Is Required for Maintaining Adult Blood-Brain Barrier Integrity and Central Nervous System Homeostasis.

PubMed

Tran, Khiem A; Zhang, Xianming; Predescu, Dan; Huang, Xiaojia; Machado, Roberto F; Göthert, Joachim R; Malik, Asrar B; Valyi-Nagy, Tibor; Zhao, You-Yang

2016-01-12

The blood-brain barrier (BBB) formed by brain endothelial cells interconnected by tight junctions is essential for the homeostasis of the central nervous system. Although studies have shown the importance of various signaling molecules in BBB formation during development, little is known about the molecular basis regulating the integrity of the adult BBB. Using a mouse model with tamoxifen-inducible endothelial cell-restricted disruption of ctnnb1 (iCKO), we show here that endothelial β-catenin signaling is essential for maintaining BBB integrity and central nervous system homeostasis in adult mice. The iCKO mice developed severe seizures accompanied by neuronal injury, multiple brain petechial hemorrhages, and central nervous system inflammation, and all had postictal death. Disruption of endothelial β-catenin induced BBB breakdown and downregulation of the specific tight junction proteins claudin-1 and -3 in adult brain endothelial cells. The clinical relevance of the data is indicated by the observation of decreased expression of claudin-1 and nuclear β-catenin in brain endothelial cells of hemorrhagic lesions of hemorrhagic stroke patients. These results demonstrate the prerequisite role of endothelial β-catenin in maintaining the integrity of adult BBB. The results suggest that BBB dysfunction secondary to defective β-catenin transcription activity is a key pathogenic factor in hemorrhagic stroke, seizure activity, and central nervous system inflammation. © 2015 American Heart Association, Inc.

Diverse Functional Outcomes of Plasmodium falciparum Ligation of EPCR: Potential Implications for Malarial Pathogenesis

PubMed Central

Gillrie, Mark R.; Avril, Marion; Brazier, Andrew J.; Davis, Shevaun P.; Stins, Monique F.; Smith, Joseph D.; Ho, May

2015-01-01

Summary P. falciparum-infected erythrocytes (IRBC) expressing the domain cassettes (DC) 8 and 13 of the cytoadherent ligand PfEMP1 adhere to the endothelial protein C receptor (EPCR). By interfering with EPCR anti-coagulant and pro-endothelial barrier functions, IRBC adhesion could promote coagulation and vascular permeability that contribute to the pathogenesis of cerebral malaria. In this study, we examined adhesion of DC8- and DC13-expressing parasite lines to endothelial cells from different microvasculature, and the consequences of EPCR engagement on endothelial cell function. We found that IRBC from IT4var19 (DC8) and IT4var07 (DC13) parasite lines adhered to human brain, lung, and dermal endothelial cells under shear stress. However, the relative contribution of EPCR to parasite cytoadherence on the different types of endothelial cell varied. We also observed divergent functional outcomes for DC8 CIDRα1.1 and DC13 CIDRα1.4 domains. IT4var07 CIDRα1.4 inhibited generation of activated protein C (APC) on lung and dermal endothelial cells and blocked the APC-EPCR binding interaction on brain endothelial cells. IT4var19 CIDRα1.1 inhibited thrombin-induced endothelial barrier dysfunction in lung endothelial cells, while IT4var07 CIDRα1.4- inhibited the protective effect of APC on thrombin-induced permeability. Overall, these findings reveal a much greater complexity of how CIDRα1-expressing parasites may modulate malaria pathogenesis through EPCR adhesion. PMID:26119044

Blood-brain barrier hyperpermeability precedes demyelination in the cuprizone model.

PubMed

Berghoff, Stefan A; Düking, Tim; Spieth, Lena; Winchenbach, Jan; Stumpf, Sina K; Gerndt, Nina; Kusch, Kathrin; Ruhwedel, Torben; Möbius, Wiebke; Saher, Gesine

2017-12-01

In neuroinflammatory disorders such as multiple sclerosis, the physiological function of the blood-brain barrier (BBB) is perturbed, particularly in demyelinating lesions and supposedly secondary to acute demyelinating pathology. Using the toxic non-inflammatory cuprizone model of demyelination, we demonstrate, however, that the onset of persistent BBB impairment precedes demyelination. In addition to a direct effect of cuprizone on endothelial cells, a plethora of inflammatory mediators, which are mainly of astroglial origin during the initial disease phase, likely contribute to the destabilization of endothelial barrier function in vivo. Our study reveals that, at different time points of pathology and in different CNS regions, the level of gliosis correlates with the extent of BBB hyperpermeability and edema. Furthermore, in mutant mice with abolished type 3 CXC chemokine receptor (CXCR3) signaling, inflammatory responses are dampened and BBB dysfunction ameliorated. Together, these data have implications for understanding the role of BBB permeability in the pathogenesis of demyelinating disease.

Role of Vitamin C in the Function of the Vascular Endothelium

PubMed Central

Harrison, Fiona E.

2013-01-01

Abstract Significance: Vitamin C, or ascorbic acid, has long been known to participate in several important functions in the vascular bed in support of endothelial cells. These functions include increasing the synthesis and deposition of type IV collagen in the basement membrane, stimulating endothelial proliferation, inhibiting apoptosis, scavenging radical species, and sparing endothelial cell-derived nitric oxide to help modulate blood flow. Although ascorbate may not be able to reverse inflammatory vascular diseases such as atherosclerosis, it may well play a role in preventing the endothelial dysfunction that is the earliest sign of many such diseases. Recent Advances: Beyond simply preventing scurvy, evidence is mounting that ascorbate is required for optimal function of many dioxygenase enzymes in addition to those involved in collagen synthesis. Several of these enzymes regulate the transcription of proteins involved in endothelial function, proliferation, and survival, including hypoxia-inducible factor-1α and histone and DNA demethylases. More recently, ascorbate has been found to acutely tighten the endothelial permeability barrier and, thus, may modulate access of ascorbate and other molecules into tissues and organs. Critical Issues: The issue of the optimal cellular content of ascorbate remains unresolved, but it appears that low millimolar ascorbate concentrations are normal in most animal tissues, in human leukocytes, and probably in the endothelium. Although there may be little benefit of increasing near maximal cellular ascorbate concentrations in normal people, many diseases and conditions have either systemic or localized cellular ascorbate deficiency as a cause for endothelial dysfunction, including early atherosclerosis, sepsis, smoking, and diabetes. Future Directions: A key focus for future studies of ascorbate and the vascular endothelium will likely be to determine the mechanisms and clinical relevance of ascorbate effects on endothelial function, permeability, and survival in diseases that cause endothelial dysfunction. Antioxid. Redox Signal. 19, 2068–2083. PMID:23581713

B7-H1 shapes T-cell-mediated brain endothelial cell dysfunction and regional encephalitogenicity in spontaneous CNS autoimmunity.

PubMed

Klotz, Luisa; Kuzmanov, Ivan; Hucke, Stephanie; Gross, Catharina C; Posevitz, Vilmos; Dreykluft, Angela; Schulte-Mecklenbeck, Andreas; Janoschka, Claudia; Lindner, Maren; Herold, Martin; Schwab, Nicholas; Ludwig-Portugall, Isis; Kurts, Christian; Meuth, Sven G; Kuhlmann, Tanja; Wiendl, Heinz

2016-10-11

Molecular mechanisms that determine lesion localization or phenotype variation in multiple sclerosis are mostly unidentified. Although transmigration of activated encephalitogenic T cells across the blood-brain barrier (BBB) is a crucial step in the disease pathogenesis of CNS autoimmunity, the consequences on brain endothelial barrier integrity upon interaction with such T cells and subsequent lesion formation and distribution are largely unknown. We made use of a transgenic spontaneous mouse model of CNS autoimmunity characterized by inflammatory demyelinating lesions confined to optic nerves and spinal cord (OSE mice). Genetic ablation of a single immune-regulatory molecule in this model [i.e., B7-homolog 1 (B7-H1, PD-L1)] not only significantly increased incidence of spontaneous CNS autoimmunity and aggravated disease course, especially in the later stages of disease, but also importantly resulted in encephalitogenic T-cell infiltration and lesion formation in normally unaffected brain regions, such as the cerebrum and cerebellum. Interestingly, B7-H1 ablation on myelin oligodendrocyte glycoprotein-specific CD4 + T cells, but not on antigen-presenting cells, amplified T-cell effector functions, such as IFN-γ and granzyme B production. Therefore, these T cells were rendered more capable of eliciting cell contact-dependent brain endothelial cell dysfunction and increased barrier permeability in an in vitro model of the BBB. Our findings suggest that a single immune-regulatory molecule on T cells can be ultimately responsible for localized BBB breakdown, and thus substantial changes in lesion topography in the context of CNS autoimmunity.

Role of reactive oxygen and nitrogen species in the vascular responses to inflammation

PubMed Central

Kvietys, Peter R.; Granger, D. Neil

2012-01-01

Inflammation is a complex and potentially life-threatening condition that involves the participation of a variety of chemical mediators, signaling pathways, and cell types. The microcirculation, which is critical for the initiation and perpetuation of an inflammatory response, exhibits several characteristic functional and structural changes in response to inflammation. These include vasomotor dysfunction (impaired vessel dilation and constriction), the adhesion and transendothelial migration of leukocytes, endothelial barrier dysfunction (increased vascular permeability), blood vessel proliferation (angiogenesis), and enhanced thrombus formation. These diverse responses of the microvasculature largely reflect the endothelial cell dysfunction that accompanies inflammation and the central role of these cells in modulating processes as varied as blood flow regulation, angiogenesis, and thrombogenesis. The importance of endothelial cells in inflammation-induced vascular dysfunction is also predicated on the ability of these cells to produce and respond to reactive oxygen and nitrogen species. Inflammation seems to upset the balance between nitric oxide and superoxide within (and surrounding) endothelial cells, which is necessary for normal vessel function. This review is focused on defining the molecular targets in the vessel wall that interact with reactive oxygen species and nitric oxide to produce the characteristic functional and structural changes that occur in response to inflammation. This analysis of the literature is consistent with the view that reactive oxygen and nitrogen species contribute significantly to the diverse vascular responses in inflammation and supports efforts that are directed at targeting these highly reactive species to maintain normal vascular health in pathological conditions that are associated with acute or chronic inflammation. PMID:22154653

Endothelial dysfunction in metabolic and vascular disorders.

PubMed

Polovina, Marija M; Potpara, Tatjana S

2014-03-01

Vascular endothelium has important regulatory functions in the cardiovascular system and a pivotal role in the maintenance of vascular health and metabolic homeostasis. It has long been recognized that endothelial dysfunction participates in the pathogenesis of atherosclerosis from early, preclinical lesions to advanced, thrombotic complications. In addition, endothelial dysfunction has been recently implicated in the development of insulin resistance and type 2 diabetes mellitus (T2DM). Considering that states of insulin resistance (eg, metabolic syndrome, impaired fasting glucose, impaired glucose tolerance, and T2DM) represent the most prevalent metabolic disorders and risk factors for atherosclerosis, it is of considerable scientific and clinical interest that both metabolic and vascular disorders have endothelial dysfunction as a common background. Importantly, endothelial dysfunction has been associated with adverse outcomes in patients with established cardiovascular disease, and a growing body of evidence indicates that endothelial dysfunction also imparts adverse prognosis in states of insulin resistance. In this review, we discuss the association of insulin resistance and T2DM with endothelial dysfunction and vascular disease, with a focus on the underlying mechanisms and prognostic implications of the endothelial dysfunction in metabolic and vascular disorders. We also address current therapeutic strategies for the improvement of endothelial dysfunction.

The Barrier Within: Endothelial Transport of Hormones

PubMed Central

Kolka, Cathryn M.; Bergman, Richard N.

2015-01-01

Hormones are involved in a plethora of processes including development and growth, metabolism, mood, and immune responses. These essential functions are dependent on the ability of the hormone to access its target tissue. In the case of endocrine hormones that are transported through the blood, this often means that the endothelium must be crossed. Many studies have shown that the concentrations of hormones and nutrients in blood can be very different from those surrounding the cells on the tissue side of the blood vessel endothelium, suggesting that transport across this barrier can be rate limiting for hormone action. This transport can be regulated by altering the surface area of the blood vessel available for diffusion through to the underlying tissue or by the permeability of the endothelium. Many hormones are known to directly or indirectly affect the endothelial barrier, thus affecting their own distribution to their target tissues. Dysfunction of the endothelial barrier is found in many diseases, particularly those associated with the metabolic syndrome. The interrelatedness of hormones may help to explain why the cluster of diseases in the metabolic syndrome occur together so frequently and suggests that treating the endothelium may ameliorate defects in more than one disease. Here, we review the structure and function of the endothelium, its contribution to the function of hormones, and its involvement in disease. PMID:22875454

The barrier within: endothelial transport of hormones.

PubMed

Kolka, Cathryn M; Bergman, Richard N

2012-08-01

Hormones are involved in a plethora of processes including development and growth, metabolism, mood, and immune responses. These essential functions are dependent on the ability of the hormone to access its target tissue. In the case of endocrine hormones that are transported through the blood, this often means that the endothelium must be crossed. Many studies have shown that the concentrations of hormones and nutrients in blood can be very different from those surrounding the cells on the tissue side of the blood vessel endothelium, suggesting that transport across this barrier can be rate limiting for hormone action. This transport can be regulated by altering the surface area of the blood vessel available for diffusion through to the underlying tissue or by the permeability of the endothelium. Many hormones are known to directly or indirectly affect the endothelial barrier, thus affecting their own distribution to their target tissues. Dysfunction of the endothelial barrier is found in many diseases, particularly those associated with the metabolic syndrome. The interrelatedness of hormones may help to explain why the cluster of diseases in the metabolic syndrome occur together so frequently and suggests that treating the endothelium may ameliorate defects in more than one disease. Here, we review the structure and function of the endothelium, its contribution to the function of hormones, and its involvement in disease.

Publisher Correction: Eternal blood vessels

NASA Astrophysics Data System (ADS)

Hindson, Jordan

2018-05-01

This article was originally published with an incorrect reference for the original article. The reference has been amended. Please see the correct reference below. Qiu, Y. et al. Microvasculature-on-a-chip for the long-term study of endothelial barrier dysfunction and microvascular obstruction in disease. Nat. Biomed. Eng. https://doi.org/10.1038/s41551-018-0224-z (2018)

Analysis of vascular endothelial dysfunction genes and related pathways in obesity through systematic bioinformatics.

PubMed

Zhang, Hui; Wang, Jing; Sun, Ling; Xu, Qiuqin; Hou, Miao; Ding, Yueyue; Huang, Jie; Chen, Ye; Cao, Lei; Zhang, Jianmin; Qian, Weiguo; Lv, Haitao

2015-01-01

Obesity has become an increasingly serious health problem and popular research topic. It is associated with many diseases, especially cardiovascular disease (CVD)-related endothelial dysfunction. This study analyzed genes related to endothelial dysfunction and obesity and then summarized their most significant signaling pathways. Genes related to vascular endothelial dysfunction and obesity were extracted from a PubMed database, and analyzed by STRING, DAVID, and Gene-Go Meta-Core software. 142 genes associated with obesity were found to play a role in endothelial dysfunction in PubMed. A significant pathway (Angiotensin system maturation in protein folding and maturation) associated with obesity and endothelial dysfunction was explored. The genes and the pathway explored may play an important role in obesity. Further studies about preventing vascular endothelial dysfunction obesity should be conducted through targeting these loci and pathways.

Compartmentalized, functional role of angiogenin during spotted fever group rickettsia-induced endothelial barrier dysfunction: evidence of possible mediation by host tRNA-derived small noncoding RNAs

PubMed Central

2013-01-01

Background Microvascular endothelial barrier dysfunction is the central enigma in spotted fever group (SFG) rickettsioses. Angiogenin (ANG) is one of the earliest identified angiogenic factors, of which some are relevant to the phosphorylation of VE-cadherins that serve as endothelial adherens proteins. Although exogenous ANG is known to translocate into the nucleus of growing endothelial cells (ECs) where it plays a functional role, nuclear ANG is not detected in quiescent ECs. Besides its nuclear role, ANG is thought to play a cytoplasmic role, owing to its RNase activity that cleaves tRNA to produce small RNAs. Recently, such tRNA-derived RNA fragments (tRFs) have been shown to be induced under stress conditions. All these observations raise an intriguing hypothesis about a novel cytoplasmic role of ANG, which is induced upon infection with Rickettsia and generates tRFs that may play roles in SFG rickettsioses. Methods C3H/HeN mice were infected intravenously with a sublethal dose of R. conorii. At days 1, 3, and 5 post infection (p.i.), liver, lung and brain were collected for immunofluorescence (IF) studies of R. conorii and angiogenin (ANG). Human umbilical vein endothelial cells (HUVECs) were infected with R. conorii for 24, 48, and 72 hrs before incubation with 1μg/ml recombinant human ANG (rANG) in normal medium for 2 hrs. HUVEC samples were subjected to IF, exogenous ANG translocation, endothelial permeability, and immunoprecipitation phosphorylation assays. To identify small non-coding RNAs (sncRNAs) upon rickettsial infection, RNAs from pulverized mouse lung tissues and HUVECs were subjected to library preparation and deep sequencing analysis using an Illumina 2000 instrument. Identified sncRNAs were confirmed by Northern hybridization, and their target mRNAs were predicted in silico using BLAST and RNA hybrid programs. Results In the present study, we have demonstrated endothelial up-regulation of ANG, co-localized with SFG rickettsial infection in vivo. We also have provided direct evidence that rickettsial infection sensitizes human ECs to the translocation of exogenous ANG in a compartmentalized pattern at different times post-infection. Typically, exogenous ANG translocates into the nucleus at 24 hrs and to the cytoplasm at 72 hrs post-infection. The ANG cytoplasmic translocation enhances phosphorylation and destabilization of VE-cadherin and attenuates endothelial barrier function. Of note, deep sequencing analysis detected tRFs, mostly derived from the 5'-halves of host tRNAs, that are induced by ANG. Northern hybridization validates the two most abundantly cloned tRFs derived from tRNA-ValGTG and tRNA-GlyGCC, in both mouse tissues and human cells. Bioinformatics analysis predicted that these tRFs may interact with transcripts associated with the endothelial barrier, the host cell inflammatory response, and autophagy. Conclusions Our data provide new insight into the role of compartmentalized ANG during SFG rickettsioses, and highlight its possible mediation through tRFs. PMID:23800282

Dengue Virus Infection Differentially Regulates Endothelial Barrier Function over Time through Type I Interferon Effects

PubMed Central

Liu, Ping; Woda, Marcia; Ennis, Francis A.; Libraty, Daniel H.

2013-01-01

Background The morbidity and mortality resulting from dengue hemorrhagic fever (DHF) are largely caused by endothelial barrier dysfunction and a unique vascular leakage syndrome. The mechanisms that lead to the location and timing of vascular leakage in DHF are poorly understood. We hypothesized that direct viral effects on endothelial responsiveness to inflammatory and angiogenesis mediators can explain the DHF vascular leakage syndrome. Methods We used an in vitro model of human endothelium to study the combined effects of dengue virus (DENV) type 2 (DENV2) infection and inflammatory mediators on paracellular macromolecule permeability over time. Results Over the initial 72 h after infection, DENV2 suppressed tumor necrosis factor (TNF)–α–mediated hyperpermeability in human umbilical vein endothelial cell (HUVEC) monolayers. This suppressive effect was mediated by type I interferon (IFN). By 1 week, TNF-α stimulation of DENV2-infected HUVECs synergistically increased cell cycling, angiogenic changes, and macromolecule permeability. This late effect could be prevented by the addition of exogenous type I IFN. Conclusions DENV infection of primary human endothelial cells differentially modulates TNF-α–driven angiogenesis and hyperpermeability over time. Type I IFN plays a central role in this process. Our findings suggest a rational model for the DHF vascular leakage syndrome. PMID:19530939

Endothelial β-Catenin Signaling Is Required for Maintaining Adult Blood-Brain Barrier Integrity and CNS Homeostasis

PubMed Central

Tran, Khiem A.; Zhang, Xianming; Predescu, Dan; Huang, Xiaojia; Machado, Roberto F.; Göthert, Joachim R.; Malik, Asrar B.; Valyi-Nagy, Tibor; Zhao, You-Yang

2015-01-01

Background The blood-brain barrier (BBB) formed by brain endothelial cells (ECs) interconnected by tight junctions (TJs) is essential for the homeostasis of the central nervous system (CNS). Although studies have shown the importance of various signaling molecules in BBB formation during development, little is known about the molecular basis regulating the integrity of the adult BBB. Methods and Results Using a mouse model with tamoxifen-inducible EC-restricted disruption of ctnnb1 (iCKO), here we show that endothelial β-catenin signaling is essential for maintaining BBB integrity and CNS homeostasis in adult. The iCKO mice developed severe seizures accompanied by neuronal injury, multiple brain petechial hemorrhages, and CNS inflammation, and all died postictal. Disruption of endothelial β-catenin induced BBB breakdown and downregulation of specific TJ proteins Claudin-1 and -3 in adult brain ECs. The clinical relevance of the data is indicated by the observation of decreased expression of Claudin-1 and nuclear β-catenin in brain ECs of hemorrhagic lesions of hemorrhagic stroke patients. Conclusion These results demonstrate the prerequisite role of endothelial β-catenin in maintaining the integrity of adult BBB. The results suggest that BBB dysfunction secondary to defective β-catenin transcription activity is a key pathogenic factor in hemorrhagic stroke, seizure activity and CNS inflammation. PMID:26538583

Endothelial Barrier Protection by Local Anesthetics: Ropivacaine and Lidocaine Block Tumor Necrosis Factor-α–induced Endothelial Cell Src Activation

PubMed Central

Piegeler, Tobias; Votta-Velis, E. Gina; Bakhshi, Farnaz R.; Mao, Mao; Carnegie, Graeme; Bonini, Marcelo G.; Schwartz, David E.; Borgeat, Alain; Beck-Schimmer, Beatrice; Minshall, Richard D.

2014-01-01

Background Pulmonary endothelial barrier dysfunction mediated in part by Src-kinase activation plays a crucial role in acute inflammatory disease. Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), activate Src via phosphatidylinositide 3-kinase/Akt-dependent nitric oxide generation, a process initiated by recruitment of phosphatidylinositide 3-kinase regulatory subunit p85 to TNF-receptor-1. Because amide-linked local anesthetics have well-established anti-inflammatory effects, the authors hypothesized that ropivacaine and lidocaine attenuate inflammatory Src signaling by disrupting the phosphatidylinositide 3-kinase–Akt–nitric oxide pathway, thus blocking Src-dependent neutrophil adhesion and endothelial hyperpermeability. Methods Human lung microvascular endothelial cells, incubated with TNFα in the absence or presence of clinically relevant concentrations of ropivacaine and lidocaine, were analyzed by Western blot, probing for phosphorylated/activated Src, endothelial nitric oxide synthase, Akt, intercellular adhesion molecule-1, and caveolin-1. The effect of ropivacaine on TNFα-induced nitric oxide generation, co-immunoprecipitation of TNF-receptor-1 with p85, neutrophil adhesion, and endothelial barrier disruption were assessed. Results Ropivacaine and lidocaine attenuated TNFα-induced Src activation (half-maximal inhibitory concentration [IC50] = 8.611 × 10−10 M for ropivacaine; IC50 = 5.864 × 10−10 M for lidocaine) and endothelial nitric oxide synthase phosphorylation (IC50 = 7.572 × 10−10 M for ropivacaine; IC50 = 6.377 × 10−10 M for lidocaine). Akt activation (n = 7; P = 0.006) and stimulus-dependent binding of TNF-receptor-1 and p85 (n = 6; P = 0.043) were blocked by 1 nM of ropivacaine. TNFα-induced neutrophil adhesion and disruption of endothelial monolayers via Src-dependent intercellular adhesion molecule-1- and caveolin-1-phosphorylation, respectively, were also attenuated. Conclusions Ropivacaine and lidocaine effectively blocked inflammatory TNFα signaling in endothelial cells by attenuating p85 recruitment to TNF-receptor-1. The resultant decrease in Akt, endothelial nitric oxide synthase, and Src phosphorylation reduced neutrophil adhesion and endothelial hyperpermeability. This novel anti-inflammatory “side-effect” of ropivacaine and lidocaine may provide therapeutic benefit in acute inflammatory disease. PMID:24525631

Endothelial barrier protection by local anesthetics: ropivacaine and lidocaine block tumor necrosis factor-α-induced endothelial cell Src activation.

PubMed

Piegeler, Tobias; Votta-Velis, E Gina; Bakhshi, Farnaz R; Mao, Mao; Carnegie, Graeme; Bonini, Marcelo G; Schwartz, David E; Borgeat, Alain; Beck-Schimmer, Beatrice; Minshall, Richard D

2014-06-01

Pulmonary endothelial barrier dysfunction mediated in part by Src-kinase activation plays a crucial role in acute inflammatory disease. Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), activate Src via phosphatidylinositide 3-kinase/Akt-dependent nitric oxide generation, a process initiated by recruitment of phosphatidylinositide 3-kinase regulatory subunit p85 to TNF-receptor-1. Because amide-linked local anesthetics have well-established anti-inflammatory effects, the authors hypothesized that ropivacaine and lidocaine attenuate inflammatory Src signaling by disrupting the phosphatidylinositide 3-kinase-Akt-nitric oxide pathway, thus blocking Src-dependent neutrophil adhesion and endothelial hyperpermeability. Human lung microvascular endothelial cells, incubated with TNFα in the absence or presence of clinically relevant concentrations of ropivacaine and lidocaine, were analyzed by Western blot, probing for phosphorylated/activated Src, endothelial nitric oxide synthase, Akt, intercellular adhesion molecule-1, and caveolin-1. The effect of ropivacaine on TNFα-induced nitric oxide generation, co-immunoprecipitation of TNF-receptor-1 with p85, neutrophil adhesion, and endothelial barrier disruption were assessed. Ropivacaine and lidocaine attenuated TNFα-induced Src activation (half-maximal inhibitory concentration [IC50] = 8.611 × 10 M for ropivacaine; IC50 = 5.864 × 10 M for lidocaine) and endothelial nitric oxide synthase phosphorylation (IC50 = 7.572 × 10 M for ropivacaine; IC50 = 6.377 × 10 M for lidocaine). Akt activation (n = 7; P = 0.006) and stimulus-dependent binding of TNF-receptor-1 and p85 (n = 6; P = 0.043) were blocked by 1 nM of ropivacaine. TNFα-induced neutrophil adhesion and disruption of endothelial monolayers via Src-dependent intercellular adhesion molecule-1- and caveolin-1-phosphorylation, respectively, were also attenuated. Ropivacaine and lidocaine effectively blocked inflammatory TNFα signaling in endothelial cells by attenuating p85 recruitment to TNF-receptor-1. The resultant decrease in Akt, endothelial nitric oxide synthase, and Src phosphorylation reduced neutrophil adhesion and endothelial hyperpermeability. This novel anti-inflammatory "side-effect" of ropivacaine and lidocaine may provide therapeutic benefit in acute inflammatory disease.

Plant-derived triterpene celastrol ameliorates oxygen glucose deprivation-induced disruption of endothelial barrier assembly via inducing tight junction proteins.

PubMed

Luo, Dan; Zhao, Jia; Rong, Jianhui

2016-12-01

The integrity and functions of blood-brain barrier (BBB) are regulated by the expression and organization of tight junction proteins. The present study was designed to explore whether plant-derived triterpenoid celastrol could regulate tight junction integrity in murine brain endothelial bEnd3 cells. We disrupted the tight junctions between endothelial bEnd3 cells by oxygen glucose deprivation (OGD). We investigated the effects of celastrol on the permeability of endothelial monolayers by measuring transepithelial electrical resistance (TEER). To clarify the tight junction composition, we analyzed the expression of tight junction proteins by RT-PCR and Western blotting techniques. We found that celastrol recovered OGD-induced TEER loss in a concentration-dependent manner. Celastrol induced occludin, claudin-5 and zonula occludens-1 (ZO-1) in endothelial cells. As a result, celastrol effectively maintained tight junction integrity and inhibited macrophage migration through endothelial monolayers against OGD challenge. Further mechanistic studies revealed that celastrol induced the expression of occludin and ZO-1) via activating MAPKs and PI3K/Akt/mTOR pathway. We also observed that celastrol regulated claudin-5 expression through different mechanisms. The present study demonstrated that celastrol effectively protected tight junction integrity against OGD-induced damage. Thus, celastrol could be a drug candidate for the treatment of BBB dysfunction in various diseases. Copyright © 2016 Elsevier GmbH. All rights reserved.

miR-98 and let-7g* protect the blood–brain barrier under neuroinflammatory conditions

PubMed Central

Rom, Slava; Dykstra, Holly; Zuluaga-Ramirez, Viviana; Reichenbach, Nancy L; Persidsky, Yuri

2015-01-01

Pathologic conditions in the central nervous system, regardless of the underlying injury mechanism, show a certain level of blood–brain barrier (BBB) impairment. Endothelial dysfunction is the earliest event in the initiation of vascular damage caused by inflammation due to stroke, atherosclerosis, trauma, or brain infections. Recently, microRNAs (miRNAs) have emerged as a class of gene expression regulators. The relationship between neuroinflammation and miRNA expression in brain endothelium remains unexplored. Previously, we showed the BBB-protective and anti-inflammatory effects of glycogen synthase kinase (GSK) 3β inhibition in brain endothelium in in vitro and in vivo models of neuroinflammation. Using microarray screening, we identified miRNAs induced in primary human brain microvascular endothelial cells after exposure to the pro-inflammatory cytokine, tumor necrosis factor-α, with/out GSK3β inhibition. Among the highly modified miRNAs, let-7 and miR-98 were predicted to target the inflammatory molecules, CCL2 and CCL5. Overexpression of let-7 and miR-98 in vitro and in vivo resulted in reduced leukocyte adhesion to and migration across endothelium, diminished expression of pro-inflammatory cytokines, and increased BBB tightness, attenuating barrier ‘leakiness' in neuroinflammation conditions. For the first time, we showed that miRNAs could be used as a therapeutic tool to prevent the BBB dysfunction in neuroinflammation. PMID:26126865

miR-98 and let-7g* protect the blood-brain barrier under neuroinflammatory conditions.

PubMed

Rom, Slava; Dykstra, Holly; Zuluaga-Ramirez, Viviana; Reichenbach, Nancy L; Persidsky, Yuri

2015-12-01

Pathologic conditions in the central nervous system, regardless of the underlying injury mechanism, show a certain level of blood-brain barrier (BBB) impairment. Endothelial dysfunction is the earliest event in the initiation of vascular damage caused by inflammation due to stroke, atherosclerosis, trauma, or brain infections. Recently, microRNAs (miRNAs) have emerged as a class of gene expression regulators. The relationship between neuroinflammation and miRNA expression in brain endothelium remains unexplored. Previously, we showed the BBB-protective and anti-inflammatory effects of glycogen synthase kinase (GSK) 3β inhibition in brain endothelium in in vitro and in vivo models of neuroinflammation. Using microarray screening, we identified miRNAs induced in primary human brain microvascular endothelial cells after exposure to the pro-inflammatory cytokine, tumor necrosis factor-α, with/out GSK3β inhibition. Among the highly modified miRNAs, let-7 and miR-98 were predicted to target the inflammatory molecules, CCL2 and CCL5. Overexpression of let-7 and miR-98 in vitro and in vivo resulted in reduced leukocyte adhesion to and migration across endothelium, diminished expression of pro-inflammatory cytokines, and increased BBB tightness, attenuating barrier 'leakiness' in neuroinflammation conditions. For the first time, we showed that miRNAs could be used as a therapeutic tool to prevent the BBB dysfunction in neuroinflammation.

Vaspin protects against LPS-induced ARDS by inhibiting inflammation, apoptosis and reactive oxygen species generation in pulmonary endothelial cells via the Akt/GSK-3β pathway

PubMed Central

Qi, Di; Wang, Daoxin; Zhang, Chunrong; Tang, Xumao; He, Jing; Zhao, Yan; Deng, Wang; Deng, Xinyu

2017-01-01

Acute respiratory distress syndrome (ARDS) is characterized by uncontrolled extravasation of protein-rich fluids, which is caused by disruption and dysfunction of the barrier of pulmonary endothelial cells (ECs). Visceral adipose tissue-derived serine protease inhibitor (vaspin) is a novel adipokine with pleiotropic properties, which has been reported to exert beneficial effects against obesity-associated systemic vascular diseases; however, its effects on ARDS remain unknown. In the present study, mice were subjected to systemic administration of adenoviral vector expressing vaspin (Ad-vaspin) to examine its effects on lipopolysaccharide (LPS)-induced ARDS in vivo. Histological analysis was then conducted, and cytokine [tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10] levels, and intercellular cell adhesion molecule-1 (ICAM-1) and adherens junctions (AJs) expression were detected. In addition, human pulmonary microvascular ECs (HPMECs) were treated with recombinant human (rh)-vaspin to further investigate its molecular basis and underlying mechanism. The mRNA expression levels of inflammatory cytokines (TNF-α and IL-6) and endothelial-specific adhesion markers [vascular cell adhesion molecule-1 and E-selectin], activation of nuclear factor-κB, and cell viability and apoptosis were then examined. Furthermore, the expression of AJs and organization of the cytoskeleton, as well as expression and activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and generation of reactive oxygen species (ROS) were determined. The results indicated that Ad-vaspin protected against LPS-induced ARDS by alleviating the pulmonary inflammatory response and pulmonary EC barrier dysfunction in mice, which was accompanied by activation of the protein kinase B (Akt)/glycogen synthase kinase (GSK)-3β pathway. In addition, pretreatment of HPMECs with rh-vaspin attenuated inflammation, apoptosis and ROS generation without alterations in AJs and cytoskeletal organization following LPS insult, which was accompanied by activation of the Akt/GSK3β pathway. In conclusion, the present study demonstrated that vaspin protects against LPS-induced ARDS by reversing EC barrier dysfunction via the suppression of inflammation, apoptosis and ROS production in pulmonary ECs, at least partially via activation of the Akt/GSK3β pathway. These findings provide evidence of a causal link between vaspin and EC dysfunction in ARDS, and suggest a potential therapeutic intervention for patients with ARDS. PMID:29039444

New therapeutic modality for corneal endothelial disease using Rho-associated kinase inhibitor eye drops.

PubMed

Koizumi, Noriko; Okumura, Naoki; Ueno, Morio; Kinoshita, Shigeru

2014-11-01

Corneal endothelial dysfunction accompanied by visual disturbance is a primary indication for corneal endothelial transplantation. However, despite the value and potential of endothelial graft surgery, a strictly pharmacological approach for treating corneal endothelial dysfunction remains an attractive proposition. Previously, we reported that the selective Rho-associated kinase (ROCK) inhibitor Y-27632 promotes cell adhesion and proliferation, and inhibits the apoptosis of primate corneal endothelial cells in culture. These findings have led us to develop a novel medical treatment for the early phase of corneal endothelial disease using ROCK inhibitor eye drops. In rabbit and monkey models of partial endothelial dysfunction, we showed that corneal endothelial wound healing was accelerated via the topical application of ROCK inhibitor to the ocular surface, resulting in the regeneration of a corneal endothelial monolayer with a high endothelial cell density. Based on these animal studies, we are now attempting to advance the clinical application of ROCK inhibitor eye drops for patients with corneal endothelial dysfunction. A pilot clinical study was performed at the Kyoto Prefectural University of Medicine, and the effects of Y-27632 eye drops after transcorneal freezing were evaluated in 8 patients with corneal endothelial dysfunction. We observed a positive effect of ROCK inhibitor eye drops in treating patients with central edema caused by Fuchs corneal endothelial dystrophy. We believe that our new findings will contribute to the establishment of a new approach for the treatment of corneal endothelial dysfunction.

Cathepsin S Cleavage of Protease-Activated Receptor-2 on Endothelial Cells Promotes Microvascular Diabetes Complications

PubMed Central

Kumar VR, Santhosh; Darisipudi, Murthy N.; Steiger, Stefanie; Devarapu, Satish Kumar; Tato, Maia; Kukarni, Onkar P.; Mulay, Shrikant R.; Thomasova, Dana; Popper, Bastian; Demleitner, Jana; Zuchtriegel, Gabriele; Reichel, Christoph; Cohen, Clemens D.; Lindenmeyer, Maja T.; Liapis, Helen; Moll, Solange; Reid, Emma; Stitt, Alan W.; Schott, Brigitte; Gruner, Sabine; Haap, Wolfgang; Ebeling, Martin; Hartmann, Guido

2016-01-01

Endothelial dysfunction is a central pathomechanism in diabetes-associated complications. We hypothesized a pathogenic role in this dysfunction of cathepsin S (Cat-S), a cysteine protease that degrades elastic fibers and activates the protease-activated receptor-2 (PAR2) on endothelial cells. We found that injection of mice with recombinant Cat-S induced albuminuria and glomerular endothelial cell injury in a PAR2-dependent manner. In vivo microscopy confirmed a role for intrinsic Cat-S/PAR2 in ischemia–induced microvascular permeability. In vitro transcriptome analysis and experiments using siRNA or specific Cat-S and PAR2 antagonists revealed that Cat-S specifically impaired the integrity and barrier function of glomerular endothelial cells selectively through PAR2. In human and mouse type 2 diabetic nephropathy, only CD68+ intrarenal monocytes expressed Cat-S mRNA, whereas Cat-S protein was present along endothelial cells and inside proximal tubular epithelial cells also. In contrast, the cysteine protease inhibitor cystatin C was expressed only in tubules. Delayed treatment of type 2 diabetic db/db mice with Cat-S or PAR2 inhibitors attenuated albuminuria and glomerulosclerosis (indicators of diabetic nephropathy) and attenuated albumin leakage into the retina and other structural markers of diabetic retinopathy. These data identify Cat-S as a monocyte/macrophage–derived circulating PAR2 agonist and mediator of endothelial dysfunction–related microvascular diabetes complications. Thus, Cat-S or PAR2 inhibition might be a novel strategy to prevent microvascular disease in diabetes and other diseases. PMID:26567242

Endothelial dysfunction is associated with activation of the type I interferon system and platelets in patients with systemic lupus erythematosus

PubMed Central

Tydén, Helena; Lood, Christian; Gullstrand, Birgitta; Nielsen, Christoffer Tandrup; Heegaard, Niels H H; Kahn, Robin; Jönsen, Andreas; Bengtsson, Anders A

2017-01-01

Objectives Endothelial dysfunction may be connected to cardiovascular disease (CVD) in systemic lupus erythematosus (SLE). Type I interferons (IFNs) are central in SLE pathogenesis and are suggested to induce both endothelial dysfunction and platelet activation. In this study, we investigated the interplay between endothelial dysfunction, platelets and type I IFN in SLE. Methods We enrolled 148 patients with SLE and 79 sex-matched and age-matched healthy controls (HCs). Type I IFN activity was assessed with a reporter cell assay and platelet activation by flow cytometry. Endothelial dysfunction was assessed using surrogate markers of endothelial activation, soluble vascular cell adhesion molecule-1 (sVCAM-1) and endothelial microparticles (EMPs), and finger plethysmograph to determine Reactive Hyperaemia Index (RHI). Results In patients with SLE, type I IFN activity was associated with endothelial activation, measured by high sVCAM-1 (OR 1.68, p<0.01) and elevated EMPs (OR 1.40, p=0.03). Patients with SLE with high type I IFN activity had lower RHI than HCs (OR 2.61, p=0.04), indicating endothelial dysfunction. Deposition of complement factors on platelets, a measure of platelet activation, was seen in patients with endothelial dysfunction. High levels of sVCAM-1 were associated with increased deposition of C4d (OR 4.57, p<0.01) and C1q (OR 4.10, p=0.04) on platelets. High levels of EMPs were associated with C4d deposition on platelets (OR 3.64, p=0.03). Conclusions Endothelial dysfunction was associated with activation of platelets and the type I IFN system. We suggest that an interplay between the type I IFN system, injured endothelium and activated platelets may contribute to development of CVD in SLE. PMID:29119007

RECOMBINANT FACTOR XIII DIMINISHES MULTIPLE ORGAN DYSFUNCTION IN RATS CAUSED BY GUT ISCHEMIA-REPERFUSION INJURY

PubMed Central

Zaets, Sergey B.; Xu, Da-Zhong; Lu, Qi; Feketova, Eleonora; Berezina, Tamara L.; Gruda, Maryann; Malinina, Inga V.; Deitch, Edwin A.; Olsen, Eva H. N.

2010-01-01

Plasma factor XIII (FXIII) is responsible for stabilization of fibrin clot at the final stage of blood coagulation. Because FXIII has also been shown to modulate inflammation and endothelial permeability, we hypothesized that FXIII diminishes multiple organ dysfunction caused by gut I/R injury. A model of superior mesenteric artery occlusion (SMAO) was used to induce gut I/R injury. Rats were subjected to 45-min SMAO or sham SMAO and treated with recombinant human FXIII A2 subunit (rFXIII) or placebo at the beginning of the reperfusion period. Lung permeability, lung and gut myeloperoxidase activity, gut histology, neutrophil respiratory burst, and microvascular blood flow in the liver and muscles were measured after a 3-h reperfusion period. The effect of activated rFXIII on transendothelial resistance of human umbilical vein endothelial cells was tested in vitro. Superior mesenteric artery occlusion–induced lung permeability as well as lung and gut myeloperoxidase activity was significantly lower in rFXIII-treated versus untreated animals. Similarly, rFXIII-treated rats had lower neutrophil respiratory burst activity and ileal mucosal injury. Rats treated with rFXIII also had higher liver microvascular blood flow compared with the placebo group. Superior mesenteric artery occlusion did not cause FXIII consumption during the study period. In vitro, activated rFXIII caused a dose-dependent increase in human umbilical vein endothelial cell monolayer resistance to thrombin-induced injury. Thus, administration of rFXIII diminishes SMAO-induced multiple organ dysfunction in rats, presumably by preservation of endothelial barrier function and the limitation of polymorphonuclear leukocyte activation. PMID:18948851

Impaired Hedgehog signalling-induced endothelial dysfunction is sufficient to induce neuropathy: implication in diabetes.

PubMed

Chapouly, Candice; Yao, Qinyu; Vandierdonck, Soizic; Larrieu-Lahargue, Frederic; Mariani, John N; Gadeau, Alain-Pierre; Renault, Marie-Ange

2016-02-01

Microangiopathy, i.e. endothelial dysfunction, has long been suggested to contribute to the development of diabetic neuropathy, although this has never been fully verified. In the present paper, we have identified the role of Hedgehog (Hh) signalling in endoneurial microvessel integrity and evaluated the impact of impaired Hh signalling in endothelial cells (ECs) on nerve function. By using Desert Hedgehog (Dhh)-deficient mice, we have revealed, that in the absence of Dhh, endoneurial capillaries are abnormally dense and permeable. Furthermore, Smoothened (Smo) conditional KO mice clarified that this increased vessel permeability is specifically due to impaired Hh signalling in ECs and is associated with a down-regulation of Claudin5 (Cldn5). Moreover, impairment of Hh signalling in ECs was sufficient to induce hypoalgesia and neuropathic pain. Finally in Lepr(db/db) type 2 diabetic mice, the loss of Dhh expression observed in the nerve was shown to be associated with increased endoneurial capillary permeability and decreased Cldn5 expression. Conversely, systemic administration of the Smo agonist SAG increased Cldn5 expression, decreased endoneurial capillary permeability, and restored thermal algesia to diabetic mice, demonstrating that loss of Dhh expression is crucial in the development of diabetic neuropathy. The present work demonstrates the critical role of Dhh in maintaining blood nerve barrier integrity and demonstrates for the first time that endothelial dysfunction is sufficient to induce neuropathy. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Regulation of lung endothelial permeability and inflammatory responses by prostaglandin A2: role of EP4 receptor

PubMed Central

Ohmura, Tomomi; Tian, Yufeng; Sarich, Nicolene; Ke, Yunbo; Meliton, Angelo; Shah, Alok S.; Andreasson, Katrin; Birukov, Konstantin G.; Birukova, Anna A.

2017-01-01

The role of prostaglandin A2 (PGA2) in modulation of vascular endothelial function is unknown. We investigated effects of PGA2 on pulmonary endothelial cell (EC) permeability and inflammatory activation and identified a receptor mediating these effects. PGA2 enhanced the EC barrier and protected against barrier dysfunction caused by vasoactive peptide thrombin and proinflammatory bacterial wall lipopolysaccharide (LPS). Receptor screening using pharmacological and molecular inhibitory approaches identified EP4 as a novel PGA2 receptor. EP4 mediated barrier-protective effects of PGA2 by activating Rap1/Rac1 GTPase and protein kinase A targets at cell adhesions and cytoskeleton: VE-cadherin, p120-catenin, ZO-1, cortactin, and VASP. PGA2 also suppressed LPS-induced inflammatory signaling by inhibiting the NFκB pathway and expression of EC adhesion molecules ICAM1 and VCAM1. These effects were abolished by pharmacological or molecular inhibition of EP4. In vivo, PGA2 was protective in two distinct models of acute lung injury (ALI): LPS-induced inflammatory injury and two-hit ALI caused by suboptimal mechanical ventilation and injection of thrombin receptor–activating peptide. These protective effects were abolished in mice with endothelial-specific EP4 knockout. The results suggest a novel role for the PGA2–EP4 axis in vascular EC protection that is critical for improvement of pathological states associated with increased vascular leakage and inflammation. PMID:28428256

Apigenin and naringenin ameliorate PKCβII-associated endothelial dysfunction via regulating ROS/caspase-3 and NO pathway in endothelial cells exposed to high glucose.

PubMed

Qin, Weiwei; Ren, Bei; Wang, Shanshan; Liang, Shujun; He, Baiqiu; Shi, Xiaoji; Wang, Liying; Liang, Jingyu; Wu, Feihua

2016-10-01

Endothelial dysfunction is a key event in the progression of atherosclerosis with diabetes. Increasing cell apoptosis may lead to endothelial dysfunction. Apigenin and naringenin are two kinds of widely used flavones. In the present study, we investigated whether and how apigenin and naringenin reduced endothelial dysfunction induced by high glucose in endothelial cells. We showed that apigenin and naringenin protected against endothelial dysfunction via inhibiting phosphorylation of protein kinase C βII (PKCβII) expression and downstream reactive oxygen species (ROS) production in endothelial cells exposed to high glucose. Furthermore, we demonstrated that apigenin and naringenin reduced high glucose-increased apoptosis, Bax expression, caspase-3 activity and phosphorylation of NF-κB in endothelial cells. Moreover, apigenin and naringenin effectively restored high glucose-reduced Bcl-2 expression and Akt phosphorylation. Importantly, apigenin and naringenin significantly increased NO production in endothelial cells subjected to high glucose challenge. Consistently, high glucose stimulation impaired acetylcholine (ACh)-mediated vasodilation in the rat aorta, apigenin and naringenin treatment restored the impaired endothelium-dependent vasodilation via dramatically increasing eNOS activity and nitric oxide (NO) level. Taken together, our results manifest that apigenin and naringenin can ameliorate endothelial dysfunction via regulating ROS/caspase-3 and NO pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

Strategies to reverse endothelial progenitor cell dysfunction in diabetes.

PubMed

Petrelli, Alessandra; Di Fenza, Raffaele; Carvello, Michele; Gatti, Francesca; Secchi, Antonio; Fiorina, Paolo

2012-01-01

Bone-marrow-derived cells-mediated postnatal vasculogenesis has been reported as the main responsible for the regulation of vascular homeostasis in adults. Since their discovery, endothelial progenitor cells have been depicted as mediators of postnatal vasculogenesis for their peculiar phenotype (partially staminal and partially endothelial), their ability to differentiate in endothelial cell line and to be incorporated into the vessels wall during ischemia/damage. Diabetes mellitus, a condition characterized by cardiovascular disease, nephropathy, and micro- and macroangiopathy, showed a dysfunction of endothelial progenitor cells. Herein, we review the mechanisms involved in diabetes-related dysfunction of endothelial progenitor cells, highlighting how hyperglycemia affects the different steps of endothelial progenitor cells lifetime (i.e., bone marrow mobilization, trafficking into the bloodstream, differentiation in endothelial cells, and homing in damaged tissues/organs). Finally, we review preclinical and clinical strategies that aim to revert diabetes-induced dysfunction of endothelial progenitor cells as a means of finding new strategies to prevent diabetic complications.

Toll-like receptor 4-induced endoplasmic reticulum stress contributes to endothelial dysfunction

USDA-ARS?s Scientific Manuscript database

Impairment of vasodilator action of insulin is associated with endothelial dysfunction and insulin resistance. Endoplasmic reticulum (ER) stress is implicated as one of the mechanisms for pathophysiology of various cardiometabolic syndromes, including insulin resistance and endothelial dysfunction. ...

Extracellular microvesicle microRNAs in children with sickle cell anaemia with divergent clinical phenotypes.

PubMed

Khalyfa, Abdelnaby; Khalyfa, Ahamed A; Akbarpour, Mahzad; Connes, Phillippe; Romana, Marc; Lapping-Carr, Gabrielle; Zhang, Chunling; Andrade, Jorge; Gozal, David

2016-09-01

Sickle cell anaemia (SCA) is the most frequent genetic haemoglobinopathy, which exhibits a highly variable clinical course characterized by hyper-coagulable and pro-inflammatory states, as well as endothelial dysfunction. Extracellular microvesicles are released into biological fluids and play a role in modifying the functional phenotype of target cells. We hypothesized that potential differences in plasma-derived extracellular microvesicles (EV) function and cargo from SCA patients may underlie divergent clinical trajectories. Plasma EV from SCA patients with mild, intermediate and severe clinical disease course were isolated, and primary endothelial cell cultures were exposed. Endothelial cell activation, monocyte adhesion, barrier disruption and exosome cargo (microRNA microarrays) were assessed. EV disrupted the endothelial barrier and induced expression of adhesion molecules and monocyte adhesion in a SCA severity-dependent manner compared to healthy children. Microarray approaches identified a restricted signature of exosomal microRNAs that readily distinguished severe from mild SCA, as well as from healthy children. The microRNA candidates were further validated using quantitative real time polymerase chain reaction assays, and revealed putative gene targets. Circulating exosomal microRNAs may play important roles in predicting the clinical course of SCA, and in delineation of individually tailored, mechanistically-based clinical treatment approaches of SCA patients in the near future. © 2016 John Wiley & Sons Ltd.

High-Throughput Screening for Identification of Blood-Brain Barrier Integrity Enhancers: A Drug Repurposing Opportunity to Rectify Vascular Amyloid Toxicity.

PubMed

Qosa, Hisham; Mohamed, Loqman A; Al Rihani, Sweilem B; Batarseh, Yazan S; Duong, Quoc-Viet; Keller, Jeffrey N; Kaddoumi, Amal

2016-07-06

The blood-brain barrier (BBB) is a dynamic interface that maintains brain homeostasis and protects it from free entry of chemicals, toxins, and drugs. The barrier function of the BBB is maintained mainly by capillary endothelial cells that physically separate brain from blood. Several neurological diseases, such as Alzheimer's disease (AD), are known to disrupt BBB integrity. In this study, a high-throughput screening (HTS) was developed to identify drugs that rectify/protect BBB integrity from vascular amyloid toxicity associated with AD progression. Assessing Lucifer Yellow permeation across in-vitro BBB model composed from mouse brain endothelial cells (bEnd3) grown on 96-well plate inserts was used to screen 1280 compounds of Sigma LOPAC®1280 library for modulators of bEnd3 monolayer integrity. HTS identified 62 compounds as disruptors, and 50 compounds as enhancers of the endothelial barrier integrity. From these 50 enhancers, 7 FDA approved drugs were identified with EC50 values ranging from 0.76-4.56 μM. Of these 7 drugs, 5 were able to protect bEnd3-based BBB model integrity against amyloid toxicity. Furthermore, to test the translational potential to humans, the 7 drugs were tested for their ability to rectify the disruptive effect of Aβ in the human endothelial cell line hCMEC/D3. Only 3 (etodolac, granisetron, and beclomethasone) out of the 5 effective drugs in the bEnd3-based BBB model demonstrated a promising effect to protect the hCMEC/D3-based BBB model integrity. These drugs are compelling candidates for repurposing as therapeutic agents that could rectify dysfunctional BBB associated with AD.

High-throughput screening for identification of blood-brain barrier integrity enhancers: a drug repurposing opportunity to rectify vascular amyloid toxicity

PubMed Central

Qosa, Hisham; Mohamed, Loqman A.; Al Rihani, Sweilem B.; Batarseh, Yazan S.; Duong, Quoc-Viet; Keller, Jeffrey N.; Kaddoumi, Amal

2016-01-01

The blood-brain barrier (BBB) is a dynamic interface that maintains brain homeostasis and protects it from free entry of chemicals, toxins and drugs. The barrier function of the BBB is maintained mainly by capillary endothelial cells that physically separate brain from blood. Several neurological diseases, such as Alzheimer’s disease (AD), are known to disrupt BBB integrity. In this study, a high-throughput screening (HTS) was developed to identify drugs that rectify/protect BBB integrity from vascular amyloid toxicity associated with AD progression. Assessing Lucifer Yellow permeation across in-vitro BBB model composed from mouse brain endothelial cells (bEnd3) grown on 96-well plate inserts was used to screen 1280 compounds of Sigma LOPAC®1280 library for modulators of bEnd3 monolayer integrity. HTS identified 62 compounds as disruptors, and 50 compounds as enhancers of the endothelial barrier integrity. From these 50 enhancers, 7 FDA approved drugs were identified with EC50 values ranging from 0.76–4.56 μM. Of these 7 drugs, five were able to protect bEnd3-based BBB model integrity against amyloid toxicity. Furthermore, to test the translational potential to humans, the 7 drugs were tested for their ability to rectify the disruptive effect of Aβ in the human endothelial cell line hCMEC/D3. Only 3 (etodolac, granisetron and beclomethasone) out of the 5 effective drugs in the bEnd3-based BBB model demonstrated a promising effect to protect the hCMEC/D3-based BBB model integrity. These drugs are compelling candidates for repurposing as therapeutic agents that could rectify dysfunctional BBB associated with AD. PMID:27392852

Drugs of abuse and blood-brain barrier endothelial dysfunction: A focus on the role of oxidative stress

PubMed Central

Sajja, Ravi K; Rahman, Shafiqur

2015-01-01

Psychostimulants and nicotine are the most widely abused drugs with a detrimental impact on public health globally. While the long-term neurobehavioral deficits and synaptic perturbations are well documented with chronic use of methamphetamine, cocaine, and nicotine, emerging human and experimental studies also suggest an increasing incidence of neurovascular complications associated with drug abuse. Short- or long-term administration of psychostimulants or nicotine is known to disrupt blood-brain barrier (BBB) integrity/function, thus leading to an increased risk of brain edema and neuroinflammation. Various pathophysiological mechanisms have been proposed to underlie drug abuse-induced BBB dysfunction suggesting a central and unifying role for oxidative stress in BBB endothelium and perivascular cells. This review discusses drug-specific effects of methamphetamine, cocaine, and tobacco smoking on brain microvascular crisis and provides critical assessment of oxidative stress-dependent molecular pathways focal to the global compromise of BBB. Additionally, given the increased risk of human immunodeficiency virus (HIV) encephalitis in drug abusers, we have summarized the synergistic pathological impact of psychostimulants and HIV infection on BBB integrity with an emphasis on unifying role of endothelial oxidative stress. This mechanistic framework would guide further investigations on specific molecular pathways to accelerate therapeutic approaches for the prevention of neurovascular deficits by drugs of abuse. PMID:26661236

Associations of low grade inflammation and endothelial dysfunction with depression - The Maastricht Study.

PubMed

van Dooren, Fleur E P; Schram, Miranda T; Schalkwijk, Casper G; Stehouwer, Coen D A; Henry, Ronald M A; Dagnelie, Pieter C; Schaper, Nicolaas C; van der Kallen, Carla J H; Koster, Annemarie; Sep, Simone J S; Denollet, Johan; Verhey, Frans R J; Pouwer, Frans

2016-08-01

The pathogenesis of depression may involve low-grade inflammation and endothelial dysfunction. We aimed to evaluate the independent associations of inflammation and endothelial dysfunction with depressive symptoms and depressive disorder, and the role of lifestyle factors in this association. In The Maastricht Study, a population-based cohort study (n=852, 55% men, m=59.8±8.5years), depressive symptoms were assessed with the Patient Health Questionnaire-9 and (major and minor) depressive disorder with the Mini-International Neuropsychiatric Interview. Plasma biomarkers of inflammation (hsCRP, SAA, sICAM-1, IL-6, IL-8, TNF-α) and endothelial dysfunction (sVCAM-1, sICAM-1, sE-selectin, vWF) were measured with sandwich immunoassays and combined into two standardized sum scores. Biomarkers of inflammation (hsCRP, TNF-α, SAA, sICAM-1) and endothelial dysfunction (sICAM-1, sE-Selectin) were univariately associated with depressive symptoms and depressive disorder. The sum scores of inflammation and endothelial dysfunction were associated with depressive disorder after adjustment for age, sex, type 2 diabetes, kidney function and prior cardiovascular disease (OR 1.54, p=0.001 and 1.40, p=0.006). Both sum scores remained significantly associated with depressive disorder after additional adjustment for lifestyle factors smoking, alcohol consumption and body mass index. The sum score of inflammation was also independently associated with depressive symptoms, while the sum score of endothelial dysfunction was not. Inflammation and endothelial dysfunction are both associated with depressive disorder, independent of lifestyle factors. Our results might suggest that inflammation and endothelial dysfunction are involved in depression. Copyright © 2016. Published by Elsevier Inc.

Leptin promotes endothelial dysfunction in chronic kidney disease through AKT/GSK3β and β-catenin signals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Nannan; Liu, Bing; Song, Jiaguang

Endothelial dysfunction (ED) is a well-recognized instigator of cardiovascular diseases and develops in chronic kidney disease (CKD) with high rate. Recent studies have implicated that leptin is associated with endothelial dysfunction. We investigated the relationship between leptin and markers of ED in CKD patients and how leptin contributed to endothelial damage. 140 CKD patients and 140 healthy subjects were studied. Serum leptin levels were significantly higher in CKD than in controls and displayed significantly positive association with the increase levels of sICAM-1 and sVCAM-1 but negative correlation with flow-mediated dilatation (FMD) reduction in patients. Our in vitro study demonstrated that leptinmore » induced overexpression of ICAM-1 and VCAM-1, led to f-actin reorganization and vinculin assembly, increased endothelial monolayer permeability for FITC-dextran, and accelerated endothelial cell migration; these changes were markedly reversed when the cells were transfected with AKT or β-catenin shRNA vectors. Notably, high leptin resulted in hyper-phosphorylation of AKT and GSK3β, along with nuclear accumulation of β-catenin. In conclusion, serum leptin was elevated in CKD patients and it might contribute to endothelial dysfunction by disarrangement of f-actin cytoskeleton via a mechanism involving the AKT/GSK3β and β-catenin pathway. - Highlights: • Serum leptin was elevated in CKD patients and it was associated with endothelial dysfunction. • Leptin induced endothelial dysfunction by remodeling cytoskeleton in HUVECs. • Leptin promoted endothelial dysfunction via a mechanism involving the AKT/GSK3β and β-catenin signals.« less

TMEM16A Contributes to Endothelial Dysfunction by Facilitating Nox2 NADPH Oxidase-Derived Reactive Oxygen Species Generation in Hypertension.

PubMed

Ma, Ming-Ming; Gao, Min; Guo, Kai-Min; Wang, Mi; Li, Xiang-Yu; Zeng, Xue-Lin; Sun, Lu; Lv, Xiao-Fei; Du, Yan-Hua; Wang, Guan-Lei; Zhou, Jia-Guo; Guan, Yong-Yuan

2017-05-01

Ca 2+ -activated Cl - channels play a crucial role in various physiological processes. However, the role of TMEM16A in vascular endothelial dysfunction during hypertension is unclear. In this study, we investigated the specific involvement of TMEM16A in regulating endothelial function and blood pressure and the underlying mechanism. Reverse transcription-polymerase chain reaction, Western blotting, coimmunoprecipitation, confocal imaging, patch-clamp recordings, and TMEM16A endothelial-specific transgenic and knockout mice were used. We found that TMEM16A was expressed abundantly and functioned as a Ca 2+ -activated Cl - channel in endothelial cells. Angiotensin II induced endothelial dysfunction with an increase in TMEM16A expression. The knockout of endothelial-specific TMEM16A significantly lowered the blood pressure and ameliorated endothelial dysfunction in angiotensin II-induced hypertension, whereas the overexpression of endothelial-specific TMEM16A resulted in the opposite effects. These results were related to the increased reactive oxygen species production, Nox2-containing NADPH oxidase activation, and Nox2 and p22phox protein expression that were facilitated by TMEM16A on angiotensin II-induced hypertensive challenge. Moreover, TMEM16A directly bound with Nox2 and reduced the degradation of Nox2 through the proteasome-dependent degradation pathway. Therefore, TMEM16A is a positive regulator of endothelial reactive oxygen species generation via Nox2-containing NADPH oxidase, which induces endothelial dysfunction and hypertension. Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated diseases. © 2017 American Heart Association, Inc.

[Carrier-mediated Transport of Cationic Drugs across the Blood-Tissue Barrier].

PubMed

Kubo, Yoshiyuki

2015-01-01

Studies of neurological dysfunction have revealed the neuroprotective effect of several cationic drugs, suggesting their usefulness in the treatment of neurological diseases. In the brain and retina, blood-tissue barriers such as blood-brain barrier (BBB) and blood-retinal barrier (BRB) are formed to restrict nonspecific solute transport between the circulating blood and neural tissues. Therefore study of cationic drug transport at these barriers is essential to achieve systemic delivery of neuroprotective agents into the neural tissues. In the retina, severe diseases such as diabetic retinopathy and macular degeneration can cause neurological dysfunction that dramatically affects patients' QOL. The BRB is formed by retinal capillary endothelial cells (inner BRB) and retinal pigment epithelial cells (outer BRB). Blood-to-retina transport of cationic drugs was investigated at the inner BRB, which is known to nourish two thirds of the retina. Blood-to-retinal transport of verapamil suggested that the barrier function of the BRB differs from that of the BBB. Moreover, carrier-mediated transport of verapamil and pyrilamine revealed the involvement of novel organic cation transporters at the inner BRB. The identified transport systems for cationic drugs are sensitive to several cationic neuroprotective and anti-angiogenic agents such as clonidine and propranolol, and the involvement of novel transporters was also suggested in their blood-to-retina transport across the inner BRB.

Endothelial dysfunction as a predictor of cardiovascular disease in type 1 diabetes

PubMed Central

Bertoluci, Marcello C; Cé, Gislaine V; da Silva, Antônio MV; Wainstein, Marco V; Boff, Winston; Puñales, Marcia

2015-01-01

Macro and microvascular disease are the main cause of morbi-mortality in type 1 diabetes (T1DM). Although there is a clear association between endothelial dysfunction and atherosclerosis in type 2 diabetes, a cause-effect relationship is less clear in T1DM. Although endothelial dysfunction (ED) precedes atherosclerosis, it is not clear weather, in recent onset T1DM, it may progress to clinical macrovascular disease. Moreover, endothelial dysfunction may either be reversed spontaneously or in response to intensive glycemic control, long-term exercise training and use of statins. Acute, long-term and post-prandial hyperglycemia as well as duration of diabetes and microalbuminuria are all conditions associated with ED in T1DM. The pathogenesis of endothelial dysfunction is closely related to oxidative-stress. NAD(P)H oxidase over activity induces excessive superoxide production inside the mitochondrial oxidative chain of endothelial cells, thus reducing nitric oxide bioavailability and resulting in peroxynitrite formation, a potent oxidant agent. Moreover, oxidative stress also uncouples endothelial nitric oxide synthase, which becomes dysfunctional, inducing formation of superoxide. Other important mechanisms are the activation of both the polyol and protein kinase C pathways as well as the presence of advanced glycation end-products. Future studies are needed to evaluate the potential clinical applicability of endothelial dysfunction as a marker for early vascular complications in T1DM. PMID:26069717

Cardiovascular risk reduction by reversing endothelial dysfunction:ARBs, ACE inhibitors, or both? Expectations from The ONTARGET Trial Programme

PubMed Central

Ruilope, Luis Miguel; Redón, Josep; Schmieder, Roland

2007-01-01

Endothelial dysfunction is the initial pathophysiological step in a progression of vascular damage that leads to overt cardiovascular and chronic kidney disease. Angiotensin II, the primary agent of the renin–angiotensin system (RAS), has a central role in endothelial dysfunction. Therefore, RAS blockade with an angiotensin receptor blocker (ARB) and/or angiotensin-converting enzyme (ACE) inhibitor provides a rational approach to reverse endothelial dysfunction, reduce microalbuminuria, and, thus, improves cardiovascular and renal prognosis. ARBs and ACE inhibitors act at different points in the RAS pathway and recent evidence suggests that there are differences regarding their effects on endothelial dysfunction. In addition to blood pressure lowering, studies have shown that ARBs reduce target-organ damage, including improvements in endothelial dysfunction, arterial stiffness, the progression of renal dysfunction in patients with type 2 diabetes, proteinuria, and left ventricular hypertrophy. The ONgoing Telmisartan Alone in combination with Ramipril Global Endpoint Trial (ONTARGET) Programme is expected to provide the ultimate evidence of whether improved endothelial function translates into reduced cardiovascular and renal events in high-risk patients, and to assess possible differential outcomes with telmisartan, the ACE inhibitor ramipril, or a combination of both (dual RAS blockade). Completion of ONTARGET is expected in 2008. PMID:17583170

C-reactive protein induces release of both endothelial microparticles and circulating endothelial cells in vitro and in vivo: further evidence of endothelial dysfunction.

PubMed

Devaraj, Sridevi; Kumaresan, Pappanaicken R; Jialal, Ishwarlal

2011-12-01

Inflammation is pivotal in atherosclerosis. A key early event in atherosclerosis is endothelial dysfunction. C-reactive protein (CRP), the prototypic marker of inflammation in humans, is a risk marker for cardiovascular disease, and there is mounting evidence to support its role in atherothrombosis. CRP has been shown to promote endothelial dysfunction both in vitro and in vivo. Emerging biomarkers of endothelial dysfunction include circulating endothelial cells (CECs) and endothelial microparticles (EMPs). However, there is a paucity of data examining the effect of CRP on CEC and EMP production in vitro and in vivo. In this report, we treated human aortic endothelial cells (HAECs) with increasing concentrations of CRP (0-50 μg/mL) or boiled CRP. We counted CECs and EMPs by flow cytometry. Although CRP treatment resulted in a significant increase in release of both CECs and EMPs, boiled CRP failed to have an effect. Pretreatment of HAECs with sepiapterin or diethylenetriamine NONOate, both of which preserve nitric oxide (NO), resulted in attenuation of CRP's effects on CECs and EMPs. CD32 and CD64 blocking antibodies but not CD16 antibody or lectin-like oxidized LDL receptor 1 small interfering RNA (LOX-1 siRNA) prevented CRP-induced production of CECs and EMPs. Furthermore, delivery of human CRP to Wistar rats compared with human serum albumin resulted in significantly increased CECs and EMPs, corroborating the in vitro findings. We provide novel data that CRP, via NO deficiency, promotes endothelial dysfunction by inducing release of CECs and EMPs, which are biomarkers of endothelial dysfunction.

Endothelial Activation and Blood-Brain Barrier Disruption in Neurotoxicity after Adoptive Immunotherapy with CD19 CAR-T Cells.

PubMed

Gust, Juliane; Hay, Kevin A; Hanafi, Laïla-Aïcha; Li, Daniel; Myerson, David; Gonzalez-Cuyar, Luis F; Yeung, Cecilia; Liles, W Conrad; Wurfel, Mark; Lopez, Jose A; Chen, Junmei; Chung, Dominic; Harju-Baker, Susanna; Özpolat, Tahsin; Fink, Kathleen R; Riddell, Stanley R; Maloney, David G; Turtle, Cameron J

2017-12-01

Lymphodepletion chemotherapy followed by infusion of CD19-targeted chimeric antigen receptor-modified T (CAR-T) cells can be complicated by neurologic adverse events (AE) in patients with refractory B-cell malignancies. In 133 adults treated with CD19 CAR-T cells, we found that acute lymphoblastic leukemia, high CD19 + cells in bone marrow, high CAR-T cell dose, cytokine release syndrome, and preexisting neurologic comorbidities were associated with increased risk of neurologic AEs. Patients with severe neurotoxicity demonstrated evidence of endothelial activation, including disseminated intravascular coagulation, capillary leak, and increased blood-brain barrier (BBB) permeability. The permeable BBB failed to protect the cerebrospinal fluid from high concentrations of systemic cytokines, including IFNγ, which induced brain vascular pericyte stress and their secretion of endothelium-activating cytokines. Endothelial activation and multifocal vascular disruption were found in the brain of a patient with fatal neurotoxicity. Biomarkers of endothelial activation were higher before treatment in patients who subsequently developed grade ≥4 neurotoxicity. Significance: We provide a detailed clinical, radiologic, and pathologic characterization of neurotoxicity after CD19 CAR-T cells, and identify risk factors for neurotoxicity. We show endothelial dysfunction and increased BBB permeability in neurotoxicity and find that patients with evidence of endothelial activation before lymphodepletion may be at increased risk of neurotoxicity. Cancer Discov; 7(12); 1404-19. ©2017 AACR. See related commentary by Mackall and Miklos, p. 1371 This article is highlighted in the In This Issue feature, p. 1355 . ©2017 American Association for Cancer Research.

Proton Pump Inhibitors Decrease Soluble fms-Like Tyrosine Kinase-1 and Soluble Endoglin Secretion, Decrease Hypertension, and Rescue Endothelial Dysfunction.

PubMed

Onda, Kenji; Tong, Stephen; Beard, Sally; Binder, Natalie; Muto, Masanaga; Senadheera, Sevvandi N; Parry, Laura; Dilworth, Mark; Renshall, Lewis; Brownfoot, Fiona; Hastie, Roxanne; Tuohey, Laura; Palmer, Kirsten; Hirano, Toshihiko; Ikawa, Masahito; Kaitu'u-Lino, Tu'uhevaha; Hannan, Natalie J

2017-03-01

Preeclampsia is a severe complication of pregnancy. Antiangiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin are secreted in excess from the placenta, causing hypertension, endothelial dysfunction, and multiorgan injury. Oxidative stress and vascular inflammation exacerbate the endothelial injury. A drug that can block these pathophysiological steps would be an attractive treatment option. Proton pump inhibitors (PPIs) are safe in pregnancy where they are prescribed for gastric reflux. We performed functional studies on primary human tissues and animal models to examine the effects of PPIs on sFlt-1 and soluble endoglin secretion, vessel dilatation, blood pressure, and endothelial dysfunction. PPIs decreased sFlt-1 and soluble endoglin secretion from trophoblast, placental explants from preeclamptic pregnancies, and endothelial cells. They also mitigated tumor necrosis factor-α-induced endothelial dysfunction: PPIs blocked endothelial vascular cell adhesion molecule-1 expression, leukocyte adhesion to endothelium, and disruption of endothelial tube formation. PPIs decreased endothelin-1 secretion and enhanced endothelial cell migration. Interestingly, the PPI esomeprazole vasodilated maternal blood vessels from normal pregnancies and cases of preterm preeclampsia, but its vasodilatory effects were lost when the vessels were denuded of their endothelium. Esomeprazole decreased blood pressure in a transgenic mouse model where human sFlt-1 was overexpressed in placenta. PPIs upregulated endogenous antioxidant defenses and decreased cytokine secretion from placental tissue and endothelial cells. We have found that PPIs decrease sFlt-1 and soluble endoglin secretion and endothelial dysfunction, dilate blood vessels, decrease blood pressure, and have antioxidant and anti-inflammatory properties. They have therapeutic potential for preeclampsia and other diseases where endothelial dysfunction is involved. © 2017 American Heart Association, Inc.

Characterization of uniaxial high-speed stretch as an in vitro model of mild traumatic brain injury on the blood-brain barrier.

PubMed

Rosas-Hernandez, Hector; Cuevas, Elvis; Escudero-Lourdes, Claudia; Lantz, Susan M; Sturdivant, Nasya M; Imam, Syed Z; Sarkar, Sumit; Slikker, William; Paule, Merle G; Balachandran, Kartik; Ali, Syed F

2018-04-13

Traumatic brain injury (TBI) occurs when external mechanical forces induce brain damage as result of impact, penetration or rapid acceleration/deceleration that causes deformation of brain tissue. Depending on its severity, TBI can be classified as mild, moderate or severe and can lead to blood-brain barrier (BBB) dysfunction. In the present study, we evaluated the effects of uniaxial high-speed stretch (HSS) at 0, 5, 10 and 15% on a pure culture of primary rat brain endothelial cells as an in vitro model of TBI to the BBB. LDH release, viability and apoptosis analysis, expression of tight junction proteins and endothelial permeability were evaluated 24 h after a single stretch episode. HSS slightly increased cell death and apoptosis at 10 and 15%, while LDH release was increased only at 15% stretch. Occludin expression was increased at 10% stretch, while claudin-5 expression was increased at 5% stretch, which also decreased the endothelial permeability. In summary, 15% HSS induced low levels of cell death, consistent with mild TBI and very low percentages of HSS (5%) enhanced the BBB properties, promoting the formation of a stronger barrier. These data support the use of 15% HSS as valuable tool in the study of mild TBI to the BBB in vitro. Published by Elsevier B.V.

Myeloid-Derived Suppressor Cells Are Involved in Lysosomal Acid Lipase Deficiency-Induced Endothelial Cell Dysfunctions

PubMed Central

Zhao, Ting; Ding, Xinchun; Du, Hong; Yan, Cong

2014-01-01

The underlying mechanisms that lysosomal acid lipase (LAL) deficiency causes infiltration of myeloid-derived suppressor cells (MDSCs) in multiple organs and subsequent inflammation remain incompletely understood. Endothelial cells (ECs), lining the inner layer of blood vessels, constitute barriers regulating leukocytes transmigration to the site of inflammation. Therefore, we hypothesized that ECs are dysfunctional in LAL-deficient (lal−/−) mice. We found that Ly6G+ cells transmigrated more efficiently across lal−/− ECs than wild-type (lal+/+) ECs, which was associated with increased level of platelet endothelial cell adhesion molecule-1 (PECAM-1) and monocyte chemoattractant protein-1 (MCP-1) in lal−/− ECs. In addition, lal−/−ECs showed enhanced migration and proliferation, decreased apoptosis, but impaired tube formation and angiogenesis. lal−/− ECs also suppressed T cell proliferation in vitro. Interestingly, lal−/− Ly6G+ cells promoted in vivo angiogenesis (including a tumor model), EC tube formation and proliferation. Finally, the mammalian target of rapamycin (mTOR) pathway was activated in lal−/− ECs, and inhibition of mTOR reversed EC dysfunctions, including decreasing Ly6G+ cell transmigration, delaying migration, and relieving suppression of T cell proliferation, which was mediated by decreasing production of reactive oxygen species (ROS). Our results indicate that LAL regulates EC functions through interaction with MDSCs and modulation of the mTOR pathway, which may provide a mechanistic basis for targeting MDSCs or mTOR to rejuvenate EC functions in LAL-deficiency related diseases. PMID:25000979

Are there Race-Dependent Endothelial Cell Responses to Exercise?

PubMed Central

Brown, Michael D.; Feairheller, Deborah L.

2013-01-01

African Americans have endothelial dysfunction which likely contributes to their high prevalence of hypertension. Endothelial cell responses to stimuli could play a role in the development of endothelial dysfunction and hypertension. High physiological levels of vascular laminar shear stress can profoundly alter endothelial cell phenotype. It is not known whether there are race-dependent endothelial cell responses to laminar shear stress. PMID:23262464

Propionyl-L-Carnitine Enhances Wound Healing and Counteracts Microvascular Endothelial Cell Dysfunction

PubMed Central

Scioli, Maria Giovanna; Lo Giudice, Pietro; Bielli, Alessandra; Tarallo, Valeria; De Rosa, Alfonso; De Falco, Sandro; Orlandi, Augusto

2015-01-01

Background Impaired wound healing represents a high cost for health care systems. Endothelial dysfunction characterizes dermal microangiopathy and contributes to delayed wound healing and chronic ulcers. Endothelial dysfunction impairs cutaneous microvascular blood flow by inducing an imbalance between vasorelaxation and vasoconstriction as a consequence of reduced nitric oxide (NO) production and the increase of oxidative stress and inflammation. Propionyl-L-carnitine (PLC) is a natural derivative of carnitine that has been reported to ameliorate post-ischemic blood flow recovery. Methods and Results We investigated the effects of PLC in rat skin flap and cutaneous wound healing. A daily oral PLC treatment improved skin flap viability and associated with reactive oxygen species (ROS) reduction, inducible nitric oxide synthase (iNOS) and NO up-regulation, accelerated wound healing and increased capillary density, likely favoring dermal angiogenesis by up-regulation for iNOS, vascular endothelial growth factor (VEGF), placental growth factor (PlGF) and reduction of NADPH-oxidase 4 (Nox4) expression. In serum-deprived human dermal microvascular endothelial cell cultures, PLC ameliorated endothelial dysfunction by increasing iNOS, PlGF, VEGF receptors 1 and 2 expression and NO level. In addition, PLC counteracted serum deprivation-induced impairment of mitochondrial β-oxidation, Nox4 and cellular adhesion molecule (CAM) expression, ROS generation and leukocyte adhesion. Moreover, dermal microvascular endothelial cell dysfunction was prevented by Nox4 inhibition. Interestingly, inhibition of β-oxidation counteracted the beneficial effects of PLC on oxidative stress and endothelial dysfunction. Conclusion PLC treatment improved rat skin flap viability, accelerated wound healing and dermal angiogenesis. The beneficial effects of PLC likely derived from improvement of mitochondrial β-oxidation and reduction of Nox4-mediated oxidative stress and endothelial dysfunction. Antioxidant therapy and pharmacological targeting of endothelial dysfunction may represent a promising tool for the treatment of delayed wound healing or chronic ulcers. PMID:26473356

Targeting Endothelial Function to Treat Heart Failure with Preserved Ejection Fraction: The Promise of Exercise Training

PubMed Central

Lemmens, Katrien; Vrints, Christiaan J.

2017-01-01

Although the burden of heart failure with preserved ejection fraction (HFpEF) is increasing, there is no therapy available that improves prognosis. Clinical trials using beta blockers and angiotensin converting enzyme inhibitors, cardiac-targeting drugs that reduce mortality in heart failure with reduced ejection fraction (HFrEF), have had disappointing results in HFpEF patients. A new “whole-systems” approach has been proposed for designing future HFpEF therapies, moving focus from the cardiomyocyte to the endothelium. Indeed, dysfunction of endothelial cells throughout the entire cardiovascular system is suggested as a central mechanism in HFpEF pathophysiology. The objective of this review is to provide an overview of current knowledge regarding endothelial dysfunction in HFpEF. We discuss the molecular and cellular mechanisms leading to endothelial dysfunction and the extent, presence, and prognostic importance of clinical endothelial dysfunction in different vascular beds. We also consider implications towards exercise training, a promising therapy targeting system-wide endothelial dysfunction in HFpEF. PMID:28706575

Sirt6 mRNA-incorporated endothelial microparticles (EMPs) attenuates DM patient-derived EMP-induced endothelial dysfunction

PubMed Central

Jing, Tong; Ya-Shu, Kuang; Xue-Jun, Wang; Han-Jing, Hou; Yan, Lai; Yi-An, Yao; Fei, Chen; Xue-Bo, Liu

2017-01-01

Background Endothelial microparticles (EMPs) are small vesicles released by endothelial cells (ECs); they are considered biomarkers for endothelial dysfunction and therapeutic targets in diabetes-related vascular disease. Sirtuins have also been shown to play important roles in diabetes by regulating endothelial dysfunction. However, the effect of sirtuin-incorporated EMPs on their parental ECs remains unknown. Aim The present study aims to investigate the diagnostic value of EMPs in diabetes and detect the protective effects of sirtuin 6 (Sirt6) mRNA -incorporated EMPs on endothelial dysfunction. Methods EMPs were prepared from cultured HUVECs and venous blood from patients with diabetes (n=10) and from healthy volunteers (n=6) after sequential centrifugation. Adv-Sirt6 or Sirt6 siRNA was used to alter Sirt6 expression. EC angiogenesis, inflammatory phenotypes, nitric oxide (NO) formation and eNOS phosphorylation were used to evaluate endothelial dysfunction. Results The levels of EMPs in diabetic patients and high glucose-cultured HUVECs are high, whereas Sirt6 expression in plasma and EMPs is low. EMPs generated from diabetic patients or high glucose-cultured HUVECs increase inflammatory chemokine release and blunt EC angiogenesis. Furthermore, EMPs enriched with Sirt6 mRNA induces EC angiogenesis, increases eNOS phosphorylation and impedes inflammatory chemokine release. Inhibition of Sirt6 mRNA expression in EMPs by siRNA hinders angiogenesis and eNOS phosphorylation but increases cellular inflammation. Conclusion The Sirt6 mRNA-carrying EMPs may ameliorate endothelial dysfunction in diabetic patients. PMID:29371988

Sirt6 mRNA-incorporated endothelial microparticles (EMPs) attenuates DM patient-derived EMP-induced endothelial dysfunction.

PubMed

Jing, Tong; Ya-Shu, Kuang; Xue-Jun, Wang; Han-Jing, Hou; Yan, Lai; Yi-An, Yao; Fei, Chen; Xue-Bo, Liu

2017-12-26

Endothelial microparticles (EMPs) are small vesicles released by endothelial cells (ECs); they are considered biomarkers for endothelial dysfunction and therapeutic targets in diabetes-related vascular disease. Sirtuins have also been shown to play important roles in diabetes by regulating endothelial dysfunction. However, the effect of sirtuin-incorporated EMPs on their parental ECs remains unknown. The present study aims to investigate the diagnostic value of EMPs in diabetes and detect the protective effects of sirtuin 6 ( Sirt6 ) mRNA -incorporated EMPs on endothelial dysfunction. EMPs were prepared from cultured HUVECs and venous blood from patients with diabetes (n=10) and from healthy volunteers (n=6) after sequential centrifugation. Adv- Sirt6 or Sirt6 siRNA was used to alter Sirt6 expression. EC angiogenesis, inflammatory phenotypes, nitric oxide (NO) formation and eNOS phosphorylation were used to evaluate endothelial dysfunction. The levels of EMPs in diabetic patients and high glucose-cultured HUVECs are high, whereas Sirt6 expression in plasma and EMPs is low. EMPs generated from diabetic patients or high glucose-cultured HUVECs increase inflammatory chemokine release and blunt EC angiogenesis. Furthermore, EMPs enriched with Sirt6 mRNA induces EC angiogenesis, increases eNOS phosphorylation and impedes inflammatory chemokine release. Inhibition of Sirt6 mRNA expression in EMPs by siRNA hinders angiogenesis and eNOS phosphorylation but increases cellular inflammation. The Sirt6 mRNA -carrying EMPs may ameliorate endothelial dysfunction in diabetic patients.

Alterations in blood-brain barrier function following acute hypertension: comparison of the blood-to-brain transfer of horseradish peroxidase with that of alpha-aminisobutyric acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ellison, M.D.B.

The blood-brain barrier (BBB) selectively restricts the blood-to-brain passage of many solutes owing to unique properties of cerebrovascular endothelial cell membranes. To date, experimental study of the BBB has been accomplished primarily through the use of two different methodological approaches. Morphological studies have mostly employed large molecular weight (MW) tracers to detect morphological alterations underlying increased permeability. Physiological studies, employing smaller, more physiologic tracers have successfully described, quantitatively, certain functional aspects of blood-to-brain transfer. The current work attempts to merge these two approaches and to consider barrier function/dysfunction from both a morphological and a functional perspective. Specifically, the study comparesmore » in rats, following acute hypertension, the cerebrovascular passage of /sup 14/C-alpha-aminoisobutyric acid (AIB) and that of horseradish peroxidase (HRP). The blood-to-brain passage of AIB and HRP were compared following acute hypertension, with regard to both the distributions of the tracer extravasation patterns and the magnitude of tracer extravasation. The results of this study suggest that traditional morphological barrier studies alone do not reveal all aspects of altered barrier status and that multiple mechanisms underlying increased BBB permeability may operate simultaneously during BBB dysfunction.« less

Reactive Oxygen Species in Inflammation and Tissue Injury

PubMed Central

Mittal, Manish; Siddiqui, Mohammad Rizwan; Tran, Khiem; Reddy, Sekhar P.

2014-01-01

Abstract Reactive oxygen species (ROS) are key signaling molecules that play an important role in the progression of inflammatory disorders. An enhanced ROS generation by polymorphonuclear neutrophils (PMNs) at the site of inflammation causes endothelial dysfunction and tissue injury. The vascular endothelium plays an important role in passage of macromolecules and inflammatory cells from the blood to tissue. Under the inflammatory conditions, oxidative stress produced by PMNs leads to the opening of inter-endothelial junctions and promotes the migration of inflammatory cells across the endothelial barrier. The migrated inflammatory cells not only help in the clearance of pathogens and foreign particles but also lead to tissue injury. The current review compiles the past and current research in the area of inflammation with particular emphasis on oxidative stress-mediated signaling mechanisms that are involved in inflammation and tissue injury. Antioxid. Redox Signal. 20, 1126–1167. PMID:23991888

Loss of Endothelial Barrier in Marfan Mice (mgR/mgR) Results in Severe Inflammation after Adenoviral Gene Therapy

PubMed Central

Weymann, Alexander; Arif, Rawa; Weber, Antje; Zaradzki, Marcin; Richter, Karsten; Ensminger, Stephan; Robinson, Peter Nicholas; Wagner, Andreas H.; Karck, Matthias; Kallenbach, Klaus

2016-01-01

Objectives Marfan syndrome is an autosomal dominant inherited disorder of connective tissue. The vascular complications of Marfan syndrome have the biggest impact on life expectancy. The aorta of Marfan patients reveals degradation of elastin layers caused by increased proteolytic activity of matrix metalloproteinases (MMPs). In this study we performed adenoviral gene transfer of human tissue inhibitor of matrix metalloproteinases-1 (hTIMP-1) in aortic grafts of fibrillin-1 deficient Marfan mice (mgR/mgR) in order to reduce elastolysis. Methods We performed heterotopic infrarenal transplantation of the thoracic aorta in female mice (n = 7 per group). Before implantation, mgR/mgR and wild-type aortas (WT, C57BL/6) were transduced ex vivo with an adenoviral vector coding for human TIMP-1 (Ad.hTIMP-1) or β-galactosidase (Ad.β-Gal). As control mgR/mgR and wild-type aortas received no gene therapy. Thirty days after surgery, overexpression of the transgene was assessed by immunohistochemistry (IHC) and collagen in situ zymography. Histologic staining was performed to investigate inflammation, the neointimal index (NI), and elastin breaks. Endothelial barrier function of native not virus-exposed aortas was evaluated by perfusion of fluorescent albumin and examinations of virus-exposed tissue were performed by transmission electron microscopy (TEM). Results IHC and ISZ revealed sufficient expression of the transgene. Severe cellular inflammation and intima hyperplasia were seen only in adenovirus treated mgR/mgR aortas (Ad.β-Gal, Ad.hTIMP-1 NI: 0.23; 0.43), but not in native and Ad.hTIMP-1 treated WT (NI: 0.01; 0.00). Compared to native mgR/mgR and Ad.hTIMP-1 treated WT aorta, the NI is highly significant greater in Ad.hTIMP-1 transduced mgR/mgR aorta (p = 0.001; p = 0.001). As expected, untreated Marfan grafts showed significant more elastolysis compared to WT (p = 0.001). However, elastolysis in Marfan aortas was not reduced by adenoviral overexpression of hTIMP-1 (compared to untreated Marfan aorta: Ad.hTIMP-1 p = 0.902; control Ad.β-Gal. p = 0.165). The virus-untreated and not transplanted mgR/mgR aorta revealed a significant increase of albumin diffusion through the endothelial barrier (p = 0.037). TEM analysis of adenovirus-exposed mgR/mgR aortas displayed disruption of the basement membrane and basolateral space. Conclusions Murine Marfan aortic grafts developed severe inflammation after adenoviral contact. We demonstrated that fibrillin-1 deficiency is associated with relevant dysfunction of the endothelial barrier that enables adenovirus to induce vessel-harming inflammation. Endothelial dysfunction may play a pivotal role in the development of the vascular phenotype of Marfan syndrome. PMID:26840980

Periodontal disease as a potential factor of migraine chronification.

PubMed

Ameijeira, Pablo; Leira, Yago; Blanco, Juan; Leira, Rogelio

2017-05-01

Migraine is a hereditary constitutional base disorder, which is characterized by recurrent episodes of headache pulsatile characteristics associated with photophobia/phonophobia, nausea and/or vomiting. The main complication in migraine is the chronicity of the process, now recognized as a chronic migraine. Although pathogenic mechanisms that may influence the pathophysiology of migraine and its possible chronicity are not fully understood, previous studies have shown in patients with migraine molecular alterations of systemic inflammation, neurogenic inflammation, endothelial dysfunction, innate immunity, dysfunction of matrix proteases and blood-brain barrier. Periodontal disease is an inflammatory lesion caused by bacteria. After the bacterial infection begins, an immune response that will be responsible for individual susceptibility appears. More advanced forms of periodontitis have demonstrated molecular alterations of inflammation, endothelial dysfunction, dysfunction of matrix proteases and innate immunity, similar to those observed in migraine. Furthermore, the main molecular mediators of neurogenic inflammation related to activation of the trigeminovascular system, which are characteristic of migraine, are overexpressed in gingival crevicular fluid and mucosa in patients with periodontal disease. Hypertension, hypercholesterolemia, insulin resistance, stroke or coronary artery disease are comorbidities that periodontal disease and migraine could share. Therefore, several mechanisms and hypotheses could explain the possible association between both diseases. However, epidemiological and molecular studies will be necessary to provide a better understanding of this potential association, which could be implicated in the chronification of migraine. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hyperglycaemia promotes human brain microvascular endothelial cell apoptosis via induction of protein kinase C-ßI and prooxidant enzyme NADPH oxidase.

PubMed

Shao, Beili; Bayraktutan, Ulvi

2014-01-01

Blood-brain barrier disruption represents a key feature in hyperglycaemia-aggravated cerebral damage after an ischaemic stroke. Although the underlying mechanisms remain largely unknown, activation of protein kinase C (PKC) is thought to play a critical role. This study examined whether apoptosis of human brain microvascular endothelial cells (HBMEC) might contribute to hyperglycaemia-evoked barrier damage and assessed the specific role of PKC in this phenomenon. Treatments with hyperglycaemia (25 mM) or phorbol myristate acetate (PMA, a protein kinase C activator, 100 nM) significantly increased NADPH oxidase activity, O2 (•-) generation, proapoptotic protein Bax expression, TUNEL-positive staining and caspase-3/7 activities. Pharmacological inhibition of NADPH oxidase, PKC-a, PKC-ß or PKC-ßI via their specific inhibitors and neutralisation of O2 (•-) by a cell-permeable superoxide dismutase mimetic, MnTBAP normalised all the aforementioned increases induced by hyperglycaemia. Suppression of these PKC isoforms also negated the stimulatory effects of hyperglycaemia on the protein expression of NADPH oxidase membrane-bound components, Nox2 and p22-phox which determine the overall enzymatic activity. Silencing of PKC-ßI gene through use of specific siRNAs abolished the effects of both hyperglycaemia and PMA on endothelial cell NADPH oxidase activity, O2 (•-) production and apoptosis and consequently improved the integrity and function of an in vitro model of human cerebral barrier comprising HBMEC, astrocytes and pericytes. Hyperglycaemia-mediated apoptosis of HBMEC contributes to cerebral barrier dysfunction and is modulated by sequential activations of PKC-ßI and NADPH oxidase.

Sex Differences Influencing Micro- and Macrovascular Endothelial Phenotype In Vitro.

PubMed

Huxley, Virginia H; Kemp, Scott S; Schramm, Christine; Sieveking, Steve; Bingaman, Susan; Yu, Yang; Zaniletti, Isabella; Stockard, Kevin; Wang, Jianjie

2018-06-09

Endothelial dysfunction is an early hallmark of multiple disease states that also display sex differences with respect to age of onset, frequency, and severity. Results of in vivo studies of basal and stimulated microvascular barrier function revealed sex differences difficult to ascribe to specific cells or environmental factors. The present study evaluated endothelial cells (EC) isolated from macro- and/or microvessels of reproductively mature rats under the controlled conditions of low-passage culture to test the assumption that EC phenotype would be sex-independent. The primary finding was that EC, regardless of where they are derived, retain a sex-bias in low-passage culture, independent of varying levels of reproductive hormones. Implications of the work include the fallacy of expecting a universal set of mechanisms derived from study of EC from one sex and/or one vascular origin to apply uniformly to all EC under unstimulated conditions no less in the disease state. Vascular endothelial cells (EC) are heterogeneous with respect to phenotype reflecting at least organ of origin, location within the vascular network, and physical forces. Sex, as an independent influence on EC functions in health or etiology, susceptibility, and progression of dysfunction in numerous disease states, has been largely ignored. The current study focussed on EC isolated from aorta (macrovascular) and skeletal muscle vessels (microvascular) of age-matched male and female rats under identical conditions of short term (passage 4) culture. We tested the hypothesis that genomic sex would not influence endothelial growth, wound healing, morphology, lactate production, or messenger RNA and protein expression of key proteins (sex hormone receptors for androgen (AR) and oestrogen (ERα and ERβ); PECAM-1 and VE-CAD mediating barrier function; α v β 3 and N-Cadherin influencing matrix interactions; ICAM-1 and VCAM-1 mediating EC/white cell adhesion). The hypothesis was rejected as EC origin (macro- versus microvessel) and sex influenced multiple phenotypic characteristics. Statistical model analysis of EC growth demonstrated an hierarchy of variable importance, recapitulated for other phenotypic characteristics, wherein predictions assuming EC homogeneity < Sex < Vessel Origin < Sex and Vessel Origin. Further, patterns of EC mRNA expression by vessel origin and by sex did not predict protein expression. Overall the study demonstrated that accurate assessment of sex-linked EC dysfunction first requires understanding of EC function by position in the vascular tree and by sex. Results from a single EC tissue source/species/sex cannot provide universal insight into the mechanisms regulating in vivo endothelial function in health, no less disease. (250) This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

NAD(P)H oxidase mediates the endothelial barrier dysfunction induced by TNF-alpha.

PubMed

Gertzberg, Nancy; Neumann, Paul; Rizzo, Victor; Johnson, Arnold

2004-01-01

We tested the hypothesis that the NAD(P)H oxidase-dependent generation of superoxide anion (O2-*) mediates tumor necrosis factor-alpha (TNF)-induced alterations in the permeability of pulmonary microvessel endothelial monolayers (PMEM). The permeability of PMEM was assessed by the clearance rate of Evans blue-labeled albumin. The NAD(P)H oxidase subcomponents p47phox and p22phox were assessed by immunofluorescent microscopy and Western blot. The reactive oxygen species O2-* was measured by the fluorescence of 6-carboxy-2',7'-dichlorodihydrofluorescein diacetatedi(acetoxymethyl ester), 5 (and 6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate-acetyl ester, and dihydroethidium. TNF treatment (50 ng/ml for 4.0 h) induced 1) p47phox translocation, 2) an increase in p22phox protein, 3) increased localization of p47phox with p22phox, 4) O2-* generation, and 5) increased permeability to albumin. p22phox antisense oligonucleotide prevented the TNF-induced effect on p22phox, p47phox, O2-*, and permeability. The scrambled nonsense oligonucleotide had no effect. The TNF-induced increase in O2-* and permeability to albumin was also prevented by the O2-* scavenger Cu-Zn superoxide dismutase (100 U/ml). The results indicate that the activation of NAD(P)H oxidase, via the generation of O2-*, mediates TNF-induced barrier dysfunction in PMEM.

Arginase Inhibitor in the Pharmacological Correction of Endothelial Dysfunction

PubMed Central

Pokrovskiy, Mihail V.; Korokin, Mihail V.; Tsepeleva, Svetlana A.; Pokrovskaya, Tatyana G.; Gureev, Vladimir V.; Konovalova, Elena A.; Gudyrev, Oleg S.; Kochkarov, Vladimir I.; Korokina, Liliya V.; Dudina, Eleonora N.; Babko, Anna V.; Terehova, Elena G.

2011-01-01

This paper is about a way of correction of endothelial dysfunction with the inhibitor of arginase: L-norvaline. There is an imbalance between vasoconstriction and vasodilatation factors of endothelium on the basis of endothelial dysfunction. Among vasodilatation agents, nitrogen oxide plays the basic role. Amino acid L-arginine serves as a source of molecules of nitrogen oxide in an organism. Because of the high activity of arginase enzyme which catalyzes the hydrolysis of L-arginine into ornithine and urea, the bioavailability of nitrogen oxide decreases. The inhibitors of arginase suppress the activity of the given enzyme, raising and production of nitrogen oxide, preventing the development of endothelial dysfunction. PMID:21747978

Physical activity on endothelial and erectile dysfunction: a literature review.

PubMed

Leoni, Luís Antônio B; Fukushima, André R; Rocha, Leandro Y; Maifrino, Laura B M M; Rodrigues, Bruno

2014-09-01

Physical inactivity, diabetes, hypertension, dyslipidemia, smoking and obesity were associated with imbalance in oxidative stress, leading to endothelial dysfunction. Such dysfunction is present in both cardiovascular disease (CVD) and erectile dysfunction (ED). ED is the persistent inability to achieve or sustain an erection sufficient for satisfactory sexual performance and is one of the first manifestations of endothelial damage in men with CVD risk factors. The purpose of this article is to review the results of studies involving physical activity, CVD, endothelial dysfunction and ED in order to verify its applicability for improving the health and quality of life of men with such disorders. There is consistent evidence that endothelial damage is intimately linked to ED, and this manifestation seems to be associated with the appearance CVDs. On the other hand, physical activity has been pointed out as an important clinical strategy in the prevention and treatment of CVDs and ED mainly associated with improvement of endothelial function. However, further experimental and clinical prospective investigations are needed to test the role of physical exercises in the modulation of endothelial function and their implications on erectile function and the appearance of CVDs.

Age-related changes in endothelial function and blood flow regulation.

PubMed

Toda, Noboru

2012-02-01

Vascular endothelial dysfunction is regarded as a primary phenotypic expression of normal human aging. This senescence-induced disorder is the likely culprit underlying the increased cardiovascular and metabolic disease risks associated with aging. The rate of this age-dependent deterioration is largely influenced by the poor-quality lifestyle choice, such as smoking, sedentary daily life, chronic alcohol ingestion, high salt intake, unbalanced diet, and mental stress; and it is accelerated by cardiovascular and metabolic diseases. Although minimizing these detrimental factors is the best course of action, nonetheless chronological age steadily impairs endothelial function through reduced endothelial nitric oxide synthase (eNOS) expression/action, accelerated nitric oxide (NO) degradation, increased phosphodiesterase activity, inhibition of NOS activity by endogenous NOS inhibitors, increased production of reactive oxygen species, inflammatory reactions, decreased endothelial progenitor cell number and function, and impaired telomerase activity or telomere shortening. Endothelial dysfunction in regional vasculatures results in cerebral hypoperfusion triggering cognitive dysfunction and Alzheimer's disease, coronary artery insufficiency, penile erectile dysfunction, and circulatory failures in other organs and tissues. Possible prophylactic measures to minimize age-related endothelial dysfunction are also summarized in this review. Copyright © 2011 Elsevier Inc. All rights reserved.

Flavanol-rich cocoa ameliorates lipemia-induced endothelial dysfunction.

PubMed

Westphal, Sabine; Luley, Claus

2011-09-01

Consumption of flavanols improves chronic endothelial dysfunction. We investigated whether it can also improve acute lipemia-induced endothelial dysfunction. In this randomized, placebo-controlled, double-blind, crossover trial, 18 healthy subjects received a fatty meal with cocoa either rich in flavanols (918 mg) or flavanol-poor. Flow-mediated dilation (FMD), triglycerides, and free fatty acids were then determined over 6 h. After the flavanol-poor fat loading, the FMD deteriorated over 4 h. The consumption of flavanol-rich cocoa, in contrast, improved this deterioration in hours 2, 3, and 4 without abolishing it completely. Flavanols did not have any influence on triglycerides or on free fatty acids. Flavanol-rich cocoa can alleviate the lipemia-induced endothelial dysfunction, probably through an improvement in endothelial NO synthase.

Nanomechanics and Sodium Permeability of Endothelial Surface Layer Modulated by Hawthorn Extract WS 1442

PubMed Central

Peters, Wladimir; Drueppel, Verena; Kusche-Vihrog, Kristina; Schubert, Carola; Oberleithner, Hans

2012-01-01

The endothelial glycocalyx (eGC) plays a pivotal role in the physiology of the vasculature. By binding plasma proteins, the eGC forms the endothelial surface layer (ESL) which acts as an interface between bloodstream and endothelial cell surface. The functions of the eGC include mechanosensing of blood flow induced shear stress and thus flow dependent vasodilation. There are indications that levels of plasma sodium concentrations in the upper range of normal and beyond impair flow dependent regulation of blood pressure and may therefore increase the risk for hypertension. Substances, therefore, that prevent sodium induced endothelial dysfunction may be attractive for the treatment of cardiovascular disease. By means of combined atomic force - epifluorescence microscopy we studied the impact of the hawthorn (Crataegus spp.) extract WS 1442, a herbal therapeutic with unknown mechanism of action, on the mechanics of the ESL of ex vivo murine aortae. Furthermore, we measured the impact of WS 1442 on the sodium permeability of endothelial EA.hy 926 cell monolayer. The data show that (i) the ESL contributes by about 11% to the total endothelial barrier resistance for sodium and (ii) WS 1442 strengthens the ESL resistance for sodium up to about 45%. This mechanism may explain some of the vasoprotective actions of this herbal therapeutic. PMID:22253842

Nanomechanics and sodium permeability of endothelial surface layer modulated by hawthorn extract WS 1442.

PubMed

Peters, Wladimir; Drüppel, Verena; Drueppel, Verena; Kusche-Vihrog, Kristina; Schubert, Carola; Oberleithner, Hans

2012-01-01

The endothelial glycocalyx (eGC) plays a pivotal role in the physiology of the vasculature. By binding plasma proteins, the eGC forms the endothelial surface layer (ESL) which acts as an interface between bloodstream and endothelial cell surface. The functions of the eGC include mechanosensing of blood flow induced shear stress and thus flow dependent vasodilation. There are indications that levels of plasma sodium concentrations in the upper range of normal and beyond impair flow dependent regulation of blood pressure and may therefore increase the risk for hypertension. Substances, therefore, that prevent sodium induced endothelial dysfunction may be attractive for the treatment of cardiovascular disease. By means of combined atomic force-epifluorescence microscopy we studied the impact of the hawthorn (Crataegus spp.) extract WS 1442, a herbal therapeutic with unknown mechanism of action, on the mechanics of the ESL of ex vivo murine aortae. Furthermore, we measured the impact of WS 1442 on the sodium permeability of endothelial EA.hy 926 cell monolayer. The data show that (i) the ESL contributes by about 11% to the total endothelial barrier resistance for sodium and (ii) WS 1442 strengthens the ESL resistance for sodium up to about 45%. This mechanism may explain some of the vasoprotective actions of this herbal therapeutic.

Nitric Oxide-Mediated Coronary Flow Regulation in Patients with Coronary Artery Disease: Recent Advances

PubMed Central

Toda, Noboru; Tanabe, Shinichi; Nakanishi, Sadanobu

2011-01-01

Nitric oxide (NO) formed via endothelial NO synthase (eNOS) plays crucial roles in the regulation of coronary blood flow through vasodilatation and decreased vascular resistance, and in inhibition of platelet aggregation and adhesion, leading to the prevention of coronary circulatory failure, thrombosis, and atherosclerosis. Endothelial function is impaired by several pathogenic factors including smoking, chronic alcohol intake, hypercholesterolemia, obesity, hyperglycemia, and hypertension. The mechanisms underlying endothelial dysfunction include reduced NO synthase (NOS) expression and activity, decreased NO bioavailability, and increased production of oxygen radicals and endogenous NOS inhibitors. Atrial fibrillation appears to be a risk factor for endothelial dysfunction. Endothelial dysfunction is an important predictor of coronary artery disease (CAD) in humans. Penile erectile dysfunction, associated with impaired bioavailability of NO produced by eNOS and neuronal NOS, is also considered to be highly predictive of ischemic heart disease. There is evidence suggesting an important role of nitrergic innervation in coronary blood flow regulation. Prophylactic and therapeutic measures to eliminate pathogenic factors inducing endothelial and nitrergic nerve dysfunction would be quite important in preventing the genesis and development of CAD. PMID:22942627

Perturbations in Endothelial Dysfunction-Associated Pathways in the Nitrofen-Induced Congenital Diaphragmatic Hernia Model.

PubMed

Zhaorigetu, Siqin; Bair, Henry; Lu, Jonathan; Jin, Di; Olson, Scott D; Harting, Matthew T

2018-01-01

Although it is well known that nitrofen induces congenital diaphragmatic hernia (CDH), including CDH-associated lung hypoplasia and pulmonary hypertension (PH) in rodents, the mechanism of pathogenesis remains largely unclear. It has been reported that pulmonary artery (PA) endothelial cell (EC) dysfunction contributes to the development of PH in CDH. Thus, we hypothesized that there is significant alteration of endothelial dysfunction-associated proteins in nitrofen-induced CDH PAs. Pregnant SD rats received either nitrofen or olive oil on gestational day 9.5. The newborn rats were sacrificed and divided into a CDH (n = 81) and a control (n = 23) group. After PA isolation, the expression of PA endothelial dysfunction-associated proteins was assessed on Western blot and immunostaining. We demonstrate that the expression of C-reactive protein and endothelin-1 and its receptors, ETA and ETB, were significantly increased in the CDH PAs. Levels of phosphorylated myosin light chain were significantly elevated, but those of phosphorylated endothelial nitric oxide synthase, caveolin-1, and mechanistic target of rapamycin were significantly decreased in the CDH PAs. In this work, we elucidate alterations in the expression of endothelial dysfunction-associated proteins specific to nitrofen-induced CDH rodent PAs, thereby advancing our understanding of the critical role of endothelial dysfunction-associated pathways in the pathogenesis of nitrofen-induced CDH. © 2017 S. Karger AG, Basel.

Endothelial mineralocorticoid receptor activation mediates endothelial dysfunction in diet-induced obesity.

PubMed

Schäfer, Nicola; Lohmann, Christine; Winnik, Stephan; van Tits, Lambertus J; Miranda, Melroy X; Vergopoulos, Athanasios; Ruschitzka, Frank; Nussberger, Jürg; Berger, Stefan; Lüscher, Thomas F; Verrey, François; Matter, Christian M

2013-12-01

Aldosterone plays a crucial role in cardiovascular disease. 'Systemic' inhibition of its mineralocorticoid receptor (MR) decreases atherosclerosis by reducing inflammation and oxidative stress. Obesity, an important cardiovascular risk factor, is an inflammatory disease associated with increased plasma aldosterone levels. We have investigated the role of the 'endothelial' MR in obesity-induced endothelial dysfunction, the earliest stage in atherogenesis. C57BL/6 mice were exposed to a normal chow diet (ND) or a high-fat diet (HFD) alone or in combination with the MR antagonist eplerenone (200 mg/kg/day) for 14 weeks. Diet-induced obesity impaired endothelium-dependent relaxation in response to acetylcholine, whereas eplerenone treatment of obese mice prevented this. Expression analyses in aortic endothelial cells isolated from these mice revealed that eplerenone attenuated expression of pro-oxidative NADPH oxidase (subunits p22phox, p40phox) and increased expression of antioxidative genes (glutathione peroxidase-1, superoxide dismutase-1 and -3) in obesity. Eplerenone did not affect obesity-induced upregulation of cyclooxygenase (COX)-1 or prostacyclin synthase. Endothelial-specific MR deletion prevented endothelial dysfunction in obese (exhibiting high 'endogenous' aldosterone) and in 'exogenous' aldosterone-infused lean mice. Pre-incubation of aortic rings from aldosterone-treated animals with the COX-inhibitor indomethacin restored endothelial function. Exogenous aldosterone administration induced endothelial expression of p22phox in the presence, but not in the absence of the endothelial MR. Obesity-induced endothelial dysfunction depends on the 'endothelial' MR and is mediated by an imbalance of oxidative stress-modulating mechanisms. Therefore, MR antagonists may represent an attractive therapeutic strategy in the increasing population of obese patients to decrease vascular dysfunction and subsequent atherosclerotic complications.

Obesity-Induced Endoplasmic Reticulum Stress Causes Lung Endothelial Dysfunction and Promotes Acute Lung Injury.

PubMed

Shah, Dilip; Romero, Freddy; Guo, Zhi; Sun, Jianxin; Li, Jonathan; Kallen, Caleb B; Naik, Ulhas P; Summer, Ross

2017-08-01

Obesity is a significant risk factor for acute respiratory distress syndrome. The mechanisms underlying this association are unknown. We recently showed that diet-induced obese mice exhibit pulmonary vascular endothelial dysfunction, which is associated with enhanced susceptibility to LPS-induced acute lung injury. Here, we demonstrate that lung endothelial dysfunction in diet-induced obese mice coincides with increased endoplasmic reticulum (ER) stress. Specifically, we observed enhanced expression of the major sensors of misfolded proteins, including protein kinase R-like ER kinase, inositol-requiring enzyme α, and activating transcription factor 6, in whole lung and in primary lung endothelial cells isolated from diet-induced obese mice. Furthermore, we found that primary lung endothelial cells exposed to serum from obese mice, or to saturated fatty acids that mimic obese serum, resulted in enhanced expression of markers of ER stress and the induction of other biological responses that typify the lung endothelium of diet-induced obese mice, including an increase in expression of endothelial adhesion molecules and a decrease in expression of endothelial cell-cell junctional proteins. Similar changes were observed in lung endothelial cells and in whole-lung tissue after exposure to tunicamycin, a compound that causes ER stress by blocking N-linked glycosylation, indicating that ER stress causes endothelial dysfunction in the lung. Treatment with 4-phenylbutyric acid, a chemical protein chaperone that reduces ER stress, restored vascular endothelial cell expression of adhesion molecules and protected against LPS-induced acute lung injury in diet-induced obese mice. Our work indicates that fatty acids in obese serum induce ER stress in the pulmonary endothelium, leading to pulmonary endothelial cell dysfunction. Our work suggests that reducing protein load in the ER of pulmonary endothelial cells might protect against acute respiratory distress syndrome in obese individuals.

PGC-1α dictates endothelial function through regulation of eNOS expression

PubMed Central

Craige, Siobhan M.; Kröller-Schön, Swenja; Li, Chunying; Kant, Shashi; Cai, Shenghe; Chen, Kai; Contractor, Mayur M.; Pei, Yongmei; Schulz, Eberhard; Keaney, John F.

2016-01-01

Endothelial dysfunction is a characteristic of many vascular related diseases such as hypertension. Peroxisome proliferator activated receptor gamma, coactivator 1α (PGC-1α) is a unique stress sensor that largely acts to promote adaptive responses. Therefore, we sought to define the role of endothelial PGC-1α in vascular function using mice with endothelial specific loss of function (PGC-1α EC KO) and endothelial specific gain of function (PGC-1α EC TG). Here we report that endothelial PGC-1α is suppressed in angiotensin-II (ATII)-induced hypertension. Deletion of endothelial PGC-1α sensitized mice to endothelial dysfunction and hypertension in response to ATII, whereas PGC-1α EC TG mice were protected. Mechanistically, PGC-1α promotes eNOS expression and activity, which is necessary for protection from ATII-induced dysfunction as mice either treated with an eNOS inhibitor (LNAME) or lacking eNOS were no longer responsive to transgenic endothelial PGC-1α expression. Finally, we determined that the orphan nuclear receptor, estrogen related receptor α (ERRα) is required to coordinate the PGC-1α -induced eNOS expression. In conclusion, endothelial PGC-1α expression protects from vascular dysfunction by promoting NO• bioactivity through ERRα induced expression of eNOS. PMID:27910955

Traumatic Brain Injury Causes Endothelial Dysfunction in the Systemic Microcirculation through Arginase-1-Dependent Uncoupling of Endothelial Nitric Oxide Synthase.

PubMed

Villalba, Nuria; Sackheim, Adrian M; Nunez, Ivette A; Hill-Eubanks, David C; Nelson, Mark T; Wellman, George C; Freeman, Kalev

2017-01-01

Endothelial dysfunction is a hallmark of many chronic diseases, including diabetes and long-term hypertension. We show that acute traumatic brain injury (TBI) leads to endothelial dysfunction in rat mesenteric arteries. Endothelial-dependent dilation was greatly diminished 24 h after TBI because of impaired nitric oxide (NO) production. The activity of arginase, which competes with endothelial NO synthase (eNOS) for the common substrate l-arginine, were also significantly increased in arteries, suggesting that arginase-mediated depletion of l-arginine underlies diminished NO production. Consistent with this, substrate restoration by exogenous application of l-arginine or inhibition of arginase recovered endothelial function. Moreover, evidence for increased reactive oxygen species production, a consequence of l-arginine starvation-dependent eNOS uncoupling, was detected in endothelium and plasma. Collectively, our findings demonstrate endothelial dysfunction in a remote vascular bed after TBI, manifesting as impaired endothelial-dependent vasodilation, with increased arginase activity, decreased generation of NO, and increased O 2 - production. We conclude that blood vessels have a "molecular memory" of neurotrauma, 24 h after injury, because of functional changes in vascular endothelial cells; these effects are pertinent to understanding the systemic inflammatory response that occurs after TBI even in the absence of polytrauma.

The vascular barrier-protecting hawthorn extract WS® 1442 raises endothelial calcium levels by inhibition of SERCA and activation of the IP3 pathway.

PubMed

Willer, Elisabeth A; Malli, Roland; Bondarenko, Alexander I; Zahler, Stefan; Vollmar, Angelika M; Graier, Wolfgang F; Fürst, Robert

2012-10-01

WS® 1442 has been proven as an effective and safe therapeutical to treat mild forms of congestive heart failure. Beyond this action, we have recently shown that WS® 1442 protects against thrombin-induced vascular barrier dysfunction and the subsequent edema formation by affecting endothelial calcium signaling. The aim of the study was to analyze the influence of WS® 1442 on intracellular calcium concentrations [Ca(2+)](i) in the human endothelium and to investigate the underlying mechanisms. Using ratiometric calcium measurements and a FRET sensor, we found that WS® 1442 concentration-dependently increased basal [Ca(2+)](i) by depletion of the endoplasmic reticulum (ER) and inhibited a subsequent histamine-triggered rise of [Ca(2+)](i). Interestingly, the augmented [Ca(2+)](i) did neither trigger an activation of the contractile machinery nor led to a barrier breakdown (macromolecular permeability). It also did not impair endothelial cell viability. As assessed by patch clamp recordings, WS® 1442 did only slightly affect endothelial Na(+)/K(+)-ATPase, but increased [Ca(2+)](i) by inhibiting the sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase (SERCA) and by activating the inositol 1,4,5-trisphosphate (IP(3)) pathway. Most importantly, WS® 1442 did not induce store-operated calcium entry (SOCE), but even irreversibly prevented histamine-induced SOCE. Taken together, WS® 1442 prevented the deleterious hyperpermeability-associated rise of [Ca(2+)](i) by a preceding, non-toxic release of Ca(2+) from the ER. WS® 1442 interfered with SERCA and the IP(3) pathway without inducing SOCE. The elucidation of this intriguing mechanism helps to understand the complex pharmacology of the cardiovascular drug WS® 1442. Copyright © 2012 Elsevier Ltd. All rights reserved.

Protein-bounded uremic toxin p-cresylsulfate induces vascular permeability alternations.

PubMed

Tang, Wei-Hua; Wang, Chao-Ping; Yu, Teng-Hung; Tai, Pei-Yang; Liang, Shih-Shin; Hung, Wei-Chin; Wu, Cheng-Ching; Huang, Sung-Hao; Lee, Yau-Jiunn; Chen, Shih-Chieh

2018-06-01

The goal of the present studies is to investigate that the impact of p-cresylsulfate (PCS) on the endothelial barrier integrity via in situ exposure and systemic exposure. Vascular permeability changes induced by local injection of PCS were evaluated by the techniques of both Evans blue (EB) and India ink tracer. Rats were intravenously injected with EB or India ink followed by intradermal injections of various doses of PCS (0, 0.4, 2, 10 and 50 µmol/site) on rat back skins. At different time points, skin EB was extracted and quantified. The administration of India ink was used to demonstrate leaky microvessels. Skin PCS levels were also determined by liquid chromatography-mass spectrometry. We also investigated whether the increased endothelial leakage occurred in the aortic endothelium in rats treated with 5/6 nephrectomy and intraperitoneal injection of PCS 50 mg/kg/day for 4 weeks. The aortic endothelial integrity was evaluated by increased immunoglobulin G (IgG) leakage. High doses of PCS, but not lower doses, significantly induced vascular leakage as compared to saline injection and EB leakage exhibited in time-dependent manner. A time-correlated increase in leaky microvessels was detected in the tissues examined. The injected PCS declined with time and displayed an inverse relationship with vascular leakage. Chronic kidney disease (CKD) rats administered with PCS, compared to control rats, had significantly higher serum levels of PCS and apparent IgG deposition in the aortic intima. Increased endothelial leakage induced by PCS in skin microvessels and the aorta of CKD rats suggests that the PCS-induced endothelial barrier dysfunction.

TLR4 activation of TRPC6-dependent calcium signaling mediates endotoxin-induced lung vascular permeability and inflammation

PubMed Central

Tauseef, Mohammad; Knezevic, Nebojsa; Chava, Koteswara R.; Smith, Monica; Sukriti, Sukriti; Gianaris, Nicholas; Obukhov, Alexander G.; Vogel, Stephen M.; Schraufnagel, Dean E.; Dietrich, Alexander; Birnbaumer, Lutz; Malik, Asrar B.

2012-01-01

Lung vascular endothelial barrier disruption and the accompanying inflammation are primary pathogenic features of acute lung injury (ALI); however, the basis for the development of both remains unclear. Studies have shown that activation of transient receptor potential canonical (TRPC) channels induces Ca2+ entry, which is essential for increased endothelial permeability. Here, we addressed the role of Toll-like receptor 4 (TLR4) intersection with TRPC6-dependent Ca2+ signaling in endothelial cells (ECs) in mediating lung vascular leakage and inflammation. We find that the endotoxin (lipopolysaccharide; LPS) induces Ca2+ entry in ECs in a TLR4-dependent manner. Moreover, deletion of TRPC6 renders mice resistant to endotoxin-induced barrier dysfunction and inflammation, and protects against sepsis-induced lethality. TRPC6 induces Ca2+ entry in ECs, which is secondary to the generation of diacylglycerol (DAG) induced by LPS. Ca2+ entry mediated by TRPC6, in turn, activates the nonmuscle myosin light chain kinase (MYLK), which not only increases lung vascular permeability but also serves as a scaffold to promote the interaction of myeloid differentiation factor 88 and IL-1R–associated kinase 4, which are required for NF-κB activation and lung inflammation. Our findings suggest that TRPC6-dependent Ca2+ entry into ECs, secondary to TLR4-induced DAG generation, participates in mediating both lung vascular barrier disruption and inflammation induced by endotoxin. PMID:23045603

Alterations in triglyceride rich lipoproteins are related to endothelial dysfunction in metabolic syndrome.

PubMed

Lucero, Diego; López, Graciela I; Gorzalczany, Susana; Duarte, Mariano; González Ballerga, Esteban; Sordá, Juan; Schreier, Laura; Zago, Valeria

2016-08-01

Our aim was to analyze the effect of circulating triglyceride rich lipoprotein (TRL) on endothelial function in metabolic syndrome (MetS). We studied 40 patients with MetS (ATPIII), divided into those presenting normal endothelial function (n=19) and those with endothelial dysfunction (n=21) by means of the evaluation of pulse wave velocity, before and after brachial artery ischemia. In fasting serum we measured lipid and lipoprotein profile, insulin and glucose (HOMA-IR). Moreover, isolated TRL (d<1006g/l) were chemically characterized. In parallel, using randomly selected TRL from MetS patients with endothelial dysfunction (n=6) and MetS patients with normal endothelial function (n=6), the ability of TRL to inhibit ACh-induced vasorelaxation (10(-9)-10(-5)mM) on aortic rings previously pre-contracted by noradrenaline (10(-8)mM) was evaluated. Interestingly, TRL isolated from MetS patients presenting endothelial dysfunction showed triglyceride over-enrichment (59.1±4.8 vs. 54.1±4.7%; p=0.04), even after adjusting by potential confounders (p=0.05). In addition, while TRL resulting from both MetS groups significantly inhibited endothelium dependent vasorelaxation (p<0.001), TRL from MetS patients with endothelial dysfunction showed a strong tendency to a greater inhibition of vasorelaxation (p=0.06). Moreover, TRL-triglyceride (%) showed a strong tendency to correlate with the grade of vasorelaxation inhibition exerted by TRL (r=0.60; p=0.05). These results, taken together, would allow inferring for the first time that the predominance of triglyceride over-enriched TRL in circulation in MetS would induce endothelial dysfunction, contributing to the inherent cardiovascular risk of MetS. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Integrated analysis of long noncoding RNA and mRNA profiling ox-LDL-induced endothelial dysfunction after atorvastatin administration.

PubMed

Jiang, Ling-Yu; Jiang, Yue-Hua; Qi, Ying-Zi; Shao, Lin-Lin; Yang, Chuan-Hua

2018-06-01

Long noncoding RNAs (lncRNAs) play a key role in the development of endothelial dysfunction. However, few lncRNAs associated with endothelial dysfunction after atorvastatin administration have been reported. In the present study, differentially expressed (DE) genes in ox-LDL versus control and ox-LDL + atorvastatin versus control were detected. Bioinformatics analysis and integrated analysis of mRNAs and lncRNAs were conducted to study the mechanisms of endothelial dysfunction after atorvastatin administration and to explore the regulation functions of lncRNAs. Here, 532 DE mRNAs and 532 DE lncRNAs were identified (among them, 195 mRNAs and 298 lncRNAs were upregulated, 337 mRNAs and 234 lncRNAs were downregulated) after ox-LDL treatment for 24 hours (fold change ≥2.0, P < .05). After ox-LDL treatment following atorvastatin administration, 750 DE mRNAs and 502 DE lncRNAs were identified (among them, 149 mRNAs and 218 lncRNAs were upregulated and 601 mRNAs and 284 lncRNAs were downregulated). After atorvastatin administration, 167 lncRNAs and 262 mRNAs were still DE. Q-PCR validated the results of microarrays. Chronic inflammatory response, nitric oxide biosynthetic process, microtubule cytoskeleton, cell proliferation and cell migration are regulated by lncRNAs, which also participated in the mainly molecular function and biological processes underlying endothelial dysfunction. Atorvastatin partly improved endothelial dysfunction, but the aspects beyond recovery were mainly concentrated in cell cycle, mitosis, and metabolism. Further exploration is required to explicit the mechanism by which lncRNAs participate in endothelial dysfunction.

Ibrolipim attenuates high glucose-induced endothelial dysfunction in cultured human umbilical vein endothelial cells via PI3K/Akt pathway.

PubMed

Xiao, Guohua; Wang, Zongbao; Zeng, Huaicai; Yu, Jian; Yin, Weidong; Zhang, Sujun; Wang, Yueting; Zhang, Yali

2011-10-01

Endothelial dysfunction is a key event in the onset and progression of atherosclerosis associated with diabetes. Increasing cell apoptosis may lead to endothelial dysfunction and contribute to vascular complications. Therefore, we aimed to elucidate the possible role and mechanism of ibrolipim in preventing endothelial dysfunction induced by high glucose. Human umbilical vein endothelial cells (HUVECs) were cultured respectively under normal glucose level (5.5mM), high glucose level (33mM), and high glucose level with ibrolipim treatment. Endothelial dysfunction was identified by the expression of ET-1 and vWF through reverse transcription PCR (RT-PCR). HUVECs apoptosis was assessed by fluorescent staining with Hoechst 33258. Akt activity was analyzed by western blot. High glucose condition significantly increased the rate of apoptotic cells, weakened cell viability, and decreased the expression of ET-1 and vWF. Ibrolipim treatment significantly attenuated these alterations of endothelial dysfunction. The lower concentrations (2, 4, 8 microM) of ibrolipim inhibited apoptosis of cultured HUVECs, improved cell viability, down-regulated the mRNA levels of ET-1, vWF, and attenuated the cytotoxicity; however, higher concentration (16, 32 microM) of ibrolipim aggravated the damage of HUVECs cultured under high glucose level. Meanwhile, high glucose induced a decrease of Akt activity which led to apoptosis, and ibrolipim prevented the decrease and attenuated apoptotic effect induced by high glucose. Furthermore, the PI3K inhibitor LY294002 significantly abolished the anti-apoptotic effect of ibrolipim, and decreased Akt phosphorylation. Although, the expression of Akt mRNA and total protein were not altered in cultured HUVECs. Ibrolipim at lower concentrations can inhibit high glucose-induced apoptosis in cultured HUVECs, which might be related to the alternation of Akt activity. Ibrolipim has the potential to attenuate endothelial dysfunction and lower the risk of diabetes-associated vascular diseases. And it might be a therapeutic agent for diabetic vascular complications.

Endothelial microparticles: Pathogenic or passive players in endothelial dysfunction in autoimmune rheumatic diseases?

PubMed

McCarthy, E M; Wilkinson, F L; Parker, B; Alexander, M Y

2016-11-01

Autoimmune rheumatic diseases are characterised by systemic inflammation and complex immunopathology, with an increased risk of cardiovascular disease, initiated by endothelial dysfunction in a chronic inflammatory environment. Endothelial microparticles (EMPs) are released into the circulation from activated endothelial cells and may therefore, reflect disease severity, vascular and endothelial dysfunction, that could influence disease pathogenesis via autocrine/paracrine signalling. The exact function of EMPs in rheumatic disease remains unknown, and this has initiated research to elucidate EMP composition and function, which may be determined by the mode of endothelial activation and the micro environment. To date, EMPs are thought to play a role in angiogenesis, thrombosis and inflammation by transferring specific proteins and microRNAs (miRs) to target cells. Here, we review the mechanisms underlying the generation and composition of EMPs and the clinical and experimental studies describing the involvement of EMPs in rheumatic diseases, since we have previously shown endothelial dysfunction and an elevated risk of cardiovascular disease are characteristics in systemic lupus erythematosus. We will also discuss the potential of EMPs as future biomarkers of cardiovascular risk in these diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultrastructural Characterization of the Glomerulopathy in Alport Mice by Helium Ion Scanning Microscopy (HIM).

PubMed

Tsuji, Kenji; Suleiman, Hani; Miner, Jeffrey H; Daley, James M; Capen, Diane E; Păunescu, Teodor G; Lu, Hua A Jenny

2017-09-15

The glomerulus exercises its filtration barrier function by establishing a complex filtration apparatus consisting of podocyte foot processes, glomerular basement membrane and endothelial cells. Disruption of any component of the glomerular filtration barrier leads to glomerular dysfunction, frequently manifested as proteinuria. Ultrastructural studies of the glomerulus by transmission electron microscopy (TEM) and conventional scanning electron microscopy (SEM) have been routinely used to identify and classify various glomerular diseases. Here we report the application of newly developed helium ion scanning microscopy (HIM) to examine the glomerulopathy in a Col4a3 mutant/Alport syndrome mouse model. Our study revealed unprecedented details of glomerular abnormalities in Col4a3 mutants including distorted podocyte cell bodies and disorganized primary processes. Strikingly, we observed abundant filamentous microprojections arising from podocyte cell bodies and processes, and presence of unique bridging processes that connect the primary processes and foot processes in Alport mice. Furthermore, we detected an altered glomerular endothelium with disrupted sub-endothelial integrity. More importantly, we were able to clearly visualize the complex, three-dimensional podocyte and endothelial interface by HIM. Our study demonstrates that HIM provides nanometer resolution to uncover and rediscover critical ultrastructural characteristics of the glomerulopathy in Col4a3 mutant mice.

Flunarizine suppresses endothelial Angiopoietin-2 in a calcium - dependent fashion in sepsis

PubMed Central

Retzlaff, Jennifer; Thamm, Kristina; Ghosh, Chandra C.; Ziegler, Wolfgang; Haller, Hermann; Parikh, Samir M.; David, Sascha

2017-01-01

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to an infection leading to systemic inflammation and endothelial barrier breakdown. The vascular-destabilizing factor Angiopoietin-2 (Angpt-2) has been implicated in these processes in humans. Here we screened in an unbiased approach FDA-approved compounds with respect to Angpt-2 suppression in endothelial cells (ECs) in vitro. We identified Flunarizine – a well-known anti-migraine calcium channel (CC) blocker – being able to diminish intracellular Angpt-2 protein in a time- and dose-dependent fashion thereby indirectly reducing the released protein. Moreover, Flunarizine protected ECs from TNFα-induced increase in Angpt-2 transcription and vascular barrier breakdown. Mechanistically, we could exclude canonical Tie2 signalling being responsible but found that three structurally distinct T-type - but not L-type - CC blockers can suppress Angpt-2. Most importantly, experimental increase in intracellular calcium abolished Flunarizine’s effect. Flunarizine was also able to block the injurious increase of Angpt-2 in murine endotoxemia in vivo. This resulted in reduced pulmonary adhesion molecule expression (intercellular adhesion molecule-1) and tissue infiltration of inflammatory cells (Gr-1). Our finding could have therapeutic implications as side effects of Flunarizine are low and specific sepsis therapeutics that target the dysregulated host response are highly desirable. PMID:28276491

Endothelial NOS activation induces the blood-brain barrier disruption via ER stress following status epilepticus.

PubMed

Ko, Ah-Reum; Kim, Ji Yang; Hyun, Hye-Won; Kim, Ji-Eun

2015-10-05

The blood-brain barrier (BBB) maintains the unique brain microenvironment, which is separated from the systemic circulating system. Since the endoplasmic reticulum (ER) is an important cell organelle that is responsible for protein synthesis, the correct folding and sorting of proteins contributing to cell survivals, ER stress is a potential cause of cell damage in various diseases. Therefore, it would be worthy to explore the the relationship between the ER stress and BBB disruption during vasogenic edema formation induced by epileptogenic insults. In the present study, we investigated the roles of ER stress in vasogenic edema and its related events in rat epilepsy models provoked by pilocarpine-induced status epilepticus (SE). SE-induced eNOS activation induces BBB breakdown via up-regulation of GRP78 expression and dysfunction of SMI-71 (an endothelial BBB marker) in the piriform cortex (PC). In addition, caveolin-1 peptide (an eNOS inhibitor) effectively attenuated GRP78 expression and down-regulation of SMI-71. Taken together, our findings suggest that eNOS-mediated ER stress may participate in SE-induced vasogenic edema formation. Therefore, the modulation of ER stress may be a considerable strategy for therapy in impairments of endothelial cell function. Copyright © 2015 Elsevier B.V. All rights reserved.

Flunarizine suppresses endothelial Angiopoietin-2 in a calcium - dependent fashion in sepsis.

PubMed

Retzlaff, Jennifer; Thamm, Kristina; Ghosh, Chandra C; Ziegler, Wolfgang; Haller, Hermann; Parikh, Samir M; David, Sascha

2017-03-09

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to an infection leading to systemic inflammation and endothelial barrier breakdown. The vascular-destabilizing factor Angiopoietin-2 (Angpt-2) has been implicated in these processes in humans. Here we screened in an unbiased approach FDA-approved compounds with respect to Angpt-2 suppression in endothelial cells (ECs) in vitro. We identified Flunarizine - a well-known anti-migraine calcium channel (CC) blocker - being able to diminish intracellular Angpt-2 protein in a time- and dose-dependent fashion thereby indirectly reducing the released protein. Moreover, Flunarizine protected ECs from TNFα-induced increase in Angpt-2 transcription and vascular barrier breakdown. Mechanistically, we could exclude canonical Tie2 signalling being responsible but found that three structurally distinct T-type - but not L-type - CC blockers can suppress Angpt-2. Most importantly, experimental increase in intracellular calcium abolished Flunarizine's effect. Flunarizine was also able to block the injurious increase of Angpt-2 in murine endotoxemia in vivo. This resulted in reduced pulmonary adhesion molecule expression (intercellular adhesion molecule-1) and tissue infiltration of inflammatory cells (Gr-1). Our finding could have therapeutic implications as side effects of Flunarizine are low and specific sepsis therapeutics that target the dysregulated host response are highly desirable.

The extracellular matrix protein laminin-10 promotes blood-brain barrier repair after hypoxia and inflammation in vitro.

PubMed

Kangwantas, Korakoch; Pinteaux, Emmanuel; Penny, Jeffrey

2016-02-01

The blood-brain barrier (BBB) of the central nervous system (CNS) is essential for normal brain function. However, the loss of BBB integrity that occurs after ischaemic injury is associated with extracellular matrix (ECM) remodelling and inflammation, and contributes to poor outcome. ECM remodelling also contributes to BBB repair after injury, but the precise mechanisms and contribution of specific ECM molecules involved are unknown. Here, we investigated the mechanisms by which hypoxia and inflammation trigger loss of BBB integrity and tested the hypothesis ECM changes could contribute to BBB repair in vitro. We used an in vitro model of the BBB, composed of primary rat brain endothelial cells grown on collagen (Col) I-, Col IV-, fibronectin (FN)-, laminin (LM) 8-, or LM10-coated tissue culture plates, either as a single monolayer culture or on Transwell® inserts above mixed glial cell cultures. Cultures were exposed to oxygen-glucose deprivation (OGD) and/or reoxygenation, in the absence or the presence of recombinant interleukin-1β (IL-1β). Cell adhesion to ECM molecules was assessed by cell attachment and cell spreading assays. BBB dysfunction was assessed by immunocytochemistry for tight junction proteins occludin and zona occludens-1 (ZO-1) and measurement of trans-endothelial electrical resistance (TEER). Change in endothelial expression of ECM molecules was assessed by semi-quantitative RT-PCR. OGD and/or IL-1 induce dramatic changes associated with loss of BBB integrity, including cytoplasmic relocalisation of membrane-associated tight junction proteins occludin and ZO-1, cell swelling, and decreased TEER. OGD and IL-1 also induced gene expression of key ECM molecules associated with the BBB, including FN, Col IV, LM 8, and LM10. Importantly, we found that LM10, but not FN, Col IV, nor LM8, plays a key role in maintenance of BBB integrity and reversed most of the key hallmarks of BBB dysfunction induced by IL-1. Our data unravel new mechanisms of BBB dysfunction induced by hypoxia and inflammation and identify LM10 as a key ECM molecule involved in BBB repair after hypoxic injury and inflammation.

Post-challenge hyperglycaemia, nitric oxide production and endothelial dysfunction: the putative role of asymmetric dimethylarginine (ADMA).

PubMed

Siervo, M; Corander, M; Stranges, S; Bluck, L

2011-01-01

The endothelium is a thin layer of cells at the internal surface of blood vessels in continuous contact with the circulating fluids. The endothelial cells represent the primary barrier for the transport of glucose from the vascular conduits into the interstitial space. Insulin and nitric oxide have an important role in the regulation of glucose transport and metabolism. Hyperglycaemia is the main criteria for the diagnosis of diabetes and is responsible for the micro- and macro-vascular pathology seen in diabetic patients. Recent evidence suggests that post-challenge hyperglycaemia is a better predictor of cardiovascular risk than fasting glucose. Acute glucose elevations have been associated with a reduced endothelial-dependent flow mediated dilation indicating a decrease in nitric oxide production. Post-prandial hyperglycaemic peaks have been directly associated with increased intima media thickness in type 2 diabetic patients indicative of an increased atherosclerotic risk. The increase in intra-cellular glucose concentrations in the endothelial cells induces a hyper-generation of reactive oxygen species via the activation of different pathways (polyol-sorbitol, hexosamine, advanced glycated end products, activation of PKC, asymmetric dimethylarginine (ADMA)). These mechanisms influence the expression of genes and release of signalling and structural molecules involved in several functions (inflammation, angiogenesis, coagulation, vascular tone and permeability, cellular migration, nutrient metabolism). ADMA is considered as a biomarker of endothelial dysfunction and it has been associated with an increased risk of atherosclerosis and cardiovascular diseases. The increased generation of ADMA and reactive oxygen species in subjects with persistent hyperglycaemia could lead to an impairment of nitric oxide synthesis. Copyright © 2010 Elsevier B.V. All rights reserved.

Transplantation of in vitro cultured endothelial progenitor cells repairs the blood-brain barrier and improves cognitive function of APP/PS1 transgenic AD mice.

PubMed

Zhang, Shishuang; Zhi, Yongle; Li, Fei; Huang, Shan; Gao, Huabin; Han, Zhaoli; Ge, Xintong; Li, Dai; Chen, Fanglian; Kong, Xiaodong; Lei, Ping

2018-04-15

To date, the pathogenesis of Alzheimer's disease (AD) remains unclear. It is well-known that excessive deposition of Aβ in the brain is a crucial part of the pathogenesis of AD. In recent years, the AD neurovascular unit hypothesis has attracted much attention. Impairment of the blood-brain barrier (BBB) leads to abnormal amyloid-β (Aβ) transport, and chronic cerebral hypoperfusion causes Aβ deposition throughout the onset and progression of AD. Endothelial progenitor cells (EPCs) are the universal cells for repairing blood vessels. Our previous studies have shown that a reduced number of EPCs in the peripheral blood results in cerebral vascular repair disorder, cerebral hypoperfusion and neurodegeneration, which might be related to the cognitive dysfunction of AD patients. This study was designed to confirm whether EPCs transplantation could repair the blood-brain barrier, stimulate angiogenesis and reduce Aβ deposition in AD. The expression of ZO-1, Occludin and Claudin-5 was up-regulated in APP/PS1 transgenic mice after hippocampal transplantation of EPCs. Consistent with previous studies, EPC transplants also increased the microvessel density. We observed that Aβ senile plaque deposition was decreased and hippocampal cell apoptosis was reduced after EPCs transplantation. The Morris water maze test showed that spatial learning and memory functions were significantly improved in mice transplanted with EPCs. Consequently, EPCs could up-regulate the expression of tight junction proteins, repair BBB tight junction function, stimulate angiogenesis, promote Aβ clearance, and decrease neuronal loss, ultimately improve cognitive function. Taken together, these data demonstrate EPCs may play an important role in the therapeutic implications for vascular dysfunction in AD. Copyright © 2018 Elsevier B.V. All rights reserved.

Olive Oil Supplements Ameliorate Endothelial Dysfunction Caused by Concentrated Ambient Particulate Matter Exposure in Healthy Human Volunteers

EPA Science Inventory

Context: Exposure to ambient particulate matter (PM) induces endothelial dysfunction, a risk factor for clinical cardiovascular events and progression of atherosclerosis. Dietary supplements such as olive oil and fish oil have beneficial effects on endothelial function, and ther...

Cerebral Autoregulation in Hypertension and Ischemic Stroke: A Mini Review

PubMed Central

Shekhar, Shashank; Liu, Ruen; Travis, Olivia K; Roman, Richard J; Fan, Fan

2017-01-01

Aging and chronic hypertension are associated with dysfunction in vascular smooth muscle, endothelial cells, and neurovascular coupling. These dysfunctions induce impaired myogenic response and cerebral autoregulation, which diminish the protection of cerebral arterioles to the cerebral microcirculation from elevated pressure in hypertension. Chronic hypertension promotes cerebral focal ischemia in response to reductions in blood pressure that are often seen in sedentary elderly patients on antihypertensive therapy. Cerebral autoregulatory dysfunction evokes Blood-Brain Barrier (BBB) leakage, allowing the circulating inflammatory factors to infiltrate the brain to activate glia. The impaired cerebral autoregulation-induced inflammatory and ischemic injury could cause neuronal cell death and synaptic dysfunction which promote cognitive deficits. In this brief review, we summarize the pathogenesis and signaling mechanisms of cerebral autoregulation in hypertension and ischemic stroke-induced cognitive deficits, and discuss our new targets including 20-Hydroxyeicosatetraenoic acid (20-HETE), Gamma-Adducin (Add3) and Matrix Metalloproteinase-9 (MMP-9) that may contribute to the altered cerebral vascular function. PMID:29333537

Hyperglycaemia promotes human brain microvascular endothelial cell apoptosis via induction of protein kinase C-ßI and prooxidant enzyme NADPH oxidase

PubMed Central

Shao, Beili; Bayraktutan, Ulvi

2014-01-01

Blood–brain barrier disruption represents a key feature in hyperglycaemia-aggravated cerebral damage after an ischaemic stroke. Although the underlying mechanisms remain largely unknown, activation of protein kinase C (PKC) is thought to play a critical role. This study examined whether apoptosis of human brain microvascular endothelial cells (HBMEC) might contribute to hyperglycaemia-evoked barrier damage and assessed the specific role of PKC in this phenomenon. Treatments with hyperglycaemia (25 mM) or phorbol myristate acetate (PMA, a protein kinase C activator, 100 nM) significantly increased NADPH oxidase activity, O2•- generation, proapoptotic protein Bax expression, TUNEL-positive staining and caspase-3/7 activities. Pharmacological inhibition of NADPH oxidase, PKC-a, PKC-ß or PKC-ßI via their specific inhibitors and neutralisation of O2•- by a cell-permeable superoxide dismutase mimetic, MnTBAP normalised all the aforementioned increases induced by hyperglycaemia. Suppression of these PKC isoforms also negated the stimulatory effects of hyperglycaemia on the protein expression of NADPH oxidase membrane-bound components, Nox2 and p22-phox which determine the overall enzymatic activity. Silencing of PKC-ßI gene through use of specific siRNAs abolished the effects of both hyperglycaemia and PMA on endothelial cell NADPH oxidase activity, O2•- production and apoptosis and consequently improved the integrity and function of an in vitro model of human cerebral barrier comprising HBMEC, astrocytes and pericytes. Hyperglycaemia-mediated apoptosis of HBMEC contributes to cerebral barrier dysfunction and is modulated by sequential activations of PKC-ßI and NADPH oxidase. PMID:24936444

Gestational diabetes, preeclampsia and cytokine release: similarities and differences in endothelial cell function.

PubMed

Rao, Rashmi; Sen, Suvajit; Han, Bing; Ramadoss, Sivakumar; Chaudhuri, Gautam

2014-01-01

Gestational diabetes, pre-eclampsia as well as intra-uterine infection during pregnancy affects the function of the endothelium both in the mother and the fetus leading to endothelial dysfunction. Gestational diabetes is also associated with an increased incidence of pre-eclampsia and it is likely that both the hyperglycemia as well as the release of cytokines especially TNFα during hyperglycemia may play an important role in the pathogenesis of endothelial dysfunction leading to preeclampsia. Similarly, some but not all studies have suggested that infection of the mother under certain circumstances can also lead to preeclampsia as women with either a bacterial or viral infection were at a higher risk of developing preeclampsia, compared to women without infection and infection also leads to a release in TNFα. Endothelial cells exposed to either high glucose or TNFα leads to an increase in the production of H2O2 and to a decrease in endothelial cell proliferation. The cellular and molecular mechanisms involved in this phenomenon are discussed.Gestational diabetes, pre-eclampsia as well as intra-uterine infection during pregnancy has profound effects on the fetus and long term effects on the neonate. All three conditions affect the function of the endothelium both in the mother and the fetus leading to endothelial dysfunction. Gestational diabetes is also associated with an increased incidence of pre-eclampsia and it is likely that both the hyperglycemia as well as the release of cytokines especially TNFα during hyperglycemia may play an important role in the pathogenesis of endothelial dysfunction leading to preeclampsia. It has also been suggested although not universally accepted that under certain circumstances maternal infection may also predispose to pre-eclampsia. Pre-eclampsia is also associated with the release of TNFα and endothelial dysfunction. However, the cellular and molecular mechanism(s) leading to the endothelial dysfunction by either hyperglycemia or by the cytokine TNFα appear to be different. In this chapter, we explore some of the similarities and differences leading to endothelial dysfunction by both hyperglycemia and by the inflammatory cytokine TNFα and the cellular and molecular mechanism(s) involved.

Injuries to the vascular endothelium: vascular wall and endothelial dysfunction.

PubMed

Fisher, Mark

2008-01-01

Vascular endothelial injury has multiple elements, and this article focuses on ischemia-related processes that have particular relevance to ischemic stroke. Distinctions between necrotic and apoptotic cell death provide a basic science context in which to better understand the significance of classical core and penumbra concepts of acute stroke, with apoptotic processes particularly prominent in the penumbra. The mitochondria are understood to serve as a reservoir of proteins that mediate apoptosis. Oxidative stress pathways generating reactive oxygen species (ROS) are prominent in endothelial injury, both ischemic and nonischemic, with prominent roles of enzyme- and nonenzymemediated pathways; mitochondria once again have a critical role, particularly in the nonenzymatic pathways generating ROS. Inflammation also contributes to vascular endothelial injury, and endothelial cells have the capacity to rapidly increase expression of inflammatory mediators following ischemic challenge; this leads to enhanced leukocyte-endothelial interactions mediated by selectins and adhesion molecules. Preconditioning consists of a minor version of an injurious event, which in turn may protect vascular endothelium from injury following a more substantial event. Presence of the blood-brain barrier creates unique responses to endothelial injury, with permeability changes due to impairment of endothelial-matrix interactions compounding altered vasomotor tone and tissue perfusion mediated by nitric oxide. Pharmacological protection against vascular endothelial injury can be provided by several of the phosphodiesterases (cilostazol and dipyridamole), along with statins. Optimal clinical responses for protection of brain vascular endothelium may use preconditioning as a model, and will likely require combined protection against apoptosis, ROS, and inflammation.

Endothelial Cells Derived from the Blood-Brain Barrier and Islets of Langerhans Differ in their Response to the Effects of Bilirubin on Oxidative Stress Under Hyperglycemic Conditions.

PubMed

Kapitulnik, Jaime; Benaim, Clara; Sasson, Shlomo

2012-01-01

Unconjugated bilirubin (UCB) is a neurotoxic degradation product of heme. Its toxic effects include induction of apoptosis, and ultimately neuronal cell death. However, at low concentrations, UCB is a potent antioxidant that may protect cells and tissues against oxidative stress by neutralizing toxic metabolites such as reactive oxygen species (ROS). High glucose levels (hyperglycemia) generate reactive metabolites. Endothelial cell dysfunction, an early vascular complication in diabetes, has been associated with hyperglycemia-induced oxidative stress. Both glucose and UCB are substrates for transport proteins in microvascular endothelial cells of the blood-brain barrier (BBB). In the current study we show that UCB (1-40 μM) induces apoptosis and reduces survival of bEnd3 cells, a mouse brain endothelial cell line which serves as an in vitro model of the BBB. These deleterious effects of UCB were enhanced in the presence of high glucose (25 mM) levels. Interestingly, the bEnd3 cells exhibited an increased sensitivity to the apoptotic effects of UCB when compared to the MS1 microcapillary endothelial cell line. MS1 cells originate from murine pancreatic islets of Langerhans, and are devoid of the barrier characteristics of BBB-derived endothelial cells. ROS production was increased in both bEnd3 and MS1 cells exposed to high glucose, as compared with cells exposed to normal (5.5 mM) glucose levels. While UCB (0.1-40 μM) did not alter ROS production in cells exposed to normal glucose, relatively low ("physiological") UCB concentrations (0.1-5 μM) attenuated ROS generation in both cell lines exposed to high glucose levels. Most strikingly, higher UCB concentrations (20-40 μM) increased ROS generation in bEnd3 cells exposed to high glucose, but not in similarly treated MS1 cells. These results may be of critical importance for understanding the vulnerability of the BBB endothelium upon exposure to increasing UCB levels under hyperglycemic conditions.

Endothelial Cells Derived from the Blood-Brain Barrier and Islets of Langerhans Differ in their Response to the Effects of Bilirubin on Oxidative Stress Under Hyperglycemic Conditions

PubMed Central

Kapitulnik, Jaime; Benaim, Clara; Sasson, Shlomo

2012-01-01

Unconjugated bilirubin (UCB) is a neurotoxic degradation product of heme. Its toxic effects include induction of apoptosis, and ultimately neuronal cell death. However, at low concentrations, UCB is a potent antioxidant that may protect cells and tissues against oxidative stress by neutralizing toxic metabolites such as reactive oxygen species (ROS). High glucose levels (hyperglycemia) generate reactive metabolites. Endothelial cell dysfunction, an early vascular complication in diabetes, has been associated with hyperglycemia-induced oxidative stress. Both glucose and UCB are substrates for transport proteins in microvascular endothelial cells of the blood-brain barrier (BBB). In the current study we show that UCB (1–40 μM) induces apoptosis and reduces survival of bEnd3 cells, a mouse brain endothelial cell line which serves as an in vitro model of the BBB. These deleterious effects of UCB were enhanced in the presence of high glucose (25 mM) levels. Interestingly, the bEnd3 cells exhibited an increased sensitivity to the apoptotic effects of UCB when compared to the MS1 microcapillary endothelial cell line. MS1 cells originate from murine pancreatic islets of Langerhans, and are devoid of the barrier characteristics of BBB-derived endothelial cells. ROS production was increased in both bEnd3 and MS1 cells exposed to high glucose, as compared with cells exposed to normal (5.5 mM) glucose levels. While UCB (0.1–40 μM) did not alter ROS production in cells exposed to normal glucose, relatively low (“physiological”) UCB concentrations (0.1–5 μM) attenuated ROS generation in both cell lines exposed to high glucose levels. Most strikingly, higher UCB concentrations (20–40 μM) increased ROS generation in bEnd3 cells exposed to high glucose, but not in similarly treated MS1 cells. These results may be of critical importance for understanding the vulnerability of the BBB endothelium upon exposure to increasing UCB levels under hyperglycemic conditions. PMID:22811666

Endothelial mineralocorticoid receptor activation mediates endothelial dysfunction in diet-induced obesity

PubMed Central

Schäfer, Nicola; Lohmann, Christine; Winnik, Stephan; van Tits, Lambertus J.; Miranda, Melroy X.; Vergopoulos, Athanasios; Ruschitzka, Frank; Nussberger, Jürg; Berger, Stefan; Lüscher, Thomas F.; Verrey, François; Matter, Christian M.

2013-01-01

Received 22 July 2012; revised 29 January 2013; accepted 4 March 2013 Aims Aldosterone plays a crucial role in cardiovascular disease. ‘Systemic’ inhibition of its mineralocorticoid receptor (MR) decreases atherosclerosis by reducing inflammation and oxidative stress. Obesity, an important cardiovascular risk factor, is an inflammatory disease associated with increased plasma aldosterone levels. We have investigated the role of the ‘endothelial’ MR in obesity-induced endothelial dysfunction, the earliest stage in atherogenesis. Methods and results C57BL/6 mice were exposed to a normal chow diet (ND) or a high-fat diet (HFD) alone or in combination with the MR antagonist eplerenone (200 mg/kg/day) for 14 weeks. Diet-induced obesity impaired endothelium-dependent relaxation in response to acetylcholine, whereas eplerenone treatment of obese mice prevented this. Expression analyses in aortic endothelial cells isolated from these mice revealed that eplerenone attenuated expression of pro-oxidative NADPH oxidase (subunits p22phox, p40phox) and increased expression of antioxidative genes (glutathione peroxidase-1, superoxide dismutase-1 and -3) in obesity. Eplerenone did not affect obesity-induced upregulation of cyclooxygenase (COX)-1 or prostacyclin synthase. Endothelial-specific MR deletion prevented endothelial dysfunction in obese (exhibiting high ‘endogenous’ aldosterone) and in ‘exogenous’ aldosterone-infused lean mice. Pre-incubation of aortic rings from aldosterone-treated animals with the COX-inhibitor indomethacin restored endothelial function. Exogenous aldosterone administration induced endothelial expression of p22phox in the presence, but not in the absence of the endothelial MR. Conclusion Obesity-induced endothelial dysfunction depends on the ‘endothelial’ MR and is mediated by an imbalance of oxidative stress-modulating mechanisms. Therefore, MR antagonists may represent an attractive therapeutic strategy in the increasing population of obese patients to decrease vascular dysfunction and subsequent atherosclerotic complications. PMID:23594590

Effects of a Physical Activity Program on Markers of Endothelial Dysfunction, Oxidative Stress, and Metabolic Status in Adolescents with Metabolic Syndrome

PubMed Central

Camarillo-Romero, Eneida; Dominguez-Garcia, Ma Victoria; Amaya-Chavez, Araceli; Camarillo-Romero, Maria del Socorro; Talavera-Piña, Juan; Huitron-Bravo, Gerardo; Majluf-Cruz, Abraham

2012-01-01

The metabolic syndrome (MetS) is a precursor of diabetes. Physical activity (PA) improves endothelial dysfunction and may benefit patients with MetS. Aims. To evaluate the effect of a physical activity (PA) program on markers of endothelial dysfunction and oxidative stress in adolescents with (MetS). Methods. We carried out a cohort study of 38 adolescents with and without MetS (18 females and 20 males). All participants completed a 3-month PA program. All variables of the MetS as well as markers of endothelial dysfunction and oxidative stress tests were evaluated. Results. Females with and without MetS showed significant differences for almost all components of the MetS, whereas males were significantly different in half of the components. After the PA program, components of the MetS were not different from baseline values except for HDL-C levels. Some baseline endothelial dysfunction markers were significantly different among adolescents with and without MetS; however, after the PA program, most of these markers significantly improved in subjects with and without MetS. Conclusion. PA improves the markers of endothelial dysfunction in adolescents with MetS although other changes in the components of the MetS were not observed. Perhaps the benefits of PA on all components of MetS would appear after a PA program with a longer duration. PMID:22888450

Effects of simvastatin administration on rodents with lipopolysaccharide-induced liver microvascular dysfunction.

PubMed

La Mura, Vincenzo; Pasarín, Marcos; Meireles, Cintia Z; Miquel, Rosa; Rodríguez-Vilarrupla, Aina; Hide, Diana; Gracia-Sancho, Jorge; García-Pagán, Juan Carlos; Bosch, Jaime; Abraldes, Juan G

2013-03-01

Endothelial dysfunction drives vascular derangement and organ failure associated with sepsis. However, the consequences of sepsis on liver sinusoidal endothelial function are largely unknown. Statins might improve microvascular dysfunction in sepsis. The present study explores liver vascular abnormalities and the effects of statins in a rat model of endotoxemia. For this purpose, lipopolysaccharide (LPS) or saline was given to: (1) rats treated with placebo; (2) rats treated with simvastatin (25 mg/kg, orally), given at 3 and 23 hours after LPS/saline challenge; (3) rats treated with simvastatin (25 mg/kg/24 h, orally) from 3 days before LPS/saline injection. Livers were isolated and perfused and sinusoidal endothelial function was explored by testing the vasodilation of the liver circulation to increasing concentrations of acetylcholine. The phosphorylated endothelial nitric oxide synthase (PeNOS)/endothelial nitric oxide synthase (eNOS) ratio was measured as a marker of eNOS activation. LPS administration induced an increase in baseline portal perfusion pressure and a decrease in vasodilation to acetylcholine (sinusoidal endothelial dysfunction). This was associated with reduced eNOS phosphorylation and liver inflammation. Simvastatin after LPS challenge did not prevent the increase in baseline portal perfusion pressure, but attenuated the development of sinusoidal endothelial dysfunction. Treatment with simvastatin from 3 days before LPS prevented the increase in baseline perfusion pressure and totally normalized the vasodilating response of the liver vasculature to acetylcholine and reduced liver inflammation. Both protocols of treatment restored a physiologic PeNOS/eNOS ratio. LPS administration induces intrahepatic endothelial dysfunction that might be prevented by simvastatin, suggesting that statins might have potential for liver protection during endotoxemia. Copyright © 2012 American Association for the Study of Liver Diseases.

Febuxostat attenuates paroxysmal atrial fibrillation-induced regional endothelial dysfunction.

PubMed

Li, YanGuang; Chen, FuKun; Deng, Long; Lin, Kun; Shi, Xiangmin; Zhaoliang, Shan; Wang, YuTang

2017-01-01

Paroxysmal atrial fibrillation (PAF) can increase thrombogenesis risk, especially in the left atrium (LA). The exact mechanism is still unclear. We assessed the effects of PAF on endothelial function, and investigated if febuxostat (FX) can attenuate endothelial dysfunction by inhibition of xanthine oxidase (XO). Eighteen male New Zealand white rabbits were divided randomly into sham-operated (S), PAF (P) or FX+pacing (FP) groups. Group P and group FP received rapid atrial pacing (RAP). Group FP was administered febuxostat (FX) for 7days before RAP. Post-procedure, blood samples were collected from the LA, right atrium (RA) and peripheral circulation. Tissues from the LA and RA were obtained. Endothelial dysfunction (thrombomodulin [TM], von Willebrand factor [VWF], asymmetric dimethylarginine [ADMA]), and indirect thrombin generation (thrombin-antithrombin complex [TAT], prothrombin fragment 1+2 [F1.2]) and oxidative stress in atrial tissue (xanthine oxidase [XO], superoxide dismutase [SOD], malondialdehyde [MDA]) were measured using an Enzyme-linked immunosorbent assay. Atrial endothelial expression of TM and VWF was measured by histology/western blotting. Endothelial dysfunction (TM, VWF, ADMA), TAT generation and oxidative stress (XO, SOD, MDA) in group P were more significant compared with that in group S (p<0.05, respectively). In group P, all of these changes occurred to a greater extent in the LA compared with those in the RA or peripheral circulation. In group FP, FX attenuated endothelial dysfunction and reduced TAT levels by inhibition of XO-mediated oxidative stress. PAF can lead to endothelial dysfunction and TAT generation by XO-mediated oxidative stress. The LA is more susceptible to these effects. FX can attenuate these changes by inhibition XO and XO-mediated oxidative stress. Copyright © 2016. Published by Elsevier Ltd.

Endoplasmic Reticulum Stress Mediates Methamphetamine-Induced Blood–Brain Barrier Damage

PubMed Central

Qie, Xiaojuan; Wen, Di; Guo, Hongyan; Xu, Guanjie; Liu, Shuai; Shen, Qianchao; Liu, Yi; Zhang, Wenfang; Cong, Bin; Ma, Chunling

2017-01-01

Methamphetamine (METH) abuse causes serious health problems worldwide, and long-term use of METH disrupts the blood–brain barrier (BBB). Herein, we explored the potential mechanism of endoplasmic reticulum (ER) stress in METH-induced BBB endothelial cell damage in vitro and the therapeutic potential of endoplasmic reticulum stress inhibitors for METH-induced BBB disruption in C57BL/6J mice. Exposure of immortalized BMVEC (bEnd.3) cells to METH significantly decreased cell viability, induced apoptosis, and diminished the tightness of cell monolayers. METH activated ER stress sensor proteins, including PERK, ATF6, and IRE1, and upregulated the pro-apoptotic protein CHOP. The ER stress inhibitors significantly blocked the upregulation of CHOP. Knockdown of CHOP protected bEnd.3 cells from METH-induced cytotoxicity. Furthermore, METH elevated the production of reactive oxygen species (ROS) and induced the dysfunction of mitochondrial characterized by a Bcl2/Bax ratio decrease, mitochondrial membrane potential collapse, and cytochrome c. ER stress release was partially reversed by ROS inhibition, and cytochrome c release was partially blocked by knockdown of CHOP. Finally, PBA significantly attenuated METH-induced sodium fluorescein (NaFluo) and Evans Blue leakage, as well as tight junction protein loss, in C57BL/6J mice. These data suggest that BBB endothelial cell damage was caused by METH-induced endoplasmic reticulum stress, which further induced mitochondrial dysfunction, and that PBA was an effective treatment for METH-induced BBB disruption. PMID:28959203

You're Only as Old as Your Arteries: Translational Strategies for Preserving Vascular Endothelial Function with Aging

PubMed Central

Kaplon, Rachelle E.; Gioscia-Ryan, Rachel A.; LaRocca, Thomas J.

2014-01-01

Endothelial dysfunction develops with age and increases the risk of age-associated vascular disorders. Nitric oxide insufficiency, oxidative stress, and chronic low-grade inflammation, induced by upregulation of adverse cellular signaling processes and imbalances in stress resistance pathways, mediate endothelial dysfunction with aging. Healthy lifestyle behaviors preserve endothelial function with aging by inhibiting these mechanisms, and novel nutraceutical compounds that favorably modulate these pathways hold promise as a complementary approach for preserving endothelial health. PMID:24985329

Endothelial dysfunction in the regulation of portal hypertension

PubMed Central

Iwakiri, Yasuko

2013-01-01

Portal hypertension is caused by an increased intrahepatic resistance, a major consequence of cirrhosis. Endothelial dysfunction in liver sinusoidal endothelial cells (LSECs) decreases the production of vasodilators, such as nitric oxide (NO) and favors vasoconstriction. This contributes to an increased vascular resistance in the intrahepatic/sinusoidal microcirculation. Portal hypertension, once developed, causes endothelial cell (EC) dysfunction in the extrahepatic, i.e. splanchnic and systemic, circulation. Unlike LSEC dysfunction, EC dysfunction in the splanchnic and systemic circulation overproduces vasodilator molecules, leading to arterial vasodilatation. In addition, portal hypertension leads to the formation of portosystemic collateral vessels. Both arterial vasodilatation and portosystemic collateral vessel formation exacerbate portal hypertension by increasing the blood flow through the portal vein. Pathologic consequences, such as esophageal varices and ascites, result. While the sequence of pathological vascular events in cirrhosis and portal hypertension have been elucidated, the underlying cellular and molecular mechanisms causing EC dysfunctions are not yet fully understood. This review article summarizes the current cellular and molecular studies on EC dysfunctions found during the development of cirrhosis and portal hypertension with a focus on intra- and extrahepatic circulation. The article ends by discussing future directions of study for EC dysfunctions. PMID:21745318

Inflammation, Endothelial Dysfunction and Arterial Stiffness as Therapeutic Targets in Cardiovascular Medicine.

PubMed

Della Corte, Vittoriano; Tuttolomondo, Antonino; Pecoraro, Rosaria; Di Raimondo, Domenico; Vassallo, Valerio; Pinto, Antonio

2016-01-01

In the last decades, many factors thought to be associated with the atherosclerotic process and cardiovascular events have been studied, and some of these have been shown to correlate with clinical outcome, such as arterial stiffness, endothelial dysfunction and immunoinflammatory markers. Arterial stiffness is an important surrogate marker that describes the capability of an artery to expand and contract in response to pressure changes. It can be assessed with different techniques, such as the evaluation of PWV and AIx. It is related to central systolic pressure and it is an independent predictor of cardiovascular morbidity and mortality in hypertensive patients, type 2 diabetes, end-stage renal disease and in elderly populations. The endothelium has emerged as the key regulator of vascular homeostasis, in fact, it has not merely a barrier function but also acts as an active signal transducer for circulating influences that modify the vessel wall phenotype. When its function is lost, it predisposes the vasculature to vasoconstriction, leukocyte adherence, platelet activation, thrombosis and atherosclerosis. Non-invasive methods were developed to evaluate endothelial function, such as the assesment of FMD, L-FMC and RHI. Moreover in the last years, a large number of studies have clarified the role of inflammation and the underlying cellular and molecular mechanisms that contribute to atherogenesis. For clinical purposes, the most promising inflammatory biomarker appears to be CRP and a variety of population-based studies have showed that baseline CRP levels predict future cardiovascular events. Each of the markers listed above has its importance from the pathophysiological and clinical point of view, and those can also be good therapeutic targets. However, it must be stressed that assessments of these vascular markers are not mutually exclusive, but rather complementary and those can offer different views of the same pathology. The purpose of this review is to analyze the role of arterial stiffness, endothelial dysfunction and immunoinflammatory markers as surrogate endpoint, assessing the correlations between these markers and evaluating the therapeutic perspectives that these offer.

Withaferin A protects against palmitic acid-induced endothelial insulin resistance and dysfunction through suppression of oxidative stress and inflammation

PubMed Central

Batumalaie, Kalaivani; Amin, Muhammad Arif; Murugan, Dharmani Devi; Sattar, Munavvar Zubaid Abdul; Abdullah, Nor Azizan

2016-01-01

Activation of inflammatory pathways via reactive oxygen species (ROS) by free fatty acids (FFA) in obesity gives rise to insulin resistance and endothelial dysfunction. Withaferin A (WA), possesses both antioxidant and anti-inflammatory properties and therefore would be a good strategy to suppress palmitic acid (PA)-induced oxidative stress and inflammation and hence, insulin resistance and dysfunction in the endothelium. Effect of WA on PA-induced insulin resistance in human umbilical vein endothelial cells (HUVECs) was determined by evaluating insulin signaling mechanisms whilst effect of this drug on PA-induced endothelial dysfunction was determined in acetylcholine-mediated relaxation in isolated rat aortic preparations. WA significantly inhibited ROS production and inflammation induced by PA. Furthermore, WA significantly decreased TNF-α and IL-6 production in endothelial cells by specifically suppressing IKKβ/NF-κβ phosphorylation. WA inhibited inflammation-stimulated IRS-1 serine phosphorylation and improved the impaired insulin PI3-K signaling, and restored the decreased nitric oxide (NO) production triggered by PA. WA also decreased endothelin-1 and plasminogen activator inhibitor type-1 levels, and restored the impaired endothelium-mediated vasodilation in isolated aortic preparations. These findings suggest that WA inhibited both ROS production and inflammation to restore impaired insulin resistance in cultured endothelial cells and improve endothelial dysfunction in rat aortic rings. PMID:27250532

Endothelial Dysfunction in Human Diabetes Is Mediated by Wnt5a-JNK Signaling.

PubMed

Bretón-Romero, Rosa; Feng, Bihua; Holbrook, Monika; Farb, Melissa G; Fetterman, Jessica L; Linder, Erika A; Berk, Brittany D; Masaki, Nobuyuki; Weisbrod, Robert M; Inagaki, Elica; Gokce, Noyan; Fuster, Jose J; Walsh, Kenneth; Hamburg, Naomi M

2016-03-01

Endothelial dysfunction is linked to insulin resistance, inflammatory activation, and increased cardiovascular risk in diabetes mellitus; however, the mechanisms remain incompletely understood. Recent studies have identified proinflammatory signaling of wingless-type family member (Wnt) 5a through c-jun N-terminal kinase (JNK) as a regulator of metabolic dysfunction with potential relevance to vascular function. We sought to gain evidence that increased activation of Wnt5a-JNK signaling contributes to impaired endothelial function in patients with diabetes mellitus. We measured flow-mediated dilation of the brachial artery and characterized freshly isolated endothelial cells by protein expression, eNOS activation, and nitric oxide production in 85 subjects with type 2 diabetes mellitus (n=42) and age- and sex-matched nondiabetic controls (n=43) and in human aortic endothelial cells treated with Wnt5a. Endothelial cells from patients with diabetes mellitus displayed 1.3-fold higher Wnt5a levels (P=0.01) along with 1.4-fold higher JNK activation (P<0.01) without a difference in total JNK levels. Higher JNK activation was associated with lower flow-mediated dilation, consistent with endothelial dysfunction (r=0.53, P=0.02). Inhibition of Wnt5a and JNK signaling restored insulin and A23187-mediated eNOS activation and improved nitric oxide production in endothelial cells from patients with diabetes mellitus. In endothelial cells from nondiabetic controls, rWnt5a treatment inhibited eNOS activation replicating the diabetic endothelial phenotype. In human aortic endothelial cells, Wnt5a-induced impairment of eNOS activation and nitric oxide production was reversed by Wnt5a and JNK inhibition. Our findings demonstrate that noncanonical Wnt5a signaling and JNK activity contribute to vascular insulin resistance and endothelial dysfunction and may represent a novel therapeutic opportunity to protect the vasculature in patients with diabetes mellitus. © 2016 American Heart Association, Inc.

Vaspin protects against LPS‑induced ARDS by inhibiting inflammation, apoptosis and reactive oxygen species generation in pulmonary endothelial cells via the Akt/GSK‑3β pathway.

PubMed

Qi, Di; Wang, Daoxin; Zhang, Chunrong; Tang, Xumao; He, Jing; Zhao, Yan; Deng, Wang; Deng, Xinyu

2017-12-01

Acute respiratory distress syndrome (ARDS) is characterized by uncontrolled extravasation of protein‑rich fluids, which is caused by disruption and dysfunction of the barrier of pulmonary endothelial cells (ECs). Visceral adipose tissue‑derived serine protease inhibitor (vaspin) is a novel adipokine with pleiotropic properties, which has been reported to exert beneficial effects against obesity‑associated systemic vascular diseases; however, its effects on ARDS remain unknown. In the present study, mice were subjected to systemic administration of adenoviral vector expressing vaspin (Ad‑vaspin) to examine its effects on lipopolysaccharide (LPS)‑induced ARDS in vivo. Histological analysis was then conducted, and cytokine [tumor necrosis factor (TNF)‑α, interleukin (IL)‑6 and IL‑10] levels, and intercellular cell adhesion molecule‑1 (ICAM‑1) and adherens junctions (AJs) expression were detected. In addition, human pulmonary microvascular ECs (HPMECs) were treated with recombinant human (rh)‑vaspin to further investigate its molecular basis and underlying mechanism. The mRNA expression levels of inflammatory cytokines (TNF‑α and IL‑6) and endothelial‑specific adhesion markers [vascular cell adhesion molecule‑1 and E‑selectin], activation of nuclear factor‑κB, and cell viability and apoptosis were then examined. Furthermore, the expression of AJs and organization of the cytoskeleton, as well as expression and activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and generation of reactive oxygen species (ROS) were determined. The results indicated that Ad‑vaspin protected against LPS‑induced ARDS by alleviating the pulmonary inflammatory response and pulmonary EC barrier dysfunction in mice, which was accompanied by activation of the protein kinase B (Akt)/glycogen synthase kinase (GSK)‑3β pathway. In addition, pretreatment of HPMECs with rh‑vaspin attenuated inflammation, apoptosis and ROS generation without alterations in AJs and cytoskeletal organization following LPS insult, which was accompanied by activation of the Akt/GSK3β pathway. In conclusion, the present study demonstrated that vaspin protects against LPS‑induced ARDS by reversing EC barrier dysfunction via the suppression of inflammation, apoptosis and ROS production in pulmonary ECs, at least partially via activation of the Akt/GSK3β pathway. These findings provide evidence of a causal link between vaspin and EC dysfunction in ARDS, and suggest a potential therapeutic intervention for patients with ARDS.

Differential Effects of Leptin and Adiponectin in Endothelial Angiogenesis

PubMed Central

Adya, Raghu; Tan, Bee K.; Randeva, Harpal S.

2015-01-01

Obesity is a major health burden with an increased risk of cardiovascular morbidity and mortality. Endothelial dysfunction is pivotal to the development of cardiovascular disease (CVD). In relation to this, adipose tissue secreted factors termed “adipokines” have been reported to modulate endothelial dysfunction. In this review, we focus on two of the most abundant circulating adipokines, that is, leptin and adiponectin, in the development of endothelial dysfunction. Leptin has been documented to influence a multitude of organ systems, that is, central nervous system (appetite regulation, satiety factor) and cardiovascular system (endothelial dysfunction leading to atherosclerosis). Adiponectin, circulating at a much higher concentration, exists in different molecular weight forms, essentially made up of the collagenous fraction and a globular domain, the latter being investigated minimally for its involvement in proinflammatory processes including activation of NF-κβ and endothelial adhesion molecules. The opposing actions of the two forms of adiponectin in endothelial cells have been recently demonstrated. Additionally, a local and systemic change to multimeric forms of adiponectin has gained importance. Thus detailed investigations on the potential interplay between these adipokines would likely result in better understanding of the missing links connecting CVD, adipokines, and obesity. PMID:25650072

Brain vascular heterogeneity: implications for disease pathogenesis and design of in vitro blood-brain barrier models.

PubMed

Noumbissi, Midrelle E; Galasso, Bianca; Stins, Monique F

2018-04-23

The vertebrate blood-brain barrier (BBB) is composed of cerebral microvascular endothelial cells (CEC). The BBB acts as a semi-permeable cellular interface that tightly regulates bidirectional molecular transport between blood and the brain parenchyma in order to maintain cerebral homeostasis. The CEC phenotype is regulated by a variety of factors, including cells in its immediate environment and within functional neurovascular units. The cellular composition of the brain parenchyma surrounding the CEC varies between different brain regions; this difference is clearly visible in grey versus white matter. In this review, we discuss evidence for the existence of brain vascular heterogeneity, focusing on differences between the vessels of the grey and white matter. The region-specific differences in the vasculature of the brain are reflective of specific functions of those particular brain areas. This BBB-endothelial heterogeneity may have implications for the course of pathogenesis of cerebrovascular diseases and neurological disorders involving vascular activation and dysfunction. This heterogeneity should be taken into account when developing BBB-neuro-disease models representative of specific brain areas.

Association Between the Female Athlete Triad and Endothelial Dysfunction in Dancers

PubMed Central

Hoch, Anne Z.; Papanek, Paula; Szabo, Aniko; Widlansky, Michael E.; Schimke, Jane E.; Gutterman, David D.

2013-01-01

Objective To determine the prevalence of the 3 components of the female athlete triad [disordered eating, menstrual dysfunction, low bone mineral density (BMD)] and their relationships with brachial artery flow-mediated dilation in professional dancers. Design Prospective study. Setting Academic institution in the Midwest. Participants Twenty-two professional ballet dancers volunteered for this study. Interventions The prevalence of the female athlete triad and its relationship to endothelial dysfunction. Main Outcome Measures Subjects completed questionnaires to assess disordered eating and menstrual status/history. They also completed a 3-day food record and wore an accelerometer for 3 days to determine energy availability. Serum baseline thyrotropin, prolactin, and hormonal concentrations were obtained. Bone mineral density and body composition were measured with a GE Lunar Prodigy dual-energy X-ray absorptiometry. Endothelial function was determined as flow-mediated vasodilation measured by high-frequency ultrasound in the brachial artery. An increase in brachial diameter <5% to hyperemic flow stimulus was defined a priori as endothelial dysfunction. Results Seventeen dancers (77%) had evidence of low/negative energy availability. Thirty-two percent had disordered eating (EDE-Q score). Thirty-six percent had menstrual dysfunction and 14% were currently using hormone contraception. Twenty-three percent had evidence of low bone density (Z-score < −1.0). Sixty-four percent had abnormal brachial artery flow-mediated dilation (<5%). Flow-mediated dilation values were significantly correlated with serum estrogen and whole-body and lumbar BMD. All the 3 components of the triad plus endothelial dysfunction were present in 14% of the subjects. Conclusions Endothelial dysfunction was correlated with reduced BMD, menstrual dysfunction, and low serum estrogen. These findings may have profound implications for cardiovascular and bone health in professional women dancers. PMID:21358502

Loss of the Endothelial Glycocalyx Links Albuminuria and Vascular Dysfunction

PubMed Central

Ferguson, Joanne K.; Burford, James L.; Gevorgyan, Haykanush; Nakano, Daisuke; Harper, Steven J.; Bates, David O.; Peti-Peterdi, Janos

2012-01-01

Patients with albuminuria and CKD frequently have vascular dysfunction but the underlying mechanisms remain unclear. Because the endothelial surface layer, a meshwork of surface-bound and loosely adherent glycosaminoglycans and proteoglycans, modulates vascular function, its loss could contribute to both renal and systemic vascular dysfunction in proteinuric CKD. Using Munich-Wistar-Fromter (MWF) rats as a model of spontaneous albuminuric CKD, multiphoton fluorescence imaging and single-vessel physiology measurements revealed that old MWF rats exhibited widespread loss of the endothelial surface layer in parallel with defects in microvascular permeability to both water and albumin, in both continuous mesenteric microvessels and fenestrated glomerular microvessels. In contrast to young MWF rats, enzymatic disruption of the endothelial surface layer in old MWF rats resulted in neither additional loss of the layer nor additional changes in permeability. Intravenous injection of wheat germ agglutinin lectin and its adsorption onto the endothelial surface layer significantly improved glomerular albumin permeability. Taken together, these results suggest that widespread loss of the endothelial surface layer links albuminuric kidney disease with systemic vascular dysfunction, providing a potential therapeutic target for proteinuric kidney disease. PMID:22797190

Endothelial dysfunction and amyloid-β-induced neurovascular alterations

PubMed Central

Koizumi, Kenzo; Wang, Gang; Park, Laibaik

2015-01-01

Alzheimer's disease (AD) and cerebrovascular diseases share common vascular risk factors that have disastrous effects on cerebrovascular regulation. Endothelial cells, lining inner walls of cerebral blood vessels, form a dynamic interface between the blood and the brain and are critical for the maintenance of neurovascular homeostasis. Accordingly, injury in endothelial cells is regarded as one of the earliest symptoms of impaired vasoregulatory mechanisms. Extracellular buildup of amyloid-β (Aβ) is a central pathogenic factor in AD. Aβ exerts potent detrimental effects on cerebral blood vessels and impairs endothelial structure and function. Recent evidence implicates vascular oxidative stress and activation of the nonselective cationic channel transient receptor potential melastatin (TRPM)-2 on endothelial cells in the mechanisms of Aβ-induced neurovascular dysfunction. Thus, Aβ triggers opening of TRPM2 channels in endothelial cells leading to intracellular Ca2+ overload and vasomotor dysfunction. The cerebrovascular dysfunction may contribute to AD pathogenesis by reducing the cerebral blood supply, leading to increased susceptibility to vascular insufficiency, and by promoting Aβ accumulation. The recent realization that vascular factors contribute to AD pathobiology suggests new targets for the prevention and treatment of this devastating disease. PMID:26328781

Proteomic study of endothelial dysfunction induced by AGEs and its possible role in diabetic cardiovascular complications.

PubMed

Banarjee, Reema; Sharma, Akshay; Bai, Shakuntala; Deshmukh, Arati; Kulkarni, Mahesh

2018-06-20

Endothelial dysfunction is one of the primary steps in the development of diabetes associated cardiovascular diseases. Hyperglycemic condition in diabetes promotes accumulation of advanced glycation end products (AGEs) in the plasma, that interact with the receptor for AGEs (RAGE) present on the endothelial cells and negatively affect their function. Using Human umbilical vascular endothelial cells (HUVECs) in culture, the effect of glycated human serum albumin on global proteomic changes was studied by SWATH-MS, a label free quantitative proteomic approach. Out of the 1860 proteins identified, 161 showed higher abundance while 123 showed lesser abundance in cells treated with glycated HSA. Bioinformatic analysis revealed that the differentially regulated proteins were involved in various processes such as apoptosis, oxidative stress etc. that are associated with endothelial dysfunction. Furthermore, the iRegulon analysis and immunofuorescence studies indicated that several of the differentially regulated proteins were transcriptionally regulated by NF-κB, that is downstream to AGE-RAGE axis. Some of the important differentially regulated proteins include ICAM1, vWF, PAI-1that affect important endothelial functions like cell adhesion and blood coagulation. qPCR analysis showed an increase in expression of the AGE receptor RAGE along with other genes involved in endothelial function. AGE treatment to HUVEC cells led to increased oxidative stress and apoptosis. This is the first proteomics study that provides insight into proteomic changes downstream to AGE-RAGE axis leading to endothelial dysfunction and predisposing to cardiovascular complications. Cardiovascular disease (CVD) is a major pathological outcome in diabetic patients and it is important to address ways that target its development before the onset. Elevated plasma AGEs in diabetes can affect endothelial function and can continue to show their effects even after blood glucose levels are back to normal. Since endothelial dysfunction acts as one of the initiating factors for the development of CVD, understanding how AGEs affect the endothelial cell proteome to cause dysfunction will provide insight into the mechanisms involved and aid designing new therapeutic approaches. Copyright © 2018. Published by Elsevier B.V.

Gliovascular and cytokine interactions modulate brain endothelial barrier in vitro.

PubMed

Chaitanya, Ganta V; Cromer, Walter E; Wells, Shannon R; Jennings, Merilyn H; Couraud, P Olivier; Romero, Ignacio A; Weksler, Babette; Erdreich-Epstein, Anat; Mathis, J Michael; Minagar, Alireza; Alexander, J Steven

2011-11-23

The glio-vascular unit (G-unit) plays a prominent role in maintaining homeostasis of the blood-brain barrier (BBB) and disturbances in cells forming this unit may seriously dysregulate BBB. The direct and indirect effects of cytokines on cellular components of the BBB are not yet unclear. The present study compares the effects of cytokines and cytokine-treated astrocytes on brain endothelial barrier. 3-dimensional transwell co-cultures of brain endothelium and related-barrier forming cells with astrocytes were used to investigate gliovascular barrier responses to cytokines during pathological stresses. Gliovascular barrier was measured using trans-endothelial electrical resistance (TEER), a sensitive index of in vitro barrier integrity. We found that neither TNF-α, IL-1β or IFN-γ directly reduced barrier in human or mouse brain endothelial cells or ECV-304 barrier (independent of cell viability/metabolism), but found that astrocyte exposure to cytokines in co-culture significantly reduced endothelial (and ECV-304) barrier. These results indicate that the barrier established by human and mouse brain endothelial cells (and other cells) may respond positively to cytokines alone, but that during pathological conditions, cytokines dysregulate the barrier forming cells indirectly through astrocyte activation involving reorganization of junctions, matrix, focal adhesion or release of barrier modulating factors (e.g. oxidants, MMPs). © 2011 Chaitanya et al; licensee BioMed Central Ltd.

Critical role of TRPP2 and TRPC1 channels in stretch-induced injury of blood-brain barrier endothelial cells.

PubMed

Berrout, Jonathan; Jin, Min; O'Neil, Roger G

2012-02-03

The microvessels of the brain are very sensitive to mechanical stresses such as observed in traumatic brain injury (TBI). Such stresses can quickly lead to dysfunction of the microvessel endothelial cells, including disruption of blood-brain barrier (BBB). It is now evident that elevation of cytosolic calcium levels ([Ca2+]i) can compromise the BBB integrity, however the mechanism by which mechanical injury can produce a [Ca2+]i increase in brain endothelial cells is unclear. To assess the effects of mechanical/stretch injury on [Ca2+]i signaling, mouse brain microvessel endothelial cells (bEnd3) were grown to confluency on elasticized membranes and [Ca2+]i monitored using fura 2 fluorescence imaging. Application of an injury, using a pressure/stretch pulse of 50 ms, induced a rapid transient increase in [Ca2+]i. In the absence of extracellular Ca2+, the injury-induced [Ca2+]i transient was greatly reduced, but not fully eliminated, while unloading of Ca2+ stores by thapsigargin treatment in the absence of extracellular Ca2+ abolished the injury transient. Application of LOE-908 and amiloride, TRPC and TRPP2 channel blockers, respectively, both reduced the transient [Ca2+]i increase. Further, siRNA knockdown assays directed at TRPC1 and TRPP2 expression also resulted in a reduction of the injury-induced [Ca2+]i response. In addition, stretch injury induced increases of NO production and actin stress fiber formation, both of which were markedly reduced upon treatment with LOE908 and/or amiloride. We conclude that mechanical injury of brain endothelial cells induces a rapid influx of calcium, mediated by TRPC1 and TRPP2 channels, which leads to NO synthesis and actin cytoskeletal rearrangement. Copyright © 2011. Published by Elsevier B.V.

Balance of autonomic nervous system in children having signs of endothelial dysfunction, that were born and are domiciled in contaminated territories.

PubMed

Kondrashova, V G; Kolpakov, I E; Vdovenko, V Yu; Leonovych, O S; Lytvynets, O M; Stepanova, E I

2014-09-01

Objective. The study examined the features of functional state of the autonomic nervous system in children having endothelial dysfunction and permanently residing in contaminated areas. Materials and methods. Clinical and instrumental examination of 101 children aged 7-18 years that were born and are domiciled in contaminated territories, including 37 persons with signs of endothelial dysfunction (subgroup IA) and 64 ones with no signs of endothelial dysfunction (IB subgroup) was conducted. The control group being comparable to the subgroups IA and IB by age, gender and clinical examination results included 37 children neither been domiciled in contaminated areas nor were belonging to the contingent of Chornobyl accident survivors. There were 20 apparently healthy children also examined. Results. Due to peculiarities of physiological pathways providing adaptive responses the children having signs of endothelial dysfunction are characterized by a more pronounced dysregulation of autonomous nervous system both in a resting state and under a functional load simulation, and also by a high strain of adaptation pathways. The lack of autonomous support of cardiovascular system is caused by inadequate adaptive responses of both central regulatory bodies (hypothalamus, vasomotor center) and peripheral receptors. Mainly the failure of segmental autonomous (parasympathetic) structures was revealed. The mode of their response to stress in this case corresponds to that in healthy individuals but at a lower functional level. There is a reduced aerobic capacity of the organism by the Robinson index, contributing to low adaptive range to non-specific stress in children being domiciled on contaminated territories including children having the endothelial dysfunction. Conclusions. Endothelial dysfunction was associated with more pronounced manifestations of autonomic dysregulation and reduced aerobic capacity of the organism being the risk factors of development of a range of somatic diseases requiring the development of prevention measures in children permanently residing in contaminated areas. autonomous nervous system balance, endothelial dysfunction, children, Chornobyl accident. V. G. Kondrashova, I. E. Kolpakov, V. Yu. Vdovenko, O. S. Leonovych, O. M. Lytvynets, E. I. Stepanova.

Monoamine oxidases are mediators of endothelial dysfunction in the mouse aorta.

PubMed

Sturza, Adrian; Leisegang, Matthias S; Babelova, Andrea; Schröder, Katrin; Benkhoff, Sebastian; Loot, Annemarieke E; Fleming, Ingrid; Schulz, Rainer; Muntean, Danina M; Brandes, Ralf P

2013-07-01

Monoamine oxidases (MAOs) generate H(2)O(2) as a by-product of their catalytic cycle. Whether MAOs are mediators of endothelial dysfunction is unknown and was determined here in the angiotensin II and lipopolysaccharide-models of vascular dysfunction in mice. Quantitative real-time polymerase chain reaction revealed that mouse aortas contain enzymes involved in catecholamine generation and MAO-A and MAO-B mRNA. MAO-A and -B proteins could be detected by Western blot not only in mouse aortas but also in human umbilical vein endothelial cells. Ex vivo incubation of mouse aorta with recombinant MAO-A increased H(2)O(2) formation and induced endothelial dysfunction that was attenuated by polyethylene glycol-catalase and MAO inhibitors. In vivo lipopolysaccharide (8 mg/kg IP overnight) or angiotensin II (1 mg/kg per day, 2 weeks, minipump) treatment induced vascular MAO-A and -B expressions and resulted in attenuated endothelium-dependent relaxation of the aorta in response to acetylcholine. MAO inhibitors reduced the lipopolysaccharide- and angiotensin II-induced aortic reactive oxygen species formation by 50% (ferrous oxidation xylenol orange assay) and partially normalized endothelium-dependent relaxation. MAO-A and MAO-B inhibitors had an additive effect; combined application completely restored endothelium-dependent relaxation. To determine how MAO-dependent H(2)O(2) formation induces endothelial dysfunction, cyclic GMP was measured. Histamine stimulation of human umbilical vein endothelial cells to activate endothelial NO synthase resulted in an increase in cyclic GMP, which was almost abrogated by MAO-A exposure. MAO inhibition prevented this effect, suggesting that MAO-induced H(2)O(2) formation is sufficient to attenuate endothelial NO release. Thus, MAO-A and MAO-B are both expressed in the mouse aorta, induced by in vivo lipopolysaccharide and angiotensin II treatment and contribute via the generation of H(2)O(2) to endothelial dysfunction in vascular disease models.

Restoration of Autophagy in Endothelial Cells from Patients with Diabetes Mellitus Improves Nitric Oxide Signaling

PubMed Central

Fetterman, Jessica L.; Holbrook, Monica; Flint, Nir; Feng, Bihua; Bretón-Romero, Rosa; Linder, Erika A.; Berk, Brittany D.; Duess, Mai-Ann; Farb, Melissa G.; Gokce, Noyan; Shirihai, Orian S.; Hamburg, Naomi M.; Vita, Joseph A.

2016-01-01

Background Endothelial dysfunction contributes to cardiovascular disease in diabetes mellitus. Autophagy is a multistep mechanism for removal of damaged proteins and organelles from the cell. Under diabetic conditions, inadequate autophagy promotes cellular dysfunction and insulin resistance in non-vascular tissue. We hypothesized that impaired autophagy contributes to endothelial dysfunction in diabetes mellitus. Methods and Results We measured autophagy markers and endothelial nitric oxide synthase (eNOS) activation in freshly isolated endothelial cells from diabetic subjects (n=45) and non-diabetic controls (n=41). p62 levels were higher in cells from diabetics (34.2±3.6 vs. 20.0±1.6, P=0.001), indicating reduced autophagic flux. Bafilomycin inhibited insulin-induced activation of eNOS (−21±5% vs. 64±22%, P=0.003) in cells from controls, confirming that intact autophagy is necessary for eNOS signaling. In endothelial cells from diabetics, activation of autophagy with spermidine restored eNOS activation, suggesting that impaired autophagy contributes to endothelial dysfunction (P=0.01). Indicators of autophagy initiation including the number of LC3-bound puncta and beclin 1 expression were similar in diabetics and controls, whereas an autophagy terminal phase indicator, the lysosomal protein Lamp2a, was higher in diabetics. In endothelial cells under diabetic conditions, the beneficial effect of spermidine on eNOS activation was blocked by autophagy inhibitors bafilomycin or 3-methyladenine. Blocking the terminal stage of autophagy with bafilomycin increased p62 (P=0.01) in cells from diabetics to a lesser extent than in cells from controls (P=0.04), suggesting ongoing, but inadequate autophagic clearance. Conclusion Inadequate autophagy contributes to endothelial dysfunction in patients with diabetes and may be a target for therapy of diabetic vascular disease. PMID:26926601

Restoration of autophagy in endothelial cells from patients with diabetes mellitus improves nitric oxide signaling.

PubMed

Fetterman, Jessica L; Holbrook, Monica; Flint, Nir; Feng, Bihua; Bretón-Romero, Rosa; Linder, Erika A; Berk, Brittany D; Duess, Mai-Ann; Farb, Melissa G; Gokce, Noyan; Shirihai, Orian S; Hamburg, Naomi M; Vita, Joseph A

2016-04-01

Endothelial dysfunction contributes to cardiovascular disease in diabetes mellitus. Autophagy is a multistep mechanism for the removal of damaged proteins and organelles from the cell. Under diabetic conditions, inadequate autophagy promotes cellular dysfunction and insulin resistance in non-vascular tissue. We hypothesized that impaired autophagy contributes to endothelial dysfunction in diabetes mellitus. We measured autophagy markers and endothelial nitric oxide synthase (eNOS) activation in freshly isolated endothelial cells from diabetic subjects (n = 45) and non-diabetic controls (n = 41). p62 levels were higher in cells from diabetics (34.2 ± 3.6 vs. 20.0 ± 1.6, P = 0.001), indicating reduced autophagic flux. Bafilomycin inhibited insulin-induced activation of eNOS (64.7 ± 22% to -47.8 ± 8%, P = 0.04) in cells from controls, confirming that intact autophagy is necessary for eNOS signaling. In endothelial cells from diabetics, activation of autophagy with spermidine restored eNOS activation, suggesting that impaired autophagy contributes to endothelial dysfunction (P = 0.01). Indicators of autophagy initiation including the number of LC3-bound puncta and beclin 1 expression were similar in diabetics and controls, whereas an autophagy terminal phase indicator, the lysosomal protein Lamp2a, was higher in diabetics. In endothelial cells under diabetic conditions, the beneficial effect of spermidine on eNOS activation was blocked by autophagy inhibitors bafilomycin or 3-methyladenine. Blocking the terminal stage of autophagy with bafilomycin increased p62 (P = 0.01) in cells from diabetics to a lesser extent than in cells from controls (P = 0.04), suggesting ongoing, but inadequate autophagic clearance. Inadequate autophagy contributes to endothelial dysfunction in patients with diabetes and may be a target for therapy of diabetic vascular disease. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Metabolic Profiling in Association with Vascular Endothelial Cell Dysfunction Following Non-Toxic Cadmium Exposure

PubMed Central

Li, Xiaofei; Nong, Qingjiao; Mao, Baoyu; Pan, Xue

2017-01-01

This study aimed to determine the metabolic profile of non-toxic cadmium (Cd)-induced dysfunctional endothelial cells using human umbilical vein endothelial cells (HUVECs). HUVECs (n = 6 per group) were treated with 0, 1, 5, or 10 μM cadmium chloride (CdCl2) for 48 h. Cell phenotypes, including nitric oxide (NO) production, the inflammatory response, and oxidative stress, were evaluated in Cd-exposed and control HUVECs. Cd-exposed and control HUVECs were analysed using gas chromatography time-of-flight/mass spectrometry. Compared to control HUVECs, Cd-exposed HUVECs were dysfunctional, exhibiting decreased NO production, a proinflammatory state, and non-significant oxidative stress. Further metabolic profiling revealed 24 significantly-altered metabolites in the dysfunctional endothelial cells. The significantly-altered metabolites were involved in the impaired tricarboxylic acid (TCA) cycle, activated pyruvate metabolism, up-regulated glucogenic amino acid metabolism, and increased pyrimidine metabolism. The current metabolic findings further suggest that the metabolic changes linked to TCA cycle dysfunction, glycosylation of the hexosamine biosynthesis pathway (HBP), and compensatory responses to genomic instability and energy deficiency may be generally associated with dysfunctional phenotypes, characterized by decreased NO production, a proinflammatory state, and non-significant oxidative stress, in endothelial cells following non-toxic Cd exposure. PMID:28872622

Endothelial Dysfunction in Human Diabetes is mediated by Wnt5a-JNK Signaling

PubMed Central

Bretón-Romero, Rosa; Feng, Bihua; Holbrook, Monika; Farb, Melissa G.; Fetterman, Jessica L.; Linder, Erika A.; Berk, Brittany D.; Masaki, Nobuyuki; Weisbrod, Robert M.; Inagaki, Elica; Gokce, Noyan; Fuster, Jose J.; Walsh, Kenneth; Hamburg, Naomi M.

2016-01-01

Objectives Endothelial dysfunction is linked to insulin resistance, inflammatory activation and increased cardiovascular risk in diabetes mellitus; however the mechanisms remain incompletely understood. Recent studies have identified pro-inflammatory signaling of Wnt5a through JNK as a regulator of metabolic dysfunction with potential relevance to vascular function. We sought to gain evidence that increased activation of Wnt5a-JNK signaling contributes to impaired endothelial function in patients with diabetes mellitus. Approach We measured flow-mediated dilation of the brachial artery and characterized freshly isolated endothelial cells by protein expression, eNOS activation, and nitric oxide production in from 85 subjects with Type 2 diabetes mellitus (n=42) and age- and sex-matched non-diabetic controls (n=43) and in human aortic endothelial cells treated with Wnt5a. Results Endothelial cells from patients with diabetes displayed 1.3-fold higher Wnt5a levels (P=0.01) along with 1.4-fold higher JNK activation (P<0.01) without a difference in total JNK levels. Higher JNK activation was associated with lower flow-mediated dilation, consistent with endothelial dysfunction (r=0.53, P=0.02). Inhibition of Wnt5a and JNK signaling restored insulin and A23187-mediated eNOS activation and improved nitric oxide production in endothelial cells from patients with diabetes. In endothelial cells from non-diabetic controls, rWnt5a treatment inhibited eNOS activation replicating the diabetic endothelial phenotype. In HAECs, Wnt5a-induced impairment of eNOS activation and nitric oxide production was reversed by Wnt5a and JNK inhibition. Conclusions Our findings demonstrate that non-canonical Wnt5a signaling and JNK activity contributes to vascular insulin resistance and endothelial dysfunction and may represent a novel therapeutic opportunity to protect the vasculature in patients with diabetes. PMID:26800561

Lung heparan sulfates modulate Kfc during increased vascular pressure: evidence for glycocalyx-mediated mechanotransduction

PubMed Central

Cluff, Mark; Kingston, Joseph; Hill, Denzil; Chen, Haiyan; Hoehne, Soeren; Malleske, Daniel T.; Kaur, Rajwinederjit

2012-01-01

Lung endothelial cells respond to changes in vascular pressure through mechanotransduction pathways that alter barrier function via non-Starling mechanism(s). Components of the endothelial glycocalyx have been shown to participate in mechanotransduction in vitro and in systemic vessels, but the glycocalyx's role in mechanosensing and pulmonary barrier function has not been characterized. Mechanotransduction pathways may represent novel targets for therapeutic intervention during states of elevated pulmonary pressure such as acute heart failure, fluid overload, and mechanical ventilation. Our objective was to assess the effects of increasing vascular pressure on whole lung filtration coefficient (Kfc) and characterize the role of endothelial heparan sulfates in mediating mechanotransduction and associated increases in Kfc. Isolated perfused rat lung preparation was used to measure Kfc in response to changes in vascular pressure in combination with superimposed changes in airway pressure. The roles of heparan sulfates, nitric oxide, and reactive oxygen species were investigated. Increases in capillary pressure altered Kfc in a nonlinear relationship, suggesting non-Starling mechanism(s). nitro-l-arginine methyl ester and heparanase III attenuated the effects of increased capillary pressure on Kfc, demonstrating active mechanotransduction leading to barrier dysfunction. The nitric oxide (NO) donor S-nitrosoglutathione exacerbated pressure-mediated increase in Kfc. Ventilation strategies altered lung NO concentration and the Kfc response to increases in vascular pressure. This is the first study to demonstrate a role for the glycocalyx in whole lung mechanotransduction and has important implications in understanding the regulation of vascular permeability in the context of vascular pressure, fluid status, and ventilation strategies. PMID:22160307

Mechanisms of Endothelial Dysfunction in Hypertensive Pregnancy and Preeclampsia

PubMed Central

Possomato-Vieira, José S.; Khalil, Raouf A.

2016-01-01

Preeclampsia is a pregnancy-related disorder characterized by hypertension, and could lead to maternal and fetal morbidity and mortality. Although the causative factors and pathophysiological mechanisms are unclear, endothelial dysfunction is a major hallmark of preeclampsia. Clinical tests and experimental research have suggested that generalized endotheliosis in the systemic, renal, cerebral and hepatic circulation could decrease endothelium-derived vasodilators such as nitric oxide, prostacyclin and hyperpolarization factor and increase vasoconstrictors such as endothelin-1 and thromboxane A2, leading to increased vasoconstriction, hypertension and other manifestation of preeclampsia. In search for the upstream mechanisms that could cause endothelial dysfunction, certain genetic, demographic and environmental risk factors have been suggested to cause abnormal expression of uteroplacental integrins, cytokines and matrix metalloproteinases, leading to decreased maternal tolerance, apoptosis of invasive trophoblast cells, inadequate spiral arteries remodeling, reduced uterine perfusion pressure (RUPP), and placental ischemia/hypoxia. RUPP may cause imbalance between the anti-angiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the pro-angiogenic factors vascular endothelial growth factor and placental growth factor, or stimulate the release of other circulating bioactive factors such as inflammatory cytokines, hypoxia-inducible factor-1, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors could then target endothelial cells and cause generalized endothelial dysfunction. Therapeutic options are currently limited, but understanding the factors involved in endothelial dysfunction could help design new approaches for prediction and management of preeclampsia. PMID:27451103

Long noncoding RNA-MEG3 is involved in diabetes mellitus-related microvascular dysfunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiu, Gui-Zhen; Tian, Wei; Fu, Hai-Tao

Microvascular dysfunction is an important characteristic of diabetic retinopathy. Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes. In this study, we investigated the role of lncRNA-MEG3 in diabetes-related microvascular dysfunction. We show that MEG3 expression level is significantly down-regulated in the retinas of STZ-induced diabetic mice, and endothelial cells upon high glucose and oxidative stress. MEG3 knockdown aggravates retinal vessel dysfunction in vivo, as shown by serious capillary degeneration, and increased microvascular leakage and inflammation. MEG3 knockdown also regulates retinal endothelial cell proliferation, migration, and tube formation in vitro. The role of MEG3 in endothelial cell function is mainlymore » mediated by the activation of PI3k/Akt signaling. MEG3 up-regulation may serve as a therapeutic strategy for treating diabetes-related microvascular complications. - Highlights: • LncRNA-MEG3 level is down-regulated upon diabetic stress. • MEG3 knockdown aggravates retinal vascular dysfunction in vivo. • MEG3 regulates retinal endothelial cell function in vitro. • MEG3 regulates endothelial cell function through PI3k/Akt signaling.« less

[Prevention and preventive therapy of age-related macular degeneration through the beneficial effect of treatment of endothelial dysfunction].

PubMed

Fischer, Tamás

2006-12-24

The beneficial effect achieved by the treatment of endothelial dysfunction in chronic cardiovascular diseases is already an evidence belonging to the basic treatment of the disease. Given the fact that the vascular system is uniform and consubstantial both physiologically, pathophysiologically and in terms of therapy, and that it plays a key role in age-related macular degeneration (AMD) - a disease leading to tragic loss of vision with its etiology and therapy being unknown -, endothelial dysfunction should be treated. The pleiotropic effects of ACE-inhibitors, AR-blockers and statins help to restitute the balance between vasodilators and vasoconstrictors in endothelial dysfunction caused by oxidative stress, the balance of growth factors and their inhibitors, pro- and anti-inflammatory substances and prothrombotic and fibrinolytic factors, inhibit the formation of oxidative stress and its harmful effects; while aspirin with its pleiotropic effects acting as an antiaggregation substance on platelets helps to set the endothelial layer back to its normal balance regarding its vasodilating, antithrombotic, anti-adhesive and anti-inflammatory functions. For the above reasons it is suggested that, as a part of long term primary and/or secondary prevention, the following groups of patients with AMD receive - taking into consideration all possible side effects - ACE-inhibitor and/or AR-blocker and statin and aspirin treatment: 1) those without maculopathy but being over the age of 50 and having risk factors inducing endothelial dysfunction; 2) those, who already developed AMD in one eye as a prevention in the second, unaffected eye; and 3) those patients who developed AMD in both eyes in order to ameliorate or merely slow the progression of the disease. Besides, it is advisory to inhibit AMD risk factors inducing oxidative stress with consecutive endothelial dysfunction.

Ticagrelor protects against AngII-induced endothelial dysfunction by alleviating endoplasmic reticulum stress.

PubMed

Wang, Xiaoyu; Han, Xuejie; Li, Minghui; Han, Yu; Zhang, Yun; Zhao, Shiqi; Li, Yue

2018-05-16

Ticagrelor has been reported to decrease cardiovascular mortality compared with clopidogrel. This benefit cannot be fully explained by the more efficient platelet inhibition. Many studies demonstrated that ticagrelor improved endothelial function, leaving the mechanism elusive though. The present study aims to investigate whether ticagrelor protects against endothelial dysfunction induced by angiotensinII (AngII) through alleviating endoplasmic reticulum (ER) stress. Male Sprague Dawley rats were infused with AngII or vehicle and administrated with ticagrelor or vehicle for 14 days. Reactive oxygen species (ROS) was detected. Aortas from normal mice were incubated with endoplasmic reticulum stress inducer tunicamycin with or without ticagrelor. Vasorecactivity was measured on wire myography. Rat aortic endothelial cells (RAECs) were pretreated with ticagrelor followed by AngII or tunicamycin. Endothelial nitric oxide synthase (eNOS) phosphorylation and ER stress markers were determined by western blotting. Impaired endothelial function, induction of ER stress, reduced eNOS phosphorylation and elevated ROS generation was restored by ticagrelor treatment in vivo. In addition, tunicamycin induced endothelial dysfunction was improved by ticagrelor. In vitro, the induction of ER stress and inhibited eNOS phosphorylation in REACs exposed to AngII as well as tunicamycin was reversed by co-culturing with ticagrelor. In conclusion, ticagrelor protects against AngII-induced endothelial dysfunction via alleviating ER stress. Copyright © 2017. Published by Elsevier Inc.

Targeting vascular (endothelial) dysfunction

PubMed Central

Steven, Sebastian; Weber, Alina; Shuvaev, Vladimir V.; Muzykantov, Vladimir R.; Laher, Ismail; Li, Huige; Lamas, Santiago

2016-01-01

Abstract Cardiovascular diseases are major contributors to global deaths and disability‐adjusted life years, with hypertension a significant risk factor for all causes of death. The endothelium that lines the inner wall of the vasculature regulates essential haemostatic functions, such as vascular tone, circulation of blood cells, inflammation and platelet activity. Endothelial dysfunction is an early predictor of atherosclerosis and future cardiovascular events. We review the prognostic value of obtaining measurements of endothelial function, the clinical techniques for its determination, the mechanisms leading to endothelial dysfunction and the therapeutic treatment of endothelial dysfunction. Since vascular oxidative stress and inflammation are major determinants of endothelial function, we have also addressed current antioxidant and anti‐inflammatory therapies. In the light of recent data that dispute the prognostic value of endothelial function in healthy human cohorts, we also discuss alternative diagnostic parameters such as vascular stiffness index and intima/media thickness ratio. We also suggest that assessing vascular function, including that of smooth muscle and even perivascular adipose tissue, may be an appropriate parameter for clinical investigations. Linked Articles This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc PMID:27187006

Traction force dynamics predict gap formation in activated endothelium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valent, Erik T.; Nieuw Amerongen, Geerten P. van; Hinsbergh, Victor W.M. van

In many pathological conditions the endothelium becomes activated and dysfunctional, resulting in hyperpermeability and plasma leakage. No specific therapies are available yet to control endothelial barrier function, which is regulated by inter-endothelial junctions and the generation of acto-myosin-based contractile forces in the context of cell-cell and cell-matrix interactions. However, the spatiotemporal distribution and stimulus-induced reorganization of these integral forces remain largely unknown. Traction force microscopy of human endothelial monolayers was used to visualize contractile forces in resting cells and during thrombin-induced hyperpermeability. Simultaneously, information about endothelial monolayer integrity, adherens junctions and cytoskeletal proteins (F-actin) were captured. This revealed a heterogeneousmore » distribution of traction forces, with nuclear areas showing lower and cell-cell junctions higher traction forces than the whole-monolayer average. Moreover, junctional forces were asymmetrically distributed among neighboring cells. Force vector orientation analysis showed a good correlation with the alignment of F-actin and revealed contractile forces in newly formed filopodia and lamellipodia-like protrusions within the monolayer. Finally, unstable areas, showing high force fluctuations within the monolayer were prone to form inter-endothelial gaps upon stimulation with thrombin. To conclude, contractile traction forces are heterogeneously distributed within endothelial monolayers and force instability, rather than force magnitude, predicts the stimulus-induced formation of intercellular gaps. - Highlights: • Endothelial monolayers exert dynamic- and heterogeneous traction forces. • High traction forces correlate with junctional areas and the F-actin cytoskeleton. • Newly formed inter-endothelial gaps are characterized by opposing traction forces. • Force stability is a key feature controlling endothelial permeability.« less

Fluorescein isothiocyanate (FITC)-Dextran Extravasation as a Measure of Blood-Brain Barrier Permeability

PubMed Central

Natarajan, Reka; Northrop, Nicole

2017-01-01

The blood-brain barrier (BBB) is formed in part by vascular endothelial cells that constitute the capillaries and microvessels of the brain. The function of this barrier is to maintain homeostasis within the brain microenvironment and buffer the brain from changes in the periphery. A dysfunction of the BBB would permit circulating molecules and pathogens typically restricted to the periphery to enter the brain and interfere with normal brain function. As increased permeability of the BBB is associated with several neuropathologies, it is important to have a reliable and sensitive method that determines BBB permeability and the degree of BBB disruption. A detailed protocol is presented for assessing the integrity of the BBB by transcardial perfusion of a 10,000 Da FITC labeled dextran molecule and its visualization to determine the degree of extravasation from brain microvessels. PMID:28398646

Inhibition of Endothelial Progenitor Cells May Explain the High Cardiovascular Event Rate in Patients with Rheumatoid Arthritis.

PubMed

Adawi, Mohamad; Pastuck, Nina; Saaida, Golan; Sirchan, Rizak; Watad, Abdalla; Blum, Arnon

2018-05-16

Rheumatoid arthritis (RA) patients may suffer cardiovascular (CV) events much more than the general population, and CV disease is the leading cause of death in patients with RA. Our hypothesis was that impaired function of endothelial progenitor cells may contribute to endothelial dysfunction and the clinical CV events of patients with RA. 27 RA patients (9 males and 18 females) with an active disease and 13 healthy subjects who served as the control group (9 males and 4 females) were enrolled to this prospective study. The ability to grow in culture colony-forming units of endothelial progenitor cells (CFU-EPCs) was measured, as well as their endothelial function using high-resolution ultrasonography of the brachial artery, and levels of C reactive protein (CRP) in the serum. For statistical analysis we used the students T-test test. As a group, patients with RA were older (p < 0.0001), had severe endothelial dysfunction (<0.0001), with impaired ability to grow CFU-EPCs (<0.0001), and a higher inflammatory state (p = 0001). No difference was observed in BMI. All RA patients had an active disease (DAS28 3.9±0.9) for 9.2±6.5 years. The same differences were observed in both genders. Patients with RA had an impaired ability to grow endothelial progenitor cells and severe endothelial dysfunction. Inability to grow colonies of endothelial progenitor cells reflects the impaired regenerative capacity of patients with RA, and may explain the endothelial dysfunction and the high CV event rate among patients with RA.

Ascorbic Acid Repletion: A Possible Therapy for Diabetic Macular Edema?

PubMed Central

May, James M.

2016-01-01

Macular edema poses a significant risk for visual loss in persons with diabetic retinopathy. It occurs when plasma constituents and fluid leak out of damaged retinal microvasculature in the area of the macula, causing loss of central vision. Apoptotic loss of pericytes surrounding capillaries is perhaps the earliest feature of diabetic vascular damage in the macula, which is also associated with dysfunction of the endothelium and loss of the otherwise very tight endothelial permeability barrier. Increased oxidative stress is a key feature of damage to both cell types, mediated by excess superoxide from glucose-induced increases in mitochondrial metabolism, as well as by activation of the receptor for advanced glycation end products (RAGE). The latter in turn activates multiple pathways, some of which lead to increased oxidative stress, such as those involving NF-κB, NADPH oxidase, and endothelial nitric oxide synthase. Such cellular oxidative stress is associated with low cellular and plasma ascorbic acid levels in many subjects with diabetes in poor glycemic control. Whether repletion of low ascorbate in retinal endothelium and pericytes might help to prevent diabetic macular edema is unknown. However, cell culture studies show that the vitamin prevents high-glucose and RAGE-induced apoptosis in both cell types, that it preserves nitric oxide generated by endothelial cells, and that it tightens the leaky endothelial permeability barrier. Although these findings need to be confirmed in pre-clinical animal studies, it is worth considering clinical trials to determine whether adequate ascorbate repletion is possible and whether it might help to delay or even reverse early diabetic macular edema. PMID:26898503

Measurement of endothelial dysfunction via peripheral arterial tonometry predicts vasculogenic erectile dysfunction

PubMed Central

Kovac, Jason R.; Gomez, Lissette; Smith, Ryan P.; Coward, Robert M.; Gonzales, Marshall A.; Khera, Mohit; Lamb, Dolores J.; Lipshultz, Larry I.

2014-01-01

Introduction Endothelial cell dysfunction is associated with cardiovascular disease and vasculogenic erectile dysfunction (ED). Measured via Peripheral Artery Tonometry (PAT), endothelial dysfunction in the penis is an independent predictor of future cardiovascular events. Aim Determine whether measurement of endothelial dysfunction differentiates men with vasculogenic ED identified by duplex ultrasound from those without. Methods A total of 142 men were retrospectively assessed using patient history, penile duplex ultrasonography (US) and PAT (EndoPAT 2000). ED was self reported and identified on history. Vasculogenic ED was identified in men who exhibited a peak systolic velocity (PSV) of ≤25 cm/s obtained 15 minutes following vasodilator injection. The reactive hyperemia index (RHI), a measurement of endothelial dysfunction in medium/small arteries and the Augmentation Index (AI), a measurement of arterial stiffness, were recorded via PAT. Results Penile duplex US separated men into those with ED (n=111) and without (n=31). The cohort with ED had a PSV of 21±1 cm/s (left cavernous artery) and 22±1 cm/s (Right). The control group without ED had values of 39±2 cm/s (Left) and 39±2 (Right). Given the potential for altered endothelial function in diabetes mellitus, we confirmed that hemoglobin A1c, urinary microalbumin, and vibration pulse threshold were not different in men with vasculogenic ED and those without. RHI in patients with ED (1.85±0.06) was significantly decreased compared to controls (2.15±0.2) (p<0.05). The AI was unchanged when examined in isolation, and when standardized to heart rate. Conclusions Measurement of endothelial function with EndoPAT differentiates men with vasculogenic ED from those without. RHI could be used as a non-invasive surrogate in the assessment of vasculogenic ED and to identify those patients with higher cardiovascular risk. PMID:24784889

Endothelial dysfunction in metabolic diseases: role of oxidation and possible therapeutic employment of N-acetylcysteine.

PubMed

Masha, A; Martina, V

2014-01-01

Several metabolic diseases present a high cardiovascular mortality due to endothelial dysfunction consequences. In the last years of the past century, it has come to light that the endothelial cells, previously considered as inert in what regards an eventual secretion activity, play a pivotal role in regulating different aspects of the vascular function (endothelial function). It was clearly demonstrated that the endothelium acts as a real active organ, owning endocrine, paracrine and autocrine modulation activities by means of which it is able to regulate the vascular homeostasis. The present review will investigate the relationship between some metabolic diseases and the endothelial dysfunction and in particular the mechanisms underlying the effects of metabolic pathologies on the endothelium. Furthermore, it will consider the possible therapeutic employment of the N-acetilcysteine in such conditions.

Peripheral vascular dysfunction in migraine: a review

PubMed Central

2013-01-01

Numerous studies have indicated an increased risk of vascular disease among migraineurs. Alterations in endothelial and arterial function, which predispose to atherosclerosis and cardiovascular diseases, have been suggested as an important link between migraine and vascular disease. However, the available evidence is inconsistent. We aimed to review and summarize the published evidence about the peripheral vascular dysfunction of migraineurs. We systematically searched in BIOSIS, the Cochrane database, Embase, Google scholar, ISI Web of Science, and Medline to identify articles, published up to April 2013, evaluating the endothelial and arterial function of migraineurs. Several lines of evidence for vascular dysfunction were reported in migraineurs. Findings regarding endothelial function are particularly controversial since studies variously indicated the presence of endothelial dysfunction in migraineurs, the absence of any difference in endothelial function between migraineurs and non-migraineurs, and even an enhanced endothelial function in migraineurs. Reports on arterial function are more consistent and suggest that functional properties of large arteries are altered in migraineurs. Peripheral vascular function, particularly arterial function, is a promising non-invasive indicator of the vascular health of subjects with migraine. However, further targeted research is needed to understand whether altered arterial function explains the increased risk of vascular disease among patients with migraine. PMID:24083826

Mitochondrial Oxidative Stress, Mitochondrial DNA Damage and Their Role in Age-Related Vascular Dysfunction

PubMed Central

Mikhed, Yuliya; Daiber, Andreas; Steven, Sebastian

2015-01-01

The prevalence of cardiovascular diseases is significantly increased in the older population. Risk factors and predictors of future cardiovascular events such as hypertension, atherosclerosis, or diabetes are observed with higher frequency in elderly individuals. A major determinant of vascular aging is endothelial dysfunction, characterized by impaired endothelium-dependent signaling processes. Increased production of reactive oxygen species (ROS) leads to oxidative stress, loss of nitric oxide (•NO) signaling, loss of endothelial barrier function and infiltration of leukocytes to the vascular wall, explaining the low-grade inflammation characteristic for the aged vasculature. We here discuss the importance of different sources of ROS for vascular aging and their contribution to the increased cardiovascular risk in the elderly population with special emphasis on mitochondrial ROS formation and oxidative damage of mitochondrial DNA. Also the interaction (crosstalk) of mitochondria with nicotinamide adenosine dinucleotide phosphate (NADPH) oxidases is highlighted. Current concepts of vascular aging, consequences for the development of cardiovascular events and the particular role of ROS are evaluated on the basis of cell culture experiments, animal studies and clinical trials. Present data point to a more important role of oxidative stress for the maximal healthspan (healthy aging) than for the maximal lifespan. PMID:26184181

Assessment of endothelial dysfunction: the role of symmetrical dimethylarginine and proinflammatory markers in chronic kidney disease and renal transplant recipients.

PubMed

Memon, Lidija; Spasojevic-Kalimanovska, Vesna; Bogavac-Stanojevic, Natasa; Kotur-Stevuljevic, Jelena; Simic-Ogrizovic, Sanja; Giga, Vojislav; Dopsaj, Violeta; Jelic-Ivanovic, Zorana; Spasic, Slavica

2013-01-01

The study was designed to evaluate associations between symmetric dimethylarginine (SDMA), inflammation, and superoxide anion (O2∙-) with endothelial function and to determine their potential for screening of endothelial dysfunction in patients with chronic kidney disease (CKD) and renal transplant (RT) recipients. We included 64 CKD and 52 RT patients. Patients were stratified according to brachial artery flow-mediated dilation (FMD). Logistic regression analysis showed that high SDMA and high sensitive C-reactive protein (hs-CRP) were associated with impaired FMD in CKD and RT patients, after adjustment for glomerular filtration rate. The ability of inflammation, SDMA, and O2∙- to detect impaired FMD was investigated by receiving operative characteristic analysis. Hs-CRP (area under the curves (AUC) = 0.754, P < 0.001), IL-6 (AUC = 0.699, P = 0.002), and SDMA (AUC = 0.689, P = 0.007) had the highest ability to detect impaired FMD. SDMA in combination with inflammatory parameters and/or O2∙- had better screening performance than SDMA alone. Our results indicate a strong predictable association between hs-CRP, SDMA, and endothelial dysfunction in CKD patients and RT recipients. The individual marker that showed the strongest discriminative ability for endothelial dysfunction is hs-CRP, but its usefulness as a discriminatory marker for efficient diagnosis of endothelial dysfunction should be examined in prospective studies.

Inhibition of Vascular c-Jun N-Terminal Kinase 2 Improves Obesity-Induced Endothelial Dysfunction After Roux-en-Y Gastric Bypass.

PubMed

Doytcheva, Petia; Bächler, Thomas; Tarasco, Erika; Marzolla, Vincenzo; Engeli, Michael; Pellegrini, Giovanni; Stivala, Simona; Rohrer, Lucia; Tona, Francesco; Camici, Giovanni G; Vanhoutte, Paul M; Matter, Christian M; Lutz, Thomas A; Lüscher, Thomas F; Osto, Elena

2017-11-14

Roux-en-Y gastric bypass (RYGB) reduces obesity-associated comorbidities and cardiovascular mortality. RYGB improves endothelial dysfunction, reducing c-Jun N-terminal kinase (JNK) vascular phosphorylation. JNK activation links obesity with insulin resistance and endothelial dysfunction. Herein, we examined whether JNK1 or JNK2 mediates obesity-induced endothelial dysfunction and if pharmacological JNK inhibition can mimic RYGB vascular benefits. After 7 weeks of a high-fat high-cholesterol diet, obese rats underwent RYGB or sham surgery; sham-operated ad libitum-fed rats received, for 8 days, either the control peptide D-TAT or the JNK peptide inhibitor D-JNKi-1 (20 mg/kg per day subcutaneous). JNK peptide inhibitor D-JNKi-1 treatment improved endothelial vasorelaxation in response to insulin and glucagon-like peptide-1, as observed after RYGB. Obesity increased aortic phosphorylation of JNK2, but not of JNK1. RYGB and JNK peptide inhibitor D-JNKi-1 treatment blunted aortic JNK2 phosphorylation via activation of glucagon-like peptide-1-mediated signaling. The inhibitory phosphorylation of insulin receptor substrate-1 was reduced, whereas the protein kinase B/endothelial NO synthase pathway was increased and oxidative stress was decreased, resulting in improved vascular NO bioavailability. Decreased aortic JNK2 phosphorylation after RYGB rapidly improves obesity-induced endothelial dysfunction. Pharmacological JNK inhibition mimics the endothelial protective effects of RYGB. These findings highlight the therapeutic potential of novel strategies targeting vascular JNK2 against the severe cardiovascular disease associated with obesity. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Mitochondria-targeted antioxidant (MitoQ) ameliorates age-related arterial endothelial dysfunction in mice.

PubMed

Gioscia-Ryan, Rachel A; LaRocca, Thomas J; Sindler, Amy L; Zigler, Melanie C; Murphy, Michael P; Seals, Douglas R

2014-06-15

Age-related arterial endothelial dysfunction, a key antecedent of the development of cardiovascular disease (CVD), is largely caused by a reduction in nitric oxide (NO) bioavailability as a consequence of oxidative stress. Mitochondria are a major source and target of vascular oxidative stress when dysregulated. Mitochondrial dysregulation is associated with primary ageing, but its role in age-related endothelial dysfunction is unknown. Our aim was to determine the efficacy of a mitochondria-targeted antioxidant, MitoQ, in ameliorating vascular endothelial dysfunction in old mice. Ex vivo carotid artery endothelium-dependent dilation (EDD) to increasing doses of acetylcholine was impaired by ∼30% in old (∼27 months) compared with young (∼8 months) mice as a result of reduced NO bioavailability (P < 0.05). Acute (ex vivo) and chronic (4 weeks in drinking water) administration of MitoQ completely restored EDD in older mice by improving NO bioavailability. There were no effects of age or MitoQ on endothelium-independent dilation to sodium nitroprusside. The improvements in endothelial function with MitoQ supplementation were associated with the normalization of age-related increases in total and mitochondria-derived arterial superoxide production and oxidative stress (nitrotyrosine abundance), as well as with increases in markers of vascular mitochondrial health, including antioxidant status. MitoQ also reversed the age-related increase in endothelial susceptibility to acute mitochondrial damage (rotenone-induced impairment in EDD). Our results suggest that mitochondria-derived oxidative stress is an important mechanism underlying the development of endothelial dysfunction in primary ageing. Mitochondria-targeted antioxidants such as MitoQ represent a promising novel strategy for the preservation of vascular endothelial function with advancing age and the prevention of age-related CVD. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Mitochondria-targeted antioxidant (MitoQ) ameliorates age-related arterial endothelial dysfunction in mice

PubMed Central

Gioscia-Ryan, Rachel A; LaRocca, Thomas J; Sindler, Amy L; Zigler, Melanie C; Murphy, Michael P; Seals, Douglas R

2014-01-01

Age-related arterial endothelial dysfunction, a key antecedent of the development of cardiovascular disease (CVD), is largely caused by a reduction in nitric oxide (NO) bioavailability as a consequence of oxidative stress. Mitochondria are a major source and target of vascular oxidative stress when dysregulated. Mitochondrial dysregulation is associated with primary ageing, but its role in age-related endothelial dysfunction is unknown. Our aim was to determine the efficacy of a mitochondria-targeted antioxidant, MitoQ, in ameliorating vascular endothelial dysfunction in old mice. Ex vivo carotid artery endothelium-dependent dilation (EDD) to increasing doses of acetylcholine was impaired by ∼30% in old (∼27 months) compared with young (∼8 months) mice as a result of reduced NO bioavailability (P < 0.05). Acute (ex vivo) and chronic (4 weeks in drinking water) administration of MitoQ completely restored EDD in older mice by improving NO bioavailability. There were no effects of age or MitoQ on endothelium-independent dilation to sodium nitroprusside. The improvements in endothelial function with MitoQ supplementation were associated with the normalization of age-related increases in total and mitochondria-derived arterial superoxide production and oxidative stress (nitrotyrosine abundance), as well as with increases in markers of vascular mitochondrial health, including antioxidant status. MitoQ also reversed the age-related increase in endothelial susceptibility to acute mitochondrial damage (rotenone-induced impairment in EDD). Our results suggest that mitochondria-derived oxidative stress is an important mechanism underlying the development of endothelial dysfunction in primary ageing. Mitochondria-targeted antioxidants such as MitoQ represent a promising novel strategy for the preservation of vascular endothelial function with advancing age and the prevention of age-related CVD. PMID:24665093

Hyperuricemia induces endothelial dysfunction via mitochondrial Na+/Ca2+ exchanger-mediated mitochondrial calcium overload.

PubMed

Hong, Quan; Qi, Ka; Feng, Zhe; Huang, Zhiyong; Cui, Shaoyuan; Wang, Liyuan; Fu, Bo; Ding, Rui; Yang, Jurong; Chen, Xiangmei; Wu, Di

2012-05-01

Uric acid (UA) has proven to be a causal agent in endothelial dysfunction in which ROS production plays an important role. Calcium overload in mitochondria can promote the mitochondrial production of ROS. We hypothesize that calcium transduction in mitochondria contributes to UA-induced endothelial dysfunction. We first demonstrated that high concentrations of UA cause endothelial dysfunction, marked by a reduction in eNOS protein expression and NO release in vitro. We further found that a high concentration of UA increased levels of [Ca2+]mito, total intracellular ROS, H2O2, and mitochondrial O2·-, and Δψmito but not the [Ca2+]cyt level. When the mitochondrial calcium channels NCXmito and MCU were blocked by CGP-37157 and Ru360, respectively, the UA-induced increases in the levels of [Ca2+]mito and total intracellular ROS were significantly reduced. Mitochondrial levels of O2·- and Δψmito were reduced by inhibition of NCXmito but not of MCU. Moreover, inhibition of NCXmito, but not of MCU, blocked the UA-induced reductions in eNOS protein expression and NO release. The increased generation of mitochondrial O2·- induced by a high concentration of UA is triggered by mitochondrial calcium overload and ultimately leads to endothelial dysfunction. In this process, the activation of NCXmito is the major cause of the influx of calcium into mitochondria. Our results provide a new pathophysiological mechanism for UA-induced endothelial dysfunction and may offer a new therapeutic target for clinicians. Copyright © 2012 Elsevier Ltd. All rights reserved.

Overview and introduction: The blood–brain barrier in health and disease

PubMed Central

Abbott, N. Joan; Friedman, Alon

2013-01-01

Summary This article introduces the special issue on “Blood–Brain Barrier and Epilepsy.” We review briefly current understanding of the structure and function of the blood–brain barrier (BBB), including its development and normal physiology, and ways in which it can be affected in pathology. The BBB formed by the endothelium of cerebral blood vessels is one of three main barrier sites protecting the central nervous system (CNS). The barrier is not a rigid structure, but a dynamic interface with a range of interrelated functions, resulting from extremely effective tight junctions, transendothelial transport systems, enzymes, and regulation of leukocyte permeation, which thereby generates the physical, transport, enzymatic, and immune regulatory functions of the BBB. The brain endothelial cells are important components of a “modular” structure, the neurovascular unit (NVU), with several associated cell types and extracellular matrix components. Modern methods have helped in identifying a range of proteins involved in barrier structure and function, and recent studies have revealed important stages, cell types, and signaling pathways important in BBB development. There is a growing list of CNS pathologies showing BBB dysfunction, with strong evidence that this can play a major role in certain disease etiologies. The articles that follow in this issue summarize in more detail reports and discussions of the recent international meeting on “BBB in Neurological Dysfunctions,” which took place recently at Ben-Gurion University of the Negev Desert Campus (Beer-Sheva, Israel), focusing on the link between experimental and clinical studies, and the ways in which these lead to improved drug treatments. PMID:23134489

The Staphylococcus aureus Alpha-Toxin Perturbs the Barrier Function in Caco-2 Epithelial Cell Monolayers by Altering Junctional Integrity

PubMed Central

Vikström, Elena; Magnusson, Karl-Eric; Vécsey-Semjén, Beatrix; Colque-Navarro, Patricia; Möllby, Roland

2012-01-01

Increased microvascular permeability is a hallmark of sepsis and septic shock. Intestinal mucosal dysfunction may allow translocation of bacteria and their products, thereby promoting sepsis and inflammation. Although Staphylococcus aureus alpha-toxin significantly contributes to sepsis and perturbs the endothelial barrier function, little is known about possible effects of S. aureus alpha-toxin on human epithelial barrier functions. We hypothesize that S. aureus alpha-toxin in the blood can impair the intestinal epithelial barrier and thereby facilitate the translocation of luminal bacteria into the blood, which may in turn aggravate a septic condition. Here, we showed that staphylococcal alpha-toxin disrupts the barrier integrity of human intestinal epithelial Caco-2 cells as evidenced by decreased transepithelial electrical resistance (TER) and reduced cellular levels of junctional proteins, such as ZO-1, ZO-3, and E-cadherin. The Caco-2 cells also responded to alpha-toxin with an elevated cytosolic calcium ion concentration ([Ca2+]i), elicited primarily by calcium influx from the extracellular environment, as well as with a significant reduction in TER, which was modulated by intracellular calcium chelation. Moreover, a significantly larger reduction in TER and amounts of the junctional proteins, viz., ZO-3 and occludin, was achieved by basolateral than by apical application of the alpha-toxin. These experimental findings thus support the hypothesis that free staphylococcal alpha-toxin in the bloodstream may cause intestinal epithelial barrier dysfunction and further aggravate the septic condition by promoting the release of intestinal bacteria into the underlying tissues and the blood. PMID:22354024

Ezetimibe in Combination With Statins Ameliorates Endothelial Dysfunction in Coronary Arteries After Stenting: The CuVIC Trial (Effect of Cholesterol Absorption Inhibitor Usage on Target Vessel Dysfunction After Coronary Stenting), a Multicenter Randomized Controlled Trial.

PubMed

Takase, Susumu; Matoba, Tetsuya; Nakashiro, Soichi; Mukai, Yasushi; Inoue, Shujiro; Oi, Keiji; Higo, Taiki; Katsuki, Shunsuke; Takemoto, Masao; Suematsu, Nobuhiro; Eshima, Kenichi; Miyata, Kenji; Yamamoto, Mitsutaka; Usui, Makoto; Sadamatsu, Kenji; Satoh, Shinji; Kadokami, Toshiaki; Hironaga, Kiyoshi; Ichi, Ikuyo; Todaka, Koji; Kishimoto, Junji; Egashira, Kensuke; Sunagawa, Kenji

2017-02-01

We sought to investigate whether treatment with ezetimibe in combination with statins improves coronary endothelial function in target vessels in coronary artery disease patients after coronary stenting. We conducted a multicenter, prospective, randomized, open-label, blinded-end point trial among 11 cardiovascular treatment centers. From 2011 to 2013, 260 coronary artery disease patients who underwent coronary stenting were randomly allocated to 2 arms (statin monotherapy, S versus ezetimibe [10 mg/d]+statin combinational therapy, E+S). We defined target vessel dysfunction as the primary composite outcome, which comprised target vessel failure during treatment and at the 6- to 8-month follow-up coronary angiography and coronary endothelial dysfunction determined via intracoronary acetylcholine testing performed in cases without target vessel failure at the follow-up coronary angiography. Coadministration of ezetimibe with statins further lowered low-density lipoprotein cholesterol levels (83±23 mg/dL in S versus 67±23 mg/dL in E+S; P<0.0001), with significant decreases in oxidized low-density lipoprotein and oxysterol levels. Among patients without target vessel failure, 46 out of 89 patients (52%) in the S arm and 34 out of 96 patients (35%) in the E+S arm were found to have coronary endothelial dysfunction (P=0.0256), and the incidence of target vessel dysfunction at follow-up was significantly decreased in the E+S arm (69/112 (62%) in S versus 47/109 (43%) in E+S; P=0.0059). A post hoc analysis of post-treatment low-density lipoprotein cholesterol-matched subgroups revealed that the incidence of both target vessel dysfunction and coronary endothelial dysfunction significantly decreased in the E+S arm, with significant reductions in oxysterol levels. The CuVIC trial (Effect of Cholesterol Absorption Inhibitor Usage on Target Vessel Dysfunction after Coronary Stenting) has shown that ezetimibe with statins, compared with statin monotherapy, improves functional prognoses, ameliorating endothelial dysfunction in stented coronary arteries, and was associated with larger decreases in oxysterol levels. © 2016 American Heart Association, Inc.

Effect of extracorporeal cytokine removal on vascular barrier function in a septic shock patient.

PubMed

David, Sascha; Thamm, Kristina; Schmidt, Bernhard M W; Falk, Christine S; Kielstein, Jan T

2017-01-01

Sepsis and septic shock are major healthcare problems, affecting millions of individuals around the world each year. Pathophysiologically, septic multiple organ dysfunction (MOD) is a life-threatening condition caused by an overwhelming systemic inflammatory response of the host's organism to an infection. We experimentally tested if high circulating cytokine levels might increase vascular permeability-a critical hallmark of the disease-and if this phenomenon can be reversed by therapeutic cytokine removal (CytoSorb®) in an exemplary patient. A 32-year-old Caucasian female presented with septic shock and accompanying acute kidney injury (Sequential Organ Failure Assessment (SOFA) = 18) to our ICU. In spite of a broad anti-infective regimen, adequate fluid resuscitation, and high doses of inotropics and catecholamines, she remained refractory hypotensive. The extraordinary severity of septic shock suggested an immense overwhelming host response assumingly accompanied by a notable cytokine storm such as known from patients with toxic shock syndrome. Thus, a CytoSorb® filter was added to the dialysis circuit to remove excess shock-perpetuating cytokines. To analyze the endothelial phenotype in vitro before and after extracorporeal cytokine removal, we tested the septic shock patient's serum on human umbilical vein endothelial cells (HUVECs). The effect on endothelial integrity was assessed both on the morphological (fluorescent immunocytochemistry for VE-cadherin and F-actin) and functional (transendothelial electrical resistance (TER)) level that was recorded in real time with an "electric cell-substrate impedance sensing" (ECIS) system (ibidi). We found (1) severe alterations of cell-cell contacts and the cytoskeletal architecture and (2) profound functional permeability changes, the putative cellular correlate of the clinical vascular leakage syndrome. However, the endothelial barrier was protected from these profound adverse effects when HUVECs were challenged with septic shock serum that was collected after extracorporeal cytokine removal. Beneficial observations of extracorporeal cytokine removal in septic shock patients might-at least in part-be promoted via protection of vascular barrier function.

Pertussis Toxin Exploits Specific Host Cell Signaling Pathways for Promoting Invasion and Translocation of Escherichia coli K1 RS218 in Human Brain-derived Microvascular Endothelial Cells*

PubMed Central

Karassek, Sascha; Starost, Laura; Solbach, Johanna; Greune, Lilo; Sano, Yasuteru; Kanda, Takashi; Kim, KwangSik; Schmidt, M. Alexander

2015-01-01

Pertussis toxin (PTx), an AB5 toxin and major virulence factor of the whooping cough-causing pathogen Bordetella pertussis, has been shown to affect the blood-brain barrier. Dysfunction of the blood-brain barrier may facilitate penetration of bacterial pathogens into the brain, such as Escherichia coli K1 (RS218). In this study, we investigated the influence of PTx on blood-brain barrier permissiveness to E. coli infection using human brain-derived endothelial HBMEC and TY10 cells as in vitro models. Our results indicate that PTx acts at several key points of host cell intracellular signaling pathways, which are also affected by E. coli K1 RS218 infection. Application of PTx increased the expression of the pathogen binding receptor gp96. Further, we found an activation of STAT3 and of the small GTPase Rac1, which have been described as being essential for bacterial invasion involving host cell actin cytoskeleton rearrangements at the bacterial entry site. In addition, we showed that PTx induces a remarkable relocation of VE-cadherin and β-catenin from intercellular junctions. The observed changes in host cell signaling molecules were accompanied by differences in intracellular calcium levels, which might act as a second messenger system for PTx. In summary, PTx not only facilitates invasion of E. coli K1 RS218 by activating essential signaling cascades; it also affects intercellular barriers to increase paracellular translocation. PMID:26324705

Targeting the Endoplasmic Reticulum Unfolded Protein Response to Counteract the Oxidative Stress-Induced Endothelial Dysfunction

PubMed Central

Moltedo, Ornella; Faraonio, Raffaella

2018-01-01

In endothelial cells, the tight control of the redox environment is essential for the maintenance of vascular homeostasis. The imbalance between ROS production and antioxidant response can induce endothelial dysfunction, the initial event of many cardiovascular diseases. Recent studies have revealed that the endoplasmic reticulum could be a new player in the promotion of the pro- or antioxidative pathways and that in such a modulation, the unfolded protein response (UPR) pathways play an essential role. The UPR consists of a set of conserved signalling pathways evolved to restore the proteostasis during protein misfolding within the endoplasmic reticulum. Although the first outcome of the UPR pathways is the promotion of an adaptive response, the persistent activation of UPR leads to increased oxidative stress and cell death. This molecular switch has been correlated to the onset or to the exacerbation of the endothelial dysfunction in cardiovascular diseases. In this review, we highlight the multiple chances of the UPR to induce or ameliorate oxidative disturbances and propose the UPR pathways as a new therapeutic target for the clinical management of endothelial dysfunction. PMID:29725497

Myeloperoxidase amplified high glucose-induced endothelial dysfunction in vasculature: Role of NADPH oxidase and hypochlorous acid.

PubMed

Tian, Rong; Ding, Yun; Peng, Yi-Yuan; Lu, Naihao

2017-03-11

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived reactive oxygen species (ROS) such as superoxide and hydrogen peroxide (H 2 O 2 ), have emerged as important molecules in the pathogenesis of diabetic endothelial dysfunction. Additionally, neutrophils-derived myeloperoxidase (MPO) and MPO-catalyzed hypochlorous acid (HOCl) play important roles in the vascular injury. However, it is unknown whether MPO can use vascular-derived ROS to induce diabetic endothelial dysfunction. In the present study, we demonstrated that NADPH oxidase was the main source of ROS formation in high glucose-cultured human umbilical vein endothelial cells (HUVECs), and played a critical role in high glucose-induced endothelial dysfunction such as cell apoptosis, loss of cell viability and reduction of nitric oxide (NO). However, the addition of MPO could amplify the high glucose-induced endothelial dysfunction which was inhibited by the presence of apocynin (NADPH oxidase inhibitor), catalase (H 2 O 2 scavenger), or methionine (HOCl scavenger), demonstrating the contribution of NADPH oxidase-H 2 O 2 -MPO-HOCl pathway in the MPO/high glucose-induced vascular injury. In high glucose-incubated rat aortas, MPO also exacerbated the NADPH oxidase-induced impairment of endothelium-dependent relaxation. Consistent with these in vitro data, in diabetic rat aortas, both MPO expresion and NADPH oxidase activity were increased while the endothelial function was simultaneously impaired. The results suggested that vascular-bound MPO could amplify high glucose-induced vascular injury in diabetes. MPO-NADPH oxidase-HOCl may represent an important pathogenic pathway in diabetic vascular diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

Endothelial dysfunction in patients with obstructive sleep apnoea independent of metabolic syndrome.

PubMed

Amra, Babak; Karbasi, Elaheh; Hashemi, Mohammad; Hoffmann-Castendiek, Birgit; Golshan, Mohammad

2009-05-01

Obstructive sleep apnoea syndrome (OSAS), characterised by intermittent hypoxia/re-oxygenation, has been identified as an independent risk factor for cardiovascular diseases and endothelial dysfunction. Our aim was to investigate flow-mediated dilatation (FMD) in patients with obstructive sleep apnoea with and without metabolic syndrome. Fifty-two subjects with OSAS diagnosed by polysomnography were classified into 2 groups according to the presence and absence of the metabolic syndrome and also according to the severity: mild to moderate OSAS group and severe OSAS group. Endothelial function of the brachial artery was evaluated by using high-resolution vascular ultrasound. Endothelial-dependent dilatation (EDD) was assessed by establishing reactive hyperaemia and endothelial-independent dilatation (EID) was determined by using sublingual isosorbide dinitrate. Spearman correlation and regression analysis were performed. EDD was not significantly different in patients with OSAS and metabolic syndrome as compared with OSAS without metabolic syndrome (4.62 +/- 0.69 versus 4.49 +/- 0.93, P >0.05). Endothelial dysfunction in OSA may be independent of metabolic syndrome.

Effects of Flavonoid-Containing Beverages and EGCG on Endothelial Function

PubMed Central

Shenouda, Sherene M.; Vita, Joseph A.

2009-01-01

Abnormalities of the vascular endothelium contribute to all stages of atherosclerosis from lesion development to clinical cardiovascular disease events. Recognized risk factors, including diabetes mellitus, hypertension, dyslipidemia, cigarette smoking, and sedentary lifestyle are associated with endothelial dysfunction. A variety of pharmacological and behavioral interventions have been shown to reverse endothelial dysfunction in patients with cardiovascular disease. A large number of epidemiological studies suggest that dietary factors, including increased intake of flavonoid-containing foods and beverages, reduce cardiovascular risk, and recent studies have shown that such beverages have favorable effects on endothelial function. These studies have engendered interest in the development of dietary supplements or drugs that would allow for more convenient and higher dose administration of flavonoids and might prove useful for prevention or treatment of cardiovascular disease. In this paper, we will review the contribution of endothelial dysfunction to the pathogenesis and clinical expression of atherosclerosis and recent data linking flavonoid and EGCG consumption to improved endothelial function and reduced cardiovascular risk. PMID:17906190

Adipokine CTRP6 improves PPARγ activation to alleviate angiotensin II-induced hypertension and vascular endothelial dysfunction in spontaneously hypertensive rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chi, Liyi; Departments of Cardiology, The 451st Hospital of People's Liberation Army; Hu, Xiaojing

Angiotensin II (AngII) is the most important component of angiotensin, which has been regarded as a major contributor to the incidence of hypertension and vascular endothelial dysfunction. The adipocytokine C1q/TNF-related protein 6 (CTRP6) was recently reported to have multiple protective effects on cardiac and cardiovascular function. However, the exact role of CTRP6 in the progression of AngII induced hypertension and vascular endothelial function remains unclear. Here, we showed that serum CTRP6 content was significantly downregulated in SHRs, accompanied by a marked increase in arterial systolic pressure and serum AngII, CRP and ET-1 content. Then, pcDNA3.1-mediated CTRP6 delivery or CTRP6 siRNAmore » was injected into SHRs. CTRP6 overexpression caused a significant decrease in AngII expression and AngII-mediated hypertension and vascular endothelial inflammation. In contrast, CTRP6 knockdown had the opposite effect to CTRP6 overexpression. Moreover, we found that CTRP6 positively regulated the activation of the ERK1/2 signaling pathway and the expression of peroxisome proliferator-activated receptor γ (PPARγ), a recently proven negative regulator of AngII, in the brain and vascular endothelium of SHRs. Finally, CTRP6 was overexpressed in endothelial cells, and caused a significant increase in PPARγ activation and suppression in AngII-mediated vascular endothelial dysfunction and apoptosis. The effect of that could be rescued by the ERK inhibitor PD98059. In contrast, silencing CTRP6 suppressed PPARγ activation and exacerbated AngII-mediated vascular endothelial dysfunction and apoptosis. In conclusion, CTRP6 improves PPARγ activation and alleviates AngII-induced hypertension and vascular endothelial dysfunction. - Highlights: • Serum CTRP6 was significantly decreased in spontaneously hypertensive rats (SHRs). • CTRP6 positively regulated the activation of the ERK1/2 signaling pathway. • CTRP6 negatively regulates PPARγ mediated Angiotensin II (AngII) expression. • CTRP6 alleviates AngII-induced hypertension and vascular endothelial dysfunction.« less

Lipopolysaccharide-induced endothelial barrier breakdown is cyclic adenosine monophosphate dependent in vivo and in vitro.

PubMed

Schlegel, Nicolas; Baumer, Yvonne; Drenckhahn, Detlev; Waschke, Jens

2009-05-01

To determine whether cyclic adenosine monophosphate (cAMP) is critically involved in lipopolysaccharide (LPS)-induced breakdown of endothelial barrier functions in vivo and in vitro. Experimental laboratory research. Research laboratory. Wistar rats and cultured human microvascular endothelial cells. Permeability measurements in single postcapillary venules in vivo and permeability measurements and cell biology techniques in vitro. We demonstrate that within 120 minutes LPS increased endothelial permeability in rat mesenteric postcapillary venules in vivo and caused a barrier breakdown in human dermal microvascular endothelial cells in vitro. This was associated with the formation of large intercellular gaps and fragmentation of vascular endothelial cadherin immunostaining. Furthermore, claudin 5 immunostaining at cell borders was drastically reduced after LPS treatment. Interestingly, activity of the small GTPase Rho A, which has previously been suggested to mediate the LPS-induced endothelial barrier breakdown, was not increased after 2 hours. However, activity of Rac 1, which is known to be important for maintenance of endothelial barrier functions, was significantly reduced to 64 +/- 8% after 2 hours. All LPS-induced changes of endothelial cells were blocked by a forskolin-mediated or rolipram-mediated increase of cAMP. Consistently, enzyme-linked immunosorbent assay-based measurements demonstrated that LPS significantly decreased intracellular cAMP. In summary, our data demonstrate that LPS disrupts endothelial barrier properties by decreasing intracellular cAMP. This mechanism may involve inactivation of Rac 1 rather than activation of Rho A.

Immortalized endothelial cell lines for in vitro blood-brain barrier models: A systematic review.

PubMed

Rahman, Nurul Adhwa; Rasil, Alifah Nur'ain Haji Mat; Meyding-Lamade, Uta; Craemer, Eva Maria; Diah, Suwarni; Tuah, Ani Afiqah; Muharram, Siti Hanna

2016-07-01

Endothelial cells play the most important role in construction of the blood-brain barrier. Many studies have opted to use commercially available, easily transfected or immortalized endothelial cell lines as in vitro blood-brain barrier models. Numerous endothelial cell lines are available, but we do not currently have strong evidence for which cell lines are optimal for establishment of such models. This review aimed to investigate the application of immortalized endothelial cell lines as in vitro blood-brain barrier models. The databases used for this review were PubMed, OVID MEDLINE, ProQuest, ScienceDirect, and SpringerLink. A narrative systematic review was conducted and identified 155 studies. As a result, 36 immortalized endothelial cell lines of human, mouse, rat, porcine and bovine origins were found for the establishment of in vitro blood-brain barrier and brain endothelium models. This review provides a summary of immortalized endothelial cell lines as a guideline for future studies and improvements in the establishment of in vitro blood-brain barrier models. It is important to establish a good and reproducible model that has the potential for multiple applications, in particular a model of such a complex compartment such as the blood-brain barrier. Copyright © 2016 Elsevier B.V. All rights reserved.

Childhood obesity-related endothelial dysfunction: an update on pathophysiological mechanisms and diagnostic advancements.

PubMed

Bruyndonckx, Luc; Hoymans, Vicky Y; Lemmens, Katrien; Ramet, José; Vrints, Christiaan J

2016-06-01

Childhood obesity jeopardizes a healthy future for our society's children as it is associated with increased cardiovascular morbidity and mortality later on in life. Endothelial dysfunction, the first step in the development of atherosclerosis, is already present in obese children and may well represent a targetable risk factor. Technological advancements in recent years have facilitated noninvasive measurements of endothelial homeostasis in children. Thereby this topic ultimately starts to get the attention it deserves. In this paper, we aim to summarize the latest insights on endothelial dysfunction in childhood obesity. We discuss methodological advancements in peripheral endothelial function measurement and newly identified diagnostic markers of vascular homeostasis. Finally, future challenges and perspectives are set forth on how to efficiently tackle the catastrophic rise in cardiovascular morbidity and mortality that will be inflicted on obese children if they are not treated optimally.

Bioactivation of organic nitrates and the mechanism of nitrate tolerance.

PubMed

Klemenska, Emila; Beresewicz, Andrzej

2009-01-01

Organic nitrates, such as nitroglycerin, are commonly used in the therapy of cardiovascular disease. Long-term therapy with these drugs, however, results in the rapid development of nitrate tolerance, limiting their hemodynamic and anti-ischemic efficacy. In addition, nitrate tolerance is associated with the expression of potentially deleterious modifications such as increased oxidative stress, endothelial dysfunction, and sympathetic activation. In this review we discuss current concepts regarding the mechanisms of organic nitrate bioactivation, nitrate tolerance, and nitrate-mediated oxidative stress and endothelial dysfunction. We also examine how hydralazine may prevent nitrate tolerance and related endothelial dysfunction.

Sinusoidal Endothelial Dysfunction Precedes Inflammation and Fibrosis in a Model of NAFLD

PubMed Central

Pasarín, Marcos; La Mura, Vincenzo; Gracia-Sancho, Jorge; García-Calderó, Héctor; Rodríguez-Vilarrupla, Aina; García-Pagán, Juan Carlos; Bosch, Jaime; Abraldes, Juan G.

2012-01-01

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. Most morbidity associated with the metabolic syndrome is related to vascular complications, in which endothelial dysfunction is a major pathogenic factor. However, whether NAFLD is associated with endothelial dysfunction within the hepatic vasculature is unknown. The aims of this study were to explore, in a model of diet-induced overweight that expresses most features of the metabolic syndrome, whether early NAFLD is associated with liver endothelial dysfunction. Wistar Kyoto rats were fed a cafeteria diet (CafD; 65% of fat, mostly saturated) or a control diet (CD) for 1 month. CafD rats developed features of the metabolic syndrome (overweight, arterial hypertension, hypertryglyceridemia, hyperglucemia and insulin resistance) and liver steatosis without inflammation or fibrosis. CafD rats had a significantly higher in vivo hepatic vascular resistance than CD. In liver perfusion livers from CafD rats had an increased portal perfusion pressure and decreased endothelium-dependent vasodilation. This was associated with a decreased Akt-dependent eNOS phosphorylation and NOS activity. In summary, we demonstrate in a rat model of the metabolic syndrome that shows features of NAFLD, that liver endothelial dysfunction occurs before the development of fibrosis or inflammation. PMID:22509248

Bicarbonate disruption of the pulmonary endothelial barrier via activation of endogenous soluble adenylyl cyclase, isoform 10

PubMed Central

Obiako, Boniface; Calchary, Wendy; Xu, Ningyong; Kunstadt, Ryan; Richardson, Bianca; Nix, Jessica

2013-01-01

It is becoming increasingly apparent that cAMP signals within the pulmonary endothelium are highly compartmentalized, and this compartmentalization is critical to maintaining endothelial barrier integrity. Studies demonstrate that the exogenous soluble bacterial toxin, ExoY, and heterologous expression of the forskolin-stimulated soluble mammalian adenylyl cyclase (AC) chimera, sACI/II, elevate cytosolic cAMP and disrupt the pulmonary microvascular endothelial barrier. The barrier-disruptive effects of cytosolic cAMP generated by exogenous soluble ACs are in contrast to the barrier-protective effects of subplasma membrane cAMP generated by transmembrane AC, which strengthens endothelial barrier integrity. Endogenous soluble AC isoform 10 (AC10 or commonly known as sAC) lacks transmembrane domains and localizes within the cytosolic compartment. AC10 is uniquely activated by bicarbonate to generate cytosolic cAMP, yet its role in regulation of endothelial barrier integrity has not been addressed. Here we demonstrate that, within the pulmonary circulation, AC10 is expressed in pulmonary microvascular endothelial cells (PMVECs) and pulmonary artery endothelial cells (PAECs), yet expression in PAECs is lower. Furthermore, pulmonary endothelial cells selectively express bicarbonate cotransporters. While extracellular bicarbonate generates a phosphodiesterase 4-sensitive cAMP pool in PMVECs, no such cAMP response is detected in PAECs. Finally, addition of extracellular bicarbonate decreases resistance across the PMVEC monolayer and increases the filtration coefficient in the isolated perfused lung above osmolality controls. Collectively, these findings suggest that PMVECs have a bicarbonate-sensitive cytosolic cAMP pool that disrupts endothelial barrier integrity. These studies could provide an alternative mechanism for the controversial effects of bicarbonate correction of acidosis of acute respiratory distress syndrome patients. PMID:23686854

Ameliorating Endothelial Mitochondrial Dysfunction Restores Coronary Function via Transient Receptor Potential Vanilloid 1-Mediated Protein Kinase A/Uncoupling Protein 2 Pathway.

PubMed

Xiong, Shiqiang; Wang, Peijian; Ma, Liqun; Gao, Peng; Gong, Liuping; Li, Li; Li, Qiang; Sun, Fang; Zhou, Xunmei; He, Hongbo; Chen, Jing; Yan, Zhencheng; Liu, Daoyan; Zhu, Zhiming

2016-02-01

Coronary heart disease arising from atherosclerosis is a leading cause of cardiogenic death worldwide. Mitochondria are the principal source of reactive oxygen species (ROS), and defective oxidative phosphorylation by the mitochondrial respiratory chain contributes to ROS generation. Uncoupling protein 2 (UCP2), an adaptive antioxidant defense factor, protects against mitochondrial ROS-induced endothelial dysfunction in atherosclerosis. The activation of transient receptor potential vanilloid 1 (TRPV1) attenuates vascular dysfunction. Therefore, whether TRPV1 activation antagonizes coronary lesions by alleviating endothelial mitochondrial dysfunction and enhancing the activity of the protein kinase A/UCP2 pathway warrants examination. ApoE(-/-), ApoE(-/-)/TRPV1(-/-), and ApoE(-/-)/UCP2(-/-) mice were fed standard chow, a high-fat diet (HFD), or the HFD plus 0.01% capsaicin. HFD intake profoundly impaired coronary vasodilatation and myocardial perfusion and shortened the survival duration of ApoE(-/-) mice. TRPV1 or UCP2 deficiency exacerbated HFD-induced coronary dysfunction and was associated with increased ROS generation and reduced nitric oxide production in the endothelium. The activation of TRPV1 by capsaicin upregulated UCP2 expression via protein kinase A phosphorylation, thereby alleviating endothelial mitochondrial dysfunction and inhibiting mitochondrial ROS generation. In vivo, dietary capsaicin supplementation enhanced coronary relaxation and prolonged the survival duration of HFD-fed ApoE(-/-) mice. These effects were not observed in ApoE(-/-) mice lacking the TRPV1 or UCP2 gene. The upregulation of protein kinase A /UCP2 via TRPV1 activation ameliorates coronary dysfunction and prolongs the lifespan of atherosclerotic mice by ameliorating endothelial mitochondrial dysfunction. Dietary capsaicin supplementation may represent a promising intervention for the primary prevention of coronary heart disease. © 2015 American Heart Association, Inc.

Blood–brain barrier dysfunction and epilepsy: Pathophysiologic role and therapeutic approaches

PubMed Central

Marchi, Nicola; Granata, Tiziana; Ghosh, Chaitali; Janigro, Damir

2016-01-01

The blood–brain barrier (BBB) is located within a unique anatomic interface and has functional ramifications to most of the brain and blood cells. In the past, the BBB was considered a pharmacokinetic impediment to antiepileptic drug penetration into the brain; nowadays it is becoming increasingly evident that targeting of the damaged or dysfunctional BBB may represent a therapeutic approach to reduce seizure burden. Several studies have investigated the mechanisms linking the onset and sustainment of seizures to BBB dysfunction. These studies have shown that the BBB is at the crossroad of a multifactorial pathophysiologic process that involves changes in brain milieu, altered neuroglial physiology, development of brain inflammation, leukocyte–endothelial interactions, faulty angiogenesis, and hemodynamic changes leading to energy mismatch. A number of knowledge gaps, conflicting points of view, and discordance between clinical and experimental data currently characterize this field of neuroscience. As more pieces are added to this puzzle, it is apparent that each mechanism needs to be validated in an appropriate clinical context. We now offer a BBB-centric view of seizure disorders, linking several aspects of seizures and epilepsy physiopathology to BBB dysfunction. We have reviewed the therapeutic, antiseizure effect of drugs that promote BBB repair. We also present BBB neuroimaging as a tool to correlate BBB restoration to seizure mitigation. Add-on cerebrovascular drug could be of efficacy in reducing seizure burden when used in association with neuronal antiepileptic drugs. PMID:22905812

MicroRNA-27b plays a role in pulmonary arterial hypertension by modulating peroxisome proliferator-activated receptor γ dependent Hsp90-eNOS signaling and nitric oxide production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bi, Rui; Bao, Chunrong; Jiang, Lianyong

Pulmonary artery endothelial dysfunction is associated with pulmonary arterial hypertension (PAH). Based on recent studies showing that microRNA (miR)-27b is aberrantly expressed in PAH, we hypothesized that miR-27b may contribute to pulmonary endothelial dysfunction and vascular remodeling in PAH. The effect of miR-27b on pulmonary endothelial dysfunction and the underlying mechanism were investigated in human pulmonary artery endothelial cells (HPAECs) in vitro and in a monocrotaline (MCT)-induced model of PAH in vivo. miR-27b expression was upregulated in MCT-induced PAH and inversely correlated with the levels of peroxisome proliferator-activated receptor (PPAR)-γ, and miR-27b inhibition attenuated MCT-induced endothelial dysfunction and remodeling and prevented PAHmore » associated right ventricular hypertrophy and systolic pressure in rats. PPARγ was confirmed as a direct target of miR-27b in HPAECs and shown to mediate the effect of miR-27b on the disruption of endothelial nitric oxide synthase (eNOS) coupling to Hsp90 and the suppression of NO production associated with the PAH phenotype. We showed that miR-27b plays a role endothelial function and NO release and elucidated a potential mechanism by which miR-27b regulates Hsp90-eNOS and NO signaling by modulating PPARγ expression, providing potential therapeutic targets for the treatment of PAH. - Highlights: • miR-27b plays a role in endothelial function and NO release. • miR-27b inhibition ameliorates MCT-induced endothelial dysfunction and PAH. • miR-27b targets PPARγ in HPAECs. • miR-27b regulates PPARγ dependent Hsp90-eNOS and NO signaling.« less

Administration of tauroursodeoxycholic acid prevents endothelial dysfunction caused by an oral glucose load

PubMed Central

Walsh, Lauren K.; Restaino, Robert M.; Neuringer, Martha; Manrique, Camila; Padilla, Jaume

2017-01-01

Postprandial hyperglycemia leads to a transient impairment in endothelial function; however, the mechanisms remain largely unknown. Previous work in cell culture models demonstrate that high glucose results in endoplasmic reticulum (ER) stress and, in animal studies, ER stress has been implicated as a cause of endothelial dysfunction. Herein we tested the hypothesis that acute oral administration of tauroursodeoxycholic acid (TUDCA, 1500mg), a chemical chaperone known to alleviate ER stress, would prevent hyperglycemia-induced endothelial dysfunction. In 12 young healthy subjects (seven men, five women), brachial artery flow-mediated dilation (FMD) was assessed at baseline, 1 hour, and 2 hours post an oral glucose challenge. Subjects were tested on two separate visits in a single-blind randomized crossover design: after oral ingestion of TUDCA or placebo capsules. FMD was reduced from baseline during hyperglycemia under the placebo condition (−32% at 1 hr and −28% at 2 hr post oral glucose load; p<0.05 from baseline) but not under the TUDCA condition (−4% at 1 hr and +0.3% at 2 hr post oral glucose load; p>0.05 from baseline). Postprandial plasma glucose and insulin were not altered by TUDCA ingestion. Plasma oxidative stress markers 3-nitrotyrosine and TBARs remained unaltered throughout the oral glucose challenge in both conditions. These results suggest that hyperglycemia-induced endothelial dysfunction can be mitigated by oral administration of TUDCA, thus supporting the hypothesis that ER stress may contribute to endothelial dysfunction during postprandial hyperglycemia. PMID:27503949

Assessment of Endothelial Dysfunction: The Role of Symmetrical Dimethylarginine and Proinflammatory Markers in Chronic Kidney Disease and Renal Transplant Recipients

PubMed Central

Giga, Vojislav; Dopsaj, Violeta; Jelic-Ivanovic, Zorana

2013-01-01

Objectives. The study was designed to evaluate associations between symmetric dimethylarginine (SDMA), inflammation, and superoxide anion (O2∙−) with endothelial function and to determine their potential for screening of endothelial dysfunction in patients with chronic kidney disease (CKD) and renal transplant (RT) recipients. Materials and Methods. We included 64 CKD and 52 RT patients. Patients were stratified according to brachial artery flow-mediated dilation (FMD). Results. Logistic regression analysis showed that high SDMA and high sensitive C-reactive protein (hs-CRP) were associated with impaired FMD in CKD and RT patients, after adjustment for glomerular filtration rate. The ability of inflammation, SDMA, and O2∙− to detect impaired FMD was investigated by receiving operative characteristic analysis. Hs-CRP (area under the curves (AUC) = 0.754, P < 0.001), IL-6 (AUC = 0.699, P = 0.002), and SDMA (AUC = 0.689, P = 0.007) had the highest ability to detect impaired FMD. SDMA in combination with inflammatory parameters and/or O2∙− had better screening performance than SDMA alone. Conclusions. Our results indicate a strong predictable association between hs-CRP, SDMA, and endothelial dysfunction in CKD patients and RT recipients. The individual marker that showed the strongest discriminative ability for endothelial dysfunction is hs-CRP, but its usefulness as a discriminatory marker for efficient diagnosis of endothelial dysfunction should be examined in prospective studies. PMID:24167363

A role for long chain myosin light chain kinase (MLCK-210) in microvascular hyperpermeability during severe burns.

PubMed

Reynoso, Rashell; Perrin, Rachel M; Breslin, Jerome W; Daines, Dayle A; Watson, Katherine D; Watterson, D Martin; Wu, Mack H; Yuan, Sarah

2007-11-01

Microvascular leakage has been implicated in the pathogenesis of multiple organ dysfunction during trauma. Previous studies suggest the involvement of myosin light chain (MLC) phosphorylation-triggered endothelial contraction in the development of microvascular hyperpermeability. Myosin light chain kinase (MLCK) plays a key role in the control of MLC-phosphorylation status; thus, it is thought to modulate barrier function through its regulation of intracellular contractile machinery. The aim of this study was to further investigate the endothelial mechanism of MLC-dependent barrier injury in burns, focusing on the long isoform of MLCK (MLCK-210) that has recently been identified as the predominant isoform expressed in vascular endothelial cells. An MLCK-210 knockout mouse model was subjected to third-degree scald burn covering 25% total body surface area. The mesenteric microcirculation was observed using intravital microscopy, and the microvascular permeability was assessed by measuring the transvenular flux of fluorescein isothiocyanate-albumin. In a separate experiment, in vivo mesenteric hydraulic conductivity (Lp) was measured using the modified Landis technique. The injury caused a profound microvascular leakage, as indicated by a 2-fold increase in albumin flux and 4-fold increase in Lp at the early stages, which was associated with a high mortality within the 24-h period. Compared with wild-type control, the MLCK-210-deficient mice displayed a significantly improved survival with a greatly attenuated microvascular hyperpermeability response to albumin and fluid. These results provide direct evidence for a role of MLCK-210 in mediating burn-induced microvascular barrier injury and validate MLCK-210 as a potential therapeutic target in the treatment of burn edema.

Interaction in endothelium of non-muscular myosin light-chain kinase and the NF-κB pathway is critical to lipopolysaccharide-induced vascular hyporeactivity.

PubMed

Recoquillon, Sylvain; Carusio, Nunzia; Lagrue-Lakhal, Anne-Hélène; Tual-Chalot, Simon; Filippelli, Amelia; Andriantsitohaina, Ramaroson; Martinez, M Carmen

2015-10-01

During sepsis, endothelial barrier dysfunction contributes to cardiovascular failure, mainly through the release of oxidative metabolites by penetrant leukocytes. We reported the non-muscular isoform of myosin light chain kinase (nmMLCK) playing a pivotal role in endotoxin shock injury associated with oxidative and nitrative stresses, and vascular hyporeactivity. The present study was aimed at understanding the molecular mechanism of lipopolysaccharide (LPS)-induced vascular alterations as well as studying a probable functional association of nmMLCK with nuclear factor κ-light-chain enhancer of activated B cells (NF-κB). Aortic rings from mice were exposed in vitro to LPS and, then, vascular reactivity was measured. Human aortic endothelial cells (HAoECs) were incubated with LPS, and interaction of nmMLCK with NF-κB was analysed. We provide evidence that nmMLCK deletion prevents vascular hyporeactivity induced by in vitro LPS treatment but not endothelial dysfunction in the aorta. Deletion of nmMLCK inhibits LPS-induced NF-κB activation and increases nitric oxide (NO) release via induction of inducible NO synthase (iNOS) within the vascular wall. Also, removal of endothelium prevented both NF-κB and iNOS expression in aortic rings. Among the proinflammatory factors released by LPS-treated endothelial cells, interleukin-6 accounts for the induction of iNOS on smooth muscle cells in response to LPS. Of particular interest is the demonstration that, in HAoECs, LPS-induced NF-κB activation occurs via increased MLCK activity sensitive to the MLCK inhibitor, ML-7, and physical interactions between nmMLCK and NF-κB. We report for the first time on NF-κB as a novel partner of nmMLCK within endothelial cells. The present study demonstrates a pivotal role of nmMLCK in vascular inflammatory pathologies. © 2015 Authors; published by Portland Press Limited.

Endothelium-derived contracting factors mediate the Ang II-induced endothelial dysfunction in the rat aorta: preventive effect of red wine polyphenols.

PubMed

Kane, Modou O; Etienne-Selloum, Nelly; Madeira, Soccoro V F; Sarr, Mamadou; Walter, Allison; Dal-Ros, Stéphanie; Schott, Christa; Chataigneau, Thierry; Schini-Kerth, Valérie B

2010-04-01

Angiotensin II (Ang II)-induced hypertension is associated with vascular oxidative stress and an endothelial dysfunction. This study examined the role of reactive oxygen species (ROS) and endothelium-derived contracting factors in Ang II-induced endothelial dysfunction and whether these effects are prevented by red wine polyphenols (RWPs), a rich source of natural antioxidants. Rats were infused with Ang II for 14 days. RWPs were administered in the drinking water 1 week before and during the Ang II infusion. Arterial pressure was measured in conscious rats. Vascular reactivity was assessed in organ chambers and cyclooxygenase-1 (COX-1) and COX-2 expression by Western blot and immunofluorescence analyses. Ang II-induced hypertension was associated with blunted endothelium-dependent relaxations and induction of endothelium-dependent contractions in the presence of nitro-L-arginine in response to acetylcholine (Ach). These effects were not affected by the combination of membrane permeant analogs of superoxide dismutase and catalase but were abolished by the thromboxane A(2) (TP) receptor antagonist GR32191B and the COX-2 inhibitor NS-398. The COX-1 inhibitor SC-560 also prevented contractile responses to Ach. Ang II increased the expression of COX-1 and COX-2 in the aortic wall. RWPs prevented Ang II-induced hypertension, endothelial dysfunction, and upregulation of COX-1 and COX-2. Thus, Ang II-induced endothelial dysfunction cannot be explained by an acute formation of ROS reducing the bioavailability of nitric oxide but rather by COX-dependent formation of contracting factors acting on TP receptors. RWPs are able to prevent the Ang II-induced endothelial dysfunction mostly due to their antioxidant properties.

Impaired activity of adherens junctions contributes to endothelial dilator dysfunction in ageing rat arteries.

PubMed

Chang, Fumin; Flavahan, Sheila; Flavahan, Nicholas A

2017-08-01

Ageing-induced endothelial dysfunction contributes to organ dysfunction and progression of cardiovascular disease. VE-cadherin clustering at adherens junctions promotes protective endothelial functions, including endothelium-dependent dilatation. Ageing increased internalization and degradation of VE-cadherin, resulting in impaired activity of adherens junctions. Inhibition of VE-cadherin clustering at adherens junctions (function-blocking antibody; FBA) reduced endothelial dilatation in young arteries but did not affect the already impaired dilatation in old arteries. After junctional disruption with the FBA, dilatation was similar in young and old arteries. Src tyrosine kinase activity and tyrosine phosphorylation of VE-cadherin were increased in old arteries. Src inhibition increased VE-cadherin at adherens junctions and increased endothelial dilatation in old, but not young, arteries. Src inhibition did not increase dilatation in old arteries treated with the VE-cadherin FBA. Ageing impairs the activity of adherens junctions, which contributes to endothelial dilator dysfunction. Restoring the activity of adherens junctions could be of therapeutic benefit in vascular ageing. Endothelial dilator dysfunction contributes to pathological vascular ageing. Experiments assessed whether altered activity of endothelial adherens junctions (AJs) might contribute to this dysfunction. Aortas and tail arteries were isolated from young (3-4 months) and old (22-24 months) F344 rats. VE-cadherin immunofluorescent staining at endothelial AJs and AJ width were reduced in old compared to young arteries. A 140 kDa VE-cadherin species was present on the cell surface and in TTX-insoluble fractions, consistent with junctional localization. Levels of the 140 kDa VE-cadherin were decreased, whereas levels of a TTX-soluble 115 kDa VE-cadherin species were increased in old compared to young arteries. Acetylcholine caused endothelium-dependent dilatation that was decreased in old compared to young arteries. Disruption of VE-cadherin clustering at AJs (function-blocking antibody, FBA) inhibited dilatation to acetylcholine in young, but not old, arteries. After the FBA, there was no longer any difference in dilatation between old and young arteries. Src activity and tyrosine phosphorylation of VE-cadherin were increased in old compared to young arteries. In old arteries, Src inhibition (saracatinib) increased: (i) 140 kDa VE-cadherin in the TTX-insoluble fraction, (ii) VE-cadherin intensity at AJs, (iii) AJ width, and (iv) acetylcholine dilatation. In old arteries treated with the FBA, saracatinib no longer increased acetylcholine dilatation. Saracatinib did not affect dilatation in young arteries. Therefore, ageing impairs AJ activity, which appears to reflect Src-induced phosphorylation, internalization and degradation of VE-cadherin. Moreover, impaired AJ activity can account for the endothelial dilator dysfunction in old arteries. Restoring endothelial AJ activity may be a novel therapeutic approach to vascular ageing. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Contractile actin cables induced by Bacillus anthracis lethal toxin depend on the histone acetylation machinery.

PubMed

Rolando, Monica; Stefani, Caroline; Doye, Anne; Acosta, Maria I; Visvikis, Orane; Yevick, Hannah G; Buchrieser, Carmen; Mettouchi, Amel; Bassereau, Patricia; Lemichez, Emmanuel

2015-10-01

It remains a challenge to decode the molecular basis of the long-term actin cytoskeleton rearrangements that are governed by the reprogramming of gene expression. Bacillus anthracis lethal toxin (LT) inhibits mitogen-activated protein kinase (MAPK) signaling, thereby modulating gene expression, with major consequences for actin cytoskeleton organization and the loss of endothelial barrier function. Using a laser ablation approach, we characterized the contractile and tensile mechanical properties of LT-induced stress fibers. These actin cables resist pulling forces that are transmitted at cell-matrix interfaces and at cell-cell discontinuous adherens junctions. We report that treating the cells with trichostatin A (TSA), a broad range inhibitor of histone deacetylases (HDACs), or with MS-275, which targets HDAC1, 2 and 3, induces stress fibers. LT decreased the cellular levels of HDAC1, 2 and 3 and reduced the global HDAC activity in the nucleus. Both the LT and TSA treatments induced Rnd3 expression, which is required for the LT-mediated induction of actin stress fibers. Furthermore, we reveal that treating the LT-intoxicated cells with garcinol, an inhibitor of histone acetyl-transferases (HATs), disrupts the stress fibers and limits the monolayer barrier dysfunctions. These data demonstrate the importance of modulating the flux of protein acetylation in order to control actin cytoskeleton organization and the endothelial cell monolayer barrier. © 2015 Wiley Periodicals, Inc.

Down-regulation of vascular PPAR-γ contributes to endothelial dysfunction in high-fat diet-induced obese mice exposed to chronic intermittent hypoxia.

PubMed

Zhang, Yanan; Zhang, Chunlian; Li, Haiou; Hou, Jingdong

2017-10-14

Obstructive sleep apnea (OSA), characterized by chronic intermittent hypoxia (CIH), is associated with endothelial dysfunction. The prevalence of OSA is linked to an epidemic of obesity. CIH has recently been reported to cause endothelial dysfunction in diet-induced obese animals by exaggerating oxidative stress and inflammation, but the underlying mechanism remains unclear. PPAR-γ, a ligand-inducible transcription factor that exerts anti-oxidant and anti-inflammatory effects, is down-regulated in the peripheral tissues in diet-induce obesity. We tested the hypothesis that down-regulation of vascular PPAR-γ in diet-induced obesity enhances inflammation and oxidative stress in response to CIH, resulting in endothelial dysfunction. Male C57BL/6 mice were fed either a high-fat diet (HFD) or a low-fat diet (LFD) and simultaneously exposed to CIH or intermittent air for 6 weeks. An additional HFD group received a combination of CIH and PPAR-γ agonist pioglitazone for 6 weeks. Endothelial-dependent vasodilation was impaired only in HFD group exposed to CIH, compared with other groups, but was restored by concomitant pioglitazone treatment. Molecular studies revealed that vascular PPAR-γ expression and activity were reduced in HFD groups, compared with LFD groups, but were reversed by pioglitazone treatment. In addition, CIH elevated vascular expression of NADPH oxidase 4 and dihydroethidium fluorescence, and increased expression of proinflammatory cytokines TNF-α and IL-1β in both LFD and HFD groups, but these increases was significantly greater in HFD group, along with decreased vascular eNOS activity. Pioglitazone treatment of HFD group prevented CIH-induced changes in above molecular markers. The results suggest that HFD-induced obesity down-regulates vascular PPAR-γ, which results in exaggerated oxidative stress and inflammation in response to CIH, contributing to endothelial dysfunction. This finding may provide new insights into the mechanisms by which OSA induces endothelial dysfunction and other cardiovascular disease in patients with obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

Copper Transporter ATP7A Protects Against Endothelial Dysfunction in Type 1 Diabetic Mice by Regulating Extracellular Superoxide Dismutase

PubMed Central

Sudhahar, Varadarajan; Urao, Norifumi; Oshikawa, Jin; McKinney, Ronald D.; Llanos, Roxana M.; Mercer, Julian F.B.; Ushio-Fukai, Masuko; Fukai, Tohru

2013-01-01

Oxidative stress and endothelial dysfunction contribute to vascular complication in diabetes. Extracellular superoxide dismutase (SOD3) is one of the key antioxidant enzymes that obtains copper via copper transporter ATP7A. SOD3 is secreted from vascular smooth muscles cells (VSMCs) and anchors at the endothelial surface. The role of SOD3 and ATP7A in endothelial dysfunction in type 1 diabetes mellitus (T1DM) is entirely unknown. Here we show that the specific activity of SOD3, but not SOD1, is decreased, which is associated with increased O2•− production in aortas of streptozotocin-induced and genetically induced Ins2Akita T1DM mice. Exogenous copper partially rescued SOD3 activity in isolated T1DM vessels. Functionally, acetylcholine-induced, endothelium-dependent relaxation is impaired in T1DM mesenteric arteries, which is rescued by SOD mimetic tempol or gene transfer of SOD3. Mechanistically, ATP7A expression in T1DM vessels is dramatically decreased whereas other copper transport proteins are not altered. T1DM-induced endothelial dysfunction and decrease of SOD3 activity are rescued in transgenic mice overexpressing ATP7A. Furthermore, SOD3-deficient T1DM mice or ATP7A mutant T1DM mice augment endothelial dysfunction and vascular O2•− production versus T1DM mice. These effects are in part due to hypoinsulinemia in T1DM mice, since insulin treatment, but not high glucose, increases ATP7A expression in VSMCs and restores SOD3 activity in the organoid culture of T1DM vessels. In summary, a decrease in ATP7A protein expression contributes to impaired SOD3 activity, resulting in O2•− overproduction and endothelial dysfunction in blood vessels of T1DM. Thus, restoring copper transporter function is an essential therapeutic approach for oxidant stress–dependent vascular and metabolic diseases. PMID:23884884

Modelling the endothelial blood-CNS barriers: a method for the production of robust in vitro models of the rat blood-brain barrier and blood-spinal cord barrier

PubMed Central

2013-01-01

Background Modelling the blood-CNS barriers of the brain and spinal cord in vitro continues to provide a considerable challenge for research studying the passage of large and small molecules in and out of the central nervous system, both within the context of basic biology and for pharmaceutical drug discovery. Although there has been considerable success over the previous two decades in establishing useful in vitro primary endothelial cell cultures from the blood-CNS barriers, no model fully mimics the high electrical resistance, low paracellular permeability and selective influx/efflux characteristics of the in vivo situation. Furthermore, such primary-derived cultures are typically labour-intensive and generate low yields of cells, limiting scope for experimental work. We thus aimed to establish protocols for the high yield isolation and culture of endothelial cells from both rat brain and spinal cord. Our aim was to optimise in vitro conditions for inducing phenotypic characteristics in these cells that were reminiscent of the in vivo situation, such that they developed into tight endothelial barriers suitable for performing investigative biology and permeability studies. Methods Brain and spinal cord tissue was taken from the same rats and used to specifically isolate endothelial cells to reconstitute as in vitro blood-CNS barrier models. Isolated endothelial cells were cultured to expand the cellular yield and then passaged onto cell culture inserts for further investigation. Cell culture conditions were optimised using commercially available reagents and the resulting barrier-forming endothelial monolayers were characterised by functional permeability experiments and in vitro phenotyping by immunocytochemistry and western blotting. Results Using a combination of modified handling techniques and cell culture conditions, we have established and optimised a protocol for the in vitro culture of brain and, for the first time in rat, spinal cord endothelial cells. High yields of both CNS endothelial cell types can be obtained, and these can be passaged onto large numbers of cell culture inserts for in vitro permeability studies. The passaged brain and spinal cord endothelial cells are pure and express endothelial markers, tight junction proteins and intracellular transport machinery. Further, both models exhibit tight, functional barrier characteristics that are discriminating against large and small molecules in permeability assays and show functional expression of the pharmaceutically important P-gp efflux transporter. Conclusions Our techniques allow the provision of high yields of robust sister cultures of endothelial cells that accurately model the blood-CNS barriers in vitro. These models are ideally suited for use in studying the biology of the blood-brain barrier and blood-spinal cord barrier in vitro and for pre-clinical drug discovery. PMID:23773766

Modelling the endothelial blood-CNS barriers: a method for the production of robust in vitro models of the rat blood-brain barrier and blood-spinal cord barrier.

PubMed

Watson, P Marc D; Paterson, Judy C; Thom, George; Ginman, Ulrika; Lundquist, Stefan; Webster, Carl I

2013-06-18

Modelling the blood-CNS barriers of the brain and spinal cord in vitro continues to provide a considerable challenge for research studying the passage of large and small molecules in and out of the central nervous system, both within the context of basic biology and for pharmaceutical drug discovery. Although there has been considerable success over the previous two decades in establishing useful in vitro primary endothelial cell cultures from the blood-CNS barriers, no model fully mimics the high electrical resistance, low paracellular permeability and selective influx/efflux characteristics of the in vivo situation. Furthermore, such primary-derived cultures are typically labour-intensive and generate low yields of cells, limiting scope for experimental work. We thus aimed to establish protocols for the high yield isolation and culture of endothelial cells from both rat brain and spinal cord. Our aim was to optimise in vitro conditions for inducing phenotypic characteristics in these cells that were reminiscent of the in vivo situation, such that they developed into tight endothelial barriers suitable for performing investigative biology and permeability studies. Brain and spinal cord tissue was taken from the same rats and used to specifically isolate endothelial cells to reconstitute as in vitro blood-CNS barrier models. Isolated endothelial cells were cultured to expand the cellular yield and then passaged onto cell culture inserts for further investigation. Cell culture conditions were optimised using commercially available reagents and the resulting barrier-forming endothelial monolayers were characterised by functional permeability experiments and in vitro phenotyping by immunocytochemistry and western blotting. Using a combination of modified handling techniques and cell culture conditions, we have established and optimised a protocol for the in vitro culture of brain and, for the first time in rat, spinal cord endothelial cells. High yields of both CNS endothelial cell types can be obtained, and these can be passaged onto large numbers of cell culture inserts for in vitro permeability studies. The passaged brain and spinal cord endothelial cells are pure and express endothelial markers, tight junction proteins and intracellular transport machinery. Further, both models exhibit tight, functional barrier characteristics that are discriminating against large and small molecules in permeability assays and show functional expression of the pharmaceutically important P-gp efflux transporter. Our techniques allow the provision of high yields of robust sister cultures of endothelial cells that accurately model the blood-CNS barriers in vitro. These models are ideally suited for use in studying the biology of the blood-brain barrier and blood-spinal cord barrier in vitro and for pre-clinical drug discovery.

Peripheral Endothelial Function After Arterial Switch Operation for D-looped Transposition of the Great Arteries.

PubMed

Sun, Heather Y; Stauffer, Katie Jo; Nourse, Susan E; Vu, Chau; Selamet Tierney, Elif Seda

2017-06-01

Coronary artery re-implantation during arterial switch operation in patients with D-looped transposition of the great arteries (D-TGA) can alter coronary arterial flow and increase shear stress, leading to local endothelial dysfunction, although prior studies have conflicting results. Endothelial pulse amplitude testing can predict coronary endothelial dysfunction by peripheral arterial testing. This study tested if, compared to healthy controls, patients with D-TGA after arterial switch operation had peripheral endothelial dysfunction. Patient inclusion criteria were (1) D-TGA after neonatal arterial switch operation; (2) age 9-29 years; (3) absence of known cardiovascular risk factors such as hypertension, diabetes, hypercholesterolemia, vascular disease, recurrent vasovagal syncope, and coronary artery disease; and (4) ability to comply with overnight fasting. Exclusion criteria included (1) body mass index ≥85th percentile, (2) use of medications affecting vascular tone, or (3) acute illness. We assessed endothelial function by endothelial pulse amplitude testing and compared the results to our previously published data in healthy controls (n = 57). We tested 20 D-TGA patients (16.4 ± 4.8 years old) who have undergone arterial switch operation at a median age of 5 days (0-61 days). Endothelial pulse amplitude testing indices were similar between patients with D-TGA and controls (1.78 ± 0.61 vs. 1.73 ± 0.54, p = 0.73).In our study population of children and young adults, there was no evidence of peripheral endothelial dysfunction in patients with D-TGA who have undergone arterial switch operation. Our results support the theory that coronary arterial wall thickening and abnormal vasodilation reported in these patients is a localized phenomenon and not reflective of overall atherosclerotic burden.

Role of endothelial dysfunction in modulating the plasma redox homeostasis in visceral leishmaniasis.

PubMed

Chowdhury, Kaustav Dutta; Sen, Gargi; Sarkar, Avik; Biswas, Tuli

2011-07-01

Evidence in the literature suggests that down-regulation of nitric oxide (NO) is associated with the pathophysiological conditions during visceral leishmaniasis (VL). Here we have investigated the mechanism that leads to the down regulation of systemic NO in the infected condition. Moreover, we have determined whether down regulation of NO is associated with increased generation of reactive oxygen species (ROS) during this disease. Therapeutic strategy targeting signaling molecules of these events was evaluated. Plasma protein-nitrotyrosine was examined by ELISA kit. Generation of superoxides and peroxynitrites was investigated by flow cytometry. NO bioavailability in endothelial cells was evaluated using DAF-2DA fluorescence. Ceramide contents were evaluated using FACS analysis, HPTLC and HPLC. L. donovani infected reticulo-endothelial cells regulated the activity of eNOS and NAD(P)H oxidase in the endothelial cells through the generation of intercellular messenger, ceramide. Activation of SMases played an important role in the generation of ceramide in animals during chronic infection. These events led to generation of ROS within endothelial cells. Modulation of redox status of plasma and accumulation of ROS in endothelial cells were critically involved in the regulation of NO bioavailability in plasma of the infected animal. Endothelial dysfunction and decline of NO were resulted from an increased production of superoxide where upregulation of eNOS expression appeared as an ineffective compensatory event. Inhibition of ceramide generation increased NO bioavailability, prevented endothelial dysfunction and concomitant oxidative stress. Decreased NO bioavailability and endothelial dysfunction were the downstream of ceramide signaling cascade. ROS accumulation promoted peroxynitrite generation and reduced NO bioavailability. Inhibition of ceramide generation may be a potential therapeutic option in preventing the co-morbidity associated with VL. 2011 Elsevier B.V. All rights reserved.

The interleukin-1 receptor antagonist anakinra improves endothelial dysfunction in streptozotocin-induced diabetic rats.

PubMed

Vallejo, Susana; Palacios, Erika; Romacho, Tania; Villalobos, Laura; Peiró, Concepción; Sánchez-Ferrer, Carlos F

2014-12-18

Endothelial dysfunction is a crucial early phenomenon in vascular diseases linked to diabetes mellitus and associated to enhanced oxidative stress. There is increasing evidence about the role for pro-inflammatory cytokines, like interleukin-1β (IL-1β), in developing diabetic vasculopathy. We aimed to determine the possible involvement of this cytokine in the development of diabetic endothelial dysfunction, analysing whether anakinra, an antagonist of IL-1 receptors, could reduce this endothelial alteration by interfering with pro-oxidant and pro-inflammatory pathways into the vascular wall. In control and two weeks evolution streptozotocin-induced diabetic rats, either untreated or receiving anakinra, vascular reactivity and NADPH oxidase activity were measured, respectively, in isolated rings and homogenates from mesenteric microvessels, while nuclear factor (NF)-κB activation was determined in aortas. Plasma levels of IL-1β and tumor necrosis factor (TNF)-α were measured by ELISA. In isolated mesenteric microvessels from control rats, two hours incubation with IL-1β (1 to 10 ng/mL) produced a concentration-dependent impairment of endothelium-dependent relaxations, which were mediated by enhanced NADPH oxidase activity via IL-1 receptors. In diabetic rats treated with anakinra (100 or 160 mg/Kg/day for 3 or 7 days before sacrifice) a partial improvement of diabetic endothelial dysfunction occurred, together with a reduction of vascular NADPH oxidase and NF-κB activation. Endothelial dysfunction in diabetic animals was also associated to higher activities of the pro-inflammatory enzymes cyclooxygenase (COX) and the inducible isoform of nitric oxide synthase (iNOS), which were markedly reduced after anakinra treatment. Circulating IL-1β and TNF-α levels did not change in diabetic rats, but they were lowered by anakinra treatment. In this short-term model of type 1 diabetes, endothelial dysfunction is associated to an IL-1 receptor-mediated activation of vascular NADPH oxidase and NF-κB, as well as to vascular inflammation. Moreover, endothelial dysfunction, vascular oxidative stress and inflammation were reduced after anakinra treatment. Whether this mechanism can be extrapolated to a chronic situation or whether it may apply to diabetic patients remain to be established. However, it may provide new insights to further investigate the therapeutic use of IL-1 receptor antagonists to obtain vascular benefits in patients with diabetes mellitus and/or atherosclerosis.

[Endothelial dysfunction and nonspecific immune reactions in development and progression of osteoarthrosis in women engaged into manual work].

PubMed

Maliutina, N N; Nevzorova, M S

2015-01-01

The article considers mechanisms of development and progression of osteoarthrosis as an occupationally conditioned disease in women of manual work. Women working in physical overstrain conditions are under occupational risk with dysfunction of many body systems. The authors set a hypothesis on association of endothelial dysfunction markers dysbalance and structural remodelling of cartilage matrix as a proof of degenerative changes.

Vascular extracellular vesicles in comorbidities of heart failure with preserved ejection fraction in men and women: The hidden players. A mini review.

PubMed

Gohar, Aisha; de Kleijn, Dominique P V; Hoes, Arno W; Rutten, Frans H; Hilfiker-Kleiner, Denise; Ferdinandy, Péter; Sluijter, Joost P G; den Ruijter, Hester M

2018-05-25

Left ventricular diastolic dysfunction, the main feature of heart failure with preserved ejection fraction (HFpEF), is thought to be primarily caused by comorbidities affecting the endothelial function of the coronary microvasculature. Circulating extracellular vesicles, released by the endothelium have been postulated to reflect endothelial damage. Therefore, we reviewed the role of extracellular vesicles, in particularly endothelium microparticles, in these comorbidities, including obesity and hypertension, to identify if they may be potential markers of the endothelial dysfunction underlying left ventricular diastolic dysfunction and HFpEF. Copyright © 2017. Published by Elsevier Inc.

Beta-adrenergic stimulation contributes to maintenance of endothelial barrier functions under baseline conditions.

PubMed

Spindler, Volker; Waschke, Jens

2011-02-01

cAMP signaling within the endothelium is known to reduce paracellular permeability and to protect against loss of barrier functions under various pathological conditions. Because activation of β-adrenergic receptors elevates cellular cAMP, we tested whether β-adrenergic receptor signaling contributes to the maintenance of baseline endothelial barrier properties. We compared hydraulic conductivity of rat postcapillary venules in vivo with resistance measurements and with reorganization of endothelial adherens junctions in cultured microvascular endothelial cells downstream of β-adrenergic receptor-mediated changes of cAMP levels. Inhibition of β-adrenergic receptors by propranolol increased hydraulic conductivity, reduced both cAMP levels and TER of microvascular endothelial cell monolayers and induced fragmentation of VE-cadherin staining. In contrast, activation by epinephrine both increased cAMP levels and TER and resulted in linearized VE-cadherin distribution, however this was not sufficient to block barrier-destabilization by propranolol. Similarly, PDE inhibition did not prevent propranolol-induced TER reduction and VE-cadherin reorganization whereas increased cAMP formation by AC activation enhanced endothelial barrier functions under baseline conditions and under conditions of propranolol treatment. Our results indicate that generation of cAMP mediated by activation of β-adrenergic receptor signaling contributes to the maintenance of endothelial barrier properties under baseline conditions. © 2011 John Wiley & Sons Ltd.

Fluid Mechanical Forces and Endothelial Mitochondria: A Bioengineering Perspective.

PubMed

Scheitlin, Christopher G; Nair, Devi M; Crestanello, Juan A; Zweier, Jay L; Alevriadou, B Rita

2014-12-01

Endothelial cell dysfunction is the hallmark of every cardiovascular disease/condition, including atherosclerosis and ischemia/reperfusion injury. Fluid shear stress acting on the vascular endothelium is known to regulate cell homeostasis. Altered hemodynamics is thought to play a causative role in endothelial dysfunction. The dysfunction is associated with/preceded by mitochondrial oxidative stress. Studies by our group and others have shown that the form and/or function of the mitochondrial network are affected when endothelial cells are exposed to shear stress in the absence or presence of additional physicochemical stimuli. The present review will summarize the current knowledge on the interconnections among intracellular Ca 2+ - nitric oxide - mitochondrial reactive oxygen species, mitochondrial fusion/fission, autophagy/mitophagy, and cell apoptosis vs. survival. More specifically, it will list the evidence on potential regulation of the above intracellular species and processes by the fluid shear stress acting on the endothelium under either physiological flow conditions or during reperfusion (following a period of ischemia). Understanding how the local hemodynamics affects mitochondrial physiology and the cell redox state may lead to development of novel therapeutic strategies for prevention or treatment of the endothelial dysfunction and, hence, of cardiovascular disease.

The relationship between vascular endothelial dysfunction and treatment frequency in neovascular age-related macular degeneration.

PubMed

Ueda-Consolvo, Tomoko; Hayashi, Atsushi; Ozaki, Mayumi; Nakamura, Tomoko; Yagou, Takaaki; Abe, Shinya

2017-07-01

To assess the correlation between endothelial dysfunction and frequency of antivascular endothelial growth factor (anti-VEGF) treatment for neovascular age-related macular degeneration (nAMD). We examined 64 consecutive patients with nAMD who were evaluated for endothelial function by use of peripheral arterial tonometry (EndoPAT 2000; Itamar Medical, Caesarea, Israel) at Toyama University Hospital from January 2015. We tallied the number of anti-VEGF treatments between January 2014 and December 2015 and determined the correlation between the number of anti-VEGF injections and endothelial function expressed as the reactive hyperemia index (RHI). Multiple regression analysis was also performed to identify the independent predictors of a larger number of injections. The mean number of anti-VEGF injections was 8.2 ± 3.3. The mean lnRHI was 0.47 ± 0.17. The lnRHI correlated with the number of anti-VEGF injections (r = -0.56; P = 0.030). The multiple regression analysis revealed that endothelial function, neovascular subtypes, and treatment regimens were associated with the number of injections. Endothelial dysfunction may affect the efficacy of anti-VEGF therapy. Neovascular subtypes may also predict a larger number of injections.

Prognostic and Pathogenic Role of Angiopoietin-1 and -2 in Pneumonia.

PubMed

Gutbier, Birgitt; Neuhauß, Anne-Kathrin; Reppe, Katrin; Ehrler, Carolin; Santel, Ansgar; Kaufmann, Jörg; Scholz, Markus; Weissmann, Norbert; Morawietz, Lars; Mitchell, Timothy J; Aliberti, Stefano; Hippenstiel, Stefan; Suttorp, Norbert; Witzenrath, Martin

2018-02-15

During pneumonia, pathogen-host interaction evokes inflammation and lung barrier dysfunction. Tie2-activation by Angiopoietin-1 reduces, while Tie2-blockade by Angiopoietin-2 increases inflammation and permeability during sepsis. The role of Angiopoietin-1/-2 in pneumonia remains unidentified. To investigate the prognostic and pathogenetic impact of Angiopoietins in regulating pulmonary vascular barrier function and inflammation in bacterial pneumonia. Serum Angiopoietin levels were quantified in pneumonia patients of two independent cohorts (n=148, n=395). Human post mortem lung tissue, pneumolysin- or Angiopoietin-2-stimulated endothelial cells, isolated perfused and ventilated mouse lungs, and mice with pneumococcal pneumonia were investigated. In pneumonia patients, decreased serum Angiopoietin-1 and increased Angiopoietin-2 levels were observed as compared to healthy subjects. Higher Angiopoietin-2 serum levels were found in community-acquired pneumonia patients who died within 28 days after diagnosis compared to survivors. ROC analysis revealed improved prognostic accuracy of CURB-65 for 28-day survival, intensive care treatment and length of hospital stay if combined with Angiopoietin-2 serum levels. In vitro, pneumolysin enhanced endothelial Angiopoietin-2 release, Angiopoietin-2 increased endothelial permeability, and Angiopoietin-1 reduced pneumolysin-evoked endothelial permeability. Ventilated and perfused lungs of mice with Angiopoietin-2-knockdown showed reduced permeability upon pneumolysin stimulation. Increased pulmonary Angiopoietin-2 and reduced Angiopoietin-1 mRNA expression were observed in S. pneumoniae infected mice. Finally, Angiopoietin-1 therapy reduced inflammation and permeability in murine pneumonia. These data suggest a central role of Angiopoietin-1/-2 in pneumonia-evoked inflammation and permeability. Increased Angiopoietin-2 serum levels predicted mortality and length of hospital stay, and Angiopoietin-1 may provide a therapeutic target for severe pneumonia.

Parmodulins inhibit thrombus formation without inducing endothelial injury caused by vorapaxar.

PubMed

Aisiku, Omozuanvbo; Peters, Christian G; De Ceunynck, Karen; Ghosh, Chandra C; Dilks, James R; Fustolo-Gunnink, Susanna F; Huang, Mingdong; Dockendorff, Chris; Parikh, Samir M; Flaumenhaft, Robert

2015-03-19

Protease-activated receptor-1 (PAR1) couples the coagulation cascade to platelet activation during myocardial infarction and to endothelial inflammation during sepsis. This receptor demonstrates marked signaling bias. Its activation by thrombin stimulates prothrombotic and proinflammatory signaling, whereas its activation by activated protein C (APC) stimulates cytoprotective and antiinflammatory signaling. A challenge in developing PAR1-targeted therapies is to inhibit detrimental signaling while sparing beneficial pathways. We now characterize a novel class of structurally unrelated small-molecule PAR1 antagonists, termed parmodulins, and compare the activity of these compounds to previously characterized compounds that act at the PAR1 ligand-binding site. We find that parmodulins target the cytoplasmic face of PAR1 without modifying the ligand-binding site, blocking signaling through Gαq but not Gα13 in vitro and thrombus formation in vivo. In endothelium, parmodulins inhibit prothrombotic and proinflammatory signaling without blocking APC-mediated pathways or inducing endothelial injury. In contrast, orthosteric PAR1 antagonists such as vorapaxar inhibit all signaling downstream of PAR1. Furthermore, exposure of endothelial cells to nanomolar concentrations of vorapaxar induces endothelial cell barrier dysfunction and apoptosis. These studies demonstrate how functionally selective antagonism can be achieved by targeting the cytoplasmic face of a G-protein-coupled receptor to selectively block pathologic signaling while preserving cytoprotective pathways. © 2015 by The American Society of Hematology.

The chromogranin A peptide vasostatin-I inhibits gap formation and signal transduction mediated by inflammatory agents in cultured bovine pulmonary and coronary arterial endothelial cells.

PubMed

Blois, Anna; Srebro, Boleslaw; Mandalà, Maurizio; Corti, Angelo; Helle, Karen B; Serck-Hanssen, Guldborg

2006-07-15

The proinflammatory agent tumour necrosis factor alpha (TNFalpha) is one of several agents causing vascular leakage. The N-terminal domain of CgA, vasostatin-I (CgA1-76), has recently been reported to inhibit TNFalpha induced gap formation in human umbilical venous endothelial cells. Here we report on the effect of recombinant human CgA1-78, vasostatin-I, on TNFalpha induced gap formation in two model systems of vascular leakage in arterial endothelial cells of bovine pulmonary (BPAEC) and coronary (BCAEC) origin. Vasostatin-I inhibited the TNFalpha induced gap formation in both models, being inactive in the unstimulated cells. The phosphorylation of p38MAP kinase in TNFalpha activated BPAEC was markedly attenuated in the presence of vasostatin-I and the inhibitory effect corresponded to that of the specific p38MAPK inhibitor SB203580. Vasostatin-I also inhibited the phosphorylation of p38MAPK induced by both thrombin and pertussis toxin in these cells. The results demonstrate that vasostatin-I has inhibitory effects on TNFalpha-induced disruption of confluent layers of cultured pulmonary and coronary arterial endothelial cells. This suggests that vasostatin-I may affect endothelial barrier dysfunction also in arterial vascular beds. Furthermore, the inhibitory activity of vasostatin-I may be associated with the p38MAPK signalling cascade via a pertussis toxin sensitive, presumably Galphai coupled mechanism.

Serum from Diesel Exhaust-Exposed Rats with Cardiac Dysfunction Alters Aortic Endothelial Cell Function In Vitro: Circulating Mediators as Causative Factors?

EPA Science Inventory

Although circulating inflammatory mediators are strongly associated with adverse cardiovascular outcomes triggered by inhaled air pollution, direct cause-effect linkage has not been established. Given that endothelial toxicity often precedes and precipitates cardiac dysfunction, ...

Asymmetric Dimethylarginine as a Surrogate Marker of Endothelial Dysfunction and Cardiovascular Risk in Patients with Systemic Rheumatic Diseases

PubMed Central

Dimitroulas, Theodoros; Sandoo, Aamer; Kitas, George D.

2012-01-01

The last few decades have witnessed an increased life expectancy of patients suffering with systemic rheumatic diseases, mainly due to improved management, advanced therapies and preventative measures. However, autoimmune disorders are associated with significantly enhanced cardiovascular morbidity and mortality not fully explained by traditional cardiovascular disease (CVD) risk factors. It has been suggested that interactions between high-grade systemic inflammation and the vasculature lead to endothelial dysfunction and atherosclerosis, which may account for the excess risk for CVD events in this population. Diminished nitric oxide synthesis—due to down regulation of endothelial nitric oxide synthase—appears to play a prominent role in the imbalance between vasoactive factors, the consequent impairment of the endothelial hemostasis and the early development of atherosclerosis. Asymmetric dimethylarginine (ADMA) is one of the most potent endogenous inhibitors of the three isoforms of nitric oxide synthase and it is a newly discovered risk factor in the setting of diseases associated with endothelial dysfunction and adverse cardiovascular events. In the context of systemic inflammatory disorders there is increasing evidence that ADMA contributes to the vascular changes and to endothelial cell abnormalities, as several studies have revealed derangement of nitric oxide/ADMA pathway in different disease subsets. In this article we discuss the role of endothelial dysfunction in patients with rheumatic diseases, with a specific focus on the nitric oxide/ADMA system and we provide an overview on the literature pertaining to ADMA as a surrogate marker of subclinical vascular disease. PMID:23202900

Impact of HIV and Type 2 diabetes on Gut Microbiota Diversity, Tryptophan Catabolism and Endothelial Dysfunction.

PubMed

Hoel, Hedda; Hove-Skovsgaard, Malene; Hov, Johannes R; Gaardbo, Julie Christine; Holm, Kristian; Kummen, Martin; Rudi, Knut; Nwosu, Felix; Valeur, Jørgen; Gelpi, Marco; Seljeflot, Ingebjørg; Ueland, Per Magne; Gerstoft, Jan; Ullum, Henrik; Aukrust, Pål; Nielsen, Susanne Dam; Trøseid, Marius

2018-04-30

HIV infection and type 2 diabetes are associated with altered gut microbiota, chronic inflammation, and increased cardiovascular risk. We aimed to investigate the combined effect of these diseases on gut microbiota composition and related metabolites, and a potential relation to endothelial dysfunction in individuals with HIV-infection only (n = 23), diabetes only (n = 16) or both conditions (n = 21), as well as controls (n = 24). Fecal microbiota was analyzed by Illumina sequencing of the 16 S rRNA gene. Markers of endothelial dysfunction (asymmetric dimethylarginine [ADMA]), tryptophan catabolism (kynurenine/tryptophan [KT]-ratio), and inflammation (neopterin) were measured by liquid chromatography-tandem mass spectrometry. The combination of HIV and type 2 diabetes was associated with reduced gut microbiota diversity, increased plasma KT-ratio and neopterin. Microbial genes related to tryptophan metabolism correlated with KT-ratio and low alpha diversity, in particular in HIV-infected with T2D. In multivariate analyses, KT-ratio associated with ADMA (β = 4.58 [95% CI 2.53-6.63], p < 0.001), whereas microbiota composition per se was not associated with endothelial dysfunction. Our results indicate that tryptophan catabolism may be related to endothelial dysfunction, with a potentially detrimental interaction between HIV and diabetes. The potential contribution of gut microbiota and the impact for cardiovascular risk should be further explored in prospective studies powered for clinical end points.

Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Bhupesh, E-mail: drbhupeshresearch@gmail.com; Sharma, P.M.

Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment ofmore » learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential in As induced VaD.« less

Intracellular ascorbate tightens the endothelial permeability barrier through Epac1 and the tubulin cytoskeleton

PubMed Central

Parker, William H.; Rhea, Elizabeth Meredith; Qu, Zhi-Chao; Hecker, Morgan R.

2016-01-01

Vitamin C, or ascorbic acid, both tightens the endothelial permeability barrier in basal cells and also prevents barrier leak induced by inflammatory agents. Barrier tightening by ascorbate in basal endothelial cells requires nitric oxide derived from activation of nitric oxide synthase. Although ascorbate did not affect cyclic AMP levels in our previous study, there remains a question of whether it might activate downstream cyclic AMP-dependent pathways. In this work, we found in both primary and immortalized cultured endothelial cells that ascorbate tightened the endothelial permeability barrier by ∼30%. In human umbilical vein endothelial cells, this occurred at what are likely physiologic intracellular ascorbate concentrations. In so doing, ascorbate decreased measures of oxidative stress and also flattened the cells to increase cell-to-cell contact. Inhibition of downstream cyclic AMP-dependent proteins via protein kinase A did not prevent ascorbate from tightening the endothelial permeability barrier, whereas inhibition of Epac1 did block the ascorbate effect. Although Epac1 was required, its mediator Rap1 was not activated. Furthermore, ascorbate acutely stabilized microtubules during depolymerization induced by colchicine and nocodazole. Over several days in culture, ascorbate also increased the amount of stable acetylated α-tubulin. Microtubule stabilization was further suggested by the finding that ascorbate increased the amount of Epac1 bound to α-tubulin. These results suggest that physiologic ascorbate concentrations tighten the endothelial permeability barrier in unstimulated cells by stabilizing microtubules in a manner downstream of cyclic AMP that might be due both to increasing nitric oxide availability and to scavenging of reactive oxygen or nitrogen species. PMID:27605450

Oxidative stress activates endothelial innate immunity via sterol regulatory element binding protein 2 (SREBP2) transactivation of microRNA-92a.

PubMed

Chen, Zhen; Wen, Liang; Martin, Marcy; Hsu, Chien-Yi; Fang, Longhou; Lin, Feng-Mao; Lin, Ting-Yang; Geary, McKenna J; Geary, Greg G; Zhao, Yongli; Johnson, David A; Chen, Jaw-Wen; Lin, Shing-Jong; Chien, Shu; Huang, Hsien-Da; Miller, Yury I; Huang, Po-Hsun; Shyy, John Y-J

2015-03-03

Oxidative stress activates endothelial innate immunity and disrupts endothelial functions, including endothelial nitric oxide synthase-derived nitric oxide bioavailability. Here, we postulated that oxidative stress induces sterol regulatory element-binding protein 2 (SREBP2) and microRNA-92a (miR-92a), which in turn activate endothelial innate immune response, leading to dysfunctional endothelium. Using cultured endothelial cells challenged by diverse oxidative stresses, hypercholesterolemic zebrafish, and angiotensin II-infused or aged mice, we demonstrated that SREBP2 transactivation of microRNA-92a (miR-92a) is oxidative stress inducible. The SREBP2-induced miR-92a targets key molecules in endothelial homeostasis, including sirtuin 1, Krüppel-like factor 2, and Krüppel-like factor 4, leading to NOD-like receptor family pyrin domain-containing 3 inflammasome activation and endothelial nitric oxide synthase inhibition. In endothelial cell-specific SREBP2 transgenic mice, locked nucleic acid-modified antisense miR-92a attenuates inflammasome, improves vasodilation, and ameliorates angiotensin II-induced and aging-related atherogenesis. In patients with coronary artery disease, the level of circulating miR-92a is inversely correlated with endothelial cell-dependent, flow-mediated vasodilation and is positively correlated with serum level of interleukin-1β. Our findings suggest that SREBP2-miR-92a-inflammasome exacerbates endothelial dysfunction during oxidative stress. Identification of this mechanism may help in the diagnosis or treatment of disorders associated with oxidative stress, innate immune activation, and endothelial dysfunction. © 2014 American Heart Association, Inc.

[Non-pharmacologic therapy of age-related macular degeneration, based on the etiopathogenesis of the disease].

PubMed

Fischer, Tamás

2015-07-12

It has a great therapeutic significance that the disorder of the vascular endothelium, which supplies the affected ocular structures, plays a major role in the development of age-related macular degeneration. Chronic inflammation is closely linked to diseases associated with endothelial dysfuncition and age-related macular degeneration is accompanied by a general inflammatory response. The vascular wall including those in chorioids may be activated by several repeated and/or prolonged mechanical, physical, chemical, microbiological, immunologic and genetic factors causing a protracted host defence response with a consequent vascular damage, which leads to age-related macular degeneration. Based on this concept, age-related macular degeneration is a local manifestation of the systemic vascular disease. This recognition should have therapeutic implications because restoration of endothelial dysfunction can stabilize the condition of chronic vascular disease including age-related macular degeneration, as well. Restoration of endothelial dysfunction by non-pharmacological or pharmacological interventions may prevent the development or improve endothelial dysfunction resulting in prevention or improvement of age-related macular degeneration. Non-pharmacological interventions which may have beneficial effect in endothelial dysfunction include (1) smoking cessation; (2) reduction of increased body weight; (3) adequate physical activity; (4) appropriate diet (a) proper dose of flavonoids, polyphenols and kurcumin; (b) omega-3 long-chain polyunsaturated fatty acids: docosahexaenoic acid and eicosapentaenoic acid; (c) carotenoids, lutein and zeaxanthins), (d) management of dietary glycemic index, (e) caloric restriction, and (5) elimination of stressful lifestyle. Non-pharmacological interventions should be preferable even if medicaments are also used for the treatment of endothelial dysfunction.

A biphasic endothelial stress-survival mechanism regulates the cellular response to vascular endothelial growth factor A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Latham, Antony M.; Odell, Adam F.; Mughal, Nadeem A.

2012-11-01

Vascular endothelial growth factor A (VEGF-A) is an essential cytokine that regulates endothelial function and angiogenesis. VEGF-A binding to endothelial receptor tyrosine kinases such as VEGFR1 and VEGFR2 triggers cellular responses including survival, proliferation and new blood vessel sprouting. Increased levels of a soluble VEGFR1 splice variant (sFlt-1) correlate with endothelial dysfunction in pathologies such as pre-eclampsia; however the cellular mechanism(s) underlying the regulation and function of sFlt-1 are unclear. Here, we demonstrate the existence of a biphasic stress response in endothelial cells, using serum deprivation as a model of endothelial dysfunction. The early phase is characterized by a highmore » VEGFR2:sFlt-1 ratio, which is reversed in the late phase. A functional consequence is a short-term increase in VEGF-A-stimulated intracellular signaling. In the late phase, sFlt-1 is secreted and deposited at the extracellular matrix. We hypothesized that under stress, increased endothelial sFlt-1 levels reduce VEGF-A bioavailability: VEGF-A treatment induces sFlt-1 expression at the cell surface and VEGF-A silencing inhibits sFlt-1 anchorage to the extracellular matrix. Treatment with recombinant sFlt-1 inhibits VEGF-A-stimulated in vitro angiogenesis and sFlt-1 silencing enhances this process. In this response, increased VEGFR2 levels are regulated by the phosphatidylinositol-3-kinase and PKB/Akt signaling pathways and increased sFlt-1 levels by the ERK1/2 signaling pathway. We conclude that during serum withdrawal, cellular sensing of environmental stress modulates sFlt-1 and VEGFR2 levels, regulating VEGF-A bioavailability and ensuring cell survival takes precedence over cell proliferation and migration. These findings may underpin an important mechanism contributing to endothelial dysfunction in pathological states. -- Highlights: Black-Right-Pointing-Pointer Endothelial cells mount a stress response under conditions of low serum. Black-Right-Pointing-Pointer Endothelial VEGFR levels are modulated during this response. Black-Right-Pointing-Pointer The cell regulates VEGF-A bioavailability and cell survival. Black-Right-Pointing-Pointer This may partly underlie endothelial dysfunction seen in many pathologies.« less

Endothelial disruptive proinflammatory effects of nicotine and e-cigarette vapor exposures.

PubMed

Schweitzer, Kelly S; Chen, Steven X; Law, Sarah; Van Demark, Mary; Poirier, Christophe; Justice, Matthew J; Hubbard, Walter C; Kim, Elena S; Lai, Xianyin; Wang, Mu; Kranz, William D; Carroll, Clinton J; Ray, Bruce D; Bittman, Robert; Goodpaster, John; Petrache, Irina

2015-07-15

The increased use of inhaled nicotine via e-cigarettes has unknown risks to lung health. Having previously shown that cigarette smoke (CS) extract disrupts the lung microvasculature barrier function by endothelial cell activation and cytoskeletal rearrangement, we investigated the contribution of nicotine in CS or e-cigarettes (e-Cig) to lung endothelial injury. Primary lung microvascular endothelial cells were exposed to nicotine, e-Cig solution, or condensed e-Cig vapor (1-20 mM nicotine) or to nicotine-free CS extract or e-Cig solutions. Compared with nicotine-containing extract, nicotine free-CS extract (10-20%) caused significantly less endothelial permeability as measured with electric cell-substrate impedance sensing. Nicotine exposures triggered dose-dependent loss of endothelial barrier in cultured cell monolayers and rapidly increased lung inflammation and oxidative stress in mice. The endothelial barrier disruptive effects were associated with increased intracellular ceramides, p38 MAPK activation, and myosin light chain (MLC) phosphorylation, and was critically mediated by Rho-activated kinase via inhibition of MLC-phosphatase unit MYPT1. Although nicotine at sufficient concentrations to cause endothelial barrier loss did not trigger cell necrosis, it markedly inhibited cell proliferation. Augmentation of sphingosine-1-phosphate (S1P) signaling via S1P1 improved both endothelial cell proliferation and barrier function during nicotine exposures. Nicotine-independent effects of e-Cig solutions were noted, which may be attributable to acrolein, detected along with propylene glycol, glycerol, and nicotine by NMR, mass spectrometry, and gas chromatography, in both e-Cig solutions and vapor. These results suggest that soluble components of e-Cig, including nicotine, cause dose-dependent loss of lung endothelial barrier function, which is associated with oxidative stress and brisk inflammation.

Inhibitive Effects of Quercetin on Myeloperoxidase-Dependent Hypochlorous Acid Formation and Vascular Endothelial Injury.

PubMed

Lu, Naihao; Sui, Yinhua; Tian, Rong; Peng, Yi-Yuan

2018-05-16

Myeloperoxidase (MPO) from activated neutrophils plays important roles in multiple human inflammatory diseases by catalyzing the formation of powerful oxidant hypochlorous acid (HOCl). As a major flavonoid in the human diet, quercetin has been suggested to act as antioxidant and anti-inflammatory agent in vitro and in vivo. In this study, we showed that quercetin inhibited MPO-mediated HOCl formation (75.0 ± 6.2% for 10 μM quercetin versus 100 ± 5.2% for control group, P < 0.01) and cytotoxicity to endothelial cells in vitro, while this flavonoid was nontoxic to endothelial cell cultures ( P > 0.05, all cases). Moreover, quercetin inhibited HOCl generation by stimulated neutrophils (a rich source of MPO) and protected endothelial cells from neutrophils-induced injury. Furthermore, quercetin could inhibit HOCl-induced endothelial dysfunction such as loss of cell viability, and decrease of nitric oxide formation in endothelial cells ( P < 0.05, all cases). Consistent with these in vitro data, quercetin attenuated lipopolysaccharide-induced endothelial dysfunction and increase of MPO activity in mouse aortas, while this flavonoid could protect against HOCl-mediated endothelial dysfunction in isolated aortas ( P < 0.05). Therefore, it was proposed that quercetin attenuated endothelial injury in inflammatory vasculature via inhibition of vascular-bound MPO-mediated HOCl formation or scavenging of HOCl. These data indicate that quercetin is a nontoxic inhibitor of MPO activity and MPO/neutrophils-induced cytotoxicity in endothelial cells and may be useful for targeting MPO-dependent vascular disease and inflammation.

Neutrophil-derived 5′-Adenosine Monophosphate Promotes Endothelial Barrier Function via CD73-mediated Conversion to Adenosine and Endothelial A2B Receptor Activation

PubMed Central

Lennon, Paul F.; Taylor, Cormac T.; Stahl, Gregory L.; Colgan, Sean P.

1998-01-01

During episodes of inflammation, polymorphonuclear leukocyte (PMN) transendothelial migration has the potential to disturb vascular barrier function and give rise to intravascular fluid extravasation and edema. However, little is known regarding innate mechanisms that dampen fluid loss during PMN-endothelial interactions. Using an in vitro endothelial paracellular permeability model, we observed a PMN-mediated decrease in endothelial paracellular permeability. A similar decrease was elicited by cell-free supernatants from activated PMN (FMLP 10−6 M), suggesting the presence of a PMN-derived soluble mediator(s). Biophysical and biochemical analysis of PMN supernatants revealed a role for PMN-derived 5′-adenosine monophosphate (AMP) and its metabolite, adenosine, in modulation of endothelial paracellular permeability. Supernatants from activated PMN contained micromolar concentrations of bioactive 5′-AMP and adenosine. Furthermore, exposure of endothelial monolayers to authentic 5′-AMP and adenosine increased endothelial barrier function more than twofold in both human umbilical vein endothelial cells and human microvascular endothelial cells. 5′-AMP bioactivity required endothelial CD73-mediated conversion of 5′-AMP to adenosine via its 5′-ectonucleotidase activity. Decreased endothelial paracellular permeability occurred through adenosine A2B receptor activation and was accompanied by a parallel increase in intracellular cAMP. We conclude that activated PMN release soluble mediators, such as 5′-AMP and adenosine, that promote endothelial barrier function. During inflammation, this pathway may limit potentially deleterious increases in endothelial paracellular permeability and could serve as a basic mechanism of endothelial resealing during PMN transendothelial migration. PMID:9782120

Pertussis Toxin Exploits Specific Host Cell Signaling Pathways for Promoting Invasion and Translocation of Escherichia coli K1 RS218 in Human Brain-derived Microvascular Endothelial Cells.

PubMed

Karassek, Sascha; Starost, Laura; Solbach, Johanna; Greune, Lilo; Sano, Yasuteru; Kanda, Takashi; Kim, KwangSik; Schmidt, M Alexander

2015-10-09

Pertussis toxin (PTx), an AB5 toxin and major virulence factor of the whooping cough-causing pathogen Bordetella pertussis, has been shown to affect the blood-brain barrier. Dysfunction of the blood-brain barrier may facilitate penetration of bacterial pathogens into the brain, such as Escherichia coli K1 (RS218). In this study, we investigated the influence of PTx on blood-brain barrier permissiveness to E. coli infection using human brain-derived endothelial HBMEC and TY10 cells as in vitro models. Our results indicate that PTx acts at several key points of host cell intracellular signaling pathways, which are also affected by E. coli K1 RS218 infection. Application of PTx increased the expression of the pathogen binding receptor gp96. Further, we found an activation of STAT3 and of the small GTPase Rac1, which have been described as being essential for bacterial invasion involving host cell actin cytoskeleton rearrangements at the bacterial entry site. In addition, we showed that PTx induces a remarkable relocation of VE-cadherin and β-catenin from intercellular junctions. The observed changes in host cell signaling molecules were accompanied by differences in intracellular calcium levels, which might act as a second messenger system for PTx. In summary, PTx not only facilitates invasion of E. coli K1 RS218 by activating essential signaling cascades; it also affects intercellular barriers to increase paracellular translocation. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Reduction of vascular leakage by imatinib is associated with preserved microcirculatory perfusion and reduced renal injury markers in a rat model of cardiopulmonary bypass.

PubMed

Koning, N J; de Lange, F; van Meurs, M; Jongman, R M; Ahmed, Y; Schwarte, L A; van Nieuw Amerongen, G P; Vonk, A B A; Niessen, H W; Baufreton, C; Boer, C

2018-06-01

Cardiopulmonary bypass during cardiac surgery leads to impaired microcirculatory perfusion. We hypothesized that vascular leakage is an important contributor to microcirculatory dysfunction. Imatinib, a tyrosine kinase inhibitor, has been shown to reduce vascular leakage in septic mice. We investigated whether prevention of vascular leakage using imatinib preserves microcirculatory perfusion and reduces organ injury markers in a rat model of cardiopulmonary bypass. Male Wistar rats underwent cardiopulmonary bypass after treatment with imatinib or vehicle (n=8 per group). Cremaster muscle microcirculatory perfusion and quadriceps microvascular oxygen saturation were measured using intravital microscopy and reflectance spectroscopy. Evans Blue extravasation was determined in separate experiments. Organ injury markers were determined in plasma, intestine, kidney, and lungs. The onset of cardiopulmonary bypass decreased the number of perfused microvessels by 40% in the control group [9.4 (8.6-10.6) to 5.7 (4.8-6.2) per microscope field; P<0.001 vs baseline], whereas this reduction was not seen in the imatinib group. In the control group, the number of perfused capillaries remained low throughout the experiment, whilst perfusion remained normal after imatinib administration. Microvascular oxygen saturation was less impaired after imatinib treatment compared with controls. Imatinib reduced vascular leakage and decreased fluid resuscitation compared with control [3 (3-6) vs 12 ml (7-16); P=0.024]. Plasma neutrophil-gelatinase-associated-lipocalin concentrations were reduced by imatinib. Prevention of endothelial barrier dysfunction using imatinib preserved microcirculatory perfusion and oxygenation during and after cardiopulmonary bypass. Moreover, imatinib-induced protection of endothelial barrier integrity reduced fluid-resuscitation requirements and attenuated renal and pulmonary injury markers. Copyright © 2017 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

Endothelial actions of atrial and B-type natriuretic peptides.

PubMed

Kuhn, Michaela

2012-05-01

The cardiac hormone atrial natriuretic peptide (ANP) is critically involved in the maintenance of arterial blood pressure and intravascular volume homeostasis. Its cGMP-producing GC-A receptor is densely expressed in the microvascular endothelium of the lung and systemic circulation, but the functional relevance is controversial. Some studies reported that ANP stimulates endothelial cell permeability, whereas others described that the peptide attenuates endothelial barrier dysfunction provoked by inflammatory agents such as thrombin or histamine. Many studies in vitro addressed the effects of ANP on endothelial proliferation and migration. Again, both pro- and anti-angiogenic properties were described. To unravel the role of the endothelial actions of ANP in vivo, we inactivated the murine GC-A gene selectively in endothelial cells by homologous loxP/Cre-mediated recombination. Our studies in these mice indicate that ANP, via endothelial GC-A, increases endothelial albumin permeability in the microcirculation of the skin and skeletal muscle. This effect is critically involved in the endocrine hypovolaemic, hypotensive actions of the cardiac hormone. On the other hand the homologous GC-A-activating B-type NP (BNP), which is produced by cardiac myocytes and many other cell types in response to stressors such as hypoxia, possibly exerts more paracrine than endocrine actions. For instance, within the ischaemic skeletal muscle BNP released from activated satellite cells can improve the regeneration of neighbouring endothelia. This review will focus on recent advancements in our understanding of endothelial NP/GC-A signalling in the pulmonary versus systemic circulation. It will discuss possible mechanisms accounting for the discrepant observations made for the endothelial actions of this hormone-receptor system and distinguish between (patho)physiological and pharmacological actions. Lastly it will emphasize the potential therapeutical implications derived from the actions of NPs on endothelial permeability and regeneration. © 2012 The Author. British Journal of Pharmacology © 2012 The British Pharmacological Society.

Arginase Inhibition Improves Microvascular Endothelial Function in Patients With Type 2 Diabetes Mellitus.

PubMed

Kövamees, Oskar; Shemyakin, Alexey; Checa, Antonio; Wheelock, Craig E; Lundberg, Jon O; Östenson, Claes-Göran; Pernow, John

2016-11-01

The development of microvascular complications in diabetes is a complex process in which endothelial dysfunction is important. Emerging evidence suggests that arginase is a key mediator of endothelial dysfunction in type 2 diabetes mellitus by reciprocally regulating nitric oxide bioavailability. The aim of this prospective intervention study was to test the hypothesis that arginase activity is increased and that arginase inhibition improves microvascular endothelial function in patients with type 2 diabetes and microvascular dysfunction. Microvascular endothelium-dependent and -independent dilatation was determined in patients with type 2 diabetes (n = 12) and healthy age-matched control subjects (n = 12) with laser Doppler flowmetry during iontophoretic application of acetylcholine and sodium nitroprusside, respectively, before and after administration of the arginase inhibitor N ω -hydroxy-nor-L-arginine (120 min). Plasma ratios of amino acids involved in arginase and nitric oxide synthase activities were determined. The laser Doppler flowmetry data were the primary outcome variable. Microvascular endothelium-dependent dilatation was impaired in subjects with type 2 diabetes (P < .05). After administration of N ω -hydroxy-nor-L-arginine, microvascular endothelial function improved significantly in patients with type 2 diabetes to the level observed in healthy controls. Endothelium-independent vasodilatation did not change significantly. Subjects with type 2 diabetes had higher levels of ornithine and higher ratios of ornithine/citrulline and ornithine/arginine (P < .05), suggesting increased arginase activity. Arginase inhibition improves microvascular endothelial function in patients with type 2 diabetes and microvascular dysfunction. Arginase inhibition may represent a novel therapeutic strategy to improve microvascular endothelial function in patients with type 2 diabetes.

The ultrastructure of cerebral blood capillaries in the ratfish, Chimaera monstrosa.

PubMed

Bundgaard, M

1982-01-01

Sharks and skates (Chondrichthyes: Elasmobranchii) have a glial blood-brain barrier, while all other vertebrates examined so far have an endothelial barrier. For comparative reasons it is desirable to examine the blood-brain barrier in species from the other subclass of cartilaginous fish, the holocephalans. The ultrastructure of cerebral capillaries in the chimaera (Chondrichthyes: Holocephali) is described in the present study. The endothelial cells are remarkably thick. Fenestrae and transendothelial channels were not observed. The endothelial cells are joined by elaborate tight junctions. The perivascular glial processes are separated by wide spaces (15-60 nm) without obliterating junctional complexes. These findings indicate that the chimaera has an endothelial blood-brain barrier.

Vascular endothelium summary statement II: Cardiovascular disease prevention and control.

PubMed

Mensah, George A; Ryan, Una S; Hooper, W Craig; Engelgau, Michael M; Callow, Allan D; Kapuku, Gaston K; Mantovani, Alberto

2007-05-01

The prevention and control of cardiovascular disease (CVD), principally ischemic heart disease and stroke, are a major clinical and public health challenge. Worldwide, CVD accounts for substantial morbidity and mortality. The major modifiable CVD risk factors are known and all of them cause endothelial activation and dysfunction. Preventing and controlling the established risk factors are associated with preserved endothelial function and reduced risk of CVD. Research advances that improve our understanding of strategies to preserve endothelial function or make the endothelial cells resilient to environmental insults may help improve our preventive interventions. This summary statement addresses the current state of the science with respect to endothelial dysfunction and CVD pathogenesis, diagnostic evaluation, and suggested strategies for public health practice and research.

Dehydrodiconiferyl alcohol suppresses monocyte adhesion to endothelial cells by attenuation of JNK signaling pathway.

PubMed

Tsuneyoshi, Tadamitsu; Kanamori, Yuta; Matsutomo, Toshiaki; Morihara, Naoaki

2015-09-25

Several clinical studies have shown that the intake of aged garlic extract improves endothelial dysfunction. Lignan compounds, (+)-(2S,3R)-dehydrodiconiferyl alcohol (DDC) and (-)-(2R,3S)-dihydrodehydrodiconiferyl alcohol (DDDC), have been isolated as antioxidants in aged garlic extract. There is evidence showing the importance of oxidative stress in endothelial dysfunction. In the present study, we examined whether DDC and DDDC enhance endothelial cell function in vitro. Cell adhesion assay was performed using THP-1 monocyte and human umbilical vein endothelial cells (HUVECs) which were activated by lipopolysaccharide (LPS) or advanced glycation end products (AGEs)-BSA. Cellular ELISA method was used for the evaluation of vascular cell adhesion molecule 1 (VCAM-1) expression on HUVECs. DDC and DDDC suppressed the adhesion of THP-1 to HUVECs which was activated by LPS or AGEs-BSA. DDC and DDDC also inhibited VCAM-1 expression induced by LPS or AGEs-BSA, but DDDC was less effective than DDC. In addition, the inhibitory effect of DDC on VCAM-1 expression involved suppressing JNK/c-Jun pathway rather than NF-κB pathway. DDC has an inhibitory effect on VCAM-1 expression via JNK pathway in endothelial cells and therefore may serve as a novel pharmacological agent to improve endothelial dysfunction. Copyright © 2015 Elsevier Inc. All rights reserved.

Endothelial dysfunction and negative emotions in adolescent girls.

PubMed

Pajer, Kathleen; Hoffman, Robert; Gardner, William; Chang, Chien-Ni; Boley, David; Wang, Wei

2016-05-01

Endothelial dysfunction predicts adult cardiovascular disorder and may be associated with negative emotions in adolescents. This study was conducted to determine if hopelessness, hostility, and depressive, anxiety, or conduct disorders were associated with compromised endothelial function and whether those associations were mediated by health risk behaviors. Endothelial function, assessed through brachial artery reactive hyperemia, was measured in a psychopathology enriched sample of 60 15-18-year-old girls. The correlations between hopelessness, hostility, and depressive, anxiety, or conduct disorders and the percent change in forearm vascular resistance (PCFVR) were measured. Possible mediation effects of health risk behaviors were tested. Hopelessness was negatively associated with PCFVR, controlling for race and body mass index. Conduct disorder without any anxiety disorder was associated with better endothelial function. The other negative emotions were not associated with PCFVR. Risky health behaviors were associated with conduct disorder and hopelessness, but not with PCFVR, so there was no evidence of mediation. The main finding was that hopelessness in adolescent girls was associated with endothelial dysfunction. This may indicate that when present, hopelessness places a girl at risk for later cardiovascular disease, whether she has a psychiatric disorder or not. Possible mechanisms for this finding are examined and the surprising finding that conduct disorder is associated with better endothelial function is also discussed. Suggestions for future research are presented.

Febuxostat improves endothelial function in hemodialysis patients with hyperuricemia: A randomized controlled study.

PubMed

Tsuruta, Yuki; Kikuchi, Kan; Tsuruta, Yukio; Sasaki, Yuko; Moriyama, Takahito; Itabashi, Mitsuyo; Takei, Takashi; Uchida, Keiko; Akiba, Takashi; Tsuchiya, Ken; Nitta, Kosaku

2015-10-01

Endothelial dysfunction is often found in both hyperuricemia and hemodialysis patients. Recent studies have shown that treating hyperuricemia with allopurinol improves endothelial dysfunction. This study is performed to assess the effect of febuxostat on endothelial dysfunction in hemodialysis patients with hyperuricemia. We randomly assigned 53 hemodialysis patients with hyperuricemia to a febuxostat (10 mg daily) group and a control group and measured flow-mediated dilation, serum uric acid (UA) levels, systolic and diastolic blood pressure, malondialdehyde-modified low-density lipoprotein (MDA-LDL), and highly sensitive C-reactive protein (hsCRP) at baseline and at the end of a 4-week study period. Flow-mediated dilation increased from 5.3% ± 2.4% to 8.9% ± 3.6% in the febuxostat group but did not change significantly in the control group. Treatment with febuxostat resulted in a significant decrease in serum UA level and a significant decrease in MDA-LDL compared with baseline, but no significant difference was observed in hsCRP level or blood pressure. No significant differences were observed in the control group. Febuxostat improved endothelial dysfunction and reduced serum UA levels and oxidative stress in hemodialysis patients with hyperuricemia. © 2015 International Society for Hemodialysis.

Allopurinol improves endothelial dysfunction in chronic heart failure.

PubMed

Farquharson, Colin A J; Butler, Robert; Hill, Alexander; Belch, Jill J F; Struthers, Allan D

2002-07-09

Increased oxidative stress in chronic heart failure is thought to contribute to endothelial dysfunction. Xanthine oxidase produces oxidative stress and therefore we examined whether allopurinol improved endothelial dysfunction in chronic heart failure. We performed a randomized, placebo-controlled, double-blind crossover study on 11 patients with New York Heart Association class II-III chronic heart failure, comparing 300 mg allopurinol daily (1 month) versus placebo. Endothelial function was assessed by standard forearm venous occlusion plethysmography with acetylcholine, nitroprusside, and verapamil. Plasma malondialdehyde levels were also compared to assess significant changes in oxidative stress. Allopurinol significantly increased the forearm blood flow response to acetylcholine (percentage change in forearm blood flow [mean+/-SEM]: 181+/-19% versus 120+/-22% allopurinol versus placebo; P=0.003). There were no significant differences in the forearm blood flow changes between the placebo and allopurinol treatment arms with regard to sodium nitroprusside or verapamil. Plasma malondialdehyde was significantly reduced with allopurinol treatment (346+/-128 nmol/L versus 461+/-101 nmol/L, allopurinol versus placebo; P=0.03), consistent with reduced oxidative stress with allopurinol therapy. We have shown that allopurinol improves endothelial dysfunction in chronic heart failure. This raises the distinct possibility that allopurinol might reduce cardiovascular events and even improve exercise capacity in chronic heart failure.

Anti-Inflammatory Activity of Marine Ovothiol A in an In Vitro Model of Endothelial Dysfunction Induced by Hyperglycemia.

PubMed

Castellano, Immacolata; Di Tomo, Pamela; Di Pietro, Natalia; Mandatori, Domitilla; Pipino, Caterina; Formoso, Gloria; Napolitano, Alessandra; Palumbo, Anna; Pandolfi, Assunta

2018-01-01

Chronic hyperglycemia is associated with oxidative stress and vascular inflammation, both leading to endothelial dysfunction and cardiovascular disease that can be weakened by antioxidant/anti-inflammatory molecules in both healthy and diabetic subjects. Among natural molecules, ovothiol A, produced in sea urchin eggs to protect eggs/embryos from the oxidative burst at fertilization and during development, has been receiving increasing interest for its use as an antioxidant. Here, we evaluated the potential antioxidative/anti-inflammatory effect of purified ovothiol A in an in vitro cellular model of hyperglycemia-induced endothelial dysfunction employing human umbilical vein endothelial cells (HUVECs) from women affected by gestational diabetes (GD) and from healthy mothers. Ovothiol A was rapidly taken up by both cellular systems, resulting in increased glutathione values in GD-HUVECs, likely due to the formation of reduced ovothiol A. In tumor necrosis factor- α -stimulated cells, ovothiol A induced a downregulation of adhesion molecule expression and decrease in monocyte-HUVEC interaction. This was associated with a reduction in reactive oxygen and nitrogen species and an increase in nitric oxide bioavailability. These results point to the potential antiatherogenic properties of the natural antioxidant ovothiol A and support its therapeutic potential in pathologies related to cardiovascular diseases associated with oxidative/inflammatory stress and endothelial dysfunction.

Heterogeneity of peripheral blood monocytes, endothelial dysfunction and subclinical atherosclerosis in patients with systemic lupus erythematosus.

PubMed

Mikołajczyk, T P; Osmenda, G; Batko, B; Wilk, G; Krezelok, M; Skiba, D; Sliwa, T; Pryjma, J R; Guzik, T J

2016-01-01

Systemic lupus erythematosus (SLE) is characterized by increased cardiovascular morbidity and mortality. SLE patients have increased prevalence of subclinical atherosclerosis, although the mechanisms of this observation remain unclear. Considering the emerging role of monocytes in atherosclerosis, we aimed to investigate the relationship between subclinical atherosclerosis, endothelial dysfunction and the phenotype of peripheral blood monocytes in SLE patients. We characterized the phenotype of monocyte subsets defined by the expression of CD14 and CD16 in 42 patients with SLE and 42 non-SLE controls. Using ultrasonography, intima-media thickness (IMT) of carotid arteries and brachial artery flow-mediated dilation (FMD) as well as nitroglycerin-induced dilation (NMD) were assessed. Patients with SLE had significantly, but only modestly, increased IMT when compared with non-SLE controls (median (25th/75th percentile) 0.65 (0.60/0.71) mm vs 0.60 (0.56/0.68) mm; p < 0.05). Importantly, in spite of early atherosclerotic complications in the studied SLE group, marked endothelial dysfunction was observed. CD14dimCD16+proinflammatory cell subpopulation was positively correlated with IMT in SLE patients. This phenomenon was not observed in control individuals. Interestingly, endothelial dysfunction assessed by FMD was not correlated with any of the studied monocyte subsets. Our observations suggest that CD14dimCD16+monocytes are associated with subclinical atherosclerosis in SLE, although the mechanism appears to be independent of endothelial dysfunction. © The Author(s) 2015.

Short- and long-term black tea consumption reverses endothelial dysfunction in patients with coronary artery disease.

PubMed

Duffy, S J; Keaney , J F; Holbrook, M; Gokce, N; Swerdloff, P L; Frei, B; Vita, J A

2001-07-10

Epidemiological studies suggest that tea consumption decreases cardiovascular risk, but the mechanisms of benefit remain undefined. Endothelial dysfunction has been associated with coronary artery disease and increased oxidative stress. Some antioxidants have been shown to reverse endothelial dysfunction, and tea contains antioxidant flavonoids. Methods and Results-- To test the hypothesis that tea consumption will reverse endothelial dysfunction, we randomized 66 patients with proven coronary artery disease to consume black tea and water in a crossover design. Short-term effects were examined 2 hours after consumption of 450 mL tea or water. Long-term effects were examined after consumption of 900 mL tea or water daily for 4 weeks. Vasomotor function of the brachial artery was examined at baseline and after each intervention with vascular ultrasound. Fifty patients completed the protocol and had technically suitable ultrasound measurements. Both short- and long-term tea consumption improved endothelium- dependent flow-mediated dilation of the brachial artery, whereas consumption of water had no effect (P<0.001 by repeated-measures ANOVA). Tea consumption had no effect on endothelium-independent nitroglycerin-induced dilation. An equivalent oral dose of caffeine (200 mg) had no short-term effect on flow-mediated dilation. Plasma flavonoids increased after short- and long-term tea consumption. Short- and long-term black tea consumption reverses endothelial vasomotor dysfunction in patients with coronary artery disease. This finding may partly explain the association between tea intake and decreased cardiovascular disease events.

Depletion of NADP(H) due to CD38 activation triggers endothelial dysfunction in the postischemic heart.

PubMed

Reyes, Levy A; Boslett, James; Varadharaj, Saradhadevi; De Pascali, Francesco; Hemann, Craig; Druhan, Lawrence J; Ambrosio, Giuseppe; El-Mahdy, Mohamed; Zweier, Jay L

2015-09-15

In the postischemic heart, coronary vasodilation is impaired due to loss of endothelial nitric oxide synthase (eNOS) function. Although the eNOS cofactor tetrahydrobiopterin (BH4) is depleted, its repletion only partially restores eNOS-mediated coronary vasodilation, indicating that other critical factors trigger endothelial dysfunction. Therefore, studies were performed to characterize the unidentified factor(s) that trigger endothelial dysfunction in the postischemic heart. We observed that depletion of the eNOS substrate NADPH occurs in the postischemic heart with near total depletion from the endothelium, triggering impaired eNOS function and limiting BH4 rescue through NADPH-dependent salvage pathways. In isolated rat hearts subjected to 30 min of ischemia and reperfusion (I/R), depletion of the NADP(H) pool occurred and was most marked in the endothelium, with >85% depletion. Repletion of NADPH after I/R increased NOS-dependent coronary flow well above that with BH4 alone. With combined NADPH and BH4 repletion, full restoration of NOS-dependent coronary flow occurred. Profound endothelial NADPH depletion was identified to be due to marked activation of the NAD(P)ase-activity of CD38 and could be prevented by inhibition or specific knockdown of this protein. Depletion of the NADPH precursor, NADP(+), coincided with formation of 2'-phospho-ADP ribose, a CD38-derived signaling molecule. Inhibition of CD38 prevented NADP(H) depletion and preserved endothelium-dependent relaxation and NO generation with increased recovery of contractile function and decreased infarction in the postischemic heart. Thus, CD38 activation is an important cause of postischemic endothelial dysfunction and presents a novel therapeutic target for prevention of this dysfunction in unstable coronary syndromes.

Tryptophan depletion under conditions that imitate insulin resistance enhances fatty acid oxidation and induces endothelial dysfunction through reactive oxygen species-dependent and independent pathways.

PubMed

Eleftheriadis, Theodoros; Pissas, Georgios; Sounidaki, Maria; Antoniadi, Georgia; Rountas, Christos; Liakopoulos, Vassilios; Stefanidis, Loannis

2017-04-01

In atherosclerosis-associated pathologic entities characterized by malnutrition and inflammation, L-tryptophan (TRP) levels are low. Insulin resistance is an independent cardiovascular risk factor and induces endothelial dysfunction by increasing fatty acid oxidation. It is also associated with inflammation and low TRP levels. Low TRP levels have been related to worse cardiovascular outcome. This study evaluated the effect of TRP depletion on endothelial dysfunction under conditions that imitate insulin resistance. Fatty acid oxidation, harmful pathways due to increased fatty acid oxidation, and endothelial dysfunction were assessed in primary human aortic endothelial cells cultured under normal glucose, low insulin conditions in the presence or absence of TRP. TRP depletion activated general control non-derepressible 2 kinase and inhibited aryl hydrocarbon receptor. It increased fatty acid oxidation by increasing expression and activity of carnitine palmitoyltransferase 1. Elevated fatty acid oxidation increased the formation of reactive oxygen species (ROS) triggering the polyol and hexosamine pathways, and enhancing protein kinase C activity and methylglyoxal production. TRP absence inhibited nitric oxide synthase activity in a ROS-dependent way, whereas it increased the expression of ICAM-1 and VCAM-1 in a ROS independent and possibly p53-dependent manner. Thus, TRP depletion, an amino acid whose low levels have been related to worse cardiovascular outcome and to inflammatory atherosclerosis-associated pathologic entities, under conditions that imitate insulin resistance enhances fatty acid oxidation and induces endothelial dysfunction through ROS-dependent and independent pathways. These findings may offer new insights at the molecular mechanisms involved in accelerated atherosclerosis that frequently accompanies malnutrition and inflammation.

Monocrotaline-Induced Pulmonary Hypertension Involves Downregulation of Antiaging Protein Klotho and eNOS Activity.

PubMed

Varshney, Rohan; Ali, Quaisar; Wu, Chengxiang; Sun, Zhongjie

2016-11-01

The objective of this study is to investigate whether stem cell delivery of secreted Klotho (SKL), an aging-suppressor protein, attenuates monocrotaline-induced pulmonary vascular dysfunction and remodeling. Overexpression of SKL in mesenchymal stem cells (MSCs) was achieved by transfecting MSCs with lentiviral vectors expressing SKL-green fluorescent protein (GFP). Four groups of rats were treated with monocrotaline, whereas an additional group was given saline (control). Three days later, 4 monocrotaline-treated groups received intravenous delivery of nontransfected MSCs, MSC-GFP, MSC-SKL-GFP, and PBS, respectively. Ex vivo vascular relaxing responses to acetylcholine were diminished in small pulmonary arteries (PAs) in monocrotaline-treated rats, indicating pulmonary vascular endothelial dysfunction. Interestingly, delivery of MSCs overexpressing SKL (MSC-SKL-GFP) abolished monocrotaline-induced pulmonary vascular endothelial dysfunction and PA remodeling. Monocrotaline significantly increased right ventricular systolic blood pressure, which was attenuated significantly by MSC-SKL-GFP, indicating improved PA hypertension. MSC-SKL-GFP also attenuated right ventricular hypertrophy. Nontransfected MSCs slightly, but not significantly, improved PA hypertension and pulmonary vascular endothelial dysfunction. MSC-SKL-GFP attenuated monocrotaline-induced inflammation, as evidenced by decreased macrophage infiltration around PAs. MSC-SKL-GFP increased SKL levels, which rescued the downregulation of SIRT1 (Sirtuin 1) expression and endothelial NO synthase (eNOS) phosphorylation in the lungs of monocrotaline-treated rats. In cultured endothelial cells, SKL abolished monocrotaline-induced downregulation of eNOS activity and NO levels and enhanced cell viability. Therefore, stem cell delivery of SKL is an effective therapeutic strategy for pulmonary vascular endothelial dysfunction and PA remodeling. SKL attenuates monocrotaline-induced PA remodeling and PA smooth muscle cell proliferation, likely by reducing inflammation and restoring SIRT1 levels and eNOS activity. © 2016 American Heart Association, Inc.

[The Role of GRK2 and Its Potential as a New Therapeutic Target in Diabetic Vascular Complications].

PubMed

Taguchi, Kumiko

2015-01-01

A decrease in nitric oxide (NO) production may induce pathological conditions associated with endothelial dysfunction and diabetes. Although a decrease in NO production caused by impaired Akt/endothelial nitric oxide synthesis (eNOS) signaling has been demonstrated at the aorta in the presence of diabetic vascular complications, little is known regarding the details of the mechanism. We identified G-protein-coupled receptor kinase 2 (GRK2) as a critical factor in diabetic endothelial dysfunction. GRK2 plays a role in many physiological functions including regulation of G-protein-coupled receptors (GPCRs). We found that the vasculature affected by type 2 diabetes expresses high levels of GRK2, which may induce endothelial dysfunction caused by impaired Akt/eNOS signaling. GRK2 activation also induces changes in the subcellular localization of GRK2 and β-arrestin 2, a downstream protein, from the cytosol to membrane. In mouse aorta GRK2 may be, on translocation, a key negative regulator and an important regulator of β-arrestin 2/Akt/eNOS signaling, which has been implicated in diabetic endothelial dysfunction. Furthermore, in the aortic membrane of type 2 diabetic model mice under insulin stimulation, the impaired Akt/eNOS signaling was improved by a selective GRK2 inhibitor. These results suggest that in diabetes the GRK2 inhibitor ameliorates vascular endothelial dysfunction via Akt/eNOS signaling by inhibiting GRK2 activity and enhancing β-arrestin 2 translocation to the membrane under GPCR or non-GPCR stimulation, thereby contributing to blood pressure- and blood glucose-lowering effects. We propose that the GRK2 inhibitor may be a promising therapeutic target for cardiovascular complications in type 2 diabetes.

Descemet Stripping Automated Endothelial Keratoplasty for Endothelial Dysfunction in Xeroderma Pigmentosum: A Clinicopathological Correlation and Review of Literature.

PubMed

Vira, Divya; Fernandes, Merle; Mittal, Ruchi

2016-07-01

Xeroderma pigmentosum (XP) mainly affects the ocular surface; however, endothelial damage may also occur. We would like to report changes in the endothelial-Descemet layer and review the literature on similar findings in patients with XP, including the role of Descemet stripping automated endothelial keratoplasty (DSAEK) in the management of a 21-year-old man who presented with nonresolving corneal edema in the right eye after excision biopsy for conjunctival intraepithelial neoplasia. His best-corrected visual acuity (BCVA) was 20/200 in the right eye and 20/20 in the left eye. On general examination, there was patchy hyperpigmentation of the exposed areas of skin suggestive of XP. On examination of the right eye, there was stromal edema involving the exposed half of cornea. The left eye appeared normal. Pachymetry readings were 860 and 600 μm in the right and left eye, respectively. Descemet stripping automated endothelial keratoplasty was performed for endothelial dysfunction and the stripped endothelium, and Descemet membrane (DM) was sent for histopathologic evaluation. Postoperatively, the donor lenticule was well apposed and the overlying stromal edema resolved. The patient achieved a BCVA of 20/30 in the right eye without progression of corneal scarring at 1-year follow-up. In the meanwhile, however, the left eye developed corneal edema. Histopathology revealed gross attenuation of endothelial cells with uniform thickness of the DM. Corneal endothelial dysfunction in XP is amenable to treatment with DSAEK.

Three-dimensional biomimetic vascular model reveals a RhoA, Rac1, and N-cadherin balance in mural cell-endothelial cell-regulated barrier function.

PubMed

Alimperti, Stella; Mirabella, Teodelinda; Bajaj, Varnica; Polacheck, William; Pirone, Dana M; Duffield, Jeremy; Eyckmans, Jeroen; Assoian, Richard K; Chen, Christopher S

2017-08-15

The integrity of the endothelial barrier between circulating blood and tissue is important for blood vessel function and, ultimately, for organ homeostasis. Here, we developed a vessel-on-a-chip with perfused endothelialized channels lined with human bone marrow stromal cells, which adopt a mural cell-like phenotype that recapitulates barrier function of the vasculature. In this model, barrier function is compromised upon exposure to inflammatory factors such as LPS, thrombin, and TNFα, as has been observed in vivo. Interestingly, we observed a rapid physical withdrawal of mural cells from the endothelium that was accompanied by an inhibition of endogenous Rac1 activity and increase in RhoA activity in the mural cells themselves upon inflammation. Using a system to chemically induce activity in exogenously expressed Rac1 or RhoA within minutes of stimulation, we demonstrated RhoA activation induced loss of mural cell coverage on the endothelium and reduced endothelial barrier function, and this effect was abrogated when Rac1 was simultaneously activated. We further showed that N -cadherin expression in mural cells plays a key role in barrier function, as CRISPR-mediated knockout of N -cadherin in the mural cells led to loss of barrier function, and overexpression of N -cadherin in CHO cells promoted barrier function. In summary, this bicellular model demonstrates the continuous and rapid modulation of adhesive interactions between endothelial and mural cells and its impact on vascular barrier function and highlights an in vitro platform to study the biology of perivascular-endothelial interactions.

Testosterone Deficiency Causes Endothelial Dysfunction via Elevation of Asymmetric Dimethylarginine and Oxidative Stress in Castrated Rats.

PubMed

Kataoka, Tomoya; Hotta, Yuji; Maeda, Yasuhiro; Kimura, Kazunori

2017-12-01

Testosterone is believed to mediate the penile erectile response by producing adequate nitric oxide; therefore, testosterone deficiency results in erectile dysfunction through decreased nitric oxide bioavailability. However, the mechanisms underlying endothelial dysfunction in testosterone deficiency remain unclear. To investigate the mechanism of endothelial dysfunction in a rat model of testosterone deficiency. Rats were distributed into 3 groups: castrated (Cast), castrated and supplemented with testosterone (Cast + T), and sham (Sham). In the Cast + T group, castrated rats were treated daily with subcutaneous testosterone (3 mg/kg daily) for 4 weeks; Sham and Cast rats received only the vehicle. Erectile function using intracavernosal pressure and mean arterial pressure measurements after electrical stimulation of the cavernous nerve, endothelial function using isometric tension, asymmetric dimethylarginine (ADMA) levels using ultra-performance liquid chromatography and tandem mass spectrometry, and inflammatory biomarker expression were performed 4 weeks after the operation. In the Cast group, the ratio of intracavernosal pressure to mean arterial pressure significantly decreased, acetylcholine-induced relaxation was lower, and serum ADMA, oxidative stress, and inflammation biomarker levels were significantly increased (P < .01). Testosterone injection significantly improved each of these parameters (P < .01). The present results provide scientific evidence of the effect of testosterone deficiency on erectile function and the effect of testosterone replacement therapy. This study provides evidence of the influence of testosterone deficiency on endothelial function by investigating ADMA and oxidative stress. A major limitation of this study is the lack of a direct link of increased ADMA by oxidative stress to inflammation. Testosterone deficiency increased not only ADMA levels but also oxidative stress and inflammation in castrated rats, which can cause damage to the corpus cavernosum, resulting in erectile dysfunction. Kataoka T, Hotta Y, Maeda Y, Kimura K. Testosterone Deficiency Causes Endothelial Dysfunction via Elevation of Asymmetric Dimethylarginine and Oxidative Stress in Castrated Rats. J Sex Med 2017;14:1540-1548. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

[Pharmacological therapy of age-related macular degeneration based on etiopathogenesis].

PubMed

Fischer, Tamás

2015-11-15

It is of great therapeutic significance that disordered function of the vascular endothelium which supply the affected ocular structures plays a major role in the pathogenesis and development of age-related macular degeneration. Chronic inflammation is closely linked to diseases associated with endothelial dysfunction, and age-related macular degeneration is accompanied by a general inflammatory response. According to current concept, age-related macular degeneration is a local manifestation of systemic vascular disease. This recognition could have therapeutic implications because restoration of endothelial dysfunction can restabilize the condition of chronic vascular disease including age-related macular degeneration as well. Restoration of endothelial dysfunction by pharmaacological or non pharmacological interventions may prevent the development or improve endothelial dysfunction, which result in prevention or improvement of age related macular degeneration as well. Medicines including inhibitors of the renin-angiotensin system (converting enzyme inhibitors, angiotensin-receptor blockers and renin inhibitors), statins, acetylsalicylic acid, trimetazidin, third generation beta-blockers, peroxisome proliferator-activated receptor gamma agonists, folate, vitamin D, melatonin, advanced glycation end-product crosslink breaker alagebrium, endothelin-receptor antagonist bosentan, coenzyme Q10; "causal" antioxidant vitamins, N-acetyl-cysteine, resveratrol, L-arginine, serotonin receptor agonists, tumor necrosis factor-alpha blockers, specific inhibitor of the complement alternative pathway, curcumin and doxycyclin all have beneficial effects on endothelial dysfunction. Restoration of endothelial dysfunction can restabilize chronic vascular disease including age-related macular degeneration as well. Considering that the human vascular system is consubstantial, medicines listed above should be given to patients (1) who have no macular degeneration but have risk factors for the disease and are older than 50 years; (2) who have been diagnosed with unilateral age-related macular degeneration in order to prevent damage of the contralateral eye; (3) who have bilateral age-related macular degeneration in order to avert deterioration and in the hope of a potential improvement. However, randomised prospective clinical trials are still needed to elucidate the potential role of these drug treatments in the prevention and treatment of age-related macular degeneration.

Tissue Vibration Induces Carotid Artery Endothelial Dysfunction: A Mechanism Linking Snoring and Carotid Atherosclerosis?

PubMed Central

Cho, Jin-Gun; Witting, Paul K.; Verma, Manisha; Wu, Ben J.; Shanu, Anu; Kairaitis, Kristina; Amis, Terence C.; Wheatley, John R.

2011-01-01

Study Objectives: We have previously identified heavy snoring as an independent risk factor for carotid atherosclerosis. In order to explore the hypothesis that snoring-associated vibration of the carotid artery induces endothelial dysfunction (an established atherogenic precursor), we utilized an animal model to examine direct effects of peri-carotid tissue vibration on carotid artery endothelial function and structure. Design: In supine anesthetized, ventilated rabbits, the right carotid artery (RCA) was directly exposed to vibrations for 6 h (peak frequency 60 Hz, energy matched to that of induced snoring in rabbits). Similarly instrumented unvibrated rabbits served as controls. Features of OSA such as hypoxemia, large intra-pleural swings and blood pressure volatility were prevented. Carotid endothelial function was then examined: (1) biochemically by measurement of tissue cyclic guanosine monophosphate (cGMP) to acetylcholine (ACh) and sodium nitroprusside (SNP); and (2) functionally by monitoring vessel relaxation with acetylcholine in a myobath. Measurement and Results: Vessel cGMP after stimulation with ACh was reduced in vibrated RCA compared with unvibrated (control) arteries in a vibration energy dose-dependent manner. Vibrated RCA also showed decreased vasorelaxation to ACh compared with control arteries. Notably, after addition of SNP (nitric oxide donor), cGMP levels did not differ between vibrated and control arteries, thereby isolating vibration-induced dysfunction to the endothelium alone. This dysfunction occurred in the presence of a morphologically intact endothelium without increased apoptosis. Conclusions: Carotid arteries subjected to 6 h of continuous peri-carotid tissue vibration displayed endothelial dysfunction, suggesting a direct plausible mechanism linking heavy snoring to the development of carotid atherosclerosis. Citation: Cho JG; Witting PK; Verma M; Wu BJ; Shanu A; Kairaitis K; Amis TC; Wheatley JR. Tissue vibration induces carotid artery endothelial dysfunction: a mechanism linking snoring and carotid atherosclerosis?. SLEEP 2011;34(6):751-757. PMID:21629363

Alcohol and red wine consumption, but not fruit, vegetables, fish or dairy products, are associated with less endothelial dysfunction and less low-grade inflammation: the Hoorn Study.

PubMed

van Bussel, B C T; Henry, R M A; Schalkwijk, C G; Dekker, J M; Nijpels, G; Feskens, E J M; Stehouwer, C D A

2018-06-01

Endothelial dysfunction and low-grade inflammation are key phenomena in the pathobiology of cardiovascular disease (CVD). Their dietary modification might explain the observed reduction in CVD that has been associated with a healthy diet rich in fruit, vegetables and fish, low in dairy products and with moderate alcohol and red wine consumption. We investigated the associations between the above food groups and endothelial dysfunction and low-grade inflammation in a population-based cohort of Dutch elderly individuals. Diet was measured by food frequency questionnaire (n = 801; women = 399; age 68.5 ± 7.2 years). Endothelial dysfunction was determined (1) by combining von Willebrand factor, and soluble intercellular adhesion molecule 1 (sICAM-1), vascular cell adhesion molecule 1, endothelial selectin and thrombomodulin, using Z-scores, into a biomarker score and (2) by flow-mediated vasodilation (FMD), and low-grade inflammation by combining C-reactive protein, serum amyloid A, interleukin 6, interleukin 8, tumour necrosis factor α and sICAM-1 into a biomarker score, with smaller FMD and higher scores representing more dysfunction and inflammation, respectively. We used linear regression analyses to adjust associations for sex, age, energy, glucose metabolism, body mass index, smoking, prior CVD, educational level, physical activity and each of the other food groups. Moderate [β (95% CI) -0.13 (-0.33; 0.07)] and high [-0.22 (-0.45; -0.003)] alcohol consumption, and red wine [-0.16 (-0.30; -0.01)] consumption, but none of the other food groups, were associated with a lower endothelial dysfunction biomarker score and a greater FMD. The associations for FMD were, however, not statistically significant. Only red wine consumption was associated with a lower low-grade inflammation biomarker score [-0.18 (-0.33; -0.04)]. Alcohol and red wine consumption may favourably influence processes involved in atherothrombosis.

Protective effects of dark chocolate on endothelial function and diabetes.

PubMed

Grassi, Davide; Desideri, Giovambattista; Ferri, Claudio

2013-11-01

Relationship between cocoa consumption and cardiovascular disease, particularly focusing on clinical implications resulting from the beneficial effects of cocoa consumption on endothelial function and insulin resistance. This could be of clinical relevance and may suggest the mechanistic explanation for the reduced risk of cardiovascular events reported in the different studies after cocoa intake. Increasing evidence supports a protective effect of cocoa consumption against cardiovascular disease. Cocoa and flavonoids from cocoa have been described to improve endothelial function and insulin resistance. A proposed mechanism could be considered in the improvement of the endothelium-derived vasodilator nitric oxide by enhancing nitric oxide synthesis or by decreasing nitric oxide breakdown. The endothelium plays a pivotal role in the arterial homeostasis, and insulin resistance is the most important pathophysiological feature in various prediabetic and diabetic states. Reduced nitric oxide bioavailability with endothelial dysfunction is considered the earliest step in the pathogenesis of atherosclerosis. Further, insulin resistance could account, at least in part, for the endothelial dysfunction. Endothelial dysfunction has been considered an important and independent predictor of future development of cardiovascular risk and events. Cocoa and flavonoids from cocoa might positively modulate these mechanisms with a putative role in cardiovascular protection.

Reactive Oxygen Species/Hypoxia-Inducible Factor-1α/Platelet-Derived Growth Factor-BB Autocrine Loop Contributes to Cocaine-Mediated Alveolar Epithelial Barrier Damage

PubMed Central

Yang, Lu; Chen, Xufeng; Simet, Samantha M.; Hu, Guoku; Cai, Yu; Niu, Fang; Kook, Yeonhee

2016-01-01

Abuse of psychostimulants, such as cocaine, has been shown to be closely associated with complications of the lung, such as pulmonary hypertension, edema, increased inflammation, and infection. However, the mechanism by which cocaine mediates impairment of alveolar epithelial barrier integrity that underlies various pulmonary complications has not been well determined. Herein, we investigate the role of cocaine in disrupting the alveolar epithelial barrier function and the associated signaling cascade. Using the combinatorial electric cell–substrate impedance sensing and FITC-dextran permeability assays, we demonstrated cocaine-mediated disruption of the alveolar epithelial barrier, as evidenced by increased epithelial monolayer permeability with a concomitant loss of the tight junction protein zonula occludens-1 (Zo-1) in both mouse primary alveolar epithelial cells and the alveolar epithelial cell line, L2 cells. To dissect the signaling pathways involved in this process, we demonstrated that cocaine-mediated induction of permeability factors, platelet-derived growth factor (PDGF-BB) and vascular endothelial growth factor, involved reactive oxygen species (ROS)-dependent induction of hypoxia-inducible factor (HIF)-1α. Interestingly, we demonstrated that ROS-dependent induction of another transcription factor, nuclear factor erythroid-2–related factor-2, that did not play a role in cocaine-mediated barrier dysfunction. Importantly, this study identifies, for the first time, that ROS/HIF-1α/PDGF-BB autocrine loop contributes to cocaine-mediated barrier disruption via amplification of oxidative stress and downstream signaling. Corroboration of these cell culture findings in vivo demonstrated increased permeability of the alveolar epithelial barrier, loss of expression of Zo-1, and a concomitantly increased expression of both HIF-1α and PDGF-BB. Pharmacological blocking of HIF-1α significantly abrogated cocaine-mediated loss of Zo-1. Understanding the mechanism(s) by which cocaine mediates barrier dysfunction could provide insights into the development of potential therapeutic targets for cocaine-mediated pulmonary hypertension. PMID:27391108

Acetone fraction from Sechium edule (Jacq.) S.w. edible roots exhibits anti-endothelial dysfunction activity.

PubMed

Trejo-Moreno, Celeste; Castro-Martínez, Gabriela; Méndez-Martínez, Marisol; Jiménez-Ferrer, Jesús Enrique; Pedraza-Chaverri, José; Arrellín, Gerardo; Zamilpa, Alejandro; Medina-Campos, Omar Noel; Lombardo-Earl, Galia; Barrita-Cruz, Gerardo Joel; Hernández, Beatriz; Ramírez, Christian Carlos; Santana, María Angélica; Fragoso, Gladis; Rosas, Gabriela

2018-06-28

A recent ethnomedical survey on medicinal plants grown in Mexico revealed that Sechium edule (Jacq.) Sw. (Cucurbitaceae) is one of the most valued plant species to treat cardiovascular diseases, including hypertension. Fruits, young leaves, buds, stems, and tuberous roots of the plant are edible. Considering that endothelial dysfunction induced by Angiotensin II plays an important role in the pathogenesis of hypertension and is accompanied by a prooxidative condition, which in turn induces an inflammatory state, vascular remodeling, and tissue damage, and that S. edule has been reported to possess antioxidant, anti-inflammatory and antihypertensive activity, its capability to control endothelial dysfunction was also assessed. To assess in vivo the anti-endothelial dysfunction activity of the acetone fraction (rSe-ACE) of the hydroalcoholic extract from S. edule roots. Endothelial dysfunction was induced in female C57BL/6 J mice by a daily intraperitoneal injection of angiotensin II for 10 weeks. Either rSe-ACE or losartan (as a control) were co-administered with angiotensin II for the same period. Blood pressure was measured at weeks 0, 5, and 10. Kidney extracts were prepared to determine IL1β, IL4, IL6, IL10, IL17, IFNγ, TNFα, and TGFβ levels by ELISA, along with the prooxidative status as assessed by the activity of antioxidant enzymes. The expression of ICAM-1 was evaluated by immunohistochemistry in kidney histological sections. Kidney and hepatic damage, as well as vascular tissue remodeling, were studied. The rSe-ACE fraction administered at a dose of 10 mg/kg was able to control hypertension, as well as the prooxidative and proinflammatory status in kidney as efficiently as losartan, returning mice to normotensive levels. Additionally, the fraction was more efficient than losartan to prevent liver and kidney damage. Phytochemical characterization identified cinnamic acid as a major compound, and linoleic, palmitic, and myristic acids as the most abundant non-polar components in the mixture, previously reported to aid in the control of hypertension, inflammation, and oxidative stress, three important components of endothelial dysfunction. this study demonstrated that rSe-ACE has anti-endothelial dysfunction activity in an experimental model and highlights the role of cinnamic acid and fatty acids in the observed effects. Copyright © 2018 Elsevier B.V. All rights reserved.

The endothelial glycocalyx

PubMed Central

Yang, Yimu; Schmidt, Eric P.

2013-01-01

Once thought to be a structure of small size and uncertain significance, the endothelial glycocalyx is now known to be an important regulator of endothelial function. Studies of the systemic vasculature have demonstrated that the glycocalyx forms a substantial in vivo endothelial surface layer (ESL) critical to inflammation, barrier function and mechanotransduction. The pulmonary ESL is significantly thicker than the systemic ESL, suggesting unique physiologic function. We have recently demonstrated that the pulmonary ESL regulates exposure of endothelial surface adhesion molecules, thereby serving as a barrier to neutrophil adhesion and extravasation. While the pulmonary ESL is not a critical structural component of the endothelial barrier to fluid and protein, it serves a major role in the mechanotransduction of vascular pressure, with impact on the active regulation of endothelial permeability. It is likely that the ESL serves numerous additional functions in vascular physiology, representing a fertile area for future investigation. PMID:24073386

Prior exercise and standing as strategies to circumvent sitting-induced leg endothelial dysfunction.

PubMed

Morishima, Takuma; Restaino, Robert M; Walsh, Lauren K; Kanaley, Jill A; Padilla, Jaume

2017-06-01

We have previously shown that local heating or leg fidgeting can prevent prolonged sitting-induced leg endothelial dysfunction. However, whether physical activity prevents subsequent sitting-induced leg endothelial dysfunction remains unknown. Herein, we tested the hypothesis that sitting-induced leg endothelial dysfunction would be prevented by prior exercise. We also examined if, in the absence of exercise, standing is an effective alternative strategy to sitting for conserving leg endothelial function. Fifteen young healthy subjects completed three randomized experimental trials: (1) sitting without prior exercise; (2) sitting with prior exercise; and (3) standing without prior exercise. Following baseline popliteal artery flow-mediated dilation (FMD) measurements, subjects maintained a supine position for 45 min in the sitting and standing trials, without prior exercise, or performed 45 min of leg cycling before sitting (i.e. sitting with prior exercise trial). Thereafter, subjects were positioned into a seated or standing position, according to the trial, for 3 h. Popliteal artery FMD measures were then repeated. Three hours of sitting without prior exercise caused a significant impairment in popliteal artery FMD (baseline: 3.8±0.5%, post-sitting: 1.5±0.5%, P <0.05), which was prevented when sitting was preceded by a bout of cycling exercise (baseline: 3.8±0.5%, post-sitting: 3.6±0.7%, P >0.05). Three hours of standing did not significantly alter popliteal artery FMD (baseline: 4.1±0.4%, post-standing: 4.3±0.4%, P >0.05). In conclusion, prolonged sitting-induced leg endothelial dysfunction can be prevented by prior aerobic exercise. In addition, in the absence of exercise, standing represents an effective substitute to sitting for preserving leg conduit artery endothelial function. © 2017 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Decreased production of neuronal NOS-derived hydrogen peroxide contributes to endothelial dysfunction in atherosclerosis

PubMed Central

Capettini, LSA; Cortes, SF; Silva, JF; Alvarez-Leite, JI; Lemos, VS

2011-01-01

BACKGROUND AND PURPOSE Reduced NO availability has been described as a key mechanism responsible for endothelial dysfunction in atherosclerosis. We previously reported that neuronal NOS (nNOS)-derived H2O2 is an important endothelium-derived relaxant factor in the mouse aorta. The role of H2O2 and nNOS in endothelial dysfunction in atherosclerosis remains undetermined. We hypothesized that a decrease in nNOS-derived H2O2 contributes to the impaired vasodilatation in apolipoprotein E-deficient mice (ApoE−/−). EXPERIMENTAL APPROACH Changes in isometric tension were recorded on a myograph; simultaneously, NO and H2O2 were measured using carbon microsensors. Antisense oligodeoxynucleotides were used to knockdown eNOS and nNOS in vivo. Western blot and confocal microscopy were used to analyse the expression and localization of NOS isoforms. KEY RESULTS Aortas from ApoE−/− mice showed impaired vasodilatation paralleled by decreased NO and H2O2 production. Inhibition of nNOS with L-ArgNO2-L-Dbu, knockdown of nNOS and catalase, which decomposes H2O2 into oxygen and water, decreased ACh-induced relaxation by half, produced a small diminution of NO production and abolished H2O2 in wild-type animals, but had no effect in ApoE−/− mice. Confocal microscopy showed increased nNOS immunostaining in endothelial cells of ApoE−/− mice. However, ACh stimulation of vessels resulted in less phosphorylation on Ser852 in ApoE−/− mice. CONCLUSIONS AND IMPLICATIONS Our data show that endothelial nNOS-derived H2O2 production is impaired and contributes to endothelial dysfunction in ApoE−/− aorta. The present study provides a new mechanism for endothelial dysfunction in atherosclerosis and may represent a novel target to elaborate the therapeutic strategy for vascular atherosclerosis. PMID:21615722

Febuxostat, a novel xanthine oxidoreductase inhibitor, improves hypertension and endothelial dysfunction in spontaneously hypertensive rats.

PubMed

Shirakura, Takashi; Nomura, Johji; Matsui, Chieko; Kobayashi, Tsunefumi; Tamura, Mizuho; Masuzaki, Hiroaki

2016-08-01

Xanthine oxidase (XO) is an enzyme responsible for the production of uric acid. XO produces considerable amount of oxidative stress throughout the body. To date, however, its pathophysiologic role in hypertension and endothelial dysfunction still remains controversial. To explore the possible involvement of XO-derived oxidative stress in the pathophysiology of vascular dysfunction, by use of a selective XO inhibitor, febuxostat, we investigated the impact of pharmacological inhibition of XO on hypertension and vascular endothelial dysfunction in spontaneously hypertensive rats (SHRs). Sixteen-week-old SHR and normotensive Wistar-Kyoto (WKY) rats were treated with tap water (control) or water containing febuxostat (3 mg/kg/day) for 6 weeks. Systolic blood pressure (SBP) in febuxostat-treated SHR (220 ± 3 mmHg) was significantly (P < 0.05) decreased compared with the control SHR (236 ± 4 mmHg) while SBP in febuxostat-treated WKY was constant. Acetylcholine-induced endothelium-dependent relaxation in aortas from febuxostat-treated SHR was significantly (P < 0.05) improved compared with the control SHR, whereas relaxation in response to sodium nitroprusside was not changed. Vascular XO activity and tissue nitrotyrosine level, a representative indicator of local oxidative stress, were considerably elevated in the control SHR compared with the control WKY, and this increment was abolished by febuxostat. Our results suggest that exaggerated XO activity and resultant increase in oxidative stress in this experimental model contribute to the hypertension and endothelial dysfunction, thereby supporting a notion that pharmacological inhibition of XO is valuable not only for hyperuricemia but also for treating hypertension and related endothelial dysfunction in human clinics.

Targeting the gut microbiota with inulin-type fructans: preclinical demonstration of a novel approach in the management of endothelial dysfunction.

PubMed

Catry, Emilie; Bindels, Laure B; Tailleux, Anne; Lestavel, Sophie; Neyrinck, Audrey M; Goossens, Jean-François; Lobysheva, Irina; Plovier, Hubert; Essaghir, Ahmed; Demoulin, Jean-Baptiste; Bouzin, Caroline; Pachikian, Barbara D; Cani, Patrice D; Staels, Bart; Dessy, Chantal; Delzenne, Nathalie M

2018-02-01

To investigate the beneficial role of prebiotics on endothelial dysfunction, an early key marker of cardiovascular diseases, in an original mouse model linking steatosis and endothelial dysfunction. We examined the contribution of the gut microbiota to vascular dysfunction observed in apolipoprotein E knockout (Apoe -/- ) mice fed an n-3 polyunsaturated fatty acid (PUFA)-depleted diet for 12 weeks with or without inulin-type fructans (ITFs) supplementation for the last 15 days. Mesenteric and carotid arteries were isolated to evaluate endothelium-dependent relaxation ex vivo. Caecal microbiota composition (Illumina Sequencing of the 16S rRNA gene) and key pathways/mediators involved in the control of vascular function, including bile acid (BA) profiling, gut and liver key gene expression, nitric oxide and gut hormones production were also assessed. ITF supplementation totally reverses endothelial dysfunction in mesenteric and carotid arteries of n-3 PUFA-depleted Apoe -/- mice via activation of the nitric oxide (NO) synthase/NO pathway. Gut microbiota changes induced by prebiotic treatment consist in increased NO-producing bacteria, replenishment of abundance in Akkermansia and decreased abundance in bacterial taxa involved in secondary BA synthesis. Changes in gut and liver gene expression also occur upon ITFs suggesting increased glucagon-like peptide 1 production and BA turnover as drivers of endothelium function preservation. We demonstrate for the first time that ITF improve endothelial dysfunction, implicating a short-term adaptation of both gut microbiota and key gut peptides. If confirmed in humans, prebiotics could be proposed as a novel approach in the prevention of metabolic disorders-related cardiovascular diseases. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

VEGI attenuates the inflammatory injury and disruption of blood-brain barrier partly by suppressing the TLR4/NF-κB signaling pathway in experimental traumatic brain injury.

PubMed

Gao, Weiwei; Zhao, Zilong; Yu, Gongjie; Zhou, Ziwei; Zhou, Yuan; Hu, Tingting; Jiang, Rongcai; Zhang, Jianning

2015-10-05

Acute traumatic brain injury (TBI) tends to cause the over-activation of inflammatory response and disruption of blood brain barrier (BBB), associating with long-term cognitive and behavioral dysfunction. Vascular endothelial growth inhibitor (VEGI), as a suppressor in the angiogenesis specifically by inducing apoptosis in proliferating endothelial cells, has been applied to different diseases, especially the tumors. But rare study had been done in the field of brain injury. So in this study, we investigated the effects and mechanisms associated with VEGI-induced neuroprotection following CNS injury in mice TBI models. We demonstrated that the VEGI treatment reduced the contusion brain tissue loss, the permeation of inflammatory cells (MPO(+)) and the activation of microglia (Iba-1(+)). The treatment up-regulated the tight junction proteins (CLN5, ZO-1 and OCLN), which are vital importance for the integrity of the blood brain barrier (BBB), the B-cell lymphoma 2 (Bcl-2) cell survival factors, while down-regulated the expression of TLR4, NF-κB and inflammatory cytokines (IL-1β, TNF-α, iNOS). The treatment also decreased the expression of reactive astrocytes (GFAP(+)), as well as the VEGF, and lowered the permeability of Evens Blue (EB). These findings suggested that the VEGI-treatment could alleviate the post-traumatic excessive inflammatory response, and maintain the stability of blood vessels, remitting the secondary brain damage. Copyright © 2015. Published by Elsevier B.V.

Bone Morphogenic Protein 4-Smad-Induced Upregulation of Platelet-Derived Growth Factor AA Impairs Endothelial Function.

PubMed

Hu, Weining; Zhang, Yang; Wang, Li; Lau, Chi Wai; Xu, Jian; Luo, Jiang-Yun; Gou, Lingshan; Yao, Xiaoqiang; Chen, Zhen-Yu; Ma, Ronald Ching Wan; Tian, Xiao Yu; Huang, Yu

2016-03-01

Bone morphogenic protein 4 (BMP4) is an important mediator of endothelial dysfunction in cardio-metabolic diseases, whereas platelet-derived growth factors (PDGFs) are major angiogenic and proinflammatory mediator, although the functional link between these 2 factors is unknown. The present study investigated whether PDGF mediates BMP4-induced endothelial dysfunction in diabetes mellitus. We generated Ad-Bmp4 to overexpress Bmp4 and Ad-Pdgfa-shRNA to knockdown Pdgfa in mice through tail intravenous injection. SMAD4-shRNA lentivirus, SMAD1-shRNA, and SMAD5 shRNA adenovirus were used for knockdown in human and mouse endothelial cells. We found that PDGF-AA impaired endothelium-dependent vasodilation in aortas and mesenteric resistance arteries. BMP4 upregulated PDGF-AA in human and mouse endothelial cells, which was abolished by BMP4 antagonist noggin or knockdown of SMAD1/5 or SMAD4. BMP4-impared relaxation in mouse aorta was also ameliorated by PDGF-AA neutralizing antibody. Tail injection of Ad-Pdgfa-shRNA ameliorates endothelial dysfunction induced by Bmp4 overexpression (Ad-Bmp4) in vivo. Serum PDGF-AA was elevated in both diabetic patients and diabetic db/db mice compared with nondiabetic controls. Pdgfa-shRNA or Bmp4-shRNA adenovirus reduced serum PDGF-AA concentration in db/db mice. PDGF-AA neutralizing antibody or tail injection with Pdgfa-shRNA adenovirus improved endothelial function in aortas and mesenteric resistance arteries from db/db mice. The effect of PDGF-AA on endothelial function in mouse aorta was also inhibited by Ad-Pdgfra-shRNA to inhibit PDGFRα. The present study provides novel evidences to show that PDGF-AA impairs endothelium-dependent vasodilation and PDGF-AA mediates BMP4-induced adverse effect on endothelial cell function through SMAD1/5- and SMAD4-dependent mechanisms. Inhibition of PGDF-AA ameliorates vascular dysfunction in diabetic mice. © 2016 American Heart Association, Inc.

Ultrastructural pathology of cortical capillary pericytes in human traumatic brain oedema.

PubMed

Castejón, Orlando J

2011-01-01

In human traumatic brain oedema pericytes exhibit remarkable oedematous changes, increased vacuolar and vesicular transport, transient transpericytal channels, and tubular structures demonstrating pericyte brain barrier dysfunction. They show nuclear invaginations, actin and myosin-like filaments, and coupled interaction with endothelial cells through the macula occludens. Some pericytes display hypertrophic and necrotic changes, and phagocytic capacity. Hypertrophic pericytes induce basement membrane splitting. Degenerated pericytes exhibit lacunar enlargement of endoplasmic reticulum, dense osmiophilic bodies, glycogen granules, vacuolization, oedematous Golgi apparatus, and pleomorphic mitochondria. Certain micropinocytotic vesicles are orientated to the Golgi complex and multivesicular bodies, suggesting that pericytes play some role in oedema resolution.

Evaluation of Vitamin C for Adjuvant Sepsis Therapy

PubMed Central

2013-01-01

Abstract Significance: Evidence is emerging that parenteral administration of high-dose vitamin C may warrant development as an adjuvant therapy for patients with sepsis. Recent Advances: Sepsis increases risk of death and disability, but its treatment consists only of supportive therapies because no specific therapy is available. The characteristics of severe sepsis include ascorbate (reduced vitamin C) depletion, excessive protein nitration in microvascular endothelial cells, and microvascular dysfunction composed of refractive vasodilation, endothelial barrier dysfunction, and disseminated intravascular coagulation. Parenteral administration of ascorbate prevents or even reverses these pathological changes and thereby decreases hypotension, edema, multiorgan failure, and death in animal models of sepsis. Critical Issues: Dehydroascorbic acid appears to be as effective as ascorbate for protection against microvascular dysfunction, organ failure, and death when injected in sepsis models, but information about pharmacodynamics and safety in human subjects is only available for ascorbate. Although the plasma ascorbate concentration in critically ill and septic patients is normalized by repletion protocols that use high doses of parenteral ascorbate, and such doses are tolerated well by most healthy subjects, whether such large amounts of the vitamin trigger adverse effects in patients is uncertain. Future Directions: Further study of sepsis models may determine if high concentrations of ascorbate in interstitial fluid have pro-oxidant and bacteriostatic actions that also modify disease progression. However, the ascorbate depletion observed in septic patients receiving standard care and the therapeutic mechanisms established in models are sufficient evidence to support clinical trials of parenteral ascorbate as an adjuvant therapy for sepsis. Antioxid. Redox Signal. 19, 2129–2140. PMID:23682970

Endothelial Dysfunction and Blood Viscosity Inpatients with Unstable Angina in Different Periods of a Solar Activity

NASA Astrophysics Data System (ADS)

Parshina, S. S.; Tokaeva, L. K.; Dolgova, E. M.; Afanas'yeva, T. N.; Strelnikova, O. A.

The origin of hemorheologic and endothelial defects in patients with unstable angina (comparing with healthy persons) is determined by a solar activity period: the blood viscosity increases in a period of high solar activity in the vessels of small, medium and macro diameters, a local decompensate dysfunction of small vessels endothelium had been fixed (microcirculation area). In the period of a low solar activity there is an increase of a blood viscosity in vessels of all diameters, generalized subcompensated endothelial dysfunction is developed (on the background of the III phase blood clotting activating). In the period of a high solar activity a higher blood viscosity had been fixed, comparing with the period of a low solar activity.

Fatty Acid-Binding Protein 5 at the Blood-Brain Barrier Regulates Endogenous Brain Docosahexaenoic Acid Levels and Cognitive Function.

PubMed

Pan, Yijun; Short, Jennifer L; Choy, Kwok H C; Zeng, Annie X; Marriott, Philip J; Owada, Yuji; Scanlon, Martin J; Porter, Christopher J H; Nicolazzo, Joseph A

2016-11-16

Fatty acid-binding protein 5 (FABP5) at the blood-brain barrier contributes to the brain uptake of docosahexaenoic acid (DHA), a blood-derived polyunsaturated fatty acid essential for maintenance of cognitive function. Given the importance of DHA in cognition, the aim of this study was to investigate whether deletion of FABP5 results in cognitive dysfunction and whether this is associated with reduced brain endothelial cell uptake of exogenous DHA and subsequent attenuation in the brain levels of endogenous DHA. Cognitive function was assessed in male and female FABP5 +/+ and FABP5 -/- mice using a battery of memory paradigms. FABP5 -/- mice exhibited impaired working memory and short-term memory, and these cognitive deficits were associated with a 14.7 ± 5.7% reduction in endogenous brain DHA levels. The role of FABP5 in the blood-brain barrier transport of DHA was assessed by measuring 14 C-DHA uptake into brain endothelial cells and capillaries isolated from FABP5 +/+ and FABP5 -/- mice. In line with a crucial role of FABP5 in the brain uptake of DHA, 14 C-DHA uptake into brain endothelial cells and brain capillaries of FABP5 -/- mice was reduced by 48.4 ± 14.5% and 14.0 ± 4.2%, respectively, relative to those of FABP5 +/+ mice. These results strongly support the hypothesis that FABP5 is essential for maintaining brain endothelial cell uptake of DHA, and that cognitive deficits observed in FABP5 -/- mice are associated with reduced CNS access of DHA. Genetic deletion of fatty acid-binding protein 5 (FABP5) in mice reduces uptake of exogenous docosahexaenoic acid (DHA) into brain endothelial cells and brain capillaries and reduces brain parenchymal levels of endogenous DHA. Therefore, FABP5 in the brain endothelial cell is a crucial contributor to the brain levels of DHA. Critically, lowered brain DHA levels in FABP5 -/- mice occurred in tandem with cognitive deficits in a battery of memory paradigms. This study provides evidence of a critical role for FABP5 in the maintenance of cognitive function via regulating the brain uptake of DHA, and suggests that upregulation of FABP5 in neurodegenerative diseases, where brain DHA levels are possibly diminished (e.g., Alzheimer's disease), may provide a novel therapeutic approach for restoring cognitive function. Copyright © 2016 the authors 0270-6474/16/3611756-13$15.00/0.

Ischemia-induced endothelial cell swelling and mitochondrial dysfunction are attenuated by cinnamtannin D1, green tea extract, and resveratrol in vitro.

PubMed

Panickar, Kiran S; Qin, Bolin; Anderson, Richard A

2015-10-01

Polyphenols possess antioxidant and anti-inflammatory properties. Oxidative stress (OS) and inflammation have been implicated in the pathogenesis of cytotoxic brain edema in cerebral ischemia. In addition, OS and pro-inflammatory cytokines also damage the endothelial cells and the neurovascular unit. Endothelial cell swelling may contribute to a leaky blood-brain barrier which may result in vasogenic edema in the continued presence of the existing cytotoxic edema. We investigated the protective effects of polyphenols on cytotoxic cell swelling in bEND3 endothelial cultures subjected to 5 hours oxygen-glucose deprivation (OGD). A polyphenol trimer from cinnamon (cinnamtannin D1), a polyphenol-rich extract from green tea, and resveratrol prevented the OGD-induced rise in mitochondrial free radicals, cell swelling, and the dissipation of the inner mitochondrial membrane potential. Monocyte chemoattractant protein (also called CCL2), a chemokine, but not tumor necrosis factor-α or interleukin-6, augmented the cell swelling. This effect of monochemoattractant protein 1-1 was attenuated by the polyphenols. Cyclosporin A, a blocker of the mitochondrial permeability transition pore, did not attenuate cell swelling but BAPTA-AM, an intracellular calcium chelator did, indicating a role of [Ca(2+)]i but not the mPT in cell swelling. These results indicate that the polyphenols reduce mitochondrial reactive oxygen species and subsequent cell swelling in endothelial cells following ischemic injury and thus may reduce brain edema and associated neural damage in ischemia. One possible mechanism by which the polyphenols may attenuate endothelial cell swelling is through the reduction in [Ca(2+)]i.

The glutathione mimic ebselen inhibits oxidative stress but not endoplasmic reticulum stress in endothelial cells.

PubMed

Ahwach, Salma Makhoul; Thomas, Melanie; Onstead-Haas, Luisa; Mooradian, Arshag D; Haas, Michael J

2015-08-01

Reactive oxygen species are associated with cardiovascular disease, diabetes, and atherosclerosis, yet the use of antioxidants in clinical trials has been ineffective at improving outcomes. In endothelial cells, high-dextrose-induced oxidative stress and endoplasmic reticulum stress promote endothelial dysfunction leading to the recruitment and activation of peripheral blood lymphocytes and the breakdown of barrier function. Ebselen, a glutathione peroxidase 1 (GPX1) mimic, has been shown to improve β-cell function in diabetes and prevent atherosclerosis. To determine if ebselen inhibits both oxidative stress and endoplasmic reticulum (ER) stress in endothelial cells, we examined its effects in human umbilical vein endothelial cells (HUVEC) and human coronary artery endothelial cells (HCAEC) with and without high-dextrose. Oxidative stress and ER stress were measured by 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-A]pyrazin-3-one hydrochloride chemiluminescence and ER stress alkaline phosphatase assays, respectively. GPX1 over-expression and knockdown were performed by transfecting cells with a GPX1 expression construct or a GPX1-specific siRNA, respectively. Ebselen inhibited dextrose-induced oxidative stress but not ER stress in both HUVEC and HCAEC. Ebselen also had no effect on tunicamycin-induced ER stress in HCAEC. Furthermore, augmentation of GPX1 activity directly by sodium selenite supplementation or transfection of a GPX1 expression plasmid decreased dextrose-induced oxidative stress but not ER stress, while GPX1 knockout enhanced oxidative stress but had no effect on ER stress. These results suggest that ebselen targets only oxidative stress but not ER stress. Copyright © 2015. Published by Elsevier Inc.

Hyperglycemia-induced PATZ1 negatively modulates endothelial vasculogenesis via repression of FABP4 signaling.

PubMed

Chen, Ren-An; Sun, Xiao-Mian; Yan, Chang-You; Liu, Li; Hao, Miao-Wang; Liu, Qiang; Jiao, Xi-Ying; Liang, Ying-Min

2016-09-02

Vascular endothelial dysfunction, a central hallmark of diabetes, predisposes diabetic patients to numerous cardiovascular complications. The POZ/BTB and AT-hook-containing zinc finger protein 1 (PATZ1), is an important transcriptional regulatory factor and regulates divergent pathways depending on the cellular context, but its role in endothelial cells remains poorly understood. Herein, we report for the first time that endothelial PATZ1 expression was abnormally upregulated in diabetic endothelial cells (ECs) regardless of diabetes classification. This stimulatory effect was further confirmed in the high glucose-treated human umbilical vein endothelial cells (HUVECs). From a functional standpoint, transgenic overexpression of PATZ1 in endothelial colony forming cells (ECFCs) blunted angiogenesis in vivo and rendered endothelial cells unresponsive to established angiogenic factors. Mechanistically, PATZ1 acted as a potent transcriptional corepressor of fatty acid-binding protein 4 (FABP4), an essential convergence point for angiogenic and metabolic signaling pathways in ECs. Taken together, endothelial PATZ1 thus potently inhibits endothelial function and angiogenesis via inhibition of FABP4 expression, and abnormal induction of endothelial PATZ1 may contribute to multiple aspects of vascular dysfunction in diabetes. Copyright © 2016. Published by Elsevier Inc.

Modulation of Endothelial Glycocalyx Structure under Inflammatory Conditions

PubMed Central

Kolářová, Hana; Ambrůzová, Barbora; Švihálková Šindlerová, Lenka; Klinke, Anna; Kubala, Lukáš

2014-01-01

The glycocalyx of the endothelium is an intravascular compartment that creates a barrier between circulating blood and the vessel wall. The glycocalyx is suggested to play an important role in numerous physiological processes including the regulation of vascular permeability, the prevention of the margination of blood cells to the vessel wall, and the transmission of shear stress. Various theoretical models and experimental approaches provide data about changes to the structure and functions of the glycocalyx under various types of inflammatory conditions. These alterations are suggested to promote inflammatory processes in vessels and contribute to the pathogenesis of number of diseases. In this review we summarize current knowledge about the modulation of the glycocalyx under inflammatory conditions and the consequences for the course of inflammation in vessels. The structure and functions of endothelial glycocalyx are briefly discussed in the context of methodological approaches regarding the determination of endothelial glycocalyx and the uncertainty and challenges involved in glycocalyx structure determination. In addition, the modulation of glycocalyx structure under inflammatory conditions and the possible consequences for pathogenesis of selected diseases and medical conditions (in particular, diabetes, atherosclerosis, ischemia/reperfusion, and sepsis) are summarized. Finally, therapeutic strategies to ameliorate glycocalyx dysfunction suggested by various authors are discussed. PMID:24803742

Effects of Fe particle irradiation on human endothelial barrier structure and function

NASA Astrophysics Data System (ADS)

Sharma, Preety; Guida, Peter; Grabham, Peter

2014-07-01

Space travel involves exposure to biologically effective heavy ion radiation and there is consequently a concern for possible degenerative disorders in humans. A significant target for radiation effects is the microvascular system, which is crucial to healthy functioning of the tissues. Its pathology is linked to disrupted endothelial barrier function and is not only a primary event in a range of degenerative diseases but also an important influencing factor in many others. Thus, an assessment of the effects of heavy ion radiation on endothelial barrier function would be useful for estimating the risks of space travel. This study was aimed at understanding the effects of high LET Fe particles (1 GeV/n) and is the first investigation of the effects of charged particles on the function of the human endothelial barrier. We used a set of established and novel endpoints to assess barrier function after exposure. These include, trans-endothelial electrical resistance (TEER), morphological effects, localization of adhesion and cell junction proteins (in 2D monolayers and in 3D tissue models), and permeability of molecules through the endothelial barrier. A dose of 0.50 Gy was sufficient to cause a progressive reduction in TEER measurements that were significant 48 hours after exposure. Concurrently, there were morphological changes and a 14% loss of cells from monolayers. Gaps also appeared in the normally continuous cell-border localization of the tight junction protein - ZO-1 but not the Platelet endothelial cell adhesion molecule (PECAM-1) in both monolayers and in 3D vessel models. Disruption of barrier function was confirmed by increased permeability to 3 kDa and 10 kDa dextran molecules. A dose of 0.25 Gy caused no detectible change in cell number, morphology, or TEER, but did cause barrier disruption since there were gaps in the cell border localization of ZO-1 and an increased permeability to 3 kDa dextran. These results indicate that Fe particles potently have impact on human endothelial barrier function and represent a risk for degenerative diseases in the space environment.

Glucocorticoids induce transactivation of tight junction genes occludin and claudin-5 in retinal endothelial cells via a novel cis-element.

PubMed

Felinski, Edward A; Cox, Amy E; Phillips, Brett E; Antonetti, David A

2008-06-01

Tight junctions between vascular endothelial cells help to create the blood-brain and blood-retinal barriers. Breakdown of the retinal tight junction complex is problematic in several disease states including diabetic retinopathy. Glucocorticoids can restore and/or preserve the endothelial barrier to paracellular permeability, although the mechanism remains unclear. We show that glucocorticoid treatment of primary retinal endothelial cells increases content of the tight junction proteins occludin and claudin-5, co-incident with an increase in barrier properties of endothelial monolayers. The glucocorticoid receptor antagonist RU486 reverses both the glucocorticoid-stimulated increase in occludin content and the increase in barrier properties. Transcriptional activity from the human occludin and claudin-5 promoters increases in retinal endothelial cells upon glucocorticoid treatment, and is dependent on the glucocorticoid receptor (GR) as demonstrated by siRNA. Deletion analysis of the occludin promoter reveals a 205bp sequence responsible for the glucocorticoid response. However, this region does not possess a canonical glucocorticoid response element and does not bind to the GR in a chromatin immunoprecipitation (ChIP) assay. Mutational analysis of this region revealed a novel 40bp occludin enhancer element (OEE), containing two highly conserved regions of 10 and 13 base pairs, that is both necessary and sufficient for glucocorticoid-induced gene expression in retinal endothelial cells. These data suggest a novel mechanism for glucocorticoid induction of vascular endothelial barrier properties through increased occludin and claudin-5 gene expression.

GLUCOCORTICOIDS INDUCE TRANSACTIVATION OF TIGHT JUNCTION GENES OCCLUDIN AND CLAUDIN-5 IN RETINAL ENDOTHELIAL CELLS VIA A NOVEL CIS-ELEMENT

PubMed Central

Felinski, Edward A.; Cox, Amy E.; Phillips, Brett E.; Antonetti, David A.

2008-01-01

Tight junctions between vascular endothelial cells help to create the blood-brain and blood-retinal barriers. Breakdown of the retinal tight junction complex is problematic in several disease states including diabetic retinopathy. Glucocorticoids can restore and/or preserve the endothelial barrier to paracellular permeability, although the mechanism remains unclear. We show that glucocorticoid treatment of primary retinal endothelial cells increases content of the tight junction proteins occludin and claudin-5, co-incident with an increase in barrier properties of endothelial monolayers. The glucocorticoid receptor antagonist RU486 reverses both the glucocorticoid-stimulated increase in occludin content and the increase in barrier properties. Transcriptional activity from the human occludin and claudin-5 promoters increases in retinal endothelial cells upon glucocorticoid treatment, and is dependent on the glucocorticoid receptor (GR) as demonstrated by siRNA. Deletion analysis of the occludin promoter reveals a 205 bp sequence responsible for the glucocorticoid response. However, this region does not posses a canonical glucocorticoid response element and does not bind to the GR in a chromatin immunoprecipitation (ChIP) assay. Mutational analysis of this region revealed a novel 40 bp occludin enhancer element (OEE), containing two highly-conserved regions of 10 and 13 base pairs, that is both necessary and sufficient for glucocorticoid-induced gene expression in retinal endothelial cells. These data suggest a novel mechanism for glucocorticoid induction of vascular endothelial barrier properties through increased occludin and claudin-5 gene expression. PMID:18501346

Activation of PPARδ prevents endothelial dysfunction induced by overexpression of amyloid-β precursor protein

PubMed Central

d'Uscio, Livius V.; Das, Pritam; Santhanam, Anantha V.R.; He, Tongrong; Younkin, Steven G.; Katusic, Zvonimir S.

2012-01-01

Aims Existing evidence suggests that amyloid-β precursor protein (APP) causes endothelial dysfunction and contributes to pathogenesis of atherosclerosis. In the present study, experiments were designed to: (1) determine the mechanisms underlying endothelial dysfunction and (2) define the effects of peroxisome proliferator-activated receptor delta (PPARδ) ligand on endothelial function in transgenic Tg2576 mice overexpressing mutated human APP. Methods and results Confocal microscopy and western blot analyses of wild-type mice aortas provided evidence that APP protein is mainly present in endothelial cells. Overexpression of APP significantly impaired endothelium-dependent relaxations to acetylcholine and phosphorylation of endothelial nitric oxide synthase at Ser1177 in aortas. HPLC analysis revealed that tetrahydrobiopterin (BH4) levels were reduced in Tg2576 mice aortas. This was caused by increased oxidation of BH4 and reduced expression and activity of GTP-cyclohydrolase I. Furthermore, gp91phox protein expression and superoxide anion production were increased in aortas of Tg2576 mice. This augmented superoxide formation was completely prevented by the NADPH oxidase inhibitor VAS2870. Expression of copper-/zinc-superoxide dismutase (Cu/ZnSOD) and extracellular SOD was downregulated. Treatment with PPARδ ligand GW501516 (2 mg/kg/day) for 14 days significantly increased BH4 bioavailability and improved endothelium-dependent relaxations in Tg2576 mice aortas. GW501516 also normalized protein expression of gp91phox and SODs, thereby reducing production of superoxide anion in the aortas. Conclusion Our results suggest that in APP transgenic mice loss of nitric oxide and increased oxidative stress are the major causes of endothelial dysfunction. The vascular protective effects of GW501516 in Tg2576 mice appear to be critically dependent on prevention of superoxide anion production. PMID:22886847

Activation of PPARδ prevents endothelial dysfunction induced by overexpression of amyloid-β precursor protein.

PubMed

d'Uscio, Livius V; Das, Pritam; Santhanam, Anantha V R; He, Tongrong; Younkin, Steven G; Katusic, Zvonimir S

2012-12-01

Existing evidence suggests that amyloid-β precursor protein (APP) causes endothelial dysfunction and contributes to pathogenesis of atherosclerosis. In the present study, experiments were designed to: (1) determine the mechanisms underlying endothelial dysfunction and (2) define the effects of peroxisome proliferator-activated receptor delta (PPARδ) ligand on endothelial function in transgenic Tg2576 mice overexpressing mutated human APP. Confocal microscopy and western blot analyses of wild-type mice aortas provided evidence that APP protein is mainly present in endothelial cells. Overexpression of APP significantly impaired endothelium-dependent relaxations to acetylcholine and phosphorylation of endothelial nitric oxide synthase at Ser(1177) in aortas. HPLC analysis revealed that tetrahydrobiopterin (BH(4)) levels were reduced in Tg2576 mice aortas. This was caused by increased oxidation of BH(4) and reduced expression and activity of GTP-cyclohydrolase I. Furthermore, gp91phox protein expression and superoxide anion production were increased in aortas of Tg2576 mice. This augmented superoxide formation was completely prevented by the NADPH oxidase inhibitor VAS2870. Expression of copper-/zinc-superoxide dismutase (Cu/ZnSOD) and extracellular SOD was downregulated. Treatment with PPARδ ligand GW501516 (2 mg/kg/day) for 14 days significantly increased BH(4) bioavailability and improved endothelium-dependent relaxations in Tg2576 mice aortas. GW501516 also normalized protein expression of gp91(phox) and SODs, thereby reducing production of superoxide anion in the aortas. Our results suggest that in APP transgenic mice loss of nitric oxide and increased oxidative stress are the major causes of endothelial dysfunction. The vascular protective effects of GW501516 in Tg2576 mice appear to be critically dependent on prevention of superoxide anion production.

Inactivation of Endothelial Small/Intermediate Conductance of Calcium-Activated Potassium Channels Contributes to Coronary Arteriolar Dysfunction in Diabetic Patients.

PubMed

Liu, Yuhong; Xie, An; Singh, Arun K; Ehsan, Afshin; Choudhary, Gaurav; Dudley, Samuel; Sellke, Frank W; Feng, Jun

2015-08-24

Diabetes is associated with coronary arteriolar endothelial dysfunction. We investigated the role of the small/intermediate (SK(Ca)/IK(Ca)) conductance of calcium-activated potassium channels in diabetes-related endothelial dysfunction. Coronary arterioles (80 to 150 μm in diameter) were dissected from discarded right atrial tissues of diabetic (glycosylated hemoglobin = 9.6±0.25) and nondiabetic patients (glycosylated hemoglobin 5.4±0.12) during coronary artery bypass graft surgery (n=8/group). In-vitro relaxation response of precontracted arterioles was examined in the presence of the selective SK(Ca)/IK(Ca) activator NS309 and other vasodilatory agents. The channel density and membrane potential of diabetic and nondiabetic endothelial cells was measured by using the whole cell patch-clamp technique. The protein expression and distribution of the SK(Ca)/IK(Ca) in the human myocardium and coronary arterioles was examined by Western blotting and immunohistochemistry. Our results indicate that diabetes significantly reduced the coronary arteriolar response to the SK(Ca)/IK(Ca) activator NS309 compared to the respective responses of nondiabetic vessels (P<0.05 versus nondiabetes). The relaxation response of diabetic arterioles to NS309 was prevented by denudation of endothelium (P=0.001 versus endothelium-intact). Diabetes significantly decreased endothelial SK(Ca)/IK(Ca) currents and hyperpolarization induced by the SK(Ca)/IK(Ca) activator NS309 as compared with that of nondiabetics. There were no significant differences in the expression and distribution of SK(Ca)/IK(Ca) proteins in the coronary microvessels. Diabetes is associated with inactivation of endothelial SK(Ca)/IK(Ca) channels, which may contribute to endothelial dysfunction in diabetic patients. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Dietary sodium restriction reverses vascular endothelial dysfunction in middle-aged/older adults with moderately elevated systolic blood pressure

PubMed Central

Jablonski, Kristen L.; Racine, Matthew L.; Geolfos, Candace J.; Gates, Phillip E.; Chonchol, Michel; McQueen, Matthew B.; Seals, Douglas R.

2013-01-01

Objectives We determined the efficacy of dietary sodium restriction (DSR) for improving vascular endothelial dysfunction in middle-aged/older adults with moderately elevated systolic blood pressure (SBP; 130–159 mmHg) and the associated physiological mechanisms. Background Vascular endothelial dysfunction develops with advancing age and elevated SBP, contributing to increased cardiovascular risk. DSR lowers BP, but its effect on vascular endothelial function and mechanisms involved are unknown. Methods Seventeen subjects (11M/6F; 62±7 yrs, mean±S.D.) completed a randomized, crossover study of 4 weeks of both low and normal sodium intake. Vascular endothelial function (endothelium-dependent dilation; EDD), nitric oxide (NO)/tetrahydrobiopterin (BH4) bioavailability and oxidative stress-associated mechanisms were assessed following each condition. Results Urinary sodium excretion was reduced by ~50% (to 70±30 mmol/day), and conduit (brachial artery flow-mediated dilation [FMDBA]) and resistance (forearm blood flow responses to acetylcholine [FBFACh]) artery EDD were 68% and 42% (peak FBFACh) higher following the low sodium diet (p<0.005). Low sodium markedly enhanced NO- mediated EDD (greater ΔFBFACh with endothelial NO synthase [eNOS] inhibition) without changing eNOS expression/activation (Ser1177 phosphorylation), restored BH4 bioactivity (less ΔFMDBA with acute BH4), abolished tonic superoxide suppression of EDD (less ΔFMDBA and ΔFBFACh with ascorbic acid infusion), and increased circulating superoxide dismutase activity (p<0.05). These effects were independent of ΔSBP. Other subject characteristics/dietary factors and endothelium-independent dilation were unchanged. Conclusions DSR largely reverses both macro- and microvascular endothelial dysfunction by enhancing NO and BH4 bioavailability and reducing oxidative stress. Our findings support the emerging concept that DSR induces “vascular protection” beyond that attributable to its BP-lowering effects. PMID:23141486

SIRT1 inhibits NADPH oxidase activation and protects endothelial function in the rat aorta: implications for vascular aging.

PubMed

Zarzuelo, María José; López-Sepúlveda, Rocío; Sánchez, Manuel; Romero, Miguel; Gómez-Guzmán, Manuel; Ungvary, Zoltan; Pérez-Vizcaíno, Francisco; Jiménez, Rosario; Duarte, Juan

2013-05-01

Vascular aging is characterized by up-regulation of NADPH oxidase, oxidative stress and endothelial dysfunction. Previous studies demonstrate that the activity of the evolutionarily conserved NAD(+)-dependent deacetylase SIRT1 declines with age and that pharmacological activators of SIRT1 confer significant anti-aging cardiovascular effects. To determine whether dysregulation of SIRT1 promotes NADPH oxidase-dependent production of reactive oxygen species (ROS) and impairs endothelial function we assessed the effects of three structurally different inhibitors of SIRT1 (nicotinamide, sirtinol, EX527) in aorta segments isolated from young Wistar rats. Inhibition of SIRT1 induced endothelial dysfunction, as shown by the significantly reduced relaxation to the endothelium-dependent vasodilators acetylcholine and the calcium ionophore A23187. Endothelial dysfunction induced by SIRT1 inhibition was prevented by treatment of the vessels with the NADPH oxidase inhibitor apocynin or superoxide dismutase. Inhibition of SIRT1 significantly increased vascular superoxide production, enhanced NADPH oxidase activity, and mRNA expression of its subunits p22(phox) and NOX4, which were prevented by resveratrol. Peroxisome proliferator-activated receptor-α (PPARα) activation mimicked the effects of resveratrol while PPARα inhibition prevented the effects of this SIRT1 activator. SIRT1 co-precipitated with PPARα and nicotinamide increased the acetylation of the PPARα coactivator PGC-1α, which was suppressed by resveratrol. In conclusion, impaired activity of SIRT1 induces endothelial dysfunction and up-regulates NADPH oxidase-derived ROS production in the vascular wall, mimicking the vascular aging phenotype. Moreover, a new mechanism for controlling endothelial function after SIRT1 activation involves a decreased PGC-1α acetylation and the subsequent PPARα activation, resulting in both decreased NADPH oxidase-driven ROS production and NO inactivation. Copyright © 2013 Elsevier Inc. All rights reserved.

Protective effect of a Chinese Medicine formula He-Ying-Qing-Re Formula on diabetic retinopathy.

PubMed

Wang, Leilei; Wang, Ning; Tan, Hor-yue; Zhang, Yinjian; Feng, Yibin

2015-07-01

He-Ying-Qing-Re Formula (HF) is a formula modified from "Si-Miao-Yong-An Decoction", a traditional Chinese medical classic emerged in the Qing dynasty and has been reported for treatment of vascular diseases. HF, containing 8 herbs, has been used in local hospital for decades as a complementary method for diabetic retinopathy (DR) with retinal vascular dysfunction. Clinical reports revealed HF could ameliorate vision defects, microaneurysms, hemorrhages and macular edema. The aim of this study is to investigate the anti-DR action of HF and its underlying mechanism experimentally. Chromatographic fingerprinting of HF and rodent model of DR were established; hypoglycemic effect of HF was measured by fasting, random blood glucose and glucose tolerance test; vascular degeneration was measured by retinal digestion; blood-retina-barrier (BRB) permeability was assessed with Evans Blue leakage assay. Advanced glycation end products (AGEs) were measured in vitro and in vivo level; Migration of retinal vascular endothelial cells were determined by wound healing and transwell chamber assays; permeability of endothelial monolayer was monitored with dextran transport. AGEs-related proteins and signaling were measured with immunoblotting and immunohistochemistry. Chlorogenic acid, ferulic acid and arctin were identified as major components in HF; HF suppresses retinal vasculature degeneration and BRB permeability damage without significant inhibition on hyperglycemia; HF reduces in vitro and in vivo formation of AGEs and AGEs-induced migration as well as permeability of retinal vascular endothelial cells. Expression of tight junction proteins Zo-1 and Claudin-1 was increased while activation of AGEs receptor and downstream signaling Akt were suppressed upon HF treatment. HF exhibits protective effect against diabetic retinopathy, which may be associated with inhibition on AGEs and recovery on endothelial dysfunction via modulation of tight junction and AGEs downstream signaling. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Human severe sepsis cytokine mixture increases β2-integrin-dependent polymorphonuclear leukocyte adhesion to cerebral microvascular endothelial cells in vitro.

PubMed

Blom, Chris; Deller, Brittany L; Fraser, Douglas D; Patterson, Eric K; Martin, Claudio M; Young, Bryan; Liaw, Patricia C; Yazdan-Ashoori, Payam; Ortiz, Angelica; Webb, Brian; Kilmer, Greg; Carter, David E; Cepinskas, Gediminas

2015-04-07

Sepsis-associated encephalopathy (SAE) is a state of acute brain dysfunction in response to a systemic infection. We propose that systemic inflammation during sepsis causes increased adhesion of leukocytes to the brain microvasculature, resulting in blood-brain barrier dysfunction. Thus, our objectives were to measure inflammatory analytes in plasma of severe sepsis patients to create an experimental cytokine mixture (CM), and to use this CM to investigate the activation and interactions of polymorphonuclear leukocytes (PMN) and human cerebrovascular endothelial cells (hCMEC/D3) in vitro. The concentrations of 41 inflammatory analytes were quantified in plasma obtained from 20 severe sepsis patients and 20 age- and sex-matched healthy controls employing an antibody microarray. Two CMs were prepared to mimic severe sepsis (SSCM) and control (CCM), and these CMs were then used for PMN and hCMEC/D3 stimulation in vitro. PMN adhesion to hCMEC/D3 was assessed under conditions of flow (shear stress 0.7 dyn/cm(2)). Eight inflammatory analytes elevated in plasma obtained from severe sepsis patients were used to prepare SSCM and CCM. Stimulation of PMN with SSCM led to a marked increase in PMN adhesion to hCMEC/D3, as compared to CCM. PMN adhesion was abolished with neutralizing antibodies to either β2 (CD18), αL/β2 (CD11α/CD18; LFA-1) or αM/β2 (CD11β/CD18; Mac-1) integrins. In addition, immune-neutralization of the endothelial (hCMEC/D3) cell adhesion molecule, ICAM-1 (CD54) also suppressed PMN adhesion. Human SSCM up-regulates PMN pro-adhesive phenotype and promotes PMN adhesion to cerebrovascular endothelial cells through a β2-integrin-ICAM-1-dependent mechanism. PMN adhesion to the brain microvasculature may contribute to SAE.

The effect of aging on brain barriers and the consequences for Alzheimer's disease development.

PubMed

Gorlé, Nina; Van Cauwenberghe, Caroline; Libert, Claude; Vandenbroucke, Roosmarijn E

2016-08-01

Life expectancy has increased in most developed countries, which has led to an increase in the proportion of elderly people in the world's population. However, this increase in life expectancy is not accompanied by a lengthening of the health span since aging is characterized with progressive deterioration in cellular and organ functions. The brain is particularly vulnerable to disease, and this is reflected in the onset of age-related neurodegenerative diseases such as Alzheimer's disease. Research shows that dysfunction of two barriers in the central nervous system (CNS), the blood-brain barrier (BBB) and the blood-cerebrospinal fluid (CSF) barrier (BCSFB), plays an important role in the progression of these neurodegenerative diseases. The BBB is formed by the endothelial cells of the blood capillaries, whereas the BCSFB is formed by the epithelial cells of the choroid plexus (CP), both of which are affected during aging. Here, we give an overview of how these barriers undergo changes during aging and in Alzheimer's disease, thereby disturbing brain homeostasis. Studying these changes is needed in order to gain a better understanding of the mechanisms of aging at the brain barriers, which might lead to the development of new therapies to lengthen the health span (including mental health) and reduce the chances of developing Alzheimer's disease.

Endovascular treatment of chronic cerebro spinal venous insufficiency in patients with multiple sclerosis modifies circulating markers of endothelial dysfunction and coagulation activation: a prospective study.

PubMed

Napolitano, Mariasanta; Bruno, Aldo; Mastrangelo, Diego; De Vizia, Marcella; Bernardo, Benedetto; Rosa, Buonagura; De Lucia, Domenico

2014-10-01

We performed a monocentric observational prospective study to evaluate coagulation activation and endothelial dysfunction parameters in patients with multiple sclerosis undergoing endovascular treatment for cerebro-spinal-venous insufficiency. Between February 2011 and July 2012, 144 endovascular procedures in 110 patients with multiple sclerosis and chronical cerebro-spinal venous insufficiency were performed and they were prospectively analyzed. Each patient was included in the study according to previously published criteria, assessed by the investigators before enrollment. Endothelial dysfunction and coagulation activation parameters were determined before the procedure and during follow-up at 1, 3, 6, 9, 12, 15 and 18 months after treatment, respectively. After the endovascular procedure, patients were treated with standard therapies, with the addition of mesoglycan. Fifty-five percent of patients experienced a favorable outcome of multiple sclerosis within 1 month after treatment, 25% regressed in the following 3 months, 24.9% did not experience any benefit. In only 0.1% patients, acute recurrence was observed and it was treated with high-dose immunosuppressive therapy. No major complications were observed. Coagulation activation and endothelial dysfunction parameters were shown to be reduced at 1 month and stable up to 12-month follow-up, and they were furthermore associated with a good clinical outcome. Endovascular procedures performed by a qualified staff are well tolerated; they can be associated with other currently adopted treatments. Correlations between inflammation, coagulation activation and neurodegenerative disorders are here supported by the observed variations in plasma levels of markers of coagulation activation and endothelial dysfunction.

Endothelial effects of emission source particles: acute toxic response gene expression profiles.

PubMed

Nadadur, Srikanth S; Haykal-Coates, Najwa; Mudipalli, Anuradha; Costa, Daniel L

2009-02-01

Air pollution epidemiology has established a strong association between exposure to ambient particulate matter (PM) and cardiovascular outcomes. Experimental studies in both humans and laboratory animals support varied biological mechanisms including endothelial dysfunction as potentially a central step to the elicitation of cardiovascular events. We therefore hypothesized that relevant early molecular alterations on endothelial cells should be assessable in vitro upon acute exposure to PM components previously shown to be involved in health outcomes. Using a model emission PM, residual oil fly ash and one of its predominant constituents (vanadium-V), we focused on the development of gene expression profiles to fingerprint that particle and its constituents to explore potential biomarkers for PM-induced endothelial dysfunction. Here we present differential gene expression and transcription factor activation profiles in human vascular endothelial cells exposed to a non-cytotoxic dose of fly ash or V following semi-global gene expression profiling of approximately 8000 genes. Both fly ash and it's prime constituent, V, induced alterations in genes involved in passive and active transport of solutes across the membrane; voltage-dependent ion pumps; induction of extracellular matrix proteins and adhesion molecules; and activation of numerous kinases involved in signal transduction pathways. These preliminary data suggest that cardiovascular effects associated with exposure to PM may be mediated by perturbations in endothelial cell permeability, membrane integrity; and ultimately endothelial dysfunction.

Glomerular Endothelial Mitochondrial Dysfunction Is Essential and Characteristic of Diabetic Kidney Disease Susceptibility.

PubMed

Qi, Haiying; Casalena, Gabriella; Shi, Shaolin; Yu, Liping; Ebefors, Kerstin; Sun, Yezhou; Zhang, Weijia; D'Agati, Vivette; Schlondorff, Detlef; Haraldsson, Börje; Böttinger, Erwin; Daehn, Ilse

2017-03-01

The molecular signaling mechanisms between glomerular cell types during initiation/progression of diabetic kidney disease (DKD) remain poorly understood. We compared the early transcriptome profile between DKD-resistant C57BL/6J and DKD-susceptible DBA/2J (D2) glomeruli and demonstrated a significant downregulation of essential mitochondrial genes in glomeruli from diabetic D2 mice, but not in C57BL/6J, with comparable hyperglycemia. Diabetic D2 mice manifested increased mitochondrial DNA lesions (8-oxoguanine) exclusively localized to glomerular endothelial cells after 3 weeks of diabetes, and these accumulated over time in addition to increased urine secretion of 8-oxo-deoxyguanosine. Detailed assessment of glomerular capillaries from diabetic D2 mice demonstrated early signs of endothelial injury and loss of fenestrae. Glomerular endothelial mitochondrial dysfunction was associated with increased glomerular endothelin-1 receptor type A (Ednra) expression and increased circulating endothelin-1 (Edn1). Selective Ednra blockade or mitochondrial-targeted reactive oxygen species scavenging prevented mitochondrial oxidative stress of endothelial cells and ameliorated diabetes-induced endothelial injury, podocyte loss, albuminuria, and glomerulosclerosis. In human DKD, increased urine 8-oxo-deoxyguanosine was associated with rapid DKD progression, and biopsies from patients with DKD showed increased mitochondrial DNA damage associated with glomerular endothelial EDNRA expression. Our studies show that DKD susceptibility was linked to mitochondrial dysfunction, mediated largely by Edn1-Ednra in glomerular endothelial cells representing an early event in DKD progression, and suggest that cross talk between glomerular endothelial injury and podocytes leads to defects and depletion, albuminuria, and glomerulosclerosis. © 2017 by the American Diabetes Association.

Lack of Fibronectin Extra Domain A Alternative Splicing Exacerbates Endothelial Dysfunction in Diabetes

PubMed Central

Gortan Cappellari, Gianluca; Barazzoni, Rocco; Cattin, Luigi; Muro, Andrés F.; Zanetti, Michela

2016-01-01

Glucose-induced changes of artery anatomy and function account for diabetic vascular complications, which heavily impact disease morbidity and mortality. Since fibronectin containing extra domain A (EDA + FN) is increased in diabetic vessels and participates to vascular remodeling, we wanted to elucidate whether and how EDA + FN is implicated in diabetes-induced endothelial dysfunction using isometric-tension recording in a murine model of diabetes. In thoracic aortas of EDA−/−, EDA+/+ (constitutively lacking and expressing EDA + FN respectively), and of wild-type mice (EDAwt/wt), streptozotocin (STZ)-induced diabetes impaired endothelial vasodilation to acetylcholine, irrespective of genotype. However STZ + EDA−/− mice exhibited increased endothelial dysfunction compared with STZ + EDA+/+ and with STZ + EDAwt/wt. Analysis of the underlying mechanisms revealed that STZ + EDA−/− mice show increased oxidative stress as demonstrated by enhanced aortic superoxide anion, nitrotyrosine levels and expression of NADPH oxidase NOX4 and TGF-β1, the last two being reverted by treatment with the antioxidant n-acetylcysteine. In contrast, NOX1 expression and antioxidant potential were similar in aortas from the three genotypes. Interestingly, reduced eNOS expression in STZ + EDA+/+ vessels is counteracted by increased eNOS coupling and function. Although EDA + FN participates to vascular remodelling, these findings show that it plays a crucial role in limiting diabetic endothelial dysfunction by preventing vascular oxidative stress. PMID:27897258

In vitro models of the blood–brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use

PubMed Central

Helms, Hans C; Abbott, N Joan; Burek, Malgorzata; Cecchelli, Romeo; Couraud, Pierre-Olivier; Deli, Maria A; Förster, Carola; Galla, Hans J; Romero, Ignacio A; Shusta, Eric V; Stebbins, Matthew J; Vandenhaute, Elodie; Weksler, Babette

2016-01-01

The endothelial cells lining the brain capillaries separate the blood from the brain parenchyma. The endothelial monolayer of the brain capillaries serves both as a crucial interface for exchange of nutrients, gases, and metabolites between blood and brain, and as a barrier for neurotoxic components of plasma and xenobiotics. This “blood-brain barrier” function is a major hindrance for drug uptake into the brain parenchyma. Cell culture models, based on either primary cells or immortalized brain endothelial cell lines, have been developed, in order to facilitate in vitro studies of drug transport to the brain and studies of endothelial cell biology and pathophysiology. In this review, we aim to give an overview of established in vitro blood–brain barrier models with a focus on their validation regarding a set of well-established blood–brain barrier characteristics. As an ideal cell culture model of the blood–brain barrier is yet to be developed, we also aim to give an overview of the advantages and drawbacks of the different models described. PMID:26868179

Endothelial cell senescence with aging in healthy humans: prevention by habitual exercise and relation to vascular endothelial function.

PubMed

Rossman, Matthew J; Kaplon, Rachelle E; Hill, Sierra D; McNamara, Molly N; Santos-Parker, Jessica R; Pierce, Gary L; Seals, Douglas R; Donato, Anthony J

2017-11-01

Cellular senescence is emerging as a key mechanism of age-related vascular endothelial dysfunction, but evidence in healthy humans is lacking. Moreover, the influence of lifestyle factors such as habitual exercise on endothelial cell (EC) senescence is unknown. We tested the hypothesis that EC senescence increases with sedentary, but not physically active, aging and is associated with vascular endothelial dysfunction. Protein expression (quantitative immunofluorescence) of p53, a transcription factor related to increased cellular senescence, and the cyclin-dependent kinase inhibitors p21 and p16 were 116%, 119%, and 128% greater (all P < 0.05), respectively, in ECs obtained from antecubital veins of older sedentary (60 ± 1 yr, n = 12) versus young sedentary (22 ± 1 yr, n = 9) adults. These age-related differences were not present (all P > 0.05) in venous ECs from older exercising adults (57 ± 1 yr, n = 13). Furthermore, venous EC protein levels of p53 ( r  = -0.49, P = 0.003), p21 ( r  = -0.38, P = 0.03), and p16 ( r  = -0.58, P = 0.002) were inversely associated with vascular endothelial function (brachial artery flow-mediated dilation). Similarly, protein expression of p53 and p21 was 26% and 23% higher (both P < 0.05), respectively, in ECs sampled from brachial arteries of healthy older sedentary (63 ± 1 yr, n = 18) versus young sedentary (25 ± 1 yr, n = 9) adults; age-related changes in arterial EC p53 and p21 expression were not observed ( P > 0.05) in older habitually exercising adults (59 ± 1 yr, n = 14). These data indicate that EC senescence is associated with sedentary aging and is linked to endothelial dysfunction. Moreover, these data suggest that prevention of EC senescence may be one mechanism by which aerobic exercise protects against endothelial dysfunction with age. NEW & NOTEWORTHY Our study provides novel evidence in humans of increased endothelial cell senescence with sedentary aging, which is associated with impaired vascular endothelial function. Furthermore, our data suggest an absence of age-related increases in endothelial cell senescence in older exercising adults, which is linked with preserved vascular endothelial function. Copyright © 2017 the American Physiological Society.

Blood-brain barrier dysfunction and amyloid precursor protein accumulation in microvascular compartment following ischemia-reperfusion brain injury with 1-year survival.

PubMed

Pluta, R

2003-01-01

This study examined the late microvascular consequences of brain ischemia due to cardiac arrest in rats. In reacted vibratome sections scattered foci of extravasated horseradish peroxidase were noted throughout the brain and did not appear to be restricted to any specific area of brain. Ultrastructural investigation of leaky sites frequently presented platelets adhering to the endothelium of venules and capillaries. Endothelial cells demonstrated pathological changes with evidence of perivascular astrocytic swelling. At the same time, we noted C-terminal of amyloid precursor protein/beta-amyloid peptide (CAPP/betaA) deposits in cerebral blood vessels, with a halo of CAPP/betaA immunoreactivity in the surrounding parenchyma suggested diffusion of CAPP/betaA out of the vascular compartment. Changes predominated in the hippocampus, cerebral and entorhinal cortex, corpus callosum, thalamus, basal ganglia and around the lateral ventricles. These data implicate delayed abnormal endothelial function of vessels following ischemia-reperfusion brain injury as a primary event in the pathogenesis of the recurrent cerebral infarction.

Endothelial barrier dysfunction caused by LPS correlates with phosphorylation of HSP27 in vivo.

PubMed

Hirano, S; Rees, R S; Yancy, S L; Welsh, M J; Remick, D G; Yamada, T; Hata, J; Gilmont, R R

2004-02-01

Lung edema during sepsis is triggered by formation of gaps between endothelial cells followed by macrophage infiltration. Endothelial gap formation has been proposed to involve changes in the structure of the actin filament cytoskeleton. Heat shock protein 27 (HSP27) is believed to modulate actin filament dynamics or structure, in a manner dependent on its phosphorylation status. We hypothesized that HSP27 may play a role in endothelial gap formation, by affecting actin dependent events in endothelial cells. As there has been no report concerning HSP27 in lung edema in vivo, we examined induction and phosphorylation of HSP27 in lung following LPS injection, as a model of sepsis. In lung, HSP27 mainly localized in capillary endothelial cells of the alveolus, and in smooth muscle cells of pulmonary arteries. HSP27 became significantly more phosphorylated at 3 h after LPS treatment, while the distribution of HSP27 remained unchanged. Pre-treatment with anti-TNFalpha antibody, which has been shown to reduce lung injury, blocked increases in HSP27 phosphorylation at 3 h. HSP27 phosphorylation was also increased in cultured rat pulmonary arterial endothelial cells (RPAEC) by treatment with TNFalpha, LPS, or H2O2. This phosphorylation was blocked by pre-treatment with SB203580, an inhibitor of the upstream kinase, p38 MAP kinase. Increased endothelial permeability caused by H2O2 in vitro was also blocked by SB203580. The amount of actin associated with HSP27 was reduced after treatment with LPS, or H2O2. In summary, HSP27 phosphorylation temporally correlated with LPS induced pathological endothelial cell gap formation in vivo and in a cell culture model system. This is the first report of increased HSP27 phosphorylation associated with pathological lung injury in an animal model of sepsis.

Periodontal treatment improves endothelial dysfunction in patients with severe periodontitis.

PubMed

Seinost, Gerald; Wimmer, Gernot; Skerget, Martina; Thaller, Erik; Brodmann, Marianne; Gasser, Robert; Bratschko, Rudolf O; Pilger, Ernst

2005-06-01

Because epidemiological studies provide evidence that periodontal infections are associated with an increased risk of progression of cardiovascular and cerebrovascular disease, we postulated that endothelial dysfunction, a critical element in the pathogenesis of atherosclerosis, would be present in patients with periodontal disease. We tested endothelial function in 30 patients with severe periodontitis and 31 control subjects using flow-mediated dilation (FMD) of the brachial artery. The groups were matched for age, sex, and cardiovascular risk factors. Three months after periodontal treatment, including both mechanical and pharmacological therapy, endothelial function was reassessed by brachial artery FMD. Markers of systemic inflammation were measured at baseline and at follow up. Flow-mediated dilation was significantly lower in patients with periodontitis than in control subjects (6.1% +/- 4.4% vs 8.5% +/- 3.4%, P = .002). Successful periodontal treatment resulted in a significant improvement in FMD (9.8% +/- 5.7%; P = .003 compared to baseline) accompanied by a significant decrease in C-reactive protein concentrations (1.1 +/- 1.9 vs 0.8 +/- 0.8 at baseline, P = .026). Endothelium-independent nitro-induced vasodilation did not differ between the study groups at baseline or after periodontal therapy. These results indicate that treatment of severe periodontitis reverses endothelial dysfunction. Whether improved endothelial function will translate into a beneficial effect on atherogenesis and cardiovascular events needs further investigation.

Endothelial mitochondrial oxidative stress determines podocyte depletion in segmental glomerulosclerosis

PubMed Central

Daehn, Ilse; Casalena, Gabriella; Zhang, Taoran; Shi, Shaolin; Fenninger, Franz; Barasch, Nicholas; Yu, Liping; D’Agati, Vivette; Schlondorff, Detlef; Kriz, Wilhelm; Haraldsson, Borje; Bottinger, Erwin P.

2014-01-01

Focal segmental glomerular sclerosis (FSGS) is a primary kidney disease that is commonly associated with proteinuria and progressive loss of glomerular function, leading to development of chronic kidney disease (CKD). FSGS is characterized by podocyte injury and depletion and collapse of glomerular capillary segments. Progression of FSGS is associated with TGF-β activation in podocytes; however, it is not clear how TGF-β signaling promotes disease. Here, we determined that podocyte-specific activation of TGF-β signaling in transgenic mice and BALB/c mice with Adriamycin-induced glomerulosclerosis is associated with endothelin-1 (EDN1) release by podocytes, which mediates mitochondrial oxidative stress and dysfunction in adjacent endothelial cells via paracrine EDN1 receptor type A (EDNRA) activation. Endothelial dysfunction promoted podocyte apoptosis, and inhibition of EDNRA or scavenging of mitochondrial-targeted ROS prevented podocyte loss, albuminuria, glomerulosclerosis, and renal failure. We confirmed reciprocal crosstalk between podocytes and endothelial cells in a coculture system. Biopsies from patients with FSGS exhibited increased mitochondrial DNA damage, consistent with EDNRA-mediated glomerular endothelial mitochondrial oxidative stress. Our studies indicate that segmental glomerulosclerosis develops as a result of podocyte-endothelial crosstalk mediated by EDN1/EDNRA-dependent mitochondrial dysfunction and suggest that targeting the reciprocal interaction between podocytes and endothelia may provide opportunities for therapeutic intervention in FSGS. PMID:24590287

Targeted antioxidant therapies in hyperglycemia-mediated endothelial dysfunction.

PubMed

de Haan, Judy B; Cooper, Mark E

2011-01-01

Although intensive glycaemic and blood pressure control have reduced the risks of micro- and macrovascular complications, diabetes remains a major cause of cardiovascular events, end-stage renal failure, blindness and neuropathy. It is therefore imperative to understand the underlying mechanisms and to establish effective treatments to prevent, retard or reverse diabetic complications. One area of increased focus is the diabetic vascular endothelium. Hyperglycaemia triggers a cascade of events, not least an increase in reactive oxygen species (ROS) leading to enhanced oxidative stress, with its negative impact on endothelial function. In this review, we explore a unifying hypothesis that increased glucose-mediated ROS leads to endothelial dysfunction as the underpinning causative event triggering accelerated micro- and macrovascular complications. In particular, the consequences of deficiencies in the antioxidant enzyme, glutathione peroxidase, on endothelial dysfunction as a trigger of diabetic micro- and macrovascular complications, will be reviewed. Furthermore, novel antioxidant therapies will be highlighted. Specifically, use of Gpx1-mimetics holds promise as a targeted antioxidant approach and an alternative adjunct therapy to reduce diabetic complications.

Regulation of Human Brain Microvascular Endothelial Cell Adhesion and Barrier Functions by Memantine.

PubMed

Wang, Fei; Zou, Zhirong; Gong, Yi; Yuan, Dong; Chen, Xun; Sun, Tao

2017-05-01

Vascular risk factors have been linked to cognitive decline and dementia in the elderly. Microvascular inflammation, especially of the endothelium, may contribute to the progression of neurodegenerative events in Alzheimer's disease (AD). Memantine, an uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, is a licensed drug used for the treatment of moderate to severe AD. However, little information is available regarding its anti-inflammatory effects on the endothelium. In this study, we investigated the effects of memantine on human brain microvascular endothelial dysfunction induced by the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α). Our results show that memantine prevents the attachment of monocyte THP-1 cells to human brain microvascular endothelial cells (HBMVEs). An in vitro BBB model experiment displayed that memantine could rescue TNF-α-induced disruption of the in vitro BBB model. In addition, memantine also interferes with monocyte transmigration across the BBB model. Our results indicate that TNF-α significantly increased the expression of cell adhesion molecules, such as ICAM-1, VCAM-1, and E-selectin, which was prevented by pretreatment with memantine. Mechanistically, memantine reversed activation of the transcription factor NF-κB by preventing the phosphorylation and degradation of its inhibitor IκBα. Our data is the first to describe a novel anti-inflammatory mechanism driven by the endothelial cell-mediated neuroprotective effects of memantine.

Brain Invasion by Mouse Hepatitis Virus Depends on Impairment of Tight Junctions and Beta Interferon Production in Brain Microvascular Endothelial Cells

PubMed Central

Bleau, Christian; Filliol, Aveline; Samson, Michel

2015-01-01

ABSTRACT Coronaviruses (CoVs) have shown neuroinvasive properties in humans and animals secondary to replication in peripheral organs, but the mechanism of neuroinvasion is unknown. The major aim of our work was to evaluate the ability of CoVs to enter the central nervous system (CNS) through the blood-brain barrier (BBB). Using the highly hepatotropic mouse hepatitis virus type 3 (MHV3), its attenuated variant, 51.6-MHV3, which shows low tropism for endothelial cells, and the weakly hepatotropic MHV-A59 strain from the murine coronavirus group, we investigated the virus-induced dysfunctions of BBB in vivo and in brain microvascular endothelial cells (BMECs) in vitro. We report here a MHV strain-specific ability to cross the BBB during acute infection according to their virulence for liver. Brain invasion was observed only in MHV3-infected mice and correlated with enhanced BBB permeability associated with decreased expression of zona occludens protein 1 (ZO-1), VE-cadherin, and occludin, but not claudin-5, in the brain or in cultured BMECs. BBB breakdown in MHV3 infection was not related to production of barrier-dysregulating inflammatory cytokines or chemokines by infected BMECs but rather to a downregulation of barrier protective beta interferon (IFN-β) production. Our findings highlight the importance of IFN-β production by infected BMECs in preserving BBB function and preventing access of blood-borne infectious viruses to the brain. IMPORTANCE Coronaviruses (CoVs) infect several mammals, including humans, and are associated with respiratory, gastrointestinal, and/or neurological diseases. There is some evidence that suggest that human respiratory CoVs may show neuroinvasive properties. Indeed, the severe acute respiratory syndrome coronavirus (SARS-CoV), causing severe acute respiratory syndrome, and the CoVs OC43 and 229E were found in the brains of SARS patients and multiple sclerosis patients, respectively. These findings suggest that hematogenously spread CoVs may gain access to the CNS at the BBB level. Herein we report for the first time that CoVs exhibit the ability to cross the BBB according to strain virulence. BBB invasion by CoVs correlates with virus-induced disruption of tight junctions on BMECs, leading to BBB dysfunction and enhanced permeability. We provide evidence that production of IFN-β by BMECs during CoV infection may prevent BBB breakdown and brain viral invasion. PMID:26202229

Brain Invasion by Mouse Hepatitis Virus Depends on Impairment of Tight Junctions and Beta Interferon Production in Brain Microvascular Endothelial Cells.

PubMed

Bleau, Christian; Filliol, Aveline; Samson, Michel; Lamontagne, Lucie

2015-10-01

Coronaviruses (CoVs) have shown neuroinvasive properties in humans and animals secondary to replication in peripheral organs, but the mechanism of neuroinvasion is unknown. The major aim of our work was to evaluate the ability of CoVs to enter the central nervous system (CNS) through the blood-brain barrier (BBB). Using the highly hepatotropic mouse hepatitis virus type 3 (MHV3), its attenuated variant, 51.6-MHV3, which shows low tropism for endothelial cells, and the weakly hepatotropic MHV-A59 strain from the murine coronavirus group, we investigated the virus-induced dysfunctions of BBB in vivo and in brain microvascular endothelial cells (BMECs) in vitro. We report here a MHV strain-specific ability to cross the BBB during acute infection according to their virulence for liver. Brain invasion was observed only in MHV3-infected mice and correlated with enhanced BBB permeability associated with decreased expression of zona occludens protein 1 (ZO-1), VE-cadherin, and occludin, but not claudin-5, in the brain or in cultured BMECs. BBB breakdown in MHV3 infection was not related to production of barrier-dysregulating inflammatory cytokines or chemokines by infected BMECs but rather to a downregulation of barrier protective beta interferon (IFN-β) production. Our findings highlight the importance of IFN-β production by infected BMECs in preserving BBB function and preventing access of blood-borne infectious viruses to the brain. Coronaviruses (CoVs) infect several mammals, including humans, and are associated with respiratory, gastrointestinal, and/or neurological diseases. There is some evidence that suggest that human respiratory CoVs may show neuroinvasive properties. Indeed, the severe acute respiratory syndrome coronavirus (SARS-CoV), causing severe acute respiratory syndrome, and the CoVs OC43 and 229E were found in the brains of SARS patients and multiple sclerosis patients, respectively. These findings suggest that hematogenously spread CoVs may gain access to the CNS at the BBB level. Herein we report for the first time that CoVs exhibit the ability to cross the BBB according to strain virulence. BBB invasion by CoVs correlates with virus-induced disruption of tight junctions on BMECs, leading to BBB dysfunction and enhanced permeability. We provide evidence that production of IFN-β by BMECs during CoV infection may prevent BBB breakdown and brain viral invasion. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Red Blood Cell Dysfunction Induced by High-Fat Diet

PubMed Central

Unruh, Dusten; Srinivasan, Ramprasad; Benson, Tyler; Haigh, Stephen; Coyle, Danielle; Batra, Neil; Keil, Ryan; Sturm, Robert; Blanco, Victor; Palascak, Mary; Franco, Robert S.; Tong, Wilson; Chatterjee, Tapan; Hui, David Y.; Davidson, W. Sean; Aronow, Bruce J.; Kalfa, Theodosia; Manka, David; Peairs, Abigail; Blomkalns, Andra; Fulton, David J.; Brittain, Julia E.; Weintraub, Neal L.; Bogdanov, Vladimir Y.

2015-01-01

Background High-fat diet (HFD) promotes endothelial dysfunction and proinflammatory monocyte activation, which contribute to atherosclerosis in obesity. We investigated whether HFD also induces the dysfunction of red blood cells (RBCs), which serve as a reservoir for chemokines via binding to Duffy antigen receptor for chemokines (DARC). Methods and Results A 60% HFD for 12 weeks, which produced only minor changes in lipid profile in C57/BL6 mice, markedly augmented the levels of monocyte chemoattractant protein-1 bound to RBCs, which in turn stimulated macrophage migration through an endothelial monolayer. Levels of RBC-bound KC were also increased by HFD. These effects of HFD were abolished in DARC−/− mice. In RBCs from HFD-fed wild-type and DARC−/− mice, levels of membrane cholesterol and phosphatidylserine externalization were increased, fostering RBC-macrophage inflammatory interactions and promoting macrophage phagocytosis in vitro. When labeled ex vivo and injected into wild-type mice, RBCs from HFD-fed mice exhibited ≈3-fold increase in splenic uptake. Finally, RBCs from HFD-fed mice induced increased macrophage adhesion to the endothelium when they were incubated with isolated aortic segments, indicating endothelial activation. Conclusions RBC dysfunction, analogous to endothelial dysfunction, occurs early during diet-induced obesity and may serve as a mediator of atherosclerosis. These findings may have implications for the pathogenesis of atherosclerosis in obesity, a worldwide epidemic. PMID:26467254

Serelaxin treatment reverses vascular dysfunction and left ventricular hypertrophy in a mouse model of Type 1 diabetes

PubMed Central

Ng, Hooi Hooi; Leo, Chen Huei; Prakoso, Darnel; Qin, Chengxue; Ritchie, Rebecca H.; Parry, Laura J.

2017-01-01

Serelaxin prevents endothelial dysfunction in the mouse aorta ex vivo and inhibits apoptosis in cardiomyocytes under acute hyperglycaemia. Less is known about the effects of serelaxin in an in vivo mouse model of diabetes. Therefore, we tested the hypothesis in streptozotocin (STZ)-treated mice that serelaxin is able to reverse diabetes-induced vascular dysfunction and cardiac remodelling. Mice were divided into citrate buffer + placebo, STZ + placebo and STZ + serelaxin (0.5 mg/kg/d, 2 weeks) groups. After 12 weeks of diabetes, sensitivity to the endothelium-dependent agonist acetylcholine (ACh) was reduced in the mesenteric artery. This was accompanied by an enhanced vasoconstrictor prostanoid contribution and a decrease in endothelium-derived hyperpolarisation (EDH)-mediated relaxation. Serelaxin restored endothelial function by increasing nitric oxide (NO)-mediated relaxation but not EDH. It also normalised the contribution of vasoconstrictor prostanoids to endothelial dysfunction and suppressed diabetes-induced hyper-responsiveness of the mesenteric artery to angiotensin II. Similarly, diabetes reduced ACh-evoked NO-mediated relaxation in the aorta which was reversed by serelaxin. In the left ventricle, diabetes promoted apoptosis, hypertrophy and fibrosis; serelaxin treatment reversed this ventricular apoptosis and hypertrophy, but had no effect on fibrosis. In summary, serelaxin reversed diabetes-induced endothelial dysfunction by enhancing NO-mediated relaxation in the mouse vasculature and attenuating left ventricular hypertrophy and apoptosis. PMID:28067255

Endothelial E-type prostanoid 4 receptors promote barrier function and inhibit neutrophil trafficking.

PubMed

Konya, Viktoria; Üllen, Andreas; Kampitsch, Nora; Theiler, Anna; Philipose, Sonia; Parzmair, Gerald P; Marsche, Gunther; Peskar, Bernhard A; Schuligoi, Rufina; Sattler, Wolfgang; Heinemann, Akos

2013-02-01

Increased vascular permeability is a fundamental characteristic of inflammation. Substances that are released during inflammation, such as prostaglandin (PG) E(2), can counteract vascular leakage, thereby hampering tissue damage. In this study we investigated the role of PGE(2) and its receptors in the barrier function of human pulmonary microvascular endothelial cells and in neutrophil trafficking. Endothelial barrier function was determined based on electrical impedance measurements. Neutrophil recruitment was assessed based on adhesion and transendothelial migration. Morphologic alterations are shown by using immunofluorescence microscopy. We observed that activation of E-type prostanoid (EP) 4 receptor by PGE(2) or an EP4-selective agonist (ONO AE1-329) enhanced the barrier function of human microvascular lung endothelial cells. EP4 receptor activation prompted similar responses in pulmonary artery and coronary artery endothelial cells. These effects were reversed by an EP4 antagonist (ONO AE3-208), as well as by blocking actin polymerization with cytochalasin B. The EP4 receptor-induced increase in barrier function was independent of the classical cyclic AMP/protein kinase A signaling machinery, endothelial nitric oxide synthase, and Rac1. Most importantly, EP4 receptor stimulation showed potent anti-inflammatory activities by (1) facilitating wound healing of pulmonary microvascular endothelial monolayers, (2) preventing junctional and cytoskeletal reorganization of activated endothelial cells, and (3) impairing neutrophil adhesion to endothelial cells and transendothelial migration. The latter effects could be partially attributed to reduced E-selectin expression after EP4 receptor stimulation. These data indicate that EP4 agonists as anti-inflammatory agents represent a potential therapy for diseases with increased vascular permeability and neutrophil extravasation. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Cancer Cells Regulate Biomechanical Properties of Human Microvascular Endothelial Cells*

PubMed Central

Mierke, Claudia Tanja

2011-01-01

Metastasis is a key event of malignant tumor progression. The capability to metastasize depends on the ability of the cancer cell to migrate into connective tissue, adhere, and possibly transmigrate through the endothelium. Previously we reported that the endothelium does not generally act as barrier for cancer cells to migrate in three-dimensional extracellular matrices (3D-ECMs). Instead, the endothelium acts as an enhancer or a promoter for the invasiveness of certain cancer cells. How invasive cancer cells diminish the endothelial barrier function still remains elusive. Therefore, this study investigates whether invasive cancer cells can decrease the endothelial barrier function through alterations of endothelial biomechanical properties. To address this, MDA-MB-231 breast cancer cells were used that invade deeper and more numerous into 3D-ECMs when co-cultured with microvascular endothelial cells. Using magnetic tweezer measurements, MDA-MB-231 cells were found to alter the mechanical properties of endothelial cells by reducing endothelial cell stiffness. Using spontaneous bead diffusion, actin cytoskeletal remodeling dynamics were shown to be increased in endothelial cells co-cultured with MDA-MB-231 cells compared with mono-cultured endothelial cells. In addition, knockdown of the α5 integrin subunit in highly transmigrating α5β1high cells derived from breast, bladder, and kidney cancer cells abolished the endothelial invasion-enhancing effect comparable with the inhibition of myosin light chain kinase. These results indicate that the endothelial invasion-enhancing effect is α5β1 integrin-dependent. Moreover, inhibition of Rac-1, Rho kinase, MEK kinase, and PI3K reduced the endothelial invasion-enhancing effect, indicating that signaling via small GTPases may play a role in the endothelial facilitated increased invasiveness of cancer cells. In conclusion, decreased stiffness and increased cytoskeletal remodeling dynamics of endothelial cells may account for the breakdown of endothelial barrier function, suggesting that biomechanical alterations are sufficient to facilitate the transmigration and invasion of invasive cancer cells into 3D-ECMs. PMID:21940631

[How does chocolate impact vascular function?].

PubMed

Flammer, Andreas J; Sudano, Isabella

2014-11-12

For thousands of years, cocoa have been a very popular food and has been linked to various beneficial health effects. Observational and epidemiological studies point towards a beneficial effect of dark chocolate on cardiovascular morbidity. Several small, albeit controlled studies indeed demonstrate an amelioration of endothelial dysfunction - the dysfunction of the inner layer of the vessels - after intake of dark, flavanol-rich chocolate. This is important, as endothelial dysfunction is an important marker of the development of atherosclerosis and an important prognosticator of future cardiovascular events. This article summarizes the actual literature in this respect.

Kalirin and CHD7: novel endothelial dysfunction indicators in circulating extracellular vesicles from hypertensive patients with albuminuria

PubMed Central

de la Cuesta, Fernando; Baldan-Martin, Montserrat; Moreno-Luna, Rafael; Alvarez-Llamas, Gloria; Gonzalez-Calero, Laura; Mourino-Alvarez, Laura; Sastre-Oliva, Tamara; López, Juan A.; Vázquez, Jesús; Ruiz-Hurtado, Gema; Segura, Julian; Vivanco, Fernando; Ruilope, Luis M.; Barderas, Maria G.

2017-01-01

Despite of the great advances in anti-hypertensive therapies, many patients under Renin-Angiotensin- System (RAS) suppression develop albuminuria, which is a clear indicator of therapeutic inefficiency. Hence, indicators of vascular function are needed to assess patients’ condition and help deciding future therapies. Proteomic analysis of circulating extracellular vesicles (EVs) showed two proteins, kalirin and chromodomain-helicase-DNA-binding protein 7 (CHD7), increased in albuminuric patients. A positive correlation of both with the expression of the endothelial activation marker E-selectin was found in EVs. In vitro analysis using TNFα-treated adult human endothelial cells proved their involvement in endothelial cell activation. Hence, we propose protein levels of kalirin and CHD7 in circulating EVs as novel endothelial dysfunction markers to monitor vascular condition in hypertensive patients with albuminuria. PMID:28152519

Endothelial glycocalyx: permeability barrier and mechanosensor.

PubMed

Curry, F E; Adamson, R H

2012-04-01

Endothelial cells are covered with a polysaccharide rich layer more than 400 nm thick, mechanical properties of which limit access of circulating plasma components to endothelial cell membranes. The barrier properties of this endothelial surface layer are deduced from the rate of tracer penetration into the layer and the mechanics of red and white cell movement through capillary microvessels. This review compares the mechanosensor and permeability properties of an inner layer (100-150 nm, close to the endothelial membrane) characterized as a quasi-periodic structure which accounts for key aspects of transvascular exchange and vascular permeability with those of the whole endothelial surface layers. We conclude that many of the barrier properties of the whole surface layer are not representative of the primary fiber matrix forming the molecular filter determining transvascular exchange. The differences between the properties of the whole layer and the inner glycocalyx structures likely reflect dynamic aspects of the endothelial surface layer including tracer binding to specific components, synthesis and degradation of key components, activation of signaling pathways in the endothelial cells when components of the surface layer are lost or degraded, and the spatial distribution of adhesion proteins in microdomains of the endothelial cell membrane.

Circular Noncoding RNA HIPK3 Mediates Retinal Vascular Dysfunction in Diabetes Mellitus.

PubMed

Shan, Kun; Liu, Chang; Liu, Bai-Hui; Chen, Xue; Dong, Rui; Liu, Xin; Zhang, Yang-Yang; Liu, Ban; Zhang, Shu-Jie; Wang, Jia-Jian; Zhang, Sheng-Hai; Wu, Ji-Hong; Zhao, Chen; Yan, Biao

2017-10-24

The vascular complications of diabetes mellitus are the major causes of morbidity and mortality among people with diabetes. Circular RNAs are a class of endogenous noncoding RNAs that regulate gene expression in eukaryotes. In this study, we investigated the role of circular RNA in retinal vascular dysfunction induced by diabetes mellitus. Quantitative polymerase chain reactions, Sanger sequencing, and Northern blots were conducted to detect circular HIPK3 (circHIPK3) expression pattern on diabetes mellitus-related stresses. MTT (3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assays, EdU (5-ethynyl-2'-deoxyuridine) incorporation assays, Transwell migration assays, and Matrigel assays were conducted to detect the role of circHIPK3 in retinal endothelial cell function in vitro. Retinal trypsin digestion, vascular permeability assays, and ELISA assays were conducted to detect the role of circHIPK3 in retinal vascular dysfunction in vivo. Bioinformatics analysis, luciferase activity assays, RNA pull-down assays, and in vitro studies were conducted to reveal the mechanism of circHIPK3-mediated retinal vascular dysfunction. circHIPK3 expression was significantly upregulated in diabetic retinas and retinal endothelial cells following stressors related to diabetes mellitus. circHIPK3 silencing or overexpressing circHIPK3 changed retinal endothelial cell viability, proliferation, migration, and tube formation in vitro. circHIPK3 silencing in vivo alleviated retinal vascular dysfunction, as shown by decreased retinal acellular capillaries, vascular leakage, and inflammation. circHIPK3 acted as an endogenous miR-30a-3p sponge to sequester and inhibit miR-30a-3p activity, which led to increased vascular endothelial growth factor-C, FZD4, and WNT2 expression. Ectopic expression of miR-30a-3p mimicked the effect of circHIPK3 silencing on vascular endothelial phenotypes in vivo and in vitro. The circular RNA circHIPK3 plays a role in diabetic retinopathy by blocking miR-30a function, leading to increased endothelial proliferation and vascular dysfunction. These data suggest that circular RNA is a potential target to control diabetic proliferative retinopathy. © 2017 American Heart Association, Inc.

Distinct Longitudinal Associations of MBL, MASP-1, MASP-2, MASP-3, and MAp44 With Endothelial Dysfunction and Intima-Media Thickness: The Cohort on Diabetes and Atherosclerosis Maastricht (CODAM) Study.

PubMed

Hertle, Elisabeth; Arts, Ilja C W; van der Kallen, Carla J H; Feskens, Edith J M; Schalkwijk, Casper G; Hoffmann-Petersen, Ingeborg T; Thiel, Steffen; Stehouwer, Coen D A; van Greevenbroek, Marleen M J

2016-06-01

Previous studies suggested that the lectin-complement pathway plays a complex role in cardiovascular disease (CVD). To date, no prospective human studies have investigated the relationship between the initiating factor of the lectin pathway, that is, mannose-binding lectin (MBL), and low-grade inflammation, endothelial dysfunction, or carotid intima-media thickness (cIMT). Moreover, MBL-associated proteases (MASPs) and MBL-associated proteins (MAps), which mediate downstream complement activation, have not been studied in the development of CVD. In a prospective cohort (n=574; age 60±7 years; 7-year follow-up), we investigated longitudinal associations of plasma MBL, MASP-1, MASP-2, MASP-3, and MAp44 with biomarker scores that reflect low-grade inflammation and endothelial dysfunction, respectively, and with cIMT. We also investigated their associations with incident CVD (n=73). In adjusted analyses, low-grade inflammation was lowest in the middle tertile (TMiddle) of MBL, that is, TMiddle was 0.19 SD (0.03 to 0.34) lower than TLow, and 0.15 SD (-0.02 to 0.31) lower than THigh. cIMT was 28 μm (-50 to -5) lower in the highest MBL tertile (THigh) than in TMiddle and did not differ between TLow and TMiddle. MBL was not associated with endothelial dysfunction or CVD. MASP-1 and MASP-2 were not associated with any cardiovascular outcomes. MASP-3 and MAp44 were, independently of MBL levels, associated with endothelial dysfunction (per 1 SD higher MASP-3: β=0.10 SD [0.02 to 0.18]; per 1 SD higher MAp44 β=0.12 SD [0.04 to 0.20]) but not with low-grade inflammation, cIMT, or CVD. High MBL may contribute to low cIMT, whereas the association of MBL with low-grade inflammation was nonlinear. MASP-1 and MASP-2 were not associated with adverse cardiovascular outcomes. MASP-3 and MAp44 may play a role in endothelial dysfunction, potentially independent of lectin-pathway activation. © 2016 American Heart Association, Inc.

Poor oral health, that is, decreased frequency of tooth brushing, is associated with endothelial dysfunction.

PubMed

Kajikawa, Masato; Nakashima, Ayumu; Maruhashi, Tatsuya; Iwamoto, Yumiko; Iwamoto, Akimichi; Matsumoto, Takeshi; Hidaka, Takayuki; Kihara, Yasuki; Chayama, Kazuaki; Goto, Chikara; Taguchi, Akira; Noma, Kensuke; Higashi, Yukihito

2014-01-01

 Poor oral health is an independent predictor of cardiovascular outcome. Endothelial dysfunction is the initial step of atherosclerosis, resulting in cardiovascular outcomes; but there is no information on the association between oral health and endothelial function. The purpose of this study was to determine the relationships between oral health and endothelial function.  A total of 190 subjects who underwent health examinations (mean age, 57±18 years), including patients with cardiovascular disease, completed a questionnaire on oral health and frequency of tooth brushing, and underwent measurement of vascular function, flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation. The subjects were divided into 2 groups according to frequency of tooth brushing (≥twice/day and

Corneal endothelial dysfunction in Pearson syndrome.

PubMed

Kasbekar, Shivani A; Gonzalez-Martin, Jose A; Shafiq, Ayad E; Chandna, Arvind; Willoughby, Colin E

2013-01-01

Mitochondrial disorders are associated with well recognized ocular manifestations. Pearson syndrome is an often fatal, multisystem, mitochondrial disorder that causes variable bone marrow, hepatic, renal and pancreatic exocrine dysfunction. Phenotypic progression of ocular disease in a 12-year-old male with Pearson syndrome is described. This case illustrates phenotypic drift from Pearson syndrome to Kearns-Sayre syndrome given the patient's longevity. Persistent corneal endothelial failure was noted in addition to ptosis, chronic external ophthalmoplegia and mid-peripheral pigmentary retinopathy. We propose that corneal edema resulting from corneal endothelial metabolic pump failure occurs within a spectrum of mitochondrial disorders.

Caloric restriction improves endothelial dysfunction during vascular aging: Effects on nitric oxide synthase isoforms and oxidative stress in rat aorta.

PubMed

Zanetti, Michela; Gortan Cappellari, Gianluca; Burekovic, Ismet; Barazzoni, Rocco; Stebel, Marco; Guarnieri, Gianfranco

2010-11-01

Aging is characterized by activation of inducible over endothelial nitric oxide synthase (iNOS and eNOS), impaired antioxidant activity and increased oxidative stress, which reduces nitric oxide bioavailability and causes endothelial dysfunction. Caloric restriction (CR) blunts oxidative stress. We investigated whether CR impacts endothelial dysfunction in aging and the underlying mechanisms. Aortas from young (YC, 6 months of age) and old (OC, 24 months of age) rats ad-libitum fed and from old rats caloric-restricted for 3-weeks (OR, 26%) were investigated. Endothelium-dependent vasorelaxation was impaired in OC, associated with reduced eNOS and increased iNOS expression (P<0.05). Aortic nitrite was similar in OC and YC, but the contribution of calcium-independent NOS to total NOS activity was increased whereas that of calcium-dependent NOS was reduced (p≤0.0003). Plasma thiobarbituric acid-reactive substances (TBARS) were elevated in OC as well as aortic nitrotyrosine (P<0.05). Expression of manganese superoxide dismutase (MnSOD) and total SOD activity were impaired in OC (P<0.05 vs. YC), whereas copper-zinc (CuZn) SOD expression was similar in OC and YC. CR restored endothelial dysfunction in old rats, reduced iNOS expression, total nitrite and calcium-independent NOS activity in aorta (P<0.05) without changes in eNOS expression and calcium-dependent NOS activity. Sirtuin-1 expression did not differ among groups. Plasma TBARS and aortic nitrotyrosine were reduced (P<0.05) in OR compared with OC. In OR CuZnSOD protein and SOD activity increased (P<0.05) without changes in MnSOD expression. Short-term CR improves age-related endothelial dysfunction. Reversal of altered iNOS/eNOS ratio, reduced oxidative stress and increased SOD enzyme activity rather than enhanced NO production appear to be involved in this effect. Copyright © 2010 Elsevier Inc. All rights reserved.

Exercise facilitates early recognition of cardiac and vascular remodeling in chronic thromboembolic pulmonary hypertension in swine.

PubMed

Stam, Kelly; van Duin, Richard W B; Uitterdijk, André; Cai, Zongye; Duncker, Dirk J; Merkus, Daphne

2018-03-01

Chronic thromboembolic pulmonary hypertension (CTEPH) develops in 4% of patients after pulmonary embolism and is accompanied by an impaired exercise tolerance, which is ascribed to the increased right ventricular (RV) afterload in combination with a ventilation/perfusion (V/Q) mismatch in the lungs. The present study aimed to investigate changes in arterial Po 2 and hemodynamics in response to graded treadmill exercise during development and progression of CTEPH in a novel swine model. Swine were chronically instrumented and received multiple pulmonary embolisms by 1) microsphere infusion (Spheres) over 5 wk, 2) endothelial dysfunction by administration of the endothelial nitric oxide synthase inhibitor N ω -nitro-l-arginine methyl ester (L-NAME) for 7 wk, 3) combined pulmonary embolisms and endothelial dysfunction (L-NAME + Spheres), or 4) served as sham-operated controls (sham). After a 9 wk followup, embolization combined with endothelial dysfunction resulted in CTEPH, as evidenced by mean pulmonary artery pressures of 39.5 ± 5.1 vs. 19.1 ± 1.5 mmHg (Spheres, P < 0.001), 22.7 ± 2.0 mmHg (L-NAME, P < 0.001), and 20.1 ± 1.5 mmHg (sham, P < 0.001), and a decrease in arterial Po 2 that was exacerbated during exercise, indicating V/Q mismatch. RV dysfunction was present after 5 wk of embolization, both at rest (trend toward increased RV end-systolic lumen area, P = 0.085, and decreased stroke volume index, P = 0.042) and during exercise (decreased stroke volume index vs. control, P = 0.040). With sustained pulmonary hypertension, RV hypertrophy (Fulton index P = 0.022) improved RV function at rest and during exercise, but this improvement was insufficient in CTEPH swine to result in an exercise-induced increase in cardiac index. In conclusion, embolization in combination with endothelial dysfunction results in CTEPH in swine. Exercise increased RV afterload, exacerbated the V/Q mismatch, and unmasked RV dysfunction. NEW & NOTEWORTHY Here, we present the first double-hit chronic thromboembolic pulmonary hypertension swine model. We show that embolization as well as endothelial dysfunction is required to induce sustained pulmonary hypertension, which is accompanied by altered exercise hemodynamics and an exacerbated ventilation/perfusion mismatch during exercise.

Relation of Biochemical Parameters with Flow-mediated Dilatation in Patients with Metabolic Syndrome

PubMed Central

Sipahioglu, Nurver Turfaner; Ilerigelen, Barıs; Gungor, Zeynep B.; Ayaz, Gulsel; Ekmekci, Hakan; Gurel, Cigdem Bayram; Can, Gunay; Sonmez, Huseyin; Ulutin, Turgut; Sipahioglu, Fikret

2017-01-01

Background: Metabolic syndrome (MetS) is one of the high cardiovascular (CV) situations. Endothelial dysfunction, which is a common finding in patients with MetS, is related with increased CV risk. In patients with MetS, the effect of the major CV risk factors, not included in the MetS definition, on endothelial dysfunction is not well known. The aim of this study was to determine the effect of major CV risk factors such as gender, smoking, family history, and biochemical parameters on endothelial dysfunction in patients with MetS. Methods: The study was performed between December 2010 and August 2014. A total of 55 patients (15 females and 40 males) with MetS and 81 healthy controls (37 females and 44 males) with a body mass index <25 kg/m2 were enrolled in the study. Endothelial dysfunction was measured by flow-mediated dilatation (FMD), oxidative stress parameters; high-sensitivity C-reactive protein (hs-CRP), oxidized low-density lipoprotein (ox-LDL), endothelial nitric oxide synthase (e-NOS), nitric oxide, and cell adhesion markers; von Willebrand factor, and e-selectin. Platelet aggregation (endothelial adenosine diphosphate), total platelet count, and mean platelet volume were additionally analyzed and demographic parameters were explored. Student's t-test, Mann-Whitney U-test, and Chi-square test were used to analyze the results. Results: The fasting blood glucose (z = 3.52, P = 0.001), hs-CRP (z = 3.23, P = 0.004), ox-LDL (z = 2.62, P = 0.013), and e-NOS (z = 2.22, P = 0.026) levels and cardiac risk score (z = 5.23, P < 0.001) were significantly higher in patients with MetS compared with the control group. Smoking was correlated with decreased FMD (χ2 = 9.26, P = 0.002) in MetS patients but not in the control group. Conclusions: Increased ox-LDL, hs-CRP, and e-NOS are likely to be a result of oxidative stress, a condition in which an imbalance occurs between the production and inactivation of reactive nitrogen and oxygen species. In addition, in patients with MetS, smoking is independently related to endothelial dysfunction. PMID:28639572

Chronic depletion of gonadal testosterone leads to blood-brain barrier dysfunction and inflammation in male mice.

PubMed

Atallah, Afnan; Mhaouty-Kodja, Sakina; Grange-Messent, Valérie

2017-09-01

A dysfunction in the blood-brain barrier (BBB) is associated with many neurological and metabolic disorders. Although sex steroid hormones have been shown to impact vascular tone, endothelial function, oxidative stress, and inflammatory responses, there are still no data on the role of testosterone in the regulation of BBB structure and function. In this context, we investigated the effects of gonadal testosterone depletion on the integrity of capillary BBB and the surrounding parenchyma in male mice. Our results show increased BBB permeability for different tracers and endogenous immunoglobulins in chronically testosterone-depleted male mice. These results were associated with disorganization of tight junction structures shown by electron tomography and a lower amount of tight junction proteins such as claudin-5 and ZO-1. BBB leakage was also accompanied by activation of astrocytes and microglia, and up-regulation of inflammatory molecules such as inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), interleukin 1 beta (IL-1β), and tumor necrosis factor (TNF). Supplementation of castrated male mice with testosterone restored BBB selective permeability, tight junction integrity, and almost completely abrogated the inflammatory features. The present demonstration that testosterone transiently impacts cerebrovascular physiology in adult male mice should help gain new insights into neurological and metabolic diseases linked to hypogonadism in men of all ages.

Clematichinenoside protects blood brain barrier against ischemic stroke superimposed on systemic inflammatory challenges through up-regulating A20.

PubMed

Han, Dan; Fang, Weirong; Zhang, Rui; Wei, Jie; Kodithuwakku, Nandani Darshika; Sha, Lan; Ma, Wenhuan; Liu, Lifang; Li, Fengwen; Li, Yunman

2016-01-01

Suppression of excessive inflammation can ameliorate blood brain barrier (BBB) injury, which shows therapeutic potential for clinical treatment of brain injury induced by stroke superimposed on systemic inflammatory diseases. In this study, we investigated whether and how clematichinenoside (AR), an anti-inflammatory triterpene saponin, protects brain injury from stroke superimposed on systemic inflammation. Lipopolysaccharide (LPS) was intraperitoneally injected immediately after middle cerebral artery occlusion (MCAO) in rats. Rat microvessel endothelial cells (rBMECs) were exposed to hypoxia/reoxygenation (H/R) coexisting with LPS. The results revealed that AR suppressed the excessive inflammation, restored BBB dysfunction, alleviated brain edema, decreased neutrophil infiltration, lessened neurological dysfunction, and decreased infarct rate. Further study demonstrated that the expression of nucleus nuclear factor kappa B (NF-κB), inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α) and interlukin-1β (IL-1β) were suppressed by AR via zinc finger protein A20. Besides, AR increased in vitro BBB integrity through A20. In conclusion, AR alleviated cerebral inflammatory injury through A20-NF-κB signal pathway, offering an alternative medication for stroke associated with systemic inflammatory diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

A dual brain-targeting curcumin-loaded polymersomes ameliorated cognitive dysfunction in intrahippocampal amyloid-β1-42-injected mice.

PubMed

Jia, Tingting; Sun, Zhiguo; Lu, Ying; Gao, Jie; Zou, Hao; Xie, Fangyuan; Zhang, Guoqing; Xu, Hao; Sun, Duxin; Yu, Yuan; Zhong, Yanqiang

2016-01-01

Due to the impermeability of the blood-brain barrier and the nonselective distribution of drugs in the brain, the therapeutic access to intractable neurological disorders is challenging. In this study, dual brain-targeting polymersomes (POs) functionalized by transferrin and Tet-1 peptide (Tf/Tet-1-POs) promoted the transportation of curcumin into the brain and provided neuroprotection. The modification of the ligands that bind to the surface of POs was revealed by X-ray photoelectron spectroscopy analysis. The cell uptake of a coculture model of mouse brain capillary endothelial cells with neurons showed that the Tf/Tet-1-POs had significant transportation properties and possessed affinity for neurons. The pharmacokinetic analysis showed that the blood-brain barrier permeability-surface efficiency of the Tf/Tet-1-POs was 0.28 mL/h/g and that the brain tissue uptake rate (% ID/g) was 0.08, which were significant compared with the controls (P<0.05). The curcumin-encapsulated Tf/Tet-1-POs provided neuroprotection and ameliorated cognitive dysfunction in intrahippocampal amyloid-β1-42-injected mice. These results suggest that the dual brain-targeting POs are more capable of drug delivery to the brain that can be exploited as a multiple noninvasive vehicle for targeting therapeutics.

Functional vascular contributions to cognitive impairment and dementia: mechanisms and consequences of cerebral autoregulatory dysfunction, endothelial impairment, and neurovascular uncoupling in aging

PubMed Central

Toth, Peter; Tarantini, Stefano; Csiszar, Anna

2017-01-01

Increasing evidence from epidemiological, clinical and experimental studies indicate that age-related cerebromicrovascular dysfunction and microcirculatory damage play critical roles in the pathogenesis of many types of dementia in the elderly, including Alzheimer’s disease. Understanding and targeting the age-related pathophysiological mechanisms that underlie vascular contributions to cognitive impairment and dementia (VCID) are expected to have a major role in preserving brain health in older individuals. Maintenance of cerebral perfusion, protecting the microcirculation from high pressure-induced damage and moment-to-moment adjustment of regional oxygen and nutrient supply to changes in demand are prerequisites for the prevention of cerebral ischemia and neuronal dysfunction. This overview discusses age-related alterations in three main regulatory paradigms involved in the regulation of cerebral blood flow (CBF): cerebral autoregulation/myogenic constriction, endothelium-dependent vasomotor function, and neurovascular coupling responses responsible for functional hyperemia. The pathophysiological consequences of cerebral microvascular dysregulation in aging are explored, including blood-brain barrier disruption, neuroinflammation, exacerbation of neurodegeneration, development of cerebral microhemorrhages, microvascular rarefaction, and ischemic neuronal dysfunction and damage. Due to the widespread attention that VCID has captured in recent years, the evidence for the causal role of cerebral microvascular dysregulation in cognitive decline is critically examined. PMID:27793855

Chronic treatment of DA-8159, a new phosphodiesterase type V inhibitor, attenuates endothelial dysfunction in stroke-prone spontaneously hypertensive rat.

PubMed

Choi, Seul Min; Kim, Jee Eun; Kang, Kyung Koo

2006-02-09

This study examined the effects of chronic treatment of a new phosphodiesterase type 5 inhibitor, DA-8159, on endothelial dysfunction in stroke-prone spontaneously hypertensive rats (SHR-SP). Six-week-old male SHR-SP were divided into 4 groups; vehicle control, DA-8159 1, 3, and 10 mg/kg/day. During a 32-week experimental period, the animals were administered DA-8159 orally and fed a 4% NaCl-loaded diet. The systolic blood pressure was measured every two weeks throughout the experimental period using the tail-cuff method. At the end of experiments, the vascular function (acetylcholine-induced vasodilation) in the endothelium-intact aortic rings was investigated. In addition, the mortality, the left ventricular hypertrophy index, the plasma parameters and the incidence of a cerebral infarction were assessed. In the DA-8159 treated-rats, the vascular reactivity improved significantly in a dose-dependent manner. Although DA-8159 did not alter the elevation of the systolic blood pressure directly, the 3 and 10 mg/kg/day DA-8159 treatment delayed the early death caused by stroke. DA-8159 significantly reduced the left ventricular heart weight/body weight ratio compared with the vehicle control group. Furthermore, the DA-8159 treatment significantly increased the plasma nitric oxide, cGMP, and the total antioxidative status. The DA-8159 treatment also reduced the occurrence of stroke-associated cerebral damage. These results indicate that DA-8159 can ameliorate an endothelial dysfunction-related vascular injury. Therefore, pharmacological intervention aimed at attenuating an endothelial dysfunction is important and might be useful in both preventing and treating endothelial dysfunction-related complications.

Effect of Febuxostat on the Endothelial Dysfunction in Hemodialysis Patients: A Randomized, Placebo-Controlled, Double-Blinded Study.

PubMed

Alshahawey, Mona; Shahin, Sara Mahmoud; Elsaid, Tamer Wahid; Sabri, Nagwa Ali

2017-01-01

Endothelial dysfunction is an important risk factor for cardiovascular diseases to occur in end-stage renal disease patients. Febuxostat, being a novel xanthine oxidase inhibitor, is apparently having a beneficial role in improving the endothelial dysfunction; however, data among hemodialysis patients are still limited. A prospective, placebo-controlled, block-randomized, double-blinded study was carried out to evaluate the effect of oral febuxostat on the endothelial dysfunction in hemodialysis patients. Fifty-seven eligible hemodialysis patients were randomly assigned to either the drug group (40 mg thrice weekly) or the placebo group. Serum Asymmetric dimethylarginine (ADMA), Serum uric acid (UA), and serum high sensitivity C-reactive protein (hsCRP) were measured at baseline and at the end of a 2-month study. Serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST), and the occurrence of pancytopenia were tested as safety parameters at baseline and at the end of study. Serum UA significantly decreased from 7.5 ± 0.8 to 5.1 ± 1.2 mg/dL in the febuxostat group, while it did not change significantly in the placebo group. Treatment with febuxostat resulted in a significant decrease in the serum ADMA level from 1.027 ± 0.116 to 0.944 ± 0.104 µmol/L and the serum hsCRP level from 12.5 ± 1.65 to 12.1 ± 1.70 mg/L. Testing of serum ALT, serum AST, and pancytopenia revealed no significant difference in both groups. Febuxostat appears to improve hyperuricemia and endothelial dysfunction and ameliorate inflammation in hemodialysis patients with no safety concerns. © 2017 S. Karger AG, Basel.

Vitamin D deficiency, coronary artery disease, and endothelial dysfunction: observations from a coronary angiographic study in Indian patients.

PubMed

Syal, Sanjeev Kumar; Kapoor, Aditya; Bhatia, Eesh; Sinha, Archana; Kumar, Sudeep; Tewari, Satyendra; Garg, Naveen; Goel, Pravin K

2012-08-01

Vitamin D deficiency has been linked to an increased risk of coronary artery disease (CAD) and cardiovascular (CV) death. Endothelial dysfunction plays an important role in pathogenesis of CAD and vitamin D deficiency is postulated to promote endothelial dysfunction. Despite rising trends of CAD in Asians, only limited data are available on the relationship between vitamin D, CAD, and endothelial dysfunction. In a study of 100 patients undergoing coronary angiography, mean 25(OH)D level was 14.8 ± 9.1 ng/mL; vitamin D deficiency was present in 80% and only 7% had optimal 25(OH)D levels. Nearly one-third (36%) were severely deficient, with 25(OH)D levels <10 ng/mL. Those with vitamin D deficiency had significantly higher prevalence of double- or triple-vessel CAD (53% vs 38%), diffuse CAD (56% vs 34%), and higher number of coronary vessels involved as compared to those with higher 25(OH)D levels. Those with lower 25(OH)D levels had significantly lower brachial artery flow-mediated dilation (FMD; 4.57% vs 10.68%: P<.001) and significantly higher prevalence of impaired FMD (values <4.5%; 50.6% vs 7%; P<.002). A graded relationship between 25(OH)D levels and FMD was observed; impaired FMD was noted in 62.2%, 38.6%, and 13.3% in those with 25(OH)D levels <10 ng/mL, 10-20 ng/mL, and >20 ng/mL, respectively. Indian patients with angiographically documented CAD frequently have vitamin D deficiency. Patients with lower 25(OH)D levels had higher prevalence of double- or triple-vessel CAD and diffuse CAD. Endothelial dysfunction as assessed by brachial artery FMD was also more frequently observed in those with low 25(OH)D levels.

The Krebs cycle and mitochondrial mass are early victims of endothelial dysfunction: proteomic approach.

PubMed

Addabbo, Francesco; Ratliff, Brian; Park, Hyeong-Cheon; Kuo, Mei-Chuan; Ungvari, Zoltan; Csiszar, Anna; Ciszar, Anna; Krasnikov, Boris; Krasnikof, Boris; Sodhi, Komal; Zhang, Fung; Nasjletti, Alberto; Goligorsky, Michael S

2009-01-01

Endothelial cell dysfunction is associated with bioavailable nitric oxide deficiency and an excessive generation of reactive oxygen species. We modeled this condition by chronically inhibiting nitric oxide generation with subpressor doses of N(G)-monomethyl-L-arginine (L-NMMA) in C57B6 and Tie-2/green fluorescent protein mouse strains. L-NMMA-treated mice exhibited a slight reduction in vasorelaxation ability, as well as detectable abnormalities in soluble adhesion molecules (soluble intercellular adhesion molecule-1 and vascular cellular adhesion molecule-1, and matrix metalloproteinase 9), which represent surrogate indicators of endothelial dysfunction. Proteomic analysis of the isolated microvasculature using 2-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy revealed abnormal expression of a cluster of mitochondrial enzymes, which was confirmed using immunodetection. Aconitase-2 and enoyl-CoA-hydratase-1 expression levels were decreased in L-NMMA-treated animals; this phenotype was absent in nitric oxide synthase-1 and -3 knockout mice. Depletion of aconitase-2 and enoyl-CoA-hydratase-1 resulted in the inhibition of the Krebs cycle and enhanced pyruvate shunting toward the glycolytic pathway. To assess mitochondrial mass in vivo, co-localization of green fluorescent protein and MitoTracker fluorescence was detected by intravital microscopy. Quantitative analysis of fluorescence intensity showed that L-NMMA-treated animals exhibited lower fluorescence of MitoTracker in microvascular endothelia as a result of reduced mitochondrial mass. These findings provide conclusive and unbiased evidence that mitochondriopathy represents an early manifestation of endothelial dysfunction, shifting cell metabolism toward "metabolic hypoxia" through the selective depletion of both aconitase-2 and enoyl-CoA-hydratase-1. These findings may contribute to an early preclinical diagnosis of endothelial dysfunction.

Polymeric stent materials dysregulate macrophage and endothelial cell functions: implications for coronary artery stent

PubMed Central

Wang, Xintong; Zachman, Angela L.; Chun, Young Wook; Shen, Fang-Wen; Hwang, Yu-Shik; Sung, Hak-Joon

2014-01-01

Background Biodegradable polymers have been applied as bulk or coating materials for coronary artery stents. The degradation of polymers, however, could induce endothelial dysfunction and aggravate neointimal formation. Here we use polymeric microparticles to simulate and demonstrate the effects of degraded stent materials on phagocytic activity, cell death and dysfunction of macrophages and endothelial cells. Methods Microparticles made of low molecular weight polyesters were incubated with human macrophages and coronary artery endothelial cells (ECs). Microparticle-induced phagocytosis, cytotoxicity, apoptosis, cytokine release and surface marker expression were determined by immunostaining or ELISA. Elastase expression was analyzed by ELISA and the elastase-mediated polymer degradation was assessed by mass spectrometry. Results We demonstrated poly(D,L-lactic acid) (PLLA) and polycaprolactone (PCL) microparticles induced cytotoxicity in macrophages and ECs, partially through cell apoptosis. The particle treatment alleviated EC phagocytosis, as opposed to macrophages, but enhanced the expression of vascular cell adhesion molecule-1 (VCAM) along with decreased nitric oxide production, indicating ECs were activated and lost their capacity to maintain homeostasis. The activation of both cell types induced release of elastase or elastase-like protease, which further accelerated polymer degradation. Conclusions This study revealed that low molecule weight PLLA and PCL microparticles increased cytotoxicity and dysregulated endothelial cell function, which in turn enhanced elastase release and polymer degradation. These indicate polymer or polymer-coated stents impose a risk of endothelial dysfunction after deployment which can potentially lead to delayed endothelialization, neointimal hyperplasia and late thrombosis. PMID:24820736

Endothelial permeability is controlled by spatially defined cytoskeletal mechanics: atomic force microscopy force mapping of pulmonary endothelial monolayer.

PubMed

Birukova, Anna A; Arce, Fernando T; Moldobaeva, Nurgul; Dudek, Steven M; Garcia, Joe G N; Lal, Ratnesh; Birukov, Konstantin G

2009-03-01

Actomyosin contraction directly regulates endothelial cell (EC) permeability, but intracellular redistribution of cytoskeletal tension associated with EC permeability is poorly understood. We used atomic force microscopy (AFM), EC permeability assays, and fluorescence microscopy to link barrier regulation, cell remodeling, and cytoskeletal mechanical properties in EC treated with barrier-protective as well as barrier-disruptive agonists. Thrombin, vascular endothelial growth factor, and hydrogen peroxide increased EC permeability, disrupted cell junctions, and induced stress fiber formation. Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine, hepatocyte growth factor, and iloprost tightened EC barriers, enhanced peripheral actin cytoskeleton and adherens junctions, and abolished thrombin-induced permeability and EC remodeling. AFM force mapping and imaging showed differential distribution of cell stiffness: barrier-disruptive agonists increased stiffness in the central region, and barrier-protective agents decreased stiffness in the center and increased it at the periphery. Attenuation of thrombin-induced permeability correlates well with stiffness changes from the cell center to periphery. These results directly link for the first time the patterns of cell stiffness with specific EC permeability responses.

Wnt/β-catenin signaling controls development of the blood–brain barrier

PubMed Central

Liebner, Stefan; Corada, Monica; Bangsow, Thorsten; Babbage, Jane; Taddei, Andrea; Czupalla, Cathrin J.; Reis, Marco; Felici, Angelina; Wolburg, Hartwig; Fruttiger, Marcus; Taketo, Makoto M.; von Melchner, Harald; Plate, Karl Heinz; Gerhardt, Holger; Dejana, Elisabetta

2008-01-01

The blood–brain barrier (BBB) is confined to the endothelium of brain capillaries and is indispensable for fluid homeostasis and neuronal function. In this study, we show that endothelial Wnt/β-catenin (β-cat) signaling regulates induction and maintenance of BBB characteristics during embryonic and postnatal development. Endothelial specific stabilization of β-cat in vivo enhances barrier maturation, whereas inactivation of β-cat causes significant down-regulation of claudin3 (Cldn3), up-regulation of plamalemma vesicle-associated protein, and BBB breakdown. Stabilization of β-cat in primary brain endothelial cells (ECs) in vitro by N-terminal truncation or Wnt3a treatment increases Cldn3 expression, BBB-type tight junction formation, and a BBB characteristic gene signature. Loss of β-cat or inhibition of its signaling abrogates this effect. Furthermore, stabilization of β-cat also increased Cldn3 and barrier properties in nonbrain-derived ECs. These findings may open new therapeutic avenues to modulate endothelial barrier function and to limit the devastating effects of BBB breakdown. PMID:18955553

Inhibition of soluble epoxide hydrolase lowers portal hypertension in cirrhotic rats by ameliorating endothelial dysfunction and liver fibrosis.

PubMed

Deng, Wensheng; Zhu, Yiming; Lin, Jiayun; Zheng, Lei; Zhang, Chihao; Luo, Meng

2017-07-01

Epoxyeicostrienoic acids (EETs) are arachidonic acid derived meditators which are catalyzed by soluble epoxide hydrolase (sEH) to less active dihydroeicostrienoics acids (DHETS). The aim of our study is to investigate the effects of sEH inhibition on hepatic and systemic hemodynamics, hepatic endothelial dysfunction, and hepatic fibrosis in CCl4 cirrhotic rats. The sEH inhibitor,trans-4-{4-[3-(4-trifluoromethoxyphenyl)-ureido]cyclohexyloxy}benzoic acid (t-TUCB) was administered to stabilize hepatic EETs by gavage at a dose of 1mg/kg/d. Our results showed that hepatic sEH expression was markedly increased in portal hypertension, and led to a lower ratio of EETs/DHETs which was effectively reversed by t-TUCB administration. t-TUCB significantly decreased portal pressure without significant changes in systemic hemodynamics, which was associated with the attenuation of intrahepatic vascular resistance (IHVR) and liver fibrosis. t-TUCB ameliorated endothelial dysfunction, increased hepatic endothelial nitric oxide synthase (eNOS) phosphorylation and nitric oxide (NO) production. In addition, t-TUCB significantly reduced alpha-Smooth Muscle Actin (α-SMA) expression and liver fibrosis, which was associated with a decrease in NF-κB signaling. Taken together, inhibition of sEH reduces portal pressure, liver fibrosis and attenuates hepatic endothelial dysfunction in cirrhotic rats. Our results indicate that sEH inhbitors may be useful in the treatment of portal hypertension in patients with cirrhosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Endothelial insulin receptor restoration rescues vascular function in male insulin receptor haploinsufficient mice.

PubMed

Sengupta, Anshuman; Patel, Peysh A; Yuldasheva, Nadira Y; Mughal, Romana S; Galloway, Stacey; Viswambharan, Hema; Walker, Andrew M N; Aziz, Amir; Smith, Jessica; Ali, Noman; Mercer, Ben N; Imrie, Helen; Sukumar, Piruthivi; Wheatcroft, Stephen B; Kearney, Mark T; Cubbon, Richard M

2018-05-15

Reduced systemic insulin signaling promotes endothelial dysfunction and diminished endogenous vascular repair. We asked whether restoration of endothelial insulin receptor expression could rescue this phenotype. Insulin receptor haploinsufficient mice (IRKO) were crossed with mice expressing a human insulin receptor transgene in the endothelium (hIRECO), to produce IRKO-hIRECO progeny. No metabolic differences were noted between IRKO and IRKO-hIRECO in glucose- and insulin-tolerance tests. In contrast with control IRKO littermates, IRKO-hIRECO exhibited normal blood pressure and aortic vasodilatation in response to acetylcholine, comparable to parameters noted in wild-type littermates. These phenotypic changes were associated with enhanced basal- and insulin-stimulated nitric oxide production. IRKO-hIRECO also demonstrated normalized endothelial repair after denuding arterial injury, which was associated with rescued endothelial cell migration in vitro, but not with changes in circulating progenitor populations or culture-derived myeloid angiogenic cells. These data show that restoration of endothelial insulin receptor expression alone is sufficient to prevent the vascular dysfunction caused by systemically reduced insulin signaling.

Eicosapentaenoic acid improves endothelial function and nitric oxide bioavailability in a manner that is enhanced in combination with a statin.

PubMed

Mason, R Preston; Dawoud, Hazem; Jacob, Robert F; Sherratt, Samuel C R; Malinski, Tadeusz

2018-07-01

The endothelium exerts many vasoprotective effects that are largely mediated by release of nitric oxide (NO). Endothelial dysfunction represents an early but reversible step in atherosclerosis and is characterized by a reduction in the bioavailability of NO. Previous studies have shown that eicosapentaenoic acid (EPA), an omega-3 fatty acid (O3FA), and statins individually improve endothelial cell function, but their effects in combination have not been tested. Through a series of in vitro experiments, this study evaluated the effects of a combined treatment of EPA and the active metabolite of atorvastatin (ATM) on endothelial cell function under conditions of oxidative stress. Specifically, the comparative and time-dependent effects of these agents on endothelial dysfunction were examined by measuring the levels of NO and peroxynitrite (ONOO - ) released from human umbilical vein endothelial cells (HUVECs). The data suggest that combined treatment with EPA and ATM is beneficial to endothelial function and was unique to EPA and ATM since similar improvements could not be recapitulated by substituting another O3FA docosahexaenoic acid (DHA) or other TG-lowering agents such as fenofibrate, niacin, or gemfibrozil. Comparable beneficial effects were observed when HUVECs were pretreated with EPA and ATM before exposure to oxidative stress. Interestingly, the kinetics of EPA-based protection of endothelial function in response to oxidation were found to be significantly different than those of DHA. Lastly, the beneficial effects on endothelial function generated by combined treatment of EPA and ATM were reproduced when this study was expanded to an ex vivo model utilizing rat glomerular endothelial cells. Taken together, these findings suggest that a combined treatment of EPA and ATM can inhibit endothelial dysfunction that occurs in response to conditions such as hyperglycemia, oxidative stress, and dyslipidemia. Copyright © 2018 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Depleted energy charge and increased pulmonary endothelial permeability induced by mitochondrial complex I inhibition are mitigated by coenzyme Q1 in the isolated perfused rat lung.

PubMed

Bongard, Robert D; Yan, Ke; Hoffmann, Raymond G; Audi, Said H; Zhang, Xiao; Lindemer, Brian J; Townsley, Mary I; Merker, Marilyn P

2013-12-01

Mitochondrial dysfunction is associated with various forms of lung injury and disease that also involve alterations in pulmonary endothelial permeability, but the relationship, if any, between the two is not well understood. This question was addressed by perfusing isolated intact rat lung with a buffered physiological saline solution in the absence or presence of the mitochondrial complex I inhibitor rotenone (20 μM). Compared to control, rotenone depressed whole lung tissue ATP from 5.66 ± 0.46 (SEM) to 2.34 ± 0.15 µmol · g(-1) dry lung, with concomitant increases in the ADP:ATP and AMP:ATP ratios. Rotenone also increased lung perfusate lactate (from 12.36 ± 1.64 to 38.62 ± 3.14 µmol · 15 min(-1) perfusion · g(-1) dry lung) and the lactate:pyruvate ratio, but had no detectable impact on lung tissue GSH:GSSG redox status. The amphipathic quinone coenzyme Q1 (CoQ1; 50 μM) mitigated the impact of rotenone on the adenine nucleotide balance, wherein mitigation was blocked by NAD(P)H-quinone oxidoreductase 1 or mitochondrial complex III inhibitors. In separate studies, rotenone increased the pulmonary vascular endothelial filtration coefficient (Kf) from 0.043 ± 0.010 to 0.156 ± 0.037 ml · min(-1) · cm H2O(-1) · g(-1) dry lung, and CoQ1 protected against the effect of rotenone on Kf. A second complex I inhibitor, piericidin A, qualitatively reproduced the impact of rotenone on Kf and the lactate:pyruvate ratio. Taken together, the observations imply that pulmonary endothelial barrier integrity depends on mitochondrial bioenergetics as reflected in lung tissue ATP levels and that compensatory activation of whole lung glycolysis cannot protect against pulmonary endothelial hyperpermeability in response to mitochondrial blockade. The study further suggests that low-molecular-weight amphipathic quinones may have therapeutic utility in protecting lung barrier function in mitochondrial insufficiency. Published by Elsevier Inc.

Endothelial dysfunction, vascular disease and stroke: the ARTICO study.

PubMed

Roquer, J; Segura, T; Serena, J; Castillo, J

2009-01-01

Endothelial dysfunction is a fundamental step in the atherosclerotic disease process. Its presence is a risk factor for the development of clinical events, and may represent a marker of atherothrombotic burden. Also, endothelial dysfunction contributes to enhanced plaque vulnerability, may trigger plaque rupture, and favors thrombus formation. The assessment of endothelial vasomotion is a useful marker of atherosclerotic vascular disease. There are different methods to assess endothelial function: endothelium-dependent vasodilatation brachial flow-mediated dilation, cerebrovascular reactivity to L-arginine, and the determination of some biomarkers such as microalbuminuria, platelet function, and C-reactive protein. Endothelial dysfunction has been observed in stroke patients and has been related to stroke physiopathology, stroke subtypes, clinical severity and outcome. Resting ankle-brachial index (ABI) is also considered an indicator of generalized atherosclerosis, and a low ABI is associated with an increase in stroke incidence in the elderly. Despite all these data, there are no studies analyzing the predictive value of ABI for new cardiovascular events in patients after suffering an acute ischemic stroke. ARTICO is an ongoing prospective, observational, multicenter study being performed in 50 Spanish hospitals. The aim of the ARTICO study is to evaluate the prognostic value of a pathological ABI (

Dietary quercetin attenuates oxidant-induced endothelial dysfunction and atherosclerosis in apolipoprotein E knockout mice fed a high-fat diet: a critical role for heme oxygenase-1.

PubMed

Shen, Yu; Ward, Natalie C; Hodgson, Jonathan M; Puddey, Ian B; Wang, Yutang; Zhang, Di; Maghzal, Ghassan J; Stocker, Roland; Croft, Kevin D

2013-12-01

Several lines of evidence indicate that quercetin, a polyphenol derived in the diet from fruit and vegetables, contributes to cardiovascular health. We aimed to investigate the effects of dietary quercetin on endothelial function and atherosclerosis in mice fed a high-fat diet. Wild-type C57BL/6 (WT) and apolipoprotein E gene knockout (ApoE(-/-)) mice were fed: (i) a high-fat diet (HFD) or (ii) a HFD supplemented with 0.05% w/w quercetin (HFD+Q), for 14 weeks. Compared with animals fed HFD, HFD+Q attenuated atherosclerosis in ApoE(-/-) mice. Treatment with the HFD+Q significantly improved endothelium-dependent relaxation of aortic rings isolated from WT but not ApoE(-/-) mice and attenuated hypochlorous acid-induced endothelial dysfunction in aortic rings of both WT and ApoE(-/-) mice. Mechanistic studies revealed that HFD+Q significantly improved plasma F2-isoprostanes, 24h urinary nitrite, and endothelial nitric oxide synthase activity, and increased heme oxygenase-1 (HO-1) protein expression in the aortas of both WT and ApoE(-/-) mice (P<0.05). HFD+Q also resulted in small changes in plasma cholesterol (P<0.05 in WT) and plasma triacylglycerols (P<0.05 in ApoE (-/-)mice). In a separate experiment, quercetin did not protect against hypochlorite-induced endothelial dysfunction in arteries obtained from heterozygous HO-1 gene knockout mice with low expression of HO-1 protein. Quercetin protects mice fed a HFD against oxidant-induced endothelial dysfunction and ApoE(-/-) mice against atherosclerosis. These effects are associated with improvements in nitric oxide bioavailability and are critically related to arterial induction of HO-1. © 2013 Elsevier Inc. All rights reserved.

False Positive Stress Testing: Does Endothelial Vascular Dysfunction Contribute to ST-Segment Depression in Women? A Pilot Study.

PubMed

Sharma, Shilpa; Mehta, Puja K; Arsanjani, Reza; Sedlak, Tara; Hobel, Zachary; Shufelt, Chrisandra; Jones, Erika; Kligfield, Paul; Mortara, David; Laks, Michael; Diniz, Marcio; Bairey Merz, C Noel

2018-06-19

The utility of exercise-induced ST-segment depression for diagnosing ischemic heart disease (IHD) in women is unclear. Based on evidence that IHD pathophysiology in women involves coronary vascular dysfunction, we hypothesized that coronary vascular dysfunction contributes to exercise electrocardiography (Ex-ECG) ST-depression in the absence of obstructive CAD, so-called "false positive" results. We tested our hypothesis in a pilot study evaluating the relationship between peripheral vascular endothelial function and Ex-ECG. Twenty-nine asymptomatic women without cardiac risk factors underwent maximal Bruce protocol exercise treadmill testing and peripheral endothelial function assessment using peripheral arterial tonometry (Itamar EndoPAT 2000) to measure reactive hyperemia index (RHI). The relationship between RHI and Ex-ECG ST-segment depression was evaluated using logistic regression and differences in subgroups using two-tailed t-tests. Mean age was 54 ± 7 years, body mass index 25 ± 4 kg/m 2 , and RHI 2.51 ± 0.66. Three women (10%) had RHI less than 1.68, consistent with abnormal peripheral endothelial function, while 18 women (62%) met criteria for a positive Ex-ECG based on ST-segment depression in contiguous leads. Women with and without ST-segment depression had similar baseline and exercise vital signs, metabolic equivalents (METS) achieved, and RHI (all p>0.05). RHI did not predict ST-segment depression. Our pilot study demonstrates a high prevalence of exercise-induced ST-segment depression in asymptomatic, middle-aged, overweight women. Peripheral vascular endothelial dysfunction did not predict Ex-ECG ST-segment depression. Further work is needed to investigate the utility of vascular endothelial testing and Ex-ECG for IHD diagnostic and management purposes in women. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Microvascular Endothelial Dysfunction in Sedentary, Obese Humans is mediated by NADPH Oxidase; Influence of Exercise Training

PubMed Central

La Favor, Justin D.; Dubis, Gabriel S.; Yan, Huimin; White, Joseph D.; Nelson, Margaret A.M.; Anderson, Ethan J.; Hickner, Robert C.

2016-01-01

Objective The objectives of this study were to determine the impact of in vivo reactive oxygen species (ROS) on microvascular endothelial function in obese human subjects and to determine the efficacy of an aerobic exercise intervention on alleviating obesity-associated dysfunctionality. Approach and Results Young, sedentary men and women were divided into lean (BMI 18–25; n=14), intermediate (BMI 28–32.5; n=13), and obese (BMI 33–40; n=15) groups. A novel microdialysis technique was utilized to detect elevated interstitial hydrogen peroxide (H2O2) and superoxide levels in the vastus lateralis of obese compared to both lean and intermediate subjects. Nutritive blood flow was monitored in the vastus lateralis via the microdialysis-ethanol technique. A decrement in acetylcholine-stimulated blood flow revealed impaired microvascular endothelial function in the obese subjects. Perfusion of apocynin, an NADPH oxidase (Nox) inhibitor, lowered (normalized) H2O2 and superoxide levels and reversed microvascular endothelial dysfunction in obese subjects. Following 8-weeks of exercise, H2O2 levels were decreased in the obese subjects and microvascular endothelial function in these subjects was restored to levels similar to lean subjects. Skeletal muscle protein expression of the Nox subunits p22phox, p47phox, and p67phox were increased in obese relative to lean subjects, where p22phox and p67phox expression was attenuated by exercise training in obese subjects. Conclusions This study implicates Nox as a source of excessive ROS production in skeletal muscle of obese individuals, and links excessive Nox derived ROS to microvascular endothelial dysfunction in obesity. Furthermore, aerobic exercise training proved to be an effective strategy for alleviating these maladies. PMID:27765769

Circulating metabolites of strawberry mediate reductions in vascular inflammation and endothelial dysfunction in db/db mice.

PubMed

Petersen, Chrissa; Bharat, Divya; Cutler, Brett Ronald; Gholami, Samira; Denetso, Christopher; Mueller, Jennifer Ellen; Cho, Jae Min; Kim, Ji-Seok; Symons, J David; Anandh Babu, Pon Velayutham

2018-07-15

Cardiovascular disease is 2-4-fold more prevalent in patients with diabetes. Human studies support the cardiovascular benefits of strawberry consumption but the effects of strawberry on diabetic vasculature are unknown. We tested the hypothesis that dietary strawberry supplementation attenuates vascular inflammation and dysfunction in diabetic mice. Seven-week-old diabetic db/db mice that consumed standard diet (db/db) or diet supplemented with 2.35% freeze-dried strawberry (db/db + SB) for ten weeks were compared to non-diabetic control mice (db/+). Indices of vascular inflammation and dysfunction were measured. Endothelial cells (ECs) were isolated from the vasculature to determine the influence of strawberry on them. The effect of metabolites of strawberry on endothelial inflammation was determined by incubating mouse aortic ECs (MAECs) with ±5% serum, obtained from strawberry fed mice (metabolites serum) or standard diet fed mice (control serum) ± 25 mM glucose and 100 μM palmitate. db/db mice exhibited an increased monocyte binding to vessel, elevated blood pressure, and reduced endothelial-dependent vasorelaxation compared with db/+ mice but each defect was attenuated in db/db + SB mice. The elevation of inflammatory molecules, NOX2 and inhibitor-κB kinase observed in ECs from db/db vs. db/+ mice was suppressed in db/db + SB mice. Glucose and palmitate increased endothelial inflammation in MAECs but were normalized by co-incubation with metabolites serum. Dietary supplementation of strawberry attenuates indices of vascular inflammation and dysfunction in diabetic db/db mice. The effect of strawberry on vasculature is endothelial-dependent and possibly mediated through their circulating metabolites. Strawberry might complement conventional therapies to improve vascular complications in diabetics. Copyright © 2017 Elsevier B.V. All rights reserved.

Silencing Of Circular RNA-ZNF609 Ameliorates Vascular Endothelial Dysfunction.

PubMed

Liu, Chang; Yao, Mu-Di; Li, Chao-Peng; Shan, Kun; Yang, Hong; Wang, Jia-Jian; Liu, Ban; Li, Xiu-Miao; Yao, Jin; Jiang, Qin; Yan, Biao

2017-01-01

Vascular dysfunction is a hallmark of ischemic, cancer, and inflammatory diseases, contributing to disease progression. Circular RNAs (circRNAs) are endogenous non-coding RNAs, which have been reported to be abnormally expressed in many human diseases. In this study, we used retinal vasculature to determine the role of circular RNA in vascular dysfunction. We revealed that cZNF609 was significantly up-regulated upon high glucose and hypoxia stress in vivo and in vitro . cZNF609 silencing decreased retinal vessel loss and suppressed pathological angiogenesis in vivo . cZNF609 silencing increased endothelial cell migration and tube formation, and protected endothelial cell against oxidative stress and hypoxia stress in vitro . By contrast, transgenic overexpression of cZNF609 showed an opposite effects. cZNF609 acted as an endogenous miR-615-5p sponge to sequester and inhibit miR-615-5p activity, which led to increased MEF2A expression. MEF2A overexpression could rescue cZNF609 silencing-mediated effects on endothelial cell migration, tube formation, and apoptosis. Moreover, dysregulated cZNF609 expression was detected in the clinical samples of the patients with diabetes, hypertension, and coronary artery disease. Intervention of cZNF609 expression is promising therapy for vascular dysfunction.

Combination therapy for treatment or prevention of atherosclerosis: Focus on the lipid-RAAS interaction☆

PubMed Central

Koh, Kwang Kon; Han, Seung Hwan; Oh, Pyung Chun; Shin, Eak Kyun; Quon, Michael J.

2010-01-01

Large clinical trials demonstrate that control of blood pressure or hyperlipidemia reduces risk for cardiovascular events by ~30%. Factors that may further reduce remaining risk are not definitively established. One potential target is atherosclerosis, a crucial feature in the pathogenesis of cardiovascular diseases whose development is determined by multiple mechanism including complex interactions between endothelial dysfunction and insulin resistance. Reciprocal relationships between endothelial dysfunction and insulin resistance as well as cross-talk between hyperlipidemia and the rennin–angiotensin–aldosterone system may contribute to development of atherosclerosis. Therefore, one appealing strategy for prevention or treatment of atherosclerosis may be to simultaneously address several risk factors with combination therapies that target multiple pathogenic mechanisms. Combination therapy with statins, peroxisome proliferators-activated receptor agonists, and rennin–angiotensin–aldosterone system blockers demonstrate additive beneficial effects on endothelial dysfunction and insulin resistance when compared with monotherapies in patients with cardiovascular risk factors. Additive beneficial effects of combined therapy are mediated by both distinct and interrelated mechanisms, consistent with both pre-clinical and clinical investigations. Thus, combination therapy may be an important concept in developing more effective strategies to treat and prevent atherosclerosis, coronary heart disease, and co-morbid metabolic disorders characterized by endothelial dysfunction and insulin resistance. PMID:19800624

The Association Between Inflammatory Markers and Hypertension. A Call for Anti-Inflammatory Strategies?

PubMed Central

García, Néstor H.; Juncos, Luis I.

2006-01-01

The most important goal of antihypertensive therapy is to prevent the complications associated with hypertension (stroke, myocardial infarction, end-stage renal disease, etc). For this, secondary targets such as left ventricular hypertrophy, proteinuria, dementia, and other signs of hypertension-induced organ damage help the physician to assess risks and monitor treatment efficacy. New treatment targets may be arising, however. One such target may be endothelial dysfunction. In effect, endothelial dysfunction not only may precede the elevation of blood pressure, but may also pave the way to conditions often associated with hypertension, such as diabetes, arteriosclerosis, microalbuminuria, congestive heart failure, and tissue hypertrophy. Because inflammation often accompanies endothelial dysfunction, approaches to counteract inflammation are now being evaluated. For this, antagonists of the renin-angiotensin-aldosterone system, statins, and beta blockers are all being tested. All of these agents seem to prevent or delay the induction of proinflammatory molecules aside from, and in addition to, their specific effects on blood pressure. The focus of this review is to update some of the animal and human research showing that hypertension sets off an inflammatory state and also to consider some of the anti-inflammatory approaches that may prevent the development of endothelial dysfunction, and the subsequent renal and cardiovascular damage.

Possible involvement of gap junctions in the barrier function of tight junctions of brain and lung endothelial cells.

PubMed

Nagasawa, Kunihiko; Chiba, Hideki; Fujita, Hiroki; Kojima, Takashi; Saito, Tsuyoshi; Endo, Toshiaki; Sawada, Norimasa

2006-07-01

Gap-junction plaques are often observed with tight-junction strands of vascular endothelial cells but the molecular interaction and functional relationships between these two junctions remain obscure. We herein show that gap-junction proteins connexin40 (Cx40) and Cx43 are colocalized and coprecipitated with tight-junction molecules occludin, claudin-5, and ZO-1 in porcine blood-brain barrier (BBB) endothelial cells. Gap junction blockers 18beta-glycyrrhetinic acid (18beta-GA) and oleamide (OA) did not influence expression of Cx40, Cx43, occludin, claudin-5, junctional adhesion molecule (JAM)-A, JAM-B, JAM-C, or ZO-1, or their subcellular localization in the porcine BBB endothelial cells. In contrast, these gap-junction blocking agents inhibited the barrier function of tight junctions in cells, determined by measurement of transendothelial electrical resistance and paracellular flux of mannitol and inulin. 18beta-GA also significantly reduced the barrier property in rat lung endothelial (RLE) cells expressing doxycycline-induced claudin-1, but did not change the interaction between Cx43 and either claudin-1 or ZO-1, nor their expression levels or subcellular distribution. These findings suggest that Cx40- and/or Cx43-based gap junctions might be required to maintain the endothelial barrier function without altering the expression and localization of the tight-junction components analyzed. Copyright 2006 Wiley-Liss, Inc.

Cyclooxygenase inhibition improves endothelial vasomotor dysfunction of visceral adipose arterioles in human obesity

PubMed Central

Farb, Melissa G.; Tiwari, Stephanie; Karki, Shakun; Ngo, Doan TM; Carmine, Brian; Hess, Donald T.; Zuriaga, Maria A.; Walsh, Kenneth; Fetterman, Jessica L.; Hamburg, Naomi M.; Vita, Joseph A.; Apovian, Caroline M.; Gokce, Noyan

2013-01-01

Objective The purpose of this study was to determine whether cyclooxygenase inhibition improves vascular dysfunction of adipose microvessels from obese humans. Design and Methods In 20 obese subjects (age 37±12 yrs, BMI 47±8 kg/m2) we collected subcutaneous and visceral fat during bariatric surgery and characterized adipose depot-specific gene expression, endothelial cell phenotype, and microvascular function. Vasomotor function was assessed in response to endothelium-dependent agonists using videomicroscopy of small arterioles from fat. Results Arterioles from visceral fat exhibited impaired endothelium-dependent, acetylcholine-mediated vasodilation, compared to the subcutaneous depot (p<0.001). Expression of mRNA transcripts relevant to the cyclooxygenase pathway were upregulated in visceral compared to subcutaneous fat. Pharmacological inhibition of cyclooxygenase with indomethacin improved endothelium-dependent vasodilator function of arterioles from visceral fat by 2-fold (p=0.01), whereas indomethacin had no effect in the subcutaneous depot. Indomethacin increased activation via serine-1177 phosphorylation of endothelial nitric oxide synthase in response to acetylcholine in endothelial cells from visceral fat. Inhibition of endothelial nitric oxide synthase with Nω-nitro-L-arginine methyl ester abrogated the effects of cyclooxygenase-inhibition suggesting that vascular actions of indomethacin were related to increased nitric oxide bioavailability. Conclusions Our findings suggest that cyclooxygenase-mediated vasoconstrictor prostanoids partly contribute to endothelial dysfunction of visceral adipose arterioles in human obesity. PMID:23640904

Association Between Inflammatory Markers and Progression to Kidney Dysfunction: Examining Different Assessment Windows in Patients With Type 1 Diabetes.

PubMed

Baker, Nathaniel L; Hunt, Kelly J; Stevens, Danielle R; Jarai, Gabor; Rosen, Glenn D; Klein, Richard L; Virella, Gabriel; Lopes-Virella, Maria F

2018-01-01

To determine whether biomarkers of inflammation and endothelial dysfunction are associated with the development of kidney dysfunction and the time frame of their association. Biomarkers were measured at four time points during 28 years of treatment and follow-up in patients with type 1 diabetes in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort. In addition to traditional biomarkers of inflammation (C-reactive protein and fibrinogen), we measured interleukin-6 (IL-6) and soluble tumor necrosis factor receptors 1 and 2 (sTNFR-1/2), markers of endothelial dysfunction (soluble intracellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin [sE-selectin]), and fibrinolysis (total and active plasminogen activator inhibitor-1 [PAI-1]). Renal outcomes were defined as progression to incident chronic kidney disease (stage 3 or more severe) or macroalbuminuria (albumin excretion rate ≥300 mg/24 h). Prospective multivariate event-time analyses were used to determine the association of each biomarker with each subsequent event within prespecified intervals (3-year and 10-year windows). Multivariate event-time models indicated that several markers of inflammation (sTNFR-1/2), endothelial dysfunction (sE-selectin), and clotting/fibrinolysis (fibrinogen and PAI-1) are significantly associated with subsequent development of kidney dysfunction. Although some markers showed variations in the associations between the follow-up windows examined, the results indicate that biomarkers (sTNFR-1/2, sE-selectin, PAI-1, and fibrinogen) are associated with progression to chronic kidney disease in both the 3-year and the 10-year windows. Plasma markers of inflammation, endothelial dysfunction, and clotting/fibrinolysis are associated with progression to kidney dysfunction in type 1 diabetes during both short-term and long-term follow-up. © 2017 by the American Diabetes Association.

Astrocyte–endothelial interactions and blood–brain barrier permeability*

PubMed Central

Abbott, N Joan

2002-01-01

The blood–brain barrier (BBB) is formed by brain endothelial cells lining the cerebral microvasculature, and is an important mechanism for protecting the brain from fluctuations in plasma composition, and from circulating agents such as neurotransmitters and xenobiotics capable of disturbing neural function. The barrier also plays an important role in the homeostatic regulation of the brain microenvironment necessary for the stable and co-ordinated activity of neurones. The BBB phenotype develops under the influence of associated brain cells, especially astrocytic glia, and consists of more complex tight junctions than in other capillary endothelia, and a number of specific transport and enzyme systems which regulate molecular traffic across the endothelial cells. Transporters characteristic of the BBB phenotype include both uptake mechanisms (e.g. GLUT-1 glucose carrier, L1 amino acid transporter) and efflux transporters (e.g. P-glycoprotein). In addition to a role in long-term barrier induction and maintenance, astrocytes and other cells can release chemical factors that modulate endothelial permeability over a time-scale of seconds to minutes. Cell culture models, both primary and cell lines, have been used to investigate aspects of barrier induction and modulation. Conditioned medium taken from growing glial cells can reproduce some of the inductive effects, evidence for involvement of diffusible factors. However, for some features of endothelial differentiation and induction, the extracellular matrix plays an important role. Several candidate molecules have been identified, capable of mimicking aspects of glial-mediated barrier induction of brain endothelium; these include TGFβ, GDNF, bFGF, IL-6 and steroids. In addition, factors secreted by brain endothelial cells including leukaemia inhibitory factor (LIF) have been shown to induce astrocytic differentiation. Thus endothelium and astrocytes are involved in two-way induction. Short-term modulation of brain endothelial permeability has been shown for a number of small chemical mediators produced by astrocytes and other nearby cell types. It is clear that endothelial cells are involved in both long- and short-term chemical communication with neighbouring cells, with the perivascular end feet of astrocytes being of particular importance. The role of barrier induction and modulation in normal physiology and in pathology is discussed. PMID:12162730

Thrombin-induced phosphorylation of the regulatory light chain of myosin II in cultured bovine corneal endothelial cells.

PubMed

Satpathy, M; Gallagher, P; Lizotte-Waniewski, M; Srinivas, S P

2004-10-01

Phosphorylation of the regulatory light chain of myosin II (referred to as myosin light chain or MLC) leads to a loss of barrier integrity in cellular monolayers by an increase in the contractility of the cortical actin cytoskeleton. This effect has been examined in corneal endothelial (CE) cells. Experiments were performed using cultured bovine CE cells (BCEC). MLC phosphorylation was induced by a thrombin-mediated activation of the proteinase-activated receptor-1 (PAR-1). Expression of MLC kinase (MLCK), a Ca2+/calmodulin-dependent protein kinase that phosphorylates MLC at its Ser-19 and Thr-18 residues, was determined by RT-PCR and Western blotting. Expression of PAR-1, RhoA, and Rho kinase-1 (effector of RhoA) was ascertained by RT-PCR. MLC phosphorylation was assessed by urea-glycerol gel electrophoresis followed by immunoblotting. The effects of Rho kinase-1 and PKC were characterized by using their selective inhibitors, Y-27632 and chelerythrine, respectively. Reorganization of the cytoskeleton was evaluated by the phalloidin staining of actin. [Ca2+]i was measured using Fura-2. The barrier integrity was assayed as permeability of BCEC monolayers to horseradish peroxidase (HRP; 44 kDa). RT-PCR showed expression of MLCK, PAR-1, Rho kinase-1, and RhoA. Western blotting indicated expression of the non-muscle and smooth muscle isoforms of MLCK. Exposure to thrombin induced an increase in [Ca2+]i with the peak unaffected by an absence of extracellular Ca2+. Pre-exposure to thrombin (2 U ml(-1); 2 min) led to mono- and di-phosphorylation of MLC. Under both basal conditions and in the presence of thrombin, MLC phosphorylation was prevented by chelerythrine (10 microm) and Y-27632 (<25 microm). Thrombin led to inter-endothelial gaps secondary to the disruption of the cortical actin cytoskeleton, which under resting conditions was organized as a perijunctional actomyosin ring (PAMR). These responses were blocked by pre-treatment with Y-27632. Thrombin also increased permeability to HRP, which was abolished by pre-treatment with Y-27632. Thrombin induces MLC phosphorylation in BCEC. The consequent increase in the contractility of the actin cytoskeleton produces a centripetal force resulting in inter-endothelial gaps and a breakdown of barrier integrity. These responses are PKC- and Rho kinase-dependent. [Ca2+]i increase, as well as sensitivity of the thrombin response to PKC and Rho kinase inhibitors, are consistent with the expression of PAR-1 receptors in BCEC. Thrombin-induced hyperpermeability is a model to investigate barrier dysfunction induced by MLC phosphorylation.

Aspirin prevents TNF-α-induced endothelial cell dysfunction by regulating the NF-κB-dependent miR-155/eNOS pathway: Role of a miR-155/eNOS axis in preeclampsia.

PubMed

Kim, Joohwan; Lee, Kyu-Sun; Kim, Ji-Hee; Lee, Dong-Keon; Park, Minsik; Choi, Seunghwan; Park, Wonjin; Kim, Suji; Choi, Yoon Kyung; Hwang, Jong Yun; Choe, Jongseon; Won, Moo-Ho; Jeoung, Dooil; Lee, Hansoo; Ryoo, Sungwoo; Ha, Kwon-Soo; Kwon, Young-Guen; Kim, Young-Myeong

2017-03-01

Preeclampsia is an inflammatory disease with endothelial cell dysfunction that occurs via decreased endothelial nitric oxide synthase/nitric oxide (eNOS/NO) activity. Aspirin reduces the incidence of hypertensive pregnancy complications. However, the underlying mechanism has not been clearly explained. Here, we found that tumor necrosis factor (TNF)-α, microRNA (miR)-155, and eNOS levels as well as endothelial redox phenotype were differentially regulated in preeclamptic patients, implying the involvement of TNF-α- and redox signal-mediated miR-155 biogenesis and eNOS downregulation in the pathogenesis of preeclampsia. Aspirin prevented the TNF-α-mediated increase in miR-155 biogenesis and decreases in eNOS expression and NO/cGMP production in cultured human umbilical vein endothelial cells (HUVECs). Similar effects of aspirin were also observed in HUVECs treated with H 2 O 2 . The preventive effects of aspirin was associated with the inhibition of nuclear factor-κB (NF-κB)-dependent MIR155HG (miR-155 host gene) expression. Aspirin recovered the TNF-α-mediated decrease in wild-type, but not mutant, eNOS 3'-untranslated region reporter activity, whose effect was blocked by miR-155 mimic. Moreover, aspirin prevented TNF-α-mediated endothelial cell dysfunction associated with impaired vasorelaxation, angiogenesis, and trophoblast invasion, and the preventive effects were blocked by miR-155 mimic or an eNOS inhibitor. Aspirin rescued TNF-α-mediated eNOS downregulation coupled with endothelial dysfunction by inhibiting NF-κB-dependent transcriptional miR-155 biogenesis. Thus, the redox-sensitive NF-κB/miR-155/eNOS axis may be crucial in the pathogenesis of vascular disorders including preeclampsia. Copyright © 2017 Elsevier Inc. All rights reserved.

Nebivolol: impact on cardiac and endothelial function and clinical utility.

PubMed

Toblli, Jorge Eduardo; DiGennaro, Federico; Giani, Jorge Fernando; Dominici, Fernando Pablo

2012-01-01

Endothelial dysfunction is a systemic pathological state of the endothelium characterized by a reduction in the bioavailability of vasodilators, essentially nitric oxide, leading to impaired endothelium-dependent vasodilation, as well as disarrangement in vascular wall metabolism and function. One of the key factors in endothelial dysfunction is overproduction of reactive oxygen species which participate in the development of hypertension, atherosclerosis, diabetes, cardiac hypertrophy, heart failure, ischemia-reperfusion injury, and stroke. Because impaired endothelial activity is believed to have a major causal role in the pathophysiology of vascular disease, hypertension, and heart failure, therapeutic agents which modify this condition are of clinical interest. Nebivolol is a third-generation β-blocker with high selectivity for β1-adrenergic receptors and causes vasodilation by interaction with the endothelial L-arginine/ nitric oxide pathway. This dual mechanism of action underscores several hemodynamic qualities of nebivolol, which include reductions in heart rate and blood pressure and improvements in systolic and diastolic function. Although nebivolol reduces blood pressure to a degree similar to that of conventional β-blockers and other types of antihypertensive drugs, it may have advantages in populations with difficult-to-treat hypertension, such as patients with heart failure along with other comorbidities, like diabetes and obesity, and elderly patients in whom nitric oxide-mediated endothelial dysfunction may be more pronounced. Furthermore, recent data indicate that nebivolol appears to be a cost-effective treatment for elderly patients with heart failure compared with standard care. Thus, nebivolol is an effective and well tolerated agent with benefits above those of traditional β-blockers due to its influence on nitric oxide release, which give it singular hemodynamic effects, cardioprotective activity, and a good tolerability profile. This paper reviews the pharmacology structure and properties of nebivolol, focusing on endothelial dysfunction, clinical utility, comparative efficacy, side effects, and quality of life in general with respect to the other antihypertensive agents.

[Endothelial dysfunction in diabetes mellitus and possible ways of pharmacological correction].

PubMed

Chernov, Iu N; Krasiukova, V A; Batishcheva, G A; Mubarakshina, O A

2010-02-01

Insulinoresistance (IR) and endothelial dysfunction (ED) take part in forming cardiovascular complications. Hyperglycemia, dyslipidemia, and compensatory hyperinsulinemia are triggering factors in the development of ED in diabetes mellitus. Hyperactivation of the renin--angiotensin--aldosterone system and increasing influence of the sympathoadrenal system play an important role in the appearance of ED, which is characterized by a decrease in the synthesis of nitric oxide and an increase in the production of vasoconstrictors. At present, drugs used for ED correction only indirectly influence the functioning of endothelial cells. Eight pharmacological groups including more than 30 drugs are reviewed, which are capable of improving the endothelial function. Progress in the pharmacotherapy of ED stimulates the development of approaches to the individual choice of drugs and the directed correction of the functional state of vascular endothelium.

S-nitrosylation of VASP at cysteine 64 mediates the inflammation-stimulated increase in microvascular permeability.

PubMed

Zamorano, Patricia; Marín, Natalie; Córdova, Francisco; Aguilar, Alejandra; Meininger, Cynthia; Boric, Mauricio P; Golenhofen, Nikola; Contreras, Jorge E; Sarmiento, José; Durán, Walter N; Sánchez, Fabiola A

2017-07-01

We tested the hypothesis that platelet-activating factor (PAF) induces S -nitrosylation of vasodilator-stimulated phosphoprotein (VASP) as a mechanism to reduce microvascular endothelial barrier integrity and stimulate hyperpermeability. PAF elevated S -nitrosylation of VASP above baseline levels in different endothelial cells and caused hyperpermeability. To ascertain the importance of endothelial nitric oxide synthase (eNOS) subcellular location in this process, we used ECV-304 cells transfected with cytosolic eNOS (GFPeNOSG2A) and plasma membrane eNOS (GFPeNOSCAAX). PAF induced S -nitrosylation of VASP in cells with cytosolic eNOS but not in cells wherein eNOS is anchored to the cell membrane. Reconstitution of VASP knockout myocardial endothelial cells with cysteine mutants of VASP demonstrated that S -nitrosylation of cysteine 64 is associated with PAF-induced hyperpermeability. We propose that regulation of VASP contributes to endothelial cell barrier integrity and to the onset of hyperpermeability. S -nitrosylation of VASP inhibits its function in barrier integrity and leads to endothelial monolayer hyperpermeability in response to PAF, a representative proinflammatory agonist. NEW & NOTEWORTHY Here, we demonstrate that S -nitrosylation of vasodilator-stimulated phosphoprotein (VASP) on C64 is a mechanism for the onset of platelet-activating factor-induced hyperpermeability. Our results reveal a dual role of VASP in endothelial permeability. In addition to its well-documented function in barrier integrity, we show that S -nitrosylation of VASP contributes to the onset of endothelial permeability. Copyright © 2017 the American Physiological Society.

Grape seed proanthocyanidin extract protects human umbilical vein endothelial cells from indoxyl sulfate-induced injury via ameliorating mitochondrial dysfunction.

PubMed

Lu, Zhaoyu; Lu, Fuhua; Zheng, Yanqun; Zeng, Yuqun; Zou, Chuan; Liu, Xusheng

2016-01-01

To investigate the effects of grape seed proanthocyanidin extract (GSPE) on indoxyl sulfate-induced Human Umbilical Vein Endothelial Cells (HUVECs) injury in vitro and study its mechanism. HUVECs were incubated with indoxyl sulfate at concentrations in the range found in uremic patients. Then we determined the effect of indoxyl sulfate on endothelial phenotype, endothelial function, ROS (reactive oxygen species), cell apoptosis and mitochondrial function. In addition, we detected whether GSPE can suppress the injury of HUVECs induced by indoxyl sulfate and probe the mechanism underlying the protective effects of GSPE by analyzing mitochondrial dysfunction. GSPE treatment significantly attenuated indoxyl sulfate-induced HVUECs injury in a dose- and time-dependent manner. GSPE-enhanced eNOS and VE-cadherin expression, inhibited intracellular ROS level and cell apoptosis, adjust mitochondrial membrane potential and reduced 8-hydroxy-desoxyguanosine (8-OHdG) level induced by indoxyl sulfate. These results suggest that GSPE prevents HUVECs from indoxyl sulfate-induced injury by ameliorating mitochondrial dysfunction and may be a promising agent for treating uremia toxin-induced injury.

RNCR3: A regulator of diabetes mellitus-related retinal microvascular dysfunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shan, Kun; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai; The Fourth School of Clinical Medicine, Nanjing Medical University, Nanjing

Retinal microvascular abnormality is an important pathological feature of diabetic retinopathy. Herein, we report the role of lncRNA-RNCR3 in diabetes mellitus-induced retinal microvascular abnormalities. We show that RNCR3 is significantly up-regulated upon high glucose stress in vivo and in vitro. RNCR3 knockdown alleviates retinal vascular dysfunction in vivo, as shown by decreased acellular capillaries, decreased vascular leakage, and reduced inflammatory response. RNCR3 knockdown decreases retinal endothelial cell proliferation, and reduces cell migration and tube formation in vitro. RNCR3 regulates endothelial cell function through RNCR3/KLF2/miR-185-5p regulatory network. RNCR3 inhibition may be a treatment option for the prevention of diabetes mellitus-induced retinal microvascular abnormalities. - Highlights:more » • RNCR3 expression is significantly up-regulated upon high glucose stress. • RNCR3 knockdown alleviates retinal vascular dysfunction in vivo. • RNCR3 regulates retinal endothelial cell function in vitro. • RNCR3 regulates retinal endothelial cell function via RNCR3/KLF2/miR-185-5p pathway.« less

Ascorbic Acid Prevents VEGF-induced Increases in Endothelial Barrier Permeability

PubMed Central

Ulker, Esad; Parker, William H.; Raj, Amita; Qu, Zhi-chao; May, James M.

2015-01-01

Vascular endothelial growth factor (VEGF) increases endothelial barrier permeability, an effect that may contribute to macular edema in diabetic retinopathy. Since vitamin C, or ascorbic acid, can tighten the endothelial permeability barrier, we examined whether it could prevent the increase in permeability due to VEGF in human umbilical vein endothelial cells (HUVECs). As previously observed, VEGF increased HUVEC permeability to radiolabeled inulin within 60 min in a concentration-dependent manner. Loading the cells with increasing concentrations of ascorbate progressively prevented the leakage caused by 100 ng/ml VEGF, with a significant inhibition at 13 μM and complete inhibition at 50 μM. Loading cells with 100 μM ascorbate also decreased basal generation of reactive oxygen species and prevented the increase caused by both 100 ng/ml VEGF. VEGF treatment decreased intracellular ascorbate by 25%, thus linking ascorbate oxidation to its prevention of VEGF-induced barrier leakage. The latter was blocked by treating the cells with 60 μM L-NAME (but not D-NAME) as well as by 30 μM sepiapterin, a precursor of tetrahydrobiopterin that is required for proper function of endothelial nitric oxide synthase (eNOS). These findings suggest that VEGF-induced barrier leakage uncouples eNOS. Ascorbate inhibition of the VEGF effect could thus be due either to scavenging superoxide or to peroxynitrite generated by the uncoupled eNOS, or more likely to its ability to recycle tetrahydrobiopterin, thus avoiding enzyme uncoupling in the first place. Ascorbate prevention of VEGF-induced increases in endothelial permeability opens the possibility that its repletion could benefit diabetic macular edema. PMID:26590088

A healthy diet is associated with less endothelial dysfunction and less low-grade inflammation over a 7-year period in adults at risk of cardiovascular disease.

PubMed

van Bussel, Bas C T; Henry, Ronald M A; Ferreira, Isabel; van Greevenbroek, Marleen M J; van der Kallen, Carla J H; Twisk, Jos W R; Feskens, Edith J M; Schalkwijk, Casper G; Stehouwer, Coen D A

2015-03-01

A healthy diet rich in fish, fruit, and vegetables, but moderate in alcohol and low in dairy products and meat, has been associated with a lower rate of incident cardiovascular disease (CVD). The underlying mechanisms, however, remain unclear. Endothelial dysfunction and low-grade inflammation play important roles in CVD. A healthy diet might modify these phenomena. We investigated the associations between the above food groups and overall biomarker scores of endothelial dysfunction and low-grade inflammation in a 7-y longitudinal study. Using longitudinal data from 557 participants at increased CVD risk from the CODAM (Cohort on Diabetes and Atherosclerosis Maastricht) Study, we assessed diet intake by food-frequency questionnaire and measured plasma biomarkers of endothelial dysfunction [von Willebrand factor, soluble vascular cell adhesion molecule 1, soluble endothelial selectin, soluble thrombomodulin, soluble intercellular adhesion molecule 1 (sICAM-1)] and low-grade inflammation [C-reactive protein, serum amyloid A, interleukin (IL)-6, IL-8, tumor necrosis factor α, and sICAM-1]. At baseline, participants were aged 59.6 ± 6.9 y. Measurements were performed then and after 7 y. Biomarkers were combined into overall scores (sum of z scores; higher scores indicating worse function). Longitudinal data were analyzed with generalized estimating equations and adjusted for sex, age, glucose metabolism, energy intake, body mass index, physical activity, alcohol consumption, and smoking. Higher consumption of fish (per 100 g/wk), but not total consumption of vegetables, fruit, alcohol-containing beverages, dairy products, or meat, was associated with a lower overall endothelial dysfunction score over 7 y (β: -0.027; 95% CI: -0.051, -0.004). No associations were observed with the overall low-grade inflammation score. Further food component analyses indicated that consumption of more lean fish (per 100 g/wk) and raw vegetables (per 100 g/d), and fewer high-fat dairy products (per 100 g/d) was associated with less endothelial dysfunction [(β: -0.038; 95% CI: -0.072, -0.005), (β: -0.095; 95% CI: -0.191, 0.000), and (β: -0.070; 95% CI: -0.131, -0.009), respectively]. Consumption of more fresh fruit (per 100 g/d), wine (per 100 mL/wk), and poultry (per 100 g/d), and fewer high-fat dairy products (per 100 g/d) was associated with less low-grade inflammation [(β: -0.074; 95% CI: -0.133, -0.015), (β:-0.006; 95% CI: -0.013, 0.001), (β:-0.247; 95% CI: -0.479, -0.014), and (β:-0.100; 95% CI: -0.182, -0.019), respectively]. These data suggest that the dietary modification of endothelial dysfunction and low-grade inflammation, processes that are important in atherothrombosis, is possible. © 2015 American Society for Nutrition.

Effect of Flow on Gene Regulation in Smooth Muscle Cells and Macromolecular Transport Across Endothelial Cell Monolayers

NASA Technical Reports Server (NTRS)

McIntire, Larry V.; Wagner, John E.; Papadaki, Maria; Whitson, Peggy A.; Eskin, Suzanne G.

1996-01-01

Endothelial cells line all of the vessels of the circulatory system, providing a non-thrombogenic conduit for blood flow; they regulate many complex functions in the vasculature, such as coagulation, fibrinolysis, platelet aggregation, vessel tone and growth, and leukocyte traffic; and they form the principal barrier to transport of substances between the blood and the surrounding tissue space. The permeability of endothelial cell changes with environmental stimuli; shear stress, in particular, applied either in vivo, or in vitro, induces changes in protein expression and secretion of vasoactive factors by endothelial cells. The ability to study the effects of shear on the macromolecular permeability of the cerebral vasculature is particularly important, since in no other place is the barrier function of the endothelium more important than in the brain. The endothelial cells of this organ have developed special barrier properties that keep the cerebral system from experiencing any drastic change in composition; together with glial cells, they form the blood brain barrier (BBB). We have studied the effect of flow on bovine BBB using flow chambers and tissue culture systems.

Pertussis toxin permeabilization enhances the traversal of Escherichia coli K1, macrophages, and monocytes in a cerebral endothelial barrier model in vitro.

PubMed

Seidel, Gabriela; Böcker, Kathrin; Schulte, Jessica; Wewer, Corinna; Greune, Lilo; Humberg, Verena; Schmidt, M Alexander

2011-03-01

The occasionally severe neurological complications following the human respiratory tract infection 'whooping cough' have been attributed to pertussis toxin (PT) expressed by the causative agent Bordetella pertussis. Disruption of the endothelial blood-brain barrier (BBB) by PT might facilitate the translocation of immune cells and of hematogenous microbial pathogens. To test this hypothesis, we investigated whether PT enhances the traversal of bacteria employing human brain microvascular endothelial cells (HBMEC) as an in vitro endothelial barrier model. PT incubation significantly increased the translocation of Escherichia coli K1 across the HBMEC barrier. Only intercellular E. coli K1 bacteria could be identified by electron microscopy suggesting paracellular translocation. In addition, the migration of differentiated HL60-derived macrophages and of human monocytic U937 cells through PT-treated HBMEC barriers was also enhanced. In comparison to E. coli C600, E. coli K1 showed prolonged survival in translocated HL60-derived and J774 macrophages as well as in U937 monocytes which suggested a contribution of the 'Trojan horse' mechanism. In summary, our findings demonstrate that the PT-induced permeabilization of endothelial barriers enhances the paracellular transmigration of microbes and immune cells. In vivo, this activity might lower the threshold of bacteremia facilitating secondary cerebral infections and the subsequent development of brain pathologies. Copyright © 2010 Elsevier GmbH. All rights reserved.

Neutrophil proteinase 3 (PR3) acts on protease-activated receptor-2 (PAR-2) to enhance vascular endothelial cell barrier function

PubMed Central

Kuckleburg, Christopher J.; Newman, Peter J.

2013-01-01

The principle role of the vascular endothelium is to present a semi-impermeable barrier to soluble factors and circulating cells, while still permitting the passage of leukocytes from the bloodstream into the tissue. The process of diapedesis involves the selective disruption of endothelial cell junctions, an event that could in theory compromise vascular integrity. It is therefore somewhat surprising that neutrophil transmigration does not significantly impair endothelial barrier function. We examined whether neutrophils might secrete factors that promote vascular integrity during the latter stages of neutrophil transmigration, and found that neutrophil proteinase 3 (PR3) – a serine protease harbored in azurophilic granules – markedly enhanced barrier function in endothelial cells. PR3 functioned in this capacity both in its soluble form and in a complex with cell-surface NB1. PR3-mediated enhancement of endothelial cell junctional integrity required its proteolytic activity, as well as endothelial cell expression of the protease-activated receptor, PAR-2. Importantly, PR3 suppressed the vascular permeability changes and disruption of junctional proteins induced by the action of PAR-1 agonists. These findings establish the potential for neutrophil-derived PR3 to play a role in reestablishing vascular integrity following leukocyte transmigration, and in protecting endothelial cells from PAR-1-induced permeability changes that occur during thrombotic and inflammatory events. PMID:23202369

Epithelial-specific A2B adenosine receptor signaling protects the colonic epithelial barrier during acute colitis

PubMed Central

Aherne, CM; Saeedi, B; Collins, CB; Masterson, JC; McNamee, EN; Perrenoud, L; Rapp, CR; Curtis, VF; Bayless, A; Fletcher, A; Glover, LE; Evans, CM; Jedlicka, P; Furuta, GT; de Zoeten, EF; Colgan, SP; Eltzschig, HK

2015-01-01

Central to inflammatory bowel disease (IBD) pathogenesis is loss of mucosal barrier function. Emerging evidence implicates extracellular adenosine signaling in attenuating mucosal inflammation. We hypothesized that adenosine-mediated protection from intestinal barrier dysfunction involves tissue-specific signaling through the A2B adenosine receptor (Adora2b) at the intestinal mucosal surface. To address this hypothesis, we combined pharmacologic studies and studies in mice with global or tissue-specific deletion of the Adora2b receptor. Adora2b−/− mice experienced a significantly heightened severity of colitis, associated with a more acute onset of disease and loss of intestinal epithelial barrier function. Comparison of mice with Adora2b deletion on vascular endothelial cells (Adora2bfl/flVeCadCre+) or intestinal epithelia (Adora2bfl/flVillinCre+) revealed a selective role for epithelial Adora2b signaling in attenuating colonic inflammation. In vitro studies with Adora2b knockdown in intestinal epithelial cultures or pharmacologic studies highlighted Adora2b-driven phosphorylation of vasodilator-stimulated phosphoprotein (VASP) as a specific barrier repair response. Similarly, in vivo studies in genetic mouse models or treatment studies with an Adora2b agonist (BAY 60-6583) recapitulate these findings. Taken together, our results suggest that intestinal epithelial Adora2b signaling provides protection during intestinal inflammation via enhancing mucosal barrier responses. PMID:25850656

Hydrogen sulfide replacement therapy protects the vascular endothelium in hyperglycemia by preserving mitochondrial function.

PubMed

Suzuki, Kunihiro; Olah, Gabor; Modis, Katalin; Coletta, Ciro; Kulp, Gabriella; Gerö, Domokos; Szoleczky, Petra; Chang, Tuanjie; Zhou, Zongmin; Wu, Lingyun; Wang, Rui; Papapetropoulos, Andreas; Szabo, Csaba

2011-08-16

The goal of the present studies was to investigate the role of changes in hydrogen sulfide (H(2)S) homeostasis in the pathogenesis of hyperglycemic endothelial dysfunction. Exposure of bEnd3 microvascular endothelial cells to elevated extracellular glucose (in vitro "hyperglycemia") induced the mitochondrial formation of reactive oxygen species (ROS), which resulted in an increased consumption of endogenous and exogenous H(2)S. Replacement of H(2)S or overexpression of the H(2)S-producing enzyme cystathionine-γ-lyase (CSE) attenuated the hyperglycemia-induced enhancement of ROS formation, attenuated nuclear DNA injury, reduced the activation of the nuclear enzyme poly(ADP-ribose) polymerase, and improved cellular viability. In vitro hyperglycemia resulted in a switch from oxidative phosphorylation to glycolysis, an effect that was partially corrected by H(2)S supplementation. Exposure of isolated vascular rings to high glucose in vitro induced an impairment of endothelium-dependent relaxations, which was prevented by CSE overexpression or H(2)S supplementation. siRNA silencing of CSE exacerbated ROS production in hyperglycemic endothelial cells. Vascular rings from CSE(-/-) mice exhibited an accelerated impairment of endothelium-dependent relaxations in response to in vitro hyperglycemia, compared with wild-type controls. Streptozotocin-induced diabetes in rats resulted in a decrease in the circulating level of H(2)S; replacement of H(2)S protected from the development of endothelial dysfunction ex vivo. In conclusion, endogenously produced H(2)S protects against the development of hyperglycemia-induced endothelial dysfunction. We hypothesize that, in hyperglycemic endothelial cells, mitochondrial ROS production and increased H(2)S catabolism form a positive feed-forward cycle. H(2)S replacement protects against these alterations, resulting in reduced ROS formation, improved endothelial metabolic state, and maintenance of normal endothelial function.

Circulating Endothelial Cells and Endothelial Function predict Major Adverse Cardiac Events and Early Adverse Left Ventricular Remodeling in Patients with ST-Segment Elevation Myocardial Infarction

PubMed Central

Magdy, Abdel Hamid; Bakhoum, Sameh; Sharaf, Yasser; Sabry, Dina; El-Gengehe, Ahmed T; Abdel-Latif, Ahmed

2016-01-01

Endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) are mobilized from the bone marrow and increase in the early phase after ST-elevation myocardial infarction (STEMI). The aim of this study was to assess the prognostic significance of CECs and indices of endothelial dysfunction in patients with STEMI. In 78 patients with acute STEMI, characterization of CD34+/VEGFR2+ CECs, and indices of endothelial damage/dysfunction such as brachial artery flow mediated dilatation (FMD) were determined. Blood samples for CECs assessment and quantification were obtained within 24 hours of admission and FMD was assessed during the index hospitalization. At 30 days follow up, the primary composite end point of major cardiac adverse events (MACE) consisting of all-cause mortality, recurrent non-fatal MI, or heart failure and the secondary endpoint of early adverse left ventricular (LV) remodeling were analyzed. The 17 patients (22%) who developed MACE had significantly higher CEC level (P = 0.004), vWF level (P =0.028), and significantly lower FMD (P = 0.006) compared to the remaining patients. Logistic regression analysis showed that CECs level and LV ejection fraction were independent predictors of MACE. The areas under the receiver operating characteristic curves (ROC) for CEC level, FMD, and the logistic model with both markers were 0.73, 0.75, and 0.82 respectively for prediction of the MACE. The 16 patients who developed the secondary endpoint had significantly higher CEC level compared to remaining patients (p =0.038). In conclusion, increased circulating endothelial cells and endothelial dysfunction predicted the occurrence of major adverse cardiac events and adverse cardiac remodeling in patients with STEMI. PMID:26864952

Nanoliposomes protect against AL amyloid light chain protein-induced endothelial injury.

PubMed

Truran, Seth; Weissig, Volkmar; Ramirez-Alvarado, Marina; Franco, Daniel A; Burciu, Camelia; Georges, Joseph; Murarka, Shishir; Okoth, Winter A; Schwab, Sara; Hari, Parameswaran; Migrino, Raymond Q

2014-03-01

A newly-recognized pathogenic mechanism underlying light chain amyloidosis (AL) involves endothelial dysfunction and cell injury caused by misfolded light chain proteins (LC). Nanoliposomes (NL) are artificial phospholipid vesicles that could attach to misfolded proteins and reduce tissue injury. To test whether co-treatment with NL reduces LC-induced endothelial dysfunction and cell death. Abdominal subcutaneous adipose arterioles from 14 non-AL subjects were cannulated; dilator response to acetylcholine and papaverine were measured at baseline and following 1-hour exposure to LC (20 µg/mL, 2 purified from AL subjects' urine, 1 from human recombinant LC [AL-09]) ± NL (phosphatidylcholine/cholesterol/phosphatidic acid 70/25/5 molar ratio) or NL alone. Human aortic artery endothelial cells (HAEC) were exposed to Oregon Green-labeled LC ± NL for 24 hours and intracellular LC and apoptosis (Hoechst stain) were measured. Circular dichroism spectroscopy was performed on AL-09 LC ± NL to follow changes in secondary structure and protein thermal stability. LC caused impaired dilation to acetylcholine that was restored by NL (control - 94.0 ± 1.8%, LC - 65.0 ± 7.1%, LC + NL - 95.3 ± 1.8%, p ≤ 0.001 LC versus control or LC + NL). NL protection was inhibited by L-NG-nitroarginine methyl ester. NL increased the beta sheet structure of LC, reduced endothelial cell internalization of LC and protected against LC-induced endothelial cell death. LC induced human adipose arteriole endothelial dysfunction and endothelial cell death, which were reversed by co-treatment with NL. This protection may partly be due to enhancing LC protein structure and reducing LC internalization. Nanoliposomes represent a promising new class of agents to ameliorate tissue injury from protein misfolding diseases such as AL.

O-GlcNAcase overexpression reverses coronary endothelial cell dysfunction in type 1 diabetic mice.

PubMed

Makino, Ayako; Dai, Anzhi; Han, Ying; Youssef, Katia D; Wang, Weihua; Donthamsetty, Reshma; Scott, Brian T; Wang, Hong; Dillmann, Wolfgang H

2015-11-01

Cardiovascular disease is the primary cause of morbidity and mortality in diabetes, and endothelial dysfunction is commonly seen in these patients. Increased O-linked N-acetylglucosamine (O-GlcNAc) protein modification is one of the central pathogenic features of diabetes. Modification of proteins by O-GlcNAc (O-GlcNAcylation) is regulated by two key enzymes: β-N-acetylglucosaminidase [O-GlcNAcase (OGA)], which catalyzes the reduction of protein O-GlcNAcylation, and O-GlcNAc transferase (OGT), which induces O-GlcNAcylation. However, it is not known whether reducing O-GlcNAcylation can improve endothelial dysfunction in diabetes. To examine the effect of endothelium-specific OGA overexpression on protein O-GlcNAcylation and coronary endothelial function in diabetic mice, we generated tetracycline-inducible, endothelium-specific OGA transgenic mice, and induced OGA by doxycycline administration in streptozotocin-induced type 1 diabetic mice. OGA protein expression was significantly decreased in mouse coronary endothelial cells (MCECs) isolated from diabetic mice compared with control MCECs, whereas OGT protein level was markedly increased. The level of protein O-GlcNAcylation was increased in diabetic compared with control mice, and OGA overexpression significantly decreased the level of protein O-GlcNAcylation in MCECs from diabetic mice. Capillary density in the left ventricle and endothelium-dependent relaxation in coronary arteries were significantly decreased in diabetes, while OGA overexpression increased capillary density to the control level and restored endothelium-dependent relaxation without changing endothelium-independent relaxation. We found that connexin 40 could be the potential target of O-GlcNAcylation that regulates the endothelial functions in diabetes. These data suggest that OGA overexpression in endothelial cells improves endothelial function and may have a beneficial effect on coronary vascular complications in diabetes. Copyright © 2015 the American Physiological Society.

Reversal of mitochondrial dysfunction by coenzyme Q10 supplement improves endothelial function in patients with ischaemic left ventricular systolic dysfunction: a randomized controlled trial.

PubMed

Dai, Yuk-Ling; Luk, Ting-Hin; Yiu, Kai-Hang; Wang, Mei; Yip, Pandora M C; Lee, Stephen W L; Li, Sheung-Wai; Tam, Sidney; Fong, Bonnie; Lau, Chu-Pak; Siu, Chung-Wah; Tse, Hung-Fat

2011-06-01

Coronary artery disease (CAD) is associated with endothelial dysfunction and mitochondrial dysfunction (MD). The aim of this study was to investigate whether co-enzyme Q10 (CoQ) supplementation, which is an obligatory coenzyme in the mitochondrial respiratory transport chain, can reverse MD and improve endothelial function in patients with ischaemic left ventricular systolic dysfunction (LVSD). We performed a randomized, double-blind, placebo-controlled trial to determine the effects of CoQ supplement (300 mg/day, n=28) vs. placebo (controls, n=28) for 8 weeks on brachial flow-mediated dilation (FMD) in patients with ischaemic LVSD(left ventricular ejection fraction <45%). Mitochondrial function was determined by plasma lactate/pyruvate ratio (LP ratio). After 8 weeks, CoQ-treated patients had significant increases in plasma CoQ concentration (treatment effect 2.20 μg/mL, P<0.001) and FMD (treatment effect 1.51%, P=0.03); and decrease in LP ratio (treatment effect -2.46, P=0.03) compared with controls. However, CoQ treatment did not alter nitroglycerin-mediated dilation, blood pressure, blood levels of fasting glucose, haemoglobin A1c, lipid profile, high-sensitivity C-reactive protein and oxidative stress as determined by serum superoxide dismutase and 8-isoprostane (all P>0.05). Furthermore, the reduction in LP ratio significantly correlated with improvement in FMD (r=-0.29, P=0.047). In patients with ischaemic LVSD, 8 weeks supplement of CoQ improved mitochondrial function and FMD; and the improvement of FMD correlated with the change in mitochondrial function, suggesting that CoQ improved endothelial function via reversal of mitochondrial dysfunction in patients with ischaemic LVSD. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Endothelial Dysfunction and Diabetes: Effects on Angiogenesis, Vascular Remodeling, and Wound Healing

PubMed Central

Kolluru, Gopi Krishna; Bir, Shyamal C.; Kevil, Christopher G.

2012-01-01

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by inappropriate hyperglycemia due to lack of or resistance to insulin. Patients with DM are frequently afflicted with ischemic vascular disease or wound healing defect. It is well known that type 2 DM causes amplification of the atherosclerotic process, endothelial cell dysfunction, glycosylation of extracellular matrix proteins, and vascular denervation. These complications ultimately lead to impairment of neovascularization and diabetic wound healing. Therapeutic angiogenesis remains an attractive treatment modality for chronic ischemic disorders including PAD and/or diabetic wound healing. Many experimental studies have identified better approaches for diabetic cardiovascular complications, however, successful clinical translation has been limited possibly due to the narrow therapeutic targets of these agents or the lack of rigorous evaluation of pathology and therapeutic mechanisms in experimental models of disease. This paper discusses the current body of evidence identifying endothelial dysfunction and impaired angiogenesis during diabetes. PMID:22611498

Pyridostigmine prevents peripheral vascular endothelial dysfunction in rats with myocardial infarction.

PubMed

Qin, Fangfang; Lu, Yi; He, Xi; Zhao, Ming; Bi, Xueyuan; Yu, Xiaojiang; Liu, Jinjun; Zang, Weijin

2014-03-01

1. Myocardial infarction (MI) is characterized by the withdrawal of vagal activity and increased sympathetic activity. We have shown previously that pyridostigmine (PYR), an acetylcholinesterase inhibitor, was able to improve vagal activity and ameliorate cardiac dysfunction following MI. However, the effect of PYR on endothelial dysfunction in peripheral arteries after MI remains unclear. 2. In the present study, MI was induced by coronary artery ligation in adult Sprague-Dawley rats. Rats were treated intragastrically with saline or PYR (approximately 31 mg/kg per day) for 2 weeks, at which time haemodynamic and parasympathetic parameters and the vascular reactivity of isolated mesenteric arteries were measured and the ultrastructure of the endothelium evaluated. 3. Compared with the MI group, PYR not only improved cardiac function, vagal nerve activity and endothelial impairment, but also reduced intravascular superoxide anion and malondialdehyde. In addition, in the PYR-treated MI group, nitric oxide (NO) bioavailability was increased and attenuated endothelium-dependent relaxations were improved, whereas restored vasodilator responses were inhibited by N(G)-nitro-L-arginine methyl ester. 4. Based on our results, PYR is able to attenuate the impairment of peripheral endothelial function and maintain endothelial ultrastructural integrity in MI rats by inhibiting reactive oxygen species production, enhancing NO bioavailability and improving vagal activity. © 2014 Wiley Publishing Asia Pty Ltd.

Covalent adduct formation between the plasmalogen-derived modification product 2-chlorohexadecanal and phloretin.

PubMed

Üllen, Andreas; Nusshold, Christoph; Glasnov, Toma; Saf, Robert; Cantillo, David; Eibinger, Gerald; Reicher, Helga; Fauler, Günter; Bernhart, Eva; Hallstrom, Seth; Kogelnik, Nora; Zangger, Klaus; Oliver Kappe, C; Malle, Ernst; Sattler, Wolfgang

2015-02-15

Hypochlorous acid added as reagent or generated by the myeloperoxidase (MPO)-H2O2-Cl(-) system oxidatively modifies brain ether-phospholipids (plasmalogens). This reaction generates a sn2-acyl-lysophospholipid and chlorinated fatty aldehydes. 2-Chlorohexadecanal (2-ClHDA), a prototypic member of chlorinated long-chain fatty aldehydes, has potent neurotoxic potential by inflicting blood-brain barrier (BBB) damage. During earlier studies we could show that the dihydrochalcone-type polyphenol phloretin attenuated 2-ClHDA-induced BBB dysfunction. To clarify the underlying mechanism(s) we now investigated the possibility of covalent adduct formation between 2-ClHDA and phloretin. Coincubation of 2-ClHDA and phloretin in phosphatidylcholine liposomes revealed a half-life of 2-ClHDA of approx. 120min, decaying at a rate of 5.9×10(-3)min(-1). NMR studies and enthalpy calculations suggested that 2-ClHDA-phloretin adduct formation occurs via electrophilic aromatic substitution followed by hemiacetal formation on the A-ring of phloretin. Adduct characterization by high-resolution mass spectroscopy confirmed these results. In contrast to 2-ClHDA, the covalent 2-ClHDA-phloretin adduct was without adverse effects on MTT reduction (an indicator for metabolic activity), cellular adenine nucleotide content, and barrier function of brain microvascular endothelial cells (BMVEC). Of note, 2-ClHDA-phloretin adduct formation was also observed in BMVEC cultures. Intraperitoneal application and subsequent GC-MS analysis of brain lipid extracts revealed that phloretin is able to penetrate the BBB of C57BL/6J mice. Data of the present study indicate that phloretin scavenges 2-ClHDA, thereby attenuating 2-ClHDA-mediated brain endothelial cell dysfunction. We here identify a detoxification pathway for a prototypic chlorinated fatty aldehyde (generated via the MPO axis) that compromises BBB function in vitro and in vivo. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Covalent adduct formation between the plasmalogen-derived modification product 2-chlorohexadecanal and phloretin

PubMed Central

Üllen, Andreas; Nusshold, Christoph; Glasnov, Toma; Saf, Robert; Cantillo, David; Eibinger, Gerald; Reicher, Helga; Fauler, Günter; Bernhart, Eva; Hallstrom, Seth; Kogelnik, Nora; Zangger, Klaus; Oliver Kappe, C.; Malle, Ernst; Sattler, Wolfgang

2015-01-01

Hypochlorous acid added as reagent or generated by the myeloperoxidase (MPO)-H2O2-Cl− system oxidatively modifies brain ether-phospholipids (plasmalogens). This reaction generates a sn2-acyl-lysophospholipid and chlorinated fatty aldehydes. 2-Chlorohexadecanal (2-ClHDA), a prototypic member of chlorinated long-chain fatty aldehydes, has potent neurotoxic potential by inflicting blood–brain barrier (BBB) damage. During earlier studies we could show that the dihydrochalcone-type polyphenol phloretin attenuated 2-ClHDA-induced BBB dysfunction. To clarify the underlying mechanism(s) we now investigated the possibility of covalent adduct formation between 2-ClHDA and phloretin. Coincubation of 2-ClHDA and phloretin in phosphatidylcholine liposomes revealed a half-life of 2-ClHDA of approx. 120 min, decaying at a rate of 5.9 × 10−3 min−1. NMR studies and enthalpy calculations suggested that 2-ClHDA-phloretin adduct formation occurs via electrophilic aromatic substitution followed by hemiacetal formation on the A-ring of phloretin. Adduct characterization by high-resolution mass spectroscopy confirmed these results. In contrast to 2-ClHDA, the covalent 2-ClHDA-phloretin adduct was without adverse effects on MTT reduction (an indicator for metabolic activity), cellular adenine nucleotide content, and barrier function of brain microvascular endothelial cells (BMVEC). Of note, 2-ClHDA-phloretin adduct formation was also observed in BMVEC cultures. Intraperitoneal application and subsequent GC–MS analysis of brain lipid extracts revealed that phloretin is able to penetrate the BBB of C57BL/6J mice. Data of the present study indicate that phloretin scavenges 2-ClHDA, thereby attenuating 2-ClHDA-mediated brain endothelial cell dysfunction. We here identify a detoxification pathway for a prototypic chlorinated fatty aldehyde (generated via the MPO axis) that compromises BBB function in vitro and in vivo. PMID:25576489

Reactive oxygen species' role in endothelial dysfunction by electron paramagnetic resonance

NASA Astrophysics Data System (ADS)

Wassall, Cynthia D.

The endothelium is a single layer of cells lining the arteries and is involved in many physiological reactions which are responsible for vascular tone. Free radicals are important participants in these chemical reactions in the endothelium. Here we quantify free radicals, ex vivo, in biological tissue with continuous wave electron paramagnetic resonance (EPR). In all of the experiments in this thesis, we use a novel EPR spin trapping technique that has been developed for tissue segments. EPR spin trapping is often considered the 'gold standard' in reactive oxygen species (ROS) detection because of its sensitivity and non-invasive nature. In all experiments, tissue was placed in physiological saline solution with 190-mM PBN (N-tert -butyl-α-phenylnitrone), 10% by volume dimethyl-sulphoxide (DMSO) for cryopreservation, and incubated in the dark for between 30 minutes up to 2 hours at 37°C while gently being stirred. Tissue and supernatant were then loaded into a syringe and frozen at -80°C until EPR analysis. In our experiments, the EPR spectra were normalized with respect to tissue volume. Conducting experiments at liquid nitrogen temperature leads to some experimental advantages. The freezing of the spin adducts renders them stable over a longer period, which allows ample time to analyze tissue samples for ROS. The dielectric constant of ice is greatly reduced over its liquid counterpart; this property of water enables larger sample volumes to be inserted into the EPR cavity without overloading it and leads to enhanced signal detection. Due to Maxwell-Boltzmann statistics, the population difference goes up as the temperature goes down, so this phenomenon enhances the signal intensity as well. With the 'gold standard' assertion in mind, we investigated whether slicing tissue to assay ROS that is commonly used in fluorescence experiments will show more free radical generation than tissue of a similar volume that remains unsliced. Sliced tissue exhibited a 76% increase in ROS generation; this implies that higher ROS concentrations in sliced tissue indicate extraneous ROS generation not associated with the ROS stimulus of interest. We also investigated the role of ROS in chronic flow overload (CFO). Elevation of shear stress that increases production of vascular ROS has not been well investigated. We hypothesize that CFO increases ROS production mediated in part by NADPH oxidase, which leads to endothelial dysfunction. ROS production increased threefold in response to CFO. The endothelium dependent vasorelaxation was compromised in the CFO group. Treatment with apocynin significantly reduced ROS production in the vessel wall, preserved endothelial function, and inhibited expressions of p22/p47phox and NOX2/NOX4. The present data implicate NADPH oxidase produced ROS and eNOS uncoupling in endothelial dysfunction at 1 wk of CFO. In further work, a swine right ventricular hypertrophy (RVH) model induced by pulmonary artery (PA) banding was used to study right coronary artery (RCA) endothelial function and ROS level. Endothelial function was compromised in RCA of RVH as attributed to insufficient endothelial nitric oxide synthase cofactor tetrahydrobiopterin. In conclusion, stretch due to outward remodeling of RCA during RVH (at constant wall shear stress), similar to vessel stretch in hypertension, appears to induce ROS elevation, endothelial dysfunction, and an increase in basal tone. Finally, although hypertension-induced vascular stiffness and dysfunction are well established in patients and animal models, we hypothesize that stretch or distension due to hypertension and outward expansion is the cause of endothelial dysfunction mediated by angiotensin II type 1 (AT1) receptor in coronary arteries. The expression and activation of AT1 receptor and the production of ROS were up regulated and endothelial function deteriorated in the RCA. The acute inhibition of AT1 receptor and NADPH oxidase partially restored the endothelial function. Stretch or distension activates the AT1 receptor which mediates ROS production; this collectively leads to endothelial dysfunction in coronary arteries.

Platelet Activating Factor-Induced Ceramide Micro-Domains Drive Endothelial NOS Activation and Contribute to Barrier Dysfunction

PubMed Central

Predescu, Sanda; Knezevic, Ivana; Bardita, Cristina; Neamu, Radu Florin; Brovcovych, Viktor; Predescu, Dan

2013-01-01

The spatial and functional relationship between platelet activating factor-receptor (PAF-R) and nitric oxide synthase (eNOS) in the lateral plane of the endothelial plasma membrane is poorly characterized. In this study, we used intact mouse pulmonary endothelial cells (ECs) as well as endothelial plasma membrane patches and subcellular fractions to define a new microdomain of plasmalemma proper where the two proteins colocalize and to demonstrate how PAF-mediated nitric oxide (NO) production fine-tunes ECs function as gatekeepers of vascular permeability. Using fluorescence microscopy and immunogold labeling electron microscopy (EM) on membrane patches we demonstrate that PAF-R is organized as clusters and colocalizes with a subcellular pool of eNOS, outside recognizable vesicular profiles. Moreover, PAF-induced acid sphingomyelinase activation generates a ceramide-based microdomain on the external leaflet of plasma membrane, inside of which a signalosome containing eNOS shapes PAF-stimulated NO production. Real-time measurements of NO after PAF-R ligation indicated a rapid (5 to 15 min) increase in NO production followed by a > 45 min period of reduction to basal levels. Moreover, at the level of this new microdomain, PAF induces a dynamic phosphorylation/dephosphorylation of Ser, Thr and Tyr residues of eNOS that correlates with NO production. Altogether, our findings establish the existence of a functional partnership PAF-R/eNOS on EC plasma membrane, at the level of PAF-induced ceramide plasma membrane microdomains, outside recognized vesicular profiles. PMID:24086643

Endothelial Dysfunction in Children With Obstructive Sleep Apnea Is Associated With Elevated Lipoprotein-Associated Phospholipase A2 Plasma Activity Levels.

PubMed

Kheirandish-Gozal, Leila; Philby, Mona F; Qiao, Zhuanghong; Khalyfa, Abdelnaby; Gozal, David

2017-02-09

Obstructive sleep apnea (OSA) is a highly prevalent condition, especially in obese children, and has been associated with increased risk for endothelial dysfunction and dislipidemia, which are precursors of atherosclerosis. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is recognized as an independent risk factor for cardiovascular risk and atheromatous plaque activity. We hypothesized that Lp-PLA2 levels would be elevated in children with OSA, particularly among obese children who also manifest evidence of endothelial dysfunction. One hundred sixty children (mean age 7.1±2.3 years), either nonobese with (n=40) and without OSA (n=40) or obese with (n=40) and without OSA (n=40) underwent overnight polysomnographic and postocclusive reperfusion evaluation and a fasting blood draw the morning after the sleep study. In addition to lipid profile, Lp-PLA2 plasma activity was assessed using a commercial kit. Obese children and OSA children had significantly elevated plasma Lp-PLA2 activity levels compared to controls. Furthermore, when both obesity and OSA were concurrently present or when endothelial function was present, Lp-PLA2 activity was higher. Treatment of OSA by adenotonsillectomy resulted in reductions of Lp-PLA2 activity (n=37; P <0.001). Lp-PLA2 plasma activity is increased in pediatric OSA and obesity, particularly when endothelial dysfunction is present, and exhibits decreases on OSA treatment. The short-term and long-term significance of these findings in relation to cardiovascular risk remain undefined. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Serum Markers of Endothelial Dysfunction and Inflammation Increase in Hypertension with Prediabetes Mellitus.

PubMed

Huang, Zhouqing; Chen, Chen; Li, Sheng; Kong, Fanqi; Shan, Peiren; Huang, Weijian

2016-06-01

The aim of this study was to examine endothelial dysfunction and inflammation in hypertension and prediabetes by studying adhesion molecules and inflammatory factors. This study included 133 outpatients. Participants were categorized into three groups based on the presence or absence of hypertension and prediabetes: control subjects without prediabetes and hypertension (N group, n = 39); patients with hypertension only (H group, n = 34); and patients with hypertension and prediabetes (HD group, n = 60). Hypertension was diagnosed according to JNC7 criteria. Prediabetes was defined according to 2010 American Diabetes Association criteria. Plasma was isolated from overnight fasting blood samples for enzyme-linked immunosorbent assay (ELISA) analysis of concentrations of intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α), P-selectin, and interleukin-6 (IL-6) as indicators of endothelial function and inflammation. We found that the H and HD groups showed significantly higher levels of all four biomarkers compared with the N group (all p < 0.01). The HD group also showed significantly higher levels of ICAM-1 (p = 0.042) and TNF-α (p < 0.01) compared with the H group; no significant differences in P-selectin (p = 0.59) and IL-6 (p = 0.70) levels were observed among these groups. Prediabetes and hypertension induce endothelial dysfunction and inflammation by elevating levels of soluble adhesion molecules and inflammatory cytokines. The comorbidity of these diseases may exacerbate inflammation and endothelial dysfunction by enhancing the expression of ICAM-1 and TNF-α.

Treatment of spontaneously hypertensive rats with rosiglitazone and/or enalapril restores balance between vasodilator and vasoconstrictor actions of insulin with simultaneous improvement in hypertension and insulin resistance.

PubMed

Potenza, Maria A; Marasciulo, Flora L; Tarquinio, Mariela; Quon, Michael J; Montagnani, Monica

2006-12-01

Spontaneously hypertensive rats (SHRs) exhibit endothelial dysfunction and insulin resistance. Reciprocal relationships between endothelial dysfunction and insulin resistance may contribute to hypertension by causing imbalanced regulation of endothelial-derived vasodilators (e.g., nitric oxide) and vasoconstrictors (e.g., endothelin-1 [ET-1]). Treatment of SHRs with rosiglitazone (insulin sensitizer) and/or enalapril (ACE inhibitor) may simultaneously improve hypertension, insulin resistance, and endothelial dysfunction by rebalancing insulin-stimulated production of vasoactive mediators. When compared with WKY control rats, 12-week-old vehicle-treated SHRs were hypertensive, overweight, and insulin resistant, with elevated fasting levels of insulin and ET-1 and reduced serum adiponectin levels. In mesenteric vascular beds (MVBs) isolated from vehicle-treated SHRs and preconstricted with norepinephrine (NE) ex vivo, vasodilator responses to insulin were significantly impaired, whereas the ability of insulin to oppose vasoconstrictor actions of NE was absent (versus WKY controls). Three-week treatment of SHRs with rosiglitazone and/or enalapril significantly reduced blood pressure, insulin resistance, fasting insulin, and ET-1 levels and increased adiponectin levels to values comparable with those observed in vehicle-treated WKY controls. By restoring phosphatidylinositol 3-kinase-dependent effects, rosiglitazone and/or enalapril therapy of SHRs also significantly improved vasodilator responses to insulin in MVB preconstricted with NE ex vivo. Taken together, our data provide strong support for the existence of reciprocal relationships between endothelial dysfunction and insulin resistance that may be relevant for developing novel therapeutic strategies for the metabolic syndrome.

Lipid Emulsions Containing Medium Chain Triacylglycerols Blunt Bradykinin-Induced Endothelium-Dependent Relaxation in Porcine Coronary Artery Rings.

PubMed

Amissi, Said; Boisramé-Helms, Julie; Burban, Mélanie; Rashid, Sherzad K; León-González, Antonio J; Auger, Cyril; Toti, Florence; Meziani, Ferhat; Schini-Kerth, Valérie B

2017-03-01

Lipid emulsions for parenteral nutrition are used to provide calories and essential fatty acids for patients. They have been associated with hypertriglyceridemia, hypercholesterolemia, and metabolic stress, which may promote the development of endothelial dysfunction in patients. The aim of the present study was to determine whether five different industrial lipid emulsions may affect the endothelial function of coronary arteries. Porcine coronary artery rings were incubated with lipid emulsions 0.5, 1, or 2% (v/v) for 30 min before the determination of vascular reactivity in organ chambers and the level of oxidative stress using electron paramagnetic resonance. Incubation of coronary artery rings with either Lipidem ® , Medialipid ® containing long- and medium-chain triacylglycerols (LCT/MCT), or SMOFlipid ® containing LCT, MCT, omega-9, and -3, significantly reduced the bradykinin-induced endothelium-dependent relaxation, affecting both the nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH) components, whereas, Intralipid ® containing LCT (soybean oil) and ClinOleic ® containing LCT (soybean and olive oil) did not have such an effect. The endothelial dysfunction induced by Lipidem ® was significantly improved by indomethacin, a cyclooxygenase (COX) inhibitor, inhibitors of oxidative stress (N-acetylcysteine, superoxide dismutase, catalase) and transition metal chelating agents (neocuproine, tetrathiomolybdate, deferoxamine and L-histidine). Lipidem ® significantly increased the arterial level of oxidative stress. The present findings indicate that lipid emulsions containing LCT/MCT induce endothelial dysfunction in coronary artery rings by blunting both NO- and EDH-mediated relaxations. The Lipidem ® -induced endothelial dysfunction is associated with increased vascular oxidative stress and the formation of COX-derived vasoconstrictor prostanoids.

Naringin ameliorates endothelial dysfunction in fructose-fed rats.

PubMed

Malakul, Wachirawadee; Pengnet, Sirinat; Kumchoom, Chanon; Tunsophon, Sakara

2018-03-01

High fructose consumption is associated with metabolic disorders including hyperglycemia and dyslipidemia, in addition to endothelial dysfunction. Naringin, a flavonoid present in citrus fruit, has been reported to exhibit lipid lowering, antioxidant, and cardiovascular protective properties. Therefore, the present study investigated the effect of naringin on fructose-induced endothelial dysfunction in rats and its underlying mechanisms. Male Sprague-Dawley rats were given 10% fructose in drinking water for 12 weeks, whereas control rats were fed drinking water alone. Naringin (100 mg/kg) was orally administered to fructose fed rats during the last 4 weeks of the study. Following 12 weeks, blood samples were collected for measurement of blood glucose, serum lipid profile and total nitrate/nitrite (NOx). Vascular function was assessed by isometric tension recording. Aortic expression of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS), and nitrotyrosine were evaluated by western blot analysis. Fructose feeding induced increased levels of blood glucose, total cholesterol, triglyceride, and low density lipoprotein. In rat aortae, fructose reduced acethycholine-induced vasorelaxation, without affecting sodium nitroprusside-induced vasorelaxation. Treatment of fructose-fed rats with naringin restored fructose-induced metabolic alterations and endothelial dysfunction. Fructose-fed rats also exhibited decreased serum NOx level, reduced eNOS and p-eNOS protein expression, and enhanced nitrotyrosine expression in aortae. These alterations were improved by naringin treatment. The results of the present study suggested that naringin treatment preserves endothelium-dependent relaxation in aortae from fructose fed rats. This effect is primarily mediated through an enhanced NO bioavailability via increased eNOS activity and decreased NO inactivated to peroxynitrite in aortae.

The FXR agonist PX20606 ameliorates portal hypertension by targeting vascular remodelling and sinusoidal dysfunction.

PubMed

Schwabl, Philipp; Hambruch, Eva; Seeland, Berit A; Hayden, Hubert; Wagner, Michael; Garnys, Lukas; Strobel, Bastian; Schubert, Tim-Lukas; Riedl, Florian; Mitteregger, Dieter; Burnet, Michael; Starlinger, Patrick; Oberhuber, Georg; Deuschle, Ulrich; Rohr-Udilova, Nataliya; Podesser, Bruno K; Peck-Radosavljevic, Markus; Reiberger, Thomas; Kremoser, Claus; Trauner, Michael

2017-04-01

Steroidal farnesoid X receptor (FXR) agonists demonstrated potent anti-fibrotic activities and lowered portal hypertension in experimental models. The impact of the novel non-steroidal and selective FXR agonist PX20606 on portal hypertension and fibrosis was explored in this study. In experimental models of non-cirrhotic (partial portal vein ligation, PPVL, 7days) and cirrhotic (carbon tetrachloride, CCl 4 , 14weeks) portal hypertension, PX20606 (PX,10mg/kg) or the steroidal FXR agonist obeticholic acid (OCA,10mg/kg) were gavaged. We then measured portal pressure, intrahepatic vascular resistance, liver fibrosis and bacterial translocation. PX decreased portal pressure in non-cirrhotic PPVL (12.6±1.7 vs. 10.4±1.1mmHg; p=0.020) and cirrhotic CCl 4 (15.2±0.5 vs. 11.8±0.4mmHg; p=0.001) rats. In PPVL animals, we observed less bacterial translocation (-36%; p=0.041), a decrease in lipopolysaccharide binding protein (-30%; p=0.024) and splanchnic tumour necrosis factor α levels (-39%; p=0.044) after PX treatment. In CCl 4 rats, PX decreased fibrotic Sirius Red area (-43%; p=0.005), hepatic hydroxyproline (-66%; p<0.001), and expression of profibrogenic proteins (Col1a1, α smooth muscle actin, transforming growth factor β). CCl 4 -PX rats had significantly lower transaminase levels and reduced hepatic macrophage infiltration. Moreover, PX induced sinusoidal vasodilation (upregulation of cystathionase, dimethylaminohydrolase (DDAH)1, endothelial nitric oxide synthase (eNOS), GTP-cyclohydrolase1) and reduced intrahepatic vasoconstriction (downregulation of endothelin-1, p-Moesin). In cirrhosis, PX improved endothelial dysfunction (decreased von-Willebrand factor) and normalized overexpression of vascular endothelial growth factor, platelet-derived growth factor and angiopoietins. While short-term 3-day PX treatment reduced portal pressure (-14%; p=0.041) by restoring endothelial function, 14week PX therapy additionally inhibited sinusoidal remodelling and decreased portal pressure to a greater extent (-22%; p=0.001). In human liver sinusoidal endothelial cells, PX increased eNOS and DDAH expression. The non-steroidal FXR agonist PX20606 ameliorates portal hypertension by reducing liver fibrosis, vascular remodelling and sinusoidal dysfunction. The novel drug PX20606 activates the bile acid receptor FXR and shows beneficial effects in experimental liver cirrhosis: In the liver, it reduces scarring and inflammation, and also widens blood vessels. Thus, PX20606 leads to an improved blood flow through the liver and decreases hypertension of the portal vein. Additionally, PX20606 improves the altered intestinal barrier and decreases bacterial migration from the gut. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Soluble receptor for advanced glycation end products mitigates vascular dysfunction in spontaneously hypertensive rats.

PubMed

Liu, Yu; Yu, Manli; Zhang, Le; Cao, Qingxin; Song, Ying; Liu, Yuxiu; Gong, Jianbin

2016-08-01

Vascular dysfunction including vascular remodeling and endothelial dysfunction in hypertension often results in poor clinical outcomes and increased risk of vascular accidents. We investigate the effect of treatment with soluble receptor for advanced glycation end products (sRAGE) on vascular dysfunction in spontaneously hypertensive rats (SHR). Firstly, the aortic AGE/RAGE pathway was investigated in SHR. Secondly, SHR received intraperitoneal injections of sRAGE daily for 4 weeks. Effect of sRAGE against vascular dysfunction in SHR and underlying mechanism was investigated. SHR aortas exhibited enhanced activity of aldose reductase, reduced activity of glyoxalase 1, accumulation of methylglyoxal and AGE, and upregulated expression of RAGE. Treatment of SHR with sRAGE had no significant effect on blood pressure, but alleviated aortic hypertrophy and endothelial dysfunction. In vitro, treatment with sRAGE reversed the effect of incubation with AGE on proliferation of smooth muscle cells and endothelial function. Treatment of SHR with sRAGE abated oxidative stress, suppressed inflammation and NF-κB activation, improved the balance between Ang II and Ang-(1-7) through reducing angiotensin-converting enzyme (ACE) activity and enhancing ACE2 expression, and upregulated peroxisome proliferator-activated receptor gamma (PPAR-γ) expression in aortas. In conclusion, treatment with sRAGE alleviated vascular adverse remodeling in SHR, possibly via suppression of oxidative stress and inflammation, improvement in RAS balance, and activation of PPAR-γ pathway.

Endothelial function is associated with myocardial diastolic function in women with systemic lupus erythematosus.

PubMed

Chin, Calvin W L; Chin, Chee-Yang; Ng, Marie X R; Le, Thu-Thao; Huang, Fei-Qiong; Fong, Kok-Yong; Thumboo, Julian; Tan, Ru-San

2014-09-01

Endothelial dysfunction is associated with traditional and systemic lupus erythematosus (SLE)-specific risk factors, and early data suggest reversibility of endothelial dysfunction with therapy. The clinical relevance of endothelial function assessment has been limited by the lack of studies, demonstrating its prognostic significance and impact on early myocardial function. Therefore, we aimed to determine the association between endothelial and myocardial diastolic function in SLE women. Women with SLE and no coronary artery disease were prospectively recruited and underwent radionuclide myocardial perfusion imaging (MPI) (Jetstream, Philips, the Netherlands) to exclude subclinical myocardial ischemia. Cardiac and vascular functions were assessed in all patients (Alpha 10, Aloka, Tokyo). Diastolic function was assessed using pulse wave early (E) and late mitral blood inflow and myocardial tissue Doppler (mean of medial and lateral annulus e') velocities. Endothelial function was measured using brachial artery flow-mediated vasodilatation (FMD%). Univariate and multivariate linear regressions were used to assess the association between FMD% and myocardial diastolic function, adjusting for potential confounders. Thirty-eight patients without detectable myocardial ischemia on MPI were studied (mean age 44 ± 10 years; mean disease duration 14 ± 6 years). About 61 % of patients had normal diastolic function (E/e' ≤ 8), and 5 % of patients had definite diastolic dysfunction with E/e' > 13 (mean 7.1 ± 2.9). FMD% was associated with E/e' (regression coefficient β = -0.35; 95 % CI -0.62 to -0.08; p = 0.01) independent of systolic blood pressure, age, and SLICC/ACR Damage Index.

Inhibitory effect of melatonin on necroptosis via repressing the Ripk3-PGAM5-CypD-mPTP pathway attenuates cardiac microvascular ischemia reperfusion injury.

PubMed

Zhou, Hao; Li, Dandan; Zhu, Pingjun; Ma, Qiang; Sam, Toan; Wang, Jin; Hu, Shunying; Chen, Yundai; Zhang, Yingmei

2018-05-16

The molecular features of necroptosis in cardiac ischemia reperfusion (IR) injury have been extensively explored. However, there have been no studies investigating the physiological regulatory mechanisms of melatonin acting on necroptosis in cardiac IR injury. This study was designed to determine the role of necroptosis in microvascular IR injury, and investigate the contribution of melatonin in repressing necroptosis and preventing IR-mediated endothelial system collapse. Our results demonstrated that Ripk3 was primarily activated by IR injury and consequently aggravated endothelial necroptosis, microvessel barrier dysfunction, capillary hyperpermeability, the inflammation response, microcirculatory vasospasms and microvascular perfusion defects. However, administration of melatonin prevented Ripk3 activation and provided a pro-survival advantage for the endothelial system in the context of cardiac IR injury, similar to the results obtained via genetic ablation of Ripk3. Functional investigations clearly illustrated that activated Ripk3 upregulated PGAM5 expression, and the latter repressed CypD phosphorylation, which obligated endothelial cells to undergo necroptosis via augmenting mPTP (mitochondrial permeability transition pore) opening. Interestingly, melatonin supplementation suppressed mPTP opening and interrupted endothelial necroptosis via blocking the Ripk3-PGAM5-CypD signal pathways. Taken together, our studies identified the Ripk3-PGAM5-CypD-mPTP axis as a new pathway responsible for reperfusion-mediated microvascular damage via initiating endothelial necroptosis. In contrast, melatonin treatment inhibited the Ripk3-PGAM5-CypD-mPTP cascade and thus reduced cellular necroptosis, conferring a protective advantage to the endothelial system in IR stress. These findings establish a new paradigm in microvascular IR injury and update the concept for cell death management handled by melatonin under the burden of reperfusion attack. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Endothelial-regenerating cells: an expanding universe.

PubMed

Steinmetz, Martin; Nickenig, Georg; Werner, Nikos

2010-03-01

Atherosclerosis is the most common cause for cardiovascular diseases and is based on endothelial dysfunction. A growing body of evidence suggests the contribution of bone marrow-derived endothelial progenitor cells, monocytic cells, and mature endothelial cells to vessel formation and endothelial rejuvenation. To this day, various subsets of these endothelial-regenerating cells have been identified according to cellular origin, phenotype, and properties in vivo and in vitro. However, the definition and biology, especially of endothelial progenitor cells, is complex and under heavy debate. In this review, we focus on current definitions of endothelial progenitor cells, highlight the clinical relevance of endothelial-regenerating cells, and provide new insights into cell-cell interactions involved in endothelial cell rejuvenation.

The impact of decreases in air temperature and increases in ozone on markers of endothelial function in individuals having type-2 diabetes

EPA Science Inventory

Several studies have reported an association between air pollution and endothelial dysfunction, especially in individuals having diabetes. However, very few studies have examined the impact of air temperature on endothelial function. The objective of this analysis was to investig...

Hypercholesterolemia-induced erectile dysfunction: endothelial nitric oxide synthase (eNOS) uncoupling in the mouse penis by NAD(P)H oxidase

PubMed Central

Musicki, Biljana; Liu, Tongyun; Lagoda, Gwen A.; Strong, Travis D.; Sezen, Sena F.; Johnson, Justin M.; Burnett, Arthur L.

2010-01-01

INTRODUCTION Hypercholesterolemia induces erectile dysfunction (ED) mostly by increasing oxidative stress and impairing endothelial function in the penis, but the mechanisms regulating reactive oxygen species (ROS) production in the penis are not understood. AIMS We evaluated whether hypercholesterolemia activates nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase in the penis, providing an initial source of ROS to induce endothelial nitric oxide synthase (eNOS) uncoupling and endothelial dysfunction resulting in ED. METHODS Low-density-lipoprotein receptor (LDLR)–null mice were fed Western diet for 4 weeks to induce early-stage hyperlipidemia. Wild type (WT) mice fed regular chow served as controls. Mice received NAD(P)H oxidase inhibitor apocynin (10 mM in drinking water) or vehicle. Erectile function was assessed in response to cavernous nerve electrical stimulation. Markers of endothelial function (phospho [P]-vasodilator-stimulated-protein [VASP]-Ser-239), oxidative stress (4-hydroxy-2-nonenal [HNE]), sources of ROS (eNOS uncoupling and NAD[P]H oxidase subunits p67phox, p47phox, and gp91phox), P-eNOS-Ser-1177, and eNOS were measured by Western blot in penes. MAIN OUTCOME MEASURES Molecular mechanisms of ROS generation and endothelial dysfunction in hypercholesterolemia-induced ED. RESULTS Erectile response was significantly (P<0.05) reduced in hypercholesterolemic LDLR-null mice compared to WT mice. Relative to WT mice, hypercholesterolemia increased (P<0.05) protein expressions of NAD(P)H oxidase subunits p67phox, p47phox and gp91phox, eNOS uncoupling, and 4-HNE-modified proteins, and reduced (P<0.05) P-VASP-Ser-239 expression in the penis. Apocynin treatment of LDLR-null mice preserved (P<0.05) maximal intracavernosal pressure, and reversed (P < 0.05) the abnormalities in protein expressions of gp67phox and gp47phox, 4-HNE, P-VASP-Ser-239, and eNOS uncoupling in the penis. Apocynin treatment of WT mice did not affect any of these parameters. Protein expressions of P-eNOS-Ser-1177 and total eNOS were unaffected by hypercholesterolemia. CONCLUSION Activated NAD(P)H oxidase in the penis is an initial source of oxidative stress resulting in eNOS uncoupling, thus providing a mechanism of eNOS uncoupling and endothelial dysfunction in hypercholesterolemia-induced ED. PMID:20626609

Curcumin and folic acid abrogated methotrexate induced vascular endothelial dysfunction.

PubMed

Sankrityayan, Himanshu; Majumdar, Anuradha S

2016-01-01

Methotrexate, an antifolate drug widely used in rheumatoid arthritis, psoriasis, and cancer, is known to cause vascular endothelial dysfunction by causing hyperhomocysteinemia, direct injury to endothelium or by increasing the oxidative stress (raising levels of 7,8-dihydrobiopterin). Curcumin is a naturally occurring polyphenol with strong antioxidant and anti-inflammatory action and therapeutic spectra similar to that of methotrexate. This study was performed to evaluate the effects of curcumin on methotrexate induced vascular endothelial dysfunction and also compare its effect with that produced by folic acid (0.072 μg·g(-1)·day(-1), p.o., 2 weeks) per se and in combination. Male Wistar rats were exposed to methotrexate (0.35 mg·kg(-1)·day(-1), i.p.) for 2 weeks to induce endothelial dysfunction. Methotrexate exposure led to shedding of endothelium, decreased vascular reactivity, increased oxidative stress, decreased serum nitrite levels, and increase in aortic collagen deposition. Curcumin (200 mg·kg(-1)·day(-1) and 400 mg·kg(-1)·day(-1), p.o.) for 4 weeks prevented the increase in oxidative stress, decrease in serum nitrite, aortic collagen deposition, and also vascular reactivity. The effects were comparable with those produced by folic acid therapy. The study shows that curcumin, when concomitantly administered with methotrexate, abrogated its vascular side effects by preventing an increase in oxidative stress and abating any reduction in physiological nitric oxide levels.

Type 2 diabetes mellitus and exercise impairment.

PubMed

Reusch, Jane E B; Bridenstine, Mark; Regensteiner, Judith G

2013-03-01

Limitations in physical fitness, a consistent finding in individuals with both type I and type 2 diabetes mellitus, correlate strongly with cardiovascular and all-cause mortality. These limitations may significantly contribute to the persistent excess cardiovascular mortality affecting this group. Exercise impairments in VO2 peak and VO2 kinetics manifest early on in diabetes, even with good glycemic control and in the absence of clinically apparent complications. Subclinical cardiac dysfunction is often present but does not fully explain the observed defect in exercise capacity in persons with diabetes. In part, the cardiac limitations are secondary to decreased perfusion with exercise challenge. This is a reversible defect. Similarly, in the skeletal muscle, impairments in nutritive blood flow correlate with slowed (or inefficient) exercise kinetics and decreased exercise capacity. Several correlations highlight the likelihood of endothelial-specific impairments as mediators of exercise dysfunction in diabetes, including insulin resistance, endothelial dysfunction, decreased myocardial perfusion, slowed tissue hemoglobin oxygen saturation, and impairment in mitochondrial function. Both exercise training and therapies targeted at improving insulin sensitivity and endothelial function improve physical fitness in subjects with type 2 diabetes. Optimization of exercise functions in people with diabetes has implications for diabetes prevention and reductions in mortality risk. Understanding the molecular details of endothelial dysfunction in diabetes may provide specific therapeutic targets for the remediation of this defect. Rat models to test this hypothesis are under study.

Hepatotoxicity and endothelial dysfunction induced by high choline diet and the protective effects of phloretin in mice.

PubMed

Ren, Daoyuan; Liu, Yafei; Zhao, Yan; Yang, Xingbin

2016-08-01

The involvement of choline and its metabolite trimethylamine-N-oxide (TMAO) in endothelial dysfunction and atherosclerosis has been repeatedly confirmed. Phloretin, a dihydrochalcone flavonoid usually present in apples, possesses a variety of biological activities including vascular nutrition. This study was designed to investigate whether phloretin could alleviate or prevent high choline-induced vascular endothelial dysfunction and liver injury in mice. Mice were provided with 3% high choline water and given phloretin orally daily for 10 weeks. The high choline-treated mice showed the significant dyslipidemia and hyperglycemia with the impaired liver and vascular endothelium (p < 0.01). Administration of phloretin at 200 and 400 mg/kg bw significantly reduced the choline-induced elevation of serum TC, TG, LDL-C, AST, ALT, ET-1 and TXA2 (p < 0.01), and markedly antagonized the choline-induced decrease of serum PGI2, HDL-C and NO levels. Furthermore, phloretin elevated hepatic SOD and GSH-Px activities and decreased hepatic MDA levels of the mice exposed to high choline water. Moreover, histopathological test with the H&E and Oil Red O staining of liver sections confirmed the high choline diet-caused liver steatosis and the hepatoprotective effect of phloretin. These findings suggest that high choline causes oxidative damage, and phloretin alleviate vascular endothelial dysfunction and liver injury. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hypercholesterolemia increases plasma saturated and n-6 fatty acids altering prostaglandin homeostasis and promotes endothelial dysfunction in rabbits.

PubMed

Medina, M; Alberto, M R; Sierra, L; Van Nieuwenhove, C; Saad, S; Isla, M I; Jerez, S

2014-07-01

The present study evaluated the plasma fatty acid levels and the vascular prostaglandin (PG) release in a rabbit model of early hypercholesterolemia with endothelial dysfunction. Rabbits were fed either a control diet (CD) or a diet containing 1 % cholesterol (HD) for 5-6 weeks. The level of fatty acids was measured in plasma. The levels of PG and nitric oxide (NO) released from the aorta were also determined. Vascular morphology of the aorta was characterized by intima and media thickness measurements. The rabbits fed with HD had higher levels of arachidonic acid (ARA) and lower levels of oleic acid. The linoleic acid level was unchanged. PGI(2) and NO were diminished and PGF(2α) levels, the PGI(2)/TXA(2) ratio and the intima/media ratio were increased in rabbits fed with HD. In conclusion, feeding HD for a short period increased ARA plasma levels and unbalanced release of vasodilator/vasoconstrictor PG redirected the pathway to vasoconstrictor metabolite release. These lipid metabolism alterations in addition to the reduced NO levels and the moderate changes in the vascular morphology contributed to the endothelial dysfunction in this animal model. Therefore, the present findings support the importance of early correction or prevention of high cholesterol levels to disrupt the endothelial dysfunction process that leads to cardiovascular disease.

Gene expression profiles of brain endothelial cells during embryonic development at bulk and single-cell levels.

PubMed

Hupe, Mike; Li, Minerva Xueting; Kneitz, Susanne; Davydova, Daria; Yokota, Chika; Kele-Olovsson, Julianna; Hot, Belma; Stenman, Jan M; Gessler, Manfred

2017-07-11

The blood-brain barrier is a dynamic interface that separates the brain from the circulatory system, and it is formed by highly specialized endothelial cells. To explore the molecular mechanisms defining the unique nature of vascular development and differentiation in the brain, we generated high-resolution gene expression profiles of mouse embryonic brain endothelial cells using translating ribosome affinity purification and single-cell RNA sequencing. We compared the brain vascular translatome with the vascular translatomes of other organs and analyzed the vascular translatomes of the brain at different time points during embryonic development. Because canonical Wnt signaling is implicated in the formation of the blood-brain barrier, we also compared the brain endothelial translatome of wild-type mice with that of mice lacking the transcriptional cofactor β-catenin ( Ctnnb1 ). Our analysis revealed extensive molecular changes during the embryonic development of the brain endothelium. We identified genes encoding brain endothelium-specific transcription factors ( Foxf2 , Foxl2 , Foxq1 , Lef1 , Ppard , Zfp551 , and Zic3 ) that are associated with maturation of the blood-brain barrier and act downstream of the Wnt-β-catenin signaling pathway. Profiling of individual brain endothelial cells revealed substantial heterogeneity in the population. Nevertheless, the high abundance of Foxf2 , Foxq1 , Ppard , or Zic3 transcripts correlated with the increased expression of genes encoding markers of brain endothelial cell differentiation. Expression of Foxf2 and Zic3 in human umbilical vein endothelial cells induced the production of blood-brain barrier differentiation markers. This comprehensive data set may help to improve the engineering of in vitro blood-brain barrier models. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Crosstalk between reticular adherens junctions and platelet endothelial cell adhesion molecule-1 regulates endothelial barrier function.

PubMed

Fernández-Martín, Laura; Marcos-Ramiro, Beatriz; Bigarella, Carolina L; Graupera, Mariona; Cain, Robert J; Reglero-Real, Natalia; Jiménez, Anaïs; Cernuda-Morollón, Eva; Correas, Isabel; Cox, Susan; Ridley, Anne J; Millán, Jaime

2012-08-01

Endothelial cells provide a barrier between the blood and tissues, which is reduced during inflammation to allow selective passage of molecules and cells. Adherens junctions (AJ) play a central role in regulating this barrier. We aim to investigate the role of a distinctive 3-dimensional reticular network of AJ found in the endothelium. In endothelial AJ, vascular endothelial-cadherin recruits the cytoplasmic proteins β-catenin and p120-catenin. β-catenin binds to α-catenin, which links AJ to actin filaments. AJ are usually described as linear structures along the actin-rich intercellular contacts. Here, we show that these AJ components can also be organized in reticular domains that contain low levels of actin. Reticular AJ are localized in areas where neighboring cells overlap and encompass the cell adhesion receptor platelet endothelial cell adhesion molecule-1 (PECAM-1). Superresolution microscopy revealed that PECAM-1 forms discrete structures distinct from and distributed along AJ, within the voids of reticular domains. Inflammatory tumor necrosis factor-α increases permeability by mechanisms that are independent of actomyosin-mediated tension and remain incompletely understood. Reticular AJ, but not actin-rich linear AJ, were disorganized by tumor necrosis factor-α. This correlated with PECAM-1 dispersal from cell borders. PECAM-1 inhibition with blocking antibodies or small interfering RNA specifically disrupted reticular AJ, leaving linear AJ intact. This disruption recapitulated typical tumor necrosis factor-α-induced alterations of barrier function, including increased β-catenin phosphorylation, without altering the actomyosin cytoskeleton. We propose that reticular AJ act coordinately with PECAM-1 to maintain endothelial barrier function in regions of low actomyosin-mediated tension. Selective disruption of reticular AJ contributes to permeability increase in response to tumor necrosis factor-α.

The urea decomposition product cyanate promotes endothelial dysfunction

PubMed Central

El-Gamal, Dalia; Rao, Shailaja Prabhakar; Holzer, Michael; Hallström, Seth; Haybaeck, Johannes; Gauster, Martin; Wadsack, Christian; Kozina, Andrijana; Frank, Saša; Schicho, Rudolf; Schuligoi, Rufina; Heinemann, Akos; Marsche, Gunther

2014-01-01

The dramatic cardiovascular mortality of chronic kidney disease patients is attributable in a significant proportion to endothelial dysfunction. Cyanate, a reactive species in equilibrium with urea, is formed in excess in chronic kidney disease. Cyanate is thought to have a causal role in promoting cardiovascular disease, but the underlying mechanisms remain unclear. Immunohistochemical analysis performed in the present study revealed that carbamylated epitopes associate mainly with endothelial cells in human atherosclerotic lesions. Cyanate treatment of human coronary artery endothelial cells reduced expression of endothelial nitric oxide synthase and increased tissue factor and plasminogen activator inhibitor-1 expression. In mice, administration of cyanate - promoting protein carbamylation at levels observed in uremic patients - attenuated arterial vasorelaxation of aortic rings in response to acetylcholine, without affecting sodium nitroprusside-induced relaxation. Total endothelial nitric oxide synthase and nitric oxide production were significantly reduced in aortic tissue of cyanate-treated mice. This coincided with a marked increase of tissue factor and plasminogen activator inhibitor-1 protein levels in aortas of cyanate-treated mice. These data provide evidence that cyanate compromises endothelial functionality in vitro and in vivo and may contribute to the dramatic cardiovascular risk of patients suffering from chronic kidney disease. PMID:24940796

Potential of Food and Natural Products to Promote Endothelial and Vascular Health.

PubMed

Auger, Cyril; Said, Amissi; Nguyen, Phuong Nga; Chabert, Philippe; Idris-Khodja, Noureddine; Schini-Kerth, Valérie B

2016-07-01

Endothelial dysfunction is now well established as a pivotal early event in the development of major cardiovascular diseases including hypertension, atherosclerosis, and diabetes. The alteration of the endothelial function is often triggered by an imbalance between the endothelial formation of vasoprotective factors including nitric oxide (NO) and endothelium-dependent hyperpolarization, and an increased level of oxidative stress involving several prooxidant enzymes such as NADPH oxidase and, often also, the appearance of cyclooxygenase-derived vasoconstrictors. Preclinical studies have indicated that polyphenol-rich food and food-derived products such as grape-derived products, black and red berries, green and black teas and cocoa, and omega-3 fatty acids can trigger activating pathways in endothelial cells promoting an increased formation of nitric oxide and endothelium-dependent hyperpolarization. Moreover, intake of such food-derived products has been associated with the prevention and/or the improvement of an established endothelial dysfunction in several experimental models of cardiovascular diseases and in humans with cardiovascular diseases. This review will discuss both experimental and clinical evidences indicating that different types of food and natural products are able to promote endothelial and vascular health, as well as the underlying mechanisms.

ASSOCIATIONS OF MACRO- AND MICROVASCULAR ENDOTHELIAL DYSFUNCTION WITH SUBCLINICAL VENTRICULAR DYSFUNCTION IN END-STAGE RENAL DISEASE

PubMed Central

Dubin, Ruth F; Guajardo, Isabella; Ayer, Amrita; Mills, Claire; Donovan, Catherine; Beussink, Lauren; Scherzer, Rebecca; Ganz, Peter; Shah, Sanjiv J

2016-01-01

Patients with end-stage renal disease (ESRD) suffer high rates of heart failure and cardiovascular mortality, and we lack a thorough understanding of what, if any, modifiable factors contribute to cardiac dysfunction in these high-risk patients. In order to evaluate endothelial function as a potentially modifiable cause of cardiac dysfunction in ESRD, we investigated cross-sectional associations of macro- and microvascular dysfunction with left and right ventricular dysfunction in a well-controlled ESRD cohort. We performed comprehensive echocardiography, including tissue Doppler imaging and speckle tracking echocardiography of the left and right ventricle, in 149 ESRD patients enrolled in an ongoing prospective, observational study. Of these participants, 123 also underwent endothelium-dependent flow-mediated dilation (FMD) of the brachial artery (macrovascular function). Microvascular function was measured as the velocity time integral (VTI) of hyperemic blood flow following cuff deflation. Impaired FMD was associated with higher LV mass, independently of age and blood pressure: per two-fold lower FMD, LV mass was 4.1% higher (95%CI [0.49, 7.7], p=0.03). After adjustment for demographics, blood pressure, comorbidities and medications, a two-fold lower VTI was associated with 9.5% higher E/e’ ratio (95% CI [1.0, 16], p=0.03) and 6.7% lower absolute RV longitudinal strain (95% CI [2.0, 12], p=0.003). Endothelial dysfunction is a major correlate of cardiac dysfunction in ESRD, particularly diastolic and right ventricular dysfunction, in patients whose volume status is well-controlled. Future investigations are needed to determine whether therapies targeting the vascular endothelium could improve cardiac outcomes in ESRD. PMID:27550915

Anti-IL-6 neutralizing antibody modulates blood-brain barrier function in the ovine fetus.

PubMed

Zhang, Jiyong; Sadowska, Grazyna B; Chen, Xiaodi; Park, Seon Yeong; Kim, Jeong-Eun; Bodge, Courtney A; Cummings, Erin; Lim, Yow-Pin; Makeyev, Oleksandr; Besio, Walter G; Gaitanis, John; Banks, William A; Stonestreet, Barbara S

2015-05-01

Impaired blood-brain barrier function represents an important component of hypoxic-ischemic brain injury in the perinatal period. Proinflammatory cytokines could contribute to ischemia-related blood-brain barrier dysfunction. IL-6 increases vascular endothelial cell monolayer permeability in vitro. However, contributions of IL-6 to blood-brain barrier abnormalities have not been examined in the immature brain in vivo. We generated pharmacologic quantities of ovine-specific neutralizing anti-IL-6 mAbs and systemically infused mAbs into fetal sheep at 126 days of gestation after exposure to brain ischemia. Anti-IL-6 mAbs were measured by ELISA in fetal plasma, cerebral cortex, and cerebrospinal fluid, blood-brain barrier permeability was quantified using the blood-to-brain transfer constant in brain regions, and IL-6, tight junction proteins, and plasmalemma vesicle protein (PLVAP) were detected by Western immunoblot. Anti-IL-6 mAb infusions resulted in increases in mAb (P < 0.05) in plasma, brain parenchyma, and cerebrospinal fluid and decreases in brain IL-6 protein. Twenty-four hours after ischemia, anti-IL-6 mAb infusions attenuated ischemia-related increases in blood-brain barrier permeability and modulated tight junction and PLVAP protein expression in fetal brain. We conclude that inhibiting the effects of IL-6 protein with systemic infusions of neutralizing antibodies attenuates ischemia-related increases in blood-brain barrier permeability by inhibiting IL-6 and modulates tight junction proteins after ischemia. © FASEB.

Trimethylamine N-oxide in atherogenesis: impairing endothelial self-repair capacity and enhancing monocyte adhesion.

PubMed

Ma, GuoHua; Pan, Bing; Chen, Yue; Guo, CaiXia; Zhao, MingMing; Zheng, LeMin; Chen, BuXing

2017-04-30

Several studies have reported a strong association between high plasma level of trimethylamine N-oxide (TMAO) and atherosclerosis development. However, the exact mechanism underlying this correlation is unknown. In the present study, we try to explore the impact of TMAO on endothelial dysfunction. After TMAO treatment, human umbilical vein endothelial cells (HUVECs) showed significant impairment in cellular proliferation and HUVECs-extracellular matrix (ECM) adhesion compared with control. Likewise, TMAO markedly suppressed HUVECs migration in transwell migration assay and wound healing assay. In addition, we found TMAO up-regulated vascular cell adhesion molecule-1 (VCAM-1) expression, promoted monocyte adherence, activated protein kinase C (PKC) and p-NF-κB. Interestingly, TMAO-stimulated VCAM-1 expression and monocyte adherence were diminished by PKC inhibitor. These results demonstrate that TMAO promotes early pathological process of atherosclerosis by accelerating endothelial dysfunction, including decreasing endothelial self-repair and increasing monocyte adhesion. Furthermore, TMAO-induced monocyte adhesion is partly attributable to activation of PKC/NF-κB/VCAM-1. © 2017 The Author(s).

Impact of diabetic serum on endothelial cells: An in-vitro-analysis of endothelial dysfunction in diabetes mellitus type 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muenzel, Daniela; Lehle, Karla; Haubner, Frank

2007-10-19

Diabetic endothelial dysfunction was characterized by altered levels of adhesion molecules and cytokines. Aim of our study was to evaluate the effects of diabetic serum on cell-growth and proinflammatory markers in human saphenous vein endothelial cells (HSVEC) from diabetic and non-diabetic patients. Diabetic serum showed (1) complementary proliferative activity for non-diabetic and diabetic HSVEC, (2) unchanged surface expression of adhesion molecules, and (3) elevated levels of sICAM-1 in HSVEC of all donors. The concentration of sVCAM-1 was increased only in diabetic cells. The proinflammatory state of diabetic HSVEC characterized by increased levels of cytokines was compensated. We concluded that evenmore » under normoglycemic conditions the serum itself contains critical factors leading to abnormal regulation of inflammation in diabetics. We introduced an in vitro model of diabetes representing the endothelial situation at the beginning of diabetes (non-diabetic cells/diabetic serum) as well as the diabetic chronic state (diabetic cells/diabetic serum)« less

Endothelial dysfunction: the early predictor of atherosclerosis.

PubMed

Mudau, Mashudu; Genis, Amanda; Lochner, Amanda; Strijdom, Hans

2012-05-01

Since the discovery in the 1980s that nitric oxide (NO) is in fact the elusive endothelium-derived relaxing factor, it has become evident that NO is not only a major cardiovascular signalling molecule, but that changes in its bioavailability are crucial in determining whether atherosclerosis will develop or not. Sustained high levels of harmful circulating stimuli associated with cardiovascular risk factors such as diabetes mellitus elicit responses in endothelial cells that appear sequentially, namely endothelial cell activation and endothelial dysfunction (ED). ED, characterised by reduced NO bioavailability, is now recognised by many as an early, reversible precursor of atherosclerosis. The pathogenesis of ED is multifactorial; however, oxidative stress appears to be the common underlying cellular mechanism in the ensuing loss of vaso-active, inflammatory, haemostatic and redox homeostasis in the body's vascular system. The role of ED as a pathophysiological link between early endothelial cell changes associated with cardiovascular risk factors and the development of ischaemic heart disease is of importance to basic scientists and clinicians alike.

Cardiovascular complications in inflammatory bowel disease

PubMed Central

Schicho, Rudolf; Marsche, Gunther; Storr, Martin

2015-01-01

Over the past years, a growing number of studies have indicated that patients suffering from inflammatory bowel disease (IBD) have an increased risk of developing cardiovascular disease. Both are chronic inflammatory diseases and share certain pathophysiological mechanisms that may influence each other. High levels of cytokines, C-reactive protein (CRP), and homocysteine in IBD patients may lead to endothelial dysfunction, an early sign of atherosclerosis. IBD patients, in general, do not show the typical risk factors for cardiovascular disease but changes in lipid profiles similar to the ones seen in cardiovascular events have been reported recently. Higher levels of coagulation factors frequently occur in IBD which may predispose to arterial thromboembolic events. Finally, the gut itself may have an impact on atherogenesis during IBD through its microbiota. Microbial products are released from the inflamed mucosa into the circulation through a leaky barrier. The induced rise in proinflammatory cytokines could contribute to endothelial damage, artherosclerosis and cardiovascular events. Although large retrospective studies favor a link between IBD and cardiovascular diseases the mechanisms behind still remain to be determined. PMID:25642719

Intracavernous Delivery of a Designed Angiopoietin-1 Variant Rescues Erectile Function by Enhancing Endothelial Regeneration in the Streptozotocin-Induced Diabetic Mouse

PubMed Central

Jin, Hai-Rong; Kim, Woo Jean; Song, Jae Sook; Piao, Shuguang; Choi, Min Ji; Tumurbaatar, Munkhbayar; Shin, Sun Hwa; Yin, Guo Nan; Koh, Gou Young; Ryu, Ji-Kan; Suh, Jun-Kyu

2011-01-01

OBJECTIVE Patients with diabetic erectile dysfunction often have severe endothelial dysfunction and respond poorly to oral phosphodiesterase-5 inhibitors. We examined the effectiveness of the potent angiopoietin-1 (Ang1) variant, cartilage oligomeric matrix protein (COMP)-Ang1, in promoting cavernous endothelial regeneration and restoring erectile function in diabetic animals. RESEARCH DESIGN AND METHODS Four groups of mice were used: controls; streptozotocin (STZ)-induced diabetic mice; STZ-induced diabetic mice treated with repeated intracavernous injections of PBS; and STZ-induced diabetic mice treated with COMP-Ang1 protein (days −3 and 0). Two and 4 weeks after treatment, we measured erectile function by electrical stimulation of the cavernous nerve. The penis was harvested for histologic examinations, Western blot analysis, and cGMP quantification. We also performed a vascular permeability test. RESULTS Local delivery of the COMP-Ang1 protein significantly increased cavernous endothelial proliferation, endothelial nitric oxide (NO) synthase (NOS) phosphorylation, and cGMP expression compared with that in the untreated or PBS-treated STZ-induced diabetic group. The changes in the group that received COMP-Ang1 restored erectile function up to 4 weeks after treatment. Endothelial protective effects, such as marked decreases in the expression of p47phox and inducible NOS, in the generation of superoxide anion and nitrotyrosine, and in the number of apoptotic cells in the corpus cavernosum tissue, were noted in COMP-Ang1–treated STZ-induced diabetic mice. An intracavernous injection of COMP-Ang1 completely restored endothelial cell-cell junction proteins and decreased cavernous endothelial permeability. COMP-Ang1–induced promotion of cavernous angiogenesis and erectile function was abolished by the NOS inhibitor, N-nitro-L-arginine methyl ester, but not by the NADPH oxidase inhibitor, apocynin. CONCLUSIONS These findings support the concept of cavernous endothelial regeneration by use of the recombinant Ang1 protein as a curative therapy for diabetic erectile dysfunction. PMID:21270241

Sevelamer reduces endothelial inflammatory response to advanced glycation end products

PubMed Central

Gregório, Paulo C; Favretto, Giane; Sassaki, Guilherme L; Cunha, Regiane S; Becker-Finco, Alessandra; Pecoits-Filho, Roberto; Souza, Wesley M; Barreto, Fellype C

2018-01-01

Abstract Background Advanced glycation end products (AGEs) have been related to the pathogenesis of cardiovascular diseases (CVD), chronic kidney disease (CKD) and diabetes mellitus. We sought to investigate the binding capacity of sevelamer to both AGEs and uremic serum in vitro and then test this pharmaceutical effect as a potential vascular anti-inflammatory strategy. Methods AGEs were prepared by albumin glycation and characterized by absorbance and electrophoresis. Human endothelial cells were incubated in culture media containing AGEs and uremic serum with or without sevelamer. Receptor for advanced glycation end product (RAGE) expression was evaluated through immunocytochemistry and western blot to explore the interactions between AGEs and the endothelium. Inflammatory and endothelial dysfunction biomarkers, such as interleukin 6 (IL-6) and IL-8, monocyte chemoattractant protein-1 (MCP-1), plasminogen activator inhibitor-1 (PAI-1) and serum amyloid A (SAA) were also measured in cell supernatant. The chemotactic property of the supernatant was evaluated. Results AGEs significantly induced the expression of RAGE, inflammatory and endothelial activation biomarkers [IL-6, (P < 0.005); IL-8, MCP-1, PAI-1 and SAA (P < 0.001)] and monocyte chemotaxis as compared with controls. In addition, AGEs increased the levels of inflammatory biomarkers, which were observed after 6 h of endothelial cell incubation with uremic serum [IL-6 (P < 0.001) IL-8, MCP-1 and PAI-1 (P < 0.05)]. On the other hand, after 6 h of endothelial cell treatment with sevelamer, RAGE expression (P < 0.05) and levels of inflammatory biomarkers [IL-6 and IL-8 (P < 0.001), MCP-1 (P < 0.01), PAI-1 and SAA (P < 0.005)] significantly decreased compared with the AGEs/uremic serum treatment alone. Conclusions Sevelamer decreased both endothelial expression of RAGE and endothelial dysfunction biomarkers, induced by AGEs, and uremic serum. Further studies are necessary for a better understanding of the potential protective role of sevelamer on uremic serum and AGEs-mediated endothelial dysfunction. PMID:29423208

In vitro studies of the blood-brain barrier using isolated brain capillaries and cultured endothelial cells.

PubMed

Goldstein, G W; Betz, A L; Bowman, P D; Dorovini-Zis, K

1986-01-01

The endothelial cells in brain capillaries are the anatomic site of the blood-brain barrier. To learn more about the biology of these specialized cells, we developed methods to prepare suspensions of purified brain microvessels as well as primary cultures of endothelial cells in monolayer. These two preparations allow for direct investigation of the metabolism, transport properties, and receptor content of the brain capillary. We used isolated brain microvessels to study distribution of membrane carriers between the luminal and the abluminal plasma membrane of endothelial cells. We found that Na+K+-ATPase and the A-system amino-acid transport system are located predominantly on the abluminal surface of brain capillary endothelial cells. This distribution of transport carriers is consistent with the low permeability of potassium and small neutral amino acids in the blood-to-brain direction. It suggests, however, that both solutes can be actively transported across brain capillaries from the brain interstitial fluid to the blood. In tissue culture, the endothelial cells form continuous tight junctions with their neighbors. This results in a cellular layer impermeable to protein tracers. When exposed to hyperosmolar solutions, in an attempt to mimic the conditions that open the blood-brain barrier in vivo, we found a reversible separation of the tight junctions between contiguous endothelial cells. No indication of activation of pinocytosis was observed. In vitro systems provide a novel approach for studying the function of the blood-brain barrier and allow for observations not possible with intact animals.

Saccharomyces cerevisiae show low levels of traversal across human endothelial barrier in vitro.

PubMed

Pérez-Torrado, Roberto; Querol, Amparo

2017-01-01

Background :   Saccharomyces cerevisiae is generally considered safe, and is involved in the production of many types of foods and dietary supplements. However, some isolates, which are genetically related to strains used in brewing and baking, have shown virulent traits, being able to produce infections in humans, mainly in immunodeficient patients. This can lead to systemic infections in humans. Methods : In this work, we studied S. cerevisiae isolates in an in vitro human endothelial barrier model, comparing their behaviour with that of several strains of the related pathogens Candida glabrata and Candida albicans . Results : The results showed that this food related yeast is able to cross the endothelial barrier in vitro . However, in contrast to C. glabrata and C. albicans , S. cerevisiae showed very low levels of traversal. Conclusions : We conclude that using an in vitro human endothelial barrier model with S. cerevisiae can be useful to evaluate the safety of S. cerevisiae strains isolated from foods.

An in vitro and in vivo study of peptide-functionalized nanoparticles for brain targeting: The importance of selective blood-brain barrier uptake.

PubMed

Bode, Gerard H; Coué, Gregory; Freese, Christian; Pickl, Karin E; Sanchez-Purrà, Maria; Albaiges, Berta; Borrós, Salvador; van Winden, Ewoud C; Tziveleka, Leto-Aikaterini; Sideratou, Zili; Engbersen, Johan F J; Singh, Smriti; Albrecht, Krystyna; Groll, Jürgen; Möller, Martin; Pötgens, Andy J G; Schmitz, Christoph; Fröhlich, Eleonore; Grandfils, Christian; Sinner, Frank M; Kirkpatrick, C James; Steinbusch, Harry W M; Frank, Hans-Georg; Unger, Ronald E; Martinez-Martinez, Pilar

2017-04-01

Targeted delivery of drugs across endothelial barriers remains a formidable challenge, especially in the case of the brain, where the blood-brain barrier severely limits entry of drugs into the central nervous system. Nanoparticle-mediated transport of peptide/protein-based drugs across endothelial barriers shows great potential as a therapeutic strategy in a wide variety of diseases. Functionalizing nanoparticles with peptides allows for more efficient targeting to specific organs. We have evaluated the hemocompatibilty, cytotoxicity, endothelial uptake, efficacy of delivery and safety of liposome, hyperbranched polyester, poly(glycidol) and acrylamide-based nanoparticles functionalized with peptides targeting brain endothelial receptors, in vitro and in vivo. We used an ELISA-based method for the detection of nanoparticles in biological fluids, investigating the blood clearance rate and in vivo biodistribution of labeled nanoparticles in the brain after intravenous injection in Wistar rats. Herein, we provide a detailed report of in vitro and in vivo observations. Copyright © 2016 Elsevier Inc. All rights reserved.

Cancer cells remodel themselves and vasculature to overcome the endothelial barrier.

PubMed

Shenoy, Anitha K; Lu, Jianrong

2016-10-01

Metastasis refers to the spread of cancer cells from a primary tumor to distant organs mostly via the bloodstream. During the metastatic process, cancer cells invade blood vessels to enter circulation, and later exit the vasculature at a distant site. Endothelial cells that line blood vessels normally serve as a barrier to the movement of cells into or out of the blood. It is thus critical to understand how metastatic cancer cells overcome the endothelial barrier. Epithelial cancer cells acquire increased motility and invasiveness through epithelial-to-mesenchymal transition (EMT), which enables them to move toward vasculature. Cancer cells also express a variety of adhesion molecules that allow them to attach to vascular endothelium. Finally, cancer cells secrete or induce growth factors and cytokines to actively prompt vascular hyperpermeability that compromises endothelial barrier function and facilitates transmigration of cancer cells through the vascular wall. Elucidation of the mechanisms underlying metastatic dissemination may help develop new anti-metastasis therapeutics. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Attenuation of endothelial dysfunction by exercise training in STZ-induced diabetic rats.

PubMed

Chakraphan, Daroonwan; Sridulyakul, Patarin; Thipakorn, Bundit; Bunnag, Srichitra; Huxley, Virginia H; Patumraj, Suthiluk

2005-01-01

The protective effects of exercise training on the diabetic-induced endothelial cell (EC) dysfunction were determined using intravital fluorescent microscopy. Male Sprague-Dawley rats were divided into three groups of control (Con), diabetes (DM), and diabetes with exercise--training (DM+Ex). Diabetes was induced by single intravenous injection of streptozotocin (STZ; 50 mg/kg BW). The exercise training protocol consisted of treadmill running, 5 times/week with the velocity of 13-15 m/min, 30 min/day periods for 12 and 24 weeks (wks). 24 wks after the STZ injection, blood glucose (BG), glycosylated hemoglobin (HbA1C), mean arterial blood pressure (MAP) and heart weight (HW) were significantly higher in DM rats (p < 0.001). However, DM+Ex rats had reduced the abnormalities of MAP (p < 0.01) and HW (p < 0.05) compared with DM rats. Furthermore, there was a significant decrease in heart rate (HR) of DM+Ex rats (p < 0.05) relative to Con rats. To examine the influence of exercise training on EC dysfunction, leukocyte-EC interactions in mesenteric venules and vascular reactivity responses to vasodilators in mesenteric arterioles were monitored by using intravital fluorescence microscopy. The diabetic state enhanced leukocyte adhesion in mesenteric postcapillary venules (p < 0.001). Moreover, an impaired vasodilatory response to the EC-dependent vasodilator, acetylcholine (Ach), not to sodium nitroprusside (SNP), was found in 12- and 24-wk diabetic rats (p < 0.01). The leukocyte adhesion and the impairment of EC-dependent vasodilation to Ach were attenuated by exercise training (p < 0.05). In addition, exercise training was also shown to have favorable preventive effects on hyperglycemia induced oxidative stress, as lower malondialdehyde (MDA) levels were observed from both groups of 12 and 24 weeks DM+Ex compared with DM (p < 0.01). In conclusion, our findings indicate that the endothelial dysfunction of diabetic rats could be characterized by increased leukocyte adhesion and impaired endothelium-dependent relaxation. Regular low intensity exercise training could improve both indices of endothelial dysfunction through amelioration of diabetic-induced oxidant/antioxidant levels. These findings support the notion that regular exercise training could be a fundamental form of therapy in preventing diabetic cardiovascular complications potentiated by endothelial dysfunction.

Interleukin 22 Promotes Blood Pressure Elevation and Endothelial Dysfunction in Angiotensin II-Treated Mice.

PubMed

Ye, Jing; Ji, Qingwei; Liu, Jianfang; Liu, Ling; Huang, Ying; Shi, Ying; Shi, Lei; Wang, Menglong; Liu, Mengling; Feng, Ying; Jiang, Huimin; Xu, Yao; Wang, Zhen; Song, Junlong; Lin, Yingzhong; Wan, Jun

2017-10-03

CD4+ T helper (Th) cells, including Th1, Th2, and Th17 cells, play critical roles in angiotensin II-induced hypertension. Th22 cells, a novel subset of Th cells, take part in cardiovascular diseases by producing IL-22 (interleukin 22). This study aimed to investigate whether IL-22 is involved in hypertension. Th22 cells and IL-22 levels were detected in angiotensin II-infused mice, and the results showed that Th22 cells and IL-22 levels significantly increased. To determine the effect of Th22/IL-22 on blood pressure regulation, angiotensin II-infused mice were treated with recombinant mouse IL-22, an anti-IL-22 neutralizing monoclonal antibody, or control. Treatment with recombinant IL-22 resulted in increased blood pressure, amplified inflammatory responses, and aggravated endothelial dysfunction, whereas the anti-IL-22 neutralizing monoclonal antibody decreased blood pressure, reduced inflammatory responses, and attenuated endothelial dysfunction. To determine whether the STAT3 (signal transducer and activator of transcription 3) pathway mediates the effect of IL-22 on blood pressure regulation, the special STAT3 pathway inhibitor S31-201 was administered to mice treated with recombinant IL-22. S31-201 treatment significantly ameliorated the IL-22 effects of increased blood pressure and endothelial dysfunction. In addition, serum IL-22 levels were significantly increased in hypertensive patients compared with healthy persons. Correlation analysis showed a positive correlation between IL-22 levels and blood pressure. IL-22 amplifies the inflammatory response, induces endothelial dysfunction and promotes blood pressure elevation in angiotensin II-induced hypertensive mice. The STAT3 pathway mediates the effect of IL-22 on hypertension. Blocking IL-22 may be a novel therapeutic strategy to prevent and treat hypertension. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Association between endothelial dysfunction, epicardial fat and subclinical atherosclerosis during menopause.

PubMed

Cabrera-Rego, Julio Oscar; Navarro-Despaigne, Daisy; Staroushik-Morel, Liudmila; Díaz-Reyes, Karel; Lima-Martínez, Marcos M; Iacobellis, Gianluca

Menopausal transition is critical for the development of early, subclinical vascular damage. Multiple factors, such as atherosclerosis, increased epicardial fat, and endothelial dysfunction can play a role. Hence, the objective of this study was the comparison of epicardial adipose tissue and carotid intima media thickness in order to establish the best predictor of carotid stiffness in middle-aged women with endothelial dysfunction. A total of 43 healthy women aged 40-59 years old with endothelial dysfunction previously demonstrated by flow mediated dilation were recruited to have anthropometric, biochemical, hormonal and ultrasound determinations of carotid intima media thickness and epicardial fat thickness. Carotid arterial stiffness parameters (local pulse wave velocity [4.7±0.7 vs 4.8±0.5 vs 5.6±0.5m/s, respectively, p<0.001], pressure strain elastic modulus [55.2±13.4 vs 59.2±11.8 vs 81.9±15.6kPa, respectively, p<0.001], arterial stiffness index β [4.4±1.4 vs 5.0±1.1 vs 6.4±1.3, respectively, p<0.001]) and epicardial fat thickness (2.98±1.4 vs 3.28±1.9 vs 4.70±1.0mm, respectively, p=0.007) showed a significant and proportional increase in the group of late post-menopausal women when compared to early post-menopausal and pre-menopausal groups, respectively. Among body fat markers, epicardial fat was the strongest predictor of local pulse wave velocity, independent of age. In menopausal women with endothelial dysfunction, menopausal transition is associated with increased carotid arterial stiffness and epicardial fat thickness, independent of age. Ultrasound measured epicardial fat was a better independent predictor of arterial stiffness than carotid intima media thickness in these women. Copyright © 2017 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

The Lack of Utility of Circulating Biomarkers of Inflammation and Endothelial Dysfunction for Type 2 Diabetes Risk Prediction Among Postmenopausal Women

PubMed Central

Chao, Chun; Song, Yiqing; Cook, Nancy; Tseng, Chi-Hong; Manson, JoAnn E.; Eaton, Charles; Margolis, Karen L.; Rodriguez, Beatriz; Phillips, Lawrence S.; Tinker, Lesley F.; Liu, Simin

2011-01-01

Background Recent studies have linked plasma markers of inflammation and endothelial dysfunction to type 2 diabetes mellitus (DM) development. However, the utility of these novel biomarkers for type 2 DM risk prediction remains uncertain. Methods The Women’s Health Initiative Observational Study (WHIOS), a prospective cohort, and a nested case-control study within the WHIOS of 1584 incident type 2 DM cases and 2198 matched controls were used to evaluate the utility of plasma markers of inflammation and endothelial dysfunction for type 2 DM risk prediction. Between September 1994 and December 1998, 93 676 women aged 50 to 79 years were enrolled in the WHIOS. Fasting plasma levels of glucose, insulin, white blood cells, tumor necrosis factor receptor 2, interleukin 6, high-sensitivity C-reactive protein, E-selectin, soluble intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 were measured using blood samples collected at baseline. A series of prediction models including traditional risk factors and novel plasma markers were evaluated on the basis of global model fit, model discrimination, net reclassification improvement, and positive and negative predictive values. Results Although white blood cell count and levels of interleukin 6, high-sensitivity C-reactive protein, and soluble intercellular adhesion molecule 1 significantly enhanced model fit, none of the inflammatory and endothelial dysfunction markers improved the ability of model discrimination (area under the receiver operating characteristic curve, 0.93 vs 0.93), net reclassification, or predictive values (positive, 0.22 vs 0.24; negative, 0.99 vs 0.99 [using 15% 6-year type 2 DM risk as the cutoff]) compared with traditional risk factors. Similar results were obtained in ethnic-specific analyses. Conclusion Beyond traditional risk factors, measurement of plasma markers of systemic inflammation and endothelial dysfunction contribute relatively little additional value in clinical type 2 DM risk prediction in a multiethnic cohort of postmenopausal women. PMID:20876407

Geraniol improves endothelial function by inhibiting NOX-2 derived oxidative stress in high fat diet fed mice.

PubMed

Wang, Xiaoyu; Zhao, Shiqi; Su, Mengqi; Sun, Li; Zhang, Song; Wang, Dingyu; Liu, Zhaorui; Yuan, Yue; Liu, Yang; Li, Yue

2016-05-20

Endothelial dysfunction occurs in obese patients and high-fat diet (HFD) fed experimental animals. While geraniol has been reported to ameliorate inflammation and oxidative stress, inhibit tumor cell proliferation, and improve atherosclerosis, its direct effect on endothelial function remains uncharacterized. The present study therefore investigated the effect of geraniol on endothelial function in HFD mice and its underlying mechanisms. C57 BL/6 mice were fed an HFD (n = 40) or a normal diet (n = 20) for 8 weeks. HFD fed mice then were randomized to intraperitoneal treatment with geraniol (n = 20) or vehicle (n = 20) for another 6 weeks. Acetylcholine (Ach)-induced endothelial dependent vasorelaxation was measured on wire myography; reactive oxygen species (ROS) generation was assessed by fluorescence imaging, and NADPH oxidases (NOXs) and adhesive molecules VCAM-1 and ICAM-1 protein expression by western blotting. Geraniol improved endothelial function in HFD fed mice, as evidenced by its: 1. restoring endothelial dependent vasorelaxation induced by Ach, and reversing increased VCAM-1 and ICAM-1 expression; 2. attenuating HFD induced increased serum TBARS and aortic ROS generation; and 3. downregulating aortic NOX-2 expression in both HFD fed mice and in palmitic acid treated endothelial cells. Geraniol therefore protects against endothelial dysfunction induced by HFD through reducing NOX-2 associated ROS generation. Copyright © 2016 Elsevier Inc. All rights reserved.

SGLT2 inhibition via dapagliflozin improves generalized vascular dysfunction and alters the gut microbiota in type 2 diabetic mice.

PubMed

Lee, Dustin M; Battson, Micah L; Jarrell, Dillon K; Hou, Shuofei; Ecton, Kayl E; Weir, Tiffany L; Gentile, Christopher L

2018-04-27

Type 2 diabetes (T2D) is associated with generalized vascular dysfunction characterized by increases in large artery stiffness, endothelial dysfunction, and vascular smooth muscle dysfunction. Sodium glucose cotransporter 2 inhibitors (SGLT2i) represent the most recently approved class of oral medications for the treatment of T2D, and have been shown to reduce cardiovascular and overall mortality. Although it is currently unclear how SGLT2i decrease cardiovascular risk, an improvement in vascular function is one potential mechanism. The aim of the current study was to examine if dapagliflozin, a widely prescribed STLT2i, improves generalized vascular dysfunction in type 2 diabetic mice. In light of several studies demonstrating a bi-directional relation between orally ingested medications and the gut microbiota, a secondary aim was to determine the effects of dapagliflozin on the gut microbiota. Male diabetic mice (Db, n = 24) and control littermates (Con; n = 23) were randomized to receive either a standard diet or a standard diet containing dapagliflozin (60 mg dapagliflozin/kg diet; 0.006%) for 8 weeks. Arterial stiffness was assessed by aortic pulse wave velocity; endothelial function and vascular smooth muscle dysfunction were assessed by dilatory responses to acetylcholine and sodium nitroprusside, respectively. Compared to untreated diabetic mice, diabetic mice treated with dapagliflozin displayed significantly lower arterial stiffness (Db = 469 cm/s vs. Db + dapa = 435 cm/s, p < 0.05), and improvements in endothelial dysfunction (area under the curve [AUC] Db = 57.2 vs. Db + dapa = 117.0, p < 0.05) and vascular smooth muscle dysfunction (AUC, Db = 201.7 vs. Db + dapa = 285.5, p < 0.05). These vascular improvements were accompanied by reductions in hyperglycemia and circulating markers of inflammation. The microbiota of Db and Con mice were distinctly different, and dapagliflozin treatment was associated with minor alterations in gut microbiota composition, particularly in Db mice, although these effects did not conclusively mediate the improvements in vascular function. Dapagliflozin treatment improves arterial stiffness, endothelial dysfunction and vascular smooth muscle dysfunction, and subtly alters microbiota composition in type 2 diabetic mice. Collectively, the improvements in generalized vascular function may represent an important mechanism underlying the cardiovascular benefits of SGLT2i treatment.

GSK-3Beta-Dependent Activation of GEF-H1/ROCK Signaling Promotes LPS-Induced Lung Vascular Endothelial Barrier Dysfunction and Acute Lung Injury.

PubMed

Yi, Lei; Huang, Xiaoqin; Guo, Feng; Zhou, Zengding; Chang, Mengling; Huan, Jingning

2017-01-01

The bacterial endotoxin or lipopolysaccharide (LPS) leads to the extensive vascular endothelial cells (EC) injury under septic conditions. Guanine nucleotide exchange factor-H1 (GEF-H1)/ROCK signaling not only involved in LPS-induced overexpression of pro-inflammatory mediator in ECs but also implicated in LPS-induced endothelial hyper-permeability. However, the mechanisms behind LPS-induced GEF-H1/ROCK signaling activation in the progress of EC injury remain incompletely understood. GEF-H1 localized on microtubules (MT) and is suppressed in its MT-bound state. MT disassembly promotes GEF-H1 release from MT and stimulates downstream ROCK-specific GEF activity. Since glycogen synthase kinase (GSK-3beta) participates in regulating MT dynamics under pathologic conditions, we examined the pivotal roles for GSK-3beta in modulating LPS-induced activation of GEF-H1/ROCK, increase of vascular endothelial permeability and severity of acute lung injury (ALI). In this study, we found that LPS induced human pulmonary endothelial cell (HPMEC) monolayers disruption accompanied by increase in GSK-3beta activity, activation of GEF-H1/ROCK signaling and decrease in beta-catenin and ZO-1 expression. Inhibition of GSK-3beta reduced HPMEC monolayers hyper-permeability and GEF-H1/ROCK activity in response to LPS. GSK-3beta/GEF-H1/ROCK signaling is implicated in regulating the expression of beta-catenin and ZO-1. In vivo , GSK-3beta inhibition attenuated LPS-induced activation of GEF-H1/ROCK pathway, lung edema and subsequent ALI. These findings present a new mechanism of GSK-3beta-dependent exacerbation of lung micro-vascular hyper-permeability and escalation of ALI via activation of GEF-H1/ROCK signaling and disruption of intracellular junctional proteins under septic condition.

Endothelial progenitor cells and rheumatic disease modifying therapy.

PubMed

Lo Gullo, Alberto; Aragona, Caterina Oriana; Michele, Scuruchi; Versace, Antonio Giovanni; Antonino, Saitta; Egidio, Imbalzano; Loddo, Saverio; Campo, Giuseppe Maurizio; Giuseppe, Mandraffino

2018-05-26

Rheumatic diseases are associated with accelerated atherosclerosis and with increased risk of cardiovascular morbidity and mortality. The mechanisms underlying the higher prevalence of cardiovascular disease are not completely clarified, but it is likely that a pivotal role is played by vascular inflammation and consequently to altered vascular endothelium homeostasis. Also, high prevalence of traditional risk factors, proatherogenic activation and endothelial dysfunction further contribute to vascular damage. Circulating endothelial progenitor cells (EPCs) can restore dysfunctional endothelium and protect against atherosclerotic vascular disease. However, abnormalities in number and function of these cells in patients with rheumatic condition have been extensively reported. During the last years, growing interest in the mechanisms of endothelial renewal and its potential as a therapy for CVD has been shown; in addition, pioneering studies show that EPC dysfunction might be improved with pharmacological strategies. However, how to restore EPC function, and whether achieving this aim may be effective in preventing cardiovascular complications in rheumatic disease, remain to be established. In this review we report an overview on the current stand of knowledge on the effect of pharmaceutical and lifestyle intervention in improving EPCs number and function in rheumatic disease. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of cognate, non-cognate and synthetic CXCR4 and ACKR3 ligands on human lung endothelial cell barrier function.

PubMed

Cheng, You-Hong; Eby, Jonathan M; LaPorte, Heather M; Volkman, Brian F; Majetschak, Matthias

2017-01-01

Recent evidence suggests that chemokine CXCL12, the cognate agonist of chemokine receptors CXCR4 and ACKR3, reduces thrombin-mediated impairment of endothelial barrier function. A detailed characterization of the effects of CXCL12 on thrombin-mediated human lung endothelial hyperpermeability is lacking and structure-function correlations are not available. Furthermore, effects of other CXCR4/ACKR3 ligands on lung endothelial barrier function are unknown. Thus, we tested the effects of a panel of CXCR4/ACKR3 ligands (CXCL12, CXCL11, ubiquitin, AMD3100, TC14012) and compared the CXCR4/ACKR3 activities of CXCL12 variants (CXCL12α/β, CXCL12(3-68), CXCL121, CXCL122, CXCL12-S-S4V, CXCL12-R47E, CXCL12-K27A/R41A/R47A) with their effects on human lung endothelial barrier function in permeability assays. CXCL12α enhanced human primary pulmonary artery endothelial cell (hPPAEC) barrier function, whereas CXCL11, ubiquitin, AMD3100 and TC14012 were ineffective. Pre-treatment of hPPAEC with CXCL12α and ubiquitin reduced thrombin-mediated hyperpermeability. CXCL12α-treatment of hPPAEC after thrombin exposure reduced barrier function impairment by 70% (EC50 0.05-0.5nM), which could be antagonized with AMD3100; ubiquitin (0.03-3μM) was ineffective. In a human lung microvascular endothelial cell line (HULEC5a), CXCL12α and ubiquitin post-treatment attenuated thrombin-induced hyperpermeability to a similar degree. CXCL12(3-68) was inefficient to activate CXCR4 in Presto-Tango β-arrestin2 recruitment assays; CXCL12-S-S4V, CXCL12-R47E and CXCL12-K27A/R41A/R47A showed significantly reduced potencies to activate CXCR4. While the potencies of all proteins in ACKR3 Presto-Tango assays were comparable, the efficacy of CXCL12(3-68) to activate ACKR3 was significantly reduced. The potencies to attenuate thrombin-mediated hPPAEC barrier function impairment were: CXCL12α/β, CXCL121, CXCL12-K27A/R41A/R47A > CXCL12-S-S4V, CXCL12-R47E > CXCL122 > CXCL12(3-68). Our findings indicate that CXCR4 activation attenuates thrombin-induced lung endothelial barrier function impairment and suggest that protective effects of CXCL12 are dictated by its CXCR4 agonist activity and interactions of distinct protein moieties with heparan sulfate on the endothelial surface. These data may facilitate development of compounds with improved pharmacological properties to attenuate thrombin-induced vascular leakage in the pulmonary circulation.

Genetic Analysis Reveals a Longevity-Associated Protein Modulating Endothelial Function and Angiogenesis.

PubMed

Villa, Francesco; Carrizzo, Albino; Spinelli, Chiara C; Ferrario, Anna; Malovini, Alberto; Maciąg, Anna; Damato, Antonio; Auricchio, Alberto; Spinetti, Gaia; Sangalli, Elena; Dang, Zexu; Madonna, Michele; Ambrosio, Mariateresa; Sitia, Leopoldo; Bigini, Paolo; Calì, Gaetano; Schreiber, Stefan; Perls, Thomas; Fucile, Sergio; Mulas, Francesca; Nebel, Almut; Bellazzi, Riccardo; Madeddu, Paolo; Vecchione, Carmine; Puca, Annibale A

2015-07-31

Long living individuals show delay of aging, which is characterized by the progressive loss of cardiovascular homeostasis, along with reduced endothelial nitric oxide synthase activity, endothelial dysfunction, and impairment of tissue repair after ischemic injury. Exploit genetic analysis of long living individuals to reveal master molecular regulators of physiological aging and new targets for treatment of cardiovascular disease. We show that the polymorphic variant rs2070325 (Ile229Val) in bactericidal/permeability-increasing fold-containing-family-B-member-4 (BPIFB4) associates with exceptional longevity, under a recessive genetic model, in 3 independent populations. Moreover, the expression of BPIFB4 is instrumental to maintenance of cellular and vascular homeostasis through regulation of protein synthesis. BPIFB4 phosphorylation/activation by protein-kinase-R-like endoplasmic reticulum kinase induces its complexing with 14-3-3 and heat shock protein 90, which is facilitated by the longevity-associated variant. In isolated vessels, BPIFB4 is upregulated by mechanical stress, and its knock-down inhibits endothelium-dependent vasorelaxation. In hypertensive rats and old mice, gene transfer of longevity-associated variant-BPIFB4 restores endothelial nitric oxide synthase signaling, rescues endothelial dysfunction, and reduces blood pressure levels. Furthermore, BPIFB4 is implicated in vascular repair. BPIFB4 is abundantly expressed in circulating CD34(+) cells of long living individuals, and its knock-down in endothelial progenitor cells precludes their capacity to migrate toward the chemoattractant SDF-1. In a murine model of peripheral ischemia, systemic gene therapy with longevity-associated variant-BPIFB4 promotes the recruitment of hematopoietic stem cells, reparative vascularization, and reperfusion of the ischemic muscle. Longevity-associated variant-BPIFB4 may represent a novel therapeutic tool to fight endothelial dysfunction and promote vascular reparative processes. © 2015 American Heart Association, Inc.

Postprandial endothelial dysfunction in subjects with new-onset type 2 diabetes: an acarbose and nateglinide comparative study

PubMed Central

2010-01-01

Background Postprandial hyperglycemia is believed to affect vascular endothelial function. The aim of our study was to compare the effects of acarbose and nateglinide on postprandial endothelial dysfunction. Methods We recruited a total of 30 patients with newly diagnosed type 2 diabetes (19 men and 11 women, age 67.8 ± 7.3 years). Patients were randomly assigned to 3 groups receiving either 300 mg/day acarbose, 270 mg/day nateglinide, or no medication. A cookie test (consisting of 75 g carbohydrate, 25 g butter fat, and 7 g protein for a total of 553 kcal) was performed as dietary tolerance testing. During the cookie test, glucose and insulin levels were determined at 0, 30, 60, and 120 min after load. In addition, endothelial function was assessed by % flow-mediated dilation (FMD) of the brachial artery at 0 and 120 min after cookie load. Results Postprandial glucose and insulin levels were similar in the 3 groups. Postprandial endothelial dysfunction was similar in the 3 groups before treatment. After 12 weeks of intervention, postprandial FMD was significantly improved in the acarbose group compared with the control group (6.8 ± 1.3% vs 5.2 ± 1.1%, p = 0.0022). Area under the curve (AUC) for insulin response was significantly increased in the nateglinide and control groups; however, no significant change was observed in the acarbose group. Conclusions Our results suggest that acarbose improves postprandial endothelial function by improvement of postprandial hyperglycemia, independent of postprandial hyperinsulinemia. Acarbose may thus have more beneficial effects on postprandial endothelial function in patients with type 2 diabetes than nateglinide. PMID:20334663

Increase in acid sphingomyelinase level in human retinal endothelial cells and CD34+ circulating angiogenic cells isolated from diabetic individuals is associated with dysfunctional retinal vasculature and vascular repair process in diabetes

PubMed Central

Kady, Nermin; Yan, Yuanqing; Salazar, Tatiana; Wang, Qi; Chakravarthy, Harshini; Huang, Chao; Beli, Eleni; Navitskaya, Svetlana; Grant, Maria; Busik, Julia

2017-01-01

Background Diabetic retinopathy (DR) is a microvascular disease that results from retinal vascular degeneration and defective repair due to diabetes induced endothelial progenitor dysfunction. Objective Understanding key molecular factors involved in vascular degeneration and repair is paramount for developing effective DR treatment strategies. We propose that diabetes-induced activation of acid sphingomyelinase (ASM) plays essential role in retinal endothelial and CD34+ circulating angiogenic cell (CAC) dysfunction in diabetes. Methods Human retinal endothelial cells (HRECs) isolated from control and diabetic donor tissue and human CD34+ CACs from control and diabetic patients were used in this study. ASM mRNA and protein expression was assessed by quantitative PCR and ELISA, respectively. To evaluate the effect of diabetes-induced ASM on HRECs and CD34+ CACs function, tube formation, CAC incorporation into endothelial tubes, and diurnal release of CD34+ CACs in diabetic individuals was determined. Results ASM expression level was significantly increased in HRECs isolated from diabetic compared to control donor tissue, as well as CD34+CACs and plasma of diabetic patients. A significant decrease in tube area was observed in HRECs from diabetic donors as compared to control HRECs. The tube formation deficiency was associated with increased expression of ASM in diabetic HRECs. Moreover, diabetic CD34+ CACs with high ASM showed defective incorporation into endothelial tubes. Diurnal release of CD34+ CACs was disrupted with the rhythmicity lost in diabetic patients. Conclusion Collectively, these findings support that diabetes-induced ASM upregulation has a marked detrimental effect on both retinal endothelial cells and CACs. PMID:28457994

Associations between endothelial dysfunction and clinical and laboratory parameters in children and adolescents with sickle cell anemia

PubMed Central

Ferreira, Tatiane Anunciação; Machado, Vinícius Ramos; Perdiz, Marya Izadora; Lyra, Isa Menezes; Nascimento, Valma Lopes; Boa-Sorte, Ney; Andrade, Bruno B.; Ladeia, Ana Marice

2017-01-01

Background Hematological changes can drive damage of endothelial cells, which potentially lead to an early endothelial dysfunction in patients with sickle cell anemia (SCA). An association may exist between endothelial dysfunction and several clinical manifestations of SCA. The present study aims to evaluate the links between changes in endothelial function and clinical and laboratory parameters in children and adolescents with SCA. Methods This study included 40 children and adolescents with stable SCA as well as 25 healthy children; aged 6–18 years. All study subjects were evaluated for endothelial function using Doppler ultrasonography. In addition, a number of laboratory assays were performed, including reticulocyte and leukocyte counts as well as measurement of circulating levels of total bilirubin, C-reactive protein (CRP), glucose, lipoproteins and peripheral oxyhemoglobin saturation. These parameters were also compared between SCA patients who were undertaking hydroxyurea (HU) and those who were not. Results Flow-mediated vasodilation (FMD) values were found to be reduced in SCA patients compared with those detected in healthy controls. SCA individuals with lower FMD values exhibited higher number of hospital admissions due to vaso-occlusive events. Additional analyses revealed that patients who had decreased FMD values exhibited higher odds of acute chest syndrome (ACS) episodes. A preliminary analysis with limited number of individuals failed to demonstrate significant differences in FMD values between SCA individuals who were treated with HU and those who were not. Conclusions Children and adolescents with SCA exhibit impaired endothelial function. Reductions in FMD values are associated with ACS. These findings underline the potential use of FMD as screening strategy of SCA patients with severe prognosis at early stages. PMID:28863145

Arachidonic acid metabolites and endothelial dysfunction of portal hypertension.

PubMed

Sacerdoti, David; Pesce, Paola; Di Pascoli, Marco; Brocco, Silvia; Cecchetto, Lara; Bolognesi, Massimo

2015-07-01

Increased resistance to portal flow and increased portal inflow due to mesenteric vasodilatation represent the main factors causing portal hypertension in cirrhosis. Endothelial cell dysfunction, defined as an imbalance between the synthesis, release, and effect of endothelial mediators of vascular tone, inflammation, thrombosis, and angiogenesis, plays a major role in the increase of resistance in portal circulation, in the decrease in the mesenteric one, in the development of collateral circulation. Reduced response to vasodilators in liver sinusoids and increased response in the mesenteric arterioles, and, viceversa, increased response to vasoconstrictors in the portal-sinusoidal circulation and decreased response in the mesenteric arterioles are also relevant to the pathophysiology of portal hypertension. Arachidonic acid (AA) metabolites through the three pathways, cyclooxygenase (COX), lipoxygenase, and cytochrome P450 monooxygenase and epoxygenase, are involved in endothelial dysfunction of portal hypertension. Increased thromboxane-A2 production by liver sinusoidal endothelial cells (LSECs) via increased COX-1 activity/expression, increased leukotriens, increased epoxyeicosatrienoic acids (EETs) (dilators of the peripheral arterial circulation, but vasoconstrictors of the portal-sinusoidal circulation), represent a major component in the increased portal resistance, in the decreased portal response to vasodilators and in the hyper-response to vasoconstrictors. Increased prostacyclin (PGI2) via COX-1 and COX-2 overexpression, and increased EETs/heme-oxygenase-1/K channels/gap junctions (endothelial derived hyperpolarizing factor system) play a major role in mesenteric vasodilatation, hyporeactivity to vasoconstrictors, and hyper-response to vasodilators. EETs, mediators of liver regeneration after hepatectomy and of angiogenesis, may play a role in the development of regenerative nodules and collateral circulation, through stimulation of vascular endothelial growth factor (VEGF) inside the liver and in the portal circulation. Pharmacological manipulation of AA metabolites may be beneficial for cirrhotic portal hypertension. Copyright © 2015 Elsevier Inc. All rights reserved.

There's life in the old dog yet: vitamin C as a therapeutic option in endothelial dysfunction.

PubMed

Rodemeister, Sandra; Biesalski, Hans K

2014-08-27

The use of vitamin C against different diseases has been controversially and emotionally discussed since Linus Pauling published his cancer studies. In vitro and animal studies showed promising results and explained the impact of vitamin C, particularly in cases with endothelial dysfunction. Indeed, studies (reviewed in this issue of Critical Care by Oudemans-van Straaten and colleagues) using high-dose vitamin C and the parenteral route of application seem to be more successful than oral vitamin C delivery.

Assessment of Nephroprotective Potential of Histochrome during Induced Arterial Hypertension.

PubMed

Agafonova, I G; Bogdanovich, R N; Kolosova, N G

2015-12-01

Magnetic resonance tomography was employed to verify endothelial dysfunction of renal arteries in Wistar and OXYS rats under conditions of induced arterial hypertension. Angiography revealed changes in the size and form of renal arteries of hypertensive animals. In hypertensive rats, histochrome exerted a benevolent therapeutic effect in renal arteries: it decreased BP, diminished thrombus formation in fi ne capillaries and arterioles, demonstrated the anticoagulant properties, partially improved endothelial dysfunction of small renal arteries, and up-regulated the glomerular filtration.

Early Endothelial Bioactivity of Serum after Diesel Exhaust ...

EPA Pesticide Factsheets

Adverse cardiovascular effects of air pollution are often associated with a spike in systemic proinflammatory biomarkers, but causative linkage between circulating factors and deleterious outcomes following exposure remains elusive. Endothelial dysfunction is a consequence of systemic inflammation and precedes multiple cardiovascular pathologies. The purpose of this study was to examine the plausibility of serum-bound factors as initiators of an air pollution-induced pathologic sequelae beginning with endothelial injury, and later, cardiac dysfunction. We hypothesized that serum taken from diesel exhaust (DE)-exposed rats that develop cardiac dysfunction would alter aortic endothelial cell function in vitro. To assess cardiac function in vivo, left ventricular pressure (LVP) assessments were conducted in rats one day after a single 4 hour whole body exposure to 150 or 500 μg/m3 DE or filtered air. Rat aortic endothelial cells (RAEC) were then exposed to diluted serum (10%) collected 1 hour after exposure from a separate cohort of similarly exposed rats for measures of VCAM-1, cell viability, nitric oxide synthase (NOS) levels, and mRNA expression of key mediators of inflammation. Exposure of rats to 150 or 500 μg/m3 DE increased heart rate (HR) after exposure relative to rats exposed to filtered air, suggesting a shift towards increased sympathetic tone. LVP and HR in DE-exposed rats (500 μg/m3 DE) failed to recover to normal levels after challenge with the

Folic Acid Supplementation Improves Vascular Function in Professional Dancers With Endothelial Dysfunction

PubMed Central

Hoch, Anne Z.; Papanek, Paula; Szabo, Aniko; Widlansky, Michael E.; Gutterman, David D.

2012-01-01

Objective To determine if folic acid supplementation improves vascular function (brachial artery flow-mediated dilation [FMD]) in professional dancers with known endothelial dysfunction. Design Prospective cross-sectional study. Setting Academic institution in the Midwestern United States. Subjects Twenty-two professional ballet dancers volunteered for this study. Main Outcome Measures Subjects completed a 3-day food record to determine caloric and micronutrient intake. Menstrual status was determined by interview and questionnaire. Endothelial function was determined as flow-induced vasodilation measured by high-frequency ultrasound of the brachial artery. A change in brachial diameter of <5% to hyperemic flow stimulus was defined a priori as endothelial dysfunction. Subjects with abnormal FMD took 10 mg of folic acid daily for 4 weeks, and FMD testing was then repeated. Serum whole blood was measured for folic acid levels before and after supplementation. Results Sixty-four percent of dancers (n = 14) had abnormal brachial artery FMD (<5%) (mean ± standard deviation, 2.9% ± 1.5%). After 4 weeks of folic acid supplementation (10 mg/day), FMD improved in all the subjects (7.1% ± 2.3%; P < .0001). Conclusions This study reveals that vascular endothelial function improves in dancers after supplementation with folic acid (10 mg/day) for at least 4 weeks. This finding may have clinically important implications for future cardiovascular disease risk prevention. PMID:21715240

Intracellular Ascorbate Prevents Endothelial Barrier Permeabilization by Thrombin*

PubMed Central

Parker, William H.; Qu, Zhi-chao; May, James M.

2015-01-01

Intracellular ascorbate (vitamin C) has previously been shown to tighten the endothelial barrier and maintain barrier integrity during acute inflammation in vitro. However, the downstream effectors of ascorbate in the regulation of endothelial permeability remain unclear. In this study, we evaluated ascorbate as a mediator of thrombin-induced barrier permeabilization in human umbilical vein endothelial cells and their immortalized hybridoma line, EA.hy926. We found that the vitamin fully prevented increased permeability to the polysaccharide inulin by thrombin in a dose-dependent manner, and it took effect both before and after subjection to thrombin. Thrombin exposure consumed intracellular ascorbate but not the endogenous antioxidant GSH. Likewise, the antioxidants dithiothreitol and tempol did not reverse permeabilization. We identified a novel role for ascorbate in preserving cAMP during thrombin stimulation, resulting in two downstream effects. First, ascorbate maintained the cortical actin cytoskeleton in a Rap1- and Rac1-dependent manner, thus preserving stable adherens junctions between adjacent cells. Second, ascorbate prevented actin polymerization and formation of stress fibers by reducing the activation of RhoA and phosphorylation of myosin light chain. Although ascorbate and thrombin both required calcium for their respective effects, ascorbate did not prevent thrombin permeabilization by obstructing calcium influx. However, preservation of cAMP by ascorbate was found to depend on both the production of nitric oxide by endothelial nitric-oxide synthase, which ascorbate is known to activate, and the subsequent generation cGMP by guanylate cyclase. Together, these data implicate ascorbate in the prevention of inflammatory endothelial barrier permeabilization and explain the underlying signaling mechanism. PMID:26152729

Omentin protects against LPS-induced ARDS through suppressing pulmonary inflammation and promoting endothelial barrier via an Akt/eNOS-dependent mechanism.

PubMed

Qi, Di; Tang, Xumao; He, Jing; Wang, Daoxin; Zhao, Yan; Deng, Wang; Deng, Xinyu; Zhou, Guoqi; Xia, Jing; Zhong, Xi; Pu, Shenglan

2016-09-08

Acute respiratory distress syndrome (ARDS) is characterized by increased pulmonary inflammation and endothelial barrier permeability. Omentin has been shown to benefit obesity-related systemic vascular diseases; however, its effects on ARDS are unknown. In the present study, the level of circulating omentin in patients with ARDS was assessed to appraise its clinical significance in ARDS. Mice were subjected to systemic administration of adenoviral vector expressing omentin (Ad-omentin) and one-shot treatment of recombinant human omentin (rh-omentin) to examine omentin's effects on lipopolysaccharide (LPS)-induced ARDS. Pulmonary endothelial cells (ECs) were treated with rh-omentin to further investigate its underlying mechanism. We found that a decreased level of circulating omentin negatively correlated with white blood cells and procalcitonin in patients with ARDS. Ad-omentin protected against LPS-induced ARDS by alleviating the pulmonary inflammatory response and endothelial barrier injury in mice, accompanied by Akt/eNOS pathway activation. Treatment of pulmonary ECs with rh-omentin attenuated inflammatory response and restored adherens junctions (AJs), and cytoskeleton organization promoted endothelial barrier after LPS insult. Moreover, the omentin-mediated enhancement of EC survival and differentiation was blocked by the Akt/eNOS pathway inactivation. Therapeutic rh-omentin treatment also effectively protected against LPS-induced ARDS via the Akt/eNOS pathway. Collectively, these data indicated that omentin protects against LPS-induced ARDS by suppressing inflammation and promoting the pulmonary endothelial barrier, at least partially, through an Akt/eNOS-dependent mechanism. Therapeutic strategies aiming to restore omentin levels may be valuable for the prevention or treatment of ARDS.

Specific Binding, Uptake, and Transport of ICAM-1-Targeted Nanocarriers Across Endothelial and Subendothelial Cell Components of the Blood-Brain Barrier

PubMed Central

Hsu, Janet; Rappaport, Jeff; Muro, Silvia

2014-01-01

Purpose The blood-brain barrier (BBB) represents a target for therapeutic intervention and an obstacle for brain drug delivery. Targeting endocytic receptors on brain endothelial cells (ECs) helps transporting drugs and carriers into and across this barrier. While most receptors tested are associated with clathrin-mediated pathways, clathrin-independent routes are rather unexplored. We have examined the potential for one of these pathways, cell adhesion molecule (CAM)-mediated endocytosis induced by targeting intercellular adhesion molecule 1 (ICAM-1), to transport drug carriers into and across BBB models. Methods Model polymer nanocarriers (NCs) coated with control IgG or antibodies against ICAM-1 (IgG NCs vs. anti-ICAM NCs; ~250-nm) were incubated with human brain ECs, astrocytes (ACs), or pericytes (PCs) grown as monocultures or bilayered (endothelial+subendothelial) co-cultures. Results ICAM-1 was present and overexpressed in disease-like conditions on ECs and, at a lesser extent, on ACs and PCs which are BBB subendothelial components. Specific targeting and CAM-mediated uptake of anti-ICAM NCs occurred in these cells, although this was greater for ECs. Anti-ICAM NCs were transported across endothelial monolayers and endothelial+subendothelial co-cultures modeling the BBB. Conclusions CAM-mediated transport induced by ICAM-1 targeting operates in endothelial and subendothelial cellular components of the BBB, which may provide an avenue to overcome this barrier. PMID:24558007

Specific binding, uptake, and transport of ICAM-1-targeted nanocarriers across endothelial and subendothelial cell components of the blood-brain barrier.

PubMed

Hsu, Janet; Rappaport, Jeff; Muro, Silvia

2014-07-01

The blood-brain barrier (BBB) represents a target for therapeutic intervention and an obstacle for brain drug delivery. Targeting endocytic receptors on brain endothelial cells (ECs) helps transport drugs and carriers into and across this barrier. While most receptors tested are associated with clathrin-mediated pathways, clathrin-independent routes are rather unexplored. We have examined the potential for one of these pathways, cell adhesion molecule (CAM)-mediated endocytosis induced by targeting intercellular adhesion molecule -1 (ICAM-1), to transport drug carriers into and across BBB models. Model polymer nanocarriers (NCs) coated with control IgG or antibodies against ICAM-1 (IgG NCs vs. anti-ICAM NCs; ~250-nm) were incubated with human brain ECs, astrocytes (ACs), or pericytes (PCs) grown as monocultures or bilayered (endothelial+subendothelial) co-cultures. ICAM-1 was present and overexpressed in disease-like conditions on ECs and, at a lesser extent, on ACs and PCs which are BBB subendothelial components. Specific targeting and CAM-mediated uptake of anti-ICAM NCs occurred in these cells, although this was greater for ECs. Anti-ICAM NCs were transported across endothelial monolayers and endothelial+subendothelial co-cultures modeling the BBB. CAM-mediated transport induced by ICAM-1 targeting operates in endothelial and subendothelial cellular components of the BBB, which may provide an avenue to overcome this barrier.

Depleted nitric oxide and prostaglandin E2 levels are correlated with endothelial dysfunction in β-thalassemia/HbE patients.

PubMed

Satitthummanid, Sudarat; Uaprasert, Noppacharn; Songmuang, Smonporn Boonyaratavej; Rojnuckarin, Ponlapat; Tosukhowong, Piyaratana; Sutcharitchan, Pranee; Srimahachota, Suphot

2017-09-01

Mechanisms of vascular disorders in β-thalassemia/HbE patients remain poorly understood. In the present study, we aimed to determine the presence of endothelial dysfunction and its association with altered vascular mediators in this population. Forty-three β-thalassemia/HbE patients without clinically documented vascular symptoms and 43 age-sex-matched healthy controls were enrolled. Endothelial function was assessed using flow-mediated dilatation (FMD) before and after administration of nitroglycerine (NTG). β-Thalassemia/HbE patients showed a significant endothelial dysfunction using FMD. The percentage change in the brachial artery diameter before NTG was significantly lower in the thalassemia group compared to the control (5.0 ± 5.9 vs. 9.0 ± 4.0%, p < 0.01) while no significant differences after NTG (18.4 ± 8.3 vs. 17.8 ± 6.3%, p = 0.71). Plasma nitric oxide metabolites (NO x ) and prostaglandin E 2 (PGE 2 ) levels were significantly decreased in β-thalassemia/HbE (117.2 ± 27.3 vs. 135.8 ± 11.3 µmol/L, p < 0.01) and (701.9 ± 676.0 vs. 1374.7 ± 716.5 pg/mL, p < 0.01), respectively, while a significant elevation in soluble thrombomodulin levels in β-thalassemia/HbE (3587.7 ± 1310.0 vs. 3093.9 ± 583.8 pg/mL, p = 0.028). NO x and PGE 2 levels were significantly correlated with FMD (r = 0.27, p = 0.025) and (r = 0.35, p = 0.003), respectively. These findings suggest roles for endothelial mediators and a new mechanism underlying endothelial dysfunction in β-thalassemia/HbE patients.

Effect of Uric Acid-Lowering Agents on Endothelial Function: A Randomized, Double-Blind, Placebo-Controlled Trial.

PubMed

Borgi, Lea; McMullan, Ciaran; Wohlhueter, Ann; Curhan, Gary C; Fisher, Naomi D; Forman, John P

2017-02-01

Higher levels of serum uric acid are independently associated with endothelial dysfunction, a mechanism for incident hypertension. Overweight/obese individuals are more prone to endothelial dysfunction than their lean counterparts. However, the effect of lowering serum uric acid on endothelial dysfunction in these individuals has not been examined thoroughly. In this randomized, double-blind, placebo-controlled trial of nonhypertensive, overweight, or obese individuals with higher serum uric acid (body mass index ≥25 kg/m 2 and serum uric acid ≥5.0 mg/dL), we assigned subjects to probenecid (500-1000 mg/d), allopurinol (300-600 mg/d), or matching placebo. The primary outcome was endothelium-dependent vasodilation measured by brachial artery ultrasound at baseline and 8 weeks. By the end of the trial, 47, 49, and 53 participants had been allocated to receive probenecid, allopurinol, and placebo, respectively. Mean serum uric acid levels significantly decreased in the probenecid (from 6.1 to 3.5 mg/dL) and allopurinol groups (from 6.1 to 2.9 mg/dL) but not in the placebo group (6.1 to 5.6 mg/dL). None of the interventions produced any significant change in endothelium-dependent vasodilation (probenecid, 7.4±5.1% at baseline and 8.3±5.1% at 8 weeks; allopurinol, 7.6±6.0% at baseline and 6.2±4.8% at 8 weeks; and placebo, 6.5±3.8% at baseline and 7.1±4.9% at 8 weeks). In this randomized, double-blind, placebo-controlled trial, uric acid lowering did not affect endothelial function in overweight or obese nonhypertensive individuals. These data do not support the hypothesis that uric acid is causally related to endothelial dysfunction, a potential mechanism for development of hypertension. © 2016 American Heart Association, Inc.

EPA:DHA 6:1 prevents angiotensin II-induced hypertension and endothelial dysfunction in rats: role of NADPH oxidase- and COX-derived oxidative stress.

PubMed

Niazi, Zahid Rasul; Silva, Grazielle C; Ribeiro, Thais Porto; León-González, Antonio J; Kassem, Mohamad; Mirajkar, Abdur; Alvi, Azhar; Abbas, Malak; Zgheel, Faraj; Schini-Kerth, Valérie B; Auger, Cyril

2017-12-01

Eicosapentaenoic acid:docosahexaenoic acid (EPA:DHA) 6:1, an omega-3 polyunsaturated fatty acid formulation, has been shown to induce a sustained formation of endothelial nitric oxide (NO) synthase-derived NO, a major vasoprotective factor. This study examined whether chronic intake of EPA:DHA 6:1 prevents hypertension and endothelial dysfunction induced by angiotensin II (Ang II) in rats. Male Wister rats received orally corn oil or EPA:DHA 6:1 (500 mg kg -1 per day) before chronic infusion of Ang II (0.4 mg kg -1 per day). Systolic blood pressure was determined by tail cuff sphingomanometry, vascular reactivity using a myograph, oxidative stress using dihydroethidium and protein expression by immunofluorescence and western blot analysis. Ang II-induced hypertension was associated with reduced acetylcholine-induced relaxations of secondary branch mesenteric artery rings affecting the endothelium-dependent hyperpolarization (EDH)- and the NO-mediated relaxations, both of which were improved by the NADPH oxidase inhibitor VAS-2870. The Ang II treatment induced also endothelium-dependent contractile responses (EDCFs), which were abolished by the cyclooxygenase (COX) inhibitor indomethacin. An increased level of vascular oxidative stress and expression of NADPH oxidase subunits (p47 phox and p22 phox ), COX-1 and COX-2, endothelial NO synthase and Ang II type 1 receptors were observed in the Ang II group, whereas SK Ca and connexin 37 were downregulated. Intake of EPA:DHA 6:1 prevented the Ang II-induced hypertension and endothelial dysfunction by improving both the NO- and EDH-mediated relaxations, and by reducing EDCFs and the expression of target proteins. The present findings indicate that chronic intake of EPA:DHA 6:1 prevented the Ang II-induced hypertension and endothelial dysfunction in rats, most likely by preventing NADPH oxidase- and COX-derived oxidative stress.

The angiopoietin1-Akt pathway regulates barrier function of the cultured spinal cord microvascular endothelial cells through Eps8.

PubMed

Liu, Xinchun; Zhou, Xiaoshu; Yuan, Wei

2014-10-15

In mammalian central nervous system (CNS), the integrity of the blood-spinal cord barrier (BSCB), formed by tight junctions (TJs) between adjacent microvascular endothelial cells near the basement membrane of capillaries and the accessory structures, is important for relatively independent activities of the cellular constituents inside the spinal cord. The barrier function of the BSCB are tightly regulated and coordinated by a variety of physiological or pathological factors, similar with but not quite the same as its counterpart, the blood-brain barrier (BBB). Herein, angiopoietin 1 (Ang1), an identified ligand of the endothelium-specific tyrosine kinase receptor Tie-2, was verified to regulate barrier functions, including permeability, junction protein interactions and F-actin organization, in cultured spinal cord microvascular endothelial cells (SCMEC) of rat through the activity of Akt. Besides, these roles of Ang1 in the BSCB in vitro were found to be accompanied with an increasing expression of epidermal growth factor receptor pathway substrate 8 (Eps8), an F-actin bundling protein. Furthermore, the silencing of Eps8 by lentiviral shRNA resulted in an antagonistic effect vs. Ang1 on the endothelial barrier function of SCMEC. In summary, the Ang1-Akt pathway serves as a regulator in the barrier function modulation of SCMEC via the actin-binding protein Eps8. Copyright © 2014 Elsevier Inc. All rights reserved.

Hypothyroidism Is Associated With Coronary Endothelial Dysfunction in Women

PubMed Central

Sara, Jaskanwal D; Zhang, Ming; Gharib, Hossein; Lerman, Lilach O; Lerman, Amir

2015-01-01

Background Hypothyroidism is associated with an increased risk of coronary artery disease, beyond that which can be explained by its association with conventional cardiovascular risk factors. Coronary endothelial dysfunction precedes atherosclerosis, has been linked to adverse cardiovascular events, and may account for some of the increased risk in patients with hypothyroidism. The aim of this study was to determine whether there is an association between epicardial and microvascular coronary endothelial dysfunction and hypothyroidism. Methods and Results In 1388 patients (mean age 50.5 [12.3] years, 34% male) presenting with stable chest pain to Mayo Clinic, Rochester, MN for diagnostic coronary angiography, and who were found to have nonobstructive coronary artery disease (<40% stenosis), we invasively assessed coronary artery endothelial-dependent microvascular and epicardial function by evaluating changes in coronary blood flow (% Δ CBF Ach) and diameter (% Δ CAD Ach), respectively, in response to intracoronary infusions of acetylcholine. Patients were divided into 2 groups: hypothyroidism, defined as a documented history of hypothyroidism or a thyroid-stimulating hormone (TSH) >10.0 mU/mL, n=188, and euthyroidism, defined as an absence of a history of hypothyroidism in the clinical record and/or 0.3

Propionyl-L-Carnitine is Efficacious in Ulcerative Colitis Through its Action on the Immune Function and Microvasculature.

PubMed

Scioli, Maria Giovanna; Stasi, Maria Antonietta; Passeri, Daniela; Doldo, Elena; Costanza, Gaetana; Camerini, Roberto; Fociani, Paolo; Arcuri, Gaetano; Lombardo, Katia; Pace, Silvia; Borsini, Franco; Orlandi, Augusto

2014-03-20

Microvascular endothelial dysfunction characterizes ulcerative colitis (UC), the most widespread form of inflammatory bowel disease. Intestinal mucosal microvessels in UC display aberrant expression of cell adhesion molecules (CAMs) and increased inflammatory cell recruitment. Propionyl-L-carnitine (PLC), an ester of L-carnitine required for the mitochondrial transport of fatty acids, ameliorates propionyl-CoA bioavailability and reduces oxidative stress in ischemic tissues. The present study aimed to document the efficacy of anti-oxidative stress properties of PLC in counteracting intestinal microvascular endothelial dysfunction and inflammation. To evaluate the efficacy in vivo, we analyzed the effects in intestinal biopsies of patients with mild-to-moderate UC receiving oral PLC co-treatment and in rat TNBS-induced colitis; in addition, we investigated antioxidant PLC action in TNF-α-stimulated human intestinal microvascular endothelial cells (HIMECs) in vitro. Four-week PLC co-treatment reduced intestinal mucosal polymorph infiltration and CD4(+) lymphocytes, ICAM-1(+) and iNOS(+) microvessels compared with placebo-treated patients with UC. Oral and intrarectal administration of PLC but not L-carnitine or propionate reduced intestinal damage and microvascular dysfunction in rat TNBS-induced acute and reactivated colitis. In cultured TNF-α-stimulated HIMECs, PLC restored β-oxidation and counteracted NADPH oxidase 4-generated oxidative stress-induced CAM expression and leukocyte adhesion. Inhibition of β-oxidation by L-aminocarnitine increased reactive oxygen species production and PLC beneficial effects on endothelial dysfunction and leukocyte adhesion. Finally, PLC reduced iNOS activity and nitric oxide accumulation in rat TNBS-induced colitis and in HIMEC cultures. Our results show that the beneficial antioxidant effect of PLC targeting intestinal microvasculature restores endothelial β-oxidation and function, and reduces mucosal inflammation in UC patients.

Propionyl-L-Carnitine is Efficacious in Ulcerative Colitis Through its Action on the Immune Function and Microvasculature

PubMed Central

Scioli, Maria Giovanna; Stasi, Maria Antonietta; Passeri, Daniela; Doldo, Elena; Costanza, Gaetana; Camerini, Roberto; Fociani, Paolo; Arcuri, Gaetano; Lombardo, Katia; Pace, Silvia; Borsini, Franco; Orlandi, Augusto

2014-01-01

Objectives: Microvascular endothelial dysfunction characterizes ulcerative colitis (UC), the most widespread form of inflammatory bowel disease. Intestinal mucosal microvessels in UC display aberrant expression of cell adhesion molecules (CAMs) and increased inflammatory cell recruitment. Propionyl-L-carnitine (PLC), an ester of L-carnitine required for the mitochondrial transport of fatty acids, ameliorates propionyl-CoA bioavailability and reduces oxidative stress in ischemic tissues. The present study aimed to document the efficacy of anti-oxidative stress properties of PLC in counteracting intestinal microvascular endothelial dysfunction and inflammation. Methods: To evaluate the efficacy in vivo, we analyzed the effects in intestinal biopsies of patients with mild-to-moderate UC receiving oral PLC co-treatment and in rat TNBS-induced colitis; in addition, we investigated antioxidant PLC action in TNF-α-stimulated human intestinal microvascular endothelial cells (HIMECs) in vitro. Results: Four-week PLC co-treatment reduced intestinal mucosal polymorph infiltration and CD4+ lymphocytes, ICAM-1+ and iNOS+ microvessels compared with placebo-treated patients with UC. Oral and intrarectal administration of PLC but not L-carnitine or propionate reduced intestinal damage and microvascular dysfunction in rat TNBS-induced acute and reactivated colitis. In cultured TNF-α-stimulated HIMECs, PLC restored β-oxidation and counteracted NADPH oxidase 4-generated oxidative stress-induced CAM expression and leukocyte adhesion. Inhibition of β-oxidation by L-aminocarnitine increased reactive oxygen species production and PLC beneficial effects on endothelial dysfunction and leukocyte adhesion. Finally, PLC reduced iNOS activity and nitric oxide accumulation in rat TNBS-induced colitis and in HIMEC cultures. Conclusions: Our results show that the beneficial antioxidant effect of PLC targeting intestinal microvasculature restores endothelial β-oxidation and function, and reduces mucosal inflammation in UC patients. PMID:24646507

Chronic hydroxychloroquine improves endothelial dysfunction and protects kidney in a mouse model of systemic lupus erythematosus.

PubMed

Gómez-Guzmán, Manuel; Jiménez, Rosario; Romero, Miguel; Sánchez, Manuel; Zarzuelo, María José; Gómez-Morales, Mercedes; O'Valle, Francisco; López-Farré, Antonio José; Algieri, Francesca; Gálvez, Julio; Pérez-Vizcaino, Francisco; Sabio, José Mario; Duarte, Juan

2014-08-01

Hydroxychloroquine has been shown to be efficacious in the treatment of autoimmune diseases, including systemic lupus erythematosus. Hydroxychloroquine-treated lupus patients showed a lower incidence of thromboembolic disease. Endothelial dysfunction, the earliest indicator of the development of cardiovascular disease, is present in lupus. Whether hydroxychloroquine improves endothelial function in lupus is not clear. The aim of this study was to analyze the effects of hydroxychloroquine on hypertension, endothelial dysfunction, and renal injury in a female mouse model of lupus. NZBWF1 (lupus) and NZW/LacJ (control) mice were treated with hydroxychloroquine 10 mg/kg per day by oral gavage, or with tempol and apocynin in the drinking water, for 5 weeks. Hydroxychloroquine treatment did not alter lupus disease activity (assessed by plasma double-stranded DNA autoantibodies) but prevented hypertension, cardiac and renal hypertrophy, proteinuria, and renal injury in lupus mice. Aortae from lupus mice showed reduced endothelium-dependent vasodilator responses to acetylcholine and enhanced contraction to phenylephrine, which were normalized by hydroxychloroquine or antioxidant treatments. No differences among all experimental groups were found in both the relaxant responses to acetylcholine and the contractile responses to phenylephrine in rings incubated with the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester. Vascular reactive oxygen species content and mRNA levels of nicotinamide adenine dinucleotide phosphate oxidase subunits NOX-1 and p47(phox) were increased in lupus mice and reduced by hydroxychloroquine or antioxidants. Chronic hydroxychloroquine treatment reduced hypertension, endothelial dysfunction, and organ damage in severe lupus mice, despite the persistent elevation of anti-double-stranded DNA, suggesting the involvement of new additional mechanisms to improve cardiovascular complications. © 2014 American Heart Association, Inc.

Reduced proliferation of endothelial colony-forming cells in unprovoked venous thromboembolic disease as a consequence of endothelial dysfunction

PubMed Central

Hernandez-Lopez, Rubicel; Chavez-Gonzalez, Antonieta; Torres-Barrera, Patricia; Moreno-Lorenzana, Dafne; Lopez-DiazGuerrero, Norma; Santiago-German, David; Isordia-Salas, Irma; Smadja, David; C. Yoder, Mervin; Majluf-Cruz, Abraham

2017-01-01

Background Venous thromboembolic disease (VTD) is a public health problem. We recently reported that endothelial colony-forming cells (ECFCs) derived from endothelial cells (EC) (ECFC-ECs) from patients with VTD have a dysfunctional state. For this study, we proposed that a dysfunctional status of these cells generates a reduction of its proliferative ability, which is also associated with senescence and reactive oxygen species (ROS). Methods and results Human mononuclear cells (MNCs) were obtained from peripheral blood from 40 healthy human volunteers (controls) and 50 patients with VTD matched by age (20−50 years) and sex to obtain ECFCs. We assayed their proliferative ability with plasma of patients and controls and supernatants of cultures from ECFC-ECs, senescence-associated β-galactosidase (SA-β-gal), ROS, and expression of ephrin-B2/Eph-B4 receptor. Compared with cells from controls, cells from VTD patients showed an 8-fold increase of ECFCs that emerged 1 week earlier, reduced proliferation at long term (39%) and, in passages 4 and 10, a highly senescent rate (30±1.05% vs. 91.3±15.07%, respectively) with an increase of ROS and impaired expression of ephrin-B2/Eph-4 genes. Proliferation potential of cells from VTD patients was reduced in endothelial medium [1.4±0.22 doubling population (DP)], control plasma (1.18±0.31 DP), or plasma from VTD patients (1.65±0.27 DP). Conclusions As compared with controls, ECFC-ECs from individuals with VTD have higher oxidative stress, proliferation stress, cellular senescence, and low proliferative potential. These findings suggest that patients with a history of VTD are ECFC-ECs dysfunctional that could be associated to permanent risk for new thrombotic events. PMID:28910333

Importance of mitochondrial calcium uniporter in high glucose-induced endothelial cell dysfunction.

PubMed

Chen, Wei; Yang, Jie; Chen, Shuhua; Xiang, Hong; Liu, Hengdao; Lin, Dan; Zhao, Shaoli; Peng, Hui; Chen, Pan; Chen, Alex F; Lu, Hongwei

2017-11-01

Mitochondrial Ca 2+ overload is implicated in hyperglycaemia-induced endothelial cell dysfunction, but the key molecular events responsible remain unclear. We examined the involvement of mitochondrial calcium uniporter, which mediates mitochondrial Ca 2+ uptake, in endothelial cell dysfunction resulting from high-glucose treatment. Human umbilical vein endothelial cells were exposed to various glucose concentrations and to high glucose (30 mM) following mitochondrial calcium uniporter inhibition or activation with ruthenium red and spermine, respectively. Subsequently, mitochondrial calcium uniporter and mitochondrial calcium uniporter regulator 1 messenger RNA and protein expression was measured by real-time polymerase chain reaction and western blotting. Ca 2+ concentrations were analysed by laser confocal microscopy, and cytoplasmic and mitochondrial oxidative stress was detected using 2',7'-dichlorofluorescein diacetate and MitoSOX Red, respectively. Apoptosis was assessed by annexin V-fluorescein isothiocyanate/propidium iodide staining, and a wound-healing assay was performed using an in vitro model. High glucose markedly upregulated mitochondrial calcium uniporter and mitochondrial calcium uniporter regulator 1 messenger RNA expression, as well as protein production, in a dose- and time-dependent manner with a maximum effect demonstrated at 72 h and 30 mM glucose concentration. Moreover, high-glucose treatment significantly raised both mitochondrial and cytoplasmic Ca 2+ and reactive oxygen species levels, increased apoptosis and compromised wound healing (all p < 0.05). These effects were enhanced by spermine and completely negated by ruthenium red, which are known to activate and inhibit mitochondrial calcium uniporter, respectively. Mitochondrial calcium uniporter plays an important role in hyperglycaemia-induced endothelial cell dysfunction and may constitute a therapeutic target to reduce vascular complications in diabetes.

Antihypertensive therapy and endothelial function.

PubMed

Nadar, Sunil; Blann, Andrew D; Lip, Gregory Y H

2004-01-01

The benefits of treating hypertension in terms of reduction of morbidity and mortality are well established. However, it is debatable whether this benefit is derived entirely from the effects of a reduced blood pressure or whether these agents exert effects over and above blood pressure reduction on the endothelium. Hypertension is associated with adverse changes (whether damage or dysfunction) in the endothelium. Indeed, endothelial damage/dysfunction has have been demonstrated to be a reliable prognostic indicator of future cardiovascular events in hypertension. Of the various drug classes, calcium channel blockers and the ACE inhibitors have significant direct effects on the endothelium. This is in contrast to the beta blockers and alpha adrenergic blockers that appear to indirectly influence endothelial function solely as a result of lowered blood pressure. Antioxidants may have a beneficial effect on endothelial function as well, although their clinical use does not seem to translate into clinical benefit.

SIRT1 activation inhibits hyperglycemia-induced apoptosis by reducing oxidative stress and mitochondrial dysfunction in human endothelial cells.

PubMed

Wang, Shengqiang; Wang, Jian; Zhao, Airong; Li, Jigang

2017-09-01

Sustained hyperglycemic stimulation of vascular cells is involved in the pathogenesis of diabetes mellitus‑induced cardiovascular complications. Silent information regulator T1 (SIRT1), a mammalian sirtuin, has been previously recognized to protect endothelial cells against hyperglycemia‑induced oxidative stress. In the present study, human umbilical vein endothelial cells (HUV‑EC‑C) were treated with D‑glucose, and the levels of oxidative stress, mitochondrial dysfunction, the rate of apoptosis and SIRT1 activity were measured. The effect of manipulated SIRT1 activity on hyperglycemia‑induced oxidative stress, mitochondrial dysfunction and apoptosis was then assessed using the SIRT1 activator, resveratrol (RSV), and the SIRT1 inhibitor, sirtinol. The present study confirmed that hyperglycemia promotes oxidative stress and mitochondrial dysfunction in HUV‑EC‑C cells. The accumulation of reactive oxygen species, the swelling of mitochondria, the ratio of adenosine 5'‑diphosphate to adenosine 5'‑triphosphate and localized mitochondrial superoxide levels were all increased following D‑glucose treatment, whereas the mitochondrial membrane potential was significantly reduced by >50 mg/ml D‑glucose treatment. In addition, hyperglycemia was confirmed to induce apoptosis in HUV‑EC‑C cells. Furthermore, the results confirmed the prevention and aggravation of hyperglycemia‑induced apoptosis by RSV treatment and sirtinol treatment, via the amelioration and enhancement of oxidative stress and mitochondrial dysfunction in HUV‑EC‑C cells, respectively. In conclusion, the present study revealed that hyperglycemia promotes oxidative stress, mitochondrial dysfunction and apoptosis in HUV‑EC‑C cells, and manipulation of SIRT1 activity regulated hyperglycemia‑induced mitochondrial dysfunction and apoptosis in HUV‑EC‑C cells. The data revealed the protective effect of SIRT1 against hyperglycemia‑induced apoptosis via the alleviation of mitochondrial dysfunction and oxidative stress.

Coffee bean polyphenols ameliorate postprandial endothelial dysfunction in healthy male adults.

PubMed

Ochiai, Ryuji; Sugiura, Yoko; Otsuka, Kazuhiro; Katsuragi, Yoshihisa; Hashiguchi, Teruto

2015-05-01

To reveal the effect of coffee bean polyphenols (CBPs) on blood vessels, this study aimed to investigate the effect of CBPs on acute postprandial endothelial dysfunction. Thirteen healthy non-diabetic men (mean age, 44.9 ± 1.4 years) consumed a test beverage (active: containing CBPs, placebo: no CBPs) before a 554-kcal test meal containing 14 g of protein, 30 g of fat and 58 g of carbohydrates. Then, a crossover analysis was performed to investigate the time-dependent changes in flow-mediated dilation (FMD) in the brachial artery. In the active group, the postprandial impairment of FMD was significantly improved, the two-hour postprandial nitric oxide metabolite levels were significantly increased and the six-hour postprandial urinary 8-epi-prostaglandin F2α levels were significantly reduced compared to the placebo group. The test meal increased the levels of blood glucose, insulin and triglycerides in both groups with no significant intergroup differences. These findings indicate that CBPs intake ameliorates postprandial endothelial dysfunction in healthy men.

Apicobasal polarity of brain endothelial cells

PubMed Central

Worzfeld, Thomas

2015-01-01

Normal brain homeostasis depends on the integrity of the blood–brain barrier that controls the access of nutrients, humoral factors, and immune cells to the CNS. The blood–brain barrier is composed mainly of brain endothelial cells. Forming the interface between two compartments, they are highly polarized. Apical/luminal and basolateral/abluminal membranes differ in their lipid and (glyco-)protein composition, allowing brain endothelial cells to secrete or transport soluble factors in a polarized manner and to maintain blood flow. Here, we summarize the basic concepts of apicobasal cell polarity in brain endothelial cells. To address potential molecular mechanisms underlying apicobasal polarity in brain endothelial cells, we draw on investigations in epithelial cells and discuss how polarity may go awry in neurological diseases. PMID:26661193

Aldehyde dehydrogenase 2 protects human umbilical vein endothelial cells against oxidative damage and increases endothelial nitric oxide production to reverse nitroglycerin tolerance.

PubMed

Hu, X Y; Fang, Q; Ma, D; Jiang, L; Yang, Y; Sun, J; Yang, C; Wang, J S

2016-06-10

Medical nitroglycerin (glyceryl trinitrate, GTN) use is limited principally by tolerance typified by a decrease in nitric oxide (NO) produced by biotransformation. Such tolerance may lead to endothelial dysfunction by inducing oxidative stress. In vivo studies have demonstrated that aldehyde dehydrogenase 2 (ALDH2) plays important roles in GTN biotransformation and tolerance. Thus, modification of ALDH2 expression represents a potentially effective strategy to prevent and reverse GTN tolerance and endothelial dysfunction. In this study, a eukaryotic expression vector containing the ALDH2 gene was introduced into human umbilical vein endothelial cells (HUVECs) by liposome-mediated transfection. An indirect immunofluorescence assay showed that ALDH2 expression increased 24 h after transfection. Moreover, real-time polymerase chain reaction and western blotting revealed significantly higher ALDH2 mRNA and protein expression in the gene-transfected group than in the two control groups. GTN tolerance was induced by treating HUVECs with 10 mM GTN for 16 h + 10 min, which significantly decreased NO levels in control cells, but not in those transfected with ALDH2. Overexpression of ALDH2 increased cell survival against GTN-induced cytotoxicity and conferred protection from oxidative damage resulting from nitrate tolerance, accompanied by decreased production of intracellular reactive oxygen species and reduced expression of heme oxygenase 1. Furthermore, ALDH2 overexpression promoted Akt phosphorylation under GTN tolerance conditions. ALDH2 gene transfection can reverse and prevent tolerance to GTN through its bioactivation and protect against oxidative damage, preventing the development of endothelial dysfunction.

REM sleep deprivation induces endothelial dysfunction and hypertension in middle-aged rats: Roles of the eNOS/NO/cGMP pathway and supplementation with L-arginine.

PubMed

Jiang, Jiaye; Gan, Zhongyuan; Li, Yuan; Zhao, Wenqi; Li, Hanqing; Zheng, Jian-Pu; Ke, Yan

2017-01-01

Sleep loss can induce or aggravate the development of cardiovascular and cerebrovascular diseases. However, the molecular mechanism underlying this phenomenon is poorly understood. The present study was designed to investigate the effects of REM sleep deprivation on blood pressure in rats and the underlying mechanisms of these effects. After Sprague-Dawley rats were subjected to REM sleep deprivation for 5 days, their blood pressures and endothelial function were measured. In addition, one group of rats was given continuous access to L-arginine supplementation (2% in distilled water) for the 5 days before and the 5 days of REM sleep deprivation to reverse sleep deprivation-induced pathological changes. The results showed that REM sleep deprivation decreased body weight, increased blood pressure, and impaired endothelial function of the aortas in middle-aged rats but not young rats. Moreover, nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) concentrations as well as endothelial NO synthase (eNOS) phosphorylation in the aorta were decreased by REM sleep deprivation. Supplementation with L-arginine could protect against REM sleep deprivation-induced hypertension, endothelial dysfunction, and damage to the eNOS/NO/cGMP signaling pathway. The results of the present study suggested that REM sleep deprivation caused endothelial dysfunction and hypertension in middle-aged rats via the eNOS/NO/cGMP pathway and that these pathological changes could be inhibited via L-arginine supplementation. The present study provides a new strategy to inhibit the signaling pathways involved in insomnia-induced or insomnia-enhanced cardiovascular diseases.

Dietary restriction but not angiotensin II type 1 receptor blockade improves DNA damage-related vasodilator dysfunction in rapidly aging Ercc1Δ/- mice.

PubMed

Wu, Haiyan; van Thiel, Bibi S; Bautista-Niño, Paula K; Reiling, Erwin; Durik, Matej; Leijten, Frank P J; Ridwan, Yanto; Brandt, Renata M C; van Steeg, Harry; Dollé, Martijn E T; Vermeij, Wilbert P; Hoeijmakers, Jan H J; Essers, Jeroen; van der Pluijm, Ingrid; Danser, A H Jan; Roks, Anton J M

2017-08-01

DNA damage is an important contributor to endothelial dysfunction and age-related vascular disease. Recently, we demonstrated in a DNA repair-deficient, prematurely aging mouse model ( Ercc1 Δ/- mice) that dietary restriction (DR) strongly increases life- and health span, including ameliorating endothelial dysfunction, by preserving genomic integrity. In this mouse mutant displaying prominent accelerated, age-dependent endothelial dysfunction we investigated the signaling pathways involved in improved endothelium-mediated vasodilation by DR, and explore the potential role of the renin-angiotensin system (RAS). Ercc1 Δ/- mice showed increased blood pressure and decreased aortic relaxations to acetylcholine (ACh) in organ bath experiments. Nitric oxide (NO) signaling and phospho-Ser 1177 -eNOS were compromised in Ercc1 Δ / - DR improved relaxations by increasing prostaglandin-mediated responses. Increase of cyclo-oxygenase 2 and decrease of phosphodiesterase 4B were identified as potential mechanisms. DR also prevented loss of NO signaling in vascular smooth muscle cells and normalized angiotensin II (Ang II) vasoconstrictions, which were increased in Ercc1 Δ/- mice. Ercc1 Δ/ - mutants showed a loss of Ang II type 2 receptor-mediated counter-regulation of Ang II type 1 receptor-induced vasoconstrictions. Chronic losartan treatment effectively decreased blood pressure, but did not improve endothelium-dependent relaxations. This result might relate to the aging-associated loss of treatment efficacy of RAS blockade with respect to endothelial function improvement. In summary, DR effectively prevents endothelium-dependent vasodilator dysfunction by augmenting prostaglandin-mediated responses, whereas chronic Ang II type 1 receptor blockade is ineffective. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Mechanisms underlying the losartan treatment-induced improvement in the endothelial dysfunction seen in mesenteric arteries from type 2 diabetic rats.

PubMed

Matsumoto, Takayuki; Ishida, Keiko; Nakayama, Naoaki; Taguchi, Kumiko; Kobayashi, Tsuneo; Kamata, Katsuo

2010-09-01

It is well known that type 2 diabetes mellitus is frequently associated with vascular dysfunction and an elevated systemic blood pressure, yet the underlying mechanisms are not completely understood. We previously reported that in mesenteric arteries from established type 2 diabetic Otsuka Long-Evans Tokushima fatty (OLETF) rats, which exhibit endothelial dysfunction, there is an imbalance between endothelium-derived vasodilators [namely, nitric oxide (NO) and hyperpolarizing factor (EDHF)] and vasoconstrictors [contracting factors (EDCFs) such as cyclooxygenase (COX)-derived prostanoids]. Here, we investigated whether the angiotensin II receptor antagonist losartan might improve endothelial dysfunction in OLETF rats at the established stage of diabetes. In mesenteric arteries isolated from OLETF rats [vs. those from age-matched control Long-Evans Tokushima Otsuka (LETO) rats]: (1) the acetylcholine (ACh)-induced relaxation was impaired, (2) the NO- and EDHF-mediated relaxations were reduced, (3) the ACh-induced EDCF-mediated contraction and the production of prostanoids were increased, and (4) superoxide generation was increased. After such OLETF rats had received losartan (25 mg/kg/day p.o. for 4 weeks), their isolated mesenteric arteries exhibited: (1) improvements in ACh-induced NO- and EDHF-mediated relaxations, (2) reduced EDCF- and arachidonic acid-induced contractions, (3) suppressed production of prostanoids, (4) reduced PGE(2)-mediated contraction, and (5) reduced superoxide generation. Within the timescale studied here, losartan did not change the protein expressions of endothelial NO synthase, COX1, or COX2 in mesenteric arteries from either OLETF or LETO rats. Losartan thus normalizes vascular dysfunction in this type 2 diabetic model, and the above effects may contribute to the reduction of adverse cardiovascular events seen in diabetic patients treated with angiotensin II receptor blockers. Copyright 2010 Elsevier Ltd. All rights reserved.

COX-2 is involved in vascular oxidative stress and endothelial dysfunction of renal interlobar arteries from obese Zucker rats.

PubMed

Muñoz, Mercedes; Sánchez, Ana; Pilar Martínez, María; Benedito, Sara; López-Oliva, Maria-Elvira; García-Sacristán, Albino; Hernández, Medardo; Prieto, Dolores

2015-07-01

Obesity is related to vascular dysfunction through inflammation and oxidative stress and it has been identified as a risk factor for chronic renal disease. In the present study, we assessed the specific relationships among reactive oxygen species (ROS), cyclooxygenase 2 (COX-2), and endothelial dysfunction in renal interlobar arteries from a genetic model of obesity/insulin resistance, the obese Zucker rats (OZR). Relaxations to acetylcholine (ACh) were significantly reduced in renal arteries from OZR compared to their counterpart, the lean Zucker rat (LZR), suggesting endothelial dysfunction. Blockade of COX with indomethacin and with the selective blocker of COX-2 restored the relaxations to ACh in obese rats. Selective blockade of the TXA2/PGH2 (TP) receptor enhanced ACh relaxations only in OZR, while inhibition of the prostacyclin (PGI2) receptor (IP) enhanced basal tone and inhibited ACh vasodilator responses only in LZR. Basal production of superoxide was increased in arteries of OZR and involved NADPH and xanthine oxidase activation and NOS uncoupling. Under conditions of NOS blockade, ACh induced vasoconstriction and increased ROS generation that were augmented in arteries from OZR and blunted by COX-2 inhibition and by the ROS scavenger tempol. Hydrogen peroxide (H2O2) evoked both endothelium- and vascular smooth muscle (VSM)-dependent contractions, as well as ROS generation that was reduced by COX-2 inhibition. In addition, COX-2 expression was enhanced in both VSM and endothelium of renal arteries from OZR. These results suggest that increased COX-2-dependent vasoconstriction contributes to renal endothelial dysfunction through enhanced (ROS) generation in obesity. COX-2 activity is in turn upregulated by ROS. Copyright © 2015 Elsevier Inc. All rights reserved.

Endothelial Effects of Emission Source particles: Acute Toxic Response Gene Expression Profiles

EPA Science Inventory

Air pollution epidemiology has established a strong association between exposure to ambient particulate matter (PM) and cardiovascular outcomes. Experimental studies in both humans and laboratory animals support varied biological mechanisms including endothelial dysfunction as po...

The effects of hydroxychloroquine on endothelial dysfunction.

PubMed

Rahman, Rahana; Murthi, Padma; Singh, Harmeet; Gurusinghe, Seshini; Mockler, Joanne C; Lim, Rebecca; Wallace, Euan M

2016-10-01

Hydroxychloroquine is an anti-malarial drug which, due to its anti-inflammatory and immunomodulatory effects, is widely used for the treatment of autoimmune diseases. In a model of systemic lupus erythematosus hydroxychloroquine has been shown to exert protective endothelial effects. In this study, we aimed to investigate whether hydroxychloroquine was endothelial protective in an in vitro model of TNF-α and preeclamptic serum induced dysfunction. We showed that hydroxychloroquine significantly reduced the production of TNF-α and preeclamptic serum induced endothelin-1 (ET-1). Hydroxychloroquine also significantly mitigated TNF-α induced impairment of angiogenesis. These findings support the further assessment of hydroxychloroquine as an adjuvant therapy in preeclampsia. Copyright © 2016 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.

Glutamate-Mediated Blood-Brain Barrier Opening: Implications for Neuroprotection and Drug Delivery.

PubMed

Vazana, Udi; Veksler, Ronel; Pell, Gaby S; Prager, Ofer; Fassler, Michael; Chassidim, Yoash; Roth, Yiftach; Shahar, Hamutal; Zangen, Abraham; Raccah, Ruggero; Onesti, Emanuela; Ceccanti, Marco; Colonnese, Claudio; Santoro, Antonio; Salvati, Maurizio; D'Elia, Alessandro; Nucciarelli, Valter; Inghilleri, Maurizio; Friedman, Alon

2016-07-20

The blood-brain barrier is a highly selective anatomical and functional interface allowing a unique environment for neuro-glia networks. Blood-brain barrier dysfunction is common in most brain disorders and is associated with disease course and delayed complications. However, the mechanisms underlying blood-brain barrier opening are poorly understood. Here we demonstrate the role of the neurotransmitter glutamate in modulating early barrier permeability in vivo Using intravital microscopy, we show that recurrent seizures and the associated excessive glutamate release lead to increased vascular permeability in the rat cerebral cortex, through activation of NMDA receptors. NMDA receptor antagonists reduce barrier permeability in the peri-ischemic brain, whereas neuronal activation using high-intensity magnetic stimulation increases barrier permeability and facilitates drug delivery. Finally, we conducted a double-blind clinical trial in patients with malignant glial tumors, using contrast-enhanced magnetic resonance imaging to quantitatively assess blood-brain barrier permeability. We demonstrate the safety of stimulation that efficiently increased blood-brain barrier permeability in 10 of 15 patients with malignant glial tumors. We suggest a novel mechanism for the bidirectional modulation of brain vascular permeability toward increased drug delivery and prevention of delayed complications in brain disorders. In this study, we reveal a new mechanism that governs blood-brain barrier (BBB) function in the rat cerebral cortex, and, by using the discovered mechanism, we demonstrate bidirectional control over brain endothelial permeability. Obviously, the clinical potential of manipulating BBB permeability for neuroprotection and drug delivery is immense, as we show in preclinical and proof-of-concept clinical studies. This study addresses an unmet need to induce transient BBB opening for drug delivery in patients with malignant brain tumors and effectively facilitate BBB closure in neurological disorders. Copyright © 2016 the authors 0270-6474/16/367727-13$15.00/0.

Glutamate-Mediated Blood–Brain Barrier Opening: Implications for Neuroprotection and Drug Delivery

PubMed Central

Vazana, Udi; Veksler, Ronel; Pell, Gaby S.; Prager, Ofer; Fassler, Michael; Chassidim, Yoash; Roth, Yiftach; Shahar, Hamutal; Zangen, Abraham; Raccah, Ruggero; Onesti, Emanuela; Ceccanti, Marco; Colonnese, Claudio; Santoro, Antonio; Salvati, Maurizio; D'Elia, Alessandro; Nucciarelli, Valter; Inghilleri, Maurizio

2016-01-01

The blood–brain barrier is a highly selective anatomical and functional interface allowing a unique environment for neuro-glia networks. Blood–brain barrier dysfunction is common in most brain disorders and is associated with disease course and delayed complications. However, the mechanisms underlying blood–brain barrier opening are poorly understood. Here we demonstrate the role of the neurotransmitter glutamate in modulating early barrier permeability in vivo. Using intravital microscopy, we show that recurrent seizures and the associated excessive glutamate release lead to increased vascular permeability in the rat cerebral cortex, through activation of NMDA receptors. NMDA receptor antagonists reduce barrier permeability in the peri-ischemic brain, whereas neuronal activation using high-intensity magnetic stimulation increases barrier permeability and facilitates drug delivery. Finally, we conducted a double-blind clinical trial in patients with malignant glial tumors, using contrast-enhanced magnetic resonance imaging to quantitatively assess blood–brain barrier permeability. We demonstrate the safety of stimulation that efficiently increased blood–brain barrier permeability in 10 of 15 patients with malignant glial tumors. We suggest a novel mechanism for the bidirectional modulation of brain vascular permeability toward increased drug delivery and prevention of delayed complications in brain disorders. SIGNIFICANCE STATEMENT In this study, we reveal a new mechanism that governs blood–brain barrier (BBB) function in the rat cerebral cortex, and, by using the discovered mechanism, we demonstrate bidirectional control over brain endothelial permeability. Obviously, the clinical potential of manipulating BBB permeability for neuroprotection and drug delivery is immense, as we show in preclinical and proof-of-concept clinical studies. This study addresses an unmet need to induce transient BBB opening for drug delivery in patients with malignant brain tumors and effectively facilitate BBB closure in neurological disorders. PMID:27445149

TRAIL death receptor 4 signaling via lysosome fusion and membrane raft clustering in coronary arterial endothelial cells: evidence from ASM knockout mice.

PubMed

Li, Xiang; Han, Wei-Qing; Boini, Krishna M; Xia, Min; Zhang, Yang; Li, Pin-Lan

2013-01-01

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptor, death receptor 4 (DR4), have been implicated in the development of endothelial dysfunction and atherosclerosis. However, the signaling mechanism mediating DR4 activation leading to endothelial injury remains unclear. We recently demonstrated that ceramide production via hydrolysis of membrane sphingomyelin by acid sphingomyelinase (ASM) results in membrane raft (MR) clustering and the formation of important redox signaling platforms, which play a crucial role in amplifying redox signaling in endothelial cells leading to endothelial dysfunction. The present study aims to investigate whether TRAIL triggers MR clustering via lysosome fusion and ASM activation, thereby conducting transmembrane redox signaling and changing endothelial function. Using confocal microscopy, we found that TRAIL induced MR clustering and co-localized with DR4 in coronary arterial endothelial cells (CAECs) isolated from wild-type (Smpd1 (+/+)) mice. Furthermore, TRAIL triggered ASM translocation, ceramide production, and NADPH oxidase aggregation in MR clusters in Smpd1 ( +/+ ) CAECs, whereas these observations were not found in Smpd1 (-/-) CAECs. Moreover, ASM deficiency reduced TRAIL-induced O(2) (-[Symbol: see text]) production in CAECs and abolished TRAIL-induced impairment on endothelium-dependent vasodilation in small resistance arteries. By measuring fluorescence resonance energy transfer, we found that Lamp-1 (lysosome membrane marker protein) and ganglioside G(M1) (MR marker) were trafficking together in Smpd1 (+/+) CAECs, which was absent in Smpd1 (-/-) CAECs. Consistently, fluorescence imaging of living cells with specific lysosome probes demonstrated that TRAIL-induced lysosome fusion with membrane was also absent in Smpd1 (-/-) CAECs. Taken together, these results suggest that ASM is essential for TRAIL-induced lysosomal trafficking, membrane fusion and formation of MR redox signaling platforms, which may play an important role in DR4-mediated redox signaling in CAECs and consequently endothelial dysfunction.

Alkamides from Echinacea angustifolia Interact with P-glycoprotein of primary brain capillary endothelial cells isolated from porcine brain blood vessels.

PubMed

Mahringer, Anne; Ardjomand-Woelkart, Karin; Bauer, Rudolf; Fricker, Gert; Efferth, Thomas

2013-03-01

The blood-brain barrier prevents the passage of toxic compounds from blood circulation into brain tissue. Unfortunately, drugs for the treatment of neurodegenerative diseases, brain tumors, and other diseases also do not cross the blood-brain barrier. In the present investigation, we used isolated porcine brain capillary endothelial cells and a flow cytometric calcein-AM assay to analyze inhibition of P-glycoprotein, a major constituent of the blood-brain barrier. We tested 8 alkamides isolated from Echinacea angustifolia and found that four of them inhibited P-glycoprotein-mediated calcein transport in porcine brain capillary endothelial cells. Georg Thieme Verlag KG Stuttgart · New York.

Bleeding complications in dengue are not associated with significant changes in the modulators of the endothelial barrier.

PubMed

Orsi, Fernanda Andrade; Angerami, Rodrigo Nogueira; Mazetto, Bruna Moraes; Quaino, Susan Kelly Picoli; De Paula, Erich Vinícius; Annichino-Bizzachi, Joyce Maria

2014-06-11

Bleeding complications in dengue may occur irrespective of the presence of plasma leakage. We compared plasma levels of modulators of the endothelial barrier among three dengue groups: bleedings without plasma leakage, dengue hemorrhagic fever, and non-complicated dengue. The aim was to evaluate whether the presence of subtle alterations in microvascular permeability could be detected in bleeding patients. Plasma levels of VEGF-A and its soluble receptors were not associated with the occurrence of bleeding in patients without plasma leakage. These results provide additional rationale for considering bleeding as a complication independent of endothelial barrier breakdown, as proposed by the 2009 WHO classification.

Early detection of endothelial injury and dysfunction in conjunction with correction of hemodynamic maladjustment can effectively restore renal function in type 2 diabetic nephropathy.

PubMed

Futrakul, Narisa; Butthep, Punnee; Vongthavarawat, Varaphon; Futrakul, Prasit; Sirisalipoch, Sasitorn; Chaivatanarat, Tawatchai; Suwanwalaikorn, Sompongse

2006-01-01

This paper was aimed to investigate (1) the early marker of endothelial injury in type 2 diabetes, (2) the intrarenal hemodynamics and renal function, and (3) the therapeutic strategy aiming to restore renal function. Fifty patients (35 normoalbuminuric and 15 albuminuric type 2 diabetes) were examined. Blood was collected for determination of circulating vascular endothelial cells (CEC) and the serum was prepared for determination of transforming growth factor beta (TGFbeta), ratio of CEC/TGFbeta, and soluble vascular cell adhesion molecule. Intrarenal hemodynamics and renal function were also assessed. The results showed that increased number of circulating EC, elevated TGFbeta and depleted ratio of CEC/TGFbeta were significantly observed. Intrarenal hemodynamic study revealed a hemodynamic maladjustment characterized by preferential constriction of the efferent arteriole, intraglomerular hypertension and reduction in peritubular capillary flow. It was concluded that early marker of endothelial injury is reflected by increasing number of CEC. Such markers correlate with the glomerular endothelial dysfunction associated with hemodynamic maladjustment. Early detection of endothelial injury and appropriate correction of hemodynamic maladjustment by multidrug vasodilators can effectively restore renal function in type 2 diabetic nephropathy.

C5a induces caspase-dependent apoptosis in brain vascular endothelial cells in experimental lupus.

PubMed

Mahajan, Supriya D; Tutino, Vincent M; Redae, Yonas; Meng, Hui; Siddiqui, Adnan; Woodruff, Trent M; Jarvis, James N; Hennon, Teresa; Schwartz, Stanley; Quigg, Richard J; Alexander, Jessy J

2016-08-01

Blood-brain barrier (BBB) dysfunction complicates central nervous system lupus, an important aspect of systemic lupus erythematosus. To gain insight into the underlying mechanism, vascular corrosion casts of brain were generated from the lupus mouse model, MRL/lpr mice and the MRL/MpJ congenic controls. Scanning electron microscopy of the casts showed loss of vascular endothelial cells in lupus mice compared with controls. Immunostaining revealed a significant increase in caspase 3 expression in the brain vascular endothelial cells, which suggests that apoptosis could be an important mechanism causing cell loss, and thereby loss of BBB integrity. Complement activation occurs in lupus resulting in increased generation of circulating C5a, which caused the endothelial layer to become 'leaky'. In this study, we show that C5a and lupus serum induced apoptosis in cultured human brain microvascular endothelial cells (HBMVECs), whereas selective C5a receptor 1 (C5aR1) antagonist reduced apoptosis in these cells, demonstrating C5a/C5aR1-dependence. Gene expression of initiator caspases, caspase 1 and caspase 8, and pro-apoptotic proteins death-associated protein kinase 1, Fas-associated protein (FADD), cell death-inducing DNA fragmentation factor 45 000 MW subunit A-like effector B (CIDEB) and BCL2-associated X protein were increased in HBMVECs treated with lupus serum or C5a, indicating that both the intrinsic and extrinsic apoptotic pathways could be critical mediators of brain endothelial cell apoptosis in this setting. Overall, our findings suggest that C5a/C5aR1 signalling induces apoptosis through activation of FADD, caspase 8/3 and CIDEB in brain endothelial cells in lupus. Further elucidation of the underlying apoptotic mechanisms mediating the reduced endothelial cell number is important in establishing the potential therapeutic effectiveness of C5aR1 inhibition that could prevent and/or reduce BBB alterations and preserve the physiological function of BBB in central nervous system lupus. © 2016 John Wiley & Sons Ltd.

Aldosterone affects blood flow and vascular tone regulated by endothelium-derived NO: therapeutic implications

PubMed Central

Toda, Noboru; Nakanishi, Sadanobu; Tanabe, Shinichi

2013-01-01

Aldosterone, in doses inappropriate to the salt status, plays an important role in the development of cardiovascular injury, including endothelial dysfunction, independent of its hypertensive effects. Acute non-genomic effects of aldosterone acting on mineralocorticoid receptors are inconsistent in healthy humans: vasoconstriction or forearm blood flow decrease via endothelial dysfunction, vasodilatation mediated by increased NO actions, or no effects. However, in studies with experimental animals, aldosterone mostly enhances vasodilatation mediated by endothelium-derived NO. Chronic exposure to aldosterone, which induces genomic responses, results in impairments of endothelial function through decreased NO synthesis and action in healthy individuals, experimental animals and isolated endothelial cells. Chronic aldosterone reduces NO release from isolated human endothelial cells only when extracellular sodium is raised. Oxidative stress is involved in the impairment of endothelial function by promoting NO degradation. Aldosterone liberates endothelin-1 (ET-1) from endothelial cells, which elicits ETA receptor–mediated vasoconstriction by inhibiting endothelial NO synthesis and action and through its own direct vasoconstrictor action. Ca2+ flux through T-type Ca2+ channels activates aldosterone synthesis and thus enhances unwanted effects of aldosterone on the endothelium. Mineralocorticoid receptor inhibitors, ETA receptor antagonists and T-type Ca2+ channel blockers appear to diminish the pathophysiological participation of aldosterone in cardiovascular disease and exert beneficial actions on bioavailability of endothelium-derived NO, particularly in resistant hypertension and aldosteronism. PMID:23190073

Establishment of pancreatic microenvironment model of ER stress: Quercetin attenuates β-cell apoptosis by invoking nitric oxide-cGMP signaling in endothelial cells.

PubMed

Suganya, Natarajan; Mani, Krishna Priya; Sireesh, Dornadula; Rajaguru, Palanisamy; Vairamani, Mariappanadar; Suresh, Thiruppathi; Suzuki, Takayoshi; Chatterjee, Suvro; Ramkumar, Kunka Mohanram

2018-05-01

The involvement of endoplasmic reticulum (ER) stress in endothelial dysfunction and diabetes-associated complications has been well documented. Inhibition of ER stress represents a promising therapeutic strategy to attenuate endothelial dysfunction in diabetes. Recent attention has focused on the development of small molecule inhibitors of ER stress to maintain endothelial homeostasis in diabetes. Here we have developed a reliable, robust co-culture system that allows a study on the endothelial cells and pancreatic β-cells crosstalk under ER stress and validated using a known ER stress modulator, quercetin. Furthermore, sensitizing of endothelial cells by quercetin (25 μM) confers protection of pancreatic β-cells against ER stress through nitric oxide (NO ∙ ) signaling. In addition, increased intracellular insulin and NO ∙ -mediated cyclic 3',5'-guanosine monophosphate (cGMP) levels in pancreatic β-cells further confirmed the mechanism of protection under co-culture system. In addition, the potential protein targets of quercetin against ER stress in the endothelial cells were investigated through proteomic profiling and its phosphoprotein targets through Bioplex analysis. On the whole, the developed in vitro co-culture set up can serve as a platform to study the signaling network between the endothelial and pancreatic β-cells as well as provides a mechanistic insight for the validation of novel ER stress modulators. Copyright © 2018 Elsevier Inc. All rights reserved.

Cardiovascular dysfunction in symptomatic primary hyperparathyroidism and its reversal after curative parathyroidectomy: results of a prospective case control study.

PubMed

Agarwal, Gaurav; Nanda, Gitika; Kapoor, Aditya; Singh, Kul Ranjan; Chand, Gyan; Mishra, Anjali; Agarwal, Amit; Verma, Ashok K; Mishra, Saroj K; Syal, Sanjeev K

2013-12-01

Cardiovascular mortality in primary hyperparathyroidism (PHPT) is attributed to myocardial and endothelial dysfunction. In this prospective, case-control study we assessed cardiovascular dysfunction in patients with symptomatic PHPT and its reversal after successful parathyroidectomy. Fifty-six patients with symptomatic PHPT underwent two-dimensional echocardiography, tissue Doppler (diastolic function assessment), serum N-terminal pro-brain natriuretic peptide (s-NTproBNP, a myocardial damage marker), and endothelial- and smooth muscle-dependent vasodilatory response (vascular dysfunction) studies before, 3, and 6 months after parathyroidectomy; 25 age-matched controls were studied similarly. Patients had greater left ventricular mass (192 ± 70 vs. 149 ± 44 g; P = .006), interventricular septal thickness (10.8 ± 2.5 vs. 9.0 ± 1.6 mm; P = .001), posterior wall thickness (9.9 ± 2.0 vs. 8.6 ± 2.2 mm; P = .004), and diastolic dysfunction (lower E/A trans-mitral flow velocity ratio [1.0 ± 0.4 vs. 1.3 ± 0.4; P = .01). Patients had greater s-NTproBNP (4,625 ± 1,130 vs. 58 ± 49 pg/mL; P = .002) and lower endothelial-mediated vasodilation (9.3 ± 8.6 vs. 11.7 ± 6.3%; P = .03) and smooth muscle-mediated vasodilation (20.1 ± 17.9 vs. 23.8 ± 11.2%; P = .01). Improvements in left ventricular mass, systolic and diastolic function, and smooth muscle-mediated vasodilation were noted from 3 to 6 months after parathyroidectomy. Endothelial-mediated vasodilation did not improve significantly. S-NTproBNP levels mirrored echocardiographic changes with a substantial, sustained decrease. Results were similar in hypertensive and normotensive patients. Symptomatic PHPT patients have substantial cardiac and vascular dysfunction, which improve by 6 months after parathyroidectomy. Objective cardiovascular evaluation may improve outcomes in symptomatic PHPT patients. Copyright © 2013 Mosby, Inc. All rights reserved.

Mechanistic link between erectile dysfunction and systemic endothelial dysfunction in type 2 diabetic rats

PubMed Central

Musicki, Biljana; Hannan, Johanna L.; Lagoda, Gwen; Bivalacqua, Trinity J.; Burnett, Arthur L.

2016-01-01

Men with type 2 diabetes mellitus (T2DM) and erectile dysfunction (ED) have greater risk of cardiovascular events than T2DM men without ED, suggesting ED as a predictor of cardiovascular events in diabetic men. However, molecular mechanisms underlying endothelial dysfunction in the diabetic penis explaining these clinical observations are not known. We evaluated whether the temporal relationship between ED and endothelial dysfunction in the systemic vasculature in T2DM involves earlier redox imbalance and endothelial nitric oxidase synthase (eNOS) dysfunction in the penis than in the systemic vasculature, such as the carotid artery. Rats were rendered T2DM by high-fat diet for 2 weeks, followed by an injection with low-dose streptozotocin. After 3 weeks, erectile function (intracavernosal pressure) was measured and penes and carotid arteries were collected for molecular analyses of eNOS uncoupling, protein S-glutathionylation, oxidative stress (4-hydroxy-2-nonenal, 4-HNE), protein expression of NADPH oxidase subunit gp91phox, endothelium-dependent vasodilation in the carotid artery, and non-andrenergic, non-cholinergic (NANC) mediated cavernosal relaxation. Erectile response to electrical stimulation of the cavernous nerve and NANC mediated cavernosal relaxation were decreased (p<0.05), while relaxation of the carotid artery to acetylcholine was not impaired in T2DM rats. eNOS monomerization, protein expressions of 4-HNE and gp91phox, and protein S-glutathionylation, were increased (p<0.05) in the penis, but not in the carotid artery, of T2DM compared to nondiabetic rats. In conclusion, redox imbalance, increased oxidative stress by NADPH oxidase, and eNOS uncoupling, occur early in T2DM in the penis, but not in the carotid artery. These molecular changes contribute to T2DM ED, while vascular function in the systemic vasculature remains preserved. PMID:27153512

Cardiovascular Implications of Erectile Dysfunction

MedlinePlus

... the penis are not able to dilate during sexual stimulation because of endothelial dysfunction, the penis cannot fill ... blood to the penis to dilate better during sexual stimulation. The PDE5-Is decrease blood pressure a little ...

Conditional Müllercell ablation causes independent neuronal and vascular pathologies in a novel transgenic model.

PubMed

Shen, Weiyong; Fruttiger, Marcus; Zhu, Ling; Chung, Sook H; Barnett, Nigel L; Kirk, Joshua K; Lee, SoRa; Coorey, Nathan J; Killingsworth, Murray; Sherman, Larry S; Gillies, Mark C

2012-11-07

Müller cells are the major glia of the retina that serve numerous functions essential to retinal homeostasis, yet the contribution of Müller glial dysfunction to retinal diseases remains largely unknown. We have developed a transgenic model using a portion of the regulatory region of the retinaldehyde binding protein 1 gene for conditional Müller cell ablation and the consequences of primary Müller cell dysfunction have been studied in adult mice. We found that selective ablation of Müller cells led to photoreceptor apoptosis, vascular telangiectasis, blood-retinal barrier breakdown and, later, intraretinal neovascularization. These changes were accompanied by impaired retinal function and an imbalance between vascular endothelial growth factor-A (VEGF-A) and pigment epithelium-derived factor. Intravitreal injection of ciliary neurotrophic factor inhibited photoreceptor injury but had no effect on the vasculopathy. Conversely, inhibition of VEGF-A activity attenuated vascular leak but did not protect photoreceptors. Our findings show that Müller glial deficiency may be an important upstream cause of retinal neuronal and vascular pathologies in retinal diseases. Combined neuroprotective and anti-angiogenic therapies may be required to treat Müller cell deficiency in retinal diseases and in other parts of the CNS associated with glial dysfunction.

Conditional Müller cell ablation causes independent neuronal and vascular pathologies in a novel transgenic model

PubMed Central

Shen, Weiyong; Fruttiger, Marcus; Zhu, Ling; Chung, Sook H.; Barnett, Nigel L.; Kirk, Joshua K.; Lee, SoRa; Coorey, Nathan J.; Killingsworth, Murray; Sherman, Larry S.; Gillies, Mark C.

2014-01-01

Müller cells are the major glia of the retina that serve numerous functions essential to retinal homeostasis, yet the contribution of Müller glial dysfunction to retinal diseases remains largely unknown. We have developed a transgenic model using a portion of the regulatory region of the retinaldehyde binding protein 1 gene for conditional Müller cell ablation and the consequences of primary Müller cell dysfunction have been studied in adult mice. We found that selective ablation of Müller cells led to photoreceptor apoptosis, vascular telangiectasis, blood-retinal barrier breakdown and, later, intraretinal neovascularization. These changes were accompanied by impaired retinal function and an imbalance between vascular endothelial growth factor-A (VEGF-A) and pigment epithelium derived factor. Intravitreal injection of cilliary neurotrophic factor inhibited photoreceptor injury but had no effect on the vasculopathy. Conversely, inhibition of VEGF-A activity attenuated vascular leak but did not protect photoreceptors. Our findings show that Müller glial deficiency may be an important upstream cause of retinal neuronal and vascular pathologies in retinal diseases. Combined neuroprotective and anti-angiogenic therapies may be required to treat Müller cell deficiency in retinal diseases and in other parts of the central nervous system associated with glial dysfunction. PMID:23136411

Endotoxin-Induced Endothelial Fibrosis Is Dependent on Expression of Transforming Growth Factors β1 and β2

PubMed Central

Echeverría, César; Montorfano, Ignacio; Tapia, Pablo; Riedel, Claudia; Cabello-Verrugio, Claudio

2014-01-01

During endotoxemia-induced inflammatory disease, bacterial endotoxins circulate in the bloodstream and interact with endothelial cells (ECs), inducing dysfunction of the ECs. We previously reported that endotoxins induce the conversion of ECs into activated fibroblasts. Through endotoxin-induced endothelial fibrosis, ECs change their morphology and their protein expression pattern, thereby suppressing endothelial markers and upregulating fibrotic proteins. The most commonly used fibrotic inducers are transforming growth factor β1 (TGF-β1) and TGF-β2. However, whether TGF-β1 and TGF-β2 participate in endotoxin-induced endothelial fibrosis remains unknown. We have shown that the endotoxin-induced endothelial fibrosis process is dependent on the TGF-β receptor, ALK5, and the activation of Smad3, a protein that is activated by ALK5 activation, thus suggesting that endotoxin elicits TGF-β production to mediate endotoxin-induced endothelial fibrosis. Therefore, we investigated the dependence of endotoxin-induced endothelial fibrosis on the expression of TGF-β1 and TGF-β2. Endotoxin-treated ECs induced the expression and secretion of TGF-β1 and TGF-β2. TGF-β1 and TGF-β2 downregulation inhibited the endotoxin-induced changes in the endothelial marker VE-cadherin and in the fibrotic proteins α-SMA and fibronectin. Thus, endotoxin induces the production of TGF-β1 and TGF-β2 as a mechanism to promote endotoxin-induced endothelial fibrosis. To the best of our knowledge, this is the first report showing that endotoxin induces endothelial fibrosis via TGF-β secretion, which represents an emerging source of vascular dysfunction. These findings contribute to understanding the molecular mechanism of endotoxin-induced endothelial fibrosis, which could be useful in the treatment of inflammatory diseases. PMID:24935972

Endotoxin-induced endothelial fibrosis is dependent on expression of transforming growth factors β1 and β2.

PubMed

Echeverría, César; Montorfano, Ignacio; Tapia, Pablo; Riedel, Claudia; Cabello-Verrugio, Claudio; Simon, Felipe

2014-09-01

During endotoxemia-induced inflammatory disease, bacterial endotoxins circulate in the bloodstream and interact with endothelial cells (ECs), inducing dysfunction of the ECs. We previously reported that endotoxins induce the conversion of ECs into activated fibroblasts. Through endotoxin-induced endothelial fibrosis, ECs change their morphology and their protein expression pattern, thereby suppressing endothelial markers and upregulating fibrotic proteins. The most commonly used fibrotic inducers are transforming growth factor β1 (TGF-β1) and TGF-β2. However, whether TGF-β1 and TGF-β2 participate in endotoxin-induced endothelial fibrosis remains unknown. We have shown that the endotoxin-induced endothelial fibrosis process is dependent on the TGF-β receptor, ALK5, and the activation of Smad3, a protein that is activated by ALK5 activation, thus suggesting that endotoxin elicits TGF-β production to mediate endotoxin-induced endothelial fibrosis. Therefore, we investigated the dependence of endotoxin-induced endothelial fibrosis on the expression of TGF-β1 and TGF-β2. Endotoxin-treated ECs induced the expression and secretion of TGF-β1 and TGF-β2. TGF-β1 and TGF-β2 downregulation inhibited the endotoxin-induced changes in the endothelial marker VE-cadherin and in the fibrotic proteins α-SMA and fibronectin. Thus, endotoxin induces the production of TGF-β1 and TGF-β2 as a mechanism to promote endotoxin-induced endothelial fibrosis. To the best of our knowledge, this is the first report showing that endotoxin induces endothelial fibrosis via TGF-β secretion, which represents an emerging source of vascular dysfunction. These findings contribute to understanding the molecular mechanism of endotoxin-induced endothelial fibrosis, which could be useful in the treatment of inflammatory diseases. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Intracellular Ascorbate Prevents Endothelial Barrier Permeabilization by Thrombin.

PubMed

Parker, William H; Qu, Zhi-chao; May, James M

2015-08-28

Intracellular ascorbate (vitamin C) has previously been shown to tighten the endothelial barrier and maintain barrier integrity during acute inflammation in vitro. However, the downstream effectors of ascorbate in the regulation of endothelial permeability remain unclear. In this study, we evaluated ascorbate as a mediator of thrombin-induced barrier permeabilization in human umbilical vein endothelial cells and their immortalized hybridoma line, EA.hy926. We found that the vitamin fully prevented increased permeability to the polysaccharide inulin by thrombin in a dose-dependent manner, and it took effect both before and after subjection to thrombin. Thrombin exposure consumed intracellular ascorbate but not the endogenous antioxidant GSH. Likewise, the antioxidants dithiothreitol and tempol did not reverse permeabilization. We identified a novel role for ascorbate in preserving cAMP during thrombin stimulation, resulting in two downstream effects. First, ascorbate maintained the cortical actin cytoskeleton in a Rap1- and Rac1-dependent manner, thus preserving stable adherens junctions between adjacent cells. Second, ascorbate prevented actin polymerization and formation of stress fibers by reducing the activation of RhoA and phosphorylation of myosin light chain. Although ascorbate and thrombin both required calcium for their respective effects, ascorbate did not prevent thrombin permeabilization by obstructing calcium influx. However, preservation of cAMP by ascorbate was found to depend on both the production of nitric oxide by endothelial nitric-oxide synthase, which ascorbate is known to activate, and the subsequent generation cGMP by guanylate cyclase. Together, these data implicate ascorbate in the prevention of inflammatory endothelial barrier permeabilization and explain the underlying signaling mechanism. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Simultaneous ultrasound-assisted water extraction and β-cyclodextrin encapsulation of polyphenols from Mangifera indica stem bark in counteracting TNFα-induced endothelial dysfunction.

PubMed

Mura, Marzia; Palmieri, Daniela; Garella, Davide; Di Stilo, Antonella; Perego, Patrizia; Cravotto, Giancarlo; Palombo, Domenico

2015-01-01

This study proposes an alternative technique to prevent heat degradation induced by classic procedures of bioactive compound extraction, comparing classical maceration/decoction in hot water of polyphenols from Mango (Mangifera indica L.) (MI) with ultrasound-assisted extraction (UAE) in a water solution of β-cyclodextrin (β-CD) at room temperature and testing their biological activity on TNFα-induced endothelial dysfunction. Both extracts counteracted TNFα effects on EAhy926 cells, down-modulating interleukin-6, interleukin-8, cyclooxygenase-2 and intracellular adhesion molecule-1, while increasing endothelial nitric oxide synthase levels. β-CD extract showed higher efficacy in improving endothelial function. These effects were abolished after pre-treatment with the oestrogen receptor inhibitor ICI1182,780. Moreover, the β-CD extract induced Akt activation and completely abolished the TNFα-induced p38MAPK phosphorylation. UAE and β-CD encapsulation provide an efficient extraction protocol that increases polyphenol bioavailability. Polyphenols from MI play a protective role on endothelial cells and may be further considered as oestrogen-like molecules with vascular protective properties.

Differential permissivity of human cerebrovascular endothelial cells to enterovirus infection and specificities of serotype EV-A71 in crossing an in vitro model of the human blood-brain barrier.

PubMed

Volle, Romain; Archimbaud, Christine; Couraud, Pierre-Olivier; Romero, Ignacio A; Weksler, Babette; Mirand, Audrey; Pereira, Bruno; Henquell, Cécile; Peigue-Lafeuille, Hélène; Bailly, Jean-Luc

2015-07-01

Human cerebral microvascular endothelial cells (hCMEC/D3 cell line) form a steady polarized barrier when cultured in vitro on a permeable membrane. Their susceptibility to enterovirus (EV) strains was analysed to investigate how these viruses may cross the blood-brain barrier. A sample of 88 virus strains was selected on phylogenetic features amongst 43 epidemiologically relevant types of the four EV species A-D. The EV-A71 genome was replicated at substantial rates, whilst the infectious virus was released at extremely low but sustained rates at both barrier sides for at least 4 days. EV-A71 antigens were detected in a limited number of cells. The properties of the endothelial barrier (structure and permeability) remained intact throughout infection. The chronic EV-A71 infection was in sharp contrast to the productive infection of cytolytic EVs (e.g. echoviruses E-6 and E-30). The hCMEC/D3 barriers infected with the latter EVs exhibited elevated proportions of apoptotic and necrotic cells, which resulted in major injuries to the endothelial barriers with a dramatic increase of paracellular permeability and virus crossing to the abluminal side. The following intracellular rearrangements were also seen: early destruction of the actin cytoskeleton, remodelling of intracellular membranes and reorganization of the mitochondrion network in a small cluster near the perinuclear space.

[A new possible strategy for prevention and preventive treatment of age-related macular degeneration resting on recent clinical and pathophysiological observations].

PubMed

Fischer, Tamás

2009-03-15

The beneficial effect achieved by the treatment of endothelial dysfunction in chronic cardiovascular diseases is already an evidence belonging to the basic treatment of the disease. Given the fact that the vascular system is uniform and consubstantial both physiologically, pathophysiologically and in terms of therapy, and that it plays a key role in age-related macular degeneration (AMD)--a disease leading to tragic loss of vision with its etiology and therapy being unknown--endothelial dysfunction should be treated. The pleiotropic effects of ACE-inhibitors, AR-blockers and statins and third generation beta blockers help to restitute the balance between vasodilators and vasoconstrictors in endothelial dysfunction caused by oxidative stress, the balance of growth factors and their inhibitors, pro- and anti-inflammatory substances and prothrombotic and fibrinolytic factors, inhibit the formation of oxidative stress and its harmful effects; while aspirin with its pleiotropic effects acting as an antiaggregation substance on platelets helps to set the endothelial layer back to its normal balance regarding its vasodilating, antithrombotic, antiadhesive and anti-inflammatory functions; trimetazidine as an adjuvant agent helps to normalize, to restore the disturbed metabolism of the retinal tissue functioning insufficiently, in the end. The angiotensin II receptor blocker telmisartan with its peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonist effect inhibits the development of choroidal neovascularisation (CNV) and improves it clinically favourably. The third generation beta adrenergic receptor blocker carvedilol and nebivolol as well as the peroxisome proliferator-activated receptor-gamma agonist pioglitazone elicit their antioxidant vascular protective effects mitochondrially. For the above reasons it is suggested that, as a part of long term primary and/or secondary prevention, the following groups of patients with AMD receive--taking into consideration all possible side effects--ACE-inhibitor and/or AR blocker and statin and aspirin treatment, and trimetazidine as adjuvant medicine, and third generation beta adrenergic receptor blockers: 1. those without macular degeneration but being above the age of 50 and having risk factors inducing endothelial dysfunction; 2. those, who already developed AMD in one eye as a prevention in the second, unaffected eye; and 3. those patients who developed AMD in both eyes in order to ameliorate or merely slow the progression of the disease. Besides, it is advisory and important to eliminate AMD risk factors (cardiovascular risk factors also) inducing oxidative stress with consecutive endothelial dysfunction.

Hydrophilic bile acids protect human blood-brain barrier endothelial cells from disruption by unconjugated bilirubin: an in vitro study

PubMed Central

Palmela, Inês; Correia, Leonor; Silva, Rui F. M.; Sasaki, Hiroyuki; Kim, Kwang S.; Brites, Dora; Brito, Maria A.

2015-01-01

Ursodeoxycholic acid and its main conjugate glycoursodeoxycholic acid are bile acids with neuroprotective properties. Our previous studies demonstrated their anti-apoptotic, anti-inflammatory, and antioxidant properties in neural cells exposed to elevated levels of unconjugated bilirubin (UCB) as in severe jaundice. In a simplified model of the blood-brain barrier, formed by confluent monolayers of a cell line of human brain microvascular endothelial cells, UCB has shown to induce caspase-3 activation and cell death, as well as interleukin-6 release and a loss of blood-brain barrier integrity. Here, we tested the preventive and restorative effects of these bile acids regarding the disruption of blood-brain barrier properties by UCB in in vitro conditions mimicking severe neonatal hyperbilirubinemia and using the same experimental blood-brain barrier model. Both bile acids reduced the apoptotic cell death induced by UCB, but only glycoursodeoxycholic acid significantly counteracted caspase-3 activation. Bile acids also prevented the upregulation of interleukin-6 mRNA, whereas only ursodeoxycholic acid abrogated cytokine release. Regarding barrier integrity, only ursodeoxycholic acid abrogated UCB-induced barrier permeability. Better protective effects were obtained by bile acid pre-treatment, but a strong efficacy was still observed by their addition after UCB treatment. Finally, both bile acids showed ability to cross confluent monolayers of human brain microvascular endothelial cells in a time-dependent manner. Collectively, data disclose a therapeutic time-window for preventive and restorative effects of ursodeoxycholic acid and glycoursodeoxycholic acid against UCB-induced blood-brain barrier disruption and damage to human brain microvascular endothelial cells. PMID:25821432

Role of Vascular and Lymphatic Endothelial Cells in Hantavirus Pulmonary Syndrome Suggests Targeted Therapeutic Approaches

PubMed Central

Gorbunova, Elena E.; Dalrymple, Nadine A.; Gavrilovskaya, Irina N.

2013-01-01

Abstract Background Hantaviruses in the Americas cause a highly lethal acute pulmonary edema termed hantavirus pulmonary syndrome (HPS). Hantaviruses nonlytically infect microvascular and lymphatic endothelial cells and cause dramatic changes in barrier functions without disrupting the endothelium. Hantaviruses cause changes in the function of infected endothelial cells that normally regulate fluid barrier functions. The endothelium of arteries, veins, and lymphatic vessels are unique and central to the function of vast pulmonary capillary beds that regulate pulmonary fluid accumulation. Results We have found that HPS-causing hantaviruses alter vascular barrier functions of microvascular and lymphatic endothelial cells by altering receptor and signaling pathway responses that serve to permit fluid tissue influx and clear tissue edema. Infection of the endothelium provides several mechanisms for hantaviruses to cause acute pulmonary edema, as well as potential therapeutic targets for reducing the severity of HPS disease. Conclusions Here we discuss interactions of HPS-causing hantaviruses with the endothelium, roles for unique lymphatic endothelial responses in HPS, and therapeutic targeting of the endothelium as a means of reducing the severity of HPS disease. PMID:24024573

Role of vascular and lymphatic endothelial cells in hantavirus pulmonary syndrome suggests targeted therapeutic approaches.

PubMed

Mackow, Erich R; Gorbunova, Elena E; Dalrymple, Nadine A; Gavrilovskaya, Irina N

2013-09-01

Hantaviruses in the Americas cause a highly lethal acute pulmonary edema termed hantavirus pulmonary syndrome (HPS). Hantaviruses nonlytically infect microvascular and lymphatic endothelial cells and cause dramatic changes in barrier functions without disrupting the endothelium. Hantaviruses cause changes in the function of infected endothelial cells that normally regulate fluid barrier functions. The endothelium of arteries, veins, and lymphatic vessels are unique and central to the function of vast pulmonary capillary beds that regulate pulmonary fluid accumulation. We have found that HPS-causing hantaviruses alter vascular barrier functions of microvascular and lymphatic endothelial cells by altering receptor and signaling pathway responses that serve to permit fluid tissue influx and clear tissue edema. Infection of the endothelium provides several mechanisms for hantaviruses to cause acute pulmonary edema, as well as potential therapeutic targets for reducing the severity of HPS disease. Here we discuss interactions of HPS-causing hantaviruses with the endothelium, roles for unique lymphatic endothelial responses in HPS, and therapeutic targeting of the endothelium as a means of reducing the severity of HPS disease.

Geraniol improves endothelial function by inhibiting NOX-2 derived oxidative stress in high fat diet fed mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xiaoyu; Zhao, Shiqi; Su, Mengqi

Endothelial dysfunction occurs in obese patients and high-fat diet (HFD) fed experimental animals. While geraniol has been reported to ameliorate inflammation and oxidative stress, inhibit tumor cell proliferation, and improve atherosclerosis, its direct effect on endothelial function remains uncharacterized. The present study therefore investigated the effect of geraniol on endothelial function in HFD mice and its underlying mechanisms. C57 BL/6 mice were fed an HFD (n = 40) or a normal diet (n = 20) for 8 weeks. HFD fed mice then were randomized to intraperitoneal treatment with geraniol (n = 20) or vehicle (n = 20) for another 6 weeks. Acetylcholine (Ach)-induced endothelial dependent vasorelaxation was measuredmore » on wire myography; reactive oxygen species (ROS) generation was assessed by fluorescence imaging, and NADPH oxidases (NOXs) and adhesive molecules VCAM-1 and ICAM-1 protein expression by western blotting. Geraniol improved endothelial function in HFD fed mice, as evidenced by its: 1. restoring endothelial dependent vasorelaxation induced by Ach, and reversing increased VCAM-1 and ICAM-1 expression; 2. attenuating HFD induced increased serum TBARS and aortic ROS generation; and 3. downregulating aortic NOX-2 expression in both HFD fed mice and in palmitic acid treated endothelial cells. Geraniol therefore protects against endothelial dysfunction induced by HFD through reducing NOX-2 associated ROS generation. -- Highlights: •Geraniol improved endothelial dependent relaxation in high fat diet fed mice. •Geraniol alleviated vascular injury in high fat diet fed mice. •Geraniol inhibited ROS generation through downregulating NOX-2 expression.« less

Flavorings in Tobacco Products Induce Endothelial Cell Dysfunction.

PubMed

Fetterman, Jessica L; Weisbrod, Robert M; Feng, Bihua; Bastin, Reena; Tuttle, Shawn T; Holbrook, Monica; Baker, Gregory; Robertson, Rose Marie; Conklin, Daniel J; Bhatnagar, Aruni; Hamburg, Naomi M

2018-06-14

Use of alternative tobacco products including electronic cigarettes is rapidly rising. The wide variety of flavored tobacco products available is of great appeal to smokers and youth. The flavorings added to tobacco products have been deemed safe for ingestion, but the cardiovascular health effects are unknown. The purpose of this study was to examine the effect of 9 flavors on vascular endothelial cell function. Freshly isolated endothelial cells from participants who use nonmenthol- or menthol-flavored tobacco cigarettes showed impaired A23187-stimulated nitric oxide production compared with endothelial cells from nonsmoking participants. Treatment of endothelial cells isolated from nonsmoking participants with either menthol (0.01 mmol/L) or eugenol (0.01 mmol/L) decreased A23187-stimulated nitric oxide production. To further evaluate the effects of flavoring compounds on endothelial cell phenotype, commercially available human aortic endothelial cells were incubated with vanillin, menthol, cinnamaldehyde, eugenol, dimethylpyrazine, diacetyl, isoamyl acetate, eucalyptol, and acetylpyrazine (0.1-100 mmol/L) for 90 minutes. Cell death, reactive oxygen species production, expression of the proinflammatory marker IL-6 (interleukin-6), and nitric oxide production were measured. Cell death and reactive oxygen species production were induced only at high concentrations unlikely to be achieved in vivo. Lower concentrations of selected flavors (vanillin, menthol, cinnamaldehyde, eugenol, and acetylpyridine) induced both inflammation and impaired A23187-stimulated nitric oxide production consistent with endothelial dysfunction. Our data suggest that short-term exposure of endothelial cells to flavoring compounds used in tobacco products have adverse effects on endothelial cell phenotype that may have relevance to cardiovascular toxicity. © 2018 American Heart Association, Inc.

Salicylate Treatment Improves Age-Associated Vascular Endothelial Dysfunction: Potential Role of Nuclear Factor κB and Forkhead Box O Phosphorylation

PubMed Central

Durrant, Jessica R.; Connell, Melanie L.; Folian, Brian J.; Donato, Anthony J.; Seals, Douglas R.

2011-01-01

We hypothesized that I kappa B kinase (IKK)-mediated nuclear factor kappa B and forkhead BoxO3a phosphorylation will be associated with age-related endothelial dysfunction. Endothelium-dependent dilation and aortic protein expression/phosphorylation were determined in young and old male B6D2F1 mice and old mice treated with the IKK inhibitor, salicylate. IKK activation was greater in old mice and was associated with greater nitrotyrosine and cytokines. Endothelium-dependent dilation, nitric oxide (NO), and endothelial NO synthase phosphorylation were lower in old mice. Endothelium-dependent dilation and NO bioavailability were restored by a superoxide dismutase mimetic. Nuclear factor kappa B and forkhead BoxO3a phosphorylation were greater in old and were associated with increased expression/activity of nicotinamide adenine dinucleotide phosphate oxidase and lower manganese superoxide dismutase expression. Salicylate lowered IKK phosphorylation and reversed age-associated changes in nitrotyrosine, endothelium-dependent dilation, NO bioavailability, endothelial NO synthase, nuclear factor kappa B and forkhead BoxO3a phosphorylation, nicotinamide adenine dinucleotide phosphate oxidase, and manganese superoxide dismutase. Increased activation of IKK with advancing age stimulates nuclear factor kappa B and inactivates forkhead BoxO3a. This altered transcription factor activation contributes to a pro-inflammatory/pro-oxidative arterial phenotype that is characterized by increased cytokines and nicotinamide adenine dinucleotide phosphate oxidase and decreased manganese superoxide dismutase leading to oxidative stress-mediated endothelial dysfunction. PMID:21303813

Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome.

PubMed

Gaubert, Mélanie; Marlinge, Marion; Alessandrini, Marine; Laine, Marc; Bonello, Laurent; Fromonot, Julien; Cautela, Jennifer; Thuny, Franck; Barraud, Jeremie; Mottola, Giovanna; Rossi, Pascal; Fenouillet, Emmanuel; Ruf, Jean; Guieu, Régis; Paganelli, Franck

2018-06-01

The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R 2  = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

Thrombomodulin, von Willebrand factor and E-selectin as plasma markers of endothelial damage/dysfunction and activation in pregnancy induced hypertension.

PubMed

Nadar, Sunil K; Al Yemeni, Eman; Blann, Andrew D; Lip, Gregory Y H

2004-01-01

Endothelial disturbance (whether activation, dysfunction or damage) is a likely pathogenic mechanism in pre-eclampsia and pregnancy-induced hypertension (PIH). We set out to determine which of three plasma markers of endothelial disturbance, indicating endothelial activation (E-selectin) or damage/dysfunction (von Willebrand factor (vWf), soluble thrombomodulin), would provide the best discriminator of PIH compared to normotensive pregnancy. Cross-sectional study of 36 consecutive women with PIH (age 31+/-6 years) and 36 consecutive women with normotensive pregnancies (age 29+/-5 years) of similar parity. Plasma levels of vWf, E-selectin and thrombomodulin were measured using ELISA. As expected, women with PIH had significantly higher levels of plasma vWf (by 19%, p=0.003), E-selectin (by 40%, p<0.001) and thrombomodulin (by 61%, p=0.01) than normotensive women. However, on stepwise multiple regression analysis, only thrombomodulin was an independent significant predictor of the presence of PIH (p=0.023). We conclude that although vWf, E-selectin and thrombomodulin are all raised in PIH, only thrombomodulin was independently associated with PIH. This molecule could potentially be useful in monitoring and in providing clues in aetiology and pathophysiology, and may have implications for the clinical complications associated with PIH.

Therapeutically targeting mitochondrial redox signalling alleviates endothelial dysfunction in preeclampsia.

PubMed

McCarthy, Cathal; Kenny, Louise C

2016-09-08

Aberrant placentation generating placental oxidative stress is proposed to play a critical role in the pathophysiology of preeclampsia. Unfortunately, therapeutic trials of antioxidants have been uniformly disappointing. There is provisional evidence implicating mitochondrial dysfunction as a source of oxidative stress in preeclampsia. Here we provide evidence that mitochondrial reactive oxygen species mediates endothelial dysfunction and establish that directly targeting mitochondrial scavenging may provide a protective role. Human umbilical vein endothelial cells exposed to 3% plasma from women with pregnancies complicated by preeclampsia resulted in a significant decrease in mitochondrial function with a subsequent significant increase in mitochondrial superoxide generation compared to cells exposed to plasma from women with uncomplicated pregnancies. Real-time PCR analysis showed increased expression of inflammatory markers TNF-α, TLR-9 and ICAM-1 respectively in endothelial cells treated with preeclampsia plasma. MitoTempo is a mitochondrial-targeted antioxidant, pre-treatment of cells with MitoTempo protected against hydrogen peroxide-induced cell death. Furthermore MitoTempo significantly reduced mitochondrial superoxide production in cells exposed to preeclampsia plasma by normalising mitochondrial metabolism. MitoTempo significantly altered the inflammatory profile of plasma treated cells. These novel data support a functional role for mitochondrial redox signaling in modulating the pathogenesis of preeclampsia and identifies mitochondrial-targeted antioxidants as potential therapeutic candidates.

Astrocytic TYMP and VEGFA drive blood–brain barrier opening in inflammatory central nervous system lesions

PubMed Central

Chapouly, Candice; Tadesse Argaw, Azeb; Horng, Sam; Castro, Kamilah; Zhang, Jingya; Asp, Linnea; Loo, Hannah; Laitman, Benjamin M.; Mariani, John N.; Straus Farber, Rebecca; Zaslavsky, Elena; Nudelman, German; Raine, Cedric S.

2015-01-01

In inflammatory central nervous system conditions such as multiple sclerosis, breakdown of the blood–brain barrier is a key event in lesion pathogenesis, predisposing to oedema, excitotoxicity, and ingress of plasma proteins and inflammatory cells. Recently, we showed that reactive astrocytes drive blood–brain barrier opening, via production of vascular endothelial growth factor A (VEGFA). Here, we now identify thymidine phosphorylase (TYMP; previously known as endothelial cell growth factor 1, ECGF1) as a second key astrocyte-derived permeability factor, which interacts with VEGFA to induce blood–brain barrier disruption. The two are co-induced NFκB1-dependently in human astrocytes by the cytokine interleukin 1 beta (IL1B), and inactivation of Vegfa in vivo potentiates TYMP induction. In human central nervous system microvascular endothelial cells, VEGFA and the TYMP product 2-deoxy-d-ribose cooperatively repress tight junction proteins, driving permeability. Notably, this response represents part of a wider pattern of endothelial plasticity: 2-deoxy-d-ribose and VEGFA produce transcriptional programs encompassing angiogenic and permeability genes, and together regulate a third unique cohort. Functionally, each promotes proliferation and viability, and they cooperatively drive motility and angiogenesis. Importantly, introduction of either into mouse cortex promotes blood–brain barrier breakdown, and together they induce severe barrier disruption. In the multiple sclerosis model experimental autoimmune encephalitis, TYMP and VEGFA co-localize to reactive astrocytes, and correlate with blood–brain barrier permeability. Critically, blockade of either reduces neurologic deficit, blood–brain barrier disruption and pathology, and inhibiting both in combination enhances tissue preservation. Suggesting importance in human disease, TYMP and VEGFA both localize to reactive astrocytes in multiple sclerosis lesion samples. Collectively, these data identify TYMP as an astrocyte-derived permeability factor, and suggest TYMP and VEGFA together promote blood–brain barrier breakdown. PMID:25805644

Mitochondrial DNA Damage Initiates Acute Lung Injury and Multi-Organ System Failure Evoked in Rats by Intra-Tracheal Pseudomonas Aeruginosa.

PubMed

Lee, Yann-Leei; Obiako, Boniface; Gorodnya, Olena M; Ruchko, Mykhaylo V; Kuck, Jamie L; Pastukh, Viktor M; Wilson, Glenn L; Simmons, Jon D; Gillespie, Mark N

2017-07-01

Although studies in rat cultured pulmonary artery endothelial cells, perfused lungs, and intact mice support the concept that oxidative mitochondrial (mt) DNA damage triggers acute lung injury (ALI), it has not yet been determined whether enhanced mtDNA repair forestalls development of ALI and its progression to multiple organ system failure (MOSF). Accordingly, here we examined the effect of a fusion protein construct targeting the DNA glycosylase, Ogg1, to mitochondria in a rat model intra-tracheal Pseudomonas aeruginosa (strain 103; PA103)-induced ALI and MOSF. Relative to controls, animals given PA103 displayed increases in lung vascular filtration coefficient accompanied by transient lung tissue oxidative mtDNA damage and variable changes in mtDNA copy number without evidence of nuclear DNA damage. The approximate 40% of animals surviving 24 h after bacterial administration exhibited multiple organ dysfunction, manifest as increased serum and tissue-specific indices of kidney and liver failure, along with depressed heart rate and blood pressure. While administration of mt-targeted Ogg1 to control animals was innocuous, the active fusion protein, but not a DNA repair-deficient mutant, prevented bacteria-induced increases in lung tissue oxidative mtDNA damage, failed to alter mtDNA copy number, and attenuated lung endothelial barrier degradation. These changes were associated with suppression of liver, kidney, and cardiovascular dysfunction and with decreased 24 h mortality. Collectively, the present findings indicate that oxidative mtDNA damage to lung tissue initiates PA103-induced ALI and MOSF in rats.

Shiga Toxin 1 Induces on Lipopolysaccharide-Treated Astrocytes the Release of Tumor Necrosis Factor-alpha that Alter Brain-Like Endothelium Integrity

PubMed Central

Landoni, Verónica I.; Schierloh, Pablo; de Campos Nebel, Marcelo; Fernández, Gabriela C.; Calatayud, Cecilia; Lapponi, María J.; Isturiz, Martín A.

2012-01-01

The hemolytic uremic syndrome (HUS) is characterized by hemolytic anemia, thrombocytopenia and renal dysfunction. The typical form of HUS is generally associated with infections by Gram-negative Shiga toxin (Stx)-producing Escherichia coli (STEC). Endothelial dysfunction induced by Stx is central, but bacterial lipopolysaccharide (LPS) and neutrophils (PMN) contribute to the pathophysiology. Although renal failure is characteristic of this syndrome, neurological complications occur in severe cases and is usually associated with death. Impaired blood-brain barrier (BBB) is associated with damage to cerebral endothelial cells (ECs) that comprise the BBB. Astrocytes (ASTs) are inflammatory cells in the brain and determine the BBB function. ASTs are in close proximity to ECs, hence the study of the effects of Stx1 and LPS on ASTs, and the influence of their response on ECs is essential. We have previously demonstrated that Stx1 and LPS induced activation of rat ASTs and the release of inflammatory factors such as TNF-α, nitric oxide and chemokines. Here, we demonstrate that rat ASTs-derived factors alter permeability of ECs with brain properties (HUVECd); suggesting that functional properties of BBB could also be affected. Additionally, these factors activate HUVECd and render them into a proagregant state promoting PMN and platelets adhesion. Moreover, these effects were dependent on ASTs secreted-TNF-α. Stx1 and LPS-induced ASTs response could influence brain ECs integrity and BBB function once Stx and factors associated to the STEC infection reach the brain parenchyma and therefore contribute to the development of the neuropathology observed in HUS. PMID:22479186

Could an endoneurial endothelial crosstalk between Wnt/β-catenin and Sonic Hedgehog pathways underlie the early disruption of the infra-orbital blood-nerve barrier following chronic constriction injury?

PubMed

Moreau, Nathan; Mauborgne, Annie; Couraud, Pierre-Olivier; Romero, Ignacio A; Weksler, Babette B; Villanueva, Luis; Pohl, Michel; Boucher, Yves

2017-01-01

Blood–nerve barrier disruption is pivotal in the development of neuroinflammation, peripheral sensitization, and neuropathic pain after peripheral nerve injury. Activation of toll-like receptor 4 and inactivation of Sonic Hedgehog signaling pathways within the endoneurial endothelial cells are key events, resulting in the infiltration of harmful molecules and immunocytes within the nerve parenchyma. However, we showed in a previous study that preemptive inactivation of toll-like receptor 4 signaling or sustained activation of Sonic Hedgehog signaling did not prevent the local alterations observed following peripheral nerve injury, suggesting the implication of another signaling pathway. Using a classical neuropathic pain model, the infraorbital nerve chronic constriction injury (IoN-CCI), we investigated the role of the Wnt/β-catenin pathway in chronic constriction injury-mediated blood–nerve barrier disruption and in its interactions with the toll-like receptor 4 and Sonic Hedgehog pathways. In the IoN-CCI model versus control, mRNA expression levels and/or immunochemical detection of major Wnt/Sonic Hedgehog pathway (Frizzled-7, vascular endothelial-cadherin, Patched-1 and Gli-1) and/or tight junction proteins (Claudin-1, Claudin-5, and Occludin) readouts were assessed. Vascular permeability was assessed by sodium fluorescein extravasation. IoN-CCI induced early alterations in the vascular endothelial-cadherin/β-catenin/Frizzled-7 complex, shown to participate in local blood–nerve barrier disruption via a β-catenin-dependent tight junction protein downregulation. Wnt pathway also mediated a crosstalk between toll-like receptor 4 and Sonic Hedgehog signaling within endoneurial endothelial cells. Nevertheless, preemptive inhibition of Wnt/β-catenin signaling before IoN-CCI could not prevent the downregulation of key Sonic Hedgehog pathway readouts or the disruption of the infraorbital blood–nerve barrier, suggesting that Sonic Hedgehog pathway inhibition observed following IoN-CCI is an independent event responsible for blood–nerve barrier disruption. A crosstalk between Wnt/β-catenin- and Sonic Hedgehog-mediated signaling pathways within endoneurial endothelial cells could mediate the chronic disruption of the blood–nerve barrier following IoN-CCI, resulting in increased irreversible endoneurial vascular permeability and neuropathic pain development.

Associations between psychological constructs and cardiac biomarkers following acute coronary syndrome

PubMed Central

Celano, Christopher M.; Beale, Eleanor E.; Beach, Scott R.; Belcher, Arianna M.; Suarez, Laura; Motiwala, Shweta R.; Gandhi, Parul U.; Gaggin, Hanna; Januzzi, James L.; Healy, Brian C.; Huffman, Jeff C.

2016-01-01

Objective Psychological constructs are associated with cardiovascular health, but the biological mechanisms mediating these relationships are unknown. We examined relationships between psychological constructs and markers of inflammation, endothelial function, and myocardial strain in a cohort of post-acute coronary syndrome (ACS) patients. Methods Participants (N=164) attended study visits 2 weeks and 6 months post-ACS. During these visits, they completed self-report measures of depressive symptoms, anxiety, optimism, and gratitude, and blood samples were collected for measurement of biomarkers reflecting inflammation, endothelial function, and myocardial strain. Generalized estimating equations and linear regression analyses were performed to examine concurrent and prospective relationships between psychological constructs and biomarkers. Results In concurrent analyses, depressive symptoms were associated with elevated markers of inflammation (interleukin-17: β=.047, 95% confidence interval [.010, .083]), endothelial dysfunction (endothelin-1: β=.020, [.004, .037]), and myocardial strain (N-terminal pro-B-type natriuretic peptide: β=.045, [.008, .083]), independent of age, sex, medical variables, and anxiety, while anxiety was not associated with these markers in multivariable adjusted models. Optimism and gratitude were associated with lower levels of markers of endothelial dysfunction (endothelin-1: gratitude: β=−.009, [−.017, −.001]; optimism: β=−.009, [−.016, −.001]; soluble intercellular adhesion molecule-1: gratitude: β=−.007, [−.014, −.000]), independent of depressive and anxiety symptoms. Psychological constructs at 2 weeks were not prospectively associated with biomarkers at 6 months. Conclusions Depressive symptoms were associated with more inflammation, myocardial strain, and endothelial dysfunction in the 6 months post-ACS, while positive psychological constructs were linked to better endothelial function. Larger, prospective studies may clarify the directionality of these relationships. PMID:27749683

Arginase Inhibition Restores Peroxynitrite-Induced Endothelial Dysfunction via L-Arginine-Dependent Endothelial Nitric Oxide Synthase Phosphorylation

PubMed Central

Nguyen, Minh Cong; Park, Jong Taek; Jeon, Yeong Gwan; Jeon, Byeong Hwa; Hoe, Kwang Lae; Kim, Young Myeong

2016-01-01

Purpose Peroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism. Materials and Methods Human umbilical vein endothelial cells (HUVECs) were treated with SIN-1, a peroxynitrite generator, and arginase activity, nitrite/nitrate production, and expression levels of proteins were measured. eNOS activation was evaluated via Western blot and dimer blot analysis. We also tested nitric oxide (NO) and reactive oxygen species (ROS) production and performed a vascular tension assay. Results SIN-1 treatment increased arginase activity in a time- and dose-dependent manner and reciprocally decreased nitrite/nitrate production that was prevented by peroxynitrite scavenger in HUVECs. Furthermore, SIN-1 induced an increase in the expression level of arginase I and II, though not in eNOS protein. The decreased eNOS phosphorylation at Ser1177 and the increased at Thr495 by SIN-1 were restored with arginase inhibitor and L-arginine. The changed eNOS phosphorylation was consistent in the stability of eNOS dimers. SIN-1 decreased NO production and increased ROS generation in the aortic endothelium, all of which was reversed by arginase inhibitor or L-arginine. NG-Nitro-L-arginine methyl ester (L-NAME) prevented SIN-1-induced ROS generation. In the vascular tension assay, SIN-1 enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxant responses to acetylcholine that were reversed by arginase inhibition. Conclusion These findings may explain the beneficial effect of arginase inhibition and L-arginine supplement on endothelial dysfunction under redox imbalance-dependent pathophysiological conditions. PMID:27593859

HZE ⁵⁶Fe-ion irradiation induces endothelial dysfunction in rat aorta: role of xanthine oxidase.

PubMed

Soucy, Kevin G; Lim, Hyun Kyo; Kim, Jae Hyung; Oh, Young; Attarzadeh, David O; Sevinc, Baris; Kuo, Maggie M; Shoukas, Artin A; Vazquez, Marcelo E; Berkowitz, Dan E

2011-10-01

Ionizing radiation has been implicated in the development of significant cardiovascular complications. Since radiation exposure is associated with space exploration, astronauts are potentially at increased risk of accelerated cardiovascular disease. This study investigated the effect of high atomic number, high-energy (HZE) iron-ion radiation on vascular and endothelial function as a model of space radiation. Rats were exposed to a single whole-body dose of iron-ion radiation at doses of 0, 0.5 or 1 Gy. In vivo aortic stiffness and ex vivo aortic tension responses were measured 6 and 8 months after exposure as indicators of chronic vascular injury. Rats exposed to 1 Gy iron ions demonstrated significantly increased aortic stiffness, as measured by pulse wave velocity. Aortic rings from irradiated rats exhibited impaired endothelial-dependent relaxation consistent with endothelial dysfunction. Acute xanthine oxidase (XO) inhibition or reactive oxygen species (ROS) scavenging restored endothelial-dependent responses to normal. In addition, XO activity was significantly elevated in rat aorta 4 months after whole-body irradiation. Furthermore, XO inhibition, initiated immediately after radiation exposure and continued until euthanasia, completely inhibited radiation-dependent XO activation. ROS production was elevated after 1 Gy irradiation while production of nitric oxide (NO) was significantly impaired. XO inhibition restored NO and ROS production. Finally, dietary XO inhibition preserved normal endothelial function and vascular stiffness after radiation exposure. These results demonstrate that radiation induced XO-dependent ROS production and nitroso-redox imbalance, leading to chronic vascular dysfunction. As a result, XO is a potential target for radioprotection. Enhancing the understanding of vascular radiation injury could lead to the development of effective methods to ameliorate radiation-induced vascular damage.

Arginase Inhibition Restores Peroxynitrite-Induced Endothelial Dysfunction via L-Arginine-Dependent Endothelial Nitric Oxide Synthase Phosphorylation.

PubMed

Nguyen, Minh Cong; Park, Jong Taek; Jeon, Yeong Gwan; Jeon, Byeong Hwa; Hoe, Kwang Lae; Kim, Young Myeong; Lim, Hyun Kyo; Ryoo, Sungwoo

2016-11-01

Peroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism. Human umbilical vein endothelial cells (HUVECs) were treated with SIN-1, a peroxynitrite generator, and arginase activity, nitrite/nitrate production, and expression levels of proteins were measured. eNOS activation was evaluated via Western blot and dimer blot analysis. We also tested nitric oxide (NO) and reactive oxygen species (ROS) production and performed a vascular tension assay. SIN-1 treatment increased arginase activity in a time- and dose-dependent manner and reciprocally decreased nitrite/nitrate production that was prevented by peroxynitrite scavenger in HUVECs. Furthermore, SIN-1 induced an increase in the expression level of arginase I and II, though not in eNOS protein. The decreased eNOS phosphorylation at Ser1177 and the increased at Thr495 by SIN-1 were restored with arginase inhibitor and L-arginine. The changed eNOS phosphorylation was consistent in the stability of eNOS dimers. SIN-1 decreased NO production and increased ROS generation in the aortic endothelium, all of which was reversed by arginase inhibitor or L-arginine. N(G)-Nitro-L-arginine methyl ester (L-NAME) prevented SIN-1-induced ROS generation. In the vascular tension assay, SIN-1 enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxant responses to acetylcholine that were reversed by arginase inhibition. These findings may explain the beneficial effect of arginase inhibition and L-arginine supplement on endothelial dysfunction under redox imbalance-dependent pathophysiological conditions.

The effect of bioresorbable vascular scaffold implantation on distal coronary endothelial function in dyslipidemic swine with and without diabetes.

PubMed

van den Heuvel, Mieke; Sorop, Oana; van Ditzhuijzen, Nienke S; de Vries, René; van Duin, Richard W B; Peters, Ilona; van Loon, Janine E; de Maat, Moniek P; van Beusekom, Heleen M; van der Giessen, Wim J; Jan Danser, A H; Duncker, Dirk J

2018-02-01

We studied the effect of bioresorbable vascular scaffold (BVS) implantation on distal coronary endothelial function, in swine on a high fat diet without (HFD) or with diabetes (DM+HFD). Five DM+HFD and five HFD swine underwent BVS implantation on top of coronary plaques, and were studied six months later. Conduit artery segments >5mm proximal and distal to the scaffold and corresponding segments of non-scaffolded coronary arteries, and segments of small arteries within the flow-territory of scaffolded and non-scaffolded arteries were harvested for in vitro vasoreactivity studies. Conduit segments proximal and distal of the BVS edges showed reduced endothelium-dependent vasodilation as compared to control vessels (p≤0.01), with distal segments being most prominently affected(p≤0.01). Endothelial dysfunction was only observed in DM±HFD swine and was principally due to a loss of NO. Endothelium-independent vasodilation and vasoconstriction were unaffected. Surprisingly, segments from the microcirculation distal to the BVS showed enhanced endothelium-dependent vasodilation (p<0.01), whereas endothelium-independent vasodilation and vasoconstriction were unaltered. This enhanced vasorelaxation was only observed in DM+HFD swine, and did not appear to be either NO- or EDHF-mediated. Six months of BVS implantation in DM+HFD swine causes NO-mediated endothelial dysfunction in nearby coronary segments, which is accompanied by a, possibly compensatory, increase in endothelial function of the distal microcirculation. Endothelial dysfunction extending into coronary conduit segments beyond the implantation-site, is in agreement with recent reports expressing concern for late scaffold thrombosis and of early BVS failure in diabetic patients. Copyright © 2017. Published by Elsevier B.V.

Hypochlorous acid-induced heme oxygenase-1 gene expression promotes human endothelial cell survival

PubMed Central

Wei, Yong; Liu, Xiao-ming; Peyton, Kelly J.; Wang, Hong; Johnson, Fruzsina K.; Johnson, Robert A.

2009-01-01

Hypochlorous acid (HOCl) is a unique oxidant generated by the enzyme myeloperoxidase that contributes to endothelial cell dysfunction and death in atherosclerosis. Since myeloperoxidase localizes with heme oxygenase-1 (HO-1) in and around endothelial cells of atherosclerotic lesions, the present study investigated whether there was an interaction between these two enzymes in vascular endothelium. Treatment of human endothelial cells with the myeloperoxidase product HOCl stimulated a concentration- and time-dependent increase in HO-1 protein that resulted in a significant rise in carbon monoxide (CO) production. The induction of HO-1 protein was preceded by a prominent increase in HO-1 mRNA and total and nuclear factor-erythroid 2-related factor 2 (Nrf2). In addition, HOCl induced a significant rise in HO-1 promoter activity that was blocked by mutating the antioxidant response element (ARE) in the promoter or by overexpressing a dominant-negative mutant of Nrf2. The HOCl-mediated induction of Nrf2 or HO-1 was blocked by the glutathione donor N-acetyl-l-cysteine but was unaffected by ascorbic or uric acid. Finally, treatment of endothelial cells with HOCl stimulated mitochondrial dysfunction, caspase-3 activation, and cell death that was potentiated by the HO inhibitor, tin protoporphyrin-IX, or by the knockdown of HO-1, and reversed by the exogenous administration of biliverdin, bilirubin, or CO. These results demonstrate that HOCl induces HO-1 gene transcription via the activation of the Nrf2/ARE pathway to counteract HOCl-mediated mitochondrial dysfunction and cell death. The ability of HOCl to activate HO-1 gene expression may represent a critical adaptive response to maintain endothelial cell viability at sites of vascular inflammation and atherosclerosis. PMID:19625608

Vitamin D Is a Regulator of Endothelial Nitric Oxide Synthase and Arterial Stiffness in Mice

PubMed Central

Andrukhova, Olena; Slavic, Svetlana; Zeitz, Ute; Riesen, Sabine C.; Heppelmann, Monika S.; Ambrisko, Tamas D.; Markovic, Mato; Kuebler, Wolfgang M.

2014-01-01

The vitamin D hormone 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] is essential for the preservation of serum calcium and phosphate levels but may also be important for the regulation of cardiovascular function. Epidemiological data in humans have shown that vitamin D insufficiency is associated with hypertension, left ventricular hypertrophy, increased arterial stiffness, and endothelial dysfunction in normal subjects and in patients with chronic kidney disease and type 2 diabetes. However, the pathophysiological mechanisms underlying these associations remain largely unexplained. In this study, we aimed to decipher the mechanisms by which 1,25(OH)2D3 may regulate systemic vascular tone and cardiac function, using mice carrying a mutant, functionally inactive vitamin D receptor (VDR). To normalize calcium homeostasis in VDR mutant mice, we fed the mice lifelong with the so-called rescue diet enriched with calcium, phosphate, and lactose. Here, we report that VDR mutant mice are characterized by lower bioavailability of the vasodilator nitric oxide (NO) due to reduced expression of the key NO synthesizing enzyme, endothelial NO synthase, leading to endothelial dysfunction, increased arterial stiffness, increased aortic impedance, structural remodeling of the aorta, and impaired systolic and diastolic heart function at later ages, independent of changes in the renin-angiotensin system. We further demonstrate that 1,25(OH)2D3 is a direct transcriptional regulator of endothelial NO synthase. Our data demonstrate the importance of intact VDR signaling in the preservation of vascular function and may provide a mechanistic explanation for epidemiological data in humans showing that vitamin D insufficiency is associated with hypertension and endothelial dysfunction. PMID:24284821

Systemic inflammation, endothelial dysfunction, and activation in clinically healthy children exposed to air pollutants.

PubMed

Calderón-Garcidueñas, L; Villarreal-Calderon, R; Valencia-Salazar, G; Henríquez-Roldán, C; Gutiérrez-Castrellón, P; Torres-Jardón, R; Osnaya-Brizuela, N; Romero, L; Torres-Jardón, R; Solt, A; Reed, W

2008-03-01

Mexico City children are chronically exposed to significant concentrations of air pollutants and exhibit chronic respiratory-tract inflammation. Epidemiological, controlled human exposures, laboratory-based animal models, and in vitro/in vivo studies have shown that inflammatory, endothelial dysfunction, and endothelial damage mediators are upregulated upon exposure to particulate matter (PM). Endothelial dysfunction is a critical event in cardiovascular disease. The focus of this work was to investigate whether exposure to ambient air pollution including PM(2.5) produces systemic inflammation and endothelial injury in healthy children. We measured markers of endothelial activation, and inflammatory mediators in 52 children age 8.6+/-0.1 yr, residents of Mexico City (n: 28) or of Polotitlán (n: 24), a city with low levels of pollutants. Mexico City children had significant increases in inflammatory mediators and vasoconstrictors, including tumor necrosis factor (TNF)alpha, prostaglandin (PG) E2, C-reactive protein, interleukin-1beta, and endothelin-1. There was a significant anti-inflammatory response, and a downregulation of vascular adhesion molecule-1, intercellular adhesion molecule-1 and -2, and selectins sE and sL. Results from linear regression found TNF a positively associated with 24- and 48-h cumulative levels of PM(2.5), while the 7-d PM(2.5) value was negatively associated with the numbers of white blood cells in peripheral blood in highly exposed children. Systemic subclinical inflammation, increased endothelin- 1, and significant downregulation of soluble adhesion molecules are seen in Mexico City children. Children chronically exposed to fine PM above the standard could be at risk of developing cardiovascular diseases, atherosclerosis, stroke, and other systemic effects later in life.

Albumin infusion improves renal blood flow autoregulation in patients with acute decompensation of cirrhosis and acute kidney injury.

PubMed

Garcia-Martinez, Rita; Noiret, Lorette; Sen, Sambit; Mookerjee, Rajeshwar; Jalan, Rajiv

2015-02-01

In cirrhotic patients with renal failure, renal blood flow autoregulation curve is shifted to the right, which is consequent upon sympathetic nervous system activation and endothelial dysfunction. Albumin infusion improves renal function in cirrhosis by mechanisms that are incompletely understood. We aimed to determine the effect of albumin infusion on systemic haemodynamics, renal blood flow, renal function and endothelial function in patients with acute decompensation of cirrhosis and acute kidney injury. Twelve patients with refractory ascites and 10 patients with acute decompensation of cirrhosis and acute kidney injury were studied. Both groups were treated with intravenous albumin infusion, 40-60 g/days over 3-4 days. Cardiac and renal haemodynamics were measured. Endothelial activation/dysfunction was assessed using von Willebrand factor and serum nitrite levels. F2α Isoprostanes, resting neutrophil burst and noradrenaline levels were quantified as markers of oxidative stress, endotoxemia and sympathetic activation respectively. Albumin infusion leads to a shift in the renal blood flow autoregulation curve towards normalization, which resulted in a significant increase in renal blood flow. Accordingly, improvement of renal function was observed. In parallel, a significant decrease in sympathetic activation, inflammation/oxidative stress and endothelial activation/dysfunction was documented. Improvement of renal blood flow correlated with improvement in endothelial activation (r = 0.741, P < 0.001). The data suggest that albumin infusion improves renal function in acutely decompensated cirrhotic patients with acute kidney injury by impacting on renal blood flow autoregulation. This is possibly achieved through endothelial stabilization and a reduction in the sympathetic tone, endotoxemia and oxidative stress. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Crossing the endothelial barrier during metastasis.

PubMed

Reymond, Nicolas; d'Água, Bárbara Borda; Ridley, Anne J

2013-12-01

During metastasis, cancer cells disseminate to other parts of the body by entering the bloodstream in a process that is called intravasation. They then extravasate at metastatic sites by attaching to endothelial cells that line blood vessels and crossing the vessel walls of tissues or organs. This Review describes how cancer cells cross the endothelial barrier during extravasation and how different receptors, signalling pathways and circulating cells such as leukocytes and platelets contribute to this process. Identification of the mechanisms that underlie cancer cell extravasation could lead to the development of new therapies to reduce metastasis.

Quantification of Malignant Breast Cancer Cell MDA-MB-231 Transmigration across Brain and Lung Microvascular Endothelium

PubMed Central

Fan, Jie; Fu, Bingmei M.

2015-01-01

Tumor cell extravasation through the endothelial barrier forming the microvessel wall is a crucial step during tumor metastasis. However, where, how and how fast tumor cells transmigrate through endothelial barriers remain unclear. Using an in vitro transwell model, we performed a transmigration assay of malignant breast tumor cells (MDA-MB-231) through brain and lung microvascular endothelial monolayers under control and pathological conditions. The locations and rates of tumor cell transmigration as well as the changes in the structural components (integrity) of endothelial monolayers were quantified by confocal microscopy. Endothelial monolayer permeability to albumin Palbumin was also quantified under the same conditions. We found that about 98% of transmigration occurred at the joints of endothelial cells instead of cell bodies; tumor cell adhesion and transmigration degraded endothelial surface glycocalyx and disrupted endothelial junction proteins, consequently increased Palbumin; more tumor cells adhered to and transmigrated through the endothelial monolayer with higher Palbumin; Palbumin and tumor transmigration were increased by vascular endothelial growth factor (VEGF), a representative of cytokines, and lipopolysaccharides (LPS), a typical systemic inflammatory factor, but reduced by adenosine 3′, 5′-cyclic monophosphate (cAMP). These results suggest that reinforcing endothelial structural integrity is an effective approach for inhibiting tumor extravasation. PMID:26603751

Influence of atrial fibrillation on plasma von willebrand factor, soluble E-selectin, and N-terminal pro B-type natriuretic peptide levels in systolic heart failure.

PubMed

Freestone, Bethan; Gustafsson, Finn; Chong, Aun Yeong; Corell, Pernille; Kistorp, Caroline; Hildebrandt, Per; Lip, Gregory Y H

2008-05-01

Endothelial dysfunction is present in patients with heart failure (HF) due to left ventricular systolic dysfunction, as well as in patients with atrial fibrillation (AF) who have normal cardiac function. It is unknown whether AF influences the degree of endothelial dysfunction in patients with systolic HF. We measured levels of plasma von Willebrand factor (vWF) and E-selectin (as indexes of endothelial damage/dysfunction and endothelial activation, respectively; both enzyme-linked immunosorbent assay) in patients with AF and HF (AF-HF), who were compared to patients with sinus rhythm and HF (SR-HF), as well as in age-matched, healthy, control subjects. We also assessed the relationship of vWF and E-selectin to plasma N-terminal pro B-type natriuretic peptide (NTpro-BNP), a marker for HF severity and prognosis. One hundred ninety patients (73% men; mean age, 69.0 +/- 10.1 years [+/- SD]) with systolic HF were studied, who were compared to 117 healthy control subjects: 52 subjects (27%) were in AF, while 138 subjects (73%) were in sinus rhythm. AF-HF patients were older than SR-HF patients (p = 0.046), but left ventricular ejection fraction and New York Heart Association class were similar. There were significant differences in NT-proBNP (p < 0.0001) and plasma vWF (p = 0.003) between patients and control subjects. On Tukey post hoc analysis, AF-HF patients had significantly increased NT-proBNP (p < 0.001) and vWF (p = 0.0183) but not E-selectin (p = 0.071) levels when compared to SR-HF patients. On multivariate analysis, the presence of AF was related to plasma vWF levels (p = 0.018). Plasma vWF was also significantly correlated with NT-proBNP levels (Spearman r = 0.139; p = 0.017). There is evidence of greater endothelial damage/dysfunction in AF-HF patients when compared to SR-HF patients. The clinical significance of this is unclear but may have prognostic value.

Elevated liver stiffness is linked to increased biomarkers of inflammation and immune activation in HIV/hepatitis C virus-coinfected patients.

PubMed

Medrano, Luz M; Garcia-Broncano, Pilar; Berenguer, Juan; González-García, Juan; Jiménez-Sousa, Ma Ángeles; Guardiola, Josep M; Crespo, Manuel; Quereda, Carmen; Sanz, José; Canorea, Isabel; Carrero, Ana; Hontañón, Victor; Muñoz-Fernández, Ma Ángeles; Resino, Salvador

2018-06-01

Immune dysregulation is a hallmark of HIV and hepatitis C virus (HCV) infections. We aimed to evaluate the relationship between liver stiffness measurement (LSM) and biomarkers of T-cell activation, bacterial translocation, inflammation, endothelial dysfunction, and coagulopathy in HIV/HCV-coinfected patients. Cross-sectional study. We studied 238 HIV/HCV-coinfected patients, 32 healthy controls, and 39 HIV-monoinfected patients. Patients were stratified according to LSM into four groups: less than 12.5, 12.5-25, 25-40, and more than 40 kPa. T-cell subsets were measured using flow cytometry and plasma biomarkers using immunoassays. HIV/HCV-coinfected patients had higher biomarker levels of immune activation in peripheral blood [T-cell activation (CD4CD38 and CD8CD38), bacterial translocation (soluble CD14), inflammation [IL-1b, IL-6, IL-8, IL-18, IFN-γ-inducible protein 10 (IP-10)] endothelial dysfunction [soluble vascular cell adhesion molecule 1 (sVCAM1), soluble intercellular cell adhesion molecule 1 (sICAM1), and soluble tumor necrosis factor receptor 1 (sTNFR1)], and coagulopathy (plasminogen activator inhibitor-1)] than healthy controls and HIV-monoinfected patients. Moreover, in HIV/HCV-coinfected patients, a direct relationship between LSM and immune activation [T-cell activation (CD8CD38 bacterial translocation (lipopolysaccharide), inflammation (IL-8, IP-10), endothelial dysfunction (sVCAM1, sICAM1, and sTNFR1), and coagulopathy (D-dimer)] was found. Subsequently, patients were stratified into different fibrosis stages, finding that patients with cirrhosis who had LSM at least 40 kPa showed higher biomarker values of immune activation [T-cell activation (CD4CD38 and CD8CD38), bacterial translocation (lipopolysaccharide), inflammation (IL-8, IL-6, IP-10), endothelial dysfunction (sVCAM1, sICAM1, and sTNFR1), and coagulopathy (D-dimer)] than patients from the other three groups (<12.5, 12.5-25, and 25-40 kPa). T-cell activation, bacterial translocation, inflammation, endothelial dysfunction, and coagulopathy increased with the severity of liver fibrosis in HIV/HCV-coinfected patients, particularly in patients who had LSM at least 40 kPa.

[Circuit resistance training improved endothelial dysfunction in obese aged women].

PubMed

Rosety, Ignacio; Pery, María Teresa; Rosety, Jesús; García, Natalia; Rodríguez-Pareja, María Antonia; Brenes-Martín, Francisco; Díaz, Antonio; Rosety-Rodríguez, Manuel; Ordoñez, Francisco Javier; Rosety, Miguel Ángel

2016-02-16

It is widely accepted that obesity is associated with endothelial dysfunction. In a recent paper, we have also found circuit resistance training may reduce visceral fat in obese aged women. Accordingly, the current study was conducted to ascertain the effects of circuit resistance training on markers of endothelial dysfunction in this population group. In the present interventional study, a total of 48 obese aged women were recruited from the community. Twenty-four of them were randomly assigned to perform a 12-week resistance circuit training programme, 3-days per week. This training was circularly performed in 6 stations: arm curl, leg extension, seated row, leg curl, triceps extension and leg press. The Jamar handgrip electronic dynamometer was used to assess maximal handgrip strength of the dominant hand. Lastly, serum samples were analysed using an immunoassay (ELISA) for endothelin-1, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). When compared to baseline, resistance training significantly reduced serum levels of endothelin-1 (2.28 ± 0.7 vs. 1.98 ± 1.1 pg/ml; p = 0.019; d = 0.67) and ICAM-1 (290 ± 69 vs. 255 ± 76 ng/ml; p = 0.004; d = 0.92) in the experimental group. No significant changes in any of the tested outcomes were found in the control group. A short-term circuit resistance program improved endothelial dysfunction in aged obese women. Further studies on this topic are still required to consolidate this approach in clinical application.