Inflammatory response and extracorporeal circulation.

PubMed

Kraft, Florian; Schmidt, Christoph; Van Aken, Hugo; Zarbock, Alexander

2015-06-01

Patients undergoing cardiac surgery with extracorporeal circulation (EC) frequently develop a systemic inflammatory response syndrome. Surgical trauma, ischaemia-reperfusion injury, endotoxaemia and blood contact to nonendothelial circuit compounds promote the activation of coagulation pathways, complement factors and a cellular immune response. This review discusses the multiple pathways leading to endothelial cell activation, neutrophil recruitment and production of reactive oxygen species and nitric oxide. All these factors may induce cellular damage and subsequent organ injury. Multiple organ dysfunction after cardiac surgery with EC is associated with an increased morbidity and mortality. In addition to the pathogenesis of organ dysfunction after EC, this review deals with different therapeutic interventions aiming to alleviate the inflammatory response and consequently multiple organ dysfunction after cardiac surgery. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

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.

Prevalence of externalized conductors in Riata and Riata ST silicone leads: results from the prospective, multicenter Riata Lead Evaluation Study.

PubMed

Hayes, David; Freedman, Roger; Curtis, Anne B; Niebauer, Mark; Neal Kay, G; Dinerman, Jay; Beau, Scott

2013-12-01

Following a class I recall of St. Jude Medical Riata/Riata ST silicone implantable cardioverter-defibrillator leads, we report on the phase I results of the Riata Lead Evaluation Study, a prospective, multicenter investigation to assess the prevalence of externalized conductors (ECs) and the electrical dysfunction in these leads. We enrolled patients previously implanted with Riata/Riata ST leads and performed cinefluoroscopy using multiple views. A physician panel adjudicated the images for the presence of EC. The prevalence of EC was stratified and compared by lead model and patient characteristics. Upon occurrence of a lead revision, another physician panel determined whether electrical dysfunction had occurred based on predefined criteria. Seven hundred seventy six patients with Riata/Riata ST silicone leads (8Fr/7Fr = 66.6%/33.4%; single-/dual-coil = 12.9%/87.1%) across 23 centers were analyzed. Implant duration was 4.8 ± 0.9 years for 7Fr and 6.5 ± 1.6 years for 8Fr leads (P <.001). The prevalence of EC was significantly lower in 7Fr compared with 8Fr leads for the entire study population (9.3% vs 24.2%, P < .001) and for leads implanted ≤6 years (9.4% vs 18.8%, P = .006). Other than lead size, there were no significant differences in lead, patient, or electrical characteristics between leads with and without EC. Over a period of 9.8 ± 2.0 months, the overall prevalence of electrical dysfunction was 1.3% (confidence interval 0.49%-2.1%), with only 3 of 10 cases occurring in leads with EC. Larger-diameter Riata leads were more prone to EC than smaller-diameter Riata ST leads. The prevalence of electrical dysfunction was not associated with EC. Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Abl Tyrosine Kinase Phosphorylates Nonmuscle Myosin Light Chain Kinase to Regulate Endothelial Barrier Function

PubMed Central

Dudek, Steven M.; Chiang, Eddie T.; Camp, Sara M.; Guo, Yurong; Zhao, Jing; Brown, Mary E.; Singleton, Patrick A.; Wang, Lichun; Desai, Anjali; Arce, Fernando T.; Lal, Ratnesh; Van Eyk, Jennifer E.; Imam, Syed Z.

2010-01-01

Nonmuscle myosin light chain kinase (nmMLCK), a multi-functional cytoskeletal protein critical to vascular homeostasis, is highly regulated by tyrosine phosphorylation. We identified multiple novel c-Abl–mediated nmMLCK phosphorylation sites by mass spectroscopy analysis (including Y231, Y464, Y556, Y846) and examined their influence on nmMLCK function and human lung endothelial cell (EC) barrier regulation. Tyrosine phosphorylation of nmMLCK increased kinase activity, reversed nmMLCK-mediated inhibition of Arp2/3-mediated actin polymerization, and enhanced binding to the critical actin-binding phosphotyrosine protein, cortactin. EC challenge with sphingosine 1-phosphate (S1P), a potent barrier-enhancing agonist, resulted in c-Abl and phosphorylated nmMLCK recruitment into caveolin-enriched microdomains, rapid increases in Abl kinase activity, and spatial targeting of c-Abl to barrier-promoting cortical actin structures. Conversely, reduced c-Abl expression in EC (siRNA) markedly attenuated S1P-mediated cortical actin formation, reduced the EC modulus of elasticity (assessed by atomic force microscopy), reduced nmMLCK and cortactin tyrosine phosphorylation, and attenuated S1P-mediated barrier enhancement. These studies indicate an essential role for Abl kinase in vascular barrier regulation via posttranslational modification of nmMLCK and strongly support c-Abl-cortactin-nmMLCK interaction as a novel determinant of cortical actin-based cytoskeletal rearrangement critical to S1P-mediated EC barrier enhancement. PMID:20861316

The Cannabinoid System and Pain

PubMed Central

Woodhams, Stephen G.; Chapman, Victoria; Finn, David P.; Hohmann, Andrea G.; Neugebauer, Volker

2018-01-01

Chronic pain states are highly prevalent and yet poorly controlled by currently available analgesics, representing an enormous clinical, societal, and economic burden. Existing pain medications have significant limitations and adverse effects including tolerance, dependence, gastrointestinal dysfunction, cognitive impairment, and a narrow therapeutic window, making the search for novel analgesics ever more important. In this article, we review the role of an important endogenous pain control system, the endocannabinoid (EC) system, in the sensory, emotional, and cognitive aspects of pain. Herein, we briefly cover the discovery of the EC system and its role in pain processing pathways, before concentrating on three areas of current major interest in EC pain research; 1. Pharmacological enhancement of endocannabinoid activity (via blockade of EC metabolism or allosteric modulation of CB1 receptors); 2. The EC System and stress-induced modulation of pain; and 3. The EC system & medial prefrontal cortex (mPFC) dysfunction in pain states. Whilst we focus predominantly on the preclinical data, we also include extensive discussion of recent clinical failures of endocannabinoid-related therapies, the future potential of these approaches, and important directions for future research on the EC system and pain. PMID:28625720

Norrin/Frizzled4 signaling in retinal vascular development and blood brain barrier plasticity.

PubMed

Wang, Yanshu; Rattner, Amir; Zhou, Yulian; Williams, John; Smallwood, Philip M; Nathans, Jeremy

2012-12-07

Norrin/Frizzled4 (Fz4) signaling activates the canonical Wnt pathway to control retinal vascular development. Using genetically engineered mice, we show that precocious Norrin production leads to premature retinal vascular invasion and delayed Norrin production leads to characteristic defects in intraretinal vascular architecture. In genetic mosaics, wild-type endothelial cells (ECs) instruct neighboring Fz4(-/-) ECs to produce an architecturally normal mosaic vasculature, a cell nonautonomous effect. However, over the ensuing weeks, Fz4(-/-) ECs are selectively eliminated from the mosaic vasculature, implying the existence of a quality control program that targets defective ECs. In the adult retina and cerebellum, gain or loss of Norrin/Fz4 signaling results in a cell-autonomous gain or loss, respectively, of blood retina barrier and blood brain barrier function, indicating an ongoing requirement for Frizzled signaling in barrier maintenance and substantial plasticity in mature CNS vascular structure. Copyright © 2012 Elsevier Inc. All rights reserved.

Endocannabinoid system dysfunction in mood and related disorders.

PubMed

Ashton, C H; Moore, P B

2011-10-01

The endocannabinoid (EC) system is widely distributed throughout the brain and modulates many functions. It is involved in mood and related disorders, and its activity may be modified by exogenous cannabinoids. This article examines the therapeutic potential of cannabinoids in psychiatric disorders. An overview is presented of the literature focussed on the functions of the EC system, its dysfunction in mood disorders and the therapeutic potential of exogenous cannabinoids. We propose (hypothesize) that the EC system, which is homoeostatic in cortical excitation and inhibition, is dysfunctional in mood and related disorders. Anandamide, tetrahydrocannabinol (THC) and cannabidiol (CBD) variously combine antidepressant, antipsychotic, anxiolytic, analgesic, anticonvulsant actions, suggesting a therapeutic potential in mood and related disorders. Currently, cannabinoids find a role in pain control. Post mortem and other studies report EC system abnormalities in depression, schizophrenia and suicide. Abnormalities in the cannabinoid-1 receptor (CNR1) gene that codes for cannabinoid-1 (CB1) receptors are reported in psychiatric disorders. However, efficacy trials of cannabinoids in psychiatric disorders are limited but offer some encouragement. Research is needed to elucidate the role of the EC system in psychiatric disorders and for clinical trials with THC, CBD and synthetic cannabinoids to assess their therapeutic potential. © 2011 John Wiley & Sons A/S.

Improving adolescent knowledge of emergency contraception: challenges and solutions

PubMed Central

Seetharaman, Sujatha; Yen, Sophia; Ammerman, Seth D

2016-01-01

Globally, unintended adolescent pregnancies pose a significant burden. One of the most important tools that can help prevent unintended pregnancy is the timely use of emergency contraception (EC), which in turn will decrease the need for abortions and complications related to adolescent pregnancies. Indications for the use of EC include unprotected sexual intercourse, contraceptive failure, or sexual assault. Use of EC is recommended within 120 hours, though is most effective if used as soon as possible after unprotected sex. To use EC, adolescents need to be equipped with knowledge about the various EC methods, and how and where EC can be accessed. Great variability in the knowledge and use of EC around the world exists, which is a major barrier to its use. The aims of this paper were to 1) provide a brief overview of EC, 2) discuss key social determinants affecting knowledge and use of EC, and 3) explore best practices for overcoming the barriers of lack of knowledge, use, and access of EC. PMID:29386948

Nuclear envelope proteins Nesprin2 and LaminA regulate proliferation and apoptosis of vascular endothelial cells in response to shear stress.

PubMed

Han, Yue; Wang, Lu; Yao, Qing-Ping; Zhang, Ping; Liu, Bo; Wang, Guo-Liang; Shen, Bao-Rong; Cheng, Binbin; Wang, Yingxiao; Jiang, Zong-Lai; Qi, Ying-Xin

2015-05-01

The dysfunction of vascular endothelial cells (ECs) influenced by flow shear stress is crucial for vascular remodeling. However, the roles of nuclear envelope (NE) proteins in shear stress-induced EC dysfunction are still unknown. Our results indicated that, compared with normal shear stress (NSS), low shear stress (LowSS) suppressed the expression of two types of NE proteins, Nesprin2 and LaminA, and increased the proliferation and apoptosis of ECs. Targeted small interfering RNA (siRNA) and gene overexpression plasmid transfection revealed that Nesprin2 and LaminA participate in the regulation of EC proliferation and apoptosis. A protein/DNA array was further used to detect the activation of transcription factors in ECs following transfection with target siRNAs and overexpression plasmids. The regulation of AP-2 and TFIID mediated by Nesprin2 and the activation of Stat-1, Stat-3, Stat-5 and Stat-6 by LaminA were verified under shear stress. Furthermore, using Ingenuity Pathway Analysis software and real-time RT-PCR, the effects of Nesprin2 or LaminA on the downstream target genes of AP-2, TFIID, and Stat-1, Stat-3, Stat-5 and Stat-6, respectively, were investigated under LowSS. Our study has revealed that NE proteins are novel mechano-sensitive molecules in ECs. LowSS suppresses the expression of Nesprin2 and LaminA, which may subsequently modulate the activation of important transcription factors and eventually lead to EC dysfunction. Copyright © 2015 Elsevier B.V. All rights reserved.

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

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.

Reaction dynamics near the barrier

NASA Astrophysics Data System (ADS)

Loveland, W.

2011-10-01

The availability of modest intensity (103-107 p/s) radioactive nuclear beams has had a significant impact on the study of nuclear reactions near the interaction barrier. The role of isospin in capture reactions is a case in point. Using heavy elements as a laboratory to explore these effects, we note that the cross section for producing an evaporation residue is σEVR(Ec . m .) = ∑ J = 0 JmaxσCN(Ec . m . , J) Wsur(Ec . m . , J) where σCN is the complete fusion cross section and Wsur is the survival probability of the completely fused system. The complete fusion cross section can be written as, σCN(Ec . m .) = ∑ J = 0 Jmaxσcapture(Ec . m .) PCN(Ec . m . , J) where σcapture(Ec.m.,J) is the ``capture'' cross section at center-of mass energy Ec.m. and spin J and PCN is the probability that the projectile-target system will evolve inside the fission saddle point to form a completely fused system rather than re-separating (quasi-fission). The systematics of the isospin dependence of the capture cross sections has been developed and the deduced interaction barriers for all known studies of capture cross sections with radioactive beams are in good agreement with recent predictions of an improved QMD model and semi-empirical models. The deduced barriers for these n-rich systems are lower than one would expect from the Bass or proximity potentials. In addition to the barrier lowering, there is an enhanced sub-barrier cross section in these n-rich systems that is of advantage in the synthesis of new heavy nuclei. Recent studies of the ``inverse fission'' of uranium (124,132Sn + 100Mo) have yielded unexpectedly low upper limits for this process due apparently to low values of the fusion probability, PCN. The fusion of halo nuclei, like 11Li with heavy nuclei, like 208Pb, promises to give new information about these and related nuclei and has led/may lead to unusual reaction mechanisms. This work was sponsored, in part, by the USDOE Office of Nuclear Physics.

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.

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

Endothelial cell metabolism: A novel player in atherosclerosis? Basic principles and therapeutic opportunities.

PubMed

Pircher, Andreas; Treps, Lucas; Bodrug, Natalia; Carmeliet, Peter

2016-10-01

Atherosclerosis is a leading cause of morbidity and mortality in Western society. Despite improved insight into disease pathogenesis and therapeutic options, additional treatment strategies are required. Emerging evidence highlights the relevance of endothelial cell (EC) metabolism for angiogenesis, and indicates that EC metabolism is perturbed when ECs become dysfunctional to promote atherogenesis. In this review, we overview the latest insights on EC metabolism and discuss current knowledge on how atherosclerosis deregulates EC metabolism, and how maladaptation of deregulated EC metabolism can contribute to atherosclerosis progression. We will also highlight possible therapeutic avenues, based on targeting EC metabolism. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Use of non-emergency contraceptive pills and concoctions as emergency contraception among Nigerian University students: results of a qualitative study.

PubMed

Ajayi, Anthony Idowu; Nwokocha, Ezebunwa Ethelbert; Akpan, Wilson; Adeniyi, Oladele Vincent

2016-10-04

Emergency contraception (EC) can significantly reduce the rate of unintended pregnancies and unsafe abortions especially in sub-Saharan Africa. Despite the increasing awareness of EC among educated young women in Nigeria, the rate of utilisation remains low. This study therefore explores the main barriers to the use of EC among female university students by analysing their knowledge of emergency contraception, methods ever used, perceived efficacy, and its acceptability. This paper brings together the findings from several focus groups (N = 5) and in-depth interviews (N = 20) conducted amongst unmarried female undergraduate students in two Nigerian universities. Participants considered the use of condom and abstinence as the most effective methods of preventing unplanned pregnancy. However, many participants were misinformed about emergency contraception. Generally, participants relied on unconventional and unproven ECs; Ampiclox, "Alabukun", salt water solution, and lime and potash and perceived them to be effective in preventing unplanned pregnancies. Furthermore, respondents' narratives about methods of preventing unwanted pregnancies revealed that inadequate information on emergency contraception, reliance on unproven crude contraceptive methods, and misconception about modern contraception constitute barriers to the use of emergency contraception. The findings suggested that female university students are misinformed about emergency contraception and their reliance on unproven ECs constitutes a barrier to the use of approved EC methods. These barriers have serious implications for prevention of unplanned pregnancies in the cohort. Behavioural interventions targeting the use of unproven emergency contraceptive methods and misperceptions about ECs would be crucial for this cohort in Nigeria.

Concerted regulation of retinal pigment epithelium basement membrane and barrier function by angiocrine factors.

PubMed

Benedicto, Ignacio; Lehmann, Guillermo L; Ginsberg, Michael; Nolan, Daniel J; Bareja, Rohan; Elemento, Olivier; Salfati, Zelda; Alam, Nazia M; Prusky, Glen T; Llanos, Pierre; Rabbany, Sina Y; Maminishkis, Arvydas; Miller, Sheldon S; Rafii, Shahin; Rodriguez-Boulan, Enrique

2017-05-19

The outer blood-retina barrier is established through the coordinated terminal maturation of the retinal pigment epithelium (RPE), fenestrated choroid endothelial cells (ECs) and Bruch's membrane, a highly organized basement membrane that lies between both cell types. Here we study the contribution of choroid ECs to this process by comparing their gene expression profile before (P5) and after (P30) the critical postnatal period when mice acquire mature visual function. Transcriptome analyses show that expression of extracellular matrix-related genes changes dramatically over this period. Co-culture experiments support the existence of a novel regulatory pathway: ECs secrete factors that remodel RPE basement membrane, and integrin receptors sense these changes triggering Rho GTPase signals that modulate RPE tight junctions and enhance RPE barrier function. We anticipate our results will spawn a search for additional roles of choroid ECs in RPE physiology and disease.

Concerted regulation of retinal pigment epithelium basement membrane and barrier function by angiocrine factors

PubMed Central

Benedicto, Ignacio; Lehmann, Guillermo L.; Ginsberg, Michael; Nolan, Daniel J.; Bareja, Rohan; Elemento, Olivier; Salfati, Zelda; Alam, Nazia M.; Prusky, Glen T.; Llanos, Pierre; Rabbany, Sina Y.; Maminishkis, Arvydas; Miller, Sheldon S.; Rafii, Shahin; Rodriguez-Boulan, Enrique

2017-01-01

The outer blood-retina barrier is established through the coordinated terminal maturation of the retinal pigment epithelium (RPE), fenestrated choroid endothelial cells (ECs) and Bruch's membrane, a highly organized basement membrane that lies between both cell types. Here we study the contribution of choroid ECs to this process by comparing their gene expression profile before (P5) and after (P30) the critical postnatal period when mice acquire mature visual function. Transcriptome analyses show that expression of extracellular matrix-related genes changes dramatically over this period. Co-culture experiments support the existence of a novel regulatory pathway: ECs secrete factors that remodel RPE basement membrane, and integrin receptors sense these changes triggering Rho GTPase signals that modulate RPE tight junctions and enhance RPE barrier function. We anticipate our results will spawn a search for additional roles of choroid ECs in RPE physiology and disease. PMID:28524846

YAP/TAZ regulates sprouting angiogenesis and vascular barrier maturation

PubMed Central

Kim, Yoo Hyung; Kim, Jaeryung; Park, Do Young; Bae, Hosung; Lee, Da-Hye; Kim, Kyun Hoo; Hong, Seon Pyo; Jang, Seung Pil; Kwon, Young-Guen; Lim, Dae-Sik

2017-01-01

Angiogenesis is a multistep process that requires coordinated migration, proliferation, and junction formation of vascular endothelial cells (ECs) to form new vessel branches in response to growth stimuli. Major intracellular signaling pathways that regulate angiogenesis have been well elucidated, but key transcriptional regulators that mediate these signaling pathways and control EC behaviors are only beginning to be understood. Here, we show that YAP/TAZ, a transcriptional coactivator that acts as an end effector of Hippo signaling, is critical for sprouting angiogenesis and vascular barrier formation and maturation. In mice, endothelial-specific deletion of Yap/Taz led to blunted-end, aneurysm-like tip ECs with fewer and dysmorphic filopodia at the vascular front, a hyper-pruned vascular network, reduced and disarranged distributions of tight and adherens junction proteins, disrupted barrier integrity, subsequent hemorrhage in growing retina and brain vessels, and reduced pathological choroidal neovascularization. Mechanistically, YAP/TAZ activates actin cytoskeleton remodeling, an important component of filopodia formation and junction assembly. Moreover, YAP/TAZ coordinates EC proliferation and metabolic activity by upregulating MYC signaling. Overall, these results show that YAP/TAZ plays multifaceted roles for EC behaviors, proliferation, junction assembly, and metabolism in sprouting angiogenesis and barrier formation and maturation and could be a potential therapeutic target for treating neovascular diseases. PMID:28805663

Long Noncoding RNA-GAS5: A Novel Regulator of Hypertension-Induced Vascular Remodeling.

PubMed

Wang, Yang-Ning-Zhi; Shan, Kun; Yao, Mu-Di; Yao, Jin; Wang, Jia-Jian; Li, Xiang; Liu, Ban; Zhang, Yang-Yang; Ji, Yong; Jiang, Qin; Yan, Biao

2016-09-01

Vascular remodeling is an important pathological feature of hypertension, leading to increased vascular resistance and reduced compliance. Endothelial cell (EC) and vascular smooth muscle cell (VSMC) dysfunction is involved in vascular remodeling. Long noncoding RNAs are potential regulators of EC and VSMC function. Herein, we determined whether long noncoding RNA-growth arrest-specific 5 (GAS5) is involved in hypertension-related vascular remodeling. We revealed that GAS5 knockdown aggravated hypertension-induced microvascular dysfunction as shown by increased retinal neovascularization and capillary leakage. GAS5 regulated the remodeling of arteries, including caudal arteries, carotid arteries, renal arteries, and thoracic arteries. GAS5 was mainly expressed in ECs and VSMCs, and its expression was significantly downregulated in hypertension. GAS5 knockdown affected endothelial activation, endothelial proliferation, VSMC phenotypic conversion, and EC-VSMC communication in vivo and in vitro. Mechanistically, GAS5 regulated EC and VSMC function through β-catenin signaling. This study identified GAS5 as a critical regulator in hypertension and demonstrated the potential of gene therapy and drug development for treating hypertension. © 2016 American Heart Association, Inc.

Transient Intervals of Hyper-Gravity Enhance Endothelial Barrier Integrity: Impact of Mechanical and Gravitational Forces Measured Electrically

PubMed Central

Szulcek, Robert; van Bezu, Jan; Boonstra, Johannes; van Loon, Jack J. W. A.; van Nieuw Amerongen, Geerten P.

2015-01-01

Background Endothelial cells (EC) guard vascular functions by forming a dynamic barrier throughout the vascular system that sensitively adapts to ‘classical’ biomechanical forces, such as fluid shear stress and hydrostatic pressure. Alterations in gravitational forces might similarly affect EC integrity, but remain insufficiently studied. Methods In an unique approach, we utilized Electric Cell-substrate Impedance Sensing (ECIS) in the gravity-simulators at the European Space Agency (ESA) to study dynamic responses of human EC to simulated micro- and hyper-gravity as well as to classical forces. Results Short intervals of micro- or hyper-gravity evoked distinct endothelial responses. Stimulated micro-gravity led to decreased endothelial barrier integrity, whereas hyper-gravity caused sustained barrier enhancement by rapid improvement of cell-cell integrity, evidenced by a significant junctional accumulation of VE-cadherin (p = 0.011), significant enforcement of peripheral F-actin (p = 0.008) and accompanied by a slower enhancement of cell-matrix interactions. The hyper-gravity triggered EC responses were force dependent and nitric-oxide (NO) mediated showing a maximal resistance increase of 29.2±4.8 ohms at 2g and 60.9±6.2 ohms at 4g vs. baseline values that was significantly suppressed by NO blockage (p = 0.011). Conclusion In conclusion, short-term application of hyper-gravity caused a sustained improvement of endothelial barrier integrity, whereas simulated micro-gravity weakened the endothelium. In clear contrast, classical forces of shear stress and hydrostatic pressure induced either short-lived or no changes to the EC barrier. Here, ECIS has proven a powerful tool to characterize subtle and distinct EC gravity-responses due to its high temporal resolution, wherefore ECIS has a great potential for the study of gravity-responses such as in real space flights providing quantitative assessment of a variety of cell biological characteristics of any adherent growing cell type in an automated and continuous fashion. PMID:26637177

The Measurement of Reversible Redox Dependent Post-translational Modifications and Their Regulation of Mitochondrial and Skeletal Muscle Function

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

Kramer, Philip A.; Duan, Jicheng; Qian, Wei-Jun

Mitochondrial oxidative stress is a common feature of skeletal myopathies across multiple conditions; however, the mechanism by which it contributes to skeletal muscle dysfunction remains controversial. Oxidative damage to proteins, lipids, and DNA has received the most attention, yet an important role for reversible redox post-translational modifications (PTMs) in pathophysiology is emerging. The possibility that these PTMs can exert dynamic control of muscle function implicates them as a mechanism contributing to skeletal muscle dysfunction in chronic disease. Herein, we discuss the significance of thiol-based redox dependent modifications to mitochondrial, myofibrillar and excitation-contraction (EC) coupling proteins with an emphasis on howmore » these changes could alter skeletal muscle performance under chronically stressed conditions. A major barrier to a better mechanistic understanding of the role of reversible redox PTMs in muscle function is the technical challenges associated with accurately measuring the changes of site-specific redox PTMs. Here we will critically review current approaches with an emphasis on sample preparation artifacts, quantitation, and specificity. Despite these challenges, the ability to accurately quantify reversible redox PTMs is critical to understanding the mechanisms by which mitochondrial oxidative stress contributes to skeletal muscle dysfunction in chronic diseases.« less

Blood-brain barrier dysfunction in brain diseases: clinical experience.

PubMed

Schoknecht, Karl; Shalev, Hadar

2012-11-01

The blood-brain barrier, a unique feature of the cerebral vasculature, is gaining attention as a feature in common neurologic disorders including stroke, traumatic brain injury, epilepsy, and schizophrenia. Although acute blood-brain barrier dysfunction can induce cerebral edema, seizures, or neuropsychiatric symptoms, epileptogenesis and cognitive decline are among the chronic effects. The mechanisms underlying blood-brain barrier dysfunction are diverse and may range from physical endothelial damage in traumatic brain injury to degradation of extracellular matrix proteins via matrix metalloproteinases as part of an inflammatory response. Clinically, blood-brain barrier dysfunction is often detected using contrast-enhanced imaging. However, these techniques do not give any insights into the underlying mechanism. Elucidating the specific pathways of blood-brain barrier dysfunction at different time points and in different brain diseases using novel imaging techniques promises a more accurate blood-brain barrier terminology as well as new treatment options and personalized treatment. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

Inflammatory Responses and Barrier Function of Endothelial Cells Derived from Human Induced Pluripotent Stem Cells.

PubMed

Halaidych, Oleh V; Freund, Christian; van den Hil, Francijna; Salvatori, Daniela C F; Riminucci, Mara; Mummery, Christine L; Orlova, Valeria V

2018-05-08

Several studies have reported endothelial cell (EC) derivation from human induced pluripotent stem cells (hiPSCs). However, few have explored their functional properties in depth with respect to line-to-line and batch-to-batch variability and how they relate to primary ECs. We therefore carried out accurate characterization of hiPSC-derived ECs (hiPSC-ECs) from multiple (non-integrating) hiPSC lines and compared them with primary ECs in various functional assays, which included barrier function using real-time impedance spectroscopy with an integrated assay of electric wound healing, endothelia-leukocyte interaction under physiological flow to mimic inflammation and angiogenic responses in in vitro and in vivo assays. Overall, we found many similarities but also some important differences between hiPSC-derived and primary ECs. Assessment of vasculogenic responses in vivo showed little difference between primary ECs and hiPSC-ECs with regard to functional blood vessel formation, which may be important in future regenerative medicine applications requiring vascularization. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

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

In Vitro Evaluation of the Impact of the Probiotic E. coli Nissle 1917 on Campylobacter jejuni's Invasion and Intracellular Survival in Human Colonic Cells.

PubMed

Helmy, Yosra A; Kassem, Issmat I; Kumar, Anand; Rajashekara, Gireesh

2017-01-01

Campylobacter jejuni is a leading cause of bacterial food poisoning in humans. Due to the rise in antibiotic-resistant Campylobacter , there exists a need to develop antibiotic-independent interventions to control infections in humans. Here, we evaluated the impact of Escherichia coli Nissle 1917 (EcN), a probiotic strain, on C. jejuni's invasion and intracellular survival in polarized human colonic cells (HT-29). To further understand how EcN mediates its impact, the expression of 84 genes associated with tight junctions and cell adhesion was profiled in HT-29 cells after treatment with EcN and challenge with C. jejuni . The pre-treatment of polarized HT-29 cells with EcN for 4 h showed a significant effect on C. jejuni 's invasion (∼2 log reduction) of the colonic cells. Furthermore, no intracellular C. jejuni were recovered from EcN pre-treated HT-29 cells at 24 h post-infection. Other probiotic strains tested had no significant impact on C. jejuni invasion and intracellular survival. C. jejuni decreased the expression of genes associated with epithelial cells permeability and barrier function in untreated HT-29 cells. However, EcN positively affected the expression of genes that are involved in enhanced intestinal barrier function, decreased cell permeability, and increased tight junction integrity. The results suggest that EcN impedes C. jejuni invasion and subsequent intracellular survival by affecting HT-29 cells barrier function and tight junction integrity. We conclude that EcN might be a viable alternative for controlling C. jejuni infections.

Matrix Metalloproteinase-Mediated Blood-Brain Barrier Dysfunction in Epilepsy.

PubMed

Rempe, Ralf G; Hartz, Anika M S; Soldner, Emma L B; Sokola, Brent S; Alluri, Satya R; Abner, Erin L; Kryscio, Richard J; Pekcec, Anton; Schlichtiger, Juli; Bauer, Björn

2018-05-02

The blood-brain barrier is dysfunctional in epilepsy, thereby contributing to seizure genesis and resistance to antiseizure drugs. Previously, several groups reported that seizures increase brain glutamate levels, which leads to barrier dysfunction. One critical component of barrier dysfunction is brain capillary leakage. Based on our preliminary data, we hypothesized that glutamate released during seizures mediates an increase in matrix-metalloproteinase (MMP) expression and activity levels, thereby contributing to barrier leakage. To test this hypothesis, we exposed isolated brain capillaries from male Sprague Dawley rats to glutamate ex vivo and used an in vivo / ex vivo approach of isolated brain capillaries from female Wistar rats that experienced status epilepticus as an acute seizure model. We found that exposing isolated rat brain capillaries to glutamate increased MMP-2 and MMP-9 protein and activity levels, and decreased tight junction protein levels, which resulted in barrier leakage. We confirmed these findings in vivo in rats after status epilepticus and in brain capillaries from male mice lacking cytosolic phospholipase A 2 Together, our data support the hypothesis that glutamate released during seizures signals an increase in MMP-2 and MMP-9 protein expression and activity levels, resulting in blood-brain barrier leakage. SIGNIFICANCE STATEMENT The mechanism leading to seizure-mediated blood-brain barrier dysfunction in epilepsy is poorly understood. In the present study, we focused on defining this mechanism in the brain capillary endothelium. We demonstrate that seizures trigger a pathway that involves glutamate signaling through cytosolic phospholipase A 2 , which increases MMP levels and decreases tight junction protein expression levels, resulting in barrier leakage. These findings may provide potential therapeutic avenues within the blood-brain barrier to limit barrier dysfunction in epilepsy and decrease seizure burden. Copyright © 2018 the authors 0270-6474/18/384301-15$15.00/0.

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

Evaluation of eddy current and magnetic techniques for inspecting rebars in bridge barrier rails

NASA Astrophysics Data System (ADS)

Lo, C. C. H.; Nakagawa, N.

2013-01-01

This paper reports on a feasibility study of using eddy current (EC) and magnetic flux leakage (MFL) methods to detect corrosion damage in rebars that anchor concrete barrier rails to the road deck of bridge structures. EC and MFL measurements were carried out on standalone rebars with and without artificial defects of 25% and 50% material loss, using a commercial EC-based rebar locator and a MFL system that was developed using giant magnetoresistance sensors to detect leakage fluxes from the defects. Both techniques can readily detect the defects at a distance of 2.5″ (63.5 mm). The amplitudes of the EC and MFL signals vary monotonically with the amount of material loss, indicating the potential of using the techniques to quantify material loss of standalone rebars.

The 1-2-3 Magic parenting program and its effect on child problem behaviors and dysfunctional parenting: a randomized controlled trial.

PubMed

Porzig-Drummond, Renata; Stevenson, Richard J; Stevenson, Caroline

2014-07-01

This study investigated the effectiveness of the 1-2-3 Magic parenting program, a brief cognitive-behavioral program, when delivered to large groups of caregivers. The effectiveness of two versions of the programs in reducing child problem behaviors and dysfunctional parenting, and the effect on emotion-related parenting style, were examined. Ninety-two participants with 2-12-year-old children were randomly assigned to one of three groups: DVD (n = 31); Emotion-coaching (EC) (n = 31); or Waitlist-control (n = 30). Both intervention groups reported significantly decreased child problem behaviors, dysfunctional parenting, parental depression and parental stress at post-intervention as compared to the control group. Additionally, the DVD group reported decreased parental anxiety, and the EC group reported a decrease in emotion-dismissing parenting style. Emotion-coaching parenting style remained unchanged for all groups at post-intervention. The results were maintained after three months. After two years, all intervention effects were maintained for the DVD group. For the EC group, effects were maintained on the main outcome variables. The results suggest that both 1-2-3 Magic programs are effective at reducing child problem behavior and dysfunctional parenting when delivered to large groups of caregivers, and that both programs are suitable for a broad delivery approach. Copyright © 2014 Elsevier Ltd. All rights reserved.

Early Detection of Junctional Adhesion Molecule-1 (JAM-1) in the Circulation after Experimental and Clinical Polytrauma

PubMed Central

Denk, Stephanie; Wiegner, Rebecca; Hönes, Felix M.; Messerer, David A. C.; Radermacher, Peter; Kalbitz, Miriam; Braumüller, Sonja; McCook, Oscar; Gebhard, Florian; Weckbach, Sebastian; Huber-Lang, Markus

2015-01-01

Severe tissue trauma-induced systemic inflammation is often accompanied by evident or occult blood-organ barrier dysfunctions, frequently leading to multiple organ dysfunction. However, it is unknown whether specific barrier molecules are shed into the circulation early after trauma as potential indicators of an initial barrier dysfunction. The release of the barrier molecule junctional adhesion molecule-1 (JAM-1) was investigated in plasma of C57BL/6 mice 2 h after experimental mono- and polytrauma as well as in polytrauma patients (ISS ≥ 18) during a 10-day period. Correlation analyses were performed to indicate a linkage between JAM-1 plasma concentrations and organ failure. JAM-1 was systemically detected after experimental trauma in mice with blunt chest trauma as a driving force. Accordingly, JAM-1 was reduced in lung tissue after pulmonary contusion and JAM-1 plasma levels significantly correlated with increased protein levels in the bronchoalveolar lavage as a sign for alveolocapillary barrier dysfunction. Furthermore, JAM-1 was markedly released into the plasma of polytrauma patients as early as 4 h after the trauma insult and significantly correlated with severity of disease and organ dysfunction (APACHE II and SOFA score). The data support an early injury- and time-dependent appearance of the barrier molecule JAM-1 in the circulation indicative of a commencing trauma-induced barrier dysfunction. PMID:26556956

Pravastatin reverses obesity-induced dysfunction of induced pluripotent stem cell-derived endothelial cells via a nitric oxide-dependent mechanism

PubMed Central

Gu, Mingxia; Mordwinkin, Nicholas M.; Kooreman, Nigel G.; Lee, Jaecheol; Wu, Haodi; Hu, Shijun; Churko, Jared M.; Diecke, Sebastian; Burridge, Paul W.; He, Chunjiang; Barron, Frances E.; Ong, Sang-Ging; Gold, Joseph D.; Wu, Joseph C.

2015-01-01

Aims High-fat diet-induced obesity (DIO) is a major contributor to type II diabetes and micro- and macro-vascular complications leading to peripheral vascular disease (PVD). Metabolic abnormalities of induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) from obese individuals could potentially limit their therapeutic efficacy for PVD. The aim of this study was to compare the function of iPSC-ECs from normal and DIO mice using comprehensive in vitro and in vivo assays. Methods and results Six-week-old C57Bl/6 mice were fed with a normal or high-fat diet. At 24 weeks, iPSCs were generated from tail tip fibroblasts and differentiated into iPSC-ECs using a directed monolayer approach. In vitro functional analysis revealed that iPSC-ECs from DIO mice had significantly decreased capacity to form capillary-like networks, diminished migration, and lower proliferation. Microarray and ELISA confirmed elevated apoptotic, inflammatory, and oxidative stress pathways in DIO iPSC-ECs. Following hindlimb ischaemia, mice receiving intramuscular injections of DIO iPSC-ECs had significantly decreased reperfusion compared with mice injected with control healthy iPSC-ECs. Hindlimb sections revealed increased muscle atrophy and presence of inflammatory cells in mice receiving DIO iPSC-ECs. When pravastatin was co-administered to mice receiving DIO iPSC-ECs, a significant increase in reperfusion was observed; however, this beneficial effect was blunted by co-administration of the nitric oxide synthase inhibitor, Nω-nitro-l-arginine methyl ester. Conclusion This is the first study to provide evidence that iPSC-ECs from DIO mice exhibit signs of endothelial dysfunction and have suboptimal efficacy following transplantation in a hindlimb ischaemia model. These findings may have important implications for future treatment of PVD using iPSC-ECs in the obese population. PMID:25368203

Prefrontal white matter pathology in air pollution exposed Mexico City young urbanites and their potential impact on neurovascular unit dysfunction and the development of Alzheimer's disease.

PubMed

Calderón-Garcidueñas, Lilian; Reynoso-Robles, Rafael; Vargas-Martínez, Javier; Gómez-Maqueo-Chew, Aline; Pérez-Guillé, Beatriz; Mukherjee, Partha S; Torres-Jardón, Ricardo; Perry, George; Gónzalez-Maciel, Angélica

2016-04-01

Millions of urban children are chronically exposed to high concentrations of air pollutants, i.e., fine particulate matter (PM2.5) and ozone, associated with increased risk for Alzheimer's disease. Compared with children living with clear air those in Mexico City (MC) exhibit systemic, brain and intrathecal inflammation, low CSF Aβ42, breakdown of the BBB, attention and short-term memory deficits, prefrontal white matter hyperintensities, damage to epithelial and endothelial barriers, tight junction and neural autoantibodies, and Alzheimer and Parkinson's hallmarks. The prefrontal white matter is a target of air pollution. We examined by light and electron microscopy the prefrontal white matter of MC dogs (n: 15, age 3.17±0.74 years), children and teens (n: 34, age: 12.64±4.2 years) versus controls. Major findings in MC residents included leaking capillaries and small arterioles with extravascular lipids and erythrocytes, lipofuscin in pericytes, smooth muscle and endothelial cells (EC), thickening of cerebrovascular basement membranes with small deposits of amyloid, patchy absence of the perivascular glial sheet, enlarged Virchow-Robin spaces and nanosize particles (20-48nm) in EC, basement membranes, axons and dendrites. Tight junctions, a key component of the neurovascular unit (NVU) were abnormal in MC versus control dogs (χ(2)<0.0001), and white matter perivascular damage was significantly worse in MC dogs (p=0.002). The integrity of the NVU, an interactive network of vascular, glial and neuronal cells is compromised in MC young residents. Characterizing the early NVU damage and identifying biomarkers of neurovascular dysfunction may provide a fresh insight into Alzheimer pathogenesis and open opportunities for pediatric neuroprotection. Copyright © 2015 Elsevier Inc. All rights reserved.

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

MicroRNA-98 rescues proliferation and alleviates ox-LDL-induced apoptosis in HUVECs by targeting LOX-1

PubMed Central

Chen, Zhibo; Wang, Mian; He, Qiong; Li, Zilun; Zhao, Yang; Wang, Wenjian; Ma, Jieyi; Li, Yongxin; Chang, Guangqi

2017-01-01

Oxidized low-density lipoprotein (ox-LDL) is a major and critical mediator of atherosclerosis, and the underlying mechanism is thought to involve the ox-LDL-induced dysfunction of endothelial cells (ECs). MicroRNAs (miRNAs), which are a group of small non-coding RNA molecules that post-transcriptionally regulate the expression of target genes, have been associated with diverse cellular functions and the pathogenesis of various diseases, including atherosclerosis. miRNA-98 (miR-98) has been demonstrated to be involved in the regulation of cellular apoptosis; however, the role of miR-98 in ox-LDL-induced dysfunction of ECs and atherosclerosis has yet to be elucidated. Therefore, the present study aimed to investigate the role of miR-98 in ox-LDL-induced dysfunction of ECs and the underlying mechanism. It was demonstrated that miR-98 expression was markedly downregulated in ox-LDL-treated human umbilical vein ECs (HUVECs) and that miR-98 promoted the proliferation and alleviated apoptosis of HUVECs exposed to ox-LDL. In addition, the results demonstrated that lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) was a direct target of miR-98 in HUVECs, as indicated by a luciferase assay. The results of the present study suggested that miR-98 may inhibit the uptake of toxic ox-LDL, maintain HUVEC proliferation and protect HUVECs against apoptosis via the suppression of LOX-1. PMID:28565756

Heme Oxygenase-1 Counteracts Contrast Media-Induced Endothelial Cell Dysfunction

PubMed Central

Chang, Chao-Fu; Liu, Xiao-Ming; Peyton, Kelly J.; Durante, William

2013-01-01

Endothelial cell (EC) dysfunction is involved in the pathogenesis of contrast-induced acute kidney injury, which is a major adverse event following coronary angiography. In this study, we evaluated the effect of contrast media (CM) on human EC proliferation, migration, and inflammation, and determined if heme oxygenase-1 (HO-1) influences the biological actions of CM. We found that three distinct CM, including high-osmolar (diatrizoate), low-osmolar (iopamidol), and iso-osmolar (iodixanol), stimulated the expression of HO-1 protein and mRNA. The induction of HO-1 was associated with an increase in NF-E2-related factor-2 (Nrf2) activity and reactive oxygen species (ROS). CM also stimulated HO-1 promoter activity and this was prevented by mutating the antioxidant responsive element or by overexpressing dominant-negative Nrf2. In addition, the CM-mediated induction of HO-1 and activation of Nrf2 was abolished by acetylcysteine. Finally, CM inhibited the proliferation and migration of ECs and stimulated the expression of intercellular adhesion molecule-1 and the adhesion of monocytes on ECs. Inhibition or silencing of HO-1 exacerbated the anti-proliferative and inflammatory actions of CM but had no effect on the anti-migratory effect. Thus, induction of HO-1 via the ROS-Nrf2 pathway counteracts the anti-proliferative and inflammatory actions of CM. Therapeutic approaches targeting HO-1 may provide a novel approach in preventing CM-induced endothelial and organ dysfunction. PMID:24239896

Theoretical studies to understand surface chemistry on carbon anodes for lithium-ion batteries: how does vinylene carbonate play its role as an electrolyte additive?

PubMed

Wang, Yixuan; Nakamura, Shinichiro; Tasaki, Ken; Balbuena, Perla B

2002-04-24

To elucidate the role of vinylene carbonate (VC) as a solvent additive in organic polar solutions for lithium-ion batteries, reductive decompositions for vinylene carbonate (VC) and ethylene carbonate (EC) molecules have been comprehensively investigated both in the gas phase and in solution by means of density functional theory calculations. The salt and solvent effects are incorporated with the clusters (EC)nLi+(VC) (n = 0-3), and further corrections that account for bulk solvent effects are added using the polarized continuum model (PCM). The electron affinities of (EC)nLi+(VC) (n = 0-3) monotonically decrease when the number of EC molecules increases; a sharp decrease of about 20.0 kcal/mol is found from n = 0 to 1 and a more gentle variation for n > 1. For (EC)nLi+(VC) (n = 1-3), the reduction of VC brings about more stable ion-pair intermediates than those due to reduction of the EC molecule by 3.1, 6.1, and 5.3 kcal/mol, respectively. This finding qualitatively agrees with the experimental fact that the reduction potential of VC in the presence of Li salt is more negative than that of EC. The calculated reduction potentials corresponding to radical anion formation are close to the experimental potentials determined with cyclic voltammetry on a gold electrode surface (-2.67, -3.19 eV on the physical scale for VC and EC respectively vs experimental values -2.96 and -2.94 eV). Regarding the decomposition mechanisms, the VC and EC moieties undergo homolytic ring opening from their respective reduction intermediates, and the energy barrier of VC is about one time higher than that of EC (e.g., 20.1 vs 8.8 kcal/mol for (EC)2Li+(VC)); both are weakly affected by the explicit solvent molecules and by a bulk solvent represented by a continuum model. Alternatively, starting from the VC-reduction intermediate, the ring opening of the EC moiety via an intramolecular electron-transfer transition state has also been located; its barrier lies between those of EC and VC (e.g., 17.2 kcal/mol for (EC)2Li+(VC)). On the basis of these results, we suggest the following explanation about the role that VC may play as additive in EC-based lithium-ion battery electrolytes; VC is initially reduced to a more stable intermediate than that from EC reduction. One possibility then is that the reduced VC decomposes to form a radical anion via a barrier of about 20 kcal/mol, which undergoes a series of reactions to give rise to more active film-forming products than those resulting from EC reduction, such as lithium divinylene dicarbonate, Li-C carbides, lithium vinylene dicarbonate, R-O-Li compound, and even oligomers with repeated vinylene and carbonate-vinylene units. Another possibility starting from the VC-reduction intermediate is that the ring opening occurs on the unreduced EC moiety instead of being on the reduced VC, via an intramolecular electron transfer transition state, the energy barrier of which is lower than that of the former, in which VC just helps the intermediate formation and is not consumed. The factors that determine the additive functioning mechanism are briefly discussed, and consequently a general rule for the selection of electrolyte additive is proposed.

Enteric-coated mycophenolate sodium experience in liver transplant patients.

PubMed

Cantisani, G P C; Zanotelli, M L; Gleisner, A L M; de Mello Brandão, A; Marroni, C A

2006-04-01

Mycophenolate sodium (EC-MPS) has been shown to be as effective and as safe as mycophenolate mofetil (MMF) in renal transplant patients. Nevertheless, compared to MMF its use in liver transplant patients has been limited. The purpose of this study was to analyze the efficacy of EC-MPS as a primary immunosuppressant or as a replacement for MMF in liver transplant patients. Ninety among 470 liver transplant recipients were receiving or had added an antimetabolite to their immunosuppressant therapy. The most common reason for this change was renal dysfunction (47.8%) or diabetes (32.2%). EC-MPS was started at a median of 30 months after liver transplantation. The mean administered daily dose was 720 mg/d. At least one gastrointestinal symptom was reported by 25 patients. Abdominal pain (16.6%) and diarrhea (14.5%) were the most frequent. EC-MPS had to be discontinued in two patients, while six others required dose reduction to resolve the symptoms. Hematological adverse events were infrequent: three patients had leukopenia and one, anemia, all of which responded to dosage reduction. There was a creatinine reduction within 6 months of drug commencement and maintenance of the lower creatinine levels at 1 year among patients who began EC-MPS for renal dysfunction. Serum low-density lipoprotein cholesterol and triglyceride levels were significantly lower among patients on EC-MPS than on MMF. In conclusion, EC-MPS appears to have a similar efficacy and safety profile as MMF in liver transplant patients. Hematological and gastrointestinal adverse events were infrequent; seldom had the drug to be discontinued.

Redox Regulation of Endothelial Cell Fate

PubMed Central

Song, Ping; Zou, Ming-Hui

2014-01-01

Endothelial cells (ECs) are present throughout blood vessels and have variable roles in both physiological and pathological settings. EC fate is altered and regulated by several key factors in physiological or pathological conditions. Reactive nitrogen species and reactive oxygen species derived from NAD(P)H oxidases, mitochondria, or nitric oxide-producing enzymes are not only cytotoxic but also compose a signaling network in the redox system. The formation, actions, key molecular interactions, and physiological and pathological relevance of redox signals in ECs remain unclear. We review the identities, sources, and biological actions of oxidants and reductants produced during EC function or dysfunction. Further, we discuss how ECs shape key redox sensors and examine the biological functions, transcriptional responses, and post-translational modifications evoked by the redox system in ECs. We summarize recent findings regarding the mechanisms by which redox signals regulate the fate of ECs and address the outcome of altered EC fate in health and disease. Future studies will examine if the redox biology of ECs can be targeted in pathophysiological conditions. PMID:24633153

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.

Human vascular tissue models formed from human induced pluripotent stem cell derived endothelial cells

PubMed Central

Belair, David G.; Whisler, Jordan A.; Valdez, Jorge; Velazquez, Jeremy; Molenda, James A.; Vickerman, Vernella; Lewis, Rachel; Daigh, Christine; Hansen, Tyler D.; Mann, David A.; Thomson, James A.; Griffith, Linda G.; Kamm, Roger D.; Schwartz, Michael P.; Murphy, William L.

2015-01-01

Here we describe a strategy to model blood vessel development using a well-defined iPSC-derived endothelial cell type (iPSC-EC) cultured within engineered platforms that mimic the 3D microenvironment. The iPSC-ECs used here were first characterized by expression of endothelial markers and functional properties that included VEGF responsiveness, TNF-α-induced upregulation of cell adhesion molecules (MCAM/CD146; ICAM1/CD54), thrombin-dependent barrier function, shear stress-induced alignment, and 2D and 3D capillary-like network formation in Matrigel. The iPSC-ECs also formed 3D vascular networks in a variety of engineering contexts, yielded perfusable, interconnected lumen when co-cultured with primary human fibroblasts, and aligned with flow in microfluidics devices. iPSC-EC function during tubule network formation, barrier formation, and sprouting was consistent with that of primary ECs, and the results suggest a VEGF-independent mechanism for sprouting, which is relevant to therapeutic anti-angiogenesis strategies. Our combined results demonstrate the feasibility of using a well-defined, stable source of iPSC-ECs to model blood vessel formation within a variety of contexts using standard in vitro formats. PMID:25190668

Thymic stromal lymphopoietin-induced HOTAIR activation promotes endothelial cell proliferation and migration in atherosclerosis

PubMed Central

Peng, Yudong; Meng, Kai; Jiang, Lili; Zhong, Yucheng; Yang, Yong; Lan, Yin

2017-01-01

Endothelial cells’ (EC) injury is a major step for the pathological progression of atherosclerosis. Recent study demonstrated that thymic stromal lymphopoietin (TSLP) exerts a protective role in atherosclerosis. However, the effect of TSLP and the exact molecular mechanism involved in EC remains unknown. In the present study, we found that long noncoding RNA (lncRNA) HOTAIR was much lower in EC from atherosclerotic plaque. Functional assays showed that HOTAIR facilitated cell proliferation and migration, and suppressed apoptosis in EC. Moreover, we demonstrated that TSLP functions upstream of HOTAIR. We found that serum level of TSLP was decreased in atherosclerosis patients and serum TSLP level positively correlated with HOTAIR expression in EC. Further investigation demonstrated that TSLP activated HOTAIR transcription through PI3K/AKT-IRF1 pathway and then regulates the EC proliferation and migration. TSLP-HOTAIR axis also plays a protective role in low-density lipoprotein (ox-LDL)-induced EC injury. Taken together, TSLP-HOTAIR may be a potential therapy for EC dysfunction in atherosclerosis. PMID:28615347

Prefrontal white matter pathology in air pollution exposed Mexico City young urbanites and their potential impact on neurovascular unit dysfunction and the development of Alzheimer's disease

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

Calderón-Garcidueñas, Lilian, E-mail: lilian.calderon-garciduenas@umontana.edu; Universidad del Valle de México, Mexico City 04850, México; Reynoso-Robles, Rafael

Millions of urban children are chronically exposed to high concentrations of air pollutants, i.e., fine particulate matter (PM{sub 2.5}) and ozone, associated with increased risk for Alzheimer's disease. Compared with children living with clear air those in Mexico City (MC) exhibit systemic, brain and intrathecal inflammation, low CSF Aβ{sub 42,} breakdown of the BBB, attention and short-term memory deficits, prefrontal white matter hyperintensities, damage to epithelial and endothelial barriers, tight junction and neural autoantibodies, and Alzheimer and Parkinson's hallmarks. The prefrontal white matter is a target of air pollution. We examined by light and electron microscopy the prefrontal white mattermore » of MC dogs (n: 15, age 3.17±0.74 years), children and teens (n: 34, age: 12.64±4.2 years) versus controls. Major findings in MC residents included leaking capillaries and small arterioles with extravascular lipids and erythrocytes, lipofuscin in pericytes, smooth muscle and endothelial cells (EC), thickening of cerebrovascular basement membranes with small deposits of amyloid, patchy absence of the perivascular glial sheet, enlarged Virchow–Robin spaces and nanosize particles (20–48 nm) in EC, basement membranes, axons and dendrites. Tight junctions, a key component of the neurovascular unit (NVU) were abnormal in MC versus control dogs (χ{sup 2}<0.0001), and white matter perivascular damage was significantly worse in MC dogs (p=0.002). The integrity of the NVU, an interactive network of vascular, glial and neuronal cells is compromised in MC young residents. Characterizing the early NVU damage and identifying biomarkers of neurovascular dysfunction may provide a fresh insight into Alzheimer pathogenesis and open opportunities for pediatric neuroprotection. - Highlights: • The prefrontal white matter is a target of air pollution. • Tight junctions, key neurovascular unit elements, are abnormal in young urbanites. • Identifying neurovascular dysfunction biomarkers is key for pediatric neuroprotection. • Early characterization of NVU damage may provide a fresh insight into AD pathogenesis.« less

LPS causes pericyte loss and microvascular dysfunction via disruption of Sirt3/angiopoietins/Tie-2 and HIF-2α/Notch3 pathways.

PubMed

Zeng, Heng; He, Xiaochen; Tuo, Qin-Hui; Liao, Duan-Fang; Zhang, Guo-Qiang; Chen, Jian-Xiong

2016-02-12

Recent studies reveal a crucial role of pericyte loss in sepsis-associated microvascular dysfunction. Sirtuin 3 (SIRT3) mediates histone protein post-translational modification related to aging and ischemic disease. This study investigated the involvement of SIRT3 in LPS-induced pericyte loss and microvascular dysfunction. Mice were exposed to LPS, expression of Sirt3, HIF-2α, Notch3 and angiopoietins/Tie-2, pericyte/endothelial (EC) coverage and vascular permeability were assessed. Mice treated with LPS significantly reduced the expression of SIRT3, HIF-2α and Notch3 in the lung. Furthermore, exposure to LPS increased Ang-2 while inhibited Ang-1/Tie-2 expression with a reduced pericyte/EC coverage. Intriguingly, knockout of Sirt3 upregulated Ang-2, but downregulated Tie-2 and HIF-2α/Notch3 expression which resulted in a dramatic reduction of pericyte/EC coverage and exacerbation of LPS-induced vascular leakage. Conversely, overexpression of Sirt3 reduced Ang-2 expression and increased Ang-1/Tie-2 and HIF-2α/Notch3 expression in the LPS treated mice. Overexpression of Sirt3 further prevented LPS-induced pericyte loss and vascular leakage. This was accompanied by a significant reduction of the mortality rate. Specific knockout of prolyl hydroxylase-2 (PHD2) increased HIF-2α/Notch3 expression, improved pericyte/EC coverage and reduced the mortality rate in the LPS-treated mice. Our study demonstrates the importance of SIRT3 in preserving vascular integrity by targeting pericytes in the setting of LPS-induced sepsis.

APOC3 induces endothelial dysfunction through TNF-α and JAM-1.

PubMed

Tao, Yun; Xiong, Yisong; Wang, Huimin; Chu, Shaopeng; Zhong, Renqian; Wang, Jianxin; Wang, Guihua; Ren, Xiumei; Yu, Juan

2016-09-13

The fatality rate for cardiovascular disease (CVD) has increased in recent years and higher levels of triglyceride have been shown to be an independent risk factor for atherosclerotic CVD. Dysfunction of endothelial cells (ECs) is also a key factor of CVD. APOC3 is an important molecule in lipid metabolism that is closely associated with hyperlipidemia and an increased risk of developing CVD. But the direct effects of APOC3 on ECs were still unknown. This study was aimed at determining the effects of APOC3 on inflammation, chemotaxis and exudation in ECs. ELISA, qRT-PCR, immunofluorescence, flow cytometry and transwell assays were used to investigate the effects of APOC3 on human umbilical vein endothelial cells (HUVECs). SiRNA-induced TNF-α and JAM-1 silencing were used to observe how APOC3 influenced the inflammatory process in the ECs. Our results showed that APOC3 was closely associated with the inflammatory process in ECs, and that this process was characterized by the increased expression of TNF-α. Inflammatory processes further disrupted the tight junctions (TJs) between HUVECs by causing increased expression of JAM-1. JAM-1 was involved in maintaining the integrity of TJs, and it promoted the assembly of platelets and the exudation of leukocytes. Changes in its expression promoted chemotaxis and the exudation of ECs, which contributed to atherosclerosis. While the integrity of the TJs was disrupted, the adhesion of THP-1 cells to HUVECs was also increased by APOC3. In this study, we describe the mechanism by which APOC3 causes inflammation, chemotaxis and the exudation of ECs, and we suggest that controlling the inflammatory reactions that are caused by APOC3 may be a new method to treat CVD.

Nitroprusside and ECS-induced retrograde amnesia.

PubMed

Sudha, S; Andrade, C; Anand, A; Guido, S; Venkataraman, B V

2001-03-01

Previous research found that the administration of verapamil and felodipine immediately before electroconvulsive shocks (ECS) attenuated ECS-induced retrograde amnesia. This study examined whether sodium nitroprusside, an antihypertensive drug that does not affect calcium channels, has a similar action. Adult male Sprague-Dawley rats received nitroprusside (0.5 mg/kg ip) or saline 3 minutes before each of three once-daily true or sham ECS. Retention of pre-ECS learning was studied 1 day after ECS using a passive avoidance task. Nitroprusside was associated with increased seizure duration in ECS-treated rats, and with enhanced recall in both true and sham ECS groups. The latter finding suggests that nitroprusside nonspecifically improves cognitive functions, and does not support the hypothesis that ECS-induced cognitive impairment is a result of blood-brain barrier breach. Nitric oxide mechanisms may underlie the benefits purveyed by nitroprusside.

Calcium/Ask1/MKK7/JNK2/c-Src signalling cascade mediates disruption of intestinal epithelial tight junctions by dextran sulfate sodium.

PubMed

Samak, Geetha; Chaudhry, Kamaljit K; Gangwar, Ruchika; Narayanan, Damodaran; Jaggar, Jonathan H; Rao, RadhaKrishna

2015-02-01

Disruption of intestinal epithelial tight junctions is an important event in the pathogenesis of ulcerative colitis. Dextran sodium sulfate (DSS) induces colitis in mice with symptoms similar to ulcerative colitis. However, the mechanism of DSS-induced colitis is unknown. We investigated the mechanism of DSS-induced disruption of intestinal epithelial tight junctions and barrier dysfunction in Caco-2 cell monolayers in vitro and mouse colon in vivo. DSS treatment resulted in disruption of tight junctions, adherens junctions and actin cytoskeleton leading to barrier dysfunction in Caco-2 cell monolayers. DSS induced a rapid activation of c-Jun N-terminal kinase (JNK), and the inhibition or knockdown of JNK2 attenuated DSS-induced tight junction disruption and barrier dysfunction. In mice, DSS administration for 4 days caused redistribution of tight junction and adherens junction proteins from the epithelial junctions, which was blocked by JNK inhibitor. In Caco-2 cell monolayers, DSS increased intracellular Ca(2+) concentration, and depletion of intracellular Ca(2+) by 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid tetrakis(acetoxymethyl ester) (BAPTA/AM) or thapsigargin attenuated DSS-induced JNK activation, tight junction disruption and barrier dysfunction. Knockdown of apoptosis signal-regulated kinase 1 (Ask1) or MKK7 blocked DSS-induced tight junction disruption and barrier dysfunction. DSS activated c-Src by a Ca2+ and JNK-dependent mechanism. Inhibition of Src kinase activity or knockdown of c-Src blocked DSS-induced tight junction disruption and barrier dysfunction. DSS increased tyrosine phosphorylation of occludin, zonula occludens-1 (ZO-1), E-cadherin and β-catenin. SP600125 abrogated DSS-induced tyrosine phosphorylation of junctional proteins. Recombinant JNK2 induced threonine phosphorylation and auto-phosphorylation of c-Src. The present study demonstrates that Ca(2+)/Ask1/MKK7/JNK2/cSrc signalling cascade mediates DSS-induced tight junction disruption and barrier dysfunction.

Caspase-1 Inflammasome Activation Mediates Homocysteine-Induced Pyrop-Apoptosis in Endothelial Cells

PubMed Central

Xi, Hang; Zhang, Yuling; Xu, Yanjie; Yang, William Y; Jiang, Xiaohua; Sha, Xiaojin; Cheng, Xiaoshu; Wang, Jingfeng; Qin, Xuebin; Yu, Jun; Ji, Yong; Yang, Xiaofeng; Wang, Hong

2016-01-01

Rationale Endothelial injury is an initial mechanism mediating cardiovascular disease. Objective Here, we investigated the effect of hyperhomocysteinemia (HHcy) on programed cell death in endothelial cells (EC). Methods and Results We established a novel flow-cytometric gating method to define pyrotosis (Annexin V−/Propidium iodide+). In cultured human EC, we found that: 1). Hcy and Lipopolysaccharide (LPS) individually and synergistically induced inflammatory pyroptotic and non-inflammatory apoptotic cell death. 2). Hcy/LPS induced caspase-1 activation prior to caspase-8, -9, -3 activations. 3). Caspase-1/3 inhibitors rescued Hcy/LPS-induced pyroptosis/apoptosis, but caspase-8/9 inhibitors had differential rescue effect. 4). Hcy/LPS induced NLRP3 protein, caused NLRP3-containing inflammasome assembly, caspase-1 activation and IL-1β cleavage/activation. 5). Hcy/LPS elevated intracellular reactive oxidative species (ROS). 6). Intracellular oxidative gradient determined cell death destiny as intermediate intracellular ROS levels are associated with pyroptosis, whereas, high ROS corresponded to apoptosis. 7). Hcy/LPS induced mitochondrial membrane potential collapse and cytochrome-c release, and increased Bax/Bcl-2 ratio which were attenuated by antioxidants and caspase-1 inhibitor. 8). Antioxidants extracellular superoxide dismutase and catalase prevented Hcy/LPS-induced caspase-1 activation, mitochondrial dysfunction and pyroptosis/apoptosis. In cystathionine β-synthase deficient (Cbs−/−) mice, severe HHcy induced caspase-1 activation in isolated lung EC and caspase-1 expression in aortic endothelium, and elevated aortic caspase-1,9 protein/activity and Bax/Bcl-2 ratio in Cbs−/− aorta and HUVEC. Finally, Hcy-induced DNA fragmentation was reversed in caspase-1−/− EC. HHcy-induced aortic endothelial dysfunction was rescued in caspase-1−/− and NLRP3−/− mice. Conclusion HHcy preferentially induces EC pyroptosis via caspase-1-dependent inflammasome activation leading to endothelial dysfunction. We termed caspase-1 responsive pyroptosis and apoptosis as pyrop-apoptosis. PMID:27006445

Beyond Plan B: A Qualitative Study of Canadian Pharmacists' Emergency Contraception Counselling Practices.

PubMed

Wong, Karen; Hum, Susan; McCarthy, Lisa; Dunn, Sheila

2017-11-01

Pharmacists are often the front-line health care providers for women seeking emergency contraception (EC). This study explored Ontario pharmacists' EC counselling practices and their perceived barriers to recommending the most effective EC method, the copper IUD (Cu-IUD). This qualitative study used one-on-one, semistructured interviews with 20 pharmacists working in pharmacies located within a 1-km radius of a large sexual health clinic that offered postcoital IUDs in downtown Toronto. All pharmacists provided counselling about levonorgestrel (LNG-EC), and all considered it important. Nevertheless, they rarely discussed the Cu-IUD, even in circumstances where LNG-EC could be less effective, such as delayed presentation or for women with BMI >25 kg/m 2 . Some pharmacists felt conflicted in their dual roles as health care and customer service provider when counselling about and selling EC, and many felt uncomfortable discussing body weight. Pharmacists were not well informed about the Cu-IUD. They identified many pharmacist-specific barriers to counselling about the Cu-IUD for EC, as well as health systems issues around Cu-IUD provision and insertion. Ontario pharmacists embraced their role in EC counselling, yet their discussions rarely included the most effective Cu-IUD option. Educating and training pharmacists about the Cu-IUD and establishing referral pathways for IUD insertion could expand their counselling about this EC option. Copyright © 2017 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.

CD146 coordinates brain endothelial cell–pericyte communication for blood–brain barrier development

PubMed Central

Chen, Jianan; Luo, Yongting; Hui, Hui; Cai, Tanxi; Huang, Hongxin; Yang, Fuquan; Feng, Jing; Zhang, Jingjing; Yan, Xiyun

2017-01-01

The blood–brain barrier (BBB) establishes a protective interface between the central neuronal system and peripheral blood circulation and is crucial for homeostasis of the CNS. BBB formation starts when the endothelial cells (ECs) invade the CNS and pericytes are recruited to the nascent vessels during embryogenesis. Despite the essential function of pericyte–EC interaction during BBB development, the molecular mechanisms coordinating the pericyte–EC behavior and communication remain incompletely understood. Here, we report a single cell receptor, CD146, that presents dynamic expression patterns in the cerebrovasculature at the stages of BBB induction and maturation, coordinates the interplay of ECs and pericytes, and orchestrates BBB development spatiotemporally. In mouse brain, CD146 is first expressed in the cerebrovascular ECs of immature capillaries without pericyte coverage; with increased coverage of pericytes, CD146 could only be detected in pericytes, but not in cerebrovascular ECs. Specific deletion of Cd146 in mice ECs resulted in reduced brain endothelial claudin-5 expression and BBB breakdown. By analyzing mice with specific deletion of Cd146 in pericytes, which have defects in pericyte coverage and BBB integrity, we demonstrate that CD146 functions as a coreceptor of PDGF receptor-β to mediate pericyte recruitment to cerebrovascular ECs. Moreover, we found that the attached pericytes in turn down-regulate endothelial CD146 by secreting TGF-β1 to promote further BBB maturation. These results reveal that the dynamic expression of CD146 controls the behavior of ECs and pericytes, thereby coordinating the formation of a mature and stable BBB. PMID:28827364

Calcium Channels and Oxidative Stress Mediate a Synergistic Disruption of Tight Junctions by Ethanol and Acetaldehyde in Caco-2 Cell Monolayers.

PubMed

Samak, Geetha; Gangwar, Ruchika; Meena, Avtar S; Rao, Roshan G; Shukla, Pradeep K; Manda, Bhargavi; Narayanan, Damodaran; Jaggar, Jonathan H; Rao, RadhaKrishna

2016-12-13

Ethanol is metabolized into acetaldehyde in most tissues. In this study, we investigated the synergistic effect of ethanol and acetaldehyde on the tight junction integrity in Caco-2 cell monolayers. Expression of alcohol dehydrogenase sensitized Caco-2 cells to ethanol-induced tight junction disruption and barrier dysfunction, whereas aldehyde dehydrogenase attenuated acetaldehyde-induced tight junction disruption. Ethanol up to 150 mM did not affect tight junction integrity or barrier function, but it dose-dependently increased acetaldehyde-mediated tight junction disruption and barrier dysfunction. Src kinase and MLCK inhibitors blocked this synergistic effect of ethanol and acetaldehyde on tight junction. Ethanol and acetaldehyde caused a rapid and synergistic elevation of intracellular calcium. Calcium depletion by BAPTA or Ca 2+ -free medium blocked ethanol and acetaldehyde-induced barrier dysfunction and tight junction disruption. Diltiazem and selective knockdown of TRPV6 or Ca V 1.3 channels, by shRNA blocked ethanol and acetaldehyde-induced tight junction disruption and barrier dysfunction. Ethanol and acetaldehyde induced a rapid and synergistic increase in reactive oxygen species by a calcium-dependent mechanism. N-acetyl-L-cysteine and cyclosporine A, blocked ethanol and acetaldehyde-induced barrier dysfunction and tight junction disruption. These results demonstrate that ethanol and acetaldehyde synergistically disrupt tight junctions by a mechanism involving calcium, oxidative stress, Src kinase and MLCK.

Male access to emergency contraception in pharmacies: a mystery shopper survey.

PubMed

Bell, David L; Camacho, Elvis J; Velasquez, Andrew B

2014-10-01

Pharmacy access to emergency contraception (EC) could involve men in pregnancy prevention. The objectives were to assess the availability and cost of EC. Male mystery shoppers visited 158 pharmacies in three neighborhoods in New York City. They asked for EC and its cost and noted weekend hours. Twenty-two (73.3%) of 30 pharmacies created barriers to get EC. The cost of EC was higher in the higher-socioeconomic status (SES) neighborhood (p<.001), and the higher-SES neighborhood pharmacies had a greater number of weekend hours (p<.001). Overall, males had a 20% probability of not being able to access EC. The national dialogue should include males. Copyright © 2014 Elsevier Inc. All rights reserved.

Endothelial cells use dynamic actin to facilitate lymphocyte transendothelial migration and maintain the monolayer barrier

PubMed Central

Mooren, Olivia L.; Li, Jinmei; Nawas, Julie; Cooper, John A.

2014-01-01

The vascular endothelium is a highly dynamic structure, and the integrity of its barrier function is tightly regulated. Normally impenetrable to cells, the endothelium actively assists lymphocytes to exit the bloodstream during inflammation. The actin cytoskeleton of the endothelial cell (EC) is known to facilitate transmigration, but the cellular and molecular mechanisms are not well understood. Here we report that actin assembly in the EC, induced by Arp2/3 complex under control of WAVE2, is important for several steps in the process of transmigration. To begin transmigration, ECs deploy actin-based membrane protrusions that create a cup-shaped docking structure for the lymphocyte. We found that docking structure formation involves the localization and activation of Arp2/3 complex by WAVE2. The next step in transmigration is creation of a migratory pore, and we found that endothelial WAVE2 is needed for lymphocytes to follow a transcellular route through an EC. Later, ECs use actin-based protrusions to close the gap behind the lymphocyte, which we discovered is also driven by WAVE2. Finally, we found that ECs in resting endothelial monolayers use lamellipodial protrusions dependent on WAVE2 to form and maintain contacts and junctions between cells. PMID:25355948

Anti-Infiltration Barrier Technology and the Battle for Southeast Asia, 1966-1972

DTIC Science & Technology

2000-04-01

to EC- 121Rs.12 The EC-121Rs (see Figure 9) of the 553rd Reconnaissance Wing at Korat RTAFB operated throughout the life of the anti-infiltration...dated April 17, 1967, JCS recommended to the SECDEF the formal establishment of the EC-121R Wing at Korat RTAFB, an F-4 Squadron at Ubon RTAFB, and a...of the system was being established air elements began arriving in Thailand. The first EC-121Rs of the 553rd Reconnaissance Wing arrived at Korat

Transgenic mice overexpressing the extracellular domain of NCAM are impaired in working memory and cortical plasticity

PubMed Central

Brennaman, Leann H.; Kochlamazashvili, Gaga; Stoenica, Luminita; Nonneman, Randall J.; Moy, Sheryl S.; Schachner, Melitta; Dityatev, Alexander; Maness, Patricia F.

2011-01-01

The neural cell adhesion molecule, NCAM, is a pivotal regulator of neural development, with key roles in axonal and dendritic growth and synaptic plasticity. Alterations in NCAM expression or proteolytic cleavage have been linked to human neuropsychiatric disorders such as schizophrenia, bipolar disorder and Alzheimer’s disease, and may contribute to cognitive dysfunction. We have generated mice overexpressing the NCAM extracellular (EC) proteolytic cleavage fragment which has been reported to be increased in schizophrenic versus normal brains. These mice show impaired GABAergic innervation and reduced number of apical dendritic spines on pyramidal neurons in the prefrontal cortex (PFC). Here, these NCAM-EC transgenic mice were subjected to behavioral tasks and electrophysiological measurements to determine the impact of structural abnormalities in the PFC on synaptic and cognitive functions. NCAM-EC mice exhibited impaired working memory in a delayed non-match-to-sample task, which requires PFC function, but showed no differences in anxiety, olfactory abilities, or sociability. Transgenic mice displayed impaired long- and short-term potentiation in the PFC but normal synaptic plasticity in the hippocampus, suggesting that the abnormal synaptic innervation in NCAM-EC mice impairs PFC plasticity and alters working memory. These findings may have implications for cognitive dysfunctions observed in neuropsychiatric disorders. PMID:21515372

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.

Heme oxygenase-1-derived bilirubin counteracts HIV protease inhibitor-mediated endothelial cell dysfunction

PubMed Central

Liu, Xiao-Ming; Durante, Zane E.; Peyton, Kelly J.; Durante, William

2016-01-01

The use of HIV protease inhibitors (PIs) has extended the duration and quality of life for HIV-positive individuals. However there is increasing concern that this antiviral therapy may promote premature cardiovascular disease by impairing endothelial cell (EC) function. In the present study, we investigated the effect of HIV PIs on EC function and determined if the enzyme heme oxygenase (HO-1) influences the biological action of these drugs. We found that three distinct PIs, including ritonavir, atazanavir, and lopinavir, stimulated the expression of HO-1 protein and mRNA. The induction of HO-1 was associated with an increase in NF-E2-related factor-2 (Nrf2) activity and reactive oxygen species (ROS). PIs also stimulated HO-1 promoter activity and this was prevented by mutating the antioxidant responsive element or by overexpressing dominant-negative Nrf2. In addition, the PI-mediated induction of HO-1 was abolished by N-acetyl-L-cysteine and rotenone. Furthermore, PIs blocked EC proliferation and migration and stimulated the expression of intercellular adhesion molecule-1 and the adhesion of monocytes on ECs. Inhibition of HO-1 activity or expression potentiated the anti-proliferative and inflammatory actions of PIs which was reversed by bilirubin but not carbon monoxide. Alternatively, adenovirus-mediated overexpression of HO-1 attenuated the growth-inhibitory and inflammatory effect of PIs. In contrast, blocking HO-1 activity failed to modify the anti-migratory effect of the PIs. Thus, induction of HO-1 via the ROS–Nrf2 pathway in human ECs counteracts the anti-proliferative and inflammatory actions of PIs by generating bilirubin. Therapeutic approaches targeting HO-1 may provide a novel approach in preventing EC dysfunction and vascular disease in HIV-infected patients undergoing antiretroviral therapy. PMID:26968795

Overexpression of hexokinase 2 reduces mitochondrial calcium overload in coronary endothelial cells of type 2 diabetic mice.

PubMed

Pan, Minglin; Han, Ying; Basu, Aninda; Dai, Anzhi; Si, Rui; Willson, Conor; Balistrieri, Angela; Scott, Brian T; Makino, Ayako

2018-03-07

Coronary microvascular rarefaction due to endothelial cell (EC) dysfunction is one of the causes of increased morbidity and mortality in diabetes. Coronary ECs in diabetes are more apoptotic due partly to mitochondrial calcium overload. This study was designed to investigate the role of hexokinase 2 (HK2, an endogenous inhibitor of voltage-dependent anion channel) in coronary endothelial dysfunction in type 2 diabetes. We used mouse coronary ECs (MCECs) isolated from type 2 diabetic mice and human coronary ECs (HCECs) from type 2 diabetic patients to examine protein levels and mitochondrial functions. ECs were more apoptotic and capillary density was lower in the left ventricle of diabetic mice than the control. MCECs from diabetic mice exhibited significant increase in mitochondrial Ca 2+ concentration ([Ca 2+ ] mito ) compared to the control. Among several regulatory proteins for [Ca 2+ ] mito , HK1 and HK2 were significantly lower in MCECs from diabetic mice than control MCECs. We also found that the level of HK2 ubiquitination was higher in MCECs from diabetic mice than in control MCECs. In line with the data from MCECs, HCECs from diabetic patients showed lower HK2 protein levels than HCECs from non-diabetic patients. High-glucose treatment, but not high-fat treatment, significantly decreased HK2 protein levels in the MCEC. HK2 overexpression in MCECs of diabetic mice not only lowered the level of [Ca 2+ ] mito , but also reduced mitochondrial ROS production toward the level seen in control MCECs. These data suggest that HK2 is a potential therapeutic target for coronary microvascular disease in diabetes by restoring mitochondrial function in coronary ECs.

Vascular oxidative stress and endothelial dysfunction in patients with chronic heart failure: role of xanthine-oxidase and extracellular superoxide dismutase.

PubMed

Landmesser, Ulf; Spiekermann, Stephan; Dikalov, Sergey; Tatge, Helma; Wilke, Ragna; Kohler, Christoph; Harrison, David G; Hornig, Burkhard; Drexler, Helmut

2002-12-10

Impaired flow-dependent, endothelium-mediated vasodilation (FDD) in patients with chronic heart failure (CHF) results, at least in part, from accelerated degradation of nitric oxide by oxygen radicals. The mechanisms leading to increased vascular radical formation, however, remain unclear. Therefore, we determined endothelium-bound activities of extracellular superoxide dismutase (ecSOD), a major vascular antioxidant enzyme, and xanthine-oxidase, a potent radical producing enzyme, and their relation to FDD in patients with CHF. ecSOD and xanthine-oxidase activities, released from endothelium into plasma by heparin bolus injection, were determined in 14 patients with CHF and 10 control subjects. FDD of the radial artery was measured using high-resolution ultrasound and was assessed before and after administration of the antioxidant vitamin C (25 mg/min; IA). In patients with CHF, endothelium-bound ecSOD activity was substantially reduced (5.0+/-0.7 versus 14.4+/-2.6 U x mL(-1) x min(-1); P<0.01) and closely related to FDD (r=0.61). Endothelium-bound xanthine-oxidase activity was increased by >200% (38+/-10 versus 12+/-4 nmol O2*- x microL(-1); P<0.05) and inversely related to FDD (r=-0.35) in patients with CHF. In patients with low ecSOD and high xanthine-oxidase activity, a greater benefit of vitamin C on FDD was observed, ie, the portion of FDD inhibited by radicals correlated negatively with ecSOD (r=-0.71) but positively with xanthine-oxidase (r=0.75). These results demonstrate that both increased xanthine-oxidase and reduced ecSOD activity are closely associated with increased vascular oxidative stress in patients with CHF. This loss of vascular oxidative balance likely represents a novel mechanism contributing to endothelial dysfunction in CHF.

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

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.

Paleoclassical transport explains electron transport barriers in RTP and TEXTOR

NASA Astrophysics Data System (ADS)

Hogeweij, G. M. D.; Callen, J. D.; RTP Team; TEXTOR Team

2008-06-01

The recently developed paleoclassical transport model sets the minimum level of electron thermal transport in a tokamak. This transport level has proven to be in good agreement with experimental observations in many cases when fluctuation-induced anomalous transport is small, i.e. in (near-)ohmic plasmas in small to medium size tokamaks, inside internal transport barriers (ITBs) or edge transport barriers (H-mode pedestal). In this paper predictions of the paleoclassical transport model are compared in detail with data from such kinds of discharges: ohmic discharges from the RTP tokamak, EC heated RTP discharges featuring both dynamic and shot-to-shot scans of the ECH power deposition radius and off-axis EC heated discharges from the TEXTOR tokamak. For ohmically heated RTP discharges the Te profiles predicted by the paleoclassical model are in reasonable agreement with the experimental observations, and various parametric dependences are captured satisfactorily. The electron thermal ITBs observed in steady state EC heated RTP discharges and transiently after switch-off of off-axis ECH in TEXTOR are predicted very well by the paleoclassical model.

Airway Epithelial Barrier Dysfunction in Chronic Obstructive Pulmonary Disease: Role of Cigarette Smoke Exposure.

PubMed

Aghapour, Mahyar; Raee, Pourya; Moghaddam, Seyed Javad; Hiemstra, Pieter S; Heijink, Irene H

2018-02-01

The epithelial lining of the airway forms the first barrier against environmental insults, such as inhaled cigarette smoke, which is the primary risk factor for the development of chronic obstructive pulmonary disease (COPD). The barrier is formed by airway epithelial junctions, which are interconnected structures that restrict permeability to inhaled pathogens and environmental stressors. Destruction of the epithelial barrier not only exposes subepithelial layers to hazardous agents in the inspired air, but also alters the normal function of epithelial cells, which may eventually contribute to the development of COPD. Of note, disruption of epithelial junctions may lead to modulation of signaling pathways involved in differentiation, repair, and proinflammatory responses. Epithelial barrier dysfunction may be particularly relevant in COPD, where repeated injury by cigarette smoke exposure, pathogens, inflammatory mediators, and impaired epithelial regeneration may compromise the barrier function. In the current review, we discuss recent advances in understanding the mechanisms of barrier dysfunction in COPD, as well as the molecular mechanisms that underlie the impaired repair response of the injured epithelium in COPD and its inability to redifferentiate into a functionally intact epithelium.

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.

Thermally stimulated capacitance in gamma irradiated epitaxial 4H-SiC Schottky barrier diodes

NASA Astrophysics Data System (ADS)

Vigneshwara Raja, P.; Narasimha Murty, N. V. L.

2018-04-01

Deep level defects in 4H-SiC Schottky barrier diodes (SBDs) fabricated on n-type epitaxial 4H-SiC have been identified by thermally stimulated capacitance (TSCAP) spectroscopy prior to and after 60Co-gamma irradiation. The TSCAP measurements on the non-irradiated SBDs reveal two electron traps at Ec-0.63 eV (˜250 K) and Ec-1.13 eV (˜525 K), whereas only one trap at Ec-0.63 eV is identified by conventional thermally stimulated current (TSC) measurements. Hence, TSCAP spectroscopy is more effective in identifying deep level defects in epitaxial 4 H-SiC SBDs as compared to the TSC spectroscopy. Upon exposure to 60Co-gamma rays up to a dose of 100 Mrad, significant changes in the concentration of the traps at Ec-0.63 eV, Ec-1.13 eV, and one new trap at Ec-0.89 eV (˜420 K) are observed. The electrical characteristics of the SBDs are considerably changed after gamma irradiation. The dominant mechanisms responsible for the irradiation induced changes in the SBD electrical characteristics are analyzed by incorporating the trap signatures in the commercial Silvaco® TCAD device simulator. The extracted trap parameters of the irradiated SBDs may be helpful in predicting the survival of 4H-SiC SBD detectors at higher irradiation levels.

Blocking mitochondrial cyclophilin D ameliorates TSH-impaired defensive barrier of artery.

PubMed

Liu, Xiaojing; Du, Heng; Chai, Qiang; Jia, Qing; Liu, Lu; Zhao, Meng; Li, Jun; Tang, Hui; Chen, Wenbin; Zhao, Lifang; Fang, Li; Gao, Ling; Zhao, Jiajun

2018-05-01

Endothelial cells (ECs) constitute the defensive barrier of vasculature, which maintains the vascular homeostasis. Mitochondrial oxidative stress (mitoOS) in ECs significantly affects the initiation and progression of vascular diseases. The higher serum thyroid stimulating hormone (TSH) level is being recognized as a nonconventional risk factor responsible for the increased risk of cardiovascular diseases in subclinical hypothyroidism (SCH). However, effects and underlying mechanisms of elevated TSH on ECs are still ambiguous. We sought to investigate whether cyclophilin D (CypD), emerging as a crucial mediator in mitoOS, regulates effects of TSH on ECs. SCH patients with TSH > = 10mIU/L showed a positive correlation between serum TSH and endothelin-1 levels. When TSH levels declined to normal in these subjects after levothyroxine therapy, serum endothelin-1 levels were significantly reduced. Supplemented with exogenous thyroxine to keep normal thyroid hormones, thyroid-specific TSH receptor (TSHR)-knockout mice with injection of exogenous TSH exhibited elevated serum TSH levels, significant endothelial oxidative injuries and disturbed endothelium-dependent vasodilation. However, Tshr -/- mice resisted to TSH-impaired vasotonia. We further confirmed that elevated TSH triggered excessive mitochondrial permeability transition pore (mPTP) opening and mitochondrial oxidative damages in mouse aorta, as well as in cultured ECs. Genetic or pharmacological inhibition of CypD (the key regulator for mPTP opening) attenuated TSH-induced mitochondrial oxidative damages and further rescued endothelial functions. Finally, we confirmed that elevated TSH could activate CypD by enhancing CypD acetylation via inhibiting adenosine monophosphate-activated protein kinase/sirtuin-3 signaling pathway in ECs. These findings reveal that elevated TSH triggers mitochondrial perturbations in ECs and provide insights that blocking mitochondrial CypD enhances the defensive ability of ECs under TSH exposure. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Akt Suppression of TGFβ Signaling Contributes to the Maintenance of Vascular Identity in Embryonic Stem Cell-Derived Endothelial Cells

PubMed Central

Israely, Edo; Ginsberg, Michael; Nolan, Daniel; Ding, Bi-Sen; James, Daylon; Elemento, Olivier; Rafii, Shahin; Rabbany, Sina Y

2016-01-01

The ability to generate and maintain stable in vitro cultures of mouse endothelial cells (EC) has great potential for genetic dissection of the numerous pathologies involving vascular dysfunction as well as therapeutic applications. However, previous efforts at achieving sustained cultures of primary stable murine vascular cells have fallen short, and the cellular requirements for EC maintenance in vitro remain undefined. In this study, we have generated vascular ECs from mouse embryonic stem (ES) cells, and show that active Akt is essential to their survival and propagation as homogeneous monolayers in vitro. These cells harbor the phenotypical, biochemical, and functional characteristics of ECs, and expand throughout long-term cultures, while maintaining their angiogenic capacity. Moreover, Akt-transduced embryonic ECs form functional perfused vessels in vivo that anastomose with host blood vessels. We provide evidence for a novel function of Akt in stabilizing EC identity, whereby the activated form of the protein protects mouse ES cell-derived ECs from TGFβ-mediated transdifferentiation by downregulating SMAD3. These findings identify a role for Akt in regulating the developmental potential of ES cell-derived ECs, and demonstrate that active Akt maintains endothelial identity in embryonic ECs by interfering with active TGFβ-mediated processes that would ordinarily usher these cells to alternate fates. PMID:23963623

Molecular mechanisms of euplotin C-induced apoptosis: involvement of mitochondrial dysfunction, oxidative stress and proteases.

PubMed

Cervia, Davide; Garcia-Gil, Mercedes; Simonetti, Elisa; Di Giuseppe, Graziano; Guella, Graziano; Bagnoli, Paola; Dini, Fernando

2007-08-01

The metabolite euplotin C (EC), isolated from the marine ciliate Euplotes crassus, is a powerful cytotoxic and pro-apoptotic agent in tumour cell lines. For instance, EC induces the rapid depletion of ryanodine Ca(2+) stores, the release of cytochrome c from the mitochondria, and the activation of caspase-3, leading to apoptosis. The purpose of this study was to gain further insight into the mechanisms of EC-induced apoptosis in rat pheochromocytoma PC12 cells. We found that EC increases Bax/Bcl-2 ratio and that Bax is responsible of the EC-induced dissipation of the mitochondrial membrane potential (Deltapsi(m)). In addition, EC induces the generation of reactive oxygene species (ROS) without involvement of p53. The inhibition of ROS generation prevents, at least in part, the pro-apoptotic effects of EC as well as the effects of EC on Bax, Deltapsi(m) and intracellular free Ca(2+), indicating a cross-talk between different pathways. However, definition of the effector cascade turns out to be more complex than expected and caspase-independent mechanisms, acting in parallel with caspases, should also be considered. Among them, EC increases the expression/activity of calpains downstream of ROS generation, although calpains seem to exert protective effects.

Akt suppression of TGFβ signaling contributes to the maintenance of vascular identity in embryonic stem cell-derived endothelial cells.

PubMed

Israely, Edo; Ginsberg, Michael; Nolan, Daniel; Ding, Bi-Sen; James, Daylon; Elemento, Olivier; Rafii, Shahin; Rabbany, Sina Y

2014-01-01

The ability to generate and maintain stable in vitro cultures of mouse endothelial cells (ECs) has great potential for genetic dissection of the numerous pathologies involving vascular dysfunction as well as therapeutic applications. However, previous efforts at achieving sustained cultures of primary stable murine vascular cells have fallen short, and the cellular requirements for EC maintenance in vitro remain undefined. In this study, we have generated vascular ECs from mouse embryonic stem (ES) cells and show that active Akt is essential to their survival and propagation as homogeneous monolayers in vitro. These cells harbor the phenotypical, biochemical, and functional characteristics of ECs and expand throughout long-term cultures, while maintaining their angiogenic capacity. Moreover, Akt-transduced embryonic ECs form functional perfused vessels in vivo that anastomose with host blood vessels. We provide evidence for a novel function of Akt in stabilizing EC identity, whereby the activated form of the protein protects mouse ES cell-derived ECs from TGFβ-mediated transdifferentiation by downregulating SMAD3. These findings identify a role for Akt in regulating the developmental potential of ES cell-derived ECs and demonstrate that active Akt maintains endothelial identity in embryonic ECs by interfering with active TGFβ-mediated processes that would ordinarily usher these cells to alternate fates. © AlphaMed Press.

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

Contraception Initiation in the Emergency Department: A Pilot Study on Providers' Knowledge, Attitudes, and Practices.

PubMed

Liles, Iyanna; Haddad, Lisa B; Lathrop, Eva; Hankin, Abigail

2016-05-01

Almost half of all pregnancies in the United States are unintended; these pregnancies are associated with adverse outcomes. Many reproductive-age females seek care in the emergency department (ED), are at risk of pregnancy, and are amenable to contraceptive services in this setting. Through a pilot study, we sought to assess ED providers' current practices; attitudes; and knowledge of emergency contraception (EC) and nonemergency contraception (non-EC), as well as barriers with respect to contraception initiation. ED physicians and associate providers in Georgia were e-mailed a link to an anonymous Internet questionnaire using state professional databases and contacts. The questionnaire included Likert scales with multiple-choice questions to assess study objectives. Descriptive statistics were generated as well as univariate analyses using χ(2) and Fisher exact tests. A total of 1232 providers were e-mailed, with 119 questionnaires completed. Participants were predominantly physicians (80%), men (59%), and individuals younger than 45 years (59%). Common practices were referrals (96%), EC prescriptions (77%), and non-EC prescriptions (40%). Common barriers were perceived as low likelihood for follow-up (63%), risk of complications (58%), and adverse effects (51%). More than 70% of participants correctly identified the highly effective contraceptive methods, 3% identified the correct maximum EC initiation time, and 42% correctly recognized pregnancy as a higher risk than hormonal contraception use for pulmonary embolism. Most ED providers in this pilot study referred patients for contraception; however, there was no universal contraceptive counseling and management. Many ED providers in this study had an incorrect understanding of the efficacy, risks, and eligibility associated with contraceptive methods. This lack of understanding may affect patient access and be a barrier to patient care.

Review: Pathogenesis of canine atopic dermatitis: skin barrier and host-micro-organism interaction.

PubMed

Santoro, Domenico; Marsella, Rosanna; Pucheu-Haston, Cherie M; Eisenschenk, Melissa N C; Nuttall, Tim; Bizikova, Petra

2015-04-01

Canine atopic dermatitis (AD) is a common, genetically predisposed, inflammatory and pruritic skin disease. The pathogenesis of canine AD is incompletely understood. The aim of this review is to provide an in-depth update on the involvement of skin barrier and host-microbiome interaction in the pathogenesis of canine AD. Online citation databases and abstracts from international meetings were searched for publications related to skin barrier and host-microbiome interaction (e.g. bacteria, yeast, antimicrobial peptides). A total of 126 publications were identified. This review article focuses on epidermal barrier dysfunction and the interaction between cutaneous microbes (bacteria and yeasts) and the host (antimicrobial peptides). Epidemiological updates on the presence of pathogenic organisms and canine AD are also provided. Major advances have been made in the investigation of skin barrier dysfunction in canine AD, although many questions still remain. Skin barrier dysfunction and host-microbiome interactions are emerging as primary alterations in canine AD. Based on this review, it is clear that future studies focused on the development of drugs able to restore the skin barrier and increase the natural defences against pathogenic organisms are needed. © 2015 ESVD and ACVD.

Culture media-based selection of endothelial cells, pericytes, and perivascular-resident macrophage-like melanocytes from the young mouse vestibular system.

PubMed

Zhang, Jinhui; Chen, Songlin; Cai, Jing; Hou, Zhiqiang; Wang, Xiaohan; Kachelmeier, Allan; Shi, Xiaorui

2017-03-01

The vestibular blood-labyrinth barrier (BLB) is comprised of perivascular-resident macrophage-like melanocytes (PVM/Ms) and pericytes (PCs), in addition to endothelial cells (ECs) and basement membrane (BM), and bears strong resemblance to the cochlear BLB in the stria vascularis. Over the past few decades, in vitro cell-based models have been widely used in blood-brain barrier (BBB) and blood-retina barrier (BRB) research, and have proved to be powerful tools for studying cell-cell interactions in their respective organs. Study of both the vestibular and strial BLB has been limited by the unavailability of primary culture cells from these barriers. To better understand how barrier component cells interact in the vestibular system to control BLB function, we developed a novel culture medium-based method for obtaining EC, PC, and PVM/M primary cells from tiny explants of the semicircular canal, sacculus, utriculus, and ampullae tissue of young mouse ears at post-natal age 8-12 d. Each phenotype is grown in a specific culture medium which selectively supports the phenotype in a mixed population of vestibular cell types. The unwanted phenotypes do not survive passaging. The protocol does not require additional equipment or special enzyme treatment. The harvesting process takes less than 2 h. Primary cell types are generated within 7-10 d. The primary culture ECs, PCs, and PVM/M shave consistent phenotypes more than 90% pure after two passages (∼ 3 weeks). The highly purified primary cell lines can be used for studying cell-cell interactions, barrier permeability, and angiogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

Capstone Report on the Application, Monitoring, and Performance of Permeable Reactive Barriers for Ground-Water Remediation: Volume 1: Performance Evaluations at Two Sites

DTIC Science & Technology

2003-08-01

sepiolite , Mg 4 (OH) 2 Si 6 O 15 ·H 2 O...EC050801-3-5 EC050801-3-3 EC050801-3-2 EC050801-3-1 In te n si ty degrees 2-theta In te n si ty In te n si ty downgradient edge upgradient edge In te n...400 b ic a rb o n a te , m g /L 0 2 4 6 8 10 12 14 16 si lic a , m g /L Figure 4.12 Average (± 1 s.d.) concentrations of Na, K , Ca,

MicroRNAs as Regulators of Endothelial Cell Functions in Cardiometabolic Diseases

PubMed Central

Araldi, Elisa; Suárez, Yajaira

2016-01-01

Endothelial cells (ECs) provide nutrients and oxygen essential for tissue homeostasis. Metabolic imbalances and other environmental stimuli, like cytokines or low shear stress, trigger endothelial inflammation, increase permeability, compromise vascular tone, promote cell proliferation and ultimately cause cell death. These factors contribute to EC dysfunction, which is crucial in the development of cardiometabolic diseases. microRNAs (miRNAs) are small non-coding RNAs that have important functions in the regulation of ECs. In the present review, we discuss the role of miRNAs in various aspects of EC pathology in cardiometabolic diseases like atherosclerosis, type 2 diabetes, obesity, and the metabolic syndrome, and in complication of those pathologies, like ischemia. We also discuss the potential therapeutic applications of miRNAs in promoting angiogenesis and neovascularization in tissues where the endothelium is damaged in different cardiometabolic diseases. PMID:26825686

Interface state density of free-standing GaN Schottky diodes

NASA Astrophysics Data System (ADS)

Faraz, S. M.; Ashraf, H.; Imran Arshad, M.; Hageman, P. R.; Asghar, M.; Wahab, Q.

2010-09-01

Schottky diodes were fabricated on the HVPE-grown, free-standing gallium nitride (GaN) layers of n- and p-types. Both contacts (ohmic and Schottky) were deposited on the top surface using Al/Ti and Pd/Ti/Au, respectively. The Schottky diode fabricated on n-GaN exhibited double barriers with values of 0.9 and 0.6 eV and better performance in the rectification factor together with reverse and forward currents with an ideality factor of 1.8. The barrier height for the p-GaN Schottky diode is 0.6 eV with an ideality factor of 4.16. From the capacitance-voltage (C-V) measurement, the net doping concentration of n-GaN is 4 × 1017 cm-3, resulting in a lower reverse breakdown of around -12 V. The interface state density (NSS) as a function of EC-ESS is found to be in the range 4.23 × 1012-3.87 × 1011 eV-1 cm-2 (below the conduction band) from Ec-0.90 to EC-0.99. Possible reasons responsible for the low barrier height and high ideality factor have been addressed.

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.

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.

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.

Emergency contraception. Widely available and effective but disappointing as a public health intervention: a review

PubMed Central

Baird, D.T.; Cameron, S.; Evers, J.L.H.; Gemzell-Danielsson, K.; Glasier, A.; Moreau, C.; Trussell, J.; von Hertzen, H.; Crosignani, P.G.; La Vecchia, C.; Volpe, A.; Glasier, A.; Crosignani, P.G.

2015-01-01

Emergency contraception (EC) prevents pregnancy after unprotected sex or contraceptive failure. Use of EC has increased markedly in countries where a product is available over the counter, yet barriers to availability and use remain. Although effective in clinical trials, it has not yet been possible to show a public health benefit of EC in terms of reduction of unintended pregnancy rates. Selective progesterone receptor modulators developed as emergency contraceptives offer better effectiveness than levonorgestrel, but still EC is less effective than use of ongoing regular contraception. Methods which inhibit ovulation whenever they are taken or which act after ovulation to prevent implantation and strategies to increase the uptake of effective ongoing contraception after EC use would prevent more pregnancies. PMID:25678571

Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction.

PubMed

Chen, M; Zhang, Y; Yu, V C; Chong, Y-S; Yoshioka, T; Ge, R

2014-05-01

Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent.

Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction

PubMed Central

Chen, M; Zhang, Y; Yu, V C; Chong, Y-S; Yoshioka, T; Ge, R

2014-01-01

Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent. PMID:24464222

A novel approach to maintain gut mucosal integrity using an oral enzyme supplement.

PubMed

Hamarneh, Sulaiman R; Mohamed, Mussa M Rafat; Economopoulos, Konstantinos P; Morrison, Sara A; Phupitakphol, Tanit; Tantillo, Tyler J; Gul, Sarah S; Gharedaghi, Mohammad Hadi; Tao, Qingsong; Kaliannan, Kanakaraju; Narisawa, Sonoko; Millán, José L; van der Wilden, Gwendolyn M; Fagenholz, Peter J; Malo, Madhu S; Hodin, Richard A

2014-10-01

To determine the role of intestinal alkaline phosphatase (IAP) in enteral starvation-induced gut barrier dysfunction and to study its therapeutic effect as a supplement to prevent gut-derived sepsis. Critically ill patients are at increased risk for systemic sepsis and, in some cases, multiorgan failure leading to death. Years ago, the gut was identified as a major source for this systemic sepsis syndrome. Previously, we have shown that IAP detoxifies bacterial toxins, prevents endotoxemia, and preserves intestinal microbiotal homeostasis. WT and IAP-KO mice were used to examine gut barrier function and tight junction protein levels during 48-hour starvation and fed states. Human ileal fluid samples were collected from 20 patients postileostomy and IAP levels were compared between fasted and fed states. To study the effect of IAP supplementation on starvation-induced gut barrier dysfunction, WT mice were fasted for 48 hours +/- IAP supplementation in the drinking water. The loss of IAP expression is associated with decreased expression of intestinal junctional proteins and impaired barrier function. For the first time, we demonstrate that IAP expression is also decreased in humans who are deprived of enteral feeding. Finally, our data demonstrate that IAP supplementation reverses the gut barrier dysfunction and tight junction protein losses due to a lack of enteral feeding. IAP is a major regulator of gut mucosal permeability and is able to ameliorate starvation-induced gut barrier dysfunction. Enteral IAP supplementation may represent a novel approach to maintain bowel integrity in critically ill patients.

Intra- and Extra-Cranial Injury Burden as Drivers of Impaired Cerebrovascular Reactivity in Traumatic Brain Injury.

PubMed

Zeiler, Frederick Adam; Donnelly, Joseph; Nourallah, Basil; Thelin, Eric Peter; Calviello, Leanne; Smieleweski, Peter; Czosnyka, Marek; Ercole, Ari; Menon, David

2018-02-12

Impaired cerebrovascular reactivity has been associated with outcome following traumatic brain injury (TBI), but it is unknown how it is affected by trauma severity. Thus, we aimed to explore the relationship between intra-cranial (IC) and extra-cranial (EC) injury burden and cerebrovascular reactivity in TBI patients. We retrospectively included critically ill TBI patients. IC injury burden included detailed lesion and computerized tomography (CT) scoring (ie. Marshall, Rotterdam, Helsinki and Stockholm Scores) on admission. EC injury burden were characterized using the injury severity score (ISS) and APACHE II score. Pressure reactivity index (PRx), pulse amplitude index (PAx) and RAC were used to assess autoregulation/cerebrovascular reactivity. We used univariate and multi-variate logistic regression techniques to explore relationships between IC and EC injury burden and autoregulation indices. A total of 358 patients were assessed. ISS and all IC CT scoring systems were poor predictors of impaired cerebrovascular reactivity. Only subdural hematomas and thickness of SAH (p<0.05, respectively) were consistently associated with dysfunctional cerebrovascular reactivity. High age (p<0.01 for all) and admission APACHE II scores (p<0.05 for all) were the two variables strongest associated with abnormal cerebrovascular reactivity. In summary, diffuse IC injury markers (thickness of SAH and the presence of a SDH) and APACHE II were most associated with dysfunction in cerebrovascular reactivity after TBI. Standard CT scoring systems and evidence of macroscopic parenchymal damage are poor predictors, implicating potentially both microscopic injury patterns and host response as drivers of dysfunctional cerebrovascular reactivity. Age remains a major variable associated with cerebrovascular reactivity.

Aerobic exercise improves microvascular dysfunction in fructose fed hamsters.

PubMed

Boa, B C S; Costa, R R; Souza, M G C; Cyrino, F Z G A; Paes, L S; Miranda, M L; Carvalho, J J; Bouskela, E

2014-05-01

Fructose is a major diet component directly related to severe damages to the microcirculation and to diseases such as obesity, diabetes and hypertension to which physical activity is pointed out as an important non-pharmacological treatment since its positive effects precede anthropometric improvements. In this study we have investigated the effects of a light/moderate aerobic exercise training (AET) on microcirculatory dysfunction elicited by carbohydrate overload during a period of 5 months. Male hamsters (Mesocricetus auratus) whose drinking water was substituted (F) or not (C) by 10% fructose solution, during 20 weeks, associated or not to AET in the last 4 weeks (EC and EF subgroups) had their microcirculatory function evaluated on the cheek pouch preparation, glucose and insulin tolerance (GTT and ITT) tested. Arterial blood was collected for pO2, pCO2, HCO3(-), pH, total CO2, saturated O2 and lactate determinations. Liver fragments were observed using an electron microscope. Microcirculatory responses to acetylcholine [Ach, an endothelium-dependent vasodilator; 10(-8)M - *123.3±7.5% (C), 119.5±1.3% (EC), *98.1±3.2% (F) and 133.6±17.2% (EF); 10(-6)M - *133.0±4.1% (C), 135.6±4.3% (EC), *103.4±4.3% (F) and 134.1±5.9% (EF); 10(-4)M - *167.2±5.0% (C), 162.8±5.4% (EC), *123.8±6.3% (F) and 140.8±5.0% (EF)] and to sodium nitroprusside [SNP, an endothelium-independent vasodilator; 10(-8)M - 118.8±6.8% (C), 114.0±5.0% (EC), 100.2±2.9% (F), 104.9±4.4% (EF); 10(-6)M - 140.6±11.7% (C), 141.7±5.5% (EC), 125.0±4.7% (F), 138.3±2.8% (EF); 10(-4)M - 150.4±10.9% (C), 147.9±6.5% (EC), 139.2±7.3% (F), 155.9±4.7% (EF)] and macromolecular permeability increase induced by 30 min ischemia/reperfusion (I/R) procedure [14.4±3.5 (C), 30.0±1.9 (EC), *112.0±8.8 (F) and *22.4±0.9 leaks/cm(2) (EF)] have shown that endothelium-dependent vasodilatation was significantly reduced and I/R induced macromolecular permeability augmented in sedentary fructose (F) subgroup and both improved after AET. Electron microscopy analysis of the liver showed significant differences between exercised and sedentary subgroups with greater amount of glycogen in F subgroups compared to other ones. No significant changes on mean arterial pressure, heart rate or blood gase between subgroups could be detected. Our results point out that AET could normalize microcirculatory dysfunction elicited by long term substitution of drinking water by 10% fructose solution. Copyright © 2014 Elsevier Inc. All rights reserved.

Studies on impact of electron cyclotron wave injection on the internal transport barriers in JT-60U weak shear plasmas

NASA Astrophysics Data System (ADS)

Ide, S.; Takenaga, H.; Isayama, A.; Sakamoto, Y.; Yoshida, M.; Gormezano, C.

2007-11-01

Impact of the electron cyclotron range of frequency wave (ECRF) on the internal transport barriers (ITBs) in a weak shear (WS) plasma has been investigated in JT-60U. The fundamental O-mode ECRF of 110 GHz injected obliquely (co-current drive) from the low field side is used. It is observed that the ion temperature (Ti) ITB in a WS plasma can be degraded by ECRF. It is clarified for the first time that the degradation depends increasingly on the EC power (PEC) but decreasingly on the plasma current (Ip). Moreover it is confirmed that ECRF affects the toroidal rotation (Vt) indirectly and results in the flattening of Vt(ρ) and therefore the radial electric field (Er) profiles regardless of the direction of the target Vt(ρ), peaking co or counter direction (relative to the Ip direction). Furthermore, it is recently found that Ti and Vt in the whole ITB region are affected with almost no delay from the EC onset even with off-axis EC deposition. These results indicate that EC injection unveiled a semi-global structure that characterizes Ti ITB in a WS plasma.

Imaging blood-brain barrier dysfunction as a biomarker for epileptogenesis.

PubMed

Bar-Klein, Guy; Lublinsky, Svetlana; Kamintsky, Lyn; Noyman, Iris; Veksler, Ronel; Dalipaj, Hotjensa; Senatorov, Vladimir V; Swissa, Evyatar; Rosenbach, Dror; Elazary, Netta; Milikovsky, Dan Z; Milk, Nadav; Kassirer, Michael; Rosman, Yossi; Serlin, Yonatan; Eisenkraft, Arik; Chassidim, Yoash; Parmet, Yisrael; Kaufer, Daniela; Friedman, Alon

2017-06-01

A biomarker that will enable the identification of patients at high-risk for developing post-injury epilepsy is critically required. Microvascular pathology and related blood-brain barrier dysfunction and neuroinflammation were shown to be associated with epileptogenesis after injury. Here we used prospective, longitudinal magnetic resonance imaging to quantitatively follow blood-brain barrier pathology in rats following status epilepticus, late electrocorticography to identify epileptic animals and post-mortem immunohistochemistry to confirm blood-brain barrier dysfunction and neuroinflammation. Finally, to test the pharmacodynamic relevance of the proposed biomarker, two anti-epileptogenic interventions were used; isoflurane anaesthesia and losartan. Our results show that early blood-brain barrier pathology in the piriform network is a sensitive and specific predictor (area under the curve of 0.96, P < 0.0001) for epilepsy, while diffused pathology is associated with a lower risk. Early treatments with either isoflurane anaesthesia or losartan prevented early microvascular damage and late epilepsy. We suggest quantitative assessment of blood-brain barrier pathology as a clinically relevant predictive, diagnostic and pharmaco!dynamics biomarker for acquired epilepsy. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A qualitative exploration of emergency contraception users' willingness to select the copper IUD.

PubMed

Wright, Rachel L; Frost, Caren J; Turok, David K

2012-01-01

The copper T intrauterine device (IUD) is an effective but underutilized method of emergency contraception (EC). This study investigates the factors influencing a woman's decision around which method of EC to select. In-depth interviews with 14 IUD and 14 oral EC users aged 18-30 years accessing public health clinics. Emergency contraception users associated long-term methods of contraception with long-term sexual relationships. Women were not aware of the possibility of using the copper IUD for EC. Cost was identified as a major barrier to accessing IUDs. Perceived side effects and impact on future pregnancies further influenced the EC method a participant selected. Women think about contraception in the context of each separate relationship and not as a long-term individual plan. Most women were unaware of the copper IUD for EC. Furthermore, there is little discussion between women and their health-care providers around EC. Copyright © 2012 Elsevier Inc. All rights reserved.

Gpr124 controls CNS angiogenesis and blood-brain barrier integrity by promoting ligand-specific canonical wnt signaling.

PubMed

Zhou, Yulian; Nathans, Jeremy

2014-10-27

Canonical Wnt signaling in endothelial cells (ECs) is required for vascularization of the central nervous system (CNS) and for formation and maintenance of barrier properties unique to CNS vasculature. Gpr124 is an orphan member of the adhesion G protein-coupled receptor family that is expressed in ECs and is essential for CNS angiogenesis and barrier formation via an unknown mechanism. Using canonical Wnt signaling assays in cell culture and genetic loss- and gain-of-function experiments in mice, we show that Gpr124 functions as a coactivator of Wnt7a- and Wnt7b-stimulated canonical Wnt signaling via a Frizzled receptor and Lrp coreceptor and that Gpr124-stimulated signaling functions in concert with Norrin/Frizzled4 signaling to control CNS vascular development. These experiments identify Gpr124 as a ligand-specific coactivator of canonical Wnt signaling.

Biological factors in plasma from diabetes mellitus patients enhance hyperglycaemia and pulsatile shear stress-induced endothelial cell apoptosis.

PubMed

Liu, X F; Yu, J Q; Dalan, R; Liu, A Q; Luo, K Q

2014-05-01

People suffering from Diabetes Mellitus (DM) are prone to an array of vascular complications leading to end organ damage. The hallmark of these vascular complications is endothelium dysfunction, which is caused by endothelial cell (EC) apoptosis. Although the endothelial cell (EC) dysfunction induced by hyperglycaemia and fluid shear stress has been studied, the effects of biological factors in the blood of DM patients on EC integrity have not been reported in the in vitro models that mimic the physiological pulsatile nature of the vascular system. This study reports the development of a hemodynamic lab-on-a-chip system to investigate this issue. The pulsatile flow was applied to a monolayer of endothelial cells expressing a fluorescence resonance energy transfer (FRET)-based biosensor that changes colour from green to blue in response to caspase-3 activation during apoptosis. Plasma samples from healthy volunteers and DM patients were compared to identify biological factors that are critical to endothelial disruption. Three types of microchannels were designed to simulate the blood vessels under healthy and partially blocked pathological conditions. The results showed that EC apoptosis rates increased with increasing glucose concentration and levels of shear stress. The rates of apoptosis further increased by a factor of 1.4-2.3 for hyperglycaemic plasma under all dynamic conditions. Under static conditions, little difference was detected in the rate of EC apoptosis between experiments using plasma from DM patients and glucose medium, suggesting that the effects of hyperglycaemia and biological factors on the induction of EC apoptosis are all shear flow-dependent. A proteomics study was then conducted to identify biological factors, demonstrating that the levels of eight proteins, including haptoglobin and clusterin, were significantly down-regulated, while six proteins, including apolipoprotein C-III, were significantly up-regulated in the plasma of DM patients compared to healthy volunteers. This hemodynamic lab-on-a-chip system can serve as a high throughput platform to assess the risk of vascular complications of DM patients and to determine the effects of therapeutics or other interventions on EC apoptosis.

Enhanced Skeletal Muscle Expression of EcSOD Mitigates Streptozotocin-Induced Diabetic Cardiomyopathy by Reducing Oxidative Stress and Aberrant Cell Signaling

PubMed Central

Call, Jarrod A.; Chain, Kristopher H.; Martin, Kyle S.; Lira, Vitor A.; Okutsu, Mitsuharu; Zhang, Mei; Yan, Zhen

2015-01-01

Background Exercise training enhances extracellular superoxide dismutase (EcSOD) expression in skeletal muscle and elicits positive health outcomes in individuals with diabetes. The goal of this study was to determine if enhanced skeletal muscle expression of EcSOD is sufficient to mitigate streptozotocin (STZ)-induced diabetic cardiomyopathy (DCM). Methods and Results Exercise training promotes EcSOD expression in skeletal muscle and provides protection against DCM; however, it is not known if enhanced EcSOD expression in skeletal muscle plays a functional role in this protection. Here, we show that skeletal muscle-specific EcSOD transgenic mice (TG) are protected from cardiac hypertrophy, fibrosis and dysfunction under the condition of type-1 diabetes induced by STZ injection. We also show that both exercise training and muscle-specific transgenic expression of EcSOD result in elevated EcSOD protein in the blood and heart without increased transcription in the heart, suggesting enhanced expression of EcSOD from skeletal muscle redistributes to the heart. Importantly, cardiac tissue in TG mice displayed significantly reduced oxidative stress, aberrant cell signaling and inflammatory cytokine expression compared with wild type mice under the same diabetic condition. Conclusions Enhanced expression of EcSOD in skeletal muscle is sufficient to mitigate STZ-induced DCM through attenuation of oxidative stress, aberrant cell signaling and inflammation, suggesting a cross-organ mechanism by which exercise training improves cardiac function in diabetes. PMID:25504759

Endothelial cells use dynamic actin to facilitate lymphocyte transendothelial migration and maintain the monolayer barrier.

PubMed

Mooren, Olivia L; Li, Jinmei; Nawas, Julie; Cooper, John A

2014-12-15

The vascular endothelium is a highly dynamic structure, and the integrity of its barrier function is tightly regulated. Normally impenetrable to cells, the endothelium actively assists lymphocytes to exit the bloodstream during inflammation. The actin cytoskeleton of the endothelial cell (EC) is known to facilitate transmigration, but the cellular and molecular mechanisms are not well understood. Here we report that actin assembly in the EC, induced by Arp2/3 complex under control of WAVE2, is important for several steps in the process of transmigration. To begin transmigration, ECs deploy actin-based membrane protrusions that create a cup-shaped docking structure for the lymphocyte. We found that docking structure formation involves the localization and activation of Arp2/3 complex by WAVE2. The next step in transmigration is creation of a migratory pore, and we found that endothelial WAVE2 is needed for lymphocytes to follow a transcellular route through an EC. Later, ECs use actin-based protrusions to close the gap behind the lymphocyte, which we discovered is also driven by WAVE2. Finally, we found that ECs in resting endothelial monolayers use lamellipodial protrusions dependent on WAVE2 to form and maintain contacts and junctions between cells. © 2014 Mooren et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Electrical parameters of Au/n-GaN and Pt/n-GaN Schottky diodes

NASA Astrophysics Data System (ADS)

Kadaoui, Mustapha Amine; Bouiadjra, Wadi Bachir; Saidane, Abdelkader; Belahsene, Sofiane; Ramdane, Abderrahim

2015-06-01

Electrical properties of Si-doped GaN epitaxial layers, grown on a c-plane sapphire substrate by MOCVD to form Schottky diodes with Gold (Au) and platinum (Pt) and using Ti/Al/Au as Ohmic contact, are investigated. Characterization was performed through I-V and C-V-f measurements at room temperature. Schottky barrier height (Φb), ideality factor (n), and series resistance (Rs) were extracted from forward I-V characteriztics using Cheung and Lien methods. Φb, doping concentration (Nd) and Rs frequency dependence were extracted from C-V-f characteriztics. Pt/n-GaN shows a non-linear behavior with a barrier height of 0.63 eV, an ideality factor of 2.3, and series resistance of 63 Ω. Au/n-GaN behaves like two diodes in parallel with two barrier heights of (0.83 and 0.9 eV), two ideality factors of (5.8 and 3.18) and two series resistance of (10.6 and 68 Ω). Interface state properties in both samples have been investigated taking into account the bias dependence of the effective barrier height. The amount of stimulated traps along the energy-gap at the interface increases with voltage bias, which increases NSS exponentially from 4.24 ṡ 1013 to 3.67 ṡ 1014 eV-1 cm-2 in the range (Ec - 0.17) to (Ec - 0.61) eV for Pt/n-GaN, and from 2.3 ṡ 1013 to 1.14 ṡ 1014 eV-1 cm-2, in the range (Ec - 0.31) to (Ec - 0.82) eV for Au/n-GaN. The values of interface states density and series resistance for both samples are found to decrease with increasing frequency. Peak intensity was a measure of active interface states. C-V-f results confirm the model of the Schottky diode with a native interfacial insulator layer along the space charge region.

Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis by inhibiting the activation of nuclear factor-kappa B

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

Cheng, Jian; Zhang, Lin; Dai, Weiqi

Aim: This study aimed to investigate the effect and underlying mechanism of ghrelin on intestinal barrier dysfunction in dextran sulfate sodium (DSS)-induced colitis. Methods and results: Acute colitis was induced in C57BL/6J mice by administering 2.5% DSS. Saline or 25, 125, 250 μg/kg ghrelin was administrated intraperitoneally (IP) to mice 1 day before colitis induction and on days 4, 5, and 6 after DSS administration. IP injection of a ghrelin receptor antagonist, [D-lys{sup 3}]-GHRP-6, was performed immediately prior to ghrelin injection. Ghrelin (125 or 250 μg/kg) could reduce the disease activity index, histological score, and myeloperoxidase activities in experimental colitis, and alsomore » prevented shortening of the colon. Ghrelin could prevent the reduction of transepithelial electrical resistance and tight junction expression, and bolstered tight junction structural integrity and regulated cytokine secretion. Ultimately, ghrelin inhibited nuclear factor kappa B (NF-κB), inhibitory κB-α, myosin light chain kinase, and phosphorylated myosin light chain 2 activation. Conclusions: Ghrelin prevented the breakdown of intestinal barrier function in DSS-induced colitis. The protective effects of ghrelin on intestinal barrier function were mediated by its receptor GHSR-1a. The inhibition of NF-κB activation might be part of the mechanism underlying the effects of ghrelin that protect against barrier dysfunction. - Highlights: • Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis. • The effect of ghrelin is mediated by GHSR-1a. • Inhibition of NF-κB activation.« less

Provision of emergency contraception at student health centers in California community colleges.

PubMed

Trieu, Sang Leng; Shenoy, Divya P; Bratton, Sally; Marshak, Helen Hopp

2011-01-01

Approximately half of all pregnancies in the United States are unintended, with the highest rates reported among college-age women. The availability of emergency contraception (EC) pills can be an important component of efforts to reduce unintended pregnancy. Student health centers at community colleges can uniquely support student retention and academic achievement among college students by making EC available to reduce the rate of unintended pregnancy and prevent college drop-out. This article highlights findings from an assessment of EC provision in student health centers within the California community college system (n = 73). A web-based survey was used to explore the provision of EC, challenges and barriers of EC administration, promotion of EC availability, and attitudes toward EC. Descriptive statistics conducted revealed that more than 6 out of 10 (62%) student health centers provided EC, 77% of which dispense EC on site during clinic visits. The most common EC promotion methods were providing brochures at the health center (80%) and through information provided at family planning or primary care visits (73%). Challenges to EC administration included a perceived lack of awareness of EC among students (71%), followed by the notion that some students may overutilize EC (40%). Attitudes toward EC provision were more favorable among health center staff whose campuses offered EC than those who did not (p < .05). This article provides recommendations for community college health centers to improve access and delivery of EC by addressing issues such as cost and offering more novel EC promotion methods. Copyright © 2011 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

Calcium-mediated oxidative stress: a common mechanism in tight junction disruption by different types of cellular stress.

PubMed

Gangwar, Ruchika; Meena, Avtar S; Shukla, Pradeep K; Nagaraja, Archana S; Dorniak, Piotr L; Pallikuth, Sandeep; Waters, Christopher M; Sood, Anil; Rao, RadhaKrishna

2017-02-20

The role of reactive oxygen species (ROS) in osmotic stress, dextran sulfate sodium (DSS) and cyclic stretch-induced tight junction (TJ) disruption was investigated in Caco-2 cell monolayers in vitro and restraint stress-induced barrier dysfunction in mouse colon in vivo Live cell imaging showed that osmotic stress, cyclic stretch and DSS triggered rapid production of ROS in Caco-2 cell monolayers, which was blocked by depletion of intracellular Ca 2+ by 1,2-bis-( o -aminophenoxy)ethane- N , N , N ', N '-tetraacetic acid. Knockdown of Ca V 1.3 or TRPV6 channels blocked osmotic stress and DSS-induced ROS production and attenuated TJ disruption and barrier dysfunction. N -Acetyl l-cysteine (NAC) and l- N G -Nitroarginine methyl ester (l-NAME) blocked stress-induced TJ disruption and barrier dysfunction. NAC and l-NAME also blocked stress-induced activation of c-Jun N -terminal kinase (JNK) and c-Src. ROS was colocalized with the mitochondrial marker in stressed cells. Cyclosporin A blocked osmotic stress and DSS-induced ROS production, barrier dysfunction, TJ disruption and JNK activation. Mitochondria-targeted Mito-TEMPO blocked osmotic stress and DSS-induced barrier dysfunction and TJ disruption. Chronic restraint stress in mice resulted in the elevation of intracellular Ca 2+ , activation of JNK and c-Src, and disruption of TJ in the colonic epithelium. Furthermore, corticosterone administration induced JNK and c-Src activation, TJ disruption and protein thiol oxidation in colonic mucosa. The present study demonstrates that oxidative stress is a common signal in the mechanism of TJ disruption in the intestinal epithelium by different types of cellular stress in vitro and bio behavioral stress in vivo . © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

Calcium-Mediated Oxidative Stress: a Common Mechanism in Tight Junction Disruption by Different Types of Cellular Stress

PubMed Central

Gangwar, Ruchika; Meena, Avtar S.; Shukla, Pradeep K.; Nagaraja, Archana S.; Dorniak, Piotr L.; Pallikuth, Sandeep; Waters, Christopher M.; Sood, Anil; Rao, RadhaKrishna

2017-01-01

The role of reactive oxygen species (ROS) in osmotic stress, dextran sulfate sodium (DSS) and cyclic stretch-induced tight junction disruption was investigated in Caco-2 cell monolayers in vitro, and restraint stress-induced barrier dysfunction in mouse colon in vivo. Live cell imaging showed that osmotic stress, cyclic stretch and DSS triggered rapid production of ROS in Caco-2 cell monolayers, which was blocked by depletion of intracellular Ca2+ by BAPTA. Knockdown of CaV1.3 or TRPV6 channels blocked osmotic stress and DSS-induced ROS production and attenuated tight junction disruption and barrier dysfunction. N-acetyl L-cysteine (NAC) and L-nitroarginine methyl ester (L-NAME) blocked stress-induced tight junction disruption and barrier dysfunction. NAC and L-NAME also blocked stress-induced activation of JNK and c-Src. ROS was co-localized with the mitochondrial marker in stressed cells. Cyclosporin A blocked osmotic stress and DSS-induced ROS production, barrier dysfunction, tight junction disruption and JNK activation. Mitochondria-targeted Mito-TEMPO blocked osmotic stress and DSS-induced barrier dysfunction and tight junction disruption. Chronic restraint stress in mice resulted in the elevation of intracellular Ca2+, activation of JNK and c-Src, and disruption of tight junction in the colonic epithelium. Furthermore, corticosterone administration induced JNK and c-Src activation, tight junction disruption and protein thiol oxidation in colonic mucosa. This study demonstrates that oxidative stress is a common signal in the mechanism of tight junction disruption in the intestinal epithelium by different types of cellular stress in vitro and bio behavioral stress in vivo. PMID:28057718

Endocannabinod Signal Dysregulation in Autism Spectrum Disorders: A Correlation Link between Inflammatory State and Neuro-Immune Alterations

PubMed Central

Brigida, Anna Lisa; Schultz, Stephen; Cascone, Mariana; Antonucci, Nicola; Siniscalco, Dario

2017-01-01

Several studies highlight a key involvement of endocannabinoid (EC) system in autism pathophysiology. The EC system is a complex network of lipid signaling pathways comprised of arachidonic acid-derived compounds (anandamide, AEA) and 2-arachidonoyl glycerol (2-AG), their G-protein-coupled receptors (cannabinoid receptors CB1 and CB2) and the associated enzymes. In addition to autism, the EC system is also involved in several other psychiatric disorders (i.e., anxiety, major depression, bipolar disorder and schizophrenia). This system is a key regulator of metabolic and cellular pathways involved in autism, such as food intake, energy metabolism and immune system control. Early studies in autism animal models have demonstrated alterations in the brain’s EC system. Autism is also characterized by immune system dysregulation. This alteration includes differential monocyte and macrophage responses, and abnormal cytokine and T cell levels. EC system dysfunction in a monocyte and macrophagic cellular model of autism has been demonstrated by showing that the mRNA and protein for CB2 receptor and EC enzymes were significantly dysregulated, further indicating the involvement of the EC system in autism-associated immunological disruptions. Taken together, these new findings offer a novel perspective in autism research and indicate that the EC system could represent a novel target option for autism pharmacotherapy. PMID:28671614

Phospholipase C-ε signaling mediates endothelial cell inflammation and barrier disruption in acute lung injury

PubMed Central

Bijli, Kaiser M.; Fazal, Fabeha; Slavin, Spencer A.; Leonard, Antony; Grose, Valerie; Alexander, William B.; Smrcka, Alan V.

2016-01-01

Phospholipase C-ε (PLC-ε) is a unique PLC isoform that can be regulated by multiple signaling inputs from both Ras family GTPases and heterotrimeric G proteins and has primary sites of expression in the heart and lung. Whereas the role of PLC-ε in cardiac function and pathology has been documented, its relevance in acute lung injury (ALI) is unclear. We used PLC-ε−/− mice to address the role of PLC-ε in regulating lung vascular inflammation and injury in an aerosolized bacterial LPS inhalation mouse model of ALI. PLC-ε−/− mice showed a marked decrease in LPS-induced proinflammatory mediators (ICAM-1, VCAM-1, TNF-α, IL-1β, IL-6, macrophage inflammatory protein 2, keratinocyte-derived cytokine, monocyte chemoattractant protein 1, and granulocyte-macrophage colony-stimulating factor), lung neutrophil infiltration and microvascular leakage, and loss of VE-cadherin compared with PLC-ε+/+ mice. These data identify PLC-ε as a critical determinant of proinflammatory and leaky phenotype of the lung. To test the possibility that PLC-ε activity in endothelial cells (EC) could contribute to ALI, we determined its role in EC inflammation and barrier disruption. RNAi knockdown of PLC-ε inhibited NF-κB activity in response to diverse proinflammatory stimuli, thrombin, LPS, TNF-α, and the nonreceptor agonist phorbol 13-myristate 12-acetate (phorbol esters) in EC. Depletion of PLC-ε also inhibited thrombin-induced expression of NF-κB target gene, VCAM-1. Importantly, PLC-ε knockdown also protected against thrombin-induced EC barrier disruption by inhibiting the loss of VE-cadherin at adherens junctions and formation of actin stress fibers. These data identify PLC-ε as a novel regulator of EC inflammation and permeability and show a hitherto unknown role of PLC-ε in the pathogenesis of ALI. PMID:27371732

Phospholipase C-ε signaling mediates endothelial cell inflammation and barrier disruption in acute lung injury.

PubMed

Bijli, Kaiser M; Fazal, Fabeha; Slavin, Spencer A; Leonard, Antony; Grose, Valerie; Alexander, William B; Smrcka, Alan V; Rahman, Arshad

2016-08-01

Phospholipase C-ε (PLC-ε) is a unique PLC isoform that can be regulated by multiple signaling inputs from both Ras family GTPases and heterotrimeric G proteins and has primary sites of expression in the heart and lung. Whereas the role of PLC-ε in cardiac function and pathology has been documented, its relevance in acute lung injury (ALI) is unclear. We used PLC-ε(-/-) mice to address the role of PLC-ε in regulating lung vascular inflammation and injury in an aerosolized bacterial LPS inhalation mouse model of ALI. PLC-ε(-/-) mice showed a marked decrease in LPS-induced proinflammatory mediators (ICAM-1, VCAM-1, TNF-α, IL-1β, IL-6, macrophage inflammatory protein 2, keratinocyte-derived cytokine, monocyte chemoattractant protein 1, and granulocyte-macrophage colony-stimulating factor), lung neutrophil infiltration and microvascular leakage, and loss of VE-cadherin compared with PLC-ε(+/+) mice. These data identify PLC-ε as a critical determinant of proinflammatory and leaky phenotype of the lung. To test the possibility that PLC-ε activity in endothelial cells (EC) could contribute to ALI, we determined its role in EC inflammation and barrier disruption. RNAi knockdown of PLC-ε inhibited NF-κB activity in response to diverse proinflammatory stimuli, thrombin, LPS, TNF-α, and the nonreceptor agonist phorbol 13-myristate 12-acetate (phorbol esters) in EC. Depletion of PLC-ε also inhibited thrombin-induced expression of NF-κB target gene, VCAM-1. Importantly, PLC-ε knockdown also protected against thrombin-induced EC barrier disruption by inhibiting the loss of VE-cadherin at adherens junctions and formation of actin stress fibers. These data identify PLC-ε as a novel regulator of EC inflammation and permeability and show a hitherto unknown role of PLC-ε in the pathogenesis of ALI. Copyright © 2016 the American Physiological Society.

Relationships of eating competence, sleep behaviors and quality, and overweight status among college students.

PubMed

Quick, Virginia; Shoff, Suzanne; Lohse, Barbara; White, Adrienne; Horacek, Tanya; Greene, Geoffrey

2015-12-01

Little is known about the relationships between eating competence (intra-individual approach to eating and food-related attitudes and behaviors that entrain positive bio-psychosocial outcomes) and sleep behaviors and quality in college students, a high-risk group for poor eating habits, weight gain, and inadequate sleep. Thus, data from full-time college students (N=1035; 82% White; 61% female) aged 18-24 years from 5 U.S. universities were obtained from online questionnaires (eating competence (ecSI), Pittsburg Sleep Quality Index (PSQI), physical activity, demographics) and physical assessments (measured height, weight), to explore sleep behavior and quality between eating-competent (EC; ecSI score≥32) and non-EC groups (ecSI<32). Generalized linear models controlling for gender, body mass index, and physical activity were utilized. A higher proportion of those in the EC group reported adequate sleep quality (67% vs. 57% in non-EC, p=0.001), sleep duration of ≥7 h nightly (58% vs. 50% in non-EC, p=0.007), and infrequent daytime dysfunction (72% vs. 65% in non-EC, p=0.02). When ecSI scores were grouped as tertiles, those in the highest tertile reported a higher prevalence of no sleep disturbances (7% vs. 2% in the lowest ecSI tertile, p=0.006) and lower prevalence of sleep medication use (10% vs. 15% in the lowest ecSI tertile, p=0.04). Results suggest that competent eaters are more likely to have better overall sleep quality and fewer sleep-related issuescompared to less competent eaters. These findings may inform future longitudinal studies, and health promotion and weight management interventions for young adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relationships of eating competence, sleep behaviors and quality, and overweight status among college students

PubMed Central

Quick, Virginia; Shoff, Suzanne; Lohse, Barbara; White, Adrienne; Horacek, Tanya; Greene, Geoffrey

2015-01-01

Little is known about the relationships between eating competence (intra-individual approach to eating and food-related attitudes and behaviors that entrains positive bio-psychosocial outcomes), and sleep behaviors and quality in college students, a high risk group for poor eating habits, weight gain and inadequate sleep. Thus, data from full-time college students (N=1035; 82% White; 61% female) aged 18-24 years from 5 U.S. universities were obtained from online questionnaires (eating competence (ecSI), Pittsburg Sleep Quality Index (PSQI), physical activity, demographics) and physical assessments (measured height, weight), to explore sleep behavior and quality between eating competent (EC; ecSI score ≥ 32) and non-EC groups (ecSI < 32). Generalized linear models controlling for gender, body mass index, and physical activity were utilized. A higher proportion of those in the EC group reported adequate sleep quality (67% vs. 57% in non-EC, p=0.001), sleep duration of ≥ 7 hours nightly (58% vs. 50% in non-EC, p=0.007), and infrequent daytime dysfunction (72% vs. 65% in non-EC, p=0.02). When ecSI scores were grouped as tertiles, those in the highest tertile reported a higher prevalence of no sleep disturbances (7% vs. 2% in the lowest ecSI tertile, p=0.006) and lower prevalence of sleep medication use (10% vs. 15% in the lowest ecSI tertile, p=0.04). Results suggest that competent eaters are more likely to have better overall sleep quality and fewer sleep-related issues, compared to less competent eaters. These findings may inform future longitudinal studies, and health promotion and weight management interventions for young adults. PMID:26164670

Reactions of singly-reduced ethylene carbonate in lithium battery electrolytes: a molecular dynamics simulation study using the ReaxFF.

PubMed

Bedrov, Dmitry; Smith, Grant D; van Duin, Adri C T

2012-03-22

We have conducted quantum chemistry calculations and gas- and solution-phase reactive molecular dynamics simulation studies of reactions involving the ethylene carbonate (EC) radical anion EC(-) using the reactive force field ReaxFF. Our studies reveal that the substantial barrier for transition from the closed (cyclic) form, denoted c-EC(-), of the radical anion to the linear (open) form, denoted o-EC(-), results in a relatively long lifetime of the c-EC(-) allowing this compound to react with other singly reduced alkyl carbonates. Using ReaxFF, we systematically investigate the fate of both c-EC(-) and o-EC(-) in the gas phase and EC solution. In the gas phase and EC solutions with a relatively low concentration of Li(+)/x-EC(-) (where x = o or c), radical termination reactions between radical pairs to form either dilithium butylene dicarbonate (CH(2)CH(2)OCO(2)Li)(2) (by reacting two Li(+)/o-EC(-)) or ester-carbonate compound (by reacting Li(+)/o-EC(-) with Li(+)/c-EC(-)) are observed. At higher concentrations of Li(+)/x-EC(-) in solution, we observe the formation of diradicals which subsequently lead to formation of longer alkyl carbonates oligomers through reaction with other radicals or, in some cases, formation of (CH(2)OCO(2)Li)(2) through elimination of C(2)H(4). We conclude that the local ionic concentration is important in determining the fate of x-EC(-) and that the reaction of c-EC(-) with o-EC(-) may compete with the formation of various alkyl carbonates from o-EC(-)/o-EC(-) reactions. © 2012 American Chemical Society

Gut epithelial barrier dysfunction in human immunodeficiency virus-hepatitis C virus coinfected patients: Influence on innate and acquired immunity.

PubMed

Márquez, Mercedes; Fernández Gutiérrez del Álamo, Clotilde; Girón-González, José Antonio

2016-01-28

Even in cases where viral replication has been controlled by antiretroviral therapy for long periods of time, human immunodeficiency virus (HIV)-infected patients have several non-acquired immunodeficiency syndrome (AIDS) related co-morbidities, including liver disease, cardiovascular disease and neurocognitive decline, which have a clear impact on survival. It has been considered that persistent innate and acquired immune activation contributes to the pathogenesis of these non-AIDS related diseases. Immune activation has been related with several conditions, remarkably with the bacterial translocation related with the intestinal barrier damage by the HIV or by hepatitis C virus (HCV)-related liver cirrhosis. Consequently, increased morbidity and mortality must be expected in HIV-HCV coinfected patients. Disrupted gut barrier lead to an increased passage of microbial products and to an activation of the mucosal immune system and secretion of inflammatory mediators, which in turn might increase barrier dysfunction. In the present review, the intestinal barrier structure, measures of intestinal barrier dysfunction and the modifications of them in HIV monoinfection and in HIV-HCV coinfection will be considered. Both pathogenesis and the consequences for the progression of liver disease secondary to gut microbial fragment leakage and immune activation will be assessed.

Regulation of Endothelial Barrier Function by Cyclic Nucleotides: The Role of Phosphodiesterases

PubMed Central

Surapisitchat, James

2014-01-01

The endothelium plays an important role in maintaining normal vascular function. Endothelial barrier dysfunction leading to increased permeability and vascular leakage is associated with several pathological conditions such as edema and sepsis. Thus, the development of drugs that improve endothelial barrier function is an active area of research. In this chapter, the current knowledge concerning the signaling pathways regulating endothelial barrier function is discussed with a focus on cyclic nucleotide second messengers (cAMP and cGMP) and cyclic nucleotide phosphodiesterases (PDEs). Both cAMP and cGMP have been shown to have differential effects on endothelial permeability in part due to the various effector molecules, crosstalk, and compartmentalization of cyclic nucleotide signaling. PDEs, by controlling the amplitude, duration, and localization of cyclic nucleotides, have been shown to play a critical role in regulating endothelial barrier function. Thus, PDEs are attractive drug targets for the treatment of disease states involving endothelial barrier dysfunction. PMID:21695641

Regulation of endothelial barrier function by cyclic nucleotides: the role of phosphodiesterases.

PubMed

Surapisitchat, James; Beavo, Joseph A

2011-01-01

The endothelium plays an important role in maintaining normal vascular function. Endothelial barrier dysfunction leading to increased permeability and vascular leakage is associated with several pathological conditions such as edema and sepsis. Thus, the development of drugs that improve endothelial barrier function is an active area of research. In this chapter, the current knowledge concerning the signaling pathways regulating endothelial barrier function is discussed with a focus on cyclic nucleotide second messengers (cAMP and cGMP) and cyclic nucleotide phosphodiesterases (PDEs). Both cAMP and cGMP have been shown to have differential effects on endothelial permeability in part due to the various effector molecules, crosstalk, and compartmentalization of cyclic nucleotide signaling. PDEs, by controlling the amplitude, duration, and localization of cyclic nucleotides, have been shown to play a critical role in regulating endothelial barrier function. Thus, PDEs are attractive drug targets for the treatment of disease states involving endothelial barrier dysfunction.

Direct Isolation, Culture and Transplant of Mouse Skeletal Muscle Derived Endothelial Cells with Angiogenic Potential

PubMed Central

Ieronimakis, Nicholas; Balasundaram, Gayathri; Reyes, Morayma

2008-01-01

Background Although diseases associated with microvascular endothelial dysfunction are among the most prevalent illnesses to date, currently no method exists to isolate pure endothelial cells (EC) from skeletal muscle for in vivo or in vitro study. Methodology By utilizing multicolor fluorescent-activated cell sorting (FACS), we have isolated a distinct population of Sca-1+, CD31+, CD34dim and CD45− cells from skeletal muscles of C57BL6 mice. Characterization of this population revealed these cells are functional EC that can be expanded several times in culture without losing their phenotype or capabilities to uptake acetylated low-density lipoprotein (ac-LDL), produce nitric oxide (NO) and form vascular tubes. When transplanted subcutaneously or intramuscularly into the tibialis anterior muscle, EC formed microvessels and integrated with existing vasculature. Conclusion This method, which is highly reproducible, can be used to study the biology and role of EC in diseases such as peripheral vascular disease. In addition this method allows us to isolate large quantities of skeletal muscle derived EC with potential for therapeutic angiogenic applications. PMID:18335025

Ultrafine particles cause cytoskeletal dysfunctions in macrophages: role of intracellular calcium

PubMed Central

Möller, Winfried; Brown, David M; Kreyling, Wolfgang G; Stone, Vicki

2005-01-01

Background Particulate air pollution is reported to cause adverse health effects in susceptible individuals. Since most of these particles are derived form combustion processes, the primary composition product is carbon with a very small diameter (ultrafine, less than 100 nm in diameter). Besides the induction of reactive oxygen species and inflammation, ultrafine particles (UFP) can cause intracellular calcium transients and suppression of defense mechanisms of alveolar macrophages, such as impaired migration or phagocytosis. Methods In this study the role of intracellular calcium transients caused by UFP was studied on cytoskeleton related functions in J774A.1 macrophages. Different types of fine and ultrafine carbon black particles (CB and ufCB, respectively), such as elemental carbon (EC90), commercial carbon (Printex 90), diesel particulate matter (DEP) and urban dust (UD), were investigated. Phagosome transport mechanisms and mechanical cytoskeletal integrity were studied by cytomagnetometry and cell viability was studied by fluorescence microscopy. Macrophages were exposed in vitro with 100 and 320 μg UFP/ml/million cells for 4 hours in serum free medium. Calcium antagonists Verapamil, BAPTA-AM and W-7 were used to block calcium channels in the membrane, to chelate intracellular calcium or to inhibit the calmodulin signaling pathways, respectively. Results Impaired phagosome transport and increased cytoskeletal stiffness occurred at EC90 and P90 concentrations of 100 μg/ml/million cells and above, but not with DEP or UD. Verapamil and W-7, but not BAPTA-AM inhibited the cytoskeletal dysfunctions caused by EC90 or P90. Additionally the presence of 5% serum or 1% bovine serum albumin (BSA) suppressed the cytoskeletal dysfunctions. Cell viability showed similar results, where co-culture of ufCB together with Verapamil, W-7, FCS or BSA produced less cell dead compared to the particles only. PMID:16202162

How does a Belgian health care provider deal with a request for emergency contraception?

PubMed

Peremans, Lieve; Verhoeven, Veronique; Philips, Hilde; Denekens, Joke; Van Royen, Paul

2007-12-01

To evaluate how Belgian health care providers deal with a request for emergency contraception. In 2002-2003 we conducted 12 focus groups with pharmacists, general practitioners and school physicians. A skilled moderator accompanied by an observer conducted the focus groups using a semi-structured screenplay. All these health care providers agree with the free access to emergency contraception (EC), but experience considerable frustration with regard to the practical aspects and the legal framework. General practitioners (GPs) claim to spend a lot of time on requests for EC and they are concerned about the quality of the counselling provided in pharmacies. Pharmacists are creative when giving counselling in the pharmacy, but there is, nevertheless, a problem with a lack of privacy. School physicians are frustrated that there is no legal possibility to respond to a request for EC when they feel they are ideally placed to advise adolescents. The over-the-counter sale of EC offers women better access, but many barriers still interfere with optimal care. Pharmacists experience a lack of skills to communicate with adolescents and a lack of privacy to give counselling. GPs have good intentions, but are confronted with a lack of willingness on the part of the patients and also financial barriers. School physicians want more possibilities to help adolescents.

Clinical Characteristics and Prognosis of Pulmonary Embolism Caused by Economy Class Syndrome.

PubMed

Abellás, María; Menéndez, Ana; Morillo, Raquel; Jara-Palomares, Luis; Barrios, Deisy; Nieto, Rosa; Barbero, Esther; Corres, Jesús; Ruiz-Artacho, Pedro; Jiménez, David

2017-09-01

Clinical presentation and short-term prognosis of patients with travel-associated acute pulmonary embolism (PE) (i.e., economy class syndrome [ECS]) is not well understood. In this retrospective cohort study of patients with acute PE identified from a single center registry, we assessed the clinical presentation and the association between ECS and the outcomes of all-cause mortality, PE-related mortality, nonfatal venous thromboembolism and nonfatal major bleeding rates through 30days after initiation of PE treatment. Of the 2,333 patients with acute symptomatic PE, 124 (5.3%; 95% confidence interval, 4.4-6.3%) had ECS. Patients with ECS were younger and had fewer comorbid diseases (recent bleeding, chronic obstructive pulmonary disease, congestive heart failure), but they presented with more signs of clinical severity (syncope [48% vs. 14%; P<.001], tachycardia [37% vs. 21%; P<.001], right ventricular dysfunction [31% vs. 19%; P<.01] and myocardial injury [57% vs. 28%; P<.001]) compared to those without ECS. Regression analyses showed a significantly lower risk of all-cause mortality for patients with ECS compared to patients without ECS (1.6% vs. 9.6%; P<.01). We did not detect a difference in PE-related mortality at 30days between those with and those without ECS (0.8% vs. 3.1%; P=.18). PE patients with ECS are younger and have fewer comorbid diseases compared to those without ECS. Though they present with more signs of clinical severity, their short-term prognosis is excellent. Copyright © 2017 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

Emergency contraception. Widely available and effective but disappointing as a public health intervention: a review.

PubMed

2015-04-01

Emergency contraception (EC) prevents pregnancy after unprotected sex or contraceptive failure. Use of EC has increased markedly in countries where a product is available over the counter, yet barriers to availability and use remain. Although effective in clinical trials, it has not yet been possible to show a public health benefit of EC in terms of reduction of unintended pregnancy rates. Selective progesterone receptor modulators developed as emergency contraceptives offer better effectiveness than levonorgestrel, but still EC is less effective than use of ongoing regular contraception. Methods which inhibit ovulation whenever they are taken or which act after ovulation to prevent implantation and strategies to increase the uptake of effective ongoing contraception after EC use would prevent more pregnancies. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Diffusion properties of molecules at the blood-brain interface: potential contributions of astrocyte endfeet to diffusion barrier functions.

PubMed

Nuriya, Mutsuo; Shinotsuka, Takanori; Yasui, Masato

2013-09-01

Molecular diffusion in the extracellular space (ECS) plays a key role in determining tissue physiology and pharmacology. The blood-brain barrier regulates the exchange of substances between the brain and the blood, but the diffusion properties of molecules at this blood-brain interface, particularly around the astrocyte endfeet, are poorly characterized. In this study, we used 2-photon microscopy and acute brain slices of mouse neocortex and directly assessed the diffusion patterns of fluorescent molecules. By observing the diffusion of unconjugated and 10-kDa dextran-conjugated Alexa Fluor 488 from the ECS of the brain parenchyma to the blood vessels, we find various degrees of diffusion barriers at the endfeet: Some allow the invasion of dye inside the endfoot network while others completely block it. Detailed analyses of the time course for dye clearance support the existence of a tight endfoot network capable of acting as a diffusion barrier. Finally, we show that this diffusion pattern collapses under pathological conditions. These data demonstrate the heterogeneous nature of molecular diffusion dynamics around the endfeet and suggest that these structures can serve as the diffusion barrier. Therefore, astrocyte endfeet may add another layer of regulation to the exchange of molecules between blood vessels and brain parenchyma.

Smooth muscle‐generated methylglyoxal impairs endothelial cell‐mediated vasodilatation of cerebral microvessels in type 1 diabetic rats

PubMed Central

Alomar, Fadhel; Singh, Jaipaul; Jang, Hee‐Seong; Rozanzki, George J; Shao, Chun Hong; Padanilam, Babu J; Mayhan, William G

2016-01-01

Background and Purpose Endothelial cell‐mediated vasodilatation of cerebral arterioles is impaired in individuals with Type 1 diabetes (T1D). This defect compromises haemodynamics and can lead to hypoxia, microbleeds, inflammation and exaggerated ischaemia‐reperfusion injuries. The molecular causes for dysregulation of cerebral microvascular endothelial cells (cECs) in T1D remains poorly defined. This study tests the hypothesis that cECs dysregulation in T1D is triggered by increased generation of the mitochondrial toxin, methylglyoxal, by smooth muscle cells in cerebral arterioles (cSMCs). Experimental Approach Endothelial cell‐mediated vasodilatation, vascular transcytosis inflammation, hypoxia and ischaemia‐reperfusion injury were assessed in brains of male Sprague‐Dawley rats with streptozotocin‐induced diabetes and compared with those in diabetic rats with increased expression of methylglyoxal‐degrading enzyme glyoxalase‐I (Glo‐I) in cSMCs. Key Results After 7–8 weeks of T1D, endothelial cell‐mediated vasodilatation of cerebral arterioles was impaired. Microvascular leakage, gliosis, macrophage/neutrophil infiltration, NF‐κB activity and TNF‐α levels were increased, and density of perfused microvessels was reduced. Transient occlusion of a mid‐cerebral artery exacerbated ischaemia‐reperfusion injury. In cSMCs, Glo‐I protein was decreased, and the methylglyoxal‐synthesizing enzyme, vascular adhesion protein 1 (VAP‐1) and methylglyoxal were increased. Restoring Glo‐I protein in cSMCs of diabetic rats to control levels via gene transfer, blunted VAP‐1 and methylglyoxal increases, cECs dysfunction, microvascular leakage, inflammation, ischaemia‐reperfusion injury and increased microvessel perfusion. Conclusions and Implications Methylglyoxal generated by cSMCs induced cECs dysfunction, inflammation, hypoxia and exaggerated ischaemia‐reperfusion injury in diabetic rats. Lowering methylglyoxal produced by cSMCs may be a viable therapeutic strategy to preserve cECs function and blunt deleterious downstream consequences in T1D. PMID:27611446

Inflammatory Bowel Disease Therapies and Gut Function in a Colitis Mouse Model

PubMed Central

Nahidi, Lily; Leach, Steven T.; Mitchell, Hazel M.; Kaakoush, Nadeem O.; Lemberg, Daniel A.; Munday, John S.; Huinao, Karina; Day, Andrew S.

2013-01-01

Background. Exclusive enteral nutrition (EEN) is a well-established approach to the management of Crohn's disease. Aim. To determine effects of EEN upon inflammation and gut barrier function in a colitis mouse model. Methods. Interleukin-10-deficient mice (IL-10−/−) were inoculated with Helicobacter trogontum and then treated with EEN, metronidazole, hydrocortisone, or EEN and metronidazole combination. Blood and tissue were collected at 2 and 4 weeks with histology, mucosal integrity, tight junction integrity, inflammation, and H. trogontum load evaluated. Results. H. trogontum induced colitis in IL-10−/− mice with histological changes in the cecum and colon. Elevated mucosal IL-8 mRNA in infected mice was associated with intestinal barrier dysfunction indicated by decreased transepithelial electrical resistance and mRNA of tight junction proteins and increased short-circuit current, myosin light chain kinase mRNA, paracellular permeability, and tumor necrosis factor-α and myeloperoxidase plasma levels (P < 0.01 for all comparisons). EEN and metronidazole, but not hydrocortisone, treatments restored barrier function, maintained gut barrier integrity, and reversed inflammatory changes along with reduction of H. trogontum load (versus infected controls P < 0.05). Conclusion. H. trogontum infection in IL-10−/− mice induced typhlocolitis with intestinal barrier dysfunction. EEN and metronidazole, but not hydrocortisone, modulate barrier dysfunction and reversal of inflammatory changes. PMID:24027765

Endothelial Microparticles From Acute Coronary Syndrome Patients Induce Premature Coronary Artery Endothelial Cell Aging and Thrombogenicity: Role of the Ang II/AT1 Receptor/NADPH Oxidase-Mediated Activation of MAPKs and PI3-Kinase Pathways.

PubMed

Abbas, Malak; Jesel, Laurence; Auger, Cyril; Amoura, Lamia; Messas, Nathan; Manin, Guillaume; Rumig, Cordula; León-González, Antonio J; Ribeiro, Thais P; Silva, Grazielle C; Abou-Merhi, Raghida; Hamade, Eva; Hecker, Markus; Georg, Yannick; Chakfe, Nabil; Ohlmann, Patrick; Schini-Kerth, Valérie B; Toti, Florence; Morel, Olivier

2017-01-17

Microparticles (MPs) have emerged as a surrogate marker of endothelial dysfunction and cardiovascular risk. This study examined the potential of MPs from senescent endothelial cells (ECs) or from patients with acute coronary syndrome (ACS) to promote premature EC aging and thrombogenicity. Primary porcine coronary ECs were isolated from the left circumflex coronary artery. MPs were prepared from ECs and venous blood from patients with ACS (n=30) and from healthy volunteers (n=4) by sequential centrifugation. The level of endothelial senescence was assessed as senescence-associated β-galactosidase activity using flow cytometry, oxidative stress using the redox-sensitive probe dihydroethidium, tissue factor activity using an enzymatic Tenase assay, the level of target protein expression by Western blot analysis, platelet aggregation using an aggregometer, and shear stress using a cone-and-plate viscometer. Senescence, as assessed by senescence-associated β-galactosidase activity, was induced by the passaging of porcine coronary artery ECs from passage P1 to P4, and was associated with a progressive shedding of procoagulant MPs. Exposure of P1 ECs to MPs shed from senescent P3 cells or circulating MPs from ACS patients induced increased senescence-associated β-galactosidase activity, oxidative stress, early phosphorylation of mitogen-activated protein kinases and Akt, and upregulation of p53, p21, and p16. Ex vivo, the prosenescent effect of circulating MPs from ACS patients was evidenced only under conditions of low shear stress. Depletion of endothelial-derived MPs from ACS patients reduced the induction of senescence. Prosenescent MPs promoted EC thrombogenicity through tissue factor upregulation, shedding of procoagulant MPs, endothelial nitric oxide synthase downregulation, and reduced nitric oxide-mediated inhibition of platelet aggregation. These MPs exhibited angiotensin-converting enzyme activity and upregulated AT1 receptors and angiotensin-converting enzyme in P1 ECs. Losartan, an AT1 receptor antagonist, and inhibitors of either mitogen-activated protein kinases or phosphoinositide 3-kinase prevented the MP-induced endothelial senescence. These findings indicate that endothelial-derived MPs from ACS patients induce premature endothelial senescence under atheroprone low shear stress and thrombogenicity through angiotensin II-induced redox-sensitive activation of mitogen-activated protein kinases and phosphoinositide 3-kinase/Akt. They further suggest that targeting endothelial-derived MP shedding and their bioactivity may be a promising therapeutic strategy to limit the development of an endothelial dysfunction post-ACS. © 2016 American Heart Association, Inc.

Vascular disruption and blood–brain barrier dysfunction in intracerebral hemorrhage

PubMed Central

2014-01-01

This article reviews current knowledge of the mechanisms underlying the initial hemorrhage and secondary blood–brain barrier (BBB) dysfunction in primary spontaneous intracerebral hemorrhage (ICH) in adults. Multiple etiologies are associated with ICH, for example, hypertension, Alzheimer’s disease, vascular malformations and coagulopathies (genetic or drug-induced). After the initial bleed, there can be continued bleeding over the first 24 hours, so-called hematoma expansion, which is associated with adverse outcomes. A number of clinical trials are focused on trying to limit such expansion. Significant progress has been made on the causes of BBB dysfunction after ICH at the molecular and cell signaling level. Blood components (e.g. thrombin, hemoglobin, iron) and the inflammatory response to those components play a large role in ICH-induced BBB dysfunction. There are current clinical trials of minimally invasive hematoma removal and iron chelation which may limit such dysfunction. Understanding the mechanisms underlying the initial hemorrhage and secondary BBB dysfunction in ICH is vital for developing methods to prevent and treat this devastating form of stroke. PMID:25120903

Electrical properties and interface state energy distributions of Cr/n-Si Schottky barrier diode

NASA Astrophysics Data System (ADS)

Karataş, Şükrü; Yildirim, Nezir; Türüt, Abdülmecit

2013-12-01

In this study, the electrical characteristics of the Cr/n-type Si (MS) Schottky barrier diode have been investigated by the current-voltage (I-V) and capacitance-voltage (C-V) measurements at 300 K temperature. Using the thermionic emission theory, the values of ideality factor and the barrier height have been obtained to be 1.22, 0.71 and 1.01, 0.83 eV, from the results of the I-V and C-V measurements, respectively. The barrier height (Φb) and the series resistance (RS) obtained from Norde’s function have been compared with those obtained from Cheung functions, and a good agreement between the results of both methods was seen. The interface state density (NSS) calculated without the RS is obtained to be increasing exponentially with bias from 2.40 × 1012 cm-2 eV-1 in (EC-0.623) eV to 1.94 × 1014 cm-2 eV-1 in (EC-0.495) eV, also, the NSS obtained taking into account the RS has increased exponentially with bias from 2.07 × 1012 cm-2 eV-1 to 1.47 × 1014 cm-2 eV-1 in the same interval.

Low p16INK4a Expression in Early Passage Human Prostate Basal Epithelial Cells Enables Immortalization by Telomerase Expression Alone.

PubMed

Graham, Mindy Kim; Principessa, Lorenzo; Antony, Lizamma; Meeker, Alan K; Isaacs, John T

2017-03-01

There are two principal senescence barriers that must be overcome to successfully immortalize primary human epithelial cells in culture, stress-induced senescence, and replicative senescence. The p16 INK4a /retinoblastoma protein (p16/Rb) pathway mediates stress-induced senescence, and is generally upregulated by primary epithelial cells in response to the artificial conditions from tissue culture. Replicative senescence is associated with telomere loss. Following each round of cell division, telomeres progressively shorten. Once telomeres shorten to a critical length, the DNA damage response pathway is activated, and the tumor suppressor p53 pathway triggers replicative senescence. Exogenous expression of telomerase in normal human epithelial cells extends the replicative capacity of cells, and in some cases, immortalizes cells. However reliable immortalization of epithelial cells usually requires telomerase activity coupled with inactivation of the p16/Rb pathway. A lentiviral vector, pLOX-TERT-iresTK (Addgene #12245), containing a CMV promoter upstream of a bicistronic coding cassette that includes loxP sites flanking the catalytic subunit of human telomerase gene (TERT) and herpes simplex virus type-1 thymidine kinase gene (HSV1-tk) was used to transduce normal prostate basal epithelial cells (PrECs) initiated in cell culture from prostate cancer patients undergoing radical prostatectomies. Transduction of early (i.e., <7) passage PrECs with TERT led to successful immortalization. However, attempts to immortalize late (i.e., >7) passage PrECs were unsuccessful. Late passage PrECs, which acquired elevated p16, were unable to overcome the senescence barrier. Immortalized PrECs (TERT-PrECs) retained a normal male karyotype and low p16 expression. Additionally, TERT-PrECs were non-tumorigenic when inoculated into intact male immunodeficient NSG mice. The present studies document that early passage human PrECs have sufficiently low p16 to permit immortalization by TERT expression alone. TERT-PrECs developed using this transduction approach provides an appropriate and experimentally facile model for clarifying the molecular mechanism(s) involved in both immortalization of human PrECs, as well as identifying genetic/epigenetic "drivers" for conversion of these immortalized non-tumorigenic cells into fully lethal prostate cancers. Notably, loxP sites flank the exogenous TERT gene in the TERT-PrECs. Cre recombinase can be used to excise TERT, and resolve whether TERT expression is required for these cells to be fully transformed into lethal cancer. Prostate 77: 374-384, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Tumour necrosis factor-α-mediated disruption of cerebrovascular endothelial barrier integrity in vitro involves the production of proinflammatory interleukin-6.

PubMed

Rochfort, Keith D; Collins, Laura E; McLoughlin, Alisha; Cummins, Philip M

2016-02-01

The co-involvement of tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) during blood-brain barrier (BBB) injury has been reported in various models of neuroinflammation, although the precise functional interplay between these archetypal proinflammatory cytokines remains largely undefined within this context. In the current paper, we tested the hypothesis that TNF-α-mediated BBB disruption is measurably attributable in-part to induction of microvascular endothelial IL-6 production. In initial experiments, we observed that treatment of human brain microvascular endothelial cells (HBMvECs) with TNF-α (0-100 ng/mL, 0-24 h) robustly elicited both time- and dose-dependent induction of IL-6 expression and release, as well as expression of the IL-6 family receptor, GP130. Further experiments demonstrated that the TNF-α-dependent generation of reactive oxygen species, down-regulation of adherens/tight junction proteins, and concomitant elevation of HBMvEC permeability, were all significantly attenuated by blockade of IL-6 signalling using either an anti-IL-6 neutralizing antibody or an IL-6 siRNA. Based on these observations, we conclude that TNF-α treatment of HBMvECs in vitro activates IL-6 production and signalling, events that were shown to synergize with TNF-α actions to elicit HBMvEC permeabilization. These novel findings offer a constructive insight into the specific contribution of downstream cytokine induction to the injurious actions of TNF-α at the BBB microvascular endothelium interface. The co-involvement of tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) during blood-brain barrier (BBB) injury has been widely reported. Using human brain microvascular endothelial cells (HBMvEC), we show that TNF-α-mediated BBB disruption is measurably attributable in-part to induction of endothelial IL-6 production and signalling. We demonstrate that the TNF-α-dependent generation of reactive oxygen species (ROS), down-regulation of interendothelial junctions, and concomitant elevation of HBMvEC permeability, could be significantly attenuated by using either an IL-6 neutralizing antibody or an IL-6-specific siRNA. These findings provide insight into the complex nature of proinflammatory cytokine injury at the BBB microvascular endothelium interface. © 2015 International Society for Neurochemistry.

The structure and function of the epidermal barrier in patients with atopic dermatitis – treatment options. Part two

PubMed Central

Czarnecka-Operacz, Magdalena; Adamski, Zygmunt

2018-01-01

Atopic dermatitis (AD) is a chronic and recurrent disease induced by underlying defects of the epidermal barrier and immunological disorders, typical of atopic diseases. The genetic and immunological mechanisms (outlined in the previous paper) affecting the dysfunction of the barrier are intensified by environmental factors, e.g. airborne and food allergens, infections and stress. For this reason, proper skin care, which prevents further damage and restores the epidermal barrier is of such importance in the field of AD therapy. Appropriate therapy is based on emollients which, coupled with anti-inflammatory and antipruritic treatment, should be used as the first-line therapy. The aim of the present paper is to outline the effects of the abovementioned factors on the dysfunction of the epidermal barrier as well as to emphasize the importance of proper atopic skin care in maintaining the integrity of the barrier and preventing exacerbation of the disease. PMID:29760610

On the Emergent Constraints of Climate Sensitivity [On proposed emergent constraints of climate sensitivity

DOE PAGES

Qu, Xin; Hall, Alex; DeAngelis, Anthony M.; ...

2018-01-11

Differences among climate models in equilibrium climate sensitivity (ECS; the equilibrium surface temperature response to a doubling of atmospheric CO2) remain a significant barrier to the accurate assessment of societally important impacts of climate change. Relationships between ECS and observable metrics of the current climate in model ensembles, so-called emergent constraints, have been used to constrain ECS. Here a statistical method (including a backward selection process) is employed to achieve a better statistical understanding of the connections between four recently proposed emergent constraint metrics and individual feedbacks influencing ECS. The relationship between each metric and ECS is largely attributable tomore » a statistical connection with shortwave low cloud feedback, the leading cause of intermodel ECS spread. This result bolsters confidence in some of the metrics, which had assumed such a connection in the first place. Additional analysis is conducted with a few thousand artificial metrics that are randomly generated but are well correlated with ECS. The relationships between the contrived metrics and ECS can also be linked statistically to shortwave cloud feedback. Thus, any proposed or forthcoming ECS constraint based on the current generation of climate models should be viewed as a potential constraint on shortwave cloud feedback, and physical links with that feedback should be investigated to verify that the constraint is real. Additionally, any proposed ECS constraint should not be taken at face value since other factors influencing ECS besides shortwave cloud feedback could be systematically biased in the models.« less

On the Emergent Constraints of Climate Sensitivity [On proposed emergent constraints of climate sensitivity

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

Qu, Xin; Hall, Alex; DeAngelis, Anthony M.

Differences among climate models in equilibrium climate sensitivity (ECS; the equilibrium surface temperature response to a doubling of atmospheric CO2) remain a significant barrier to the accurate assessment of societally important impacts of climate change. Relationships between ECS and observable metrics of the current climate in model ensembles, so-called emergent constraints, have been used to constrain ECS. Here a statistical method (including a backward selection process) is employed to achieve a better statistical understanding of the connections between four recently proposed emergent constraint metrics and individual feedbacks influencing ECS. The relationship between each metric and ECS is largely attributable tomore » a statistical connection with shortwave low cloud feedback, the leading cause of intermodel ECS spread. This result bolsters confidence in some of the metrics, which had assumed such a connection in the first place. Additional analysis is conducted with a few thousand artificial metrics that are randomly generated but are well correlated with ECS. The relationships between the contrived metrics and ECS can also be linked statistically to shortwave cloud feedback. Thus, any proposed or forthcoming ECS constraint based on the current generation of climate models should be viewed as a potential constraint on shortwave cloud feedback, and physical links with that feedback should be investigated to verify that the constraint is real. Additionally, any proposed ECS constraint should not be taken at face value since other factors influencing ECS besides shortwave cloud feedback could be systematically biased in the models.« less

Increased endothelial apoptotic cell density in human diabetic erectile tissue--comparison with clinical data.

PubMed

Costa, Carla; Soares, Raquel; Castela, Angela; Adães, Sara; Hastert, Véronique; Vendeira, Pedro; Virag, Ronald

2009-03-01

Erectile dysfunction (ED) is a common complication of diabetes. Endothelial cell (EC) dysfunction is one of the main mechanisms of diabetic ED. However, loss of EC integrity has never been assessed in human diabetic corpus cavernosum. To identify and quantify apoptotic cells in human diabetic and normal erectile tissue and to compare these results with each patient's clinical data and erection status. Eighteen cavernosal samples were collected, 13 from diabetics with ED and 5 from nondiabetic individuals. Cavernosal structure and cell proliferation status were evaluated by immunohistochemistry. Tissue integrity was assessed by terminal transferase dUTP nick end labeling assay, an index of apoptotic cell density (ACD) established and compared with each patient age, type of diabetes, arterial risk factors number, arterial/veno-occlusive disease, response to intracavernous vasoactive injections (ICI), and penile nitric oxide release test (PNORT). Establish an index of ACD and correlate those results with patient clinical data. Nondiabetic samples presented few scattered cells in apoptosis and an ACD of 7.15 +/- 0.44 (mean apoptotic cells/tissue area mm(2) +/- standard error). The diabetic group showed an increased ACD of 23.82 +/- 1.53, and apoptotic cells were located specifically at vascular sites. Rehabilitation of these endothelial lesions seemed impaired, as no evidence of EC proliferation was observed. Furthermore, higher ACD in diabetic individuals correlated to poor response to PNORT and to ICI. We provided evidence for the first time that loss of cavernosal EC integrity is a crucial event involved in diabetic ED. Furthermore, we were able to establish a threshold between ACD values and cavernosal tissue functionality, as assessed by PNORT and vasoactive ICI.

Deficiency in DNA damage response of enterocytes accelerates intestinal stem cell aging in Drosophila.

PubMed

Park, Joung-Sun; Jeon, Ho-Jun; Pyo, Jung-Hoon; Kim, Young-Shin; Yoo, Mi-Ae

2018-03-07

Stem cell dysfunction is closely linked to tissue and organismal aging and age-related diseases, and heavily influenced by the niche cells' environment. The DNA damage response (DDR) is a key pathway for tissue degeneration and organismal aging; however, the precise protective role of DDR in stem cell/niche aging is unclear. The Drosophila midgut is an excellent model to study the biology of stem cell/niche aging because of its easy genetic manipulation and its short lifespan. Here, we showed that deficiency of DDR in Drosophila enterocytes (ECs) accelerates intestinal stem cell (ISC) aging. We generated flies with knockdown of Mre11 , Rad50 , Nbs1 , ATM , ATR , Chk1 , and Chk2 , which decrease the DDR system in ECs. EC-specific DDR depletion induced EC death, accelerated the aging of ISCs, as evidenced by ISC hyperproliferation, DNA damage accumulation, and increased centrosome amplification, and affected the adult fly's survival. Our data indicated a distinct effect of DDR depletion in stem or niche cells on tissue-resident stem cell proliferation. Our findings provide evidence of the essential role of DDR in protecting EC against ISC aging, thus providing a better understanding of the molecular mechanisms of stem cell/niche aging.

Monitoring of approved studies: A difficult tightrope walk by Ethics Committees.

PubMed

Davis, Sanish

2018-01-01

Continuing review of studies approved by the Ethics Committees (ECs) involves review of the progress of the study, annual reports, protocol deviations/violations, serious adverse event monitoring, and on-site monitoring. International and national regulations and guidelines for continuing review state that it is an opportunity for the EC to be assured that risks to subjects are minimized and is are reasonable in relation to anticipated benefits if any to the subjects and the knowledge it will generate. There are several barriers (e.g. lack of workforce, lack of training of members for conducting onsite review, and poor infrastructure) for ECs to do ongoing review of projects approved by them. Industry is an important stakeholder for the research enterprise in India and strongly advocates that ECs should at a minimum have pragmatic standard operating procedures for continuing review/monitoring of studies initially approved. ECs which deal with larger volume of studies with well-functioning secretariat, appropriately trained EC members and funding should definitely conduct onsite review/monitoring in addition to the ongoing review.

Follistatin-Like 3 Enhances the Function of Endothelial Cells Derived from Pluripotent Stem Cells by Facilitating β-Catenin Nuclear Translocation Through Inhibition of Glycogen Synthase Kinase-3β Activity.

PubMed

Kelaini, Sophia; Vilà-González, Marta; Caines, Rachel; Campbell, David; Eleftheriadou, Magdalini; Tsifaki, Marianna; Magee, Corey; Cochrane, Amy; O'neill, Karla; Yang, Chunbo; Stitt, Alan W; Zeng, Lingfang; Grieve, David J; Margariti, Andriana

2018-03-23

The fight against vascular disease requires functional endothelial cells (ECs) which could be provided by differentiation of induced Pluripotent Stem Cells (iPS Cells) in great numbers for use in the clinic. However, the great promise of the generated ECs (iPS-ECs) in therapy is often restricted due to the challenge in iPS-ECs preserving their phenotype and function. We identified that Follistatin-Like 3 (FSTL3) is highly expressed in iPS-ECs, and, as such, we sought to clarify its possible role in retaining and improving iPS-ECs function and phenotype, which are crucial in increasing the cells' potential as a therapeutic tool. We overexpressed FSTL3 in iPS-ECs and found that FSTL3 could induce and enhance endothelial features by facilitating β-catenin nuclear translocation through inhibition of glycogen synthase kinase-3β activity and induction of Endothelin-1. The angiogenic potential of FSTL3 was also confirmed both in vitro and in vivo. When iPS-ECs overexpressing FSTL3 were subcutaneously injected in in vivo angiogenic model or intramuscularly injected in a hind limb ischemia NOD.CB17-Prkdcscid/NcrCrl SCID mice model, FSTL3 significantly induced angiogenesis and blood flow recovery, respectively. This study, for the first time, demonstrates that FSTL3 can greatly enhance the function and maturity of iPS-ECs. It advances our understanding of iPS-ECs and identifies a novel pathway that can be applied in cell therapy. These findings could therefore help improve efficiency and generation of therapeutically relevant numbers of ECs for use in patient-specific cell-based therapies. In addition, it can be particularly useful toward the treatment of vascular diseases instigated by EC dysfunction. Stem Cells 2018. © 2018 The Authors STEM CELLS published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Recruitment, adherence, and retention of endometrial cancer survivors in a behavioural lifestyle programme: the Diet and Exercise in Uterine Cancer Survivors (DEUS) parallel randomised pilot trial.

PubMed

Koutoukidis, Dimitrios A; Beeken, Rebecca J; Manchanda, Ranjit; Michalopoulou, Moscho; Burnell, Matthew; Knobf, M Tish; Lanceley, Anne

2017-10-08

Healthy eating and physical activity may help endometrial cancer survivors (ECS) improve their quality of life. However, most ECS do not meet the relevant guidelines. This pilot trial aimed to test the study feasibility procedures for a definitive trial of a behavioural lifestyle programme. This 24-week parallel two-arm randomised pilot trial took place in two hospitals in London, UK (April 2015-June 2016). Sixty disease-free ECS within 3 years of diagnosis. Participants were randomised using minimisation to receive the intervention or care as usual. The 'Shape-Up following cancer treatment' programme used self-monitoring, goal-setting, self-incentives, problem-solving and group social support for 12 hours over 8 weeks to help survivors improve their eating and physical activity. The main outcome measures were recruitment, adherence, and retention rates. Further outcomes included barriers to participation and feedback on programme satisfaction. Of the 296 potentially eligible ECS, 20% (n=60) were randomly allocated to the active intervention (n=29) or control group (n=31). Three participants in each arm were deemed ineligible after randomisation and excluded from analysis. Twenty participants (77%; 95% CI 61% to 93%) adhered to the intervention and provided generally favourable feedback. At 24 weeks, 25/26 (96%; 95% CI 89% to 100%) intervention and 24/28 (86%; 95% CI 73% to 99%) control participants completed their assessment. No intervention-related adverse events were reported. Among eligible survivors who declined study participation (n=83), inconvenience (78%; 95% CI 69% to 87%) was the most common barrier. The trial was feasible to deliver based on the a priori feasibility criteria. Enhancing recruitment and adherence in a definitive trial will require designs that promote convenience and consider ECS-reported barriers. NCT02433080; Pre-results. University College London, St. Bartholomew's Hospital Nurses League, and NIHR University College London Hospitals Biomedical Research Centre. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Therapeutic effect of Tripterygium wilfordii Hook F multiglycosides on gut barrier dysfunction in rats with acute necrotizing pancreatitis.

PubMed

Wang, Jie; Wu, Gang; Ma, Baojin; Wu, Jianhua; Cai, Duan

2013-02-01

The aim of the current study was to investigate the therapeutic effect of Tripterygium wilfordii Hook F multiglycosides (TWG) on gut barrier dysfunction in rats with acute necrotizing pancreatitis (ANP). ANP was induced in rats using 3.5% sodium taurocholate. The rats were divided into 3 groups: the sham operation (SO), ANP and ANP+TWG groups. Biochemical and pathological change of pancreatic tissue and ileal mucosa, bacterial cultures and the survival rate were measured following surgery and treatment. TWG treatment significantly decreased amylase and lipase activities and plasma endotoxin and D-lactate levels. Edema and inflammation in the pancreas and ileal mucosa were alleviated. Positive bacterial cultures were significantly reduced. The survival rate of the rats in the ANP+TWG group was higher than that of the rats in the ANP group. TWG treatment showed beneficial effects by protecting the pancreas from bacterial infection caused by gut barrier dysfunction and improving the outcomes of the rats with ANP.

Targeting the vascular and perivascular niches as a regenerative therapy for lung and liver fibrosis

PubMed Central

Cao, Zhongwei; Ye, Tinghong; Sun, Yue; Ji, Gaili; Shido, Koji; Chen, Yutian; Luo, Lin; Na, Feifei; Li, Xiaoyan; Huang, Zhen; Ko, Jane L.; Mittal, Vivek; Qiao, Lina; Chen, Chong; Martinez, Fernando J.; Rafii, Shahin; Ding, Bi-Sen

2017-01-01

The regenerative capacity of lung and liver is sometimes impaired by chronic or overwhelming injury. Orthotopic transplantation of parenchymal stem cells to damaged organs might reinstate their self-repair ability. However, parenchymal cell engraftment is frequently hampered by the microenvironment in diseased recipient organs. Here, we show that targeting both the vascular niche and perivascular fibroblasts establishes “hospitable soil” to foster incorporation of “seed”, in this case the engraftment of parenchymal cells in injured organs. Specifically, ectopic induction of endothelial cell (EC)-expressed paracrine/angiocrine hepatocyte growth factor (HGF) and inhibition of perivascular NADPH Oxidase 4 (NOX4) synergistically enabled reconstitution of mouse and human parenchymal cells in damaged organs. Reciprocally, genetic knockout of Hgf in mouse ECs (HgfiΔEC/iΔEC) aberrantly upregulated perivascular NOX4 during liver and lung regeneration. Dysregulated HGF and NOX4 pathways subverted the function of vascular and perivascular cells from an epithelially-inductive niche to a microenvironment that inhibited parenchymal reconstitution. Perivascular NOX4 induction in HgfiΔEC/iΔEC mice recapitulated the phenotype of human and mouse fibrotic livers and lungs. Consequently, EC-directed HGF and NOX4 inhibitor GKT137831 stimulated regenerative integration of mouse and human parenchymal cells in chronically injured lung and liver. Our data suggest that targeting dysfunctional perivascular and vascular cells in diseased organs can bypass fibrosis and enable reparative cell engraftment to reinstate lung and liver regeneration. PMID:28855398

Endothelial mineralocorticoid receptor ablation does not alter blood pressure, kidney function or renal vessel contractility

PubMed Central

Laursen, Sidsel B.; Finsen, Stine; Marcussen, Niels; Quaggin, Susan E.

2018-01-01

Aldosterone blockade confers substantial cardiovascular and renal protection. The effects of aldosterone on mineralocorticoid receptors (MR) expressed in endothelial cells (EC) within the renal vasculature have not been delineated. We hypothesized that lack of MR in EC may be protective in renal vasculature and examined this by ablating the Nr3c2 gene in endothelial cells (EC-MR) in mice. Blood pressure, heart rate and PAH clearance were measured using indwelling catheters in conscious mice. The role of the MR in EC on contraction and relaxation was investigated in the renal artery and in perfused afferent arterioles. Urinary sodium excretion was determined by use of metabolic cages. EC-MR transgenics had markedly decreased MR expression in isolated aortic endothelial cells as compared to littermates (WT). Blood pressure and effective renal plasma flow at baseline and following AngII infusion was similar between groups. No differences in contraction and relaxation were observed between WT and EC-MR KO in isolated renal arteries during baseline or following 2 or 4 weeks of AngII infusion. The constriction or dilatations of afferent arterioles between genotypes were not different. No changes were found between the groups with respect to urinary excretion of sodium after 4 weeks of AngII infusion, or in urinary albumin excretion and kidney morphology. In conclusion, deletion of the EC-MR does not confer protection towards the development of hypertension, endothelial dysfunction of renal arteries or renal function following prolonged AngII-infusion. PMID:29466427

HSP27 phosphorylation protects against endothelial barrier dysfunction under burn serum challenge.

PubMed

Sun, Huan-bo; Ren, Xi; Liu, Jie; Guo, Xiao-wei; Jiang, Xu-pin; Zhang, Dong-xia; Huang, Yue-sheng; Zhang, Jia-ping

2015-07-31

F-actin rearrangement is an early event in burn-induced endothelial barrier dysfunction. HSP27, a target of p38 MAPK/MK2 pathway, plays an important role in actin dynamics through phosphorylation. The question of whether HSP27 participates in burn-related endothelial barrier dysfunction has not been identified yet. Here, we showed that burn serum induced a temporal appearance of central F-actin stress fibers followed by a formation of irregular dense peripheral F-actin in pulmonary endothelial monolayer, concomitant with a transient increase of HSP27 phosphorylation that conflicted with the persistent activation of p38 MAPK/MK2 unexpectedly. The appearance of F-actin stress fibers and transient increase of HSP27 phosphorylation occurred prior to the burn serum-induced endothelial hyperpermeability. Overexpressing phospho-mimicking HSP27 (HSP27(Asp)) reversed the burn serum-induced peripheral F-actin rearrangement with the augmentation of central F-actin stress fibers, and more importantly, attenuated the burn serum-induced endothelial hyperpermeability; such effects were not observed by HSP27(Ala), a non-phosphorylated mutant of HSP27. HSP27(Asp) overexpression also rendered the monolayer more resistant to barrier disruption caused by Cytochalasin D, a chemical reagent that depolymerizes F-actin specifically. Further study showed that phosphatases and sumoylation-inhibited MK2 activity contributed to the blunting of HSP27 phosphorylation during the burn serum-induced endothelial hyperpermeability. Our study identifies HSP27 phosphorylation as a protective response against burn serum-induced endothelial barrier dysfunction, and suggests that targeting HSP27 wound be a promising therapeutic strategy in ameliorating burn-induced lung edema and shock development. Copyright © 2015 Elsevier Inc. All rights reserved.

Pregnane X receptor agonists enhance intestinal epithelial wound healing and repair of the intestinal barrier following the induction of experimental colitis.

PubMed

Terc, Joshua; Hansen, Ashleigh; Alston, Laurie; Hirota, Simon A

2014-05-13

The intestinal epithelial barrier plays a key role in the maintenance of homeostasis within the gastrointestinal tract. Barrier dysfunction leading to increased epithelial permeability is associated with a number of gastrointestinal disorders including the inflammatory bowel diseases (IBD) - Crohn's disease and ulcerative colitis. It is thought that the increased permeability in patients with IBD may be driven by alterations in the epithelial wound healing response. To this end considerable study has been undertaken to identify signaling pathways that may accelerate intestinal epithelial wound healing and normalize the barrier dysfunction observed in IBD. In the current study we examined the role of the pregnane X receptor (PXR) in modulating the intestinal epithelial wound healing response. Mutations and reduced mucosal expression of the PXR are associated with IBD, and others have reported that PXR agonists can dampen intestinal inflammation. Furthermore, stimulation of the PXR has been associated with increased cell migration and proliferation, two of the key processes involved in wound healing. We hypothesized that PXR agonists would enhance intestinal epithelial repair. Stimulation of Caco-2 intestinal epithelial cells with rifaximin, rifampicin and SR12813, all potent agonists of the PXR, significantly increased wound closure. This effect was driven by p38 MAP kinase-dependent cell migration, and occurred in the absence of cell proliferation. Treating mice with a rodent specific PXR agonist, pregnenolone 16α-carbonitrile (PCN), attenuated the intestinal barrier dysfunction observed in the dextran sulphate sodium (DSS) model of experimental colitis, an effect that occurred independent of the known anti-inflammatory effects of PCN. Taken together our data indicate that the activation of the PXR can enhance intestinal epithelial repair and suggest that targeting the PXR may help to normalize intestinal barrier dysfunction observed in patients with IBD. Furthermore, our data provide additional insight into the potential mechanisms through which rifaximin elicits its clinical efficacy in the treatment of IBD. Copyright © 2014 Elsevier B.V. All rights reserved.

Barrier Epithelial Cells and the Control of Type 2 Immunity.

PubMed

Hammad, Hamida; Lambrecht, Bart N

2015-07-21

Type-2-cell-mediated immunity, rich in eosinophils, basophils, mast cells, CD4(+) T helper 2 (Th2) cells, and type 2 innate lymphoid cells (ILC2s), protects the host from helminth infection but also drives chronic allergic diseases like asthma and atopic dermatitis. Barrier epithelial cells (ECs) represent the very first line of defense and express pattern recognition receptors to recognize type-2-cell-mediated immune insults like proteolytic allergens or helminths. These ECs mount a prototypical response made up of chemokines, innate cytokines such as interleukin-1 (IL-1), IL-25, IL-33, and thymic stromal lymphopoietin (TSLP), as well as the alarmins uric acid, ATP, HMGB1, and S100 proteins. These signals program dendritic cells (DCs) to mount Th2-cell-mediated immunity and in so doing boost ILC2, basophil, and mast cell function. Here we review the general mechanisms of how different stimuli trigger type-2-cell-mediated immunity at mucosal barriers and how this leads to protection or disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Importins α and β signaling mediates endothelial cell inflammation and barrier disruption.

PubMed

Leonard, Antony; Rahman, Arshad; Fazal, Fabeha

2018-04-01

Nucleocytoplasmic shuttling via importins is central to the function of eukaryotic cells and an integral part of the processes that lead to many human diseases. In this study, we addressed the role of α and β importins in the mechanism of endothelial cell (EC) inflammation and permeability, important pathogenic features of many inflammatory diseases such as acute lung injury and atherosclerosis. RNAi-mediated knockdown of importin α4 or α3 each inhibited NF-κB activation, proinflammatory gene (ICAM-1, VCAM-1, and IL-6) expression, and thereby endothelial adhesivity towards HL-60 cells, upon thrombin challenge. The inhibitory effect of α4 and α3 knockdown was associated with impaired nuclear import and consequently, DNA binding of RelA/p65 subunit of NF-κB and occurred independently of IκBα degradation. Intriguingly, knockdown of importins α4 and α3 also inhibited thrombin-induced RelA/p65 phosphorylation at Ser 536 , showing a novel role of α importins in regulating transcriptional activity of RelA/p65. Similarly, knockdown of importin β1, but not β2, blocked thrombin-induced activation of RelA/p65 and its target genes. In parallel studies, TNFα-mediated inflammatory responses in EC were refractory to knockdown of importins α4, α3 or β1, indicating a stimulus-specific regulation of RelA/p65 and EC inflammation by these importins. Importantly, α4, α3, or β1 knockdown also protected against thrombin-induced EC barrier disruption by inhibiting the loss of VE-cadherin at adherens junctions and by regulating actin cytoskeletal rearrangement. These results identify α4, α3 and β1 as critical mediators of EC inflammation and permeability associated with intravascular coagulation. Copyright © 2018 Elsevier Inc. All rights reserved.

Access to Emergency Contraception in the Over-the-Counter Era

PubMed Central

Cleland, Kelly; Bass, Jamie; Doci, Florida; Foster, Angel M.

2016-01-01

Introduction After years of complex regulatory changes, levonorgestrel emergency contraception (LNG EC) is now approved for unrestricted sale in the US. Timely access to EC pills is critical because they are more likely to work the sooner they are taken. This study assesses whether LNG EC is sold in accordance with current Food and Drug Administration regulations. Methods We distributed an online questionnaire through an EC-focused listserv for reproductive health professionals, asking data collectors to visit local stores and document product names, price, over-the-counter (OTC) shelf availability, and misinformation about age restrictions. We used Chi-square analysis to assess bivariate associations and t-tests and Wilcoxon rank-sum tests to determine differences in means. Results We collected information about 220 stores. The majority (65%) stocked EC on OTC shelves, although only 22% of these displayed it without a locked security enclosure. Chain pharmacies were more likely to shelf-stock EC than independent pharmacies (77% vs 5%; p=0.000), but variation existed among stores within the same chain. Among stores that were asked, 40% incorrectly reported an age restriction for non-prescription purchase of LNG EC, while 95% correctly reported that men can buy LNG EC. The average price of branded and generic LNG EC was $49.64 and $40.05, respectively. Conclusion Changes in the regulatory status of LNG EC have resulted in widespread confusion about how EC can be sold, and its high price contributes to access barriers. Retailers should ensure that consumers can access LNG EC quickly and easily by stocking the product on OTC shelves and educating staff about current regulations. PMID:27682018

Emergency Contraception in Mexico: Trends in Knowledge and Ever-Use 2006-2014.

PubMed

Han, Leo; Saavedra-Avendano, Biani; Lambert, William; Fu, Rongwei; Rodriguez, Maria I; Edelman, Alison; Darney, Blair

2017-11-01

Objectives A package of interventions to introduce emergency contraception (EC) to Mexico was implemented, resulting in the addition of EC to the national family planning guidelines in 2004. We describe EC knowledge and use among women in Mexico over time. Methods We used the 2006, 2009, and 2014 of waves of a nationally representative demographic survey (ENADID). We assessed EC knowledge and usage in women ages 15-29 who are not using permanent methods and tested whether EC knowledge and use is changing over time after controlling for socio-demographic characteristics using logistic regression. Results Our sample included n = 99,223 (population N = 40,234,355) women ages 15-29. Overall, knowledge of EC increased over time: 62% in 2006 to 79% in 2009 to 83% in 2014 (p < 0.001). Among young women who have used contraception (n = 42,883; N = 16,816,701), the proportion that reported EC use increased from 3 to 11% to 29% (p < 0.001). Compared to non-users, women who had ever used EC were more likely to be using no method of contraception (44 vs. 35%) or barrier method (22 vs. 17%). Demographic factors including lower wealth, lower education, indigenous status and rural living are significantly associated with less EC knowledge and use. Stratified multivariate analysis found that demographic disadvantages magnify lower EC use among rural residents compared to non-rural residents. Conclusions for Practice Knowledge and use of EC are growing rapidly in Mexico, but disparities persist in demographically disadvantaged women, particularly those living in rural areas. Women who use EC appear to be at higher risk of unintended pregnancy based on current contraceptive use.

NITROTYROSINATION OF A TUBULIN INDUCES EPITHELIAL BARRIER DYSFUNCTION

EPA Science Inventory

Nitrotyrosination of a-Tubulin Induces Epithelial Transport Dysfunction. Yuh-Chin Huang, Lisa Dailey, Wen-Li Zhang and Ilona Jaspers. ORD, Environmental Protection Agency and CEMLB, University of North Carolina

a-Tubulin undergoes a cyclic removal and readdition of tyrosin...

Phytochemical genistein in the regulation of vascular function: new insights.

PubMed

Si, Hongwei; Liu, Dongmin

2007-01-01

Genistein, a natural bioactive compound derived from legumes, has drawn wide attention during the last decade because of its potentially beneficial effects on some human degenerative diseases. It has a weak estrogenic effect and is a well-known non-specific tyrosine kinase inhibitor at pharmacological doses. Epidemiological studies show that genistein intake is inversely associated with the risk of cardiovascular diseases. Data from animal and in vitro studies suggest a protective role of genistein in cardiovascular events. However, the mechanisms of the genistein action on vascular protective effects are unclear. Past extensive studies exploring its hypolipidemic effect resulted in contradictory data. Genistein also is a relatively poor antioxidant. However, genistein protects against pro-inflammatory factor-induced vascular endothelial barrier dysfunction and inhibits leukocyte-endothelium interaction, thereby modulating vascular inflammation, a major event in the pathogenesis of atherosclerosis. Recent studies found that genistein exerts a novel non-genomic action by targeting on important signaling molecules in vascular endothelial cells (ECs). Genistein rapidly activates endothelial nitric oxide synthase and production of nitric oxide in ECs. This genistein effect is novel since it is independent of its known effects, but mediated by the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) cascade. Further studies demonstrated that genistein directly stimulates the plasma membrane-associated adenylate cyclases, leading to activation of the cAMP signaling pathway. In addition, genistein activates peroxisome proliferator-activated receptors, ligand-activated nuclear receptors important to normal vascular function. Furthermore, genistein reduces reactive oxygen species (ROS) by attenuating the expression of ROS-producing enzymes. These new findings reveal the novel roles for genistein in the regulation of vascular function and provide a basis for further investigating its therapeutic potential for inflammatory-related vascular disease.

Astrocytic modulation of blood brain barrier: perspectives on Parkinson's disease.

PubMed

Cabezas, Ricardo; Avila, Marcos; Gonzalez, Janneth; El-Bachá, Ramon Santos; Báez, Eliana; García-Segura, Luis Miguel; Jurado Coronel, Juan Camilo; Capani, Francisco; Cardona-Gomez, Gloria Patricia; Barreto, George E

2014-01-01

The blood-brain barrier (BBB) is a tightly regulated interface in the Central Nervous System (CNS) that regulates the exchange of molecules in and out from the brain thus maintaining the CNS homeostasis. It is mainly composed of endothelial cells (ECs), pericytes and astrocytes that create a neurovascular unit (NVU) with the adjacent neurons. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted factors that lead to the adequate association between the cells of the BBB and the formation of strong tight junctions. Under neurological disorders, such as chronic cerebral ischemia, brain trauma, Epilepsy, Alzheimer and Parkinson's Diseases, a disruption of the BBB takes place, involving a lost in the permeability of the barrier and phenotypical changes in both the ECs and astrocytes. In this aspect, it has been established that the process of reactive gliosis is a common feature of astrocytes during BBB disruption, which has a detrimental effect on the barrier function and a subsequent damage in neuronal survival. In this review we discuss the implications of astrocyte functions in the protection of the BBB, and in the development of Parkinson's disease (PD) and related disorders. Additionally, we highlight the current and future strategies in astrocyte protection aimed at the development of restorative therapies for the BBB in pathological conditions.

A Novel Multilayered Multidisk Oral Tablet for Chronotherapeutic Drug Delivery

PubMed Central

Khan, Zaheeda; Choonara, Yahya E.; du Toit, Lisa C.; Ndesendo, Valence M. K.; Pillay, Viness

2013-01-01

A Multilayered Multidisk Tablet (MLMDT) comprising two drug-loaded disks enveloped by three drug-free barrier layers was developed for use in chronotherapeutic disorders, employing two model drugs, theophylline and diltiazem HCl. The MLMDT was designed to achieve two pulses of drug release separated by a lag phase. The polymer disk comprised hydroxyethylcellulose (HEC) and ethylcellulose (EC) granulated using an aqueous dispersion of EC. The polymeric barrier layers constituted a combination of pectin/Avicel (PBL) (1st barrier layer) and hydroxypropylmethylcellulose (HPMC) (HBL1 and HBL2) as the 2nd and 3rd barrier layers, respectively. Sodium bicarbonate was incorporated into the diltiazem-containing formulation for delayed drug release. Erosion and swelling studies confirmed the manner in which the drug was released with theophylline formulations exhibiting a maximum swelling of 97% and diltiazem containing formulations with a maximum swelling of 119%. FTIR spectra displayed no interactions between drugs and polymers. Molecular mechanics simulations were undertaken to predict the possible orientation of the polymer morphologies most likely affecting the MLMDT performance. The MLMDT provided two pulses of drug release, separated by a lag phase, and additionally it displayed desirable friability, hardness, and uniformity of mass indicating a stable formulation that may be a desirable candidate for chronotherapeutic drug delivery. PMID:24024200

Evaluation of cell responses toward adhesives with different photoinitiating systems.

PubMed

Van Landuyt, Kirsten L; Krifka, Stephanie; Hiller, Karl-Anton; Bolay, Carola; Waha, Claudia; Van Meerbeek, Bart; Schmalz, Gottfried; Schweikl, Helmut

2015-08-01

The photoinitiator diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) is more reactive than a camphorquinone/amine (CQ) system, and TPO-based adhesives obtained a higher degree of conversion (DC) with fewer leached monomers. The hypothesis tested here is that a TPO-based adhesive is less toxic than a CQ-based adhesive. A CQ-based adhesive (SBU-CQ) (Scotchbond Universal, 3M ESPE) and its experimental counterpart with TPO (SBU-TPO) were tested for cytotoxicity in human pulp-derived cells (tHPC). Oxidative stress was analyzed by the generation of reactive oxygen species (ROS) and by the expression of antioxidant enzymes. A dentin barrier test (DBT) was used to evaluate cell viability in simulated clinical circumstances. Unpolymerized SBU-TPO was significantly more toxic than SBU-CQ after a 24h exposure, and TPO alone (EC50=0.06mM) was more cytotoxic than CQ (EC50=0.88mM), EDMAB (EC50=0.68mM) or CQ/EDMAB (EC50=0.50mM). Cultures preincubated with BSO (l-buthionine sulfoximine), an inhibitor of glutathione synthesis, indicated a minor role of glutathione in cytotoxic responses toward the adhesives. Although the generation of ROS was not detected, a differential expression of enzymatic antioxidants revealed that cells exposed to unpolymerized SBU-TPO or SBU-CQ are subject to oxidative stress. Polymerized SBU-TPO was more cytotoxic than SBU-CQ under specific experimental conditions only, but no cytotoxicity was detected in a DBT with a 200μm dentin barrier. Not only DC and monomer-release determine the biocompatibility of adhesives, but also the cytotoxicity of the (photo-)initiator should be taken into account. Addition of TPO rendered a universal adhesive more toxic compared to CQ; however, this effect could be annulled by a thin dentin barrier. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Executive Functioning, Barriers to Adherence, and Nonadherence in Adolescent and Young Adult Transplant Recipients.

PubMed

Gutiérrez-Colina, Ana M; Eaton, Cyd K; Lee, Jennifer L; Reed-Knight, Bonney; Loiselle, Kristin; Mee, Laura L; LaMotte, Julia; Liverman, Rochelle; Blount, Ronald L

2016-08-01

OBJECTIVE : To evaluate levels of executive functioning in a sample of adolescent and young adult (AYA) transplant recipients, and to examine executive functioning in association with barriers to adherence and medication nonadherence.  METHOD : In all, 41 caregivers and 39 AYAs were administered self- and proxy-report measures.  RESULTS : AYA transplant recipients have significant impairments in executive functioning abilities. Greater dysfunction in specific domains of executive functioning was significantly associated with more barriers to adherence and greater medication nonadherence.  CONCLUSION : AYA transplant recipients are at increased risk for executive dysfunction. The assessment of executive functioning abilities may guide intervention efforts designed to decrease barriers to adherence and promote developmentally appropriate levels of treatment responsibility. © The Author 2015. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

"I'll look it up on the Web first": Barriers and overcoming barriers to consult for sexual dysfunction among young men.

PubMed

Akre, Christina; Michaud, Pierre-André; Suris, Joan-Carles

2010-06-12

Our aim was to identify the barriers young men face to consult a health professional when they encounter sexual dysfunctions and where they turn to, if so, for answers. We conducted an exploratory qualitative research including 12 young men aged 16-20 years old seen in two focus groups. Discussions were triggered through vignettes about sexual dysfunction. Young men preferred not to talk about sexual dysfunction problems with anyone and to solve them alone as it is considered an intimate and embarrassing subject which can negatively impact their masculinity. Confidentiality appeared to be the most important criterion in disclosing an intimate subject to a health professional. Participants raised the problem of males' accessibility to services and lack of reason to consult. Two criteria to address the problem were if it was long-lasting or considered as physical. The Internet was unanimously considered as an initial solution to solve a problem, which could guide them to a face-to-face consultation if necessary. Results suggest that Internet-based tools should be developed to become an easy access door to sexual health services for young men. Wherever they consult and for whatever problem, sexual health must be on the agenda.

FABP4 induces asthmatic airway epithelial barrier dysfunction via ROS-activated FoxM1.

PubMed

Wu, Gaohui; Yang, Liteng; Xu, Yi; Jiang, Xiaohong; Jiang, Xiaomin; Huang, Lisha; Mao, Ling; Cai, Shaoxi

2018-01-01

Functional abnormal airway epithelial cells, along with activated inflammatory cells, resulting in chronic airway inflammation, are considered as the characteristic of asthma. Fatty Acid Binding Protein 4 (FABP4) takes part in glucose and lipid homeostasis, and also have an important role in allergic airway inflammation. However, whether FABP4 influence barrier function of airway epithelial cells is unknown. In vivo, a HDM-induced murine model of asthma was obtained to assessed airway inflammation and protein expression of E-cadherin and Forkhead Box M1 (FoxM1). In vitro, 16-HBE was cultured and was treated with hrFABP4, siFABP4, FABPF4 inhibitor BMS, or FoxM1 inhibitor RCM-1. IL-4, IL-5, and IL-13 level was determined by ELISA. Transepithelial electrical resistance (TER), paracellular permeability and E-cadherin-special immunofluorescence were measured to value airway epithelial barrier function. Intracellular ROS production was determined by DCF-DA fluorescence. FABP4 inhibitor BMS alleviate airway inflammation and destruction of E-cad in allergic mouse. Treatment with HDM or hrFABP4 aggravated inflammatory response, damaged airway epithelial barrier, which could be inhibited by siFABP4 and BMS. Treatment with HDM or hrFABP4 also enhanced levels of FoxM1, and Inhibited FoxM1 suppressed HDM- and hrFABP4-induced inflammation and airway epithelial barrier dysfunction. In addition, H 2 O 2 promoted FoxM1 expression, HDM and hrFABP4 induced-FoxM1 could be inhibited by NAC, leading to decreased inflammation and improved airway epithelial barrier. Upregulated ROS induced by FABP4 was of significance in activating FoxM1 leading to airway inflammation and epithelial barrier dysfunction. Copyright © 2017 Elsevier Inc. All rights reserved.

Role of kinase-independent and -dependent functions of FAK in endothelial cell survival and barrier function during embryonic development.

PubMed

Zhao, Xiaofeng; Peng, Xu; Sun, Shaogang; Park, Ann Y J; Guan, Jun-Lin

2010-06-14

Focal adhesion kinase (FAK) is essential for vascular development as endothelial cell (EC)-specific knockout of FAK (conditional FAK knockout [CFKO] mice) leads to embryonic lethality. In this study, we report the differential kinase-independent and -dependent functions of FAK in vascular development by creating and analyzing an EC-specific FAK kinase-defective (KD) mutant knockin (conditional FAK knockin [CFKI]) mouse model. CFKI embryos showed apparently normal development through embryonic day (E) 13.5, whereas the majority of CFKO embryos died at the same stage. Expression of KD FAK reversed increased EC apoptosis observed with FAK deletion in embryos and in vitro through suppression of up-regulated p21. However, vessel dilation and defective angiogenesis of CFKO embryos were not rescued in CFKI embryos. ECs without FAK or expressing KD FAK showed increased permeability, abnormal distribution of vascular endothelial cadherin (VE-cadherin), and reduced VE-cadherin Y658 phosphorylation. Together, our data suggest that kinase-independent functions of FAK can support EC survival in vascular development through E13.5 but are insufficient for maintaining EC function to allow for completion of embryogenesis.

hiPSC-derived neural stem cells from patients with schizophrenia induce an impaired angiogenesis.

PubMed

Casas, Bárbara S; Vitória, Gabriela; do Costa, Marcelo N; Madeiro da Costa, Rodrigo; Trindade, Pablo; Maciel, Renata; Navarrete, Nelson; Rehen, Stevens K; Palma, Verónica

2018-02-22

Schizophrenia is a neurodevelopmental disease characterized by cerebral connectivity impairment and loss of gray matter. It was described in adult schizophrenia patients (SZP) that concentration of VEGFA, a master angiogenic factor, is decreased. Recent evidence suggests cerebral hypoperfusion related to a dysfunctional Blood Brain Barrier (BBB) in SZP. Since neurogenesis and blood-vessel formation occur in a coincident and coordinated fashion, a defect in neurovascular development could result in increased vascular permeability and, therefore, in poor functionality of the SZP's neurons. Here, we characterized the conditioned media (CM) of human induced Pluripotent Stem Cells (hiPSC)-derived Neural Stem Cells of SZP (SZP NSC) versus healthy subjects (Ctrl NSC), and its impact on angiogenesis. Our results reveal that SZP NSC have an imbalance in the secretion and expression of several angiogenic factors, among them non-canonical neuro-angiogenic guidance factors. SZP NSC migrated less and their CM was less effective in inducing migration and angiogenesis both in vitro and in vivo. Since SZP originates during embryonic brain development, our findings suggest a defective crosstalk between NSC and endothelial cells (EC) during the formation of the neuro-angiogenic niche.

IGF-1 decreases portal vein endotoxin via regulating intestinal tight junctions and plays a role in attenuating portal hypertension of cirrhotic rats.

PubMed

Zhao, Tian-Yu; Su, Li-Ping; Ma, Chun-Ye; Zhai, Xiao-Han; Duan, Zhi-Jun; Zhu, Ying; Zhao, Gang; Li, Chun-Yan; Wang, Li-Xia; Yang, Dong

2015-07-08

Intestinal barrier dysfunction is not only the consequence of liver cirrhosis, but also an active participant in the development of liver cirrhosis. Previous studies showed that external administration of insulin-like growth factor 1 (IGF-1) improved intestinal barrier function in liver cirrhosis. However, the mechanism of IGF-1 on intestinal barrier in liver cirrhosis is not fully elucidated. The present study aims to investigate the mechanisms of IGF-1 improving intestinal barrier function via regulating tight junctions in intestines. We used carbon tetrachloride induced liver cirrhotic rats to investigate the effect of IGF-1 on intestinal claudin-1 and occludin expressions, serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, severity of liver fibrosis, portal pressures, enterocytic apoptosis and lipopolysaccharides (LPS) levels in portal vein. The changes of IGF-1 in serum during the development of rat liver cirrhosis were also evaluated. Additionally, we assessed the effect of IGF-1 on claudin-1 and occludin expressions, changes of transepithelial electrical resistance (TEER) and apoptosis in Caco-2 cells to confirm in vivo findings. Serum IGF-1 levels were decreased in the development of rat liver cirrhosis, and external administration of IGF-1 restored serum IGF-1 levels. External administration of IGF-1 reduced serum ALT and AST levels, severity of liver fibrosis, LPS levels in portal vein, enterocytic apoptosis and portal pressure in cirrhotic rats. External administration of IGF-1 increased the expressions of claudin-1 and occludin in enterocytes, and attenuated tight junction dysfunction in intestines of cirrhotic rats. LPS decreased TEER in Caco-2 cell monolayer. LPS also decreased claudin-1 and occludin expressions and increased apoptosis in Caco-2 cells. Furthermore, IGF-1 attenuated the effect of LPS on TEER, claudin-1 expression, occludin expression and apoptosis in Caco-2 cells. Tight junction dysfunction develops during the development of liver cirrhosis, and endotoxemia will develop subsequently. Correspondingly, increased endotoxin in portal system worsens tight junction dysfunction via decreasing intestinal occludin and claudin-1 expressions and increasing enterocytic apoptosis. Endotoxemia and intestinal barrier dysfunction form a vicious circle. External administration of IGF-1 breaks this vicious circle. Improvement of tight junctions might be one possible mechanism of the restoration of intestinal barrier function mediated by IGF-1.

Imbalance of gut microbiome and intestinal epithelial barrier dysfunction in patients with high blood pressure

PubMed Central

Kim, Seungbum; Goel, Ruby; Kumar, Ashok; Qi, Yanfei; Lobaton, Gil; Hosaka, Koji; Mohammed, Mohammed; Handberg, Eileen M.; Richards, Elaine M.; Pepine, Carl J.; Raizada, Mohan K.

2018-01-01

Recent evidence indicates a link between gut pathology and microbiome with hypertension (HTN) in animal models. However, whether this association exists in humans is unknown. Thus, our objectives in the present study were to test the hypotheses that high blood pressure (BP) patients have distinct gut microbiomes and that gut–epithelial barrier function markers and microbiome composition could predict systolic BP (SBP). Fecal samples, analyzed by shotgun metagenomics, displayed taxonomic and functional changes, including altered butyrate production between patients with high BP and reference subjects. Significant increases in plasma of intestinal fatty acid binding protein (I-FABP), lipopolysaccharide (LPS), and augmented gut-targetting proinflammatory T helper 17 (Th17) cells in high BP patients demonstrated increased intestinal inflammation and permeability. Zonulin, a gut epithelial tight junction protein regulator, was markedly elevated, further supporting gut barrier dysfunction in high BP. Zonulin strongly correlated with SBP (R2 = 0.5301, P<0.0001). Two models predicting SBP were built using stepwise linear regression analysis of microbiome data and circulating markers of gut health, and validated in a separate cohort by prediction of SBP from zonulin in plasma (R2 = 0.4608, P<0.0001). The mouse model of HTN, chronic angiotensin II (Ang II) infusion, was used to confirm the effects of butyrate and gut barrier function on the cardiovascular system and BP. These results support our conclusion that intestinal barrier dysfunction and microbiome function are linked to HTN in humans. They suggest that manipulation of gut microbiome and its barrier functions could be the new therapeutic and diagnostic avenues for HTN. PMID:29507058

Help-seeking behaviour for pelvic floor dysfunction in women over 55: drivers and barriers.

PubMed

Tinetti, Amy; Weir, Nicole; Tangyotkajohn, Usanee; Jacques, Angela; Thompson, Judith; Briffa, Kathy

2018-03-19

Our aim was to identify drivers of and barriers to help-seeking behaviour of older women with pelvic floor dysfunction (PFD) living independently in Australia . Women aged ≥55 years were recruited to this cross-sectional study during July and August 2016. Bladder, bowel, pelvic organ prolapse (POP) and sexual dysfunction were assessed with the Australian Pelvic Floor Questionnaire (APFQ). Drivers and barriers were based on the Barriers to Incontinence Care Seeking Questionnaire. Univariate analyses were used to assess any significant relationships between PFD, age, education level, self-reported PFD, barriers and drivers. Of the 376 study participants [mean, standard deviation (SD) age 68.6 (10.5) years], 67% reported symptoms of PFD and 98.7% scored >0 on the APFQ. Women were more likely to seek help if they scored higher on the APFQ (p < 0.001). The main barrier to seeking help was the perception that PFD was a normal part of ageing (22.4%). Of those who did seek help (50%), the main factor was increased level of symptom bother (51.4%). There was no difference in age or education level between women who did and did not seek help. Women are more likely to seek help for PFD if scoring higher on the APFQ or symptoms are becoming more bothersome. They are less likely to seek help if they view their symptoms as normal. Future direction should be taken to raise awareness of normal pelvic floor function as well as the availability of help for PFD.

Enhanced endothelial cell senescence by lithium-induced matrix metalloproteinase-1 expression.

PubMed

Struewing, Ian T; Durham, Samuel N; Barnett, Corey D; Mao, Catherine D

2009-06-26

Endothelial cell (EC) senescence and dysfunction occurring after chronic injury and inflammation are highly associated with the development and progression of cardiovascular diseases. However, the factors involved in the establishment of EC senescence remain poorly understood. We have previously shown that lithium, an inhibitor of glycogen synthase kinase (GSK)-3beta and activator of the Wnt/beta-catenin signaling pathway, induces an EC senescent-like phenotype. Herein, we show that lithium induces a rapid and pronounced up-regulation of the matrix metalloproteinase (MMP)-1, an inflammation and senescent cell marker, at the mRNA and protein levels, whereas the induction of two other senescent cell markers is either weak (interleukin-8) or delayed (plasminogen activator inhibitor-1). Lithium effect on MMP-1 expression is also specific among other MMPs and not mediated by GSK3beta inhibition. Lithium affects MMP-1 expression mainly at the transcriptional level but neither the AP1/Ets regulatory sites nor the redox sensitive (-1607/2G) site in MMP-1 promoter are involved in lithium-dependent MMP-1 regulation. However, down-regulation of p53, a target of lithium in EC, dampens both basal and lithium-induced MMP-1 expression, which further links MMP-1 up-regulation with the establishment of cell senescence. Although increased MMP-1 levels are usually associated with angiogenesis in enabled proliferative EC, the exogenous addition of activated MMP-1 on lithium- arrested EC increases the number of EC positive for the senescent-associated-beta-galactosidase marker. Conversely, down-regulation of MMP-1 expression by small interfering RNAs blunts the lithium-dependent increase in senescent-associated-beta-galactosidase positive cells. Altogether our data indicate that lithium-induced MMP-1 may participate in the reinforcement of EC senescence and reveal a novel mechanism for lithium-induced tissue remodeling.

Unplanned pregnancy-risks and use of emergency contraception: a survey of two Nigerian Universities.

PubMed

Ajayi, Anthony Idowu; Nwokocha, Ezebunwa Ethelbert; Adeniyi, Oladele Vincent; Ter Goon, Daniel; Akpan, Wilson

2017-06-02

The vulnerabilities of young women of low socio-economic status and those with little or no formal education tend to dominate the discourse on unplanned pregnancy, unsafe abortion and emergency contraception (EC) in sub-Saharan Africa. This article draws on a survey conducted among female undergraduate students to shed light on sexual behaviour and the dynamics of emergency contraceptive use among this cohort. The survey involved 420 female undergraduate students drawn using a multistage sampling technique, while a self-administered questionnaire was used for data collection. Univariate and bivariate analyses were applied to examine the factors associated with the use of emergency contraception. Of the 176 female students who reported being sexually active in the year preceding the survey, only 38.6% reported the use of condom during the entire year. Of those who reported unplanned pregnancy anxiety n = 94, about 30.1% used EC, 20.4% used non-EC pills as EC, while others reported having used no EC. A few respondents (n = 3) had terminated a pregnancy under unsafe conditions. Awareness of EC (p < 0.001), knowledge of timing of EC (p = 0.001), perceived risk of unplanned pregnancy (p < 0.001), and level of study (p = 0.013), were significantly correlated with the use of EC. The study revealed that educated youths engaged in high-risk sexual activities and also, sought recourse to unproven and unsafe contraceptive methods. Poor knowledge of EC methods and timing of use, as well as wrong perception about EC side effects, are barriers to the utilisation of EC for the prevention of unplanned pregnancy among the study participants.

Lychee (Litchi chinensis Sonn.) Pulp Phenolic Extract Provides Protection against Alcoholic Liver Injury in Mice by Alleviating Intestinal Microbiota Dysbiosis, Intestinal Barrier Dysfunction, and Liver Inflammation.

PubMed

Xiao, Juan; Zhang, Ruifen; Zhou, Qiuyun; Liu, Lei; Huang, Fei; Deng, Yuanyuan; Ma, Yongxuan; Wei, Zhencheng; Tang, Xiaojun; Zhang, Mingwei

2017-11-08

Liver injury is the most common consequence of alcohol abuse, which is promoted by the inflammatory response triggered by gut-derived endotoxins produced as a consequence of intestinal microbiota dysbiosis and barrier dysfunction. The aim of this study was to investigate whether modulation of intestinal microbiota and barrier function, and liver inflammation contributes to the hepatoprotective effect of lychee pulp phenolic extract (LPPE) in alcohol-fed mice. Mice were treated with an ethanol-containing liquid diet alone or in combination with LPPE for 8 weeks. LPPE supplementation alleviated ethanol-induced liver injury and downregulated key markers of inflammation. Moreover, LPPE supplementation reversed the ethanol-induced alteration of intestinal microbiota composition and increased the expression of intestinal tight junction proteins, mucus protecting proteins, and antimicrobial proteins. Furthermore, in addition to decreasing serum endotoxin level, LPPE supplementation suppressed CD14 and toll-like receptor 4 expression, and repressed the activation of nuclear factor-κB p65 in the liver. These data suggest that intestinal microbiota dysbiosis, intestinal barrier dysfunction, and liver inflammation are improved by LPPE, and therefore, the intake of LPPE or Litchi pulp may be an effective strategy to alleviate the susceptibility to alcohol-induced hepatic diseases.

Neuropathology of White Matter Lesions, Blood-Brain Barrier Dysfunction, and Dementia.

PubMed

Hainsworth, Atticus H; Minett, Thais; Andoh, Joycelyn; Forster, Gillian; Bhide, Ishaan; Barrick, Thomas R; Elderfield, Kay; Jeevahan, Jamuna; Markus, Hugh S; Bridges, Leslie R

2017-10-01

We tested whether blood-brain barrier dysfunction in subcortical white matter is associated with white matter abnormalities or risk of clinical dementia in older people (n=126; mean age 86.4, SD: 7.7 years) in the MRC CFAS (Medical Research Council Cognitive Function and Ageing Study). Using digital pathology, we quantified blood-brain barrier dysfunction (defined by immunohistochemical labeling for the plasma marker fibrinogen). This was assessed within subcortical white matter tissue samples harvested from postmortem T 2 magnetic resonance imaging (MRI)-detected white matter hyperintensities, from normal-appearing white matter (distant from coexistent MRI-defined hyperintensities), and from equivalent areas in MRI normal brains. Histopathologic lesions were defined using a marker for phagocytic microglia (CD68, clone PGM1). Extent of fibrinogen labeling was not significantly associated with white matter abnormalities defined either by MRI (odds ratio, 0.90; 95% confidence interval, 0.79-1.03; P =0.130) or by histopathology (odds ratio, 0.93; 95% confidence interval, 0.77-1.12; P =0.452). Among participants with normal MRI (no detectable white matter hyperintensities), increased fibrinogen was significantly related to decreased risk of clinical dementia (odds ratio, 0.74; 95% confidence interval, 0.58-0.94; P =0.013). Among participants with histological lesions, increased fibrinogen was related to increased risk of dementia (odds ratio, 2.26; 95% confidence interval, 1.25-4.08; P =0.007). Our data suggest that some degree of blood-brain barrier dysfunction is common in older people and that this may be related to clinical dementia risk, additional to standard MRI biomarkers. © 2017 American Heart Association, Inc.

Beneficial Autoimmunity at Body Surfaces – Immune Surveillance and Rapid Type 2 Immunity Regulate Tissue Homeostasis and Cancer

PubMed Central

Dalessandri, Tim; Strid, Jessica

2014-01-01

Epithelial cells (ECs) line body surface tissues and provide a physicochemical barrier to the external environment. Frequent microbial and non-microbial challenges such as those imposed by mechanical disruption, injury or exposure to noxious environmental substances including chemicals, carcinogens, ultraviolet-irradiation, or toxins cause activation of ECs with release of cytokines and chemokines as well as alterations in the expression of cell-surface ligands. Such display of epithelial stress is rapidly sensed by tissue-resident immunocytes, which can directly interact with self-moieties on ECs and initiate both local and systemic immune responses. ECs are thus key drivers of immune surveillance at body surface tissues. However, ECs have a propensity to drive type 2 immunity (rather than type 1) upon non-invasive challenge or stress – a type of immunity whose regulation and function still remain enigmatic. Here, we review the induction and possible role of type 2 immunity in epithelial tissues and propose that rapid immune surveillance and type 2 immunity are key regulators of tissue homeostasis and carcinogenesis. PMID:25101088

Intact urothelial barrier function in a mouse model of ketamine-induced voiding dysfunction

PubMed Central

Rajandram, Retnagowri; Ong, Teng Aik; Razack, Azad H. A.; MacIver, Bryce; Zeidel, Mark

2016-01-01

Ketamine is a popular choice for young drug abusers. Ketamine abuse causes lower urinary tract symptoms, with the underlying pathophysiology poorly understood. Disruption of urothelial barrier function has been hypothesized to be a major mechanism for ketamine cystitis, yet the direct evidence of impaired urothelial barrier function is still lacking. To address this question, 8-wk-old female C57BL/6J mice were injected intraperitoneally with 30 mg·kg−1·day−1 ketamine for 12 wk to induce ketamine cystitis. A spontaneous voiding spot assay showed that ketamine-treated mice had increased primary voiding spot numbers and smaller primary voiding spot sizes than control mice (P < 0.05), indicating a contracted bladder and bladder overactivity. Consistently, significantly increased voiding frequency was observed in ketamine-treated mice on cystometrograms. These functional experiments indicate that ketamine induces voiding dysfunction in mice. Surprisingly, urothelial permeability in ketamine-treated mice was not changed when measured using an Ussing chamber system with isotopic urea and water. Mouse urothelial structure was also not altered, and intact umbrella cell structure was observed by both transmission and scanning electron microscopy. Furthermore, immunostaining and confocal microscopy confirmed the presence of a well-defined distribution of zonula occuldens-1 in tight junctions and uroplakin in umbrella cells. In conclusion, these data indicate that ketamine injection induces voiding dysfunction in mice but does not necessarily disrupt mouse bladder barrier function. Disruption of urothelial barrier function may not be the major mechanism in ketamine cystitis. PMID:26911853

A Decrease in Glomerular Endothelial Cells and Endothelial-mesenchymal Transition during Glomerulosclerosis in the Tensin2-deficient Mice (ICGN strain).

PubMed

Kato, Takashi; Mizuno, Shinya; Ito, Akihiko

2014-01-01

The ICR-derived glomerulonephritis (ICGN) mouse is a unique model of nephrotic syndrome, and albuminuria becomes evident in a neonatal stage, due to a genetic mutation of tensin2. We previously provided evidence that an apparent decrease in nephrin, caused by tensin2-deficiencient states, leads to podocytopathy, albuminuria and eventually, chronic renal failure. In general, glomerular endothelial cells (ECs) function as a barrier through tight attachment of glomerular basement membrane to podocytes, while decreased ECs can worsen renal failure. Nevertheless, it is still unknown whether glomerular ECs are altered under the tensin-2-deficient states during the manifestation of chronic renal failure. Herein, we examined the changes of glomerular ECs, with focus on the expression of PECAM-1 and VE-cadherin (EC-specific markers), or of α-SMA (myofibroblast marker) in this mouse model by histological methods. Compared with the non-nephrotic (+/nep) mice, the nephrotic (nep/nep) mice exhibited the reduced expression of PECAM-1, or of VE-cadherin, in glomerular area. Notably, some glomerular ECs showed the positive stainings for both PECAM-1 and α-SMA, suggesting endothelial-to-mesenchymal transition (EndoMT) during progression of glomerular sclerosis. This is the first report showing that a decrease in glomerular ECs, at least in part, via EndoMT is involved in tensin2-deficient pathological conditions.

Efficient gene disruption in cultured primary human endothelial cells by CRISPR/Cas9.

PubMed

Abrahimi, Parwiz; Chang, William G; Kluger, Martin S; Qyang, Yibing; Tellides, George; Saltzman, W Mark; Pober, Jordan S

2015-07-03

The participation of endothelial cells (EC) in many physiological and pathological processes is widely modeled using human EC cultures, but genetic manipulation of these untransformed cells has been technically challenging. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 nuclease (Cas9) technology offers a promising new approach. However, mutagenized cultured cells require cloning to yield homogeneous populations, and the limited replicative lifespan of well-differentiated human EC presents a barrier for doing so. To create a simple but highly efficient method using CRISPR/Cas9 to generate biallelic gene disruption in untransformed human EC. To demonstrate proof-of-principle, we used CRISPR/Cas9 to disrupt the gene for the class II transactivator. We used endothelial colony forming cell-derived EC and lentiviral vectors to deliver CRISPR/Cas9 elements to ablate EC expression of class II major histocompatibility complex molecules and with it, the capacity to activate allogeneic CD4(+) T cells. We show the observed loss-of-function arises from biallelic gene disruption in class II transactivator that leaves other essential properties of the cells intact, including self-assembly into blood vessels in vivo, and that the altered phenotype can be rescued by reintroduction of class II transactivator expression. CRISPR/Cas9-modified human EC provides a powerful platform for vascular research and for regenerative medicine/tissue engineering. © 2015 American Heart Association, Inc.

Deep level defects in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Farzana, Esmat; Ahmadi, Elaheh; Speck, James S.; Arehart, Aaron R.; Ringel, Steven A.

2018-04-01

Deep level defects were characterized in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy (PAMBE) using deep level optical spectroscopy (DLOS) and deep level transient (thermal) spectroscopy (DLTS) applied to Ni/β-Ga2O3:Ge (010) Schottky diodes that displayed Schottky barrier heights of 1.50 eV. DLOS revealed states at EC - 2.00 eV, EC - 3.25 eV, and EC - 4.37 eV with concentrations on the order of 1016 cm-3, and a lower concentration level at EC - 1.27 eV. In contrast to these states within the middle and lower parts of the bandgap probed by DLOS, DLTS measurements revealed much lower concentrations of states within the upper bandgap region at EC - 0.1 - 0.2 eV and EC - 0.98 eV. There was no evidence of the commonly observed trap state at ˜EC - 0.82 eV that has been reported to dominate the DLTS spectrum in substrate materials synthesized by melt-based growth methods such as edge defined film fed growth (EFG) and Czochralski methods [Zhang et al., Appl. Phys. Lett. 108, 052105 (2016) and Irmscher et al., J. Appl. Phys. 110, 063720 (2011)]. This strong sensitivity of defect incorporation on crystal growth method and conditions is unsurprising, which for PAMBE-grown β-Ga2O3:Ge manifests as a relatively "clean" upper part of the bandgap. However, the states at ˜EC - 0.98 eV, EC - 2.00 eV, and EC - 4.37 eV are reminiscent of similar findings from these earlier results on EFG-grown materials, suggesting that possible common sources might also be present irrespective of growth method.

Investigation of low leakage current radiation detectors on n-type 4H-SiC epitaxial layers

NASA Astrophysics Data System (ADS)

Nguyen, Khai V.; Chaudhuri, Sandeep K.; Mandal, Krishna C.

2014-09-01

The surface leakage current of high-resolution 4H-SiC epitaxial layer Schottky barrier detectors has been improved significantly after surface passivations of 4H-SiC epitaxial layers. Thin (nanometer range) layers of silicon dioxide (SiO2) and silicon nitride (Si3N4) were deposited on 4H-SiC epitaxial layers using plasma enhanced chemical vapor deposition (PECVD) on 20 μm thick n-type 4H-SiC epitaxial layers followed by the fabrication of large area (~12 mm2) Schottky barrier radiation detectors. The fabricated detectors have been characterized through current-voltage (I-V), capacitance-voltage (C-V), and alpha pulse height spectroscopy measurements; the results were compared with that of detectors fabricated without surface passivations. Improved energy resolution of ~ 0.4% for 5486 keV alpha particles was observed after passivation, and it was found that the performance of these detectors were limited by the presence of macroscopic and microscopic crystal defects affecting the charge transport properties adversely. Capacitance mode deep level transient studies (DLTS) revealed the presence of a titanium impurity related shallow level defects (Ec-0.19 eV), and two deep level defects identified as Z1/2 and Ci1 located at Ec-0.62 and ~ Ec-1.40 eV respectively.

Reck and Gpr124 Are Essential Receptor Cofactors for Wnt7a/Wnt7b-Specific Signaling in Mammalian CNS Angiogenesis and Blood-Brain Barrier Regulation.

PubMed

Cho, Chris; Smallwood, Philip M; Nathans, Jeremy

2017-08-30

Reck, a GPI-anchored membrane protein, and Gpr124, an orphan GPCR, have been implicated in Wnt7a/Wnt7b signaling in the CNS vasculature. We show here that vascular endothelial cell (EC)-specific reduction in Reck impairs CNS angiogenesis and that EC-specific postnatal loss of Reck, combined with loss of Norrin, impairs blood-brain barrier (BBB) maintenance. The most N-terminal domain of Reck binds to the leucine-rich repeat (LRR) and immunoglobulin (Ig) domains of Gpr124, and weakening this interaction by targeted mutagenesis reduces Reck/Gpr124 stimulation of Wnt7a signaling in cell culture and impairs CNS angiogenesis. Finally, a soluble Gpr124(LRR-Ig) probe binds to cells expressing Frizzled, Wnt7a or Wnt7b, and Reck, and a soluble Reck(CC1-5) probe binds to cells expressing Frizzled, Wnt7a or Wnt7b, and Gpr124. These experiments indicate that Reck and Gpr124 are part of the cell surface protein complex that transduces Wnt7a- and Wnt7b-specific signals in mammalian CNS ECs to promote angiogenesis and regulate the BBB. Copyright © 2017 Elsevier Inc. All rights reserved.

Recapitulating physiological and pathological shear stress and oxygen to model vasculature in health and disease

NASA Astrophysics Data System (ADS)

Abaci, Hasan Erbil; Shen, Yu-I.; Tan, Scott; Gerecht, Sharon

2014-05-01

Studying human vascular disease in conventional cell cultures and in animal models does not effectively mimic the complex vascular microenvironment and may not accurately predict vascular responses in humans. We utilized a microfluidic device to recapitulate both shear stress and O2 levels in health and disease, establishing a microfluidic vascular model (μVM). Maintaining human endothelial cells (ECs) in healthy-mimicking conditions resulted in conversion to a physiological phenotype namely cell elongation, reduced proliferation, lowered angiogenic gene expression and formation of actin cortical rim and continuous barrier. We next examined the responses of the healthy μVM to a vasotoxic cancer drug, 5-Fluorouracil (5-FU), in comparison with an in vivo mouse model. We found that 5-FU does not induce apoptosis rather vascular hyperpermeability, which can be alleviated by Resveratrol treatment. This effect was confirmed by in vivo findings identifying a vasoprotecting strategy by the adjunct therapy of 5-FU with Resveratrol. The μVM of ischemic disease demonstrated the transition of ECs from a quiescent to an activated state, with higher proliferation rate, upregulation of angiogenic genes, and impaired barrier integrity. The μVM offers opportunities to study and predict human ECs with physiologically relevant phenotypes in healthy, pathological and drug-treated environments.

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.

Vascular Repair by Circumferential Cell Therapy Using Magnetic Nanoparticles and Tailored Magnets.

PubMed

Vosen, Sarah; Rieck, Sarah; Heidsieck, Alexandra; Mykhaylyk, Olga; Zimmermann, Katrin; Bloch, Wilhelm; Eberbeck, Dietmar; Plank, Christian; Gleich, Bernhard; Pfeifer, Alexander; Fleischmann, Bernd K; Wenzel, Daniela

2016-01-26

Cardiovascular disease is often caused by endothelial cell (EC) dysfunction and atherosclerotic plaque formation at predilection sites. Also surgical procedures of plaque removal cause irreversible damage to the EC layer, inducing impairment of vascular function and restenosis. In the current study we have examined a potentially curative approach by radially symmetric re-endothelialization of vessels after their mechanical denudation. For this purpose a combination of nanotechnology with gene and cell therapy was applied to site-specifically re-endothelialize and restore vascular function. We have used complexes of lentiviral vectors and magnetic nanoparticles (MNPs) to overexpress the vasoprotective gene endothelial nitric oxide synthase (eNOS) in ECs. The MNP-loaded and eNOS-overexpressing cells were magnetic, and by magnetic fields they could be positioned at the vascular wall in a radially symmetric fashion even under flow conditions. We demonstrate that the treated vessels displayed enhanced eNOS expression and activity. Moreover, isometric force measurements revealed that EC replacement with eNOS-overexpressing cells restored endothelial function after vascular injury in eNOS(-/-) mice ex and in vivo. Thus, the combination of MNP-based gene and cell therapy with custom-made magnetic fields enables circumferential re-endothelialization of vessels and improvement of vascular function.

Cerebroprotection of Flavanol (−)-Epicatechin after Traumatic Brain Injury via Nrf2-dependent and –independent Pathways

PubMed Central

Cheng, Tian; Wang, Wenzhu; Li, Qian; Han, Xiaoning; Xing, Jing; Qi, Cunfang; Lan, Xi; Wan, Jieru; Potts, Alexa; Guan, Fangxia; Wang, Jian

2016-01-01

Traumatic brain injury (TBI), which leads to disability, dysfunction, and even death, is a prominent health problem worldwide with no effective treatment. A brain-permeable flavonoid named (−)-epicatechin (EC) modulates redox/oxidative stress and has been shown to be beneficial for vascular and cognitive function in humans and for ischemic and hemorrhagic stroke in rodents. Here we examined whether EC is able to protect the brain against TBI-induced brain injury in mice and if so, whether it exerts neuroprotection by modulating the NF-E2-related factor (Nrf2) pathway. We used the controlled cortical impact model to mimic TBI. EC was administered orally at 3 h after TBI and then every 24 h for either 3 or 7 days. We evaluated lesion volume, brain edema, white matter injury, neurologic deficits, cognitive performance and emotion-like behaviors, neutrophil infiltration, reactive oxygen species (ROS), and a variety of injury-related protein markers. Nrf2 knockout mice were used to determine the role of the Nrf2 signaling pathway after EC treatment. In wild-type mice, EC significantly reduced lesion volume, edema, and cell death and improved neurologic function on days 3 and 28; cognitive performance and depression-like behaviors were also improved with EC administration. In addition, EC reduced white matter injury, heme oxygenase-1 expression, and ferric iron deposition after TBI. These changes were accompanied by attenuation of neutrophil infiltration and oxidative insults, reduced activity of matrix metalloproteinase 9, decreased Keap 1 expression, increased Nrf2 nuclear accumulation, and increased expression of superoxide dismutase 1 and quinone 1. However, EC did not significantly reduce lesion volume or improve neurologic deficits in Nrf2 knockout mice after TBI. Our results show that EC protects the TBI brain by activating the Nrf2 pathway, inhibiting heme oxygenase-1 protein expression, and reducing iron deposition. The latter two effects could represent an Nrf2-independent mechanism in this model of TBI. PMID:26724590

Endothelial Hypoxia-Inducible Factor-1α Promotes Atherosclerosis and Monocyte Recruitment by Upregulating MicroRNA-19a.

PubMed

Akhtar, Shamima; Hartmann, Petra; Karshovska, Ela; Rinderknecht, Fatuma-Ayaan; Subramanian, Pallavi; Gremse, Felix; Grommes, Jochen; Jacobs, Michael; Kiessling, Fabian; Weber, Christian; Steffens, Sabine; Schober, Andreas

2015-12-01

Chemokines mediate monocyte adhesion to dysfunctional endothelial cells (ECs) and promote arterial inflammation during atherosclerosis. Hypoxia-inducible factor (HIF)-1α is expressed in various cell types of atherosclerotic lesions and is associated with lesional inflammation. However, the impact of endothelial HIF-1α in atherosclerosis is unclear. HIF-1α was detectable in the nucleus of ECs covering murine and human atherosclerotic lesions. To study the role of endothelial HIF-1α in atherosclerosis, deletion of the Hif1a gene was induced in ECs from apolipoprotein E knockout mice (EC-Hif1a(-/-)) by Tamoxifen injection. The formation of atherosclerotic lesions, the lesional macrophage accumulation, and the expression of CXCL1 in ECs were reduced after partial carotid ligation in EC-Hif1a(-/-) compared with control mice. Moreover, the lesion area and the lesional macrophage accumulation were decreased in the aortas of EC-Hif1a(-/-) mice compared with control mice during diet-induced atherosclerosis. In vitro, mildly oxidized low-density lipoprotein or lysophosphatidic acid 20:4 increased endothelial CXCL1 expression and monocyte adhesion by inducing HIF-1α expression. Moreover, endothelial Hif1a deficiency resulted in downregulation of miR-19a in atherosclerotic arteries determined by microRNA profiling. In vitro, HIF-1α-induced miR-19a expression mediated the upregulation of CXCL1 in mildly oxidized low-density lipoprotein-stimulated ECs. These results indicate that hyperlipidemia upregulates HIF-1α expression in ECs by mildly oxidized low-density lipoprotein-derived unsaturated lysophosphatidic acid. Endothelial HIF-1α promoted atherosclerosis by triggering miR-19a-mediated CXCL1 expression and monocyte adhesion, indicating that inhibition of the endothelial HIF-1α/miR-19a pathway may be a therapeutic option against atherosclerosis. © 2015 American Heart Association, Inc.

[Research progress of relationship between diabetes and intestinal epithelial tight junction barrier and intervetion of berberine].

PubMed

Qin, Xin; Dong, Hui; Lu, Fu-Er

2016-06-01

Intestinal tight junction is an important part of the small intestinal mucosa barrier. It plays a very significant role in maintaining the intestinal mucosal permeability and integrity, preventing the bacterial endotoxin and toxic macromolecular substances into the body so as to keep a stable internal environment. Numerous studies have shown that intestinal mucosal barrier dysfunction is closely related to the development of diabetes. Therefore, protecting intestinal tight junction and maintaining the mucosal barrier have great significance in the prevention and treatment of diabetes. The effect of berberine in diabetes treatment is obvious. However, the pharmacological study found that the bioavailability of berberine is extremely low. Some scholars put forward that the major site of pharmaceutical action of berberine might be in the gut. Studies have shown that berberine could regulate the intestinal flora and intestinal hormone secretion, protect the intestinal barrier, inhibit the absorption of glucose, eliminate the intestinal inflammation and so on. Recently studies have found that the hypoglycemic effect of berberine is likely to relate with the influence on intestinal tight junction and the protection of mucosal barrier. Here is the review about the association between intestinal tight junction barrier dysfunction and diabetes, and the related hypoglycemic mechanism of berberine. Copyright© by the Chinese Pharmaceutical Association.

Astrocytic modulation of blood brain barrier: perspectives on Parkinson’s disease

PubMed Central

Cabezas, Ricardo; Ávila, Marcos; Gonzalez, Janneth; El-Bachá, Ramon Santos; Báez, Eliana; García-Segura, Luis Miguel; Jurado Coronel, Juan Camilo; Capani, Francisco; Cardona-Gomez, Gloria Patricia; Barreto, George E.

2014-01-01

The blood–brain barrier (BBB) is a tightly regulated interface in the Central Nervous System (CNS) that regulates the exchange of molecules in and out from the brain thus maintaining the CNS homeostasis. It is mainly composed of endothelial cells (ECs), pericytes and astrocytes that create a neurovascular unit (NVU) with the adjacent neurons. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted factors that lead to the adequate association between the cells of the BBB and the formation of strong tight junctions. Under neurological disorders, such as chronic cerebral ischemia, brain trauma, Epilepsy, Alzheimer and Parkinson’s Diseases, a disruption of the BBB takes place, involving a lost in the permeability of the barrier and phenotypical changes in both the ECs and astrocytes. In this aspect, it has been established that the process of reactive gliosis is a common feature of astrocytes during BBB disruption, which has a detrimental effect on the barrier function and a subsequent damage in neuronal survival. In this review we discuss the implications of astrocyte functions in the protection of the BBB, and in the development of Parkinson’s disease (PD) and related disorders. Additionally, we highlight the current and future strategies in astrocyte protection aimed at the development of restorative therapies for the BBB in pathological conditions. PMID:25136294

Severe Burn-Induced Intestinal Epithelial Barrier Dysfunction Is Associated With Endoplasmic Reticulum Stress and Autophagy in Mice

PubMed Central

Huang, Yalan; Feng, Yanhai; Wang, Yu; Wang, Pei; Wang, Fengjun; Ren, Hui

2018-01-01

The disruption of intestinal barrier plays a vital role in the pathophysiological changes after severe burn injury, however, the underlying mechanisms are poorly understood. Severe burn causes the disruption of intestinal tight junction (TJ) barrier. Previous studies have shown that endoplasmic reticulum (ER) stress and autophagy are closely associated with the impairment of intestinal mucosa. Thus, we hypothesize that ER stress and autophagy are likely involved in burn injury-induced intestinal epithelial barrier dysfunction. Mice received a 30% total body surface area (TBSA) full-thickness burn, and were sacrificed at 0, 1, 2, 6, 12 and 24 h postburn. The results showed that intestinal permeability was increased significantly after burn injury, accompanied by the damage of mucosa and the alteration of TJ proteins. Severe burn induced ER stress, as indicated by increased intraluminal chaperone binding protein (BIP), CCAAT/enhancer-binding protein homologous protein (CHOP) and inositol-requiring enzyme 1(IRE1)/X-box binding protein 1 splicing (XBP1). Autophagy was activated after burn injury, as evidenced by the increase of autophagy related protein 5 (ATG5), Beclin 1 and LC3II/LC3I ratio and the decrease of p62. Besides, the number of autophagosomes was also increased after burn injury. The levels of p-PI3K(Ser191), p-PI3K(Ser262), p-AKT(Ser473), and p-mTOR were decreased postburn, suggesting that autophagy-related PI3K/AKT/mTOR pathway is involved in the intestinal epithelial barrier dysfunction following severe burn. In summary, severe burn injury induces the ER stress and autophagy in intestinal epithelia, leading to the disruption of intestinal barrier. PMID:29740349

Endothelial FoxM1 Mediates Bone Marrow Progenitor Cell-Induced Vascular Repair and Resolution of Inflammation following Inflammatory Lung Injury

PubMed Central

Zhao, Yidan D.; Huang, Xiaojia; Yi, Fan; Dai, Zhiyu; Qian, Zhijian; Tiruppathi, Chinnaswamy; Tran, Khiem; Zhao, You-Yang

2015-01-01

Adult stem cell treatment is a potential novel therapeutic approach for acute respiratory distress syndrome. Given the extremely low rate of cell engraftment, it is believed that these cells exert their beneficial effects via paracrine mechanisms. However, the endogenous mediator(s) in the pulmonary vasculature remains unclear. Employing the mouse model with endothelial cell (EC)-restricted disruption of FoxM1 (FoxM1 CKO), here we show that endothelial expression of the reparative transcriptional factor FoxM1 is required for the protective effects of bone marrow progenitor cells (BMPC) against LPS-induced inflammatory lung injury and mortality. BMPC treatment resulted in rapid induction of FoxM1 expression in WT but not FoxM1 CKO lungs. BMPC-induced inhibition of lung vascular injury, resolution of lung inflammation, and survival, as seen in WT mice, were abrogated in FoxM1 CKO mice following LPS challenge. Mechanistically, BMPC treatment failed to induce lung EC proliferation in FoxM1 CKO mice, which was associated with impaired expression of FoxM1 target genes essential for cell cycle progression. We also observed that BMPC treatment enhanced endothelial barrier function in WT, but not in FoxM1-deficient EC monolayers. Restoration of β-catenin expression in FoxM1-deficient ECs normalized endothelial barrier enhancement in response to BMPC treatment. These data demonstrate the requisite role of endothelial FoxM1 in the mechanism of BMPC-induced vascular repair to restore vascular integrity and accelerate resolution of inflammation, thereby promoting survival following inflammatory lung injury. PMID:24578354

Substrate stiffness-dependent exacerbation of endothelial permeability and inflammation: mechanisms and potential implications in ALI and PH (2017 Grover Conference Series)

PubMed Central

Karki, Pratap; Birukova, Anna A.

2018-01-01

The maintenance of endothelial barrier integrity is absolutely essential to prevent the vascular leak associated with pneumonia, pulmonary edema resulting from inhalation of toxins, acute elevation to high altitude, traumatic and septic lung injury, acute lung injury (ALI), and its life-threatening complication, acute respiratory distress syndrome (ARDS). In addition to the long-known edemagenic and inflammatory agonists, emerging evidences suggest that factors of endothelial cell (EC) mechanical microenvironment such as blood flow, mechanical strain of the vessel, or extracellular matrix stiffness also play an essential role in the control of endothelial permeability and inflammation. Recent studies from our group and others have demonstrated that substrate stiffening causes endothelial barrier disruption and renders EC more susceptible to agonist-induced cytoskeletal rearrangement and inflammation. Further in vivo studies have provided direct evidence that proinflammatory stimuli increase lung microvascular stiffness which in turn exacerbates endothelial permeability and inflammation and perpetuates a vicious circle of lung inflammation. Accumulating evidence suggests a key role for RhoA GTPases signaling in stiffness-dependent mechanotransduction mechanisms defining EC permeability and inflammatory responses. Vascular stiffening is also known to be a key contributor to other cardiovascular diseases such as arterial pulmonary hypertension (PH), although the precise role of stiffness in the development and progression of PH remains to be elucidated. This review summarizes the current understanding of stiffness-dependent regulation of pulmonary EC permeability and inflammation, and discusses potential implication of pulmonary vascular stiffness alterations at macro- and microscale in development and modulation of ALI and PH. PMID:29714090

Antiviral Nucleotide Incorporation by Recombinant Human Mitochondrial RNA Polymerase Is Predictive of Increased In Vivo Mitochondrial Toxicity Risk

PubMed Central

Lin, Xiaodong; Yokokawa, Fumiaki; Sweeney, Zachary; Saunders, Oliver; Xie, Lili; Lim, Siew Pheng; Uteng, Marianne; Uehara, Kyoko; Warne, Robert; Gang, Wang; Jones, Christopher; Yendluri, Satya; Gu, Helen; Mansfield, Keith; Boisclair, Julie; Heimbach, Tycho; Catoire, Alexandre; Bracken, Kathryn; Weaver, Margaret; Moser, Heinz; Zhong, Weidong

2016-01-01

Nucleoside or nucleotide inhibitors are a highly successful class of antivirals due to selectivity, potency, broad coverage, and high barrier to resistance. Nucleosides are the backbone of combination treatments for HIV, hepatitis B virus, and, since the FDA approval of sofosbuvir in 2013, also for hepatitis C virus (HCV). However, many promising nucleotide inhibitors have advanced to clinical trials only to be terminated due to unexpected toxicity. Here we describe the in vitro pharmacology of compound 1, a monophosphate prodrug of a 2′-ethynyluridine developed for the treatment of HCV. Compound 1 inhibits multiple HCV genotypes in vitro (50% effective concentration [EC50], 0.05 to 0.1 μM) with a selectivity index of >300 (50% cytotoxic concentration [CC50], 30 μM in MT-4 cells). The active triphosphate metabolite of compound 1, compound 2, does not inhibit human α, β, or γ DNA polymerases but was a substrate for incorporation by the human mitochondrial RNA polymerase (POLRMT). In dog, the oral administration of compound 1 resulted in elevated serum liver enzymes and microscopic changes in the liver. Transmission electron microscopy showed significant mitochondrial swelling and lipid accumulation in hepatocytes. Gene expression analysis revealed dose-proportional gene signature changes linked to loss of hepatic function and increased mitochondrial dysfunction. The potential of in vivo toxicity through mitochondrial polymerase incorporation by nucleoside analogs has been previously shown. This study shows that even moderate levels of nucleotide analog incorporation by POLRMT increase the risk of in vivo mitochondrial dysfunction. Based on these results, further development of compound 1 as an anti-HCV compound was terminated. PMID:27645237

Barrier dysfunction and bacterial uptake in the follicle-associated epithelium of ileal Crohn's disease.

PubMed

Keita, Asa V; Söderholm, Johan D

2012-07-01

The ability to control uptake across the mucosa and protect from harmful substances in the gut lumen is defined as intestinal barrier function. The etiology of Crohn's disease is unknown, but genetic, environmental, and immunological factors all contribute. The frontline between these factors lies in the intestinal barrier. The most important inflammation-driving environmental factor in Crohn's disease is the microbiota, where Esherichia coli strains have been assigned a key role. The first observable signs of Crohn's disease are small aphtoid ulcers over Peyer's patches and lymphoid follicles. The overlaying follicle-associated epithelium (FAE) is specialized for luminal sampling and is an entry site for antigens and bacteria. We have demonstrated increased E. coli uptake across the FAE in Crohn's disease, which may initiate inflammation. This short review will discuss barrier dysfunction and bacteria in the context of ileal Crohn's disease, and how the FAE might be the site of initial inflammation. © 2012 New York Academy of Sciences.

NADPH Oxidase-Dependent Signaling in Endothelial Cells: Role in Physiology and Pathophysiology

PubMed Central

Ushio-Fukai, Masuko; Malik, Asrar B.

2009-01-01

Abstract Reactive oxygen species (ROS) including superoxide (O2·−) and hydrogen peroxide (H2O2) are produced endogenously in response to cytokines, growth factors; G-protein coupled receptors, and shear stress in endothelial cells (ECs). ROS function as signaling molecules to mediate various biological responses such as gene expression, cell proliferation, migration, angiogenesis, apoptosis, and senescence in ECs. Signal transduction activated by ROS, “oxidant signaling,” has received intense investigation. Excess amount of ROS contribute to various pathophysiologies, including endothelial dysfunction, atherosclerosis, hypertension, diabetes, and acute respiratory distress syndrome (ARDS). The major source of ROS in EC is a NADPH oxidase. The prototype phagaocytic NADPH oxidase is composed of membrane-bound gp91phox and p22hox, as well as cytosolic subunits such as p47phox, p67phox and small GTPase Rac. In ECs, in addition to all the components of phagocytic NADPH oxidases, homologues of gp91phox (Nox2) including Nox1, Nox4, and Nox5 are expressed. The aim of this review is to provide an overview of the emerging area of ROS derived from NADPH oxidase and oxidant signaling in ECs linked to physiological and pathophysiological functions. Understanding these mechanisms may provide insight into the NADPH oxidase and oxidant signaling components as potential therapeutic targets. Antioxid. Redox Signal. 11, 791–810. PMID:18783313

Ultrasonically targeted delivery into endothelial and smooth muscle cells in ex vivo arteries

PubMed Central

Hallow, Daniel M.; Mahajan, Anuj D.; Prausnitz, Mark R.

2007-01-01

This study tested the hypothesis that ultrasound can target intracellular uptake of drugs into vascular endothelial cells (ECs) at low to intermediate energy and into smooth muscle cells (SMCs) at high energy. Ultrasound-enhanced delivery has been shown to enhance and target intracellular drug and gene delivery in the vasculature to treat cardiovascular disease, but quantitative studies of the delivery process are lacking. Viable ex vivo porcine carotid arteries were placed in a solution containing a model drug, TO-PRO®-1, and Optison® microbubbles. Arteries were exposed to ultrasound at 1.1 MHz and acoustic energies of 5.0, 66, or 630 J/cm2. Using confocal microscopy and fluorescent labeling of cells, the artery endothelium and media were imaged to determine the localization and to quantify intracellular uptake and cell death. At low to intermediate ultrasound energy, ultrasound was shown to target intracellular delivery into viable cells that represented 9 – 24% of exposed ECs. These conditions also typically caused 7 – 25% EC death. At high energy, intracellular delivery was targeted to SMCs, which was associated with denuding or death of proximal ECs. This work represents the first known in-depth study to evaluate intracellular uptake into cells in tissue. We conclude that significant intracellular uptake of molecules can be targeted into ECs and SMCs by ultrasound-enhanced delivery suggesting possible applications for treatment of cardivascular diseases and dysfunctions. PMID:17291619

Ursodeoxycholic Acid (UDCA) Exerts Anti-Atherogenic Effects by Inhibiting Endoplasmic Reticulum (ER) Stress Induced by Disturbed Flow.

PubMed

Chung, Jihwa; Kim, Kyoung Hwa; Lee, Seok Cheol; An, Shung Hyun; Kwon, Kihwan

2015-10-01

Disturbed blood flow with low-oscillatory shear stress (OSS) is a predominant atherogenic factor leading to dysfunctional endothelial cells (ECs). Recently, it was found that disturbed flow can directly induce endoplasmic reticulum (ER) stress in ECs, thereby playing a critical role in the development and progression of atherosclerosis. Ursodeoxycholic acid (UDCA), a naturally occurring bile acid, has long been used to treat chronic cholestatic liver disease and is known to alleviate endoplasmic reticulum (ER) stress at the cellular level. However, its role in atherosclerosis remains unexplored. In this study, we demonstrated the anti-atherogenic activity of UDCA via inhibition of disturbed flow-induced ER stress in atherosclerosis. UDCA effectively reduced ER stress, resulting in a reduction in expression of X-box binding protein-1 (XBP-1) and CEBP-homologous protein (CHOP) in ECs. UDCA also inhibits the disturbed flow-induced inflammatory responses such as increases in adhesion molecules, monocyte adhesion to ECs, and apoptosis of ECs. In a mouse model of disturbed flow-induced atherosclerosis, UDCA inhibits atheromatous plaque formation through the alleviation of ER stress and a decrease in adhesion molecules. Taken together, our results revealed that UDCA exerts anti-atherogenic activity in disturbed flow-induced atherosclerosis by inhibiting ER stress and the inflammatory response. This study suggests that UDCA may be a therapeutic agent for prevention or treatment of atherosclerosis.

Impact of Cyanidin-3-Glucoside on Glycated LDL-Induced NADPH Oxidase Activation, Mitochondrial Dysfunction and Cell Viability in Cultured Vascular Endothelial Cells

PubMed Central

Xie, Xueping; Zhao, Ruozhi; Shen, Garry X.

2012-01-01

Elevated levels of glycated low density lipoprotein (glyLDL) are frequently detected in diabetic patients. Previous studies demonstrated that glyLDL increased the production of reactive oxygen species (ROS), activated NADPH oxidase (NOX) and suppressed mitochondrial electron transport chain (mETC) enzyme activities in vascular endothelial cells (EC). The present study examined the effects of cyanidin-3-glucoside (C3G), a type of anthocyanin abundant in dark-skinned berries, on glyLDL-induced ROS production, NOX activation and mETC enzyme activity in porcine aortic EC (PAEC). Co-treatment of C3G prevented glyLDL-induced upregulation of NOX4 and intracellular superoxide production in EC. C3G normalized glyLDL-induced inhibition on the enzyme activities of mETC Complex I and III, as well as the abundances of NADH dehydrogenase 1 in Complex I and cytochrome b in Complex III in EC. Blocking antibody for the receptor of advanced glycation end products (RAGE) prevented glyLDL-induced changes in NOX and mETC enzymes. Combination of C3G and RAGE antibody did not significantly enhance glyLDL-induced inhibition of NOX or mETC enzymes. C3G reduced glyLDL-induced RAGE expression with the presence of RAGE antibody. C3G prevented prolonged incubation with the glyLDL-induced decrease in cell viability and the imbalance between key regulators for cell viability (cleaved caspase 3 and B cell Lyphoma-2) in EC. The findings suggest that RAGE plays an important role in glyLDL-induced oxidative stress in vascular EC. C3G may prevent glyLDL-induced NOX activation, the impairment of mETC enzymes and cell viability in cultured vascular EC. PMID:23443099

Targeting the vascular and perivascular niches as a regenerative therapy for lung and liver fibrosis.

PubMed

Cao, Zhongwei; Ye, Tinghong; Sun, Yue; Ji, Gaili; Shido, Koji; Chen, Yutian; Luo, Lin; Na, Feifei; Li, Xiaoyan; Huang, Zhen; Ko, Jane L; Mittal, Vivek; Qiao, Lina; Chen, Chong; Martinez, Fernando J; Rafii, Shahin; Ding, Bi-Sen

2017-08-30

The regenerative capacity of lung and liver is sometimes impaired by chronic or overwhelming injury. Orthotopic transplantation of parenchymal stem cells to damaged organs might reinstate their self-repair ability. However, parenchymal cell engraftment is frequently hampered by the microenvironment in diseased recipient organs. We show that targeting both the vascular niche and perivascular fibroblasts establishes "hospitable soil" to foster the incorporation of "seed," in this case, the engraftment of parenchymal cells in injured organs. Specifically, ectopic induction of endothelial cell (EC)-expressed paracrine/angiocrine hepatocyte growth factor (HGF) and inhibition of perivascular NOX4 [NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidase 4] synergistically enabled reconstitution of mouse and human parenchymal cells in damaged organs. Reciprocally, genetic knockout of Hgf in mouse ECs ( Hgf iΔEC/iΔEC ) aberrantly up-regulated perivascular NOX4 during liver and lung regeneration. Dysregulated HGF and NOX4 pathways subverted the function of vascular and perivascular cells from an epithelially inductive niche to a microenvironment that inhibited parenchymal reconstitution. Perivascular NOX4 induction in Hgf iΔEC/iΔEC mice recapitulated the phenotype of human and mouse liver and lung fibrosis. Consequently, EC-directed HGF and NOX4 inhibitor GKT137831 stimulated regenerative integration of mouse and human parenchymal cells in chronically injured lung and liver. Our data suggest that targeting dysfunctional perivascular and vascular cells in diseased organs can bypass fibrosis and enable reparative cell engraftment to reinstate lung and liver regeneration. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Impact of cyanidin-3-glucoside on glycated LDL-induced NADPH oxidase activation, mitochondrial dysfunction and cell viability in cultured vascular endothelial cells.

PubMed

Xie, Xueping; Zhao, Ruozhi; Shen, Garry X

2012-11-27

Elevated levels of glycated low density lipoprotein (glyLDL) are frequently detected in diabetic patients. Previous studies demonstrated that glyLDL increased the production of reactive oxygen species (ROS), activated NADPH oxidase (NOX) and suppressed mitochondrial electron transport chain (mETC) enzyme activities in vascular endothelial cells (EC). The present study examined the effects of cyanidin-3-glucoside (C3G), a type of anthocyanin abundant in dark-skinned berries, on glyLDL-induced ROS production, NOX activation and mETC enzyme activity in porcine aortic EC (PAEC). Co-treatment of C3G prevented glyLDL-induced upregulation of NOX4 and intracellular superoxide production in EC. C3G normalized glyLDL-induced inhibition on the enzyme activities of mETC Complex I and III, as well as the abundances of NADH dehydrogenase 1 in Complex I and cytochrome b in Complex III in EC. Blocking antibody for the receptor of advanced glycation end products (RAGE) prevented glyLDL-induced changes in NOX and mETC enzymes. Combination of C3G and RAGE antibody did not significantly enhance glyLDL-induced inhibition of NOX or mETC enzymes. C3G reduced glyLDL-induced RAGE expression with the presence of RAGE antibody. C3G prevented prolonged incubation with the glyLDL-induced decrease in cell viability and the imbalance between key regulators for cell viability (cleaved caspase 3 and B cell Lyphoma-2) in EC. The findings suggest that RAGE plays an important role in glyLDL-induced oxidative stress in vascular EC. C3G may prevent glyLDL-induced NOX activation, the impairment of mETC enzymes and cell viability in cultured vascular EC.

The Dual Edema-Preventing Molecular Mechanism of the Crataegus Extract WS 1442 Can Be Assigned to Distinct Phytochemical Fractions.

PubMed

Fuchs, Simone; Bischoff, Iris; Willer, Elisabeth A; Bräutigam, Jacqueline; Bubik, Martin F; Erdelmeier, Clemens A J; Koch, Egon; Faleschini, Maria T; De Mieri, Maria; Bauhart, Milena; Zahler, Stefan; Hensel, Andreas; Hamburger, Matthias; Potterat, Olivier; Fürst, Robert

2017-05-01

The hawthorn ( Crataegus spp.) extract WS 1442 is used against mild forms of chronic heart failure. This disease is associated with endothelial barrier dysfunction and edema formation. We have recently shown that WS 1442 protects against this dysfunction by a dual mechanism: it both promotes endothelial barrier integrity by activation of a barrier-enhancing pathway (cortactin activation) and inhibits endothelial hyperpermeability by blocking a barrier disruptive pathway (calcium signaling). In this study, we aimed to identify the bioactive compounds responsible for these actions by using a bioactivity-guided fractionation approach. From the four fractions generated from WS 1442 by successive elution with water, 95 % ethanol, methanol, and 70 % acetone, only the water fraction was inactive, whereas the other three triggered a reduction of endothelial hyperpermeability. Analyses of intracellular calcium levels and cortactin phosphorylation were used as readouts to estimate the bioactivity of subfractions and isolated compounds. Interestingly, only the ethanolic fraction interfered with the calcium signaling, whereas only the methanolic fraction led to an activation of cortactin. Thus, the dual mode of action of WS 1442 could be clearly assigned to two distinct fractions. Although the identification of the calcium-active substance(s) was not successful, we could exclude an involvement of phenolic compounds. Cortactin activation, however, could be clearly attributed to oligomeric procyanidins with a distinct degree of polymerization. Taken together, our study provides the first approach to identify the active constituents of WS 1442 that address different cellular pathways leading to the inhibition of endothelial barrier dysfunction. Georg Thieme Verlag KG Stuttgart · New York.

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

Bosche, Bert, E-mail: bert.bosche@uk-essen.de; Max Planck Institute for Neurological Research with Klaus-Joachim-Zülch Laboratories of the Max Planck Society and the Medical Faculty of the University of Cologne; Schäfer, Matthias, E-mail: matthias.schaefer@sanofi.com

Highlights: •We investigate free calcium as a central signalling element in endothelial cells. •Inhibition of glycolysis with 2-deoxy-D-glucose reduces cellular ATP. •This manoeuvre leads to a biphasic increase and overload of free calcium. •Pre-treatment with lithium for 24 h abolishes both phases of the calcium increase. •This provides a new strategy to protect endothelial calcium homeostasis and barrier function. -- Abstract: Cytosolic free calcium concentration ([Ca{sup 2+}]{sub i}) is a central signalling element for the maintenance of endothelial barrier function. Under physiological conditions, it is controlled within narrow limits. Metabolic inhibition during ischemia/reperfusion, however, induces [Ca{sup 2+}]{sub i} overload, whichmore » results in barrier failure. In a model of cultured porcine aortic endothelial monolayers (EC), we addressed the question of whether [Ca{sup 2+}]{sub i} overload can be prevented by lithium treatment. [Ca{sup 2+}]{sub i} and ATP were analysed using Fura-2 and HPLC, respectively. The combined inhibition of glycolytic and mitochondrial ATP synthesis by 2-desoxy-D-glucose (5 mM; 2-DG) plus sodium cyanide (5 mM; NaCN) caused a significant decrease in cellular ATP content (14 ± 1 nmol/mg protein vs. 18 ± 1 nmol/mg protein in the control, n = 6 culture dishes, P < 0.05), an increase in [Ca{sup 2+}]{sub i} (278 ± 24 nM vs. 71 ± 2 nM in the control, n = 60 cells, P < 0.05), and the formation of gaps between adjacent EC. These observations indicate that there is impaired barrier function at an early state of metabolic inhibition. Glycolytic inhibition alone by 10 mM 2-DG led to a similar decrease in ATP content (14 ± 2 nmol/mg vs. 18 ± 1 nmol/mg in the control, P < 0.05) with a delay of 5 min. The [Ca{sup 2+}]{sub i} response of EC was biphasic with a peak after 1 min (183 ± 6 nM vs. 71 ± 1 nM, n = 60 cells, P < 0.05) followed by a sustained increase in [Ca{sup 2+}]{sub i}. A 24-h pre-treatment with 10 mM of lithium chloride before the inhibition of ATP synthesis abolished both phases of the 2-DG-induced [Ca{sup 2+}]{sub i} increase. This effect was not observed when lithium chloride was added simultaneously with 2-DG. We conclude that lithium chloride abolishes the injurious [Ca{sup 2+}]{sub i} overload in EC and that this most likely occurs by preventing inositol 3-phosphate-sensitive Ca{sup 2+}-release from the endoplasmic reticulum. Though further research is needed, these findings provide a novel option for therapeutic strategies to protect the endothelium against imminent barrier failure.« less

N‐Acetylcysteine, a glutathione precursor, reverts vascular dysfunction and endothelial epigenetic programming in intrauterine growth restricted guinea pigs

PubMed Central

Herrera, Emilio A.; Cifuentes‐Zúñiga, Francisca; Figueroa, Esteban; Villanueva, Cristian; Hernández, Cherie; Alegría, René; Arroyo‐Jousse, Viviana; Peñaloza, Estefania; Farías, Marcelo; Uauy, Ricardo; Casanello, Paola

2016-01-01

Key points Intrauterine growth restriction (IUGR) is associated with vascular dysfunction, oxidative stress and signs of endothelial epigenetic programming of the umbilical vessels.There is no evidence that this epigenetic programming is occurring on systemic fetal arteries.In IUGR guinea pigs we studied the functional and epigenetic programming of endothelial nitric oxide synthase (eNOS) (Nos3 gene) in umbilical and systemic fetal arteries, addressing the role of oxidative stress in this process by maternal treatment with N‐acetylcysteine (NAC) during the second half of gestation.The present study suggests that IUGR endothelial cells have common molecular markers of programming in umbilical and systemic arteries. Notably, maternal treatment with NAC restores fetal growth by increasing placental efficiency and reverting the functional and epigenetic programming of eNOS in arterial endothelium in IUGR guinea pigs. Abstract In humans, intrauterine growth restriction (IUGR) is associated with vascular dysfunction, oxidative stress and signs of endothelial programming in umbilical vessels. We aimed to determine the effects of maternal antioxidant treatment with N‐acetylcysteine (NAC) on fetal endothelial function and endothelial nitric oxide synthase (eNOS) programming in IUGR guinea pigs. IUGR was induced by implanting ameroid constrictors on uterine arteries of pregnant guinea pigs at mid gestation, half of the sows receiving NAC in the drinking water (from day 34 until term). Fetal biometry and placental vascular resistance were followed by ultrasound throughout gestation. At term, umbilical arteries and fetal aortae were isolated to assess endothelial function by wire‐myography. Primary cultures of endothelial cells (ECs) from fetal aorta, femoral and umbilical arteries were used to determine eNOS mRNA levels by quantitative PCR and analyse DNA methylation in the Nos3 promoter by pyrosequencing. Doppler ultrasound measurements showed that NAC reduced placental vascular resistance in IUGR (P < 0.05) and recovered fetal weight (P < 0.05), increasing fetal‐to‐placental ratio at term (∼40%) (P < 0.001). In IUGR, NAC treatment restored eNOS‐dependent relaxation in aorta and umbilical arteries (P < 0.05), normalizing eNOS mRNA levels in EC fetal and umbilical arteries (P < 0.05). IUGR‐derived ECs had a decreased DNA methylation (∼30%) at CpG −170 (from the transcription start site) and this epigenetic signature was absent in NAC‐treated fetuses (P < 0.001). These data show that IUGR‐ECs have common molecular markers of eNOS programming in umbilical and systemic arteries and this effect is prevented by maternal treatment with antioxidants. PMID:27739590

Emergency contraception: a primer for pediatric providers.

PubMed

Clements, Alana L; Daley, Alison Moriarty

2006-01-01

Emergency contraception (EC) is a contraceptive method used safely and successfully by women for more than 30 years to prevent pregnancy. Nurses at all levels are often the first point of contact for a woman who is requesting EC, thus it is particularly important for them to stay abreast of both the facts regarding the use of this product and the current political controversies. It is particularly important for Nurse Practitioners (NPs) working in primary care with adolescents to remain cognizant of the significant barriers that remain for many women of all ages trying to access this important contraceptive tool.

Nrf2 Deficiency Exacerbates Obesity-Induced Oxidative Stress, Neurovascular Dysfunction, Blood-Brain Barrier Disruption, Neuroinflammation, Amyloidogenic Gene Expression, and Cognitive Decline in Mice, Mimicking the Aging Phenotype.

PubMed

Tarantini, Stefano; Valcarcel-Ares, M Noa; Yabluchanskiy, Andriy; Tucsek, Zsuzsanna; Hertelendy, Peter; Kiss, Tamas; Gautam, Tripti; Zhang, Xin A; Sonntag, William E; de Cabo, Rafael; Farkas, Eszter; Elliott, Michael H; Kinter, Michael T; Deak, Ferenc; Ungvari, Zoltan; Csiszar, Anna

2018-06-14

Obesity has deleterious effects on cognitive function in the elderly adults. In mice, aging exacerbates obesity-induced oxidative stress, microvascular dysfunction, blood-brain barrier (BBB) disruption, and neuroinflammation, which compromise cognitive health. However, the specific mechanisms through which aging and obesity interact to remain elusive. Previously, we have shown that Nrf2 signaling plays a critical role in microvascular resilience to obesity and that aging is associated with progressive Nrf2 dysfunction, promoting microvascular impairment. To test the hypothesis that Nrf2 deficiency exacerbates cerebromicrovascular dysfunction induced by obesity Nrf2+/+ and Nrf2-/-, mice were fed an adipogenic high-fat diet (HFD). Nrf2 deficiency significantly exacerbated HFD-induced oxidative stress and cellular senescence, impairment of neurovascular coupling responses, BBB disruption, and microglia activation, mimicking the aging phenotype. Obesity in Nrf2-/- mice elicited complex alterations in the amyloidogenic gene expression profile, including upregulation of amyloid precursor protein. Nrf2 deficiency and obesity additively reduced long-term potentiation in the CA1 area of the hippocampus. Collectively, Nrf2 dysfunction exacerbates the deleterious effects of obesity, compromising cerebromicrovascular and brain health by impairing neurovascular coupling mechanisms, BBB integrity and synaptic function and promoting neuroinflammation. These results support a possible role for age-related Nrf2 dysfunction in the pathogenesis of vascular cognitive impairment and Alzheimer's disease.

Lactoferrin and lysozyme to reduce environmental enteric dysfunction and stunting in Malawian children: Study protocol for a randomized controlled trial

USDA-ARS?s Scientific Manuscript database

Chronic childhood malnutrition, as manifested by stunted linear growth, remains a persistent barrier to optimal child growth and societal development. Environmental enteric dysfunction (EED) is a significant underlying factor in the causal pathway to stunting, delayed cognitive development, and ulti...

Glial diffusion barriers during aging and pathological states.

PubMed

Syková, E

2001-01-01

In conclusion, glial cells control not only ECS ionic composition, but also ECS size and geometry. Since ECS ionic and volume changes have been shown to play an important role in modulating the complex synaptic and extrasynaptic signal transmission in the CNS, glial cells may thus affect neuronal interaction, synchronization and neuron-glia communication. As shown in Fig. 2, a link between ionic and volume changes and signal transmission has been proposed as a model for the non-specific feedback mechanism suppressing neuronal activity (Syková, 1997; Ransom, 2000). First, neuronal activity results in the accumulation of [K+]e, which in turn depolarizes glial cells, and this depolarization induces an alkaline shift in glial pHi. Second, the glial cells extrude acid and the resulting acid shift causes a decrease in the neuronal excitability. Because ionic transmembrane shifts are always accompanied by water, this feedback mechanism is amplified by activity-related glial swelling compensated for by ECS volume shrinkage and by increased tortuosity, presumably by the crowding of molecules of the ECS matrix and/or by the swelling of fine glial processes. This, in turn, results in a larger accumulation of ions and other neuroactive substances in the brain due to increased diffusion hinderance in the ECS. Astrocyte hypertrophy, proliferation and swelling influence the size of the ECS volume and tortuosity around neurons, slowing diffusion in the ECS. Their organization may also affect diffusion anisotropy, which could be an underlying mechanism for the specificity of extrasynaptic transmission, including 'cross-talk' between distinct synapses (Barbour and Hausser, 1997; Kullmann and Asztely, 1998). An increased concentration of transmitter released into a synapse (e.g. repetitive adequate stimuli or during high frequency electrical stimulation which induces LTP) results in a significant activation of high-affinity receptors at neighboring synapses. The efficacy of such synaptic cross-talk would be dependent on the extracellular space surrounding the synapses, i.e. on intersynaptic geometry and diffusion parameters. Other recent studies have also suggested an important role for proteoglycans, known to participate in multiple cellular processes, such as axonal outgrowth, axonal branching and synaptogenesis (Hardington and Fosang, 1992; Margolis and Margolis, 1993) that are important for the formation of memory traces. Recent observation of a decrease of fibronectin and chondroitin sulfate proteoglycan staining in the hippocampus of behaviorally impaired aged rats (Syková et al., 1998a,b) supports this hypothesis. It is reasonable to assume that besides neuronal and glial processes, macromolecules of the extracellular matrix contribute to diffusion barriers in the ECS. It is therefore apparent that glial cells play an important role in the local architecture of the CNS and they may also be involved in the modulation of signal transmission, in plastic changes, LTP, LTD and in changes of behavior and memory formation.

Nerve growth factor and diarrhea-predominant irritable bowel syndrome (IBS-D): a potential therapeutic target?

PubMed

Xu, Xiao-juan; Liu, Liang; Yao, Shu-kun

2016-01-01

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder characterized by recurrent abdominal pain or discomfort associated with abnormal bowel habits. Diarrhea-predominant IBS (IBS-D) is a major subtype of IBS, the predominant manifestations of which are abdominal pain and diarrhea. The pathogenesis of IBS-D remained unknown until recently. The effects of psychosocial stress, central hypervigilance, neuroendocrine abnormality, disturbed gastrointestinal motility, mucosal immune activation, intestinal barrier dysfunction, visceral hypersensitivity (VH), altered gut flora, and genetic susceptibility may be involved in its development. Recently, increased attention has been placed on the neural-immune-endocrine network mechanism in IBS-D, especially the role of various neuroendocrine mediators. As a member of the neurotrophin family, nerve growth factor (NGF) has diverse biological effects, and participates in the pathogenesis of many diseases. Basic studies have demonstrated that NGF is associated with inflammatory- and stress-related VH, as well as stress-related intestinal barrier dysfunction. The aim of this study is to summarize recent literature and discuss the role of NGF in the pathophysiology of IBS-D, especially in VH and intestinal barrier dysfunction, as well as its potential as a therapeutic target in IBS-D.

Diffusion in Brain Extracellular Space

PubMed Central

Syková, Eva; Nicholson, Charles

2009-01-01

Diffusion in the extracellular space (ECS) of the brain is constrained by the volume fraction and the tortuosity and a modified diffusion equation represents the transport behavior of many molecules in the brain. Deviations from the equation reveal loss of molecules across the blood-brain barrier, through cellular uptake, binding or other mechanisms. Early diffusion measurements used radiolabeled sucrose and other tracers. Presently, the real-time iontophoresis (RTI) method is employed for small ions and the integrative optical imaging (IOI) method for fluorescent macromolecules, including dextrans or proteins. Theoretical models and simulations of the ECS have explored the influence of ECS geometry, effects of dead-space microdomains, extracellular matrix and interaction of macromolecules with ECS channels. Extensive experimental studies with the RTI method employing the cation tetramethylammonium (TMA) in normal brain tissue show that the volume fraction of the ECS typically is about 20% and the tortuosity about 1.6 (i.e. free diffusion coefficient of TMA is reduced by 2.6), although there are regional variations. These parameters change during development and aging. Diffusion properties have been characterized in several interventions, including brain stimulation, osmotic challenge and knockout of extracellular matrix components. Measurements have also been made during ischemia, in models of Alzheimer's and Parkinson's diseases and in human gliomas. Overall, these studies improve our conception of ECS structure and the roles of glia and extracellular matrix in modulating the ECS microenvironment. Knowledge of ECS diffusion properties are valuable in contexts ranging from understanding extrasynaptic volume transmission to the development of paradigms for drug delivery to the brain. PMID:18923183

Distinct endothelial phenotypes evoked by arterial waveforms derived from atherosclerosis-susceptible and -resistant regions of human vasculature

NASA Astrophysics Data System (ADS)

Dai, Guohao; Kaazempur-Mofrad, Mohammad R.; Natarajan, Sripriya; Zhang, Yuzhi; Vaughn, Saran; Blackman, Brett R.; Kamm, Roger D.; García-Cardeña, Guillermo; Gimbrone, Michael A., Jr.

2004-10-01

Atherosclerotic lesion localization to regions of disturbed flow within certain arterial geometries, in humans and experimental animals, suggests an important role for local hemodynamic forces in atherogenesis. To explore how endothelial cells (EC) acquire functional/dysfunctional phenotypes in response to vascular region-specific flow patterns, we have used an in vitro dynamic flow system to accurately reproduce arterial shear stress waveforms on cultured human EC and have examined the effects on EC gene expression by using a high-throughput transcriptional profiling approach. The flow patterns in the carotid artery bifurcations of several normal human subjects were characterized by using 3D flow analysis based on actual vascular geometries and blood flow profiles. Two prototypic arterial waveforms, "athero-prone" and "athero-protective," were defined as representative of the wall shear stresses in two distinct regions of the carotid artery (carotid sinus and distal internal carotid artery) that are typically "susceptible" or "resistant," respectively, to atherosclerotic lesion development. These two waveforms were applied to cultured EC, and cDNA microarrays were used to analyze the differential patterns of EC gene expression. In addition, the differential effects of athero-prone vs. athero-protective waveforms were further characterized on several parameters of EC structure and function, including actin cytoskeletal organization, expression and localization of junctional proteins, activation of the NF-B transcriptional pathway, and expression of proinflammatory cytokines and adhesion molecules. These global gene expression patterns and functional data reveal a distinct phenotypic modulation in response to the wall shear stresses present in atherosclerosis-susceptible vs. atherosclerosis-resistant human arterial geometries.

Flow Cytometric Quantification of Peripheral Blood Cell β-Adrenergic Receptor Density and Urinary Endothelial Cell-Derived Microparticles in Pulmonary Arterial Hypertension.

PubMed

Rose, Jonathan A; Wanner, Nicholas; Cheong, Hoi I; Queisser, Kimberly; Barrett, Patrick; Park, Margaret; Hite, Corrine; Naga Prasad, Sathyamangla V; Erzurum, Serpil; Asosingh, Kewal

2016-01-01

Pulmonary arterial hypertension (PAH) is a heterogeneous disease characterized by severe angiogenic remodeling of the pulmonary artery wall and right ventricular hypertrophy. Thus, there is an increasing need for novel biomarkers to dissect disease heterogeneity, and predict treatment response. Although β-adrenergic receptor (βAR) dysfunction is well documented in left heart disease while endothelial cell-derived microparticles (Ec-MPs) are established biomarkers of angiogenic remodeling, methods for easy large clinical cohort analysis of these biomarkers are currently absent. Here we describe flow cytometric methods for quantification of βAR density on circulating white blood cells (WBC) and Ec-MPs in urine samples that can be used as potential biomarkers of right heart failure in PAH. Biotinylated β-blocker alprenolol was synthesized and validated as a βAR specific probe that was combined with immunophenotyping to quantify βAR density in circulating WBC subsets. Ec-MPs obtained from urine samples were stained for annexin-V and CD144, and analyzed by a micro flow cytometer. Flow cytometric detection of alprenolol showed that βAR density was decreased in most WBC subsets in PAH samples compared to healthy controls. Ec-MPs in urine was increased in PAH compared to controls. Furthermore, there was a direct correlation between Ec-MPs and Tricuspid annular plane systolic excursion (TAPSE) in PAH patients. Therefore, flow cytometric quantification of peripheral blood cell βAR density and urinary Ec-MPs may be useful as potential biomarkers of right ventricular function in PAH.

Flow Cytometric Quantification of Peripheral Blood Cell β-Adrenergic Receptor Density and Urinary Endothelial Cell-Derived Microparticles in Pulmonary Arterial Hypertension

PubMed Central

Rose, Jonathan A.; Wanner, Nicholas; Cheong, Hoi I.; Queisser, Kimberly; Barrett, Patrick; Park, Margaret; Hite, Corrine; Naga Prasad, Sathyamangla V.; Erzurum, Serpil; Asosingh, Kewal

2016-01-01

Pulmonary arterial hypertension (PAH) is a heterogeneous disease characterized by severe angiogenic remodeling of the pulmonary artery wall and right ventricular hypertrophy. Thus, there is an increasing need for novel biomarkers to dissect disease heterogeneity, and predict treatment response. Although β-adrenergic receptor (βAR) dysfunction is well documented in left heart disease while endothelial cell-derived microparticles (Ec-MPs) are established biomarkers of angiogenic remodeling, methods for easy large clinical cohort analysis of these biomarkers are currently absent. Here we describe flow cytometric methods for quantification of βAR density on circulating white blood cells (WBC) and Ec-MPs in urine samples that can be used as potential biomarkers of right heart failure in PAH. Biotinylated β-blocker alprenolol was synthesized and validated as a βAR specific probe that was combined with immunophenotyping to quantify βAR density in circulating WBC subsets. Ec-MPs obtained from urine samples were stained for annexin-V and CD144, and analyzed by a micro flow cytometer. Flow cytometric detection of alprenolol showed that βAR density was decreased in most WBC subsets in PAH samples compared to healthy controls. Ec-MPs in urine was increased in PAH compared to controls. Furthermore, there was a direct correlation between Ec-MPs and Tricuspid annular plane systolic excursion (TAPSE) in PAH patients. Therefore, flow cytometric quantification of peripheral blood cell βAR density and urinary Ec-MPs may be useful as potential biomarkers of right ventricular function in PAH. PMID:27270458

Microfluidically supported biochip design for culture of endothelial cell layers with improved perfusion conditions.

PubMed

Raasch, Martin; Rennert, Knut; Jahn, Tobias; Peters, Sven; Henkel, Thomas; Huber, Otmar; Schulz, Ingo; Becker, Holger; Lorkowski, Stefan; Funke, Harald; Mosig, Alexander

2015-03-02

Hemodynamic forces generated by the blood flow are of central importance for the function of endothelial cells (ECs), which form a biologically active cellular monolayer in blood vessels and serve as a selective barrier for macromolecular permeability. Mechanical stimulation of the endothelial monolayer induces morphological remodeling in its cytoskeleton. For in vitro studies on EC biology culture devices are desirable that simulate conditions of flow in blood vessels and allow flow-based adhesion/permeability assays under optimal perfusion conditions. With this aim we designed a biochip comprising a perfusable membrane that serves as cell culture platform multi-organ-tissue-flow (MOTiF biochip). This biochip allows an effective supply with nutrition medium, discharge of catabolic cell metabolites and defined application of shear stress to ECs under laminar flow conditions. To characterize EC layers cultured in the MOTiF biochip we investigated cell viability, expression of EC marker proteins and cell adhesion molecules of ECs dynamically cultured under low and high shear stress, and compared them with an endothelial culture in established two-dimensionally perfused flow chambers and under static conditions. We show that ECs cultured in the MOTiF biochip form a tight EC monolayer with increased cellular density, enhanced cell layer thickness, presumably as the result of a rapid and effective adaption to shear stress by remodeling of the cytoskeleton. Moreover, endothelial layers in the MOTiF biochip express higher amounts of EC marker proteins von-Willebrand-factor and PECAM-1. EC layers were highly responsive to stimulation with TNFα as detected at the level of ICAM-1, VCAM-1 and E-selectin expression and modulation of endothelial permeability in response to TNFα/IFNγ treatment under flow conditions. Compared to static and two-dimensionally perfused cell culture condition we consider MOTiF biochips as a valuable tool for studying EC biology in vitro under advanced culture conditions more closely resembling the in vivo situation.

Dual role of ALCAM in neuroinflammation and blood–brain barrier homeostasis

PubMed Central

Saint-Laurent, Olivia; Bourbonnière, Lyne; Larouche, Sandra; Larochelle, Catherine; Michel, Laure; Charabati, Marc; Abadier, Michael; Zandee, Stephanie; Haghayegh Jahromi, Neda; Gowing, Elizabeth; Pittet, Camille; Lyck, Ruth; Engelhardt, Britta

2017-01-01

Activated leukocyte cell adhesion molecule (ALCAM) is a cell adhesion molecule found on blood–brain barrier endothelial cells (BBB-ECs) that was previously shown to be involved in leukocyte transmigration across the endothelium. In the present study, we found that ALCAM knockout (KO) mice developed a more severe myelin oligodendrocyte glycoprotein (MOG)35–55–induced experimental autoimmune encephalomyelitis (EAE). The exacerbated disease was associated with a significant increase in the number of CNS-infiltrating proinflammatory leukocytes compared with WT controls. Passive EAE transfer experiments suggested that the pathophysiology observed in active EAE was linked to the absence of ALCAM on BBB-ECs. In addition, phenotypic characterization of unimmunized ALCAM KO mice revealed a reduced expression of BBB junctional proteins. Further in vivo, in vitro, and molecular analysis confirmed that ALCAM is associated with tight junction molecule assembly at the BBB, explaining the increased permeability of CNS blood vessels in ALCAM KO animals. Collectively, our data point to a biologically important function of ALCAM in maintaining BBB integrity. PMID:28069965

Plastic roles of pericytes in the blood-retinal barrier.

PubMed

Park, Do Young; Lee, Junyeop; Kim, Jaeryung; Kim, Kangsan; Hong, Seonpyo; Han, Sangyeul; Kubota, Yoshiaki; Augustin, Hellmut G; Ding, Lei; Kim, Jin Woo; Kim, Hail; He, Yulong; Adams, Ralf H; Koh, Gou Young

2017-05-16

The blood-retinal barrier (BRB) consists of tightly interconnected capillary endothelial cells covered with pericytes and glia, but the role of the pericytes in BRB regulation is not fully understood. Here, we show that platelet-derived growth factor (PDGF)-B/PDGF receptor beta (PDGFRβ) signalling is critical in formation and maturation of BRB through active recruitment of pericytes onto growing retinal vessels. Impaired pericyte recruitment to the vessels shows multiple vascular hallmarks of diabetic retinopathy (DR) due to BRB disruption. However, PDGF-B/PDGFRβ signalling is expendable for maintaining BRB integrity in adult mice. Although selective pericyte loss in stable adult retinal vessels surprisingly does not cause BRB disintegration, it sensitizes retinal vascular endothelial cells (ECs) to VEGF-A, leading to upregulation of angiopoietin-2 (Ang2) in ECs through FOXO1 activation and triggering a positive feedback that resembles the pathogenesis of DR. Accordingly, either blocking Ang2 or activating Tie2 greatly attenuates BRB breakdown, suggesting potential therapeutic approaches to reduce retinal damages upon DR progression.

A New Approach to Look at the Electrical Conductivity of Streamflow: Decomposing a Bulk Signal to Recover Individual Solute Concentrations at High-Frequency

NASA Astrophysics Data System (ADS)

Benettin, P.; Van Breukelen, B. M.

2017-12-01

The ability to evaluate stream hydrochemistry is often constrained by the capacity to sample streamwater at an adequate frequency. While technology is no longer a limiting factor, economic and management efforts can still be a barrier to high-resolution water quality instrumentation. We propose a new framework to investigate the electrical conductivity (EC) of streamwater, which can be measured continuously through inexpensive sensors. We show that EC embeds information on ion content which can be isolated to retrieve solute concentrations at high resolution. The approach can already be applied to a number of datasets worldwide where water quality campaigns are conducted, provided continuous EC measurements can be collected. The essence of the approach is the decomposition of the EC signal into its "harmonics", i.e. the specific contributions of the major ions which conduct current in water. The ion contribution is used to explore water quality patterns and to develop algorithms that reconstruct solute concentrations during periods where solute measurements are not available. The approach is validated on a hydrochemical dataset from Plynlimon, Wales. Results show that the decomposition of EC is feasible and for at least two major elements the methodology provided improved estimates of high-frequency solute dynamics. Our results support the installation of EC probes to complement water quality campaigns and suggest that the potential of EC measurements in rivers is currently far from being fully exploited.

[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.

ACE2-EPC-EXs protect ageing ECs against hypoxia/reoxygenation-induced injury through the miR-18a/Nox2/ROS pathway.

PubMed

Zhang, Cheng; Wang, Jinju; Ma, Xiaotang; Wang, Wenjun; Zhao, Bin; Chen, Yanfang; Chen, Can; Bihl, Ji C

2018-03-01

Oxidative stress is one of the mechanisms of ageing-associated vascular dysfunction. Angiotensin-converting enzyme 2 (ACE2) and microRNA (miR)-18a have shown to be down-regulated in ageing cells. Our previous study has shown that ACE2-primed endothelial progenitor cells (ACE2-EPCs) have protective effects on endothelial cells (ECs), which might be due to their released exosomes (EXs). Here, we aimed to investigate whether ACE2-EPC-EXs could attenuate hypoxia/reoxygenation (H/R)-induced injury in ageing ECs through their carried miR-18a. Young and angiotensin II-induced ageing ECs were subjected to H/R and co-cultured with vehicle (medium), EPC-EXs, ACE2-EPCs-EXs, ACE2-EPCs-EXs + DX600 or ACE2-EPCs-EXs with miR-18a deficiency (ACE2-EPCs-EXs anti-miR-18a ). Results showed (1) ageing ECs displayed increased senescence, apoptosis and ROS production, but decreased ACE2 and miR-18a expressions and tube formation ability; (2) under H/R condition, ageing ECs showed higher rate of apoptosis, ROS overproduction and nitric oxide reduction, up-regulation of Nox2, down-regulation of ACE2, miR-18a and eNOS, and compromised tube formation ability; (3) compared with EPC-EXs, ACE2-EPC-EXs had better efficiencies on protecting ECs from H/R-induced changes; (4) The protective effects were less seen in ACE2-EPCs-EXs + DX600 and ACE2-EPCs-EXs anti-miR-18a groups. These data suggest that ACE-EPCs-EXs have better protective effects on H/R injury in ageing ECs which could be through their carried miR-18a and subsequently down-regulating the Nox2/ROS pathway. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Hippocampal α-Synuclein in Dementia with Lewy Bodies Contributes to Memory Impairment and Is Consistent with Spread of Pathology

PubMed Central

Roy, Subhojit; Galasko, Douglas R.; Hansen, Lawrence A.; Masliah, Eliezer

2017-01-01

Despite considerable research to uncover them, the anatomic and neuropathologic correlates of memory impairment in dementia with Lewy bodies (DLB) remain unclear. While some studies have implicated Lewy bodies in the neocortex, others have pointed to α-synuclein pathology in the hippocampus. We systematically examined hippocampal Lewy pathology and its distribution in hippocampal subfields in 95 clinically and neuropathologically characterized human cases of DLB, finding that α-synuclein pathology was highest in two hippocampal-related subregions: the CA2 subfield and the entorhinal cortex (EC). While the EC had numerous classic somatic Lewy bodies, CA2 contained mainly Lewy neurites in presumed axon terminals, suggesting the involvement of the EC → CA2 circuitry in the pathogenesis of DLB symptoms. Clinicopathological correlations with measures of verbal and visual memory supported a role for EC Lewy pathology, but not CA2, in causing these memory deficits. Lewy pathology in CA1—the main output region for CA2—correlated best with results from memory testing despite a milder pathology. This result indicates that CA1 may be more functionally relevant than CA2 in the context of memory impairment in DLB. These correlations remained significant after controlling for several factors, including concurrent Alzheimer's pathology (neuritic plaques and neurofibrillary tangles) and the interval between time of testing and time of death. Our data suggest that although hippocampal Lewy pathology in DLB is predominant in CA2 and EC, memory performance correlates most strongly with CA1 burden. SIGNIFICANCE STATEMENT This study provides a detailed neuropathologic analysis of hippocampal Lewy pathology in human patients with autopsy-confirmed dementia with Lewy bodies. The approach—informed by regional molecular markers, concurrent Alzheimer's pathology analysis, and relevant clinical data—helps tease out the relative contribution of Lewy pathology to memory dysfunction in the disease. Levels of Lewy pathology were found to be highest in the hippocampal CA2 subregion and entorhinal cortex, implicating a potentially overlooked circuit in disease pathogenesis. However, correlation with memory performance was strongest with CA1. This unexpected finding suggests that Lewy pathology must reach a critical burden across hippocampal circuitry to contribute to memory dysfunction beyond that related to other factors, notably coexisting Alzheimer's disease tau pathology. PMID:28039370

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

Increased retinoic acid levels through ablation of Cyp26b1 determine the processes of embryonic skin barrier formation and peridermal development

PubMed Central

Okano, Junko; Lichti, Ulrike; Mamiya, Satoru; Aronova, Maria; Zhang, Guofeng; Yuspa, Stuart H.; Hamada, Hiroshi; Sakai, Yasuo; Morasso, Maria I.

2012-01-01

The process by which the periderm transitions to stratified epidermis with the establishment of the skin barrier is unknown. Understanding the cellular and molecular processes involved is crucial for the treatment of human pathologies, where abnormal skin development and barrier dysfunction are associated with hypothermia and perinatal dehydration. For the first time, we demonstrate that retinoic acid (RA) levels are important for periderm desquamation, embryonic skin differentiation and barrier formation. Although excess exogenous RA has been known to have teratogenic effects, little is known about the consequences of elevated endogenous retinoids in skin during embryogenesis. Absence of cytochrome P450, family 26, subfamily b, polypeptide 1 (Cyp26b1), a retinoic-acid-degrading enzyme, results in aberrant epidermal differentiation and filaggrin expression, defective cornified envelopes and skin barrier formation, in conjunction with peridermal retention. We show that these alterations are RA dependent because administration of exogenous RA in vivo and to organotypic skin cultures phenocopy Cyp26b1−/− skin abnormalities. Furthermore, utilizing the Flaky tail (Ft/Ft) mice, a mouse model for human ichthyosis, characterized by mutations in the filaggrin gene, we establish that proper differentiation and barrier formation is a prerequisite for periderm sloughing. These results are important in understanding pathologies associated with abnormal embryonic skin development and barrier dysfunction. PMID:22366455

Endothelium-targeted overexpression of heat shock protein 27 ameliorates blood–brain barrier disruption after ischemic brain injury

PubMed Central

Jiang, Xiaoyan; Zhang, Lili; Pu, Hongjian; Hu, Xiaoming; Zhang, Wenting; Cai, Wei; Gao, Yanqin; Leak, Rehana K.; Keep, Richard F.; Bennett, Michael V. L.; Chen, Jun

2017-01-01

The damage borne by the endothelial cells (ECs) forming the blood–brain barrier (BBB) during ischemic stroke and other neurological conditions disrupts the structure and function of the neurovascular unit and contributes to poor patient outcomes. We recently reported that structural aberrations in brain microvascular ECs—namely, uncontrolled actin polymerization and subsequent disassembly of junctional proteins, are a possible cause of the early onset BBB breach that arises within 30–60 min of reperfusion after transient focal ischemia. Here, we investigated the role of heat shock protein 27 (HSP27) as a direct inhibitor of actin polymerization and protectant against BBB disruption after ischemia/reperfusion (I/R). Using in vivo and in vitro models, we found that targeted overexpression of HSP27 specifically within ECs—but not within neurons—ameliorated BBB impairment 1–24 h after I/R. Mechanistically, HSP27 suppressed I/R-induced aberrant actin polymerization, stress fiber formation, and junctional protein translocation in brain microvascular ECs, independent of its protective actions against cell death. By preserving BBB integrity after I/R, EC-targeted HSP27 overexpression attenuated the infiltration of potentially destructive neutrophils and macrophages into brain parenchyma, thereby improving long-term stroke outcome. Notably, early poststroke administration of HSP27 attached to a cell-penetrating transduction domain (TAT-HSP27) rapidly elevated HSP27 levels in brain microvessels and ameliorated I/R-induced BBB disruption and subsequent neurological deficits. Thus, the present study demonstrates that HSP27 can function at the EC level to preserve BBB integrity after I/R brain injury. HSP27 may be a therapeutic agent for ischemic stroke and other neurological conditions involving BBB breakdown. PMID:28137866

Erectile Dysfunction Precedes Coronary Artery Endothelial Dysfunction in Rats Fed a High-Fat, High-Sucrose, Western Pattern Diet

PubMed Central

La Favor, Justin D.; Anderson, Ethan J.; Hickner, Robert C.; Wingard, Christopher J.

2016-01-01

Introduction It is suggested that erectile dysfunction (ED) may be an early risk factor for cardiovascular disease. Aim The goal of this study was to determine whether development of ED precedes the onset of coronary artery endothelial dysfunction in response to a Western diet (WD), thereby establishing whether the WD differentially impacts the endothelium in a time-dependent manner. Additionally, a goal was to determine if diet-induced ED is reversible with intracavernosal sepiapterin treatment. Methods Male Sprague-Dawley rats were fed a WD for 4, 8, or 12 weeks, or a control diet for 8 weeks. Erectile function was evaluated by measuring the mean arterial pressure (MAP) and intracavernosal pressure (ICP) in response to electrical field stimulation of the cavernosal nerve near the major pelvic ganglion, in the absence and presence of sepiapterin. Coronary artery endothelial function was evaluated ex vivo with cumulative doses of acetylcholine (ACh) applied to segments of the left anterior descending coronary artery preconstricted with serotonin. Main Outcome Measures Erectile function was assessed as the ICP response to electrical field stimulation (EFS), normalized to MAP. Coronary artery endothelial function was assessed as the effective concentration producing 50% of a maximal response (EC50) of the ACh response. Results The ICP/MAP response to EFS was significantly attenuated following both 8 and 12 weeks of the WD compared with the control diet (P < 0.05). Sepiapterin treatment augmented the ICP/MAP response in all WD groups (P < 0.05). The coronary artery EC50 of the ACh response was not different from control following 4 or 8 weeks but was significantly elevated following 12 weeks of the WD (P < 0.01). Conclusions These data suggest that erectile function is reduced prior to coronary artery endothelial function in response to the WD. Improvement of erectile function with sepiapterin in WD rats indicates that nitric oxide synthase uncoupling is a key mechanism in diet-induced ED. PMID:23170997

Novel insights on the relationship between T-tubular defects and contractile dysfunction in a mouse model of hypertrophic cardiomyopathy.

PubMed

Crocini, C; Ferrantini, C; Scardigli, M; Coppini, R; Mazzoni, L; Lazzeri, E; Pioner, J M; Scellini, B; Guo, A; Song, L S; Yan, P; Loew, L M; Tardiff, J; Tesi, C; Vanzi, F; Cerbai, E; Pavone, F S; Sacconi, L; Poggesi, C

2016-02-01

Abnormalities of cardiomyocyte Ca(2+) homeostasis and excitation-contraction (E-C) coupling are early events in the pathogenesis of hypertrophic cardiomyopathy (HCM) and concomitant determinants of the diastolic dysfunction and arrhythmias typical of the disease. T-tubule remodelling has been reported to occur in HCM but little is known about its role in the E-C coupling alterations of HCM. Here, the role of T-tubule remodelling in the electro-mechanical dysfunction associated to HCM is investigated in the Δ160E cTnT mouse model that expresses a clinically-relevant HCM mutation. Contractile function of intact ventricular trabeculae is assessed in Δ160E mice and wild-type siblings. As compared with wild-type, Δ160E trabeculae show prolonged kinetics of force development and relaxation, blunted force-frequency response with reduced active tension at high stimulation frequency, and increased occurrence of spontaneous contractions. Consistently, prolonged Ca(2+) transient in terms of rise and duration are also observed in Δ160E trabeculae and isolated cardiomyocytes. Confocal imaging in cells isolated from Δ160E mice reveals significant, though modest, remodelling of T-tubular architecture. A two-photon random access microscope is employed to dissect the spatio-temporal relationship between T-tubular electrical activity and local Ca(2+) release in isolated cardiomyocytes. In Δ160E cardiomyocytes, a significant number of T-tubules (>20%) fails to propagate action potentials, with consequent delay of local Ca(2+) release. At variance with wild-type, we also observe significantly increased variability of local Ca(2+) transient rise as well as higher Ca(2+)-spark frequency. Although T-tubule structural remodelling in Δ160E myocytes is modest, T-tubule functional defects determine non-homogeneous Ca(2+) release and delayed myofilament activation that significantly contribute to mechanical dysfunction. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Pulmonary Cerium Dioxide Nanoparticles Exposure Differentially Impairs Coronary and Mesenteric Arteriolar Reactivity

PubMed Central

Minarchick, Valerie C; Stapleton, Phoebe A; Porter, Dale W; Wolfarth, Michael G; Çiftyürek, Engin; Barger, Mark; Sabolsky, Edward M.; Nurkiewicz, Timothy R

2013-01-01

Cerium dioxide nanoparticles (CeO2 NPs) are an engineered nanomaterial that possesses unique catalytic, oxidative and reductive properties. Currently, CeO2 NPs are being used as a fuel catalyst but these properties are also utilized in the development of potential drug treatments for radiation and stroke protection. These uses of CeO2 NPs present a risk for human exposure; however, to date no studies have investigated the effects of CeO2 NPs on the microcirculation following pulmonary exposure. Previous studies in our laboratory with other nanomaterials have shown impairments in normal microvascular function after pulmonary exposures. Therefore, we predicted that CeO2 NP exposure would cause microvascular dysfunction that is dependent on the tissue bed and dose. Twenty-four hour post exposure to CeO2 NPs (0–400 μg), mesenteric and coronary arterioles were isolated and microvascular function was assessed. Our results provided evidence that pulmonary CeO2 NP exposure impairs endothelium-dependent and -independent arteriolar dilation in a dose-dependent manner. The CeO2 NP exposure dose which causes a 50% impairment in arteriolar function (EC50) was calculated and ranged from 15 – 100 μg depending on the chemical agonist and microvascular bed. Microvascular assessments with acetylcholine revealed a 33–75% reduction in function following exposure. Additionally, there was a greater sensitivity to CeO2 NP exposure in the mesenteric microvasculature due to the 40% decrease in the calculated EC50 compared to the coronary microvasculature EC50. CeO2 NP exposure increased mean arterial pressure in some groups. Taken together these observed microvascular changes may likely have detrimental effects on local blood flow regulation and contribute to cardiovascular dysfunction associated with particle exposure. PMID:23645470

Can Eosinophil Count, Platelet Count, and Mean Platelet Volume Be a Positive Predictive Factor in Penile Arteriogenic Erectile Dysfunction Etiopathogenesis?

PubMed Central

Sönmez, Mehmet Giray; Göğer, Yunus Emre; Sönmez, Leyla Öztürk; Aydın, Arif; Balasar, Mehmet; Kara, Cengiz

2016-01-01

Blood count parameters of patients referring with erectile dysfunction (ED) were examined in this study and it was investigated whether eosinophil count (EC), platelet count (PC), and mean platelet volume values among the suspected predictive parameters which may play a role in especially penile arteriogenic ED etiopathogenesis had a contribution on pathogenesis. Patients referring with ED complaint were evaluated. Depending on the medical story, ED degree was determined by measuring International Index of Erectile Function. Penile Doppler ultrasonography was taken in patients suspected to have vasculogenic ED. According to penile Doppler ultrasonography result, patients with arterial deficiency were included in the penile arteriogenic ED group and the patients with normal results were included in the nonvasculogenic ED group. A total of 36 patients participated in the study from the penile arteriogenic ED group and 32 patients from the nonvasculogenic ED group. Compared with the nonvasculogenic ED group, the penile arteriogenic ED group’s low International Index of Erectile Function score, high EC, mean platelet volume and PC values were detected to be statistically significant (p < .001, p = .021, p = .018, p = .034, respectively). No statistically significant difference was observed among the two groups when age, white blood cells, red blood cells, and hemoglobin values were considered. Pansystolic volume velocities were detected as statistically significantly low compared with the nonvasculogenic ED group in the measurements made in 5th, 10th, 15th, and 20th minutes on the right and left sides in the penile arteriogenic ED group. High MPV value and PC is a significant predictive factor for penile arteriogenic ED and vasculogenic ED and high EC is specifically predictive of arteriogenic ED. PMID:27895254

Blood-brain barrier dysfunction and cerebral small vessel disease (arteriolosclerosis) in brains of older people.

PubMed

Bridges, Leslie R; Andoh, Joycelyn; Lawrence, Andrew J; Khoong, Cheryl H L; Poon, Wayne; Esiri, Margaret M; Markus, Hugh S; Hainsworth, Atticus H

2014-11-01

The blood-brain barrier protects brain tissue from potentially harmful plasma components. Small vessel disease (SVD; also termed arteriolosclerosis) is common in the brains of older people and is associated with lacunar infarcts, leukoaraiosis, and vascular dementia. To determine whether plasma extravasation is associated with SVD, we immunolabeled the plasma proteins fibrinogen and immunoglobulin G, which are assumed to reflect blood-brain barrier dysfunction, in deep gray matter (DGM; anterior caudate-putamen) and deep subcortical white matter (DWM) in the brains of a well-characterized cohort of donated brains with minimal Alzheimer disease pathology (Braak Stages 0-II) (n = 84; aged 65 years or older). Morphometric measures of fibrinogen labeling were compared between people with neuropathologically defined SVD and aged control subjects. Parenchymal cellular labeling with fibrinogen and immunoglobulin G was detectable in DGM and DWM in many subjects (>70%). Quantitative measures of fibrinogen were not associated with SVD in DGM or DWM; SVD severity was correlated between DGM and DWM (p < 0.0001). Fibrinogen in DGM showed a modest association with a history of hypertension; DWM fibrinogen was associated with dementia and cerebral amyloid angiopathy (all p < 0.05). In DWM, SVD was associated with leukoaraiosis identified in life (p < 0.05), but fibrinogen was not. Our data suggest that, in aged brains, plasma extravasation and hence local blood-brain barrier dysfunction are common but do not support an association with SVD.

Eicosapentaenoic Acid Enhances Heat Stress-Impaired Intestinal Epithelial Barrier Function in Caco-2 Cells

PubMed Central

Xiao, Guizhen; Tang, Liqun; Yuan, Fangfang; Zhu, Wei; Zhang, Shaoheng; Liu, Zhifeng; Geng, Yan; Qiu, Xiaowen

2013-01-01

Objective Dysfunction of the intestinal epithelial tight junction (TJ) barrier is known to have an important etiologic role in the pathophysiology of heat stroke. N-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), play a role in maintaining and protecting the TJ structure and function. This study is aimed at investigating whether n-3 PUFAs could alleviate heat stress-induced dysfunction of intestinal tight junction. Methods Human intestinal epithelial Caco-2 cells were pre-incubated with EPA, DHA or arachidonic acid (AA) and then exposed to heat stress. Transepithelial electrical resistance (TEER) and Horseradish Peroxidase (HRP) permeability were measured to analyze barrier integrity. Levels of TJ proteins, including occludin, ZO-1 and claudin-2, were analyzed by Western blot and localized by immunofluorescence microscopy. Messenger RNA levels were determined by quantitative real time polymerase chain reaction (Q-PCR). TJ morphology was observed by transmission electron microscopy. Results EPA effectively attenuated the decrease in TEER and impairment of intestinal permeability in HRP flux induced by heat exposure. EPA significantly elevated the expression of occludin and ZO-1, while DHA was less effective and AA was not at all effective. The distortion and redistribution of TJ proteins, and disruption of morphology were also effectively prevented by pretreatment with EPA. Conclusion This study indicates for the first time that EPA is more potent than DHA in protecting against heat-induced permeability dysfunction and epithelial barrier damage of tight junction. PMID:24066055

Propofol ameliorates electroconvulsive shock-induced learning and memory impairment by regulation of synaptic metaplasticity via autophosphorylation of CaMKIIa at Thr 305 in stressed rats.

PubMed

Ren, Li; Zhang, Fan; Min, Su; Hao, Xuechao; Qin, Peipei; Zhu, Xianlin

2016-06-30

Electroconvulsive therapy (ECT) is an effective treatment for depression, but it can induce learning and memory impairment. Our previous study found propofol (γ-aminobutyric acid (GABA) receptor agonist) could ameliorate electroconvulsive shock (ECS, an analog of ECT to animals)-induced cognitive impairment, however, the underlying molecular mechanisms remain unclear. This study aimed to investigate the effects of propofol on metaplasticity and autophosphorylation of CaMKIIa in stressed rats receiving ECS. Depressive-like behavior and learning and memory function were assessed by sucrose preference test and Morris water test respectively. LTP were tested by electrophysiological experiment, the expression of CaMKIIa, p-T305-CaMKII in hippocampus and CaMKIIα in hippocampal PSD fraction were evaluated by western blot. Results suggested ECS raised the baseline fEPSP and impaired the subsequent LTP, increased the expression of p-T305-CaMKII and decreased the expression of CaMKIIα in hippocampal PSD fraction, leading to cognitive dysfunction in stressed rats. Propofol could down-regulate the baseline fEPSP and reversed the impairment of LTP partly, decreased the expression of p-T305-CaMKII and increased the expression of CaMKIIα in hippocampal PSD fraction and alleviated ECS-induced learning and memory impairment. In conclusion, propofol ameliorates ECS-induced learning and memory impairment, possibly by regulation of synaptic metaplasticity via p-T305-CaMKII. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Emergency contraception in Albania: a multimethods qualitative study of awareness, knowledge, attitudes and practices.

PubMed

Doci, Florida; Thaci, Jonida; Foster, Angel M

2018-04-11

Contraceptive prevalence is relatively low in Albania, and abortion is the mainstay of family planning. Although levonorgestrel-only emergency contraceptive pills are available, uptake of this method is minimal. Emergency contraception (EC) could play a significant role in addressing women's need for an effective and discreet pregnancy prevention method. However, information about the dynamics surrounding EC is limited. In 2016-2017, we conducted a multimethods qualitative study that aimed to explore awareness, knowledge, attitudes and practices toward EC in Albania. This project comprised four components: a community-based survey with 115 respondents, six focus group discussions with women of reproductive age, 19 semistructured key informant interviews, and 16 structured interviews with retail pharmacists. We analyzed our data using descriptive statistics and for content and themes. Our findings suggest that EC is widely available in pharmacies in Albania. However, a quarter of our survey participants did not know whether EC was available, and more than a third did not think EC was safe to use. Women face numerous barriers to accessing this form of contraception. Misconceptions about hormonal contraceptives, in general, and about progestin-only EC in particular, lack of training among providers, and stigma and fear of judgment were common obstacles identified by participants. Misinformation and lack of knowledge about EC among women and providers in Albania appears common. Training health service providers, raising awareness among women, and developing linguistically and culturally resonant materials for distribution could be keys to improving access to and use of EC. Although the availability of progestin-only EC is widespread in Albania, our findings suggest that more work needs to be done to align national regulatory policies with international standards, facilitate evidence-based service delivery, and increase access to medically accurate information in Albanian. Copyright © 2018 Elsevier Inc. All rights reserved.

THE ENDOTHELIUM IN SEPSIS

PubMed Central

Ince, Can; Mayeux, Philip R.; Nguyen, Trung; Gomez, Hernando; Kellum, John A.; Ospina-Tascón, Gustavo A.; Hernandez, Glenn; Murray, Patrick; De Backer, Daniel

2017-01-01

Sepsis affects practically all aspects of endothelial cell (EC) function and is thought to be the key factor in the progression from sepsis to organ failure. Endothelial functions affected by sepsis include vasoregulation, barrier function, inflammation, and hemostasis. These are among other mechanisms often mediated by glycocalyx shedding, such as abnormal nitric oxide metabolism, up-regulation of reactive oxygen species generation due to down-regulation of endothelial-associated antioxidant defenses, transcellular communication, proteases, exposure of adhesion molecules, and activation of tissue factor. This review covers current insight in EC-associated hemostatic responses to sepsis and the EC response to inflammation. The endothelial cell lining is highly heterogeneous between different organ systems and consequently also in its response to sepsis. In this context, we discuss the response of the endothelial cell lining to sepsis in the kidney, liver, and lung. Finally, we discuss evidence as to whether the EC response to sepsis is adaptive or maladaptive. This study is a result of an Acute Dialysis Quality Initiative XIV Sepsis Workgroup meeting held in Bogota, Columbia, between October 12 and 15, 2014. PMID:26871664

Intentionally induced intestinal barrier dysfunction causes inflammation, affects metabolism, and reduces productivity in lactating Holstein cows

USDA-ARS?s Scientific Manuscript database

Study objectives were to evaluate the effects of intentionally reduced intestinal barrier function on productivity, metabolism, and inflammatory indices in otherwise healthy dairy cows. Fourteen lactating Holstein cows (parity 2.6 ± 0.3; 117 ± 18 days in milk) were enrolled in two experimental perio...

Endothelial connexin 32 regulates tissue factor expression induced by inflammatory stimulation and direct cell-cell interaction with activated cells.

PubMed

Okamoto, Takayuki; Akita, Nobuyuki; Hayashi, Tatsuya; Shimaoka, Motomu; Suzuki, Koji

2014-10-01

Endothelial cell (EC) interacts with adjacent EC through gap junction, and abnormal expression or function of Cxs is associated with cardiovascular diseases. In patients with endothelial dysfunction, the up-regulation of tissue factor (TF) expression promotes the pathogenic activation of blood coagulation, however the relationship between gap junctions and TF expression in ECs remains uncharacterized. ECs express the gap junction (GJ) proteins connexin32 (Cx32), Cx37, Cx40 and Cx43. We investigated the role of endothelial gap junctions, particularly Cx32, in modulating TF expression during vascular inflammation. Human umbilical vein endothelial cells (HUVECs) were stimulated with tumor necrosis factor-α (TNF-α) and TF activity was assessed in the presence of GJ blockers and an inhibitory anti-Cx32 monoclonal antibody. Treatment with GJ blockers and anti-Cx32 monoclonal antibody enhanced the TNF-α-induced TF activity and mRNA expression in HUVECs. TNF-α-activated effector HUVECs or mouse MS-1 cells were co-cultured with non-stimulated acceptor HUVECs and TF expression in acceptor HUVECs was detected. Effector EC induced TF expression in adjacent acceptor HUVECs through direct cell-cell interaction. Cell-cell interaction induced TF expression was reduced by anti-intercellular adhesion molecule-1 (ICAM1) monoclonal antibody. Soluble ICAM1-Fc fusion protein promotes TF expression. GJ blockers and anti-Cx32 monoclonal antibody enhanced TF expression induced by cell-cell interaction and ICAM1-Fc treatment. Blockade of endothelial Cx32 increased TF expression induced by TNF-α stimulation and cell-cell interaction which was at least partly dependent upon ICAM1. These results suggest that direct Cx32-mediated interaction modulates TF expression in ECs during vascular inflammation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Association between left atrial phasic conduit function and early atrial fibrillation recurrence in patients undergoing electrical cardioversion.

PubMed

Degiovanni, Anna; Boggio, Enrico; Prenna, Eleonora; Sartori, Chiara; De Vecchi, Federica; Marino, Paolo N

2018-04-01

Diastolic dysfunction promotes atrial fibrillation (AF) inducing left atrial (LA) remodeling, with chamber dilation and fibrosis. Predominance of LA phasic conduit (LAC) function should reflect not only chamber alterations but also underlying left ventricular (LV) filling impairment. Thus, LAC was tested as possible predictor of early AF relapse after electrical cardioversion (EC). 96 consecutive patients, who underwent EC for persistent non-valvular AF, were prospectively enrolled. Immediately after successful EC (3 h ± 15 min), an echocardiographic apical four-chamber view was acquired with transmitral velocities, annular tissue Doppler and simultaneous LV and LA three-dimensional full-volume datasets. Then, from LA-LV volumetric curves we computed LAC as: [(LV maximum - LV minimum) - (LA maximum - LA minimum) volume], expressed as % LV stroke volume. LA pump, immediately post-EC, was assumed and verified as being negligible. Sinus rhythm persistence at 1 month was checked with ECG-Holter monitoring. At 1 month 62 patients were in sinus rhythm and 34 in AF. AF patients presented pre-EC higher E/é values (p = 0.012), no major LA volume differences (p = NS), but a stiffer LV cavity (p = 0.012) for a comparable LV capacitance (p = 0.461). Conduit contributed more (p < 0.001) to LV stroke volume in AF subpopulation. Multiple regression revealed LAC as the most significant AF predictor (p = 0.013), even after correction for biometric characteristics and pharmacotherapy (p = 0.008). Our data suggest that LAC larger contribution to LV filling soon after EC reflects LA-LV stiffening, which skews atrioventricular interaction leading to AF perpetuation and makes conduit dominance a powerful predictor of early AF recurrence.

Endotoxin induces fibrosis in vascular endothelial cells through a mechanism dependent on transient receptor protein melastatin 7 activity.

PubMed

Echeverría, Cesar; Montorfano, Ignacio; Hermosilla, Tamara; Armisén, Ricardo; Velásquez, Luis A; Cabello-Verrugio, Claudio; Varela, Diego; Simon, Felipe

2014-01-01

The pathogenesis of systemic inflammatory diseases, including endotoxemia-derived sepsis syndrome, is characterized by endothelial dysfunction. It has been demonstrated that the endotoxin lipopolysaccharide (LPS) induces the conversion of endothelial cells (ECs) into activated fibroblasts through endothelial-to-mesenchymal transition mechanism. Fibrogenesis is highly dependent on intracellular Ca2+ concentration increases through the participation of calcium channels. However, the specific molecular identity of the calcium channel that mediates the Ca2+ influx during endotoxin-induced endothelial fibrosis is still unknown. Transient receptor potential melastatin 7 (TRPM7) is a calcium channel that is expressed in many cell types, including ECs. TRPM7 is involved in a number of crucial processes such as the conversion of fibroblasts into activated fibroblasts, or myofibroblasts, being responsible for the development of several characteristics of them. However, the role of the TRPM7 ion channel in endotoxin-induced endothelial fibrosis is unknown. Thus, our aim was to study whether the TRPM7 calcium channel participates in endotoxin-induced endothelial fibrosis. Using primary cultures of ECs, we demonstrated that TRPM7 is a crucial protein involved in endotoxin-induced endothelial fibrosis. Suppression of TRPM7 expression protected ECs from the fibrogenic process stimulated by endotoxin. Downregulation of TRPM7 prevented the endotoxin-induced endothelial markers decrease and fibrotic genes increase in ECs. In addition, TRPM7 downregulation abolished the endotoxin-induced increase in ECM proteins in ECs. Furthermore, we showed that intracellular Ca2+ levels were greatly increased upon LPS challenge in a mechanism dependent on TRPM7 expression. These results demonstrate that TRPM7 is a key protein involved in the mechanism underlying endotoxin-induced endothelial fibrosis.

Combined Quantum Chemical/Raman Spectroscopic Analyses of Li+ Cation Solvation: Cyclic Carbonate Solvents - Ethylene Carbonate and Propylene Earbonate

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

Allen, Joshua L.; Borodin, Oleg; Seo, D. M.

2014-12-01

Combined computational/Raman spectroscopic analyses of ethylene carbonate (EC) and propylene carbonate (PC) solvation interactions with lithium salts are reported. It is proposed that previously reported Raman analyses of (EC)n-LiX mixtures have utilized faulty assumptions. In the present studies, density functional theory (DFT) calculations have provided corrections in terms of both the scaling factors for the solvent's Raman band intensity variations and information about band overlap. By accounting for these factors, the solvation numbers obtained from two different EC solvent bands are in excellent agreement with one another. The same analysis for PC, however, was found to be quite challenging. Commerciallymore » available PC is a racemic mixture of (S)- and (R)-PC isomers. Based upon the quantum chemistry calculations, each of these solvent isomers may exist as multiple conformers due to a low energy barrier for ring inversion, making deconvolution of the Raman bands daunting and inherently prone to significant error. Thus, Raman spectroscopy is able to accurately determine the extent of the EC...Li+ cation solvation interactions using the provided methodology, but a similar analysis of PC...Li+ cation solvation results in a significant underestimation of the actual solvation numbers.« less

Retinal vascular injuries and intravitreal human embryonic stem cell-derived haemangioblasts.

PubMed

Wang, Jin-Da; An, Ying; Zhang, Jing-Shang; Wan, Xiu-Hua; Zhang, Wei; Lanza, Robert; Lu, Shi-Jiang; Jonas, Jost B; Xu, Liang

2017-09-01

To investigate whether intravitreally applied haemangioblasts (HB) derived from human embryonic stem cells (hESCs) are helpful for the repair of vascular damage caused in animals by an oxygen-induced retinopathy (OIR), by an induced diabetic retinopathy (DR) or by an induced retinal ischaemia with subsequent reperfusion. Human embryonic stem cell-derived HBs were transplanted intravitreally into C57BL/6J mice (OIR model), into male Wistar rats with an induced DR and into male Wistar rats undergoing induced retinal ischaemia with subsequent reperfusion. Control groups of animals received an intravitreal injection of endothelial cells (ECs) or phosphate-buffered saline (PBS). We examined the vasculature integrity in the mice with OIR, the blood-retina barrier in the rats with induced DR, and retinal thickness and retinal ganglion cell density in retina flat mounts of the rats with the retinal ischaemic-reperfusion retinopathy. In the OIR model, the study group versus control groups showed a significantly (p < 0.001) smaller retinal avascular area [5.1 ± 2.7%;n = 18 animals versus 12.2 ± 2.8% (PBS group; n = 10 animals) and versus 11.8 ± 3.7% (EC group; n = 8 animals)] and less retinal neovascularization [6.3 ± 2.5%;n = 18 versus 15.2 ± 6.3% (n = 10; PBS group) and versus 15.8 ± 3.3% (n = 8; EC group)]. On retinal flat mounts, hESC-HBs were integrated into damaged retinal vessels and stained positive for PECAM (CD31) as EC marker. In the DR model, the study group versus the EC control group showed a significantly (p = 0.001) better blood-retina barrier function as measured at 2 days after the intravitreal injections [study group: 20.2 ± 12.8 μl/(g × hr); n = 6; versus EC control group: 52.9 ± 9.9 μl/(g × hr; n = 6)]. In the retinal ischaemia-reperfusion model, the groups did not differ significantly in retinal thickness and retinal ganglion cell density at 2, 5 and 7 days after baseline. By integrating into damaged retinal vessels and differentiating into ECs, intravitreally administered hESC-HBs may have partially repaired a retinal vascular injury caused by OIR model and DR. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Carbachol inhibits TNF-α-induced endothelial barrier dysfunction through alpha 7 nicotinic receptors.

PubMed

Li, Yu-zhen; Liu, Xiu-hua; Rong, Fei; Hu, Sen; Sheng, Zhi-yong

2010-10-01

To test whether carbachol can influence endothelial barrier dysfunction induced by tumor necrosis factor (TNF)-α and whether the alpha 7 nicotinic receptor can mediate this process. Rat cardiac microvascular endothelial cells were exposed to carbachol followed by TNF-α treatment in the presence or the absence of α-bungarotoxin (an antagonist of the alpha 7 nicotinic receptor). Permeability of endothelial cells cultured on Transwell filters was assayed using FITC-albumin. F-actin was stained with FITC- phalloidin. Expression of vascular endothelial cadherin, intercellular adhesion molecule 1 (ICAM-1), phosphor-ERK1/2 and phosphor-JNK was detected using Western blot. Carbachol (2 μmol/L-2 mmol/L) prevented increase in endothelial cell permeability induced by TNF-α (500 ng/mL) in a dose-dependent manner. Further, it attenuated the down-regulation of vascular endothelial cadherin and the up-regulation of ICAM-1 induced by TNF-α. In addition, treatment of endothelial cells with carbachol decreased phosphor-ERK1/2 and phosphor-JNK. These effects of carbachol were blocked by α-bungarotoxin 3 μg/mL. These data suggest that the inhibitory effect of carbachol on TNF-α-induced endothelial barrier dysfunction mediated by the alpha 7 nicotinic receptor.

Carbachol inhibits TNF-α-induced endothelial barrier dysfunction through alpha 7 nicotinic receptors

PubMed Central

Li, Yu-zhen; Liu, Xiu-hua; Rong, Fei; Hu, Sen; Sheng, Zhi-yong

2010-01-01

Aim: To test whether carbachol can influence endothelial barrier dysfunction induced by tumor necrosis factor (TNF)-α and whether the alpha 7 nicotinic receptor can mediate this process. Methods: Rat cardiac microvascular endothelial cells were exposed to carbachol followed by TNF-α treatment in the presence or the absence of α-bungarotoxin (an antagonist of the alpha 7 nicotinic receptor). Permeability of endothelial cells cultured on Transwell filters was assayed using FITC-albumin. F-actin was stained with FITC- phalloidin. Expression of vascular endothelial cadherin, intercellular adhesion molecule 1 (ICAM-1), phosphor-ERK1/2 and phosphor-JNK was detected using Western blot. Results: Carbachol (2 μmol/L-2 mmol/L) prevented increase in endothelial cell permeability induced by TNF-α (500 ng/mL) in a dose-dependent manner. Further, it attenuated the down-regulation of vascular endothelial cadherin and the up-regulation of ICAM-1 induced by TNF-α. In addition, treatment of endothelial cells with carbachol decreased phosphor-ERK1/2 and phosphor-JNK. These effects of carbachol were blocked by α-bungarotoxin 3 μg/mL. Conclusion: These data suggest that the inhibitory effect of carbachol on TNF-α-induced endothelial barrier dysfunction mediated by the alpha 7 nicotinic receptor. PMID:20871620

Addressing Water Consumption of Evaporative Coolers with Greywater

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

Sahai, Rashmi; Shah, Nihar; Phadke, Amol

Evaporative coolers (ECs) provide significant gains in energy efficiency compared to vapor compression air conditioners, but simultaneously have significant onsite water demand. This can be a major barrier to deployment in areas of the world with hot and arid climates. To address this concern, this study determined where in the world evaporative cooling is suitable, the water consumption of ECs in these cities, and the potential that greywater can be used reduce the consumption of potable water in ECs. ECs covered 69percent of the cities where room air conditioners are may be deployed, based on comfort conditions alone. The averagemore » water consumption due to ECs was found to be 400 L/household/day in the United States and Australia, with the potential for greywater to provide 50percent this amount. In the rest of the world, the average water consumption was 250 L/household/day, with the potential for greywater to supply 80percent of this amount. Home size was the main factor that contributed to this difference. In the Mediterranean, the Middle East, Northern India, and the Midwestern and Southwestern United States alkalinity levels are high and water used for bleeding will likely contribute significantly to EC water consumption. Although technically feasible, upfront costs for household GW systems are currently high. In both developed and developing parts of the world, however, a direct EC and GW system is cost competitive with conventional vapor compression air conditioners. Moreover, in regions of the world that face problems of water scarcity the benefits can substantially outweigh the costs.« less

Gαq/11-mediated intracellular calcium responses to retrograde flow in endothelial cells.

PubMed

Melchior, Benoît; Frangos, John A

2012-08-15

Disturbed flow patterns, including reversal in flow direction, are key factors in the development of dysfunctional endothelial cells (ECs) and atherosclerotic lesions. An almost immediate response of ECs to fluid shear stress is the increase in cytosolic calcium concentration ([Ca(2+)](i)). Whether the source of [Ca(2+)](i) is extracellular, released from Ca(2+) intracellular stores, or both is still undefined, though it is likely dependent on the nature of forces involved. We have previously shown that a change in flow direction (retrograde flow) on a flow-adapted endothelial monolayer induces the remodeling of the cell-cell junction along with a dramatic [Ca(2+)](i) burst compared with cells exposed to unidirectional or orthograde flow. The heterotrimeric G protein-α q and 11 subunit (Gα(q/11)) is a likely candidate in effecting shear-induced increases in [Ca(2+)](i) since its expression is enriched at the junction and has been previously shown to be activated within seconds after onset of flow. In flow-adapted human ECs, we have investigated to what extent the Gα(q/11) pathway mediates calcium dynamics after reversal in flow direction. We observed that the elapsed time to peak [Ca(2+)](i) response to a 10 dyn/cm(2) retrograde shear stress was increased by 11 s in cells silenced with small interfering RNA directed against Gα(q/11). A similar lag in [Ca(2+)](i) transient was observed after cells were treated with the phospholipase C (PLC)-βγ inhibitor, U-73122, or the phosphatidylinositol-specific PLC inhibitor, edelfosine, compared with controls. Lower levels of inositol 1,4,5-trisphosphate accumulation seconds after the onset of flow correlated with the increased lag in [Ca(2+)](i) responses observed with the different treatments. In addition, inhibition of the inositol 1,4,5-trisphosphate receptor entirely abrogated flow-induced [Ca(2+)](i). Taken together, our results identify the Gα(q/11)-PLC pathway as the initial trigger for retrograde flow-induced endoplasmic reticulum calcium store release, thereby offering a novel approach to regulating EC dysfunctions in regions subjected to the reversal of blood flow.

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.

Views and Experiences of Malaysian Family Medicine Trainees of Female Sexual Dysfunction.

PubMed

Lai, Pauline Siew Mei; Tan, Sing Yee; Liew, Su May

2016-11-01

Sociocultural factors have been shown to be important influencers of sexual health and sexuality. Hence, the aim of our study was to explore the views and experiences of family medicine trainees regarding female sexual dysfunction (FSD) with a focus on the barriers and facilitators towards the initiation of conversation on this topic. A qualitative study design involving semi-structured focus group discussions (FGDs) was conducted with 19 family medicine trainees in Malaysia. The conceptual framework used was based on the Theory of Planned Behavior. Thematic approach was used to analyze the data. Participants perceived FSD as being uncommon and unimportant. According to our participants, patients often presented with indirect complaints, and doctors were not proactive in asking about FSD. Three main barriers were identified: doctor factors, perceived patient factors, and system factors. Lack of confidence, knowledge, experience, time, and embarrassment were the key barriers identified at the doctors' level. Lack of awareness, among patients regarding FSD, and local cultural and religious norms were the perceived patient barriers. System barriers were lack of time and privacy. Various facilitators, such as continuous medical education and public forums, were suggested as means to encourage family medicine trainees to initiate discussion on sexual matters during consultations. In conclusion, family medicine trainees found it difficult to initiate conversation on FSD with patients. Interventions to encourage conversation on FSD should target this and other identified barriers.

Cordyceps sinensis preserves intestinal mucosal barrier and may be an adjunct therapy in endotoxin-induced sepsis rat model: a pilot study

PubMed Central

Gu, Guo-Sheng; Ren, Jian-An; Li, Guan-Wei; Yuan, Yu-Jie; Li, Ning; Li, Jie-Shou

2015-01-01

Background: Cordyceps sinensis (C. sinensis), a traditional Chinese medicine, exhibits various pharmacological activities such as reparative, antioxidant, and apoptosis inhibitory effects. Intestinal barrier dysfunction plays a vital role in the progression of sepsis. We aimed to explore the effect of C. sinensis on the gut barrier and evaluate its efficacy in sepsis. Methods: A murine model of gut barrier dysfunction was created by intraperitoneal injection of endotoxin. C. sinensis or saline was administered orally after the induction of sepsis. Alterations of intestinal barrier were evaluated and compared in terms of epithelial cell apoptosis, proliferation index (PI), intercellular tight junction (TJ) and proliferating cell nuclear antigen (PCNA). Results: C. sinensis significantly decreased the percentage of apoptotic cells and promoted mucosal cells proliferation indicated by enhanced PI and PCNA expression in the intestinal mucosa compared to control group. The TJs between epithelial cells which were disrupted in septic rats were also restored by treatment of C. sinensis. In survival studies, C. sinensis was demonstrated to confer a protection against the lethal effect of sepsis. Conclusion: These results suggest that C. sinensis has gut barrier-protection effect in endotoxin-induced sepsis by promoting the proliferation and inhibiting the apoptosis of intestinal mucosal cells, as well as restoring the TJs of intestinal mucosa. C. sinensis may have the potential to be a useful adjunct therapy for sepsis. PMID:26221273

Cordyceps sinensis preserves intestinal mucosal barrier and may be an adjunct therapy in endotoxin-induced sepsis rat model: a pilot study.

PubMed

Gu, Guo-Sheng; Ren, Jian-An; Li, Guan-Wei; Yuan, Yu-Jie; Li, Ning; Li, Jie-Shou

2015-01-01

Cordyceps sinensis (C. sinensis), a traditional Chinese medicine, exhibits various pharmacological activities such as reparative, antioxidant, and apoptosis inhibitory effects. Intestinal barrier dysfunction plays a vital role in the progression of sepsis. We aimed to explore the effect of C. sinensis on the gut barrier and evaluate its efficacy in sepsis. A murine model of gut barrier dysfunction was created by intraperitoneal injection of endotoxin. C. sinensis or saline was administered orally after the induction of sepsis. Alterations of intestinal barrier were evaluated and compared in terms of epithelial cell apoptosis, proliferation index (PI), intercellular tight junction (TJ) and proliferating cell nuclear antigen (PCNA). C. sinensis significantly decreased the percentage of apoptotic cells and promoted mucosal cells proliferation indicated by enhanced PI and PCNA expression in the intestinal mucosa compared to control group. The TJs between epithelial cells which were disrupted in septic rats were also restored by treatment of C. sinensis. In survival studies, C. sinensis was demonstrated to confer a protection against the lethal effect of sepsis. These results suggest that C. sinensis has gut barrier-protection effect in endotoxin-induced sepsis by promoting the proliferation and inhibiting the apoptosis of intestinal mucosal cells, as well as restoring the TJs of intestinal mucosa. C. sinensis may have the potential to be a useful adjunct therapy for sepsis.

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.

Blood-brain barrier dysfunction in mice induced by lipopolysaccharide is attenuated by dapsone.

PubMed

Zhou, Ting; Zhao, Lei; Zhan, Rui; He, Qihua; Tong, Yawei; Tian, Xiaosheng; Wang, Hecheng; Zhang, Tao; Fu, Yaoyun; Sun, Yang; Xu, Feng; Guo, Xiangyang; Fan, Dongsheng; Han, Hongbin; Chui, Dehua

2014-10-24

Blood-brain barrier (BBB) dysfunction is a key event in the development of many central nervous system (CNS) diseases, such as septic encephalopathy and stroke. 4,4'-Diaminodiphenylsulfone (DDS, Dapsone) has displayed neuroprotective effect, but whether DDS has protective role on BBB integrity is not clear. This study was designed to examine the effect of DDS on lipopolysaccharide (LPS)-induced BBB disruption and oxidative stress in brain vessels. Using in vivo multiphoton imaging, we found that DDS administration significantly restored BBB integrity compromised by LPS. DDS also increased the expression of tight junction proteins occludin, zona occludens-1 (ZO-1) and claudin-5 in brain vessels. Level of reactive oxygen species (ROS) was reduced by DDS treatment, which may due to decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and NOX2 expression. Our results showed that LPS-induced BBB dysfunction could be attenuated by DDS, indicated that DDS has a therapeutic potential for treating CNS infection and other BBB related diseases. Copyright © 2014 Elsevier Inc. All rights reserved.

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

Inward rectifier potassium (Kir2.1) channels as end-stage boosters of endothelium-dependent vasodilators.

PubMed

Sonkusare, Swapnil K; Dalsgaard, Thomas; Bonev, Adrian D; Nelson, Mark T

2016-06-15

Increase in endothelial cell (EC) calcium activates calcium-sensitive intermediate and small conductance potassium (IK and SK) channels, thereby causing hyperpolarization and endothelium-dependent vasodilatation. Endothelial cells express inward rectifier potassium (Kir) channels, but their role in endothelium-dependent vasodilatation is not clear. In the mesenteric arteries, only ECs, but not smooth muscle cells, displayed Kir currents that were predominantly mediated by the Kir2.1 isoform. Endothelium-dependent vasodilatations in response to muscarinic receptor, TRPV4 (transient receptor potential vanilloid 4) channel and IK/SK channel agonists were highly attenuated by Kir channel inhibitors and by Kir2.1 channel knockdown. These results point to EC Kir channels as amplifiers of vasodilatation in response to increases in EC calcium and IK/SK channel activation and suggest that EC Kir channels could be targeted to treat endothelial dysfunction, which is a hallmark of vascular disorders. Endothelium-dependent vasodilators, such as acetylcholine, increase intracellular Ca(2+) through activation of transient receptor potential vanilloid 4 (TRPV4) channels in the plasma membrane and inositol trisphosphate receptors in the endoplasmic reticulum, leading to stimulation of Ca(2+) -sensitive intermediate and small conductance K(+) (IK and SK, respectively) channels. Although strong inward rectifier K(+) (Kir) channels have been reported in the native endothelial cells (ECs) their role in EC-dependent vasodilatation is not clear. Here, we test the idea that Kir channels boost the EC-dependent vasodilatation of resistance-sized arteries. We show that ECs, but not smooth muscle cells, of small mesenteric arteries have Kir currents, which are substantially reduced in EC-specific Kir2.1 knockdown (EC-Kir2.1(-/-) ) mice. Elevation of extracellular K(+) to 14 mm caused vasodilatation of pressurized arteries, which was prevented by endothelial denudation and Kir channel inhibitors (Ba(2+) , ML-133) or in the arteries from EC-Kir2.1(-/-) mice. Potassium-induced dilatations were unaffected by inhibitors of TRPV4, IK and SK channels. The Kir channel blocker, Ba(2+) , did not affect currents through TRPV4, IK or SK channels. Endothelial cell-dependent vasodilatations in response to activation of muscarinic receptors, TRPV4 channels or IK/SK channels were reduced, but not eliminated, by Kir channel inhibitors or EC-Kir2.1(-/-) . In angiotensin II-induced hypertension, the Kir channel function was not altered, although the endothelium-dependent vasodilatation was severely impaired. Our results support the concept that EC Kir2 channels boost vasodilatory signals that are generated by Ca(2+) -dependent activation of IK and SK channels. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

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

Extracorporeal membrane oxygenation causes loss of intestinal epithelial barrier in the newborn piglet.

PubMed

Kurundkar, Ashish R; Killingsworth, Cheryl R; McIlwain, R Britt; Timpa, Joseph G; Hartman, Yolanda E; He, Dongning; Karnatak, Rajendra K; Neel, Mary L; Clancy, John P; Anantharamaiah, G M; Maheshwari, Akhil

2010-08-01

Extracorporeal membrane oxygenation (ECMO) is an important life-support system used in neonates and young children with intractable cardiorespiratory failure. In this study, we used our porcine neonatal model of venoarterial ECMO to investigate whether ECMO causes gut barrier dysfunction. We subjected 3-wk-old previously healthy piglets to venoarterial ECMO for up to 8 h and evaluated gut mucosal permeability, bacterial translocation, plasma levels of bacterial products, and ultrastructural changes in gut epithelium. We also measured plasma lipopolysaccharide (LPS) levels in a small cohort of human neonates receiving ECMO. In our porcine model, ECMO caused a rapid increase in gut mucosal permeability within the first 2 h of treatment, leading to a 6- to 10-fold rise in circulating bacterial products. These changes in barrier function were associated with cytoskeletal condensation in epithelial cells, which was explained by phosphorylation of a myosin II regulatory light chain. In support of these findings, we also detected elevated plasma LPS levels in human neonates receiving ECMO, indicating a similar loss of gut barrier function in these infants. On the basis of these data, we conclude that ECMO is an independent cause of gut barrier dysfunction and bacterial translocation may be an important contributor to ECMO-related inflammation.

Extracorporeal Membrane Oxygenation Causes Loss of Intestinal Epithelial Barrier in the Newborn Piglet

PubMed Central

Kurundkar, Ashish R.; Killingsworth, Cheryl R.; McILwain, R. Britt; Timpa, Joseph G.; Hartman, Yolanda E.; He, Dongning; Karnatak, Rajendra K.; Neel, Mary Lauren; Clancy, John P.; Anantharamaiah, G. M.; Maheshwari, Akhil

2010-01-01

Extracorporeal membrane oxygenation (ECMO) is an important life-support system used in neonates and young children with intractable cardiorespiratory failure. In this study, we used our porcine neonatal model of venoarterial ECMO to investigate whether ECMO causes gut barrier dysfunction. We subjected 3-week-old previously-healthy piglets to venoarterial ECMO for up to 8 hours and evaluated gut mucosal permeability, bacterial translocation, plasma levels of bacterial products, and ultrastructural changes in gut epithelium. We also measured plasma lipopolysaccharide (LPS) levels in a small cohort of human neonates receiving ECMO. In our porcine model, ECMO caused a rapid increase in gut mucosal permeability within the first 2 hours of treatment, leading to a 6–10 fold rise in circulating bacterial products. These changes in barrier function were associated with cytoskeletal condensation in epithelial cells, which was explained by phosphorylation of a myosin II regulatory light chain. In support of these findings, we also detected elevated plasma LPS levels in human neonates receiving ECMO, indicating a similar loss of gut barrier function in these infants. Based on these data, we conclude that ECMO is an independent cause of gut barrier dysfunction, and that bacterial translocation may be an important contributor to ECMO-related inflammation. PMID:20442689

Radio-frequency current drive efficiency in the presence of ITBs and a dc electric field

NASA Astrophysics Data System (ADS)

Rosa, P. R. da S.; Mourão, R.; Ziebell, L. F.

2009-05-01

This paper discusses the current drive efficiency by the combined action of EC and LH waves in the presence of a dc electric field and transport, with an internal transport barrier. The transport is assumed to be produced by magnetic fluctuations. The study explores the different barrier parameters and their influence on the current drive efficiency. We study the subject by numerically solving the Fokker-Planck equation. Our main result is that the barrier depth and barrier width are important to determine the correct shape of the current density profile but not to determine the current drive efficiency, which is very little influenced by these parameters. We also found similar results for the influence of the level of magnetic fluctuations on the current density profile and on the current drive efficiency.

N-Acetylcysteine, a glutathione precursor, reverts vascular dysfunction and endothelial epigenetic programming in intrauterine growth restricted guinea pigs.

PubMed

Herrera, Emilio A; Cifuentes-Zúñiga, Francisca; Figueroa, Esteban; Villanueva, Cristian; Hernández, Cherie; Alegría, René; Arroyo-Jousse, Viviana; Peñaloza, Estefania; Farías, Marcelo; Uauy, Ricardo; Casanello, Paola; Krause, Bernardo J

2017-02-15

Intrauterine growth restriction (IUGR) is associated with vascular dysfunction, oxidative stress and signs of endothelial epigenetic programming of the umbilical vessels. There is no evidence that this epigenetic programming is occurring on systemic fetal arteries. In IUGR guinea pigs we studied the functional and epigenetic programming of endothelial nitric oxide synthase (eNOS) (Nos3 gene) in umbilical and systemic fetal arteries, addressing the role of oxidative stress in this process by maternal treatment with N-acetylcysteine (NAC) during the second half of gestation. The present study suggests that IUGR endothelial cells have common molecular markers of programming in umbilical and systemic arteries. Notably, maternal treatment with NAC restores fetal growth by increasing placental efficiency and reverting the functional and epigenetic programming of eNOS in arterial endothelium in IUGR guinea pigs. In humans, intrauterine growth restriction (IUGR) is associated with vascular dysfunction, oxidative stress and signs of endothelial programming in umbilical vessels. We aimed to determine the effects of maternal antioxidant treatment with N-acetylcysteine (NAC) on fetal endothelial function and endothelial nitric oxide synthase (eNOS) programming in IUGR guinea pigs. IUGR was induced by implanting ameroid constrictors on uterine arteries of pregnant guinea pigs at mid gestation, half of the sows receiving NAC in the drinking water (from day 34 until term). Fetal biometry and placental vascular resistance were followed by ultrasound throughout gestation. At term, umbilical arteries and fetal aortae were isolated to assess endothelial function by wire-myography. Primary cultures of endothelial cells (ECs) from fetal aorta, femoral and umbilical arteries were used to determine eNOS mRNA levels by quantitative PCR and analyse DNA methylation in the Nos3 promoter by pyrosequencing. Doppler ultrasound measurements showed that NAC reduced placental vascular resistance in IUGR (P < 0.05) and recovered fetal weight (P < 0.05), increasing fetal-to-placental ratio at term (∼40%) (P < 0.001). In IUGR, NAC treatment restored eNOS-dependent relaxation in aorta and umbilical arteries (P < 0.05), normalizing eNOS mRNA levels in EC fetal and umbilical arteries (P < 0.05). IUGR-derived ECs had a decreased DNA methylation (∼30%) at CpG -170 (from the transcription start site) and this epigenetic signature was absent in NAC-treated fetuses (P < 0.001). These data show that IUGR-ECs have common molecular markers of eNOS programming in umbilical and systemic arteries and this effect is prevented by maternal treatment with antioxidants. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Low Immunogenic Endothelial Cells Maintain Morphological and Functional Properties Required for Vascular Tissue Engineering.

PubMed

Lau, Skadi; Eicke, Dorothee; Carvalho Oliveira, Marco; Wiegmann, Bettina; Schrimpf, Claudia; Haverich, Axel; Blasczyk, Rainer; Wilhelmi, Mathias; Figueiredo, Constança; Böer, Ulrike

2018-03-01

The limited availability of native vessels suitable for the application as hemodialysis shunts or bypass material demands new strategies in cardiovascular surgery. Tissue-engineered vascular grafts containing autologous cells are considered ideal vessel replacements due to the low risk of rejection. However, endothelial cells (EC), which are central components of natural blood vessels, are difficult to obtain from elderly patients of poor health. Umbilical cord blood represents a promising alternative source for EC, but their allogeneic origin corresponds with the risk of rejection after allotransplantation. To reduce this risk, the human leukocyte antigen class I (HLA I) complex was stably silenced by lentiviral vector-mediated RNA interference (RNAi) in EC from peripheral blood and umbilical cord blood and vein. EC from all three sources were transduced by 93.1% ± 4.8% and effectively, HLA I-silenced by up to 67% compared to nontransduced (NT) cells or transduced with a nonspecific short hairpin RNA, respectively. Silenced EC remained capable to express characteristic endothelial surface markers such as CD31 and vascular endothelial cadherin important for constructing a tight barrier, as well as von Willebrand factor and endothelial nitric oxide synthase important for blood coagulation and vessel tone regulation. Moreover, HLA I-silenced EC were still able to align under unidirectional flow, to take up acetylated low-density lipoprotein, and to form capillary-like tube structures in three-dimensional fibrin gels similar to NT cells. In particular, addition of adipose tissue-derived mesenchymal stem cells significantly improved tube formation capability of HLA I-silenced EC toward long and widely branched vascular networks necessary for prevascularizing vascular grafts. Thus, silencing HLA I by RNAi represents a promising technique to reduce the immunogenic potential of EC from three different sources without interfering with EC-specific morphological and functional properties required for vascular tissue engineering. This extends the spectrum of available cell sources from autologous to allogeneic sources, thereby accelerating the generation of tissue-engineered vascular grafts in acute clinical cases.

Reversal of cigarette smoke extract-induced sinonasal epithelial cell barrier dysfunction through Nrf2 Activation.

PubMed

Tharakan, Anuj; Halderman, Ashleigh A; Lane, Andrew P; Biswal, Shyam; Ramanathan, Murugappan

2016-11-01

Environmental factors such as inhaled pollutants like cigarette smoke may play a significant role in diseases of the upper airway including chronic rhinosinusitis (CRS). Recent studies have shown that cigarette smoke causes impaired airway epithelial cell barrier function likely through environmental oxidative stress related pathways. The purpose of this study is to explore whether enhancing nuclear factor erythroid 2 [NF-E2]-related factor 2 [Nrf2], the body's master antioxidant system, can ameliorate cigarette smoke-induced sinonasal epithelial cell (SNEC) barrier dysfunction. Human SNECs (HSNECs) were grown from control patients at the air-liquid interface (ALI). HSNECs were stimulated with cigarette smoke extract (CSE) with and without pharmacologic activation of Nrf2. HSNECs were then stained for the epithelial cell junctional proteins zonula occludens 1 (ZO-1) and junctional adhesion molecule A (JAM-A) using confocal microscopy. In addition, transepithelial electrical resistance (TER) was measured in cultures before and after stimulation with CSE. CSE stimulation caused a global disruption of the epithelial junctional proteins ZO-1 and JAM-A along with an associated decrease in TER levels. Enhancing Nrf2 levels prior to stimulation with CSE was associated with increased localization of ZO-1 and JAM-A levels at the cell surface and statistically significant increases in TER levels. This is the first study to demonstrate that cigarette smoke induced SNEC barrier dysfunction is reversible by Nrf2 activation. The Nrf2 antioxidant pathway may represent a potential therapeutic target for cigarette smoke-associated sinonasal inflammation. © 2016 ARS-AAOA, LLC.

Cell-Specific Imd-NF-κB Responses Enable Simultaneous Antibacterial Immunity and Intestinal Epithelial Cell Shedding upon Bacterial Infection.

PubMed

Zhai, Zongzhao; Boquete, Jean-Philippe; Lemaitre, Bruno

2018-05-03

Intestinal infection triggers potent immune responses to combat pathogens and concomitantly drives epithelial renewal to maintain barrier integrity. Current models propose that epithelial renewal is primarily driven by damage caused by reactive oxygen species (ROS). Here we found that in Drosophila, the Imd-NF-κB pathway controlled enterocyte (EC) shedding upon infection, via a mechanism independent of ROS-associated apoptosis. Mechanistically, the Imd pathway synergized with JNK signaling to induce epithelial cell shedding specifically in the context of bacterial infection, requiring also the reduced expression of the transcription factor GATAe. Furthermore, cell-specific NF-κB responses enabled simultaneous production of antimicrobial peptides (AMPs) and epithelial shedding in different EC populations. Thus, the Imd-NF-κB pathway is central to the intestinal antibacterial response by mediating both AMP production and the maintenance of barrier integrity. Considering the similarities between Drosophila Imd signaling and mammalian TNFR pathway, our findings suggest the existence of an evolutionarily conserved genetic program in immunity-induced epithelial shedding. Copyright © 2018 Elsevier Inc. All rights reserved.

Lyophilized plasma attenuates vascular permeability, inflammation and lung injury in hemorrhagic shock.

PubMed

Pati, Shibani; Peng, Zhanglong; Wataha, Katherine; Miyazawa, Byron; Potter, Daniel R; Kozar, Rosemary A

2018-01-01

In severe trauma and hemorrhage the early and empiric use of fresh frozen plasma (FFP) is associated with decreased morbidity and mortality. However, utilization of FFP comes with the significant burden of shipping and storage of frozen blood products. Dried or lyophilized plasma (LP) can be stored at room temperature, transported easily, reconstituted rapidly with ready availability in remote and austere environments. We have previously demonstrated that FFP mitigates the endothelial injury that ensues after hemorrhagic shock (HS). In the current study, we sought to determine whether LP has similar properties to FFP in its ability to modulate endothelial dysfunction in vitro and in vivo. Single donor LP was compared to single donor FFP using the following measures of endothelial cell (EC) function in vitro: permeability and transendothelial monolayer resistance; adherens junction preservation; and leukocyte-EC adhesion. In vivo, using a model of murine HS, LP and FFP were compared in measures of HS- induced pulmonary vascular inflammation and edema. Both in vitro and in vivo in all measures of EC function, LP demonstrated similar effects to FFP. Both FFP and LP similarly reduced EC permeability, increased transendothelial resistance, decreased leukocyte-EC binding and persevered adherens junctions. In vivo, LP and FFP both comparably reduced pulmonary injury, inflammation and vascular leak. Both FFP and LP have similar potent protective effects on the vascular endothelium in vitro and in lung function in vivo following hemorrhagic shock. These data support the further development of LP as an effective plasma product for human use after trauma and hemorrhagic shock.

Increased c-kit and stem cell factor expression in the pulmonary vasculature of nitrofen-induced congenital diaphragmatic hernia.

PubMed

Takahashi, Toshiaki; Friedmacher, Florian; Zimmer, Julia; Puri, Prem

2016-05-01

Persistent pulmonary hypertension(PPH) in congenital diaphragmatic hernia (CDH) is caused by increased vascular cell proliferation and endothelial cell (EC) dysfunction, thus leading to obstructive changes in the pulmonary vasculature. C-Kit and its ligand, stem cell factor(SCF), are expressed by ECs in the developing lung mesenchyme, suggesting an important role during lung vascular formation. Conversely, absence of c-Kit expression has been demonstrated in ECs of dysplastic alveolar capillaries. We hypothesized that c-Kit and SCF expression is increased in the pulmonary vasculature of nitrofen-induced CDH. Timed-pregnant rats received nitrofen or vehicle on gestational day 9(D9). Fetuses were sacrificed on D15, D18, and D21, and divided into control and CDH group. Pulmonary gene expression levels of c-Kit and SCF were analyzed by qRT-PCR. Immunofluorescence double staining for c-Kit and SCF was combined with CD34 to evaluate protein expression in ECs of the pulmonary vasculature. Relative mRNA levels of c-Kit and SCF were significantly increased in lungs of CDH fetuses on D15, D18, and D21 compared to controls. Confocal laser scanning microscopy confirmed markedly increased vascular c-Kit and SCF expression in mesenchymal ECs of CDH lungs on D15, D18, and D21 compared to controls. Increased expression of c-Kit and SCF in the pulmonary vasculature of nitrofen-induced CDH lungs suggest that increased c-Kit signaling during lung vascular formation may contribute to vascular remodeling and thus to PPH. Copyright © 2016 Elsevier Inc. All rights reserved.

Tumor necrosis factor α (TNF-α) receptor-II is required for TNF-α–induced leukocyte-endothelial interaction in vivo

PubMed Central

Chandrasekharan, Unni M.; Siemionow, Maria; Unsal, Murat; Yang, Lin; Poptic, Earl; Bohn, Justin; Ozer, Kagan; Zhou, Zhongmin; Howe, Philip H.; Penn, Marc

2007-01-01

Tumor necrosis factor-α (TNF-α) binds to 2 distinct cell-surface receptors: TNF-α receptor-I (TNFR-I: p55) and TNF-α receptor-II (TNFR-II: p75). TNF-α induces leukocyte adhesion molecules on endothelial cells (ECs), which mediate 3 defined steps of the inflammatory response; namely, leukocyte rolling, firm adhesion, and transmigration. In this study, we have investigated the role of p75 in TNF-α–induced leukocyte adhesion molecules using cultured ECs derived from wild-type (WT), p75-null (p75−/−), or p55-null (p55−/−) mice. We observed that p75 was essential for TNF-α–induced E-selectin, vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule 1 (ICAM-1) expression. We also investigated the putative role of p75 in inflammation in vivo using an intravital microscopic approach with a mouse cremaster muscle model. TNF-α–stimulated leukocyte rolling, firm adhesion to ECs, and transmigration were dramatically reduced in p75−/− mice. Transplanted WT cremaster in p75−/− mice showed a robust leukocyte rolling and firm adhesion upon TNF-α activation, suggesting that the impairment in EC-leukocyte interaction in p75−/− mice is due to EC dysfunction. These results demonstrate, for the first time, that endothelial p75 is essential for TNF-α–induced leukocyte–endothelial-cell interaction. Our findings may contribute to the identification of novel p75-targeted therapeutic approaches for inflammatory diseases. PMID:17068152

Homocysteine up-regulates vascular transmembrane chemokine CXCL16 and induces CXCR6+ lymphocyte recruitment in vitro and in vivo.

PubMed

Postea, O; Koenen, R R; Hristov, M; Weber, C; Ludwig, A

2008-01-01

Hyperhomocysteinemia induces endothelial dysfunction and promotes atherosclerotic vascular disease. Infiltrates of activated macrophages and lymphocytes are observed in human and experimental atherosclerotic lesions, their emigration being guided by endothelial-leukocyte adhesion molecules and chemoattractants. The CXC-chemokine CXCL16 functions as an adhesion molecule by interacting with its receptor (CXCR6) and also as a scavenger for oxidized low density lipoprotein (oxLDL). We investigated the modulation of CXCL16 on cultured endothelial cells (EC) and the recruitment of CXCR6(+) lymphocytes in response to homocysteine (Hcy), in vitro and in vivo. Hcy-stimulated EC show a significant increase in CXCL16 mRNA and protein expression. Incubation of EC with d,l-Hcy and l-Hcy significantly increased CXCR6(+) lymphocyte adhesion to EC while l-Cysteine (l-Cys) had no effect. Furthermore, EC stimulation with Hcy increased uptake of DiI-oxLDL. An anti-CXCL16 monoclonal antibody, antioxidants (Tiron) and PPAR-gamma agonists (Pioglitazone) considerably reduced CXCR6(+) lymphocyte adhesion and uptake of DiI-oxLDL. Upon injection in the peritoneal cavities of mice, l-Hcy and not l-Cys, increased the number of CXCR6(+) lymphocytes, which was reduced by coinjection with Pioglitazone or anti-human CXCL16 antibody. Hyperhomocysteinemia up-regulates CXCL16 leading to increased recruitment of CXCR6(+) lymphocytes and scavenging of modified lipids via a potential involvement of a PPAR-gamma-dependent mechanism. CXCL16 may therefore contribute to the formation and progression of atherosclerotic lesions under conditions of hyperhomocysteinemia.

Homocysteine up-regulates vascular transmembrane chemokine CXCL16 and induces CXCR6+ lymphocyte recruitment in vitro and in vivo

PubMed Central

Postea, O; Koenen, R R; Hristov, M; Weber, C; Ludwig, A

2008-01-01

Abstract Objective: Hyperhomocysteinemia induces endothelial dysfunction and promotes atherosclerotic vascular disease. Infiltrates of activated macrophages and lymphocytes are observed in human and experimental atherosclerotic lesions, their emigration being guided by endothelial-leukocyte adhesion molecules and chemoattractants. The CXC-chemokine CXCL16 functions as an adhesion molecule by interacting with its receptor (CXCR6) and also as a scavenger for oxidized low density lipoprotein (oxLDL). We investigated the modulation of CXCL16 on cultured endothelial cells (EC) and the recruitment of CXCR6+ lymphocytes in response to homocysteine (Hcy), in vitro and in vivo. Methods and Results: Hcy-stimulated EC show a significant increase in CXCL16 mRNA and protein expression. Incubation of EC with d,l-Hcy and l-Hcy significantly increased CXCR6+ lymphocyte adhesion to EC while l-Cysteine (l-Cys) had no effect. Furthermore, EC stimulation with Hcy increased uptake of DiI-oxLDL. An anti-CXCL16 monoclonal antibody, antioxidants (Tiron) and PPAR-γ agonists (Pioglitazone) considerably reduced CXCR6+ lymphocyte adhesion and uptake of DiI-oxLDL. Upon injection in the peritoneal cavities of mice, l-Hcy and not l-Cys, increased the number of CXCR6+ lymphocytes, which was reduced by coinjection with Pioglitazone or anti-human CXCL16 antibody. Conclusions: Hyperhomocysteinemia up-regulates CXCL16 leading to increased recruitment of CXCR6+ lymphocytes and scavenging of modified lipids via a potential involvement of a PPAR-γ-dependent mechanism. CXCL16 may therefore contribute to the formation and progression of atherosclerotic lesions under conditions of hyperhomocysteinemia. PMID:18194461

Serum creatinine detection by a conducting-polymer-based electrochemical sensor to identify allograft dysfunction.

PubMed

Wei, Fang; Cheng, Scott; Korin, Yael; Reed, Elaine F; Gjertson, David; Ho, Chih-ming; Gritsch, H Albin; Veale, Jeffrey

2012-09-18

Kidney transplant recipients who have abnormally high creatinine levels in their blood often have allograft dysfunction secondary to rejection. Creatinine has become the preferred marker for renal dysfunction and is readily available in hospital clinical settings. We developed a rapid and accurate polymer-based electrochemical point-of-care (POC) assay for creatinine detection from whole blood to identify allograft dysfunction. The creatinine concentrations of 19 blood samples from transplant recipients were measured directly from clinical serum samples by the conducting polymer-based electrochemical (EC) sensor arrays. These measurements were compared to the traditional clinical laboratory assay. The time required for detection was <5 min from sample loading. Sensitivity of the detection was found to be 0.46 mg/dL of creatinine with only 40 μL sample in the creatinine concentration range of 0 mg/dL to 11.33 mg/dL. Signal levels that were detected electrochemically correlated closely with the creatinine blood concentration detected by the UCLA Ronald Reagan Medical Center traditional clinical laboratory assay (correlation coefficient = 0.94). This work is encouraging for the development of a rapid and accurate POC device for measuring creatinine levels in whole blood.

Nutrients affecting gastric barrier.

PubMed

Gasbarrini, Antonio; D'Aversa, Francesca; Di Rienzo, Teresa; Franceschi, Francesco

2014-01-01

The gastric barrier could be considered an active tissue involved in many synthetic and metabolic functions, as the immunological defense, by activating mucosal immune system. Barrier integrity results from a balance between protective and aggressive endogenous factors and from their interaction with exogenous factors (steroidal or nonsteroidal anti-inflammatory drugs, dietary nitrates, nitrites and/or NaCl, stress, Helicobacter pylori infection, food allergens and contaminants, metals, chemicals, radiation, smoking and alcohol intake). Nutrients represent the most important exogenous factors affecting gastric barrier because of the impact on people's everyday life. We report evidence from the literature about nutrients affecting gastric barrier and we investigate the possible effect that nutrients can play to determining or maintaining a gastric barrier dysfunction. © 2014 S. Karger AG, Basel.

The endocannabinoid/endovanilloid N-arachidonoyl dopamine (NADA) and synthetic cannabinoid WIN55,212-2 abate the inflammatory activation of human endothelial cells.

PubMed

Wilhelmsen, Kevin; Khakpour, Samira; Tran, Alphonso; Sheehan, Kayla; Schumacher, Mark; Xu, Fengyun; Hellman, Judith

2014-05-09

Although cannabinoids, such as Δ(9)-tetrahydrocannabinol, have been studied extensively for their psychoactive effects, it has become apparent that certain cannabinoids possess immunomodulatory activity. Endothelial cells (ECs) are centrally involved in the pathogenesis of organ injury in acute inflammatory disorders, such as sepsis, because they express cytokines and chemokines, which facilitate the trafficking of leukocytes to organs, and they modulate vascular barrier function. In this study, we find that primary human ECs from multiple organs express the cannabinoid receptors CB1R, GPR18, and GPR55, as well as the ion channel transient receptor potential cation channel vanilloid type 1. In contrast to leukocytes, CB2R is only minimally expressed in some EC populations. Furthermore, we show that ECs express all of the known endocannabinoid (eCB) metabolic enzymes. Examining a panel of cannabinoids, we demonstrate that the synthetic cannabinoid WIN55,212-2 and the eCB N-arachidonoyl dopamine (NADA), but neither anandamide nor 2-arachidonoylglycerol, reduce EC inflammatory responses induced by bacterial lipopeptide, LPS, and TNFα. We find that endothelial CB1R/CB2R are necessary for the effects of NADA, but not those of WIN55,212-2. Furthermore, transient receptor potential cation channel vanilloid type 1 appears to counter the anti-inflammatory properties of WIN55,212-2 and NADA, but conversely, in the absence of these cannabinoids, its inhibition exacerbates the inflammatory response in ECs activated with LPS. These data indicate that the eCB system can modulate inflammatory activation of the endothelium and may have important implications for a variety of acute inflammatory disorders that are characterized by EC activation.

The Endocannabinoid/Endovanilloid N-Arachidonoyl Dopamine (NADA) and Synthetic Cannabinoid WIN55,212-2 Abate the Inflammatory Activation of Human Endothelial Cells*

PubMed Central

Wilhelmsen, Kevin; Khakpour, Samira; Tran, Alphonso; Sheehan, Kayla; Schumacher, Mark; Xu, Fengyun; Hellman, Judith

2014-01-01

Although cannabinoids, such as Δ9-tetrahydrocannabinol, have been studied extensively for their psychoactive effects, it has become apparent that certain cannabinoids possess immunomodulatory activity. Endothelial cells (ECs) are centrally involved in the pathogenesis of organ injury in acute inflammatory disorders, such as sepsis, because they express cytokines and chemokines, which facilitate the trafficking of leukocytes to organs, and they modulate vascular barrier function. In this study, we find that primary human ECs from multiple organs express the cannabinoid receptors CB1R, GPR18, and GPR55, as well as the ion channel transient receptor potential cation channel vanilloid type 1. In contrast to leukocytes, CB2R is only minimally expressed in some EC populations. Furthermore, we show that ECs express all of the known endocannabinoid (eCB) metabolic enzymes. Examining a panel of cannabinoids, we demonstrate that the synthetic cannabinoid WIN55,212-2 and the eCB N-arachidonoyl dopamine (NADA), but neither anandamide nor 2-arachidonoylglycerol, reduce EC inflammatory responses induced by bacterial lipopeptide, LPS, and TNFα. We find that endothelial CB1R/CB2R are necessary for the effects of NADA, but not those of WIN55,212-2. Furthermore, transient receptor potential cation channel vanilloid type 1 appears to counter the anti-inflammatory properties of WIN55,212-2 and NADA, but conversely, in the absence of these cannabinoids, its inhibition exacerbates the inflammatory response in ECs activated with LPS. These data indicate that the eCB system can modulate inflammatory activation of the endothelium and may have important implications for a variety of acute inflammatory disorders that are characterized by EC activation. PMID:24644287

Mechanisms of lung endothelial barrier disruption induced by cigarette smoke: role of oxidative stress and ceramides.

PubMed

Schweitzer, Kelly S; Hatoum, Hadi; Brown, Mary Beth; Gupta, Mehak; Justice, Matthew J; Beteck, Besem; Van Demark, Mary; Gu, Yuan; Presson, Robert G; Hubbard, Walter C; Petrache, Irina

2011-12-01

The epithelial and endothelial cells lining the alveolus form a barrier essential for the preservation of the lung respiratory function, which is, however, vulnerable to excessive oxidative, inflammatory, and apoptotic insults. Whereas profound breaches in this barrier function cause pulmonary edema, more subtle changes may contribute to inflammation. The mechanisms by which cigarette smoke (CS) exposure induce lung inflammation are not fully understood, but an early alteration in the epithelial barrier function has been documented. We sought to investigate the occurrence and mechanisms by which soluble components of mainstream CS disrupt the lung endothelial cell barrier function. Using cultured primary rat microvascular cell monolayers, we report that CS induces endothelial cell barrier disruption in a dose- and time-dependent manner of similar magnitude to that of the epithelial cell barrier. CS exposure triggered a mechanism of neutral sphingomyelinase-mediated ceramide upregulation and p38 MAPK and JNK activation that were oxidative stress dependent and that, along with Rho kinase activation, mediated the endothelial barrier dysfunction. The morphological changes in endothelial cell monolayers induced by CS included actin cytoskeletal rearrangement, junctional protein zonula occludens-1 loss, and intercellular gap formation, which were abolished by the glutathione modulator N-acetylcysteine and ameliorated by neutral sphingomyelinase inhibition. The direct application of ceramide recapitulated the effects of CS, by disrupting both endothelial and epithelial cells barrier, by a mechanism that was redox and apoptosis independent and required Rho kinase activation. Furthermore, ceramide induced dose-dependent alterations of alveolar microcirculatory barrier in vivo, measured by two-photon excitation microscopy in the intact rat. In conclusion, soluble components of CS have direct endothelial barrier-disruptive effects that could be ameliorated by glutathione modulators or by inhibitors of neutral sphingomyelinase, p38 MAPK, JNK, and Rho kinase. Amelioration of endothelial permeability may alleviate lung and systemic vascular dysfunction associated with smoking-related chronic obstructive lung diseases.

Increasing Type 1 Poliovirus Capsid Stability by Thermal Selection

PubMed Central

Adeyemi, Oluwapelumi O.; Nicol, Clare

2016-01-01

ABSTRACT Poliomyelitis is a highly infectious disease caused by poliovirus (PV). It can result in paralysis and may be fatal. Integrated global immunization programs using live-attenuated oral (OPV) and/or inactivated (IPV) PV vaccines have systematically reduced its spread and paved the way for eradication. Immunization will continue posteradication to ensure against reintroduction of the disease, but there are biosafety concerns for both OPV and IPV. They could be addressed by the production and use of virus-free virus-like particle (VLP) vaccines that mimic the “empty” capsids (ECs) normally produced in viral infection. Although ECs are antigenically indistinguishable from mature virus particles, they are less stable and readily convert into an alternative conformation unsuitable for vaccine purposes. Stabilized ECs, expressed recombinantly as VLPs, could be ideal candidate vaccines for a polio-free world. However, although genome-free PV ECs have been expressed as VLPs in a variety of systems, their inherent antigenic instability has proved a barrier to further development. In this study, we selected thermally stable ECs of type 1 PV (PV-1). The ECs are antigenically stable at temperatures above the conversion temperature of wild-type (wt) virions. We have identified mutations on the capsid surface and in internal networks that are responsible for EC stability. With reference to the capsid structure, we speculate on the roles of these residues in capsid stability and postulate that such stabilized VLPs could be used as novel vaccines. IMPORTANCE Poliomyelitis is a highly infectious disease caused by PV and is on the verge of eradication. There are biosafety concerns about reintroduction of the disease from current vaccines that require live virus for production. Recombinantly expressed virus-like particles (VLPs) could address these inherent problems. However, the genome-free capsids (ECs) of wt PV are unstable and readily change antigenicity to a form not suitable as a vaccine. Here, we demonstrate that the ECs of type 1 PV can be stabilized by selecting heat-resistant viruses. Our data show that some capsid mutations stabilize the ECs and could be applied as candidates to synthesize stable VLPs as future genome-free poliovirus vaccines. PMID:27928008

The externally corrected coupled cluster approach with four- and five-body clusters from the CASSCF wave function.

PubMed

Xu, Enhua; Li, Shuhua

2015-03-07

An externally corrected CCSDt (coupled cluster with singles, doubles, and active triples) approach employing four- and five-body clusters from the complete active space self-consistent field (CASSCF) wave function (denoted as ecCCSDt-CASSCF) is presented. The quadruple and quintuple excitation amplitudes within the active space are extracted from the CASSCF wave function and then fed into the CCSDt-like equations, which can be solved in an iterative way as the standard CCSDt equations. With a size-extensive CASSCF reference function, the ecCCSDt-CASSCF method is size-extensive. When the CASSCF wave function is readily available, the computational cost of the ecCCSDt-CASSCF method scales as the popular CCSD method (if the number of active orbitals is small compared to the total number of orbitals). The ecCCSDt-CASSCF approach has been applied to investigate the potential energy surface for the simultaneous dissociation of two O-H bonds in H2O, the equilibrium distances and spectroscopic constants of 4 diatomic molecules (F2(+), O2(+), Be2, and NiC), and the reaction barriers for the automerization reaction of cyclobutadiene and the Cl + O3 → ClO + O2 reaction. In most cases, the ecCCSDt-CASSCF approach can provide better results than the CASPT2 (second order perturbation theory with a CASSCF reference function) and CCSDT methods.

Tear dysfunction and the cornea: LXVIII Edward Jackson Memorial Lecture.

PubMed

Pflugfelder, Stephen C

2011-12-01

To describe the cause and consequence of tear dysfunction-related corneal disease. Perspective on effects of tear dysfunction on the cornea. Evidence is presented on the effects of tear dysfunction on corneal morphology, function, and health, as well as efficacy of therapies for tear dysfunction-related corneal disease. Tear dysfunction is a prevalent eye disease and the most frequent cause for superficial corneal epithelial disease that results in corneal barrier disruption, an irregular optical surface, light scattering, optical aberrations, and exposure and sensitization of pain-sensing nerve endings (nociceptors). Tear dysfunction-related corneal disease causes irritation and visual symptoms such as photophobia and blurred and fluctuating vision that may decrease quality of life. Dysfunction of 1 or more components of the lacrimal functional unit results in changes in tear composition, including elevated osmolarity and increased concentrations of matrix metalloproteinases, inflammatory cytokines, and chemokines. These tear compositional changes promote disruption of tight junctions, alter differentiation, and accelerate death of corneal epithelial cells. Corneal epithelial disease resulting from tear dysfunction causes eye irritation and decreases visual function. Clinical and basic research has improved understanding of the pathogenesis of tear dysfunction-related corneal epithelial disease, as well as treatment outcomes. Copyright © 2011 Elsevier Inc. All rights reserved.

Decreased TESK1-mediated cofilin 1 phosphorylation in the jejunum of IBS-D patients may explain increased female predisposition to epithelial dysfunction.

PubMed

Rodiño-Janeiro, Bruno K; Martínez, Cristina; Fortea, Marina; Lobo, Beatriz; Pigrau, Marc; Nieto, Adoración; González-Castro, Ana María; Salvo-Romero, Eloísa; Guagnozzi, Danila; Pardo-Camacho, Cristina; Iribarren, Cristina; Azpiroz, Fernando; Alonso-Cotoner, Carmen; Santos, Javier; Vicario, Maria

2018-02-02

Disturbed intestinal epithelial barrier and mucosal micro-inflammation characterize irritable bowel syndrome (IBS). Despite intensive research demonstrating ovarian hormones modulation of IBS severity, there is still limited knowledge on the mechanisms underlying female predominance in this disorder. Our aim was to identify molecular pathways involved in epithelial barrier dysfunction and female predominance in diarrhea-predominant IBS (IBS-D) patients. Total RNA and protein were obtained from jejunal mucosal biopsies from healthy controls and IBS-D patients meeting the Rome III criteria. IBS severity was recorded based on validated questionnaires. Gene and protein expression profiles were obtained and data integrated to explore biological and molecular functions. Results were validated by western blot. Tight junction signaling, mitochondrial dysfunction, regulation of actin-based motility by Rho, and cytoskeleton signaling were differentially expressed in IBS-D. Decreased TESK1-dependent cofilin 1 phosphorylation (pCFL1) was confirmed in IBS-D, which negatively correlated with bowel movements only in female participants. In conclusion, deregulation of cytoskeleton dynamics through TESK1/CFL1 pathway underlies epithelial intestinal dysfunction in the small bowel mucosa of IBS-D, particularly in female patients. Further understanding of the mechanisms involving sex-mediated regulation of mucosal epithelial integrity may have significant preventive, diagnostic, and therapeutic implications for IBS.

Targeting palmitoyl acyltransferase ZDHHC21 improves gut epithelial barrier dysfunction resulting from burn-induced systemic inflammation.

PubMed

Haines, R J; Wang, C Y; Yang, C G Y; Eitnier, R A; Wang, F; Wu, M H

2017-12-01

Clinical studies in burn patients demonstrate a close association between leaky guts and increased incidence or severity of sepsis and other complications. Severe thermal injury triggers intestinal inflammation that contributes to intestinal epithelial hyperpermeability, which exacerbates systemic response leading to multiple organ failure and sepsis. In this study, we identified a significant function of a particular palmitoyl acyltransferase, zinc finger DHHC domain-containing protein-21 (ZDHHC21), in mediating signaling events required for gut hyperpermeability induced by inflammation. Using quantitative PCR, we show that ZDHHC21 mRNA production was enhanced twofold when intestinal epithelial cells were treated with TNF-α-IFN-γ in vitro. In addition, pharmacological targeting of palmitoyl acyltransferases with 2-bromopalmitate (2-BP) showed significant improvement in TNF-α-IFN-γ-mediated epithelial barrier dysfunction by using electric cell-substrate impedance-sensing assays, as well as FITC-labeled dextran permeability assays. Using acyl-biotin exchange assay and click chemistry, we show that TNF-α-IFN-γ treatment of intestinal epithelial cells results in enhanced detection of total palmitoylated proteins and this response is inhibited by 2-BP. Using ZDHHC21-deficient mice or wild-type mice treated with 2-BP, we showed that mice with impaired ZDHHC21 expression or pharmacological inhibition resulted in attenuated intestinal barrier dysfunction caused by thermal injury. Moreover, hematoxylin and eosin staining of the small intestine, as well as transmission electron microscopy, showed that mice with genetic interruption of ZDHHC21 had attenuated villus structure disorganization associated with thermal injury-induced intestinal barrier damage. Taken together, these results suggest an important role of ZDHHC21 in mediating gut hyperpermeability resulting from thermal injury. NEW & NOTEWORTHY Increased mucosal permeability in the gut is one of the major complications following severe burn. Here we report the novel finding that zinc finger DHHC domain-containing protein-21 (ZDHHC21) mediates gut epithelial hyperpermeability resulting from an experimental model of thermal injury. The hyperpermeability response was significantly attenuated with a pharmacological inhibitor of palmitoyl acyltransferases and in mice with genetic ablation of ZDHHC21. These findings suggest that ZDHHC21 may serve as a novel therapeutic target for treating burn-induced intestinal barrier dysfunction. Copyright © 2017 the American Physiological Society.

Impaired calcium sensing distinguishes primary hyperparathyroidism (PHPT) patients with low bone mineral density.

PubMed

Weber, Thomas J; Koh, James; Thomas, Samantha M; Hogue, Joyce A; Scheri, Randall P; Roman, Sanziana A; Sosa, Julie A

2017-09-01

A subset of PHPT patients exhibit a more severe disease phenotype characterized by bone loss, fractures, recurrent nephrolithiasis, and other dysfunctions, but the underlying reasons for this disparity in clinical presentation remain unknown. We sought to identify new mechanistic indices that could inform more personalized management of PHPT. Pre-, peri-, and postoperative data and demographic, clinical, and pathological information from patients undergoing parathyroidectomy for PHPT were collected. Univariate and partial Spearman correlation was used to estimate the association of parathyroid tumor calcium sensing capacity with select variables. An unselected series of 237 patients aged >18years and undergoing parathyroidectomy for PHPT were enrolled. Calcium sensing capacity, expressed as the concentration required for half-maximal biochemical response (EC50), was evaluated in parathyroid tumors from an unselected series of 74 patients and assessed for association with clinical parameters. The hypothesis was that greater disease severity would be associated with attenuated calcium sensitivity and biochemically autonomous parathyroid tumor behavior. Parathyroid tumors segregated into two distinct groups of calcium responsiveness (EC50<3.0 and ≥3.0mM). The low EC50 group (n=27) demonstrated a mean calcium EC50 value of 2.49mM [95% confidence interval (CI): 2.43-2.54mM], consistent with reference normal activity. In contrast, the high EC50 group (n=47) displayed attenuated calcium sensitivity with a mean EC50 value of 3.48mM [95% CI: 3.41-3.55mM]. Retrospective analysis of the clinical registry data suggested that high calcium EC50 patients presented with a more significant preoperative bone mineral density (BMD) deficit with a t-score of -2.7, (95% CI: -3.4 to -1.9) versus 0.9, (95% CI: -2.1 to -0.4) in low EC50 patients (p<0.001). After adjusting for gender, age, BMI, 25 OH vitamin D level and preoperative iPTH, lowest t-score and calcium EC50 were inversely correlated, with a partial Spearman correlation coefficient of -0.35 (p=0.02). Impaired calcium sensing in parathyroid tumors is selectively observed in a subset of patients with more severe bone mineral density deficit. Assessment of parathyroid tumor biochemical behavior may be a useful predictor of disease severity as measured by bone mineral density in patients with PHPT. Copyright © 2017 Elsevier Inc. All rights reserved.

The Blood–Brain Barrier

PubMed Central

Daneman, Richard; Prat, Alexandre

2015-01-01

Blood vessels are critical to deliver oxygen and nutrients to all of the tissues and organs throughout the body. The blood vessels that vascularize the central nervous system (CNS) possess unique properties, termed the blood–brain barrier, which allow these vessels to tightly regulate the movement of ions, molecules, and cells between the blood and the brain. This precise control of CNS homeostasis allows for proper neuronal function and also protects the neural tissue from toxins and pathogens, and alterations of these barrier properties are an important component of pathology and progression of different neurological diseases. The physiological barrier is coordinated by a series of physical, transport, and metabolic properties possessed by the endothelial cells (ECs) that form the walls of the blood vessels, and these properties are regulated by interactions with different vascular, immune, and neural cells. Understanding how these different cell populations interact to regulate the barrier properties is essential for understanding how the brain functions during health and disease. PMID:25561720

Quantitative Visualization of Dynamic Tracer Transportation in the Extracellular Space of Deep Brain Regions Using Tracer-Based Magnetic Resonance Imaging.

PubMed

Hou, Jin; Wang, Wei; Quan, Xianyue; Liang, Wen; Li, Zhiming; Chen, Deji; Han, Hongbin

2017-09-03

BACKGROUND This study assessed an innovative tracer-based magnetic resonance imaging (MRI) system to visualize the dynamic transportation of tracers in regions of deep brain extracellular space (ECS) and to measure transportation ability and ECS structure. MATERIAL AND METHODS Gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) was the chosen tracer and was injected into the caudate nucleus and thalamus. Real-time dynamic transportation of Gd-DTPA in ECS was observed and the results were verified by laser scanning confocal microscopy. Using Transwell assay across the blood-brain barrier, a modified diffusion equation was further simplified. Effective diffusion coefficient D* and tortuosity λ were calculated. Immunohistochemical staining and Western blot analysis were used to investigate the extracellular matrix contributing to ECS structure. RESULTS Tracers injected into the caudate nucleus were transported to the ipsilateral frontal and temporal cortices away from the injection points, while both of them injected into the thalamus were only distributed on site. Although the caudate nucleus was closely adjacent to the thalamus, tracer transportation between partitions was not observed. In addition, D* and the λ showed statistically significant differences between partitions. ECS was shown to be a physiologically partitioned system, and its division is characterized by the unique distribution territory and transportation ability of substances located in it. Versican and Tenascin R are possible contributors to the tortuosity of ECS. CONCLUSIONS Tracer-based MRI will improve our understanding of the brain microenvironment, improve the techniques for local delivery of drugs, and highlight brain tissue engineering fields in the future.

Loss of proteostasis induced by amyloid beta peptide in brain endothelial cells.

PubMed

Fonseca, Ana Catarina; Oliveira, Catarina R; Pereira, Cláudia F; Cardoso, Sandra M

2014-06-01

Abnormal accumulation of amyloid-β (Aβ) peptide in the brain is a pathological hallmark of Alzheimer's disease (AD). In addition to neurotoxic effects, Aβ also damages brain endothelial cells (ECs) and may thus contribute to the degeneration of cerebral vasculature, which has been proposed as an early pathogenic event in the course of AD and is able to trigger and/or potentiate the neurodegenerative process and cognitive decline. However, the mechanisms underlying Aβ-induced endothelial dysfunction are not completely understood. Here we hypothesized that Aβ impairs protein quality control mechanisms both in the secretory pathway and in the cytosol in brain ECs, leading cells to death. In rat brain RBE4 cells, we demonstrated that Aβ1-40 induces the failure of the ER stress-adaptive unfolded protein response (UPR), deregulates the ubiquitin-proteasome system (UPS) decreasing overall proteasome activity with accumulation of ubiquitinated proteins and impairs the autophagic protein degradation pathway due to failure in the autophagic flux, which culminates in cell demise. In conclusion, Aβ deregulates proteostasis in brain ECs and, as a consequence, these cells die by apoptosis. Copyright © 2014 Elsevier B.V. All rights reserved.

Neuroinflammation in hepatic encephalopathy: mechanistic aspects.

PubMed

Jayakumar, Arumugam R; Rama Rao, Kakulavarapu V; Norenberg, Michael D

2015-03-01

Hepatic encephalopathy (HE) is a major neurological complication of severe liver disease that presents in acute and chronic forms. While elevated brain ammonia level is known to be a major etiological factor in this disorder, recent studies have shown a significant role of neuroinflammation in the pathogenesis of both acute and chronic HE. This review summarizes the involvement of ammonia in the activation of microglia, as well as the means by which ammonia triggers inflammatory responses in these cells. Additionally, the role of ammonia in stimulating inflammatory events in brain endothelial cells (ECs), likely through the activation of the toll-like receptor-4 and the associated production of cytokines, as well as the stimulation of various inflammatory factors in ECs and in astrocytes, are discussed. This review also summarizes the inflammatory mechanisms by which activation of ECs and microglia impact on astrocytes leading to their dysfunction, ultimately contributing to astrocyte swelling/brain edema in acute HE. The role of microglial activation and its contribution to the progression of neurobehavioral abnormalities in chronic HE are also briefly presented. We posit that a better understanding of the inflammatory events associated with acute and chronic HE will uncover novel therapeutic targets useful in the treatment of patients afflicted with HE.

MMP‐2 and MMP‐14 Silencing Inhibits VEGFR2 Cleavage and Induces the Differentiation of Porcine Adipose‐Derived Mesenchymal Stem Cells to Endothelial Cells

PubMed Central

Almalki, Sami G.; Llamas Valle, Yovani

2017-01-01

Abstract The molecular mechanisms that control the ability of adipose‐derived mesenchymal stem cells (AMSCs) to remodel three‐dimensional extracellular matrix barriers during differentiation are not clearly understood. Herein, we studied the expression of matrix metalloproteinases (MMPs) during the differentiation of AMSCs to endothelial cells (ECs) in vitro. MSCs were isolated from porcine abdominal adipose tissue, and characterized by immunopositivity to CD44, CD90, CD105, and immunonegativity to CD14 and CD45. Plasticity of AMSCs was confirmed by multilineage differentiation. The mRNA transcripts for MMPs and Tissue Inhibitor of Metalloproteinases (TIMPs), and protein expression of EC markers were analyzed. The enzyme activity and protein expression were analyzed by gelatin zymography, enzyme‐linked immunosorbent assay (ELISA), and Western blot. The differentiation of AMSCs to ECs was confirmed by mRNA and protein expressions of the endothelial markers. The mRNA transcripts for MMP‐2 and MMP‐14 were significantly increased during the differentiation of MSCs into ECs. Findings revealed an elevated MMP‐14 and MMP‐2 expression, and MMP2 enzyme activity. Silencing of MMP‐2 and MMP‐14 significantly increased the expression of EC markers, formation of capillary tubes, and acetylated‐low‐density lipoprotein uptake, and decreased the cleavage of vascular endothelial growth factor receptor type 2 (VEGFR2). Inhibition of VEGFR2 significantly decreased the expression of EC markers. These novel findings demonstrate that the upregulation of MMP2 and MMP14 has an inhibitory effect on the differentiation of AMSCs to ECs, and silencing these MMPs inhibit the cleavage of VEGFR2 and stimulate the differentiation of AMSCs to ECs. These findings provide a potential mechanism for the regulatory role of MMP‐2 and MMP‐14 in the re‐endothelialization of coronary arteries following intervention. Stem Cells Translational Medicine 2017;6:1385–1398 PMID:28213979

"I don't know what I would have done." Women's experiences acquiring ulipristal acetate emergency contraception online from 2011 to 2015.

PubMed

Smith, Nicole K; Cleland, Kelly; Wagner, Brandon; Trussell, James

2017-04-01

This study describes women's reasons for seeking ulipristal acetate (UPA) for emergency contraception (EC) through the only authorized online retailer for UPA EC in the US. Women aged 14 to 59 years, living in states that allow prescription medications to be shipped from out-of-state, accessed the KwikMed online pharmacy between January 2011 and December 2015. After completing a medical eligibility screener, women answered optional multiple-choice questions. To obtain UPA through KwikMed, individuals must be female, 50 years of age or younger, not currently pregnant or breastfeeding and not attempting to order UPA more than once within 30 days or more than four times per year. Over the 5-year period, KwikMed provided 8019 prescriptions for UPA, and the number of women using this service more than tripled over time. Among women who responded to the survey questions (n=7133; response rate = 89%), most sought EC because of a condom failure (45.3%) or because they did not use regular contraception (41.2%). More than half (53.5%) of women reported that they chose UPA because of its effectiveness compared to levonorgestrel EC pills, and 58.9% preferred ordering UPA online because they found it easier than getting it from a doctor, clinic or pharmacy. This study documents the importance of providing confidential services for acquiring EC online. Benefits of online access include convenience, less embarrassment, avoiding situations in which a provider might refuse to provide EC because of their own ideological belief and more reliable availability for this time-sensitive contraceptive. Though physical, logistical and societal barriers can restrict women's access to EC, this study demonstrates that providing access to UPA online empowers women to obtain EC when they need it. Copyright © 2016 Elsevier Inc. All rights reserved.

Defenders and Challengers of Endothelial Barrier Function

PubMed Central

Rahimi, Nader

2017-01-01

Regulated vascular permeability is an essential feature of normal physiology and its dysfunction is associated with major human diseases ranging from cancer to inflammation and ischemic heart diseases. Integrity of endothelial cells also play a prominent role in the outcome of surgical procedures and organ transplant. Endothelial barrier function and integrity are regulated by a plethora of highly specialized transmembrane receptors, including claudin family proteins, occludin, junctional adhesion molecules (JAMs), vascular endothelial (VE)-cadherin, and the newly identified immunoglobulin (Ig) and proline-rich receptor-1 (IGPR-1) through various distinct mechanisms and signaling. On the other hand, vascular endothelial growth factor (VEGF) and its tyrosine kinase receptor, VEGF receptor-2, play a central role in the destabilization of endothelial barrier function. While claudins and occludin regulate cell–cell junction via recruitment of zonula occludens (ZO), cadherins via catenin proteins, and JAMs via ZO and afadin, IGPR-1 recruits bullous pemphigoid antigen 1 [also called dystonin (DST) and SH3 protein interacting with Nck90/WISH (SH3 protein interacting with Nck)]. Endothelial barrier function is moderated by the function of transmembrane receptors and signaling events that act to defend or destabilize it. Here, I highlight recent advances that have provided new insights into endothelial barrier function and mechanisms involved. Further investigation of these mechanisms could lead to the discovery of novel therapeutic targets for human diseases associated with endothelial dysfunction. PMID:29326721

Measurement of transepidermal water loss (TEWL) in cats with experimental skin barrier dysfunction using a closed chamber system.

PubMed

Momota, Yutaka; Shimada, Kenichiro; Gin, Azusa; Matsubara, Takako; Azakami, Daigo; Ishioka, Katsumi; Nakamura, Yuka; Sako, Toshinori

2016-10-01

A closed chamber evaporimeter is suitable for measuring transepidermal water loss (TEWL) in cats because of the compact device size, tolerance to sudden movement and short measuring time. TEWL is a representative parameter for skin barrier dysfunction, which is one of the clinical signs of atopic dermatitis in humans and dogs. Measurement of feline TEWL has been reported, but applicability of this parameter has not been validated. The aims of this study were to determine if tape stripping is a valid experimental model in cats for studying TEWL and to determine if a closed chambered system is a suitable measurement tool for cats. Ten clinically normal cats. In order to evaluate variation of the measured values, TEWL was measured at the right and left side of the three clipped regions (axillae, lateral thigh and groin). Subsequently, TEWL was measured using sequential tape stripping of the stratum corneum as a model of acute barrier disruption. The variations between both sides of the three regions showed no significant difference. Sequential tape stripping was associated with increasing values for TEWL. Feline TEWL was shown to reflect changes in the skin barrier in an experimental model using a closed chamber system and has the potential for evaluating skin barrier function in cats with skin diseases. © 2016 ESVD and ACVD.

[Bacterial Translocation from Intestine: Microbiological, Immunological and Pathophysiological Aspects].

PubMed

Podoprigora, G I; Kafarskaya, L I; Bainov, N A; Shkoporov, A N

2015-01-01

Bacterial translocation (BT) is both pathology and physiology phenomenon. In healthy newborns it accompanies the process of establishing the autochthonous intestinal microbiota and the host microbiome. In immunodeficiency it can be an aethio-pathogenetic link and a manifestation of infection or septic complications. The host colonization resistance to exogenous microbic colonizers is provided by gastrointestinal microbiota in concert with complex constitutional and adaptive defense mechanisms. BT may be result of barrier dysfunction and self-purification mechanisms involving the host myeloid cell phagocytic system and opsonins. Dynamic cell humoral response to microbial molecular patterns that occurs on the mucous membranes initiates receptorsignalingpathways and cascade ofreactions. Their vector and results are largely determined by cross-reactivity between microbiome and the host genome. Enterocyte barriers interacting with microbiota play leading role in providing adaptive, homeostatic and stress host reactivity. Microcirculatory ischemic tissue alterations and inflammatory reactions increase the intestinal barrier permeability and BT These processes a well as mechanisms for apoptotic cells and bacteria clearance are justified to be of prospective research interest. The inflammatory and related diseases caused by alteration and dysfunction of the intestinal barrier are reasonably considered as diseases of single origin. Maternal microbiota affects theformation of the innate immune system and the microbiota of the newborn, including intestinal commensal translocation during lactation. Deeper understanding of intestinal barrier mechanisms needs complex microbiological, immunological, pathophysiological, etc. investigations using adequate biomodels, including gnotobiotic animals.

Steps and Tools to Guide Planning and Implementation of a Comprehensive System to Address Barriers to Learning and Teaching

ERIC Educational Resources Information Center

Center for Mental Health in Schools at UCLA, 2007

2007-01-01

The data are clear: Too many students are not doing well in school. Too many are experiencing interfering barriers, most of which are not internal dysfunctions but are associated with neighborhood, family, school, and peer factors. If the situation is to change, schools must play a greater role in providing supports for students experiencing…

Replication of CMV in the gut of HIV-infected individuals and epithelial barrier dysfunction

PubMed Central

Somsouk, Ma; Hunt, Peter W.

2017-01-01

Although invasive cytomegalovirus (CMV) disease is uncommon in the era of antiretroviral therapy (ART), asymptomatic CMV coinfection is nearly ubiquitous in HIV infected individuals. While microbial translocation and gut epithelial barrier dysfunction may promote persistent immune activation in treated HIV infection, potentially contributing to morbidity and mortality, it has been unclear whether CMV replication in individuals with no symptoms of CMV disease might play a role in this process. We hypothesized that persistent CMV replication in the intestinal epithelium of HIV/CMV-coinfected individuals impairs gut epithelial barrier function. Using a combination of state-of-the-art in situ hybridization technology (RNAscope) and immunohistochemistry, we detected CMV DNA and proteins and evidence of intestinal damage in rectosigmoid samples from CMV-positive individuals with both untreated and ART-suppressed HIV infection. Two different model systems, primary human intestinal cells differentiated in vitro to form polarized monolayers and a humanized mouse model of human gut, together demonstrated that intestinal epithelial cells are fully permissive to CMV replication. Independent of HIV, CMV disrupted tight junctions of polarized intestinal cells, significantly reducing transepithelial electrical resistance, a measure of monolayer integrity, and enhancing transepithelial permeability. The effect of CMV infection on the intestinal epithelium is mediated, at least in part, by the CMV-induced proinflammatory cytokine IL-6. Furthermore, letermovir, a novel anti-CMV drug, dampened the effects of CMV on the epithelium. Together, our data strongly suggest that CMV can disrupt epithelial junctions, leading to bacterial translocation and chronic inflammation in the gut and that CMV could serve as a target for therapeutic intervention to prevent or treat gut epithelial barrier dysfunction during HIV infection. PMID:28241080

Cyclooxygenase-2 Deficiency Leads to Intestinal Barrier Dysfunction and Increased Mortality During Polymicrobial Sepsis 1

PubMed Central

Fredenburgh, Laura E.; Velandia, Margarita M. Suarez; Ma, Jun; Olszak, Torsten; Cernadas, Manuela; Englert, Joshua A.; Chung, Su Wol; Liu, Xiaoli; Begay, Cynthia; Padera, Robert F.; Blumberg, Richard S.; Walsh, Stephen R.; Baron, Rebecca M.; Perrella, Mark A.

2011-01-01

Sepsis remains the leading cause of death in critically ill patients despite modern advances in critical care. Intestinal barrier dysfunction may lead to secondary bacterial translocation and the development of the multiple organ dysfunction syndrome during sepsis. Cyclooxygenase-2 (COX-2) is highly upregulated in the intestine during sepsis and we hypothesized that it may be critical in the maintenance of intestinal epithelial barrier function during peritonitis-induced polymicrobial sepsis. COX-2−/− and COX-2+/+ BALB/c mice underwent cecal ligation and puncture (CLP) or sham surgery. Mice chimeric for COX-2 were derived by bone marrow transplantation and underwent CLP. C2BBe1 cells, an intestinal epithelial cell line, were treated with the COX-2 inhibitor NS-398, PGD2, or vehicle and stimulated with cytokines. COX-2−/− mice developed exaggerated bacteremia and increased mortality compared with COX-2+/+ mice following CLP. Mice chimeric for COX-2 exhibited the recipient phenotype suggesting that epithelial COX-2 expression in the ileum attenuates bacteremia following CLP. Absence of COX-2 significantly increased epithelial permeability of the ileum and reduced expression of the tight junction proteins zonula occludens-1 (ZO-1), occludin, and claudin-1 in the ileum following CLP. Furthermore, PGD2 attenuated cytokine-induced hyperpermeability and ZO-1 downregulation in NS-398-treated C2BBe1 cells. Our findings reveal that absence of COX-2 is associated with enhanced intestinal epithelial permeability and leads to exaggerated bacterial translocation and increased mortality during peritonitis-induced sepsis. Taken together, our results suggest that epithelial expression of COX-2 in the ileum is a critical modulator of tight junction protein expression and intestinal barrier function during sepsis. PMID:21967897

The mitochondrially targeted antioxidant MitoQ protects the intestinal barrier by ameliorating mitochondrial DNA damage via the Nrf2/ARE signaling pathway.

PubMed

Hu, Qiongyuan; Ren, Jianan; Li, Guanwei; Wu, Jie; Wu, Xiuwen; Wang, Gefei; Gu, Guosheng; Ren, Huajian; Hong, Zhiwu; Li, Jieshou

2018-03-14

Disruption of the mucosal barrier following intestinal ischemia reperfusion (I/R) is life threatening in clinical practice. Mitochondrial dysfunction and oxidative stress significantly contribute to the early phase of I/R injury and amplify the inflammatory response. MitoQ is a mitochondrially targeted antioxidant that exerts protective effects following I/R injury. In the present study, we aimed to determine whether and how MitoQ protects intestinal epithelial cells (IECs) from I/R injury. In both in vivo and in vitro studies, we found that MitoQ pretreatment downregulated I/R-induced oxidative stress and stabilized the intestinal barrier, as evidenced by MitoQ-treated I/R mice exhibiting attenuated intestinal hyperpermeability, inflammatory response, epithelial apoptosis, and tight junction damage compared to controls. Mechanistically, I/R elevated mitochondrial 8-hydroxyguanine content, reduced mitochondrial DNA (mtDNA) copy number and mRNA transcription levels, and induced mitochondrial disruption in IECs. However, MitoQ pretreatment dramatically inhibited these deleterious effects. mtDNA depletion alone was sufficient to induce apoptosis and mitochondrial dysfunction of IECs. Mitochondrial transcription factor A (TFAM), a key activator of mitochondrial transcription, was significantly reduced during I/R injury, a phenomenon that was prevented by MitoQ treatment. Furthermore, we observed that thee protective properties of MitoQ were affected by upregulation of cellular antioxidant genes, including HO-1, NQO-1, and γ-GCLC. Transfection with Nrf2 siRNA in IECs exposed to hypoxia/reperfusion conditions partially blocked the effects of MitoQ on mtDNA damage and mitochondrial oxidative stress. In conclusion, our data suggest that MitoQ exerts protective effect on I/R-induced intestinal barrier dysfunction.

Modeling the light-induced electric potential difference ΔΨ across the thylakoid membrane based on the transition state rate theory.

PubMed

Lyu, Hui; Lazár, Dušan

2017-03-01

In photosynthesis, electron transport-coupled proton movement initiates the formation of the light-induced electric potential difference, ΔΨ, across the thylakoid membrane (TM). Ions are transported across the TM to counterbalance the charge of protons accumulated in the lumen. The objective of this work is to construct range of mathematical models for simulation of ΔΨ, using the transition state rate theory (TSRT) for description of movement of ions through the channels. The TSRT considers either single-ion (TSRT-SI) or multi-ion occupancy (TSRT-MI) in the channels. Movement of ions through the channel pore is described by means of energy barriers and binding sites; ions move in and out of vacant sites with rate constants that depend on the barrier heights and well depths, as well as on the interionic repulsion in TSRT-MI model. Three energy motifs are used to describe the TSRT-SI model: two-barrier one-site (2B1S), three-barrier two-site (3B2S), and four-barrier three-site (4B3S). The 3B2S energy motif is used for the TSRT-MI model. The accumulation of cations due to the TM surface negative fixed charges is also taken into account. A model employing the electro-diffusion theory instead of the TSRT is constructed for comparison. The dual wavelength transmittance signal (ΔA515-560nm) measuring the electrochromic shift (ECS) provides a proxy for experimental light-induced ΔΨ. The simulated ΔΨ traces qualitatively agree with the measured ECS traces. The models can simulate different channel conducting regimes and assess their impact on ΔΨ. The ionic flux coupling in the TSRT-MI model suggests that an increase in the internal or external K + concentration may block the outward or the inward Mg 2+ current, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Adaptations to the air breathing in the posterior intestine of the catfish (Corydoras aeneus, Callichthyidae). A histological and ultrastructural study.

PubMed

Podkowa, Dagmara; Goniakowska-Witalińska, Lucyna

2002-01-01

A light and transmission electron microscopic study of the intestine of catfish C. aeneus shows that the anterior part of the intestine is a site of digestion and absorption and its structure is typical of that of other teleostean fishes. However, in this species the thin-walled posterior intestine is adapted to air breathing. In this region mucosa is smooth and lined with respiratory epithelium with capillary network. Several types of cells are observed in the epithelium: flattened respiratory epithelial cells with short microvili, goblet cells, scarce epithelial cells with numerous longer microvilli, and two types of endocrine cells (EC). The solitary brush cells with several long and thick microvilli described here are the first observation of such cells in the gastrointestinal tract of fishes. Bodies of respiratory epithelial cells lie between capillaries. Their cytoplasm, apart from typical organelles contains dense and lamellar bodies, which are a site of accumulation of surfactant. In regions where capillaries are covered by thin cytoplasmic sheets of respiratory epithelial cells, a thin (0.24-3.00 microm) air-blood barrier is formed, thus enabling gas exchange. Epithelial cells with longer microvilli do not participate in the formation of the air-blood barrier and are probably responsible for absorbtion. EC of the closed type are dispersed within the epithelium. Their cytoplasm contains characteristic round or oval dense core vesicles 69 to 230 nm in diameter. The role of EC and brush cells in the regulation of processes related to absorbtion, and to respiration, is disscused.

Nanoscale drug delivery systems and the blood-brain barrier.

PubMed

Alyautdin, Renad; Khalin, Igor; Nafeeza, Mohd Ismail; Haron, Muhammad Huzaimi; Kuznetsov, Dmitry

2014-01-01

The protective properties of the blood-brain barrier (BBB) are conferred by the intricate architecture of its endothelium coupled with multiple specific transport systems expressed on the surface of endothelial cells (ECs) in the brain's vasculature. When the stringent control of the BBB is disrupted, such as following EC damage, substances that are safe for peripheral tissues but toxic to neurons have easier access to the central nervous system (CNS). As a consequence, CNS disorders, including degenerative diseases, can occur independently of an individual's age. Although the BBB is crucial in regulating the biochemical environment that is essential for maintaining neuronal integrity, it limits drug delivery to the CNS. This makes it difficult to deliver beneficial drugs across the BBB while preventing the passage of potential neurotoxins. Available options include transport of drugs across the ECs through traversing occludins and claudins in the tight junctions or by attaching drugs to one of the existing transport systems. Either way, access must specifically allow only the passage of a particular drug. In general, the BBB allows small molecules to enter the CNS; however, most drugs with the potential to treat neurological disorders other than infections have large structures. Several mechanisms, such as modifications of the built-in pumping-out system of drugs and utilization of nanocarriers and liposomes, are among the drug-delivery systems that have been tested; however, each has its limitations and constraints. This review comprehensively discusses the functional morphology of the BBB and the challenges that must be overcome by drug-delivery systems and elaborates on the potential targets, mechanisms, and formulations to improve drug delivery to the CNS.

Pharmacy-based interventions for initiating effective contraception following the use of emergency contraception: a pilot study.

PubMed

Michie, L; Cameron, S T; Glasier, A; Larke, N; Muir, A; Lorimer, A

2014-10-01

In Scotland most women get emergency contraception (EC) from pharmacies. Pharmacists currently cannot provide effective ongoing contraception after EC. In this pilot study, we aimed to determine the feasibility of a larger study designed to ascertain if pharmacy-based interventions can increase the uptake of effective contraception after EC. This is a pilot study of women presenting for levonorgestrel EC to community pharmacies in Edinburgh, UK, in 2012. Pharmacies were cluster randomized to provide either standard care or one of two interventions: (a) one packet of progestogen-only pills (POPs), giving women 1 month to arrange ongoing contraception; (b) invitation to present the empty EC packet to a family planning clinic (FPC) for contraceptive advice (rapid access). One hundred sixty-eight women were recruited from 11 pharmacies to POP (n=56), rapid access (n=58) and standard care (N=54) groups, respectively. Telephone follow-up was conducted successfully in 102 women (61%) 6-8 weeks later to determine current contraceptive use. In the POP arm, 35/39 (90%) women used the pills provided, and 9/28 women (32%) in the rapid access arm attended the FPC. The proportion of women using effective contraception at follow-up was significantly greater in both POP [56% (22/39), p=<0.001] and rapid access [52% (13/25), p=0.006] groups compared to standard care [16% (5/31)]. The relative probability of a woman using an effective method of contraception versus barrier/no method, after use of EC, was 3.13 [95% confidence interval (CI), 1.90-5.13] in the POP group and 2.57 (95% CI, 1.55-4.27) in the rapid access group. This promising pilot study suggests that simple pharmacy-based interventions may increase the uptake of effective contraception after EC. A larger study is required to provide further validation of these findings. For women obtaining EC from a pharmacy, simple interventions such as supplying 1 month of a POP, or offering rapid access to a FPC, hold promise as strategies to increase the uptake of effective contraception after EC. Copyright © 2014 Elsevier Inc. All rights reserved.

External heating and current drive source requirements towards steady-state operation in ITER

NASA Astrophysics Data System (ADS)

Poli, F. M.; Kessel, C. E.; Bonoli, P. T.; Batchelor, D. B.; Harvey, R. W.; Snyder, P. B.

2014-07-01

Steady state scenarios envisaged for ITER aim at optimizing the bootstrap current, while maintaining sufficient confinement and stability to provide the necessary fusion yield. Non-inductive scenarios will need to operate with internal transport barriers (ITBs) in order to reach adequate fusion gain at typical currents of 9 MA. However, the large pressure gradients associated with ITBs in regions of weak or negative magnetic shear can be conducive to ideal MHD instabilities, reducing the no-wall limit. The E × B flow shear from toroidal plasma rotation is expected to be low in ITER, with a major role in the ITB dynamics being played by magnetic geometry. Combinations of heating and current drive (H/CD) sources that sustain reversed magnetic shear profiles throughout the discharge are the focus of this work. Time-dependent transport simulations indicate that a combination of electron cyclotron (EC) and lower hybrid (LH) waves is a promising route towards steady state operation in ITER. The LH forms and sustains expanded barriers and the EC deposition at mid-radius freezes the bootstrap current profile stabilizing the barrier and leading to confinement levels 50% higher than typical H-mode energy confinement times. Using LH spectra with spectrum centred on parallel refractive index of 1.75-1.85, the performance of these plasma scenarios is close to the ITER target of 9 MA non-inductive current, global confinement gain H98 = 1.6 and fusion gain Q = 5.

HLA-B35 Upregulates Endothelin-1 and Downregulates Endothelial Nitric Oxide Synthase via Endoplasmic Reticulum Stress Response in Endothelial Cells

PubMed Central

Lenna, Stefania; Townsend, Danyelle M.; Tan, Filemon K.; Kapanadze, Bagrat; Markiewicz, Malgorzata; Trojanowska, Maria; Scorza, Raffaella

2013-01-01

The presence of the HLA-B35 allele has emerged as an important risk factor for the development of isolated pulmonary hypertension in patients with scleroderma, however the mechanisms underlying this association have not been fully elucidated. The goal of our study was to determine the molecular mechanisms that mediate the biological effects of HLA-B35 in endothelial cells (ECs). Our data demonstrate that HLA-B35 expression at physiological levels via adenoviral vector resulted in significantly increased endothelin-1 (ET-1) and a significantly decreased endothelial NO synthase (eNOS), mRNA, and protein levels. Furthermore, HLA-B35 greatly upregulated expression of chaperones, including heat shock proteins (HSPs) HSP70 (HSPA1A and HSPA1B) and HSP40 (DNAJB1 and DNAJB9), suggesting that HLA-B35 induces the endoplasmic reticulum (ER) stress and unfolded protein response in ECs. Examination of selected mediators of the unfolded protein response, including H chain binding protein (BiP; GRP78), C/Ebp homologous protein (CHOP; GADD153), endoplasmic reticulum oxidase, and protein disulfide isomerase has revealed a consistent increase of BiP expression levels. Accordingly, thapsigargin, a known ER stress inducer, stimulated ET-1mRNAand protein levels in ECs. This study suggests that HLA-B35 could contribute to EC dysfunction via ER stress-mediated induction of ET-1 in patients with pulmonary hypertension. PMID:20335527

HLA-B35 upregulates endothelin-1 and downregulates endothelial nitric oxide synthase via endoplasmic reticulum stress response in endothelial cells.

PubMed

Lenna, Stefania; Townsend, Danyelle M; Tan, Filemon K; Kapanadze, Bagrat; Markiewicz, Malgorzata; Trojanowska, Maria; Scorza, Raffaella

2010-05-01

The presence of the HLA-B35 allele has emerged as an important risk factor for the development of isolated pulmonary hypertension in patients with scleroderma, however the mechanisms underlying this association have not been fully elucidated. The goal of our study was to determine the molecular mechanisms that mediate the biological effects of HLA-B35 in endothelial cells (ECs). Our data demonstrate that HLA-B35 expression at physiological levels via adenoviral vector resulted in significantly increased endothelin-1 (ET-1) and a significantly decreased endothelial NO synthase (eNOS), mRNA, and protein levels. Furthermore, HLA-B35 greatly upregulated expression of chaperones, including heat shock proteins (HSPs) HSP70 (HSPA1A and HSPA1B) and HSP40 (DNAJB1 and DNAJB9), suggesting that HLA-B35 induces the endoplasmic reticulum (ER) stress and unfolded protein response in ECs. Examination of selected mediators of the unfolded protein response, including H chain binding protein (BiP; GRP78), C/Ebp homologous protein (CHOP; GADD153), endoplasmic reticulum oxidase, and protein disulfide isomerase has revealed a consistent increase of BiP expression levels. Accordingly, thapsigargin, a known ER stress inducer, stimulated ET-1 mRNA and protein levels in ECs. This study suggests that HLA-B35 could contribute to EC dysfunction via ER stress-mediated induction of ET-1 in patients with pulmonary hypertension.

Rescue of perfluorooctanesulfonate (PFOS)-mediated Sertoli cell injury by overexpression of gap junction protein connexin 43

NASA Astrophysics Data System (ADS)

Li, Nan; Mruk, Dolores D.; Chen, Haiqi; Wong, Chris K. C.; Lee, Will M.; Cheng, C. Yan

2016-07-01

Perfluorooctanesulfonate (PFOS) is an environmental toxicant used in developing countries, including China, as a stain repellent for clothing, carpets and draperies, but it has been banned in the U.S. and Canada since the late 2000s. PFOS perturbed the Sertoli cell tight junction (TJ)-permeability barrier, causing disruption of actin microfilaments in cell cytosol, perturbing the localization of cell junction proteins (e.g., occluden-ZO-1, N-cadherin-ß-catenin). These changes destabilized Sertoli cell blood-testis barrier (BTB) integrity. These findings suggest that human exposure to PFOS might induce BTB dysfunction and infertility. Interestingly, PFOS-induced Sertoli cell injury associated with a down-regulation of the gap junction (GJ) protein connexin43 (Cx43). We next investigated if overexpression of Cx43 in Sertoli cells could rescue the PFOS-induced cell injury. Indeed, overexpression of Cx43 in Sertoli cells with an established TJ-barrier blocked the disruption in PFOS-induced GJ-intercellular communication, resulting in the re-organization of actin microfilaments, which rendered them similar to those in control cells. Furthermore, cell adhesion proteins that utilized F-actin for attachment became properly distributed at the cell-cell interface, resealing the disrupted TJ-barrier. In summary, Cx43 is a good target that might be used to manage PFOS-induced reproductive dysfunction.

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.

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

Indoleamine 2,3-dioxygenase 1 and overall survival of patients diagnosed with esophageal cancer

PubMed Central

Rosenberg, Ari J.; Wainwright, Derek A.; Rademaker, Alfred; Galvez, Carlos; Genet, Matthew; Zhai, Lijie; Lauing, Kristen L.; Mulcahy, Mary F.; Hayes, John P.; Odell, David D.; Horbinski, Craig; Komanduri, Srinadh; Tetreault, Marie-Pier; Kim, Kwang-Youn A.; Villaflor, Victoria M.

2018-01-01

Background Indoleamine 2,3-dioxygenase 1 (IDO1) is an enzyme with immunomodulatory properties that has emerged as a potential immunotherapeutic target in human cancer. However, the role, expression pattern, and relevance of IDO1 in esophageal cancer (EC) are poorly understood. Here, we utilize gene expression analysis of the cancer genome atlas (TCGA) and immunohistochemistry (IHC) to better understand the role and prognostic significance of IDO1 in EC. Results High IDO1 mRNA levels were associated with worse overall survival (OS) in both esophageal squamous cell carcinoma (SCC) (P = 0.02) and adenocarcinoma (AC) (P = 0.036). High co-expression of IDO1 and programmed death ligand 1 (PD-L1) was associated with worse OS in SCC (P = 0.0031) and AC (P = 0.0186). IHC for IDO1 in SCC showed a significant correlation with PD-L1 (P < 0.0001) and CD3ε (P < 0.0001). Conclusions EC with high IDO1 and PD-L1 expression is significantly correlated with decreased patient survival, and may correlate with increased T-cells. These data suggest that simultaneous inhibition of IDO1 and PD-(L)1 may overcome important barriers to T-cell mediated immune rejection of EC. Materials and Methods mRNA expression data from TCGA (SCC N = 87; AC N = 97). IHC in a second cohort of EC (N = 93) were stained for IDO1, PD-L1, and CD3ε, followed by light microscopic analysis. PMID:29805749

Cytokine-mediated dysregulation of zonula occludens-1 properties in human brain microvascular endothelium.

PubMed

Rochfort, Keith D; Cummins, Philip M

2015-07-01

Zonula occludens-1 (ZO-1) is essential to the proper assembly of interendothelial junction complexes that control blood-brain barrier (BBB) integrity. The goal of the current paper was to improve our understanding of how proinflammatory cytokines modulate ZO-1 properties within the human BBB microvascular endothelium. In this respect, we investigated the effects of TNF-α and IL-6 on ZO-1 using human brain microvascular endothelial cells (HBMvECs). Following treatment of HBMvECs with either cytokine (0-100 ng/ml, 18 h), we observed significantly decreased ZO-1 expression and ZO-1:occludin co-association, in parallel with increased ZO-1 phosphorylation (pTyr and pThr). All effects were dose-dependent. Either cytokine also caused extensive cell-cell border delocalization of ZO-1 in parallel with elevated HBMvEC permeability. Furthermore, pre-treatment of HBMvECs with antioxidants (superoxide dismutase, catalase, apocynin, N-acetylcysteine), or employing targeted inhibition of NADPH oxidase activation (NSC23766, gp91/p47 siRNA), were all found to comparably attenuate the cytokine-dependent decrease in ZO-1 protein expression. In summary, we present an in vitro model of how different proinflammatory cytokines can dysregulate ZO-1 properties in HBMvECs. A causal role for NADPH oxidase activation and oxidant signalling is also confirmed. Our findings add mechanistic depth to current in vivo models of BBB injury manifesting ZO-1 dysregulation. Copyright © 2015 Elsevier Inc. All rights reserved.

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

Astrocytes and extracellular matrix in extrasynaptic volume transmission.

PubMed

Vargová, Lýdia; Syková, Eva

2014-10-19

Volume transmission is a form of intercellular communication that does not require synapses; it is based on the diffusion of neuroactive substances across the brain extracellular space (ECS) and their binding to extrasynaptic high-affinity receptors on neurons or glia. Extracellular diffusion is restricted by the limited volume of the ECS, which is described by the ECS volume fraction α, and the presence of diffusion barriers, reflected by tortuosity λ, that are created, for example, by fine astrocytic processes or extracellular matrix (ECM) molecules. Organized astrocytic processes, ECM scaffolds or myelin sheets channel the extracellular diffusion so that it is facilitated in a certain direction, i.e. anisotropic. The diffusion properties of the ECS are profoundly influenced by various processes such as the swelling and morphological rebuilding of astrocytes during either transient or persisting physiological or pathological states, or the remodelling of the ECM in tumorous or epileptogenic tissue, during Alzheimer's disease, after enzymatic treatment or in transgenic animals. The changing diffusion properties of the ECM influence neuron-glia interaction, learning abilities, the extent of neuronal damage and even cell migration. From a clinical point of view, diffusion parameter changes occurring during pathological states could be important for diagnosis, drug delivery and treatment. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Silicone adhesive matrix of verapamil hydrochloride to provide pH-independent sustained release.

PubMed

Tolia, Gaurav; Li, S Kevin

2014-02-01

Providing pH-independent oral release of weakly basic drugs with conventional matrix tablets can be challenging because of the pH-dependent solubility characteristics of the drugs and the changing pH environment along the gastrointestinal tract. The aim of the present study was to use a hydrophobic polymer to overcome the issue of pH-dependent release of weakly basic model drug verapamil hydrochloride from matrix tablets without the use of organic buffers in the matrix formulations. Silicone pressure-sensitive adhesive (PSA) polymer was evaluated because of its unique properties of low surface energy, hydrophobicity, low glass transition temperature, high electrical resistance, and barrier to hydrogen ion diffusion. Drug release, hydrogen ion diffusion, tablet contact angle, and internal tablet microenvironment pH with matrix tablets prepared using PSA were compared with those using water-insoluble ethyl cellulose (EC). Silicone PSA films showed higher resistance to hydrogen ion diffusion compared with EC films. Verapamil hydrochloride tablets prepared using silicone PSA showed higher hydrophobicity and lower water uptake than EC tablets. Silicone PSA tablets also showed pH-independent release of verapamil and decreased in dimensions during drug dissolution. By contrast, verapamil hydrochloride tablets prepared using EC did not achieve pH-independent release.

Organ culture storage of pre-prepared corneal donor material for Descemet's membrane endothelial keratoplasty

PubMed Central

Bhogal, Maninder; Matter, Karl; Balda, Maria S; Allan, Bruce D

2016-01-01

Purpose To evaluate the effect of media composition and storage method on pre-prepared Descemet's membrane endothelial keratoplasty (DMEK) grafts. Methods 50 corneas were used. Endothelial wound healing and proliferation in different media were assessed using a standard injury model. DMEK grafts were stored using three methods: peeling with free scroll storage; partial peeling with storage on the stroma and fluid bubble separation with storage on the stroma. Endothelial cell (EC) phenotype and the extent of endothelial overgrowth were examined. Global cell viability was assessed for storage methods that maintained a normal cell phenotype. Results 1 mm wounds healed within 4 days. Enhanced media did not increase EC proliferation but may have increased EC migration into the wounded area. Grafts that had been trephined showed evidence of EC overgrowth, whereas preservation of a physical barrier in the bubble group prevented this. In grafts stored in enhanced media or reapposed to the stroma after trephination, endothelial migration occurred sooner and cells underwent endothelial-mesenchymal transformation. Ongoing cell loss, with new patterns of cell death, was observed after returning grafts to storage. Grafts stored as free scrolls retained more viable ECs than grafts prepared with the fluid bubble method (74.2± 3% vs 60.3±6%, p=0.04 (n=8). Conclusion Free scroll storage is superior to liquid bubble and partial peeling techniques. Free scrolls only showed overgrowth of ECs after 4 days in organ culture, indicating a viable time window for the clinical use of pre-prepared DMEK donor material using this method. Methods for tissue preparation and storage media developed for whole corneas should not be used in pre-prepared DMEK grafts without prior evaluation. PMID:27543290

Compensation and persistent photocapacitance in homoepitaxial Sn-doped β-Ga2O3

NASA Astrophysics Data System (ADS)

Polyakov, A. Y.; Smirnov, N. B.; Shchemerov, I. V.; Gogova, D.; Tarelkin, S. A.; Pearton, S. J.

2018-03-01

The electrical properties of epitaxial β-Ga2O3 doped with Sn (1016-9 × 1018 cm-3) and grown by metalorganic chemical vapor deposition on semi-insulating β-Ga2O3 substrates are reported. Shallow donors attributable to Sn were observed only in a narrow region near the film/substrate interface and with a much lower concentration than the total Sn density. For heavily Sn doped films (Sn concentration, 9 × 1018 cm-3), the electrical properties in the top portion of the layer were determined by deep centers with a level at Ec-0.21 eV not described previously. In more lightly doped layers, the Ec-0.21 eV centers and deeper traps at Ec-0.8 eV were present, with the latter pinning the Fermi level. Low temperature photocapacitance and capacitance voltage measurements of illuminated samples indicated the presence of high densities (1017-1018 cm-3) of deep acceptors with an optical ionization threshold of 2.3 eV. Optical deep level transient spectroscopy (ODLTS) and photoinduced current transient spectroscopy (PICTS) detected electron traps at Ec-0.8 eV and Ec-1.1 eV. For lightly doped layers, the compensation of film conductivity was mostly provided by the Ec-2.3 eV acceptors. For heavily Sn doped films, deep acceptor centers possibly related to Ga vacancies were significant. The photocapacitance and the photocurrent caused by illumination at low temperatures were persistent, with an optical threshold of 1.9 eV and vanished only at temperatures of ˜400 K. The capture barrier for electrons causing the persistent photocapacitance effect was estimated from ODLTS and PICTS to be 0.25-0.35 eV.

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

Blood-cerebrospinal fluid barrier permeability in Alzheimer's disease.

PubMed

Chalbot, Sonia; Zetterberg, Henrik; Blennow, Kaj; Fladby, Tormod; Andreasen, Niels; Grundke-Iqbal, Inge; Iqbal, Khalid

2011-01-01

The role of blood-cerebrospinal fluid barrier (BCB) dysfunction in Alzheimer's disease (AD) has been addressed but not yet established. We evaluated the BCB integrity in 179 samples of cerebrospinal fluid (CSF) retrospectively collected from AD patients and control cases using both CSF/serum albumin ratio (QAlb) and CSF secretory Ca2+-dependent phospholipase A2 (sPLA2) activity. These analyses were supplemented with the measurement of total tau, amyloid-β1-42 (Aβ1-42), and ubiquitin CSF levels. We found that due to its higher sensitivity, CSF sPLA2 activity could 1) discriminate AD from healthy controls and 2) showed BCB impairment in neurological control cases while QAlb could not. Moreover, the CSF sPLA2 activity measurement showed that around half of the AD patients were characterized by a BCB impairment. The BCB dysfunction observed in AD was independent from Mini-Mental State Examination score as well as CSF levels of total tau, Aβ1-42, and ubiquitin. Finally, the BCB dysfunction was not limited to any of the CSF biomarkers-based previously identified subgroups of AD. These results suggest that the BCB damage occurs independent of and probably precedes both Aβ and tau pathologies in a restricted subgroup of AD patients.

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

Estrogen has opposing effects on vascular reactivity in obese, insulin-resistant male Zucker rats

NASA Technical Reports Server (NTRS)

Brooks-Asplund, Esther M.; Shoukas, Artin A.; Kim, Soon-Yul; Burke, Sean A.; Berkowitz, Dan E.

2002-01-01

We hypothesized that estradiol treatment would improve vascular dysfunction commonly associated with obesity, hyperlipidemia, and insulin resistance. A sham operation or 17beta-estradiol pellet implantation was performed in male lean and obese Zucker rats. Maximal vasoconstriction (VC) to phenylephrine (PE) and potassium chloride was exaggerated in control obese rats compared with lean rats, but estradiol significantly attenuated VC in the obese rats. Estradiol reduced the PE EC50 in all groups. This effect was cyclooxygenase independent, because preincubation with indomethacin reduced VC response to PE similarly in a subset of control and estrogen-treated lean rats. Endothelium-independent vasodilation (VD) to sodium nitroprusside was similar among groups, but endothelium-dependent VD to ACh was significantly impaired in obese compared with lean rats. Estradiol improved VD in lean and obese rats by decreasing EC50 but impaired function by decreasing maximal VD. The shift in EC50 corresponded to an upregulation in nitric oxide synthase III protein expression in the aorta of the estrogen-treated obese rats. In summary, estrogen treatment improves vascular function in male insulin-resistant, obese rats, partially via an upregulation of nitric oxide synthase III protein expression. These effects are counteracted by adverse factors, such as hyperlipidemia and, potentially, a release of an endothelium-derived contractile agent.

Lung preservation with Euro-Collins, University of Wisconsin, Wallwork, and low-potassium-dextran solution. Université++ Paris-Sud Lung Transplant Group.

PubMed

Xiong, L; Mazmanian, M; Chapelier, A R; Reignier, J; Weiss, M; Dartevelle, P G; Hervé, P

1994-09-01

Using isolated rat lungs, we compared prevention of ischemia-reperfusion injury provided by flushing the lungs with modified Euro-Collins solution (EC), University of Wisconsin solution (UW), low-potassium-dextran solution (LPD), or Wallwork solution (WA). After 4 hours' and 6 hours' cold ischemia, reperfusion injury was assessed on the basis of changes in filtration coefficients (Kfc) and pressure-flow curves, characterized by the slope of the curves (incremental resistance) and the extrapolation of this slope to zero flow (pulmonary pressure intercept [Ppi]). After 4 hours, Kfc and Ppi were higher with EC than with UW, LPD, and WA, and the incremental resistance was higher with EC and UW. After 6 hours, Kfc and incremental resistance Ppi were higher with LPD than with WA. Because ischemia-reperfusion injury is associated with decreased endothelial synthesis of prostacyclin and nitric oxide, we tested whether the addition of prostacyclin or the nitric oxide precursor L-arginine to WA would improve preservation. The Kfc and Ppi were lower with both treatments. In conclusion, ischemia-reperfusion injury was best prevented by using WA. The favorable effect of prostacyclin or L-arginine emphasizes the role played by endothelial dysfunction in ischemia-reperfusion injury.

Angiotensin II promotes iron accumulation and depresses PGI₂ and NO synthesis in endothelial cells: effects of losartan and propranolol analogs.

PubMed

Mak, I Tong; Landgraf, Kenneth M; Chmielinska, Joanna J; Weglicki, William B

2012-10-01

Angiotensin may promote endothelial dysfunction through iron accumulation. To research this, bovine endothelial cells (ECs) were incubated with iron (30 µmol·L⁻¹) with or without angiotensin II (100 nmol·L⁻¹). After incubation for 6 h, it was observed that the addition of angiotensin enhanced EC iron accumulation by 5.1-fold compared with a 1.8-fold increase for cells incubated with iron only. This enhanced iron uptake was attenuated by losartan (100 nmol·L⁻¹), d-propranolol (10 µmol·L⁻¹), 4-HO-propranolol (5 µmol·L⁻¹), and methylamine, but not by vitamin E or atenolol. After 6 h of incubation, angiotensin plus iron provoked intracellular oxidant formation (2'7'-dichlorofluorescein diacetate (DCF-DA) fluorescence) and elevated oxidized glutathione; significant loss of cell viability occurred at 48 h. Stimulated prostacyclin release decreased by 38% (6 h) and NO synthesis was reduced by 41% (24 h). Both oxidative events and functional impairment were substantially attenuated by losartan or d-propranolol. It is concluded that angiotensin promoted non-transferrin-bound iron uptake via AT-1 receptor activation, leading to EC oxidative functional impairment. The protective effects of d-propranolol and 4-HO-propranolol may be related to their lysosomotropic properties.

In vitro comparison of the antiproliferative effects of rhenium-186 and rhenium-188 on human aortic endothelial cells.

PubMed

Sauter, Alexander; Arthasana, Daniel; Dittmann, Helmut; Pritzkow, Maren; Wiesinger, Benjamin; Schmehl, Joerg; Brechtel, Klaus; Bantleon, Rüdiger; Claussen, Claus; Kehlbach, Rainer

2011-08-01

Rhenium-186 ((186)Re) and rhenium-188 ((188)Re) are promising radionuclides for the inhibition of restenosis after percutaneous transluminal angioplasty or other vascular interventions. Until now the maximal dose tolerance of endothelial cells has not been clearly known. To characterize the effects of local irradiation treatment, human aortic endothelial cells (ECs) were incubated with different doses of (186)Re and (188)Re. Two days after plating, ECs received treatment for a period of 5 days. The total radiation doses applied were 1, 4, 8, 16, and 32 Gy. On days 1, 3, 5, 7, and 12 after initial rhenium incubation, cell growth, clonogenic activity, cell-cycle distribution, and cytoskeletal architecture were evaluated. From the first day on, a dose-dependent growth inhibition was observed. Cumulative doses of ≥32 Gy caused a weak colony formation and significant alterations in the cytoskeletal architecture. An increased fraction of cells in G2/M phase was seen for cumulative radiation doses of ≥16 Gy. Interestingly, there were no significant differences between (186)Re and (188)Re. Even for low dose rates of β particles a dose-dependent proliferation inhibition of ECs is seen. Doses beyond 32 Gy alter the cytoskeletal architecture with possibly endothelial dysfunction and late thrombosis.

Intestinal epithelial barrier function and tight junction proteins with heat and exercise

PubMed Central

Zuhl, Micah N.; Moseley, Pope L.

2015-01-01

A single layer of enterocytes and tight junctions (intercellular multiprotein complexes) form the intestinal epithelial barrier that controls transport of molecules through transcellular and paracellular pathways. A dysfunctional or “leaky” intestinal tight junction barrier allows augmented permeation of luminal antigens, endotoxins, and bacteria into the blood stream. Various substances and conditions have been shown to affect the maintenance of the intestinal epithelial tight junction barrier. The primary focus of the present review is to analyze the effects of exertional or nonexertional (passive hyperthermia) heat stress on tight junction barrier function in in vitro and in vivo (animals and humans) models. Our secondary focus is to review changes in tight junction proteins in response to exercise or hyperthermic conditions. Finally, we discuss some pharmacological or nutritional interventions that may affect the cellular mechanisms involved in maintaining homeostasis of the intestinal epithelial tight junction barrier during heat stress or exercise. PMID:26359485

Lysosomal storage diseases and the blood-brain barrier.

PubMed

Begley, David J; Pontikis, Charles C; Scarpa, Maurizio

2008-01-01

The blood-brain barrier becomes a crucial issue in neuronopathic lysosomal storage diseases for three reasons. Firstly, the function of the blood-brain barrier may be compromised in many of the lysosomal storage diseases and this barrier dysfunction may contribute to the neuropathology seen in the diseases and accelerate cell death. Secondly, the substrate reduction therapies, which successfully reduce peripheral lysosomal storage, because of the blood-brain barrier may not have as free an access to brain cells as they do to peripheral cells. And thirdly, enzyme replacement therapy appears to have little access to the central nervous system as the mannose and mannose-6-phosphate receptors involved in their cellular uptake and transport to the lysosome do not appear to be expressed at the adult blood-brain barrier. This review will discuss in detail these issues and their context in the development of new therapeutic strategies.

Intestinal epithelial barrier function and tight junction proteins with heat and exercise.

PubMed

Dokladny, Karol; Zuhl, Micah N; Moseley, Pope L

2016-03-15

A single layer of enterocytes and tight junctions (intercellular multiprotein complexes) form the intestinal epithelial barrier that controls transport of molecules through transcellular and paracellular pathways. A dysfunctional or "leaky" intestinal tight junction barrier allows augmented permeation of luminal antigens, endotoxins, and bacteria into the blood stream. Various substances and conditions have been shown to affect the maintenance of the intestinal epithelial tight junction barrier. The primary focus of the present review is to analyze the effects of exertional or nonexertional (passive hyperthermia) heat stress on tight junction barrier function in in vitro and in vivo (animals and humans) models. Our secondary focus is to review changes in tight junction proteins in response to exercise or hyperthermic conditions. Finally, we discuss some pharmacological or nutritional interventions that may affect the cellular mechanisms involved in maintaining homeostasis of the intestinal epithelial tight junction barrier during heat stress or exercise. Copyright © 2016 the American Physiological Society.

Nanoscale drug delivery systems and the blood–brain barrier

PubMed Central

Alyautdin, Renad; Khalin, Igor; Nafeeza, Mohd Ismail; Haron, Muhammad Huzaimi; Kuznetsov, Dmitry

2014-01-01

The protective properties of the blood–brain barrier (BBB) are conferred by the intricate architecture of its endothelium coupled with multiple specific transport systems expressed on the surface of endothelial cells (ECs) in the brain’s vasculature. When the stringent control of the BBB is disrupted, such as following EC damage, substances that are safe for peripheral tissues but toxic to neurons have easier access to the central nervous system (CNS). As a consequence, CNS disorders, including degenerative diseases, can occur independently of an individual’s age. Although the BBB is crucial in regulating the biochemical environment that is essential for maintaining neuronal integrity, it limits drug delivery to the CNS. This makes it difficult to deliver beneficial drugs across the BBB while preventing the passage of potential neurotoxins. Available options include transport of drugs across the ECs through traversing occludins and claudins in the tight junctions or by attaching drugs to one of the existing transport systems. Either way, access must specifically allow only the passage of a particular drug. In general, the BBB allows small molecules to enter the CNS; however, most drugs with the potential to treat neurological disorders other than infections have large structures. Several mechanisms, such as modifications of the built-in pumping-out system of drugs and utilization of nanocarriers and liposomes, are among the drug-delivery systems that have been tested; however, each has its limitations and constraints. This review comprehensively discusses the functional morphology of the BBB and the challenges that must be overcome by drug-delivery systems and elaborates on the potential targets, mechanisms, and formulations to improve drug delivery to the CNS. PMID:24550672

Lipid rafts regulate PCB153-induced disruption of occludin and brain endothelial barrier function through protein phosphatase 2A and matrix metalloproteinase-2

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

Eum, Sung Yong, E-mail: seum@miami.edu; Jaraki, Dima; András, Ibolya E.

Occludin is an essential integral transmembrane protein regulating tight junction (TJ) integrity in brain endothelial cells. Phosphorylation of occludin is associated with its localization to TJ sites and incorporation into intact TJ assembly. The present study is focused on the role of lipid rafts in polychlorinated biphenyl (PCB)-induced disruption of occludin and endothelial barrier function. Exposure of human brain endothelial cells to 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153) induced dephosphorylation of threonine residues of occludin and displacement of occludin from detergent-resistant membrane (DRM)/lipid raft fractions within 1 h. Moreover, lipid rafts modulated the reduction of occludin level through activation of matrix metalloproteinase 2 (MMP-2)more » after 24 h PCB153 treatment. Inhibition of protein phosphatase 2A (PP2A) activity by okadaic acid or fostriecin markedly protected against PCB153-induced displacement of occludin and increased permeability of endothelial cells. The implication of lipid rafts and PP2A signaling in these processes was further defined by co-immunoprecipitation of occludin with PP2A and caveolin-1, a marker protein of lipid rafts. Indeed, a significant MMP-2 activity was observed in lipid rafts and was increased by exposure to PCB153. The pretreatment of MMP-2 inhibitors protected against PCB153-induced loss of occludin and disruption of lipid raft structure prevented the increase of endothelial permeability. Overall, these results indicate that lipid raft-associated processes, such as PP2A and MMP-2 activation, participate in PCB153-induced disruption of occludin function in brain endothelial barrier. This study contributes to a better understanding of the mechanisms leading to brain endothelial barrier dysfunction in response to exposure to environmental pollutants, such as ortho-substituted PCBs. - Highlights: • PCB153 disturbed human brain endothelial barrier through disruption of occludin. • Lipid raft-associated PP2A/MMP-2 induced PCB153-induced dysfunction of occludin. • Disrupted lipid rafts modulated PCB153-induced increase of permeability. • Lipid rafts act as a signaling platform for PCB153-induced dysfunction of occludin.« less

Sexual history taking and sexually transmitted infection screening in patients initiating erectile dysfunction medication therapy.

PubMed

Holman, Katherine M; Carr, James Andrew; Baddley, John W; Hook, Edward W

2013-11-01

Erectile dysfunction medications are being prescribed frequently; however, little is known about the amount of sexual health screening occurring in this setting. A retrospective cohort study evaluating sexual health and sexually transmitted infection screening occurring in veterans receiving initial erectile dysfunction medication prescription was conducted. A total of 252 patients received initial erectile dysfunction medication prescriptions between October 1, 2009, and December 31, 2009; had at least 1 health care provider visit 12 months before the date of initial prescription; and had no documentation of previous erectile dysfunction medication use. Approximately 3% of these patients had any aspect of a sexual history recorded in the 24 months surrounding initial erectile dysfunction medication prescription. Sexually transmitted infection screening was 9.9% for syphilis, 4.8% for HIV, and 4.3% for gonorrhea/chlamydia before prescription, with only a slight increase in HIV screening after prescription. Minimal sexual health assessment is being performed during the time surrounding initial prescription of erectile dysfunction medication. Further work needs to evaluate patient and provider barriers to basic elements of sexual health care, such as taking sexual histories or screening for sexually transmitted infections.

Rescue of perfluorooctanesulfonate (PFOS)-mediated Sertoli cell injury by overexpression of gap junction protein connexin 43

PubMed Central

Li, Nan; Mruk, Dolores D.; Chen, Haiqi; Wong, Chris K. C.; Lee, Will M.; Cheng, C. Yan

2016-01-01

Perfluorooctanesulfonate (PFOS) is an environmental toxicant used in developing countries, including China, as a stain repellent for clothing, carpets and draperies, but it has been banned in the U.S. and Canada since the late 2000s. PFOS perturbed the Sertoli cell tight junction (TJ)-permeability barrier, causing disruption of actin microfilaments in cell cytosol, perturbing the localization of cell junction proteins (e.g., occluden-ZO-1, N-cadherin-ß-catenin). These changes destabilized Sertoli cell blood-testis barrier (BTB) integrity. These findings suggest that human exposure to PFOS might induce BTB dysfunction and infertility. Interestingly, PFOS-induced Sertoli cell injury associated with a down-regulation of the gap junction (GJ) protein connexin43 (Cx43). We next investigated if overexpression of Cx43 in Sertoli cells could rescue the PFOS-induced cell injury. Indeed, overexpression of Cx43 in Sertoli cells with an established TJ-barrier blocked the disruption in PFOS-induced GJ-intercellular communication, resulting in the re-organization of actin microfilaments, which rendered them similar to those in control cells. Furthermore, cell adhesion proteins that utilized F-actin for attachment became properly distributed at the cell-cell interface, resealing the disrupted TJ-barrier. In summary, Cx43 is a good target that might be used to manage PFOS-induced reproductive dysfunction. PMID:27436542

Assessing Diffusion in the Extra-Cellular Space of Brain Tissue by Dynamic MRI Mapping of Contrast Agent Concentrations

NASA Astrophysics Data System (ADS)

Mériaux, Sébastien; Conti, Allegra; Larrat, Benoît

2018-05-01

The characterization of extracellular space (ECS) architecture represents valuable information for the understanding of transport mechanisms occurring in brain parenchyma. ECS tortuosity reflects the hindrance imposed by cell membranes to molecular diffusion. Numerous strategies have been proposed to measure the diffusion through ECS and to estimate its tortuosity. The first method implies the perfusion for several hours of a radiotracer which effective diffusion coefficient D* is determined after post mortem processing. The most well-established techniques are real-time iontophoresis that measures the concentration of a specific ion at known distance from its release point, and integrative optical imaging that relies on acquiring microscopy images of macromolecules labelled with fluorophore. After presenting these methods, we focus on a recent Magnetic Resonance Imaging (MRI)-based technique that consists in acquiring concentration maps of a contrast agent diffusing within ECS. Thanks to MRI properties, molecular diffusion and tortuosity can be estimated in 3D for deep brain regions. To further discuss the reliability of this technique, we point out the influence of the delivery method on the estimation of D*. We compare the value of D* for a contrast agent intracerebrally injected, with its value when the agent is delivered to the brain after an ultrasound-induced blood-brain barrier (BBB) permeabilization. Several studies have already shown that tortuosity may be modified in pathological conditions. Therefore, we believe that MRI-based techniques could be useful in a clinical context for characterizing the diffusion properties of pathological ECS and thus predicting the drug biodistribution into the targeted area.

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

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

Organotypic vasculature: From descriptive heterogeneity to functional pathophysiology.

PubMed

Augustin, Hellmut G; Koh, Gou Young

2017-08-25

Blood vessels form one of the body's largest surfaces, serving as a critical interface between the circulation and the different organ environments. They thereby exert gatekeeper functions on tissue homeostasis and adaptation to pathologic challenge. Vascular control of the tissue microenvironment is indispensable in development, hemostasis, inflammation, and metabolism, as well as in cancer and metastasis. This multitude of vascular functions is mediated by organ-specifically differentiated endothelial cells (ECs), whose cellular and molecular heterogeneity has long been recognized. Yet distinct organotypic functional attributes and the molecular mechanisms controlling EC differentiation and vascular bed-specific functions have only become known in recent years. Considering the involvement of vascular dysfunction in numerous chronic and life-threatening diseases, a better molecular understanding of organotypic vasculatures may pave the way toward novel angiotargeted treatments to cure hitherto intractable diseases. This Review summarizes recent progress in the understanding of organotypic vascular differentiation and function. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Heterozygous Null Bone Morphogenetic Protein Receptor Type 2 Mutations Promote SRC Kinase-dependent Caveolar Trafficking Defects and Endothelial Dysfunction in Pulmonary Arterial Hypertension*

PubMed Central

Prewitt, Allison R.; Ghose, Sampa; Frump, Andrea L.; Datta, Arumima; Austin, Eric D.; Kenworthy, Anne K.; de Caestecker, Mark P.

2015-01-01

Hereditary pulmonary arterial hypertension (HPAH) is a rare, fatal disease of the pulmonary vasculature. The majority of HPAH patients inherit mutations in the bone morphogenetic protein type 2 receptor gene (BMPR2), but how these promote pulmonary vascular disease is unclear. HPAH patients have features of pulmonary endothelial cell (PEC) dysfunction including increased vascular permeability and perivascular inflammation associated with decreased PEC barrier function. Recently, frameshift mutations in the caveolar structural protein gene Caveolin-1 (CAV-1) were identified in two patients with non-BMPR2-associated HPAH. Because caveolae regulate endothelial function and vascular permeability, we hypothesized that defects in caveolar function might be a common mechanism by which BMPR2 mutations promote pulmonary vascular disease. To explore this, we isolated PECs from mice carrying heterozygous null Bmpr2 mutations (Bmpr2+/−) similar to those found in the majority of HPAH patients. We show that Bmpr2+/− PECs have increased numbers and intracellular localization of caveolae and caveolar structural proteins CAV-1 and Cavin-1 and that these defects are reversed after blocking endocytosis with dynasore. SRC kinase is also constitutively activated in Bmpr2+/− PECs, and localization of CAV-1 to the plasma membrane is restored after treating Bmpr2+/− PECs with the SRC kinase inhibitor 3-(4-chlorophenyl)-1-(1,1-dimethylethyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine (PP2). Late outgrowth endothelial progenitor cells isolated from HPAH patients show similar increased activation of SRC kinase. Moreover, Bmpr2+/− PECs have impaired endothelial barrier function, and barrier function is restored after treatment with PP2. These data suggest that heterozygous null BMPR2 mutations promote SRC-dependent caveolar trafficking defects in PECs and that this may contribute to pulmonary endothelial barrier dysfunction in HPAH patients. PMID:25411245

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.

RhoB controls endothelial barrier recovery by inhibiting Rac1 trafficking to the cell border

PubMed Central

Marcos-Ramiro, Beatriz; García-Weber, Diego; Barroso, Susana; Feito, Jorge; Ortega, María C.; Cernuda-Morollón, Eva; Reglero-Real, Natalia; Fernández-Martín, Laura; Durán, Maria C.; Alonso, Miguel A.; Correas, Isabel; Cox, Susan; Ridley, Anne J.

2016-01-01

Endothelial barrier dysfunction underlies chronic inflammatory diseases. In searching for new proteins essential to the human endothelial inflammatory response, we have found that the endosomal GTPase RhoB is up-regulated in response to inflammatory cytokines and expressed in the endothelium of some chronically inflamed tissues. We show that although RhoB and the related RhoA and RhoC play additive and redundant roles in various aspects of endothelial barrier function, RhoB specifically inhibits barrier restoration after acute cell contraction by preventing plasma membrane extension. During barrier restoration, RhoB trafficking is induced between vesicles containing RhoB nanoclusters and plasma membrane protrusions. The Rho GTPase Rac1 controls membrane spreading and stabilizes endothelial barriers. We show that RhoB colocalizes with Rac1 in endosomes and inhibits Rac1 activity and trafficking to the cell border during barrier recovery. Inhibition of endosomal trafficking impairs barrier reformation, whereas induction of Rac1 translocation to the plasma membrane accelerates it. Therefore, RhoB-specific regulation of Rac1 trafficking controls endothelial barrier integrity during inflammation. PMID:27138256

Clinical use of a ceramide-based moisturizer for treating dogs with atopic dermatitis

PubMed Central

Jung, Ji-young; Nam, Eui-hwa; Park, Seol-hee; Han, Seung-hee

2013-01-01

In humans, skin barrier dysfunction is thought to be responsible for enhanced penetration of allergens. Similar to conditions seen in humans, canine atopic dermatitis (CAD) is characterized by derangement of corneocytes and disorganization of intercellular lipids in the stratum corenum (SC) with decreased ceramide levels. This study was designed to evaluate the effects of a moisturizer containing ceramide on dogs with CAD. Dogs (n = 20, 3~8 years old) with mild to moderate clinical signs were recruited and applied a moisturizer containing ceramide for 4 weeks. Transepidermal water loss (TEWL), skin hydration, pruritus index for canine atopic dermatitis (PICAD) scores, and canine atopic dermatitis extent and severity index (CADESI) scores of all dogs were evaluated. Skin samples from five dogs were also examined with transmission electron microscopy (TEM) using ruthenium tetroxide. TEWL, PICAD, and CADESI values decreased (p < 0.05) and skin hydration increased dramatically over time (p < 0.05). Electron micrographs showed that the skin barrier of all five dogs was partially restored (p < 0.05). In conclusion, these results demonstrated that moisturizer containing ceramide was effective for treating skin barrier dysfunction and CAD symptoms. PMID:23814473

Inhibition of cyclooxygenase-2 alleviates liver cirrhosis via improvement of the dysfunctional gut-liver axis in rats.

PubMed

Gao, Jin-Hang; Wen, Shi-Lei; Tong, Huan; Wang, Chun-Hui; Yang, Wen-Juan; Tang, Shi-Hang; Yan, Zhao-Ping; Tai, Yang; Ye, Cheng; Liu, Rui; Huang, Zhi-Yin; Tang, Ying-Mei; Yang, Jin-Hui; Tang, Cheng-Wei

2016-06-01

Inflammatory transport through the gut-liver axis may facilitate liver cirrhosis. Cyclooxygenase-2 (COX-2) has been considered as one of the important molecules that regulates intestinal epithelial barrier function. This study was aimed to test the hypothesis that inhibition of COX-2 by celecoxib might alleviate liver cirrhosis via reduction of intestinal inflammatory transport in thiacetamide (TAA) rat model. COX-2/prostaglandin E2 (PGE2)/EP-2/p-ERK integrated signal pathways regulated the expressions of intestinal zonula occludens-1 (ZO-1) and E-cadherin, which maintain the function of intestinal epithelial barrier. Celecoxib not only decreased the intestinal permeability to a 4-kDa FITC-dextran but also significantly increased expressions of ZO-1 and E-cadherin. When celecoxib greatly decreased intestinal levels of LPS, TNF-α, and IL-6, it significantly enhanced T cell subsets reduced by TAA. As a result, liver fibrosis induced by TAA was significantly alleviated in the celecoxib group. These data indicated that celecoxib improved the integrity of intestinal epithelial barrier, blocked inflammatory transport through the dysfunctional gut-liver axis, and ameliorated the progress of liver cirrhosis. Copyright © 2016 the American Physiological Society.

High protective efficacy of rice bran against human rotavirus diarrhea via enhancing probiotic growth, gut barrier function, and innate immunity.

PubMed

Yang, Xingdong; Twitchell, Erica; Li, Guohua; Wen, Ke; Weiss, Mariah; Kocher, Jacob; Lei, Shaohua; Ramesh, Ashwin; Ryan, Elizabeth P; Yuan, Lijuan

2015-10-13

Previously, we showed that rice bran (RB) was able to reduce human rotavirus (HRV) diarrhea in gnotobiotic pigs. Here, we investigated its effect on the growth of diarrhea-reducing probiotic Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle (EcN), and the resulting effects on HRV diarrhea, gut epithelial health, permeability and innate immune responses during virulent HRV challenge. On 3, 5, and 7 days of age pigs were inoculated with 2 × 10(4) colony-forming-units LGG+EcN to initiate colonization. Daily RB supplementation (replacing 10% calorie intake) was started at 5 days of age and continued until euthanasia. A subset of pigs in each group was challenged orally with 10(5) focus-forming-units of virulent HRV at 33 days of age. RB completely prevented HRV diarrhea in LGG+EcN colonized pigs. RB significantly promoted the growth of both probiotic strains in the gut (~5 logs) and increased the body-weight-gain at 4-5 weeks of age compared to non-RB group. After HRV challenge, RB-fed pigs had significantly lower ileal mitotic index and villus width, and significantly increased intestinal IFN-γ and total IgA levels compared to non-RB group. Therefore, RB plus LGG+EcN colonization may represent a highly effective therapeutic approach against HRV and potentially a variety of other diarrhea-inducing enteric pathogens.

Evaluation of emerging contaminants in a drinking water treatment plant using electrodialysis reversal technology.

PubMed

Gabarrón, S; Gernjak, W; Valero, F; Barceló, A; Petrovic, M; Rodríguez-Roda, I

2016-05-15

Emerging contaminants (EC) have gained much attention with globally increasing consumption and detection in aquatic ecosystems during the last two decades from ng/L to lower ug/L. The aim of this study was to evaluate the occurrence and removal of pharmaceutically active compounds (PhACs), endocrine disrupting chemicals (EDCs) and related compounds in a Drinking Water Treatment Plant (DWTP) treating raw water from the Mediterranean Llobregat River. The DWTP combined conventional treatment steps with the world's largest electrodialysis reversal (EDR) facility. 49 different PhACs, EDCs and related compounds were found above their limit of quantification in the influent of the DWTP, summing up to a total concentration of ECs between 1600-4200 ng/L. As expected, oxidation using chlorine dioxide and granular activated carbon filters were the most efficient technologies for EC removal. However, despite the low concentration detected in the influent of the EDR process, it was also possible to demonstrate that this process partially removed ionized compounds, thereby constituting an additional barrier against EC pollution in the product. In the product of the EDR system, only 18 out of 49 compounds were quantifiable in at least one of the four experimental campaigns, showing in all cases removals higher than 65% and often beyond 90% for the overall DWTP process. Copyright © 2016 Elsevier B.V. All rights reserved.

Physical activity for an ethnically diverse sample of endometrial cancer survivors: a needs assessment and pilot intervention

PubMed Central

Rossi, Amerigo; Moadel-Robblee, Alyson; Garber, Carol Ewing; Kuo, Dennis; Goldberg, Gary; Einstein, Mark

2015-01-01

Objective To determine the physical activity (PA) behavior, needs and preferences for underserved, ethnically diverse women with a history of endometrial cancer (EC). Methods Women with a history of EC (41 non-Hispanic black, 40 non-Hispanic white, and 18 Hispanic) completed a needs assessment during their regular follow-up appointments at Montefiore Medical Center in Bronx, NY, USA. An 8-week pilot PA intervention based on the results of the needs assessment was conducted with 5 EC survivors. Results Mean body mass index (BMI) among the 99 respondents was 34.1±7.6 kg/m2, and 66% did not exercise regularly. Self-described weight status was significantly lower than actual BMI category (p<0.001). Of the 86% who were interested in joining an exercise program, 95% were willing to attend at least once weekly. The primary motivations were improving health, losing weight, and feeling better physically. Despite the high interest in participation, volunteer rate was very low (8%). However, adherence to the 8-week pilot PA intervention was high (83%), and there were no adverse events. Body weight decreased in all pilot participants. Conclusion These data show that ethnically diverse EC survivors have a great need for, and are highly interested in, PA interventions. However, greater care needs to be taken to assess and identify barriers to increase participation in such programs. PMID:25872894

European Economic and Monetary Union: Why Should We Care?

DTIC Science & Technology

1992-04-15

economic, if not political unification, that calls for a single market, a central european bank and a single currency. Why, in one short decade, did the EC...directives to eliminate fiscal and technical barriers to trade, services, banking , insurance, transportation, and securities transactions. The Single...implications. A logical outgrowth of this is the establishment of a single european currency and a central bank to issue this currency. These are 12

Cross section measurements in the 12C+12C system

NASA Astrophysics Data System (ADS)

Courtin, S.; Jiang, C. L.; Fruet, G.; Heine, M.; Jenkins, D. G.; Adsley, P.; Morris, L. G.; Regan, P. H.; Rudigier, M.; Montanari, D.; Della Negra, S.; de Séréville, N.; Haas, F.; Hammache, F.; Kirsebom, O. S.; Lesrel, J.; Meyer, A.; Montanari, D.; Auranen, K.; Avila, M. L.; Ayangeakaa, A. D.; Back, B. B.; Bottoni, S.; Carpenter, M.; Dickerson, C.; DiGiovine, B.; Greene, J. P.; Henderson, D. J.; Hoffman, C. R.; Janssens, R. V. F.; Kay, B. P.; Kuvin, S. A.; Lauritsen, T.; Pardo, R. C.; Rehm, K. E.; Santiago-Gonzalez, D.; Sethi, J.; Seweryniak, D.; Talwar, R.; Ugalde, C.; Zhu, S.; Deibel, C. M.; Marley, S. T.; Bourgin, D.; Stodel, C.; Lefebvre-Schuhl, A.; Almaraz-Calderon, S.; Fang, X.; Tang, X. D.; Alcorta, M.; Bucher, B.; Albers, M.; Bertone, P.

2018-01-01

The 12C+12C fusion reaction is one of the most important for nuclear astrophysics since it determines the carbon ignition in stellar environments. Two experiments which make use of the gamma-particle coincidence technique to measure the 12C+12C S-factors at deep sub barrier energies are discussed. Results are presented showing a decrease of the S-factor below Ec.m. = 3 MeV.

Endothelial cells are critical regulators of iron transport in a model of the human blood-brain barrier.

PubMed

Chiou, Brian; Neal, Emma H; Bowman, Aaron B; Lippmann, Ethan S; Simpson, Ian A; Connor, James R

2018-01-01

Iron delivery to the brain is essential for multiple neurological processes such as myelination, neurotransmitter synthesis, and energy production. Loss of brain iron homeostasis is a significant factor in multiple neurological disorders. Understanding the mechanism by which the transport of iron across the blood-brain barrier (BBB) is regulated is crucial to address the impact of iron deficiency on brain development and excessive accumulation of iron in neurodegenerative diseases. Using induced pluripotent stem cell (iPSC)-derived brain endothelial cells (huECs) as a human BBB model, we demonstrate the ability of transferrin, hepcidin, and DMT1 to impact iron transport and release. Our model reveals a new function for H-ferritin to transport iron across the BBB by binding to the T-cell immunoglobulin and mucin receptor 1. We show that huECs secrete both transferrin and H-ferritin, which can serve as iron sources for the brain. Based on our data, brain iron status can exert control of iron transport across the endothelial cells that constitute the BBB. These data address a number of pertinent questions such as how brain iron uptake is regulated at the regional level, the source of iron delivery to the brain, and the clinical strategies for attempting to treat brain iron deficiency.

MOBILE-izing Adolescent Sexual and Reproductive Health Care: A Pilot Study Using a Mobile Health Unit in Chicago.

PubMed

Stefansson, Lilja S; Webb, M Elizabeth; Hebert, Luciana E; Masinter, Lisa; Gilliam, Melissa L

2018-03-01

Adolescents experience numerous barriers to obtaining sexual and reproductive health care (SRHC). Mobile Health Units (MHUs) can remove some barriers by traveling to the community. This pilot study developed Mobile SRHC through an iterative process on an existing MHU and evaluated it among adolescents and providers. Mobile SRHC was developed through a mixed-method, multiphase study. Three key informant interviews with MHU providers, an adolescent needs assessment survey, and a Youth Model Development Session informed model development. Emergency contraception (EC), oral contraceptive pills (OCPs), and depot-medroxyprogesterone acetate (DMPA) were sequentially incorporated into MHU services. Administrative data assessed method distribution and surveys assessed patient satisfaction. Key informants held positive attitudes toward implementing Mobile SRHC into their practice. Needs assessment surveys (N = 103) indicated a majority was interested in learning about sexual health (66.0%) and obtaining birth control (54.4%) on an MHU. Over 3 months, 123 adolescents participated in Mobile SRHC. Seven packs and 9 prescriptions of EC, 8 3-month packs and 10 prescriptions of OCPs, and 5 injections and 5 prescriptions of DMPA were distributed. Ninety-two percent of adolescent participants reported they would recommend Mobile SRHC to friends. Mobile SRHC is a feasible approach for reproductive health care among adolescents. © 2018, American School Health Association.

Neurotoxicology of the Brain Barrier System: New Implications

PubMed Central

Zheng, Wei

2014-01-01

The concept of a barrier system in the brain has existed for nearly a century. The barrier that separates the blood from the cerebral interstitial fluid is defined as the blood-brain barrier, while the one that discontinues the circulation between the blood and cerebrospinal fluid is named the blood-cerebrospinal fluid barrier. Evidence in the past decades suggests that brain barriers are subject to toxic insults from neurotoxic chemicals circulating in blood. The aging process and some disease states render barriers more vulnerable to insults arising inside and outside the barriers. The implication of brain barriers in certain neurodegenerative diseases is compelling, although the contribution of chemical-induced barrier dysfunction in the etiology of any of these disorders remains poorly understood. This review examines what is currently understood about brain barrier systems in central nervous system disorders by focusing on chemical-induced neurotoxicities including those associated with nitrobenzenes, N-methyl-D-aspartate, cyclosporin A, pyridostigmine bromide, aluminum, lead, manganese, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, and 3-nitropropionic acid. Contemporary research questions arising from this growing understanding show enormous promises for brain researchers, toxicologists, and clinicians. PMID:11778669

Endothelial cell dysfunction and cytoskeletal changes associated with repression of p16INK4a during immortalization

PubMed Central

Kan, C-Y; Wen, V W; Pasquier, E; Jankowski, K; Chang, M; Richards, L A; Kavallaris, M; MacKenzie, K L

2012-01-01

The immortalization process is a fundamental step in the development of most (if not all) human cancers, including the aggressive endothelial cell (EC)-derived malignancy angiosarcoma. Inactivation of the tumor suppressor p16INK4a and the development of multiple chromosomal abnormalities are features of angiosarcoma that are recapitulated during telomerase-mediated immortalization of human ECs in vitro. The present study used a panel of telomerase-immortalized bone marrow EC (BMEC) lines to define the consequences of inactivation of p16INK4a on EC function and to identify molecular changes associated with repression of p16INK4a. In a comparison of two immortalized BMEC mass cultures and six clones, the cell lines that repressed p16INK4a showed a higher rate of proliferation and an impaired ability to undergo morphogenic differentiation and form vessel-like structures in vitro. Proteomic comparison of a p16INK4a-negative and a p16INK4a-positive BMEC mass culture at early- and late-passage time points following transduction with telomerase reverse transcriptase (hTERT) revealed altered expression of cytoskeletal proteins, including vimentin and α-tropomyosin (αTm), in the immortal cells. Immunoblot analyses of a panel of 11 immortal clones showed that cells that lacked p16INK4a expression tended to accumulate more dramatic changes in these cytoskeletal proteins than cells that retained p16INK4a expression. This corresponded with aberrant cytoskeletal architectures among p16INK4a-negative clones, which featured thicker actin stress fibers and less fluid membrane ruffles than p16INK4a-positive cells. A direct link between p16INK4a repression and defective EC function was confirmed by analysis of normal cells transfected with small interfering RNA (siRNA) targeting p16INK4a. siRNA-mediated repression of p16INK4a significantly impaired random motility and vessel formation in vitro. This report is the first to demonstrate that ECs that repress the expression of p16INK4a are prone to defects in motility, morphogenesis and cytoskeletal organization. These defects are likely to reflect alterations that occur during the development of EC-derived malignancies. PMID:22310292

Counterregulation between thymic stromal lymphopoietin- and IL-23-driven immune axes shapes skin inflammation in mice with epidermal barrier defects.

PubMed

Li, Jiagui; Leyva-Castillo, Juan Manuel; Hener, Pierre; Eisenmann, Aurelie; Zaafouri, Sarra; Jonca, Nathalie; Serre, Guy; Birling, Marie-Christine; Li, Mei

2016-07-01

Epidermal barrier dysfunction has been recognized as a critical factor in the initiation and exacerbation of skin inflammation, particularly in patients with atopic dermatitis (AD) and AD-like congenital disorders, including peeling skin syndrome type B. However, inflammatory responses developed in barrier-defective skin, as well as the underlying mechanisms, remained incompletely understood. We aimed to decipher inflammatory axes and the cytokine network in mouse skin on breakdown of epidermal stratum corneum barrier. We generated Cdsn(iep-/-) mice with corneodesmosin ablation in keratinocytes selectively in an inducible manner. We characterized inflammatory responses and cytokine expression by using histology, immunohistochemistry, ELISA, and quantitative PCR. We combined mouse genetic tools, antibody-mediated neutralization, signal-blocking reagents, and topical antibiotic treatment to explore the inflammatory axes. We show that on breakdown of the epidermal stratum corneum barrier, type 2 and type 17 inflammatory responses are developed simultaneously, driven by thymic stromal lymphopoietin (TSLP) and IL-23, respectively. Importantly, we reveal a counterregulation between these 2 inflammatory axes. Furthermore, we show that protease-activated receptor 2 signaling is involved in mediating the TSLP/type 2 axis, whereas skin bacteria are engaged in induction of the IL-23/type 17 axis. Moreover, we find that IL-1β is induced in skin of Cdsn(iep-/-) mice and that blockade of IL-1 signaling suppresses both TSLP and IL-23 expression and ameliorates skin inflammation. The inflammatory phenotype in barrier-defective skin is shaped by counterregulation between the TSLP/type 2 and IL-23/type 17 axes. Targeting IL-1 signaling could be a promising therapeutic option for controlling skin inflammation in patients with peeling skin syndrome type B and other diseases related to epidermal barrier dysfunction, including AD. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Low humidity environmental challenge causes barrier disruption and cornification of the mouse corneal epithelium via a c-jun N-terminal kinase 2 (JNK2) pathway.

PubMed

Pelegrino, F S A; Pflugfelder, S C; De Paiva, C S

2012-01-01

Patients with tear dysfunction often experience increased irritation symptoms when subjected to drafty and/or low humidity environmental conditions. The purpose of this study was to investigate the effects of low humidity stress (LHS) on corneal barrier function and expression of cornified envelope (CE) precursor proteins in the epithelium of C57BL/6 and c-jun N-terminal kinase 2 (JNK2) knockout (KO) mice. LHS was induced in both strains by exposure to an air draft for 15 (LHS15D) or 30 days (LHS30D) at a relative humidity <30%RH. Nonstressed (NS) mice were used as controls. Oregon-green-dextran uptake was used to measure corneal barrier function. Levels of small proline-rich protein (SPRR)-2, involucrin, occludin, and MMP-9 were evaluated by immunofluorescent staining in cornea sections. Wholemount corneas immunostained for occludin were used to measure mean apical cell area. Gelatinase activity was evaluated by in situ zymography. Expression of MMP, CE and inflammatory cytokine genes was evaluated by qPCR. C57BL/6 mice exposed to LHS15D showed corneal barrier dysfunction, decreased apical corneal epithelial cell area, higher MMP-9 expression and gelatinase activity and increased involucrin and SPRR-2 immunoreactivity in the corneal epithelium compared to NS mice. JNK2KO mice were resistant to LHS-induced corneal barrier disruption. MMP-3,-9,-13, IL-1α, IL-1β, involucrin and SPRR-2a RNA transcripts were significantly increased in C57BL/6 mice at LHS15D, while no change was noted in JNK2KO mice. LHS is capable of altering corneal barrier function, promoting pathologic alteration of the TJ complex and stimulating production of CE proteins by the corneal epithelium. Activation of the JNK2 signaling pathway contributes to corneal epithelial barrier disruption in LHS. Copyright © 2011 Elsevier Ltd. All rights reserved.

microRNAs as Pharmacological Targets in Endothelial Cell Function and Dysfunction

PubMed Central

Chamorro-Jorganes, Aránzazu; Araldi, Elisa; Suárez, Yajaira

2013-01-01

Endothelial cell dysfunction is a term which implies the dysregulation of normal endothelial cell functions, including impairment of the barrier functions, control of vascular tone, disturbance of proliferative, migratory and morphogenic capacities of endothelial cells, as well as control of leukocyte trafficking. MicroRNAs (miRNAs) are short non-coding RNAs that have emerged as critical regulators of gene expression acting predominantly at the post-transcriptional level. This review summarizes the latest insights in the identification of endothelial-specific miRNAs and their targets, as well as their roles in controlling endothelial cell functions in both autocrine and paracrine manner. In addition, we discuss the therapeutic potential for the treatment of endothelial cell dysfunction and associated vascular pathophysiological conditions. PMID:23603154

The Outward Spiral: A vicious cycle model of obesity and cognitive dysfunction.

PubMed

Hargrave, Sara L; Jones, Sabrina; Davidson, Terry L

2016-06-01

Chronic failure to suppress intake during states of positive energy balance leads to weight gain and obesity. The ability to use context - including interoceptive satiety states - to inhibit responding to previously rewarded cues appears to depend on the functional integrity of the hippocampus. Recent evidence implicates energy dense Western diets in several types of hippocampal dysfunction, including reduced expression of neurotrophins and nutrient transporters, increased inflammation, microglial activation, and blood brain barrier permeability. The functional consequences of such insults include impairments in an animal's ability to modulate responding to a previously reinforced cues. We propose that such deficits promote overeating, which can further exacerbate hippocampal dysfunction and thus initiate a vicious cycle of both obesity and progressive cognitive decline.

Promoting the dissemination of decision aids: an odyssey in a dysfunctional health care financing system.

PubMed

Billings, John

2004-01-01

The usefulness of patient decision aids (PtDAs) is well documented, yet they are not in widespread use. Barriers include assuring balance and fairness (auspices matter), the cost of producing and maintaining them, and getting them into the hands of patients at the right time. The Foundation for Informed Medical Decision Making and its for-profit partner, Health Dialog, have developed a creative business model that helps overcome these barriers and has greatly expanded the reach of decision aids.

Participation of reactive oxygen species in diabetes-induced endothelial dysfunction.

PubMed

Zúrová-Nedelcevová, Jana; Navarová, Jana; Drábiková, Katarína; Jancinová, Viera; Petríková, Margita; Bernátová, Iveta; Kristová, Viera; Snirc, Vladimír; Nosál'ová, Viera; Sotníková, Ruzena

2006-12-01

In the present study, the relationship between diabetes-induced hyperglycemia, reactive oxygen species production and endothelium-mediated arterial function was examined. The effect of antioxidant on the reactive oxygen species induced damage was tested. Diabetes was induced by streptozotocin (STZ), 3 x 30 mg/kg i.p., administered on three consecutive days. After 10 weeks of diabetes, the functional state of the endothelium of the aorta was tested, endothelemia evaluation was performed and systolic blood pressure was measured. Reactive oxygen species (ROS) formation in blood and the aorta was measured using luminol-enhanced chemiluminescence (CL). Levels of reduced glutathione (GSH) were determined in the aorta, kidney, and plasma. To study the involvement of hyperglycemia in functional impairment of the endothelium, aortal rings incubated in solution with high glucose concentration were tested in in vitro experiments. After 10 weeks of diabetes, endothelial injury was observed, exhibited by diminished endothelium-dependent relaxation of the aorta, increased endothelemia and by elevated systolic blood pressure. Using luminol-enhanced CL, a significant increase of ROS production was found in arterial tissue and blood. GSH levels were significantly increased in the kidney, while there were no GSH changes in plasma and the aorta. Incubation of aortic rings in solution with high glucose concentration led to impairment of endothelium-dependent relaxation. The synthetic antioxidant SMe1EC2 was able to restore reduced endothelium-mediated relaxation. Our results suggest an important role of hyperglycemia-induced ROS production in mediating endothelial dysfunction in experimental diabetes, confirmed by CL and the protective effect of the antioxidant SMe1EC2.

Open Science as a Knowledge Transfer strategy

NASA Astrophysics Data System (ADS)

Grigorov, Ivo; Dalmeier-Thiessen, Suenje

2015-04-01

Beyond providing basic understanding of how our Blue Planet functions, flows and breathes, the collection of Earth & Marine Research disciplines are of major service to most of today's Societal Challenges: from Food Security and Sustainable Resource Management, to Renewable Energies, Climate Mitigation & Ecosystem Services and Hazards. Natural Resources are a key commodity in the long-term strategy of the EU Innovation Union(1), and better understanding of the natural process governing them, as well as science-based management are seen as a key area for stimulating future economic growth. Such potential places responsibility on research project managers to devise innovative methods to ensure effective transfer of new research to public and private sector users, and society at large. Open Science is about removing all barriers to full sphere basic research knowledge and outputs, not just the publishable part of research but also the data, the software code, and failed experiments. The concept is central to EU's Responsible Research and Innovation philosophy(2), and removing barriers to basic research measurably contributes to the EU's Blue Growth Agenda(3). Despite the potential of the internet age to deliver on that promise, only 50% of today's basic research is freely available(4). The talk will demonstrate how and why Open Science can be a first, passive but effective strategy for any research project to transfer knowledge to society by allowing access and dicoverability to the full sphere of new knowledge, not just the published outputs. Apart from contributing to economic growth, Open Science can also optimize collaboration, within academia, assist with better engagement of citizen scientists into the research process and co-creation of solutions to societal challenges, as well as providing a solid ground for more sophisticated communication strategies and Ocean/Earth Literacy initiatives targeting policy makers and the public at large. (1)EC Digital Agenda & Access to Knowledge http://ec.europa.eu/digital-agenda/en/open-access-scientific-knowledge-0 (2)Responsible Research and Innovation for Societal Challenges http://ec.europa.eu/research/science-society/document_library/pdf_06/responsible-research-and-innovation-leaflet_en.pdf (3)Houghton, J., Swan, A., Brown, S., 2011. Access to research and technical information in Denmark [WWW Document]. URL http://www.deff.dk/uploads/media/Access_to_Research_and_Technical_Information_in_Denmark.pdf (4)Proportion of OA Peer-Reviewed Papers at the European & World Levels 2004-2011, EC Report http://www.science-metrix.com/pdf/SM_EC_OA_Availability_2004-2011.pdf

Role of oxidative stress in multiparity-induced endothelial dysfunction.

PubMed

Tawfik, Huda E; Cena, Jonathan; Schulz, Richard; Kaufman, Susan

2008-10-01

Multiparity is associated with increased risk of cardiovascular disease. We tested whether multiparity induces oxidative stress in rat vascular tissue. Coronary arteries and thoracic aorta were isolated from multiparous and age-matched virgin rats. Relaxation to ACh and sodium nitroprusside (SNP) was measured by wire myography. We also tested the effect of the superoxide dismutase mimetic MnTE2PyP (30 microM), the NADPH oxidase inhibitor apocynin (10 microM), and the peroxynitrite scavenger FeTPPs (10 microM) on ACh-mediated relaxation in coronary arteries. Vascular superoxide anion was measured using the luminol derivative L-012 and nitric oxide (NO) generation by the Griess reaction. Multiparity reduced maximal response and sensitivity to ACh in coronary arteries [maximal relaxation (E(max)): multiparous 49+/-3% vs. virgins 95%+/-3%; EC(50): multiparous 135+/-1 nM vs. virgins 60+/-1 nM], and in aortic rings (E(max): multiparous 38+/-3% vs. virgins 79+/-4%; EC(50): multiparous 160+/-2 nM vs. virgins 90+/-3 nM). Coronary arteries from the two groups relaxed similarly to SNP. Superoxide anions formation was significantly higher in both coronary arteries (2.8-fold increase) and aorta (4.1-fold increase) from multiparous rats compared with virgins. In multiparous rats, incubation with MnTE2PyP, apocynin, and FeTPPs improved maximal relaxation to ACh (MnTE2PyP: 74+/-5%; vehicle: 41+/-5%; apocynin: 73+/-3% vs. vehicle: 41+/-3%; FeTPPs: 72+/-3% vs. vehicle: 46+/-3%) and increased sensitivity (EC(50): MnTE2PyP: 61+/-0.5 nM vs. vehicle: 91+/-1 nM; apocynin: 45+/-3 nM vs. vehicle: 91+/-6 nM; FeTPP: 131 +/- 2 nM vs. vehicle: 185+/-1 nM). Multiparity also reduced total nitrate/nitrite levels (multiparous: 2.5+/-2 micromol/mg protein vs. virgins: 7+/-1 micromol/mg protein) and endothelial nitric oxide synthase protein levels (multiparous: 0.53+/-0.1 protein/actin vs. virgins: 1.0+/-0.14 protein/actin). These data suggest that multiparity induces endothelial dysfunction through decreased NO bioavailability and increased reactive oxygen species formation.

Human Intestinal Barrier Function in Health and Disease

PubMed Central

König, Julia; Wells, Jerry; Cani, Patrice D; García-Ródenas, Clara L; MacDonald, Tom; Mercenier, Annick; Whyte, Jacqueline; Troost, Freddy; Brummer, Robert-Jan

2016-01-01

The gastrointestinal tract consists of an enormous surface area that is optimized to efficiently absorb nutrients, water, and electrolytes from food. At the same time, it needs to provide a tight barrier against the ingress of harmful substances, and protect against a reaction to omnipresent harmless compounds. A dysfunctional intestinal barrier is associated with various diseases and disorders. In this review, the role of intestinal permeability in common disorders such as infections with intestinal pathogens, inflammatory bowel disease, irritable bowel syndrome, obesity, celiac disease, non-celiac gluten sensitivity, and food allergies will be discussed. In addition, the effect of the frequently prescribed drugs proton pump inhibitors and non-steroidal anti-inflammatory drugs on intestinal permeability, as well as commonly used methods to assess barrier function will be reviewed. PMID:27763627

Claudins, dietary milk proteins, and intestinal barrier regulation.

PubMed

Kotler, Belinda M; Kerstetter, Jane E; Insogna, Karl L

2013-01-01

The family of claudin proteins plays an important role in regulating the intestinal barrier by modulating the permeability of tight junctions. The impact of dietary protein on claudin biology has not been studied extensively. Whey proteins have been reported to improve intestinal barrier function, but their mechanism of action is not clear. Recent studies, however, have demonstrated increased intestinal claudin expression in response to milk protein components. Reviewed here are new findings suggesting that whey-protein-derived transforming growth factor β transcriptionally upregulates claudin-4 expression via a Smad-4-dependent pathway. These and other data, including limited clinical studies, are summarized below and, in the aggregate, suggest a therapeutic role for whey protein in diseases of intestinal barrier dysfunction, perhaps, in part, by regulating claudin expression. © 2013 International Life Sciences Institute.

Protein tyrosine phosphatase non-receptor type 2 and inflammatory bowel disease.

PubMed

Spalinger, Marianne R; McCole, Declan F; Rogler, Gerhard; Scharl, Michael

2016-01-21

Genome wide association studies have associated single nucleotide polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) with the onset of inflammatory bowel disease (IBD) and other inflammatory disorders. Expression of PTPN2 is enhanced in actively inflamed intestinal tissue featuring a marked up-regulation in intestinal epithelial cells. PTPN2 deficient mice suffer from severe intestinal and systemic inflammation and display aberrant innate and adaptive immune responses. In particular, PTPN2 is involved in the regulation of inflammatory signalling cascades, and critical for protecting intestinal epithelial barrier function, regulating innate and adaptive immune responses, and finally for maintaining intestinal homeostasis. On one hand, dysfunction of PTPN2 has drastic effects on innate host defence mechanisms, including increased secretion of pro-inflammatory cytokines, limited autophagosome formation in response to invading pathogens, and disruption of the intestinal epithelial barrier. On the other hand, PTPN2 function is crucial for controlling adaptive immune functions, by regulating T cell proliferation and differentiation as well as maintaining T cell tolerance. In this way, dysfunction of PTPN2 contributes to the manifestation of IBD. The aim of this review is to present an overview of recent findings on the role of PTPN2 in intestinal homeostasis and the impact of dysfunctional PTPN2 on intestinal inflammation.

Exploring gay couples' experience with sexual dysfunction after radical prostatectomy: a qualitative study.

PubMed

Hartman, Mary-Ellen; Irvine, Jane; Currie, Kristen L; Ritvo, Paul; Trachtenberg, Lianne; Louis, Alyssa; Trachtenberg, John; Jamnicky, Leah; Matthew, Andrew G

2014-01-01

This exploratory study examines the experience of three gay couples managing sexual dysfunction as a result of undergoing a radical prostatectomy. Semi-structured interviews were conducted as part of a larger study at an urban hospital in Toronto, Ontario, Canada. Interview transcripts were transcribed verbatim, and analyzed using interpretative phenomenological analysis. The authors clustered 18 subordinate themes under 3 superordinate themes: (a) acknowledging change in sexual experience (libido, erectile function, sexual activity, orgasmic function); (b) accommodating change in sexual experience (strategies: emphasizing intimacy, embracing plan B, focus on the other; barriers: side-effect concerns, loss of naturalness, communication breakdown, failure to initiate, trial and failure, partner confounds); and (c) accepting change in sexual experience (indicators: emphasizing health, age attributions, finding a new normal; barriers: uncertain outcomes, treatment regrets). Although gay couples and heterosexual couples share many similar challenges, we discovered that gay men have particular sexual roles and can engage in novel accommodation practices, such as open relationships, that have not been noted in heterosexual couples. All couples, regardless of their level of sexual functioning, highlighted the need for more extensive programming related to sexual rehabilitation. Equitable rehabilitative support is critical to assist homosexual couples manage distress associated with prostatectomy-related sexual dysfunction.

Organ culture storage of pre-prepared corneal donor material for Descemet's membrane endothelial keratoplasty.

PubMed

Bhogal, Maninder; Matter, Karl; Balda, Maria S; Allan, Bruce D

2016-11-01

To evaluate the effect of media composition and storage method on pre-prepared Descemet's membrane endothelial keratoplasty (DMEK) grafts. 50 corneas were used. Endothelial wound healing and proliferation in different media were assessed using a standard injury model. DMEK grafts were stored using three methods: peeling with free scroll storage; partial peeling with storage on the stroma and fluid bubble separation with storage on the stroma. Endothelial cell (EC) phenotype and the extent of endothelial overgrowth were examined. Global cell viability was assessed for storage methods that maintained a normal cell phenotype. 1 mm wounds healed within 4 days. Enhanced media did not increase EC proliferation but may have increased EC migration into the wounded area. Grafts that had been trephined showed evidence of EC overgrowth, whereas preservation of a physical barrier in the bubble group prevented this. In grafts stored in enhanced media or reapposed to the stroma after trephination, endothelial migration occurred sooner and cells underwent endothelial-mesenchymal transformation. Ongoing cell loss, with new patterns of cell death, was observed after returning grafts to storage. Grafts stored as free scrolls retained more viable ECs than grafts prepared with the fluid bubble method (74.2± 3% vs 60.3±6%, p=0.04 (n=8). Free scroll storage is superior to liquid bubble and partial peeling techniques. Free scrolls only showed overgrowth of ECs after 4 days in organ culture, indicating a viable time window for the clinical use of pre-prepared DMEK donor material using this method. Methods for tissue preparation and storage media developed for whole corneas should not be used in pre-prepared DMEK grafts without prior evaluation. 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/.

Papers on New Models of Community Recreation for Handicapped. Institute Report #3. National Institute on New Models of Community Based Recreation and Leisure Programs and Services for Handicapped Children and Youth.

ERIC Educational Resources Information Center

Nesbitt, John A., Ed.

Fifty-seven papers on new models of community recreation for the handicapped comprise the third report in the series (EC 114 401-409). Papers deal with the following topics (sample subtopics in parentheses): administration (management by objectives); advocacy; areas and equipment (outdoor playground equipment); attitudes; barriers (an analysis of…

Federal Funding for Special Recreation. Institute Report #4. National Institute on New Models of Community Based Recreation and Leisure Programs and Services for Handicapped Children and Youth.

ERIC Educational Resources Information Center

Nesbitt, John A.

The fourth of nine documents on community based recreation for handicapped persons (EC 114 401-409) examines federal funding for special recreation. The first section reviews functions of assistance in the federal budget, scope of federal programs, and barriers to receiving funds. Three major problem areas (lack of funds for provision of local…

Can vitamin d suppress endothelial cells apoptosis in multiple sclerosis patients?

PubMed

Dehghani, Leila; Meamar, Rokhsareh; Etemadifar, Masoud; Sheshde, Zahra Dehghani; Shaygannejad, Vahid; Sharifkhah, Mostafa; Tahani, Soheil

2013-05-01

Multiple sclerosis (MS) is an autoimmune disease of central nerves system, in which neurological disabilities occur in young adults. Despite increasing number of studies on MS, some aspects of this disorder are still unclear. In the previous studies, it has been proven that there is direct relation between MS incidence and vitamin D deficiency. Thereby, strong evidence in MS pathogenesis suggests that endothelial cells (EC) could be harmed in MS. In addition, functional changes in EC and macrovascular injuries lead blood-brain barrier disruption in MS. Current study is the first investigation to elucidate positive influences of vitamin D against EC apoptosis in MS. Human umbilical vein endothelial cells (HUVECs) were cultured and then treated with sera from patients with active MS (in relapse) and sera from healthy volunteer participants as control group (each group n=15). 3-(4,5-dimethylthiazol-2-yl)-5- (3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay for cell surveillance and cell-death detection kit for evaluating apoptosis were used in this study. There was a significant decrease in apoptosis rate by the serum of patients, just when 1,25(OH)2D3 applied before treating HUVECs with sera from active MS (in relapse). Furthermore, the cells surveillance increased markedly with the presence of 1,25(OH)(2)D(3) in culture, too. Withregard to increment in EC apoptosis rate, which treated by the sera from MS patients and decrement in apoptosis rate by the presence of vitamin D in culture media, it could be proposed that vitamin D pre-treatment can be used for MS patients, due to its beneficial effects on protecting EC apoptosis.

Reduced Human α-defensin 6 in Noninflamed Jejunal Tissue of Patients with Crohn's Disease.

PubMed

Hayashi, Ryohei; Tsuchiya, Kiichiro; Fukushima, Keita; Horita, Nobukatsu; Hibiya, Shuji; Kitagaki, Keisuke; Negi, Mariko; Itoh, Eisaku; Akashi, Takumi; Eishi, Yoshinobu; Okada, Eriko; Araki, Akihiro; Ohtsuka, Kazuo; Fukuda, Shinji; Ohno, Hiroshi; Okamoto, Ryuichi; Nakamura, Tetsuya; Tanaka, Shinji; Chayama, Kazuaki; Watanabe, Mamoru

2016-05-01

Mucosal barrier dysfunction is considered a critical component of Crohn's disease (CD) pathogenesis after the identification of susceptibility genes. However, the precise mechanism underlying mucosal barrier dysfunction has not yet been elucidated. We therefore aimed to elucidate the molecular mechanism underlying the expression of human α-defensin 6 (HD6) in patients with CD. HD6 expression was induced by the transfection of an atonal homolog 1 (Atoh1) transgene and was assessed by reverse transcription polymerase chain reaction. The HD6 promoter region targeted by Atoh1 and β-catenin was determined by reporter analysis and chromatin immunoprecipitation assay. HD5/HD6/Atoh1/β-catenin expression in noninflamed jejunal samples collected by balloon endoscopy from 15 patients with CD and 9 non-inflammatory bowel disease patients were assessed by immunofluorescence. Both promoter activity and gene expression of HD6 was significantly upregulated by the Atoh1 transgene in human colonic cancer cell line. We identified a TCF4 binding site and an E-box site, critical for the regulation of HD6 transcriptional activity by directly binding of Atoh1 in the 200-bp HD6 promoter region. The treatment with β-catenin inhibitor also decreases HD6 promoter activity and gene expression. Moreover, HD6 expression, but not HD5 expression, was found to be decreased in noninflamed jejunal regions from patients with CD. In HD6-negative crypts, nuclear accumulation of β-catenin was impaired. HD6 expression was found to be regulated by cooperation between Atoh1 and β-catenin within the HD6 promoter region. Downregulation of HD6 in noninflamed mucosa may contribute to mucosal barrier dysfunction of patients with CD.

Enterocyte-specific epidermal growth factor prevents barrier dysfunction and improves mortality in murine peritonitis.

PubMed

Clark, Jessica A; Gan, Heng; Samocha, Alexandr J; Fox, Amy C; Buchman, Timothy G; Coopersmith, Craig M

2009-09-01

Systemic administration of epidermal growth factor (EGF) decreases mortality in a murine model of septic peritonitis. Although EGF can have direct healing effects on the intestinal mucosa, it is unknown whether the benefits of systemic EGF in peritonitis are mediated through the intestine. Here, we demonstrate that enterocyte-specific overexpression of EGF is sufficient to prevent intestinal barrier dysfunction and improve survival in peritonitis. Transgenic FVB/N mice that overexpress EGF exclusively in enterocytes (IFABP-EGF) and wild-type (WT) mice were subjected to either sham laparotomy or cecal ligation and puncture (CLP). Intestinal permeability, expression of the tight junction proteins claudins-1, -2, -3, -4, -5, -7, and -8, occludin, and zonula occludens-1; villus length; intestinal epithelial proliferation; and epithelial apoptosis were evaluated. A separate cohort of mice was followed for survival. Peritonitis induced a threefold increase in intestinal permeability in WT mice. This was associated with increased claudin-2 expression and a change in subcellular localization. Permeability decreased to basal levels in IFABP-EGF septic mice, and claudin-2 expression and localization were similar to those of sham animals. Claudin-4 expression was decreased following CLP but was not different between WT septic mice and IFABP-EGF septic mice. Peritonitis-induced decreases in villus length and proliferation and increases in apoptosis seen in WT septic mice did not occur in IFABP-EGF septic mice. IFABP-EGF mice had improved 7-day mortality compared with WT septic mice (6% vs. 64%). Since enterocyte-specific overexpression of EGF is sufficient to prevent peritonitis-induced intestinal barrier dysfunction and confers a survival advantage, the protective effects of systemic EGF in septic peritonitis appear to be mediated in an intestine-specific fashion.

Epidermal Dysfunction Leads to an Age-Associated Increase in Levels of Serum Inflammatory Cytokines.

PubMed

Hu, Lizhi; Mauro, Theodora M; Dang, Erle; Man, George; Zhang, Jing; Lee, Dale; Wang, Gang; Feingold, Kenneth R; Elias, Peter M; Man, Mao-Qiang

2017-06-01

Even though elderly populations lack visible or other clinical signs of inflammation, their serum cytokine and C-reactive protein levels typically are elevated. However, the origin of age-associated systemic inflammation is unknown. Our previous studies showed that abnormalities in epidermal function provoke cutaneous inflammation, and because intrinsically aged skin displays compromised permeability barrier homeostasis and reduced stratum corneum hydration, we hypothesized here that epidermal dysfunction could contribute to the elevations in serum cytokines in the elderly. Our results show first that acute disruption of the epidermal permeability barrier in young mice leads not only to a rapid increase in cutaneous cytokine mRNA expression but also an increase in serum cytokine levels. Second, cytokine levels in both the skin and serum increase in otherwise normal, aged mice (>12 months). Third, expression of tumor necrosis factor-α and amyloid A mRNA levels increased in the epidermis, but not in the liver, in parallel with a significant elevation in serum levels of cytokines. Fourth, disruption of the permeability barrier induced similar elevations in epidermal and serum cytokine levels in normal and athymic mice, suggesting that T cells play a negligible role in the elevations in cutaneous and serum inflammatory cytokines induced by epidermal dysfunction. Fifth, correction of epidermal function significantly reduced cytokine levels not only in the skin but also in the serum of aged mice. Together, these results indicate that the sustained abnormalities in epidermal function in chronologically aged skin contribute to the elevated serum levels of inflammatory cytokines, potentially predisposing the elderly to the subsequent development or exacerbation of chronic inflammatory disorders. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

The effects of moderate exercise on chronic stress-induced intestinal barrier dysfunction and antimicrobial defense.

PubMed

Luo, Beibei; Xiang, Dao; Nieman, David C; Chen, Peijie

2014-07-01

The purpose of this study was to examine the effect of moderate exercise on repeated restraint stress (RRS)-induced intestinal barrier dysfunction and explore possible mechanisms in a mouse model. Male Balb/c mice (6weeks) were randomized into 7 groups: CON functioned as controls with no intervention; RRS was subjected to 6h per day RRS for 7 consecutive days; RRS+SWIM received 30min per day of swimming prior to RRS; CON+SWIM only received 30min per day of swimming; and the other groups received one session of 30min swimming prior to sacrifice at 1-, 3- and 6h recovery. Intestinal permeability was quantified with FITC-dextran. Bacterial translocation was determined by quantification of bacterial colony forming units (CFUs) in cultured mesenteric lymph nodes (MLN), and with fluorescence in situ hybridization (FISH). Antimicrobial related gene expression at baseline and 1h after one session of 30min swimming was tested by quantitative real-time polymerase chain reaction (Q-PCR) in small intestinal segments. Protein expression of 5 genes with statistically significant increase was measured at baseline, and 1-, 3- and 6h post-swimming using enzyme-linked immunosorbent assay (ELISA). Thirty minutes per day of swimming before RRS attenuated bacterial translocations and maintained intestinal permeability. Gene expression and protein levels for four antimicrobial peptides (α-defensin 5, β-defensin 1, RegIIIβ and RegIIIγ) were significantly increased after one 30min swimming session. In conclusion, moderate exercise attenuated chronic stress-induced intestinal barrier dysfunction in mice, possibly due to augmentation of antimicrobial responses in the small intestine. Copyright © 2013 Elsevier Inc. All rights reserved.

Glutamine Supplementation Attenuates Ethanol-Induced Disruption of Apical Junctional Complexes in Colonic Epithelium and Ameliorates Gut Barrier Dysfunction and Fatty Liver in Mice

PubMed Central

Chaudhry, Kamaljit K.; Shukla, Pradeep K.; Mir, Hina; Manda, Bhargavi; Gangwar, Ruchika; Yadav, Nikki; McMullen, Megan; Nagy, Laura E.; Rao, RadhaKrishna

2015-01-01

Previous in vitro studies showed that glutamine (Gln) prevents acetaldehyde-induced disruption of tight junctions and adherens junctions in Caco-2 cell monolayers and human colonic mucosa. In the present study, we evaluated the effect of Gln supplementation on ethanol-induced gut barrier dysfunction and liver injury in mice in vivo. Ethanol feeding caused a significant increase in inulin permeability in distal colon. Elevated permeability was associated with a redistribution of tight junction and adherens junction proteins and depletion of detergent-insoluble fractions of these proteins, suggesting that ethanol disrupts apical junctional complexes in colonic epithelium and increases paracellular permeability. Ethanol-induced increase in colonic mucosal permeability and disruption of junctional complexes were most severe in mice fed Gln-free diet. Gln supplementation attenuated ethanol-induced mucosal permeability and disruption of tight junctions and adherens junctions in a dose-dependent manner, indicating the potential role of glutamine in nutritional intervention to alcoholic tissue injury. Gln supplementation dose-dependently elevated reduced-protein thiols in colon without affecting the level of oxidized-protein thiols. Ethanol feeding depleted reduced protein thiols and elevated oxidized protein thiols. Ethanol-induced protein thiol oxidation was most severe in mice fed Gln-free diet and absent in mice fed Gln-supplemented diet, suggesting that antioxidant effect is one of the likely mechanisms involved in Gln-mediated amelioration of ethanol-induced gut barrier dysfunction. Ethanol feeding elevated plasma transaminase and liver triglyceride, which was accompanied by histopathologic lesions in the liver; ethanol-induced liver damage was attenuated by Gln supplementation. These results indicate that Gln supplementation ameliorates alcohol-induced gut and liver injury. PMID:26365579

Effects of Mindfulness Training on Body Awareness to Sexual Stimuli: Implications for Female Sexual Dysfunction

PubMed Central

Silverstein, R. Gina; Brown, Anne-Catharine H.; Roth, Harold D.; Britton, Willoughby B.

2013-01-01

Objectives Treatments of female sexual dysfunction have been largely unsuccessful because they do not address the psychological factors that underlie female sexuality. Negative self-evaluative processes interfere with the ability to attend and register physiological changes (interoceptive awareness). This study explores the effect of mindfulness meditation training on interoceptive awareness and the three categories of known barriers to healthy sexual functioning: attention, self-judgment, and clinical symptoms. Methods Forty-four college students (30 women) participated in either a 12-week course containing a “meditation laboratory” or an active control course with similar content or laboratory format. Interoceptive awareness was measured by reaction time in rating physiological response to sexual stimuli. Psychological barriers were assessed with self-reported measures of mindfulness and psychological well-being. Results Women who participated in the meditation training became significantly faster at registering their physiological responses (interoceptive awareness) to sexual stimuli compared with active controls (F(1,28) = 5.45, p = .03, ηp2 = 0.15). Female meditators also improved their scores on attention (t = 4.42, df = 11, p = .001), self-judgment, (t = 3.1, df = 11, p = .01), and symptoms of anxiety (t = −3.17, df = 11, p = .009) and depression (t = −2.13, df = 11, p < .05). Improvements in interoceptive awareness were correlated with improvements in the psychological barriers to healthy sexual functioning (r = −0.44 for attention, r = −0.42 for self-judgment, and r = 0.49 for anxiety; all p < .05). Conclusions Mindfulness-based improvements in interoceptive awareness highlight the potential of mindfulness training as a treatment of female sexual dysfunction. PMID:22048839

CORM-A1 prevents blood-brain barrier dysfunction caused by ionotropic glutamate receptor-mediated endothelial oxidative stress and apoptosis.

PubMed

Basuroy, Shyamali; Leffler, Charles W; Parfenova, Helena

2013-06-01

In cerebral microvascular endothelial cells (CMVEC) of newborn pigs, glutamate at excitotoxic concentrations (mM) causes apoptosis mediated by reactive oxygen species (ROS). Carbon monoxide (CO) produced by CMVEC or delivered by a CO-releasing molecule, CORM-A1, has antioxidant properties. We tested the hypothesis that CORM-A1 prevents cerebrovascular endothelial barrier dysfunction caused by glutamate excitotoxicity. First, we identified the glutamate receptors (GluRs) and enzymatic sources of ROS involved in the mechanism of endothelial apoptosis. In glutamate-exposed CMVEC, ROS formation and apoptosis were blocked by rotenone, 2-thenoyltrifluoroacetone (TTFA), and antimycin, indicating that mitochondrial complexes I, II, and III are the major sources of oxidative stress. Agonists of ionotropic GluRs (iGluRs) N-methyl-D-aspartate (NMDA), cis-ACPD, AMPA, and kainate increased ROS production and apoptosis, whereas iGluR antagonists exhibited antiapoptotic properties, suggesting that iGluRs mediate glutamate-induced endothelial apoptosis. The functional consequences of endothelial injury were tested in the model of blood-brain barrier (BBB) composed of CMVEC monolayer on semipermeable membranes. Glutamate and iGluR agonists reduced transendothelial electrical resistance and increased endothelial paracellular permeability to 3-kDa dextran. CORM-A1 exhibited potent antioxidant and antiapoptotic properties in CMVEC and completely prevented BBB dysfunction caused by glutamate and iGluR agonists. Overall, the endothelial component of the BBB is a cellular target for excitotoxic glutamate that, via a mechanism involving a iGluR-mediated activation of mitochondrial ROS production and apoptosis, leads to BBB opening that may be prevented by the antioxidant and antiapoptotic actions of CORMs. Antioxidant CORMs therapy may help preserve BBB functional integrity in neonatal cerebrovascular disease.

Microgravity Effects on Transendothelial Transport

NASA Technical Reports Server (NTRS)

Tarbell, John M.

1996-01-01

The Endothelial Cell (EC) layer which lines blood vessels from the aorta to the capillaries provides the principal barrier to transport of water and solutes between blood and underlying tissue. Endothelial cells are continuously exposed to the mechanical shearing force (shear stress) and normal force (pressure) imposed by flowing blood on their surface, and they are adapted to this mechanical environment. When the cardiovascular system is exposed to microgravity, the mechanical environmental of endothelial cells is perturbed drastically and the transport properties of EC layers are altered in response. We have shown recently that step changes in shear stress have an acute effect on transport properties of EC layers in a cell culture model, and several recent studies in different vessels of live animals have confirmed the shear-dependent transport properties of the endothelium. We hypothesize that alterations in mechanical forces induced by microgravity and their resultant influence on transendothelial transport of water and solutes are, in large measure, responsible for the characteristic cephalad fluid shift observed in humans experiencing microgravity. To study the effects of altered mechanical forces on transendothelial transport and to test pharmacologic agents as counter measures to microgravity induced fluid shifts we have proposed ground-based studies using well defined cell culture models.

Cytotoxicity evaluation of gold nanoparticles on microalga Dunaliella salina in microplate test system

NASA Astrophysics Data System (ADS)

Chumakov, Daniil; Prilepskii, Artur; Dykman, Lev; Khlebtsov, Boris; Khlebtsov, Nikolai; Bogatyrev, Vladimir

2018-04-01

Gold nanoparticles are intensively studied in biomedicine. Assessment of their biocompatibility is highly important. Currently there is lack of evidence, concerning nanotoxicity of ultrasmall gold nanoparticles < 5 nm. Existing data are rather contradictory. The aim of that study was to evaluate the toxicity of 2 nm colloidal gold, using microalga Dunaliella salina. Cellular barriers of that microalga are very similar to animal cells so it might be considered as a valuable model for nanotoxicity testing. Chlorophyll content as a test-function was used. Spectrophotometric method for chlorophyll determination in vivo in suspensions of D.salina cultures was applied. Calculated EC50 48h value of ionic gold was 25.8 +/- 0.3 mg Au/L. EC50 value of phosphine-stabilized gold nanoclusters was 32.2 +/-1.1 mg Au/L. It was not possible to calculate EC50 for 15 nm citrate gold nanoparticles, as they were non-toxic at all concentrations tested. These results are confirmed by fluorescent -microscopic monitoring of the same probes. It was shown that 10-fold growth of phosphine-stabilized gold nanoparticles (from 2.3 +/- 0.9 nm to 21.1 +/- 7.5 nm) led to 7-fold decrease of their toxicity.

Pathologic Mechanical Stress and Endotoxin Exposure Increases Lung Endothelial Microparticle Shedding

PubMed Central

Letsiou, Eleftheria; Sammani, Saad; Zhang, Wei; Zhou, Tong; Quijada, Hector; Moreno-Vinasco, Liliana; Dudek, Steven M.

2015-01-01

Acute lung injury (ALI) results from infectious challenges and from pathologic lung distention produced by excessive tidal volume delivered during mechanical ventilation (ventilator-induced lung injury [VILI]) and is characterized by extensive alveolar and vascular dysfunction. Identification of novel ALI therapies is hampered by the lack of effective ALI/VILI biomarkers. We explored endothelial cell (EC)-derived microparticles (EMPs) (0.1–1 μm) as potentially important markers and potential mediators of lung vascular injury in preclinical models of ALI and VILI. We characterized EMPs (annexin V and CD31 immunoreactivity) produced from human lung ECs exposed to physiologic or pathologic mechanical stress (5 or 18% cyclic stretch [CS]) or to endotoxin (LPS). EC exposure to 18% CS or to LPS resulted in increased EMP shedding compared with static cells (∼ 4-fold and ∼ 2.5-fold increases, respectively). Proteomic analysis revealed unique 18% CS–derived (n = 10) and LPS-derived EMP proteins (n = 43). VILI-challenged mice (40 ml/kg, 4 h) exhibited increased plasma and bronchoalveolar lavage CD62E (E-selectin)-positive MPs compared with control mice. Finally, mice receiving intratracheal instillation of 18% CS–derived EMPs displayed significant lung inflammation and injury. These findings indicate that ALI/VILI-producing stimuli induce significant shedding of distinct EMP populations that may serve as potential ALI biomarkers and contribute to the severity of lung injury. PMID:25029266

FLICE-like inhibitory protein (FLIP) protects against apoptosis and suppresses NF-kappaB activation induced by bacterial lipopolysaccharide.

PubMed

Bannerman, Douglas D; Eiting, Kristine T; Winn, Robert K; Harlan, John M

2004-10-01

Bacterial lipopolysaccharide (LPS) via its activation of Toll-like receptor-4 contributes to much of the vascular injury/dysfunction associated with gram-negative sepsis. Inhibition of de novo gene expression has been shown to sensitize endothelial cells (EC) to LPS-induced apoptosis, the onset of which correlates with decreased expression of FLICE-like inhibitory protein (FLIP). We now have data that conclusively establish a role for FLIP in protecting EC against LPS-induced apoptosis. Overexpression of FLIP protected against LPS-induced apoptosis, whereas down-regulation of FLIP using antisense oligonucleotides sensitized EC to direct LPS killing. Interestingly, FLIP overexpression suppressed NF-kappaB activation induced by LPS, but not by phorbol ester, suggesting a specific role for FLIP in mediating LPS activation. Conversely, mouse embryo fibroblasts (MEF) obtained from FLIP -/- mice showed enhanced LPS-induced NF-kappaB activation relative to those obtained from wild-type mice. Reconstitution of FLIP-/- MEF with full-length FLIP reversed the enhanced NF-kappaB activity elicited by LPS in the FLIP -/- cells. Changes in the expression of FLIP had no demonstrable effect on other known LPS/Tlr-4-activated signaling pathways including the p38, Akt, and Jnk pathways. Together, these data support a dual role for FLIP in mediating LPS-induced apoptosis and NF-kappaB activation.

Mutation of EpCAM leads to intestinal barrier and ion transport dysfunction.

PubMed

Kozan, Philip A; McGeough, Matthew D; Peña, Carla A; Mueller, James L; Barrett, Kim E; Marchelletta, Ronald R; Sivagnanam, Mamata

2015-05-01

Congenital tufting enteropathy (CTE) is a devastating diarrheal disease seen in infancy that is typically associated with villous changes and the appearance of epithelial tufts. We previously found mutations in epithelial cell adhesion molecule (EpCAM) to be causative in CTE. We developed a knock-down cell model of CTE through transfection of an EpCAM shRNA construct into T84 colonic epithelial cells to elucidate the in vitro role of EpCAM in barrier function and ion transport. Cells with EpCAM deficiency exhibited decreased electrical resistance, increased permeability, and decreased ion transport. Based on mutations in CTE patients, an in vivo mouse model was developed, with tamoxifen-inducible deletion of exon 4 in Epcam resulting in mutant protein with decreased expression. Tamoxifen treatment of Epcam (Δ4/Δ4) mice resulted in pathological features of villous atrophy and epithelial tufts, similar to those in human CTE patients, within 4 days post induction. Epcam (Δ4/Δ4) mice also showed decreased expression of tight junctional proteins, increased permeability, and decreased ion transport in the intestines. Taken together, these findings reveal mechanisms that may underlie disease in CTE. Knock-down EpCAM cell model of congenital tufting enteropathy was developed. In vivo inducible mouse model was developed resulting in mutant EpCAM protein. Cells with EpCAM deficiency demonstrated barrier and ion transport dysfunction. Tamoxifen-treated Epcam (Δ4/Δ4) mice demonstrated pathological features. Epcam (Δ4/Δ4) mice showed improper barrier function and ion transport.

Material System Engineering for Advanced Electrocaloric Cooling Technology

NASA Astrophysics Data System (ADS)

Qian, Xiaoshi

Electrocaloric effect refers to the entropy change and/or temperature change in dielectrics caused by the electric field induced polarization change. Recent discovery of giant ECE provides an opportunity to realize highly efficient cooling devices for a broad range of applications ranging from household appliances to industrial applications, from large-scale building thermal management to micro-scale cooling devices. The advances of electrocaloric (EC) based cooling device prototypes suggest that highly efficient cooling devices with compact size are achievable, which could lead to revolution in next generation refrigeration technology. This dissertation focuses on both EC based materials and cooling devices with their recent advances that address practical issues. Based on better understandings in designing an EC device, several EC material systems are studied and improved to promote the performances of EC based cooling devices. In principle, applying an electric field to a dielectric would cause change of dipolar ordering states and thus a change of dipolar entropy. Giant ECE observed in ferroelectrics near ferroelectric-paraelectric (FE-PE) transition temperature is owing to the large dipolar orientation change, between random-oriented dipolar states in paraelectric phase and spontaneous-ordered dipolar states in ferroelectric phases, which is induced by external electric fields. Besides pursuing large ECE, studies on EC cooling devices indicated that EC materials are required to possess wide operational temperature window, in which large ECE can be maintained for efficient operations. Although giant ECE was first predicted in ferroelectric polymers, where the large effect exhibits near FEPE phase transition, the narrow operation temperature window poses obstacles for these normal ferroelectrics to be conveniently perform in wide range of applications. In this dissertation, we demonstrated that the normal ferroelectric polymers can be converted to relaxor ferroelectric polymers which possess both giant ECE (27 Kelvin temperature drop) and much wider operating temperature window (over 50 kelvin covering RT) by proper defect modification which delicately tailors ferroelectrics in meso-, micro- and molecular scales. In addition, in order to be practical, EC device requires EC material can be driven at low electric fields upon achieve the large ECE. It is demonstrated in this dissertation that by facially modifying materials structure in meso-, micro- and molecular scale, lowfield ECE can be greatly improved. Large ECE, induced by low electric fields and existing in wide temperature window, is a major improvement in EC materials for practical applications. Besides EC polymers, this thesis also investigated EC ceramics. Due to several unique opportunities offered by the EC ceramics, Ba(ZrxTi 1-x)O3 (BZT), that is studied. (i) This class of EC ceramics offers a possibility to explore the invariant critical point (ICP), which maximizes the number of coexistent phase and provides a nearly vanishing energy barrier for switching among different phases. As demonstrated in this thesis, the BZT bulk ceramics at x˜ 0.2 exhibits a large adiabatic temperature drop DeltaTc=4.5 K, a large isothermal entropy change DeltaS = 8 Jkg-1K-1, a large EC coefficient (|DeltaT c/DeltaE| = 0.52x10-6 KmV-1 and DeltaS/DeltaE=0.93x10 -6 Jmkg-1K-1V-1) over a wide operating temperature range Tspan>30K. (ii) The thermal conductivity of EC ceramics is in general, much higher than that of EC polymers, and consequently they will allow EC cooling configurations which are not accessible by the EC polymers. Moreover, in the same device configuration, the high thermal conductivity of EC ceramics (kappa> 5 W/mK, compared with EC polymer, ˜ 0.25 W/mK) allows higher operation frequency and therefore a higher cooling power. (iii) Well-established fabrication processes of multilayer ceramic capacitor (MLCC) provide a foundation for the EC ceramic toward mass production. In this thesis, BZT thick film double layers have been fabricated and large ECE has been directly measured. EC induced temperature drop (DeltaT) around 6.3 °C and entropy change (DeltaS) of 11.0 Jkg-1K -1 are observed under an electric field of DeltaE=14.6 MV/m at 40 °C was observed in BZT thick film double layers. The result encourages further investigations on ECE in MLCC for practical applications. (Abstract shortened by ProQuest.).

PECAM1 regulates flow-mediated Gab1 tyrosine phosphorylation and signaling

PubMed Central

Xu, Suowen; Ha, Chang Hoon; Wang, Weiye; Xu, Xiangbin; Yin, Meimei; Jin, Felix Q.; Mastrangelo, Michael; Koroleva, Marina; Fujiwara, Keigi; Jin, Zheng Gen

2016-01-01

Endothelial dysfunction, characterized by impaired activation of endothelial nitric oxide (NO) synthase (eNOS) and ensued decrease of NO production, is a common mechanism of various cardiovascular pathologies, including hypertension and atherosclerosis. Laminar blood flow-mediated specific signaling cascades modulate vascular endothelial cells (ECs) structure and functions. We have previously shown that flow-stimulated Gab1 (Grb2-associated binder-1) tyrosine phosphorylation mediates eNOS activation in ECs, which in part confers laminar flow atheroprotective action. However, the molecular mechanisms whereby flow regulates Gab1 tyrosine phosphorylation and its downstream signaling events remain unclear. Here we show that platelet endothelial cell adhesion molecule-1 (PECAM1), a key molecule in an endothelial mechanosensing complex, specifically mediates Gab1 tyrosine phosphorylation and its downstream Akt and eNOS activation in ECs upon flow rather than hepatocyte growth factor (HGF) stimulation. Small interfering RNA (siRNA) targeting PECAM1 abolished flow- but not HGF-induced Gab1 tyrosine phosphorylation and Akt, eNOS activation as well as Gab1 membrane translocation. Protein-tyrosine phosphatase SHP2, which has been shown to interact with Gab1, was involved in flow signaling and HGF signaling, as SHP2 siRNA diminished the flow- and HGF-induced Gab1 tyrosine phosphorylation, membrane localization and downstream signaling. Pharmacological inhibition of PI3K decreased flow-, but not HGF-mediated Gab1 phosphorylation and membrane localization as well as eNOS activation. Finally, we observed that flow-mediated Gab1 and eNOS phosphorylation in vivo induced by voluntary wheel running was reduced in PECAM1 knockout mice. These results demonstrate a specific role of PECAM1 in flow-mediated Gab1 tyrosine phosphorylation and eNOS signaling in ECs. PMID:26706435

L. fermentum CECT 5716 prevents stress-induced intestinal barrier dysfunction in newborn rats.

PubMed

Vanhaecke, T; Aubert, P; Grohard, P-A; Durand, T; Hulin, P; Paul-Gilloteaux, P; Fournier, A; Docagne, F; Ligneul, A; Fressange-Mazda, C; Naveilhan, P; Boudin, H; Le Ruyet, P; Neunlist, M

2017-08-01

Intestinal epithelial barrier (IEB) dysfunction plays a critical role in various intestinal disorders affecting infants and children, including the development of food allergies and colitis. Recent studies highlighted the role of probiotics in regulating IEB functions and behavior in adults, but their effects in the newborn remain largely unknown. We therefore characterized in rat pups, the impact of Lactobacillus fermentum CECT 5716 (L. fermentum) on stress-induced IEB dysfunction, systemic immune response and exploratory behavior. Newborn rats received daily by gavage either L. fermentum or water. Intestinal permeability to fluorescein sulfonic acid (FSA) and horseradish peroxidase (HRP) was measured following maternal separation (MS) and water avoidance stress (WAS). Immunohistochemical, transcriptomic, and Western blot analysis of zonula occludens-1 (ZO-1) distribution and expression were performed. Anxiety-like and exploratory behavior was assessed using the elevated plus maze test. Cytokine secretion of activated splenocytes was also evaluated. L. fermentum prevented MS and WAS-induced IEB dysfunction in vivo. L. fermentum reduced permeability to both FSA and HRP in the small intestine but not in the colon. L. fermentum increased expression of ZO-1 and prevented WAS-induced ZO-1 disorganization in ileal epithelial cells. L. fermentum also significantly reduced stress-induced increase in plasma corticosteronemia. In activated splenocytes, L. fermentum enhanced IFNγ secretion while it prevented IL-4 secretion. Finally, L. fermentum increased exploratory behavior. These results suggest that L. fermentum could provide a novel tool for the prevention and/or treatment of gastrointestinal disorders associated with altered IEB functions in the newborn. © 2017 John Wiley & Sons Ltd.

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.

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.

Probiotic E. coli Nissle 1917 biofilms on silicone substrates for bacterial interference against pathogen colonization.

PubMed

Chen, Quan; Zhu, Zhiling; Wang, Jun; Lopez, Analette I; Li, Siheng; Kumar, Amit; Yu, Fei; Chen, Haoqing; Cai, Chengzhi; Zhang, Lijuan

2017-03-01

Bacterial interference is an alternative strategy to fight against device-associated bacterial infections. Pursuing this strategy, a non-pathogenic bacterial biofilm is used as a live, protective barrier to fence off pathogen colonization. In this work, biofilms formed by probiotic Escherichia coli strain Nissle 1917 (EcN) are investigated for their potential for long-term bacterial interference against infections associated with silicone-based urinary catheters and indwelling catheters used in the digestive system, such as feeding tubes and voice prostheses. We have shown that EcN can form stable biofilms on silicone substrates, particularly those modified with a biphenyl mannoside derivative. These biofilms greatly reduced the colonization by pathogenic Enterococcus faecalis in Lysogeny broth (LB) for 11days. Bacterial interference is an alternative strategy to fight against device-associated bacterial infections. Pursuing this strategy, we use non-pathogenic bacteria to form a biofilm that serves as a live, protective barrier against pathogen colonization. Herein, we report the first use of preformed probiotic E. coli Nissle 1917 biofilms on the mannoside-presenting silicone substrates to prevent pathogen colonization. The biofilms serve as a live, protective barrier to fence off the pathogens, whereas current antimicrobial/antifouling coatings are subjected to gradual coverage by the biomass from the rapidly growing pathogens in a high-nutrient environment. It should be noted that E. coli Nissle 1917 is commercially available and has been used in many clinical trials. We also demonstrated that this probiotic strain performed significantly better than the non-commercial, genetically modified E. coli strain that we previously reported. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Dysfunctions at human intestinal barrier by water-borne protozoan parasites: lessons from cultured human fully differentiated colon cancer cell lines.

PubMed

Liévin-Le Moal, Vanessa

2013-06-01

Some water-borne protozoan parasites induce diseases through their membrane-associated functional structures and virulence factors that hijack the host cellular molecules and signalling pathways leading to structural and functional lesions in the intestinal barrier. In this Microreview we analyse the insights on the mechanisms of pathogenesis of Entamoeba intestinalis, Giardia and Cryptosporidium observed in the human colon carcinoma fully differentiated colon cancer cell lines, cell subpopulations and clones expressing the structural and functional characteristics of highly specialized fully differentiated epithelial cells lining the intestinal epithelium and mimicking structurally and functionally an intestinal barrier. © 2013 John Wiley & Sons Ltd.

Recognizing and addressing barriers to the effective management of ADHD in college students.

PubMed

Culpepper, Larry

2013-07-01

Several barriers can hinder the diagnosis of ADHD in college students, especially those with unrecognized symptoms, dysfunctional behavior, or psychiatric conditions. One specific barrier includes the misuse of prescription stimulants among college students, perhaps to improve academic performance or to self-treat undiagnosed ADHD symptoms. Because of the dangers, both medical and legal, that nonmedical stimulant use can cause, clinicians must recognize these undiagnosed students and initiate proper treatment. By establishing a therapeutic relationship with students, clinicians can provide education, monitoring, and treatment options that will help minimize misuse of prescriptions while giving students the support they need to successfully complete college. © Copyright 2013 Physicians Postgraduate Press, Inc.

Disappearance of the telomere dysfunction-induced stress response in fully senescent cells.

PubMed

Bakkenist, Christopher J; Drissi, Rachid; Wu, Jing; Kastan, Michael B; Dome, Jeffrey S

2004-06-01

Replicative senescence is a natural barrier to cellular proliferation that is triggered by telomere erosion and dysfunction. Here, we demonstrate that ATM activation and H2AX-gamma nuclear focus formation are sensitive markers of telomere dysfunction in primary human fibroblasts. Whereas the activated form of ATM and H2AX-gamma foci were rarely observed in early-passage cells, they were readily detected in late-passage cells. The ectopic expression of telomerase in late-passage cells abrogated ATM activation and H2AX-gamma focus formation, suggesting that these stress responses were the consequence of telomere dysfunction. ATM activation was induced in quiescent fibroblasts by inhibition of TRF2 binding to telomeres, indicating that telomere uncapping is sufficient to initiate the telomere signaling response; breakage of chromosomes with telomeric associations is not required for this activation. Although ATM activation and H2AX-gamma foci were readily observed in late-passage cells, they disappeared once cells became fully senescent, indicating that constitutive signaling from dysfunctional telomeres is not required for the maintenance of senescence.

Curcumin improves intestinal barrier function: modulation of intracellular signaling, and organization of tight junctions.

PubMed

Wang, Jing; Ghosh, Siddhartha S; Ghosh, Shobha

2017-04-01

Association between circulating lipopolysaccharide (LPS) and metabolic diseases (such as type 2 diabetes and atherosclerosis) has shifted the focus from high-fat high-cholesterol containing Western-type diet (WD)-induced changes in gut microbiota per se to release of gut bacteria-derived products (e.g., LPS) into circulation due to intestinal barrier dysfunction as the possible mechanism for the chronic inflammatory state underlying the development of these diseases. We demonstrated earlier that oral supplementation with curcumin attenuates WD-induced development of type 2 diabetes and atherosclerosis. Poor bioavailability of curcumin has precluded the establishment of a causal relationship between oral supplementation and it is in vivo effects. We hypothesized that curcumin attenuates WD-induced chronic inflammation and associated metabolic diseases by modulating the function of intestinal epithelial cells (IECs) and the intestinal barrier function. The objective of the present study was to delineate the underlying mechanisms. The human IEC lines Caco-2 and HT-29 were used for these studies and modulation of direct as well as indirect effects of LPS on intracellular signaling as well as tight junctions were examined. Pretreatment with curcumin significantly attenuated LPS-induced secretion of master cytokine IL-1β from IECs and macrophages. Furthermore, curcumin also reduced IL-1β-induced activation of p38 MAPK in IECs and subsequent increase in expression of myosin light chain kinase involved in the phosphorylation of tight junction proteins and ensuing disruption of their normal arrangement. The major site of action of curcumin is, therefore, likely the IECs and the intestinal barrier, and by reducing intestinal barrier dysfunction, curcumin modulates chronic inflammatory diseases despite poor bioavailability. Copyright © 2017 the American Physiological Society.

Protective effects of Lactobacillus plantarum against epithelial barrier dysfunction of human colon cell line NCM460

PubMed Central

Liu, Zhi-Hua; Shen, Tong-Yi; Zhang, Peng; Ma, Yan-Lei; Moyer, Mary Pat; Qin, Huan-Long

2010-01-01

AIM: To investigate the effects of Lactobacillus plantarum (L. plantarum) in the intestinal permeability and expression of tight junction (TJ) using the normal human colon cell line NCM460. METHODS: Paracellular permeability of NCM460 monolayers was determined by transepithelial electrical resistance and dextran permeability. Expression of TJ proteins in NCM460 cell monolayers was detected by Western blotting and quantitative real-time polymerase chain reaction. RESULTS: L. plantarum played an important role in increasing transepithelial electrical resistance and decreasing the permeability to macromolecules of NCM460 monolayers against the disruption caused by enteropathogenic Escherichia coli (E. coli) or enteroinvasive E. coli. L. plantarum also prevented the decrease in the expression of TJ proteins and F-actin in NCM460 cells. CONCLUSION: L. plantarum can protect against dysfunction of NCM460 intestinal epithelial barrier caused by enteropathogenic E. coli or enteroinvasive E. coli, and thus can be a potential candidate of therapeutic agents for the treatment of intestinal diseases. PMID:21128328

[Immune dysfunction and cognitive deficit in stress and physiological aging. Part II: New approaches to cognitive disorder prevention and treatment ].

PubMed

Pukhal'skiĭ, A L; Shmarina, G V; Aleshkin, V A

2014-01-01

Long-term stress as well as physiological aging result in similar immunological and hormonal disturbances including hypothalamic-pituitary-adrenal) axis depletion, aberrant immune response (regulatory T-cells, Tregs, and T(h17)-lymphocyte accumulation) and decreased dehydroepian-drosterone synthesis both in the brain and in the adrenal glands. Since the main mechanisms of inflammation control, "prompt" (stress hormones) and "delayed" (Tregs), are broken, serum cytokine levels increase and become sufficient for blood-brain-barrier disruption. As a result peripheral cytokines penetrate into the brain where they begin to perform new functions. Structural and functional alterations of blood-brain-barrier as well as stress- (or age-) induced neuroinflammation promote influx of bone marrow derived dendritic cells and lymphocyte effectors into the brain parenchyma. Thereafter, mass intrusion ofpro-inflammatory mediators and immune cells having a lot of specific targets alters the brain work that we can observe both in humans and in animal experiments. The concept of stressful cognitive dysfunction, which is under consideration in this review, allows picking out several therapeutic targets: 1) reduction of excessive Treg accumulation; 2) supporting hypothalamic-pituitary-adrenal axis and inflammatory reaction attenuation; 3) recovery of dehydroepiandrosterone level; 4) improvement of blood-brain-barrier function.

Erlotinib promotes endoplasmic reticulum stress-mediated injury in the intestinal epithelium

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

Fan, Lu; Hu, Lingna; Yang, Baofang

Erlotinib, a popular drug for treating non-small cell lung cancer (NSCLC), causes diarrhea in approximately 55% of patients receiving this drug. In the present study, we found that erlotinib induced barrier dysfunction in rat small intestine epithelial cells (IEC-6) by increasing epithelial permeability and down-regulating E-cadherin. The mRNA levels of various pro-inflammatory cytokines (Il-6, Il-25 and Il-17f) were increased after erlotinib treatment in IEC-6 cells. Erlotinib concentration- and time-dependently induced apoptosis and endoplasmic reticulum (ER) stress in both IEC-6 and human colon epithelial cells (CCD 841 CoN). Intestinal epithelial injury was also observed in male C57BL/6J mice administrated with erlotinib.more » Knockdown of C/EBP homologous protein (CHOP) with small interference RNA partially reversed erlotinib-induced apoptosis, production of IL-6 and down-regulation of E-cadherin in cultured intestinal epithelial cells. In conclusion, erlotinib caused ER stress-mediated injury in the intestinal epithelium, contributing to its side effects of diarrhea in patients. - Highlights: • Erlotinib destroyed barrier integrity both in vitro and in vivo. • Erlotinib induced inflammation both in vitro and in vivo. • Erlotinib induced apoptosis both in vitro and in vivo. • ER stress contributed to erlotinib-induced barrier dysfunction.« less

Expression of PKA inhibitor (PKI) gene abolishes cAMP-mediated protection to endothelial barrier dysfunction.

PubMed

Lum, H; Jaffe, H A; Schulz, I T; Masood, A; RayChaudhury, A; Green, R D

1999-09-01

We investigated the hypothesis that cAMP-dependent protein kinase (PKA) protects against endothelial barrier dysfunction in response to proinflammatory mediators. An E1-, E3-, replication-deficient adenovirus (Ad) vector was constructed containing the complete sequence of PKA inhibitor (PKI) gene (AdPKI). Infection of human microvascular endothelial cells (HMEC) with AdPKI resulted in overexpression of PKI. Treatment with 0.5 microM thrombin increased transendothelial albumin clearance rate (0.012 +/- 0.003 and 0.035 +/- 0.005 microl/min for control and thrombin, respectively); the increase was prevented with forskolin + 3-isobutyl-1-methylxanthine (F + I) treatment. Overexpression of PKI resulted in abrogation of the F + I-induced inhibition of the permeability increase. However, with HMEC infected with ultraviolet-inactivated AdPKI, the F + I-induced inhibition was present. Also, F + I treatment of HMEC transfected with reporter plasmid containing the cAMP response element-directed transcription of the luciferase gene resulted in an almost threefold increase in luciferase activity. Overexpression of PKI inhibited this induction of luciferase activity. The results show that Ad-mediated overexpression of PKI in endothelial cells abrogated the cAMP-mediated protection against increased endothelial permeability, providing direct evidence that cAMP-dependent protein kinase promotes endothelial barrier function.

Environmental risk assessment of effluents as a whole emerging contaminant: Efficiency of alternative tertiary treatments for wastewater depuration.

PubMed

Díaz-Garduño, B; Pintado-Herrera, M G; Biel-Maeso, M; Rueda-Márquez, J J; Lara-Martín, P A; Perales, J A; Manzano, M A; Garrido-Pérez, C; Martín-Díaz, M L

2017-08-01

Emerging contaminants (ECs) and regulated compounds (RCs) from three different WWTP effluents were measured in the current study. The efficiency of two tertiary treatments, Photobiotreatment (PhtBio) and Multi-Barrier Treatment (MBT), for removing contaminants was determined. Results indicated different percentages of removal depending on the treatment and the origin of the effluent. Risk Quotients (RQs) were determined for different species of algae, Daphnia, and fish. RQ results revealed diverse risk values depending on the bioindicator species. Tonalide, galaxolide (fragrances), and ofloxacin (antibiotic) were the most persistent and harmful substances in tested effluents. "Negligible risk" category was reached since a wide diversity of ECs were removed by MBT with high removal percentages. Contrarily, PhtBio was effective only in the depuration of certain chemical compounds, and its efficiency depended on the composition of the raw effluent. Copyright © 2017 Elsevier Ltd. All rights reserved.

KLF2 and KLF4 control endothelial identity and vascular integrity

PubMed Central

Sangwung, Panjamaporn; Zhou, Guangjin; Nayak, Lalitha; Chan, E. Ricky; Kang, Dong-Won; Zhang, Rongli; Lu, Yuan; Sugi, Keiki; Fujioka, Hisashi; Shi, Hong; Lapping, Stephanie D.; Ghosh, Chandra C.; Higgins, Sarah J.; Parikh, Samir M.; Jain, Mukesh K.

2017-01-01

Maintenance of vascular integrity in the adult animal is needed for survival, and it is critically dependent on the endothelial lining, which controls barrier function, blood fluidity, and flow dynamics. However, nodal regulators that coordinate endothelial identity and function in the adult animal remain poorly characterized. Here, we show that endothelial KLF2 and KLF4 control a large segment of the endothelial transcriptome, thereby affecting virtually all key endothelial functions. Inducible endothelial-specific deletion of Klf2 and/or Klf4 reveals that a single allele of either gene is sufficient for survival, but absence of both (EC-DKO) results in acute death from myocardial infarction, heart failure, and stroke. EC-DKO animals exhibit profound compromise in vascular integrity and profound dysregulation of the coagulation system. Collectively, these studies establish an absolute requirement for KLF2/4 for maintenance of endothelial and vascular integrity in the adult animal. PMID:28239661

Mechanisms of intestinal barrier dysfunction in sepsis

PubMed Central

Yoseph, Benyam P.; Klingensmith, Nathan J.; Liang, Zhe; Breed, Elise R.; Burd, Eileen M.; Mittal, Rohit; Dominguez, Jessica A.; Petrie, Benjamin; Ford, Mandy L.; Coopersmith, Craig M.

2016-01-01

Intestinal barrier dysfunction is thought to contribute to the development of multiple organ dysfunction syndrome in sepsis. Although there are similarities in clinical course following sepsis, there are significant differences in the host response depending on the initiating organism and time course of the disease, and pathways of gut injury vary widely in different preclinical models of sepsis. The purpose of this study was to determine whether the timecourse and mechanisms of intestinal barrier dysfunction are similar in disparate mouse models of sepsis with similar mortalities. FVB/N mice were randomized to receive cecal ligation and puncture (CLP) or sham laparotomy, and permeability was measured to fluoresceinisothiocyanate conjugated-dextran (FD-4) six to 48 hours later. Intestinal permeability was elevated following CLP at all timepoints measured, peaking at six to 12 hours. Tight junction proteins claudin 1, 2, 3, 4, 5, 7, 8, 13 and 15, JAM-A, occludin, and ZO-1 were than assayed by Western blot, real-time polymerase chain reaction, and immunohistochemistry 12 hours after CLP to determine potential mechanisms underlying increases in intestinal permeability. Claudin 2 and JAM-A were increased by sepsis whereas claudin-5 and occludin were decreased by sepsis. All other tight junction proteins were unchanged. A further timecourse experiment demonstrated that alterations in claudin-2 and occludin were detectable as early as 1 hour after the onset of sepsis. Similar experiments were then performed in a different group of mice subjected to Pseudomonas aeruginosa pneumonia. Mice with pneumonia had an increase in intestinal permeability similar in timecourse and magnitude to that seen in CLP. Similar changes in tight junction proteins were seen in both models of sepsis although mice subjected to pneumonia also had a marked decrease in ZO-1 not seen in CLP. These results indicate that two disparate, clinically relevant models of sepsis induce a significant increase in intestinal permeability mediated through a common pathway involving alterations in claudin 2, claudin 5, JAM-A and occludin although model-specific differences in ZO-1 were also identified. PMID:27299587

Mechanisms of Intestinal Barrier Dysfunction in Sepsis.

PubMed

Yoseph, Benyam P; Klingensmith, Nathan J; Liang, Zhe; Breed, Elise R; Burd, Eileen M; Mittal, Rohit; Dominguez, Jessica A; Petrie, Benjamin; Ford, Mandy L; Coopersmith, Craig M

2016-07-01

Intestinal barrier dysfunction is thought to contribute to the development of multiple organ dysfunction syndrome in sepsis. Although there are similarities in clinical course following sepsis, there are significant differences in the host response depending on the initiating organism and time course of the disease, and pathways of gut injury vary widely in different preclinical models of sepsis. The purpose of this study was to determine whether the timecourse and mechanisms of intestinal barrier dysfunction are similar in disparate mouse models of sepsis with similar mortalities. FVB/N mice were randomized to receive cecal ligation and puncture (CLP) or sham laparotomy, and permeability was measured to fluoresceinisothiocyanate conjugated-dextran (FD-4) six to 48 h later. Intestinal permeability was elevated following CLP at all timepoints measured, peaking at 6 to 12 h. Tight junction proteins claudin 1, 2, 3, 4, 5, 7, 8, 13, and 15, Junctional Adhesion Molecule-A (JAM-A), occludin, and ZO-1 were than assayed by Western blot, real-time polymerase chain reaction, and immunohistochemistry 12 h after CLP to determine potential mechanisms underlying increases in intestinal permeability. Claudin 2 and JAM-A were increased by sepsis, whereas claudin-5 and occludin were decreased by sepsis. All other tight junction proteins were unchanged. A further timecourse experiment demonstrated that alterations in claudin-2 and occludin were detectable as early as 1 h after the onset of sepsis. Similar experiments were then performed in a different group of mice subjected to Pseudomonas aeruginosa pneumonia. Mice with pneumonia had an increase in intestinal permeability similar in timecourse and magnitude to that seen in CLP. Similar changes in tight junction proteins were seen in both models of sepsis although mice subjected to pneumonia also had a marked decrease in ZO-1 not seen in CLP. These results indicate that two disparate, clinically relevant models of sepsis induce a significant increase in intestinal permeability mediated through a common pathway involving alterations in claudin 2, claudin 5, JAM-A, and occludin although model-specific differences in ZO-1 were also identified.

EICOSAPENTAENOIC ACID ENHANCES HEATSTROKE-IMPAIRED INTESTINAL EPITHELIAL BARRIER FUNCTION IN RATS.

PubMed

Xiao, Guizhen; Yuan, Fangfang; Geng, Yan; Qiu, Xiaowen; Liu, Zhifeng; Lu, Jiefu; Tang, Liqun; Zhang, Yali; Su, Lei

2015-10-01

Dysfunction of the intestinal barrier plays an important role in the pathological process of heatstroke. Omega-3 (or n-3) polyunsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), help protect the intestinal mucosal barrier. This study assessed if pretreating rats with EPA or DHA could alleviate heat stress-induced damage to the intestinal barrier caused by experimental heatstroke. Male Wistar rats were pregavaged with either EPA, DHA, corn oil, or normal saline (all 1 g/kg) for 21 days before the heatstroke experiment (control rats were not exposed to heat). Experimental rats were exposed to an ambient temperature of 37°C and 60% humidity to induce heatstroke, and then they were allowed to recover at room temperature after rapid cooling. Survival time of rats was monitored after heatstroke. Horseradish peroxidase flux from the gut lumen and the level of plasma D-lactate were measured to analyze intestinal permeability at 6 h after heatstroke. Plasma endotoxin levels were determined using a limulus amoebocyte lysate assay. Expressions of the tight junction (TJ) proteins occludin and ZO-1 were analyzed by Western blot and localized by immunofluorescence microscopy. Tight junction protein morphology was observed by transmission electron microscopy. Fatty acids of ileal mucosa were analyzed using gas chromatography-mass selective detector. Eicosapentaenoic acid significantly increased survival time after heatstroke. Eicosapentaenoic acid significantly decreased intestinal permeability and plasma endotoxin levels. Eicosapentaenoic acid effectively attenuated the heatstroke-induced disruption of the intestinal structure and improved the histology score, whereas DHA was less effective, and corn oil was ineffective. Pretreatment with EPA also increased expression of occludin and ZO-1 to effectively prevent TJ disruption. Eicosapentaenoic acid pretreatment enriched itself in the membrane of intestinal cells. Our results indicate that EPA pretreatment is more effective than DHA pretreatment in attenuating heat-induced intestinal dysfunction and preventing TJ damage. Enhanced expression of TJ proteins that support the epithelial barrier integrity may be important for maintaining a functional intestinal barrier during heatstroke.

Inflammation in dry eye.

PubMed

Stern, Michael E; Pflugfelder, Stephen C

2004-04-01

Dry eye is a condition of altered tear composition that results from a diseased or dysfunctional lacrimal functional unit. Evidence suggests that inflammation causes structural alterations and/or functional paralysis of the tear-secreting glands. Changes in tear composition resulting from lacrimal dysfunction, increased evaporation and/or poor clearance have pro-inflammatory effects on the ocular surface. This inflammation is responsible in part for the irritation symptoms, ocular surface epithelial disease, and altered corneal epithelial barrier function in dry eye. Anti-inflammatory therapies for dry eye target one or more of the inflammatory mediators/pathways that have been identified in dry eye.

Pharmacotherapy for Irritable Bowel Syndrome

PubMed Central

Camilleri, Michael

2017-01-01

Irritable bowel syndrome (IBS) is a disorder of the brain-gut axis; the pathophysiological mechanisms include altered colonic motility, bile acid metabolism, neurohormonal regulation, immune dysfunction, alterations in the epithelial barrier and secretory properties of the gut. This article reviews the mechanisms, efficacy, and safety of current pharmacotherapy, and medications that are in phase III trials for the treatment of IBS. There remains a significant unmet need for effective treatments—particularly for the pain component of IBS—although the introduction of drugs directed at secretion, motility and a non-absorbable antibiotic provide options for the bowel dysfunction in IBS. PMID:29077050

Electron transport in gold colloidal nanoparticle-based strain gauges.

PubMed

Moreira, Helena; Grisolia, Jérémie; Sangeetha, Neralagatta M; Decorde, Nicolas; Farcau, Cosmin; Viallet, Benoit; Chen, Ke; Viau, Guillaume; Ressier, Laurence

2013-03-08

A systematic approach for understanding the electron transport mechanisms in resistive strain gauges based on assemblies of gold colloidal nanoparticles (NPs) protected by organic ligands is described. The strain gauges were fabricated from parallel micrometer wide wires made of 14 nm gold (Au) colloidal NPs on polyethylene terephthalate substrates, elaborated by convective self-assembly. Electron transport in such devices occurs by inter-particle electron tunneling through the tunnel barrier imposed by the organic ligands protecting the NPs. This tunnel barrier was varied by changing the nature of organic ligands coating the nanoparticles: citrate (CIT), phosphines (BSPP, TDSP) and thiols (MPA, MUDA). Electro-mechanical tests indicate that only the gold NPs protected by phosphine and thiol ligands yield high gauge sensitivity. Temperature-dependent resistance measurements are explained using the 'regular island array model' that extracts transport parameters, i.e., the tunneling decay constant β and the Coulomb charging energy E(C). This reveals that the Au@CIT nanoparticle assemblies exhibit a behavior characteristic of a strong-coupling regime, whereas those of Au@BSPP, Au@TDSP, Au@MPA and Au@MUDA nanoparticles manifest a weak-coupling regime. A comparison of the parameters extracted from the two methods indicates that the most sensitive gauges in the weak-coupling regime feature the highest β. Moreover, the E(C) values of these 14 nm NPs cannot be neglected in determining the β values.

Electron transport in gold colloidal nanoparticle-based strain gauges

NASA Astrophysics Data System (ADS)

Moreira, Helena; Grisolia, Jérémie; Sangeetha, Neralagatta M.; Decorde, Nicolas; Farcau, Cosmin; Viallet, Benoit; Chen, Ke; Viau, Guillaume; Ressier, Laurence

2013-03-01

A systematic approach for understanding the electron transport mechanisms in resistive strain gauges based on assemblies of gold colloidal nanoparticles (NPs) protected by organic ligands is described. The strain gauges were fabricated from parallel micrometer wide wires made of 14 nm gold (Au) colloidal NPs on polyethylene terephthalate substrates, elaborated by convective self-assembly. Electron transport in such devices occurs by inter-particle electron tunneling through the tunnel barrier imposed by the organic ligands protecting the NPs. This tunnel barrier was varied by changing the nature of organic ligands coating the nanoparticles: citrate (CIT), phosphines (BSPP, TDSP) and thiols (MPA, MUDA). Electro-mechanical tests indicate that only the gold NPs protected by phosphine and thiol ligands yield high gauge sensitivity. Temperature-dependent resistance measurements are explained using the ‘regular island array model’ that extracts transport parameters, i.e., the tunneling decay constant β and the Coulomb charging energy EC. This reveals that the Au@CIT nanoparticle assemblies exhibit a behavior characteristic of a strong-coupling regime, whereas those of Au@BSPP, Au@TDSP, Au@MPA and Au@MUDA nanoparticles manifest a weak-coupling regime. A comparison of the parameters extracted from the two methods indicates that the most sensitive gauges in the weak-coupling regime feature the highest β. Moreover, the EC values of these 14 nm NPs cannot be neglected in determining the β values.

The intestinal barrier in multiple sclerosis: implications for pathophysiology and therapeutics.

PubMed

Camara-Lemarroy, Carlos R; Metz, Luanne; Meddings, Jonathan B; Sharkey, Keith A; Wee Yong, V

2018-05-30

Biological barriers are essential for the maintenance of homeostasis in health and disease. Breakdown of the intestinal barrier is an essential aspect of the pathophysiology of gastrointestinal inflammatory diseases, such as inflammatory bowel disease. A wealth of recent studies has shown that the intestinal microbiome, part of the brain-gut axis, could play a role in the pathophysiology of multiple sclerosis. However, an essential component of this axis, the intestinal barrier, has received much less attention. In this review, we describe the intestinal barrier as the physical and functional zone of interaction between the luminal microbiome and the host. Besides its essential role in the regulation of homeostatic processes, the intestinal barrier contains the gut mucosal immune system, a guardian of the integrity of the intestinal tract and the whole organism. Gastrointestinal disorders with intestinal barrier breakdown show evidence of CNS demyelination, and content of the intestinal microbiome entering into the circulation can impact the functions of CNS microglia. We highlight currently available studies suggesting that there is intestinal barrier dysfunction in multiple sclerosis. Finally, we address the mechanisms by which commonly used disease-modifying drugs in multiple sclerosis could alter the intestinal barrier and the microbiome, and we discuss the potential of barrier-stabilizing strategies, including probiotics and stabilization of tight junctions, as novel therapeutic avenues in multiple sclerosis.

Compound mechanism hypothesis on +Gz induced brain injury and dysfunction of learning and memory

NASA Astrophysics Data System (ADS)

Sun, Xi-Qing; Li, Jin-Sheng; Cao, Xin-Sheng; Wu, Xing-Yu

2005-08-01

We systematically studied the effect of high- sustained +Gz on the brain and its mechanism in past ten years by animal centrifuge experiments. On the basis of the facts we observed and the more recent advances in acceleration physiology, we put forward a compound mechanism hypothesis to offer a possible explanation for +Gz-induced brain injury and dysfunction of learning and memory. It states that, ischemia during high G exposure might be the main factor accounting for +Gz-induced brain injury and dysfunction of learning and memory, including transient depression of brain energy metabolism, disturbance of ion homeostasis, increased blood-brain barrier permeability, increased brain nitric oxide synthase expression, and the protective effect of heat shock protein 70. In addition, the large rapid change of intracranial pressure and increased stress during +Gz exposure, and the hemorrheologic change after +Gz exposure might be one of the important factors accounting for +Gz-induced brain injury and dysfunction of learning and memory.

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

[Sexuality in the elderly].

PubMed

Wilk, Bartosz

2015-03-01

Sustaining and strengthening the ability of the elderly to continue their sexual needs can be realized as part of improving their quality of life, health and well-being. There is no age at which ends the expression of sexuality and intimacy. Through education, quality of life and advances in medicine, the average life expectancy is still increasing. Sexual activity of older people society usually describe using pejorative terms as an inappropriate, bizarre or obscene, but these labels are different than reality. Hormonal changes and other physiological changes associated with aging affect sexual interest. Erectile dysfunction is a problem in men increasing with age. There is no evidence that premature ejaculation is more common in older age. Cross-sectional studies showed no difference in sexual dysfunction between older and younger women. Age is not a barrier to sexually transmitted diseases. The most common pathogenetic factors for male erectile dysfunction are vascular diseases. In women, the most important symptoms of sexual dysfunction are lack of emotional wellbeing and a sense of intimacy during sexual intercourse. © 2015 MEDPRESS.

Near-barrier Fusion Evaporation and Fission of 28Si+174Yb and 32S+170Er

NASA Astrophysics Data System (ADS)

Wang, Dongxi; Lin, Chengjian; Jia, Huiming; Ma, Nanru; Sun, Lijie; Xu, Xinxing; Yang, Lei; Yang, Feng; Zhang, Huanqiao; Bao, Pengfei

2017-11-01

Fusion evaporation residues and fission fragments have been measured, respectively, at energies around the Coulomb barrier for the 28Si+174Yb and 32S+170Er systems forming the same compound nucleus 202Po. The excitation function of fusion evaporation, fission as well as capture reactions were deduced. Coupled-channels analyses reveal that couplings to the deformations of targets and the two-phonon states of projectiles contribute much to the enhancement of capture cross sections at sub-barrier energies. The mass and total kinetic energy of fission fragments were deduced by the time-difference method assuming full momentum transfer in a two-body kinematics. The mass-energy and mass-angle distributions were obtained and no obvious quasi-fission components were observed in this bombarding energy range. Further, mass distributions of fission fragments were fitted to extract their widths. Results show that the mass widths decrease monotonically with decreasing energy, but might start to increase when Ec.m./VB < 0.95 for both systems.

Involvement of dendritic cells in allograft rejection new implications of dendritic cell-endothelial cell interactions.

PubMed

Schlichting, C L; Schareck, W D; Kofler, S; Weis, M

2007-04-01

For almost half a century immunologists have tried to tear down the MHC barrier, which separates two unrelated individuals during transplantation. Latest experimental data suggest that a breakthrough in vitro is imminent. Dendritic cells (DCs), which activate naïve allo-reactive T-cells (TCs), play a central role in the establishment of allo-antigen-specific immunity. Allograft solid organ rejection is initiated at the foreign endothelial cell (EC) layer, which forms an immunogenic barrier for migrating DCs. Thus, DC/EC interactions might play a crucial role in antigen-specific allograft rejection. Organ rejection is mediated by host allo-reactive TCs, which are activated by donor DCs (direct activation) or host DCs (indirect activation). Direct allo-antigen presentation by regulatory dendritic cells (DCreg) can play an instructive role towards tolerance induction. Several groups established that, DCregs, if transplanted beforehand, enter host thymus, spleen, or bone marrow where they might eventually establish allo-antigen-specific tolerance. A fundamental aspect of DC function is migration throughout the entire organism. After solid organ transplantation, host DCs bind to ECs, invade allograft tissues, and finally transmigrate into lymphoid vessels and secondary lymphoid organs, where they present allo-antigens to naïve host TCs. Recent data suggest that in vitro manipulated DCregs may mediate allo-transplantation tolerance induction. However, the fundamental mechanisms on how such DCregs cause host TCs in the periphery towards tolerance remain unclear. One very promising experimental concept is the simultaneous manipulation of DC direct and indirect TC activation/suppression, towards donor antigen-specific allo-transplantation tolerance. The allo-antigen-specific long-term tolerance induction mediated by DCreg pre-transplantation (with simultaneous short-term immunosuppression) has become reproducible in the laboratory animal setting. Despite the shortcomings of laboratory animal studies, strong promises are deriving from these studies for clinical kidney, heart, and liver transplantation.

Agmatine Improves Cognitive Dysfunction and Prevents Cell Death in a Streptozotocin-Induced Alzheimer Rat Model

PubMed Central

Song, Juhyun; Hur, Bo Eun; Bokara, Kiran Kumar; Yang, Wonsuk; Cho, Hyun Jin; Park, Kyung Ah; Lee, Won Taek; Lee, Kyoung Min

2014-01-01

Purpose Alzheimer's disease (AD) results in memory impairment and neuronal cell death in the brain. Previous studies demonstrated that intracerebroventricular administration of streptozotocin (STZ) induces pathological and behavioral alterations similar to those observed in AD. Agmatine (Agm) has been shown to exert neuroprotective effects in central nervous system disorders. In this study, we investigated whether Agm treatment could attenuate apoptosis and improve cognitive decline in a STZ-induced Alzheimer rat model. Materials and Methods We studied the effect of Agm on AD pathology using a STZ-induced Alzheimer rat model. For each experiment, rats were given anesthesia (chloral hydrate 300 mg/kg, ip), followed by a single injection of STZ (1.5 mg/kg) bilaterally into each lateral ventricle (5 µL/ventricle). Rats were injected with Agm (100 mg/kg) daily up to two weeks from the surgery day. Results Agm suppressed the accumulation of amyloid beta and enhanced insulin signal transduction in STZ-induced Alzheimer rats [experimetal control (EC) group]. Upon evaluation of cognitive function by Morris water maze testing, significant improvement of learning and memory dysfunction in the STZ-Agm group was observed compared with the EC group. Western blot results revealed significant attenuation of the protein expressions of cleaved caspase-3 and Bax, as well as increases in the protein expressions of Bcl2, PI3K, Nrf2, and γ-glutamyl cysteine synthetase, in the STZ-Agm group. Conclusion Our results showed that Agm is involved in the activation of antioxidant signaling pathways and activation of insulin signal transduction. Accordingly, Agm may be a promising therapeutic agent for improving cognitive decline and attenuating apoptosis in AD. PMID:24719136

Inward rectifier potassium (Kir2.1) channels as end‐stage boosters of endothelium‐dependent vasodilators

PubMed Central

Dalsgaard, Thomas; Bonev, Adrian D.; Nelson, Mark T.

2016-01-01

Key points Increase in endothelial cell (EC) calcium activates calcium‐sensitive intermediate and small conductance potassium (IK and SK) channels, thereby causing hyperpolarization and endothelium‐dependent vasodilatation.Endothelial cells express inward rectifier potassium (Kir) channels, but their role in endothelium‐dependent vasodilatation is not clear.In the mesenteric arteries, only ECs, but not smooth muscle cells, displayed Kir currents that were predominantly mediated by the Kir2.1 isoform.Endothelium‐dependent vasodilatations in response to muscarinic receptor, TRPV4 (transient receptor potential vanilloid 4) channel and IK/SK channel agonists were highly attenuated by Kir channel inhibitors and by Kir2.1 channel knockdown.These results point to EC Kir channels as amplifiers of vasodilatation in response to increases in EC calcium and IK/SK channel activation and suggest that EC Kir channels could be targeted to treat endothelial dysfunction, which is a hallmark of vascular disorders. Abstract Endothelium‐dependent vasodilators, such as acetylcholine, increase intracellular Ca2+ through activation of transient receptor potential vanilloid 4 (TRPV4) channels in the plasma membrane and inositol trisphosphate receptors in the endoplasmic reticulum, leading to stimulation of Ca2+‐sensitive intermediate and small conductance K+ (IK and SK, respectively) channels. Although strong inward rectifier K+ (Kir) channels have been reported in the native endothelial cells (ECs) their role in EC‐dependent vasodilatation is not clear. Here, we test the idea that Kir channels boost the EC‐dependent vasodilatation of resistance‐sized arteries. We show that ECs, but not smooth muscle cells, of small mesenteric arteries have Kir currents, which are substantially reduced in EC‐specific Kir2.1 knockdown (EC‐Kir2.1 −/−) mice. Elevation of extracellular K+ to 14 mm caused vasodilatation of pressurized arteries, which was prevented by endothelial denudation and Kir channel inhibitors (Ba2+, ML‐133) or in the arteries from EC‐Kir2.1 −/− mice. Potassium‐induced dilatations were unaffected by inhibitors of TRPV4, IK and SK channels. The Kir channel blocker, Ba2+, did not affect currents through TRPV4, IK or SK channels. Endothelial cell‐dependent vasodilatations in response to activation of muscarinic receptors, TRPV4 channels or IK/SK channels were reduced, but not eliminated, by Kir channel inhibitors or EC‐Kir2.1 −/−. In angiotensin II‐induced hypertension, the Kir channel function was not altered, although the endothelium‐dependent vasodilatation was severely impaired. Our results support the concept that EC Kir2 channels boost vasodilatory signals that are generated by Ca2+‐dependent activation of IK and SK channels. PMID:26840527

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.

The impact of microglial activation on blood-brain barrier in brain diseases

PubMed Central

da Fonseca, Anna Carolina Carvalho; Matias, Diana; Garcia, Celina; Amaral, Rackele; Geraldo, Luiz Henrique; Freitas, Catarina; Lima, Flavia Regina Souza

2014-01-01

The blood-brain barrier (BBB), constituted by an extensive network of endothelial cells (ECs) together with neurons and glial cells, including microglia, forms the neurovascular unit (NVU). The crosstalk between these cells guarantees a proper environment for brain function. In this context, changes in the endothelium-microglia interactions are associated with a variety of inflammation-related diseases in brain, where BBB permeability is compromised. Increasing evidences indicate that activated microglia modulate expression of tight junctions, which are essential for BBB integrity and function. On the other hand, the endothelium can regulate the state of microglial activation. Here, we review recent advances that provide insights into interactions between the microglia and the vascular system in brain diseases such as infectious/inflammatory diseases, epilepsy, ischemic stroke and neurodegenerative disorders. PMID:25404894

Divergent effects of 17-{beta}-estradiol on human vascular smooth muscle and endothelial cell function diminishes TNF-{alpha}-induced neointima formation

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

Nintasen, Rungrat; Multidisciplinary Cardiovascular Research Center; Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University

2012-04-20

Highlights: Black-Right-Pointing-Pointer TNF-{alpha} augments neointimal hyperplasia in human saphenous vein. Black-Right-Pointing-Pointer TNF-{alpha} induces detrimental effects on endothelial and smooth muscle cell function. Black-Right-Pointing-Pointer Estradiol exerts modulatory effects on TNF-induced vascular cell functions. Black-Right-Pointing-Pointer The modulatory effects of estradiol are discriminatory and cell-type specific. -- Abstract: Coronary heart disease (CHD) is a condition characterized by increased levels of proinflammatory cytokines, including tumor necrosis factor-{alpha} (TNF-{alpha}). TNF-{alpha} can induce vascular endothelial cell (EC) and smooth muscle cell (SMC) dysfunction, central events in development of neointimal lesions. The reduced incidence of CHD in young women is believed to be due to the protectivemore » effects of estradiol (E2). We therefore investigated the effects of TNF-{alpha} on human neointima formation and SMC/EC functions and any modulatory effects of E2. Saphenous vein (SV) segments were cultured in the presence of TNF-{alpha} (10 ng/ml), E2 (2.5 nM) or both in combination. Neointimal thickening was augmented by incubation with TNF-{alpha}, an effect that was abolished by co-culture with E2. TNF-{alpha} increased SV-SMC proliferation in a concentration-dependent manner that was optimal at 10 ng/ml (1.5-fold increase), and abolished by E2 at all concentrations studied (1-50 nM). Surprisingly, E2 itself at low concentrations (1 and 5 nM) stimulated SV-SMC proliferation to a level comparable to that of TNF-{alpha} alone. SV-EC migration was significantly impaired by TNF-{alpha} (42% of control), and co-culture with E2 partially restored the ability of SV-EC to migrate and repair the wound. In contrast, TNF-{alpha} increased SV-SMC migration by 1.7-fold, an effect that was completely reversed by co-incubation with E2. Finally, TNF-{alpha} potently induced ICAM-1 and VCAM-1 expression in both SV-EC and SV-SMC. However there was no modulation by E2 in either cell-type. In conclusion, TNF-{alpha} induced SV neointima formation, increased SMC proliferation and migration, impaired SV-EC migration and increased expression of adhesion molecules. E2 exerted distinct cell-type and function-specific modulation, the mechanisms underlying which are worthy of further detailed study.« less

Cytokine-mediated blood brain barrier disruption as a conduit for cancer/chemotherapy-associated neurotoxicity and cognitive dysfunction.

PubMed

Wardill, Hannah R; Mander, Kimberley A; Van Sebille, Ysabella Z A; Gibson, Rachel J; Logan, Richard M; Bowen, Joanne M; Sonis, Stephen T

2016-12-15

Neurotoxicity is a common side effect of chemotherapy treatment, with unclear molecular mechanisms. Clinical studies suggest that the most frequent neurotoxic adverse events affect memory and learning, attention, concentration, processing speeds and executive function. Emerging preclinical research points toward direct cellular toxicity and induction of neuroinflammation as key drivers of neurotoxicity and subsequent cognitive impairment. Emerging data now show detectable levels of some chemotherapeutic agents within the CNS, indicating potential disruption of blood brain barrier integrity or transport mechanisms. Blood brain barrier disruption is a key aspect of many neurocognitive disorders, particularly those characterized by a proinflammatory state. Importantly, many proinflammatory mediators able to modulate the blood brain barrier are generated by tissues and organs that are targets for chemotherapy-associated toxicities. This review therefore aims to explore the hypothesis that peripherally derived inflammatory cytokines disrupt blood brain barrier permeability, thereby increasing direct access of chemotherapeutic agents into the CNS to facilitate neuroinflammation and central neurotoxicity. © 2016 UICC.

Blood-CSF-barrier dysfunction is a marker for encephalitic involvement in patients with aseptic meningitis/meningoencephalitis.

PubMed

Hoyer, C; Eisele, P; Ebert, A D; Schneider, S; Gass, A; Fatar, M; Szabo, K; Alonso, A

2016-11-01

The term "aseptic meningitis" encompasses cases of meningitis with negative bacterial CSF culture, which predominantly are of viral etiology. While the clinical course is usually benign, complications such as encephalitic involvement resulting in a more severe clinical course may occur. Dysfunction of the blood-brain-barrier (BBB), which is a prerequisite for viral entry into the brain parenchyma, can be approximated using the CSF/serum albumin ratio, readily obtainable in routine CSF analysis. Analysis of CSF patterns in patients with aseptic meningitis/meningoencephalitis with a focus on BBB dysfunction as a marker for encephalitic involvement. Retrospective chart review of patients admitted to our hospital between 2004 and 2016 with a diagnosis of aseptic meningitis/meningoencephalitis. Patients with aseptic meningitis displaying clinical, MR-tomographic or electroencephalographic signs of encephalitic involvement were significantly older than patients without these features (47.4 vs. 35.5 yrs., p=0.002). In patients with meningoencephalitis, CSF analysis revealed a more severe disruption of BBB, approximated by the CSF/serum albumin ratio (p=0.002). Compromised BBB function correlated positively with length of hospitalization (p=0.007), indicative of a more severe clinical course. The number of CSF lymphocytes was found to predict the severity of the BBB disruption, which additionally was more frequently observed when herpesviridae were identified as infectious agents. We suggest that the CSF/serum albumin ratio as an estimate for BBB function should be attended to in the evaluation of patients with aseptic meningitis. Severe BBB dysfunction, older age and infection with herpesviridae appear to raise the risk for encephalitic involvement. Copyright © 2016 Elsevier B.V. All rights reserved.

Seizure-Induced Regulations of Amyloid-β, STEP61, and STEP61 Substrates Involved in Hippocampal Synaptic Plasticity

PubMed Central

Jang, Sung-Soo; Royston, Sara E.; Lee, Gunhee; Wang, Shuwei; Chung, Hee Jung

2016-01-01

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline. Pathologic accumulation of soluble amyloid-β (Aβ) oligomers impairs synaptic plasticity and causes epileptic seizures, both of which contribute to cognitive dysfunction in AD. However, whether seizures could regulate Aβ-induced synaptic weakening remains unclear. Here we show that a single episode of electroconvulsive seizures (ECS) increased protein expression of membrane-associated STriatal-Enriched protein tyrosine Phosphatase (STEP61) and decreased tyrosine-phosphorylation of its substrates N-methyl D-aspartate receptor (NMDAR) subunit GluN2B and extracellular signal regulated kinase 1/2 (ERK1/2) in the rat hippocampus at 2 days following a single ECS. Interestingly, a significant decrease in ERK1/2 expression and an increase in APP and Aβ levels were observed at 3-4 days following a single ECS when STEP61 level returned to the baseline. Given that pathologic levels of Aβ increase STEP61 activity and STEP61-mediated dephosphorylation of GluN2B and ERK1/2 leads to NMDAR internalization and ERK1/2 inactivation, we propose that upregulation of STEP61 and downregulation of GluN2B and ERK1/2 phosphorylation mediate compensatory weakening of synaptic strength in response to acute enhancement of hippocampal network activity, whereas delayed decrease in ERK1/2 expression and increase in APP and Aβ expression may contribute to the maintenance of this synaptic weakening. PMID:27127657

A role for solvents in the toxicity of agricultural organophosphorus pesticides

PubMed Central

Eddleston, Michael; Street, Jonathan M.; Self, Ian; Thompson, Adrian; King, Tim; Williams, Nicola; Naredo, Gregorio; Dissanayake, Kosala; Yu, Ly-Mee; Worek, Franz; John, Harald; Smith, Sionagh; Thiermann, Horst; Harris, John B.; Eddie Clutton, R.

2012-01-01

Organophosphorus (OP) insecticide self-poisoning is responsible for about one-quarter of global suicides. Treatment focuses on the fact that OP compounds inhibit acetylcholinesterase (AChE); however, AChE-reactivating drugs do not benefit poisoned humans. We therefore studied the role of solvent coformulants in OP toxicity in a novel minipig model of agricultural OP poisoning. Gottingen minipigs were orally poisoned with clinically relevant doses of agricultural emulsifiable concentrate (EC) dimethoate, dimethoate active ingredient (AI) alone, or solvents. Cardiorespiratory physiology and neuromuscular (NMJ) function, blood AChE activity, and arterial lactate concentration were monitored for 12 h to assess poisoning severity. Poisoning with agricultural dimethoate EC40, but not saline, caused respiratory arrest within 30 min, severe distributive shock and NMJ dysfunction, that was similar to human poisoning. Mean arterial lactate rose to 15.6 [SD 2.8] mM in poisoned pigs compared to 1.4 [0.4] in controls. Moderate toxicity resulted from poisoning with dimethoate AI alone, or the major solvent cyclohexanone. Combining dimethoate with cyclohexanone reproduced severe poisoning characteristic of agricultural dimethoate EC poisoning. A formulation without cyclohexanone showed less mammalian toxicity. These results indicate that solvents play a crucial role in dimethoate toxicity. Regulatory assessment of pesticide toxicity should include solvents as well as the AIs which currently dominate the assessment. Reformulation of OP insecticides to ensure that the agricultural product has lower mammalian toxicity could result in fewer deaths after suicidal ingestion and rapidly reduce global suicide rates. PMID:22365945

Dobesilate enhances endothelial nitric oxide synthase-activity in macro- and microvascular endothelial cells

PubMed Central

Suschek, Christoph; Kolb, Hubert; Kolb-Bachofen, Victoria

1997-01-01

Dobesilate is used for normalizing vascular dysfunction in a number of diseases. In search for an effect on endothelial NO production, macrovascular endothelial cells from rat aorta, microvascular endothelial cells from rat exocrine pancreatic tissue, and capillary endothelial cells from rat islets, were cultured in the presence or absence of Mg-Dobesilate. The activity of constitutive nitric oxide synthase (ecNOS) in resident cells as well as of inducible nitric oxide synthase (iNOS) in cytokine-activated cells was measured indirectly by recording the citrulline concentrations in culture supernatants.In each of the different endothelial cells Mg-Dobesilate incubation (0.25–1 mM) for 24 h led to a significant and concentration-dependent increase in ecNOS-activities. With cytokine-activated endothelial cell cultures only moderate effects were seen with little or no concentration-dependency. Addition of the NOS-inhibitor NG-monomethyl-L-arginine led to a significant suppression of citrulline formation in all cultures as an evidence for the enzyme specificity of these effects.iNOS- and ecNOS-specific reverse transcription and semi-quantitative polymerase chain reaction (RT–PCR) with RNA from resident or cytokine-activated endothelial cells gave no evidence for an increase in NOS-specific mRNA after Mg-Dobesilate-treatment. Furthermore, Dobesilate-mediated enhancement of NO synthesis in resting endothelial cells was not due to iNOS induction in these cells, as no iNOS-specific signal was found by RT–PCR. PMID:9421302

Skin Barrier and Calcium.

PubMed

Lee, Sang Eun; Lee, Seung Hun

2018-06-01

Epidermal barrier formation and the maintenance of barrier homeostasis are essential to protect us from the external environments and organisms. Moreover, impaired keratinocytes differentiation and dysfunctional skin barrier can be the primary causes or aggravating factors for many inflammatory skin diseases including atopic dermatitis and psoriasis. Therefore, understanding the regulation mechanisms of keratinocytes differentiation and skin barrier homeostasis is important to understand many skin diseases and establish an effective treatment strategy. Calcium ions (Ca 2+ ) and their concentration gradient in the epidermis are essential in regulating many skin functions, including keratinocyte differentiation, skin barrier formation, and permeability barrier homeostasis. Recent studies have suggested that the intracellular Ca 2+ stores such as the endoplasmic reticulum (ER) are the major components that form the epidermal calcium gradient and the ER calcium homeostasis is crucial for regulating keratinocytes differentiation, intercellular junction formation, antimicrobial barrier, and permeability barrier homeostasis. Thus, both Ca 2+ release from intracellular stores, such as the ER and Ca 2+ influx mechanisms are important in skin barrier. In addition, growing evidences identified the functional existence and the role of many types of calcium channels which mediate calcium flux in keratinocytes. In this review, the origin of epidermal calcium gradient and their role in the formation and regulation of skin barrier are focused. We also focus on the role of ER calcium homeostasis in skin barrier. Furthermore, the distribution and role of epidermal calcium channels, including transient receptor potential channels, store-operated calcium entry channel Orai1, and voltage-gated calcium channels in skin barrier are discussed.

Joint road safety operations in tunnels and open roads

NASA Astrophysics Data System (ADS)

Adesiyun, Adewole; Avenoso, Antonio; Dionelis, Kallistratos; Cela, Liljana; Nicodème, Christophe; Goger, Thierry; Polidori, Carlo

2017-09-01

The objective of the ECOROADS project is to overcome the barrier established by the formal interpretation of the two Directives 2008/96/EC and 2004/54/EC, which in practice do not allow the same Road Safety Audits/Inspections to be performed inside tunnels. The projects aims at the establishment of a common enhanced approach to road infrastructure and tunnel safety management by using the concepts and criteria of the Directive 2008/96/CE on road infrastructure safety management and the results of related European Commission (EC) funded projects. ECOROADS has already implemented an analysis of national practices regarding Road Safety Inspections (RSI), two Workshops with the stakeholders, and an exchange of best practices between European tunnel experts and road safety professionals, which led to the definition of common agreed safety procedures. In the second phase of the project, different groups of experts and observers applied the above common procedures by inspecting five European road sections featuring both open roads and tunnels in Belgium, Albania, Germany, Serbia and Former Yugoslav Republic of Macedonia. This paper shows the feedback of the 5 joint safety operations and how they are being used for a set of - recommendations and guidelines for the application of the RSA and RSI concepts within the tunnel safety operations.

Alk5/Runx1 signaling mediated by extracellular vesicles promotes vascular repair in acute respiratory distress syndrome.

PubMed

Shah, Trushil; Qin, Shanshan; Vashi, Mona; Predescu, Dan N; Jeganathan, Niranjan; Bardita, Cristina; Ganesh, Balaji; diBartolo, Salvatore; Fogg, Louis F; Balk, Robert A; Predescu, Sanda A

2018-06-22

Pulmonary endothelial cells' (ECs) injury and apoptotic death are necessary and sufficient for the pathogenesis of the acute respiratory distress syndrome (ARDS), regardless of epithelial damage. Interaction of dysfunctional ECs with circulatory extracellular vesicles (EVs) holds therapeutic promise in ARDS. However, the presence in the blood of long-term ARDS survivors of EVs with a distinct phenotype compared to the EVs of non-surviving patients is not reported. With a multidisciplinary translational approach, we studied EVs from the blood of 33 patients with moderate-to-severe ARDS. The EVs were isolated from the blood of ARDS and control subjects. Immunoblotting and magnetic beads immunoisolation complemented by standardized flow cytometry and nanoparticles tracking analyses identified in the ARDS patients a subset of EVs with mesenchymal stem cell (MSC) origin (CD73 + CD105 + Cd34 - CD45 - ). These EVs have 4.7-fold greater counts compared to controls and comprise the transforming growth factor-beta receptor I (TβRI)/Alk5 and the Runx1 transcription factor. Time course analyses showed that the expression pattern of two Runx1 isoforms is critical for ARDS outcome: the p52 isoform shows a continuous expression, while the p66 is short-lived. A high ratio Runx1p66/p52 provided a survival advantage, regardless of age, sex, disease severity or length of stay in the intensive care unit. Moreover, the Runx1p66 isoform is transiently expressed by cultured human bone marrow-derived MSCs, it is released in the EVs recoverable from the conditioned media and stimulates the proliferation of lipopolysaccharide (LPS)-treated ECs. The findings are consistent with a causal effect of Runx1p66 expression on EC proliferation. Furthermore, morphological and functional assays showed that the EVs bearing the Runx1p66 enhanced junctional integrity of LPS-injured ECs and decreased lung histological severity in the LPS-treated mice. The expression pattern of Runx1 isoforms might be a reliable circulatory biomarker of ARDS activity and a novel determinant of the molecular mechanism for lung vascular/tissue repair and recovery after severe injury.

In Vitro Efficacy of Ebselen and BAY 11-7082 Against Naegleria fowleri.

PubMed

Debnath, Anjan; Nelson, Andrew T; Silva-Olivares, Angélica; Shibayama, Mineko; Siegel, Dionicio; McKerrow, James H

2018-01-01

Primary amebic meningoencephalitis (PAM) is a fatal infection caused by the free-living ameba Naegleria fowleri , popularly known as the "brain-eating ameba." The drugs of choice in treating PAM are the antifungal amphotericin B and an antileishmanial miltefosine, but these are not FDA-approved for this indication and use of amphotericin B is associated with severe adverse effects. Moreover, very few patients treated with the combination therapy have survived PAM. Therefore, development of efficient drugs is a critical unmet need to avert future deaths of children. Since N. fowleri causes extensive inflammation in the brain it is important to select compounds that can enter brain to kill ameba. In this study, we identified two central nervous system (CNS) active compounds, ebselen and BAY 11-7082 as amebicidal with EC 50 of 6.2 and 1.6 μM, respectively. The closely related BAY 11-7085 was also found active against N. fowleri with EC 50 similar to BAY 11-7082. We synthesized a soluble ebselen analog, which had amebicidal activity similar to ebselen. Transmission electron microscopy of N. fowleri trophozoites incubated for 48 h with EC 50 concentration of ebselen showed alteration in the cytoplasmic membrane, loss of the nuclear membrane, and appearance of electron-dense granules. Incubation of N. fowleri trophozoites with EC 50 concentrations of BAY 11-7082 and BAY 11-7085 for 48 h showed the presence of large lipid droplets in the cytoplasm, disruption of cytoplasmic and nuclear membranes and appearance of several vesicles and chromatin residues. Blood-brain barrier permeable amebicidal compounds have potential as new drug leads for Naegleria infection.

The cytotoxic effect of palytoxin on Caco-2 cells hinders their use for in vitro absorption studies.

PubMed

Pelin, M; Sosa, S; Della Loggia, R; Poli, M; Tubaro, A; Decorti, G; Florio, C

2012-02-01

Palytoxin (PLTX), found in Palythoa zoanthids and Ostreopsis dinoflagellates, has also been detected in crabs and fish, through which it can enter into the food chain. Indeed, PLTX is considered the causative agent of several cases of human seafood poisoning resulting in systemic symptoms. Available epidemiological data on PLTX human toxicity suggest that the intestinal tract may be one of its in vivo targets and its potential site of access into the bloodstream. Hence, the purpose of this study was to investigate the suitability of the human intestinal Caco-2 cell line for evaluating PLTX oral absorption. A detailed analysis of PLTX cytotoxicity revealed a high sensitivity of Caco-2 cells: 4h toxin exposure reduced mitochondrial activity (MTT assay, EC(50) of 8.9±3.7×10(-12)M), cell density (SRB assay, EC(50) of 2.0±0.6×10(-11)M) and membrane integrity (LDH release, EC(50) of 4.5±1.4×10(-9)M and PI uptake, EC(50) of 1.0±0.8×10(-8)M). After low PLTX concentration (1.0×10(-11)M) exposure for 1-8h, followed by 24h recovery time in toxin-free medium, cell density reduction was only partially reversible. These results indicate that, due to the high susceptibility to PLTX cytotoxic effects, Caco-2 cells do not represent an appropriate and reliable model for investigating intestinal barrier permeation by this toxin. Copyright © 2011 Elsevier Ltd. 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

Surgery upregulates high mobility group box-1 and disrupts the blood-brain barrier causing cognitive dysfunction in aged rats.

PubMed

He, Hui-Juan; Wang, Yi; Le, Yuan; Duan, Kai-Ming; Yan, Xue-Bin; Liao, Qin; Liao, Yan; Tong, Jian-Bin; Terrando, Niccolò; Ouyang, Wen

2012-12-01

Postoperative cognitive dysfunction (POCD) is a growing and largely underestimated problem without defined etiology. Herein, we sought to determine the relationship between cognitive decline, blood-brain barrier (BBB) permeability, and inflammation, namely high mobility group box-1 (HMGB1), after surgery in aged rats. Aged rats were randomly assigned as surgery group (n = 45, splenectomy under general anesthesia), anesthesia (n = 45, 2% isoflurane for 2 h), and naïve control (n = 15). Markers of inflammation were measured in plasma and brain. Blood-brain barrier ultrastructure and permeability were measured by transmission electron microscope (TEM) and IgG immunohistochemistry. Cognitive function was assessed in a reversal learning version of the Morris water maze (MWM). Surgical trauma under general anesthesia caused distinct changes in systemic and central proinflammatory cytokines. Levels of HMGB1 and the receptor for advanced glycation end products (RAGE) were significantly upregulated in the hippocampus of operated animals. Immunohistochemistry and TEM showed BBB disruption induced by surgery and anesthesia. These molecular changes were associated with cognitive impairment in latency with the MWM up to postoperative day 3. HMGB1 and RAGE signaling appear pivotal mediators of surgery-induced cognitive decline and may contribute to the changes in BBB permeability after peripheral surgical trauma. © 2012 Blackwell Publishing Ltd.

Blood-C.S.F. barriers dysfunction in the chronic organic brain syndrome; a R.I.A. study.

PubMed

Vardi, Y; Czerniak, P; Rabey, Y; Flechter, S; Boruchowsky, S; Streifler, M

1978-01-01

C.S.F. samples of 35 patients, who suffered from verified chronic, non-tumorous organic brain syndrome, were radioimmunoassayed for T4 and T.S.H., and were compared to C.S.F.-R.I.A. samples from a control group of patients who underwent myelography because of lumbar disc. In addition T4 and T.S.H. plasma levels were evaluated in the O.B.S. patients. C.S.F. T4 and T.S.H. levels were significantly higher in 65% of the O.B.S. group of patients than those of the control group. The average determinations for T4 were: 0.77 muh/100 ml in O.B.S. group as against 0--0.4 micrograms/100 ml in the C.S.F.'s of the control group. P greater than 0,001 T.S.H. C.S.F. levels were 1.33 microU/ml in the O.B.S. group, and 0--0.6 microU/ml in the control group (P greater than 0.005). It is suggested that the elevated R.I.A. values of these hormones in the C.S.F. of the O.B.S. patients reflect a disruption of blood-C.S.F. barriers. Therefore in the organic brain syndrome there seems to exist a pathophysiological dysfunction of brain barriers in addition of the neural damage.

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.

Autoantibodies and an immune-based rat model of inflammatory bowel disease.

PubMed

Esmaily, Hadi; Sanei, Yara; Abdollahi, Mohammad

2013-11-21

The exact causes of inflammatory bowel disease (IBD) are not yet fully defined. From a vast body of literature, we know that the immune response has long been involved in the pathogenesis of IBD, including both ulcerative colitis and Crohn's disease. A variety of specific alterations can lead to immune activation and inflammation directed to the colon, as revealed by some animal models. Current research has focused on the role of antibodies in downstream events and mechanisms of autoimmunity and inflammation. It is not well known whether the production of antibodies is a serologic consequence of IBD, or if it is a result of barrier dysfunction induced by inflammation. Here, we present a new hypothesis to distinguish the complex links between genetic susceptibility, barrier dysfunction, commensal and pathologic microbial factors and inflammatory response (especially autoantibodies) in the pathogenesis of IBD. To ascertain the hypothesis, we developed a pilot model with the concept of the presence of antibodies against enteric bacterial antigens in IBD. Results confirmed our hypothesis. Our hypothesis suggests the possibility of subcutaneous vaccination of animals with administration of all or specific enteric bacterial antigens.

Endothelial Cell Permeability during Hantavirus Infection Involves Factor XII-Dependent Increased Activation of the Kallikrein-Kinin System

PubMed Central

Taylor, Shannon L.; Wahl-Jensen, Victoria; Copeland, Anna Maria; Jahrling, Peter B.; Schmaljohn, Connie S.

2013-01-01

Hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS) are diseases caused by hantavirus infections and are characterized by vascular leakage due to alterations of the endothelial barrier. Hantavirus-infected endothelial cells (EC) display no overt cytopathology; consequently, pathogenesis models have focused either on the influx of immune cells and release of cytokines or on increased degradation of the adherens junction protein, vascular endothelial (VE)-cadherin, due to hantavirus-mediated hypersensitization of EC to vascular endothelial growth factor (VEGF). To examine endothelial leakage in a relevant in vitro system, we co-cultured endothelial and vascular smooth muscle cells (vSMC) to generate capillary blood vessel-like structures. In contrast to results obtained in monolayers of cultured EC, we found that despite viral replication in both cell types as well as the presence of VEGF, infected in vitro vessels neither lost integrity nor displayed evidence of VE-cadherin degradation. Here, we present evidence for a novel mechanism of hantavirus-induced vascular leakage involving activation of the plasma kallikrein-kinin system (KKS). We show that incubation of factor XII (FXII), prekallikrein (PK), and high molecular weight kininogen (HK) plasma proteins with hantavirus-infected EC results in increased cleavage of HK, higher enzymatic activities of FXIIa/kallikrein (KAL) and increased liberation of bradykinin (BK). Measuring cell permeability in real-time using electric cell-substrate impedance sensing (ECIS), we identified dramatic increases in endothelial cell permeability after KKS activation and liberation of BK. Furthermore, the alterations in permeability could be prevented using inhibitors that directly block BK binding, the activity of FXIIa, or the activity of KAL. Lastly, FXII binding and autoactivation is increased on the surface of hantavirus-infected EC. These data are the first to demonstrate KKS activation during hantavirus infection and could have profound implications for treatment of hantavirus infections. PMID:23874198

The "Aging Factor" Eotaxin-1 (CCL11) Is Detectable in Transfusion Blood Products and Increases with the Donor's Age.

PubMed

Hoefer, Julia; Luger, Markus; Dal-Pont, Christian; Culig, Zoran; Schennach, Harald; Jochberger, Stefan

2017-01-01

Background : High blood levels of the chemokine eotaxin-1 (CCL11) have recently been associated with aging and dementia, as well as impaired memory and learning in humans. Importantly, eotaxin-1 was shown to pass the blood-brain-barrier (BBB) and has been identified as crucial mediator of decreased neurogenesis and cognitive impairment in young mice after being surgically connected to the vessel system of old animals in a parabiosis model. It thus has to be assumed that differences in eotaxin-1 levels between blood donors and recipients might influence cognitive functions also in humans. However, it is unknown if eotaxin-1 is stable during processing and storage of transfusion blood components. This study assesses eotaxin-1 concentrations in fresh-frozen plasma (FFP), erythrocyte concentrate (EC), and platelet concentrate (PC) in dependence of storage time as well as the donor's age and gender. Methods : Eotaxin-1 was measured in FFP ( n = 168), EC ( n = 160) and PC ( n = 8) ready-to-use for transfusion employing a Q-Plex immunoassay for eotaxin-1. Absolute quantification of eotaxin-1 was performed with Q-view software. Results : Eotaxin-1 was consistently detected at a physiological level in FFP and EC but not PC. Eotaxin-1 levels were comparable in male and female donors but increased significantly with rising age of donors in both, FFP and EC. Furthermore, eotaxin-1 was not influenced by storage time of either blood component. Finally, eotaxin-1 is subject to only minor fluctuations within one donor over a longer period of time. Conclusion : Eotaxin-1 is detectable and stable in FFP and EC and increases with donor's age. Considering the presumed involvement in aging and cognitive malfunction, differences in donor- and recipient eotaxin-1 levels might affect mental factors after blood transfusion.

Detection of thermally grown oxides in thermal barrier coatings by nondestructive evaluation

NASA Astrophysics Data System (ADS)

Fahr, A.; Rogé, B.; Thornton, J.

2006-03-01

The thermal-barrier coatings (TBC) sprayed on hot-section components of aircraft turbine engines commonly consist of a partially stabilized zirconia top-coat and an intermediate bond-coat applied on the metallic substrate. The bond-coat is made of an aluminide alloy that at high engine temperatures forms thermally grown oxides (TGO). Although formation of a thin layer of aluminum oxide at the interface between the ceramic top-coat and the bond-coat has the beneficial effect of protecting the metallic substrate from hot gases, oxide formation at splat boundaries or pores within the bond-coat is a source of weakness. In this study, plasma-sprayed TBC specimens are manufactured from two types of bond-coat powders and exposed to elevated temperatures to form oxides at the ceramic-bond-coat boundary and within the bond-coat. The specimens are then tested using nondestructive evaluation (NDE) and destructive metallography and compared with the as-manufactured samples. The objective is to determine if NDE can identify the oxidation within the bond-coat and give indication of its severity. While ultrasonic testing can provide some indication of the degree of bond-coat oxidation, the eddy current (EC) technique clearly identifies severe oxide formation within the bond-coat. Imaging of the EC signals as the function of probe location provides information on the spatial variations in the degree of oxidation, and thereby identifies which components or areas are prone to premature damage.

Factors associated with sexual functioning in women following spinal cord injury.

PubMed

Harrison, J; Glass, C A; Owens, R G; Soni, B M

1995-12-01

Research into sexuality following spinal cord injury (SCI) has tended to concentrate on male experiences and the physical capabilities for sexual intercourse. The sexuality of women following SCI has only recently been addressed and studies are limited to small numbers and the use of non-standardised measures. The present investigation utilised standard measures of affective state and body satisfaction together with pre and post-injury questionnaire information of sexual dysfunction, feelings about sex and importance of sexual activity in a group of 85 women with SCI. Sexual dysfunction increased significantly post-injury, whilst feelings about sex and it's importance were unaffected. Sexual dysfunction and the importance of sex were inversely correlated. General and Head satisfaction estimates were not significantly different to control samples, whilst Body Satisfaction was increased for women with disabilities. None of the body satisfaction measures were related to the sexual functioning measure. General dissatisfaction was associated depression. Both anxiety and depression were experienced by the same individuals, and anxiety related to current sexual dysfunction. Qualitative data supported previous findings concerning the effects of social and attitudinal barriers on sexual functioning.

Blood-brain Barrier Disruption Leads to Postoperative Cognitive Dysfunction.

PubMed

Wang, Bin; Li, Siyuan; Cao, Xipeng; Dou, Xinghui; Li, Jingzhu; Wang, Ling; Wang, Mingshan; Bi, Yanlin

2017-01-01

Postoperative Cognitive Dysfunction (POCD) has received considerable attention as one of the main postoperative complications. The underlying mechanism of POCD in elderly subjects has not been fully elucidated to date. The Central Nervous System (CNS) is isolated from the bloodstream by the Blood Brain Barrier (BBB) that consists of endothelial cells, capillary blood vessels and tight junctions. The tight junctions carry out significant biological functions that are associated with the CNS and blood circulation. In this review, I present a hypothesis that blood-brain barrier disruption leads to postoperative cognitive dysfunction. A total of 81 healthy male Wistar rats were used for the present study. All the experimental animals were randomly divided into 3 groups: normal control group, isoflurane group and splenectomy group. The control group was not subjected to any form of treatment. The rats in isoflurane group were given 1.5-2% isoflurane under intubation and mechanical ventilation. The rats in splenectomy group underwent splenectomy under the same anesthesia as the isoflurane group. The Morris water maze was used to examine the learning and memory ability of the animals. The expression of the Tight Junctions Proteins (TJPs) in the hippocampus was analyzed using Western blotting. The concentration of Evans Blue (EB) in the supernatant was analyzed using UV spectroscopy. Ultrastructure changes in the basal laminas, the Tight Junctions (TJs), mitochondria and the endoplasmic reticulum surrounding the capillaries were assessed by Transmission Electron Microscopy (TEM). Following splenectomy, the rats displayed concomitant significant cognitive deficits in the Morris water maze test. Taken together, the results indicate that the expression levels of occludin (65KD) following splenectomy were reduced on days one and three in aged rats. No significant difference was noted in the expression levels of claudin-5, except for a reduction after surgery on day one. The leakage of EB was higher following splenectomy than control group and isoflurane group. The ultrastructure of the neurovascular unit was monitored on the day prior to surgery and on the 1st, 3rd and 7th day following surgery using a transmission electronmicroscope. The alterations in the levels of tight junction proteins following splenectomy may contribute to the BBB permeability increase, which in turn will induce postoperative cognitive dysfunction. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Dimethyl sulfoxide inhibits zymosan-induced intestinal inflammation and barrier dysfunction

PubMed Central

Li, Yu-Meng; Wang, Hai-Bin; Zheng, Jin-Guang; Bai, Xiao-Dong; Zhao, Zeng-Kai; Li, Jing-Yuan; Hu, Sen

2015-01-01

AIM: To investigate whether dimethyl sulfoxide (DMSO) inhibits gut inflammation and barrier dysfunction following zymosan-induced systemic inflammatory response syndrome and multiple organ dysfunction syndrome. METHODS: Sprague-Dawley rats were randomly divided into four groups: sham with administration of normal saline (SS group); sham with administration of DMSO (SD group); zymosan with administration of normal saline (ZS group); and zymosan with administration of DMSO (ZD group). Each group contained three subgroups according to 4 h, 8 h, and 24 h after surgery. At 4 h, 8 h, and 24 h after intraperitoneal injection of zymosan (750 mg/kg), the levels of intestinal inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-10] and oxides (myeloperoxidase, malonaldehyde, and superoxide dismutase) were examined. The levels of diamine oxidase (DAO) in plasma and intestinal mucosal blood flow (IMBF) were determined. Intestinal injury was also evaluated using an intestinal histological score and apoptosis of intestinal epithelial cells was determined by deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The intestinal epithelial tight junction protein, ZO-1, was observed by immunofluorescence. RESULTS: DMSO decreased TNF-α and increased IL-10 levels in the intestine compared with the ZS group at the corresponding time points. The activity of intestinal myeloperoxidase in the ZS group was higher than that in the ZD group 24 h after zymosan administration (P < 0.05). DMSO decreased the content of malondialdehyde (MDA) and increased the activity of superoxide dehydrogenase (SOD) 24 h after zymosan administration. The IMBF was lowest at 24 h and was 49.34% and 58.26% in the ZS group and ZD group, respectively (P < 0.05). DMSO alleviated injury in intestinal villi, and the gut injury score was significantly lower than the ZS group (3.6 ± 0.2 vs 4.2 ± 0.3, P < 0.05). DMSO decreased the level of DAO in plasma compared with the ZS group (65.1 ± 4.7 U/L vs 81.1 ± 5.0 U/L, P < 0.05). DMSO significantly preserved ZO-1 protein expression and localization 24 h after zymosan administration. The TUNEL analysis indicated that the number of apoptotic intestinal cells in the ZS group was much higher than the ZD group (P < 0.05). CONCLUSION: DMSO inhibited intestinal cytokines and protected against zymosan-induced gut barrier dysfunction. PMID:26478676

Dimethyl sulfoxide inhibits zymosan-induced intestinal inflammation and barrier dysfunction.

PubMed

Li, Yu-Meng; Wang, Hai-Bin; Zheng, Jin-Guang; Bai, Xiao-Dong; Zhao, Zeng-Kai; Li, Jing-Yuan; Hu, Sen

2015-10-14

To investigate whether dimethyl sulfoxide (DMSO) inhibits gut inflammation and barrier dysfunction following zymosan-induced systemic inflammatory response syndrome and multiple organ dysfunction syndrome. Sprague-Dawley rats were randomly divided into four groups: sham with administration of normal saline (SS group); sham with administration of DMSO (SD group); zymosan with administration of normal saline (ZS group); and zymosan with administration of DMSO (ZD group). Each group contained three subgroups according to 4 h, 8 h, and 24 h after surgery. At 4 h, 8 h, and 24 h after intraperitoneal injection of zymosan (750 mg/kg), the levels of intestinal inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-10] and oxides (myeloperoxidase, malonaldehyde, and superoxide dismutase) were examined. The levels of diamine oxidase (DAO) in plasma and intestinal mucosal blood flow (IMBF) were determined. Intestinal injury was also evaluated using an intestinal histological score and apoptosis of intestinal epithelial cells was determined by deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The intestinal epithelial tight junction protein, ZO-1, was observed by immunofluorescence. DMSO decreased TNF-α and increased IL-10 levels in the intestine compared with the ZS group at the corresponding time points. The activity of intestinal myeloperoxidase in the ZS group was higher than that in the ZD group 24 h after zymosan administration (P < 0.05). DMSO decreased the content of malondialdehyde (MDA) and increased the activity of superoxide dehydrogenase (SOD) 24 h after zymosan administration. The IMBF was lowest at 24 h and was 49.34% and 58.26% in the ZS group and ZD group, respectively (P < 0.05). DMSO alleviated injury in intestinal villi, and the gut injury score was significantly lower than the ZS group (3.6 ± 0.2 vs 4.2 ± 0.3, P < 0.05). DMSO decreased the level of DAO in plasma compared with the ZS group (65.1 ± 4.7 U/L vs 81.1 ± 5.0 U/L, P < 0.05). DMSO significantly preserved ZO-1 protein expression and localization 24 h after zymosan administration. The TUNEL analysis indicated that the number of apoptotic intestinal cells in the ZS group was much higher than the ZD group (P < 0.05). DMSO inhibited intestinal cytokines and protected against zymosan-induced gut barrier dysfunction.

Is cerebral glucose metabolism related to blood-brain barrier dysfunction and intrathecal IgG synthesis in Alzheimer disease?: A 18F-FDG PET/CT study.

PubMed

Chiaravalloti, Agostino; Fiorentini, Alessandro; Ursini, Francesco; Martorana, Alessandro; Koch, Giacomo; Belli, Lorena; Toniolo, Sofia; Di Pietro, Barbara; Motta, Caterina; Schillaci, Orazio

2016-09-01

The aim of this study was to investigate the relationships between blood-brain barrier (BBB) dysfunction, intrathecal IgG synthesis, and brain glucose consumption as detectable by means of serum/cerebrospinal fluid (CSF) albumin index (Qalb) and IgG index [(CSF IgG/serum IgG) × Serum albumin/CSF albumin)] and 2-deoxy-2-(F) fluoro-D-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT) in a selected population affected by Alzheimer disease (AD). The study included 134 newly diagnosed AD patients according to the NINCDS-ADRDA criteria. The mean (±SD) age of the patients was 70 (±6) years; 60 were male and 64 were female. Mini mental State Examination was equal to 18.9 (±7.2). All patients underwent a CSF assay and magnetic resonance before F-FDG PET scanning. The relationships were evaluated by means of statistical parametric mapping (SPM8). We found a significant negative correlation between the increase of Qalb and F-FDG uptake in the Brodmann Area 42 and 22 that corresponds to the left superior temporal gyrus, with higher Qalb values being related to a reduced glucose consumption in these areas. No significant relationships have been found between brain glucose consumption and IgG index. The results of our study suggest that BBB dysfunction is related to reduction of cortical activity in the left temporal cortex in AD subjects.

Dietary glutamine and oral antibiotics each improve indexes of gut barrier function in rat short bowel syndrome.

PubMed

Tian, Junqiang; Hao, Li; Chandra, Prakash; Jones, Dean P; Willams, Ifor R; Gewirtz, Andrew T; Ziegler, Thomas R

2009-02-01

Short bowel syndrome (SBS) is associated with gut barrier dysfunction. We examined effects of dietary glutamine (GLN) or oral antibiotics (ABX) on indexes of gut barrier function in a rat model of SBS. Adult rats underwent a 60% distal small bowel + proximal colonic resection (RX) or bowel transection (TX; control). Rats were pair fed diets with or without l-GLN for 20 days after operation. Oral ABX (neomycin, metronidazole, and polymyxin B) were given in some RX rats fed control diet. Stool secretory immunoglobulin A (sIgA) was measured serially. On day 21, mesenteric lymph nodes (MLN) were cultured for gram-negative bacteria. IgA-positive plasma cells in jejunum, stool levels of flagellin- and lipopolysaccharide (LPS)-specific sIgA, and serum total, anti-flagellin- and anti-LPS IgG levels were determined. RX caused gram-negative bacterial translocation to MLN, increased serum total and anti-LPS IgG and increased stool total sIgA. After RX, dietary GLN tended to blunt bacterial translocation to MLN (-29%, P = NS) and significantly decreased anti-LPS IgG levels in serum, increased both stool and jejunal mucosal sIgA and increased stool anti-LPS-specific IgA. Oral ABX eliminated RX-induced bacterial translocation, significantly decreased total and anti-LPS IgG levels in serum, significantly decreased stool total IgA and increased stool LPS-specific IgA. Partial small bowel-colonic resection in rats is associated with gram-negative bacterial translocation from the gut and a concomitant adaptive immune response to LPS. These indexes of gut barrier dysfunction are ameliorated or blunted by administration of dietary GLN or oral ABX, respectively. Dietary GLN upregulates small bowel sIgA in this model.

Rhinovirus Delays Cell Repolarization in a Model of Injured/Regenerating Human Airway Epithelium

PubMed Central

Faris, Andrea N.; Ganesan, Shyamala; Chattoraj, Asamanja; Chattoraj, Sangbrita S.; Comstock, Adam T.; Unger, Benjamin L.; Hershenson, Marc B.

2016-01-01

Rhinovirus (RV), which causes exacerbation in patients with chronic airway diseases, readily infects injured airway epithelium and has been reported to delay wound closure. In this study, we examined the effects of RV on cell repolarization and differentiation in a model of injured/regenerating airway epithelium (polarized, undifferentiated cells). RV causes only a transient barrier disruption in a model of normal (mucociliary-differentiated) airway epithelium. However, in the injury/regeneration model, RV prolongs barrier dysfunction and alters the differentiation of cells. The prolonged barrier dysfunction caused by RV was not a result of excessive cell death but was instead associated with epithelial-to-mesenchymal transition (EMT)-like features, such as reduced expression of the apicolateral junction and polarity complex proteins, E-cadherin, occludin, ZO-1, claudins 1 and 4, and Crumbs3 and increased expression of vimentin, a mesenchymal cell marker. The expression of Snail, a transcriptional repressor of tight and adherence junctions, was also up-regulated in RV-infected injured/regenerating airway epithelium, and inhibition of Snail reversed RV-induced EMT-like features. In addition, compared with sham-infected cells, the RV-infected injured/regenerating airway epithelium showed more goblet cells and fewer ciliated cells. Inhibition of epithelial growth factor receptor promoted repolarization of cells by inhibiting Snail and enhancing expression of E-cadherin, occludin, and Crumbs3 proteins, reduced the number of goblet cells, and increased the number of ciliated cells. Together, these results suggest that RV not only disrupts barrier function, but also interferes with normal renewal of injured/regenerating airway epithelium by inducing EMT-like features and subsequent goblet cell hyperplasia. PMID:27119973

Synergistic efficacy of γ-radiation together with gallium trichloride and/or doxorubicin against Ehrlich carcinoma in female mice.

PubMed

Kandil, Eman; Aziz, Nahed Abdel

2016-02-01

Combining chemotherapy with radiotherapy represents a key oncology strategy for a more comprehensive attack toward cancers and improves treatment outcome for various solid tumor malignancies. The present study aims to evaluate the synergistic antitumor effect of γ-radiation together with gallium trichloride (GaCl3) and/or doxorubicin (DOX) against solid Ehrlich carcinoma (EC) in female mice. GaCl3 (300 mg/kg body weight (b.w.)) was administered by gavages daily on the seventh day after tumor inoculation, while the cytotoxic drug DOX (4 mg/kg b.w.) was administered intraperitoneally once a week. Whole-body γ-radiation was carried out at a dose 2 Gy once a week. Biochemical analysis showed that solid EC induced a significant increase in malondialdehyde (MDA) content with a significant decrease in the antioxidant state (glutathione peroxidase (GPx) and catalase (CAT) activities) and depleted serum iron concentration compared to normal control. Moreover, a significant increase was observed in calcium level and caspase-3 concentrations in both serum and tumor homogenate respectively associated with a significant alteration in heart, liver, and kidney functions, as compared to control. Treatment of EC-bearing mice with GaCl3and/or DOX combined with γ-radiation exposure significantly reduced tumor volume and displayed a significant improvement in most studied markers which may indicate a synergistic effect of this combination against organ dysfunction and cellular injury. The histopathologically investigation showed that treatment of animals bearing EC with GaCl3and/or DOX with γ-radiation exposure showed shrinkage in tumor lesions and wide zones of apoptotic cells with signs of regenerations. It was concluded that the combination of GaCl3and/or DOX with γ-radiation exposure resulted in super-additive cytotoxic effects on treatment of cancer cells.

Neocortical Transplants in the Mammalian Brain Lack a Blood-Brain Barrier to Macromolecules

NASA Astrophysics Data System (ADS)

Rosenstein, Jeffrey M.

1987-02-01

In order to determine whether the blood-brain barrier was present in transplants of central nervous tissue, fetal neocortex, which already possesses blood-brain and blood-cerebrospinal fluid barriers to protein, was grafted into the undamaged fourth ventricle or directly into the neocortex of recipient rats. Horseradish peroxidase or a conjugated human immunoglobulin G-peroxidase molecule was systemically administered into the host. These proteins were detected within the cortical transplants within 2 minutes regardless of the age of the donor or postoperative time. At later times these compounds, which normally do not cross the blood-brain barrier, inundated the grafts and adjacent host brain and also entered the cerebrospinal fluid. Endogenous serum albumin detected immunocytochemically in untreated hosts had a comparable although less extensive distribution. Thus, transplants of fetal central nervous tissue have permanent barrier dysfunction, probably due to microvascular changes, and are not integrated physiologically within the host. Blood-borne compounds, either systemically administered or naturally occurring, which should never contact normal brain tissue, have direct access to these transplants and might affect neuronal function.

Abnormal Barrier Function in Gastrointestinal Disorders.

PubMed

Farré, Ricard; Vicario, María

2017-01-01

There is increasing concern in identifying the mechanisms underlying the intimate control of the intestinal barrier, as deregulation of its function is strongly associated with digestive (organic and functional) and a number of non-digestive (schizophrenia, diabetes, sepsis, among others) disorders. The intestinal barrier is a complex and effective defensive functional system that operates to limit luminal antigen access to the internal milieu while maintaining nutrient and electrolyte absorption. Intestinal permeability to substances is mainly determined by the physicochemical properties of the barrier, with the epithelium, mucosal immunity, and neural activity playing a major role. In functional gastrointestinal disorders (FGIDs), the absence of structural or biochemical abnormalities that explain chronic symptoms is probably close to its end, as recent research is providing evidence of structural gut alterations, at least in certain subsets, mainly in functional dyspepsia (FD) and irritable bowel syndrome (IBS). These alterations are associated with increased permeability, which seems to reflect mucosal inflammation and neural activation. The participation of each anatomical and functional component of barrier function in homeostasis and intestinal dysfunction is described, with a special focus on FGIDs.

Endocannabinoids as a Target for the Treatment of Traumatic Brain Injury

DTIC Science & Technology

2013-11-01

COVERED 4 October 201 - 3 October 201 4. TITLE AND SUBTITLE Endocannabinoids as a Target for the Treatment of Traumatic Brain Injury 5a. CONTRACT...injury, blood brain barrier, neuroinflammation, neurological dysfunction, endocannabinoids Table of Contents Introduction...promote neuroinflammation and potentially lead to neurodegeneration. We have previously demonstrated that treatments to the endocannabinoid system 2

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)

A stable and reproducible human blood-brain barrier model derived from hematopoietic stem cells.

PubMed

Cecchelli, Romeo; Aday, Sezin; Sevin, Emmanuel; Almeida, Catarina; Culot, Maxime; Dehouck, Lucie; Coisne, Caroline; Engelhardt, Britta; Dehouck, Marie-Pierre; Ferreira, Lino

2014-01-01

The human blood brain barrier (BBB) is a selective barrier formed by human brain endothelial cells (hBECs), which is important to ensure adequate neuronal function and protect the central nervous system (CNS) from disease. The development of human in vitro BBB models is thus of utmost importance for drug discovery programs related to CNS diseases. Here, we describe a method to generate a human BBB model using cord blood-derived hematopoietic stem cells. The cells were initially differentiated into ECs followed by the induction of BBB properties by co-culture with pericytes. The brain-like endothelial cells (BLECs) express tight junctions and transporters typically observed in brain endothelium and maintain expression of most in vivo BBB properties for at least 20 days. The model is very reproducible since it can be generated from stem cells isolated from different donors and in different laboratories, and could be used to predict CNS distribution of compounds in human. Finally, we provide evidence that Wnt/β-catenin signaling pathway mediates in part the BBB inductive properties of pericytes.

[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.

CD40-CD40 Ligand Pathway is a Major Component of Acute Neuroinflammation and Contributes to Long-term Cognitive Dysfunction after Sepsis.

PubMed

Michels, Monique; Danieslki, Lucinéia Gainski; Vieira, Andriele; Florentino, Drielly; Dall'Igna, Dhébora; Galant, Letícia; Sonai, Beatriz; Vuolo, Francieli; Mina, Franciele; Pescador, Bruna; Dominguini, Diogo; Barichello, Tatiana; Quevedo, João; Dal-Pizzol, Felipe; Petronilho, Fabrícia

2015-03-26

Sepsis-associated encephalopathy (SAE) is associated with an increased rate of morbidity and mortality. It is not understood what the exact mechanism is for the brain dysfunction that occurs in septic patients, but brain inflammation and oxidative stress are a possible theory. Such events can occur through the alteration of molecules that perpetuate the inflammatory response. Thus, it is possible to postulate that CD40 may be involved in this process. The aim of this work is to evaluate the role of CD40-CD40L pathway activation in brain dysfunction associated with sepsis in an animal model. Microglia activation induces the upregulation of CD40-CD40L, both in vitro and in vivo. The inhibition of microglia activation decreases levels of CD40-CD40L in the brain and decreases brain inflammation, oxidative damage and blood brain barrier dysfunction. Despite this, anti-CD40 treatment does not improve mortality in this model. However, it is able to improve long-term cognitive impairment in sepsis survivors. In conclusion, there is a major involvement of the CD40-CD40L signaling pathway in long-term brain dysfunction in an animal model of sepsis.

CD40–CD40 Ligand Pathway Is a Major Component of Acute Neuroinflammation and Contributes to Long-term Cognitive Dysfunction after Sepsis

PubMed Central

Michels, Monique; Danieslki, Lucinéia Gainski; Vieira, Andriele; Florentino, Drielly; Dall’Igna, Dhébora; Galant, Letícia; Sonai, Beatriz; Vuolo, Francieli; Mina, Franciele; Pescador, Bruna; Dominguini, Diogo; Barichello, Tatiana; Quevedo, João; Dal-Pizzol, Felipe; Petronilho, Fabrícia

2015-01-01

Sepsis-associated encephalopathy (SAE) is associated with an increased rate of morbidity and mortality. It is not understood what the exact mechanism is for the brain dysfunction that occurs in septic patients, but brain inflammation and oxidative stress are a possible theory. Such events can occur through the alteration of molecules that perpetuate the inflammatory response. Thus, it is possible to postulate that CD40 may be involved in this process. The aim of this work is to evaluate the role of CD40–CD40L pathway activation in brain dysfunction associated with sepsis in an animal model. Microglia activation induces the upregulation of CD40–CD40L, both in vitro and in vivo. The inhibition of microglia activation decreases levels of CD40–CD40L in the brain and decreases brain inflammation, oxidative damage and blood brain barrier dysfunction. Despite this, anti-CD40 treatment does not improve mortality in this model. However, it is able to improve long-term cognitive impairment in sepsis survivors. In conclusion, there is a major involvement of the CD40–CD40L signaling pathway in long-term brain dysfunction in an animal model of sepsis. PMID:25822797

Provision of contraception after emergency contraception from the pharmacy: evaluating the acceptability of pharmacy for providing sexual and reproductive health services.

PubMed

Michie, L; Cameron, S T; Glasier, A; Chen, Z E; Milne, D; Wilson, S

2016-06-01

Community pharmacies in the United Kingdom (UK) provide sexual and reproductive health (SRH) services such as emergency contraception (EC), although there is scope for provision of additional services. We conducted a pilot study of pharmacy based interventions for initiating effective contraception after EC. By determining the views of participating women and pharmacists we aimed to identify barriers and facilitators to providing interventions from pharmacies routinely. In the pilot study, women presenting for levonorgestrel EC to community pharmacies, were provided with either standard care or one of two interventions: one packet of progestogen-only pills (POPs); or an invitation to present the empty EC packet to a local family planning clinic for contraception. A sample of women participating were asked to undergo a further interview. Operational difficulties with research in the community pharmacy were also documented by the research team. Semi-structured interviews were conducted with 12 women, four from each arm of the pilot study, using a standardised topic guide. Pre- and post-study interviews were conducted with the pharmacists involved. All women welcomed the interventions indicating the benefit of having different options available. They also identified possible advantages and disadvantages of each intervention. All pharmacists were positive about their involvement in the study. Methodological problems included difficulty in retention of participating pharmacists, slow recruitment and failure to accurately complete study paperwork. Women welcomed the interventions offered. Pharmacists viewed their participation in the study positively. The problems encountered provide valuable feedback to inform the development larger scale studies of such interventions. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Enhanced Re-Endothelialization of Decellularized Rat Lungs

PubMed Central

Stabler, Collin T.; Caires, Luiz C.; Mondrinos, Mark J.; Marcinkiewicz, Cezary; Lazarovici, Philip; Wolfson, Marla R.

2016-01-01

Decellularized lung tissue has been recognized as a potential platform to engineer whole lung organs suitable for transplantation or for modeling a variety of lung diseases. However, many technical hurdles remain before this potential may be fully realized. Inability to efficiently re-endothelialize the pulmonary vasculature with a functional endothelium appears to be the primary cause of failure of recellularized lung scaffolds in early transplant studies. Here, we present an optimized approach for enhanced re-endothelialization of decellularized rodent lung scaffolds with rat lung microvascular endothelial cells (ECs). This was achieved by adjusting the posture of the lung to a supine position during cell seeding through the pulmonary artery. The supine position allowed for significantly more homogeneous seeding and better cell retention in the apex regions of all lobes than the traditional upright position, especially in the right upper and left lobes. Additionally, the supine position allowed for greater cell retention within large diameter vessels (proximal 100–5000 μm) than the upright position, with little to no difference in the small diameter distal vessels. EC adhesion in the proximal regions of the pulmonary vasculature in the decellularized lung was dependent on the binding of EC integrins, specifically α1β1, α2β1, and α5β1 integrins to, respectively, collagen type-I, type-IV, and fibronectin in the residual extracellular matrix. Following in vitro maturation of the seeded constructs under perfusion culture, the seeded ECs spread along the vascular wall, leading to a partial reestablishment of endothelial barrier function as inferred from a custom-designed leakage assay. Our results suggest that attention to cellular distribution within the whole organ is of paramount importance for restoring proper vascular function. PMID:26935764

Epithelial-mesenchymal transition and nuclear β-catenin induced by conditional intestinal disruption of Cdh1 with Apc is E-cadherin EC1 domain dependent

PubMed Central

Carter, Emma J.; Barnes, David; Hoppe, Hans-Jürgen; Hughes, Jennifer; Cobbold, Stephen; Harper, James; Morreau, Hans; Surakhy, Mirvat; Hassan, A. Bassim

2016-01-01

Two important protein-protein interactions establish E-cadherin (Cdh1) in the adhesion complex; homophilic binding via the extra-cellular (EC1) domain and cytoplasmic tail binding to β-catenin. Here, we evaluate whether E-cadherin binding can inhibit β-catenin when there is loss of Adenomatous polyposis coli (APC) from the β-catenin destruction complex. Combined conditional loss of Cdh1 and Apc were generated in the intestine, intestinal adenoma and adenoma organoids. Combined intestinal disruption (Cdh1fl/flApcfl/flVil-CreERT2) resulted in lethality, breakdown of the intestinal barrier, increased Wnt target gene expression and increased nuclear β-catenin localization, suggesting that E-cadherin inhibits β-catenin. Combination with an intestinal stem cell Cre (Lgr5CreERT2) resulted in ApcΔ/Δ recombination and adenoma, but intact Cdh1fl/fl alleles. Cultured ApcΔ/ΔCdh1fl/fl adenoma cells infected with adenovirus-Cre induced Cdh1fl/fl recombination (Cdh1Δ/Δ), disruption of organoid morphology, nuclear β-catenin localization, and cells with an epithelial-mesenchymal phenotype. Complementation with adenovirus expressing wild-type Cdh1 (Cdh1-WT) rescued adhesion and β-catenin membrane localization, yet an EC1 specific double mutant defective in homophilic adhesion (Cdh1-MutW2A, S78W) did not. These data suggest that E-cadherin inhibits β-catenin in the context of disruption of the APC-destruction complex, and that this function is also EC1 domain dependent. Both binding functions of E-cadherin may be required for its tumour suppressor activity. PMID:27566565

In Vitro Efficacy of Ebselen and BAY 11-7082 Against Naegleria fowleri

PubMed Central

Debnath, Anjan; Nelson, Andrew T.; Silva-Olivares, Angélica; Shibayama, Mineko; Siegel, Dionicio; McKerrow, James H.

2018-01-01

Primary amebic meningoencephalitis (PAM) is a fatal infection caused by the free-living ameba Naegleria fowleri, popularly known as the “brain-eating ameba.” The drugs of choice in treating PAM are the antifungal amphotericin B and an antileishmanial miltefosine, but these are not FDA-approved for this indication and use of amphotericin B is associated with severe adverse effects. Moreover, very few patients treated with the combination therapy have survived PAM. Therefore, development of efficient drugs is a critical unmet need to avert future deaths of children. Since N. fowleri causes extensive inflammation in the brain it is important to select compounds that can enter brain to kill ameba. In this study, we identified two central nervous system (CNS) active compounds, ebselen and BAY 11-7082 as amebicidal with EC50 of 6.2 and 1.6 μM, respectively. The closely related BAY 11-7085 was also found active against N. fowleri with EC50 similar to BAY 11-7082. We synthesized a soluble ebselen analog, which had amebicidal activity similar to ebselen. Transmission electron microscopy of N. fowleri trophozoites incubated for 48 h with EC50 concentration of ebselen showed alteration in the cytoplasmic membrane, loss of the nuclear membrane, and appearance of electron-dense granules. Incubation of N. fowleri trophozoites with EC50 concentrations of BAY 11-7082 and BAY 11-7085 for 48 h showed the presence of large lipid droplets in the cytoplasm, disruption of cytoplasmic and nuclear membranes and appearance of several vesicles and chromatin residues. Blood-brain barrier permeable amebicidal compounds have potential as new drug leads for Naegleria infection. PMID:29559968

Preconditioning with Endoplasmic Reticulum Stress Ameliorates Endothelial Cell Inflammation

PubMed Central

Leonard, Antony; Paton, Adrienne W.; El-Quadi, Monaliza; Paton, James C.; Fazal, Fabeha

2014-01-01

Endoplasmic Reticulum (ER) stress, caused by disturbance in ER homeostasis, has been implicated in several pathological conditions such as ischemic injury, neurodegenerative disorders, metabolic diseases and more recently in inflammatory conditions. Our present study aims at understanding the role of ER stress in endothelial cell (EC) inflammation, a critical event in the pathogenesis of acute lung injury (ALI). We found that preconditioning human pulmonary artery endothelial cells (HPAEC) to ER stress either by depleting ER chaperone and signaling regulator BiP using siRNA, or specifically cleaving (inactivating) BiP using subtilase cytotoxin (SubAB), alleviates EC inflammation. The two approaches adopted to abrogate BiP function induced ATF4 protein expression and the phosphorylation of eIF2α, both markers of ER stress, which in turn resulted in blunting the activation of NF-κB, and restoring endothelial barrier integrity. Pretreatment of HPAEC with BiP siRNA inhibited thrombin-induced IκBα degradation and its resulting downstream signaling pathway involving NF-κB nuclear translocation, DNA binding, phosphorylation at serine536, transcriptional activation and subsequent expression of adhesion molecules. However, TNFα-mediated NF-κB signaling was unaffected upon BiP knockdown. In an alternative approach, SubAB-mediated inactivation of NF-κB was independent of IκBα degradation. Mechanistic analysis revealed that pretreatment of EC with SubAB interfered with the binding of the liberated NF-κB to the DNA, thereby resulting in reduced expression of adhesion molecules, cytokines and chemokines. In addition, both knockdown and inactivation of BiP stimulated actin cytoskeletal reorganization resulting in restoration of endothelial permeability. Together our studies indicate that BiP plays a central role in EC inflammation and injury via its action on NF-κB activation and regulation of vascular permeability. PMID:25356743

Preconditioning with endoplasmic reticulum stress ameliorates endothelial cell inflammation.

PubMed

Leonard, Antony; Paton, Adrienne W; El-Quadi, Monaliza; Paton, James C; Fazal, Fabeha

2014-01-01

Endoplasmic Reticulum (ER) stress, caused by disturbance in ER homeostasis, has been implicated in several pathological conditions such as ischemic injury, neurodegenerative disorders, metabolic diseases and more recently in inflammatory conditions. Our present study aims at understanding the role of ER stress in endothelial cell (EC) inflammation, a critical event in the pathogenesis of acute lung injury (ALI). We found that preconditioning human pulmonary artery endothelial cells (HPAEC) to ER stress either by depleting ER chaperone and signaling regulator BiP using siRNA, or specifically cleaving (inactivating) BiP using subtilase cytotoxin (SubAB), alleviates EC inflammation. The two approaches adopted to abrogate BiP function induced ATF4 protein expression and the phosphorylation of eIF2α, both markers of ER stress, which in turn resulted in blunting the activation of NF-κB, and restoring endothelial barrier integrity. Pretreatment of HPAEC with BiP siRNA inhibited thrombin-induced IκBα degradation and its resulting downstream signaling pathway involving NF-κB nuclear translocation, DNA binding, phosphorylation at serine536, transcriptional activation and subsequent expression of adhesion molecules. However, TNFα-mediated NF-κB signaling was unaffected upon BiP knockdown. In an alternative approach, SubAB-mediated inactivation of NF-κB was independent of IκBα degradation. Mechanistic analysis revealed that pretreatment of EC with SubAB interfered with the binding of the liberated NF-κB to the DNA, thereby resulting in reduced expression of adhesion molecules, cytokines and chemokines. In addition, both knockdown and inactivation of BiP stimulated actin cytoskeletal reorganization resulting in restoration of endothelial permeability. Together our studies indicate that BiP plays a central role in EC inflammation and injury via its action on NF-κB activation and regulation of vascular permeability.

Neurocognitive deficits as a barrier to psychosocial function in schizophrenia: effects on learning, coping, & self-concept.

PubMed

Lysaker, Paul H; Buck, Kelly D

2007-07-01

Recently, research has linked deficits in neurocognition, which emerge early in schizophrenia, with psychosocial impairments. However, it is uncertain how these deficits lead to sustained dysfunction. In this review, we explore how neurocognitive deficits could disrupt function at three levels: learning, coping preference, and self-concept. We offer a model in which neurocognitive impairment may directly limit skills acquisition and the development of a rich personal narrative. We suggest that both limited skills acquisition and an impoverished narrative may subsequently feed into a habitual style of avoidant coping, leading to a cycle of sustained dysfunction. Implications for cognitive, rehabilitation, and psychotherapeutic interventions are discussed.

Evaluation of Barrier Treatments on Native Vegetation in a Southern California Desert Habitat

DTIC Science & Technology

2009-01-01

B . LOTHROP,3 MELISSA SNELLING,3 ARTURO GUTIERREZ3 AND HUGH D...OF PAGES 10 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b . ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev...treatment of artificial surfacesT a b le 2 . C u le x ta rs a li s co ll ec te d in m o sq u it o tr a p s in th e 9 st u d y p lo ts . C o u n ts a

GPR55 agonist lysophosphatidylinositol and lysophosphatidylcholine inhibit endothelial cell hyperpolarization via GPR-independent suppression of Na+-Ca2+ exchanger and endoplasmic reticulum Ca2+ refilling.

PubMed

Bondarenko, Alexander I; Montecucco, Fabrizio; Panasiuk, Olga; Sagach, Vadim; Sidoryak, Nataliya; Brandt, Karim J; Mach, François

2017-02-01

Lysophosphatidylinositol (LPI) and lysophosphatidylcholine (LPC) are lipid signaling molecules that induce endothelium-dependent vasodilation. In addition, LPC suppresses acetylcholine (Ach)-induced responses. We aimed to determine the influence of LPC and LPI on hyperpolarizing responses in vitro and in situ endothelial cells (EC) and identify the underlying mechanisms. Using patch-clamp method, we show that LPI and LPC inhibit EC hyperpolarization to histamine and suppress Na + /Ca 2+ exchanged (NCX) currents in a concentration-dependent manner. The inhibition is non-mode-specific and unaffected by intracellular GDPβS infusion and tempol, a superoxide dismutase mimetic. In excised mouse aorta, LPI strongly inhibits the sustained and the peak endothelial hyperpolarization induced by Ach, but not by SKA-31, an opener of Ca 2+ -dependent K + channels of intermediate and small conductance. The hyperpolarizing responses to consecutive histamine applications are strongly reduced by NCX inhibition. In a Ca 2+ -re-addition protocol, bepridil, a NCX inhibitor, and KB-R7943, a blocker of reversed NCX, inhibit the hyperpolarizing responses to Ca 2+ -re-addition following Ca 2+ stores depletion. These finding indicate that LPC and LPI inhibit endothelial hyperpolarization to Ach and histamine independently of G-protein coupled receptors and superoxide anions. Reversed NCX is critical for ER Ca 2+ refilling in EC. The inhibition of NCX by LPI and LPC underlies diminished endothelium-dependent responses and endothelial dysfunction accompanied by increased levels of these lipids in the blood. Copyright © 2017 Elsevier Inc. All rights reserved.

Brain structure and verbal function across adulthood while controlling for cerebrovascular risks.

PubMed

Sanfratello, L; Lundy, S L; Qualls, C; Knoefel, J E; Adair, J C; Caprihan, A; Stephen, J M; Aine, C J

2017-04-08

The development and decline of brain structure and function throughout adulthood is a complex issue, with cognitive aging trajectories influenced by a host of factors including cerebrovascular risk. Neuroimaging studies of age-related cognitive decline typically reveal a linear decrease in gray matter (GM) volume/density in frontal regions across adulthood. However, white matter (WM) tracts mature later than GM, particularly in regions necessary for executive functions and memory. Therefore, it was predicted that a middle-aged group (MC: 35-45 years) would perform best on a verbal working memory task and reveal greater regional WM integrity, compared with both young (YC: 18-25 years) and elder groups (EC: 60+ years). Diffusion tensor imaging (DTI) and magnetoencephalography (MEG) were obtained from 80 healthy participants. Objective measures of cerebrovascular risk and cognition were also obtained. As predicted, MC revealed best verbal working memory accuracy overall indicating some maturation of brain function between YC and MC. However, contrary to the prediction fractional anisotropy values (FA), a measure of WM integrity, were not greater in MC (i.e., there were no significant differences in FA between YC and MC but both groups showed greater FA than EC). An overall multivariate model for MEG ROIs showed greater peak amplitudes for MC and YC, compared with EC. Subclinical cerebrovascular risk factors (systolic blood pressure and blood glucose) were negatively associated with FA in frontal callosal, limbic, and thalamic radiation regions which correlated with executive dysfunction and slower processing speed, suggesting their contribution to age-related cognitive decline. Hum Brain Mapp, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

N-methyl-D-aspartate receptor antagonist effects on prefrontal cortical connectivity better model early than chronic schizophrenia.

PubMed

Anticevic, Alan; Corlett, Philip R; Cole, Michael W; Savic, Aleksandar; Gancsos, Mark; Tang, Yanqing; Repovs, Grega; Murray, John D; Driesen, Naomi R; Morgan, Peter T; Xu, Ke; Wang, Fei; Krystal, John H

2015-03-15

Prefrontal cortex (PFC) function contributes to schizophrenia onset and progression. However, little is known about neural mechanisms behind PFC functional alterations along illness stages. Recent pharmacologic studies indicate that glutamate dysfunction may produce increased functional connectivity. However, pharmacologic models of schizophrenia overlook effects of illness progression on PFC function. This study compared N-methyl-D-aspartate glutamate receptor (NMDAR) antagonist effects in healthy volunteers with stages of schizophrenia with respect to PFC functional connectivity. First, we tested ketamine effects on PFC functional connectivity in healthy volunteers in a data-driven way (n = 19). Next, we compared healthy subjects (n = 96) with three clinical groups: individuals at high risk for schizophrenia (n = 21), people early in their course of schizophrenia (EC-SCZ) (n = 28), and patients with chronic illness (n = 20). Across independent analyses, we used data-driven global brain connectivity techniques restricted to PFC to identify functional dysconnectivity. Results revealed robust PFC hyperconnectivity in healthy volunteers administered ketamine (Cohen's d = 1.46), resembling individuals at high risk for schizophrenia and EC-SCZ. Hyperconnectivity was not found in patients with chronic illness relative to EC-SCZ patients. Results provide the first evidence that ketamine effects on PFC functional connectivity resemble early course but not chronic schizophrenia. Results suggest an illness phase-specific relevance of NMDAR antagonist administration for prefrontal dysconnectivity associated with schizophrenia. This finding has implications for the neurobiology of illness progression and for the widespread use of NMDAR antagonists in the development of therapeutics for schizophrenia. Copyright © 2015. Published by Elsevier Inc.

Reduction of obesity, as induced by leptin, reverses endothelial dysfunction in obese (Lep(ob)) mice

NASA Technical Reports Server (NTRS)

Winters, B.; Mo, Z.; Brooks-Asplund, E.; Kim, S.; Shoukas, A.; Li, D.; Nyhan, D.; Berkowitz, D. E.

2000-01-01

Obesity is a major health care problem and is associated with significant cardiovascular morbidity. Leptin, a neuroendocrine hormone released by adipose tissue, is important in modulating obesity by signaling satiety and increasing metabolism. Moreover, leptin receptors are expressed on vascular endothelial cells (ECs) and mediate angiogenesis. We hypothesized that leptin may also play an important role in vasoregulation. We investigated vasoregulatory mechanisms in the leptin-deficient obese (ob/ob) mouse model and determined the influence of leptin replacement on endothelial-dependent vasorelaxant responses. The direct effect of leptin on EC nitric oxide (NO) production was also tested by using 4, 5-diaminofluorescein-2 diacetate staining and measurement of nitrate and nitrite concentrations. Vasoconstrictor responses to phenylephrine, norepinephrine, and U-46619 were markedly enhanced in aortic rings from ob/ob mice and were modulated by NO synthase inhibition. Vasorelaxant responses to ACh were markedly attenuated in mesenteric microvessels from ob/ob mice. Leptin replacement resulted in significant weight loss and reversal of the impaired endothelial-dependent vasorelaxant responses observed in ob/ob mice. Preincubation of ECs with leptin enhanced the release of NO production. Thus leptin-deficient ob/ob mice demonstrate marked abnormalities in vasoregulation, including impaired endothelial-dependent vasodilation, which is reversed by leptin replacement. These findings may be partially explained by the direct effect of leptin on endothelial NO production. These vascular abnormalities are similar to those observed in obese, diabetic, leptin-resistant humans. The ob/ob mouse may, therefore, be an excellent new model for the study of the cardiovascular effects of obesity.

A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility.

PubMed

Desai, Mahesh S; Seekatz, Anna M; Koropatkin, Nicole M; Kamada, Nobuhiko; Hickey, Christina A; Wolter, Mathis; Pudlo, Nicholas A; Kitamoto, Sho; Terrapon, Nicolas; Muller, Arnaud; Young, Vincent B; Henrissat, Bernard; Wilmes, Paul; Stappenbeck, Thaddeus S; Núñez, Gabriel; Martens, Eric C

2016-11-17

Despite the accepted health benefits of consuming dietary fiber, little is known about the mechanisms by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic mouse model, in which animals were colonized with a synthetic human gut microbiota composed of fully sequenced commensal bacteria, we elucidated the functional interactions between dietary fiber, the gut microbiota, and the colonic mucus barrier, which serves as a primary defense against enteric pathogens. We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation, together with a fiber-deprived, mucus-eroding microbiota, promotes greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium. Our work reveals intricate pathways linking diet, the gut microbiome, and intestinal barrier dysfunction, which could be exploited to improve health using dietary therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

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

Intestinal barrier dysfunction in cirrhosis: Current concepts in pathophysiology and clinical implications

PubMed Central

Tsiaoussis, Georgios I; Assimakopoulos, Stelios F; Tsamandas, Athanassios C; Triantos, Christos K; Thomopoulos, Konstantinos C

2015-01-01

The intestinal lumen is a host place for a wide range of microbiota and sets a unique interplay between local immune system, inflammatory cells and intestinal epithelium, forming a physical barrier against microbial invaders and toxins. Bacterial translocation is the migration of viable or nonviable microorganisms or their pathogen-associated molecular patterns, such as lipopolysaccharide, from the gut lumen to the mesenteric lymph nodes, systemic circulation and other normally sterile extraintestinal sites. A series of studies have shown that translocation of bacteria and their products across the intestinal barrier is a commonplace in patients with liver disease. The deterioration of intestinal barrier integrity and the consulting increased intestinal permeability in cirrhotic patients play a pivotal pathophysiological role in the development of severe complications as high rate of infections, spontaneous bacterial peritonitis, hepatic encephalopathy, hepatorenal syndrome, variceal bleeding, progression of liver injury and hepatocellular carcinoma. Nevertheless, the exact cellular and molecular mechanisms implicated in the phenomenon of microbial translocation in liver cirrhosis have not been fully elucidated yet. PMID:26301048

Recovery Effects of Oral Administration of Glucosylceramide and Beet Extract on Skin Barrier Destruction by UVB in Hairless Mice.

PubMed

Tokudome, Yoshihiro; Masutani, Noriomi; Uchino, Shohei; Fukai, Hisano

2017-10-27

Purified glucosylceramide from beet extract (beet GlcCer) and beet extract containing an equal amount of GlcCer were administered orally to ultra violet B (UVB)-irradiated mice, and differences in the protective effects against skin barrier dysfunction caused by UVB irradiation were compared. In the beet GlcCer group, epidermal thickening and the decrease in stratum corneum (SC) ceramide content caused by UVB irradiation were reduced. In the group that was orally administered beet extract containing glucosylceramide, effects similar to those in the beet GlcCer group were observed. Oral administration of beet GlcCer had no obvious effects against an increase in TEWL or decrease in SC water content after UVB irradiation, but there was improvement in the beet extract group. Oral administration of beet GlcCer is effective in improving skin barrier function in UVB-irradiated mice. Beet extract contains constituents other than GlcCer that are also effective in improving skin barrier function.

Management of Patients with Atopic Dermatitis: The Role of Emollient Therapy

PubMed Central

Catherine Mack Correa, M.; Nebus, Judith

2012-01-01

Atopic dermatitis is a common inflammatory skin disorder that afflicts a growing number of young children. Genetic, immune, and environmental factors interact in a complex fashion to contribute to disease expression. The compromised stratum corneum found in atopic dermatitis leads to skin barrier dysfunction, which results in aggravation of symptoms by aeroallergens, microbes, and other insults. Infants—whose immune system and epidermal barrier are still developing—display a higher frequency of atopic dermatitis. Management of patients with atopic dermatitis includes maintaining optimal skin care, avoiding allergic triggers, and routinely using emollients to maintain a hydrated stratum corneum and to improve barrier function. Flares of atopic dermatitis are often managed with courses of topical corticosteroids or calcineurin inhibitors. This paper discusses the role of emollients in the management of atopic dermatitis, with particular emphasis on infants and young children. PMID:23008699

ROS-activated calcium signaling mechanisms regulating endothelial barrier function.

PubMed

Di, Anke; Mehta, Dolly; Malik, Asrar B

2016-09-01

Increased vascular permeability is a common pathogenic feature in many inflammatory diseases. For example in acute lung injury (ALI) and its most severe form, the acute respiratory distress syndrome (ARDS), lung microvessel endothelia lose their junctional integrity resulting in leakiness of the endothelial barrier and accumulation of protein rich edema. Increased reactive oxygen species (ROS) generated by neutrophils (PMNs) and other inflammatory cells play an important role in increasing endothelial permeability. In essence, multiple inflammatory syndromes are caused by dysfunction and compromise of the barrier properties of the endothelium as a consequence of unregulated acute inflammatory response. This review focuses on the role of ROS signaling in controlling endothelial permeability with particular focus on ALI. We summarize below recent progress in defining signaling events leading to increased endothelial permeability and ALI. Copyright © 2016 Elsevier Ltd. All rights reserved.

How to address barriers to peritoneal dialysis in the elderly.

PubMed

Brown, Edwina A

2011-03-01

Older patients on dialysis have unique needs and characteristics and their outcomes vary from that of their younger counterparts. Comparatively fewer will start or be maintained on peritoneal dialysis (PD) compared to younger patients, despite the fact that hemodialysis is often poorly tolerated. Barriers to PD for older patients include poor vision, frailty, cognitive dysfunction, accommodation issues, and a bias from renal teams that older patients cannot do PD. The development of assisted PD can overcome many of these barriers. The ability of older patients to use PD as their dialysis modality should not be determined by whether they live in an area where the nephrologist is a PD enthusiast. All patients should be given nonbiased information so they can choose the dialysis modality that gives them the best quality of life and suits their and their family's lifestyle.

Gag-Positive Reservoir Cells Are Susceptible to HIV-Specific Cytotoxic T Lymphocyte Mediated Clearance In Vitro and Can Be Detected In Vivo

PubMed Central

Graf, Erin H.; Pace, Matthew J.; Peterson, Bennett A.; Lynch, Lindsay J.; Chukwulebe, Steve B.; Mexas, Angela M.; Shaheen, Farida; Martin, Jeffrey N.; Deeks, Steven G.; Connors, Mark; Migueles, Stephen A.; O’Doherty, Una

2013-01-01

Resting CD4+ T cells infected with HIV persist in the presence of suppressive anti-viral therapy (ART) and are barriers to a cure. One potential curative approach, therapeutic vaccination, is fueled by recognition of the ability of a subset of elite controllers (EC) to control virus without therapy due to robust anti-HIV immune responses. Controllers have low levels of integrated HIV DNA and low levels of replication competent virus, suggesting a small reservoir. As our recent data indicates some reservoir cells can produce HIV proteins (termed GPR cells for Gag-positive reservoir cells), we hypothesized that a fraction of HIV-expressing resting CD4+ T cells could be efficiently targeted and cleared in individuals who control HIV via anti-HIV cytotoxic T lymphocytes (CTL). To test this we examined if superinfected resting CD4+ T cells from EC express HIV Gag without producing infectious virus and the susceptibility of these cells to CTL. We found that resting CD4+ T cells expressed HIV Gag and were cleared by autologous CD8+ T cells from EC. Importantly, we found the extent of CTL clearance in our in vitro assay correlates with in vivo reservoir size and that a population of Gag expressing resting CD4+ T cells exists in vivo in patients well controlled on therapy. PMID:23951263

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.

Cutaneous exposure to clinically-relevant pigeon pea (Cajanus cajan) proteins promote TH2-dependent sensitization and IgE-mediated anaphylaxis in Balb/c mice.

PubMed

Kumar Gupta, Rinkesh; Kumar, Sandeep; Gupta, Kriti; Sharma, Akanksha; Roy, Ruchi; Kumar Verma, Alok; Chaudhari, Bhushan P; Das, Mukul; Ahmad Ansari, Irfan; Dwivedi, Premendra D

2016-11-01

Epicutaneous (EC) sensitization to food allergens may occur when the skin has been lightly damaged. The study here tested whether cutaneous exposure to pigeon pea protein(s) may cause allergic sensitization. BALB/c mice were either orally gavaged or epicutaneously sensitized by repeated application of pigeon pea crude protein extract (CPE) on undamaged areas of skin without any adjuvant; afterwards, both groups were orally challenged with the pigeon pea CPE. Anaphylactic symptoms along with measures of body temperature, MCPT-1, TSLP, pigeon pea-specific IgE and IgG 1 , myeloperoxidase (MPO) activity, T H 2 cytokines, T H 2 transcription factors (TFs) and filaggrin expression were determined. Mast cell staining, eosinophil levels and histopathological analysis of the skin and intestines were also performed. In the epicutaneously-sensitized mice, elevated levels of specific IgE and IgG 1 , as well as of MCPT-1, TSLP, T H 2 cytokines and TFs, higher anaphylactic scores and histological changes in the skin and intestine were indicative of sensitization ability via both routes in the pigeon pea CPE-treated hosts. Elevated levels of mast cells were observed in both the skin and intestine; increased levels of eosinophils and MPO activity were noted only in the skin. Decreased levels of filaggrin in skin may have played a key role in the skin barrier dysfunction, increasing the chances of sensitization. Therefore, the experimental data support the hypothesis that in addition to oral exposure, skin exposure to food allergens can promote T H 2-dependent sensitization, IgE-mediated anaphylaxis and intestinal changes after oral challenge. Based on this, an avoidance of cutaneous exposures to allergens might prevent development of food anaphylaxis.

Topical Apigenin Improves Epidermal Permeability Barrier Homeostasis in Normal Murine Skin by Divergent Mechanisms

PubMed Central

Hou, Maihua; Sun, Richard; Hupe, Melanie; Kim, Peggy L.; Park, Kyungho; Crumrine, Debra; Lin, Tzu-kai; Santiago, Juan Luis; Mauro, Theodora M.; Elias, Peter M.; Man, Mao-Qiang

2013-01-01

The beneficial effects of certain herbal medicines on cutaneous function have been appreciated for centuries. Among these agents, Chrysanthemum extract, apigenin, has been used for skin care, particularly in China, for millennia. However, the underlying mechanisms by which apigenin benefits the skin are not known. In the present study, we first determined whether topical apigenin positively influences permeability barrier homeostasis, and then the basis thereof. Hairless mice were treated topically with either 0.1% apigenin or vehicle alone twice-daily for 9 days. At the end of treatments, permeability barrier function was assessed with either an electrolytic water analyzer or a Tewameter. Our results show that topical apigenin significantly enhanced permeability barrier homeostasis after tape stripping, though basal permeability barrier function remained unchanged. Improved barrier function correlated with enhanced filaggrin expression and lamellar body production, which was paralleled by elevated mRNA levels for the epidermal ABCA12. The mRNA levels for key lipid synthetic enzymes also were up-regulated by apigenin. Finally, both CAMP and mBD3 immunostaining were increased by apigenin. We conclude that topical apigenin improves epidermal permeability barrier function by stimulating epidermal differentiation, lipid synthesis and secretion, as well as cutaneous antimicrobial peptide production. Apigenin could be useful for the prevention and treatment of skin disorders characterized by permeability barrier dysfunction, associated with reduced filaggrin levels, and impaired antimicrobial defenses, such as atopic dermatitis. PMID:23489424

Simulation of real I-V characteristics of metal/GaN/AlGaN heterostructure based on the 12-EXT model of trap-assisted tunnelling

NASA Astrophysics Data System (ADS)

Racko, Juraj; Benko, Peter; Mikolášek, Miroslav; Granzner, Ralf; Kittler, Mario; Schwierz, Frank; Harmatha, Ladislav; Breza, Juraj

2017-02-01

The contribution employs electrical simulation to assess the effect of the distribution of aluminium in the metal/GaN/AlGaN heterostructure on the leakage current. The heterostructure is characterized by a high density of traps causing an increase of the leakage current consisting of the thermionic emission component and of a non-negligible contribution of trap-assisted tunnelling. The leakage current is highly sensitive to the bending of the potential barrier Ec in the subsurface region of the GaN/AlGaN structure. The band bending is strongly affected by the sheet bound charge at the first GaN/AlGaN/GaN interface due to spontaneous and piezoelectric polarization. The overall charge depends on the concentration of Al, the distribution of Al at the first heterointerface having a strong effect on the formation of the potential barrier.

Computer-facilitated rapid HIV testing in emergency care settings: provider and patient usability and acceptability.

PubMed

Spielberg, Freya; Kurth, Ann E; Severynen, Anneleen; Hsieh, Yu-Hsiang; Moring-Parris, Daniel; Mackenzie, Sara; Rothman, Richard

2011-06-01

Providers in emergency care settings (ECSs) often face barriers to expanded HIV testing. We undertook formative research to understand the potential utility of a computer tool, "CARE," to facilitate rapid HIV testing in ECSs. Computer tool usability and acceptability were assessed among 35 adult patients, and provider focus groups were held, in two ECSs in Washington State and Maryland. The computer tool was usable by patients of varying computer literacy. Patients appreciated the tool's privacy and lack of judgment and their ability to reflect on HIV risks and create risk reduction plans. Staff voiced concerns regarding ECS-based HIV testing generally, including resources for follow-up of newly diagnosed people. Computer-delivered HIV testing support was acceptable and usable among low-literacy populations in two ECSs. Such tools may help circumvent some practical barriers associated with routine HIV testing in busy settings though linkages to care will still be needed.

Overview of physics research on the TCV tokamak

NASA Astrophysics Data System (ADS)

Fasoli, A.; TCV Team

2009-10-01

The Tokamak à Configuration Variable (TCV) tokamak is equipped with high-power (4.5 MW), real-time-controllable EC systems and flexible shaping, and plays an important role in fusion research by broadening the parameter range of reactor relevant regimes, by investigating tokamak physics questions and by developing new control tools. Steady-state discharges are achieved, in which the current is entirely self-generated through the bootstrap mechanism, a fundamental ingredient for ITER steady-state operation. The discharge remains quiescent over several current redistribution times, demonstrating that a self-consistent, 'bootstrap-aligned' equilibrium state is possible. Electron internal transport barrier regimes sustained by EC current drive have also been explored. MHD activity is shown to be crucial in scenarios characterized by large and slow oscillations in plasma confinement, which in turn can be modified by small Ohmic current perturbations altering the barrier strength. In studies of the relation between anomalous transport and plasma shape, the observed dependences of the electron thermal diffusivity on triangularity (direct) and collisionality (inverse) are qualitatively reproduced by non-linear gyro-kinetic simulations and shown to be governed by TEM turbulence. Parallel SOL flows are studied for their importance for material migration. Flow profiles are measured using a reciprocating Mach probe by changing from lower to upper single-null diverted equilibria and shifting the plasmas vertically. The dominant, field-direction-dependent Pfirsch-Schlüter component is found to be in good agreement with theoretical predictions. A field-direction-independent component is identified and is consistent with flows generated by transient over-pressure due to ballooning-like interchange turbulence. Initial high-resolution infrared images confirm that ELMs have a filamentary structure, while fast, localized radiation measurements reveal that ELM activity first appears in the X-point region. Real time control techniques are currently being applied to EC multiple independent power supplies and beam launchers, e.g. to control the plasma current in fully non-inductive conditions, and the plasma elongation through current broadening by far-off-axis heating at constant shaping field.

Probing the extracellular diffusion of antibodies in brain using in vivo integrative optical imaging and ex vivo fluorescence imaging.

PubMed

Wolak, Daniel J; Pizzo, Michelle E; Thorne, Robert G

2015-01-10

Antibody-based therapeutics exhibit great promise in the treatment of central nervous system (CNS) disorders given their unique customizable properties. Although several clinical trials have evaluated therapeutic antibodies for treatment of CNS disorders, success to date has likely been limited in part due to complex issues associated with antibody delivery to the brain and antibody distribution within the CNS compartment. Major obstacles to effective CNS delivery of full length immunoglobulin G (IgG) antibodies include transport across the blood-brain and blood-cerebrospinal fluid barriers. IgG diffusion within brain extracellular space (ECS) may also play a role in limiting central antibody distribution; however, IgG transport in brain ECS has not yet been explored using established in vivo methods. Here, we used real-time integrative optical imaging to measure the diffusion properties of fluorescently labeled, non-targeted IgG after pressure injection in both free solution and in adult rat neocortex in vivo, revealing IgG diffusion in free medium is ~10-fold greater than in brain ECS. The pronounced hindered diffusion of IgG in brain ECS is likely due to a number of general factors associated with the brain microenvironment (e.g. ECS volume fraction and geometry/width) but also molecule-specific factors such as IgG size, shape, charge and specific binding interactions with ECS components. Co-injection of labeled IgG with an excess of unlabeled Fc fragment yielded a small yet significant increase in the IgG effective diffusion coefficient in brain, suggesting that binding between the IgG Fc domain and endogenous Fc-specific receptors may contribute to the hindered mobility of IgG in brain ECS. Importantly, local IgG diffusion coefficients from integrative optical imaging were similar to those obtained from ex vivo fluorescence imaging of transport gradients across the pial brain surface following controlled intracisternal infusions in anesthetized animals. Taken together, our results confirm the importance of diffusive transport in the generation of whole brain distribution profiles after infusion into the cerebrospinal fluid, although convective transport in the perivascular spaces of cerebral blood vessels was also evident. Our quantitative in vivo diffusion measurements may allow for more accurate prediction of IgG brain distribution after intrathecal or intracerebroventricular infusion into the cerebrospinal fluid across different species, facilitating the evaluation of both new and existing strategies for CNS immunotherapy. Copyright © 2014 Elsevier B.V. All rights reserved.

Probing the extracellular diffusion of antibodies in brain using in vivo integrative optical imaging and ex vivo fluorescence imaging

PubMed Central

Wolak, Daniel J.; Pizzo, Michelle E.; Thorne, Robert G.

2014-01-01

Antibody-based therapeutics exhibit great promise in the treatment of central nervous system (CNS) disorders given their unique customizable properties. Although several clinical trials have evaluated therapeutic antibodies for treatment of CNS disorders, success to date has likely been limited in part due to complex issues associated with antibody delivery to the brain and antibody distribution within the CNS compartment. Major obstacles to effective CNS delivery of full length immunoglobulin G (IgG) antibodies include transport across the blood-brain and blood-cerebrospinal fluid barriers. IgG diffusion within brain extracellular space (ECS) may also play a role in limiting central antibody distribution; however, IgG transport in brain ECS has not yet been explored using established in vivo methods. Here, we used real-time integrative optical imaging to measure the diffusion properties of fluorescently labeled, non-targeted IgG after pressure injection in both free solution and in adult rat neocortex in vivo, revealing IgG diffusion in free medium is ~10-fold greater than in brain ECS. The pronounced hindered diffusion of IgG in brain ECS is likely due to a number of general factors associated with the brain microenvironment (e.g. ECS volume fraction and geometry/width) but also molecule-specific factors such as IgG size, shape, charge and specific binding interactions with ECS components. Co-injection of labeled IgG with an excess of unlabeled Fc fragment yielded a small yet significant increase in the IgG effective diffusion coefficient in brain, suggesting that binding between the IgG Fc domain and endogenous Fc-specific receptors may contribute to the hindered mobility of IgG in brain ECS. Importantly, local IgG diffusion coefficients from integrative optical imaging were similar to those obtained from ex vivo fluorescence imaging of transport gradients across the pial brain surface following controlled intracisternal infusions in anesthetized animals. Taken together, our results confirm the importance of diffusive transport in the generation of whole brain distribution profiles after infusion into the cerebrospinal fluid, although convective transport in the perivascular spaces of cerebral blood vessels was also evident. Our quantitative in vivo diffusion measurements may allow for more accurate prediction of IgG brain distribution after intrathecal or intracerebroventricular infusion into the cerebrospinal fluid across different species, facilitating the evaluation of both new and existing strategies for CNS immunotherapy. PMID:25449807

Genetic and Transcriptomic Bases of Intestinal Epithelial Barrier Dysfunction in Inflammatory Bowel Disease.

PubMed

Vancamelbeke, Maaike; Vanuytsel, Tim; Farré, Ricard; Verstockt, Sare; Ferrante, Marc; Van Assche, Gert; Rutgeerts, Paul; Schuit, Frans; Vermeire, Séverine; Arijs, Ingrid; Cleynen, Isabelle

2017-10-01

Intestinal barrier defects are common in patients with inflammatory bowel disease (IBD). To identify which components could underlie these changes, we performed an in-depth analysis of epithelial barrier genes in IBD. A set of 128 intestinal barrier genes was selected. Polygenic risk scores were generated based on selected barrier gene variants that were associated with Crohn's disease (CD) or ulcerative colitis (UC) in our study. Gene expression was analyzed using microarray and quantitative reverse transcription polymerase chain reaction. Influence of barrier gene variants on expression was studied by cis-expression quantitative trait loci mapping and comparing patients with low- and high-risk scores. Barrier risk scores were significantly higher in patients with IBD than controls. At single-gene level, the associated barrier single-nucleotide polymorphisms were most significantly enriched in PTGER4 for CD and HNF4A for UC. As a group, the regulating proteins were most enriched for CD and UC. Expression analysis showed that many epithelial barrier genes were significantly dysregulated in active CD and UC, with overrepresentation of mucus layer genes. In uninflamed CD ileum and IBD colon, most barrier gene levels restored to normal, except for MUC1 and MUC4 that remained persistently increased compared with controls. Expression levels did not depend on cis-regulatory variants nor combined genetic risk. We found genetic and transcriptomic dysregulations of key epithelial barrier genes and components in IBD. Of these, we believe that mucus genes, in particular MUC1 and MUC4, play an essential role in the pathogenesis of IBD and could represent interesting targets for treatment.

Parents’ role in adolescent depression care: primary care provider perspectives

PubMed Central

Radovic, Ana; Reynolds, Kerry; McCauley, Heather L.; Sucato, Gina S.; Stein, Bradley D.; Miller, Elizabeth

2015-01-01

Objective To understand how primary care providers (PCPs) perceive barriers to adolescent depression care to inform strategies to increase treatment engagement. Study design We conducted semi-structured interviews with 15 PCPs recruited from community pediatric offices with access to integrated behavioral health services (i.e., low system-level barriers to care) who participated in a larger study on treating adolescent depression. Interviews addressed PCP perceptions of barriers to adolescents’ uptake of care for depression. Interviews were audio-recorded, transcribed, and coded for key themes. Results Although PCPs mentioned several adolescent barriers to care, they thought parents played a critical role in assisting adolescents in accessing mental health services. Important aspects of the parental role in accessing treatment included transportation, financial support, and social support. PCP’s perceived that parental unwillingness to accept the depression diagnosis, family dysfunction and trauma were common barriers. PCPs contrasted this with examples of good family support they believed would enable adolescents to attend follow-up appointments and have a “life coach” at home to help monitor for side effects and watch for increased suicidality when starting antidepressants. Conclusions In this PCP population, which had enhanced access to mental health specialists, PCPs primarily reported attitudinal barriers to adolescent depression treatment, focusing mainly on perceived parent barriers. The results of these qualitative interviews provide a framework for understanding PCP perceptions of parental barriers to care, identifying that addressing complex parental barriers to care may be important for future interventions. PMID:26143382

Barriers to Serving Children with Traumatic Brain Injury in the Public Schools: Problems and Solutions.

ERIC Educational Resources Information Center

James, Elizabeth Murdoch; Reynolds, Cecil R.

Traumatic brain injury (TBI) is a federally recognized disabling condition which involves behavioral and academic difficulties. Dysfunction varies with the type and location of injury and with the age of the child. School personnel traditionally have had little exposure to TBI, and there is great potential for problems to occur due to lack of…

Circadian Disruption Changes Gut Microbiome Taxa and Functional Gene Composition.

PubMed

Deaver, Jessica A; Eum, Sung Y; Toborek, Michal

2018-01-01

Disrupted circadian rhythms and alterations of the gut microbiome composition were proposed to affect host health. Therefore, the aim of this research was to identify whether these events are connected and if circadian rhythm disruption by abnormal light-dark (LD) cycles affects microbial community gene expression and host vulnerability to intestinal dysfunction. Mice were subjected to either a 4-week period of constant 24-h light or of normal 12-h LD cycles. Stool samples were collected at the beginning and after the circadian rhythm disruption. A metatranscriptomic analysis revealed an increase in Ruminococcus torques , a bacterial species known to decrease gut barrier integrity, and a decrease in Lactobacillus johnsonii , a bacterium that helps maintain the intestinal epithelial cell layer, after circadian rhythm disruption. In addition, genes involved in pathways promoting host beneficial immune responses were downregulated, while genes involved in the synthesis and transportation of the endotoxin lipopolysaccharide were upregulated in mice with disrupted circadian cycles. Importantly, these mice were also more prone to dysfunction of the intestinal barrier. These results further elucidate the impact of light-cycle disruption on the gut microbiome and its connection with increased incidence of disease in response to circadian rhythm disturbances.

Circadian Disruption Changes Gut Microbiome Taxa and Functional Gene Composition

PubMed Central

Deaver, Jessica A.; Eum, Sung Y.; Toborek, Michal

2018-01-01

Disrupted circadian rhythms and alterations of the gut microbiome composition were proposed to affect host health. Therefore, the aim of this research was to identify whether these events are connected and if circadian rhythm disruption by abnormal light–dark (LD) cycles affects microbial community gene expression and host vulnerability to intestinal dysfunction. Mice were subjected to either a 4-week period of constant 24-h light or of normal 12-h LD cycles. Stool samples were collected at the beginning and after the circadian rhythm disruption. A metatranscriptomic analysis revealed an increase in Ruminococcus torques, a bacterial species known to decrease gut barrier integrity, and a decrease in Lactobacillus johnsonii, a bacterium that helps maintain the intestinal epithelial cell layer, after circadian rhythm disruption. In addition, genes involved in pathways promoting host beneficial immune responses were downregulated, while genes involved in the synthesis and transportation of the endotoxin lipopolysaccharide were upregulated in mice with disrupted circadian cycles. Importantly, these mice were also more prone to dysfunction of the intestinal barrier. These results further elucidate the impact of light-cycle disruption on the gut microbiome and its connection with increased incidence of disease in response to circadian rhythm disturbances. PMID:29706947

The Autodigestion Hypothesis for Shock and Multi-organ Failure

PubMed Central

Schmid-Schönbein, Geert W.; Chang, Marisol

2013-01-01

An important medical problem with high mortality is shock, sepsis and multi-organ failure. They have currently no treatments other than alleviation of symptoms. Shock is accompanied by strong markers for inflammation and involves a cascade of events that leads to failure in organs even if they are not involved in the initial insult. Recent evidence indicates that pancreatic digestive enzymes carried in the small intestine after mixing with ingested food are a major cause for multi-organ failure. These concentrated and relatively non-specific enzymes are usually compartmentalized inside the intestinal lumen as requirement for normal digestion. But after breakdown of the mucosal barrier they leak into the wall of the intestine and start an autodigestion process that includes destruction of villi in the intestine. Digestive enzymes also generate cytotoxic mediators, which together are transported into the systemic circulation via the portal venous system, the intestinal lymphatics and via the peritoneum. They cause various degrees of cell and organ dysfunction that can reach the point of complete organ failure. Blockade of digestive enzymes in the lumen of the intestine in experimental forms of shock serves to reduce breakdown of the mucosal barrier and autodigestion of the intestine, organ dysfunctions and mortality. PMID:23989761

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.

Microscopic description of production cross sections including deexcitation effects

NASA Astrophysics Data System (ADS)

Sekizawa, Kazuyuki

2017-07-01

Background: At the forefront of the nuclear science, production of new neutron-rich isotopes is continuously pursued at accelerator laboratories all over the world. To explore the currently unknown territories in the nuclear chart far away from the stability, reliable theoretical predictions are inevitable. Purpose: To provide a reliable prediction of production cross sections taking into account secondary deexcitation processes, both particle evaporation and fission, a new method called TDHF+GEMINI is proposed, which combines the microscopic time-dependent Hartree-Fock (TDHF) theory with a sophisticated statistical compound-nucleus deexcitation model, GEMINI++. Methods: Low-energy heavy ion reactions are described based on three-dimensional Skyrme-TDHF calculations. Using the particle-number projection method, production probabilities, total angular momenta, and excitation energies of primary reaction products are extracted from the TDHF wave function after collision. Production cross sections for secondary reaction products are evaluated employing GEMINI++. Results are compared with available experimental data and widely used grazing calculations. Results: The method is applied to describe cross sections for multinucleon transfer processes in 40Ca+124Sn (Ec .m .≃128.54 MeV ), 48Ca+124Sn (Ec .m .≃125.44 MeV ), 40Ca+208Pb (Ec .m .≃208.84 MeV ), 58Ni+208Pb (Ec .m .≃256.79 MeV ), 64Ni+238U (Ec .m .≃307.35 MeV ), and 136Xe+198Pt (Ec .m .≃644.98 MeV ) reactions at energies close to the Coulomb barrier. It is shown that the inclusion of secondary deexcitation processes, which are dominated by neutron evaporation in the present systems, substantially improves agreement with the experimental data. The magnitude of the evaporation effects is very similar to the one observed in grazing calculations. TDHF+GEMINI provides better description of the absolute value of the cross sections for channels involving transfer of more than one proton, compared to the grazing results. However, there remain discrepancies between the measurements and the calculated cross sections, indicating a limit of the theoretical framework that works with a single mean-field potential. Possible causes of the discrepancies are discussed. Conclusions: To perfectly reproduce experimental cross sections for multinucleon transfer processes, one should go beyond the standard self-consistent mean-field description. Nevertheless, the proposed method will provide valuable information to optimize production mechanisms of new neutron-rich nuclei through its microscopic, nonempirical predictions.

Mitochondrial dysfunction in obesity.

PubMed

de Mello, Aline Haas; Costa, Ana Beatriz; Engel, Jéssica Della Giustina; Rezin, Gislaine Tezza

2018-01-01

Obesity leads to various changes in the body. Among them, the existing inflammatory process may lead to an increase in the production of reactive oxygen species (ROS) and cause oxidative stress. Oxidative stress, in turn, can trigger mitochondrial changes, which is called mitochondrial dysfunction. Moreover, excess nutrients supply (as it commonly is the case with obesity) can overwhelm the Krebs cycle and the mitochondrial respiratory chain, causing a mitochondrial dysfunction, and lead to a higher ROS formation. This increase in ROS production by the respiratory chain may also cause oxidative stress, which may exacerbate the inflammatory process in obesity. All these intracellular changes can lead to cellular apoptosis. These processes have been described in obesity as occurring mainly in peripheral tissues. However, some studies have already shown that obesity is also associated with changes in the central nervous system (CNS), with alterations in the blood-brain barrier (BBB) and in cerebral structures such as hypothalamus and hippocampus. In this sense, this review presents a general view about mitochondrial dysfunction in obesity, including related alterations, such as inflammation, oxidative stress, and apoptosis, and focusing on the whole organism, covering alterations in peripheral tissues, BBB, and CNS. Copyright © 2017 Elsevier Inc. All rights reserved.

BP180 dysfunction triggers spontaneous skin inflammation in mice.

PubMed

Zhang, Yang; Hwang, Bin-Jin; Liu, Zhen; Li, Ning; Lough, Kendall; Williams, Scott E; Chen, Jinbo; Burette, Susan W; Diaz, Luis A; Su, Maureen A; Xiao, Shengxiang; Liu, Zhi

2018-06-04

BP180, also known as collagen XVII, is a hemidesmosomal component and plays a key role in maintaining skin dermal/epidermal adhesion. Dysfunction of BP180, either through genetic mutations in junctional epidermolysis bullosa (JEB) or autoantibody insult in bullous pemphigoid (BP), leads to subepidermal blistering accompanied by skin inflammation. However, whether BP180 is involved in skin inflammation remains unknown. To address this question, we generated a BP180-dysfunctional mouse strain and found that mice lacking functional BP180 (termed Δ NC16A ) developed spontaneous skin inflammatory disease, characterized by severe itch, defective skin barrier, infiltrating immune cells, elevated serum IgE levels, and increased expression of thymic stromal lymphopoietin (TSLP). Severe itch is independent of adaptive immunity and histamine, but dependent on increased expression of TSLP by keratinocytes. In addition, a high TSLP expression is detected in BP patients. Our data provide direct evidence showing that BP180 regulates skin inflammation independently of adaptive immunity, and BP180 dysfunction leads to a TSLP-mediated itch. The newly developed mouse strain could be a model for elucidation of disease mechanisms and development of novel therapeutic strategies for skin inflammation and BP180-related skin conditions.

Long-Term Outcomes of Renal Transplant in Recipients With Lower Urinary Tract Dysfunction.

PubMed

Wilson, Rebekah S; Courtney, Aisling E; Ko, Dicken S C; Maxwell, Alexander P; McDaid, James

2018-01-02

Lower urinary tract dysfunction can lead to chronic kidney disease, which, despite surgical intervention, will progress to end-stage renal disease, requiring dialysis. Urologic pathology may damage a transplanted kidney, limiting patient and graft survival. Although smaller studies have suggested that urinary tract dysfunction does not affect graft or patient survival, this is not universally accepted. Northern Ireland has historically had the highest incidence of neural tube defects in Europe, giving rich local experience in caring for patients with lower urinary tract dysfunction. Here, we analyzed outcomes of renal transplant recipients with lower urinary tract dysfunction versus control recipients. We identified 3 groups of kidney transplant recipients treated between 2001 and 2010; those in group 1 had end-stage renal disease due to lower urinary tract dysfunction with prior intervention (urologic surgery, long-term catheter, or intermittent self-catheterization), group 2 had end-stage renal disease secondary to lower urinary tract dysfunction without intervention, and group 3 had end-stage renal disease due to polycystic kidney disease (chosen as a relatively healthy control cohort without comorbid burden of other causes of end-stage renal disease such as diabetes). The primary outcome measured, graft survival, was death censored, with graft loss defined as requirement for renal replacement therapy or retransplant. Secondary outcomes included patient survival and graft function. In 150 study patients (16 patients in group 1, 64 in group 2, and 70 in group 3), 5-year death-censored graft survival was 93.75%, 90.6%, and 92.9%, respectively, with no significant differences in graft failure among groups (Cox proportional hazards model). Five-year patient survival was 100%, 100%, and 94.3%, respectively. Individuals with a history of lower urinary tract dysfunction had graft and patient survival rates similar to the control group. When appropriately treated, lower urinary tract dysfunction is not a barrier to successful renal transplant.

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

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

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.

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.

Is intestinal inflammation linking dysbiosis to gut barrier dysfunction during liver disease?

PubMed Central

Brandl, Katharina

2016-01-01

Changes in the intestinal microbiota composition contribute to the pathogenesis of many disorders including gastrointestinal and liver diseases. Recent studies have broadened our understanding of the “gut-liver” axis. Dietary changes, other environmental and genetic factors can lead to alterations in the microbiota. Dysbiosis can further disrupt the integrity of the intestinal barrier leading to pathological bacterial translocation and the initiation of an inflammatory response in the liver. In this article, the authors dissect the different steps involved in disease pathogenesis to further refine approaches for the medical management of liver diseases. The authors will specifically discuss the role of dysbiosis in inducing intestinal inflammation and increasing intestinal permeability. PMID:26088524

Evaluation of procoagulant tissue factor expression in canine hemangiosarcoma cell lines.

PubMed

Witter, Lauren E; Gruber, Erika J; Lean, Fabian Z X; Stokol, Tracy

2017-01-01

OBJECTIVE To evaluate expression of procoagulant tissue factor (TF) by canine hemangiosarcoma cells in vitro. SAMPLES 4 canine hemangiosarcoma cell lines (SB-HSA [mouse-passaged cutaneous tumor], Emma [primary metastatic brain tumor], and Frog and Dal-1 [primary splenic tumors]) and 1 nonneoplastic canine endothelial cell line (CnAoEC). PROCEDURES TF mRNA and TF antigen expression were evaluated by quantitative real-time PCR assay and flow cytometry, respectively. Thrombin generation was measured in canine plasma and in coagulation factor-replete or specific coagulation factor-deficient human plasma by calibrated automated thrombography. Corn trypsin inhibitor and annexin V were used to examine contributions of contact activation and membrane-bound phosphatidylserine, respectively, to thrombin generation. RESULTS All cell lines expressed TF mRNA and antigen, with significantly greater expression of both products in SB-HSA and Emma cells than in CnAoEC. A greater percentage of SB-HSA cells expressed TF antigen, compared with other hemangiosarcoma cell lines. All hemangiosarcoma cell lines generated significantly more thrombin than did CnAoEC in canine or factor-replete human plasma. Thrombin generation induced by SB-HSA cells was significantly lower in factor VII-deficient plasma than in factor-replete plasma and was abolished in factor X-deficient plasma; residual thrombin generation in factor VII-deficient plasma was abolished by incubation of cells with annexin V. Thrombin generation by SB-HSA cells was unaffected by the addition of corn trypsin inhibitor. CONCLUSIONS AND CLINICAL RELEVANCE Hemangiosarcoma cell lines expressed procoagulant TF in vitro. Further research is needed to determine whether TF can be used as a biomarker for hemostatic dysfunction in dogs with hemangiosarcoma.

Evaluation of procoagulant tissue factor expression in canine hemangiosarcoma cell lines

PubMed Central

Witter, Lauren E.; Gruber, Erika J.; Lean, Fabian Z. X.; Stokol, Tracy

2017-01-01

OBJECTIVE To evaluate expression of procoagulant tissue factor (TF) by canine hemangiosarcoma cells in vitro. SAMPLES 4 canine hemangiosarcoma cell lines (SB-HSA [mouse-passaged cutaneous tumor], Emma [primary metastatic brain tumor], and Frog and Dal-1 [primary splenic tumors]) and 1 nonneoplastic canine endothelial cell line (CnAoEC). PROCEDURES TF mRNA and TF antigen expression were evaluated by quantitative real-time PCR assay and flow cytometry, respectively. Thrombin generation was measured in canine plasma and in coagulation factor–replete or specific coagulation factor–deficient human plasma by calibrated automated thrombography. Corn trypsin inhibitor and annexin V were used to examine contributions of contact activation and membrane-bound phosphatidylserine, respectively, to thrombin generation. RESULTS All cell lines expressed TF mRNA and antigen, with significantly greater expression of both products in SB-HSA and Emma cells than in CnAoEC. A greater percentage of SB-HSA cells expressed TF antigen, compared with other hemangiosarcoma cell lines. All hemangiosarcoma cell lines generated significantly more thrombin than did CnAoEC in canine or factor-replete human plasma. Thrombin generation induced by SB-HSA cells was significantly lower in factor VII-deficient plasma than in factor-replete plasma and was abolished in factor X–deficient plasma; residual thrombin generation in FVII-deficient plasma was abolished by incubation of cells with annexin V. Thrombin generation by SB-HSA cells was unaffected by the addition of corn trypsin inhibitor. CONCLUSIONS AND CLINICAL RELEVANCE Hemangiosarcoma cell lines expressed procoagulant TF in vitro. Further research is needed to determine whether TF can be used as a biomarker for hemostatic dysfunction in dogs with hemangiosarcoma. PMID:28029283

Resting-state functional magnetic resonance imaging of the subthalamic microlesion and stimulation effects in Parkinson's disease: Indications of a principal role of the brainstem

PubMed Central

Holiga, Štefan; Mueller, Karsten; Möller, Harald E.; Urgošík, Dušan; Růžička, Evžen; Schroeter, Matthias L.; Jech, Robert

2015-01-01

During implantation of deep-brain stimulation (DBS) electrodes in the target structure, neurosurgeons and neurologists commonly observe a “microlesion effect” (MLE), which occurs well before initiating subthalamic DBS. This phenomenon typically leads to a transitory improvement of motor symptoms of patients suffering from Parkinson's disease (PD). Mechanisms behind MLE remain poorly understood. In this work, we exploited the notion of ranking to assess spontaneous brain activity in PD patients examined by resting-state functional magnetic resonance imaging in response to penetration of DBS electrodes in the subthalamic nucleus. In particular, we employed a hypothesis-free method, eigenvector centrality (EC), to reveal motor-communication-hubs of the highest rank and their reorganization following the surgery; providing a unique opportunity to evaluate the direct impact of disrupting the PD motor circuitry in vivo without prior assumptions. Penetration of electrodes was associated with increased EC of functional connectivity in the brainstem. Changes in connectivity were quantitatively related to motor improvement, which further emphasizes the clinical importance of the functional integrity of the brainstem. Surprisingly, MLE and DBS were associated with anatomically different EC maps despite their similar clinical benefit on motor functions. The DBS solely caused an increase in connectivity of the left premotor region suggesting separate pathophysiological mechanisms of both interventions. While the DBS acts at the cortical level suggesting compensatory activation of less affected motor regions, the MLE affects more fundamental circuitry as the dysfunctional brainstem predominates in the beginning of PD. These findings invigorate the overlooked brainstem perspective in the understanding of PD and support the current trend towards its early diagnosis. PMID:26509113

Transient CD15-positive endothelial phenotype in the human placenta correlates with physiological and pathological fetoplacental immaturity.

PubMed

Seidmann, L; Suhan, T; Unger, R; Gerein, V; Kirkpatrick, C J

2014-09-01

Placental growth and villous maturation are critical parameters of placental function at the end of pregnancy. A failure in these processes leads to the development of placental dysfunction, as well as fetal and neonatal mortality and morbidity. The aim of the study was to determine the relevant diagnostic markers associated with pathological placental development. Forty tissue samples from normal placentas of different gestational age and 68 pathological term placentas with defective villous maturation (GDM, idiopathic IUFD, preeclamsia, HELLP syndrome) comprised the comparative immunohistochemical study (CD15, CD45 and CD34). Positive immunohistochemical reactions were quantitatively assessed in the chorionic plate and vessels of the villi of different histological type. Physiologically immature placentas of the first and second trimester and pathologically immature term placentas were characterized by marked endothelial CD15-immunostaining. A significant loss of CD15-positive endothelium of the placentas was associated with a physiological and accelerated villous maturity. A spatio-temporal correlation was shown for CD15+ endothelial cells (ECs) and the number of CD45+ stromal cells (SCs). A negative temporal correlation was shown for CD15+ ECs and CD15+ myelomonocytes in the fetal blood. CD34 expression in the ECs was stable during the pregnancy. A correlation between a transient CD15-positive endothelial phenotype and a physiological and pathological fetoplacental immaturity was demonstrated. Physiological and accelerated placental maturation was accompanied by a significant disappearance of CD15-positive endothelium. We propose that "immature" CD15+ endothelium is an important diagnostic marker of the physiological and pathological fetoplacental immaturity. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Resting-state functional magnetic resonance imaging of the subthalamic microlesion and stimulation effects in Parkinson's disease: Indications of a principal role of the brainstem.

PubMed

Holiga, Štefan; Mueller, Karsten; Möller, Harald E; Urgošík, Dušan; Růžička, Evžen; Schroeter, Matthias L; Jech, Robert

2015-01-01

During implantation of deep-brain stimulation (DBS) electrodes in the target structure, neurosurgeons and neurologists commonly observe a "microlesion effect" (MLE), which occurs well before initiating subthalamic DBS. This phenomenon typically leads to a transitory improvement of motor symptoms of patients suffering from Parkinson's disease (PD). Mechanisms behind MLE remain poorly understood. In this work, we exploited the notion of ranking to assess spontaneous brain activity in PD patients examined by resting-state functional magnetic resonance imaging in response to penetration of DBS electrodes in the subthalamic nucleus. In particular, we employed a hypothesis-free method, eigenvector centrality (EC), to reveal motor-communication-hubs of the highest rank and their reorganization following the surgery; providing a unique opportunity to evaluate the direct impact of disrupting the PD motor circuitry in vivo without prior assumptions. Penetration of electrodes was associated with increased EC of functional connectivity in the brainstem. Changes in connectivity were quantitatively related to motor improvement, which further emphasizes the clinical importance of the functional integrity of the brainstem. Surprisingly, MLE and DBS were associated with anatomically different EC maps despite their similar clinical benefit on motor functions. The DBS solely caused an increase in connectivity of the left premotor region suggesting separate pathophysiological mechanisms of both interventions. While the DBS acts at the cortical level suggesting compensatory activation of less affected motor regions, the MLE affects more fundamental circuitry as the dysfunctional brainstem predominates in the beginning of PD. These findings invigorate the overlooked brainstem perspective in the understanding of PD and support the current trend towards its early diagnosis.

Baryon number violation and nonperturbative weak processes at Superconducting Super Collider energies

NASA Astrophysics Data System (ADS)

Shuryak, E. V.; Verbaarschot, J. J. M.

1992-04-01

Baryon number violation and multiple production of W and Higgs bosons are described semiclassically in terms of the instanton-anti-instanton valley. We find (i) two saddle points, one describing reflection from a barrier and the other describing tunneling through it. We find (ii) a critical energy Ec~35 TeV where the cross section is suppressed as exp(-const/g2w), but the formulas are no longer valid; (iii) however, depending on the (still uncertain) Higgs bosson action, the cross section at this point may be large enough to be observable.

Zika Virus Persistently Infects and Is Basolaterally Released from Primary Human Brain Microvascular Endothelial Cells.

PubMed

Mladinich, Megan C; Schwedes, John; Mackow, Erich R

2017-07-11

Zika virus (ZIKV) is a mosquito-borne Flavivirus that has emerged as the cause of encephalitis and fetal microencephaly in the Americas. ZIKV uniquely persists in human bodily fluids for up to 6 months, is sexually transmitted, and traverses the placenta and the blood-brain barrier (BBB) to damage neurons. Cells that support persistent ZIKV replication and mechanisms by which ZIKV establishes persistence remain enigmatic but central to ZIKV entry into protected neuronal compartments. The endothelial cell (EC) lining of capillaries normally constrains transplacental transmission and forms the BBB, which selectively restricts access of blood constituents to neurons. We found that ZIKV (strain PRVABC59) persistently infects and continuously replicates in primary human brain microvascular ECs (hBMECs), without cytopathology, for >9 days and following hBMEC passage. ZIKV did not permeabilize hBMECs but was released basolaterally from polarized hBMECs, suggesting a direct mechanism for ZIKV to cross the BBB. ZIKV-infected hBMECs were rapidly resistant to alpha interferon (IFN-α) and transiently induced, but failed to secrete, IFN-β and IFN-λ. Global transcriptome analysis determined that ZIKV constitutively induced IFN regulatory factor 7 (IRF7), IRF9, and IFN-stimulated genes (ISGs) 1 to 9 days postinfection, despite persistently replicating in hBMECs. ZIKV constitutively induced ISG15, HERC5, and USP18, which are linked to hepatitis C virus (HCV) persistence and IFN regulation, chemokine CCL5, which is associated with immunopathogenesis, as well as cell survival factors. Our results reveal that hBMECs act as a reservoir of persistent ZIKV replication, suggest routes for ZIKV to cross hBMECs into neuronal compartments, and define novel mechanisms of ZIKV persistence that can be targeted to restrict ZIKV spread. IMPORTANCE ZIKV persists in patients, crossing placental and neuronal barriers, damaging neurons, and causing fetal microencephaly. We found that ZIKV persistently infects brain endothelial cells that normally protect neurons from viral exposure. hBMECs are not damaged by ZIKV infection and, analogous to persistent HCV infection, ZIKV constitutively induces and evades antiviral ISG and IFN responses to continuously replicate in hBMECs. As a result, hBMECs provide a protective niche for systemic ZIKV spread and a viral reservoir localized in the normally protective blood-brain barrier. Consistent with the spread of ZIKV into neuronal compartments, ZIKV was released basolaterally from hBMECs. Our findings define hBMEC responses that contribute to persistent ZIKV infection and potential targets for clearing ZIKV infections from hBMECs. These results further suggest roles for additional ZIKV-infected ECs to facilitate viral spread and persistence in the protected placental, retinal, and testicular compartments. Copyright © 2017 Mladinich et al.

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.

Sexual functioning in military personnel: preliminary estimates and predictors.

PubMed

Wilcox, Sherrie L; Redmond, Sarah; Hassan, Anthony M

2014-10-01

Although the military is a young and vigorous force, service members and veterans may experience sexual functioning problems (SFPs) as a result of military service. Sexual functioning can be impaired by physical, psychological, and social factors and can impact quality of life (QOL) and happiness. This study aims to estimate rates and correlates of SFPs in male military personnel across demographic and psychosocial characteristics, to examine the QOL concomitants, and to evaluate barriers for treatment seeking. This exploratory cross-sectional study was conducted using data from a larger nationwide study conducted between October 2013 and November 2013. This sample consists of 367 male active duty service members and recent veterans (military personnel) age 40 or younger. Erectile dysfunction (ED) was determined using the five-item International Index of Erectile Function, sexual dysfunction (SD) was determined using the Arizona Sexual Experiences Scale, Male, and QOL was determined using the World Health Organization Quality of Life, Brief. SFPs were associated with various demographic, physical, and psychosocial risk factors. The rates of SD and ED were 8.45% and 33.24%, respectively, for male military personnel aged 21-40. Those who were 36-40, nonmarried, nonwhite, and of lower educational attainment reported the highest rates of SFPs. Male military personnel with poor physical and psychosocial health presented the greatest risk for ED and SD. SFPs were associated with reduced QOL and lower happiness, and barriers for treatment were generally related to social barriers. SFPs in young male military personnel are an important public health concern that can severely impact QOL and happiness. © 2014 International Society for Sexual Medicine.

Betacaryophyllene - A phytocannabinoid as potential therapeutic modality for human sepsis?

PubMed

Meza, Angel; Lehmann, Christian

2018-01-01

Sepsis is a clinical condition resulting from a dysregulated immune response to an infection that leads to organ dysfunction. Despite numerous efforts to optimize treatment, sepsis remains to be the main cause of death in most intensive care units. The endogenous cannabinoid system (ECS) plays an important role in inflammation. Cannabinoid receptor 2 (CB2R) activation is immunosuppressive, which might be beneficial during the hyper-inflammatory phase of sepsis. Beta-caryophyllene (BCP) is a non-psychoactive natural cannabinoid (phytocannabinoid) found in Cannabis sativa and in essential oils of spices and food plants, that acts as a selective agonist of CB2R. We propose BCP administration as novel treatment to reduce hyper-inflammation in human sepsis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Emergency contraception: Knowledge and practice among women and the spouses seeking termination of pregnancy.

PubMed

Kathpalia, S K

2016-04-01

India was one of the first countries to launch a formal family planning program. Initially, the main thrust of the program was on sterilization but subsequently it has got evolved and now the stress is to bring about awareness of contraception and make informed choices. Emergency contraception has been included in its armamentarium. This study was conducted to find out about the awareness among the cases who report for induced abortion. A total of 784 willing cases were enrolled in the study; there were no exclusion criteria except unwillingness. A parallel group was also included consisting of their spouses. Information that was being sought about Emergency Contraception (EC) included its knowledge, details of administration, and availability. Of the 784 cases, a large number, 742 (94.6%), underwent first trimester abortion and only 42 (5.3%) underwent second trimester abortion. 286 (36.4%) patients had not used any contraceptive. A large number had used natural methods (35.3%), like lactation, abstinence, or coitus interruptus, and 25.7% had used barrier contraception inconsistently. A very small percentage in both the groups knew about EC; more number of men knew about EC than women. Awareness about emergency contraception is low, as reported in many other studies, though it is available for many years. Awareness about contraceptives needs to be improved and emergency contraceptive should be advocated as a backup method. More efforts are required to generate awareness about regular use of effective contraception and emergency contraception if required.

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.

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

The protective role of Sirt1 in vascular tissue: its relationship to vascular aging and atherosclerosis.

PubMed

Kitada, Munehiro; Ogura, Yoshio; Koya, Daisuke

2016-10-15

Cardiovascular disease (CVD) due to atherosclerosis is the main cause of death in both the elderly and patients with metabolic diseases, including diabetes. Aging processes contribute to the pathogenesis of atherosclerosis. Calorie restriction (CR) is recognized as a dietary intervention for promoting longevity and delaying age-related diseases, including atherosclerosis. Sirt1, an NAD + -dependent deacetylase, is considered an anti-aging molecule and is induced during CR. Sirt1 deacetylates target proteins and is linked to cellular metabolism, the redox state and survival pathways. Sirt1 expression/activation is decreased in vascular tissue undergoing senescence. Sirt1 deficiency in endothelial cells (ECs), vascular smooth muscle cells (VSMCs) and monocytes/macrophages contributes to increased oxidative stress, inflammation, foam cell formation, senescences impaired nitric oxide production and autophagy, thereby promoting vascular aging and atherosclerosis. Endothelial dysfunction, activation of monocytes/macrophages, and the functional and phenotypical plasticity of VSMCs are critically implicated in the pathogenesis of atherosclerosis through multiple mechanisms. Therefore, the activation of Sirt1 in vascular tissue, which includes ECs, monocytes/macrophages and VSMCs, may be a new therapeutic strategy against atherosclerosis and the increasing resistance to the metabolic disorder-related causal factors of CVD. In this review, we discuss the protective role of Sirt1 in the pathophysiology of vascular aging and atherosclerosis.

Androgen actions on endothelium functions and cardiovascular diseases

PubMed Central

Cai, Jing-Jing; Wen, Juan; Jiang, Wei-Hong; Lin, Jian; Hong, Yuan; Zhu, Yuan-Shan

2016-01-01

The roles of androgens on cardiovascular physiology and pathophysiology are controversial as both beneficial and detrimental effects have been reported. Although the reasons for this discrepancy are unclear, multiple factors such as genetic and epigenetic variation, sex-specificity, hormone interactions, drug preparation and route of administration may contribute. Recently, growing evidence suggests that androgens exhibit beneficial effects on cardiovascular function though the mechanism remains to be elucidated. Endothelial cells (ECs) which line the interior surface of blood vessels are distributed throughout the circulatory system, and play a crucial role in cardiovascular function. Endothelial progenitor cells (EPCs) are considered an indispensable element for the reconstitution and maintenance of an intact endothelial layer. Endothelial dysfunction is regarded as an initiating step in development of atherosclerosis and cardiovascular diseases. The modulation of endothelial functions by androgens through either genomic or nongenomic signal pathways is one possible mechanism by which androgens act on the cardiovascular system. Obtaining insight into the mechanisms by which androgens affect EC and EPC functions will allow us to determine whether androgens possess beneficial effects on the cardiovascular system. This in turn may be critical in the prevention and therapy of cardiovascular diseases. This article seeks to review recent progress in androgen regulation of endothelial function, the sex-specificity of androgen actions, and its clinical applications in the cardiovascular system. PMID:27168746

Endothelial microvesicles in hypoxic hypoxia diseases.

PubMed

Deng, Fan; Wang, Shuang; Xu, Riping; Yu, Wenqian; Wang, Xianyu; Zhang, Liangqing

2018-05-29

Hypoxic hypoxia, including abnormally low partial pressure of inhaled oxygen, external respiratory dysfunction-induced respiratory hypoxia and venous blood flow into the arterial blood, is characterized by decreased arterial oxygen partial pressure, resulting in tissue oxygen deficiency. The specific characteristics include reduced arterial oxygen partial pressure and oxygen content. Hypoxic hypoxia diseases (HHDs) have attracted increased attention due to their high morbidity and mortality and mounting evidence showing that hypoxia-induced oxidative stress, coagulation, inflammation and angiogenesis play extremely important roles in the physiological and pathological processes of HHDs-related vascular endothelial injury. Interestingly, endothelial microvesicles (EMVs), which can be induced by hypoxia, hypoxia-induced oxidative stress, coagulation and inflammation in HHDs, have emerged as key mediators of intercellular communication and cellular functions. EMVs shed from activated or apoptotic endothelial cells (ECs) reflect the degree of ECs damage, and elevated EMVs levels are present in several HHDs, including obstructive sleep apnoea syndrome and chronic obstructive pulmonary disease. Furthermore, EMVs have procoagulant, proinflammatory and angiogenic functions that affect the pathological processes of HHDs. This review summarizes the emerging roles of EMVs in the diagnosis, staging, treatment and clinical prognosis of HHDs. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

The protective role of Sirt1 in vascular tissue: its relationship to vascular aging and atherosclerosis

PubMed Central

Kitada, Munehiro; Ogura, Yoshio; Koya, Daisuke

2016-01-01

Cardiovascular disease (CVD) due to atherosclerosis is the main cause of death in both the elderly and patients with metabolic diseases, including diabetes. Aging processes contribute to the pathogenesis of atherosclerosis. Calorie restriction (CR) is recognized as a dietary intervention for promoting longevity and delaying age-related diseases, including atherosclerosis. Sirt1, an NAD+-dependent deacetylase, is considered an anti-aging molecule and is induced during CR. Sirt1 deacetylates target proteins and is linked to cellular metabolism, the redox state and survival pathways. Sirt1 expression/activation is decreased in vascular tissue undergoing senescence. Sirt1 deficiency in endothelial cells (ECs), vascular smooth muscle cells (VSMCs) and monocytes/macrophages contributes to increased oxidative stress, inflammation, foam cell formation, senescences impaired nitric oxide production and autophagy, thereby promoting vascular aging and atherosclerosis. Endothelial dysfunction, activation of monocytes/macrophages, and the functional and phenotypical plasticity of VSMCs are critically implicated in the pathogenesis of atherosclerosis through multiple mechanisms. Therefore, the activation of Sirt1 in vascular tissue, which includes ECs, monocytes/macrophages and VSMCs, may be a new therapeutic strategy against atherosclerosis and the increasing resistance to the metabolic disorder-related causal factors of CVD. In this review, we discuss the protective role of Sirt1 in the pathophysiology of vascular aging and atherosclerosis. PMID:27744418

Lycium barbarum polysaccharide protects against LPS-induced ARDS by inhibiting apoptosis, oxidative stress, and inflammation in pulmonary endothelial cells.

PubMed

Chen, Lan; Li, Wen; Qi, Di; Wang, Daoxin

2018-04-01

Acute respiratory distress syndrome (ARDS) is a heterogenous syndrome characterised by diffuse alveolar damage, with an increase in lung endothelial and epithelial permeability. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses antiapoptotic and antioxidative effects in distinct situations. In the present study, the protective effects and potential molecular mechanisms of LBP against lipopolysaccharide (LPS)-induced ARDS were investigated in the mice and in the human pulmonary microvascular endothelial cells (HPMECs). The data indicated that pretreatment with LBP significantly attenuated LPS-induced lung inflammation and pulmonary oedema in vivo. LBP significantly reversed LPS-induced decrease in cell viability, increase in apoptosis and oxidative stress via inhibiting caspase-3 activation and intracellular reactive oxygen species (ROS) production in vitro. Moreover, the scratch assay verified that LBP restored the dysfunction of endothelial cells (ECs) migration induced by LPS stimulation. Furthermore, LBP also significantly suppressed LPS-induced NF-κB activation, and subsequently reversed the release of cytochrome c. These results showed the antiapoptosis and antioxidant LBP could partially protect against LPS-induced ARDS through promoting the ECs survival and scavenging ROS via inhibition of NF-κB signalling pathway. Thus, LBP could be potentially used for ARDS against pulmonary inflammation and pulmonary oedema.

The role of brassinosteroids in the regulation of the plasma membrane H+-ATPase and NADPH oxidase under cadmium stress.

PubMed

Jakubowska, Dagmara; Janicka, Małgorzata

2017-11-01

The present research aim was to define the role of brassinosteroids (BRs) in plant adaptation to cadmium stress. We observed a stimulating effect of exogenous BR on the activity of two plasma membrane enzymes which play a key role in plants adaptation to cadmium stress, H + -ATPase (EC 3.6.3.14) and NADPH oxidase (EC 1.6.3.1). Using anti-phosphothreonine antibody we showed that modification of PM H + -ATPase activity under BR action could result from phosphorylation of the enzyme protein. Also the relative expression of genes encoding both PM H + -ATPase and NADPH oxidase was affected by BR. To confirm the role of BR in the cadmium stimulating effect on activity of both studied plasma membrane enzymes, an assay in the presence of a BR biosynthesis inhibitor (propiconazole) was performed. Moreover, as a tool in our work we used commercially available plant mutants unable to BR biosynthesis or with dysfunctional BR signaling pathway, to further confirm participation of BR in plant adaptation to heavy metal stress. Presented results demonstrate some elements of the brassinosteroid-induced pathway activated under cadmium stress, wherein H + -ATPase and NADPH oxidase are key factors. Copyright © 2017 Elsevier B.V. All rights reserved.

Barriers and enablers to implementing clinical treatment protocols for fever, hyperglycaemia, and swallowing dysfunction in the Quality in Acute Stroke Care (QASC) Project--a mixed methods study.

PubMed

Dale, Simeon; Levi, Christopher; Ward, Jeanette; Grimshaw, Jeremy M; Jammali-Blasi, Asmara; D'Este, Catherine; Griffiths, Rhonda; Quinn, Clare; Evans, Malcolm; Cadilhac, Dominique; Cheung, N Wah; Middleton, Sandy

2015-02-01

The Quality in Acute Stroke Care (QASC) trial evaluated systematic implementation of clinical treatment protocols to manage fever, sugar, and swallow (FeSS protocols) in acute stroke care. This cluster-randomised controlled trial was conducted in 19 stroke units in Australia. To describe perceived barriers and enablers preimplementation to the introduction of the FeSS protocols and, postimplementation, to determine which of these barriers eventuated as actual barriers. Preimplementation: Workshops were held at the intervention stroke units (n = 10). The first workshop involved senior clinicians who identified perceived barriers and enablers to implementation of the protocols, the second workshop involved bedside clinicians. Postimplementation, an online survey with stroke champions from intervention sites was conducted. A total of 111 clinicians attended the preimplementation workshops, identifying 22 barriers covering four main themes: (a) need for new policies, (b) limited workforce (capacity), (c) lack of equipment, and (d) education and logistics of training staff. Preimplementation enablers identified were: support by clinical champions, medical staff, nursing management and allied health staff; easy adaptation of current protocols, care-plans, and local policies; and presence of specialist stroke unit staff. Postimplementation, only five of the 22 barriers identified preimplementation were reported as actual barriers to adoption of the FeSS protocols, namely, no previous use of insulin infusions; hyperglycaemic protocols could not be commenced without written orders; medical staff reluctance to use the ASSIST swallowing screening tool; poor level of engagement of medical staff; and doctors' unawareness of the trial. The process of identifying barriers and enablers preimplementation allowed staff to take ownership and to address barriers and plan for change. As only five of the 22 barriers identified preimplementation were reported to be actual barriers at completion of the trial, this suggests that barriers are often overcome whilst some are only ever perceived rather than actual barriers. © 2015 Sigma Theta Tau International.