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Sample records for deficiency impairs pericyte

  1. N-cadherin deficiency impairs pericyte recruitment, and not endothelial differentiation or sprouting, in embryonic stem cell-derived angiogenesis

    SciTech Connect

    Tillet, Emmanuelle . E-mail: emmanuelle.tillet@cea.fr; Vittet, Daniel; Feraud, Olivier; Moore, Robert; Kemler, Rolf; Huber, Philippe

    2005-11-01

    Endothelial cells express two classical cadherins, VE-cadherin and N-cadherin. VE-cadherin is absolutely required for vascular morphogenesis, but N-cadherin is thought to participate in vessel stabilization by interacting with periendothelial cells during vessel formation. However, recent data suggest a more critical role for N-cadherin in endothelium that would regulate angiogenesis, in part by controlling VE-cadherin expression. In this study, we have assessed N-cadherin function in vascular development using an in vitro model derived from embryonic stem (ES) cell differentiation. We show that pluripotent ES cells genetically null for N-cadherin can differentiate normally into endothelial cells. In addition, sprouting angiogenesis was unaltered, suggesting that N-cadherin is not essential for the early events of angiogenesis. However, the lack of N-cadherin led to an impairment in pericyte covering of endothelial outgrowths. We conclude that N-cadherin is necessary neither for vasculogenesis nor proliferation and migration of endothelial cells but is required for the subsequent maturation of endothelial sprouts by interacting with pericytes.

  2. Combined deficiency of Notch1 and Notch3 causes pericyte dysfunction, models CADASIL, and results in arteriovenous malformations

    PubMed Central

    Kofler, Natalie M.; Cuervo, Henar; Uh, Minji K.; Murtomäki, Aino; Kitajewski, Jan

    2015-01-01

    Pericytes regulate vessel stability and pericyte dysfunction contributes to retinopathies, stroke, and cancer. Here we define Notch as a key regulator of pericyte function during angiogenesis. In Notch1+/−; Notch3−/− mice, combined deficiency of Notch1 and Notch3 altered pericyte interaction with the endothelium and reduced pericyte coverage of the retinal vasculature. Notch1 and Notch3 were shown to cooperate to promote proper vascular basement membrane formation and contribute to endothelial cell quiescence. Accordingly, loss of pericyte function due to Notch deficiency exacerbates endothelial cell activation caused by Notch1 haploinsufficiency. Mice mutant for Notch1 and Notch3 develop arteriovenous malformations and display hallmarks of the ischemic stroke disease CADASIL. Thus, Notch deficiency compromises pericyte function and contributes to vascular pathologies. PMID:26563570

  3. Photoreceptor degeneration, structural remodeling and glial activation: a morphological study on a genetic mouse model for pericyte deficiency.

    PubMed

    Genové, G; Mollick, T; Johansson, K

    2014-10-24

    Interaction between pericytes and endothelial cells via platelet-derived growth factor B (PDGF-B) signaling is critical for the development of the retinal microvasculature. The PDGF-B retention motif controls the spatial distribution range of the growth factor in the vicinity of its producing endothelial cells allowing its recognition by PDGF receptor beta-(PDGFR-β)-carrying pericytes; this promotes recruitment of pericytes to the vascular basement membrane. Impairment of the PDGF-B signaling mechanism causes development of vascular abnormalities, and in the retina this consequently leads to defects in the neurological circuitry. The vascular pathology in the pdgf-b(ret/ret) (PDGF-B retention motif knockout) mouse retina has been previously reported; our study investigates the progressive neuronal defects and changes in the retinal morphology of this pericyte-deficient mouse model. Immunohistochemical analysis revealed retinal injuries to occur as early as postnatal day (P) 10 with substantial damage progressing from P15 and onward. Vascular abnormalities were apparent from P10, however, prominent neuronal defects were mostly observed from P15, beginning with the compromised integrity of the laminated retinal structure characterized by the presence of rosettes and focally distorted regions. Photoreceptor degeneration was observed by loss of both rod and cone cells, including the disassembly and altered structure of their synaptic terminals. Significant shortening of cone outer segments was observed from P10 and later stages; however, decrease in cone density was only observed at P28. Disorganization and dendrite remodeling of rod bipolar cells also added to the diminished neural and synaptic integrity. Moreover, in response to retinal injuries, Müller and microglial cells were observed to be in the reactive phenotype from P15 and onward. Such a sequence of events indicates that the pdgf-b(ret/ret) mouse model displays a short time frame between P10 and P15

  4. A Novel In Vitro Model to Study Pericytes in the Neurovascular Unit of the Developing Cortex

    PubMed Central

    Zehendner, Christoph M.; Wedler, Hannah E.; Luhmann, Heiko J.

    2013-01-01

    Cortical function is impaired in various disorders of the central nervous system including Alzheimer’s disease, autism and schizophrenia. Some of these disorders are speculated to be associated with insults in early brain development. Pericytes have been shown to regulate neurovascular integrity in development, health and disease. Hence, precisely controlled mechanisms must have evolved in evolution to operate pericyte proliferation, repair and cell fate within the neurovascular unit (NVU). It is well established that pericyte deficiency leads to NVU injury resulting in cognitive decline and neuroinflammation in cortical layers. However, little is known about the role of pericytes in pathophysiological processes of the developing cortex. Here we introduce an in vitro model that enables to precisely study pericytes in the immature cortex and show that moderate inflammation and hypoxia result in caspase-3 mediated pericyte loss. Using heterozygous EYFP-NG2 mouse mutants we performed live imaging of pericytes for several days in vitro. In addition we show that pericytes maintain their capacity to proliferate which may allow cell-based therapies like reprogramming of pericytes into induced neuronal cells in the presented approach. PMID:24278454

  5. What is a pericyte?

    PubMed

    Attwell, David; Mishra, Anusha; Hall, Catherine N; O'Farrell, Fergus M; Dalkara, Turgay

    2016-02-01

    Pericytes, spatially isolated contractile cells on capillaries, have been reported to control cerebral blood flow physiologically, and to limit blood flow after ischaemia by constricting capillaries and then dying. Paradoxically, a recent paper dismisses the idea of pericytes controlling cerebral blood flow, despite confirming earlier data showing a role for pericytes. We show that these discrepancies are apparent rather than real, and depend on the new paper defining pericytes differently from previous reports. An objective definition of different sub-classes of pericyte along the capillary bed is needed to develop novel therapeutic approaches for stroke and disorders caused by pericyte malfunction. PMID:26661200

  6. Oxidative stress induces loss of pericyte coverage and vascular instability in PGC-1α-deficient mice.

    PubMed

    García-Quintans, Nieves; Sánchez-Ramos, Cristina; Prieto, Ignacio; Tierrez, Alberto; Arza, Elvira; Alfranca, Arantzazu; Redondo, Juan Miguel; Monsalve, María

    2016-04-01

    Peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) is a regulator of mitochondrial oxidative metabolism and reactive oxygen species (ROS) homeostasis that is known to be inactivated in diabetic subjects. This study aimed to investigate the contribution of PGC-1α inactivation to the development of oxygen-induced retinopathy. We analyzed retinal vascular development in PGC-1α(-/-) mice. Retinal vasculature of PGC-1α(-/-) mice showed reduced pericyte coverage, a de-structured vascular plexus, and low perfusion. Exposure of PGC-1α(-/-) mice to hyperoxia during retinal vascular development exacerbated these vascular abnormalities, with extensive retinal hemorrhaging and highly unstructured areas as compared with wild-type mice. Structural analysis demonstrated a reduction in membrane-bound VE-cadherin, which was suggestive of defective intercellular junctions. Interestingly, PGC-1α(-/-) retinas showed a constitutive activation of the VEGF-A signaling pathway. This phenotype could be partially reversed by antioxidant administration, indicating that elevated production of ROS in the absence of PGC-1α could be a relevant factor in the alteration of the VEGF-A signaling pathway. Collectively, our findings suggest that PGC-1α control of ROS homeostasis plays an important role in the regulation of de novo angiogenesis and is required for vascular stability. PMID:26951478

  7. Omega-3 deficiency impairs honey bee learning

    PubMed Central

    Arien, Yael; Dag, Arnon; Zarchin, Shlomi; Masci, Tania

    2015-01-01

    Deficiency in essential omega-3 polyunsaturated fatty acids (PUFAs), particularly the long-chain form of docosahexaenoic acid (DHA), has been linked to health problems in mammals, including many mental disorders and reduced cognitive performance. Insects have very low long-chain PUFA concentrations, and the effect of omega-3 deficiency on cognition in insects has not been studied. We show a low omega-6:3 ratio of pollen collected by honey bee colonies in heterogenous landscapes and in many hand-collected pollens that we analyzed. We identified Eucalyptus as an important bee-forage plant particularly poor in omega-3 and high in the omega-6:3 ratio. We tested the effect of dietary omega-3 deficiency on olfactory and tactile associative learning of the economically highly valued honey bee. Bees fed either of two omega-3–poor diets, or Eucalyptus pollen, showed greatly reduced learning abilities in conditioned proboscis-extension assays compared with those fed omega-3–rich diets, or omega-3–rich pollen mixture. The effect on performance was not due to reduced sucrose sensitivity. Omega-3 deficiency also led to smaller hypopharyngeal glands. Bee brains contained high omega-3 concentrations, which were only slightly affected by diet, suggesting additional peripheral effects on learning. The shift from a low to high omega-6:3 ratio in the Western human diet is deemed a primary cause of many diseases and reduced mental health. A similar shift seems to be occurring in bee forage, possibly an important factor in colony declines. Our study shows the detrimental effect on cognitive performance of omega-3 deficiency in a nonmammal. PMID:26644556

  8. Pericyte TIMP3 and ADAMTS1 Modulate Vascular Stability after Kidney Injury

    PubMed Central

    Schrimpf, Claudia; Xin, Cuiyan; Campanholle, Gabriella; Gill, Sean E.; Stallcup, William; Lin, Shuei-Liong; Davis, George E.; Gharib, Sina A.; Humphreys, Benjamin D.

    2012-01-01

    Kidney pericytes are progenitors of scar-forming interstitial myofibroblasts that appear after injury. The function of kidney pericytes as microvascular cells and how these cells detach from peritubular capillaries and migrate to the interstitial space, however, are poorly understood. Here, we used an unbiased approach to identify genes in kidney pericytes relevant to detachment and differentiation in response to injury in vivo, with a particular focus on genes regulating proteolytic activity and angiogenesis. Kidney pericytes rapidly activated expression of a disintegrin and metalloprotease with thrombospondin motifs-1 (ADAMTS1) and downregulated its inhibitor, tissue inhibitor of metalloproteinase 3 (TIMP3) in response to injury. Similarly to brain pericytes, kidney pericytes bound to and stabilized capillary tube networks in three-dimensional gels and inhibited metalloproteolytic activity and angiogenic signaling in endothelial cells. In contrast, myofibroblasts did not have these vascular stabilizing functions despite their derivation from kidney pericytes. Pericyte-derived TIMP3 stabilized and ADAMTS1 destabilized the capillary tubular networks. Furthermore, mice deficient in Timp3 had a spontaneous microvascular phenotype in the kidney resulting from overactivated pericytes and were more susceptible to injury-stimulated microvascular rarefaction with an exuberant fibrotic response. Taken together, these data support functions for kidney pericytes in microvascular stability, highlight central roles for regulators of extracellular proteolytic activity in capillary homoeostasis, and identify ADAMTS1 as a marker of activation of kidney pericytes. PMID:22383695

  9. Brain and Retinal Pericytes: Origin, Function and Role.

    PubMed

    Trost, Andrea; Lange, Simona; Schroedl, Falk; Bruckner, Daniela; Motloch, Karolina A; Bogner, Barbara; Kaser-Eichberger, Alexandra; Strohmaier, Clemens; Runge, Christian; Aigner, Ludwig; Rivera, Francisco J; Reitsamer, Herbert A

    2016-01-01

    Pericytes are specialized mural cells located at the abluminal surface of capillary blood vessels, embedded within the basement membrane. In the vascular network these multifunctional cells fulfil diverse functions, which are indispensable for proper homoeostasis. They serve as microvascular stabilizers, are potential regulators of microvascular blood flow and have a central role in angiogenesis, as they for example regulate endothelial cell proliferation. Furthermore, pericytes, as part of the neurovascular unit, are a major component of the blood-retina/brain barrier. CNS pericytes are a heterogenic cell population derived from mesodermal and neuro-ectodermal germ layers acting as modulators of stromal and niche environmental properties. In addition, they display multipotent differentiation potential making them an intriguing target for regenerative therapies. Pericyte-deficiencies can be cause or consequence of many kinds of diseases. In diabetes, for instance, pericyte-loss is a severe pathological process in diabetic retinopathy (DR) with detrimental consequences for eye sight in millions of patients. In this review, we provide an overview of our current understanding of CNS pericyte origin and function, with a special focus on the retina in the healthy and diseased. Finally, we highlight the role of pericytes in de- and regenerative processes. PMID:26869887

  10. Brain and Retinal Pericytes: Origin, Function and Role

    PubMed Central

    Trost, Andrea; Lange, Simona; Schroedl, Falk; Bruckner, Daniela; Motloch, Karolina A.; Bogner, Barbara; Kaser-Eichberger, Alexandra; Strohmaier, Clemens; Runge, Christian; Aigner, Ludwig; Rivera, Francisco J.; Reitsamer, Herbert A.

    2016-01-01

    Pericytes are specialized mural cells located at the abluminal surface of capillary blood vessels, embedded within the basement membrane. In the vascular network these multifunctional cells fulfil diverse functions, which are indispensable for proper homoeostasis. They serve as microvascular stabilizers, are potential regulators of microvascular blood flow and have a central role in angiogenesis, as they for example regulate endothelial cell proliferation. Furthermore, pericytes, as part of the neurovascular unit, are a major component of the blood-retina/brain barrier. CNS pericytes are a heterogenic cell population derived from mesodermal and neuro-ectodermal germ layers acting as modulators of stromal and niche environmental properties. In addition, they display multipotent differentiation potential making them an intriguing target for regenerative therapies. Pericyte-deficiencies can be cause or consequence of many kinds of diseases. In diabetes, for instance, pericyte-loss is a severe pathological process in diabetic retinopathy (DR) with detrimental consequences for eye sight in millions of patients. In this review, we provide an overview of our current understanding of CNS pericyte origin and function, with a special focus on the retina in the healthy and diseased. Finally, we highlight the role of pericytes in de- and regenerative processes. PMID:26869887

  11. Impaired clot lysis in copper-deficient mice

    SciTech Connect

    Lynch, S.M.; Klevay, L.M. )

    1991-03-15

    Cu-deficient mice exhibit atrial thrombosis but have significantly lowered plasma coagulation factor V and VIII activities. To investigate the effects of a dietary Cu deficiency on clot lysis, groups of adult male and female Swiss-Webster mice were fed Cu-supplemented or -deficient diets with deionized water for 49 days. Animals were exsanguinated under pentobarbital anesthesia; platelet-poor plasma prepared and assayed for euglobulin clot lysis time (ECLT) and antithrombin III activity. A protamine sulfate test was also performed. The highly significant ECLT prolongation in Cu-deficient mice clearly demonstrates that critical components of the physiological clot-lysing mechanism must be severely impaired in these animals. These results may help to explain the thrombotic sequelae of a dietary Cu deficiency in mice.

  12. Behavioral impairments in animal models for zinc deficiency

    PubMed Central

    Hagmeyer, Simone; Haderspeck, Jasmin Carmen; Grabrucker, Andreas Martin

    2015-01-01

    Apart from teratogenic and pathological effects of zinc deficiency such as the occurrence of skin lesions, anorexia, growth retardation, depressed wound healing, altered immune function, impaired night vision, and alterations in taste and smell acuity, characteristic behavioral changes in animal models and human patients suffering from zinc deficiency have been observed. Given that it is estimated that about 17% of the worldwide population are at risk for zinc deficiency and that zinc deficiency is associated with a variety of brain disorders and disease states in humans, it is of major interest to investigate, how these behavioral changes will affect the individual and a putative course of a disease. Thus, here, we provide a state of the art overview about the behavioral phenotypes observed in various models of zinc deficiency, among them environmentally produced zinc deficient animals as well as animal models based on a genetic alteration of a particular zinc homeostasis gene. Finally, we compare the behavioral phenotypes to the human condition of mild to severe zinc deficiency and provide a model, how zinc deficiency that is associated with many neurodegenerative and neuropsychological disorders might modify the disease pathologies. PMID:25610379

  13. Fancb deficiency impairs hematopoietic stem cell function

    PubMed Central

    Du, Wei; Amarachintha, Surya; Erden, Ozlem; Wilson, Andrew; Meetei, Amom Ruhikanta; Andreassen, Paul R.; Namekawa, Satoshi H.; Pang, Qishen

    2015-01-01

    Fanconi anemia (FA) is a genetic disorder characterized by bone marrow failure, variable congenital malformations and a predisposition to malignancies. FANCB (also known as FAAP95), is the only X-linked FA gene discovered thus far. In the present study, we investigated hematopoiesis in adult Fancb deficient (Fancb−/y) mice and found that Fancb−/y mice have decreased hematopoietic stem cell (HSC) quiescence accompanied by reduced progenitor activity in vitro and reduced repopulating capacity in vivo. Like other FA mouse models previously reported, the hematopoietic system of Fancb−/y mice is hypersensitive to DNA cross-linking agent mitomycin C (MMC), which induces bone marrow failure in Fancb−/y mice. Furthermore, Fancb−/y BM exhibits slower recovery kinetics and less tolerance to myelotoxic stress induced by 5-fluorouracil than wild-type littermates. RNA-seq analysis reveals altered expression of genes involved in HSC function and cell cycle regulation in Fancb−/y HSC and progenitor cells. Thus, this Fancb−/y mouse model provides a novel approach for studying the critical role of the FA pathway not only in germ cell development but also in the maintenance of HSC function. PMID:26658157

  14. Essential fatty acid deficiency in mice impairs lactose digestion.

    PubMed

    Lukovac, S; Los, E L; Stellaard, F; Rings, E H H M; Verkade, H J

    2008-09-01

    Essential fatty acid (EFA) deficiency in mice induces fat malabsorption. We previously reported indications that the underlying mechanism is located at the level of the intestinal mucosa. We have investigated the effects of EFA deficiency on small intestinal morphology and function. Mice were fed an EFA-deficient or control diet for 8 wk. A 72-h fat balance, the EFA status, and small intestinal histology were determined. Carbohydrate absorptive and digestive capacities were assessed by stable isotope methodology after administration of [U-(13)C]glucose and [1-(13)C]lactose. The mRNA expression and enzyme activity of lactase, and concentrations of the EFA linoleic acid (LA) were measured in small intestinal mucosa. Mice fed the EFA-deficient diet were markedly EFA-deficient with a profound fat malabsorption. EFA deficiency did not affect the histology or proliferative capacity of the small intestine. Blood [13C6]glucose appearance and disappearance were similar in both groups, indicating unaffected monosaccharide absorption. In contrast, blood appearance of [13C]glucose, originating from [1-(13)C]lactose, was delayed in EFA-deficient mice. EFA deficiency profoundly reduced lactase activity (-58%, P<0.01) and mRNA expression (-55%, P<0.01) in mid-small intestine. Both lactase activity and its mRNA expression strongly correlated with mucosal LA concentrations (r=0.77 and 0.79, respectively, P<0.01). EFA deficiency in mice inhibits the capacity to digest lactose but does not affect small intestinal histology. These data underscore the observation that EFA deficiency functionally impairs the small intestine, which in part may be mediated by low LA levels in the enterocytes. PMID:18653724

  15. Inherited BCL10 deficiency impairs hematopoietic and nonhematopoietic immunity.

    PubMed

    Torres, Juan Manuel; Martinez-Barricarte, Rubén; García-Gómez, Sonia; Mazariegos, Marina S; Itan, Yuval; Boisson, Bertrand; Rholvarez, Rita; Jiménez-Reinoso, Anaïs; del Pino, Lucia; Rodríguez-Pena, Rebeca; Ferreira, Antonio; Hernández-Jiménez, Enrique; Toledano, Victor; Cubillos-Zapata, Carolina; Díaz-Almirón, Mariana; López-Collazo, Eduardo; Unzueta-Roch, José L; Sánchez-Ramón, Silvia; Regueiro, Jose R; López-Granados, Eduardo; Casanova, Jean-Laurent; Pérez de Diego, Rebeca

    2014-12-01

    Heterotrimers composed of B cell CLL/lymphoma 10 (BCL10), mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), and caspase recruitment domain-containing (CARD) family adaptors play a role in NF-κB activation and have been shown to be involved in both the innate and the adaptive arms of immunity in murine models. Moreover, individuals with inherited defects of MALT1, CARD9, and CARD11 present with immunological and clinical phenotypes. Here, we characterized a case of autosomal-recessive, complete BCL10 deficiency in a child with a broad immunodeficiency, including defects of both hematopoietic and nonhematopoietic immunity. The patient died at 3 years of age and was homozygous for a loss-of-expression, loss-of-function BCL10 mutation. The effect of BCL10 deficiency was dependent on the signaling pathway, and, for some pathways, the cell type affected. Despite the noted similarities to BCL10 deficiency in mice, including a deficient adaptive immune response, human BCL10 deficiency in this patient resulted in a number of specific features within cell populations. Treatment of the patient's myeloid cells with a variety of pathogen-associated molecular pattern molecules (PAMPs) elicited a normal response; however, NF-κB-mediated fibroblast functions were dramatically impaired. The results of this study indicate that inherited BCL10 deficiency should be considered in patients with combined immunodeficiency with B cell, T cell, and fibroblast defects. PMID:25365219

  16. Inherited BCL10 deficiency impairs hematopoietic and nonhematopoietic immunity

    PubMed Central

    Torres, Juan Manuel; Martinez-Barricarte, Rubén; García-Gómez, Sonia; Mazariegos, Marina S.; Itan, Yuval; Boisson, Bertrand; ρlvarez, Rita; Jiménez-Reinoso, Anaïs; del Pino, Lucia; Rodríguez-Pena, Rebeca; Ferreira, Antonio; Hernández-Jiménez, Enrique; Toledano, Victor; Cubillos-Zapata, Carolina; Díaz-Almirón, Mariana; López-Collazo, Eduardo; Unzueta-Roch, José L.; Sánchez-Ramón, Silvia; Regueiro, Jose R.; López-Granados, Eduardo; Casanova, Jean-Laurent; Pérez de Diego, Rebeca

    2014-01-01

    Heterotrimers composed of B cell CLL/lymphoma 10 (BCL10), mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), and caspase recruitment domain–containing (CARD) family adaptors play a role in NF-κB activation and have been shown to be involved in both the innate and the adaptive arms of immunity in murine models. Moreover, individuals with inherited defects of MALT1, CARD9, and CARD11 present with immunological and clinical phenotypes. Here, we characterized a case of autosomal-recessive, complete BCL10 deficiency in a child with a broad immunodeficiency, including defects of both hematopoietic and nonhematopoietic immunity. The patient died at 3 years of age and was homozygous for a loss-of-expression, loss-of-function BCL10 mutation. The effect of BCL10 deficiency was dependent on the signaling pathway, and, for some pathways, the cell type affected. Despite the noted similarities to BCL10 deficiency in mice, including a deficient adaptive immune response, human BCL10 deficiency in this patient resulted in a number of specific features within cell populations. Treatment of the patient’s myeloid cells with a variety of pathogen-associated molecular pattern molecules (PAMPs) elicited a normal response; however, NF-κB–mediated fibroblast functions were dramatically impaired. The results of this study indicate that inherited BCL10 deficiency should be considered in patients with combined immunodeficiency with B cell, T cell, and fibroblast defects. PMID:25365219

  17. Activation of the Wnt/Planar Cell Polarity Pathway Is Required for Pericyte Recruitment during Pulmonary Angiogenesis

    PubMed Central

    Yuan, Ke; Orcholski, Mark E.; Panaroni, Cristina; Shuffle, Eric M.; Huang, Ngan F.; Jiang, Xinguo; Tian, Wen; Vladar, Eszter K.; Wang, Lingli; Nicolls, Mark R.; Wu, Joy Y.; de Jesus Perez, Vinicio A.

    2016-01-01

    Pericytes are perivascular cells localized to capillaries that promote vessel maturation, and their absence can contribute to vessel loss. Whether impaired endothelial–pericyte interaction contributes to small vessel loss in pulmonary arterial hypertension (PAH) is unclear. Using 3G5-specific, immunoglobulin G–coated magnetic beads, we isolated pericytes from the lungs of healthy subjects and PAH patients, followed by lineage validation. PAH pericytes seeded with healthy pulmonary microvascular endothelial cells failed to associate with endothelial tubes, resulting in smaller vascular networks compared to those with healthy pericytes. After the demonstration of abnormal polarization toward endothelium via live-imaging and wound-healing studies, we screened PAH pericytes for abnormalities in the Wnt/planar cell polarity (PCP) pathway, which has been shown to regulate cell motility and polarity in the pulmonary vasculature. PAH pericytes had reduced expression of frizzled 7 (Fzd7) and cdc42, genes crucial for Wnt/PCP activation. With simultaneous knockdown of Fzd7 and cdc42 in healthy pericytes in vitro and in a murine model of angiogenesis, motility and polarization toward pulmonary microvascular endothelial cells were reduced, whereas with restoration of both genes in PAH pericytes, endothelial–pericyte association was improved, with larger vascular networks. These studies suggest that the motility and polarity of pericytes during pulmonary angiogenesis are regulated by Wnt/PCP activation, which can be targeted to prevent vessel loss in PAH. PMID:25447046

  18. Impaired degradation of leukotrienes in patients with peroxisome deficiency disorders.

    PubMed Central

    Mayatepek, E; Lehmann, W D; Fauler, J; Tsikas, D; Frölich, J C; Schutgens, R B; Wanders, R J; Keppler, D

    1993-01-01

    The degradation of leukotrienes by beta-oxidation from the omega-end proceeds in peroxisomes (Jedlitschky et al. J. Biol. Chem. 1991. 266:24763-24772). Peroxisomal degradation of leukotrienes was studied in humans by analyses of endogenous leukotrienes in urines from eight patients with biochemically established peroxisome deficiency disorder and eight age- and sex-matched healthy infant controls. Leukotriene metabolites were separated by high-performance liquid chromatography, quantified by radioimmunoassays, and identified as well as quantified by gas chromatography-mass spectrometry. Urinary leukotriene E4 (LTE4) and N-acetyl-LTE4 excretions, relative to creatinine, were increased > 10-fold in the patients in comparison to healthy infants. The beta-oxidation product omega-carboxy-tetranor-LTE3 averaged 0.05 mumol/mol creatinine in the controls but was not detectable in the patients. However, omega-carboxy-LTE4 (median 13.6 mumol/mol creatinine) was significantly increased in the patients' urine, whereas LTB4 (median 0.07 mumol/mol creatinine) and omega-carboxy-LTB4 were detected exclusively in the urines of the patients. These data indicate an impairment of the inactivation and degradation of both LTE4 and LTB4 in patients with peroxisomal deficiency. The increased levels of the biologically active, proinflammatory mediators LTE4 and LTB4 might be of pathophysiological significance in peroxisome deficiency disorders. This is the first and so far only condition with a pronounced urinary excretion of omega-carboxy-LTE4, omega-carboxy-LTB4, and LTB4. This impaired catabolism of leukotrienes and the altered pattern of metabolites may be of diagnostic value. These findings underline the essential role of peroxisomes in the catabolism of leukotrienes in humans. PMID:8450067

  19. Fibroblast growth factor 15 deficiency impairs liver regeneration in mice

    PubMed Central

    Kong, Bo; Huang, Jiansheng; Zhu, Yan; Li, Guodong; Williams, Jessica; Shen, Steven; Aleksunes, Lauren M.; Richardson, Jason R.; Apte, Udayan; Rudnick, David A.

    2014-01-01

    Fibroblast growth factor (FGF) 15 (human homolog, FGF19) is an endocrine FGF highly expressed in the small intestine of mice. Emerging evidence suggests that FGF15 is critical for regulating hepatic functions; however, the role of FGF15 in liver regeneration is unclear. This study assessed whether liver regeneration is altered in FGF15 knockout (KO) mice following 2/3 partial hepatectomy (PHx). The results showed that FGF15 KO mice had marked mortality, with the survival rate influenced by genetic background. Compared with wild-type mice, the KO mice displayed extensive liver necrosis and marked elevation of serum bile acids and bilirubin. Furthermore, hepatocyte proliferation was reduced in the KO mice because of impaired cell cycle progression. After PHx, the KO mice had weaker activation of signaling pathways that are important for liver regeneration, including signal transducer and activator of transcription 3, nuclear factor-κB, and mitogen-activated protein kinase. Examination of the KO mice at early time points after PHx revealed a reduced and/or delayed induction of immediate-early response genes, including growth-control transcription factors that are critical for liver regeneration. In conclusion, the results suggest that FGF15 deficiency severely impairs liver regeneration in mice after PHx. The underlying mechanism is likely the result of disrupted bile acid homeostasis and impaired priming of hepatocyte proliferation. PMID:24699334

  20. Carnitine palmitoyltransferase 1C deficiency causes motor impairment and hypoactivity.

    PubMed

    Carrasco, Patricia; Jacas, Jordi; Sahún, Ignasi; Muley, Helena; Ramírez, Sara; Puisac, Beatriz; Mezquita, Pau; Pié, Juan; Dierssen, Mara; Casals, Núria

    2013-11-01

    Carnitine palmitoyltransferase 1c (CPT1C), a brain-specific protein localized in the endoplasmic reticulum of neurons, is expressed in almost all brain regions, but its only known functions to date are involved in the hypothalamic control of energy homeostasis and in hippocampus-dependent spatial learning. To identify other physiological and behavioral functions of this protein, we performed a battery of neurological tests on Cpt1c-deficient mice. The animals showed intact autonomic and sensory systems, but some motor disturbances were observed. A more detailed study of motor function revealed impaired coordination and gait, severe muscle weakness, and reduced daily locomotor activity. Analysis of motor function in these mice at ages of 6-24 weeks showed that motor disorders were already present in young animals and that impairment increased progressively with age. Analysis of CPT1C expression in different motor brain areas during development revealed that CPT1C levels were low from birth to postnatal day 10 and then rapidly increased peaking at postnatal day 21, which suggests that CPT1C plays a relevant role in motor function during and after weaning. As CPT1C is known to regulate ceramide levels, we measured these biolipids in different motor areas in adult mice. Cerebellar, striatum, and motor cortex extracts from Cpt1c knockout mice showed reduced levels of ceramide and its derivative sphingosine when compared to wild-type animals. Our results indicate that altered ceramide metabolism in motor brain areas induced by Cpt1c deficiency causes progressive motor dysfunction from a young age. PMID:23973755

  1. Iron Deficiency Impairs Intra-Hepatic Lymphocyte Mediated Immune Response.

    PubMed

    Bonaccorsi-Riani, Eliano; Danger, Richard; Lozano, Juan José; Martinez-Picola, Marta; Kodela, Elisavet; Mas-Malavila, Roser; Bruguera, Miquel; Collins, Helen L; Hider, Robert C; Martinez-Llordella, Marc; Sanchez-Fueyo, Alberto

    2015-01-01

    Hepatic expression of iron homeostasis genes and serum iron parameters predict the success of immunosuppression withdrawal following clinical liver transplantation, a phenomenon known as spontaneous operational tolerance. In experimental animal models, spontaneous liver allograft tolerance is established through a process that requires intra-hepatic lymphocyte activation and deletion. Our aim was to determine if changes in systemic iron status regulate intra-hepatic lymphocyte responses. We used a murine model of lymphocyte-mediated acute liver inflammation induced by Concanavalin A (ConA) injection employing mice fed with an iron-deficient (IrDef) or an iron-balanced diet (IrRepl). While the mild iron deficiency induced by the IrDef diet did not significantly modify the steady state immune cell repertoire and systemic cytokine levels, it significantly dampened inflammatory liver damage after ConA challenge. These findings were associated with a marked decrease in T cell and NKT cell activation following ConA injection in IrDef mice. The decreased liver injury observed in IrDef mice was independent from changes in the gut microflora, and was replicated employing an iron specific chelator that did not modify intra-hepatic hepcidin secretion. Furthermore, low-dose iron chelation markedly impaired the activation of isolated T cells in vitro. All together, these results suggest that small changes in iron homeostasis can have a major effect in the regulation of intra-hepatic lymphocyte mediated responses. PMID:26287688

  2. Toll-Like Receptor 4 Deficiency Impairs Motor Coordination

    PubMed Central

    Zhu, Jian-Wei; Li, Yi-Fei; Wang, Zhao-Tao; Jia, Wei-Qiang; Xu, Ru-Xiang

    2016-01-01

    The cerebellum plays an essential role in balance and motor coordination. Purkinje cells (PCs) are the sole output neurons of the cerebellar cortex and are critical for the execution of its functions, including motor coordination. Toll-like receptor (TLR) 4 is involved in the innate immune response and is abundantly expressed in the central nervous system; however, little is known about its role in cerebellum-related motor functions. To address this question, we evaluated motor behavior in TLR4 deficient mice. We found that TLR4−∕− mice showed impaired motor coordination. Morphological analyses revealed that TLR4 deficiency was associated with a reduction in the thickness of the molecular layer of the cerebellum. TLR4 was highly expressed in PCs but not in Bergmann glia or cerebellar granule cells; however, loss of TLR4 decreased the number of PCs. These findings suggest a novel role for TLR4 in cerebellum-related motor coordination through maintenance of the PC population. PMID:26909014

  3. Cathepsin E Deficiency Impairs Autophagic Proteolysis in Macrophages

    PubMed Central

    Tsukuba, Takayuki; Yanagawa, Michiyo; Kadowaki, Tomoko; Takii, Ryosuke; Okamoto, Yoshiko; Sakai, Eiko; Okamoto, Kuniaki; Yamamoto, Kenji

    2013-01-01

    Cathepsin E is an endosomal aspartic proteinase that is predominantly expressed in immune-related cells. Recently, we showed that macrophages derived from cathepsin E-deficient (CatE−/−) mice display accumulation of lysosomal membrane proteins and abnormal membrane trafficking. In this study, we demonstrated that CatE−/− macrophages exhibit abnormalities in autophagy, a bulk degradation system for aggregated proteins and damaged organelles. CatE−/− macrophages showed increased accumulation of autophagy marker proteins such as LC3 and p62, and polyubiquitinated proteins. Cathepsin E deficiency also altered autophagy-related signaling pathways such as those mediated by the mammalian target of rapamycin (mTOR), Akt, and extracellular signal-related kinase (ERK). Furthermore, immunofluorescence microscopy analyses showed that LC3-positive vesicles were merged with acidic compartments in wild-type macrophages, but not in CatE−/− macrophages, indicating inhibition of fusion of autophagosome with lysosomes in CatE−/− cells. Delayed degradation of LC3 protein was also observed under starvation-induced conditions. Since the autophagy system is involved in the degradation of damaged mitochondria, we examined the accumulation of damaged mitochondria in CatE−/− macrophages. Several mitochondrial abnormalities such as decreased intracellular ATP levels, depolarized mitochondrial membrane potential, and decreased mitochondrial oxygen consumption were observed. Such mitochondrial dysfunction likely led to the accompanying oxidative stress. In fact, CatE−/− macrophages showed increased reactive oxygen species (ROS) production and up-regulation of oxidized peroxiredoxin-6, but decreased antioxidant glutathione. These results indicate that cathepsin E deficiency causes autophagy impairment concomitantly with increased aberrant mitochondria as well as increased oxidative stress. PMID:24340026

  4. Pericytes in chronic lung disease.

    PubMed

    Rowley, Jessica E; Johnson, Jill R

    2014-01-01

    Pericytes are mesenchymal cells embedded within the abluminal surface of the endothelium of microvessels such as capillaries, pre-capillary arterioles, post-capillary and collecting venules, where they maintain microvascular homeostasis and participate in angiogenesis. In addition to their roles in supporting the vasculature and facilitating leukocyte extravasation, pericytes have been recently investigated as a subpopulation of mesenchymal stem cells (MSCs) due to their capacity to differentiate into numerous cell types including the classic MSC triad, i.e. osteocytes, chondrocytes and adipocytes. Other studies in models of fibrotic inflammatory disease of the lung have demonstrated a vital role of pericytes in myofibroblast activation, collagen deposition and microvascular remodelling, which are hallmark features of chronic lung diseases such as asthma, chronic obstructive pulmonary disorder, pulmonary fibrosis and pulmonary hypertension. Further studies into the mechanisms of the pericyte-to-myofibroblast transition and migration to fibrotic foci will hopefully clarify the role of these cells in chronic lung disease and confirm the importance of pericytes in human fibrotic pulmonary disease. PMID:25034005

  5. Ferroportin deficiency impairs manganese metabolism in flatiron mice

    PubMed Central

    Seo, Young Ah; Wessling-Resnick, Marianne

    2015-01-01

    We examined the physiologic role of ferroportin (Fpn) in manganese (Mn) export using flatiron (ffe/+) mice, a genetic model of Fpn deficiency. Blood (0.0123 vs. 0.0107 mg/kg; P = 0.0003), hepatic (1.06 vs. 0.96 mg/kg; P = 0.0125), and bile Mn levels (79 vs. 38 mg/kg; P = 0.0204) were reduced in ffe/+ mice compared to +/+ controls. Erythrocyte Mn–superoxide dismutase was also reduced at 6 (0.154 vs. 0.096, P = 0.0101), 9 (0.131 vs. 0.089, P = 0.0162), and 16 weeks of age (0.170 vs. 0.090 units/mg protein/min; P < 0.0001). 54Mn uptake after intragastric gavage was markedly reduced in ffe/+ mice (0.0187 vs. 0.0066% dose; P = 0.0243), while clearance of injected isotope was similar in ffe/+ and +/+ mice. These values were compared to intestinal absorption of 59Fe, which was significantly reduced in ffe/+ mice (8.751 vs. 3.978% dose; P = 0.0458). The influence of the ffe mutation was examined in dopaminergic SH-SY5Y cells and human embryonic HEK293T cells. While expression of wild-type Fpn reversed Mn-induced cytotoxicity, ffe mutant H32R failed to confer protection. These combined results demonstrate that Fpn plays a central role in Mn transport and that flatiron mice provide an excellent genetic model to explore the role of this exporter in Mn homeostasis.—Seo, Y. A., Wessling-Resnick, M. Ferroportin deficiency impairs manganese metabolism in flatiron mice. PMID:25782988

  6. Crybb2 deficiency impairs fertility in female mice

    SciTech Connect

    Gao, Qian; Sun, Li-Li; Xiang, Fen-Fen; Gao, Li; Jia, Yin; Zhang, Jian-Rong; Tao, Hai-Bo; Zhang, Jun-Jie; Li, Wen-Jie

    2014-10-10

    Highlights: • Crybb2 deletion impaired female fertility. • Crybb2 deletion dramatically affected the production of reproduction-related hormones and hormone response. • Crybb2 deletion impaired follicular development and inhibited the proliferation of granulosa cells. • Crybb2 deletion promoted follicular atresia and apoptosis in granulosa cells. - Abstract: Beta-B2-crystallin (CRYBB2), encoded by Crybb2 gene, is a major protein in the mammalian eye lens that plays an important role in maintaining the transparency of the ocular lens. However, CRYBB2 also plays important roles in many extra-lenticular tissues and organs such as the retina, brain and testis. Our previous studies demonstrated that male Crybb2 deficient (Crybb2{sup −/−}) mice have reduced fertility compared with wild-type (WT) mice, while female Crybb2{sup −/−} mice exhibited reduced ovary weights and shorter estrous cycle percentages. Here we specifically investigated the role of CRYBB2 in the female reproductive system. Our studies revealed that ovaries from female Crybb2{sup −/−} mice exhibited significantly reduced numbers of primordial, secondary and pre-ovulatory follicles when compared with WT mice, while the rate of atretic follicles was also increased. Additionally, fewer eggs were collected from the oviduct of Crybb2{sup −/−} female mice after superovulation. Estrogen levels were higher in the metestrus and diestrus cycles of female Crybb2{sup −/−} mice, while progesterone levels were lower in diestrus cycles. Furthermore, the expression of survival and cell cycle genes, Bcl-2, Cdk4 and Ccnd2, were significantly decreased in granulosa cells isolated from female Crybb2{sup −/−} mice, consistent with the predominant expression of CRYBB2 in ovarian granulosa cells. Our results reveal a critical role for CRYBB2 in female fertility and specific effects on the proliferation and survival status of ovarian granulosa cells.

  7. Pericyte Antigens in Perivascular Soft Tissue Tumors

    PubMed Central

    Shen, Jia; Shrestha, Swati; Yen, Yu-Hsin; Asatrian, Greg; Mravic, Marco; Soo, Chia; Ting, Kang; Dry, Sarah M.; Peault, Bruno; James, Aaron W.

    2015-01-01

    Introduction Perivascular soft tissue tumors are relatively uncommon neoplasms of unclear line of differentiation, although most are presumed to originate from pericytes or modified perivascular cells. Among these, glomus tumor, myopericytoma, and angioleiomyoma share a spectrum of histologic findings and a perivascular growth pattern. In contrast, solitary fibrous tumor (previously termed hemangiopericytoma) was once hypothesized to have pericytic differentiation. Methods Here, we systematically examine pericyte immunohistochemical markers among glomus tumor (including malignant glomus tumor), myopericytoma, angioleiomyoma, and solitary fibrous tumor. Immunohistochemical staining and semiquantification was performed using well-defined pericyte antigens, including αSMA, CD146, and PDGFRβ. Results Glomus tumor and myopericytoma demonstrate diffuse staining for all pericyte markers, including immunohistochemical reactivity for αSMA, CD146, and PDGFRβ. Malignant glomus tumors all showed some degree of pericyte marker immunoreactivity, although it was significantly reduced. Angioleiomyoma shared a similar αSMA + CD146 + PDGFRβ+ immunophenotype; however, this was predominantly seen in the areas of perivascular tumor growth. Solitary fibrous tumors showed patchy PDGFRβ immunoreactivity only. Discussion In summary, pericyte marker expression is a ubiquitous finding in glomus tumor, myopericytoma, and angioleiomyoma. Malignant glomus tumor shows a comparative reduction in pericyte marker expression, which may represent partial loss of pericytic differentiation. Pericyte markers are essentially not seen in solitary fibrous tumor. The combination of αSMA, CD146, and PDGFRβ immunohistochemical stainings may be of utility for the evaluation of pericytic differentiation in soft tissue tumors. PMID:26085647

  8. Impaired Calcium Entry into Cells Is Associated with Pathological Signs of Zinc Deficiency12

    PubMed Central

    O’Dell, Boyd L.; Browning, Jimmy D.

    2013-01-01

    Zinc is an essential trace element whose deficiency gives rise to specific pathological signs. These signs occur because an essential metabolic function is impaired as the result of failure to form or maintain a specific metal-ion protein complex. Although zinc is a component of many essential metalloenzymes and transcription factors, few of these have been identified with a specific sign of incipient zinc deficiency. Zinc also functions as a structural component of other essential proteins. Recent research with Swiss murine fibroblasts, 3T3 cells, has shown that zinc deficiency impairs calcium entry into cells, a process essential for many cell functions, including proliferation, maturation, contraction, and immunity. Impairment of calcium entry and the subsequent failure of cell proliferation could explain the growth failure associated with zinc deficiency. Defective calcium uptake is associated with impaired nerve transmission and pathology of the peripheral nervous system, as well as the failure of platelet aggregation and the bleeding tendency of zinc deficiency. There is a strong analogy between the pathology of genetic diseases that result in impaired calcium entry and other signs of zinc deficiency, such as decreased and cyclic food intake, taste abnormalities, abnormal water balance, skin lesions, impaired reproduction, depressed immunity, and teratogenesis. This analogy suggests that failure of calcium entry is involved in these signs of zinc deficiency as well. PMID:23674794

  9. Impaired calcium entry into cells is associated with pathological signs of zinc deficiency.

    PubMed

    O'Dell, Boyd L; Browning, Jimmy D

    2013-05-01

    Zinc is an essential trace element whose deficiency gives rise to specific pathological signs. These signs occur because an essential metabolic function is impaired as the result of failure to form or maintain a specific metal-ion protein complex. Although zinc is a component of many essential metalloenzymes and transcription factors, few of these have been identified with a specific sign of incipient zinc deficiency. Zinc also functions as a structural component of other essential proteins. Recent research with Swiss murine fibroblasts, 3T3 cells, has shown that zinc deficiency impairs calcium entry into cells, a process essential for many cell functions, including proliferation, maturation, contraction, and immunity. Impairment of calcium entry and the subsequent failure of cell proliferation could explain the growth failure associated with zinc deficiency. Defective calcium uptake is associated with impaired nerve transmission and pathology of the peripheral nervous system, as well as the failure of platelet aggregation and the bleeding tendency of zinc deficiency. There is a strong analogy between the pathology of genetic diseases that result in impaired calcium entry and other signs of zinc deficiency, such as decreased and cyclic food intake, taste abnormalities, abnormal water balance, skin lesions, impaired reproduction, depressed immunity, and teratogenesis. This analogy suggests that failure of calcium entry is involved in these signs of zinc deficiency as well. PMID:23674794

  10. Improved effect of Pycnogenol on impaired spatial memory function in partial androgen deficiency rat model.

    PubMed

    Hasegawa, Noboru; Mochizuki, Miyako

    2009-06-01

    The improved effect of Pycnogenol on impaired spatial memory function was studied in orchidectomized rats. Endogenous testosterone levels were decreased by approximately one-half for 3 months after castration. In the radial arm maze, castration significantly impaired working and reference memory function without lowering motor function. Pycnogenol increased the NGF content in the hippocampus and cortex, and improved the spatial memory impairment. These observations confirmed that diagnostic accuracy can be improved by Pycnogenol in androgen-deficient rats. PMID:19142987

  11. Folliculostellate cell interacts with pericyte via TGFβ2 in rat anterior pituitary.

    PubMed

    Tsukada, Takehiro; Azuma, Morio; Horiguchi, Kotaro; Fujiwara, Ken; Kouki, Tom; Kikuchi, Motoshi; Yashiro, Takashi

    2016-05-01

    The anterior pituitary gland comprises five types of endocrine cells plus non-endocrine cells including folliculostellate cells, endothelial cells, and capillary mural cells (pericytes). In addition to being controlled by the hypothalamic-pituitary-target organ axis, the functions of these cells are likely regulated by local cell and extracellular matrix (ECM) interactions. However, these complex interactions are not fully understood. We investigated folliculostellate cell-mediated cell-to-cell interaction. Using S100β-GFP transgenic rats, which express GFP in folliculostellate cells, we designed a three-dimensional cell culture to examine the effects of folliculostellate cells. Interestingly, removal of folliculostellate cells reduced collagen synthesis (Col1a1 and Col3a1). Because pericytes are important collagen-producing cells in the gland, we stained for desmin (a pericyte marker). Removal of folliculostellate cells resulted in fewer desmin-positive pericytes and less desmin mRNA. We then attempted to identify the factor mediating folliculostellate cell-pericyte interaction. RT-PCR and in situ hybridization revealed that the important profibrotic factor transforming growth factor beta-2 (TGFβ2) was specifically expressed in folliculostellate cells and that TGFβ receptor II was expressed in pericytes, endothelial cells, and parenchymal cells. Immunocytochemistry showed that TGFβ2 induced SMAD2 nuclear translocation in pericytes. TGFβ2 increased collagen synthesis in a dose-dependent manner. This action was completely blocked by TGFβ receptor I inhibitor (SB431542). Diminished collagen synthesis in folliculostellate cell-deficient cell aggregates was partially recovered by TGFβ2. TGFβ2-mediated folliculostellate cell-pericyte interaction appears to be essential for collagen synthesis in rat anterior pituitary. This finding sheds new light on local cell-ECM interactions in the gland. PMID:26957638

  12. GRK5 deficiency leads to susceptibility to intermittent hypoxia-induced cognitive impairment.

    PubMed

    Singh, Prabhakar; Peng, Wei; Zhang, Qiang; Ding, XueFeng; Suo, William Z

    2016-04-01

    Obstructive sleep apnea (OSA) leads to cognitive impairment in about 25% patients, though it remains elusive what makes one more susceptible than the other to be cognitively impaired. G protein-coupled receptor kinase-5 (GRK5) deficiency is recently found to render subjects more susceptible to cognitive impairment triggered by over-expression of Swedish mutant ß-amyloid precursor protein. This study is to determine whether GRK5 deficiency also renders subjects more susceptible to the OSA-triggered cognitive impairment. Both wild type (WT) and GRK5 knockout (KO) mice were placed in conditions absence and presence of intermittent hypoxia (IH) with 8%/21% O2 90-s cycle for 8h a day for a month, and then followed by behavioral assessments with battery of tasks. We found that the selected IH condition only induced marginally abnormal behavior (slightly elevated anxiety with most others unchanged) in the WT mice but it caused significantly more behavioral deficits in the KO mice, ranging from elevated anxiety, impaired balancing coordination, and impaired short-term spatial memory. These results suggest that GRK5 deficiency indeed makes the mice more susceptible to wide range of behavioral impairments, including cognitive impairments. PMID:26778781

  13. Impaired neurotransmission in ether lipid-deficient nerve terminals

    PubMed Central

    Brodde, Alexander; Teigler, Andre; Brugger, Britta; Lehmann, Wolf D.; Wieland, Felix; Berger, Johannes; Just, Wilhelm W.

    2016-01-01

    Isolated defects of ether lipid (EL) biosynthesis in humans cause rhizomelic chondrodysplasia punctata type 2 and type 3, serious peroxisomal disorders. Using a previously described mouse model [Rodemer, C., Thai, T.P., Brugger, B., Kaercher, T., Werner, H., Nave, K.A., Wieland, F., Gorgas, K., and Just, W.W. (2003) Inactivation of ether lipid biosynthesis causes male infertility, defects in eye development and optic nerve hypoplasia in mice. Hum. Mol. Genet., 12, 1881–1895], we investigated the effect of EL deficiency in isolated murine nerve terminals (synaptosomes) on the pre-synaptic release of the neurotransmitters (NTs) glutamate and acetylcholine. Both Ca2+-dependent exocytosis and Ca2+-independent efflux of the transmitters were affected. EL-deficient synaptosomes respire at a reduced rate and exhibit a lowered adenosin-5′-triphosphate/adenosine diphosphate (ATP/ADP) ratio. Consequently, ATP-driven processes, such as synaptic vesicle cycling and maintenance of Na+, K+ and Ca2+ homeostasis, might be disturbed. Analyzing reactive oxygen species in EL-deficient neural and non-neural tissues revealed that plasmalogens (PLs), the most abundant EL species in mammalian central nervous system, considerably contribute to the generation of the lipid peroxidation product malondialdehyde. Although EL-deficient tissue contains less lipid peroxidation products, fibroblasts lacking ELs are more susceptible to induced oxidative stress. In summary, these results suggest that due to the reduced energy state of EL-deficient tissue, the Ca2+-independent efflux of NTs increases while the Ca2+-dependent release declines. Furthermore, lack of PLs is mainly compensated for by an increase in the concentration of phosphatidylethanolamine and results in a significantly lowered level of lipid peroxidation products in the brain cortex and cerebellum. PMID:22403185

  14. Impaired T cell function in argininosuccinate synthetase deficiency

    PubMed Central

    Tarasenko, Tatyana N.; Gomez-Rodriguez, Julio; McGuire, Peter J.

    2015-01-01

    ASS1 is a cytosolic enzyme that plays a role in the conversion of citrulline to arginine. In human and mouse tissues, ASS1 protein is found in several components of the immune system, including the thymus and T cells. However, the role of ASS1 in these tissues remains to be defined. Considerable attention has been focused recently on the role of metabolism in T cell differentiation and function. Based on the expression of ASS1 in the immune system, we hypothesized that ASS1 deficiency would result in T cell defects. To evaluate this question, we characterized immune function in hypomorphic fold/fold mice. Analysis of splenic T cells by flow cytometry showed a marked reduction in T cell numbers with normal expression of activation surface markers. Gene therapy correction of liver ASS1 to enhance survival resulted in a partial recovery of splenic T cells for characterization. In vitro and in vivo studies demonstrated the persistence of the ASS1 enzyme defect in T cells and abnormal T cell differentiation and function. Overall, our work suggests that ASS1 plays a role in T cell function, and deficiency produces primary immune dysfunction. In addition, these data suggest that patients with ASS1 deficiency (citrullinemia type I) may have T cell dysfunction. PMID:25492936

  15. Interstitial pericytes decrease in aged mouse kidneys.

    PubMed

    Stefanska, Ania; Eng, Diana; Kaverina, Natalya; Duffield, Jeremy S; Pippin, Jeffrey W; Rabinovitch, Peter; Shankland, Stuart J

    2015-06-01

    With increasing age, the kidney undergoes characteristic changes in the glomerular and tubulo-interstitial compartments, which are ultimately accompanied by reduced kidney function. Studies have shown age-related loss of peritubular vessels. Normal peritubular vessel tone, function and survival depend on neighboring pericytes. Pericyte detachment leads to vascular damage, which can be accompanied by their differentiation to fibroblasts and myofibroblasts, a state that favors matrix production. To better understand the fate of pericytes in the aged kidney, 27 month-old mice were studied. Compared to 3 month-old young adult mice, aged kidneys showed a substantial decrease in capillaries, identified by CD31 staining, in both cortex and medulla. This was accompanied by a marked decrease in surrounding NG2+ / PDGFRβ+ pericytes. This decrease was more pronounced in the medulla. Capillaries devoid of pericytes were typically dilated in aged mice. Aged kidneys were also characterized by interstitial fibrosis due to increased collagen-I and -III staining. This was accompanied by an increase in the number of pericytes that acquired a pro-fibrotic phenotype, identified by increased PDGFRβ+ / αSMA+ staining. These findings are consistent with the decline in kidney interstitial pericytes as a critical step in the development of changes to the peritubular vasculature with aging, and accompanying fibrosis. PMID:26081073

  16. Interstitial pericytes decrease in aged mouse kidneys

    PubMed Central

    Stefanska, Ania; Eng, Diana; Kaverina, Natalya; Duffield, Jeremy S.; Pippin, Jeffrey W.; Rabinovitch, Peter; Shankland, Stuart J.

    2015-01-01

    With increasing age, the kidney undergoes characteristic changes in the glomerular and tubulo-interstitial compartments, which are ultimately accompanied by reduced kidney function. Studies have shown age-related loss of peritubular vessels. Normal peritubular vessel tone, function and survival depend on neighboring pericytes. Pericyte detachment leads to vascular damage, which can be accompanied by their differentiation to fibroblasts and myofibroblasts, a state that favors matrix production. To better understand the fate of pericytes in the aged kidney, 27 month-old mice were studied. Compared to 3 month-old young adult mice, aged kidneys showed a substantial decrease in capillaries, identified by CD31 staining, in both cortex and medulla. This was accompanied by a marked decrease in surrounding NG2+/PDGFRß+ pericytes. This decrease was more pronounced in the medulla. Capillaries devoid of pericytes were typically dilated in aged mice. Aged kidneys were also characterized by interstitial fibrosis due to increased collagen-I and -III staining. This was accompanied by an increase in the number of pericytes that acquired a pro-fibrotic phenotype, identified by increased PDGFRß+/αSMA+ staining. These findings are consistent with the decline in kidney interstitial pericytes as a critical step in the development of changes to the peritubular vasculature with aging, and accompanying fibrosis. PMID:26081073

  17. Hypothyroxinemia induced by maternal mild iodine deficiency impairs hippocampal myelinated growth in lactational rats.

    PubMed

    Wei, Wei; Wang, Yi; Dong, Jing; Wang, Yuan; Min, Hui; Song, Binbin; Shan, Zhongyan; Teng, Weiping; Xi, Qi; Chen, Jie

    2015-11-01

    Hypothyroxinemia induced by maternal mild iodine deficiency causes neurological deficits and impairments of brain function in offspring. Hypothyroxinemia is prevalent in developing and developed countries alike. However, the mechanism underlying these deficits remains less well known. Given that the myelin plays an important role in learning and memory function, we hypothesize that hippocampal myelinated growth may be impaired in rat offspring exposed to hypothyroxinemia induced by maternal mild iodine deficiency. To test this hypothesis, the female Wistar rats were used and four experimental groups were prepared: (1) control; (2) maternal mild iodine deficiency diet inducing hypothyroxinemia; (3) hypothyroidism induced by maternal severe iodine deficiency diet; (4) hypothyroidism induced by maternal methimazole water. The rats were fed the diet from 3 months before pregnancy to the end of lactation. Our results showed that the physiological changes occuring in the hippocampal myelin were altered in the mild iodine deficiency group as indicated by the results of immunofluorescence of myelin basic proteins on postnatal day 14 and postnatal day 21. Moreover, hypothyroxinemia reduced the expressions of oligodendrocyte lineage transcription factor 2 and myelin-related proteins in the treatments on postnatal day 14 and postnatal day 21. Our data suggested that hypothyroxinemia induced by maternal mild iodine deficiency may impair myelinated growth of the offspring. PMID:24753110

  18. Pericytes, microvasular dysfunction and chronic rejection

    PubMed Central

    Kloc, Malgorzata; Kubiak, Jacek Z.; Li, Xian C.; Ghobrial, Rafik M.

    2014-01-01

    Chronic rejection of transplanted organs remains the main obstacle in the long-term success of organ transplantation. Thus, there is a persistent quest for development of anti-chronic rejection therapies and identification of novel molecular and cellular targets. One of the potential targets is the pericytes, the mural cells of microvessels, which regulate microvascular permeability, development and maturation by controlling endothelial cell functions and regulating tissue fibrosis and inflammatory response. In this review we discuss the potential of targeting pericytes in development of microvasular dysfunction and the molecular pathways involved in regulation of pericyte activities for anti-chronic rejection intervention. PMID:25793439

  19. Rcan1 deficiency impairs neuronal migration and causes periventricular heterotopia.

    PubMed

    Li, Yang; Wang, Jie; Zhou, Yang; Li, Dan; Xiong, Zhi-Qi

    2015-01-14

    Periventricular heterotopia (PH) is a cortical malformation characterized by aggregation of neurons lining the lateral ventricles due to abnormal neuronal migration. The molecular mechanism underlying the pathogenesis of PH is unclear. Here we show that Regulators of calcineurin 1 (Rcan1), a Down syndrome-related gene, plays an important role in radial migration of rat cortical neurons. Downregulation of Rcan1 by expressing shRNA impaired neural progenitor proliferation and led to defects in radial migration and PH. Two isoforms of Rcan1 (Rcan1-1 and Rcan1-4) are expressed in the rat brain. Migration defects due to downregulation of Rcan1 could be prevented by shRNA-resistant expression of Rcan1-1 but not Rcan1-4. Furthermore, we found that Rcan1 knockdown significantly decreased the expression level of Flna, an F-actin cross-linking protein essential for cytoskeleton rearrangement and cell migration, mutation of which causes the most common form of bilateral PH in humans. Finally, overexpression of FLNA in Rcan1 knockdown neurons prevented migration abnormalities. Together, these findings demonstrate that Rcan1 acts upstream from Flna in regulating radial migration and suggest that impairment of Rcan1-Flna pathway may underlie PH pathogenesis. PMID:25589755

  20. Non-motor behavioural impairments in parkin-deficient mice.

    PubMed

    Zhu, Xin-Ran; Maskri, Lyutha; Herold, Christina; Bader, Verian; Stichel, Christine C; Güntürkün, Onur; Lübbert, Hermann

    2007-10-01

    Mutations in the parkin gene are the major cause of early-onset familial Parkinson's disease (PD). We previously reported the generation and analysis of a knockout mouse carrying a deletion of exon 3 in the parkin gene. F1 hybrid pa+/- mice were backcrossed to wild-type C57Bl/6 for three more generations to establish a pa-/-(F4) mouse line. The appearance of tyrosine hydroxylase-positive neurons was normal in young and aged pa-/- (F4) animals. Loss of parkin function in mice did not enhance vulnerability of dopaminergic neurons to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity. However, the pa-/- (F4) mice displayed impaired exploration and habituation to a new environment and exhibited thigmotaxis behaviour in the open field and Morris water maze. Abnormal anxiety-related behaviour of pa-/- (F4) mice was also observed in the light/dark exploration test paradigm. Dopamine metabolism was enhanced in the striatum of pa-/- (F4) mice, as revealed by increased homovanillic acid (HVA) content and a reduced ratio of dihydroxyphenylacetic acid (DOPAC)/HVA. The alterations found in the dopaminergic system could be responsible for the behavioural impairments of pa-/- (F4) mice. Consistent with a recent observation of cognitive dysfunction in parkin-linked patients with PD, our findings provide evidence of a physiological role of parkin in non-motor behaviour, possibly representing a disease stage that precedes dopaminergic neuron loss. PMID:17883413

  1. Isotonic contractile impairment due to genetic CLC-1 chloride channel deficiency in myotonic mouse diaphragm muscle.

    PubMed

    van Lunteren, Erik; Pollarine, Jennifer; Moyer, Michelle

    2007-07-01

    The hallmark of genetic CLC-1 chloride channel deficiency in myotonic humans, goats and mice is delayed muscle relaxation resulting from persistent electrical discharges. In addition to the ion channel defect, muscles from myotonic humans and mice also have major changes in fibre type and myosin isoform composition, but the extent to which this affects isometric contractions remains controversial. Many muscles, including the diaphragm, shorten considerably during normal activities, but shortening contractions have never been assessed in myotonic muscle. The present study tested the hypothesis that CLC-1 deficiency leads to an impairment of muscle isotonic contractile performance. This was tested in vitro on diaphragm muscle from SWR/J-Clcn1(adr-mto)/J myotonic mice. The CLC-1-deficient muscle demonstrated delayed relaxation, as expected. During the contractile phase, there were significant reductions in power and work across a number of stimulation frequencies and loads in CLC-1-deficient compared with normal muscle, the magnitude of which in many instances exceeded 50%. Reductions in shortening and velocity of shortening occurred, and were more pronounced when calculated as a function of absolute than relative load. However, the maximal unloaded shortening velocity calculated from Hill's equation was not altered significantly. The impaired isotonic contractile performance of CLC-1-deficient muscle persisted during fatigue-inducing stimulation. These data indicate that genetic CLC-1 chloride channel deficiency in mice not only produces myotonia but also substantially worsens the isotonic contractile performance of diaphragm muscle. PMID:17483199

  2. Impaired mechanical stability, migration and contractile capacity in vimentin-deficient fibroblasts

    NASA Technical Reports Server (NTRS)

    Eckes, B.; Dogic, D.; Colucci-Guyon, E.; Wang, N.; Maniotis, A.; Ingber, D.; Merckling, A.; Langa, F.; Aumailley, M.; Delouvee, A.; Koteliansky, V.; Babinet, C.; Krieg, T.

    1998-01-01

    Loss of a vimentin network due to gene disruption created viable mice that did not differ overtly from wild-type littermates. Here, primary fibroblasts derived from vimentin-deficient (-/-) and wild-type (+/+) mouse embryos were cultured, and biological functions were studied in in vitro systems resembling stress situations. Stiffness of -/- fibroblasts was reduced by 40% in comparison to wild-type cells. Vimentin-deficient cells also displayed reduced mechanical stability, motility and directional migration towards different chemo-attractive stimuli. Reorganization of collagen fibrils and contraction of collagen lattices were severely impaired. The spatial organization of focal contact proteins, as well as actin microfilament organization was disturbed. Thus, absence of a vimentin filament network does not impair basic cellular functions needed for growth in culture, but cells are mechanically less stable, and we propose that therefore they are impaired in all functions depending upon mechanical stability.

  3. Dietary n-3 PUFAs Deficiency Increases Vulnerability to Inflammation-Induced Spatial Memory Impairment.

    PubMed

    Delpech, Jean-Christophe; Thomazeau, Aurore; Madore, Charlotte; Bosch-Bouju, Clementine; Larrieu, Thomas; Lacabanne, Chloe; Remus-Borel, Julie; Aubert, Agnès; Joffre, Corinne; Nadjar, Agnès; Layé, Sophie

    2015-11-01

    Dietary n-3 polyunsaturated fatty acids (PUFAs) are critical components of inflammatory response and memory impairment. However, the mechanisms underlying the sensitizing effects of low n-3 PUFAs in the brain for the development of memory impairment following inflammation are still poorly understood. In this study, we examined how a 2-month n-3 PUFAs deficiency from pre-puberty to adulthood could increase vulnerability to the effect of inflammatory event on spatial memory in mice. Mice were given diets balanced or deficient in n-3 PUFAs for a 2-month period starting at post-natal day 21, followed by a peripheral administration of lipopolysaccharide (LPS), a bacterial endotoxin, at adulthood. We first showed that spatial memory performance was altered after LPS challenge only in n-3 PUFA-deficient mice that displayed lower n-3/n-6 PUFA ratio in the hippocampus. Importantly, long-term depression (LTD), but not long-term potentiation (LTP) was impaired in the hippocampus of LPS-treated n-3 PUFA-deficient mice. Proinflammatory cytokine levels were increased in the plasma of both n-3 PUFA-deficient and n-3 PUFA-balanced mice. However, only n-3 PUFA-balanced mice showed an increase in cytokine expression in the hippocampus in response to LPS. In addition, n-3 PUFA-deficient mice displayed higher glucocorticoid levels in response to LPS as compared with n-3 PUFA-balanced mice. These results indicate a role for n-3 PUFA imbalance in the sensitization of the hippocampal synaptic plasticity to inflammatory stimuli, which is likely to contribute to spatial memory impairment. PMID:25948102

  4. Glucocerebrosidase deficiency and mitochondrial impairment in experimental Parkinson disease.

    PubMed

    Noelker, Carmen; Lu, Lixia; Höllerhage, Matthias; Vulinovic, Franca; Sturn, Annekathrin; Roscher, René; Höglinger, Günter U; Hirsch, Etienne C; Oertel, Wolfgang H; Alvarez-Fischer, Daniel; Andreas, Hartmann

    2015-09-15

    Gaucher disease is an autosomal recessive disease, caused by a lack or functional deficiency of the lysosomal enzyme, glucocerebrosidase (GCase). Recently, mutations in the glucocerebrosidase gene (GBA) have been associated with Parkinson's disease (PD) and GBA mutations are now considered the most important genetic vulnerability factor for PD. In this study, we have investigated (i) in vivo whether inhibition of the enzyme glucosylceramide synthase by miglustat may protect C57Bl/6 mice against subchronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication and (ii) in vitro whether a decrease of GCase activity may render dopaminergic neurons susceptible to MPP(+) (1-methyl-4-phenylpyridinium) or alpha-synuclein (α-Syn) toxicity and amenable to miglustat treatment. We could demonstrate that reduction of glucocerebroside by inhibition of glucosylceramide synthase partially protects mice against MPTP-induced toxicity. Conversely, we could show that inhibition of GCase activity with conduritol-B-epoxide (CBE) enhances both α-Syn and MPP(+) induced toxicity in vitro. However, only CBE-induced enhancement of MPP(+) toxicity could be reversed by miglustat. Moreover, we were unable to reveal any alterations of complex I activity or cell respiration upon treatment with either CBE or miglustat. Our findings suggest that the reduction of GCase activity rather than an accumulation of glucocerebroside increases aSyn toxicity. PMID:26104567

  5. ClC-7 Deficiency Impairs Tooth Development and Eruption.

    PubMed

    Wang, He; Pan, Meng; Ni, Jinwen; Zhang, Yanli; Zhang, Yutao; Gao, Shan; Liu, Jin; Wang, Zhe; Zhang, Rong; He, Huiming; Wu, Buling; Duan, Xiaohong

    2016-01-01

    CLCN7 gene encodes the voltage gated chloride channel 7 (ClC-7) in humans. The mutations in CLCN7 have been associated with osteopetrosis in connection to the abnormal osteoclasts functions. Previously, we found that some osteopetrosis patients with CLCN7 mutations suffered from impacted teeth and root dysplasia. Here we set up two in vivo models under a normal or an osteoclast-poor environment to investigate how ClC-7 affects tooth development and tooth eruption. Firstly, chitosan-Clcn7-siRNA nanoparticles were injected around the first maxillary molar germ of newborn mice and caused the delay of tooth eruption and deformed tooth with root dysplasia. Secondly, E13.5 molar germs infected with Clcn7 shRNA lentivirus were transplanted under the kidney capsule and presented the abnormal changes in dentin structure, periodontal tissue and cementum. All these teeth changes have been reported in the patients with CLCN7 mutation. In vitro studies of ameloblasts, odontoblasts and dental follicle cells (DFCs) were conducted to explore the involved mechanism. We found that Clcn7 deficiency affect the differentiation of these cells, as well as the interaction between DFCs and osteoclasts through RANKL/OPG pathway. We conclude that ClC-7 may affect tooth development by directly targeting tooth cells, and regulate tooth eruption through DFC mediated osteoclast pathway. PMID:26829236

  6. Impaired theta-gamma coupling in APP-deficient mice

    PubMed Central

    Zhang, Xiaomin; Zhong, Wewei; Brankačk, Jurij; Weyer, Sascha W.; Müller, Ulrike C.; Tort, Adriano B. L.; Draguhn, Andreas

    2016-01-01

    Amyloid precursor protein (APP) is critically involved in the pathophysiology of Alzheimer’s disease, but its physiological functions remain elusive. Importantly, APP knockout (APP-KO) mice exhibit cognitive deficits, suggesting that APP plays a role at the neuronal network level. To investigate this possibility, we recorded local field potentials (LFPs) from the posterior parietal cortex, dorsal hippocampus and lateral prefrontal cortex of freely moving APP-KO mice. Spectral analyses showed that network oscillations within the theta- and gamma-frequency bands were not different between APP-KO and wild-type mice. Surprisingly, however, while gamma amplitude coupled to theta phase in all recorded regions of wild-type animals, in APP-KO mice theta-gamma coupling was strongly diminished in recordings from the parietal cortex and hippocampus, but not in LFPs recorded from the prefrontal cortex. Thus, lack of APP reduces oscillatory coupling in LFP recordings from specific brain regions, despite not affecting the amplitude of the oscillations. Together, our findings reveal reduced cross-frequency coupling as a functional marker of APP deficiency at the network level. PMID:26905287

  7. ClC-7 Deficiency Impairs Tooth Development and Eruption

    PubMed Central

    Wang, He; Pan, Meng; Ni, Jinwen; Zhang, Yanli; Zhang, Yutao; Gao, Shan; Liu, Jin; Wang, Zhe; Zhang, Rong; He, Huiming; Wu, Buling; Duan, Xiaohong

    2016-01-01

    CLCN7 gene encodes the voltage gated chloride channel 7 (ClC-7) in humans. The mutations in CLCN7 have been associated with osteopetrosis in connection to the abnormal osteoclasts functions. Previously, we found that some osteopetrosis patients with CLCN7 mutations suffered from impacted teeth and root dysplasia. Here we set up two in vivo models under a normal or an osteoclast-poor environment to investigate how ClC-7 affects tooth development and tooth eruption. Firstly, chitosan-Clcn7-siRNA nanoparticles were injected around the first maxillary molar germ of newborn mice and caused the delay of tooth eruption and deformed tooth with root dysplasia. Secondly, E13.5 molar germs infected with Clcn7 shRNA lentivirus were transplanted under the kidney capsule and presented the abnormal changes in dentin structure, periodontal tissue and cementum. All these teeth changes have been reported in the patients with CLCN7 mutation. In vitro studies of ameloblasts, odontoblasts and dental follicle cells (DFCs) were conducted to explore the involved mechanism. We found that Clcn7 deficiency affect the differentiation of these cells, as well as the interaction between DFCs and osteoclasts through RANKL/OPG pathway. We conclude that ClC-7 may affect tooth development by directly targeting tooth cells, and regulate tooth eruption through DFC mediated osteoclast pathway. PMID:26829236

  8. Pericyte-targeting drug delivery and tissue engineering

    PubMed Central

    Kang, Eunah; Shin, Jong Wook

    2016-01-01

    Pericytes are contractile mural cells that wrap around the endothelial cells of capillaries and venules. Depending on the triggers by cellular signals, pericytes have specific functionality in tumor microenvironments, properties of potent stem cells, and plasticity in cellular pathology. These features of pericytes can be activated for the promotion or reduction of angiogenesis. Frontier studies have exploited pericyte-targeting drug delivery, using pericyte-specific peptides, small molecules, and DNA in tumor therapy. Moreover, the communication between pericytes and endothelial cells has been applied to the induction of vessel neoformation in tissue engineering. Pericytes may prove to be a novel target for tumor therapy and tissue engineering. The present paper specifically reviews pericyte-specific drug delivery and tissue engineering, allowing insight into the emerging research targeting pericytes. PMID:27313454

  9. Pericyte-targeting drug delivery and tissue engineering.

    PubMed

    Kang, Eunah; Shin, Jong Wook

    2016-01-01

    Pericytes are contractile mural cells that wrap around the endothelial cells of capillaries and venules. Depending on the triggers by cellular signals, pericytes have specific functionality in tumor microenvironments, properties of potent stem cells, and plasticity in cellular pathology. These features of pericytes can be activated for the promotion or reduction of angiogenesis. Frontier studies have exploited pericyte-targeting drug delivery, using pericyte-specific peptides, small molecules, and DNA in tumor therapy. Moreover, the communication between pericytes and endothelial cells has been applied to the induction of vessel neoformation in tissue engineering. Pericytes may prove to be a novel target for tumor therapy and tissue engineering. The present paper specifically reviews pericyte-specific drug delivery and tissue engineering, allowing insight into the emerging research targeting pericytes. PMID:27313454

  10. Vitamin D receptor deficiency impairs inner ear development in zebrafish.

    PubMed

    Kwon, Hye-Joo

    2016-09-16

    The biological actions of vitamin D are largely mediated through binding to the vitamin D receptor (VDR), a member of the nuclear hormone receptor family, which regulates gene expression in a wide variety of tissues and cells. Mutations in VDR gene have been implicated in ear disorders (hearing loss and balance disorder) but the mechanisms are not well established. In this study, to investigate the role of VDR in inner ear development, morpholino-mediated gene knockdown approaches were used in zebrafish model system. Two paralogs for VDR, vdra and vdrb, have been identified in zebrafish. Knockdown of vdra had no effect on ear development, whereas knockdown of vdrb displayed morphological ear defects including smaller otic vesicles with malformed semicircular canals and abnormal otoliths. Loss-of-vdrb resulted in down-regulation of pre-otic markers, pax8 and pax2a, indicating impairment of otic induction. Furthermore, zebrafish embryos lacking vdrb produced fewer sensory hair cells in the ears and showed disruption of balance and motor coordination. These data reveal that VDR signaling plays an important role in ear development. PMID:27526995

  11. Impaired brain development and reduced cognitive function in phospholipase D-deficient mice.

    PubMed

    Burkhardt, Ute; Stegner, David; Hattingen, Elke; Beyer, Sandra; Nieswandt, Bernhard; Klein, Jochen

    2014-06-20

    The phospholipases D (PLD1 and 2) are signaling enzymes that catalyze the hydrolysis of phosphatidylcholine to phosphatidic acid, a lipid second messenger involved in cell proliferation, and choline, a precursor of acetylcholine (ACh). In the present study, we investigated development and cognitive function in mice that were deficient for PLD1, or PLD2, or both. We found that PLD-deficient mice had reduced brain growth at 14-27 days post partum when compared to wild-type mice. In adult PLD-deficient mice, cognitive function was impaired in social and object recognition tasks. Using brain microdialysis, we found that wild-type mice responded with a 4-fold increase of hippocampal ACh release upon behavioral stimulation in the open field, while PLD-deficient mice released significantly less ACh. These results may be relevant for cognitive dysfunctions observed in fetal alcohol syndrome and in Alzheimer' disease. PMID:24813107

  12. Serotonin transporter deficiency in rats contributes to impaired object memory.

    PubMed

    Olivier, J D A; Jans, L A W; Blokland, A; Broers, N J; Homberg, J R; Ellenbroek, B A; Cools, A R

    2009-11-01

    Serotonin is well known for its role in affection, but less known for its role in cognition. The serotonin transporter (SERT) has an essential role in serotonergic neurotransmission as it determines the magnitude and duration of the serotonin signal in the synaptic cleft. There is evidence to suggest that homozygous SERT knockout rats (SERT(-/-)), as well as humans with the short SERT allele, show stronger cognitive effects than wild-type control rats (SERT(+/+)) and humans with the long SERT allele after acute tryptophan depletion. In rats, SERT genotype is known to affect brain serotonin levels, with SERT(-/-) rats having lower intracellular basal serotonin levels than wild-type rats in several brain areas. In the present study, it was investigated whether SERT genotype affects memory performance in an object recognition task with different inter-trial intervals. SERT(-/-), heterozygous SERT knockout (SERT(+/-)) and SERT(+/+) rats were tested in an object recognition test applying an inter-trial interval of 2, 4 and 8 h. SERT(-/-) and SERT(+/-) rats showed impaired object memory with an 8 h inter-trial interval, whereas SERT(+/+) rats showed intact object memory with this inter-trial interval. Although brain serotonin levels cannot fully explain the SERT genotype effect on object memory in rats, these results do indicate that serotonin is an important player in object memory in rats, and that lower intracellular serotonin levels lead to enhanced memory loss. Given its resemblance with the human SERT-linked polymorphic region and propensity to develop depression-like symptoms, our findings may contribute to further understanding of mechanisms underlying cognitive deficits in depression. PMID:19740092

  13. Pericyte plasticity - comparative investigation of the angiogenic and multilineage potential of pericytes from different human tissues.

    PubMed

    Herrmann, M; Bara, J J; Sprecher, C M; Menzel, U; Jalowiec, J M; Osinga, R; Scherberich, A; Alini, M; Verrier, S

    2016-01-01

    Pericyte recruitment is essential for the stability of newly formed vessels. It was also suggested that pericytes represent common ancestor cells giving rise to mesenchymal stem cells (MSCs) in the adult. Here, we systematically investigated pericytes and MSCs from different human tissues in terms of their angiogenic and multilineage differentiation potential in vitro in order to assess the suitability of the different cell types for the regeneration of vascularised tissues. Magnetic-activated cell sorting (MACS®) was used to enrich CD34-CD146+ pericytes from adipose tissue (AT) and bone marrow (BM). The multilineage potential of pericytes was assessed by testing their capability to differentiate towards osteogenic, adipogenic and chondrogenic lineage in vitro. Pericytes and endothelial cells were co-seeded on Matrigel™ and the formation of tube-like structures was examined to study the angiogenic potential of pericytes. MSCs from AT and BM were used as controls. CD34-CD146+ cells were successfully enriched from AT and BM. Only BM-derived cells exhibited trilineage differentiation potential. AT-derived cells displayed poor chondrogenic differentiation upon stimulation with transforming growth factor-β1. Interestingly, osteogenic differentiation was more efficient in AT-PC and BM-PC compared to the respective full MSC population. Matrigel™ assays revealed that pericytes from all tissues integrated into tube-like structures. We show that MACS®-enriched pericytes from BM and AT have the potential to regenerate tissues of different mesenchymal lineages and support neovascularisation. MACS® represents a simple enrichment strategy of cells, which is of particular interest for clinical application. Finally, our results suggest that the regenerative potential of pericytes depends on their tissue origin, which is an important consideration for future studies. PMID:27062725

  14. Pericyte antigens in angiomyolipoma and PEComa family tumors.

    PubMed

    Shen, Jia; Shrestha, Swati; Yen, Yu-Hsin; Scott, Michelle A; Asatrian, Greg; Barnhill, Raymond; Lugassy, Claire; Soo, Chia; Ting, Kang; Peault, Bruno; Dry, Sarah M; James, Aaron W

    2015-08-01

    Perivascular epithelioid cell tumors (PEComas) are an uncommon family of soft tissue tumors with dual myoid-melanocytic differentiation. Although PEComa family tumors commonly demonstrate a perivascular growth pattern, pericyte antigen expression has not yet been examined among this unique tumor group. Previously, we demonstrated that a subset of perivascular soft tissue tumors exhibit a striking pericytic immunophenotype, with diffuse expression of αSMA, CD146, and PDGFRβ. Here, we describe the presence of pericyte antigens across a diverse group of PEComa family tumors (n = 19 specimens). Results showed that pericyte antigens differed extensively by histological appearance. Typical angiomyolipoma (AML) specimens showed variable expression of pericyte antigens among both perivascular and myoid-appearing cells. In contrast, AML specimens with a predominant spindled morphology showed diffuse expression of pericyte markers, including αSMA, CD146, and PDGFRβ. AML samples with predominant epithelioid morphology showed a marked reduction in or the absence of immunoreactivity for pericyte markers. Lymphangiomyoma samples showed more variable and partial pericyte marker expression. In summary, pericyte antigen expression is variable among PEComa family tumors and largely varies by tumor morphology. Pericytic marker expression in PEComa may represent a true pericytic cell of origin, or alternatively aberrant pericyte marker adoption. Markers of pericytic differentiation may be of future diagnostic utility for the evaluation of mesenchymal tumors, or identify actionable signaling pathways for future therapeutic intervention. PMID:26123600

  15. Maternal Vitamin C Deficiency during Pregnancy Persistently Impairs Hippocampal Neurogenesis in Offspring of Guinea Pigs

    PubMed Central

    Tveden-Nyborg, Pernille; Vogt, Lucile; Schjoldager, Janne G.; Jeannet, Natalie; Hasselholt, Stine; Paidi, Maya D.

    2012-01-01

    While having the highest vitamin C (VitC) concentrations in the body, specific functions of VitC in the brain have only recently been acknowledged. We have shown that postnatal VitC deficiency in guinea pigs causes impairment of hippocampal memory function and leads to 30% less neurons. This study investigates how prenatal VitC deficiency affects postnatal hippocampal development and if any such effect can be reversed by postnatal VitC repletion. Eighty pregnant Dunkin Hartley guinea pig dams were randomized into weight stratified groups receiving High (900 mg) or Low (100 mg) VitC per kg diet. Newborn pups (n = 157) were randomized into a total of four postnatal feeding regimens: High/High (Control); High/Low (Depleted), Low/Low (Deficient); and Low/High (Repleted). Proliferation and migration of newborn cells in the dentate gyrus was assessed by BrdU labeling and hippocampal volumes were determined by stereology. Prenatal VitC deficiency resulted in a significant reduction in postnatal hippocampal volume (P<0.001) which was not reversed by postnatal repletion. There was no difference in postnatal cellular proliferation and survival rates in the hippocampus between dietary groups, however, migration of newborn cells into the granular layer of the hippocampus dentate gyrus was significantly reduced in prenatally deficient animals (P<0.01). We conclude that a prenatal VitC deficiency in guinea pigs leads to persistent impairment of postnatal hippocampal development which is not alleviated by postnatal repletion. Our findings place attention on a yet unrecognized consequence of marginal VitC deficiency during pregnancy. PMID:23119033

  16. Renal pericytes: regulators of medullary blood flow

    PubMed Central

    Kennedy-Lydon, T M; Crawford, C; Wildman, S S P; Peppiatt-Wildman, C M

    2013-01-01

    Regulation of medullary blood flow (MBF) is essential in maintaining normal kidney function. Blood flow to the medulla is supplied by the descending vasa recta (DVR), which arise from the efferent arterioles of juxtamedullary glomeruli. DVR are composed of a continuous endothelium, intercalated with smooth muscle-like cells called pericytes. Pericytes have been shown to alter the diameter of isolated and in situ DVR in response to vasoactive stimuli that are transmitted via a network of autocrine and paracrine signalling pathways. Vasoactive stimuli can be released by neighbouring tubular epithelial, endothelial, red blood cells and neuronal cells in response to changes in NaCl transport and oxygen tension. The experimentally described sensitivity of pericytes to these stimuli strongly suggests their leading role in the phenomenon of MBF autoregulation. Because the debate on autoregulation of MBF fervently continues, we discuss the evidence favouring a physiological role for pericytes in the regulation of MBF and describe their potential role in tubulo-vascular cross-talk in this region of the kidney. Our review also considers current methods used to explore pericyte activity and function in the renal medulla. PMID:23126245

  17. TRAF1 Deficiency Attenuates Atherosclerosis in Mice by Impairing Monocyte Recruitment to the Vessel Wall

    PubMed Central

    Missiou, Anna; Köstlin, Natascha; Varo, Nerea; Rudolf, Philipp; Aichele, Peter; Ernst, Sandra; Münkel, Christian; Walter, Carina; Stachon, Peter; Sommer, Benjamin; Pfeifer, Dietmar; Zirlik, Katja; MacFarlane, Lindsey; Wolf, Dennis; Tsitsikov, Erdyni; Bode, Christoph; Libby, Peter; Zirlik, Andreas

    2010-01-01

    Background Members of the tumor necrosis factor (TNF) superfamily, such as TNFα, potently promote atherogenesis in mice and humans. TNF receptor-associated factors (TRAFs) are cytoplasmic adaptor proteins for this group of cytokines. Methods and Results This study tested the hypothesis that TRAF1 modulates atherogenesis in vivo. TRAF1−/−/LDLR−/− mice consuming a high-cholesterol diet for 18 weeks developed significantly smaller atherosclerotic lesions compared with LDLR−/− (low density lipoprotein receptor) control animals. As the most prominent change in histologic composition, plaques of TRAF1-deficient animals contained significantly fewer macrophages. Bone marrow transplantations revealed that TRAF1 deficiency on both hematopoetic as well as vascular resident cells contributed to the reduction in atherogenesis observed. Mechanistic studies showed that deficiency of TRAF1 in endothelial cells and monocytes reduced adhesion of inflammatory cells to the endothelium in static and dynamic assays. Impaired adhesion coincided with reduced cell spreading, actin polymerization, and CD29 expression in macrophages, as well as decreased expression of the adhesion molecules ICAM-1 and VCAM-1 on endothelial cells. SiRNA studies on human cells verified these findings. Furthermore, TRAF1 mRNA levels were significantly elevated in blood of patients with acute coronary syndrome. Conclusions TRAF1 deficiency attenuates atherogenesis in mice, most likely due to impaired monocyte recruitment to the vessel wall. These data identify TRAF1 as a potential treatment target for atherosclerosis. PMID:20421522

  18. The complex mural cell: pericyte function in health and disease.

    PubMed

    van Dijk, Christian G M; Nieuweboer, Frederieke E; Pei, Jia Yi; Xu, Yan Juan; Burgisser, Petra; van Mulligen, Elise; el Azzouzi, Hamid; Duncker, Dirk J; Verhaar, Marianne C; Cheng, Caroline

    2015-01-01

    Pericytes are perivascular cells that can be distinguished from vascular smooth muscle cells by their specific morphology and expression of distinct molecular markers. Found in the microvascular beds distributed throughout the body, they are well known for their regulation of a healthy vasculature. In this review, we examine the mechanism of pericyte support to vasomotion, and the known pathways that regulate pericyte response in angiogenesis and neovascular stabilization. We will also discuss the role of pericytes in vascular basement membrane and endothelial barrier function regulation. In contrast, recent findings have indicated that pericyte dysfunction, characterized by changes in pericyte contractility or pericyte loss of microvascular coverage, plays an important role in onset and progression of vascular-related and fibrogenic diseases. From a therapeutic point of view, pericytes have recently been identified as a putative pool of endogenous mesenchymal stem cells that could be activated in response to tissue injury to contribute to the regenerative process on multiple levels. We will discuss the mechanisms via which pericytes are involved in disease onset and development in a number of pathophysiological conditions, as well as present the evidence that supports a role for multipotent pericytes in tissue regeneration. The emerging field of pericyte research will not only contribute to the identification of new drug targets in pericyte dysfunction associated diseases, but may also boost the use of this cell type in future cell-based regenerative strategies. PMID:25918055

  19. Dose-Response Analysis of Developmental Iodide Deficiency: Reductions in Thyroid Hormones and Impaired Hippocampal Synaptic Transmission

    EPA Science Inventory

    Iodide is an essential nutrient for thyroid hormone synthesis and severe iodide deficiency (ID) during early development is associated with neurological impairments. Several environmental contaminants can perturb the thyroid axis and this perturbation may be more acute under cond...

  20. Heat Shock Protein B1-Deficient Mice Display Impaired Wound Healing

    PubMed Central

    McNamee, Kay; Przybycien, Paulina M.; Lu, Xin; Williams, Richard O.; Bou-Gharios, George; Saklatvala, Jeremy; Dean, Jonathan L. E.

    2013-01-01

    There is large literature describing in vitro experiments on heat shock protein (hsp)B1 but understanding of its function in vivo is limited to studies in mice overexpressing human hspB1 protein. Experiments in cells have shown that hspB1 has chaperone activity, a cytoprotective role, regulates inflammatory gene expression, and drives cell proliferation. To investigate the function of the protein in vivo we generated hspB1-deficient mice. HspB1-deficient fibroblasts display increased expression of the pro-inflammatory cytokine, interleukin-6, compared to wild-type cells, but reduced proliferation. HspB1-deficient fibroblasts exhibit reduced entry into S phase and increased expression of cyclin-dependent kinase inhibitors p27kip1 and p21waf1. The expression of hspB1 protein and mRNA is also controlled by the cell cycle. To investigate the physiological function of hspB1 in regulating inflammation and cell proliferation we used an excisional cutaneous wound healing model. There was a significant impairment in the rate of healing of wounds in hspB1-deficient mice, characterised by reduced re-epithelialisation and collagen deposition but also increased inflammation. HspB1 deficiency augments neutrophil infiltration in wounds, driven by increased chemokine (C-X-C motif) ligand 1 expression. This appears to be a general mechanism as similar results were obtained in the air-pouch and peritonitis models of acute inflammation. PMID:24143227

  1. Combined Effects of Pericytes in the Tumor Microenvironment

    PubMed Central

    Ribeiro, Aline Lopes; Okamoto, Oswaldo Keith

    2015-01-01

    Pericytes are multipotent perivascular cells whose involvement in vasculature development is well established. Evidences in the literature also suggest that pericytes display immune properties and that these cells may serve as an in vivo reservoir of stem cells, contributing to the regeneration of diverse tissues. Pericytes are also capable of tumor homing and are important cellular components of the tumor microenvironment (TME). In this review, we highlight the contribution of pericytes to some classical hallmarks of cancer, namely, tumor angiogenesis, growth, metastasis, and evasion of immune destruction, and discuss how collectively these hallmarks could be tackled by therapies targeting pericytes, providing a rationale for cancer drugs aiming at the TME. PMID:26000022

  2. Combined effects of pericytes in the tumor microenvironment.

    PubMed

    Ribeiro, Aline Lopes; Okamoto, Oswaldo Keith

    2015-01-01

    Pericytes are multipotent perivascular cells whose involvement in vasculature development is well established. Evidences in the literature also suggest that pericytes display immune properties and that these cells may serve as an in vivo reservoir of stem cells, contributing to the regeneration of diverse tissues. Pericytes are also capable of tumor homing and are important cellular components of the tumor microenvironment (TME). In this review, we highlight the contribution of pericytes to some classical hallmarks of cancer, namely, tumor angiogenesis, growth, metastasis, and evasion of immune destruction, and discuss how collectively these hallmarks could be tackled by therapies targeting pericytes, providing a rationale for cancer drugs aiming at the TME. PMID:26000022

  3. IDH2 deficiency impairs mitochondrial function in endothelial cells and endothelium-dependent vasomotor function.

    PubMed

    Park, Jung-Bum; Nagar, Harsha; Choi, Sujeong; Jung, Saet-Byel; Kim, Hyun-Woo; Kang, Shin Kwang; Lee, Jun Wan; Lee, Jin Hyup; Park, Jeen-Woo; Irani, Kaikobad; Jeon, Byeong Hwa; Song, Hee-Jung; Kim, Cuk-Seong

    2016-05-01

    Mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDH2) plays an essential role protecting cells against oxidative stress-induced damage. A deficiency in IDH2 leads to mitochondrial dysfunction and the production of reactive oxygen species (ROS) in cardiomyocytes and cancer cells. However, the function of IDH2 in vascular endothelial cells is mostly unknown. In this study the effects of IDH2 deficiency on mitochondrial and vascular function were investigated in endothelial cells. IDH2 knockdown decreased the expression of mitochondrial oxidative phosphorylation (OXPHOS) complexes I, II and III, which lead to increased mitochondrial superoxide. In addition, the levels of fission and fusion proteins (Mfn-1, OPA-1, and Drp-1) were significantly altered and MnSOD expression also was decreased by IDH2 knockdown. Furthermore, knockdown of IDH2 decreased eNOS phosphorylation and nitric oxide (NO) concentration in endothelial cells. Interestingly, treatment with Mito-TEMPO, a mitochondrial-specific superoxide scavenger, recovered mitochondrial fission-fusion imbalance and blunted mitochondrial superoxide production, and reduced the IDH2 knockdown-induced decrease in MnSOD expression, eNOS phosphorylation and NO production in endothelial cells. Endothelium-dependent vasorelaxation was impaired, and the concentration of bioavailable NO decreased in the aortic ring in IDH2 knockout mice. These findings suggest that IDH2 deficiency induces endothelial dysfunction through the induction of dynamic mitochondrial changes and impairment in vascular function. PMID:26898144

  4. Descending Vasa Recta Endothelial Membrane Potential Response Requires Pericyte Communication

    PubMed Central

    Zhang, Zhong; Payne, Kristie; Pallone, Thomas L.

    2016-01-01

    Using dual-cell electrophysiological recording, we examined the routes for equilibration of membrane potential between the pericytes and endothelia that comprise the descending vasa recta (DVR) wall. We measured equilibration between pericytes in intact vessels, between pericytes and endothelium in intact vessels and between pericytes physically separated from the endothelium. Dual pericyte recording on the abluminal surface of DVR showed that both resting potential and subsequent time-dependent voltage fluctuations after vasoconstrictor stimulation remained closely equilibrated, regardless of the agonist employed (angiotensin II, vasopressin or endothelin 1). When pericytes where removed from the vessel wall but retained physical contact with one another, membrane potential responses were also highly coordinated. In contrast, responses of pericytes varied independently when they were isolated from both the endothelium and from contact with one another. When pericytes and endothelium were in contact, their resting potentials were similar and their temporal responses to stimulation were highly coordinated. After completely isolating pericytes from the endothelium, their mean resting potentials became discordant. Finally, complete endothelial isolation eliminated all membrane potential responses to angiotensin II. We conclude that cell-to-cell transmission through the endothelium is not needed for pericytes to equilibrate their membrane potentials. AngII dependent responses of DVR endothelia may originate from gap junction coupling to pericytes rather than via receptor dependent signaling in the endothelium, per se. PMID:27171211

  5. Impairment of blastogenic response of splenic lymphocytes from iron-deficient mice: in vivo repletion.

    PubMed

    Kuvibidila, S; Nauss, K M; Baliga, B S; Suskind, R M

    1983-01-01

    Iron-deficiency anemia impaired the blastogenic response of splenic lymphocytes and partially purified T cells to Concanavalin A and phytohemagglutinin. The response of splenic lymphocytes and partially B cells to bacterial lipopolysaccharide was also significantly impaired. Caloric restriction in pair-fed mice did not have any significant effect. Blastogenic response to the three mitogens was restored to normal after anemic mice were fed the regular diet containing 25 to 30 mg Fe/kg (FeSO4) for approximately 10 days. We also found that in the anemic mice the mean wet weights per 100 g of body of spleen, heart, brain, and kidney increased, while those of the thymus and liver decreased. In the pair-fed mice only the mean wet weight of the liver significantly decreased. There was a small but significant decrease in the white blood count and peripheral lymphocyte count in the anemic but not the pair-fed mice. The mechanism by which iron deficiency impairs the cell-mediated immune response is discussed. PMID:6600368

  6. Pericytes: A newly recognized player in wound healing.

    PubMed

    Bodnar, Richard J; Satish, Latha; Yates, Cecelia C; Wells, Alan

    2016-03-01

    Pericytes have generally been considered in the context of stabilizing vessels, ensuring the blood barriers, and regulating the flow through capillaries. However, new reports suggest that pericytes may function at critical times to either drive healing with minimal scarring or, perversely, contribute to fibrosis and ongoing scar formation. Beneficially, pericytes probably drive much of the vascular involution that occurs during the transition from the regenerative to the resolution phases of healing. Pathologically, pericytes can assume a fibrotic phenotype and promote scarring. This perspective will discuss pericyte involvement in wound repair and the relationship pericytes form with the parenchymal cells of the skin. We will further evaluate the role pericytes may have in disease progression in relation to chronic wounds and fibrosis. PMID:26969517

  7. The Role of Pericyte Detachment in Vascular Rarefaction

    PubMed Central

    Schrimpf, Claudia; Teebken, Omke E.; Wilhelmi, Mathias; Duffield, Jeremy S.

    2015-01-01

    Background Pericytes surround endothelial cells at the perivascular interface. Signaling between endothelial cells and pericytes is crucial for capillary homeostasis, as pericytes stabilize vessels and regulate many microvascular functions. Recently it has been shown that pericytes are able to detach from the vascular wall and contribute to fibrosis by becoming scar-forming myofibroblasts in many organs including the kidney. At the same time, the loss of pericytes within the perivascular compartment results in vulnerable capillaries which are prone to instability, pathological angiogenesis, and, ultimately, rarefaction. Aims This review will give an overview of pericyte-endothelial cell interactions, summarize the signaling pathways that have been identified to be involved in pericyte detachment from the vascular wall, and present pathological endothelial responses in the context of disease of the kidney. PMID:25195856

  8. Impaired responsiveness of platelets to epinephrine due to α2A adrenoreceptor deficiency in Male Chinese.

    PubMed

    Lin, Tsun-Mei; Lin, Jih-Shyan; Tseng, Jen-Yu; Wu, Shang-Yin; Chen, Tsai-Yun

    2016-01-01

    Epinephrine is known as a weak, but important, agonist for platelet activation. It has been reported that the responsiveness of platelets to epinephrine was markedly impaired in 6% of Caucasians and in 16% of Japanese. The purpose of this study was to screen and characterize this abnormality in healthy Taiwanese Chinese volunteers. We used aggregometry, flow cytometry and platelet function analyzer (PFA)-100 system to assess in 50 healthy male volunteers the responsiveness of platelets to epinephrine stimulation. Using α2A adrenoceptor antagonist BRL44408 maleate competition and a [(3)H]yohimbin binding assay, we evaluated α2A adrenoceptors on platelets. The aggregation of platelets after stimulation with 10 μM of epinephrine indicated two distinct groups of study participants: 24 (48.0%) good- and 26 (52.0%) impaired-responders to epinephrine. Flow cytometric analysis of platelets after stimulated with 1 μM epinephrine showed that glycoprotein (GP) IIb/IIIa and P-selectin expression of epinephrine good- and impaired-responders were 27.1 ± 11.0% vs. 9.9 ± 5.4% (p = 0.003) and 12.2 ± 6.2% vs. 3.6 ± 3.5% (p < 0.001), respectively. The PFA-100 system showed that epinephrine-impaired-responders had a longer collagen-epinephrine induced closure time. Good-responder platelets incubated with BRL44408 maleate had an impaired response to epinephrine stimulation. [(3)H]yohimbine binding studies showed fewer α2A adrenoreceptors on the platelets of epinephrine-impaired-responders than on those of good-responders. The prevalence of impaired responsiveness to epinephrine was high and probably due to α2A adrenoreceptor deficiency in male Taiwanese Chinese. PMID:26083800

  9. Cognitive impairment in folate-deficient rats corresponds to depleted brain phosphatidylcholine and is prevented by methionine without lowering homocysteine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poor folate status is associated with cognitive decline and dementia in older adults. Although impaired brain methylation activity and homocysteine toxicity are widely believed to account for this association, how folate deficiency impairs cognition is uncertain. To better define the role of folate ...

  10. Thiamin deficiency impairs endotoxin-induced increases in hepatic glucose output.

    PubMed

    Molina, P E; Yousef, K A; Smith, R M; Tepper, P G; Lang, C H; Abumrad, N N

    1994-05-01

    We addressed the role of thiamin, a cofactor for several enzymes involved in glucose metabolism, in the glucose metabolic response to endotoxin. Characterized by hyperglycemia, increased hepatic glucose production exceeding elevated rates of whole-body glucose utilization, this response is mediated by hormones and cytokines and is dependent on the immune and nutritional status of the host. We hypothesized that a thiamin-deficient state would impair the metabolic response to endotoxin. Rats were fed a thiamin-deficient or control diet for 6 wk before in vivo assessment of glucose kinetics. In control rats, Escherichia coli endotoxin increased the rate of glucose appearance (+76%), disappearance (+70%), and metabolic clearance (+50%). Thiamin deficiency resulted in increased plasma glucose (18%) and lactate (3- to 4-fold) as well as in a 30% decrease in insulin and an increase in glucagon (2.6-fold) and corticosterone (3.6-fold). Thiamin deficiency inhibited the endotoxin-induced hyperglycemia and the rise in hepatic glucose production, glucose utilization, and metabolic clearance rate. PMID:8172089

  11. Impaired cerebral cortex development and blood pressure regulation in FGF-2-deficient mice.

    PubMed

    Dono, R; Texido, G; Dussel, R; Ehmke, H; Zeller, R

    1998-08-01

    Fibroblast growth factor-2 (FGF-2) has been implicated in various signaling processes which control embryonic growth and differentiation, adult physiology and pathology. To analyze the in vivo functions of this signaling molecule, the FGF-2 gene was inactivated by homologous recombination in mouse embryonic stem cells. FGF-2-deficient mice are viable, but display cerebral cortex defects at birth. Bromodeoxyuridine pulse labeling of embryos showed that proliferation of neuronal progenitors is normal, whereas a fraction of them fail to colonize their target layers in the cerebral cortex. A corresponding reduction in parvalbumin-positive neurons is observed in adult cortical layers. Neuronal defects are not limited to the cerebral cortex, as ectopic parvalbumin-positive neurons are present in the hippocampal commissure and neuronal deficiencies are observed in the cervical spinal cord. Physiological studies showed that FGF-2-deficient adult mice are hypotensive. They respond normally to angiotensin II-induced hypertension, whereas neural regulation of blood pressure by the baroreceptor reflex is impaired. The present genetic study establishes that FGF-2 participates in controlling fates, migration and differentiation of neuronal cells, whereas it is not essential for their proliferation. The observed autonomic dysfunction in FGF-2-deficient adult mice uncovers more general roles in neural development and function. PMID:9687490

  12. Impaired cerebral cortex development and blood pressure regulation in FGF-2-deficient mice.

    PubMed Central

    Dono, R; Texido, G; Dussel, R; Ehmke, H; Zeller, R

    1998-01-01

    Fibroblast growth factor-2 (FGF-2) has been implicated in various signaling processes which control embryonic growth and differentiation, adult physiology and pathology. To analyze the in vivo functions of this signaling molecule, the FGF-2 gene was inactivated by homologous recombination in mouse embryonic stem cells. FGF-2-deficient mice are viable, but display cerebral cortex defects at birth. Bromodeoxyuridine pulse labeling of embryos showed that proliferation of neuronal progenitors is normal, whereas a fraction of them fail to colonize their target layers in the cerebral cortex. A corresponding reduction in parvalbumin-positive neurons is observed in adult cortical layers. Neuronal defects are not limited to the cerebral cortex, as ectopic parvalbumin-positive neurons are present in the hippocampal commissure and neuronal deficiencies are observed in the cervical spinal cord. Physiological studies showed that FGF-2-deficient adult mice are hypotensive. They respond normally to angiotensin II-induced hypertension, whereas neural regulation of blood pressure by the baroreceptor reflex is impaired. The present genetic study establishes that FGF-2 participates in controlling fates, migration and differentiation of neuronal cells, whereas it is not essential for their proliferation. The observed autonomic dysfunction in FGF-2-deficient adult mice uncovers more general roles in neural development and function. PMID:9687490

  13. Invasive fungal infection and impaired neutrophil killing in human CARD9 deficiency.

    PubMed

    Drewniak, Agata; Gazendam, Roel P; Tool, Anton T J; van Houdt, Michel; Jansen, Machiel H; van Hamme, John L; van Leeuwen, Ester M M; Roos, Dirk; Scalais, Emmanuel; de Beaufort, Carine; Janssen, Hans; van den Berg, Timo K; Kuijpers, Taco W

    2013-03-28

    Caspase recruitment domain-containing protein 9 (CARD9) is an adaptor molecule in the cytosol of myeloid cells, required for induction of T-helper cells producing interleukin-17 (Th17 cells) and important in antifungal immunity. In a patient suffering from Candida dubliniensis meningoencephalitis, mutations in the CARD9 gene were found to result in the loss of protein expression. Apart from the reduced numbers of CD4(+) Th17 lymphocytes, we identified a lack of monocyte-derived cytokines in response to Candida strains. Importantly, CARD9-deficient neutrophils showed a selective Candida albicans killing defect with abnormal ultrastructural phagolysosomes and outgrowth of hyphae. The neutrophil killing defect was independent of the generation of reactive oxygen species by the reduced NAD phosphate oxidase system. Taken together, this demonstrates that human CARD9 deficiency results in selective defect in the host defense against invasive fungal infection, caused by an impaired phagocyte killing. PMID:23335372

  14. Grasping motor impairments in autism: not action planning but movement execution is deficient.

    PubMed

    Stoit, Astrid M B; van Schie, Hein T; Slaats-Willemse, Dorine I E; Buitelaar, Jan K

    2013-12-01

    Different views on the origin of deficits in action chaining in autism spectrum disorders (ASD) have been posited, ranging from functional impairments in action planning to internal models supporting motor control. Thirty-one children and adolescents with ASD and twenty-nine matched controls participated in a two-choice reach-to-grasp paradigm wherein participants received cueing information indicating either the object location or the required manner of grasping. A similar advantage for location cueing over grip cueing was found in both groups. Both accuracy and reaction times of the ASD group were indistinguishable from the control group. In contrast, movement times of the ASD group were significantly delayed in comparison with controls. These findings suggest that movement execution rather than action planning is deficient in ASD, and that deficits in action chaining derive from impairments in internal action models supporting action execution. PMID:23619948

  15. Impaired Exercise Performance and Skeletal Muscle Mitochondrial Function in Rats with Secondary Carnitine Deficiency

    PubMed Central

    Bouitbir, Jamal; Haegler, Patrizia; Singh, François; Joerin, Lorenz; Felser, Andrea; Duthaler, Urs; Krähenbühl, Stephan

    2016-01-01

    Purpose: The effects of carnitine depletion upon exercise performance and skeletal muscle mitochondrial function remain largely unexplored. We therefore investigated the effect of N-trimethyl-hydrazine-3-propionate (THP), a carnitine analog inhibiting carnitine biosynthesis and renal carnitine reabsorption, on physical performance and skeletal muscle mitochondrial function in rats. Methods: Male Sprague Dawley rats were treated daily with water (control rats; n = 12) or with 20 mg/100 g body weight THP (n = 12) via oral gavage for 3 weeks. Following treatment, half of the animals of each group performed an exercise test until exhaustion. Results: Distance covered and exercise performance were lower in THP-treated compared to control rats. In the oxidative soleus muscle, carnitine depletion caused atrophy (–24%) and impaired function of complex II and IV of the mitochondrial electron transport chain. The free radical leak (ROS production relative to oxygen consumption) was increased and the cellular glutathione pool decreased. Moreover, mRNA expression of markers of mitochondrial biogenesis and mitochondrial DNA were decreased in THP-treated compared to control rats. In comparison, in the glycolytic gastrocnemius muscle, carnitine depletion was associated with impaired function of complex IV and increased free radical leak, whilst muscle weight and cellular glutathione pool were maintained. Markers of mitochondrial proliferation and mitochondrial DNA were unaffected. Conclusions: Carnitine deficiency is associated with impaired exercise capacity in rats treated with THP. THP-induced carnitine deficiency is associated with impaired function of the electron transport chain in oxidative and glycolytic muscle as well as with atrophy and decreased mitochondrial DNA in oxidative muscle. PMID:27559315

  16. Dietary calcium deficiency in laying ducks impairs eggshell quality by suppressing shell biomineralization.

    PubMed

    Chen, Wei; Zhao, Fei; Tian, Zhi Mei; Zhang, Han Xing; Ruan, Dong; Li, Yan; Wang, Shuang; Zheng, Chun Tian; Lin, Ying Cai

    2015-10-01

    The objective of this study was to determine the effects of dietary calcium deficiency on the process of shell formation. Four hundred and fifty female ducks (Anas platyrhynchos) at 22 weeks were randomly assigned to three groups. Ducks were fed one of two calcium-deficient diets (containing 1.8% or 0.38% calcium, respectively) or a calcium-adequate control diet (containing 3.6% calcium) for 67 days (depletion period) and then all ducks were fed a calcium-adequate diet for an additional 67 days (repletion period). Compared with the calcium-adequate control, the average shell thickness, egg shell weight, breaking strength, mammillae density and mammillary knob thickness of shell from ducks that consumed the diet with 0.38% calcium were significantly decreased (P<0.05) during the depletion period, accompanied by reduced tibia quality. The mRNA expression of both secreted phosphoprotein 1 (SPP1) and carbonic anhydrase 2 (CA2) in the uterus was decreased after feeding calcium-deficient diets (1.8% or 0.38% calcium). mRNA transcripts of calbindin 1 (CALB1), an important protein responsible for calcium transport, and the matrix protein genes ovocalyxin-32 (OCX-32) and ovocleidin-116 (OC-116) were reduced in ducks fed 0.38% calcium but not 1.8% calcium. Plasma estradiol concentration was decreased by both of the calcium-deficient diets (P<0.05). The impaired shell quality and suppressed functional proteins involved in shell formation could be reversed by repletion of dietary calcium. The results of the present study suggest that dietary calcium deficiency negatively affects eggshell quality and microarchitecture, probably by suppressing shell biomineralization. PMID:26385336

  17. Pancreas Recovery Following Caerulein-induced Pancreatitis is Impaired in Plasminogen Deficient Mice

    PubMed Central

    Lugea, Aurelia; Nan, Li; French, Samuel W.; Bezerra, Jorge A.; Gukovskaya, Anna S; Pandol, Stephen J.

    2006-01-01

    Background & Aims: The plasminogen (plg) system participates in tissue repair in several organs, but its role in pancreas repair remains poorly characterized. To better understand the role of plg in pancreas recovery following injury, we examined the course of caerulein-induced pancreatitis in plg deficient and sufficient mice. Methods: Pancreatitis was induced by caerulein administration (50 μg/kg, 7 ip injections). Mice were sacrificed either at the acute phase (7 hours after the first caerulein injection) or during recovery (at 2, 4 and 7 days). In pancreatic sections we examined: pancreatic morphology, trypsin activation, inflammatory cell infiltration, acinar cell death, cell proliferation, extracellular matrix (ECM) deposition, activation of stellate cells (PSCs), and components of the plg and metalloproteinase systems. Results: In plg sufficient mice, pancreatic plg levels and plasmin activity increased during the acute phase and remained elevated during recovery. Pancreatitis resolved in plg sufficient mice within 7 days. Pancreas recovery involved reorganization of the parenchyma structure, removal of necrotic debris, cell proliferation, transient activation of PSCs and moderate deposition of ECM proteins. Acute pancreatitis (7-h) was indistinguishable between plg deficient and sufficient mice. In contrast, pancreas recovery was impaired in plg deficient mice. Plg deficiency led to disorganized parenchyma, extensive acinar cell loss, poor removal of necrotic debris, reduced cell proliferation and fibrosis. Fibrosis was characterized by deposition of collagens and fibronectin, persistent activation of PSCs and upregulation of pancreatic TGF-β1. Conclusions: Plg/plasmin deficiency leads to features similar to those found in chronic pancreatitis such as parenchymal atrophy and fibrosis. PMID:16952557

  18. Impaired intestinal wound healing in Fhl2-deficient mice is due to disturbed collagen metabolism

    SciTech Connect

    Kirfel, Jutta Pantelis, Dimitrios; Kabba, Mustapha; Kahl, Philip; Roeper, Anke; Kalff, Joerg C.; Buettner, Reinhard

    2008-12-10

    Four and one half LIM domain protein FHL2 participates in many cellular processes involved in tissue repair such as regulation of gene expression, cytoarchitecture, cell adhesion, migration and signal transduction. The repair process after wounding is initiated by the release of peptides and bioactive lipids. These molecules induce synthesis and deposition of a provisional extracellular matrix. We showed previously that sphingosine-1-phosphate (S1P) triggers a signal transduction cascade mediating nuclear translocation of FHL2 in response to activation of the RhoA GTPase. Our present study shows that FHL2 is an important signal transducer influencing the outcome of intestinal anastomotic healing. Early wound healing is accompanied by reconstitution and remodelling of the extracellular matrix and collagen is primarily responsible for wound strength. Our results show that impaired intestinal wound healing in Fhl2-deficient mice is due to disturbed collagen III metabolism. Impaired collagen III synthesis reduced the mechanical stability of the anastomoses and led to lower bursting pressure in Fhl2-deficient mice after surgery. Our data confirm that FHL2 is an important factor regulating collagen expression in the early phase of wound healing, and thereby is critically involved in the physiologic process of anastomosis healing after bowel surgery and thus may represent a new therapeutic target.

  19. High dose zinc supplementation induces hippocampal zinc deficiency and memory impairment with inhibition of BDNF signaling.

    PubMed

    Yang, Yang; Jing, Xiao-Peng; Zhang, Shou-Peng; Gu, Run-Xia; Tang, Fang-Xu; Wang, Xiu-Lian; Xiong, Yan; Qiu, Mei; Sun, Xu-Ying; Ke, Dan; Wang, Jian-Zhi; Liu, Rong

    2013-01-01

    Zinc ions highly concentrate in hippocampus and play a key role in modulating spatial learning and memory. At a time when dietary fortification and supplementation of zinc have increased the zinc consuming level especially in the youth, the toxicity of zinc overdose on brain function was underestimated. In the present study, weaning ICR mice were given water supplemented with 15 ppm Zn (low dose), 60 ppm Zn (high dose) or normal lab water for 3 months, the behavior and brain zinc homeostasis were tested. Mice fed high dose of zinc showed hippocampus-dependent memory impairment. Unexpectedly, zinc deficiency, but not zinc overload was observed in hippocampus, especially in the mossy fiber-CA3 pyramid synapse. The expression levels of learning and memory related receptors and synaptic proteins such as NMDA-NR2A, NR2B, AMPA-GluR1, PSD-93 and PSD-95 were significantly decreased in hippocampus, with significant loss of dendritic spines. In keeping with these findings, high dose intake of zinc resulted in decreased hippocampal BDNF level and TrkB neurotrophic signaling. At last, increasing the brain zinc level directly by brain zinc injection induced BDNF expression, which was reversed by zinc chelating in vivo. These results indicate that zinc plays an important role in hippocampus-dependent learning and memory and BDNF expression, high dose supplementation of zinc induces specific zinc deficiency in hippocampus, which further impair learning and memory due to decreased availability of synaptic zinc and BDNF deficit. PMID:23383172

  20. Innate immunity against bacterial infection following hyperoxia exposure is impaired in Nrf2-deficient mice

    PubMed Central

    Reddy, Narsa M.; Suryanarayana, Vegiraju; Kalvakolanu, Dhananjaya V; Yamamoto, Masayuki; Kensler, Thomas W.; Hassoun, Paul M.; Kleeberger, Steven R.; Reddy, Sekhar P.

    2010-01-01

    Summary Oxygen supplementation is used as therapy to support critically ill patients with severe respiratory impairment. Although hyperoxia has been shown to enhance the lung susceptibility to subsequent bacterial infection, the mechanisms underlying enhanced susceptibility remain enigmatic. We have reported that disruption of Nrf2, a master transcription regulator of various stress response pathways, enhances susceptibility to hyperoxia-induced acute lung injury (ALI) in mice, and have also demonstrated an association between a polymorphism in the NRF2 promoter and increased susceptibility to ALI. In this study, we show that Nrf2-deficient (Nrf2−/−) but not wild-type (Nrf2+/+) mice exposed to sub-lethal hyperoxia succumbed to death during recovery after P. aeruginosa infection. Nrf2-deficiency caused persistent bacterial pulmonary burden and enhanced levels of inflammatory cell infiltration as well as edema. Alveolar macrophages isolated from Nrf2−/− mice exposed to hyperoxia displayed persistent oxidative stress and inflammatory cytokine expression concomitant with diminished levels of antioxidant enzymes, such as Gclc, required for GSH biosynthesis. In vitro exposure of Nrf2−/− macrophages to hyperoxia strongly diminished their antibacterial activity and enhanced inflammatory cytokine expression compared to Nrf2+/+ cells. However, GSH supplementation during hyperoxic insult restored the ability of Nrf2−/− cells to mount antibacterial response and suppressed cytokine expression. Thus, loss of Nrf2 impairs lung innate immunity and promotes susceptibility to bacterial infection after hyperoxia exposure, ultimately leading to death of the host. PMID:19734219

  1. Vitamin D deficiency in pregnant women impairs regulatory T cell function.

    PubMed

    Vijayendra Chary, A; Hemalatha, R; Seshacharyulu, M; Vasudeva Murali, M; Jayaprakash, D; Dinesh Kumar, B

    2015-03-01

    .02) pregnant women. Regulatory cytokines, TGF β and IL-10 were lower (p<0.05) in 25(OH)D3 insufficient and deficient subjects. In the placenta tissue of women with 25(OH)D3 deficiency, the regulatory T cell transcription factor FOXP3, vitamin D receptor (VDR) and retinoic acid receptor (RXR) expressions were downregulated. In contrast, CD23, CD21 and VDBP expressions were upregulated in 25(OH)D3 deficient and insufficient women. Vitamin D regulating enzymes (CYP24A1, CYP2R1 and CYP27B1) expression were also altered in women with 25(OH)D3 deficiency. The current study shows that impaired maternal 25(OH)D3 during pregnancy influences the spectrum of immune cells such as regulatory T cells and B cells with IgE receptors and this in turn may be linked to allergy and asthma in neonates. PMID:25448751

  2. Reprint of "Vitamin D deficiency in pregnant women impairs regulatory T cell function".

    PubMed

    Vijayendra Chary, A; Hemalatha, R; Seshacharyulu, M; Vasudeva Murali, M; Jayaprakash, D; Dinesh Kumar, B

    2015-04-01

    and IL-10 were lower (p<0.05) in 25(OH)D3 insufficient and deficient subjects. In the placenta tissue of women with 25(OH)D3 deficiency, the regulatory T cell transcription factor FOXP3, vitamin D receptor (VDR) and retinoic acid receptor (RXR) expressions were downregulated. In contrast, CD23, CD21 and VDBP expressions were upregulated in 25(OH)D3 deficient and insufficient women. Vitamin D regulating enzymes (CYP24A1, CYP2R1 and CYP27B1) expression were also altered in women with 25(OH)D3 deficiency. The current study shows that impaired maternal 25(OH)D3 during pregnancy influences the spectrum of immune cells such as regulatory T cells and B cells with IgE receptors and this in turn may be linked to allergy and asthma in neonates. PMID:25644204

  3. Impaired neurogenesis in embryonic spinal cord of Phgdh knockout mice, a serine deficiency disorder model.

    PubMed

    Kawakami, Yuriko; Yoshida, Kazuyuki; Yang, Jung Hoon; Suzuki, Takeshi; Azuma, Norihiro; Sakai, Kazuhisa; Hashikawa, Tsutomu; Watanabe, Masahiko; Yasuda, Kaori; Kuhara, Satoru; Hirabayashi, Yoshio; Furuya, Shigeki

    2009-03-01

    Mutations in the d-3-phosphoglycerate dehydrogenase (PHGDH; EC 1.1.1.95) gene, which encodes an enzyme involved in de novol-serine biosynthesis, are shown to cause human serine deficiency disorder. This disorder has been characterized by severe neurological symptoms including congenital microcephaly and psychomotor retardation. Our previous work demonstrated that targeted disruption of mouse Phgdh leads to a marked decrease in serine and glycine, severe growth retardation of the central nervous system, and lethality after embryonic day 13.5. To clarify how a serine deficiency causes neurodevelopmental defects, we characterized changes in metabolites, gene expression and morphological alterations in the spinal cord of Phgdh knockout mice. BeadChip microarray analysis revealed significant dysregulation of genes involved in the cell cycle. Ingenuity Pathway Analysis also revealed a significant perturbation of regulatory networks that operate in the cell cycle progression. Moreover, morphological examinations of the knockout spinal cord demonstrated a marked deficit in dorsal horn neurons. Radial glia cells, native neural stem/progenitor cells, accumulated in the dorsal ventricular zone, but they did not proceed to a G(0)-like quiescent state. The present integrative study provides in vivo evidence that normal cell cycle progression and subsequent neurogenesis of radial glia cells are severely impaired by serine deficiency. PMID:19114063

  4. Dectin-3 Deficiency Promotes Colitis Development due to Impaired Antifungal Innate Immune Responses in the Gut

    PubMed Central

    Wang, Tingting; Pan, Deng; Zhou, Zhicheng; You, Yun; Jiang, Changying; Zhao, Xueqiang; Lin, Xin

    2016-01-01

    Interactions between commensal fungi and gut immune system are critical for establishing colonic homeostasis. Here we found that mice deficient in Dectin-3 (Clec4d-/-), a C-type lectin receptor that senses fungal infection, were more susceptible to dextran sodium sulfate (DSS)-induced colitis compared with wild-type mice. The specific fungal burden of Candida (C.) tropicalis was markedly increased in the gut after DSS treatment in Clec4d-/- mice, and supplementation with C. tropicalis aggravated colitis only in Clec4d-/- mice, but not in wild-type controls. Mechanistically, Dectin-3 deficiency impairs phagocytic and fungicidal abilities of macrophages, and C. tropicalis-induced NF-κB activation and cytokine production. The conditioned media derived from Dectin-3-deficient macrophages were defective in promoting tissue repairing in colonic epithelial cells. Finally, anti-fungal therapy was effective in treating colitis in Clec4d-/- mice. These studies identified the role of Dectin-3 and its functional interaction with commensal fungi in intestinal immune system and regulation of colonic homeostasis. PMID:27280399

  5. Subclinical zinc deficiency impairs pancreatic digestive enzyme activity and digestive capacity of weaned piglets.

    PubMed

    Brugger, Daniel; Windisch, Wilhelm M

    2016-08-01

    This study investigated the effects of short-term subclinical Zn deficiency on exocrine pancreatic activity and changes in digestive capacity. A total of forty-eight weaned piglets were fed ad libitum a basal diet (maize and soyabean meal) with adequate Zn supply (88 mg Zn/kg diet) during a 2-week acclimatisation phase. Animals were then assigned to eight dietary treatment groups (n 6) according to a complete randomised block design considering litter, live weight and sex. All pigs were fed restrictively (450 g diet/d) the basal diet but with varying ZnSO4.7H2O additions, resulting in 28·1, 33·6, 38·8, 42·7, 47·5, 58·2, 67·8 and 88·0 mg Zn/kg diet for a total experimental period of 8 d. Pancreatic Zn concentrations and pancreatic activities of trypsin, chymotrypsin, carboxypeptidase A and B, elastase and α-amylase exhibited a broken-line response to stepwise reduction in dietary Zn by declining beneath thresholds of 39·0, 58·0, 58·0, 41·2, 47·5, 57·7 and 58·0 mg Zn/kg diet, respectively. Furthermore, carboxypeptidase B and α-amylase activities were significantly lower in samples with reduced pancreatic Zn contents. Coefficients of faecal digestibility of DM, crude protein, total lipids and crude ash responded similarly to pancreatic enzyme activities by declining below dietary thresholds of 54·7, 45·0, 46·9 and 58·2 mg Zn/kg diet, respectively. In conclusion, (1) subclinical Zn deficiency impaired pancreatic exocrine enzymes, (2) this response was connected to pancreatic Zn metabolism and (3) the decline in catalytic activity impaired faecal digestibility already after 1 week of insufficient alimentary Zn supply and very early before clinical deficiency symptoms arise. PMID:27230230

  6. ABCG2 deficiency in skin impairs re-epithelialization in cutaneous wound healing.

    PubMed

    Chang, Hsiao-Min; Huang, Wen-Yen; Lin, Sung-Jan; Huang, Wei-Chao; Shen, Chia-Rui; Mao, Wan-Yu; Shen, Chia-Ning

    2016-05-01

    The ATP-binding cassette transporter ABCG2 is expressed in the interfollicular epidermis and mediates the side-population phenotype in skin cells. However, the role of ABCG2 in skin is unclear. Increased expression levels of ABCG2 were found at the basal layer of transitional epidermis adjacent to cutaneous wounds in human patients, indicating that ABCG2 may be involved in regulating the wound healing process. To investigate the role of ABCG2 in cutaneous wound healing, full-thickness skin wounds were created in ABCG2 knockout (ABCG2-KO) and wild-type mice. The healing process was analysed and revealed that ABCG2 deficiency in skin results in delays in wound closure and impairments in re-epithelialization, as evidenced by reductions in both suprabasal differentiation and in p63-expressing keratinocytes migrating from transitional epidermis to epithelial tongues. The reduction in p63-expressing cells may be due to elevated levels of reactive oxygen species in ABCG2-KO epidermis, which can cause DNA damage and lead to proliferation arrest. To determine whether ABCG2 deficiency affects the potency of epidermal stem/progenitor cells (EPCs), transplantation studies were carried out, which demonstrated that ABCG2-KO EPCs display higher levels of γH2AX and lose the capacity to differentiate into suprabasal keratinocytes. A competitive repopulation assay confirmed that ABCG2 expression is critical for the proper expansion and differentiation of EPCs in cutaneous wounds. As EPCs are known to contribute to the healing of larger wounds, the current findings imply a functional role for ABCG2 in the expansion and differentiation of p63-expressing EPCs. Thus, ABCG2 deficiency in skin impairs re-epithelialization in cutaneous wound healing. PMID:26739701

  7. Thiamine deficiency decreases glutamate uptake in the prefrontal cortex and impairs spatial memory performance in a water maze test.

    PubMed

    Carvalho, Fabiana M; Pereira, Silvia R C; Pires, Rita G W; Ferraz, Vany P; Romano-Silva, Marco Aurélio; Oliveira-Silva, Ieda F; Ribeiro, Angela M

    2006-04-01

    Using an animal model of Wernicke-Korsakoff syndrome, in which rats were submitted to a chronic ethanol treatment with or without a thiamine deficiency episode, the glutamate uptake in the prefrontal cortex and spatial memory aspects were studied. It was found that (i) thiamine deficiency, but not chronic ethanol consumption, induced a significant decrease of glutamate uptake; (ii) thiamine-deficient subjects showed an impaired performance in the water maze spatial memory test though these animals were able to learn the task during the acquisition. In spite of the fact that thiamine deficiency affects both glutamate uptake and spatial reference memory, there was no significant correlation between these two data. The present results show that, although prefrontal cortex is considered by some authors a not vulnerable area to lesions caused by thiamine deficiency, this vitamin deficiency does cause a neurochemistry dysfunction in that region. PMID:16687165

  8. Impairment of survival signaling and efferocytosis in TRPC3-deficient macrophages

    SciTech Connect

    Tano, Jean-Yves; Smedlund, Kathryn; Lee, Robert; Abramowitz, Joel; Birnbaumer, Lutz; Vazquez, Guillermo

    2011-07-08

    Highlights: {yields} We examined the role of TRPC3 channel in macrophage survival, apoptosis and efferocytic properties. {yields} TRPC3-deficient macrophages exhibit impaired survival signaling, increased apoptosis and impaired efferocytosis. {yields} These findings suggest that macrophage TRPC3 is an essential component for macrophage survival and clearance of apoptotic cells. -- Abstract: We have recently shown that in macrophages proper operation of the survival pathways phosphatidylinositol-3-kinase (PI3K)/AKT and nuclear factor kappa B (NFkB) has an obligatory requirement for constitutive, non-regulated Ca{sup 2+} influx. In the present work we examined if Transient Receptor Potential Canonical 3 (TRPC3), a member of the TRPC family of Ca{sup 2+}-permeable cation channels, contributes to the constitutive Ca{sup 2+} influx that supports macrophage survival. We used bone marrow-derived macrophages obtained from TRPC3{sup -/-} mice to determine the activation status of survival signaling pathways, apoptosis and their efferocytic properties. Treatment of TRPC3{sup +/+} macrophages with the pro-apoptotic cytokine TNF{alpha} induced time-dependent phosphorylation of I{kappa}B{alpha}, AKT and BAD, and this was drastically reduced in TRPC3{sup -/-} macrophages. Compared to TRPC3{sup +/+} cells TRPC3{sup -/-} macrophages exhibited reduced constitutive cation influx, increased apoptosis and impaired efferocytosis. The present findings suggest that macrophage TRPC3, presumably through its constitutive function, contributes to survival signaling and efferocytic properties.

  9. 25-Hydroxyvitamin D3 Deficiency Independently Predicts Cognitive Impairment in Patients with Systemic Lupus Erythematosus

    PubMed Central

    Tay, Sen Hee; Ho, Chung Shun; Ho, Roger Chun-Man; Mak, Anselm

    2015-01-01

    Objectives Cognitive dysfunction has been reported in 20–80% of SLE patients. Converging evidence has indicated the importance of vitamin D as a neuroimmunomodulator for cognitive function. In this study, we evaluated the relationship between vitamin D and cognitive dysfunction. Methods Consecutive age- and gender-matched SLE patients and healthy controls (HCs) were administered Automated Neuropsychological Assessment Metrics in this cross-sectional study. The primary outcome was the total throughput score (TTS). Anxiety and depression were measured using the Hospital Anxiety and Depression Scale (HADS). Levels of 25-hydroxyvitamin D [25(OH)D3 and total 25(OH)D] were measured using Liquid Chromatography-Tandem Mass Spectrometry. Results In total, 61 SLE patients and 61 HCs were studied. SLE patients scored significantly lower than HCs in the TTS (p = 0.004). There were no statistically significant differences in 25(OH)D3 levels, total 25(OH)D levels and total 25(OH)D deficiency between SLE patients and HCs. However, more SLE patients had 25(OH)D3 deficiency compared to HCs [12 (19.7%) versus 2 (3.3%), p = 0.003]. Deficiency of 25(OH)D3 (β = -63.667, SE = 27.456, p = 0.025), but not other vitamin D variables, independently predicted worse TTS after adjusting for age, education, gender, ethnicity, HADS-Total, duration of SLE, SELENA-SLEDAI, SLICC/ACR Damage Index and cumulative steroid dose in SLE patients. Age (β = -4.261, SE = 0.866, p < 0.001) was the only predictor of TTS after adjusting for education, gender, ethnicity, HADS-Total, vitamin D levels or status in HCs. Conclusions Deficiency of 25(OH)D3, a potentially modifiable risk factor, independently predicted cognitive impairment in SLE patients. PMID:26636681

  10. Isolation and Transfection of Primary Culture Bovine Retinal Pericytes.

    PubMed

    Primo, Vincent A; Arboleda-Velasquez, Joseph F

    2016-01-01

    This protocol describes an enzymatic approach for isolating homogeneous cultures of pericytes from retinas of bovine source. In summary, retinas are dissected, washed, digested, filtered, cultured in specific media to select for pericytes, and finally expanded for a low passage culture of about 14 million bovine retinal pericytes (BRP) within 4-6 weeks. This protocol also describes a liposomal-based technique for transfection of BRPs. PMID:27172949

  11. Pericytes as a new target for pathological processes in CADASIL.

    PubMed

    Dziewulska, Dorota; Lewandowska, Eliza

    2012-10-01

    CADASIL is a generalized angiopathy caused by mutations in NOTCH 3 gene leading to degeneration and loss of vascular smooth muscle cells (VSMC) in small arteries and arterioles. Since the receptor protein encoded by NOTCH 3 gene is expressed not only on VSMC but also on pericytes, pericytes and capillary vessels can be damaged by CADASIL. To check this hypothesis we examined microvessels in autopsy brains and skin-muscle biopsies of CADASIL patients. We found degeneration and loss of pericytes in capillary vessels. Pericytes were shrunken and their cytoplasm contained numerous vacuoles, big vesicular structures and complexes of enlarged pathological mitochondria. Degenerative changes were also observed within endothelial-pericytic connections, especially within peg-and-socket junctions. Nearby pericyte cell membranes or inside infoldings, deposits of granular osmiophilic material (GOM) were usually seen. In the affected capillaries endothelial cells revealed features of degeneration, selective death or swelling, leading to narrowing or occlusion of the capillary lumen. Our findings indicate that in CADASIL not only VSMC but also pericytes are severely damaged. Pericyte involvement in CADASIL can result in increased permeability of capillary vessels and disturbances in cerebral microcirculation, leading to white matter injury. Since in capillaries pericytes regulate vessel contractility, their degeneration can also cause defective vasomotor reactivity, the phenomenon observed very early in CADASIL, before development of histopathological changes in vessel walls. PMID:22239429

  12. Runx1 deficiency permits granulocyte lineage commitment but impairs subsequent maturation.

    PubMed

    Ng, K P; Hu, Z; Ebrahem, Q; Negrotto, S; Lausen, J; Saunthararajah, Y

    2013-01-01

    First-hits in the multi-hit process of leukemogenesis originate in germline or hematopoietic stem cells (HSCs), yet leukemia-initiating cells (LICs) usually have a lineage-committed phenotype. The molecular mechanisms underlying this compartment shift during leukemia evolution have not been a major focus of investigation and remain poorly understood. Here a mechanism underlying this shift was examined in the context of Runx1 deficiency, a frequent leukemia-initiating event. Lineage-negative cells isolated from the bone marrow of Runx1-haploinsufficient and wild-type control mice were cultured in granulocyte-colony-stimulating factor to force lineage commitment. Runx1-haploinsufficient cells demonstrated significantly greater and persistent exponential cell growth than wild-type controls. Not surprisingly, the Runx1-haploinsufficient cells were differentiation-impaired, by morphology and by flow-cytometric evaluation for granulocyte differentiation markers. Interestingly, however, this impaired differentiation was not because of decreased granulocyte lineage commitment, as RNA and protein upregulation of the master granulocyte lineage-commitment transcription factor Cebpa, and Hoxb4 repression, was similar in wild-type and Runx1-haploinsufficient cells. Instead, RNA and protein expression of Cebpe, a key driver of progressive maturation after lineage commitment, were significantly decreased in Runx1-haploinsufficient cells. Primary acute myeloid leukemia cells with normal cytogenetics and RUNX1 mutation also demonstrated this phenotype of very high CEBPA mRNA expression but paradoxically low expression of CEBPE, a CEBPA target gene. Chromatin-immunoprecipitation analyses suggested a molecular mechanism for this phenotype: in wild-type cells, Runx1 binding was substantially greater at the Cebpe than at the Cebpa enhancer. Furthermore, Runx1 deficiency substantially diminished high-level Runx1 binding at the Cebpe enhancer, but lower-level binding at the Cebpa

  13. Deficient Wnt signalling triggers striatal synaptic degeneration and impaired motor behaviour in adult mice

    PubMed Central

    Galli, Soledad; Lopes, Douglas M.; Ammari, Rachida; Kopra, Jaakko; Millar, Sarah E.; Gibb, Alasdair; Salinas, Patricia C.

    2014-01-01

    Synapse degeneration is an early and invariant feature of neurodegenerative diseases. Indeed, synapse loss occurs prior to neuronal degeneration and correlates with the symptom severity of these diseases. However, the molecular mechanisms that trigger synaptic loss remain poorly understood. Here we demonstrate that deficient Wnt signalling elicits synaptic degeneration in the adult striatum. Inducible expression of the secreted Wnt antagonist Dickkopf1 (Dkk1) in adult mice (iDkk1) decreases the number of cortico-striatal glutamatergic synapses and of D1 and D2 dopamine receptor clusters. Synapse loss occurs in the absence of axon retraction or cell death. The remaining excitatory terminals contain fewer synaptic vesicles and have a reduced probability of evoked transmitter release. IDkk1 mice show impaired motor coordination and are irresponsive to amphetamine. These studies identify Wnts as key endogenous regulators of synaptic maintenance and suggest that dysfunction in Wnt signalling contributes to synaptic degeneration at early stages in neurodegenerative diseases. PMID:25318560

  14. Autosomal recessive PGM3 mutations link glycosylation defects to atopy, immune deficiency, autoimmunity, and neurocognitive impairment

    PubMed Central

    Zhang, Yu; Yu, Xiaomin; Ichikawa, Mie; Lyons, Jonathan J.; Datta, Shrimati; Lamborn, Ian T.; Jing, Huie; Kim, Emily S.; Biancalana, Matthew; Wolfe, Lynne A.; DiMaggio, Thomas; Matthews, Helen F.; Kranick, Sarah M.; Stone, Kelly D.; Holland, Steven M.; Reich, Daniel S.; Hughes, Jason D.; Mehmet, Huseyin; McElwee, Joshua; Freeman, Alexandra F.; Freeze, Hudson H.; Su, Helen C.; Milner, Joshua D.

    2014-01-01

    Background Identifying genetic syndromes that lead to significant atopic disease can open new pathways for investigation and intervention in allergy. Objective To define a genetic syndrome of severe atopy, elevated serum IgE, immune deficiency, autoimmunity, and motor and neurocognitive impairment. Methods Eight patients from two families who had similar syndromic features were studied. Thorough clinical evaluations, including brain MRI and sensory evoked potentials, were performed. Peripheral lymphocyte flow cytometry, antibody responses, and T cell cytokine production were measured. Whole exome sequencing was performed to identify disease-causing mutations. Immunoblotting, qRT-PCR, enzymatic assays, nucleotide sugar and sugar phosphate analyses along with MALDI-TOF mass spectrometry of glycans were used to determine the molecular consequences of the mutations. Results Marked atopy and autoimmunity were associated with increased TH2 and TH17 cytokine production by CD4+ T cells. Bacterial and viral infection susceptibility were noted along with T cell lymphopenia, particularly of CD8+ T cells, and reduced memory B cells. Apparent brain hypomyelination resulted in markedly delayed evoked potentials and likely contributed to neurological abnormalities. Disease segregated with novel autosomal recessive mutations in a single gene, phosphoglucomutase 3 (PGM3). Although PGM3 protein expression was variably diminished, impaired function was demonstrated by decreased enzyme activity and reduced UDP-GlcNAc, along with decreased O- and N-linked protein glycosylation in patients’ cells. These results define a new Congenital Disorder of Glycosylation. Conclusions Autosomal recessive, hypomorphic PGM3 mutations underlie a disorder of severe atopy, immune deficiency, autoimmunity, intellectual disability and hypomyelination. PMID:24589341

  15. Msh2 deficiency leads to dysmyelination of the corpus callosum, impaired locomotion, and altered sensory function in mice

    PubMed Central

    Diouf, Barthelemy; Devaraju, Prakash; Janke, Laura J.; Fan, Yiping; Frase, Sharon; Eddins, Donnie; Peters, Jennifer L.; Kim, Jieun; Pei, Deqing; Cheng, Cheng; Zakharenko, Stanislav S.; Evans, William E.

    2016-01-01

    A feature in patients with constitutional DNA-mismatch repair deficiency is agenesis of the corpus callosum, the cause of which has not been established. Here we report a previously unrecognized consequence of deficiency in MSH2, a protein known primarily for its function in correcting nucleotide mismatches or insertions and deletions in duplex DNA caused by errors in DNA replication or recombination. We documented that Msh2 deficiency causes dysmyelination of the axonal projections in the corpus callosum. Evoked action potentials in the myelinated corpus callosum projections of Msh2-null mice were smaller than wild-type mice, whereas unmyelinated axons showed no difference. Msh2-null mice were also impaired in locomotive activity and had an abnormal response to heat. These findings reveal a novel pathogenic consequence of MSH2 deficiency, providing a new mechanistic hint to previously recognized neurological disorders in patients with inherited DNA-mismatch repair deficiency. PMID:27476972

  16. Methionine deficiency leads to hepatic fat accretion via impairment of fatty acid import by carnitine palmitoyltransferase I.

    PubMed

    Kikusato, M; Sudo, S; Toyomizu, M

    2015-04-01

    1. To clarify the underlying mechanism of hepatic fat accretion due to methionine (Met) deficiency in broiler chickens, the present study investigated the effect of Met deficiency on the hepatic carnitine palmitoyltransferase (CPT) system, which imports fatty acids into mitochondria. 2. Fifteen-d-old male meat-type chickens were fed on either a control diet (containing 0.52 g/100 g Met) or a Met-deficient diet (containing 0.27 g Met/100 g). After a 10-d feeding period, the birds were killed by decapitation and their livers excised to determine hepatic CPT1 and CPT2 mRNA levels and for the related hepatic fatty acid-supported mitochondrial respiration to be measured. 3. Met deficiency decreased body weight gain and feed efficiency and increased hepatic lipid content compared to the control group. Whereas the hepatic CPT2 mRNA level in the Met-deficient group remained unchanged compared to that of the control group, the CPT1 mRNA level was decreased in the Met-deficient group and CPT1-dependent hepatic mitochondrial respiration was impaired. 4. Our results suggest that the hepatic lipid accretion that occurs in response to Met deficiency might be attributable to the impairment of CPT1-mediated fatty acid import into mitochondria. PMID:25561085

  17. Impaired Fracture Healing Caused by Deficiency of the Immunoreceptor Adaptor Protein DAP12.

    PubMed

    Kamimura, Masayuki; Mori, Yu; Sugahara-Tobinai, Akiko; Takai, Toshiyuki; Itoi, Eiji

    2015-01-01

    Osteoclasts play an important role in bone metabolism, but their exact role in fracture healing remains unclear. DAP12 is an immunoadaptor protein with associated immunoreceptors on myeloid lineage cells, including osteoclasts. Its deficiency causes osteopetrosis due to suppression of osteoclast development and activation. In this report, we assessed the impact of DAP12 on the fracture healing process using C57BL/6 (B6) and DAP12-/- mice. Healing was evaluated using radiography, micro-CT, histology, immunohistochemistry and real-time RT-PCR. Radiography showed lower callus volume and lower callus radiolucency in DAP12-/- mice during later stages. Micro-CT images and quantitative structural analysis indicated that DAP12-/- mice developed calluses of dense trabecular structures and experienced deteriorated cortical shell formation on the surface. Histologically, DAP12-/- mice showed less cartilaginous resorption and woven bone formation. In addition, prominent cortical shell formation was much less in DAP12-/- mice. Immunohistochemistry revealed lower invasion of F4/80 positive monocytes and macrophages into the fracture hematoma in DAP12-/- mice. The expression levels of Col1a1, Col2a1 and Col10a1 in DAP12-/- mice increased and subsequently became higher than those in B6 mice. There was a decrease in the gene expression of Tnf during the early stages in DAP12-/- mice. Our results indicate that DAP12 deficiency impairs fracture healing, suggesting a significant role of DAP12 in the initial inflammatory response, bone remodeling and regeneration. PMID:26030755

  18. Vitamin D deficiency during pregnancy may impair maternal and fetal outcomes.

    PubMed

    Lapillonne, Alexandre

    2010-01-01

    Over the past decade, new evidence has shown that vitamin D deficiency may contribute to the risk of developing a wide range of common chronic diseases that are different from the classic action on calcium and bone homeostasis. Acting through the vitamin D receptor, vitamin D can produce a wide array of favorable biological effects via genomic, non-genomic or intracrine mechanisms and, therefore, contributes to the improvement of human health in humans. We hypothesize that some of these effects may be even more critical during pregnancy. The focus of this paper is to review the data on the classic and non-classic actions of vitamin D with regards to pregnancy. It appears that vitamin D insufficiency during pregnancy is potentially associated with increased risk of preeclampsia, insulin resistance and gestational diabetes mellitus. Furthermore, experimental data also anticipate that vitamin D sufficiency is critical for fetal development, and especially for fetal brain development and immunological functions. Vitamin D deficiency during pregnancy may, therefore, not only impair maternal skeletal preservation and fetal skeletal formation but also be vital to the fetal "imprinting" that may affect chronic disease susceptibility soon after birth as well as later in life. PMID:19692182

  19. Impairment of dendritic cell functions in patients with adaptor protein-3 complex deficiency.

    PubMed

    Prandini, Alberto; Salvi, Valentina; Colombo, Francesca; Moratto, Daniele; Lorenzi, Luisa; Vermi, William; De Francesco, Maria Antonia; Notarangelo, Lucia Dora; Porta, Fulvio; Plebani, Alessandro; Facchetti, Fabio; Sozzani, Silvano; Badolato, Raffaele

    2016-06-30

    Hermansky-Pudlak syndrome type 2 (HPS2) is a primary immunodeficiency due to adaptor protein-3 (AP-3) complex deficiency. HPS2 patients present neutropenia, partial albinism, and impaired lysosomal vesicles formation in hematopoietic cells. Given the role of dendritic cells (DCs) in the immune response, we studied monocyte-derived DCs (moDCs) and plasmacytoid DCs (pDCs) in two HPS2 siblings. Mature HPS2 moDCs showed impaired expression of CD83 and DC-lysosome-associated membrane protein (LAMP), low levels of MIP1-β/CCL4, MIG/CXCL9, and severe defect of interleukin-12 (IL-12) secretion. DCs in lymph-node biopsies from the same patients showed a diffuse cytoplasm reactivity in a large fraction of DC-LAMP(+) cells, instead of the classical dot-like stain. In addition, analysis of pDC-related functions of blood-circulating mononuclear cells revealed reduced interferon-α secretion in response to herpes simplex virus-1 (HSV-1), whereas granzyme-B induction upon IL-3/IL-10 stimulation was normal. Finally, T-cell costimulatory activity, as measured by mixed lymphocyte reaction assay, was lower in patients, suggesting that function and maturation of DCs is abnormal in patients with HPS2. PMID:27207797

  20. Impaired dopamine release and synaptic plasticity in the striatum of PINK1-deficient mice.

    PubMed

    Kitada, Tohru; Pisani, Antonio; Porter, Douglas R; Yamaguchi, Hiroo; Tscherter, Anne; Martella, Giuseppina; Bonsi, Paola; Zhang, Chen; Pothos, Emmanuel N; Shen, Jie

    2007-07-01

    Parkinson's disease (PD) is characterized by the selective vulnerability of the nigrostriatal dopaminergic circuit. Recently, loss-of-function mutations in the PTEN-induced kinase 1 (PINK1) gene have been linked to early-onset PD. How PINK1 deficiency causes dopaminergic dysfunction and degeneration in PD patients is unknown. Here, we investigate the physiological role of PINK1 in the nigrostriatal dopaminergic circuit through the generation and multidisciplinary analysis of PINK1(-/-) mutant mice. We found that numbers of dopaminergic neurons and levels of striatal dopamine (DA) and DA receptors are unchanged in PINK1(-/-) mice. Amperometric recordings, however, revealed decreases in evoked DA release in striatal slices and reductions in the quantal size and release frequency of catecholamine in dissociated chromaffin cells. Intracellular recordings of striatal medium spiny neurons, the major dopaminergic target, showed specific impairments of corticostriatal long-term potentiation and long-term depression in PINK1(-/-) mice. Consistent with a decrease in evoked DA release, these striatal plasticity impairments could be rescued by either DA receptor agonists or agents that increase DA release, such as amphetamine or l-dopa. These results reveal a critical role for PINK1 in DA release and striatal synaptic plasticity in the nigrostriatal circuit and suggest that altered dopaminergic physiology may be a pathogenic precursor to nigrostriatal degeneration. PMID:17563363

  1. CX3CR1 deficiency leads to impairment of hippocampal cognitive function and synaptic plasticity

    PubMed Central

    Justin, T. Rogers; Josh, M. Morganti; Adam, D. Bachstetter; Charles, E. Hudson; Melinda, M. Peters; Bethany, A. Grimmig; Edwin, J. Weeber; Paula, C. Bickford; Gemma, Carmelina

    2011-01-01

    The protective/neurotoxic role of fractalkine (CX3CL1) and its receptor CX3C chemokine receptor 1 (CX3CR1) signaling in neurodegenerative disease is an intricate and highly debated research topic and it is becoming even more complicated as new studies reveal discordant results. It appears that the CX3CL1/CX3CR1 axis plays a direct role in neurodegeneration and/or neuroprotection depending upon the CNS insult. However, all the above studies focused on the role of CX3CL1/CX3CR1 signaling in pathological conditions, ignoring the relevance of CX3CL1/CX3CR1 signaling under physiological conditions. No approach to date has been taken to decipher the significance of defects in CX3CL1/CX3CR1 signaling in physiological condition. In the present study we used CX3CR1−/−, CX3CR1+/− and wild-type mice to investigate the physiological role of CX3CR1 receptor in cognition and synaptic plasticity. Our results demonstrated for the first time that mice lacking CX3CR1 receptor show contextual fear conditioning and Morris water maze deficits. CX3CR1 deficiency also affects motor learning. Importantly, mice lacking the receptor have a significant impairment in long term potentiation (LTP). Infusion with IL-1β receptor antagonist significantly reversed the deficit in cognitive function and impairment in LTP. Our results reveal that under physiological conditions, disruption in CX3CL1 signaling will lead to impairment in cognitive function and synaptic plasticity via increased action of IL-1β. PMID:22072675

  2. Foxc1 is required by pericytes during fetal brain angiogenesis

    PubMed Central

    Siegenthaler, Julie A.; Choe, Youngshik; Patterson, Katelin P.; Hsieh, Ivy; Li, Dan; Jaminet, Shou-Ching; Daneman, Richard; Kume, Tsutomu; Huang, Eric J.; Pleasure, Samuel J.

    2013-01-01

    Summary Brain pericytes play a critical role in blood vessel stability and blood–brain barrier maturation. Despite this, how brain pericytes function in these different capacities is only beginning to be understood. Here we show that the forkhead transcription factor Foxc1 is expressed by brain pericytes during development and is critical for pericyte regulation of vascular development in the fetal brain. Conditional deletion of Foxc1 from pericytes and vascular smooth muscle cells leads to late-gestation cerebral micro-hemorrhages as well as pericyte and endothelial cell hyperplasia due to increased proliferation of both cell types. Conditional Foxc1 mutants do not have widespread defects in BBB maturation, though focal breakdown of BBB integrity is observed in large, dysplastic vessels. qPCR profiling of brain microvessels isolated from conditional mutants showed alterations in pericyte-expressed proteoglycans while other genes previously implicated in pericyte–endothelial cell interactions were unchanged. Collectively these data point towards an important role for Foxc1 in certain brain pericyte functions (e.g. vessel morphogenesis) but not others (e.g. barriergenesis). PMID:23862012

  3. Experimental Branch Retinal Vein Occlusion Induces Upstream Pericyte Loss and Vascular Destabilization

    PubMed Central

    Dominguez, Elisa; Raoul, William; Calippe, Bertrand; Sahel, José-Alain; Guillonneau, Xavier; Paques, Michel; Sennlaub, Florian

    2015-01-01

    Aims Branch retinal vein occlusion (BRVO) leads to extensive vascular remodeling and is important cause of visual impairment. Although the vascular morphological changes following experimental vein occlusion have been described in a variety of models using angiography, the underlying cellular events are ill defined. Methods and Results We here show that laser-induced experimental BRVO in mice leads to a wave of TUNEL-positive endothelial cell (EC) apoptosis in the upstream vascular network associated with a transient edema and hemorrhages. Subsequently, we observe an induction of EC proliferation within the dilated vein and capillaries, detected by EdU incorporation, and the edema resolves. However, the pericytes of the upstream capillaries are severely reduced, which was associated with continuing EC apoptosis and proliferation. The vascular remodeling was associated with increased expression of TGFβ, TSP-1, but also FGF2 expression. Exposure of the experimental animals to hypoxia, when pericyte (PC) dropout had occurred, led to a dramatic increase in endothelial cell proliferation, confirming the vascular instability induced by the experimental BRVO. Conclusion Experimental BRVO leads to acute endothelial cells apoptosis and increased permeability. Subsequently the upstream vascular network remains destabilized, characterized by pericyte dropout, un-physiologically high endothelial cells turnover and sensitivity to hypoxia. These early changes might pave the way for capillary loss and subsequent chronic ischemia and edema that characterize the late stage disease. PMID:26208283

  4. CCR5 deficiency accelerates lipopolysaccharide-induced astrogliosis, amyloid-beta deposit and impaired memory function.

    PubMed

    Hwang, Chul Ju; Park, Mi Hee; Hwang, Jae Yeon; Kim, Ju Hwan; Yun, Na Young; Oh, Sang Yeon; Song, Ju Kyung; Seo, Hyun Ok; Kim, Yun-Bae; Hwang, Dae Yeon; Oh, Ki-Wan; Han, Sang-Bae; Hong, Jin Tae

    2016-03-15

    Chemokine receptors are implicated in inflammation and immune responses. Neuro-inflammation is associated with activation of astrocyte and amyloid-beta (Aβ) generations that lead to pathogenesis of Alzheimer disease (AD). Previous our study showed that deficiency of CC chemokine receptor 5 (CCR5) results in activation of astrocytes and Aβ deposit, and thus memory dysfunction through increase of CC chemokine receptor 2 (CCR2) expression. CCR5 knockout mice were used as an animal model with memory dysfunction. For the purpose LPS was injected i.p. daily (0.25 mg/kg/day). The memory dysfunctions were much higher in LPS-injected CCR5 knockout mice compared to CCR5 wild type mice as well as non-injected CCR5 knockout mice. Associated with severe memory dysfuction in LPS injected CCR5 knockout mice, LPS injection significant increase expression of inflammatory proteins, astrocyte activation, expressions of β-secretase as well as Aβ deposition in the brain of CCR5 knockout mice as compared with that of CCR5 wild type mice. In CCR5 knockout mice, CCR2 expressions were high and co-localized with GFAP which was significantly elevated by LPS. Expression of monocyte chemoattractant protein-1 (MCP-1) which ligands of CCR2 also increased by LPS injection, and increment of MCP-1 expression is much higher in CCR5 knockout mice. BV-2 cells treated with CCR5 antagonist, D-ala-peptide T-amide (DAPTA) and cultured astrocytes isolated from CCR5 knockout mice treated with LPS (1 μg/ml) and CCR2 antagonist, decreased the NF-ĸB activation and Aβ level. These findings suggest that the deficiency of CCR5 enhances response of LPS, which accelerates to neuro-inflammation and memory impairment. PMID:26910914

  5. Colitis-associated variant of TLR2 causes impaired mucosal repair due to TFF3 deficiency

    PubMed Central

    Podolsky, Daniel K.; Gerken, Guido; Eyking, Annette; Cario, Elke

    2009-01-01

    Background & aims Goblet cells (GC) facilitate mucosal protection and epithelial barrier repair, yet the innate immune mechanisms that selectively drive GC functions have not been defined. The aim of this study was to determine whether TLR2 and modulation of GC-derived TFF3 are functionally linked in the intestine. Methods GC modulation was assessed using qRT-PCR, western blotting and confocal microscopy. DSS colitis was induced in wild-type, TFF3−/− and TLR2−/− mice. Recombinant TLR2 ligand or TFF3 peptide were orally administered after DSS termination. Caco-2 overexpressing full-length TLR2 or mutant TLR2-R753Q were tested for TFF3 synthesis and functional-related effects in a wounding-assay. Results Data from in-vitro (Ls174T) and ex-vivo models of murine and human GC reveal that TLR2 activation selectively induces synthesis of TFF3. In-vivo studies using TFF3−/− or TLR2−/− mice demonstrate the ability for oral treatment with a TLR2 agonist to confer anti-apoptotic protection of the intestinal mucosa against inflammatory stress-induced damage through TFF3. Recombinant TFF3 rescues TLR2-deficient mice from increased morbidity and mortality during acute colonic injury. Severe ulcerative colitis has recently been found to be associated with the R753Q polymorphism of the TLR2 gene. The relevance of the observed functional effect of TLR2 in regulating GC is confirmed by the finding that the UC-associated TLR2-R753Q variant is functionally deficient in the ability to induce TFF3 synthesis, thus leading to impaired wound healing. Conclusions These data demonstrate a novel function of TLR2 in intestinal GC that links products of commensal bacteria to innate immune protection of the host via TFF3. PMID:19303021

  6. CCR5 deficiency accelerates lipopolysaccharide-induced astrogliosis, amyloid-beta deposit and impaired memory function

    PubMed Central

    Hwang, Jae Yeon; Kim, Ju Hwan; Yun, Na Young; Oh, Sang Yeon; Song, Ju Kyung; Seo, Hyun Ok; Kim, Yun-Bae; Hwang, Dae Yeon; Oh, Ki-Wan; Han, Sang-Bae; Hong, Jin Tae

    2016-01-01

    Chemokine receptors are implicated in inflammation and immune responses. Neuro-inflammation is associated with activation of astrocyte and amyloid-beta (Aβ) generations that lead to pathogenesis of Alzheimer disease (AD). Previous our study showed that deficiency of CC chemokine receptor 5 (CCR5) results in activation of astrocytes and Aβ deposit, and thus memory dysfunction through increase of CC chemokine receptor 2 (CCR2) expression. CCR5 knockout mice were used as an animal model with memory dysfunction. For the purpose LPS was injected i.p. daily (0.25 mg/kg/day). The memory dysfunctions were much higher in LPS-injected CCR5 knockout mice compared to CCR5 wild type mice as well as non-injected CCR5 knockout mice. Associated with severe memory dysfuction in LPS injected CCR5 knockout mice, LPS injection significant increase expression of inflammatory proteins, astrocyte activation, expressions of β-secretase as well as Aβ deposition in the brain of CCR5 knockout mice as compared with that of CCR5 wild type mice. In CCR5 knockout mice, CCR2 expressions were high and co-localized with GFAP which was significantly elevated by LPS. Expression of monocyte chemoattractant protein-1 (MCP-1) which ligands of CCR2 also increased by LPS injection, and increment of MCP-1 expression is much higher in CCR5 knockout mice. BV-2 cells treated with CCR5 antagonist, D-ala-peptide T-amide (DAPTA) and cultured astrocytes isolated from CCR5 knockout mice treated with LPS (1 μg/ml) and CCR2 antagonist, decreased the NF-ĸB activation and Aβ level. These findings suggest that the deficiency of CCR5 enhances response of LPS, which accelerates to neuro-inflammation and memory impairment. PMID:26910914

  7. Leaky RAG Deficiency in Adult Patients with Impaired Antibody Production against Bacterial Polysaccharide Antigens

    PubMed Central

    Geier, Christoph B.; Piller, Alexander; Linder, Angela; Sauerwein, Kai M. T.; Eibl, Martha M.; Wolf, Hermann M.

    2015-01-01

    Loss of function mutations in the recombination activating genes RAG1 and RAG2 have been reported to cause a T-B-NK+ type of severe combined immunodeficiency. In addition identification of hypomorphic mutations in RAG1 and RAG2 has led to an expansion of the spectrum of disease to include Omenn syndrome, early onset autoimmunity, granuloma, chronic cytomegalovirus- or EBV-infection with expansion of gamma/delta T-cells, idiophatic CD4 lymphopenia and a phenotype resembling common variable immunodeficiency. Herein we describe a novel presentation of leaky RAG1 and RAG2 deficiency in two unrelated adult patients with impaired antibody production against bacterial polysaccharide antigens. Clinical manifestation included recurrent pneumonia, sinusitis, otitis media and in one patient recurrent cutaneous vasculitis. Both patients harbored a combination of a null mutation on one allele with a novel hypomorphic RAG1/2 mutation on the other allele. One of these novel mutations affected the start codon of RAG1 and resulted in an aberrant gene and protein expression. The second novel RAG2 mutation leads to a truncated RAG2 protein, lacking the C-terminus with intact core RAG2 and reduced VDJ recombination capacity as previously described in a mouse model. Both patients presented with severely decreased numbers of naïve CD4+ T cells and defective T independent IgG responses to bacterial polysaccharide antigens, while T cell-dependent IgG antibody formation e.g. after tetanus or TBEV vaccination was intact. In conclusion, hypomorphic mutations in genes responsible for SCID should be considered in adults with predominantly antibody deficiency. PMID:26186701

  8. Impaired female fertility in tubulointerstitial antigen-like 1-deficient mice

    PubMed Central

    TAKAHASHI, Akihito; RAHIM, Ajalli; TAKEUCHI, Miki; FUKUI, Emiko; YOSHIZAWA, Midori; MUKAI, Kuniaki; SUEMATSU, Makoto; HASUWA, Hidetoshi; OKABE, Masaru; MATSUMOTO, Hiromichi

    2015-01-01

    Tubulointerstitial nephritis antigen-like 1 (Tinagl1, also known as adrenocortical zonation factor 1 [AZ-1] or lipocalin 7) is a matricellular protein. Previously, we demonstrated that Tinagl1 expression was restricted to extraembryonic regions during the postimplantation period and detected marked expression in mouse Reichert’s membranes. In uteri, Tinagl1 is markedly expressed in the decidual endometrium during the postimplantation period, suggesting that it plays a physical and physiological role in embryo development and/or decidualization of the uterine endometrium during pregnancy. In the present study, in order to determine the role of Tinagl1 during embryonic development and pregnancy, we generated Tinagl1-deficient mice. Although Tinagl1–/– embryos were not lethal during development to term, homologous matings of Tinagl1–/– females and Tinagl1–/– males showed impaired fertility during pregnancy, including failure to carry pregnancy to term and perinatal lethality. To examine ovarian function, ovulation was induced with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG); the number of ovulated oocytes did not differ between Tinagl1–/– and Tinagl1flox/flox. In vitro fertilization followed by embryo culture also demonstrated the normal developmental potential of Tinagl1-null embryos during the preimplantation period. Our results demonstrate that Tinagl1 deficiency affects female mice and results in subfertility phenotypes, and they suggest that although the potential of Tinagl1–/– oocytes is normal, Tinagl1 is related to fertility in adult females but is not essential for either fertilization or preimplantation development in vitro. PMID:26522507

  9. Impaired Coronary and Renal Vascular Function in Spontaneously Type 2 Diabetic Leptin-Deficient Mice

    PubMed Central

    Westergren, Helena U.; Grönros, Julia; Heinonen, Suvi E.; Miliotis, Tasso; Jennbacken, Karin; Sabirsh, Alan; Ericsson, Anette; Jönsson-Rylander, Ann-Cathrine; Svedlund, Sara; Gan, Li-Ming

    2015-01-01

    Background Type 2 diabetes is associated with macro- and microvascular complications in man. Microvascular dysfunction affects both cardiac and renal function and is now recognized as a main driver of cardiovascular mortality and morbidity. However, progression of microvascular dysfunction in experimental models is often obscured by macrovascular pathology and consequently demanding to study. The obese type 2 diabetic leptin-deficient (ob/ob) mouse lacks macrovascular complications, i.e. occlusive atherosclerotic disease, and may therefore be a potential model for microvascular dysfunction. The present study aimed to test the hypothesis that these mice with an insulin resistant phenotype might display microvascular dysfunction in both coronary and renal vascular beds. Methods and Results In this study we used non-invasive Doppler ultrasound imaging to characterize microvascular dysfunction during the progression of diabetes in ob/ob mice. Impaired coronary flow velocity reserve was observed in the ob/ob mice at 16 and 21 weeks of age compared to lean controls. In addition, renal resistivity index as well as pulsatility index was higher in the ob/ob mice at 21 weeks compared to lean controls. Moreover, plasma L-arginine was lower in ob/ob mice, while asymmetric dimethylarginine was unaltered. Furthermore, a decrease in renal vascular density was observed in the ob/ob mice. Conclusion In parallel to previously described metabolic disturbances, the leptin-deficient ob/ob mice also display cardiac and renal microvascular dysfunction. This model may therefore be suitable for translational, mechanistic and interventional studies to improve the understanding of microvascular complications in type 2 diabetes. PMID:26098416

  10. Impaired Fracture Healing Caused by Deficiency of the Immunoreceptor Adaptor Protein DAP12

    PubMed Central

    Kamimura, Masayuki; Mori, Yu; Sugahara-Tobinai, Akiko; Takai, Toshiyuki; Itoi, Eiji

    2015-01-01

    Osteoclasts play an important role in bone metabolism, but their exact role in fracture healing remains unclear. DAP12 is an immunoadaptor protein with associated immunoreceptors on myeloid lineage cells, including osteoclasts. Its deficiency causes osteopetrosis due to suppression of osteoclast development and activation. In this report, we assessed the impact of DAP12 on the fracture healing process using C57BL/6 (B6) and DAP12–/– mice. Healing was evaluated using radiography, micro-CT, histology, immunohistochemistry and real-time RT-PCR. Radiography showed lower callus volume and lower callus radiolucency in DAP12–/– mice during later stages. Micro-CT images and quantitative structural analysis indicated that DAP12–/– mice developed calluses of dense trabecular structures and experienced deteriorated cortical shell formation on the surface. Histologically, DAP12–/– mice showed less cartilaginous resorption and woven bone formation. In addition, prominent cortical shell formation was much less in DAP12–/– mice. Immunohistochemistry revealed lower invasion of F4/80 positive monocytes and macrophages into the fracture hematoma in DAP12–/– mice. The expression levels of Col1a1, Col2a1 and Col10a1 in DAP12–/– mice increased and subsequently became higher than those in B6 mice. There was a decrease in the gene expression of Tnf during the early stages in DAP12–/– mice. Our results indicate that DAP12 deficiency impairs fracture healing, suggesting a significant role of DAP12 in the initial inflammatory response, bone remodeling and regeneration. PMID:26030755

  11. Human TLR1 deficiency is associated with impaired mycobacterial signaling and protection from leprosy reversal reaction.

    PubMed

    Misch, Elizabeth A; Macdonald, Murdo; Ranjit, Chaman; Sapkota, Bishwa R; Wells, Richard D; Siddiqui, M Ruby; Kaplan, Gilla; Hawn, Thomas R

    2008-01-01

    Toll-like receptors (TLRs) are important regulators of the innate immune response to pathogens, including Mycobacterium leprae, which is recognized by TLR1/2 heterodimers. We previously identified a transmembrane domain polymorphism, TLR1_T1805G, that encodes an isoleucine to serine substitution and is associated with impaired signaling. We hypothesized that this TLR1 SNP regulates the innate immune response and susceptibility to leprosy. In HEK293 cells transfected with the 1805T or 1805G variant and stimulated with extracts of M. leprae, NF-kappaB activity was impaired in cells with the 1805G polymorphism. We next stimulated PBMCs from individuals with different genotypes for this SNP and found that 1805GG individuals had significantly reduced cytokine responses to both whole irradiated M. leprae and cell wall extracts. To investigate whether TLR1 variation is associated with clinical presentations of leprosy or leprosy immune reactions, we examined 933 Nepalese leprosy patients, including 238 with reversal reaction (RR), an immune reaction characterized by a Th1 T cell cytokine response. We found that the 1805G allele was associated with protection from RR with an odds ratio (OR) of 0.51 (95% CI 0.29-0.87, p = 0.01). Individuals with 1805 genotypes GG or TG also had a reduced risk of RR in comparison to genotype TT with an OR of 0.55 (95% CI 0.31-0.97, p = 0.04). To our knowledge, this is the first association of TLR1 with a Th1-mediated immune response. Our findings suggest that TLR1 deficiency influences adaptive immunity during leprosy infection to affect clinical manifestations such as nerve damage and disability. PMID:18461142

  12. The pericyte antigen RGS5 in perivascular soft tissue tumors.

    PubMed

    Shen, Jia; Shrestha, Swati; Yen, Yu-Hsin; Scott, Michelle A; Soo, Chia; Ting, Kang; Peault, Bruno; Dry, Sarah M; James, Aaron W

    2016-01-01

    Perivascular soft tissue tumors are relatively uncommon neoplasms of unclear lineage of differentiation, although most are presumed to originate from or differentiate to pericytes or a modified perivascular cell. Among these, glomus tumor, myopericytoma, and angioleiomyoma share a spectrum of histologic findings and a perivascular growth pattern. In contrast, solitary fibrous tumor was once hypothesized to have pericytic differentiation--although little bona fide evidence of pericytic differentiation exists. Likewise the perivascular epithelioid cell tumor (PEComa) family shares a perivascular growth pattern, but with distinctive dual myoid-melanocytic differentiation. RGS5, regulator of G-protein signaling 5, is a novel pericyte antigen with increasing use in animal models. Here, we describe the immunohistochemical expression patterns of RGS5 across perivascular soft tissue tumors, including glomus tumor (n = 6), malignant glomus tumor (n = 4), myopericytoma (n = 3), angioleiomyoma (n = 9), myofibroma (n = 4), solitary fibrous tumor (n = 10), and PEComa (n = 19). Immunohistochemical staining and semi-quantification was performed, and compared to αSMA (smooth muscle actin) expression. Results showed that glomus tumor (including malignant glomus tumor), myopericytoma, and angioleiomyoma shared a similar diffuse immunoreactivity for RGS5 and αSMA across all tumors examined. In contrast, myofibroma, solitary fibrous tumor and PEComa showed predominantly focal to absent RGS5 immunoreactivity. These findings further support a common pericytic lineage of differentiation in glomus tumors, myopericytoma and angioleiomyoma. The pericyte marker RGS5 may be of future clinical utility for the evaluation of pericytic differentiation in soft tissue tumors. PMID:26558691

  13. Muc-2-deficient mice display a sex-specific, COX-2-related impairment of gastric mucosal repair.

    PubMed

    Wallace, John L; Vong, Linda; Dharmani, Poonam; Srivastava, Vikas; Chadee, Kris

    2011-03-01

    Mucus is known to contribute significantly to the prevention and repair of mucosal damage throughout the gastrointestinal tract. Although not normally expressed in the stomach, mucin-2 (MUC-2, encoded by the MUC2 gene) is expressed in certain disease states. The aim of this study was to determine in a mouse model whether the absence of Muc-2 would result in impaired susceptibility to and healing of gastric mucosal injury. Acute gastric damage was induced in mice deficient in Muc-2 and in wild-type controls, through oral administration of indomethacin. Chronic gastric ulcers were induced by serosal application of acetic acid. The extent of injury and the extent of healing of the damage over time were examined in both models. Indomethacin administration caused similar levels of gastric damage in Muc-2-deficient and wild-type mice, but the erosions healed more slowly in the former. Acetic acid-induced gastric ulcers were initially similar in size in Muc-2-deficient and wild-type mice of both sexes, but ulcer healing was significantly impaired in male Muc-2-deficient mice. Induction of cyclooxygenase-2 in the stomach, in response to indomethacin- or acetic acid-induced ulceration, was significantly reduced in male Muc-2-deficient mice. This phenomenon, and the sex specificity, was also apparent in bone marrow-derived macrophages stimulated with endotoxin. These results demonstrate a marked impairment of gastric mucosal repair in male Muc-2-deficient mice that may be related to an insufficient induction of cyclooxygenase-2, an enzyme known to contribute to mucosal repair. PMID:21356364

  14. Impaired immunological synapse in sperm associated antigen 6 (SPAG6) deficient mice

    PubMed Central

    Cooley, Lauren Folgosa; El Shikh, Mohey Eldin; Li, Wei; Keim, Rebecca C.; Zhang, Zhengang; Strauss, Jerome F.; Zhang, Zhibing; Conrad, Daniel H.

    2016-01-01

    Sperm associated antigen 6 (SPAG6), a component of the central apparatus of the “9 + 2” axoneme, plays a central role in ciliary and flagellar motility; but, its contribution to adaptive immunity and immune system development is completely unknown. While immune cells lack a cilium, the immunological synapse is a surrogate cilium as it utilizes the same machinery as ciliogenesis including the nucleation of microtubules at the centrosome. This prompted our hypothesis that SPAG6 critically regulates the formation and function of immunological synapses. Using bone marrow reconstitution studies of adult WT mice, we demonstrate that SPAG6 is expressed in primary and secondary lymphoid tissues, is associated with the centrosome in lymphocytes, and its deficiency results in synapse disruption due to loss of centrosome polarization and actin clearance at the synaptic cleft. Improper synapse formation in Spag6KO mice was associated with defective CTL functions and impaired humoral immunity as indicated by reduced germinal centers reactions, follicular CD4 T cells, and production of class-switched antibody, together with expansion of B1 B cells. This novel report demonstrates the requirement of SPAG6 for optimal synapse formation and function, its direct role in immune cell function, and provides a novel mechanism for infertility disorders related to SPAG6. PMID:27169488

  15. Combined prenatal and chronic postnatal vitamin D deficiency in rats impairs prepulse inhibition of acoustic startle.

    PubMed

    Burne, Thomas H J; Féron, François; Brown, Jillanne; Eyles, Darryl W; McGrath, John J; Mackay-Sim, Alan

    2004-06-01

    There is growing evidence that 1,25-dihydroxyvitamin D3 is involved in normal brain development. The aim of this study was to examine the impact of prenatal and postnatal hypovitaminosis D on prepulse inhibition (PPI) of acoustic startle in adult rats. We compared six groups of rats: control rats with normal vitamin D throughout life and normal litter size (Litter); control rats with normal vitamin D but with a reduced litter size of two (Control); offspring from reduced litters of vitamin D deplete mothers who were repleted at birth (Birth), repleted at weaning (Weaning) or remained on a deplete diet until 10 weeks of age (Life); or control rats that were placed on a vitamin D-deficient diet from 5 to 10 weeks of age (Adult). All rats were tested in acoustic startle chambers at 5 and 10 weeks of age for acoustic startle responses and for PPI. There were no significant group differences at 5 weeks of age on the acoustic startle response or on PPI. At 10 weeks of age, rats in the Life group only had impaired PPI despite having normal acoustic startle responses. We conclude that combined prenatal and chronic postnatal hypovitaminosis D, but not early life hypovitaminosis D, alters PPI. PMID:15178159

  16. Choline or methionine reverses impaired secretion of VLDL by hepatocytes from choline-deficient rats

    SciTech Connect

    Yao, Z.; Vance, D.E.

    1987-05-01

    Male rats fed a choline-deficient (CD) diet for three days accumulated triacylglycerol (TG) in the liver. Hepatocytes from these rats were cultured and maintained in a medium + choline. The rate of secretion of TG was reduced by 50% in the CD cells. Correspondingly, (/sup 3/H)oleate and (/sup 3/H)glycerol were incorporated at a 2-fold higher rate into TG secreted by choline-supplemented cells compared to CD cells. Isolation of lipoprotein fractions by ultracentrifugation showed that the reduced secretion of TG by CD hepatocytes was mainly due to an impaired secretion of very low density lipoprotein (VLDL). Incorporation of (/sup 3/H)leucine into secreted apoB/sub H/, apoB/sub L/ and apoE was markedly reduced in CD cells compared to choline-supplemented cells. Secretion of high density lipoprotein was not reduced in the CD hepatocytes. Normal secretion of VLDL was resumed upon addition of methionine to the CD cells.

  17. Farnesoid X receptor (FXR) gene deficiency impairs urine concentration in mice.

    PubMed

    Zhang, Xiaoyan; Huang, Shizheng; Gao, Min; Liu, Jia; Jia, Xiao; Han, Qifei; Zheng, Senfeng; Miao, Yifei; Li, Shuo; Weng, Haoyu; Xia, Xuan; Du, Shengnan; Wu, Wanfu; Gustafsson, Jan-Åke; Guan, Youfei

    2014-02-11

    The farnesoid X receptor (FXR) is a ligand-activated transcription factor belonging to the nuclear receptor superfamily. FXR is mainly expressed in liver and small intestine, where it plays an important role in bile acid, lipid, and glucose metabolism. The kidney also has a high FXR expression level, with its physiological function unknown. Here we demonstrate that FXR is ubiquitously distributed in renal tubules. FXR agonist treatment significantly lowered urine volume and increased urine osmolality, whereas FXR knockout mice exhibited an impaired urine concentrating ability, which led to a polyuria phenotype. We further found that treatment of C57BL/6 mice with chenodeoxycholic acid, an FXR endogenous ligand, significantly up-regulated renal aquaporin 2 (AQP2) expression, whereas FXR gene deficiency markedly reduced AQP2 expression levels in the kidney. In vitro studies showed that the AQP2 gene promoter contained a putative FXR response element site, which can be bound and activated by FXR, resulting in a significant increase of AQP2 transcription in cultured primary inner medullary collecting duct cells. In conclusion, the present study demonstrates that FXR plays a critical role in the regulation of urine volume, and its activation increases urinary concentrating capacity mainly via up-regulating its target gene AQP2 expression in the collecting ducts. PMID:24464484

  18. CALHM1 deficiency impairs cerebral neuron activity and memory flexibility in mice

    PubMed Central

    Vingtdeux, Valérie; Chang, Eric H.; Frattini, Stephen A.; Zhao, Haitian; Chandakkar, Pallavi; Adrien, Leslie; Strohl, Joshua J.; Gibson, Elizabeth L.; Ohmoto, Makoto; Matsumoto, Ichiro; Huerta, Patricio T.; Marambaud, Philippe

    2016-01-01

    CALHM1 is a cell surface calcium channel expressed in cerebral neurons. CALHM1 function in the brain remains unknown, but recent results showed that neuronal CALHM1 controls intracellular calcium signaling and cell excitability, two mechanisms required for synaptic function. Here, we describe the generation of Calhm1 knockout (Calhm1−/−) mice and investigate CALHM1 role in neuronal and cognitive functions. Structural analysis revealed that Calhm1−/− brains had normal regional and cellular architecture, and showed no evidence of neuronal or synaptic loss, indicating that CALHM1 deficiency does not affect brain development or brain integrity in adulthood. However, Calhm1−/− mice showed a severe impairment in memory flexibility, assessed in the Morris water maze, and a significant disruption of long-term potentiation without alteration of long-term depression, measured in ex vivo hippocampal slices. Importantly, in primary neurons and hippocampal slices, CALHM1 activation facilitated the phosphorylation of NMDA and AMPA receptors by protein kinase A. Furthermore, neuronal CALHM1 activation potentiated the effect of glutamate on the expression of c-Fos and C/EBPβ, two immediate-early gene markers of neuronal activity. Thus, CALHM1 controls synaptic activity in cerebral neurons and is required for the flexible processing of memory in mice. These results shed light on CALHM1 physiology in the mammalian brain. PMID:27066908

  19. Impaired immunological synapse in sperm associated antigen 6 (SPAG6) deficient mice.

    PubMed

    Cooley, Lauren Folgosa; El Shikh, Mohey Eldin; Li, Wei; Keim, Rebecca C; Zhang, Zhengang; Strauss, Jerome F; Zhang, Zhibing; Conrad, Daniel H

    2016-01-01

    Sperm associated antigen 6 (SPAG6), a component of the central apparatus of the "9 + 2" axoneme, plays a central role in ciliary and flagellar motility; but, its contribution to adaptive immunity and immune system development is completely unknown. While immune cells lack a cilium, the immunological synapse is a surrogate cilium as it utilizes the same machinery as ciliogenesis including the nucleation of microtubules at the centrosome. This prompted our hypothesis that SPAG6 critically regulates the formation and function of immunological synapses. Using bone marrow reconstitution studies of adult WT mice, we demonstrate that SPAG6 is expressed in primary and secondary lymphoid tissues, is associated with the centrosome in lymphocytes, and its deficiency results in synapse disruption due to loss of centrosome polarization and actin clearance at the synaptic cleft. Improper synapse formation in Spag6KO mice was associated with defective CTL functions and impaired humoral immunity as indicated by reduced germinal centers reactions, follicular CD4 T cells, and production of class-switched antibody, together with expansion of B1 B cells. This novel report demonstrates the requirement of SPAG6 for optimal synapse formation and function, its direct role in immune cell function, and provides a novel mechanism for infertility disorders related to SPAG6. PMID:27169488

  20. Mice Deficient in AKAP13 (BRX) Are Osteoporotic and Have Impaired Osteogenesis.

    PubMed

    Koide, Hisashi; Holmbeck, Kenn; Lui, Julian C; Guo, Xiaoxiao C; Driggers, Paul; Chu, Tiffany; Tatsuno, Ichiro; Quaglieri, Caroline; Kino, Tomoshige; Baron, Jeffrey; Young, Marian F; Robey, Pamela G; Segars, James H

    2015-10-01

    Mechanical stimulation is crucial to bone growth and triggers osteogenic differentiation through a process involving Rho and protein kinase A. We previously cloned a gene (AKAP13, aka BRX) encoding a protein kinase A-anchoring protein in the N-terminus, a guanine nucleotide-exchange factor for RhoA in the mid-section, coupled to a carboxyl region that binds to estrogen and glucocorticoid nuclear receptors. Because of the critical role of Rho, estrogen, and glucocorticoids in bone remodeling, we examined the multifunctional role of Akap13. Akap13 was expressed in bone, and mice haploinsufficient for Akap13 (Akap13(+/-)) displayed reduced bone mineral density, reduced bone volume/total volume, and trabecular number, and increased trabecular spacing; resembling the changes observed in osteoporotic bone. Consistent with the osteoporotic phenotype, Colony forming unit-fibroblast numbers were diminished in Akap13(+/-) mice, as were osteoblast numbers and extracellular matrix production when compared to control littermates. Transcripts of Runx2, an essential transcription factor for the osteogenic lineage, and alkaline phosphatase (Alp), an indicator of osteogenic commitment, were both reduced in femora of Akap13(+/-) mice. Knockdown of Akap13 reduced levels of Runx2 and Alp transcripts in immortalized bone marrow stem cells. These findings suggest that Akap13 haploinsufficient mice have a deficiency in early osteogenesis with a corresponding reduction in osteoblast number, but no impairment of mature osteoblast activity. PMID:25892096

  1. Nxf7 deficiency impairs social exploration and spatio-cognitive abilities as well as hippocampal synaptic plasticity in mice

    PubMed Central

    Callaerts-Vegh, Zsuzsanna; Ahmed, Tariq; Vermaercke, Ben; Marynen, Peter; Balschun, Detlef; Froyen, Guy; D’Hooge, Rudi

    2015-01-01

    Nuclear RNA export factors (NXF) are conserved in all metazoans and are deemed essential for shuttling RNA across the nuclear envelope and other post-transcriptional processes (such as mRNA metabolism, storage and stability). Disruption of human NXF5 has been implicated in intellectual and psychosocial disabilities. In the present report, we use recently described Nxf7 knockout (KO) mice as an experimental model to analyze in detail the behavioral consequences of clinical NXF5 deficiency. We examined male Nxf7 KO mice using an extended cognitive and behavioral test battery, and recorded extracellular field potentials in the hippocampal CA1 region. We observed various cognitive and behavioral changes including alterations in social exploration, impaired spatial learning and spatio-cognitive abilities. We also defined a new experimental paradigm to discriminate search strategies in Morris water maze and showed significant differences between Nxf7 KO and control animals. Furthermore, while we observed no difference in a nose poke suppression in an conditioned emotional response (CER) protocol, Nxf7 KO mice were impaired in discriminating between differentially reinforced cues in an auditory fear conditioning protocol. This distinct neurocognitive phenotype was accompanied by impaired hippocampal Long-term potentiation (LTP), while long-term depression (LTD) was not affected by Nxf7 deficiency. Our data demonstrate that disruption of murine Nxf7 leads to behavioral phenotypes that may relate to the intellectual and social deficits in patients with NXF5 deficiency. PMID:26217206

  2. Deficiency of prolactin-inducible protein leads to impaired Th1 immune response and susceptibility to Leishmania major in mice.

    PubMed

    Li, Jintao; Liu, Dong; Mou, Zhirong; Ihedioha, Olivia C; Blanchard, Anne; Jia, Ping; Myal, Yvonne; Uzonna, Jude E

    2015-04-01

    Although the strategic production of prolactin-inducible protein (PIP) at several ports of pathogen entry into the body suggests it might play a role in host defense, no study has directly implicated it in immunity against any infectious agent. Here, we show for the first time that PIP deficiency is associated with reduced numbers of CD4(+) T cells in peripheral lymphoid tissues and impaired CD4(+) Th1-cell differentiation in vitro. In vivo, CD4(+) T cells from OVA-immunized, PIP-deficient mice showed significantly impaired proliferation and IFN-γ production following in vitro restimulation. Furthermore, PIP-deficient mice were highly susceptible to Leishmani major infection and failed to control lesion progression and parasite proliferation. This susceptibility was associated with impaired NO production and leishmanicidal activity of PIP KO macrophages following IFN-γ and LPS stimulation. Collectively, our findings implicate PIP as an important regulator of CD4(+) Th1-cell-mediated immunity. PMID:25594453

  3. Impairment of caveolae formation and T-system disorganization in human muscular dystrophy with caveolin-3 deficiency.

    PubMed

    Minetti, Carlo; Bado, Massimo; Broda, Paolo; Sotgia, Federica; Bruno, Claudio; Galbiati, Ferruccio; Volonte, Daniela; Lucania, Giuseppe; Pavan, Antonio; Bonilla, Eduardo; Lisanti, Michael P; Cordone, Giuseppe

    2002-01-01

    Caveolin-3, a muscle specific caveolin-related protein, is the principal structural protein of caveolar membranes. We have recently identified an autosomal dominant form of limb girdle muscular dystrophy (LGMD-1C) that is due to caveolin-3 deficiency and caveolin-3 gene mutations. Here, we studied by electron microscopy, including freeze-fracture and lanthanum staining, the distribution of caveolae and the organization of the T-tubule system in caveolin-3 deficient human muscle fibers. We found a severe impairment of caveolae formation at the muscle cell surface, demonstrating that caveolin-3 is essential for the formation and organization of caveolae in muscle fibers. In addition, we also detected a striking disorganization of the T-system openings at the sub-sarcolemmal level in LGMD-1C muscle fibers. These observations provide new perspectives in our understanding of the role of caveolin-3 in muscle and of the pathogenesis of muscle weakness in caveolin-3 deficient muscle. PMID:11786420

  4. Pericytes of the neurovascular unit: key functions and signaling pathways.

    PubMed

    Sweeney, Melanie D; Ayyadurai, Shiva; Zlokovic, Berislav V

    2016-05-26

    Pericytes are vascular mural cells embedded in the basement membrane of blood microvessels. They extend their processes along capillaries, pre-capillary arterioles and post-capillary venules. CNS pericytes are uniquely positioned in the neurovascular unit between endothelial cells, astrocytes and neurons. They integrate, coordinate and process signals from their neighboring cells to generate diverse functional responses that are critical for CNS functions in health and disease, including regulation of the blood-brain barrier permeability, angiogenesis, clearance of toxic metabolites, capillary hemodynamic responses, neuroinflammation and stem cell activity. Here we examine the key signaling pathways between pericytes and their neighboring endothelial cells, astrocytes and neurons that control neurovascular functions. We also review the role of pericytes in CNS disorders including rare monogenic diseases and complex neurological disorders such as Alzheimer's disease and brain tumors. Finally, we discuss directions for future studies. PMID:27227366

  5. Folate deficiency impairs decidualization and alters methylation patterns of the genome in mice.

    PubMed

    Geng, Yanqing; Gao, Rufei; Chen, Xuemei; Liu, Xueqing; Liao, Xinggui; Li, Yanli; Liu, Shangjing; Ding, Yubin; Wang, Yingxiong; He, Junlin

    2015-11-01

    Existing evidence suggests that adverse pregnancy outcomes are closely related with dietary factors. Previous studies in mice have focused on the harm of folate deficiency (FD) on development of embryo, while the effect of low maternal folate levels on maternal intrauterine environment during early pregnancy remains unclear. Since our previous study found that FD treatment of mice causes no apparent defects in embryo implantation but is accompanied by female subfertility, we next chose to investigate a potential role of FD on molecular events after implantation. We observed that the decidual bulges began to be stunted on pregnancy day 6. The results of functional experiments in vivo and in vitro showed that FD inhibited the process of endometrial decidualization. It has been confirmed that DNA methylation participates in decidualization, and folate as a methyl donor could change the methylation patterns of genes. Thus, we hypothesized that FD impairs maternal endometrial decidualization by altering the methylation profiles of related genes. Reduced representation bisulphite sequencing was carried out to detect the methylation profiles of endometrium on pregnancy day 6-8, which is equivalent to the decidualization period in mice. The results confirmed that FD changes the methylation patterns of genome, and GO analysis of the differentially methylated regions revealed that the associated genes mainly participate in biological adhesion, biological regulation, cell proliferation, development, metabolism and signalling. In addition, we found some candidates for regulators of decidual transformation, such as Nr1h3 and Nr5a1. The data indicate that FD inhibits decidualization, possibly by altering methylation patterns of the genome in mice. PMID:26246607

  6. Olfactomedin 1 Deficiency Leads to Defective Olfaction and Impaired Female Fertility.

    PubMed

    Li, Rong; Diao, Honglu; Zhao, Fei; Xiao, Shuo; El Zowalaty, Ahmed E; Dudley, Elizabeth A; Mattson, Mark P; Ye, Xiaoqin

    2015-09-01

    Olfactomedin 1 (OLFM1) is a glycoprotein highly expressed in the brain. Olfm1(-/-) female mice were previously reported to have reduced fertility. Previous microarray analysis revealed Olfm1 among the most highly upregulated genes in the uterine luminal epithelium upon embryo implantation, which was confirmed by in situ hybridization. We hypothesized that Olfm1 deficiency led to defective embryo implantation and thus impaired fertility. Indeed, Olfm1(-/-) females had defective embryo implantation. However, Olfm1(-/-) females rarely mated and those that mated rarely became pregnant. Ovarian histology indicated the absence of corpora lutea in Olfm1(-/-) females, indicating defective ovulation. Superovulation using equine chorionic gonadotropin-human chorionic gonadotropin rescued mating, ovulation, and pregnancy, and equine chorionic gonadotropin alone rescued ovulation in Olfm1(-/-) females. Olfm1(-/-) females had a 13% reduction of hypothalamic GnRH neurons but comparable basal serum LH levels and GnRH-induced LH levels compared with wild-type controls. These results indicated no obvious local defects in the female reproductive system and a functional hypothalamic-pituitary-gonadal axis. Olfm1(-/-) females were unresponsive to the effects of male bedding stimulation on pubertal development and estrous cycle. There were 41% fewer cFos-positive cells in the mitral cell layer of accessory olfactory bulb upon male urine stimulation for 90 minutes. OLFM1 was expressed in the main and accessory olfactory systems including main olfactory epithelium, vomeronasal organ, main olfactory bulb, and accessory olfactory bulb, with the highest expression detected in the axon bundles of olfactory sensory neurons. These data demonstrate that defective fertility in Olfm1(-/-) females is most likely a secondary effect of defective olfaction. PMID:26107991

  7. Olfactomedin 1 Deficiency Leads to Defective Olfaction and Impaired Female Fertility

    PubMed Central

    Li, Rong; Diao, Honglu; Zhao, Fei; Xiao, Shuo; El Zowalaty, Ahmed E.; Dudley, Elizabeth A.; Mattson, Mark P.

    2015-01-01

    Olfactomedin 1 (OLFM1) is a glycoprotein highly expressed in the brain. Olfm1−/− female mice were previously reported to have reduced fertility. Previous microarray analysis revealed Olfm1 among the most highly upregulated genes in the uterine luminal epithelium upon embryo implantation, which was confirmed by in situ hybridization. We hypothesized that Olfm1 deficiency led to defective embryo implantation and thus impaired fertility. Indeed, Olfm1−/− females had defective embryo implantation. However, Olfm1−/− females rarely mated and those that mated rarely became pregnant. Ovarian histology indicated the absence of corpora lutea in Olfm1−/− females, indicating defective ovulation. Superovulation using equine chorionic gonadotropin-human chorionic gonadotropin rescued mating, ovulation, and pregnancy, and equine chorionic gonadotropin alone rescued ovulation in Olfm1−/− females. Olfm1−/− females had a 13% reduction of hypothalamic GnRH neurons but comparable basal serum LH levels and GnRH-induced LH levels compared with wild-type controls. These results indicated no obvious local defects in the female reproductive system and a functional hypothalamic-pituitary-gonadal axis. Olfm1−/− females were unresponsive to the effects of male bedding stimulation on pubertal development and estrous cycle. There were 41% fewer cFos-positive cells in the mitral cell layer of accessory olfactory bulb upon male urine stimulation for 90 minutes. OLFM1 was expressed in the main and accessory olfactory systems including main olfactory epithelium, vomeronasal organ, main olfactory bulb, and accessory olfactory bulb, with the highest expression detected in the axon bundles of olfactory sensory neurons. These data demonstrate that defective fertility in Olfm1−/− females is most likely a secondary effect of defective olfaction. PMID:26107991

  8. Impaired intrinsic immunity to HSV-1 in human iPSC-derived TLR3-deficient CNS cells

    PubMed Central

    Lafaille, Fabien G; Pessach, Itai M.; Zhang, Shen-Ying; Ciancanelli, Michael J.; Herman, Melina; Abhyankar, Avinash; Ying, Shui-Wang; Keros, Sotirios; Goldstein, Peter A.; Mostoslavsky, Gustavo; Ordovas-Montanes, Jose; Jouanguy, Emmanuelle; Plancoulaine, Sabine; Tu, Edmund; Elkabetz, Yechiel; Al-Muhsen, Saleh; Tardieu, Marc; Schlaeger, Thorsten M.; Daley, George Q.; Abel, Laurent; Casanova, Jean-Laurent; Studer, Lorenz; Notarangelo, Luigi D.

    2012-01-01

    In the course of primary infection with herpes simplex virus 1 (HSV-1), children with inborn errors of TLR3 immunity are prone to HSV-1 encephalitis (HSE) 1–3. We tested the hypothesis that the pathogenesis of HSE involves non hematopoietic central nervous system (CNS)-resident cells. We derived induced pluripotent stem cells (iPSCs) from the dermal fibroblasts of TLR3- and UNC-93B-deficient patients and from controls. These iPSCs were differentiated into highly purified populations of neural stem cells (NSCs), neurons, astrocytes and oligodendrocytes. The induction of IFN-β and/or IFN-γ1 in response to poly(I:C) stimulation was dependent on TLR3 and UNC-93B in all cells tested. However, the induction of IFN-β and IFN-γ1 in response to HSV-1 infection was impaired selectively in UNC-93B-deficient neurons and oligodendrocytes. These cells were also much more susceptible to HSV-1 infection than control cells, whereas UNC-93B-deficient NSCs and astrocytes were not. TLR3-deficient neurons were also found to be susceptible to HSV-1 infection. The rescue of UNC-93B- and TLR3-deficient cells with the corresponding wild-type allele demonstrated that the genetic defect was the cause of the poly(I:C) and HSV-1 phenotypes. The viral infection phenotype was further rescued by treatment with exogenous IFN-α/β, but not IFN-γ1.Thus, impaired TLR3- and UNC-93B-dependent IFN-α/β intrinsic immunity to HSV-1 in the CNS, in neurons and oligodendrocytes in particular, may underlie the pathogenesis of HSE in children with TLR3 pathway deficiencies. PMID:23103873

  9. Human Myocardial Pericytes: Multipotent Mesodermal Precursors Exhibiting Cardiac Specificity

    PubMed Central

    Chen, William C.W.; Baily, James E.; Corselli, Mirko; Diaz, Mary; Sun, Bin; Xiang, Guosheng; Gray, Gillian A.; Huard, Johnny; Péault, Bruno

    2015-01-01

    Perivascular mesenchymal precursor cells (i.e. pericytes) reside in skeletal muscle where they contribute to myofiber regeneration; however, the existence of similar microvessel-associated regenerative precursor cells in cardiac muscle has not yet been documented. We tested whether microvascular pericytes within human myocardium exhibit phenotypes and multipotency similar to their anatomically and developmentally distinct counterparts. Fetal and adult human heart pericytes (hHPs) express canonical pericyte markers in situ, including CD146, NG2, PDGFRβ, PDGFRα, αSMA, and SM-MHC, but not CD117, CD133 and desmin, nor endothelial cell (EC) markers. hHPs were prospectively purified to homogeneity from ventricular myocardium by flow cytometry, based on a combination of positive- (CD146) and negative-selection (CD34, CD45, CD56, and CD117) cell lineage markers. Purified hHPs expanded in vitro were phenotypically similar to human skeletal muscle-derived pericytes (hSkMPs). hHPs express MSC markers in situ and exhibited osteo- chondro-, and adipogenic potentials but, importantly, no ability for skeletal myogenesis, diverging from pericytes of all other origins. hHPs supported network formation with/without ECs in Matrigel cultures; hHPs further stimulated angiogenic responses under hypoxia, markedly different from hSkMPs. The cardiomyogenic potential of hHPs was examined following 5-azacytidine treatment and neonatal cardiomyocyte co-culture in vitro, and intramyocardial transplantation in vivo. Results indicated cardiomyocytic differentiation in a small fraction of hHPs. In conclusion, human myocardial pericytes share certain phenotypic and developmental similarities with their skeletal muscle homologs, yet exhibit different antigenic, myogenic, and angiogenic properties. This is the first example of an anatomical restriction in the developmental potential of pericytes as native mesenchymal stem cells. PMID:25336400

  10. Capillary pericytes regulate cerebral blood flow in health and disease

    PubMed Central

    Sutherland, Brad A.; O’Farrell, Fergus M.; Buchan, Alastair M.; Lauritzen, Martin; Attwell, David

    2014-01-01

    Brain blood flow increases, evoked by neuronal activity, power neural computation and are the basis of BOLD functional imaging. It is controversial whether blood flow is controlled solely by arteriole smooth muscle, or also by capillary pericytes. We demonstrate that neuronal activity and the neurotransmitter glutamate evoke the release of messengers that dilate capillaries by actively relaxing pericytes. Dilation is mediated by prostaglandin E2, but requires nitric oxide release to suppress vasoconstricting 20-HETE synthesis. In vivo, when sensory input increases blood flow, capillaries dilate before arterioles and are estimated to produce 84% of the blood flow increase. In pathology, ischaemia evokes capillary constriction by pericytes. We show that this is followed by pericyte death in rigor, which may irreversibly constrict capillaries and damage the blood-brain barrier. Thus, pericytes are major regulators of cerebral blood flow and initiators of functional imaging signals. Prevention of pericyte constriction and death may reduce the long-lasting blood flow decrease which damages neurons after stroke. PMID:24670647

  11. Human Surfactant Protein A2 Gene Mutations Impair Dimmer/Trimer Assembly Leading to Deficiency in Protein Sialylation and Secretion

    PubMed Central

    Shen, Haitao; Li, Hui; Yang, Wenbing; Pan, Bing; Huang, Guowei; Lin, Guangyu; Ma, Lian; Willard, Belinda; Gu, Jiang; Zheng, Lemin; Wang, Yongyu

    2012-01-01

    Surfactant protein A2 (SP-A2) plays an essential role in surfactant metabolism and lung host defense. SP-A2 mutations in the carbohydrate recognition domain have been related to familial pulmonary fibrosis and can lead to a recombinant protein secretion deficiency in vitro. In this study, we explored the molecular mechanism of protein secretion deficiency and the subsequent biological effects in CHO-K1 cells expressing both wild-type and several different mutant forms of SP-A2. We demonstrate that the SP-A2 G231V and F198S mutants impair the formation of dimmer/trimer SP-A2 which contributes to the protein secretion defect. A deficiency in sialylation, but not N-linked glycosylation, is critical to the observed dimmer/trimer impairment-induced secretion defect. Furthermore, both mutant forms accumulate in the ER and form NP-40-insoluble aggregates. In addition, the soluble mutant SP-A2 could be partially degraded through the proteasome pathway but not the lysosome or autophagy pathway. Intriguingly, 4-phenylbutyrate acid (4-PBA), a chemical chaperone, alleviates aggregate formation and partially rescued the protein secretion of SP-A2 mutants. In conclusion, SP-A2 G231V and F198S mutants impair the dimmer/trimer assembly, which contributes to the protein sialylation and secretion deficiency. The intracellular protein mutants could be partially degraded through the proteasome pathway and also formed aggregates. The treatment of the cells with 4-PBA resulted in reduced aggregation and rescued the secretion of mutant SP-A2. PMID:23056344

  12. Cerebral perfusion and oxygenation are impaired by folate deficiency in rat: absolute measurements with noninvasive near-infrared spectroscopy

    PubMed Central

    Hallacoglu, Bertan; Sassaroli, Angelo; Fantini, Sergio; Troen, Aron M

    2011-01-01

    Brain microvascular pathology is a common finding in Alzheimer's disease and other dementias. However, the extent to which microvascular abnormalities cause or contribute to cognitive impairment is unclear. Noninvasive near-infrared spectroscopy (NIRS) can address this question, but its use for clarifying the role of microvascular dysfunction in dementia has been limited due to theoretical and practical considerations. We developed a new noninvasive NIRS method to obtain quantitative, dynamic measurements of absolute brain hemoglobin concentration and oxygen saturation and used it to show significant cerebrovascular impairments in a rat model of diet-induced vascular cognitive impairment. We fed young rats folate-deficient (FD) and control diets and measured absolute brain hemoglobin and hemodynamic parameters at rest and during transient mild hypoxia and hypercapnia. With respect to control animals, FD rats featured significantly lower brain hemoglobin concentration (72±4 μmol/L versus 95±6 μmol/L) and oxygen saturation (54%±3% versus 65%±2%). By contrast, resting arterial oxygen saturation was the same for both groups (96%±4%), indicating that decrements in brain hemoglobin oxygenation were independent of blood oxygen carrying capacity. Vasomotor reactivity in response to hypercapnia was also impaired in FD rats. Our results implicate microvascular abnormality and diminished oxygen delivery as a mechanism of cognitive impairment. PMID:21386853

  13. Optineurin deficiency in mice contributes to impaired cytokine secretion and neutrophil recruitment in bacteria-driven colitis.

    PubMed

    Chew, Thean S; O'Shea, Nuala R; Sewell, Gavin W; Oehlers, Stefan H; Mulvey, Claire M; Crosier, Philip S; Godovac-Zimmermann, Jasminka; Bloom, Stuart L; Smith, Andrew M; Segal, Anthony W

    2015-08-01

    Crohn's disease (CD) is associated with delayed neutrophil recruitment and bacterial clearance at sites of acute inflammation as a result of impaired secretion of proinflammatory cytokines by macrophages. To investigate the impaired cytokine secretion and confirm our previous findings, we performed transcriptomic analysis in macrophages and identified a subgroup of individuals with CD who had low expression of the autophagy receptor optineurin (OPTN). We then clarified the role of OPTN deficiency in: macrophage cytokine secretion; mouse models of bacteria-driven colitis and peritonitis; and zebrafish Salmonella infection. OPTN-deficient bone-marrow-derived macrophages (BMDMs) stimulated with heat-killed Escherichia coli secreted less proinflammatory TNFα and IL6 cytokines despite similar gene transcription, which normalised with lysosomal and autophagy inhibitors, suggesting that TNFα is mis-trafficked to lysosomes via bafilomycin-A-dependent pathways in the absence of OPTN. OPTN-deficient mice were more susceptible to Citrobacter colitis and E. coli peritonitis, and showed reduced levels of proinflammatory TNFα in serum, diminished neutrophil recruitment to sites of acute inflammation and greater mortality, compared with wild-type mice. Optn-knockdown zebrafish infected with Salmonella also had higher mortality. OPTN plays a role in acute inflammation and neutrophil recruitment, potentially via defective macrophage proinflammatory cytokine secretion, which suggests that diminished OPTN expression in humans might increase the risk of developing CD. PMID:26044960

  14. Optineurin deficiency in mice contributes to impaired cytokine secretion and neutrophil recruitment in bacteria-driven colitis

    PubMed Central

    Chew, Thean S.; O'Shea, Nuala R.; Sewell, Gavin W.; Oehlers, Stefan H.; Mulvey, Claire M.; Crosier, Philip S.; Godovac-Zimmermann, Jasminka; Bloom, Stuart L.; Smith, Andrew M.; Segal, Anthony W.

    2015-01-01

    ABSTRACT Crohn's disease (CD) is associated with delayed neutrophil recruitment and bacterial clearance at sites of acute inflammation as a result of impaired secretion of proinflammatory cytokines by macrophages. To investigate the impaired cytokine secretion and confirm our previous findings, we performed transcriptomic analysis in macrophages and identified a subgroup of individuals with CD who had low expression of the autophagy receptor optineurin (OPTN). We then clarified the role of OPTN deficiency in: macrophage cytokine secretion; mouse models of bacteria-driven colitis and peritonitis; and zebrafish Salmonella infection. OPTN-deficient bone-marrow-derived macrophages (BMDMs) stimulated with heat-killed Escherichia coli secreted less proinflammatory TNFα and IL6 cytokines despite similar gene transcription, which normalised with lysosomal and autophagy inhibitors, suggesting that TNFα is mis-trafficked to lysosomes via bafilomycin-A-dependent pathways in the absence of OPTN. OPTN-deficient mice were more susceptible to Citrobacter colitis and E. coli peritonitis, and showed reduced levels of proinflammatory TNFα in serum, diminished neutrophil recruitment to sites of acute inflammation and greater mortality, compared with wild-type mice. Optn-knockdown zebrafish infected with Salmonella also had higher mortality. OPTN plays a role in acute inflammation and neutrophil recruitment, potentially via defective macrophage proinflammatory cytokine secretion, which suggests that diminished OPTN expression in humans might increase the risk of developing CD. PMID:26044960

  15. Marginal copper deficiency impairs endothelium-dependent relaxation responses across two generations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The generational effects of marginal copper (Cu) deficiency on vascular function have not been characterized.In this study, the vascular consequences of marginal Cu deficiency were determined by relaxation responses in mesenteric arteries of dams and two generations of offspring. Pups from dams (fir...

  16. Marginal Zinc Deficiency Increases Magnesium Retention and Impairs Calcium Utilization in Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experiment with rats was conducted to determine whether magnesium retention is increased and calcium utilization is altered by, and whether increased oxidative stress induced by a marginal copper deficiency exacerbated responses to, a marginal zinc deficiency. Weanling rats were assigned to six g...

  17. Increased Pyruvate Dehydrogenase Kinase 4 Expression in Lung Pericytes Is Associated with Reduced Endothelial-Pericyte Interactions and Small Vessel Loss in Pulmonary Arterial Hypertension.

    PubMed

    Yuan, Ke; Shao, Ning-Yi; Hennigs, Jan K; Discipulo, Marielle; Orcholski, Mark E; Shamskhou, Elya; Richter, Alice; Hu, Xinqian; Wu, Joseph C; de Jesus Perez, Vinicio A

    2016-09-01

    Reduced endothelial-pericyte interactions are linked to progressive small vessel loss in pulmonary arterial hypertension (PAH), but the molecular mechanisms underlying this disease remain poorly understood. To identify relevant gene candidates associated with aberrant pericyte behavior, we performed a transcriptome analysis of patient-derived donor control and PAH lung pericytes followed by functional genomics analysis. Compared with donor control cells, PAH pericytes had significant enrichment of genes involved in various metabolic processes, the top hit being PDK4, a gene coding for an enzyme that suppresses mitochondrial activity in favor of glycolysis. Given reports that link reduced mitochondrial activity with increased PAH cell proliferation, we hypothesized that increased PDK4 is associated with PAH pericyte hyperproliferation and reduced endothelial-pericyte interactions. We found that PDK4 gene and protein expression was significantly elevated in PAH pericytes and correlated with reduced mitochondrial metabolism, higher rates of glycolysis, and hyperproliferation. Importantly, reducing PDK4 levels restored mitochondrial metabolism, reduced cell proliferation, and improved endothelial-pericyte interactions. To our knowledge, this is the first study that documents significant differences in gene expression between human donor control and PAH lung pericytes and the link between mitochondrial dysfunction and aberrant endothelial-pericyte interactions in PAH. Comprehensive characterization of these candidate genes could provide novel therapeutic targets to improve endothelial-pericyte interactions and prevent small vessel loss in PAH. PMID:27456128

  18. Cerebral microvascular pericytes and neurogliovascular signaling in health and disease.

    PubMed

    Dalkara, Turgay; Alarcon-Martinez, Luis

    2015-10-14

    Increases in neuronal activity cause an enhanced blood flow to the active brain area. This neurovascular coupling is regulated by multiple mechanisms: Adenosine and lactate produced as metabolic end-products couple activity with flow by inducing vasodilation. As a specific mechanism to the brain, synaptic activity-induced Ca(2+) increases in astrocytes, interneurons and neurons translate neuronal activity to vasoactive signals such as arachidonic acid metabolites and NO. K(+) released onto smooth muscle cells through Ca(2+)-activated K(+) channels on end-feet can also induce vasodilation during neuronal activity. An intense communication between the endothelia, pericytes and astrocytes is required for development and functioning of the neurovascular unit as well as the BBB. The ratio of pericytes to endothelial cells is higher in the cerebral microcirculation than other tissues. Pericytes play a role in distribution of microvascular blood flow in response to the local demand as a final regulatory step after arterioles, which feed a larger cohort of cells. Pericyte-endothelial communication is essential for vasculogenesis. Pericyte also take part in leukocyte infiltration and immune responses. The microvascular injury induced by ischemia/reperfusion plays a critical role in tissue survival after recanalization by inducing sustained pericyte contraction and microcirculatory clogging (no-reflow) and by disrupting BBB integrity. Suppression of oxidative/nitrative stress or sustained adenosine delivery during re-opening of an occluded artery improves the outcome of recanalization by promoting microcirculatory reflow. Pericyte dysfunction in retinal microvessels is the main cause of diabetic retinopathy. Recent findings suggest that the age-related microvascular dysfunction may initiate the neurodegenerative changes seen Alzheimer׳s dementia. This article is part of a Special Issue entitled SI: Cell Interactions In Stroke. PMID:25862573

  19. Vitamin D deficiency impairs skeletal muscle function in a smoking mouse model.

    PubMed

    Cielen, Nele; Heulens, Nele; Maes, Karen; Carmeliet, Geert; Mathieu, Chantal; Janssens, Wim; Gayan-Ramirez, Ghislaine

    2016-05-01

    Chronic obstructive pulmonary disease (COPD) is associated with skeletal muscle dysfunction. Vitamin D plays an important role in muscle strength and performance in healthy individuals. Vitamin D deficiency is highly prevalent in COPD, but its role in skeletal muscle dysfunction remains unclear. We examined the time-course effect of vitamin D deficiency on limb muscle function in mice with normal or deficient vitamin D serum levels exposed to air or cigarette smoke for 6, 12 or 18 weeks. The synergy of smoking and vitamin D deficiency increased lung inflammation and lung compliance from 6 weeks on with highest emphysema scores observed at 18 weeks. Smoking reduced body and muscle mass of the soleus and extensor digitorum longus (EDL), but did not affect contractility, despite type II atrophy. Vitamin D deficiency did not alter muscle mass but reduced muscle force over time, downregulated vitamin D receptor expression, and increased muscle lipid peroxidation but did not alter actin and myosin expression, fiber dimensions or twitch relaxation time. The combined effect of smoking and vitamin D deficiency did not further deteriorate muscle function but worsened soleus mass loss and EDL fiber atrophy at 18 weeks. We conclude that the synergy of smoking and vitamin D deficiency in contrast to its effect on lung disease, had different, independent but important noxious effects on skeletal muscles in a mouse model of mild COPD. PMID:26906744

  20. Abnormal Brain Iron Metabolism in Irp2 Deficient Mice Is Associated with Mild Neurological and Behavioral Impairments

    PubMed Central

    Zumbrennen-Bullough, Kimberly B.; Becker, Lore; Garrett, Lillian; Hölter, Sabine M.; Calzada-Wack, Julia; Mossbrugger, Ilona; Quintanilla-Fend, Leticia; Racz, Ildiko; Rathkolb, Birgit; Klopstock, Thomas; Wurst, Wolfgang; Zimmer, Andreas; Wolf, Eckhard; Fuchs, Helmut; Gailus-Durner, Valerie; de Angelis, Martin Hrabě; Romney, Steven J.; Leibold, Elizabeth A.

    2014-01-01

    Iron Regulatory Protein 2 (Irp2, Ireb2) is a central regulator of cellular iron homeostasis in vertebrates. Two global knockout mouse models have been generated to explore the role of Irp2 in regulating iron metabolism. While both mouse models show that loss of Irp2 results in microcytic anemia and altered body iron distribution, discrepant results have drawn into question the role of Irp2 in regulating brain iron metabolism. One model shows that aged Irp2 deficient mice develop adult-onset progressive neurodegeneration that is associated with axonal degeneration and loss of Purkinje cells in the central nervous system. These mice show iron deposition in white matter tracts and oligodendrocyte soma throughout the brain. A contrasting model of global Irp2 deficiency shows no overt or pathological signs of neurodegeneration or brain iron accumulation, and display only mild motor coordination and balance deficits when challenged by specific tests. Explanations for conflicting findings in the severity of the clinical phenotype, brain iron accumulation and neuronal degeneration remain unclear. Here, we describe an additional mouse model of global Irp2 deficiency. Our aged Irp2−/− mice show marked iron deposition in white matter and in oligodendrocytes while iron content is significantly reduced in neurons. Ferritin and transferrin receptor 1 (TfR1, Tfrc), expression are increased and decreased, respectively, in the brain from Irp2−/− mice. These mice show impairments in locomotion, exploration, motor coordination/balance and nociception when assessed by neurological and behavioral tests, but lack overt signs of neurodegenerative disease. Ultrastructural studies of specific brain regions show no evidence of neurodegeneration. Our data suggest that Irp2 deficiency dysregulates brain iron metabolism causing cellular dysfunction that ultimately leads to mild neurological, behavioral and nociceptive impairments. PMID:24896637

  1. Reversible acute axonal polyneuropathy associated with Wernicke-Korsakoff syndrome: impaired physiological nerve conduction due to thiamine deficiency?

    PubMed

    Ishibashi, S; Yokota, T; Shiojiri, T; Matunaga, T; Tanaka, H; Nishina, K; Hirota, H; Inaba, A; Yamada, M; Kanda, T; Mizusawa, H

    2003-05-01

    Acute axonal polyneuropathy and Wernicke-Korsakoff encephalopathy developed simultaneously in three patients. Nerve conduction studies (NCS) detected markedly decreased compound muscle action potentials (CMAPs) and sensory nerve action potentials (SNAPs) with minimal conduction slowing; sympathetic skin responses (SSRs) were also notably decreased. Sural nerve biopsies showed only mild axonal degeneration with scattered myelin ovoid formation. The symptoms of neuropathy lessened within two weeks after an intravenous thiamine infusion. CMAPs, SNAPs, and SSRs also increased considerably. We suggest that this is a new type of peripheral nerve impairment: physiological conduction failure with minimal conduction delay due to thiamine deficiency. PMID:12700319

  2. Impairment of olfactory, auditory, and spatial serial reversal learning in rats recovered from pyrithiamine-induced thiamine deficiency.

    PubMed

    Mair, R G; Knoth, R L; Rabchenuk, S A; Langlais, P J

    1991-06-01

    Rats that had recovered from pyrithiamine-induced thiamine deficiency (PTD) were compared with controls for spatial, auditory, and olfactory serial reversal learning (SRL); spatial matching to sample (MTS); auditory go-no-go discrimination; and open-field exploration. PTD rats made more errors reaching criterion for SRL in all modalities but showed normal transfer effects between problems. PTD rats were also impaired in learning the go-no-go and MTS tasks and showed consistent alterations in exploratory activity. It is argued that the PTD rat, like human Korsakoff patients, have impairments of learning and memory (but spared capacity for reference memory) that extend across sensory modalities. Postmortem analyses showed normal indices of cortical cholinergic, noradrenergic, dopaminergic, and serotonergic function and consistent bilateral lesions of the thalamus, which were centered on the internal medullary lamina, and the medial mammillary nucleus. PMID:1907457

  3. Non-anemic Iron Deficiency from Birth to Weaning Does Not Impair Growth or Memory in Piglets

    PubMed Central

    Antonides, Alexandra; van Laarhoven, Serana; van der Staay, Franz J.; Nordquist, Rebecca E.

    2016-01-01

    Early iron deficiency is associated with impaired (cognitive) development, the severity of which depends on the timing and duration of the under-supply of iron. To design effective treatment and prevention strategies for iron deficiency in humans, suited animal models are needed. In an earlier study (Antonides et al., 2015b) we separated 10 pairs of piglets from their mothers within a few days after birth and reared one sibling with artificial iron-deficient (ID) and the other with balanced control milk until weaning. ID piglets grew slower and showed poorer reference memory (RM) performance than their controls in a spatial holeboard task, even weeks after iron repletion. One putative intervening factor in that study was pre-weaning maternal deprivation. In an attempt to refine the piglet iron-deficiency model, we assessed whether piglets reared by sows, but withheld iron supplementation, can serve as animal model of iron deficiency. As sow milk is inherently ID, piglets normally receive a prophylactic iron injection. Ten pairs of piglets were housed with foster sows until weaning (4 weeks). One sibling per pair was randomly assigned to the control group (receiving iron dextran injections: 40 mg iron per kilogram body mass on days 3 and 10), the other to the ID group. From weaning, all pigs were fed a balanced commercial diet. Blood samples were taken in week 1, 3.5, 6, and 12. Pre-weaning blood iron values of ID piglets were lower than those of controls, but recovered to normal values after weaning. Hemoglobin of ID piglets did not reach anemic values. Hematocrit and hemoglobin of ID animals did not decrease, and serum iron even increased pre-weaning, suggesting that the piglets had access to an external source of iron, e.g., spilled feed or feces of the foster sows. Growth, and spatial memory assessed in the holeboard from 10 to 16 weeks of age, was unaffected in ID pigs. We conclude that sow-raised piglets are not a suitable model for iron-deficiency induced

  4. Non-anemic Iron Deficiency from Birth to Weaning Does Not Impair Growth or Memory in Piglets.

    PubMed

    Antonides, Alexandra; van Laarhoven, Serana; van der Staay, Franz J; Nordquist, Rebecca E

    2016-01-01

    Early iron deficiency is associated with impaired (cognitive) development, the severity of which depends on the timing and duration of the under-supply of iron. To design effective treatment and prevention strategies for iron deficiency in humans, suited animal models are needed. In an earlier study (Antonides et al., 2015b) we separated 10 pairs of piglets from their mothers within a few days after birth and reared one sibling with artificial iron-deficient (ID) and the other with balanced control milk until weaning. ID piglets grew slower and showed poorer reference memory (RM) performance than their controls in a spatial holeboard task, even weeks after iron repletion. One putative intervening factor in that study was pre-weaning maternal deprivation. In an attempt to refine the piglet iron-deficiency model, we assessed whether piglets reared by sows, but withheld iron supplementation, can serve as animal model of iron deficiency. As sow milk is inherently ID, piglets normally receive a prophylactic iron injection. Ten pairs of piglets were housed with foster sows until weaning (4 weeks). One sibling per pair was randomly assigned to the control group (receiving iron dextran injections: 40 mg iron per kilogram body mass on days 3 and 10), the other to the ID group. From weaning, all pigs were fed a balanced commercial diet. Blood samples were taken in week 1, 3.5, 6, and 12. Pre-weaning blood iron values of ID piglets were lower than those of controls, but recovered to normal values after weaning. Hemoglobin of ID piglets did not reach anemic values. Hematocrit and hemoglobin of ID animals did not decrease, and serum iron even increased pre-weaning, suggesting that the piglets had access to an external source of iron, e.g., spilled feed or feces of the foster sows. Growth, and spatial memory assessed in the holeboard from 10 to 16 weeks of age, was unaffected in ID pigs. We conclude that sow-raised piglets are not a suitable model for iron-deficiency induced

  5. Diverse functions of pericytes in cerebral blood flow regulation and ischemia

    PubMed Central

    Fernández-Klett, Francisco; Priller, Josef

    2015-01-01

    Pericytes are mural cells with contractile properties. Here, we provide evidence that microvascular pericytes modulate cerebral blood flow in response to neuronal activity (‘functional hyperemia'). Besides their role in neurovascular coupling, pericytes are responsive to brain damage. Cerebral ischemia is associated with constrictions and death of capillary pericytes, followed by fibrotic reorganization of the ischemic tissue. The data suggest that precapillary arterioles and capillaries are major sites of hemodynamic regulation in the brain. PMID:25853910

  6. IMPAIRED INTESTINAL VITAMIN B1 (THIAMIN) UPTAKE IN THIAMIN TRANSPORTER-2 DEFICIENT MICE

    PubMed Central

    Reidling, Jack C.; Lambrecht, Nils; Kassir, Mohammad; Said, Hamid M.

    2016-01-01

    BACKGROUND & AIMS Intestinal thiamin uptake process is vital for maintaining normal body homeostasis of the vitamin; in vitro studies suggest that both thiamin transporter-1 (THTR-1) and -2 (THTR-2) are involved. Mutations in THTR-1 cause thiamin-responsive megaloblastic anemia (TRMA), a tissue specific disease associated with diabetes mellitus, megaloblastic anemia, and sensorineural deafness. However in patients with TRMA, plasma thiamin levels are within normal range, indicating that THTR2 (or another carrier) could provide sufficient intestinal thiamin absorption. We tested this possibility and examined the role of THTR-2 in uptake of thiamin in the intestine of mice. METHODS THTR-2 deficient mice were generated by SLC19A3 gene knockout and used to examine intestinal uptake of thiamin in vitro (isolated cells) and in vivo (intact intestinal loops). We also examined intestinal thiamin uptake in THTR-1 deficient mice. RESULTS Intestine of THTR-2 deficient mice had reduced uptake of thiamin compared to those of wild –type littermate mice (p<0.01); this reduction was associated with a decrease (p<0.01) in blood thiamin levels in THTR-2 deficient mice. However, intestinal uptake of thiamin in THTR-1 deficient mice was not significantly different from that of wild-type littermate animals. Level of expression of THTR-1 was not altered in the intestine of THTR-2 deficient mice, but level of expression of THTR-2 was up-regulated in the intestine of THTR-1 deficient mice. CONCLUSION THTR-2 is required for normal uptake of thiamin in the intestine and can fulfill normal levels of uptake in conditions associated with THTR-1 dysfunction. PMID:19879271

  7. Reduced endoplasmic reticulum stress-induced apoptosis and impaired unfolded protein response in TRPC3-deficient M1 macrophages

    PubMed Central

    Solanki, Sumeet; Dube, Prabhatchandra R.; Tano, Jean-Yves; Birnbaumer, Lutz

    2014-01-01

    Endoplasmic reticulum (ER) stress is a prominent mechanism of macrophage apoptosis in advanced atherosclerotic lesions. Recent studies from our laboratory showed that advanced atherosclerotic plaques in Apoe−/− mice with bone marrow deficiency of the calcium-permeable channel Transient Receptor Potential Canonical 3 (TRPC3) are characterized by reduced areas of necrosis and fewer apoptotic macrophages than animals transplanted with Trpc3+/+ bone marrow. In vitro, proinflammatory M1 but not anti-inflammatory M2 macrophages derived from Trpc3−/−Apoe−/− animals exhibited reduced ER stress-induced apoptosis. However, whether this was due to a specific effect of TRPC3 deficiency on macrophage ER stress signaling remained to be determined. In the present work we used polarized macrophages derived from mice with macrophage-specific deficiency of TRPC3 to examine the expression level of ER stress markers and the activation status of some typical mediators of macrophage apoptosis. We found that the reduced susceptibility of TRPC3-deficient M1 macrophages to ER stress-induced apoptosis correlates with an impaired unfolded protein response (UPR), reduced mitochondrion-dependent apoptosis, and reduced activation of the proapoptotic molecules calmodulin-dependent protein kinase II and signal transducer and activator of transcription 1. Notably, none of these pathways was altered in TRPC3-deficient M2 macrophages. These findings show for the first time an obligatory requirement for a member of the TRPC family of cation channels in ER stress-induced apoptosis in macrophages, underscoring a rather selective role of the TRPC3 channel on mechanisms related to the UPR signaling in M1 macrophages. PMID:25031020

  8. Effects of the Histone Deacetylase Inhibitor Valproic Acid on Human Pericytes In Vitro

    PubMed Central

    Friman, Tomas; Dencker, Lennart; Sundberg, Christian; Scholz, Birger

    2011-01-01

    Microvascular pericytes are of key importance in neoformation of blood vessels, in stabilization of newly formed vessels as well as maintenance of angiostasis in resting tissues. Furthermore, pericytes are capable of differentiating into pro-fibrotic collagen type I producing fibroblasts. The present study investigates the effects of the histone deacetylase (HDAC) inhibitor valproic acid (VPA) on pericyte proliferation, cell viability, migration and differentiation. The results show that HDAC inhibition through exposure of pericytes to VPA in vitro causes the inhibition of pericyte proliferation and migration with no effect on cell viability. Pericyte exposure to the potent HDAC inhibitor Trichostatin A caused similar effects on pericyte proliferation, migration and cell viability. HDAC inhibition also inhibited pericyte differentiation into collagen type I producing fibroblasts. Given the importance of pericytes in blood vessel biology a qPCR array focusing on the expression of mRNAs coding for proteins that regulate angiogenesis was performed. The results showed that HDAC inhibition promoted transcription of genes involved in vessel stabilization/maturation in human microvascular pericytes. The present in vitro study demonstrates that VPA influences several aspects of microvascular pericyte biology and suggests an alternative mechanism by which HDAC inhibition affects blood vessels. The results raise the possibility that HDAC inhibition inhibits angiogenesis partly through promoting a pericyte phenotype associated with stabilization/maturation of blood vessels. PMID:21966390

  9. Angiopoietin 2 induces pericyte apoptosis via α3β1 integrin signaling in diabetic retinopathy.

    PubMed

    Park, Sung Wook; Yun, Jang-Hyuk; Kim, Jin Hyoung; Kim, Kyu-Won; Cho, Chung-Hyun; Kim, Jeong Hun

    2014-09-01

    Pericyte loss is an early characteristic change in diabetic retinopathy (DR). Despite accumulating evidence that hyperglycemia-induced angiopoietin 2 (Ang2) has a central role in pericyte loss, the precise molecular mechanism has not been elucidated. This study investigated the role of Ang2 in pericyte loss in DR. We demonstrated that pericyte loss occurred with Ang2 increase in the diabetic mouse retina and that the source of Ang2 could be the endothelial cell. Ang2 induced pericyte apoptosis via the p53 pathway under high glucose, whereas Ang2 alone did not induce apoptosis. Integrin, not Tie-2 receptor, was involved for Ang2-induced pericyte apoptosis under high glucose as an Ang2 receptor. High glucose changed the integrin expression pattern, which increased integrin α3 and β1 in the pericyte. Furthermore, Ang2-induced pericyte apoptosis in vitro was effectively attenuated via p53 suppression by blocking integrin α3 and β1. Although intravitreal injection of Ang2 induced pericyte loss in C57BL/6J mice retina in vivo, intravitreal injection of anti-integrin α3 and β1 antibodies attenuated Ang2-induced pericyte loss. Taken together, Ang2 induced pericyte apoptosis under high glucose via α3β1 integrin. Glycemic control or blocking Ang2/integrin signaling could be a potential therapeutic target to prevent pericyte loss in early DR. PMID:24722242

  10. Pericytes Regulate Vascular Basement Membrane Remodeling and Govern Neutrophil Extravasation during Inflammation

    PubMed Central

    Wang, Shijun; Cao, Canhong; Chen, Zhongming; Bankaitis, Vytas; Tzima, Eleni; Sheibani, Nader; Burridge, Keith

    2012-01-01

    During inflammation polymorphonuclear neutrophils (PMNs) traverse venular walls, composed of the endothelium, pericyte sheath and vascular basement membrane. Compared to PMN transendothelial migration, little is known about how PMNs penetrate the latter barriers. Using mouse models and intravital microscopy, we show that migrating PMNs expand and use the low expression regions (LERs) of matrix proteins in the vascular basement membrane (BM) for their transmigration. Importantly, we demonstrate that this remodeling of LERs is accompanied by the opening of gaps between pericytes, a response that depends on PMN engagement with pericytes. Exploring how PMNs modulate pericyte behavior, we discovered that direct PMN-pericyte contacts induce relaxation rather than contraction of pericyte cytoskeletons, an unexpected response that is mediated by inhibition of the RhoA/ROCK signaling pathway in pericytes. Taking our in vitro results back into mouse models, we present evidence that pericyte relaxation contributes to the opening of the gaps between pericytes and to the enlargement of the LERs in the vascular BM, facilitating PMN extravasation. Our study demonstrates that pericytes can regulate PMN extravasation by controlling the size of pericyte gaps and thickness of LERs in venular walls. This raises the possibility that pericytes may be targeted in therapies aimed at regulating inflammation. PMID:23029055

  11. Behavioral reinforcement of long-term potentiation is impaired in aged rats with cognitive deficiencies.

    PubMed

    Bergado, J A; Almaguer, W; Ravelo, J; Rosillo, J C; Frey, J U

    2001-01-01

    Behavioral stimuli with emotional/motivational content can reinforce long-term potentiation in the dentate gyrus, if presented within a distinct time window. A similar effect can be obtained by stimulating the basolateral amygdala, a limbic structure related to emotions. We have previously shown that aging impairs amygdala-hippocampus interactions during long-term potentiation. In this report we show that behavioral reinforcement of long-term potentiation is also impaired in aged rats with cognitive deficits. While among young water-deprived animals drinking 15 min after induction of long-term potentiation leads to a significant prolongation of potentiation, cognitively impaired aged rats are devoid of such reinforcing effects. In contrast, a slight but statistically significant depression develops after drinking in this group of animals. We suggest that an impaired mechanism of emotional/motivational reinforcement of synaptic plasticity might be functionally related to the cognitive deficits shown by aged animals. PMID:11738126

  12. N-glycosylation deficiency reduces ICAM-1 induction and impairs inflammatory response

    PubMed Central

    He, Ping; Srikrishna, Geetha; Freeze, Hudson H

    2014-01-01

    Congenital disorders of glycosylation (CDGs) result from mutations in various N-glycosylation genes. The most common type, phosphomannomutase-2 (PMM2)-CDG (CDG-Ia), is due to deficient PMM2 (Man-6-P → Man-1-P). Many patients die from recurrent infections, but the mechanism is unknown. We found that glycosylation-deficient patient fibroblasts have less intercellular adhesion molecule-1 (ICAM-1), and because of its role in innate immune response, we hypothesized that its reduction might help explain recurrent infections in CDG patients. We, therefore, studied mice with mutations in Mpi encoding phosphomannose isomerase (Fru-6-P → Man-6-P), the cause of human MPI-CDG. We challenged MPI-deficient mice with an intraperitoneal injection of zymosan to induce an inflammatory response and found decreased neutrophil extravasation compared with control mice. Immunohistochemistry of mesenteries showed attenuated neutrophil egress, presumably due to poor ICAM-1 response to acute peritonitis. Since phosphomannose isomerase (MPI)-CDG patients and their cells improve glycosylation when given mannose, we provided MPI-deficient mice with mannose-supplemented water for 7 days. This restored ICAM-1 expression on mesenteric endothelial cells and enhanced transendothelial migration of neutrophils during acute inflammation. Attenuated inflammatory response in glycosylation-deficient mice may result from a failure to increase ICAM-1 on the vascular endothelial surface and may help explain recurrent infections in patients. PMID:24474243

  13. Extracellular superoxide dismutase deficiency impairs wound healing in advanced age by reducing neovascularization and fibroblast function

    PubMed Central

    Fujiwara, Toshihiro; Duscher, Dominik; Rustad, Kristine C.; Kosaraju, Revanth; Rodrigues, Melanie; Whittam, Alexander J.; Januszyk, Michael; Maan, Zeshaan N.; Gurtner, Geoffrey C.

    2016-01-01

    Advanced age is characterized by impairments in wound healing, and evidence is accumulating that this may be due in part to a concomitant increase in oxidative stress. Extended exposure to reactive oxygen species (ROS) is thought to lead to cellular dysfunction and organismal death via the destructive oxidation of intra-cellular proteins, lipids and nucleic acids. Extracellular superoxide dismutase (ecSOD/SOD3) is a prime antioxidant enzyme in the extracellular space that eliminates ROS. Here, we demonstrate that reduced SOD3 levels contribute to healing impairments in aged mice. These impairments include delayed wound closure, reduced neovascularization, impaired fibroblast proliferation and increased neutrophil recruitment. We further establish that SOD3 KO and aged fibroblasts both display reduced production of TGF-β1, leading to decreased differentiation of fibroblasts into myofibroblasts. Taken together, these results suggest that wound healing impairments in ageing are associated with increased levels of ROS, decreased SOD3 expression and impaired extracellular oxidative stress regulation. Our results identify SOD3 as a possible target to correct age-related cellular dysfunction in wound healing. PMID:26663425

  14. Quality of life in adolescents with hearing deficiencies and visual impairments

    PubMed Central

    Marques Freire Torres, Vanthauze; Lidianne Alencar Marinho, Christielle; Gabriela Gomes de Oliveira, Carolina; Conceição Maria Vieira, Sandra

    2013-01-01

    Summary Introduction: The term quality of life (in Portuguese, Qualidade de Vida; QV) has been expanded and modified over the years and has come to signify social development in terms of education, health, and leisure as well as economic issues. Objective: To analyze the perception of QV in adolescents with hearing and visual impairments and the effects of socio-demographic characteristics on the domains of QV. Method: This descriptive series study comprised 42 adolescents aged 10 to 19 years who were students at Recife's state schools. The World Health Organization Quality of Life-Abbreviated questionnaire was used to evaluate QV. The data were analyzed using descriptive statistics and the Mann-Whitney and Kruskal-Wallis tests with a significance level of p < 0.05. Results: The global perception of QV was higher among adolescents with visual impairments than among those with hearing impairments. Among the individual components of QV, the environment domain garnered the lowest scores independent of the type of impairment. The subjects with visual impairments reported higher scores for social relationships, while the psychological domain scored higher among those with hearing impairments. The students integrated into normal classrooms perceived better QV in the psychological and social relationships domains than did those who sat in special classrooms. Conclusion: The environmental domain was the worst component of the QV of handicapped adolescents, suggesting a need for greater investments in policies to improve the QV of this population. PMID:26029272

  15. Pre-weaning dietary iron deficiency impairs spatial learning and memory in the cognitive holeboard task in piglets

    PubMed Central

    Antonides, Alexandra; Schoonderwoerd, Anne C.; Scholz, Gabi; Berg, Brian M.; Nordquist, Rebecca E.; van der Staay, Franz Josef

    2015-01-01

    Iron deficiency is the most common nutritional deficiency in humans, affecting more than two billion people worldwide. Early-life iron deficiency can lead to irreversible deficits in learning and memory. The pig represents a promising model animal for studying such deficits, because of its similarities to humans during early development. We investigated the effects of pre-weaning dietary iron deficiency in piglets on growth, blood parameters, cognitive performance, and brain histology later in life. Four to six days after birth, 10 male sibling pairs of piglets were taken from 10 different sows. One piglet of each pair was given a 200 mg iron dextran injection and fed a control milk diet for 28 days (88 mg Fe/kg), whereas the other sibling was given a saline injection and fed an iron deficient (ID) milk diet (21 mg Fe/kg). Due to severely retarded growth of two of the ID piglets, only eight ID piglets were tested behaviorally. After dietary treatment, all piglets were fed a balanced commercial pig diet (190–240 mg Fe/kg). Starting at 7.5 weeks of age, piglets were tested in a spatial cognitive holeboard task. In this task, 4 of 16 holes contain a hidden food reward, allowing measurement of working (short-term) memory and reference (long-term) memory (RM) simultaneously. All piglets received 40–60 acquisition trials, followed by a 16-trial reversal phase. ID piglets showed permanently retarded growth and a strong decrease in blood iron parameters during dietary treatment. After treatment, ID piglets' blood iron values restored to normal levels. In the holeboard task, ID piglets showed impaired RM learning during acquisition and reversal. Iron staining at necropsy at 12 weeks of age showed that ID piglets had fewer iron-containing cells in hippocampal regions CA1 and dentate gyrus (DG). The number of iron-containing cells in CA3 correlated positively with the average RM score during acquisition across all animals. Our results support the hypothesis that early

  16. Mfn2 deficiency links age-related sarcopenia and impaired autophagy to activation of an adaptive mitophagy pathway.

    PubMed

    Sebastián, David; Sorianello, Eleonora; Segalés, Jessica; Irazoki, Andrea; Ruiz-Bonilla, Vanessa; Sala, David; Planet, Evarist; Berenguer-Llergo, Antoni; Muñoz, Juan Pablo; Sánchez-Feutrie, Manuela; Plana, Natàlia; Hernández-Álvarez, María Isabel; Serrano, Antonio L; Palacín, Manuel; Zorzano, Antonio

    2016-08-01

    Mitochondrial dysfunction and accumulation of damaged mitochondria are considered major contributors to aging. However, the molecular mechanisms responsible for these mitochondrial alterations remain unknown. Here, we demonstrate that mitofusin 2 (Mfn2) plays a key role in the control of muscle mitochondrial damage. We show that aging is characterized by a progressive reduction in Mfn2 in mouse skeletal muscle and that skeletal muscle Mfn2 ablation in mice generates a gene signature linked to aging. Furthermore, analysis of muscle Mfn2-deficient mice revealed that aging-induced Mfn2 decrease underlies the age-related alterations in metabolic homeostasis and sarcopenia. Mfn2 deficiency reduced autophagy and impaired mitochondrial quality, which contributed to an exacerbated age-related mitochondrial dysfunction. Interestingly, aging-induced Mfn2 deficiency triggers a ROS-dependent adaptive signaling pathway through induction of HIF1α transcription factor and BNIP3. This pathway compensates for the loss of mitochondrial autophagy and minimizes mitochondrial damage. Our findings reveal that Mfn2 repression in muscle during aging is a determinant for the inhibition of mitophagy and accumulation of damaged mitochondria and triggers the induction of a mitochondrial quality control pathway. PMID:27334614

  17. PX-RICS-deficient mice mimic autism spectrum disorder in Jacobsen syndrome through impaired GABAA receptor trafficking

    PubMed Central

    Nakamura, Tsutomu; Arima-Yoshida, Fumiko; Sakaue, Fumika; Nasu-Nishimura, Yukiko; Takeda, Yasuko; Matsuura, Ken; Akshoomoff, Natacha; Mattson, Sarah N.; Grossfeld, Paul D.; Manabe, Toshiya; Akiyama, Tetsu

    2016-01-01

    Jacobsen syndrome (JBS) is a rare congenital disorder caused by a terminal deletion of the long arm of chromosome 11. A subset of patients exhibit social behavioural problems that meet the diagnostic criteria for autism spectrum disorder (ASD); however, the underlying molecular pathogenesis remains poorly understood. PX-RICS is located in the chromosomal region commonly deleted in JBS patients with autistic-like behaviour. Here we report that PX-RICS-deficient mice exhibit ASD-like social behaviours and ASD-related comorbidities. PX-RICS-deficient neurons show reduced surface γ-aminobutyric acid type A receptor (GABAAR) levels and impaired GABAAR-mediated synaptic transmission. PX-RICS, GABARAP and 14-3-3ζ/θ form an adaptor complex that interconnects GABAAR and dynein/dynactin, thereby facilitating GABAAR surface expression. ASD-like behavioural abnormalities in PX-RICS-deficient mice are ameliorated by enhancing inhibitory synaptic transmission with a GABAAR agonist. Our findings demonstrate a critical role of PX-RICS in cognition and suggest a causal link between PX-RICS deletion and ASD-like behaviour in JBS patients. PMID:26979507

  18. Impaired Neurite Contact Guidance in Ubiquitin Ligase E3a (Ube3a)-Deficient Hippocampal Neurons on Nanostructured Substrates.

    PubMed

    Tonazzini, I; Meucci, S; Van Woerden, G M; Elgersma, Y; Cecchini, M

    2016-04-01

    Recent discoveries indicate that during neuronal development the signaling processes that regulate extracellular sensing (e.g., adhesion, cytoskeletal dynamics) are important targets for ubiquitination-dependent regulation, in particular through E3 ubiquitin ligases. Among these, Ubiquitin E3a ligase (UBE3A) has a key role in brain functioning, but its function and how its deficiency results in the neurodevelopmental disorder Angelman syndrome is still unclear. Here, the role of UBE3A is investigated in neurite contact guidance during neuronal development, in vitro. The microtopography sensing of wild-type and Ube3a-deficient hippocampal neurons is studied by exploiting gratings with different topographical characteristics, with the aim to compare their capabilities to read and follow physical directional stimuli. It is shown that neuronal contact guidance is defective in Ube3a-deficient neurons, and this behavior is linked to an impaired activation of the focal adhesion signaling pathway. Taken together, the results suggest that the neuronal contact sensing machinery might be affected in Angelman syndrome. PMID:26845073

  19. DJ-1 deficiency impairs glutamate uptake into astrocytes via the regulation of flotillin-1 and caveolin-1 expression

    PubMed Central

    Kim, Jin-Mo; Cha, Seon-Heui; Choi, Yu Ree; Jou, Ilo; Joe, Eun-Hye; Park, Sang Myun

    2016-01-01

    Parkinson’s disease (PD) is a common chronic and progressive neurodegenerative disorder. Although the cause of PD is still poorly understood, mutations in many genes including SNCA, parkin, PINK1, LRRK2, and DJ-1 have been identified in the familial forms of PD. It was recently proposed that alterations in lipid rafts may cause the neurodegeneration shown in PD. Here, we observe that DJ-1 deficiency decreased the expression of flotillin-1 (flot-1) and caveolin-1 (cav-1), the main protein components of lipid rafts, in primary astrocytes and MEF cells. As a mechanism, DJ-1 regulated flot-1 stability by direct interaction, however, decreased cav-1 expression may not be a direct effect of DJ-1, but rather as a result of decreased flot-1 expression. Dysregulation of flot-1 and cav-1 by DJ-1 deficiency caused an alteration in the cellular cholesterol level, membrane fluidity, and alteration in lipid rafts-dependent endocytosis. Moreover, DJ-1 deficiency impaired glutamate uptake into astrocytes, a major function of astrocytes in the maintenance of CNS homeostasis, by altering EAAT2 expression. This study will be helpful to understand the role of DJ-1 in the pathogenesis of PD, and the modulation of lipid rafts through the regulation of flot-1 or cav-1 may be a novel therapeutic target for PD. PMID:27346864

  20. PX-RICS-deficient mice mimic autism spectrum disorder in Jacobsen syndrome through impaired GABAA receptor trafficking.

    PubMed

    Nakamura, Tsutomu; Arima-Yoshida, Fumiko; Sakaue, Fumika; Nasu-Nishimura, Yukiko; Takeda, Yasuko; Matsuura, Ken; Akshoomoff, Natacha; Mattson, Sarah N; Grossfeld, Paul D; Manabe, Toshiya; Akiyama, Tetsu

    2016-01-01

    Jacobsen syndrome (JBS) is a rare congenital disorder caused by a terminal deletion of the long arm of chromosome 11. A subset of patients exhibit social behavioural problems that meet the diagnostic criteria for autism spectrum disorder (ASD); however, the underlying molecular pathogenesis remains poorly understood. PX-RICS is located in the chromosomal region commonly deleted in JBS patients with autistic-like behaviour. Here we report that PX-RICS-deficient mice exhibit ASD-like social behaviours and ASD-related comorbidities. PX-RICS-deficient neurons show reduced surface γ-aminobutyric acid type A receptor (GABAAR) levels and impaired GABAAR-mediated synaptic transmission. PX-RICS, GABARAP and 14-3-3ζ/θ form an adaptor complex that interconnects GABAAR and dynein/dynactin, thereby facilitating GABAAR surface expression. ASD-like behavioural abnormalities in PX-RICS-deficient mice are ameliorated by enhancing inhibitory synaptic transmission with a GABAAR agonist. Our findings demonstrate a critical role of PX-RICS in cognition and suggest a causal link between PX-RICS deletion and ASD-like behaviour in JBS patients. PMID:26979507

  1. IRAK-4 and MyD88 deficiencies impair IgM responses against T-independent bacterial antigens.

    PubMed

    Maglione, Paul J; Simchoni, Noa; Black, Samuel; Radigan, Lin; Overbey, Jessica R; Bagiella, Emilia; Bussel, James B; Bossuyt, Xavier; Casanova, Jean-Laurent; Meyts, Isabelle; Cerutti, Andrea; Picard, Capucine; Cunningham-Rundles, Charlotte

    2014-12-01

    IRAK-4 and MyD88 deficiencies impair interleukin 1 receptor and Toll-like receptor (TLR) signaling and lead to heightened susceptibility to invasive bacterial infections. Individuals with these primary immunodeficiencies have fewer immunoglobulin M (IgM)(+)IgD(+)CD27(+) B cells, a population that resembles murine splenic marginal zone B cells that mount T-independent antibody responses against bacterial antigens. However, the significance of this B-cell subset in humans is poorly understood. Using both a 610 carbohydrate array and enzyme-linked immunosorbent assay, we found that patients with IRAK-4 and MyD88 deficiencies have reduced serum IgM, but not IgG antibody, recognizing T-independent bacterial antigens. Moreover, the quantity of specific IgM correlated with IgM(+)IgD(+)CD27(+) B-cell frequencies. As with mouse marginal zone B cells, human IgM(+)CD27(+) B cells activated by TLR7 or TLR9 agonists produced phosphorylcholine-specific IgM. Further linking splenic IgM(+)IgD(+)CD27(+) B cells with production of T-independent IgM, serum from splenectomized subjects, who also have few IgM(+)IgD(+)CD27(+) B cells, had reduced antibacterial IgM. IRAK-4 and MyD88 deficiencies impaired TLR-induced proliferation of this B-cell subset, suggesting a means by which loss of this activation pathway leads to reduced cell numbers. Thus, by bolstering the IgM(+)IgD(+)CD27(+) B-cell subset, IRAK-4 and MyD88 promote optimal T-independent IgM antibody responses against bacteria in humans. PMID:25320238

  2. Grammatical Difficulties in Children with Specific Language Impairment: Is Learning Deficient?

    ERIC Educational Resources Information Center

    Hsu, Hsinjen Julie; Bishop, Dorothy V. M.

    2010-01-01

    Theoretical accounts of grammatical limitations in specific language impairment (SLI) have been polarized between those that postulate problems with domain-specific grammatical knowledge, and those that regard grammatical deficits as downstream consequences of perceptual or memory limitations. Here we consider an alternative view that grammatical…

  3. B-vitamin deficiency causes hyperhomocysteinemia and vascular cognitive impairment in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In older adults, mildly elevated plasma total homocysteine (Hyperhomocysteinemia) is associated with increased risk of cognitive impairment, cerebrovascular disease and Alzheimer’s disease, but it is uncertain whether this is due to underlying metabolic, neurotoxic or vascular processes. We report h...

  4. Grasping Motor Impairments in Autism: Not Action Planning but Movement Execution Is Deficient

    ERIC Educational Resources Information Center

    Stoit, Astrid M. B.; van Schie, Hein T.; Slaats-Willemse, Dorine I. E.; Buitelaar, Jan K.

    2013-01-01

    Different views on the origin of deficits in action chaining in autism spectrum disorders (ASD) have been posited, ranging from functional impairments in action planning to internal models supporting motor control. Thirty-one children and adolescents with ASD and twenty-nine matched controls participated in a two-choice reach-to-grasp paradigm…

  5. Cellular Model of Atherogenesis Based on Pluripotent Vascular Wall Pericytes

    PubMed Central

    Ivanova, Ekaterina A.; Orekhov, Alexander N.

    2016-01-01

    Pericytes are pluripotent cells that can be found in the vascular wall of both microvessels and large arteries and veins. They have distinct morphology with long branching processes and form numerous contacts with each other and with endothelial cells, organizing the vascular wall cells into a three-dimensional network. Accumulating evidence demonstrates that pericytes may play a key role in the pathogenesis of vascular disorders, including atherosclerosis. Macrovascular pericytes are able to accumulate lipids and contribute to growth and vascularization of the atherosclerotic plaque. Moreover, they participate in the local inflammatory process and thrombosis, which can lead to fatal consequences. At the same time, pericytes can represent a useful model for studying the atherosclerotic process and for the development of novel therapeutic approaches. In particular, they are suitable for testing various substances' potential for decreasing lipid accumulation induced by the incubation of cells with atherogenic low-density lipoprotein. In this review we will discuss the application of cellular models for studying atherosclerosis and provide several examples of successful application of these models to drug research. PMID:26880986

  6. Cellular Model of Atherogenesis Based on Pluripotent Vascular Wall Pericytes.

    PubMed

    Ivanova, Ekaterina A; Orekhov, Alexander N

    2016-01-01

    Pericytes are pluripotent cells that can be found in the vascular wall of both microvessels and large arteries and veins. They have distinct morphology with long branching processes and form numerous contacts with each other and with endothelial cells, organizing the vascular wall cells into a three-dimensional network. Accumulating evidence demonstrates that pericytes may play a key role in the pathogenesis of vascular disorders, including atherosclerosis. Macrovascular pericytes are able to accumulate lipids and contribute to growth and vascularization of the atherosclerotic plaque. Moreover, they participate in the local inflammatory process and thrombosis, which can lead to fatal consequences. At the same time, pericytes can represent a useful model for studying the atherosclerotic process and for the development of novel therapeutic approaches. In particular, they are suitable for testing various substances' potential for decreasing lipid accumulation induced by the incubation of cells with atherogenic low-density lipoprotein. In this review we will discuss the application of cellular models for studying atherosclerosis and provide several examples of successful application of these models to drug research. PMID:26880986

  7. Pericytes are progenitors for coronary artery smooth muscle.

    PubMed

    Volz, Katharina S; Jacobs, Andrew H; Chen, Heidi I; Poduri, Aruna; McKay, Andrew S; Riordan, Daniel P; Kofler, Natalie; Kitajewski, Jan; Weissman, Irving; Red-Horse, Kristy

    2015-01-01

    Epicardial cells on the heart's surface give rise to coronary artery smooth muscle cells (caSMCs) located deep in the myocardium. However, the differentiation steps between epicardial cells and caSMCs are unknown as are the final maturation signals at coronary arteries. Here, we use clonal analysis and lineage tracing to show that caSMCs derive from pericytes, mural cells associated with microvessels, and that these cells are present in adults. During development following the onset of blood flow, pericytes at arterial remodeling sites upregulate Notch3 while endothelial cells express Jagged-1. Deletion of Notch3 disrupts caSMC differentiation. Our data support a model wherein epicardial-derived pericytes populate the entire coronary microvasculature, but differentiate into caSMCs at arterial remodeling zones in response to Notch signaling. Our data are the first demonstration that pericytes are progenitors for smooth muscle, and their presence in adult hearts reveals a new potential cell type for targeting during cardiovascular disease. PMID:26479710

  8. Impaired endochondral ossification and angiogenesis in mice deficient in membrane-type matrix metalloproteinase I

    PubMed Central

    Zhou, Zhongjun; Apte, Suneel S.; Soininen, Raija; Cao, Renhai; Baaklini, George Y.; Rauser, Richard W.; Wang, Jianming; Cao, Yihai; Tryggvason, Karl

    2000-01-01

    Membrane-type matrix metalloproteinase I (MT1-MMP)-deficient mice were found to have severe defects in skeletal development and angiogenesis. The craniofacial, axial, and appendicular skeletons were severely affected, leading to a short and domed skull, marked deceleration of postnatal growth, and death by 3 wk of age. Shortening of bones is a consequence of decreased chondrocyte proliferation in the proliferative zone of the growth plates. Defective vascular invasion of cartilage leads to enlargement of hypertrophic zones of growth plates and delayed formation of secondary ossification centers in long bones. In an in vivo corneal angiogenesis assay, null mice did not have angiogenic response to implanted FGF-2, suggesting that the defect in angiogenesis is not restricted to cartilage alone. In tissues from null mice, activation of latent matrix metalloproteinase 2 was deficient, suggesting that MT1-MMP is essential for its activation in vivo. PMID:10737763

  9. Impaired endochondral ossification and angiogenesis in mice deficient in membrane-type matrix metalloproteinase I.

    PubMed

    Zhou, Z; Apte, S S; Soininen, R; Cao, R; Baaklini, G Y; Rauser, R W; Wang, J; Cao, Y; Tryggvason, K

    2000-04-11

    Membrane-type matrix metalloproteinase I (MT1-MMP)-deficient mice were found to have severe defects in skeletal development and angiogenesis. The craniofacial, axial, and appendicular skeletons were severely affected, leading to a short and domed skull, marked deceleration of postnatal growth, and death by 3 wk of age. Shortening of bones is a consequence of decreased chondrocyte proliferation in the proliferative zone of the growth plates. Defective vascular invasion of cartilage leads to enlargement of hypertrophic zones of growth plates and delayed formation of secondary ossification centers in long bones. In an in vivo corneal angiogenesis assay, null mice did not have angiogenic response to implanted FGF-2, suggesting that the defect in angiogenesis is not restricted to cartilage alone. In tissues from null mice, activation of latent matrix metalloproteinase 2 was deficient, suggesting that MT1-MMP is essential for its activation in vivo. PMID:10737763

  10. Impaired self-awareness in human addiction: Deficient attribution of personal relevance

    PubMed Central

    Moeller, Scott J.; Goldstein, Rita Z.

    2014-01-01

    Compromised self-awareness of illness-related deficits and behaviors in psychopathology (e.g., schizophrenia) has been associated with deficient functioning of cortical midline regions including the ventromedial prefrontal cortex (vmPFC), implicated in personal relevance. Here, we review and critically analyze recent evidence to suggest that vmPFC abnormalities could similarly underlie deficient tagging of personal relevance in drug addiction, evidenced by a constellation of behaviors encompassing drug-biased attention, negative outcome insensitivity, self-report/behavior dissociation, and social inappropriateness. This novel framework might clarify, for example, why drug-addicted individuals often ruin long-standing relationships or forego important job opportunities while continuing to engage in uncontrolled drug-taking. Therapeutic interventions targeting personal relevance and associated vmPFC functioning could enhance self-awareness and facilitate more adaptive behavior in this chronically relapsing psychopathology. PMID:25278368

  11. ARID1A Deficiency Impairs the DNA Damage Checkpoint and Sensitizes Cells to PARP Inhibitors

    PubMed Central

    Shen, Jianfeng; Peng, Yang; Wei, Leizhen; Zhang, Wei; Yang, Lin; Lan, Li; Kapoor, Prabodh; Ju, Zhenlin; Mo, Qianxing; Shih, Ie-Ming; Uray, Ivan P.; Wu, Xiangwei; Brown, Powel H.; Shen, Xuetong; Mills, Gordon B.; Peng, Guang

    2015-01-01

    ARID1A, a chromatin remodeler of the SWI/SNF family, is a recently identified tumor suppressor that is mutated in a broad spectrum of human cancers. Thus, it is of fundamental clinical importance to understand its molecular functions and determine whether ARID1A deficiency can be exploited therapeutically. In this manuscript, we report a key function of ARID1A in regulating the DNA damage checkpoint. ARID1A is recruited to DNA double strand breaks (DSBs) via its interaction with the upstream DNA damage checkpoint kinase ATR. At the molecular level, ARID1A facilitates efficient processing of DSB to single strand ends, and sustains DNA damage signaling. Importantly, ARID1A deficiency sensitizes cancer cells to PARP inhibitors in vitro and in vivo providing a potential therapeutic strategy for patients with ARID1A-mutant tumors. PMID:26069190

  12. CARD9 deficiencies linked to impaired neutrophil functions against Phialophora verrucosa.

    PubMed

    Liang, Pin; Wang, Xiaowen; Wang, Runchao; Wan, Zhe; Han, Wenling; Li, Ruoyu

    2015-06-01

    Caspase recruitment domain-containing protein 9 (CARD9) is an adaptor molecule that is critical for NF-κB activation and forms a complex with B cell lymphoma 10 and mucosa-associated lymphoid tissue lymphoma translocation gene 1 that mediates C-type lectin receptors (CLRs)-triggered intracellular signaling during antifungal immunity. However, the role of CARD9 in the host defense against Phialophora verrucosa (P. verrucosa) infection remains to be elucidated. In the present study, we investigated the functions of polymorphonuclear neutrophils (PMNs) from patients with CARD9 deficiencies against P. verrucosa. By isolating PMNs from patients and healthy blood donors and subsequently challenging the cells with P. verrucosa, we demonstrated that, compared with healthy donors, CARD9-deficient PMNs exhibited defects in P. verrucosa killing and pro-inflammatory cytokine productions, which can be rescued in the presence of serum; however, the CARD9-deficient PMNs exhibited normal reactive oxygen species generation and phagocytotic ability. In conclusion, our results indicate that CARD9 is indispensable for P. verrucosa killing by PMNs, and serum opsonization acts as a CARD9-independent way, which could be a promising immunotherapy in the future. PMID:25790941

  13. Bif-1 deficiency impairs lipid homeostasis and causes obesity accompanied by insulin resistance

    PubMed Central

    Liu, Ying; Takahashi, Yoshinori; Desai, Neelam; Zhang, Jun; Serfass, Jacob M.; Shi, Yu-Guang; Lynch, Christopher J.; Wang, Hong-Gang

    2016-01-01

    Bif-1 is a membrane-curvature inducing protein that is implicated in the regulation of autophagy and tumorigenesis. Here, we report that Bif-1 plays a critical role in regulating lipid catabolism to control the size of lipid droplets and prevent the development of obesity and insulin resistance upon aging or dietary challenge. Our data show that Bif-1 deficiency promotes the expansion of adipose tissue mass without altering food intake or physical activities. While Bif-1 is dispensable for adipose tissue development, its deficiency reduces the basal rate of adipose tissue lipolysis and results in adipocyte hypertrophy upon aging. The importance of Bif-1 in lipid turnover is not limited to adipose tissue since fasting and refeeding-induced lipid droplet clearance is also attenuated by Bif-1 loss in the liver. Interestingly, obesity induced by a high fat-diet or Bif-1 deficiency downregulates the expression of proteins involved in the autophagy-lysosomal pathway, including Atg9a and Lamp1 in the adipose tissue. These findings thus identify Bif-1 as a novel regulator of lipid homeostasis to prevent the pathogenesis of obesity and its associated metabolic complications. PMID:26857140

  14. Bif-1 deficiency impairs lipid homeostasis and causes obesity accompanied by insulin resistance.

    PubMed

    Liu, Ying; Takahashi, Yoshinori; Desai, Neelam; Zhang, Jun; Serfass, Jacob M; Shi, Yu-Guang; Lynch, Christopher J; Wang, Hong-Gang

    2016-01-01

    Bif-1 is a membrane-curvature inducing protein that is implicated in the regulation of autophagy and tumorigenesis. Here, we report that Bif-1 plays a critical role in regulating lipid catabolism to control the size of lipid droplets and prevent the development of obesity and insulin resistance upon aging or dietary challenge. Our data show that Bif-1 deficiency promotes the expansion of adipose tissue mass without altering food intake or physical activities. While Bif-1 is dispensable for adipose tissue development, its deficiency reduces the basal rate of adipose tissue lipolysis and results in adipocyte hypertrophy upon aging. The importance of Bif-1 in lipid turnover is not limited to adipose tissue since fasting and refeeding-induced lipid droplet clearance is also attenuated by Bif-1 loss in the liver. Interestingly, obesity induced by a high fat-diet or Bif-1 deficiency downregulates the expression of proteins involved in the autophagy-lysosomal pathway, including Atg9a and Lamp1 in the adipose tissue. These findings thus identify Bif-1 as a novel regulator of lipid homeostasis to prevent the pathogenesis of obesity and its associated metabolic complications. PMID:26857140

  15. Deficiency of sphingomyelin synthase-1 but not sphingomyelin synthase-2 causes hearing impairments in mice.

    PubMed

    Lu, Mei-Hong; Takemoto, Makoto; Watanabe, Ken; Luo, Huan; Nishimura, Masataka; Yano, Masato; Tomimoto, Hidekazu; Okazaki, Toshiro; Oike, Yuichi; Song, Wen-Jie

    2012-08-15

    Sphingomyelin (SM) is a sphingolipid reported to function as a structural component of plasma membranes and to participate in signal transduction. The role of SM metabolism in the process of hearing remains controversial. Here, we examined the role of SM synthase (SMS), which is subcategorized into the family members SMS1 and SMS2, in auditory function. Measurements of auditory brainstem response (ABR) revealed hearing impairment in SMS1−/− mice in a low frequency range (4–16 kHz). As a possible mechanism of this impairment, we found that the stria vascularis (SV) in these mice exhibited atrophy and disorganized marginal cells. Consequently, SMS1−/− mice exhibited significantly smaller endocochlear potentials (EPs). As a possible mechanism for EP reduction, we found altered expression patterns and a reduced level of KCNQ1 channel protein in the SV of SMS1−/− mice. These mice also exhibited reduced levels of distortion product otoacoustic emissions. Quantitative comparison of the SV atrophy, KCNQ1 expression, and outer hair cell density at the cochlear apical and basal turns revealed no location dependence, but more macrophage invasion into the SV was observed in the apical region than the basal region, suggesting a role of cochlear location-dependent oxidative stress in producing the frequency dependence of hearing loss in SMS1−/− mice. Elevated ABR thresholds, decreased EPs, and abnormal KCNQ1 expression patterns in SMS1−/− mice were all found to be progressive with age. Mice lacking SMS2, however, exhibited neither detectable hearing loss nor changes in their EPs. Taken together, our results suggest that hearing impairments occur in SMS1−/− but not SMS2−/− mice. Defects in the SV with subsequent reductions in EPs together with hair cell dysfunction may account, at least partially, for hearing impairments in SMS1−/− mice. PMID:22641779

  16. Parental origin impairment of synaptic functions and behaviors in cytoplasmic FMRP interacting protein 1 (Cyfip1) deficient mice.

    PubMed

    Chung, Leeyup; Wang, Xiaoming; Zhu, Li; Towers, Aaron J; Cao, Xinyu; Kim, Il Hwan; Jiang, Yong-hui

    2015-12-10

    CYFIP1 maps to the interval between proximal breakpoint 1 (BP1) and breakpoint 2 (BP2) of chromosomal 15q11-q13 deletions that are implicated in the Angelman (AS) and Prader-Willi syndrome (PWS). There is only one breakpoint (BP3) at the distal end of deletion. CYFIP1 is deleted in AS patients with the larger class I deletion (BP1 to BP3) and the neurological presentations in these patients are more severe than that of patients with class II (BP2 to BP3) deletion. The haploinsufficiency of CYFIP1 is hypothesized to contribute to more severe clinical presentations in class I AS patients. The expression of CYFIP1 is suggested to be bi-allelic in literature but the possibility of parental origin of expression is not completely excluded. We generated and characterized Cyfip1 mutant mice. Homozygous Cyfip1 mice were early embryonic lethal. However, there was a parental origin specific effect between paternal Cyfip1 deficiency (m+/p-) and maternal deficiency (m-/p+) on both synaptic transmissions and behaviors in hippocampal CA1 synapses despite no evidence supporting the parental origin difference for the expression. Both m-/p+ and m+/p- showed the impaired input-output response and paired-pulse facilitation. While the long term-potentiation and group I mGluR mediated long term depression induced by DHPG was not different between Cyfip1 m-/p+ and m+/p- mice, the initial DHPG induced response was significantly enhanced in m-/p+ but not in m+/p- mice. m+/p- but not m-/p+ mice displayed increased freezing in cued fear conditioning and abnormal transitions in zero-maze test. The impaired synaptic transmission and behaviors in haploinsufficiency of Cyfip1 mice provide the evidence supporting the role of CYFIP1 modifying the clinical presentation of class I AS patients and in human neuropsychiatric disorders. PMID:26474913

  17. Impaired platelet activation and cAMP homeostasis in MRP4-deficient mice

    PubMed Central

    Decouture, Benoit; Dreano, Elise; Belleville-Rolland, Tiphaine; Kuci, Orjeta; Dizier, Blandine; Bazaa, Amine; Coqueran, Bérard; Lompre, Anne-Marie; Denis, Cécile V.; Hulot, Jean-Sébastien; Gaussem, Pascale

    2015-01-01

    Molecules that reduce the level of cyclic adenosine 5′-monophosphate (cAMP) in the platelet cytosol, such as adenosine 5′-diphosphate (ADP) secreted from dense granules, trigger platelet activation. Therefore, any change in the distribution and/or availability of cyclic nucleotides or ADP may interfere with platelet reactivity. In this study, we evaluated the role of multidrug resistance protein 4 (MRP4, or ABCC4), a nucleotide transporter, in platelet functions in vivo and in vitro by investigating MRP4-deficient mice. MRP4 deletion resulted in a slight increase in platelet count but had no impact on platelet ultrastructure. In MRP4-deficient mice, the arterial occlusion was delayed and the tail bleeding time was prolonged. In a model of platelet depletion and transfusion mimicking a platelet-specific knockout, mice injected with MRP4−/− platelets also showed a significant increase in blood loss compared with mice injected with wild-type platelets. Defective thrombus formation and platelet activation were confirmed in vitro by studying platelet adhesion to collagen in flow conditions, integrin αIIbβ3 activation, washed platelet secretion, and aggregation induced by low concentrations of proteinase-activated receptor 4–activating peptide, U46619, or ADP. We found no role of MRP4 in ADP dense-granule storage, but MRP4 redistributed cAMP from the cytosol to dense granules, as confirmed by increased vasodilator-stimulated phosphoprotein phosphorylation in MRP4-deficient platelets. These data suggest that MRP4 promotes platelet aggregation by modulating the cAMP–protein kinase A signaling pathway, suggesting that MRP4 might serve as a target for novel antiplatelet agents. PMID:26316625

  18. Deficiency in the inner mitochondrial membrane peptidase 2-like (Immp21) gene increases ischemic brain damage and impairs mitochondrial function

    PubMed Central

    Ma, Yi; Mehta, Suresh L.; Lu, Baisong; Andy Li, P.

    2011-01-01

    Mitochondrial dysfunction plays an important role in mediating ischemic brain damage. Immp2l is an inner mitochondrial membrane peptidase that processes mitochondrial proteins cytochrome c1 (Cyc1). Homozygous mutation of Immp2l (Immp2lTg(Tyr)979Ove or Immp2l−/−) elevates mitochondrial membrane potential, increases superoxide (•O2−) production in the brain and impairs fertility. The objectives of this study are to explore the effects of heterozygous mutation of lmmp2l (Immp2l+/−) on ischemic outcome and to determine the influence of Immp2l deficiency on brain mitochondria after stroke. Male Immp2l+/− and wild-type (WT) mice were subjected to 1-h focal cerebral ischemia. Their brains were harvested after 5 and 24-h of reperfusion. The results showed that infarct volume and DNA oxidative damage significantly increased in the Immp2l+/− mice. There were no obvious cerebral vasculature abnormalities between the two types of mice viewed by Indian ink perfusion. The increased damage in Immp2l+/− mice was associated with early increase in •O2− production. Mitochondrial respiratory rate, total mitochondrial respiratory capacity and mitochondrial respiratory complex activities were decreased at 5-h of recirculation in Immp2l+/− mice compared to WT mice. Our results suggest that lmmp2l deficiency increases ischemic brain damage by enhancing •O2− production and damaging mitochondrial functional performance. PMID:21824519

  19. A Novel Animal Model of Impaired Glucose Tolerance Induced by the Interaction of Vitamin E Deficiency and 60Co Radiation

    PubMed Central

    Guan, Yue; Cheng, Yan; Yin, Ying; Duan, Jialin; Wei, Guo; Weng, Yan; Guo, Chao; Zhu, Yanrong; Wang, Yanhua; Xi, Miaomiao; Wen, Aidong

    2015-01-01

    Impaired glucose tolerance (IGT), known as the prediabetes stage, is usually induced by habits of life or environmental factors. Established IGT animal models are mostly conducted with chemical compounds such as streptozocin or genetic modification. However, the occasion of exposure to these factors in daily life is seldom. The objective of this study was to establish a new animal model of IGT induced by VE deficiency in diet and exposure to radiation. SD rats were treated individually or in combination of these two factors. In the combination group, the calculated insulin sensitivity index decreased; then HOMA-β value increased. Oxidative damage and IGT were observed. Insulin secretion level in perfusate from pancreas response to glucose was characterized by a rapid but reduced first phase and an obviously defective second phase upon pancreas perfusion. Histopathological images demonstrated the pathological changes. Western blotting analysis showed that the insulin signaling pathway was downregulated. The interaction of VE deficiency in diet and exposure to radiation could break the equilibrium of oxidation and antioxidation and result in IGT. More importantly, a new IGT model was successfully established which may be conducive to further research into development of drugs against human IGT. PMID:25954750

  20. High-Iron Consumption Impairs Growth and Causes Copper-Deficiency Anemia in Weanling Sprague-Dawley Rats.

    PubMed

    Ha, Jung-Heun; Doguer, Caglar; Wang, Xiaoyu; Flores, Shireen R; Collins, James F

    2016-01-01

    Iron-copper interactions were described decades ago; however, molecular mechanisms linking the two essential minerals remain largely undefined. Investigations in humans and other mammals noted that copper levels increase in the intestinal mucosa, liver and blood during iron deficiency, tissues all important for iron homeostasis. The current study was undertaken to test the hypothesis that dietary copper influences iron homeostasis during iron deficiency and iron overload. We thus fed weanling, male Sprague-Dawley rats (n = 6-11/group) AIN-93G-based diets containing high (~8800 ppm), adequate (~80) or low (~11) iron in combination with high (~183), adequate (~8) or low (~0.9) copper for 5 weeks. Subsequently, the iron- and copper-related phenotype of the rats was assessed. Rats fed the low-iron diets grew slower than controls, with changes in dietary copper not further influencing growth. Unexpectedly, however, high-iron (HFe) feeding also impaired growth. Furthermore, consumption of the HFe diet caused cardiac hypertrophy, anemia, low serum and tissue copper levels and decreased circulating ceruloplasmin activity. Intriguingly, these physiologic perturbations were prevented by adding extra copper to the HFe diet. Furthermore, higher copper levels in the HFe diet increased serum nonheme iron concentration and transferrin saturation, exacerbated hepatic nonheme iron loading and attenuated splenic nonheme iron accumulation. Moreover, serum erythropoietin levels, and splenic erythroferrone and hepatic hepcidin mRNA levels were altered by the dietary treatments in unanticipated ways, providing insight into how iron and copper influence expression of these hormones. We conclude that high-iron feeding of weanling rats causes systemic copper deficiency, and further, that copper influences the iron-overload phenotype. PMID:27537180

  1. Contrasting impairments in IgM and IgG responses of vitamin A-deficient mice.

    PubMed Central

    Smith, S M; Hayes, C E

    1987-01-01

    Mice fed a semipurified, vitamin A-deficient diet (A- mice) and control animals fed the same diet with added retinyl acetate (A+ mice) were used to investigate the effect of vitamin A deficiency on primary immunoglobulin responses to protein antigens. At age 6 weeks, A- mice had serum retinol concentrations that were 46% of A+ controls. When immunized with a single antigen dose, these mice produced an antigen-specific IgM response equivalent to controls, but their IgG1 and IgG3 responses were sharply diminished (less than 30% of A+ controls). At age 8 weeks, A- mice had 20% of A+ serum retinol concentrations and less than 17% of A+ liver retinyl palmitate levels. Responding to a single antigen dose, A- mice produced approximately equal to 70% as much IgM as A+ controls. Their IgG1 response was less than 30% and their IgG3 response less than 3% of A+ controls. The IgG1 response kinetics were identical in A- and A+ mice. Diminished serum antibody responses in A- mice were attributable to fewer immunoglobulin-secreting plasma cells rather than to a decline in IgM or IgG secretion rate per cell. Total serum IgG3 levels, irrespective of antigen specificity, were slightly elevated in A- mice compared to A+ controls. The inefficient clonal expansion of responding B lymphocytes and contrasting impairment of IgM and IgG responses observed in vitamin A-deficient mice are discussed with respect to a possible helper/inducer-T-lymphocyte defect. PMID:3475707

  2. High-Iron Consumption Impairs Growth and Causes Copper-Deficiency Anemia in Weanling Sprague-Dawley Rats

    PubMed Central

    Ha, Jung-Heun; Doguer, Caglar; Wang, Xiaoyu; Flores, Shireen R.; Collins, James F.

    2016-01-01

    Iron-copper interactions were described decades ago; however, molecular mechanisms linking the two essential minerals remain largely undefined. Investigations in humans and other mammals noted that copper levels increase in the intestinal mucosa, liver and blood during iron deficiency, tissues all important for iron homeostasis. The current study was undertaken to test the hypothesis that dietary copper influences iron homeostasis during iron deficiency and iron overload. We thus fed weanling, male Sprague-Dawley rats (n = 6-11/group) AIN-93G-based diets containing high (~8800 ppm), adequate (~80) or low (~11) iron in combination with high (~183), adequate (~8) or low (~0.9) copper for 5 weeks. Subsequently, the iron- and copper-related phenotype of the rats was assessed. Rats fed the low-iron diets grew slower than controls, with changes in dietary copper not further influencing growth. Unexpectedly, however, high-iron (HFe) feeding also impaired growth. Furthermore, consumption of the HFe diet caused cardiac hypertrophy, anemia, low serum and tissue copper levels and decreased circulating ceruloplasmin activity. Intriguingly, these physiologic perturbations were prevented by adding extra copper to the HFe diet. Furthermore, higher copper levels in the HFe diet increased serum nonheme iron concentration and transferrin saturation, exacerbated hepatic nonheme iron loading and attenuated splenic nonheme iron accumulation. Moreover, serum erythropoietin levels, and splenic erythroferrone and hepatic hepcidin mRNA levels were altered by the dietary treatments in unanticipated ways, providing insight into how iron and copper influence expression of these hormones. We conclude that high-iron feeding of weanling rats causes systemic copper deficiency, and further, that copper influences the iron-overload phenotype. PMID:27537180

  3. TopBP1 deficiency impairs V(D)J recombination during lymphocyte development

    PubMed Central

    Kim, Jieun; Kyu Lee, Sung; Jeon, Yoon; Kim, Yehyun; Lee, Changjin; Ho Jeon, Sung; Shim, Jaegal; Kim, In-Hoo; Hong, Seokmann; Kim, Nayoung; Lee, Ho; Seong, Rho Hyun

    2014-01-01

    TopBP1 was initially identified as a topoisomerase II-β-binding protein and it plays roles in DNA replication and repair. We found that TopBP1 is expressed at high levels in lymphoid tissues and is essential for early lymphocyte development. Specific abrogation of TopBP1 expression resulted in transitional blocks during early lymphocyte development. These defects were, in major part, due to aberrant V(D)J rearrangements in pro-B cells, double-negative and double-positive thymocytes. We also show that TopBP1 was located at sites of V(D)J rearrangement. In TopBP1-deficient cells, γ-H2AX foci were found to be increased. In addition, greater amount of γ-H2AX product was precipitated from the regions where TopBP1 was localized than from controls, indicating that TopBP1 deficiency results in inefficient DNA double-strand break repair. The developmental defects were rescued by introducing functional TCR αβ transgenes. Our data demonstrate a novel role for TopBP1 as a crucial factor in V(D)J rearrangement during the development of B, T and iNKT cells. PMID:24442639

  4. LCAT deficiency does not impair amyloid metabolism in APP/PS1 mice.

    PubMed

    Stukas, Sophie; Freeman, Lita; Lee, Michael; Wilkinson, Anna; Ossoli, Alice; Vaisman, Boris; Demosky, Stephen; Chan, Jeniffer; Hirsch-Reinshagen, Veronica; Remaley, Alan T; Wellington, Cheryl L

    2014-08-01

    A key step in plasma HDL maturation from discoidal to spherical particles is the esterification of cholesterol to cholesteryl ester, which is catalyzed by LCAT. HDL-like lipoproteins in cerebrospinal fluid (CSF) are also spherical, whereas nascent lipoprotein particles secreted from astrocytes are discoidal, suggesting that LCAT may play a similar role in the CNS. In plasma, apoA-I is the main LCAT activator, while in the CNS, it is believed to be apoE. apoE is directly involved in the pathological progression of Alzheimer's disease, including facilitating β-amyloid (Aβ) clearance from the brain, a function that requires its lipidation by ABCA1. However, whether apoE particle maturation by LCAT is also required for Aβ clearance is unknown. Here we characterized the impact of LCAT deficiency on CNS lipoprotein metabolism and amyloid pathology. Deletion of LCAT from APP/PS1 mice resulted in a pronounced decrease of apoA-I in plasma that was paralleled by decreased apoA-I levels in CSF and brain tissue, whereas apoE levels were unaffected. Furthermore, LCAT deficiency did not increase Aβ or amyloid in APP/PS1 LCAT(-/-) mice. Finally, LCAT expression and plasma activity were unaffected by age or the onset of Alzheimer's-like pathology in APP/PS1 mice. Taken together, these results suggest that apoE-containing discoidal HDLs do not require LCAT-dependent maturation to mediate efficient Aβ clearance. PMID:24950691

  5. Fibroblast growth factor 21-deficient mice demonstrate impaired adaptation to ketosis.

    PubMed

    Badman, Michael K; Koester, Anja; Flier, Jeffrey S; Kharitonenkov, Alexei; Maratos-Flier, Eleftheria

    2009-11-01

    Fibroblast growth factor 21 (FGF21) is a key metabolic regulator. Expressed primarily in liver and adipose tissue, FGF21 is induced via peroxisome proliferator-activated receptor (PPAR) pathways during states requiring increased fatty acid oxidation including fasting and consumption of a ketogenic diet. To test the hypothesis that FGF21 is a physiological regulator that plays a role in lipid oxidation, we generated mice with targeted disruption of the Fgf21 locus (FGF21 knockout). Mice lacking FGF21 had mild weight gain and slightly impaired glucose homeostasis, indicating a role in long-term energy homeostasis. Furthermore, FGF21KO mice tolerated a 24-h fast, indicating that FGF21 is not essential in the early stages of starvation. In contrast to wild-type animals in which feeding KD leads to dramatic weight loss, FGF21KO mice fed KD gained weight, developed hepatosteatosis, and showed marked impairments in ketogenesis and glucose control. This confirms the physiological importance of FGF21 in the adaptation to KD feeding. At a molecular level, these effects were accompanied by lower levels of expression of PGC1alpha and PGC1beta in FGF21KO mice, strongly implicating these key transcriptional regulators in the action of FGF21. Furthermore, within the liver, the maturation of the lipogenic transcription factor sterol regulatory element-binding protein-1c was increased in FGF21KO mice, implicating posttranscriptional events in the maladaptation of FGF21KO mice to KD. These data reinforce the role of FGF21 is a critical regulator of long-term energy balance and metabolism. Mice lacking FGF21 cannot respond appropriately to a ketogenic diet, resulting in an impaired ability to mobilize and utilize lipids. PMID:19819944

  6. Apelin Protects Primary Rat Retinal Pericytes from Chemical Hypoxia-Induced Apoptosis

    PubMed Central

    Chen, Li; Tao, Yong; Feng, Jing; Jiang, Yan Rong

    2015-01-01

    Pericytes are a population of cells that participate in normal vessel architecture and regulate permeability. Apelin, as the endogenous ligand of G protein-coupled receptor APJ, participates in a number of physiological and pathological processes. To date, the effect of apelin on pericyte is not clear. Our study aimed to investigate the potential protection mechanisms of apelin, with regard to primary rat retinal pericytes under hypoxia. Immunofluorescence staining revealed that pericytes colocalized with APJ in the fibrovascular membranes dissected from proliferative diabetic retinopathy patients. In the in vitro studies, we first demonstrated that the expression of apelin/APJ was upregulated in pericytes under hypoxia, and apelin increased pericytes proliferation and migration. Moreover, knockdown of apelin in pericyte was achieved via lentivirus-mediated RNA interference. After the inhibition of apelin, pericytes proliferation was inhibited significantly in hypoxia culture condition. Furthermore, exogenous recombinant apelin effectively prevented hypoxia-induced apoptosis through downregulating active-caspase 3 expression and increasing the ratio of B cell lymphoma-2 (Bcl-2)/Bcl-2 associated X protein (Bax) in pericytes. These results suggest that apelin suppressed hypoxia-induced pericytes injury, which indicated that apelin could be a potential therapeutic target for retinal angiogenic diseases. PMID:26491547

  7. Angiogenesis of the blood-brain barrier in vitro and the function of cerebral pericytes.

    PubMed

    Ramsauer, Markus; Krause, Dorothee; Dermietzel, Rolf

    2002-08-01

    Cerebral pericytes constitute an essential component of the blood-brain barrier (BBB) and are involved in blood vessel assembly. Recently, we reported on the induction of a BBB-specific enzyme expressed by cerebral pericytes (pericytic aminopeptidase N/pAPN) in coculture with cerebral endothelial cells. We completed this in vitro BBB system by adding astrocytes to these mixed cultures of endothelial cells and pericytes. Under these triculture conditions, endothelial cells and pericytes reorganize into capillary-like structures (CLSs). Capillary formation can also be achieved by the application of transforming growth factor beta 1 (TGF-b1) in the culture medium of endothelial-pericyte cultures lacking astrocytes. In contrast to the effect achieved by astrocytes, pericytes did not assemble with endothelial cells. In both cases (application of astrocytes or TGF-b1), endothelial cells underwent apoptosis. However, endothelial cells that form CLSs in the presence of pericytes appeared to be resistant to induction of apoptosis. On the basis of these observations, we concluded that astrocytes have a profound influence on the morphogenetic events underlying the organization of the vessel wall; that the effect of TGF-b1 is different from the astrocytic effect because it lacks induction of endothelial-pericyte association; and that pericytes stabilize CLSs formed by endothelial cells in coculture with astrocytes. PMID:12153997

  8. Cortical Structure Alterations and Social Behavior Impairment in p50-Deficient Mice

    PubMed Central

    Bonini, Sara Anna; Mastinu, Andrea; Maccarinelli, Giuseppina; Mitola, Stefania; Premoli, Marika; La Rosa, Luca Rosario; Ferrari-Toninelli, Giulia; Grilli, Mariagrazia; Memo, Maurizio

    2016-01-01

    Alterations in genes that regulate neurodevelopment can lead to cortical malformations, resulting in malfunction during postnatal life. The NF-κB pathway has a key role during neurodevelopment by regulating the maintenance of the neural progenitor cell pool and inhibiting neuronal differentiation. In this study, we evaluated whether mice lacking the NF-κB p50 subunit (KO) present alterations in cortical structure and associated behavioral impairment. We found that, compared with wild type (WT), KO mice at postnatal day 2 present an increase in radial glial cells, an increase in Reelin protein expression levels, in addition to an increase of specific layer thickness. Moreover, adult KO mice display abnormal columnar organization in the somatosensory cortex, a specific decrease in somatostatin- and parvalbumin-expressing interneurons, altered neurite orientation, and a decrease in Synapsin I protein levels. Concerning behavior, KO mice, in addition to an increase in locomotor and exploratory activity, display impairment in social behaviors, with a reduction in social interaction. Finally, we found that risperidone treatment decreased hyperactivity of KO mice, but had no effect on defective social interaction. Altogether, these data add complexity to a growing body of data, suggesting a link between dysregulation of the NF-κB pathway and neurodevelopmental disorders pathogenesis. PMID:26946128

  9. Cortical Structure Alterations and Social Behavior Impairment in p50-Deficient Mice.

    PubMed

    Bonini, Sara Anna; Mastinu, Andrea; Maccarinelli, Giuseppina; Mitola, Stefania; Premoli, Marika; La Rosa, Luca Rosario; Ferrari-Toninelli, Giulia; Grilli, Mariagrazia; Memo, Maurizio

    2016-06-01

    Alterations in genes that regulate neurodevelopment can lead to cortical malformations, resulting in malfunction during postnatal life. The NF-κB pathway has a key role during neurodevelopment by regulating the maintenance of the neural progenitor cell pool and inhibiting neuronal differentiation. In this study, we evaluated whether mice lacking the NF-κB p50 subunit (KO) present alterations in cortical structure and associated behavioral impairment. We found that, compared with wild type (WT), KO mice at postnatal day 2 present an increase in radial glial cells, an increase in Reelin protein expression levels, in addition to an increase of specific layer thickness. Moreover, adult KO mice display abnormal columnar organization in the somatosensory cortex, a specific decrease in somatostatin- and parvalbumin-expressing interneurons, altered neurite orientation, and a decrease in Synapsin I protein levels. Concerning behavior, KO mice, in addition to an increase in locomotor and exploratory activity, display impairment in social behaviors, with a reduction in social interaction. Finally, we found that risperidone treatment decreased hyperactivity of KO mice, but had no effect on defective social interaction. Altogether, these data add complexity to a growing body of data, suggesting a link between dysregulation of the NF-κB pathway and neurodevelopmental disorders pathogenesis. PMID:26946128

  10. Impaired cardiac contractility response to hemodynamic stress in S100A1-deficient mice.

    PubMed

    Du, Xiao-Jun; Cole, Timothy J; Tenis, Nora; Gao, Xiao-Ming; Köntgen, Frank; Kemp, Bruce E; Heierhorst, Jörg

    2002-04-01

    Ca(2+) signaling plays a central role in cardiac contractility and adaptation to increased hemodynamic demand. We have generated mice with a targeted deletion of the S100A1 gene coding for the major cardiac isoform of the large multigenic S100 family of EF hand Ca(2+)-binding proteins. S100A1(-/-) mice have normal cardiac function under baseline conditions but have significantly reduced contraction rate and relaxation rate responses to beta-adrenergic stimulation that are associated with a reduced Ca(2+) sensitivity. In S100A1(-/-) mice, basal left-ventricular contractility deteriorated following 3-week pressure overload by thoracic aorta constriction despite a normal adaptive hypertrophy. Surprisingly, heterozygotes also had an impaired response to acute beta-adrenergic stimulation but maintained normal contractility in response to chronic pressure overload that coincided with S100A1 upregulation to wild-type levels. In contrast to other genetic models with impaired cardiac contractility, loss of S100A1 did not lead to cardiac hypertrophy or dilation in aged mice. The data demonstrate that high S100A1 protein levels are essential for the cardiac reserve and adaptation to acute and chronic hemodynamic stress in vivo. PMID:11909974

  11. Impaired Cardiac Contractility Response to Hemodynamic Stress in S100A1-Deficient Mice

    PubMed Central

    Du, Xiao-Jun; Cole, Timothy J.; Tenis, Nora; Gao, Xiao-Ming; Köntgen, Frank; Kemp, Bruce E.; Heierhorst, Jörg

    2002-01-01

    Ca2+ signaling plays a central role in cardiac contractility and adaptation to increased hemodynamic demand. We have generated mice with a targeted deletion of the S100A1 gene coding for the major cardiac isoform of the large multigenic S100 family of EF hand Ca2+-binding proteins. S100A1−/− mice have normal cardiac function under baseline conditions but have significantly reduced contraction rate and relaxation rate responses to β-adrenergic stimulation that are associated with a reduced Ca2+ sensitivity. In S100A1−/− mice, basal left-ventricular contractility deteriorated following 3-week pressure overload by thoracic aorta constriction despite a normal adaptive hypertrophy. Surprisingly, heterozygotes also had an impaired response to acute β-adrenergic stimulation but maintained normal contractility in response to chronic pressure overload that coincided with S100A1 upregulation to wild-type levels. In contrast to other genetic models with impaired cardiac contractility, loss of S100A1 did not lead to cardiac hypertrophy or dilation in aged mice. The data demonstrate that high S100A1 protein levels are essential for the cardiac reserve and adaptation to acute and chronic hemodynamic stress in vivo. PMID:11909974

  12. TLR3 deficiency impairs spinal cord synaptic transmission, central sensitization, and pruritus in mice

    PubMed Central

    Liu, Tong; Berta, Temugin; Xu, Zhen-Zhong; Park, Chul-Kyu; Zhang, Ling; Lü, Ning; Liu, Qin; Liu, Yang; Gao, Yong-Jing; Liu, Yen-Chin; Ma, Qiufu; Dong, Xinzhong; Ji, Ru-Rong

    2012-01-01

    Itch, also known as pruritus, is a common, intractable symptom of several skin diseases, such as atopic dermatitis and xerosis. TLRs mediate innate immunity and regulate neuropathic pain, but their roles in pruritus are elusive. Here, we report that scratching behaviors induced by histamine-dependent and -independent pruritogens are markedly reduced in mice lacking the Tlr3 gene. TLR3 is expressed mainly by small-sized primary sensory neurons in dorsal root ganglions (DRGs) that coexpress the itch signaling pathway components transient receptor potential subtype V1 and gastrin-releasing peptide. Notably, we found that treatment with a TLR3 agonist induces inward currents and action potentials in DRG neurons and elicited scratching in WT mice but not Tlr3–/– mice. Furthermore, excitatory synaptic transmission in spinal cord slices and long-term potentiation in the intact spinal cord were impaired in Tlr3–/– mice but not Tlr7–/– mice. Consequently, central sensitization–driven pain hypersensitivity, but not acute pain, was impaired in Tlr3–/– mice. In addition, TLR3 knockdown in DRGs also attenuated pruritus in WT mice. Finally, chronic itch in a dry skin condition was substantially reduced in Tlr3–/– mice. Our findings demonstrate a critical role of TLR3 in regulating sensory neuronal excitability, spinal cord synaptic transmission, and central sensitization. TLR3 may serve as a new target for developing anti-itch treatment. PMID:22565312

  13. Mycobacterial disease and impaired IFN-γ immunity in humans with inherited ISG15 deficiency.

    PubMed

    Bogunovic, Dusan; Byun, Minji; Durfee, Larissa A; Abhyankar, Avinash; Sanal, Ozden; Mansouri, Davood; Salem, Sandra; Radovanovic, Irena; Grant, Audrey V; Adimi, Parisa; Mansouri, Nahal; Okada, Satoshi; Bryant, Vanessa L; Kong, Xiao-Fei; Kreins, Alexandra; Velez, Marcela Moncada; Boisson, Bertrand; Khalilzadeh, Soheila; Ozcelik, Ugur; Darazam, Ilad Alavi; Schoggins, John W; Rice, Charles M; Al-Muhsen, Saleh; Behr, Marcel; Vogt, Guillaume; Puel, Anne; Bustamante, Jacinta; Gros, Philippe; Huibregtse, Jon M; Abel, Laurent; Boisson-Dupuis, Stéphanie; Casanova, Jean-Laurent

    2012-09-28

    ISG15 is an interferon (IFN)-α/β-inducible, ubiquitin-like intracellular protein. Its conjugation to various proteins (ISGylation) contributes to antiviral immunity in mice. Here, we describe human patients with inherited ISG15 deficiency and mycobacterial, but not viral, diseases. The lack of intracellular ISG15 production and protein ISGylation was not associated with cellular susceptibility to any viruses that we tested, consistent with the lack of viral diseases in these patients. By contrast, the lack of mycobacterium-induced ISG15 secretion by leukocytes-granulocyte, in particular-reduced the production of IFN-γ by lymphocytes, including natural killer cells, probably accounting for the enhanced susceptibility to mycobacterial disease. This experiment of nature shows that human ISGylation is largely redundant for antiviral immunity, but that ISG15 plays an essential role as an IFN-γ-inducing secreted molecule for optimal antimycobacterial immunity. PMID:22859821

  14. Mycobacterial disease and impaired IFN-γ immunity in humans with inherited ISG15 deficiency

    PubMed Central

    Bogunovic, Dusan; Byun, Minji; Durfee, Larissa A.; Abhyankar, Avinash; Sanal, Ozden; Mansouri, Davood; Salem, Sandra; Radovanovic, Irena; Grant, Audrey V.; Adimi, Parisa; Mansouri, Nahal; Okada, Satoshi; Bryant, Vanessa L.; Kong, Xiao-Fei; Kreins, Alexandra; Velez, Marcela Moncada; Boisson, Bertrand; Khalilzadeh, Soheila; Ozcelik, Ugur; Darazam, Ilad Alavi; Schoggins, John W.; Rice, Charles M.; Al-Muhsen, Saleh; Behr, Marcel; Vogt, Guillaume; Puel, Anne; Bustamante, Jacinta; Gros, Philippe; Huibregtse, Jon M.; Abel, Laurent; Boisson-Dupuis, Stéphanie; Casanova, Jean-Laurent

    2012-01-01

    ISG15 is an interferon (IFN)-α/β-inducible, ubiquitin-like intracellular protein. Its conjugation to various proteins (ISGylation) contributes to antiviral immunity in mice. We describe human patients with inherited ISG15 deficiency and mycobacterial, but not viral diseases. The lack of intracellular ISG15 production and protein ISGylation was not associated with cellular susceptibility to any viruses tested, consistent with the lack of viral diseases in these patients. By contrast, the lack of mycobacterium-induced ISG15 secretion by leukocytes — granulocytes in particular — reduced the production of IFN-γ by lymphocytes, including natural killer cells, probably accounting for the enhanced susceptibility to mycobacterial disease. This experiment of Nature shows that human ISGylation is largely redundant for antiviral immunity, but that ISG15 plays an essential role as an IFN-γ-inducing secreted molecule for optimal antimycobacterial immunity. PMID:22859821

  15. Neural tube defects and impaired neural progenitor cell proliferation in Gbeta1-deficient mice.

    PubMed

    Okae, Hiroaki; Iwakura, Yoichiro

    2010-04-01

    Heterotrimeric G proteins are well known for their roles in signal transduction downstream of G protein-coupled receptors (GPCRs), and both Galpha subunits and tightly associated Gbetagamma subunits regulate downstream effector molecules. Compared to Galpha subunits, the physiological roles of individual Gbeta and Ggamma subunits are poorly understood. In this study, we generated mice deficient in the Gbeta1 gene and found that Gbeta1 is required for neural tube closure, neural progenitor cell proliferation, and neonatal development. About 40% Gbeta1(-/-) embryos developed neural tube defects (NTDs) and abnormal actin organization was observed in the basal side of neuroepithelium. In addition, Gbeta1(-/-) embryos without NTDs showed microencephaly and died within 2 days after birth. GPCR agonist-induced ERK phosphorylation, cell proliferation, and cell spreading, which were all found to be regulated by Galphai and Gbetagamma signaling, were abnormal in Gbeta1(-/-) neural progenitor cells. These data indicate that Gbeta1 is required for normal embryonic neurogenesis. PMID:20186915

  16. Deficiency of caspase 3 in tumor xenograft impairs therapeutic effect of measles virus Edmoston strain.

    PubMed

    Wang, Biao; Yan, Xu; Guo, Qingguo; Li, Yan; Zhang, Haiyan; Xie, Ji Sheng; Meng, Xin

    2015-06-30

    The oncolytic measles virus Edmonston (MV-Edm) strain shows considerable oncolytic activity against a variety of human tumors. In this study, we report MV-Edm is able to trigger apoptosis pathways in infected tumor cells and elucidate the roles of cellular apoptosis in the whole oncolytic process. We also show that activated caspase 3, a key executioner of apoptosis, plays key roles in the oncolytic virotherapy. Activated caspase 3 can accelerate viral replication in cervical cancer cells and enhance the killing effects of the virus. Deficiency of caspase 3 either in tumor cells or in tumor xenograft significantly desensitized tumor to oncolysis with MV-Edm. In the infected cells, caspase 3 regulates interferon α release, which can inhibit viral replication in neighboring tumor cells. We propose that caspase-3 activation enhances the oncolytic effects of MV-Edm, thus inhibiting tumor growth in mice. PMID:25909216

  17. LCAT deficiency does not impair amyloid metabolism in APP/PS1 mice[S

    PubMed Central

    Stukas, Sophie; Freeman, Lita; Lee, Michael; Wilkinson, Anna; Ossoli, Alice; Vaisman, Boris; Demosky, Stephen; Chan, Jeniffer; Hirsch-Reinshagen, Veronica; Remaley, Alan T.; Wellington, Cheryl L.

    2014-01-01

    A key step in plasma HDL maturation from discoidal to spherical particles is the esterification of cholesterol to cholesteryl ester, which is catalyzed by LCAT. HDL-like lipoproteins in cerebrospinal fluid (CSF) are also spherical, whereas nascent lipoprotein particles secreted from astrocytes are discoidal, suggesting that LCAT may play a similar role in the CNS. In plasma, apoA-I is the main LCAT activator, while in the CNS, it is believed to be apoE. apoE is directly involved in the pathological progression of Alzheimer’s disease, including facilitating β-amyloid (Aβ) clearance from the brain, a function that requires its lipidation by ABCA1. However, whether apoE particle maturation by LCAT is also required for Aβ clearance is unknown. Here we characterized the impact of LCAT deficiency on CNS lipoprotein metabolism and amyloid pathology. Deletion of LCAT from APP/PS1 mice resulted in a pronounced decrease of apoA-I in plasma that was paralleled by decreased apoA-I levels in CSF and brain tissue, whereas apoE levels were unaffected. Furthermore, LCAT deficiency did not increase Aβ or amyloid in APP/PS1 LCAT−/− mice. Finally, LCAT expression and plasma activity were unaffected by age or the onset of Alzheimer’s-like pathology in APP/PS1 mice. Taken together, these results suggest that apoE-containing discoidal HDLs do not require LCAT-dependent maturation to mediate efficient Aβ clearance. PMID:24950691

  18. Myeloid PTEN deficiency impairs tumor-immune surveillance via immune-checkpoint inhibition.

    PubMed

    Kuttke, M; Sahin, E; Pisoni, J; Percig, S; Vogel, A; Kraemmer, D; Hanzl, L; Brunner, J S; Paar, H; Soukup, K; Halfmann, A; Dohnal, A M; Steiner, C W; Blüml, S; Basilio, J; Hochreiter, B; Salzmann, M; Hoesel, B; Lametschwandtner, G; Eferl, R; Schmid, J A; Schabbauer, G

    2016-07-01

    Tumor-host interaction is determined by constant immune surveillance, characterized by tumor infiltration of myeloid and lymphoid cells. A malfunctioning or diverted immune response promotes tumor growth and metastasis. Recent advances had been made, by treating of certain tumor types, such as melanoma, with T-cell checkpoint inhibitors. This highlights the importance of understanding the molecular mechanisms underlying the crosstalk between tumors and their environment, in particular myeloid and lymphoid cells. Our aim was to study the contribution of the myeloid PI3K/PTEN-signaling pathway in the regulation of tumor-immune surveillance in murine models of cancer. We made use of conditional PTEN-deficient mice, which exhibit sustained activation of the PI3K-signaling axis in a variety of myeloid cell subsets such as macrophages and dendritic cells (DCs). In colitis-associated colon cancer (CAC), mice deficient in myeloid PTEN showed a markedly higher tumor burden and decreased survival. We attributed this observation to the increased presence of immune-modulatory conventional CD8α(+) DCs in the spleen, whereas other relevant myeloid cell subsets were largely unaffected. Notably, we detected enhanced surface expression of PD-L1 and PD-L2 on these DCs. As a consequence, tumoricidal T-cell responses were hampered or redirected. Taken together, our findings indicated an unanticipated role for the PI3K/PTEN-signaling axis in the functional regulation of splenic antigen-presenting cells (APCs). Our data pointed at potential, indirect, tumoricidal effects of subclass-specific PI3K inhibitors, which are currently under clinical investigation for treatment of tumors, via myeloid cell activation. PMID:27622019

  19. Myeloid PTEN deficiency impairs tumor-immune surveillance via immune-checkpoint inhibition

    PubMed Central

    Kuttke, M.; Sahin, E.; Pisoni, J.; Percig, S.; Vogel, A.; Kraemmer, D.; Hanzl, L.; Brunner, J. S.; Paar, H.; Soukup, K.; Halfmann, A.; Dohnal, A. M.; Steiner, C. W.; Blüml, S.; Basilio, J.; Hochreiter, B.; Salzmann, M.; Hoesel, B.; Lametschwandtner, G.; Eferl, R.; Schmid, J. A.; Schabbauer, G.

    2016-01-01

    ABSTRACT Tumor–host interaction is determined by constant immune surveillance, characterized by tumor infiltration of myeloid and lymphoid cells. A malfunctioning or diverted immune response promotes tumor growth and metastasis. Recent advances had been made, by treating of certain tumor types, such as melanoma, with T-cell checkpoint inhibitors. This highlights the importance of understanding the molecular mechanisms underlying the crosstalk between tumors and their environment, in particular myeloid and lymphoid cells. Our aim was to study the contribution of the myeloid PI3K/PTEN-signaling pathway in the regulation of tumor-immune surveillance in murine models of cancer. We made use of conditional PTEN-deficient mice, which exhibit sustained activation of the PI3K-signaling axis in a variety of myeloid cell subsets such as macrophages and dendritic cells (DCs). In colitis-associated colon cancer (CAC), mice deficient in myeloid PTEN showed a markedly higher tumor burden and decreased survival. We attributed this observation to the increased presence of immune-modulatory conventional CD8α+ DCs in the spleen, whereas other relevant myeloid cell subsets were largely unaffected. Notably, we detected enhanced surface expression of PD-L1 and PD-L2 on these DCs. As a consequence, tumoricidal T-cell responses were hampered or redirected. Taken together, our findings indicated an unanticipated role for the PI3K/PTEN-signaling axis in the functional regulation of splenic antigen-presenting cells (APCs). Our data pointed at potential, indirect, tumoricidal effects of subclass-specific PI3K inhibitors, which are currently under clinical investigation for treatment of tumors, via myeloid cell activation. PMID:27622019

  20. Impaired Eye-Blink Conditioning in waggler, a Mutant Mouse With Cerebellar BDNF Deficiency

    PubMed Central

    Bao, Shaowen; Chen, Lu; Qiao, Xiaoxi; Knusel, Beat; Thompson, Richard F.

    1998-01-01

    In addition to their trophic functions, neurotrophins are also implicated in synaptic modulation and learning and memory. Although gene knockout techniques have been used widely in studying the roles of neurotrophins at molecular and cellular levels, behavioral studies using neurotrophin knockouts are limited by the early-onset lethality and various sensory deficits associated with the gene knockout mice. In the present study, we found that in a spontaneous mutant mouse, waggler, the expression of brain-derived neurotrophic factor (BDNF) was selectively absent in the cerebellar granule cells. The cytoarchitecture of the waggler cerebellum appeared to be normal at the light microscope level. The mutant mice exhibited no sensory deficits to auditory stimuli or heat-induced pain. However, they were massively impaired in classic eye-blink conditioning. These results suggest that BDNF may have a role in normal cerebellar neuronal function, which, in turn, is essential for classic eye-blink conditioning. PMID:10454360

  1. MCP-1 deficiency causes altered inflammation with impaired skeletal muscle regeneration.

    PubMed

    Shireman, Paula K; Contreras-Shannon, Verónica; Ochoa, Oscar; Karia, Bijal P; Michalek, Joel E; McManus, Linda M

    2007-03-01

    We examined the role of MCP-1, a potent chemotactic and activating factor for macrophages, in perfusion, inflammation, and skeletal muscle regeneration post-ischemic injury. MCP-1-/- or C57Bl/6J control mice [wild-type (WT)] underwent femoral artery excision (FAE). Muscles were collected for histology, assessment of tissue chemokines, and activity measurements of lactate dehydrogenase (LDH) and myeloperoxidase. In MCP-1-/- mice, restoration of perfusion was delayed, and LDH and fiber size, indicators of muscle regeneration, were decreased. Altered inflammation was observed with increased neutrophil accumulation in MCP-1-/- versus WT mice at Days 1 and 3 (P< or =0.003), whereas fewer macrophages were present in MCP-1-/- mice at Day 3. As necrotic tissue was removed in WT mice, macrophages decreased (Day 7). In contrast, macrophage accumulation in MCP-1-/- was increased in association with residual necrotic tissue and impaired muscle regeneration. Consistent with altered inflammation, neutrophil chemotactic factors (keratinocyte-derived chemokine and macrophage inflammatory protein-2) were increased at Day 1 post-FAE. The macrophage chemotactic factor MCP-5 was increased significantly in WT mice at Day 3 compared with MCP-1-/- mice. However, at post-FAE Day 7, MCP-5 was significantly elevated in MCP-1-/- mice versus WT mice. Addition of exogenous MCP-1 did not induce proliferation in murine myoblasts (C2C12 cells) in vitro. MCP-1 is essential for reperfusion and the successful completion of normal skeletal muscle regeneration after ischemic tissue injury. Impaired muscle regeneration in MCP-1-/- mice suggests an important role for macrophages and MCP-1 in tissue reparative processes. PMID:17135576

  2. Impaired splenic function and tuftsin deficiency in patients with intestinal failure on long term intravenous nutrition

    PubMed Central

    Zoli, G; Corazza, G; Wood, S; Bartoli, R; Gasbarrini, G; Farthing, M

    1998-01-01

    Background—Reticuloendothelial system function is impaired in humans receiving lipid regimens. 
Aims—To evaluate the effects of long term administration of long chain triglyceride emulsions on reticuloendothelial system function. 
Methods—Splenic function and tuftsin activity were measured in 20 patients on intravenous nutrition for intestinal failure, 20 patients with Crohn's disease who were not receiving intravenous nutrition, and 50 healthy controls. 
Results—Pitted red cells counts in patients on intravenous nutrition (8.0%) were significantly higher (p<0.001) than in healthy controls (0.6%) and in patients with Crohn's disease (0.9%). No difference was found between healthy controls and patients with Crohn's disease. There was a correlation (r=0.50; p<0.03) between percentage of pitted red cells and duration of intravenous nutrition. Tuftsin activity was significantly reduced in the intravenous nutrition patient group (6%) compared with both disease controls (16.5%, p<0.01) and healthy volunteers (17.8%, p<0.001) . An inverse correlation between tuftsin activity and pitted red cell percentage was found in the patients on intravenous nutrition (rs =−0.44, p<0.05). No relation was found in the patients on intravenous nutrition between pitted red cell percentage or tuftsin activity and type of disease, percentage of ideal body weight, residual length of small intestine, or administration (quantity and frequency) of lipid emulsion. Eight patients on intravenous nutrition had serious infections within the previous 12months. 
Conclusions—Patients with a short bowel treated with long term intravenous nutrition have impaired splenic function, reduced tuftsin activity, and an increased risk of infection. 

 Keywords: splenic function; hyposplenism; tuftsin; home parenteral nutrition; short bowel syndrome PMID:9824601

  3. Impaired Erectile Function in CD73-deficient Mice with Reduced Endogenous Penile Adenosine Production

    PubMed Central

    Wen, Jiaming; Dai, Yingbo; Zhang, Yujin; Zhang, Weiru; Kellems, Rodney E.; Xia, Yang

    2012-01-01

    Introduction Adenosine has been implicated in normal and abnormal penile erection. However, a direct role of endogenous adenosine in erectile physiology and pathology has not been established. Aim To determine the functional role of endogenous adenosine production in erectile function. Methods CD73-deficient mice (CD73−/−) and age-matched wild-type (WT) mice were used. Some WT mice were treated with alpha, beta-methylene adenosine diphosphate (ADP) (APCP), a CD73-specific inhibitor. High-performance liquid chromatography was used to measure adenosine levels in mouse penile tissues. In vivo assessment of intracorporal pressure (ICP) normalized to mean arterial pressure (MAP) in response to electrical stimulation (ES) of the cavernous nerve was used. Main Outcome Measurement The main outcome measures of this study were the in vivo assessment of initiation and maintenance of penile erection in WT mice and mice with deficiency in CD73 (ecto-5′-nucleotidase), a key cell-surface enzyme to produce extracellular adenosine. Results Endogenous adenosine levels were elevated in the erected state induced by ES of cavernous nerve compared to the flaccid state in WT mice but not in CD73−/− mice. At cellular levels, we identified that CD73 was highly expressed in the neuronal, endothelial cells, and vascular smooth muscle cells in mouse penis. Functionally, we found that the ratio of ES-induced ICP to MAP in CD73−/− mice was reduced from 0.48 ± 0.03 to 0.33 ± 0.05 and ES-induced slope was reduced from 0.30 ± 0.13 mm Hg/s to 0.15 ± 0.05 mm Hg/s (both P < 0.05). The ratio of ES-induced ICP to MAP in APCP-treated WT mice was reduced from 0.49 ± 0.03 to 0.38 ± 0.06 and ES-induced slope was reduced from 0.29 ± 0.11 mm Hg/s to 0.19 ± 0.04 mm Hg/s (both P < 0.05). Conclusion Overall, our findings demonstrate that CD73-dependent production of endogenous adenosine plays a direct role in initiation and maintenance of penile erection. PMID:21595838

  4. Folate- and vitamin B12-deficient diet during gestation and lactation alters cerebellar synapsin expression via impaired influence of estrogen nuclear receptor α.

    PubMed

    Pourié, Grégory; Martin, Nicolas; Bossenmeyer-Pourié, Carine; Akchiche, Nassila; Guéant-Rodriguez, Rosa Maria; Geoffroy, Andréa; Jeannesson, Elise; El Hajj Chehadeh, Sarah; Mimoun, Khalid; Brachet, Patrick; Koziel, Violette; Alberto, Jean-Marc; Helle, Deborah; Debard, Renée; Leininger, Brigitte; Daval, Jean-Luc; Guéant, Jean-Louis

    2015-09-01

    Deficiency in the methyl donors vitamin B12 and folate during pregnancy and postnatal life impairs proper brain development. We studied the consequences of this combined deficiency on cerebellum plasticity in offspring from rat mothers subjected to deficient diet during gestation and lactation and in rat neuroprogenitor cells expressing cerebellum markers. The major proteomic change in cerebellum of 21-d-old deprived females was a 2.2-fold lower expression of synapsins, which was confirmed in neuroprogenitors cultivated in the deficient condition. A pathway analysis suggested that these proteomic changes were related to estrogen receptor α (ER-α)/Src tyrosine kinase. The influence of impaired ER-α pathway was confirmed by abnormal negative geotaxis test at d 19-20 and decreased phsophorylation of synapsins in deprived females treated by ER-α antagonist 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole dihydrochloride (MPP). This effect was consistent with 2-fold decreased expression and methylation of ER-α and subsequent decreased ER-α/PPAR-γ coactivator 1 α (PGC-1α) interaction in deficiency condition. The impaired ER-α pathway led to decreased expression of synapsins through 2-fold decreased EGR-1/Zif-268 transcription factor and to 1.7-fold reduced Src-dependent phosphorylation of synapsins. The treatment of neuroprogenitors with either MPP or PP1 (4-(4'-phenoxyanilino)-6,7-dimethoxyquinazoline, 6,7-dimethoxy-N-(4-phenoxyphenyl)-4-quinazolinamine, SKI-1, Src-l1) Src inhibitor produced similar effects. In conclusion, the deficiency during pregnancy and lactation impairs the expression of synapsins through a deregulation of ER-α pathway. PMID:26018677

  5. DOCK8 deficiency impairs CD8 T cell survival and function in humans and mice.

    PubMed

    Randall, Katrina L; Chan, Stephanie S-Y; Ma, Cindy S; Fung, Ivan; Mei, Yan; Yabas, Mehmet; Tan, Andy; Arkwright, Peter D; Al Suwairi, Wafaa; Lugo Reyes, Saul Oswaldo; Yamazaki-Nakashimada, Marco A; Garcia-Cruz, Maria de la Luz; Smart, Joanne M; Picard, Capucine; Okada, Satoshi; Jouanguy, Emmanuelle; Casanova, Jean-Laurent; Lambe, Teresa; Cornall, Richard J; Russell, Sarah; Oliaro, Jane; Tangye, Stuart G; Bertram, Edward M; Goodnow, Christopher C

    2011-10-24

    In humans, DOCK8 immunodeficiency syndrome is characterized by severe cutaneous viral infections. Thus, CD8 T cell function may be compromised in the absence of DOCK8. In this study, by analyzing mutant mice and humans, we demonstrate a critical, intrinsic role for DOCK8 in peripheral CD8 T cell survival and function. DOCK8 mutation selectively diminished the abundance of circulating naive CD8 T cells in both species, and in DOCK8-deficient humans, most CD8 T cells displayed an exhausted CD45RA(+)CCR7(-) phenotype. Analyses in mice revealed the CD8 T cell abnormalities to be cell autonomous and primarily postthymic. DOCK8 mutant naive CD8 T cells had a shorter lifespan and, upon encounter with antigen on dendritic cells, exhibited poor LFA-1 synaptic polarization and a delay in the first cell division. Although DOCK8 mutant T cells underwent near-normal primary clonal expansion after primary infection with recombinant influenza virus in vivo, they showed greatly reduced memory cell persistence and recall. These findings highlight a key role for DOCK8 in the survival and function of human and mouse CD8 T cells. PMID:22006977

  6. Claudin-16 Deficiency Impairs Tight Junction Function in Ameloblasts, Leading to Abnormal Enamel Formation.

    PubMed

    Bardet, Claire; Courson, Frédéric; Wu, Yong; Khaddam, Mayssam; Salmon, Benjamin; Ribes, Sandy; Thumfart, Julia; Yamaguti, Paulo M; Rochefort, Gael Y; Figueres, Marie-Lucile; Breiderhoff, Tilman; Garcia-Castaño, Alejandro; Vallée, Benoit; Le Denmat, Dominique; Baroukh, Brigitte; Guilbert, Thomas; Schmitt, Alain; Massé, Jean-Marc; Bazin, Dominique; Lorenz, Georg; Morawietz, Maria; Hou, Jianghui; Carvalho-Lobato, Patricia; Manzanares, Maria Cristina; Fricain, Jean-Christophe; Talmud, Deborah; Demontis, Renato; Neves, Francisco; Zenaty, Delphine; Berdal, Ariane; Kiesow, Andreas; Petzold, Matthias; Menashi, Suzanne; Linglart, Agnes; Acevedo, Ana Carolina; Vargas-Poussou, Rosa; Müller, Dominik; Houillier, Pascal; Chaussain, Catherine

    2016-03-01

    Claudin-16 protein (CLDN16) is a component of tight junctions (TJ) with a restrictive distribution so far demonstrated mainly in the kidney. Here, we demonstrate the expression of CLDN16 also in the tooth germ and show that claudin-16 gene (CLDN16) mutations result in amelogenesis imperfecta (AI) in the 5 studied patients with familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC). To investigate the role of CLDN16 in tooth formation, we studied a murine model of FHHNC and showed that CLDN16 deficiency led to altered secretory ameloblast TJ structure, lowering of extracellular pH in the forming enamel matrix, and abnormal enamel matrix protein processing, resulting in an enamel phenotype closely resembling human AI. This study unravels an association of FHHNC owing to CLDN16 mutations with AI, which is directly related to the loss of function of CLDN16 during amelogenesis. Overall, this study indicates for the first time the importance of a TJ protein in tooth formation and underlines the need to establish a specific dental follow-up for these patients. PMID:26426912

  7. Neuropilin 1 deficiency on CD4+Foxp3+ regulatory T cells impairs mouse melanoma growth

    PubMed Central

    Hutzler, Marina; Abel, Simone; Alter, Christina; Stockmann, Christian; Kliche, Stefanie; Albert, Juliane; Sparwasser, Tim; Sakaguchi, Shimon; Westendorf, Astrid M.; Schadendorf, Dirk; Buer, Jan; Helfrich, Iris

    2012-01-01

    Infiltration of Foxp3+ regulatory T (T reg) cells is considered to be a critical step during tumor development and progression. T reg cells supposedly suppress locally an effective anti-tumor immune response within tumor tissues, although the precise mechanism by which T reg cells infiltrate the tumor is still unclear. We provide evidence that Neuropilin 1 (Nrp-1), highly expressed by Foxp3+ T reg cells, regulates the immunological anti-tumor control by guiding T reg cells into the tumor in response to tumor-derived vascular endothelial growth factor (VEGF). We demonstrate for the first time that T cell–specific ablation of Nrp-1 expression results in a significant breakdown in tumor immune escape in various transplantation models and in a spontaneous, endogenously driven melanoma model associated with strongly reduced tumor growth and prolonged tumor-free survival. Strikingly, numbers of tumor-infiltrating Foxp3+ T reg cells were significantly reduced accompanied by enhanced activation of CD8+ T cells within tumors of T cell–specific Nrp-1–deficient mice. This phenotype can be reversed by adoptive transfer of Nrp-1+ T reg cells from wild-type mice. Thus, our data strongly suggest that Nrp-1 acts as a key mediator of Foxp3+ T reg cell infiltration into the tumor site resulting in a dampened anti-tumor immune response and enhanced tumor progression. PMID:23045606

  8. M line–deficient titin causes cardiac lethality through impaired maturation of the sarcomere

    PubMed Central

    Weinert, Stefanie; Bergmann, Nora; Luo, Xiuju; Erdmann, Bettina; Gotthardt, Michael

    2006-01-01

    Titin, the largest protein known to date, has been linked to sarcomere assembly and function through its elastic adaptor and signaling domains. Titin's M-line region contains a unique kinase domain that has been proposed to regulate sarcomere assembly via its substrate titin cap (T-cap). In this study, we use a titin M line–deficient mouse to show that the initial assembly of the sarcomere does not depend on titin's M-line region or the phosphorylation of T-cap by the titin kinase. Rather, titin's M-line region is required to form a continuous titin filament and to provide mechanical stability of the embryonic sarcomere. Even without titin integrating into the M band, sarcomeres show proper spacing and alignment of Z discs and M bands but fail to grow laterally and ultimately disassemble. The comparison of disassembly in the developing and mature knockout sarcomere suggests diverse functions for titin's M line in embryonic development and the adult heart that not only involve the differential expression of titin isoforms but also of titin-binding proteins. PMID:16702235

  9. Impaired conditioned fear response and startle reactivity in epinephrine-deficient mice.

    PubMed

    Toth, Mate; Ziegler, Michael; Sun, Ping; Gresack, Jodi; Risbrough, Victoria

    2013-02-01

    Norepinephrine and epinephrine signaling is thought to facilitate cognitive processes related to emotional events and heightened arousal; however, the specific role of epinephrine in these processes is less known. To investigate the selective impact of epinephrine on arousal and fear-related memory retrieval, mice unable to synthesize epinephrine (phenylethanolamine N-methyltransferase knockout, PNMT-KO) were tested for contextual and cued-fear conditioning. To assess the role of epinephrine in other cognitive and arousal-based behaviors these mice were also tested for acoustic startle, prepulse inhibition, novel object recognition, and open-field activity. Our results show that compared with wild-type mice, PNMT-KO mice showed reduced contextual fear but normal cued fear. Mice exhibited normal memory performance in the short-term version of the novel object recognition task, suggesting that PNMT mice exhibit more selective memory effects on highly emotional and/or long-term memories. Similarly, open-field activity was unaffected by epinephrine deficiency, suggesting that differences in freezing are not related to changes in overall anxiety or exploratory drive. Startle reactivity to acoustic pulses was reduced in PNMT-KO mice, whereas prepulse inhibition was increased. These findings provide further evidence for a selective role of epinephrine in contextual-fear learning and support its potential role in acoustic startle. PMID:23268986

  10. Prostacyclin Prevents Pericyte Loss and Demyelination Induced by Lysophosphatidylcholine in the Central Nervous System*

    PubMed Central

    Muramatsu, Rieko; Kuroda, Mariko; Matoba, Ken; Lin, Hsiaoyun; Takahashi, Chisato; Koyama, Yoshihisa; Yamashita, Toshihide

    2015-01-01

    Pericytes play pivotal roles in physiological and pathophysiological conditions in the central nervous system. As pericytes prevent vascular leakage, they can halt neuronal damage stemming from a compromised blood-brain barrier. Therefore, pericytes may be a good target for the treatment of neurodegenerative disorders, although evidence is lacking. In this study, we show that prostacyclin attenuates lysophosphatidylcholine (LPC)-mediated vascular dysfunction through pericyte protection in the adult mouse spinal cord. LPC decreased the number of pericytes in an in vitro blood-brain barrier model, and this decrease was prevented by iloprost treatment, a prostacyclin analog. Intrathecal administration of iloprost attenuated vascular barrier disruption after LPC injection in the mouse spinal cord. Furthermore, iloprost treatment diminished demyelination and motor function deficits in mice injected with LPC. These results support the notion that prostacyclin acts on pericytes to maintain vascular barrier integrity. PMID:25795781

  11. Inhibition of GSK-3β Rescues the Impairments in Bone Formation and Mechanical Properties Associated with Fracture Healing in Osteoblast Selective Connexin 43 Deficient Mice

    PubMed Central

    Loiselle, Alayna E.; Lloyd, Shane A. J.; Paul, Emmanuel M.; Lewis, Gregory S.; Donahue, Henry J.

    2013-01-01

    Connexin 43 (Cx43) is the most abundant gap junction protein in bone and is required for osteoblastic differentiation and bone homeostasis. During fracture healing, Cx43 is abundantly expressed in osteoblasts and osteocytes, while Cx43 deficiency impairs bone formation and healing. In the present study we selectively deleted Cx43 in the osteoblastic lineage from immature osteoblasts through osteocytes and tested the hypothesis that Cx43 deficiency results in delayed osteoblastic differentiation and impaired restoration of biomechanical properties due to attenuated β-catenin expression relative to wild type littermates. Here we show that Cx43 deficiency results in alterations in the mineralization and remodeling phases of healing. In Cx43 deficient fractures the mineralization phase is marked by delayed expression of osteogenic genes. Additionally, the decrease in the RankL/ Opg ratio, osteoclast number and osteoclast size suggest decreased osteoclast bone resorption and remodeling. These changes in healing result in functional deficits as shown by a decrease in ultimate torque at failure. Consistent with these impairments in healing, β-catenin expression is attenuated in Cx43 deficient fractures at 14 and 21 days, while Sclerostin (Sost) expression, a negative regulator of bone formation is increased in Cx43cKO fractures at 21 days, as is GSK-3β, a key component of the β-catenin proteasomal degradation complex. Furthermore, we show that alterations in healing in Cx43 deficient fractures can be rescued by inhibiting GSK-3β activity using Lithium Chloride (LiCl). Treatment of Cx43 deficient mice with LiCl restores both normal bone formation and mechanical properties relative to LiCl treated WT fractures. This study suggests that Cx43 is a potential therapeutic target to enhance fracture healing and identifies a previously unknown role for Cx43 in regulating β-catenin expression and thus bone formation during fracture repair. PMID:24260576

  12. Neurogenin 3-Specific Dipeptidyl Peptidase-2 Deficiency Causes Impaired Glucose Tolerance, Insulin Resistance, and Visceral Obesity

    PubMed Central

    Danilova, Olga V.; Tai, Albert K.; Mele, Deanna A.; Beinborn, Martin; Leiter, Andrew B.; Greenberg, Andrew S.; Perfield, James W.; DeFuria, Jason; Singru, Praful S.; Lechan, Ronald M.; Huber, Brigitte T.

    2009-01-01

    The control of glucose metabolism is a complex process, and dysregulation at any level can cause impaired glucose tolerance and insulin resistance. These two defects are well-known characteristics associated with obesity and onset of type 2 diabetes. Here we introduce the N-terminal dipeptidase, DPP2, as a novel regulator of the glucose metabolism. We generated mice with a neurogenin 3 (NGN3)-specific DPP2 knockdown (kd) to explore a possible role of DPP2 in maintaining metabolic homeostasis. These mice spontaneously developed hyperinsulinemia, glucose intolerance, and insulin resistance by 4 months of age. In addition, we observed an increase in food intake in DPP2 kd mice, which was associated with a significant increase in adipose tissue mass and enhanced liver steatosis but no difference in body weight. In accordance with these findings, the mutant mice had a higher rate of respiratory exchange than the control littermates. This phenotype was exacerbated with age and when challenged with a high-fat diet. We report, for the first time, that DPP2 enzyme activity is essential for preventing hyperinsulinemia and maintaining glucose homeostasis. Interestingly, the phenotype of NGN3-DPP2 kd mice is opposite that of DPP4 knockout mice with regard to glucose metabolism, namely the former have normal glucagon-like peptide 1 levels but present with glucose intolerance, whereas the latter have increased glucagon-like peptide 1, which is accompanied by augmented glucose tolerance. PMID:19819973

  13. Age-related prefrontal impairments implicate deficient prediction of future reward in older adults.

    PubMed

    Eppinger, Ben; Heekeren, Hauke R; Li, Shu-Chen

    2015-08-01

    Foresighted decision-making depends on the ability to learn the value of future outcomes and the sequential choices necessary to achieve them. Using a 3-stage Markov decision task and functional magnetic resonance imaging, we investigated age differences in the ability to extract state transition structures while learning to predict future reward. In younger adults learning was associated with enhanced activity in the prefrontal cortex (PFC). In older adults (OA) we found no evidence for PFC recruitment. However, high-performing OA showed enhanced striatal activity, suggesting that they may engage in a model-free (experience-based) learning strategy. Change point analyses revealed that in younger adults learning was characterized by distinct and abrupt shifts in PFC activity, which were predictive of behavioral change points. In OA PFC activity was less pronounced and not predictive of behavior. Our findings suggest that age-related impairments in learning future reward value can be attributed to a deficit in extracting sequential state transition structures. This deficit may lead to myopic decisions in OA if contextual information has to be temporally integrated. PMID:26004018

  14. Shp2 Deficiency Impairs the Inflammatory Response Against Haemophilus influenzae by Regulating Macrophage Polarization.

    PubMed

    Zhao, Lifang; Xia, Jingyan; Li, Tiantian; Zhou, Hui; Ouyang, Wei; Hong, Zhuping; Ke, Yuehai; Qian, Jing; Xu, Feng

    2016-08-15

    Macrophages can polarize and differentiate to regulate initiation, development, and cessation of inflammation during pulmonary infection with nontypeable Haemophilus influenzae (NTHi). However, the underlying molecular mechanisms driving macrophage phenotypic differentiation are largely unclear. Our study investigated the role of Shp2, a Src homology 2 domain-containing phosphatase, in the regulation of pulmonary inflammation and bacterial clearance. Shp2 levels were increased upon NTHi stimulation. Selective inhibition of Shp2 in mice led to an attenuated inflammatory response by skewing macrophages toward alternatively activated macrophage (M2) polarization. Upon pulmonary NTHi infection, Shp2(-/-) mice, in which the gene encoding Shp2 in monocytes/macrophages was deleted, showed an impaired inflammatory response and decreased antibacterial ability, compared with wild-type controls. In vitro data demonstrated that Shp2 regulated activated macrophage (M1) gene expression via activation of p65-nuclear factor-κB signaling, independent of p38 and extracellular regulated kinase-mitogen-activated proteins kinase signaling pathways. Taken together, our study indicates that Shp2 is required to orchestrate macrophage function and regulate host innate immunity against pulmonary bacterial infection. PMID:27330052

  15. Tumor necrosis factor-alpha deficiency impairs host defense against Streptococcus pneumoniae

    PubMed Central

    Jeong, Dong-Gu; Seo, Jin-Hee; Heo, Seung-Ho; Choi, Yang-Kyu

    2015-01-01

    Streptococcus pneumoniae is a major human pathogen that is involved in community-acquired pneumonia. Tumor necrosis factor-alpha (TNF-α) is a pro-inflammatory cytokine that activates immune responses against infection, invasion, injury, or inflammation. To study the role of TNF-α during S. pneumoniae infection, a murine pneumococcal pneumonia model was used. We intranasally infected C57BL/6J wild-type (WT) and TNF-α knockout (KO) mice with S. pneumoniae D39 serotype 2. In TNF-α KO mice, continuous and distinct loss of body weight, and low survival rates were observed. Bacterial counts in the lungs and blood of TNF-α KO mice were significantly higher than those in WT mice. Histopathological lesions in the spleen of TNF-α KO mice were more severe than those in WT mice. In TNF-α KO mice, severe depletion of white pulp was observed and the number of apoptotic cells was significantly increased. Interferon-gamma (IFN-γ), IL-12p70 and IL-10 levels in serum were significantly increased in TNF-α KO mice. TNF-α is clearly involved in the regulation of S. pneumoniae infections. Early death and low survival rates of TNF-α KO mice were likely caused by a combination of impaired bacterial clearance and damage to the spleen. Our findings suggest that TNF-α plays a critical role in protecting the host from systemic S. pneumoniae infection. PMID:26155202

  16. Impaired fertility in mice deficient for the testicular germ-cell protease PC4

    PubMed Central

    Mbikay, Majambu; Tadros, Haidy; Ishida, Norito; Lerner, Charlie P.; De Lamirande, Eve; Chen, Andrew; El-Alfy, Mohamed; Clermont, Yves; Seidah, Nabil G.; Chrétien, Michel; Gagnon, Claude; Simpson, Elizabeth M.

    1997-01-01

    PC4 is a member of the proprotein convertase family of serine proteases implicated in the processing of a variety of polypeptides including prohormones, proneuropeptides, and cell surface proteins. In rodents, PC4 transcripts have been detected in spermatocytes and round spermatids exclusively, suggesting a reproductive function for this enzyme. In an effort to elucidate this function, we have disrupted its locus (Pcsk4) by homologous recombination in embryonic stem cells and have produced mice carrying the mutation. In intercrosses of heterozygous mutant mice, there was low transmission of the mutant Pcsk4 allele to the progeny, resulting in lower than expected incidence of heterozygosity and null homozygosity. The in vivo fertility of homozygous mutant males was severely impaired in the absence of any evident spermatogenic abnormality. In vitro, the fertilizing ability of Pcsk4 null spermatozoa was also found to be significantly reduced. Moreover, eggs fertilized by these spermatozoa failed to grow to the blastocyst stage. These results suggest that PC4 in the male may be important for achieving fertilization and for supporting early embryonic development in mice. PMID:9192653

  17. Numb deficiency in cerebellar Purkinje cells impairs synaptic expression of metabotropic glutamate receptor and motor coordination.

    PubMed

    Zhou, Liang; Yang, Dong; Wang, De-Juan; Xie, Ya-Jun; Zhou, Jia-Huan; Zhou, Lin; Huang, Hao; Han, Shuo; Shao, Chong-Yu; Li, Hua-Shun; Zhu, J Julius; Qiu, Meng-Sheng; De Zeeuw, Chris I; Shen, Ying

    2015-12-15

    Protein Numb, first identified as a cell-fate determinant in Drosophila, has been shown to promote the development of neurites in mammals and to be cotransported with endocytic receptors in clathrin-coated vesicles in vitro. Nevertheless, its function in mature neurons has not yet been elucidated. Here we show that cerebellar Purkinje cells (PCs) express high levels of Numb during adulthood and that conditional deletion of Numb in PCs is sufficient to impair motor coordination despite maintenance of a normal cerebellar cyto-architecture. Numb proved to be critical for internalization and recycling of metabotropic glutamate 1 receptor (mGlu1) in PCs. A significant decrease of mGlu1 and an inhibition of long-term depression at the parallel fiber-PC synapse were observed in conditional Numb knockout mice. Indeed, the trafficking of mGlu1 induced by agonists was inhibited significantly in these mutants, but the expression of ionotropic glutamate receptor subunits and of mGlu1-associated proteins was not affected by the loss of Numb. Moreover, transient and persistent forms of mGlu1 plasticity were robustly induced in mutant PCs, suggesting that they do not require mGlu1 trafficking. Together, our data demonstrate that Numb is a regulator for constitutive expression and dynamic transport of mGlu1. PMID:26621723

  18. Impaired maturation of large dense-core vesicles in muted-deficient adrenal chromaffin cells.

    PubMed

    Hao, Zhenhua; Wei, Lisi; Feng, Yaqin; Chen, Xiaowei; Du, Wen; Ma, Jing; Zhou, Zhuan; Chen, Liangyi; Li, Wei

    2015-04-01

    The large dense-core vesicle (LDCV), a type of lysosome-related organelle, is involved in the secretion of hormones and neuropeptides in specialized secretory cells. The granin family is a driving force in LDCV biogenesis, but the machinery for granin sorting to this biogenesis pathway is largely unknown. The mu mutant mouse, which carries a spontaneous null mutation on the Muted gene (also known as Bloc1s5), which encodes a subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), is a mouse model of Hermansky-Pudlak syndrome. Here, we found that LDCVs were enlarged in mu adrenal chromaffin cells. Chromogranin A (CgA, also known as CHGA) was increased in mu adrenals and muted-knockdown cells. The increased CgA in mu mice was likely due a failure to export this molecule out of immature LDCVs, which impairs LDCV maturation and docking. In mu chromaffin cells, the size of readily releasable pool and the vesicle release frequency were reduced. Our studies suggest that the muted protein is involved in the selective export of CgA during the biogenesis of LDCVs. PMID:25673877

  19. Preserved otolith organ function in caspase-3 deficient mice with impaired horizontal semicircular canal function

    PubMed Central

    Armstrong, Patrick A; Wood, Scott J; Shimizu, Naoki; Kuster, Kael; Perachio, Adrian; Makishima, Tomoko

    2015-01-01

    Genetically engineered mice are valuable models for elucidation of auditory and vestibular pathology. Our goal was to establish a comprehensive vestibular function testing system in mice using: 1) horizontal angular vestibular-ocular reflex (hVOR) to evaluate semicircular canal function, and 2) otolith-ocular reflex (OOR) to evaluate otolith organ function, and to validate the system by characterizing mice with vestibular dysfunction. We used pseudo-off vertical axis rotation (pOVAR) to induce an otolith-only stimulus using a custom-made centrifuge. For the OOR, horizontal slow phase eye velocity (HEV) and vertical eye position (VEP) was evaluated as a function of acceleration. Using this system, we characterized hVOR and OOR in the caspase-3 (Casp3) mutant mice. Casp3 −/− mice had severely impaired hVOR gain, while Casp3 +/− mice had an intermediate response compared to WT mice. Evaluation of OOR revealed that at low to mid frequencies and stimulus intensity, Casp3 mutants and WT mice had similar responses. At higher frequencies and stimulus intensity, the Casp3 mutants displayed mildly reduced otolith organ related responses. These findings suggest that the Casp3 gene is important for the proper function of the semicircular canals but less important for the otolith organ function. PMID:25827332

  20. Pericytes Derived from Adipose-Derived Stem Cells Protect against Retinal Vasculopathy

    PubMed Central

    Mendel, Thomas A.; Clabough, Erin B. D.; Kao, David S.; Demidova-Rice, Tatiana N.; Durham, Jennifer T.; Zotter, Brendan C.; Seaman, Scott A.; Cronk, Stephen M.; Rakoczy, Elizabeth P.; Katz, Adam J.; Herman, Ira M.; Peirce, Shayn M.; Yates, Paul A.

    2013-01-01

    Background Retinal vasculopathies, including diabetic retinopathy (DR), threaten the vision of over 100 million people. Retinal pericytes are critical for microvascular control, supporting retinal endothelial cells via direct contact and paracrine mechanisms. With pericyte death or loss, endothelial dysfunction ensues, resulting in hypoxic insult, pathologic angiogenesis, and ultimately blindness. Adipose-derived stem cells (ASCs) differentiate into pericytes, suggesting they may be useful as a protective and regenerative cellular therapy for retinal vascular disease. In this study, we examine the ability of ASCs to differentiate into pericytes that can stabilize retinal vessels in multiple pre-clinical models of retinal vasculopathy. Methodology/Principal Findings We found that ASCs express pericyte-specific markers in vitro. When injected intravitreally into the murine eye subjected to oxygen-induced retinopathy (OIR), ASCs were capable of migrating to and integrating with the retinal vasculature. Integrated ASCs maintained marker expression and pericyte-like morphology in vivo for at least 2 months. ASCs injected after OIR vessel destabilization and ablation enhanced vessel regrowth (16% reduction in avascular area). ASCs injected intravitreally before OIR vessel destabilization prevented retinal capillary dropout (53% reduction). Treatment of ASCs with transforming growth factor beta (TGF-β1) enhanced hASC pericyte function, in a manner similar to native retinal pericytes, with increased marker expression of smooth muscle actin, cellular contractility, endothelial stabilization, and microvascular protection in OIR. Finally, injected ASCs prevented capillary loss in the diabetic retinopathic Akimba mouse (79% reduction 2 months after injection). Conclusions/Significance ASC-derived pericytes can integrate with retinal vasculature, adopting both pericyte morphology and marker expression, and provide functional vascular protection in multiple murine models of

  1. CCR2 Deficiency Impairs Macrophage Infiltration and Improves Cognitive Function after Traumatic Brain Injury

    PubMed Central

    Niemi, Erene C.; Wang, Sarah H.; Lee, Chih Cheng; Bingham, Deborah; Zhang, Jiasheng; Cozen, Myrna L.; Charo, Israel; Huang, Eric J.; Liu, Jialing; Nakamura, Mary C.

    2014-01-01

    Abstract Traumatic brain injury (TBI) provokes inflammatory responses, including a dramatic rise in brain macrophages in the area of injury. The pathway(s) responsible for macrophage infiltration of the traumatically injured brain and the effects of macrophages on functional outcomes are not well understood. C-C-chemokine receptor 2 (CCR2) is known for directing monocytes to inflamed tissues. To assess the role of macrophages and CCR2 in TBI, we determined outcomes in CCR2-deficient (Ccr2−/−) mice in a controlled cortical impact model. We quantified brain myeloid cell numbers post-TBI by flow cytometry and found that Ccr2−/− mice had greatly reduced macrophage numbers (∼80–90% reduction) early post-TBI, compared with wild-type mice. Motor, locomotor, and cognitive outcomes were assessed. Lack of Ccr2 improved locomotor activity with less hyperactivity in open field testing, but did not affect anxiety levels or motor coordination on the rotarod three weeks after TBI. Importantly, Ccr2−/− mice demonstrated greater spatial learning and memory, compared with wild-type mice eight weeks after TBI. Although there was no difference in the volume of tissue loss, Ccr2−/− mice had significantly increased neuronal density in the CA1-CA3 regions of the hippocampus after TBI, compared with wild-type mice. These data demonstrate that Ccr2 directs the majority of macrophage homing to the brain early after TBI and indicates that Ccr2 may facilitate harmful responses. Lack of Ccr2 improves functional recovery and neuronal survival. These results suggest that therapeutic blockade of CCR2-dependent responses may improve outcomes following TBI. PMID:24806994

  2. Impaired glucose and lipid metabolism in ageing aryl hydrocarbon receptor deficient mice

    PubMed Central

    Biljes, Daniel; Hammerschmidt-Kamper, Christiane; Kadow, Stephanie; Diel, Patrick; Weigt, Carmen; Burkart, Volker; Esser, Charlotte

    2015-01-01

    Disturbed homeostasis of glucose and lipid metabolism are dominant features of the so-called metabolic syndrome (MetS) and can increase the risk for the development of type 2 diabetes (T2D), a severe metabolic disease. T2D prevalence increases with age. The aryl hydrocarbon receptor (AHR) is a sensor of small molecules including dietary components. AHR has been identified as potential regulator of glucose homeostasis and lipid metabolism. Epidemiologically, exposure to xenobiotic AHR ligands such as polycyclic aromatic hydrocarbons is linked to T2D. We assess here the potential role of the AHR in disturbances of glucose and lipid metabolism in young (age 2-5 months) and old (age > 1,5 years) AHR-deficient (AHR KO) mice. Fasted young wildtype (WT) and AHR-KO mice displayed similar blood glucose kinetics after challenge with intra-peritoneal glucose injection. However, old AHR-KO mice showed lower tolerance than WT to i.p. administered glucose, i.e. glucose levels rose higher and returned more slowly to normal levels. Old mice had overall higher insulin levels than young mice, and old AHR-KO had a somewhat disturbed insulin kinetic in the serum after glucose challenge. Surprisingly, young AHR-KO mice had significantly lower triglycerides, cholesterol, high density lipoprotein values than WT, i.e., a dyslipidemic profile. With ageing, AHR-KO and WT mice did not differ in these lipid levels, except for slightly reduced levels of triglycerides and cholesterol. In conclusion, our findings in AHR KO mice suggest that AHR expression is relevant for the maintenance of glucose and lipid homeostasis in old mice. PMID:26664351

  3. Impaired hepcidin expression in alpha-1-antitrypsin deficiency associated with iron overload and progressive liver disease.

    PubMed

    Schaefer, Benedikt; Haschka, David; Finkenstedt, Armin; Petersen, Britt-Sabina; Theurl, Igor; Henninger, Benjamin; Janecke, Andreas R; Wang, Chia-Yu; Lin, Herbert Y; Veits, Lothar; Vogel, Wolfgang; Weiss, Günter; Franke, Andre; Zoller, Heinz

    2015-11-01

    Liver disease due to alpha-1-antitrypsin deficiency (A1ATD) is associated with hepatic iron overload in a subgroup of patients. The underlying cause for this association is unknown. The aim of the present study was to define the genetics of this correlation and the effect of alpha-1-antitrypsin (A1AT) on the expression of the iron hormone hepcidin. Full exome and candidate gene sequencing were carried out in a family with A1ATD and hepatic iron overload. Regulation of hepcidin expression by A1AT was studied in primary murine hepatocytes. Cells co-transfected with hemojuvelin (HJV) and matriptase-2 (MT-2) were used as a model to investigate the molecular mechanism of this regulation. Observed familial clustering of hepatic iron overload with A1ATD suggests a genetic cause, but genotypes known to be associated with hemochromatosis were absent. Individuals homozygous for the A1AT Z-allele with environmental or genetic risk factors such as steatosis or heterozygosity for the HAMP non-sense mutation p.Arg59* presented with severe hepatic siderosis. In hepatocytes, A1AT induced hepcidin mRNA expression in a dose-dependent manner. Experiments in overexpressing cells show that A1AT reduces cleavage of the hepcidin inducing bone morphogenetic protein co-receptor HJV via inhibition of the membrane-bound serine protease MT-2. The acute-phase protein A1AT is an inducer of hepcidin expression. Through this mechanism, A1ATD could be a trigger of hepatic iron overload in genetically predisposed individuals or patients with environmental risk factors for hepatic siderosis. PMID:26310624

  4. Fibroblast Growth Factor Receptor 3 Deficiency Does Not Impair the Osteoanabolic Action of Parathyroid Hormone on Mice

    PubMed Central

    Xie, Yangli; Yi, Lingxian; Weng, Tujun; Huang, Junlan; Luo, Fengtao; Jiang, Wanling; Xian, Cory J; Du, Xiaolan; Chen, Lin

    2016-01-01

    Summary: PTH stimulates bone formation in Fgfr3 knockout mice through promotion of proliferation and differentiation in osteoblasts. Introduction: Previous studies showed that endogenous fibroblast growth factor 2 (FGF-2) is required for parathyroid hormone (PTH)-stimulated bone anabolic effects, however, the exact mechanisms by which PTH stimulate bone formation and the function of FGF receptors in mediating these actions are not fully defined. FGF receptor 3 (FGFR3) has been characterized as an important regulator of bone metabolism and is confirmed to cross-talk with PTH/PTHrP signal in cartilage and bone development. Methods: Fgfr3 knockout and wild-type mice at 2-month-old and 4-month-old were intraperitoneally injected with PTH intermittently for 4 weeks and then the skeletal responses to PTH were assessed by dual energy X-ray absorptiometry (DEXA), micro-computed tomography (μCT) and bone histomorphometry. Results: Intermittent PTH treatment improved bone mineral density (BMD) and femoral mechanical properties in both Fgfr3-/- and wild-type mice. Histomorphometric analysis showed that bone formation and bone resorption were increased in both genotypes following PTH treatment. PTH treatment increased trabecular bone volume (BV/TV) in WT and Fgfr3-deficient mice. The anabolic response in Fgfr3-deficient and wild-type bone is characterized by an increase of both bone formation and resorption-related genes following PTH treatment. In addition, we found that Fgfr3 null osteoblasts (compared to wild-type controls) maintained normal abilities to response to PTH-stimulated increase of proliferation, differentiation, expression of osteoblastic marker genes (Cbfa1, Osteopontin and Osteocalcin), and phosphorylation of Erk1/2. Conclusions: Bone anabolic effects of PTH were not impaired by the absence of FGFR3, suggesting that the FGFR3 signaling may not be required for osteoanabolic effects of PTH activities. PMID:27489502

  5. Impaired hippocampal plasticity and altered neurogenesis in adult Ube3a maternal deficient mouse model for Angelman syndrome.

    PubMed

    Mardirossian, Sandrine; Rampon, Claire; Salvert, Denise; Fort, Patrice; Sarda, Nicole

    2009-12-01

    Angelman syndrome (AS) is a severe neurodevelopmental disorder characterized by mental retardation, seizures and sleep disturbances. It results from lack of the functional maternal allele of UBE3A gene. Ube3a maternal-deficient mice (Ube3a m-/p+), animal models for AS, are impaired in hippocampal-dependent learning tasks as compared with control (Ube3a m+/p+) mice. We first examined the basal expression of immediate early genes which expression is required for synaptic plasticity and memory formation. We found that basal expression of c-fos and Arc genes is reduced in the DG of Ube3a maternal deficient mice compared to their non-transgenic littermates. We then examined whether adult hippocampal neurogenesis, which likely serves as a mechanism toward brain plasticity, is altered in these transgenic mice. Neurogenesis occurs throughout life in mammalian dentate gyrus (DG) and recent findings suggest that newborn granule cells are involved in some forms of learning and memory. Whether maternal Ube3a deletion is detrimental on hippocampal neurogenesis is unclear. Herein, we show, using the mitotic marker Ki67, the birthdating marker 5-bromo-2'-dexoyuridine (BrdU) and the marker doublecortin (DCX) to respectively label cell proliferation, cell survival or young neuron production, that the Ube3a maternal deletion does not affect the proliferation nor the survival of newborn cells in the hippocampus. In contrast, using the postmitotic neuronal marker (NeuN), we show that Ube3a maternal deletion is associated with a lower fraction of BrdU+/NeuN+ newborn neurons among the population of surviving new cells in the hippocampus. Collectively, these findings suggest that some aspects of adult neurogenesis and plasticity are affected by Ube3a deletion and may contribute to the hippocampal dysfunction observed in AS mice. PMID:19782683

  6. SIRT3 deficiency impairs mitochondrial and contractile function in the heart.

    PubMed

    Koentges, Christoph; Pfeil, Katharina; Schnick, Tilman; Wiese, Sebastian; Dahlbock, Rabea; Cimolai, Maria C; Meyer-Steenbuck, Maximilian; Cenkerova, Katarina; Hoffmann, Michael M; Jaeger, Carsten; Odening, Katja E; Kammerer, Bernd; Hein, Lutz; Bode, Christoph; Bugger, Heiko

    2015-01-01

    Sirtuin 3 (SIRT3) is a mitochondrial NAD(+)-dependent deacetylase that regulates energy metabolic enzymes by reversible protein lysine acetylation in various extracardiac tissues. The role of SIRT3 in myocardial energetics and in the development of mitochondrial dysfunction in cardiac pathologies, such as the failing heart, remains to be elucidated. To investigate the role of SIRT3 in the regulation of myocardial energetics and function SIRT3(-/-) mice developed progressive age-related deterioration of cardiac function, as evidenced by a decrease in ejection fraction and an increase in enddiastolic volume at 24 but not 8 weeks of age using echocardiography. Four weeks following transverse aortic constriction, ejection fraction was further decreased in SIRT3(-/-) mice compared to WT mice, accompanied by a greater degree of cardiac hypertrophy and fibrosis. In isolated working hearts, a decrease in cardiac function in SIRT3(-/-) mice was accompanied by a decrease in palmitate oxidation, glucose oxidation, and oxygen consumption, whereas rates of glycolysis were increased. Respiratory capacity and ATP synthesis were decreased in cardiac mitochondria of SIRT3(-/-) mice. HPLC measurements revealed a decrease of the myocardial ATP/AMP ratio and of myocardial energy charge. Using LC-MS/MS, we identified increased acetylation of 84 mitochondrial proteins, including 6 enzymes of fatty acid import and oxidation, 50 subunits of the electron transport chain, and 3 enzymes of the tricarboxylic acid cycle. Lack of SIRT3 impairs mitochondrial and contractile function in the heart, likely due to increased acetylation of various energy metabolic proteins and subsequent myocardial energy depletion. PMID:25962702

  7. Impairments of hepatic gluconeogenesis and ketogenesis in PPARα-deficient neonatal mice

    PubMed Central

    Cotter, David G.; Ercal, Baris; André d'Avignon, D.; Dietzen, Dennis J.

    2014-01-01

    Peroxisome proliferator activated receptor-α (PPARα) is a master transcriptional regulator of hepatic metabolism and mediates the adaptive response to fasting. Here, we demonstrate the roles for PPARα in hepatic metabolic adaptations to birth. Like fasting, nutrient supply is abruptly altered at birth when a transplacental source of carbohydrates is replaced by a high-fat, low-carbohydrate milk diet. PPARα-knockout (KO) neonatal mice exhibit relative hypoglycemia due to impaired conversion of glycerol to glucose. Although hepatic expression of fatty acyl-CoA dehydrogenases is imparied in PPARα neonates, these animals exhibit normal blood acylcarnitine profiles. Furthermore, quantitative metabolic fate mapping of the medium-chain fatty acid [13C]octanoate in neonatal mouse livers revealed normal contribution of this fatty acid to the hepatic TCA cycle. Interestingly, octanoate-derived carbon labeled glucose uniquely in livers of PPARα-KO neonates. Relative hypoketonemia in newborn PPARα-KO animals could be mechanistically linked to a 50% decrease in de novo hepatic ketogenesis from labeled octanoate. Decreased ketogenesis was associated with diminished mRNA and protein abundance of the fate-committing ketogenic enzyme mitochondrial 3-hydroxymethylglutaryl-CoA synthase (HMGCS2) and decreased protein abundance of the ketogenic enzyme β-hydroxybutyrate dehydrogenase 1 (BDH1). Finally, hepatic triglyceride and free fatty acid concentrations were increased 6.9- and 2.7-fold, respectively, in suckling PPARα-KO neonates. Together, these findings indicate a primary defect of gluconeogenesis from glycerol and an important role for PPARα-dependent ketogenesis in the disposal of hepatic fatty acids during the neonatal period. PMID:24865983

  8. Fibrillin-1 impairment enhances blood-brain barrier permeability and xanthoma formation in brains of apolipoprotein E-deficient mice.

    PubMed

    Van der Donckt, C; Roth, L; Vanhoutte, G; Blockx, I; Bink, D I; Ritz, K; Pintelon, I; Timmermans, J-P; Bauters, D; Martinet, W; Daemen, M J; Verhoye, M; De Meyer, G R Y

    2015-06-01

    We recently reported that apolipoprotein E (ApoE)-deficient mice with a mutation in the fibrillin-1 gene (ApoE(-/-)Fbn1(C1039G+/-)) develop accelerated atherosclerosis with enhanced inflammation, atherosclerotic plaque rupture, myocardial infarction and sudden death. In the brain, fibrillin-1 functions as an attachment protein in the basement membrane, providing structural support to the blood-brain barrier (BBB). Here, we investigated whether fibrillin-1 impairment affects the permeability of the BBB proper and the blood-cerebrospinal fluid barrier (BCSFB), and whether this leads to the accelerated accumulation of lipids (xanthomas) in the brain. ApoE(-/-) (n=61) and ApoE(-/-)Fbn1(C1039G+/-) (n=73) mice were fed a Western-type diet (WD). After 14 weeks WD, a significantly higher permeability of the BBB was observed in ApoE(-/-)Fbn1(C1039G+/-) mice compared to age-matched ApoE(-/-) mice. This was accompanied by leukocyte infiltration, enhanced expression of pro-inflammatory cytokines, matrix metalloproteinases and transforming growth factor-β, and by decreased expression of tight junction proteins claudin-5 and occludin. After 20 weeks WD, 83% of ApoE(-/-)Fbn1(C1039G+/-) mice showed xanthomas in the brain, compared to 23% of their ApoE(-/-) littermates. Xanthomas were mainly located in fibrillin-1-rich regions, such as the choroid plexus and the neocortex. Our findings demonstrate that dysfunctional fibrillin-1 impairs BBB/BCSFB integrity, facilitating peripheral leukocyte infiltration, which further degrades the BBB/BCSFB. As a consequence, lipoproteins can enter the brain, resulting in accelerated formation of xanthomas. PMID:25797463

  9. Monogalactosyldiacylglycerol deficiency in Arabidopsis affects pigment composition in the prolamellar body and impairs thylakoid membrane energization and photoprotection in leaves.

    PubMed

    Aronsson, Henrik; Schöttler, Mark A; Kelly, Amélie A; Sundqvist, Christer; Dörmann, Peter; Karim, Sazzad; Jarvis, Paul

    2008-09-01

    Monogalactosyldiacylglycerol (MGDG) is the major lipid constituent of chloroplast membranes and has been proposed to act directly in several important plastidic processes, particularly during photosynthesis. In this study, the effect of MGDG deficiency, as observed in the monogalactosyldiacylglycerol synthase1-1 (mgd1-1) mutant, on chloroplast protein targeting, phototransformation of pigments, and photosynthetic light reactions was analyzed. The targeting of plastid proteins into or across the envelope, or into the thylakoid membrane, was not different from wild-type in the mgd1 mutant, suggesting that the residual amount of MGDG in mgd1 was sufficient to maintain functional targeting mechanisms. In dark-grown plants, the ratio of bound protochlorophyllide (Pchlide, F656) to free Pchlide (F631) was increased in mgd1 compared to the wild type. Increased levels of the photoconvertible pigment-protein complex (F656), which is photoprotective and suppresses photooxidative damage caused by an excess of free Pchlide, may be an adaptive response to the mgd1 mutation. Leaves of mgd1 suffered from a massively impaired capacity for thermal dissipation of excess light due to an inefficient operation of the xanthophyll cycle; the mutant contained less zeaxanthin and more violaxanthin than wild type after 60 min of high-light exposure and suffered from increased photosystem II photoinhibition. This is attributable to an increased conductivity of the thylakoid membrane at high light intensities, so that the proton motive force is reduced and the thylakoid lumen is less acidic than in wild type. Thus, the pH-dependent activation of the violaxanthin de-epoxidase and of the PsbS protein is impaired. PMID:18641085

  10. Impaired myogenesis in estrogen-related receptor γ (ERRγ)-deficient skeletal myocytes due to oxidative stress

    PubMed Central

    Murray, Jennifer; Auwerx, Johan; Huss, Janice M.

    2013-01-01

    Specialized contractile function and increased mitochondrial number and oxidative capacity are hallmark features of myocyte differentiation. The estrogen-related receptors (ERRs) can regulate mitochondrial biogenesis or mitochondrial enzyme expression in skeletal muscle, suggesting that ERRs may have a role in promoting myogenesis. Therefore, we characterized myogenic programs in primary myocytes isolated from wild-type (M-ERRγWT) and muscle-specific ERRγ−/− (M-ERRγ−/−) mice. Myotube maturation and number were decreased throughout differentiation in M-ERRγ−/− primary myocytes, resulting in myotubes with reduced mitochondrial content and sarcomere assembly. Compared with M-ERRγWT myocytes at the same differentiation stage, the glucose oxidation rate was reduced by 30% in M-ERRγ−/− myotubes, while medium-chain fatty acid oxidation was increased by 34% in M-ERRγ−/− myoblasts and 36% in M-ERRγ−/− myotubes. Concomitant with increased reliance on mitochondrial β-oxidation, H2O2 production was significantly increased by 40% in M-ERRγ−/− myoblasts and 70% in M-ERRγ−/− myotubes compared to M-ERRγWT myocytes. ROS activation of FoxO and NF-κB and their downstream targets, atrogin-1 and MuRF1, was observed in M-ERRγ−/− myocytes. The antioxidant N-acetyl cysteine rescued myotube formation and atrophy gene induction in M-ERRγ−/− myocytes. These results suggest that loss of ERRγ causes metabolic defects and oxidative stress that impair myotube formation through activation of skeletal muscle atrophy pathways.—Murray, J., Auwerx, J., Huss, J. M. Impaired myogenesis in estrogen-related receptor γ (ERRγ)-deficient skeletal myocytes due to oxidative stress. PMID:23038752

  11. Emerging roles of pericytes in the regulation of the neurovascular unit in health and disease

    PubMed Central

    Hill, Jeremy; Rom, Slava; Ramirez, Servio H.; Persidsky, Yuri

    2014-01-01

    Pericytes of the central nervous system (CNS) are uniquely positioned within a multicellular structure termed the neurovascular unit (NVU) to provide crucial support to blood brain barrier (BBB) formation, maintenance, and stability. Numerous CNS diseases are associated with some aspect of BBB dysfunction. A dysfunction can manifest as one or multiple disruptions to any of the following barriers: physical, metabolic, immunological and transport barrier. A breach in the BBB can notably result in BBB hyper-permeability, endothelial activation and enhanced immune-endothelial interaction. How the BBB is regulated within this integrated unit remains largely unknown, especially as it relates to pericyte-endothelial interaction. We summarize the latest findings on pericyte origin, possible marker expression, and availability within different organ systems. We highlight pericyte-endothelial cell interactions, concentrating on extra- and intra- cellular signaling mechanisms linked to platelet derived growth factor-B, transforming growth factor -β, angiopoietins, Notch, and gap junctions. We discuss the role of pericytes in the NVU under inflammatory insult, focusing on how pericytes may indirectly affect leukocyte CNS infiltration, the direct role of pericyte-mediated basement membrane modifications, and immune responses. We review new findings of pericyte actions in CNS pathologies including Alzheimer’s disease, stroke, multiple sclerosis, diabetic retinopathy, and HIV-1 infection. The uncovering of the regulatory role of pericytes on the BBB will provide key insight into how barrier integrity can be re-established during neuroinflammation. PMID:25119834

  12. Peroxisome Proliferator–Activated Receptor α Protects Capillary Pericytes in the Retina

    PubMed Central

    Ding, Lexi; Cheng, Rui; Hu, Yang; Takahashi, Yusuke; Jenkins, Alicia J.; Keech, Anthony C.; Humphries, Kenneth M.; Gu, Xiaowu; Elliott, Michael H.; Xia, Xiaobo; Ma, Jian-xing

    2015-01-01

    Pericyte degeneration is an early event in diabetic retinopathy and plays an important role in progression of diabetic retinopathy. Clinical studies have shown that fenofibrate, a peroxisome proliferator–activated receptor α (PPARα) agonist, has robust therapeutic effects on diabetic retinopathy in type 2 diabetic patients. We evaluated the protective effect of PPARα against pericyte loss in diabetic retinopathy. In streptozotocin-induced diabetic mice, fenofibrate treatment significantly ameliorated retinal acellular capillary formation and pericyte loss. In contrast, PPARα−/− mice with diabetes developed more severe retinal acellular capillary formation and pericyte dropout, compared with diabetic wild-type mice. Furthermore, PPARα knockout abolished the protective effect of fenofibrate against diabetes-induced retinal pericyte loss. In cultured primary human retinal capillary pericytes, activation and expression of PPARα both significantly reduced oxidative stress–induced apoptosis, decreased reactive oxygen species production, and down-regulated NAD(P)H oxidase 4 expression through blockade of NF-κB activation. Furthermore, activation and expression of PPARα both attenuated the oxidant-induced suppression of mitochondrial O2 consumption in human retinal capillary pericytes. Primary retinal pericytes from PPARα−/− mice displayed more apoptosis, compared with those from wild-type mice under the same oxidative stress. These findings identified a protective effect of PPARα on retinal pericytes, a novel function of endogenous PPARα in the retina. PMID:25108226

  13. Vitamin D deficiency is associated with impaired disease control in asthma–COPD overlap syndrome patients

    PubMed Central

    Odler, Balázs; Ivancsó, István; Somogyi, Vivien; Benke, Kálmán; Tamási, Lilla; Gálffy, Gabriella; Szalay, Balázs; Müller, Veronika

    2015-01-01

    Introduction The association between vitamin D and clinical parameters in obstructive lung diseases (OLDs), including COPD and bronchial asthma, was previously investigated. As asthma–COPD overlap syndrome (ACOS) is a new clinical entity, the prevalence of vitamin D levels in ACOS is unknown. Aim Our aim was to assess the levels of circulating vitamin D (25-hydroxyvitamin D [25(OH)D]) in different OLDs, including ACOS patients, and its correlation with clinical parameters. Methods A total of 106 men and women (control, n=21; asthma, n=44; COPD, n=21; and ACOS, n=20) were involved in the study. All patients underwent detailed clinical examinations; disease control and severity was assessed by disease-specific questionnaires (COPD assessment test, asthma control test, and modified Medical Research Council); furthermore, 25(OH)D levels were measured in all patients. Results The 25(OH)D level was significantly lower in ACOS and COPD groups compared to asthma group (16.86±1.79 ng/mL and 14.27±1.88 ng/mL vs 25.66±1.91 ng/mL). A positive correlation was found between 25(OH)D level and forced expiratory volume in 1 second (r=0.4433; P<0.0001), forced vital capacity (FVC) (r=0.3741; P=0.0004), forced expiratory flow between 25% and 75% of FVC (r=0.4179; P<0.0001), and peak expiratory flow (r=0.4846; P<0.0001) in OLD patient groups. Asthma control test total scores and the 25(OH)D level showed a positive correlation in the ACOS (r=0.4761; P=0.0339) but not in the asthma group. Higher COPD assessment test total scores correlated with decreased 25(OH)D in ACOS (r=−0.4446; P=0.0495); however, this was not observed in the COPD group. Conclusion Vitamin D deficiency is present in ACOS patients and circulating 25(OH)D level may affect disease control and severity. PMID:26451099

  14. The pericyte as a cellular regulator of penile erection and a novel therapeutic target for erectile dysfunction

    PubMed Central

    Yin, Guo Nan; Das, Nando Dulal; Choi, Min Ji; Song, Kang-Moon; Kwon, Mi-Hye; Ock, Jiyeon; Limanjaya, Anita; Ghatak, Kalyan; Kim, Woo Jean; Hyun, Jae Seog; Koh, Gou Young; Ryu, Ji-Kan; Suh, Jun-Kyu

    2015-01-01

    Pericytes are known to play critical roles in vascular development and homeostasis. However, the distribution of cavernous pericytes and their roles in penile erection is unclear. Herein we report that the pericytes are abundantly distributed in microvessels of the subtunical area and dorsal nerve bundle of mice, followed by dorsal vein and cavernous sinusoids. We further confirmed the presence of pericytes in human corpus cavernosum tissue and successfully isolated pericytes from mouse penis. Cavernous pericyte contents from diabetic mice and tube formation of cultured pericytes in high glucose condition were greatly reduced compared with those in normal conditions. Suppression of pericyte function with anti-PDGFR-β blocking antibody deteriorated erectile function and tube formation in vivo and in vitro diabetic condition. In contrast, enhanced pericyte function with HGF protein restored cavernous pericyte content in diabetic mice, and significantly decreased cavernous permeability in diabetic mice and in pericytes-endothelial cell co-culture system, which induced significant recovery of erectile function. Overall, these findings showed the presence and distribution of pericytes in the penis of normal or pathologic condition and documented their role in the regulation of cavernous permeability and penile erection, which ultimately explore novel therapeutics of erectile dysfunction targeting pericyte function. PMID:26044953

  15. Tsc1 deficiency impairs mammary development in mice by suppression of AKT, nuclear ERα, and cell-cycle-driving proteins.

    PubMed

    Qin, Zhenqi; Zheng, Hang; Zhou, Ling; Ou, Yanhua; Huang, Bin; Yan, Bo; Qin, Zhenshu; Yang, Cuilan; Su, Yongchun; Bai, Xiaochun; Guo, Jiasong; Lin, Jun

    2016-01-01

    Loss of Tsc1/Tsc2 results in excess cell growth that eventually forms hamartoma in multiple organs. Our study using a mouse model with Tsc1 conditionally knockout in mammary epithelium showed that Tsc1 deficiency impaired mammary development. Phosphorylated S6 was up-regulated in Tsc1(-/-) mammary epithelium, which could be reversed by rapamycin, suggesting that mTORC1 was hyperactivated in Tsc1(-/-) mammary epithelium. The mTORC1 inhibitor rapamycin restored the development of Tsc1(-/-) mammary glands whereas suppressed the development of Tsc1(wt/wt) mammary glands, indicating that a modest activation of mTORC1 is critical for mammary development. Phosphorylated PDK1 and AKT, nuclear ERα, nuclear IRS-1, SGK3, and cell cycle regulators such as Cyclin D1, Cyclin E, CDK2, CDK4 and their target pRB were all apparently down-regulated in Tsc1(-/-) mammary glands, which could be reversed by rapamycin, suggesting that suppression of AKT by hyperactivation of mTORC1, inhibition on nuclear ERα signaling, and down-regulation of cell-cycle-driving proteins play important roles in the retarded mammary development induced by Tsc1 deletion. This study demonstrated for the first time the in vivo role of Tsc1 in pubertal mammary development of mice, and revealed that loss of Tsc1 does not necessarily lead to tissue hyperplasia. PMID:26795955

  16. Impaired differentiation of macrophage lineage cells attenuates bone remodeling and inflammatory angiogenesis in Ndrg1 deficient mice

    PubMed Central

    Watari, Kosuke; Shibata, Tomohiro; Nabeshima, Hiroshi; Shinoda, Ai; Fukunaga, Yuichi; Kawahara, Akihiko; Karasuyama, Kazuyuki; Fukushi, Jun-ichi; Iwamoto, Yukihide; Kuwano, Michihiko; Ono, Mayumi

    2016-01-01

    N-myc downstream regulated gene 1 (NDRG1) is a responsible gene for a hereditary motor and sensory neuropathy-Lom (Charcot–Marie–Tooth disease type 4D). This is the first study aiming to assess the contribution of NDRG1 to differentiation of macrophage lineage cells, which has important implications for bone remodeling and inflammatory angiogenesis. Ndrg1 knockout (KO) mice exhibited abnormal curvature of the spine, high trabecular bone mass, and reduced number of osteoclasts. We observed that serum levels of macrophage colony-stimulating factor (M-CSF) and macrophage-related cytokines were markedly decreased in KO mice. Differentiation of bone marrow (BM) cells into osteoclasts, M1/M2-type macrophages and dendritic cells was all impaired. Furthermore, KO mice also showed reduced tumor growth and angiogenesis by cancer cells, accompanied by decreased infiltration of tumor-associated macrophages. The transfer of BM-derived macrophages from KO mice into BM-eradicated wild type (WT) mice induced much less tumor angiogenesis than observed in WT mice. Angiogenesis in corneas in response to inflammatory stimuli was also suppressed with decreased infiltration of macrophages. Taken together, these results indicate that NDRG1 deficiency attenuates the differentiation of macrophage lineage cells, suppressing bone remodeling and inflammatory angiogenesis. This study strongly suggests the crucial role of NDRG1 in differentiation process for macrophages. PMID:26778110

  17. Kras activation in p53-deficient myoblasts results in high-grade sarcoma formation with impaired myogenic differentiation

    PubMed Central

    McKinnon, Timothy; Venier, Rosemarie; Dickson, Brendan C.; Kabaroff, Leah; Alkema, Manon; Chen, Li; Shern, Jack F.; Yohe, Marielle E.; Khan, Javed; Gladdy, Rebecca A.

    2015-01-01

    While genomic studies have improved our ability to classify sarcomas, the molecular mechanisms involved in the formation and progression of many sarcoma subtypes are unknown. To better understand developmental origins and genetic drivers involved in rhabdomyosarcomagenesis, we describe a novel sarcoma model system employing primary murine p53-deficient myoblasts that were isolated and lentivirally transduced with KrasG12D. Myoblast cell lines were characterized and subjected to proliferation, anchorage-independent growth and differentiation assays to assess the effects of transgenic KrasG12D expression. KrasG12D overexpression transformed p53−/− myoblasts as demonstrated by an increased anchorage-independent growth. Induction of differentiation in parental myoblasts resulted in activation of key myogenic regulators. In contrast, Kras-transduced myoblasts had impaired terminal differentiation. p53−/− myoblasts transformed by KrasG12D overexpression resulted in rapid, reproducible tumor formation following orthotopic injection into syngeneic host hindlimbs. Pathological analysis revealed high-grade sarcomas with myogenic differentiation based on the expression of muscle-specific markers, such as Myod1 and Myog. Gene expression patterns of murine sarcomas shared biological pathways with RMS gene sets as determined by gene set enrichment analysis (GSEA) and were 61% similar to human RMS as determined by metagene analysis. Thus, our novel model system is an effective means to model high-grade sarcomas along the RMS spectrum. PMID:25992772

  18. Not All MSCs Can Act as Pericytes: Functional In Vitro Assays to Distinguish Pericytes from Other Mesenchymal Stem Cells in Angiogenesis

    PubMed Central

    Blocki, Anna; Wang, Yingting; Koch, Maria; Peh, Priscilla; Beyer, Sebastian; Law, Ping; Hui, James

    2013-01-01

    Pericytes play a crucial role in angiogenesis and vascular maintenance. They can be readily identified in vivo and isolated as CD146+CD34− cells from various tissues. Whether these and other markers reliably identify pericytes in vitro is unclear. CD146+CD34− selected cells exhibit multilineage potential. Thus, their perivascular location might represent a stem cell niche. This has spurred assumptions that not only all pericytes are mesenchymal stromal cells (MSCs), but also that all MSCs can act as pericytes. Considering this hypothesis, we developed functional assays by confronting test cells with endothelial cultures based on matrigel assay, spheroid sprouting, and cord formation. We calibrated these assays first with commercial cell lines [CD146+CD34− placenta-derived pericytes (Pl-Prc), bone marrow (bm)MSCs and fibroblasts]. We then functionally compared the angiogenic abilities of CD146+CD34−selected bmMSCs with CD146− selected bmMSCs from fresh human bm aspirates. We show here that only CD146+CD34− selected Pl-Prc and CD146+CD34− selected bmMSCs maintain endothelial tubular networks on matrigel and improve endothelial sprout morphology. CD146− selected bmMSCs neither showed these abilities, nor did they attain pericyte function despite progressive CD146 expression once passaged. Thus, cell culture conditions appear to influence expression of this and other reported pericyte markers significantly without correlation to function. The newly developed assays, therefore, promise to close a gap in the in vitro identification of pericytes via function. Indeed, our functional data suggest that pericytes represent a subpopulation of MSCs in bm with a specialized role in vascular biology. However, these functions are not inherent to all MSCs. PMID:23600480

  19. Pericytic mimicry in well-differentiated liposarcoma/atypical lipomatous tumor.

    PubMed

    Shen, Jia; Shrestha, Swati; Rao, P Nagesh; Asatrian, Greg; Scott, Michelle A; Nguyen, Vi; Giacomelli, Paulina; Soo, Chia; Ting, Kang; Eilber, Fritz C; Peault, Bruno; Dry, Sarah M; James, Aaron W

    2016-08-01

    Pericytes are modified smooth muscle cells that closely enwrap small blood vessels, regulating and supporting the microvasculature through direct endothelial contact. Pericytes demonstrate a distinct immunohistochemical profile, including expression of smooth muscle actin, CD146, platelet-derived growth factor receptor β, and regulator of G-protein signaling 5. Previously, pericyte-related antigens have been observed to be present among a group of soft tissue tumors with a perivascular growth pattern, including glomus tumor, myopericytoma, and angioleiomyoma. Similarly, malignant tumor cells have been shown to have a pericyte-like immunoprofile when present in a perivascular location, seen in malignant melanoma, glioblastoma, and adenocarcinoma. Here, we examine well-differentiated liposarcoma specimens, which showed some element of perivascular areas with the appearance of smooth muscle (n = 7 tumors). Immunohistochemical staining was performed for pericyte antigens, including smooth muscle actin, CD146, platelet-derived growth factor receptor β, and regulator of G-protein signaling 5. Results showed consistent pericytic marker expression among liposarcoma tumor cells within a perivascular distribution. MDM2 immunohistochemistry and fluorescence in situ hybridization for MDM2 revealed that these perivascular cells were of tumor origin (7/7 tumors), whereas double immunohistochemical detection for CD31/CD146 ruled out an endothelial cell contribution. These findings further support the concept of pericytic mimicry, already established in diverse malignancies, and its presence in well-differentiated liposarcoma. The extent to which pericytic mimicry has prognostic significance in liposarcoma is as yet unknown. PMID:27063472

  20. Traumatic brain injury results in rapid pericyte loss followed by reactive pericytosis in the cerebral cortex.

    PubMed

    Zehendner, Christoph M; Sebastiani, Anne; Hugonnet, André; Bischoff, Florian; Luhmann, Heiko J; Thal, Serge C

    2015-01-01

    Accumulating evidence suggests a pivotal role of PDGFRß positive cells, a specific marker for central nervous system (CNS) pericytes, in tissue scarring. Identification of cells that contribute to tissue reorganization in the CNS upon injury is a crucial step to develop novel treatment strategies in regenerative medicine. It has been shown that pericytes contribute to scar formation in the spinal cord. It is further known that ischemia initially triggers pericyte loss in vivo, whilst brain trauma is capable of inducing pericyte detachment from cerebral vessels. These data point towards a significant role of pericytes in CNS injury. The temporal and spatial dynamics of PDGFRß cells and their responses in traumatic brain injury are poorly understood. Here we show that PDGFRß positive cells initially decline in the acute phase following experimental traumatic brain injury. However, PDGFRß positive cells increase significantly in the trauma zone days after brain injury. Using various pericyte markers we identify these cells to be pericytes that are demarcated by reactive gliosis. Our data indicate that brain trauma causes a biphasic response of pericytes in the early phase of brain trauma that may be of relevance for the understanding of pathological cellular responses in traumatic brain injury. PMID:26333872

  1. Traumatic brain injury results in rapid pericyte loss followed by reactive pericytosis in the cerebral cortex

    PubMed Central

    Zehendner, Christoph M.; Sebastiani, Anne; Hugonnet, André; Bischoff, Florian; Luhmann, Heiko J.; Thal, Serge C.

    2015-01-01

    Accumulating evidence suggests a pivotal role of PDGFRß positive cells, a specific marker for central nervous system (CNS) pericytes, in tissue scarring. Identification of cells that contribute to tissue reorganization in the CNS upon injury is a crucial step to develop novel treatment strategies in regenerative medicine. It has been shown that pericytes contribute to scar formation in the spinal cord. It is further known that ischemia initially triggers pericyte loss in vivo, whilst brain trauma is capable of inducing pericyte detachment from cerebral vessels. These data point towards a significant role of pericytes in CNS injury. The temporal and spatial dynamics of PDGFRß cells and their responses in traumatic brain injury are poorly understood. Here we show that PDGFRß positive cells initially decline in the acute phase following experimental traumatic brain injury. However, PDGFRß positive cells increase significantly in the trauma zone days after brain injury. Using various pericyte markers we identify these cells to be pericytes that are demarcated by reactive gliosis. Our data indicate that brain trauma causes a biphasic response of pericytes in the early phase of brain trauma that may be of relevance for the understanding of pathological cellular responses in traumatic brain injury. PMID:26333872

  2. Engineering of a Biomimetic Pericyte-Covered 3D Microvascular Network

    PubMed Central

    Kim, Sudong; Jo, Dong Hyun; Kim, Jeong Hun; Jeon, Noo Li

    2015-01-01

    Pericytes enveloping the endothelium play an important role in the physiology and pathology of microvessels, especially in vessel maturation and stabilization. However, our understanding of fundamental pericyte biology is limited by the lack of a robust in vitro model system that allows researchers to evaluate the interactions among multiple cell types in perfusable blood vessels. The present work describes a microfluidic platform that can be used to investigate interactions between pericytes and endothelial cells (ECs) during the sprouting, growth, and maturation steps of neovessel formation. A mixture of ECs and pericytes was attached to the side of a pre-patterned three dimensional fibrin matrix and allowed to sprout across the matrix. The effects of intact coverage and EC maturation by the pericytes on the perfused EC network were confirmed using a confocal microscope. Compared with EC monoculture conditions, EC-pericyte co-cultured vessels showed a significant reduction in diameter, increased numbers of junctions and branches and decreased permeability. In response to biochemical factors, ECs and pericytes in the platform showed the similar features with previous reports from in vivo experiments, thus reflect various pathophysiological conditions of in vivo microvessels. Taken together, these results support the physiological relevancy of our three-dimensional microfluidic culture system but also that the system can be used to screen drug effect on EC-pericyte biology. PMID:26204526

  3. A Cardiolipin-Deficient Mutant of Rhodobacter sphaeroides Has an Altered Cell Shape and Is Impaired in Biofilm Formation

    PubMed Central

    Lin, Ti-Yu; Santos, Thiago M. A.; Kontur, Wayne S.; Donohue, Timothy J.

    2015-01-01

    ABSTRACT Cell shape has been suggested to play an important role in the regulation of bacterial attachment to surfaces and the formation of communities associated with surfaces. We found that a cardiolipin synthase (Δcls) mutant of the rod-shaped bacterium Rhodobacter sphaeroides—in which synthesis of the anionic, highly curved phospholipid cardiolipin (CL) is reduced by 90%—produces ellipsoid-shaped cells that are impaired in biofilm formation. Reducing the concentration of CL did not cause significant defects in R. sphaeroides cell growth, swimming motility, lipopolysaccharide and exopolysaccharide production, surface adhesion protein expression, and membrane permeability. Complementation of the CL-deficient mutant by ectopically expressing CL synthase restored cells to their rod shape and increased biofilm formation. Treating R. sphaeroides cells with a low concentration (10 μg/ml) of the small-molecule MreB inhibitor S-(3,4-dichlorobenzyl)isothiourea produced ellipsoid-shaped cells that had no obvious growth defect yet reduced R. sphaeroides biofilm formation. This study demonstrates that CL plays a role in R. sphaeroides cell shape determination, biofilm formation, and the ability of the bacterium to adapt to its environment. IMPORTANCE Membrane composition plays a fundamental role in the adaptation of many bacteria to environmental stress. In this study, we build a new connection between the anionic phospholipid cardiolipin (CL) and cellular adaptation in Rhodobacter sphaeroides. We demonstrate that CL plays a role in the regulation of R. sphaeroides morphology and is important for the ability of this bacterium to form biofilms. This study correlates CL concentration, cell shape, and biofilm formation and provides the first example of how membrane composition in bacteria alters cell morphology and influences adaptation. This study also provides insight into the potential of phospholipid biosynthesis as a target for new chemical strategies designed to

  4. Impaired Self-Renewal and Increased Colitis and Dysplastic Lesions in Colonic Mucosa of AKR1B8 Deficient Mice

    PubMed Central

    Shen, Yi; Ma, Jun; Yan, Ruilan; Ling, Hongyan; Li, Xiaoning; Yang, Wancai; Gao, John; Huang, Chenfei; Bu, Yiwen; Cao, Yu; He, Yingchun; Wan, Laxiang; Zu, Xuyu; Liu, Jianghua; Huang, Mei Chris; Stenson, William F; Liao, Duan-Fang; Cao, Deliang

    2015-01-01

    Purpose Ulcerative colitis (UC) and colitis-associated colorectal cancer (CAC) is a serious health issue, but etiopathological factors remain unclear. Aldo-keto reductase 1B10 (AKR1B10) is specifically expressed in the colonic epithelium, but down-regulated in colorectal cancer. This study was aimed to investigate the etiopathogenic role of AKR1B10 in UC and CAC. Experimental design UC and CAC biopsies (paraffin-embedded sections) and frozen tissues were collected to examine AKR1B10 expression. Aldo-keto reductase 1B8 (the ortholog of human AKR1B10) knockout (AKR1B8 −/−) mice were produced to estimate its role in the susceptibility and severity of chronic colitis and associated dysplastic lesions, induced by dextran sulfate sodium (DSS) at a low dose (2%). Genome-wide Exome sequencing was used to profile DNA damage in DSS-induced colitis and tumors. Results AKR1B10 expression was markedly diminished in over 90% of UC and CAC tissues. AKR1B8 deficiency led to reduced lipid synthesis from butyrate and diminished proliferation of colonic epithelial cells. The DSS-treated AKR1B8 −/− mice demonstrated impaired injury repair of colonic epithelium and more severe bleeding, inflammation, and ulceration. These AKR1B8 −/− mice had more severe oxidative stress and DNA damage, and dysplasias were more frequent and at a higher grade in the AKR1B8 −/− mice than in wild type mice. Palpable masses were seen in the AKR1B8 −/− mice only, not in wild type. Conclusion AKR1B8 is a critical protein in the proliferation and injury repair of the colonic epithelium and in the pathogenesis of UC and CAC, being a new etiopathogenic factor of these diseases. PMID:25538260

  5. Metallothionein I,II deficient mice do not exhibit significantly worse long-term behavioral outcomes following neonatal hypoxia-ischemia: MT-I,II deficient mice have inherent behavioral impairments.

    PubMed

    McAuliffe, John J; Joseph, Bernadin; Hughes, Elizabeth; Miles, Lili; Vorhees, Charles V

    2008-01-23

    Metallothionein I and II are small metal binding proteins with a high affinity for zinc. They are found in the CNS and are thought to play a role in modulating the effects of free zinc. We hypothesized that MT-I,II deficient mice would have more neurological deficits both functionally and anatomically following a neonatal hypoxic-ischemic (HI) insult than wild-type mice subjected to the same insult. Forty wild-type and 40 MT-I,II deficient C57 X 129T2 F1 P10 mice were randomized to either 45 min of HI or sham HI. Beginning on P50, the mice were given a series of behavioral tests including locomotor activity, novel object recognition, Morris water maze (cued, hidden platform, reduced platform), a 2-week-delayed probe trial and an apomorphine-induced rotation test. At the conclusion of testing, the brains were removed for histological analysis including staining with NeuN and GFAP to assess neuronal loss and reactive gliosis. There were no significant differences in functional or anatomic measures between the wild-type HI mice and the MT-I,II deficient HI mice. The MT-I,II deficient mice exhibited an impaired rate of learning in the spatially oriented mazes but once learned retained the information as well as the wild-type mice. The absence of functional MT-I,II proteins does not result in significantly worse injury following 45 min of HI on P10. The MT-I,II deficient mice have baseline impairments in spatial learning but not retention. PMID:18083145

  6. Zinc deficiency induced in Swiss 3T3 cells by a low-zinc medium impairs calcium entry and two mechanisms of entry are involved.

    PubMed

    O'Dell, Boyd L; Browning, Jimmy D

    2013-04-01

    Zinc deficiency in 3T3 cells induced by the use of diethylenetriaminepentaacetate (DTPA) has been shown to impair calcium entry associated with failure of proliferation when the cells are stimulated with polypeptide growth factors (GF). These functions of zinc have been evaluated here in the same clone of cells by simple depletion using a low-zinc medium (0.05 μmol/L zinc) without chelator. Confluent cells were maintained for 1 day in the low-zinc medium without GF, then loaded with Fluo-4, and stimulated with GF. Calcium entry was measured by the increase in sustained fluorescence. It was preceded by the release of stored calcium as observed in the previous study using DTPA. Zinc deprivation decreased calcium entry when calcium was added at 0 or 0.05 mmol/L but not when 0.1 mmol/L or higher. Cell proliferation reflected similar effects of zinc and calcium concentrations. In a newly acquired clone of 3T3 cells, GF did not induce internal calcium release but thapsigargin (TG) did. When added in a low-calcium medium, both agonists stimulated calcium entry when external calcium was added, suggesting that two different mechanisms of entry were impaired by zinc deficiency. Zinc deficiency produced by DTPA in the newer clones gave similar results, decreasing calcium entry induced by both agonists. The effects of GF and TG were not additive. The results confirm the earlier observation that zinc deficiency impairs calcium entry into 3T3 cells when stimulated by GF and show that the cells can take up calcium by either store-operated or receptor-operated mechanisms. PMID:23292302

  7. The pericyte: a forgotten cell type with important implications for Alzheimer's disease?

    PubMed

    Winkler, Ethan A; Sagare, Abhay P; Zlokovic, Berislav V

    2014-07-01

    Pericytes are cells in the blood-brain barrier (BBB) that degenerate in Alzheimer's disease (AD), a neurodegenerative disorder characterized by early neurovascular dysfunction, elevation of amyloid β-peptide (Aβ), tau pathology and neuronal loss, leading to progressive cognitive decline and dementia. Pericytes are uniquely positioned within the neurovascular unit between endothelial cells of brain capillaries, astrocytes and neurons. Recent studies have shown that pericytes regulate key neurovascular functions including BBB formation and maintenance, vascular stability and angioarchitecture, regulation of capillary blood flow, and clearance of toxic cellular by-products necessary for normal functioning of the central nervous system (CNS). Here, we review the concept of the neurovascular unit and neurovascular functions of CNS pericytes. Next, we discuss vascular contributions to AD and review new roles of pericytes in the pathogenesis of AD such as vascular-mediated Aβ-independent neurodegeneration, regulation of Aβ clearance and contributions to tau pathology, neuronal loss and cognitive decline. We conclude that future studies should focus on molecular mechanisms and pathways underlying aberrant signal transduction between pericytes and its neighboring cells within the neurovascular unit, that is, endothelial cells, astrocytes and neurons, which could represent potential therapeutic targets to control pericyte degeneration in AD and the resulting secondary vascular and neuronal degeneration. PMID:24946075

  8. An anti-inflammatory role for C/EBPδ in human brain pericytes

    PubMed Central

    Rustenhoven, Justin; Scotter, Emma L.; Jansson, Deidre; Kho, Dan T.; Oldfield, Robyn L.; Bergin, Peter S.; Mee, Edward W.; Faull, Richard L. M.; Curtis, Maurice A.; Graham, Scott E.; Park, Thomas I-H.; Dragunow, Mike

    2015-01-01

    Neuroinflammation contributes to the pathogenesis of several neurological disorders and pericytes are implicated in brain inflammatory processes. Cellular inflammatory responses are orchestrated by transcription factors but information on transcriptional control in pericytes is lacking. Because the transcription factor CCAAT/enhancer binding protein delta (C/EBPδ) is induced in a number of inflammatory brain disorders, we sought to investigate its role in regulating pericyte immune responses. Our results reveal that C/EBPδ is induced in a concentration- and time-dependent fashion in human brain pericytes by interleukin-1β (IL-1β). To investigate the function of the induced C/EBPδ in pericytes we used siRNA to knockdown IL-1β-induced C/EBPδ expression. C/EBPδ knockdown enhanced IL-1β-induced production of intracellular adhesion molecule-1 (ICAM-1), interleukin-8, monocyte chemoattractant protein-1 (MCP-1) and IL-1β, whilst attenuating cyclooxygenase-2 and superoxide dismutase-2 gene expression. Altered ICAM-1 and MCP-1 protein expression were confirmed by cytometric bead array and immunocytochemistry. Our results show that knock-down of C/EBPδ expression in pericytes following immune stimulation increased chemokine and adhesion molecule expression, thus modifying the human brain pericyte inflammatory response. The induction of C/EBPδ following immune stimulation may act to limit infiltration of peripheral immune cells, thereby preventing further inflammatory responses in the brain. PMID:26166618

  9. Pericyte contractility controls endothelial cell cycle progression and sprouting: insights into angiogenic switch mechanics.

    PubMed

    Durham, Jennifer T; Surks, Howard K; Dulmovits, Brian M; Herman, Ira M

    2014-11-01

    Microvascular stability and regulation of capillary tonus are regulated by pericytes and their interactions with endothelial cells (EC). While the RhoA/Rho kinase (ROCK) pathway has been implicated in modulation of pericyte contractility, in part via regulation of the myosin light chain phosphatase (MLCP), the mechanisms linking Rho GTPase activity with actomyosin-based contraction and the cytoskeleton are equivocal. Recently, the myosin phosphatase-RhoA-interacting protein (MRIP) was shown to mediate the RhoA/ROCK-directed MLCP inactivation in vascular smooth muscle. Here we report that MRIP directly interacts with the β-actin-specific capping protein βcap73. Furthermore, manipulation of MRIP expression influences pericyte contractility, with MRIP silencing inducing cytoskeletal remodeling and cellular hypertrophy. MRIP knockdown induces a repositioning of βcap73 from the leading edge to stress fibers; thus MRIP-silenced pericytes increase F-actin-driven cell spreading twofold. These hypertrophied and cytoskeleton-enriched pericytes demonstrate a 2.2-fold increase in contractility upon MRIP knockdown when cells are plated on a deformable substrate. In turn, silencing pericyte MRIP significantly affects EC cycle progression and angiogenic activation. When MRIP-silenced pericytes are cocultured with capillary EC, there is a 2.0-fold increase in EC cycle entry. Furthermore, in three-dimensional models of injury and repair, silencing pericyte MRIP results in a 1.6-fold elevation of total tube area due to EC network formation and increased angiogenic sprouting. The pivotal role of MRIP expression in governing pericyte contractile phenotype and endothelial growth should lend important new insights into how chemomechanical signaling pathways control the "angiogenic switch" and pathological angiogenic induction. PMID:25143350

  10. Topiramate Protects Pericytes from Glucotoxicity: Role for Mitochondrial CA VA in Cerebromicrovascular Disease in Diabetes

    PubMed Central

    Patrick, Ping; Price, Tulin O.; Diogo, Ana L.; Sheibani, Nader; Banks, William A.; Shah, Gul N.

    2015-01-01

    Hyperglycemia in diabetes mellitus causes oxidative stress and pericyte depletion from the microvasculature of the brain thus leading to the Blood-Brain Barrier (BBB) disruption. The compromised BBB exposes the brain to circulating substances, resulting in neurotoxicity and neuronal cell death. The decline in pericyte numbers in diabetic mouse brain and pericyte apoptosis in high glucose cultures are caused by excess superoxide produced during enhanced respiration (mitochondrial oxidative metabolism of glucose). Superoxide is precursor to all Reactive Oxygen Species (ROS) which, in turn, cause oxidative stress. The rate of respiration and thus the ROS production is regulated by mitochondrial carbonic anhydrases (mCA) VA and VB, the two isoforms expressed in the mitochondria. Inhibition of both mCA: decreases the oxidative stress and restores the pericyte numbers in diabetic brain; and reduces high glucose-induced respiration, ROS, oxidative stress, and apoptosis in cultured brain pericytes. However, the individual role of the two isoforms has not been established. To investigate the contribution of mCA VA in ROS production and apoptosis, a mCA VA overexpressing brain pericyte cell line was engineered. These cells were exposed to high glucose and analyzed for the changes in ROS and apoptosis. Overexpression of mCA VA significantly increased pericyte ROS and apoptosis. Inhibition of mCA VA with topiramate prevented increases both in glucose-induced ROS and pericyte death. These results demonstrate, for the first time, that mCA VA regulates the rate of pericyte respiration. These findings identify mCA VA as a novel and specific therapeutic target to protect the cerebromicrovascular bed in diabetes. PMID:26167540

  11. Pericyte Chemomechanics and the Angiogenic Switch: Insights Into the Pathogenesis of Proliferative Diabetic Retinopathy?

    PubMed Central

    Durham, Jennifer T.; Dulmovits, Brian M.; Cronk, Stephen M.; Sheets, Anthony R.; Herman, Ira M.

    2015-01-01

    Purpose. To establish the regulatory roles that pericytes have in coordinating retinal endothelial cell (EC) growth and angiogenic potential. Methods. Pericytes were derived from donor diabetic (DHuRP) or normal (NHuRP) human retinae, and characterized using vascular markers, coculture, contraction, morphogenesis, and proliferation assays. To investigate capillary “cross-talk,” pericyte-endothelial coculture growth, and connexin-43 (Cx43) expression assays were performed. Paracrine effects were examined via treating EC with pericyte-derived conditioned media (CM) in proliferation, angiogenesis, and angiocrine assays. The effects of sphingosine 1-phosphate (S1P) were assessed using receptor antagonists. Results. The DHuRP exhibit unique proliferative and morphologic properties, reflecting distinctive cytoskeletal and isoactin expression patterns. Unlike NHuRP, DHuRP are unable to sustain EC growth arrest in coculture and display reduced Cx43 expression. Further, CM from DHuRP (DPCM) markedly stimulates EC proliferation and tube formation. Treatment with S1P receptor antagonists mitigates DPCM growth-promotion in EC and S1P-mediated pericyte contraction. Angiocrine assays on normal and diabetic pericyte secretomes reveal factors involved in angiogenic control, inflammation, and metabolism. Conclusions. Effects from the diabetic microenvironment appear sustainable in cell culture: pericytes derived from diabetic donor eyes seemingly possess a “metabolic memory” in vitro, which may be linked to original donor health status. Diabetes- and pericyte-dependent effects on EC growth and angiogenesis may reflect alterations in bioactive lipid, angiocrine, and chemomechanical signaling. Altogether, our results suggest that diabetes alters pericyte contractile phenotype and cytoskeletal signaling, which ultimately may serve as a key, initiating event required for retinal endothelial reproliferation, angiogenic activation, and the pathological neovascularization

  12. Activation, Impaired Tumor Necrosis Factor-α Production, and Deficiency of Circulating Mucosal-Associated Invariant T Cells in Patients with Scrub Typhus

    PubMed Central

    Won, Eun Jeong; Cho, Young-Nan; Jung, Hyun-Ju; Kwon, Yong-Soo; Kee, Hae Jin; Ju, Jae Kyun; Kim, Jung-Chul; Kim, Uh Jin; Jang, Hee-Chang; Jung, Sook-In; Kee, Seung-Jung; Park, Yong-Wook

    2016-01-01

    Background Mucosal-associated invariant T (MAIT) cells contribute to protection against certain microorganism infections. However, little is known about the role of MAIT cells in Orientia tsutsugamushi infection. Hence, the aims of this study were to examine the level and function of MAIT cells in patients with scrub typhus and to evaluate the clinical relevance of MAIT cell levels. Methodology/Principal Findings Thirty-eight patients with scrub typhus and 53 health control subjects were enrolled in the study. The patients were further divided into subgroups according to disease severity. MAIT cell level and function in the peripheral blood were measured by flow cytometry. Circulating MAIT cell levels were found to be significantly reduced in scrub typhus patients. MAIT cell deficiency reflects a variety of clinical conditions. In particular, MAT cell levels reflect disease severity. MAIT cells in scrub typhus patients displayed impaired tumor necrosis factor (TNF)-α production, which was restored during the remission phase. In addition, the impaired production of TNF-α by MAIT cells was associated with elevated CD69 expression. Conclusions This study shows that circulating MAIT cells are activated, numerically deficient, and functionally impaired in TNF-α production in patients with scrub typhus. These abnormalities possibly contribute to immune system dysregulation in scrub typhus infection. PMID:27463223

  13. Voltage-gated divalent currents in descending vasa recta pericytes.

    PubMed

    Zhang, Zhong; Lin, Hai; Cao, Chunhua; Khurana, Sandeep; Pallone, Thomas L

    2010-10-01

    Multiple voltage-gated Ca(2+) channel (Ca(V)) subtypes have been reported to participate in control of the juxtamedullary glomerular arterioles of the kidney. Using the patch-clamp technique, we examined whole cell Ca(V) currents of pericytes that contract descending vasa recta (DVR). The dihydropyridine Ca(V) agonist FPL64176 (FPL) stimulated inward Ca(2+) and Ba(2+) currents that activated with threshold depolarizations to -40 mV and maximized between -20 and -10 mV. These currents were blocked by nifedipine (1 μM) and Ni(2+) (100 and 1,000 μM), exhibited slow inactivation, and conducted Ba(2+) > Ca(2+) at a ratio of 2.3:1, consistent with "long-lasting" L-type Ca(V). In FPL, with 1 mM Ca(2+) as charge carrier, Boltzmann fits yielded half-maximal activation potential (V(1/2)) and slope factors of -57.9 mV and 11.0 for inactivation and -33.3 mV and 4.4 for activation. In the absence of FPL stimulation, higher concentrations of divalent charge carriers were needed to measure basal currents. In 10 mM Ba(2+), pericyte Ca(V) currents activated with threshold depolarizations to -30 mV, were blocked by nifedipine, exhibited voltage-dependent block by diltiazem (10 μM), and conducted Ba(2+) > Ca(2+) at a ratio of ∼2:1. In Ca(2+), Boltzmann fits to the data yielded V(1/2) and slope factors of -39.6 mV and 10.0 for inactivation and 2.8 mV and 7.7 for activation. In Ba(2+), V(1/2) and slope factors were -29.2 mV and 9.2 for inactivation and -5.6 mV and 6.1 for activation. Neither calciseptine (10 nM), mibefradil (1 μM), nor ω-agatoxin IVA (20 and 100 nM) blocked basal Ba(2+) currents. Calciseptine (10 nM) and mibefradil (1 μM) also failed to reverse ANG II-induced DVR vasoconstriction, although raising mibefradil concentration to 10 μM was partially effective. We conclude that DVR pericytes predominantly express voltage-gated divalent currents that are carried by L-type channels. PMID:20630935

  14. Gestational methyl donor deficiency alters key proteins involved in neurosteroidogenesis in the olfactory bulbs of newborn female rats and is associated with impaired olfactory performance.

    PubMed

    El Hajj Chehadeh, Sarah; Pourié, Grégory; Martin, Nicolas; Alberto, Jean-Marc; Daval, Jean-Luc; Guéant, Jean-Louis; Leininger-Muller, Brigitte

    2014-03-28

    Gestational methyl donor deficiency (MDD) leads to growth retardation as well as to cognitive and motor disorders in 21-d-old rat pups. These disorders are related to impaired neurogenesis in the cerebral neurogenic areas. Olfactory bulbs (OB), the main target of neuronal progenitors originating from the subventricular zone, play a critical role during the postnatal period by allowing the pups to identify maternal odour. We hypothesised that growth retardation could result from impaired suckling due to impaired olfactory discrimination through imbalanced apoptosis/neurogenesis in the OB. Since neurosteroidogenesis modulates neurogenesis in OB, in the present study, we investigated whether altered neurosteroidogenesis could explain some these effects. Pups born to dams fed a normal diet (n 24) and a MDD diet (n 27) were subjected to olfactory tests during the lactation and weaning periods (n 24 and 20, respectively). We studied the markers of apoptosis/neurogenesis and the expression levels of the key neurosteroidogenic enzyme aromatase, the cholesterol-transfer protein StAR (steroidogenic acute regulatory protein) and the ERα oestrogen receptor and the content of oestradiol in OB. The 21-d-old MDD female pups displayed lower body weight and impaired olfactory discrimination when compared with the control pups. MDD led to greater homocysteine accumulation and more pronounced apoptosis, along with impaired cell proliferation in the OB of female pups. The expression levels of aromatase, StAR and ERα as well as the content of oestradiol were lower in the OB of the MDD female pups than in those of the control female pups. In conclusion, gestational MDD may alter olfactory discrimination performances by affecting neurogenesis, apoptosis and neurosteroidogenesis in OB in a sex-dependent manner. It may be involved in growth retardation through impaired suckling. PMID:24229781

  15. Mice deficient for striatal Vesicular Acetylcholine Transporter (VAChT) display impaired short-term but normal long-term object recognition memory.

    PubMed

    Palmer, Daniel; Creighton, Samantha; Prado, Vania F; Prado, Marco A M; Choleris, Elena; Winters, Boyer D

    2016-09-15

    Substantial evidence implicates Acetylcholine (ACh) in the acquisition of object memories. While most research has focused on the role of the cholinergic basal forebrain and its cortical targets, there are additional cholinergic networks that may contribute to object recognition. The striatum contains an independent cholinergic network comprised of interneurons. In the current study, we investigated the role of this cholinergic signalling in object recognition using mice deficient for Vesicular Acetylcholine Transporter (VAChT) within interneurons of the striatum. We tested whether these striatal VAChT(D2-Cre-flox/flox) mice would display normal short-term (5 or 15min retention delay) and long-term (3h retention delay) object recognition memory. In a home cage object recognition task, male and female VAChT(D2-Cre-flox/flox) mice were impaired selectively with a 15min retention delay. When tested on an object location task, VAChT(D2-Cre-flox/flox) mice displayed intact spatial memory. Finally, when object recognition was tested in a Y-shaped apparatus, designed to minimize the influence of spatial and contextual cues, only females displayed impaired recognition with a 5min retention delay, but when males were challenged with a 15min retention delay, they were also impaired; neither males nor females were impaired with the 3h delay. The pattern of results suggests that striatal cholinergic transmission plays a role in the short-term memory for object features, but not spatial location. PMID:27233822

  16. Nonsteroidal anti-inflammatory drugs alter vasa recta diameter via pericytes.

    PubMed

    Kennedy-Lydon, Teresa; Crawford, Carol; Wildman, Scott S; Peppiatt-Wildman, Claire M

    2015-10-01

    We have previously shown that vasa recta pericytes are known to dilate vasa recta capillaries in the presence of PGE2 and contract vasa recta capillaries when endogenous production of PGE2 is inhibited by the nonselective nonsteroidal anti-inflammatory drug (NSAID) indomethacin. In the present study, we used a live rat kidney slice model to build on these initial observations and provide novel data that demonstrate that nonselective, cyclooxygenase-1-selective, and cyclooxygenase -2-selective NSAIDs act via medullary pericytes to elicit a reduction of vasa recta diameter. Real-time images of in situ vasa recta were recorded, and vasa recta diameters at pericyte and nonpericyte sites were measured offline. PGE2 and epoprostenol (a prostacyclin analog) evoked dilation of vasa recta specifically at pericyte sites, and PGE2 significantly attenuated pericyte-mediated constriction of vasa recta evoked by both endothelin-1 and ANG II. NSAIDs (indomethacin > SC-560 > celecoxib > meloxicam) evoked significantly greater constriction of vasa recta capillaries at pericyte sites than at nonpericyte sites, and indomethacin significantly attenuated the pericyte-mediated vasodilation of vasa recta evoked by PGE2, epoprostenol, bradykinin, and S-nitroso-N-acetyl-l-penicillamine. Moreover, a reduction in PGE2 was measured using an enzyme immune assay after superfusion of kidney slices with indomethacin. In addition, immunohistochemical techniques were used to demonstrate the population of EP receptors in the medulla. Collectively, these data demonstrate that pericytes are sensitive to changes in PGE2 concentration and may serve as the primary mechanism underlying NSAID-associated renal injury and/or further compound-associated tubular damage. PMID:26202223

  17. Structural and Genetic Studies Demonstrate Neurologic Dysfunction in Triosephosphate Isomerase Deficiency Is Associated with Impaired Synaptic Vesicle Dynamics

    PubMed Central

    Roland, Bartholomew P.; Zeccola, Alison M.; Larsen, Samantha B.; Amrich, Christopher G.; Talsma, Aaron D.; Stuchul, Kimberly A.; Heroux, Annie; Levitan, Edwin S.; VanDemark, Andrew P.; Palladino, Michael J.

    2016-01-01

    Triosephosphate isomerase (TPI) deficiency is a poorly understood disease characterized by hemolytic anemia, cardiomyopathy, neurologic dysfunction, and early death. TPI deficiency is one of a group of diseases known as glycolytic enzymopathies, but is unique for its severe patient neuropathology and early mortality. The disease is caused by missense mutations and dysfunction in the glycolytic enzyme, TPI. Previous studies have detailed structural and catalytic changes elicited by disease-associated TPI substitutions, and samples of patient erythrocytes have yielded insight into patient hemolytic anemia; however, the neuropathophysiology of this disease remains a mystery. This study combines structural, biochemical, and genetic approaches to demonstrate that perturbations of the TPI dimer interface are sufficient to elicit TPI deficiency neuropathogenesis. The present study demonstrates that neurologic dysfunction resulting from TPI deficiency is characterized by synaptic vesicle dysfunction, and can be attenuated with catalytically inactive TPI. Collectively, our findings are the first to identify, to our knowledge, a functional synaptic defect in TPI deficiency derived from molecular changes in the TPI dimer interface. PMID:27031109

  18. Detrimental role of pericyte Nox4 in the acute phase of brain ischemia.

    PubMed

    Nishimura, Ataru; Ago, Tetsuro; Kuroda, Junya; Arimura, Koichi; Tachibana, Masaki; Nakamura, Kuniyuki; Wakisaka, Yoshinobu; Sadoshima, Junichi; Iihara, Koji; Kitazono, Takanari

    2016-06-01

    Pericytes are mural cells abundantly present in cerebral microvessels and play important roles, including the formation and maintenance of the blood-brain barrier. Nox4 is a major source of reactive oxygen species in cardiovascular cells and modulate cellular functions, particularly under pathological conditions. In the present study, we found that the expression of Nox4 was markedly induced in microvascular cells, including pericytes, in peri-infarct areas after middle cerebral artery occlusion stroke models in mice. The upregulation of Nox4 was greater in a permanent middle cerebral artery occlusion model compared with an ischemia/reperfusion transient middle cerebral artery occlusion model. We performed permanent middle cerebral artery occlusion on mice with Nox4 overexpression in pericytes (Tg-Nox4). Infarct volume was significantly greater with enhanced reactive oxygen species production and blood-brain barrier breakdown in peri-infarct areas in Tg-Nox4, compared with littermate controls. In cultured brain pericytes, Nox4 was significantly upregulated by hypoxia and was promptly downregulated by reoxygenation. Phosphorylation of NFκB and production of matrix metalloproteinase 9 were significantly increased in both cultured pericytes overexpressing Nox4 and in peri-infarct areas in Tg-Nox4. Collectively, Nox4 is upregulated in pericytes in peri-infarct areas after acute brain ischemia and may enhance blood-brain barrier breakdown through activation of NFκB and matrix metalloproteinase 9, thereby causing enlargement of infarct volume. PMID:26661159

  19. The Role of Pericytes in Neurovascular Unit Remodeling in Brain Disorders

    PubMed Central

    ElAli, Ayman; Thériault, Peter; Rivest, Serge

    2014-01-01

    Neurons are extremely vulnerable cells that tightly rely on the brain’s highly dynamic and complex vascular network that assures an accurate and adequate distribution of nutrients and oxygen. The neurovascular unit (NVU) couples neuronal activity to vascular function, controls brain homeostasis, and maintains an optimal brain microenvironment adequate for neuronal survival by adjusting blood-brain barrier (BBB) parameters based on brain needs. The NVU is a heterogeneous structure constituted by different cell types that includes pericytes. Pericytes are localized at the abluminal side of brain microvessels and contribute to NVU function. Pericytes play essential roles in the development and maturation of the neurovascular system during embryogenesis and stability during adulthood. Initially, pericytes were described as contractile cells involved in controlling neurovascular tone. However, recent reports have shown that pericytes dynamically respond to stress induced by injury upon brain diseases, by chemically and physically communicating with neighboring cells, by their immune properties and by their potential pluripotent nature within the neurovascular niche. As such, in this paper, we would like to review the role of pericytes in NVU remodeling, and their potential as targets for NVU repair strategies and consequently neuroprotection in two pathophysiologically distinct brain disorders: ischemic stroke and Alzheimer’s disease (AD). PMID:24743889

  20. Dopamine receptor D5 deficiency results in a selective reduction of hippocampal NMDA receptor subunit NR2B expression and impaired memory.

    PubMed

    Moraga-Amaro, Rodrigo; González, Hugo; Ugalde, Valentina; Donoso-Ramos, Juan Pablo; Quintana-Donoso, Daisy; Lara, Marcelo; Morales, Bernardo; Rojas, Patricio; Pacheco, Rodrigo; Stehberg, Jimmy

    2016-04-01

    Pharmacological evidence associates type I dopamine receptors, including subtypes D1 and D5, with learning and memory. Analyses using genetic approaches have determined the relative contribution of dopamine receptor D1 (D1R) in cognitive tasks. However, the lack of drugs that can discriminate between D1R and D5R has made the pharmacological distinction between the two receptors difficult. Here, we aimed to determine the role of D5R in learning and memory. In this study we tested D5R knockout mice and wild-type littermates in a battery of behavioral tests, including memory, attention, locomotion, anxiety and motivational evaluations. Our results show that genetic deficiency of D5R significantly impairs performance in the Morris water maze paradigm, object location and object recognition memory, indicating a relevant role for D5R in spatial memory and recognition memory. Moreover, the lack of D5R resulted in decreased exploration and locomotion. In contrast, D5R deficiency had no impact on working memory, anxiety and depressive-like behavior, measured using the spontaneous alternation, open-field, tail suspension test, and forced swimming test. Electrophysiological analyses performed on hippocampal slices showed impairment in long-term-potentiation in mice lacking D5R. Further analyses at the molecular level showed that genetic deficiency of D5R results in a strong and selective reduction in the expression of the NMDA receptor subunit NR2B in the hippocampus. These findings demonstrate the relevant contribution of D5R in memory and suggest a functional interaction of D5R with hippocampal glutamatergic pathways. PMID:26714288

  1. COOH-Terminal Collagen Q (COLQ) Mutants Causing Human Deficiency of Endplate Acetylcholinesterase Impair the Interaction of ColQ with Proteins of the Basal Lamina

    PubMed Central

    Arredondo, Juan; Lara, Marian; Ng, Fiona; Gochez, Danielle A.; Lee, Diana C.; Logia, Stephanie P.; Nguyen, Joanna; Maselli, Ricardo A.

    2014-01-01

    Collagen Q (ColQ) is a key multidomain functional protein of the neuromuscular junction (NMJ), crucial for anchoring acetylcholinesterase (AChE) to the basal lamina (BL) and accumulating AChE at the NMJ. The attachment of AChE to the BL is primarily accomplished by the binding of the ColQ collagen domain to the heparan sulfate proteoglycan perlecan and the COOH-terminus to the muscle-specific receptor tyrosine kinase (MuSK), which in turn plays a fundamental role in the development and maintenance of the NMJ. Yet, the precise mechanism by which ColQ anchors AChE at the NMJ remains unknown. We identified five novel mutations at the COOH-terminus of ColQ in seven patients from five families affected with endplate (EP) AChE deficiency. We found that the mutations do not affect the assembly of ColQ with AChE to form asymmetric forms of AChE or impair the interaction of ColQ with perlecan. By contrast, all mutations impair in varied degree the interaction of ColQ to MuSK as well as basement membrane extract (BME) that have no detectable MuSK. Our data confirm that the interaction of ColQ to perlecan and MuSK is crucial for anchoring AChE to the NMJ. In addition, the identified COOH-terminal mutants not only reduce the interaction of ColQ with MuSK, but also diminish the interaction of ColQ with BME. These findings suggest that the impaired attachment of COOH-terminal mutants causing EP AChE deficiency is in part independent of MuSK, and that the COOH-terminus of ColQ may interact with other proteins at the BL. PMID:24281389

  2. Folate–vitamin B-12 interaction in relation to cognitive impairment, anemia, and biochemical indicators of vitamin B-12 deficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous reports on pernicious anemia treatment suggested that high folic acid intake adversely influences the natural history of vitamin B-12 deficiency, which affects many elderly individuals. However, experimental investigation of this hypothesis is unethical, and the few existing observational d...

  3. Micronutrient deficiencies are associated with impaired immune response and higher burden of respiratory infections in elderly Ecuadorians

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The proportion of the population in Latin America above the age of 60 is expected to rise substantially. To better define the prevalence of infectious diseases and micronutrient deficiencies, to assess immunological status, and to evaluate associations between nutritional status and infection, we pe...

  4. Micronutrient Deficiencies Are Associated with Impaired Immune Response and Higher Burden of Respiratory Infections in Elderly Ecuadorians12

    PubMed Central

    Hamer, Davidson H.; Sempértegui, Fernando; Estrella, Bertha; Tucker, Katherine L.; Rodríguez, Alicia; Egas, Josefina; Dallal, Gerard E.; Selhub, Jacob; Griffiths, Jeffrey K.; Meydani, Simin Nikbin

    2009-01-01

    The proportion of the Latin American population above age 65 y is expected to rise substantially. To better define the prevalence of infectious diseases and micronutrient deficiencies, assess immunological status, and evaluate associations between nutritional status and infection, we performed a cross-sectional study of elderly Ecuadorians in a low-income peri-urban community in Quito, Ecuador. Culturally adapted questionnaires, delayed type hypersensitivity (DTH) skin response, micronutrient, and immunological assays were performed in randomly selected Ecuadorians aged ≥65 y. Multiple linear and logistic regression models were developed to assess relationships between micronutrient concentrations and history of infection, DTH, and immune function. Participants (n = 352; mean age ± SD, 74.4 ± 6.4 y) recalled recent episodes of colds/influenza-like syndromes (62.8%), cough (61.0%), urinary tract infection (37.9%), diarrhea (32.2%), fever (24.1%), and pneumonia (3.5%). A prospective substudy of respiratory infections (RI) in 203 elderly revealed similar findings. Colds and pneumonia occurred in 42.8 and 7.9% of participants, respectively, during 737 person-weeks of observation (3.6 ± 1.1 wk per person). Anemia and micronutrient deficiencies, especially for vitamins C, D, B-6, and B-12 and folic acid and zinc, were common. Plasma vitamin C was associated with interferon-γ (IFNγ) (P < 0.01) and zinc with IFNγ and interleukin-2 (each P < 0.0001). RI history was associated with any micronutrient deficiency (P < 0.001). The burden of infectious diseases, micronutrient deficiencies, and anemia was substantial in this elderly Ecuadorian population. Deficiencies of essential vitamins and minerals place these elderly adults at risk for infections through their negative impact on immune function. PMID:19056665

  5. Excess and deficient omega-3 fatty acid during pregnancy and lactation cause impaired neural transmission in rat pups.

    PubMed

    Church, M W; Jen, K-L C; Dowhan, L M; Adams, B R; Hotra, J W

    2008-01-01

    Omega-3 fatty acids (omega-3 FA) consumption during pregnancy and lactation is beneficial to fetal and infant growth and may reduce the severity of preterm births. Thus, scientists and clinicians are recommending increasingly higher omega-3 FA doses for pregnant women and nursing babies for advancing the health of preterm, low birth weight, and normal babies. In contrast, some studies report that over-supplementation with omega-3 FA can have adverse effects on fetal and infant development by causing a form of nutritional toxicity. Our goal was to assess the effects of omega-3 FA excess and deficiency during pregnancy and lactation on the offspring's neural transmission as evidenced by their auditory brainstem responses (ABR). Female Wistar rats were given one of three diets from day 1 of pregnancy through lactation. The three diets were the Control omega-3 FA condition (omega-3/omega-6 ratio approximately 0.14), the Deficient omega-3 FA condition (omega-3/omega-6 ratio approximately 0%) and the Excess omega-3 FA condition (omega-3/omega-6 ratio approximately 14.0). The Control diet contained 7% soybean oil, whereas the Deficient diet contained 7% safflower oil and the Excess diet contained 7% fish oil. The offspring were ABR-tested on postnatal day 24. The rat pups in the Excess group had prolonged ABR latencies in comparison to the Control group, indicating slowed neural transmission times. The pups in the Excess group also showed postnatal growth restriction. The Deficient group showed adverse effects that were milder than those seen in the Excess group. Milk fatty acid profiles reflected the fatty acid profiles of the maternal diets. In conclusion, excess or deficient amounts of omega-3 FA during pregnancy and lactation adversely affected the offspring's neural transmission times and postnatal thriving. Consuming either large or inadequate amounts of omega-3 FA during pregnancy and lactation seems inadvisable because of the potential for adverse effects on

  6. MTHFR deficiency or reduced intake of folate or choline in pregnant mice results in impaired short-term memory and increased apoptosis in the hippocampus of wild-type offspring.

    PubMed

    Jadavji, N M; Deng, L; Malysheva, O; Caudill, M A; Rozen, R

    2015-08-01

    Genetic or nutritional disturbances in one-carbon metabolism, with associated hyperhomocysteinemia, can result in complex disorders including pregnancy complications and neuropsychiatric diseases. In earlier work, we showed that mice with a complete deficiency of methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in folate and homocysteine metabolism, had cognitive impairment with disturbances in choline metabolism. Maternal demands for folate and choline are increased during pregnancy and deficiencies of these nutrients result in several negative outcomes including increased resorption and delayed development. The goal of this study was to investigate the behavioral and neurobiological impact of a maternal genetic deficiency in MTHFR or maternal nutritional deficiency of folate or choline during pregnancy on 3-week-old Mthfr(+/+) offspring. Mthfr(+/+) and Mthfr(+/-) females were placed on control diets (CD); and Mthfr(+/+) females were placed on folate-deficient diets (FD) or choline-deficient diets (ChDD) throughout pregnancy and lactation until their offspring were 3weeks of age. Short-term memory was assessed in offspring, and hippocampal tissue was evaluated for morphological changes, apoptosis, proliferation and choline metabolism. Maternal MTHFR deficiency resulted in short-term memory impairment in offspring. These dams had elevated levels of plasma homocysteine when compared with wild-type dams. There were no differences in plasma homocysteine in offspring. Increased apoptosis and proliferation was observed in the hippocampus of offspring from Mthfr(+/-) mothers. In the maternal FD and ChDD study, offspring also showed short-term memory impairment with increased apoptosis in the hippocampus; increased neurogenesis was observed in ChDD offspring. Choline acetyltransferase protein was increased in the offspring hippocampus of both dietary groups and betaine was decreased in the hippocampus of FD offspring. Our results reveal short-term memory

  7. Pericytes: Properties, Functions and Applications in Tissue Engineering.

    PubMed

    Gökçinar-Yagci, Beyza; Uçkan-Çetinkaya, Duygu; Çelebi-Saltik, Betül

    2015-08-01

    Mesenchymal stem cells (MSCs) are one of the most studied adult stem cells and in recent years. They have become attractive agents/cell source for cellular therapy and regenerative medicine applications. During investigations about their origin, researchers hypothesized that perivascular regions are the common anatomical regions where MSCs come from and perivascular cells like pericytes (PCs) (Rouget cells, mural cells) are in vivo counterparts of MSCs. Beside capillaries and microvessels as their most common locations, PCs are also found in large vessels (arteries and veins). They can be isolated from several tissues and organs particularly from retina and brain. There are different approaches about their isolation, characterization and culture but there has been no common protocol yet because of the lack of defined PC-specific marker. They make special contact with endothelial cells in the basement membrane and have very important functions in several tissues and organs. They participate in vascular development, stabilization, maturation, and remodeling, blood pressure control, endothelial cell proliferation and differentiation, contractility of vascular smooth muscle cells, wound healing, vasculogenesis and angiogenesis, long-term maintenance of hematopoietic stem cells in bone marrow niche. Their multipotential differentiation capacity and participation in many events in the body make PCs preferred cells in tissue engineering applications including 3D blood-brain barrier models, skeletal muscle constructs, bone tissue engineering and tissue-engineered vascular grafts. PMID:25865146

  8. Matrix metalloproteinase-9 deficiency impairs host defense mechanisms against Streptococcus pneumoniae in a mouse model of bacterial meningitis.

    PubMed

    Böttcher, Tobias; Spreer, Annette; Azeh, Ivo; Nau, Roland; Gerber, Joachim

    2003-03-01

    Matrix metalloproteinase-9 (MMP-9) appears to contribute to blood-brain barrier damage and neuronal injury in bacterial meningitis. To further explore the function of MMP-9 in meningeal inflammation, we injected 10(4) colony forming units (CFU) of a Streptoccocus pneumoniae type 3 strain into the right forebrain of MMP-9 deficient mice (MMP-9(-/-), n=16) and wild-type controls (129 x B6, n=15). The clinical course of the disease, leukocyte recruitment into the subarachnoid space and bacterial titers in the brain did not differ. Yet, clearance of the bacteria from blood (log CFU/ml 4.7 [3.8/5.4] vs. 3.6 [3.0/4.0]; P=0.005) and spleen homogenates (log CFU/ml 5.3 [4.8/5.5] vs. 4.0 [2.8/4.7]; P=0.01) was reduced in MMP-9 deficient mice. A reduced systemic bacterial clearance of MMP-9(-/-) mice was confirmed in experimental S. pneumoniae peritonitis/sepsis. This implies a compromised systemic, but not intracerebral host response against S. pneumoniae in MMP-9 deficiency. PMID:12581831

  9. PICK1 and ICA69 control insulin granule trafficking and their deficiencies lead to impaired glucose tolerance.

    PubMed

    Cao, Mian; Mao, Zhuo; Kam, Chuen; Xiao, Nan; Cao, Xiaoxing; Shen, Chong; Cheng, Kenneth K Y; Xu, Aimin; Lee, Kwong-Man; Jiang, Liwen; Xia, Jun

    2013-01-01

    Diabetes is a metabolic disorder characterized by hyperglycemia. Insulin, which is secreted by pancreatic beta cells, is recognized as the critical regulator of blood glucose, but the molecular machinery responsible for insulin trafficking remains poorly defined. In particular, the roles of cytosolic factors that govern the formation and maturation of insulin granules are unclear. Here we report that PICK1 and ICA69, two cytosolic lipid-binding proteins, formed heteromeric BAR-domain complexes that associated with insulin granules at different stages of their maturation. PICK1-ICA69 heteromeric complexes associated with immature secretory granules near the trans-Golgi network (TGN). A brief treatment of Brefeldin A, which blocks vesicle budding from the Golgi, increased the amount of PICK1 and ICA69 at TGN. On the other hand, mature secretory granules were associated with PICK1 only, not ICA69. PICK1 deficiency in mice caused the complete loss of ICA69 and led to increased food and water intake but lower body weight. Glucose tolerance tests demonstrated that these mutant mice had high blood glucose, a consequence of insufficient insulin. Importantly, while the total insulin level was reduced in PICK1-deficient beta cells, proinsulin was increased. Lastly, ICA69 knockout mice also displayed similar phenotype as the mice deficient in PICK1. Together, our results indicate that PICK1 and ICA69 are key regulators of the formation and maturation of insulin granules. PMID:23630453

  10. Impairment of Respiratory Chain under Nutrient Deficiency in Plants: Does it Play a Role in the Regulation of Iron and Sulfur Responsive Genes?

    PubMed Central

    Vigani, Gianpiero; Briat, Jean-François

    2016-01-01

    Plant production and plant product quality strongly depend on the availability of mineral nutrients. Among them, sulfur (S) and iron (Fe) play a central role, as they are needed for many proteins of the respiratory chain. Plant mitochondria play essential bioenergetic and biosynthetic functions as well as they have an important role in signaling processes into the cell. Here, by comparing several transcriptomic data sets from plants impaired in their respiratory function with the genes regulated under Fe or S deficiencies obtained from other data sets, nutrient-responsive genes potentially regulated by hypothetical mitochondrial retrograde signaling pathway are evidenced. It leads us to hypothesize that plant mitochondria could be, therefore, required for regulating the expression of key genes involved both in Fe and S metabolisms. PMID:26779219

  11. A role for VEGF as a negative regulator of pericyte function and vessel maturation.

    PubMed

    Greenberg, Joshua I; Shields, David J; Barillas, Samuel G; Acevedo, Lisette M; Murphy, Eric; Huang, Jianhua; Scheppke, Lea; Stockmann, Christian; Johnson, Randall S; Angle, Niren; Cheresh, David A

    2008-12-11

    Angiogenesis does not only depend on endothelial cell invasion and proliferation: it also requires pericyte coverage of vascular sprouts for vessel stabilization. These processes are coordinated by vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) through their cognate receptors on endothelial cells and vascular smooth muscle cells (VSMCs), respectively. PDGF induces neovascularization by priming VSMCs/pericytes to release pro-angiogenic mediators. Although VEGF directly stimulates endothelial cell proliferation and migration, its role in pericyte biology is less clear. Here we define a role for VEGF as an inhibitor of neovascularization on the basis of its capacity to disrupt VSMC function. Specifically, under conditions of PDGF-mediated angiogenesis, VEGF ablates pericyte coverage of nascent vascular sprouts, leading to vessel destabilization. At the molecular level, VEGF-mediated activation of VEGF-R2 suppresses PDGF-Rbeta signalling in VSMCs through the assembly of a previously undescribed receptor complex consisting of PDGF-Rbeta and VEGF-R2. Inhibition of VEGF-R2 not only prevents assembly of this receptor complex but also restores angiogenesis in tissues exposed to both VEGF and PDGF. Finally, genetic deletion of tumour cell VEGF disrupts PDGF-Rbeta/VEGF-R2 complex formation and increases tumour vessel maturation. These findings underscore the importance of VSMCs/pericytes in neovascularization and reveal a dichotomous role for VEGF and VEGF-R2 signalling as both a promoter of endothelial cell function and a negative regulator of VSMCs and vessel maturation. PMID:18997771

  12. Interferon Consensus Sequence Binding Protein–deficient Mice Display Impaired Resistance to Intracellular Infection Due to a Primary Defect in Interleukin 12 p40 Induction

    PubMed Central

    Scharton-Kersten, Tanya; Contursi, Cristina; Masumi, Atsuko; Sher, Alan; Ozato, Keiko

    1997-01-01

    Mice lacking the transcription factor interferon consensus sequence binding protein (ICSBP), a member of the interferon regulatory factor family of transcription proteins, were infected with the intracellular protozoan, Toxoplasma gondii. ICSBP-deficient mice exhibited unchecked parasite replication in vivo and rapidly succumbed within 14 d after inoculation with an avirulent Toxoplasma strain. In contrast, few intracellular parasites were observed in wild-type littermates and these animals survived for at least 60 d after infection. Analysis of cytokine synthesis in vitro and in vivo revealed a major deficiency in the expression of both interferon (IFN)-γ and interleukin (IL)-12 p40 in the T. gondii exposed ICSBP−/− animals. In related experiments, macrophages from uninfected ICSBP−/− mice were shown to display a selective impairment in the mRNA expression of IL-12 p40 but not IL-1α, IL-1β, IL-1Ra, IL-6, IL-10, or TNF-α in response to live parasites, parasite antigen, lipopolysaccharide, or Staphylococcus aureus. This selective defect in IL-12 p40 production was observed regardless of whether the macrophages had been primed with IFN-γ. We hypothesize that the impaired synthesis of IL-12 p40 in ICSBP−/− animals is the primary lesion responsible for the loss in resistance to T. gondii because IFN-γ–induced parasite killing was unimpaired in vitro and, more importantly, administration of exogenous IL-12 in vivo significantly prolonged survival of the infected mice. Together these findings implicate ICSBP as a major transcription factor which directly or indirectly regulates IL-12 p40 gene activation and, as a consequence, IFN-γ–dependent host resistance. PMID:9348310

  13. Testosterone deficiency induced by progressive stages of diabetes mellitus impairs glucose metabolism and favors glycogenesis in mature rat Sertoli cells.

    PubMed

    Rato, Luís; Alves, Marco G; Duarte, Ana I; Santos, Maria S; Moreira, Paula I; Cavaco, José E; Oliveira, Pedro F

    2015-09-01

    The incidence of type 2 diabetes mellitus and its prodromal stage, pre-diabetes, is rapidly increasing among young men, leading to disturbances in testosterone synthesis. However, the impact of testosterone deficiency induced by these progressive stages of diabetes on the metabolic behavior of Sertoli cells remains unknown. We evaluated the effects of testosterone deficiency associated with pre-diabetes and type 2 diabetes on Sertoli cells metabolism, by measuring (1) the expression and/or activities of glycolysis and glycogen metabolism-related proteins and (2) the metabolite secretion/consumption in Sertoli cells obtained from rat models of different development stages of the disease, to unveil the mechanisms by which testosterone deregulation may affect spermatogenesis. Glucose and pyruvate uptake were decreased in cells exposed to the testosterone concentration found in pre-diabetic rats (600nM), whereas the decreased testosterone concentrations found in type 2 diabetic rats (7nM) reversed this profile. Lactate production was not altered, although the expression and/or activity of lactate dehydrogenase and monocarboxylate transporter 4 were affected by progressive testosterone-deficiency. Sertoli cells exposed to type 2 diabetic conditions exhibited intracellular glycogen accumulation. These results illustrate that gradually reduced levels of testosterone, induced by progressive stages of diabetes mellitus, favor a metabolic reprogramming toward glycogen synthesis. Our data highlights a pivotal role for testosterone in the regulation of spermatogenesis metabolic support by Sertoli cells, particularly in individuals suffering from metabolic diseases. Such alterations may be in the basis of male subfertility/infertility associated with the progression of diabetes mellitus. PMID:26148570

  14. Decreased Npas4 and Arc mRNA Levels in the Hippocampus of Aged Memory-Impaired Wild-Type But Not Memory Preserved 11β-HSD1 Deficient Mice.

    PubMed

    Qiu, J; Dunbar, D R; Noble, J; Cairns, C; Carter, R; Kelly, V; Chapman, K E; Seckl, J R; Yau, J L W

    2016-01-01

    Mice deficient in the glucocorticoid-regenerating enzyme 11β-HSD1 resist age-related spatial memory impairment. To investigate the mechanisms and pathways involved, we used microarrays to identify differentially expressed hippocampal genes that associate with cognitive ageing and 11β-HSD1. Aged wild-type mice were separated into memory-impaired and unimpaired relative to young controls according to their performance in the Y-maze. All individual aged 11β-HSD1-deficient mice showed intact spatial memory. The majority of differentially expressed hippocampal genes were increased with ageing (e.g. immune/inflammatory response genes) with no genotype differences. However, the neuronal-specific transcription factor, Npas4, and immediate early gene, Arc, were reduced (relative to young) in the hippocampus of memory-impaired but not unimpaired aged wild-type or aged 11β-HSD1-deficient mice. A quantitative reverse transcriptase-polymerase chain reaction and in situ hybridisation confirmed reduced Npas4 and Arc mRNA expression in memory-impaired aged wild-type mice. These findings suggest that 11β-HSD1 may contribute to the decline in Npas4 and Arc mRNA levels associated with memory impairment during ageing, and that decreased activity of synaptic plasticity pathways involving Npas4 and Arc may, in part, underlie the memory deficits seen in cognitively-impaired aged wild-type mice. PMID:26563879

  15. 4-Ethylphenyl-Cobalamin Impairs Tissue Uptake of Vitamin B12 and Causes Vitamin B12 Deficiency in Mice

    PubMed Central

    Mutti, Elena; Ruetz, Markus; Birn, Henrik; Kräutler, Bernhard; Nexo, Ebba

    2013-01-01

    Coβ-4-ethylphenyl-cob(III) alamin (EtPhCbl) is an organometallic analogue of vitamin B12 (CNCbl) which binds to transcobalamin (TC), a plasma protein that facilitates the cellular uptake of cobalamin (Cbl). In vitro assays with key enzymes do not convert EtPhCbl to the active coenzyme forms of Cbl suggesting that administration of EtPhCbl may cause cellular Cbl deficiency. Here, we investigate the in vivo effect of EtPhCbl in mice and its ability, if any, to induce Cbl deficiency. We show that EtPhCbl binds to mouse TC and we examined mice that received 3.5 nmol/24h EtPhCbl (n=6), 3.5 nmol/24h CNCbl (n=7) or NaCl (control group) (n=5) through osmotic mini-pumps for four weeks. We analyzed plasma, urine, liver, spleen, submaxillary glands and spinal cord for Cbl and markers of Cbl deficiency including methylmalonic acid (MMA) and homocysteine (tHcy). Plasma MMA (mean±SEM) was elevated in animals treated with EtPhCbl (1.01±0.12 µmol/L) compared to controls (0.30±0.02 µmol/L) and CNCbl (0.29±0.01 µmol/L) treated animals. The same pattern was observed for tHcy. Plasma total Cbl concentration was higher in animals treated with EtPhCbl (128.82±1.87 nmol/L) than in CNCbl treated animals (87.64±0.93 nmol/L). However, the organ levels of total Cbl were significantly lower in animals treated with EtPhCbl compared to CNCbl treated animals or controls, notably in the liver (157.07±8.56 pmol/g vs. 603.85±20.02 pmol/g, and 443.09±12.32 pmol/g, respectively). Differences between the three groups was analysed using one-way ANOVA and, Bonferroni post-hoc test. EtPhCbl was present in all tissues, except the spinal cord, accounting for 35-90% of total Cbl. In conclusion, treatment with EtPhCbl induces biochemical evidence of Cbl deficiency. This may in part be caused by a compromised tissue accumulation of Cbl. PMID:24073261

  16. Digalactosyl-diacylglycerol deficiency impairs the capacity for photosynthetic intersystem electron transport and state transitions in Arabidopsis thaliana due to photosystem I acceptor-side limitations.

    PubMed

    Ivanov, Alexander G; Hendrickson, Luke; Krol, Marianna; Selstam, Eva; Oquist, Gunnar; Hurry, Vaughan; Huner, Norman P A

    2006-08-01

    Compared with wild type, the dgd1 mutant of Arabidopsis thaliana exhibited a lower amount of PSI-related Chl-protein complexes and lower abundance of the PSI-associated polypeptides, PsaA, PsaB, PsaC, PsaL and PsaH, with no changes in the levels of Lhca1-4. Functionally, the dgd1 mutant exhibited a significantly lower light-dependent, steady-state oxidation level of P700 (P700(+)) in vivo, a higher intersystem electron pool size, restricted linear electron transport and a higher rate of reduction of P700(+) in the dark, indicating an increased capacity for PSI cyclic electron transfer compared with the wild type. Concomitantly, the dgd1 mutant exhibited a higher sensitivity to and incomplete recovery of photoinhibition of PSI. Furthermore, dgd1 exhibited a lower capacity to undergo state transitions compared with the wild type, which was associated with a higher reduction state of the plastoquinone (PQ) pool. We conclude that digalactosyl-diacylglycerol (DGDG) deficiency results in PSI acceptor-side limitations that alter the flux of electrons through the photosynthetic electron chain and impair the regulation of distribution of excitation energy between the photosystems. These results are discussed in terms of thylakoid membrane domain reorganization in response to DGDG deficiency in A. thaliana. PMID:16854937

  17. ACE2 deficiency reduces β-cell mass and impairs β-cell proliferation in obese C57BL/6 mice.

    PubMed

    Shoemaker, Robin; Yiannikouris, Frederique; Thatcher, Sean; Cassis, Lisa

    2015-10-01

    Drugs that inhibit the renin-angiotensin system (RAS) decrease the onset of type 2 diabetes (T2D). Pancreatic islets express RAS components, including angiotensin-converting enzyme 2 (ACE2), which cleaves angiotensin II (Ang II) to angiotensin-(1-7) [Ang-(1-7)]. Overexpression of ACE2 in pancreas of diabetic mice improved glucose homeostasis. The purpose of this study was to determine if deficiency of endogenous ACE2 contributes to islet dysfunction and T2D. We hypothesized that ACE2 deficiency potentiates the decline in β-cell function and augments the development of diet-induced T2D. Male Ace2(+/y) or Ace2(-/y) mice were fed a low-fat (LF) or high-fat (HF) diet for 1 or 4 mo. A subset of 1-mo HF-fed mice were infused with Sal (Sal), losartan (Los), or Ang-(1-7). At 4 mo, while both genotypes of HF-fed mice developed a similar level of insulin resistance, adaptive hyperinsulinemia was reduced in Ace2(-/y) vs. Ace2(+/y) mice. Similarly, in vivo glucose-stimulated insulin secretion (GSIS) was reduced in 1-mo HF-fed Ace2(-/y) compared with Ace2(+/y) mice, resulting in augmented hyperglycemia. The average islet area was significantly smaller in both LF- and HF-fed Ace2(-/y) vs. Ace2(+/y) mice. Additionally, β-cell mass and proliferation were reduced significantly in HF-fed Ace2(-/y) vs. Ace2(+/y) mice. Neither infusion of Los nor Ang-(1-7) was able to correct impaired in vivo GSIS of HF-fed ACE2-deficient mice. These results demonstrate a critical role for endogenous ACE2 in the adaptive β-cell hyperinsulinemic response to HF feeding through regulation of β-cell proliferation and growth. PMID:26389599

  18. Deficiency of prohormone convertase dPC2 (AMONTILLADO) results in impaired production of bioactive neuropeptide hormones in Drosophila.

    PubMed

    Wegener, Christian; Herbert, Henrik; Kahnt, Jörg; Bender, Michael; Rhea, Jeanne M

    2011-08-01

    Peptide hormones synthesized by secretory neurons in the CNS are important regulators of physiology, behavior, and development. Like other neuropeptides, they are synthesized from larger precursor molecules by a specific set of enzymes. Using a combination of neurogenetics, immunostainings, and direct mass spectrometric profiling, we show that the presence of Drosophila prohormone convertase 2 encoded by the gene amontillado (amon) is a prerequisite for the proper processing of neuropeptide hormones from the major neurohemal organs of the CNS. A loss of amon correlates with a loss of neuropeptide hormone signals from the larval ring gland and perisympathetic organs. Neuropeptide hormone signals were still detectable in the adult corpora cardiaca of older amon-deficient flies which were amon heat-shock-rescued until eclosion. A semiquantification by direct peptide profiling using stable isotopic standards showed, however, that their neuropeptide hormone levels are strongly reduced. Targeted expression of GFP under the control of amon regulatory regions revealed a co-localization with the investigated peptide hormones in secretory neurons of the brain and ventral nerve cord. The lack of AMON activity resulted in a deficiency of L3 larva to enter the wandering phase. In conclusion, our findings provide the first direct evidence that AMON is a key enzyme in the production of neuropeptides in the fruitfly. PMID:21138435

  19. Inherited human cPLA2α deficiency is associated with impaired eicosanoid biosynthesis, small intestinal ulceration, and platelet dysfunction

    PubMed Central

    Adler, David H.; Cogan, Joy D.; Phillips, John A.; Schnetz-Boutaud, Nathalie; Milne, Ginger L.; Iverson, Tina; Stein, Jeffrey A.; Brenner, David A.; Morrow, Jason D.; Boutaud, Olivier; Oates, John A.

    2008-01-01

    Cytosolic phospholipase A2α (cPLA2α) hydrolyzes arachidonic acid from cellular membrane phospholipids, thereby providing enzymatic substrates for the synthesis of eicosanoids, such as prostaglandins and leukotrienes. Considerable understanding of cPLA2α function has been derived from investigations of the enzyme and from cPLA2α-null mice, but knowledge of discrete roles for this enzyme in humans is limited. We investigated a patient hypothesized to have an inherited prostanoid biosynthesis deficiency due to his multiple, complicated small intestinal ulcers despite no use of cyclooxygenase inhibitors. Levels of thromboxane B2 and 12-hydroxyeicosatetraenoic acid produced by platelets and leukotriene B4 released from calcium ionophore–activated blood were markedly reduced, indicating defective enzymatic release of the arachidonic acid substrate for the corresponding cyclooxygenase and lipoxygenases. Platelet aggregation and degranulation induced by adenosine diphosphate or collagen were diminished but were normal in response to arachidonic acid. Two heterozygous single base pair mutations and a known SNP were found in the coding regions of the patient’s cPLA2α genes (p.[Ser111Pro]+[Arg485His; Lys651Arg]). The total PLA2 activity in sonicated platelets was diminished, and the urinary metabolites of prostacyclin, prostaglandin E2, prostaglandin D2, and thromboxane A2 were also reduced. These findings characterize what we believe is a novel inherited deficiency of cPLA2. PMID:18451993

  20. Senescence Marker Protein-30 (SMP30) Deficiency Impairs Myocardium-Induced Dilation of Coronary Arterioles Associated with Reactive Oxygen Species

    PubMed Central

    Mizukami, Hiroyuki; Saitoh, Shu-ichi; Machii, Hirofumi; Yamada, Shinya; Hoshino, Yasuto; Misaka, Tomofumi; Ishigami, Akihito; Takeishi, Yasuchika

    2013-01-01

    Senescence marker protein-30 (SMP30) decreases with aging. Mice with SMP30 deficiency, a model of aging, have a short lifespan with increased oxidant stress. To elucidate SMP30’s effect on coronary circulation derived from myocytes, we measured the changes in the diameter of isolated coronary arterioles in wild-type (WT) mice exposed to supernatant collected from isolated paced cardiac myocytes from SMP30 KO or WT mice. Pacing increased hydrogen peroxide in myocytes, and hydrogen peroxide was greater in SMP30 KO myocytes compared to WT myocytes. Antimycin enhanced and FCCP (oxidative phosphorylation uncoupler in mitochondria) decreased superoxide production in both groups. Addition of supernatant from stimulated myocytes, either SMP30 KO or WT, caused vasodilation. The degree of the vasodilation response to supernatant was smaller in SMP30 KO mice compared to WT mice. Administration of catalase to arterioles eliminated vasodilation in myocyte supernatant of WT mice and converted vasodilation to vasoconstriction in myocyte supernatant of SMP30 KO mice. This vasoconstriction was eliminated by olmesartan, an angiotensin II receptor antagonist. Thus, SMP30 deficiency combined with oxidant stress increases angiotensin and hydrogen peroxide release from cardiac myocytes. SMP30 plays an important role in the regulation of coronary vascular tone by myocardium. PMID:23629672

  1. Early retinal neurodegeneration and impaired Ran-mediated nuclear import of TDP-43 in progranulin-deficient FTLD

    PubMed Central

    Ward, Michael E.; Taubes, Alice; Chen, Robert; Miller, Bruce L.; Sephton, Chantelle F.; Gelfand, Jeffrey M.; Minami, Sakura; Boscardin, John; Martens, Lauren Herl; Seeley, William W.; Yu, Gang; Herz, Joachim; Filiano, Anthony J.; Arrant, Andrew E.; Roberson, Erik D.; Kraft, Timothy W.; Farese, Robert V.; Green, Ari

    2014-01-01

    Frontotemporal dementia (FTD) is the most common cause of dementia in people under 60 yr of age and is pathologically associated with mislocalization of TAR DNA/RNA binding protein 43 (TDP-43) in approximately half of cases (FLTD-TDP). Mutations in the gene encoding progranulin (GRN), which lead to reduced progranulin levels, are a significant cause of familial FTLD-TDP. Grn-KO mice were developed as an FTLD model, but lack cortical TDP-43 mislocalization and neurodegeneration. Here, we report retinal thinning as an early disease phenotype in humans with GRN mutations that precedes dementia onset and an age-dependent retinal neurodegenerative phenotype in Grn-KO mice. Retinal neuron loss in Grn-KO mice is preceded by nuclear depletion of TDP-43 and accompanied by reduced expression of the small GTPase Ran, which is a master regulator of nuclear import required for nuclear localization of TDP-43. In addition, TDP-43 regulates Ran expression, likely via binding to its 3′-UTR. Augmented expression of Ran in progranulin-deficient neurons restores nuclear TDP-43 levels and improves their survival. Our findings establish retinal neurodegeneration as a new phenotype in progranulin-deficient FTLD, and suggest a pathological loop involving reciprocal loss of Ran and nuclear TDP-43 as an underlying mechanism. PMID:25155018

  2. Deficiency of the microglial receptor CX3CR1 impairs postnatal functional development of thalamocortical synapses in the barrel cortex.

    PubMed

    Hoshiko, Maki; Arnoux, Isabelle; Avignone, Elena; Yamamoto, Nobuhiko; Audinat, Etienne

    2012-10-24

    Accumulative evidence indicates that microglial cells influence the normal development of brain synapses. Yet, the mechanisms by which these immune cells target maturating synapses and influence their functional development at early postnatal stages remain poorly understood. Here, we analyzed the role of CX3CR1, a microglial receptor activated by the neuronal chemokine CX3CL1 (or fractalkine) which controls key functions of microglial cells. In the whisker-related barrel field of the mouse somatosensory cortex, we show that the recruitment of microglia to the sites where developing thalamocortical synapses are concentrated (i.e., the barrel centers) occurs only after postnatal day 5 and is controlled by the fractalkine/CX3CR1 signaling pathway. Indeed, at this developmental stage fractalkine is overexpressed within the barrels and CX3CR1 deficiency delays microglial cell recruitment into the barrel centers. Functional analysis of thalamocortical synapses shows that CX3CR1 deficiency also delays the functional maturation of postsynaptic glutamate receptors which normally occurs at these synapses between the first and second postnatal week. These results show that reciprocal interactions between neurons and microglial cells control the functional maturation of cortical synapses. PMID:23100431

  3. Impaired hair follicle morphogenesis and cycling with abnormal epidermal differentiation in nackt mice, a cathepsin L-deficient mutation.

    PubMed

    Benavides, Fernando; Starost, Matthew F; Flores, Mónica; Gimenez-Conti, Irma B; Guénet, Jean-Louis; Conti, Claudio J

    2002-08-01

    We previously described an autosomal-recessive mutation named nackt (nkt) exhibiting partial alopecia associated with CD4(+) T-cell deficiency. Also, we recently reported that nkt (now Ctsl(nkt)) comprises a deletion in the cathepsin L (Ctsl) gene. Another recent study reported that Ctsl knockout mice have CD4(+) T-cell deficiency and periodic shedding of hair, which recapitulate the nkt mutation and the old furless (fs) mutation. The current study focuses on the dermatological aspects of the nkt mutation. Careful histological analysis of skin development of homozygous nkt mice revealed a delayed hair follicle morphogenesis and late onset of the first catagen stage. The skin of Ctsl(nkt)/Ctsl(nkt) mice showed mild epidermal hyperplasia and hyperkeratosis, severe hyperplasia of the sebaceous glands, and structural alterations of hair follicles. Epidermal differentiation seems to be affected in nkt skin, with overexpression of involucrin and profilaggrin/filaggrin along with focal areas of keratin 6 expression in the interfollicular epidermis. Severe epidermal hyperplasia, acanthosis, orthokeratosis, and hyperkeratosis were only observed in mice maintained in nonpathogen-free environments. The analysis of Rag2-/- Ctsl(nkt)/Ctsl(nkt) double-mutant mice indicates that the skin defect remains under the absence of T and B cells. This animal model provides in vivo evidence that cysteine protease cathepsin L plays a critical role in hair follicle morphogenesis and cycling, as well as epidermal differentiation. PMID:12163394

  4. Impaired Hair Follicle Morphogenesis and Cycling with Abnormal Epidermal Differentiation in nackt Mice, a Cathepsin L-Deficient Mutation

    PubMed Central

    Benavides, Fernando; Starost, Matthew F.; Flores, Mónica; Gimenez-Conti, Irma B.; Guénet, Jean-Louis; Conti, Claudio J.

    2002-01-01

    We previously described an autosomal-recessive mutation named nackt (nkt) exhibiting partial alopecia associated with CD4+ T-cell deficiency. Also, we recently reported that nkt (now Ctslnkt) comprises a deletion in the cathepsin L (Ctsl) gene. Another recent study reported that Ctsl knockout mice have CD4+ T-cell deficiency and periodic shedding of hair, which recapitulate the nkt mutation and the old furless (fs) mutation. The current study focuses on the dermatological aspects of the nkt mutation. Careful histological analysis of skin development of homozygous nkt mice revealed a delayed hair follicle morphogenesis and late onset of the first catagen stage. The skin of Ctslnkt/Ctslnkt mice showed mild epidermal hyperplasia and hyperkeratosis, severe hyperplasia of the sebaceous glands, and structural alterations of hair follicles. Epidermal differentiation seems to be affected in nkt skin, with overexpression of involucrin and profilaggrin/filaggrin along with focal areas of keratin 6 expression in the interfollicular epidermis. Severe epidermal hyperplasia, acanthosis, orthokeratosis, and hyperkeratosis were only observed in mice maintained in nonpathogen-free environments. The analysis of Rag2−/− Ctslnkt/Ctslnkt double-mutant mice indicates that the skin defect remains under the absence of T and B cells. This animal model provides in vivo evidence that cysteine protease cathepsin L plays a critical role in hair follicle morphogenesis and cycling, as well as epidermal differentiation. PMID:12163394

  5. Mice with Deficient BK Channel Function Show Impaired Prepulse Inhibition and Spatial Learning, but Normal Working and Spatial Reference Memory

    PubMed Central

    Azzopardi, Erin; Ruettiger, Lukas; Ruth, Peter; Schmid, Susanne

    2013-01-01

    Genetic variations in the large-conductance, voltage- and calcium activated potassium channels (BK channels) have been recently implicated in mental retardation, autism and schizophrenia which all come along with severe cognitive impairments. In the present study we investigate the effects of functional BK channel deletion on cognition using a genetic mouse model with a knock-out of the gene for the pore forming α-subunit of the channel. We tested the F1 generation of a hybrid SV129/C57BL6 mouse line in which the slo1 gene was deleted in both parent strains. We first evaluated hearing and motor function to establish the suitability of this model for cognitive testing. Auditory brain stem responses to click stimuli showed no threshold differences between knockout mice and their wild-type littermates. Despite of muscular tremor, reduced grip force, and impaired gait, knockout mice exhibited normal locomotion. These findings allowed for testing of sensorimotor gating using the acoustic startle reflex, as well as of working memory, spatial learning and memory in the Y-maze and the Morris water maze, respectively. Prepulse inhibition on the first day of testing was normal, but the knockout mice did not improve over the days of testing as their wild-type littermates did. Spontaneous alternation in the y-maze was normal as well, suggesting that the BK channel knock-out does not impair working memory. In the Morris water maze knock-out mice showed significantly slower acquisition of the task, but normal memory once the task was learned. Thus, we propose a crucial role of the BK channels in learning, but not in memory storage or recollection. PMID:24303038

  6. Susceptibility to Aspergillus Infections in Rats with Chronic Obstructive Pulmonary Disease via Deficiency Function of Alveolar Macrophages and Impaired Activation of TLR2.

    PubMed

    Wu, Yuting; Xu, Hong; Li, Li; Yuan, Weifeng; Zhang, Deming; Huang, Wenjie

    2016-08-01

    Clinical evidence indicates that patients with severe chronic obstructive pulmonary disease (COPD) are more susceptible to Aspergillus. However, the exact mechanisms underlying this effect are not known. In this study, we used cigarette smoke exposure to generate COPD rat model. colony-forming units (CFU) count assessment and phagocytosis were applied to evaluate the defense function of COPD rats against Aspergillus challenge. ELISA, western blotting, and GST-Rac1 pull-down assays were conducted to determine the expressions of cytokines and TLR2-associated signaling pathway. Our data showed that Aspergillus burdens increased, phagocytosis of Aspergillus as well as the expressions of inflammatory cytokines from alveolar macrophages (AMs) were impaired in COPD rats compared with normal rats. Though TLR2 signaling-related proteins were induced in response to the stimulation of Aspergillus or Pam3csk4 (TLR2 agonist), the activation of TLR2-associated signaling pathway was apparently interfered in rats with COPD, compared to that in normal rats. Taken together, our study demonstrated that COPD caused the deficiency of AMs function and impaired the activation of TLR2/PI3K/Rac 1 signaling pathway, leading to invasion of Aspergillus infection, which also provides a future basis for the infection control in COPD patients. PMID:27312383

  7. Lgr4 protein deficiency induces ataxia-like phenotype in mice and impairs long term depression at cerebellar parallel fiber-Purkinje cell synapses.

    PubMed

    Guan, Xin; Duan, Yanhong; Zeng, Qingwen; Pan, Hongjie; Qian, Yu; Li, Dali; Cao, Xiaohua; Liu, Mingyao

    2014-09-19

    Cerebellar dysfunction causes ataxia characterized by loss of balance and coordination. Until now, the molecular and neuronal mechanisms of several types of inherited cerebellar ataxia have not been completely clarified. Here, we report that leucine-rich G protein-coupled receptor 4 (Lgr4/Gpr48) is highly expressed in Purkinje cells (PCs) in the cerebellum. Deficiency of Lgr4 leads to an ataxia-like phenotype in mice. Histologically, no obvious morphological changes were observed in the cerebellum of Lgr4 mutant mice. However, the number of PCs was slightly but significantly reduced in Lgr4(-/-) mice. In addition, in vitro electrophysiological analysis showed an impaired long term depression (LTD) at parallel fiber-PC (PF-PC) synapses in Lgr4(-/-) mice. Consistently, immunostaining experiments showed that the level of phosphorylated cAMP-responsive element-binding protein (Creb) was significantly decreased in Lgr4(-/-) PCs. Furthermore, treatment with forskolin, an adenylyl cyclase agonist, rescued phospho-Creb in PCs and reversed the impairment in PF-PC LTD in Lgr4(-/-) cerebellar slices, indicating that Lgr4 is an upstream regulator of Creb signaling, which is underlying PF-PC LTD. Together, our findings demonstrate for first time an important role for Lgr4 in motor coordination and cerebellar synaptic plasticity and provide a potential therapeutic target for certain types of inherited cerebellar ataxia. PMID:25063812

  8. Transforming Growth Factor β-1 Stimulates Profibrotic Epithelial Signaling to Activate Pericyte-Myofibroblast Transition in Obstructive Kidney Fibrosis

    PubMed Central

    Wu, Ching-Fang; Chiang, Wen-Chih; Lai, Chun-Fu; Chang, Fan-Chi; Chen, Yi-Ting; Chou, Yu-Hsiang; Wu, Ting-Hui; Linn, Geoffrey R.; Ling, Hong; Wu, Kwan-Dun; Tsai, Tun-Jun; Chen, Yung-Ming; Duffield, Jeremy S.; Lin, Shuei-Liong

    2014-01-01

    Pericytes have been identified as the major source of precursors of scar-producing myofibroblasts during kidney fibrosis. The underlying mechanisms triggering pericyte-myofibroblast transition are poorly understood. Transforming growth factor β-1 (TGF-β1) is well recognized as a pluripotent cytokine that drives organ fibrosis. We investigated the role of TGF-β1 in inducing profibrotic signaling from epithelial cells to activate pericyte-myofibroblast transition. Increased expression of TGF-β1 was detected predominantly in injured epithelium after unilateral ureteral obstruction, whereas downstream signaling from the TGF-β1 receptor increased in both injured epithelium and pericytes. In mice with ureteral obstruction that were treated with the pan anti–TGF-β antibody (1D11) or TGF-β receptor type I inhibitor (SB431542), kidney pericyte-myofibroblast transition was blunted. The consequence was marked attenuation of fibrosis. In addition, epithelial cell cycle G2/M arrest and production of profibrotic cytokines were both attenuated. Although TGF-β1 alone did not trigger pericyte proliferation in vitro, it robustly induced α smooth muscle actin (α-SMA). In cultured kidney epithelial cells, TGF-β1 stimulated G2/M arrest and production of profibrotic cytokines that had the capacity to stimulate proliferation and transition of pericytes to myofibroblasts. In conclusion, this study identified a novel link between injured epithelium and pericyte-myofibroblast transition through TGF-β1 during kidney fibrosis. PMID:23142380

  9. Astrocytic laminin regulates pericyte differentiation and maintains blood brain barrier integrity

    NASA Astrophysics Data System (ADS)

    Yao, Yao; Chen, Zu-Lin; Norris, Erin H.; Strickland, Sidney

    2014-03-01

    Blood brain barrier (BBB) breakdown is not only a consequence of but also contributes to many neurological disorders, including stroke and Alzheimer’s disease. How the basement membrane (BM) contributes to the normal functioning of the BBB remains elusive. Here we use conditional knockout mice and an acute adenovirus-mediated knockdown model to show that lack of astrocytic laminin, a brain-specific BM component, induces BBB breakdown. Using functional blocking antibody and RNAi, we further demonstrate that astrocytic laminin, by binding to integrin α2 receptor, prevents pericyte differentiation from the BBB-stabilizing resting stage to the BBB-disrupting contractile stage, and thus maintains the integrity of BBB. Additionally, loss of astrocytic laminin decreases aquaporin-4 (AQP4) and tight junction protein expression. Altogether, we report a critical role for astrocytic laminin in BBB regulation and pericyte differentiation. These results indicate that astrocytic laminin maintains the integrity of BBB through, at least in part, regulation of pericyte differentiation.

  10. PICK1 and ICA69 Control Insulin Granule Trafficking and Their Deficiencies Lead to Impaired Glucose Tolerance

    PubMed Central

    Kam, Chuen; Xiao, Nan; Cao, Xiaoxing; Shen, Chong; Cheng, Kenneth K. Y.; Xu, Aimin; Lee, Kwong-Man; Jiang, Liwen; Xia, Jun

    2013-01-01

    Diabetes is a metabolic disorder characterized by hyperglycemia. Insulin, which is secreted by pancreatic beta cells, is recognized as the critical regulator of blood glucose, but the molecular machinery responsible for insulin trafficking remains poorly defined. In particular, the roles of cytosolic factors that govern the formation and maturation of insulin granules are unclear. Here we report that PICK1 and ICA69, two cytosolic lipid-binding proteins, formed heteromeric BAR-domain complexes that associated with insulin granules at different stages of their maturation. PICK1-ICA69 heteromeric complexes associated with immature secretory granules near the trans-Golgi network (TGN). A brief treatment of Brefeldin A, which blocks vesicle budding from the Golgi, increased the amount of PICK1 and ICA69 at TGN. On the other hand, mature secretory granules were associated with PICK1 only, not ICA69. PICK1 deficiency in mice caused the complete loss of ICA69 and led to increased food and water intake but lower body weight. Glucose tolerance tests demonstrated that these mutant mice had high blood glucose, a consequence of insufficient insulin. Importantly, while the total insulin level was reduced in PICK1-deficient beta cells, proinsulin was increased. Lastly, ICA69 knockout mice also displayed similar phenotype as the mice deficient in PICK1. Together, our results indicate that PICK1 and ICA69 are key regulators of the formation and maturation of insulin granules. Author Summary Insulin is a key regulator of blood glucose and insufficient insulin leads to diabetes. Insulin is synthesized as proinsulin, processed in endoplasmic reticulum and Golgi, and eventually packaged into insulin granules, a type of dense core vesicles. Despite its importance, the molecular mechanisms governing the biogenesis and maturation of insulin granules are not fully understood. In this study, we identified two cytosolic proteins, PICK1 and ICA69, as important regulators of insulin granule

  11. Impairment of Nitrergic System and Delayed Gastric Emptying in Low Density Lipoprotein Receptor (LDLR) Deficient Female Mice

    PubMed Central

    Gangula, Pandu R.; Chinnathambi, Vijayakumar; Hale, Ashley B.; Mukhopadhyay, Sutapa; Channon, Keith M.; Ravella, Kalpana

    2011-01-01

    Background In the current study, we have investigated whether low density lipoprotein receptor knockout mice (LDLR-KO), moderate oxidative stress model and cholesteremia burden display gastroparesis and if so whether nitrergic system is involved in this setting. In addition, we have investigated if sepiapterin (SEP) supplementation attenuated impaired nitrergic system and delayed gastric emptying. Methods Gastric emptying and nitrergic relaxation were measured in overnight fasting mice. nNOSα dimerization, anti-oxidant markers such as Nrf2, GCLM, GCLC, HO-1, catalase (CAT) and superoxide dismutase (SOD1) were measured using standard methods. Biopterin levels and intestinal transit time were measured using HPLC and dye migration assay, respectively. Wild type (WT) and LDLR-KO were supplemented with SEP. Key Results In LDLR null stomachs, 1) significant reduction in rate of gastric emptying, gastric pyloric and fundus nitrergic relaxation & nNOSα dimerization, 2) elevated oxidized biopterins and reduced ratio of BH4/BH2+B, 3) reduced Nrf2 and GCLC protein expression & no change in GCLM, HO-1, Cat, Sod1 and 4) accelerated small intestinal motility were noticed. Supplementation of SEP restored delayed gastric emptying, impaired pyloric and fundus nitrergic relaxation with restoration of nNOS dimerization and nNOS expression. Conclusions and Inferences This novel data suggests that hyperlipidemia and/or suppression of selective antioxidants may be a potential cause of developing gastroparesis in diabetic patients. PMID:21414103

  12. Iron deficiency.

    PubMed

    Scrimshaw, N S

    1991-10-01

    The world's leading nutritional problem is iron deficiency. 66% of children and women aged 15-44 years in developing countries have it. Further, 10-20% of women of childbearing age in developed countries are anemic. Iron deficiency is identified with often irreversible impairment of a child's learning ability. It is also associated with low capacity for adults to work which reduces productivity. In addition, it impairs the immune system which reduces the body's ability to fight infection. Iron deficiency also lowers the metabolic rate and the body temperature when exposed to cold. Hemoglobin contains nearly 73% of the body's iron. This iron is always being recycled as more red blood cells are made. The rest of the needed iron does important tasks for the body, such as binds to molecules that are reservoirs of oxygen for muscle cells. This iron comes from our diet, especially meat. Even though some plants, such as spinach, are high in iron, the body can only absorb 1.4-7% of the iron in plants whereas it can absorb 20% of the iron in red meat. In many developing countries, the common vegetarian diets contribute to high rates of iron deficiency. Parasitic diseases and abnormal uterine bleeding also promote iron deficiency. Iron therapy in anemic children can often, but not always, improve behavior and cognitive performance. Iron deficiency during pregnancy often contributes to maternal and perinatal mortality. Yet treatment, if given to a child in time, can lead to normal growth and hinder infections. However, excess iron can be damaging. Too much supplemental iron in a malnourished child promotes fatal infections since the excess iron is available for the pathogens use. Many countries do not have an effective system for diagnosing, treating, and preventing iron deficiency. Therefore a concerted international effort is needed to eliminate iron deficiency in the world. PMID:1745900

  13. Osteoprotegerin, Pericytes and Bone-Like Vascular Calcification Are Associated with Carotid Plaque Stability

    PubMed Central

    Davaine, Jean-Michel; Quillard, Thibaut; Brion, Régis; Lapérine, Olivier; Guyomarch, Béatrice; Merlini, Thierry; Chatelais, Mathias; Guilbaud, Florian; Brennan, Meadhbh Áine; Charrier, Céline; Heymann, Dominique; Gouëffic, Yann; Heymann, Marie-Françoise

    2014-01-01

    Background and Purpose Vascular calcification, recapitulating bone formation, has a profound impact on plaque stability. The aim of the present study was to determine the influence of bone-like vascular calcification (named osteoid metaplasia = OM) and of osteoprotegerin on plaque stability. Methods Tissue from carotid endarterectomies were analysed for the presence of calcification and signs of vulnerability according to AHA grading system. Osteoprotegerin (OPG), pericytes and endothelial cells were sought using immuno-histochemistry. Symptoms and preoperative imaging findings (CT-scan, MRI and Doppler-scan) were analyzed. Human pericytes were cultured to evaluate their ability to secrete OPG and to influence mineralization in the plaque. Results Seventy-three carotid plaques (49 asymptomatic and 24 symptomatic) were harvested. A significantly higher presence of OM (18.4% vs 0%, p<0.01), OPG (10.2% of ROI vs 3.4% of ROI, p<0.05) and pericytes (19% of ROI vs 3.8% of ROI, p<0.05) were noted in asymptomatic compared to symptomatic plaques. Consistently, circulating OPG levels were higher in the plasma of asymptomatic patients (3.2 ng/mL vs 2.5 ng/mL, p = 0.05). In vitro, human vascular pericytes secreted considerable amounts of OPG and underwent osteoblastic differentiation. Pericytes also inhibited the osteoclastic differentiation of CD14+ cells through their secretion of OPG. Conclusions OPG (intraplaque an plasmatic) and OM are associated with carotid plaque stability. Pericytes may be involved in the secretion of intraplaque OPG and in the formation of OM. PMID:25259713

  14. NADPH oxidase 4 deficiency leads to impaired wound repair and reduced dityrosine-crosslinking, but does not affect myofibroblast formation.

    PubMed

    Lévigne, Dominik; Modarressi, Ali; Krause, Karl-Heinz; Pittet-Cuénod, Brigitte

    2016-07-01

    NADPH oxidases (NOX) mediate redox signaling by generating superoxide and/or hydrogen peroxide, which are involved in biosynthetic pathways, e.g. thyroid hormone generation, dityrosine crosslinking, as well as bacterial killing. Data investigating the role of NOX enzymes in cutaneous wound repair is limited and specifically their function in skin myofibroblast expression is unknown. The isoform NOX4 was recently shown to be a pre-requisite for the differentiation of cardiac and pulmonary myofibroblasts. In this study we investigate the role of NOX4 in wound repair using a wound model in NOX4 knockout mice (n=16) and wildtype mice (n=16). Wounds were photographed daily until complete wound closure. Mice were sacrificed at day 3, 7, 14; wound tissue was harvested. NOX4-deficient mice healed significantly slower (22 days, SD=1.9) than wild-type mice (17 days, SD=1.4, p<0.005). However, there was no difference in myofibroblast expression. Strong dityrosine formation was observed, but was significantly weaker in NOX4-/- mice (p<0.05). NOX2, HIF1α and CD31 expression was significantly weaker in NOX4-/- mice (p<0.05). In this study we show for the first time that NOX4 plays a role in cutaneous wound repair. Our data suggests that NOX4 mediates HIF1α expression and neoangiogenesis during wound repair. NOX4 deletion led to a decreased expression of NOX2, implying a role of NOX4 in phagocytic cell recruitment. NOX4 was required for effective wound contraction but not myofibroblast expression. We suggest that myofibroblast contraction in NOX4-deficient mice is less effective in contracting the wound because of insufficient dityrosine-crosslinking of the ECM, providing the first indication for a physiological function of dityrosine crosslinking in higher animals. PMID:27140231

  15. CYP2R1 Mutations Impair Generation of 25-hydroxyvitamin D and Cause an Atypical Form of Vitamin D Deficiency

    PubMed Central

    Fischer, Philip R.; Singh, Ravinder J.; Roizen, Jeffrey; Levine, Michael A.

    2015-01-01

    Context: Production of the active vitamin D hormone 1,25-dihydroxyvitamin D requires hepatic 25-hydroxylation of vitamin D. The CYP2R1 gene encodes the principal vitamin D 25-hydroxylase in humans. Objective: This study aimed to determine the prevalence of CYP2R1 mutations in Nigerian children with familial rickets and vitamin D deficiency and assess the functional effect on 25-hydroxylase activity. Design and Participants: We sequenced the CYP2R1 gene in subjects with sporadic rickets and affected subjects from families in which more than one member had rickets. Main Outcome Measures: Function of mutant CYP2R1 genes as assessed in vivo by serum 25-hydroxyvitamin D values after administration of vitamin D and in vitro by analysis of mutant forms of the CYP2R1. Results: CYP2R1 sequences were normal in 27 children with sporadic rickets, but missense mutations were identified in affected members of 2 of 12 families, a previously identified L99P, and a novel K242N. In silico analyses predicted that both substitutions would have deleterious effects on the variant proteins, and in vitro studies showed that K242N and L99P had markedly reduced or complete loss of 25-hydroxylase activity, respectively. Heterozygous subjects were less affected than homozygous subjects, and oral administration of vitamin D led to significantly lower increases in serum 25-hydroxyvitamin D in heterozygous than in control subjects, whereas homozygous subjects showed negligible increases. Conclusion: These studies confirm that CYP2R1 is the principal 25-hydroxylase in humans and demonstrate that CYP2R1 alleles have dosage-dependent effects on vitamin D homeostasis. CYP2R1 mutations cause a novel form of genetic vitamin D deficiency with semidominant inheritance. PMID:25942481

  16. Vitamin A Deficiency Impairs Mucin Expression and Suppresses the Mucosal Immune Function of the Respiratory Tract in Chicks.

    PubMed

    Fan, Xiaoxiao; Liu, Shaoqiong; Liu, Guanhua; Zhao, Jingpeng; Jiao, Hongchao; Wang, Xiaojuan; Song, Zhigang; Lin, Hai

    2015-01-01

    The chicken immune system is immature at the time of hatching. The development of the respiratory immune system after hatching is vital to young chicks. The aim of this study was to investigate the effect of dietary vitamin A supplement levels on respiratory mucin and IgA production in chicks. In this study, 120 one-day-old broiler chicks were randomly divided into 4 groups consisting of three replicates of 10 broilers and subjected to dietary vitamin A supplement levels of 0, 1,500, 6,000, or 12,000 IU/kg for seven days. Compared with control birds, vitamin A supplementation significantly increased the mucin and IgA levels in the bronchoalveolar lavage fluid (BALF) as well as the IgA level in serum. In the lungs, vitamin A supplementation downregulated TNF-α and EGFR mRNA expression. The TGF-β and MUC5AC mRNA expression levels were upregulated by vitamin A supplementation at a dose of 6,000 IU/kg, and the IL-13 mRNA expression level was increased at the 12,000 IU/kg supplement level. Vitamin A deficiency (control) significantly decreased the mRNA expression levels of MUC2, IgA, EGFR, IL-13 and TGF-β in trachea tissue. Histological section analysis revealed that the number of goblet cells in the tracheal epithelium was less in the 0 and 12,000 IU/kg vitamin A supplement groups than in the other groups. In conclusion, vitamin A deficiency suppressed the immunity of the airway by decreasing the IgA and mucin concentrations in neonatal chicks. This study suggested that a suitable level of vitamin A is essential for the secretion of IgA and mucin in the respiratory tract by regulating the gene expression of cytokines and epithelial growth factors. PMID:26422233

  17. Vitamin A Deficiency Impairs Mucin Expression and Suppresses the Mucosal Immune Function of the Respiratory Tract in Chicks

    PubMed Central

    Liu, Guanhua; Zhao, Jingpeng; Jiao, Hongchao; Wang, Xiaojuan; Song, Zhigang; Lin, Hai

    2015-01-01

    The chicken immune system is immature at the time of hatching. The development of the respiratory immune system after hatching is vital to young chicks. The aim of this study was to investigate the effect of dietary vitamin A supplement levels on respiratory mucin and IgA production in chicks. In this study, 120 one-day-old broiler chicks were randomly divided into 4 groups consisting of three replicates of 10 broilers and subjected to dietary vitamin A supplement levels of 0, 1,500, 6,000, or 12,000 IU/kg for seven days. Compared with control birds, vitamin A supplementation significantly increased the mucin and IgA levels in the bronchoalveolar lavage fluid (BALF) as well as the IgA level in serum. In the lungs, vitamin A supplementation downregulated TNF-α and EGFR mRNA expression. The TGF-β and MUC5AC mRNA expression levels were upregulated by vitamin A supplementation at a dose of 6,000 IU/kg, and the IL-13 mRNA expression level was increased at the 12,000 IU/kg supplement level. Vitamin A deficiency (control) significantly decreased the mRNA expression levels of MUC2, IgA, EGFR, IL-13 and TGF-β in trachea tissue. Histological section analysis revealed that the number of goblet cells in the tracheal epithelium was less in the 0 and 12,000 IU/kg vitamin A supplement groups than in the other groups. In conclusion, vitamin A deficiency suppressed the immunity of the airway by decreasing the IgA and mucin concentrations in neonatal chicks. This study suggested that a suitable level of vitamin A is essential for the secretion of IgA and mucin in the respiratory tract by regulating the gene expression of cytokines and epithelial growth factors. PMID:26422233

  18. Endoplasmic reticulum polymers impair luminal protein mobility and sensitise to cellular stress in α1-antitrypsin deficiency

    PubMed Central

    Ordóñez, Adriana; Snapp, Erik L; Tan, Lu; Miranda, Elena; Marciniak, Stefan J; Lomas, David A

    2013-01-01

    Point mutants of α1-antitrypsin form ordered polymers that are retained as inclusions within the endoplasmic reticulum (ER) of hepatocytes in association with neonatal hepatitis, cirrhosis and hepatocellular carcinoma. These inclusions cause cell damage and predispose to ER stress in the absence of the classical unfolded protein response (UPR). The pathophysiology underlying this ER stress was explored by generating cell models that conditionally express wildtype α1-antitrypsin, two mutants that cause polymer-mediated inclusions and liver disease (E342K [the Z allele] and H334D) and a truncated mutant (Null Hong Kong, NHK) that induces classical ER stress and is removed by ER associated degradation. Expression of the polymeric mutants resulted in gross changes in the ER luminal environment that recapitulated the changes seen in liver sections from individuals with PI*ZZ α1-antitrypsin deficiency. In contrast expression of NHK α1-antitrypsin caused electron lucent dilatation and expansion of the ER throughout the cell. Photobleaching microscopy in live cells demonstrated a decrease in the mobility of soluble luminal proteins in cells that express E342K and H334D α1-antitrypsin when compared to those that express wildtype and NHK α1-antitrypsin (0.34±0.05, 0.22±0.03, 2.83±0.30 and 2.84±0.55 μm2/s respectively). There was no effect on protein mobility within ER membranes indicating that cisternal connectivity was not disrupted. Polymer expression alone was insufficient to induce the UPR but the resulting protein overload rendered cells hypersensitive to ER stress induced by either tunicamycin or glucose depletion. Conclusion Changes in protein diffusion provide an explanation for the cellular consequences of ER protein overload in mutants that cause inclusion body formation and α1-antitrypsin deficiency. PMID:23197448

  19. Pericytes: multitasking cells in the regeneration of injured, diseased, and aged skeletal muscle

    PubMed Central

    Birbrair, Alexander; Zhang, Tan; Wang, Zhong-Min; Messi, Maria L.; Mintz, Akiva; Delbono, Osvaldo

    2014-01-01

    Pericytes are perivascular cells that envelop and make intimate connections with adjacent capillary endothelial cells. Recent studies show that they may have a profound impact in skeletal muscle regeneration, innervation, vessel formation, fibrosis, fat accumulation, and ectopic bone formation throughout life. In this review, we summarize and evaluate recent advances in our understanding of pericytes' influence on adult skeletal muscle pathophysiology. We also discuss how further elucidating their biology may offer new approaches to the treatment of conditions characterized by muscle wasting. PMID:25278877

  20. Glycoprotein A33 deficiency: a new mouse model of impaired intestinal epithelial barrier function and inflammatory disease.

    PubMed

    Williams, Benjamin B; Tebbutt, Niall C; Buchert, Michael; Putoczki, Tracy L; Doggett, Karen; Bao, Shisan; Johnstone, Cameron N; Masson, Frederick; Hollande, Frederic; Burgess, Antony W; Scott, Andrew M; Ernst, Matthias; Heath, Joan K

    2015-08-01

    The cells of the intestinal epithelium provide a selectively permeable barrier between the external environment and internal tissues. The integrity of this barrier is maintained by tight junctions, specialised cell-cell contacts that permit the absorption of water and nutrients while excluding microbes, toxins and dietary antigens. Impairment of intestinal barrier function contributes to multiple gastrointestinal disorders, including food hypersensitivity, inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). Glycoprotein A33 (GPA33) is an intestinal epithelium-specific cell surface marker and member of the CTX group of transmembrane proteins. Roles in cell-cell adhesion have been demonstrated for multiple CTX family members, suggesting a similar function for GPA33 within the gastrointestinal tract. To test a potential requirement for GPA33 in intestinal barrier function, we generated Gpa33(-/-) mice and subjected them to experimental regimens designed to produce food hypersensitivity, colitis and CAC. Gpa33(-/-) mice exhibited impaired intestinal barrier function. This was shown by elevated steady-state immunosurveillance in the colonic mucosa and leakiness to oral TRITC-labelled dextran after short-term exposure to dextran sodium sulphate (DSS) to injure the intestinal epithelium. Gpa33(-/-) mice also exhibited rapid onset and reduced resolution of DSS-induced colitis, and a striking increase in the number of colitis-associated tumours produced by treatment with the colon-specific mutagen azoxymethane (AOM) followed by two cycles of DSS. In contrast, Gpa33(-/-) mice treated with AOM alone showed no increase in sporadic tumour formation, indicating that their increased tumour susceptibility is dependent on inflammatory stimuli. Finally, Gpa33(-/-) mice displayed hypersensitivity to food allergens, a common co-morbidity in humans with IBD. We propose that Gpa33(-/-) mice provide a valuable model to study the mechanisms linking intestinal

  1. Leptin deficiency impairs maturation of dendritic cells and enhances induction of regulatory T and Th17 cells

    PubMed Central

    Moraes-Vieira, Pedro M.M.; Larocca, Rafael A.; Bassi, Enio J.; Peron, Jean Pierre S.; Andrade-Oliveira, Vinícius; Wasinski, Frederick; Araujo, Ronaldo; Thornley, Thomas; Quintana, Francisco J.; Basso, Alexandre S.; Strom, Terry B.; Câmara, Niels O.S.

    2016-01-01

    Leptin is an adipose-secreted hormone that plays an important role in both metabolism and immunity. Leptin has been shown to induce Th1-cell polarization and inhibit Th2-cell responses. Additionally, leptin induces Th17-cell responses, inhibits regulatory T (Treg) cells and modulates autoimmune diseases. Here, we investigated whether leptin mediates its activity on T cells by influencing dendritic cells (DCs) to promote Th17 and Treg-cell immune responses in mice. We observed that leptin deficiency (i) reduced the expression of DC maturation markers, (ii) decreased DC production of IL-12, TNF-α, and IL-6, (iii) increased DC production of TGF-β, and (iv) limited the capacity of DCs to induce syngeneic CD4+ T-cell proliferation. As a consequence of this unique phenotype, DCs generated under leptin-free conditions induced Treg or TH17 cells more efficiently than DCs generated in the presence of leptin. These data indicate important roles for leptin in DC homeostasis and the initiation and maintenance of inflammatory and regulatory immune responses by DCs. PMID:24271843

  2. Neurogenetic Impairments of Brain Reward Circuitry Links to Reward Deficiency Syndrome (RDS): Potential Nutrigenomic Induced Dopaminergic Activation

    PubMed Central

    Blum, K; Oscar-Berman, M; Giordano, J; Downs, BW; Simpatico, T; Han, D; Femino, John

    2012-01-01

    Work from our laboratory in both in-patient and outpatient facilities utilizing the Comprehensive Analysis of Reported Drugs (CARD)™ found a significant lack of compliance to prescribed treatment medications and a lack of abstinence from drugs of abuse during active recovery. This unpublished, ongoing research provides an impetus to develop accurate genetic diagnosis and holistic approaches that will safely activate brain reward circuitry in the mesolimbic dopamine system. This editorial focuses on the neurogenetics of brain reward systems with particular reference to genes related to dopaminergic function. The terminology “Reward Deficiency Syndrome” (RDS), used to describe behaviors found to have an association with gene-based hypodopaminergic function, is a useful concept to help expand our understanding of Substance Use Disorder (SUD), process addictions, and other obsessive, compulsive and impulsive behaviors. This editorial covers the neurological basis of pleasure and the role of natural and unnatural reward in motivating and reinforcing behaviors. Additionally, it briefly describes the concept of natural dopamine D2 receptor agonist therapy coupled with genetic testing of a panel of reward genes, the Genetic Addiction Risk Score (GARS). It serves as a spring-board for this combination of novel approaches to the prevention and treatment of RDS that was developed from fundamental genomic research. We encourage further required studies. PMID:23264886

  3. High levels of plasma cortisol and impaired hypoosmoregulation in a mutant medaka deficient in P450c17I.

    PubMed

    Takahashi, Hideya; Sato, Tadashi; Ikeuchi, Toshitaka; Saito, Kazuhiro; Sakaizumi, Mitsuru; Sakamoto, Tatsuya

    2016-07-15

    scl is a spontaneous medaka mutant deficient in P450c17I, which is required for production of sex steroids, but not of cortisol, the major role of which is osmoregulation in teleost fish. The scl mutant provides a new model to study the functions of these hormones. We first found that fish homozygous for this mutation have plasma cortisol constitutively at a high physiological level (1000 nM). Since we previously showed that this level reversed the seawater-type differentiation of the medaka gastrointestinal tract, hypoosmoregulation of the scl mutant was analyzed. Muscle water contents in freshwater were normal in scl homozygotes, but the contents were lower than those of the wild type (WT) after seawater transfer. There were no differences in gill mRNA levels of corticosteroid receptors or ion transporters between scl homozygotes and WT. In the intestine, expression of glucocorticoid receptors and Na(+)/K(+)/2Cl(-) cotransporter were induced in WT during seawater acclimation, but not in scl homozygotes. The high plasma cortisol may prevent hypoosmoregulation by inhibition of increased intestinal water absorption, essentially by the Na(+)/K(+)/2Cl(-) cotransporter, in seawater. PMID:27107936

  4. Loss of the starvation-induced gene Rack1 leads to glycogen deficiency and impaired autophagic responses in Drosophila

    PubMed Central

    Érdi, Balázs; Nagy, Péter; Zvara, Ágnes; Varga, Ágnes; Pircs, Karolina; Ménesi, Dalma; Puskás, László G.; Juhász, Gábor

    2012-01-01

    Autophagy delivers cytoplasmic material for lysosomal degradation in eukaryotic cells. Starvation induces high levels of autophagy to promote survival in the lack of nutrients. We compared genome-wide transcriptional profiles of fed and starved control, autophagy-deficient Atg7 and Atg1 null mutant Drosophila larvae to search for novel regulators of autophagy. Genes involved in catabolic processes including autophagy were transcriptionally upregulated in all cases. We also detected repression of genes involved in DNA replication in autophagy mutants compared with control animals. The expression of Rack1 (receptor of activated protein kinase C 1) increased 4.1- to 5.5-fold during nutrient deprivation in all three genotypes. The scaffold protein Rack1 plays a role in a wide range of processes including translation, cell adhesion and migration, cell survival and cancer. Loss of Rack1 led to attenuated autophagic response to starvation, and glycogen stores were decreased 11.8-fold in Rack1 mutant cells. Endogenous Rack1 partially colocalized with GFP-Atg8a and early autophagic structures on the ultrastructural level, suggesting its involvement in autophagosome formation. Endogenous Rack1 also showed a high degree of colocalization with glycogen particles in the larval fat body, and with Shaggy, the Drosophila homolog of glycogen synthase kinase 3B (GSK-3B). Our results, for the first time, demonstrated the fundamental role of Rack1 in autophagy and glycogen synthesis. PMID:22562043

  5. Rad51C deficiency destabilizes XRCC3, impairs recombination and radiosensitizes S/G2-phase cells

    SciTech Connect

    Lio, Yi-Ching; Schild, David; Brenneman, Mark A.; Redpath, J. Leslie; Chen, David J.

    2004-05-01

    The highly conserved Rad51 protein plays an essential role in repairing DNA damage through homologous recombination. In vertebrates, five Rad51 paralogs (Rad51B, Rad51C, Rad51D, XRCC2, XRCC3) are expressed in mitotically growing cells, and are thought to play mediating roles in homologous recombination, though their precise functions remain unclear. Here we report the use of RNA interference to deplete expression of Rad51C protein in human HT1080 and HeLa cells. In HT1080 cells, depletion of Rad51C by small interfering RNA caused a significant reduction of frequency in homologous recombination. The level of XRCC3 protein was also sharply reduced in Rad51C-depleted HeLa cells, suggesting that XRCC3 is dependent for its stability upon heterodimerization with Rad51C. In addition, Rad51C-depleted HeLa cells showed hypersensitivity to the DNA cross-linking agent mitomycin C, and moderately increased sensitivity to ionizing radiation. Importantly, the radiosensitivity of Rad51C-deficient HeLa cells was evident in S and G{sub 2}/M phases of the cell cycle but not in G{sub 1} phase. Together, these results provide direct cellular evidence for the importance of human Rad51C in homologous recombinational repair.

  6. Keratinocytes from APP/APLP2-deficient mice are impaired in proliferation, adhesion and migration in vitro

    SciTech Connect

    Siemes, Christina; Quast, Thomas; Kummer, Christiane; Wehner, Sven; Kirfel, Gregor; Mueller, Ulrike; Herzog, Volker . E-mail: Herzog@uni-bonn.de

    2006-07-01

    Growing evidence shows that the soluble N-terminal form (sAPP{alpha}) of the amyloid precursor protein (APP) represents an epidermal growth factor fostering keratinocyte proliferation, migration and adhesion. APP is a member of a protein family including the two mammalian amyloid precursor-like proteins APLP1 and APLP2. In the mammalian epidermis, only APP and APLP2 are expressed. APP and APLP2-deficient mice die shortly after birth but do not display a specific epidermal phenotype. In this report, we investigated the epidermis of APP and/or APLP2 knockout mice. Basal keratinocytes showed reduced proliferation in vivo by about 40%. Likewise, isolated keratinocytes exhibited reduced proliferation rates in vitro, which could be completely rescued by either exogenously added recombinant sAPP{alpha}, or by co-culture with dermal fibroblasts derived from APP knockout mice. Moreover, APP-knockout keratinocytes revealed reduced migration velocity resulting from severely compromised cell substrate adhesion. Keratinocytes from double knockout mice died within the first week of culture, indicating essential functions of APP-family members for survival in vitro. Our data indicate that sAPP{alpha} has to be considered as an essential epidermal growth factor which, however, in vivo can be functionally compensated to a certain extent by other growth factors, e.g., factors released from dermal fibroblasts.

  7. Deficiency for the Cysteine Protease Cathepsin L Impairs Myc-Induced Tumorigenesis in a Mouse Model of Pancreatic Neuroendocrine Cancer

    PubMed Central

    Brindle, Nicola R.; Joyce, Johanna A.; Rostker, Fanya; Lawlor, Elizabeth R.; Swigart-Brown, Lamorna; Evan, Gerard; Hanahan, Douglas; Shchors, Ksenya

    2015-01-01

    Motivated by the recent implication of cysteine protease cathepsin L as a potential target for anti-cancer drug development, we used a conditional MycERTAM;Bcl-xL model of pancreatic neuroendocrine tumorigenesis (PNET) to assess the role of cathepsin L in Myc-induced tumor progression. By employing a cysteine cathepsin activity probe in vivo and in vitro, we first established that cathepsin activity increases during the initial stages of MycERTAM;Bcl-xL tumor development. Among the cathepsin family members investigated, only cathepsin L was predominately produced by beta-tumor cells in neoplastic pancreata and, consistent with this, cathepsin L mRNA expression was rapidly upregulated following Myc activation in the beta cell compartment. By contrast, cathepsins B, S and C were highly enriched in tumor-infiltrating leukocytes. Genetic deletion of cathepsin L had no discernible effect on the initiation of neoplastic growth or concordant angiogenesis. However, the tumors that developed in the cathepsin L-deficient background were markedly reduced in size relative to their typical wild-type counterparts, indicative of a role for cathepsin L in enabling expansive tumor growth. Thus, genetic blockade of cathepsin L activity is inferred to retard Myc-driven tumor growth, encouraging the potential utility of pharmacological inhibitors of cysteine cathepsins in treating late stage tumors. PMID:25927437

  8. Impaired Nutrient Signaling and Body Weight Control in a Na+ Neutral Amino Acid Cotransporter (Slc6a19)-deficient Mouse*

    PubMed Central

    Bröer, Angelika; Juelich, Torsten; Vanslambrouck, Jessica M.; Tietze, Nadine; Solomon, Peter S.; Holst, Jeff; Bailey, Charles G.; Rasko, John E. J.; Bröer, Stefan

    2011-01-01

    Amino acid uptake in the intestine and kidney is mediated by a variety of amino acid transporters. To understand the role of epithelial neutral amino acid uptake in whole body homeostasis, we analyzed mice lacking the apical broad-spectrum neutral (0) amino acid transporter B0AT1 (Slc6a19). A general neutral aminoaciduria was observed similar to human Hartnup disorder which is caused by mutations in SLC6A19. Na+-dependent uptake of neutral amino acids into the intestine and renal brush-border membrane vesicles was abolished. No compensatory increase of peptide transport or other neutral amino acid transporters was detected. Mice lacking B0AT1 showed a reduced body weight. When adapted to a standard 20% protein diet, B0AT1-deficient mice lost body weight rapidly on diets containing 6 or 40% protein. Secretion of insulin in response to food ingestion after fasting was blunted. In the intestine, amino acid signaling to the mammalian target of rapamycin (mTOR) pathway was reduced, whereas the GCN2/ATF4 stress response pathway was activated, indicating amino acid deprivation in epithelial cells. The results demonstrate that epithelial amino acid uptake is essential for optimal growth and body weight regulation. PMID:21636576

  9. Impaired nutrient signaling and body weight control in a Na+ neutral amino acid cotransporter (Slc6a19)-deficient mouse.

    PubMed

    Bröer, Angelika; Juelich, Torsten; Vanslambrouck, Jessica M; Tietze, Nadine; Solomon, Peter S; Holst, Jeff; Bailey, Charles G; Rasko, John E J; Bröer, Stefan

    2011-07-29

    Amino acid uptake in the intestine and kidney is mediated by a variety of amino acid transporters. To understand the role of epithelial neutral amino acid uptake in whole body homeostasis, we analyzed mice lacking the apical broad-spectrum neutral (0) amino acid transporter B(0)AT1 (Slc6a19). A general neutral aminoaciduria was observed similar to human Hartnup disorder which is caused by mutations in SLC6A19. Na(+)-dependent uptake of neutral amino acids into the intestine and renal brush-border membrane vesicles was abolished. No compensatory increase of peptide transport or other neutral amino acid transporters was detected. Mice lacking B(0)AT1 showed a reduced body weight. When adapted to a standard 20% protein diet, B(0)AT1-deficient mice lost body weight rapidly on diets containing 6 or 40% protein. Secretion of insulin in response to food ingestion after fasting was blunted. In the intestine, amino acid signaling to the mammalian target of rapamycin (mTOR) pathway was reduced, whereas the GCN2/ATF4 stress response pathway was activated, indicating amino acid deprivation in epithelial cells. The results demonstrate that epithelial amino acid uptake is essential for optimal growth and body weight regulation. PMID:21636576

  10. Glycoprotein A33 deficiency: a new mouse model of impaired intestinal epithelial barrier function and inflammatory disease

    PubMed Central

    Williams, Benjamin B.; Tebbutt, Niall C.; Buchert, Michael; Putoczki, Tracy L.; Doggett, Karen; Bao, Shisan; Johnstone, Cameron N.; Masson, Frederick; Hollande, Frederic; Burgess, Antony W.; Scott, Andrew M.; Ernst, Matthias; Heath, Joan K.

    2015-01-01

    ABSTRACT The cells of the intestinal epithelium provide a selectively permeable barrier between the external environment and internal tissues. The integrity of this barrier is maintained by tight junctions, specialised cell-cell contacts that permit the absorption of water and nutrients while excluding microbes, toxins and dietary antigens. Impairment of intestinal barrier function contributes to multiple gastrointestinal disorders, including food hypersensitivity, inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). Glycoprotein A33 (GPA33) is an intestinal epithelium-specific cell surface marker and member of the CTX group of transmembrane proteins. Roles in cell-cell adhesion have been demonstrated for multiple CTX family members, suggesting a similar function for GPA33 within the gastrointestinal tract. To test a potential requirement for GPA33 in intestinal barrier function, we generated Gpa33−/− mice and subjected them to experimental regimens designed to produce food hypersensitivity, colitis and CAC. Gpa33−/− mice exhibited impaired intestinal barrier function. This was shown by elevated steady-state immunosurveillance in the colonic mucosa and leakiness to oral TRITC-labelled dextran after short-term exposure to dextran sodium sulphate (DSS) to injure the intestinal epithelium. Gpa33−/− mice also exhibited rapid onset and reduced resolution of DSS-induced colitis, and a striking increase in the number of colitis-associated tumours produced by treatment with the colon-specific mutagen azoxymethane (AOM) followed by two cycles of DSS. In contrast, Gpa33−/− mice treated with AOM alone showed no increase in sporadic tumour formation, indicating that their increased tumour susceptibility is dependent on inflammatory stimuli. Finally, Gpa33−/− mice displayed hypersensitivity to food allergens, a common co-morbidity in humans with IBD. We propose that Gpa33−/− mice provide a valuable model to study the mechanisms linking

  11. Sleep Deficiency is a Modifiable Risk Factor for Obesity and Cognitive Impairment and Associated with Elevated Visfatin

    PubMed Central

    Kazem, Yusr M. I.; Shebini, Salwa M. El; Moaty, Maha I. A.; Fouad, Suzanne; Tapozada, Salwa T.

    2015-01-01

    AIM: To study the interaction between sleep deprivation, obesity and cognitive functions, and the effect of following a balanced low caloric diet and increasing sleep duration on those variables. SUBJECTS AND METHODS: Ninety two obese females with mean age 47.00 ± 2.00 years and body mass index (BMI) 36.14 ± 3.00 kg/m² were divided into 3 groups according to their sleeping hours. They followed balanced low-caloric diet and were instructed to increase sleeping hours. Full clinical examination, 24 hours dietary intake recall, anthropometric measurements, mini mental state test, questionnaire for subjective sleep and life style evaluation were performed at baseline and after 2 months. Serum visfatin, fasting blood glucose and C-peptide were assessed; Modified homeostatic model assessment of insulin resistance was calculated. RESULTS: About one third of our sample slept less than 6 hours daily, group (1), all patients had elevated visfatin serum level (33.87 ± 2.8 ng/ml) with the highest level in group (1). At base line, group (1) showed the highest BMI, lowest cognitive functions, highest visfatin level and highest insulin resistance (P < 0.05). After 2 months of intervention, improvement was recorded in all variables, with the best improvement in group (1) after extending sleep duration (P < 0.05). CONCLUSION: Sleep deprivation may be a modifiable risk factor for obesity, cognitive impairment and visfatin elevation.

  12. Impaired myogenesis in estrogen-related receptor γ (ERRγ)-deficient skeletal myocytes due to oxidative stress.

    PubMed

    Murray, Jennifer; Auwerx, Johan; Huss, Janice M

    2013-01-01

    Specialized contractile function and increased mitochondrial number and oxidative capacity are hallmark features of myocyte differentiation. The estrogen-related receptors (ERRs) can regulate mitochondrial biogenesis or mitochondrial enzyme expression in skeletal muscle, suggesting that ERRs may have a role in promoting myogenesis. Therefore, we characterized myogenic programs in primary myocytes isolated from wild-type (M-ERRγWT) and muscle-specific ERRγ(-/-) (M-ERRγ(-/-)) mice. Myotube maturation and number were decreased throughout differentiation in M-ERRγ(-/-) primary myocytes, resulting in myotubes with reduced mitochondrial content and sarcomere assembly. Compared with M-ERRγWT myocytes at the same differentiation stage, the glucose oxidation rate was reduced by 30% in M-ERRγ(-/-) myotubes, while medium-chain fatty acid oxidation was increased by 34% in M-ERRγ(-/-) myoblasts and 36% in M-ERRγ(-/-) myotubes. Concomitant with increased reliance on mitochondrial β-oxidation, H(2)O(2) production was significantly increased by 40% in M-ERRγ(-/-) myoblasts and 70% in M-ERRγ(-/-) myotubes compared to M-ERRγWT myocytes. ROS activation of FoxO and NF-κB and their downstream targets, atrogin-1 and MuRF1, was observed in M-ERRγ(-/-) myocytes. The antioxidant N-acetyl cysteine rescued myotube formation and atrophy gene induction in M-ERRγ(-/-) myocytes. These results suggest that loss of ERRγ causes metabolic defects and oxidative stress that impair myotube formation through activation of skeletal muscle atrophy pathways. PMID:23038752

  13. Impaired development and competitive refinement of the cortical frequency map in tumor necrosis factor-α-deficient mice.

    PubMed

    Yang, Sungchil; Zhang, Li S; Gibboni, Robert; Weiner, Benjamin; Bao, Shaowen

    2014-07-01

    Early experience shapes sensory representations in a critical period of heightened plasticity. This adaptive process is thought to involve both Hebbian and homeostatic synaptic plasticity. Although Hebbian plasticity has been investigated as a mechanism for cortical map reorganization, less is known about the contribution of homeostatic plasticity. We investigated the role of homeostatic synaptic plasticity in the development and refinement of frequency representations in the primary auditory cortex using the tumor necrosis factor-α (TNF-α) knockout (KO), a mutant mouse with impaired homeostatic but normal Hebbian plasticity. Our results indicate that these mice develop weaker tonal responses and incomplete frequency representations. Rearing in a single-frequency revealed a normal expansion of cortical representations in KO mice. However, TNF-α KOs lacked homeostatic adjustments of cortical responses following exposure to multiple frequencies. Specifically, while this sensory over-stimulation resulted in competitive refinement of frequency tuning in wild-type controls, it broadened frequency tuning in TNF-α KOs. Our results suggest that homeostatic plasticity plays an important role in gain control and competitive interaction in sensory cortical development. PMID:23448874

  14. Polyphosphate Deficiency in Mycobacterium tuberculosis Is Associated with Enhanced Drug Susceptibility and Impaired Growth in Guinea Pigs

    PubMed Central

    Singh, Mamta; Arora, Garima; Kumar, Santosh; Tiwari, Prabhakar; Kidwai, Saqib

    2013-01-01

    Inorganic polyphosphate (polyP), a linear polymer of hundreds of phosphate residues linked by ATP-like phosphoanhydride bonds, is found in all organisms and performs a wide variety of functions. This study shows that polyP accumulation occurs in Mycobacterium tuberculosis upon exposure to various stress conditions. M. tuberculosis possesses a single homolog of ppk-1, and we have disrupted ppk-1 in the M. tuberculosis genome by allelic replacement. The mutant strain exhibited negligible levels of intracellular polyP, decreased expression of sigF and phoP, and reduced growth in the stationary phase and displayed a survival defect in response to nitrosative stress and in THP-1 macrophages compared to the wild-type strain. We report that reduction in polyP levels is associated with increased susceptibility of M. tuberculosis to certain TB drugs and impairs its ability to cause disease in guinea pigs. These results suggest that polyP contributes to persistence of M. tuberculosis in vitro and plays an important role in the physiology of bacteria residing within guinea pigs. PMID:23585537

  15. Impaired renal secretion of substrates for the multidrug resistance protein 2 in mutant transport-deficient (TR-) rats.

    PubMed

    Masereeuw, Rosalinde; Notenboom, Sylvia; Smeets, Pascal H E; Wouterse, Alfons C; Russel, Frans G M

    2003-11-01

    Previous studies with mutant transport-deficient rats (TR(-)), in which the multidrug resistance protein 2 (Mrp2) is lacking, have emphasized the importance of this transport protein in the biliary excretion of a wide variety of glutathione conjugates, glucuronides, and other organic anions. Mrp2 is also present in the luminal membrane of proximal tubule cells of the kidney, but little information is available on its role in the renal excretion of xenobiotics. The authors compared renal transport of the fluorescent Mrp2 substrates calcein, fluo-3, and lucifer yellow (LY) between perfused kidneys isolated from Wistar Hannover (WH) and TR(-) rats. Isolated rat kidneys were perfused with 100 nM of the nonfluorescent calcein-AM or 500 nM fluo3-AM, which enter the tubular cells by diffusion and are hydrolyzed intracellularly into the fluorescent anion. The urinary excretion rates of calcein and fluo-3 were 3 to 4 times lower in perfused kidneys from TR(-) rats compared with WH rats. In contrast, the renal excretion of LY (10 micro M, free anion) was somewhat delayed but appeared unimpaired in TR(-) rats. Membrane vesicles from Sf9 cells expressing human MRP2 or human MRP4 indicated that MRP2 exhibits a preferential affinity for calcein and fluo-3, whereas LY is a better substrate for MRP4. We conclude that the renal clearance of the Mrp2 substrates calcein and fluo-3 is significantly reduced in TR(-) rat; for LY, the absence of the transporter may be compensated for by (an)other organic anion transporter(s). PMID:14569083

  16. Vitamin C deficiency in the brain impairs cognition, increases amyloid accumulation and deposition, and oxidative stress in APP/PSEN1 and normally aging mice.

    PubMed

    Dixit, Shilpy; Bernardo, Alexandra; Walker, Jennifer Michelle; Kennard, John Andrew; Kim, Grace Youngeun; Kessler, Eric Sean; Harrison, Fiona Edith

    2015-04-15

    Subclinical vitamin C deficiency is widespread in many populations, but its role in both Alzheimer's disease and normal aging is understudied. In the present study, we decreased brain vitamin C in the APPSWE/PSEN1deltaE9 mouse model of Alzheimer's disease by crossing APP/PSEN1(+) bigenic mice with SVCT2(+/-) heterozygous knockout mice, which have lower numbers of the sodium-dependent vitamin C transporter required for neuronal vitamin C transport. SVCT2(+/-) mice performed less well on the rotarod task at both 5 and 12 months of age compared to littermates. SVCT2(+/-) and APP/PSEN1(+) mice and the combination genotype SVCT2(+/-)APP/PSEN1(+) were also impaired on multiple tests of cognitive ability (olfactory memory task, Y-maze alternation, conditioned fear, Morris water maze). In younger mice, both low vitamin C (SVCT2(+/-)) and APP/PSEN1 mutations increased brain cortex oxidative stress (malondialdehyde, protein carbonyls, F2-isoprostanes) and decreased total glutathione compared to wild-type controls. SVCT2(+/-) mice also had increased amounts of both soluble and insoluble Aβ1-42 and a higher Aβ1-42/1-40 ratio. By 14 months of age, oxidative stress levels were similar among groups, but there were more amyloid-β plaque deposits in both hippocampus and cortex of SVCT2(+/-)APP/PSEN1(+) mice compared to APP/PSEN1(+) mice with normal brain vitamin C. These data suggest that even moderate intracellular vitamin C deficiency plays an important role in accelerating amyloid pathogenesis, particularly during early stages of disease development, and that these effects are likely modulated by oxidative stress pathways. PMID:25642732

  17. Vitamin C deficiency in the brain impairs cognition, increases amyloid accumulation and deposition, and oxidative stress in APP/PSEN1 and normally-aging mice

    PubMed Central

    Dixit, Shilpy; Bernardo, Alexandra; Walker, Michelle Jennifer; Kennard, John Andrew; Kim, Grace Youngeun; Kessler, Eric Sean; Harrison, Fiona Edith

    2015-01-01

    Subclinical vitamin C deficiency is widespread in many populations, but its role in both Alzheimer’s disease and normal aging is understudied. In the present study we decreased brain vitamin C in the APPSWE/PSEN1deltaE9 mouse model of Alzheimer’s disease, by crossing APP/PSEN1+ bigenic mice with SVCT2+/− heterozygous knockout mice, which have lower numbers of the sodium-dependent vitamin C transporter required for neuronal vitamin C transport. SVCT2+/− mice performed less well on the rotarod task at both 5 and 12 months of age compared to littermates. SVCT2+/− and APP/PSEN1+, mice, and the combination genotype SVCT2+/−APP/PSEN1+, were also impaired on multiple tests of cognitive ability (olfactory memory task, Y-maze alternation, conditioned fear, Morris water maze). In younger mice, both low vitamin C (SVCT2+/−) and APP/PSEN1 mutations increased brain cortex oxidative stress (malondialdehyde, protein carbonyls, F2-isoprostanes) and decreased total glutathione compared to wild-type controls. SVCT2+/− mice also had increased amounts of both soluble and insoluble Aβ1-42 and a higher Aβ1-42/1-40 ratio. By 14 months of age, oxidative stress levels were similar among groups, but there were more amyloid-β plaque deposits in both hippocampus and cortex of SVCT2+/−APP/PSEN1+ mice compared to APP/PSEN1+ mice with normal brain vitamin C. The data suggest that even moderate intracellular vitamin C deficiency plays an important role in accelerating amyloid pathogenesis, particularly during early stages of disease development, and that these effects are likely modulated by oxidative stress pathways. PMID:25642732

  18. Retrieval Deficiency in Brain Activity of Working Memory in Amnesic Mild Cognitive Impairment Patients: A Brain Event-Related Potentials Study.

    PubMed

    Li, Bin-Yin; Tang, Hui-Dong; Chen, Sheng-Di

    2016-01-01

    In the early stage of Alzheimer disease (AD) or mild cognitive impairment (MCI), working memory (WM) deficiency is prominent and could be attributed to failure in encoding, maintenance or retrieval of information. However, evidence for a retention or retrieval deficit remains equivocal. It is also unclear what cognitive mechanism in WM is impaired in MCI or early AD. We enrolled 46 subjects from our Memory Clinics and community, with 24 amnesic MCI patients and 22 normal subjects. After neurological and cognitive assessments, they performed a classic delayed match to sample (DMS) task with simultaneous event-related potential (ERP) recorded. The ERPs in encoding and retrieval epoch during WM were analyzed separately. The latency and amplitude of every ERP component were compared between two groups, and then analyzed to explore their relationship with neuropsychological performance. Finally, the locations of maximal difference in cortex were calculated by standard low-resolution tomographic analysis. A total of five components were found: P1, N1, P2, N2, and P300. The amplitude of P2 and P300 was larger in normal subjects than in MCI patients only during retrieval, not encoding epoch, while the latency did not show statistical difference. The latency and amplitude of P1 and N1 were similar in two groups. P2 amplitude in the retrieval epoch positively correlated with memory test (auditory verbal learning test) and visual spatial score of Chinese Addenbrooke's Cognitive Examination-Revised (ACE-R), while P300 amplitude correlated with ACE-R. The activation difference in P2 time range was maximal at medial frontal gyrus. However, the difference in cortex activation during P300 time range did not show significance. The amplitude of P2 indicated deficiency in memory retrieval process, potentially due to dysfunction of central executive in WM model. Regarding the location of P2 during WM task, medial frontal plays important role in memory retrieval. The findings in the

  19. Retrieval Deficiency in Brain Activity of Working Memory in Amnesic Mild Cognitive Impairment Patients: A Brain Event-Related Potentials Study

    PubMed Central

    Li, Bin-Yin; Tang, Hui-Dong; Chen, Sheng-Di

    2016-01-01

    In the early stage of Alzheimer disease (AD) or mild cognitive impairment (MCI), working memory (WM) deficiency is prominent and could be attributed to failure in encoding, maintenance or retrieval of information. However, evidence for a retention or retrieval deficit remains equivocal. It is also unclear what cognitive mechanism in WM is impaired in MCI or early AD. We enrolled 46 subjects from our Memory Clinics and community, with 24 amnesic MCI patients and 22 normal subjects. After neurological and cognitive assessments, they performed a classic delayed match to sample (DMS) task with simultaneous event-related potential (ERP) recorded. The ERPs in encoding and retrieval epoch during WM were analyzed separately. The latency and amplitude of every ERP component were compared between two groups, and then analyzed to explore their relationship with neuropsychological performance. Finally, the locations of maximal difference in cortex were calculated by standard low-resolution tomographic analysis. A total of five components were found: P1, N1, P2, N2, and P300. The amplitude of P2 and P300 was larger in normal subjects than in MCI patients only during retrieval, not encoding epoch, while the latency did not show statistical difference. The latency and amplitude of P1 and N1 were similar in two groups. P2 amplitude in the retrieval epoch positively correlated with memory test (auditory verbal learning test) and visual spatial score of Chinese Addenbrooke's Cognitive Examination-Revised (ACE-R), while P300 amplitude correlated with ACE-R. The activation difference in P2 time range was maximal at medial frontal gyrus. However, the difference in cortex activation during P300 time range did not show significance. The amplitude of P2 indicated deficiency in memory retrieval process, potentially due to dysfunction of central executive in WM model. Regarding the location of P2 during WM task, medial frontal plays important role in memory retrieval. The findings in the

  20. In vivo administration of fluorescent dextrans for the specific and sensitive localization of brain vascular pericytes and their characterization in normal and neurotoxin exposed brains.

    PubMed

    Sarkar, Sumit; Schmued, Larry

    2012-06-01

    We have aimed to develop novel histochemical markers for the labeling of brain pericytes and characterize their morphology in the normal and the excitotoxin-exposed brain, as this class of cells has received little attention until recently. Pericyte labeling was accomplished by the intracerebroventricular injection of certain fluorescent dextran conjugates, such as Fluoro-Gold-dextran, FR-dextran, FITC-dextran and Fluoro-Turquoise (FT)-dextran. 1-7 days after the tracer injection, extensive labeling of vascular pericytes was seen throughout the entire brain. These cells were found distal to the endothelial cells and exhibited large dye containing vacuoles. The morphology of the pericytes was somewhat variable, exhibiting round or amoeboid shapes within larger intracellular vesicles, while those wrapping around capillaries exhibited a more elongated appearance with finger-like projections. The use of FG-dextran resulted in bluish yellow fluorescently labeled pericytes, while FR-dextran resulted in red fluorescent labeled pericytes, FITC-dextran exhibited green fluorescent pericytes and FT-dextran showed fluorescent blue pericytes in the brain. We have used these tracers to study possible changes in morphology and pericyte number following kainic acid insult, observing that the number of pericytes in the injured or lesioned areas of the brain is dramatically reduced compared to the non-injured areas. These novel fluorochromes should be of use for studies involving the detection and localization of pericytes in both normal and pathological brain tissues. PMID:22525936

  1. Characterization of mec1 Kinase-Deficient Mutants and of New Hypomorphic mec1 Alleles Impairing Subsets of the DNA Damage Response Pathway

    PubMed Central

    Paciotti, Vera; Clerici, Michela; Scotti, Maddalena; Lucchini, Giovanna; Longhese, Maria Pia

    2001-01-01

    DNA damage checkpoints lead to the inhibition of cell cycle progression following DNA damage. The Saccharomyces cerevisiae Mec1 checkpoint protein, a phosphatidylinositol kinase-related protein, is required for transient cell cycle arrest in response to DNA damage or DNA replication defects. We show that mec1 kinase-deficient (mec1kd) mutants are indistinguishable from mec1Δ cells, indicating that the Mec1 conserved kinase domain is required for all known Mec1 functions, including cell viability and proper DNA damage response. Mec1kd variants maintain the ability to physically interact with both Ddc2 and wild-type Mec1 and cause dominant checkpoint defects when overproduced in MEC1 cells, impairing the ability of cells to slow down S phase entry and progression after DNA damage in G1 or during S phase. Conversely, an excess of Mec1kd in MEC1 cells does not abrogate the G2/M checkpoint, suggesting that Mec1 functions required for response to aberrant DNA structures during specific cell cycle stages can be separable. In agreement with this hypothesis, we describe two new hypomorphic mec1 mutants that are completely defective in the G1/S and intra-S DNA damage checkpoints but properly delay nuclear division after UV irradiation in G2. The finding that these mutants, although indistinguishable from mec1Δ cells with respect to the ability to replicate a damaged DNA template, do not lose viability after UV light and methyl methanesulfonate treatment suggests that checkpoint impairments do not necessarily result in hypersensitivity to DNA-damaging agents. PMID:11359899

  2. Cultured pericytes from human brain show phenotypic and functional differences associated with differential CD90 expression

    PubMed Central

    Park, Thomas I-H.; Feisst, Vaughan; Brooks, Anna E. S.; Rustenhoven, Justin; Monzo, Hector J.; Feng, Sheryl X.; Mee, Edward W.; Bergin, Peter S.; Oldfield, Robyn; Graham, E. Scott; Curtis, Maurice A.; Faull, Richard L. M.; Dunbar, P. Rod; Dragunow, Mike

    2016-01-01

    The human brain is a highly vascular organ in which the blood-brain barrier (BBB) tightly regulates molecules entering the brain. Pericytes are an integral cell type of the BBB, regulating vascular integrity, neuroinflammation, angiogenesis and wound repair. Despite their importance, identifying pericytes amongst other perivascular cell types and deciphering their specific role in the neurovasculature remains a challenge. Using primary adult human brain cultures and fluorescent-activated cell sorting, we identified two CD73+CD45− mesenchymal populations that showed either high or low CD90 expression. CD90 is known to be present on neurons in the brain and peripheral blood vessels. We found in the human brain, that CD90 immunostaining localised to the neurovasculature and often associated with pericytes. In vitro, CD90+ cells exhibited higher basal proliferation, lower expression of markers αSMA and CD140b, produced less extracellular matrix (ECM) proteins, and exhibited lesser pro-inflammatory responses when compared to the CD90− population. Thus, CD90 distinguishes two interrelated, yet functionally distinct pericyte populations in the adult human brain that may have discrete roles in neurovascular function, immune response and scar formation. PMID:27215737

  3. Pericytes contribute to airway remodeling in a mouse model of chronic allergic asthma.

    PubMed

    Johnson, Jill R; Folestad, Erika; Rowley, Jessica E; Noll, Elisa M; Walker, Simone A; Lloyd, Clare M; Rankin, Sara M; Pietras, Kristian; Eriksson, Ulf; Fuxe, Jonas

    2015-04-01

    Myofibroblast accumulation, subepithelial fibrosis, and vascular remodeling are complicating features of chronic asthma, but the mechanisms are not clear. Platelet-derived growth factors (PDGFs) regulate the fate and function of various mesenchymal cells and have been implicated as mediators of lung fibrosis. However, it is not known whether PDGF-BB signaling via PDGFRβ, which is critical for the recruitment of pericytes to blood vessels, plays a role in airway remodeling in chronic asthma. In the present study, we used a selective PDGFRβ inhibitor (CP-673451) to investigate the role of PDGFRβ signaling in the development of airway remodeling and lung dysfunction in an established mouse model of house dust mite-induced chronic allergic asthma. Unexpectedly, we found that pharmacological inhibition of PDGFRβ signaling in the context of chronic aeroallergen exposure led to exacerbated lung dysfunction and airway smooth muscle thickening. Further studies revealed that the inflammatory response to aeroallergen challenge in mice was associated with decreased PDGF-BB expression and the loss of pericytes from the airway microvasculature. In parallel, cells positive for pericyte markers accumulated in the subepithelial region of chronically inflamed airways. This process was exacerbated in animals treated with CP-673451. The results indicate that perturbed PDGF-BB/PDGFRβ signaling and pericyte accumulation in the airway wall may contribute to airway remodeling in chronic allergic asthma. PMID:25637607

  4. A novel lineage restricted, pericyte-like cell line isolated from human embryonic stem cells.

    PubMed

    Greenwood-Goodwin, Midori; Yang, Jiwei; Hassanipour, Mohammad; Larocca, David

    2016-01-01

    Pericytes (PCs) are endothelium-associated cells that play an important role in normal vascular function and maintenance. We developed a method comparable to GMP quality protocols for deriving self-renewing perivascular progenitors from the human embryonic stem cell (hESC), line ESI-017. We identified a highly scalable, perivascular progenitor cell line that we termed PC-A, which expressed surface markers common to mesenchymal stromal cells. PC-A cells were not osteogenic or adipogenic under standard differentiation conditions and showed minimal angiogenic support function in vitro. PC-A cells were capable of further differentiation to perivascular progenitors with limited differentiation capacity, having osteogenic potential (PC-O) or angiogenic support function (PC-M), while lacking adipogenic potential. Importantly, PC-M cells expressed surface markers associated with pericytes. Moreover, PC-M cells had pericyte-like functionality being capable of co-localizing with human umbilical vein endothelial cells (HUVECs) and enhancing tube stability up to 6 days in vitro. We have thus identified a self-renewing perivascular progenitor cell line that lacks osteogenic, adipogenic and angiogenic potential but is capable of differentiation toward progenitor cell lines with either osteogenic potential or pericyte-like angiogenic function. The hESC-derived perivascular progenitors described here have potential applications in vascular research, drug development and cell therapy. PMID:27109637

  5. A novel lineage restricted, pericyte-like cell line isolated from human embryonic stem cells

    PubMed Central

    Greenwood-Goodwin, Midori; Yang, Jiwei; Hassanipour, Mohammad; Larocca, David

    2016-01-01

    Pericytes (PCs) are endothelium-associated cells that play an important role in normal vascular function and maintenance. We developed a method comparable to GMP quality protocols for deriving self-renewing perivascular progenitors from the human embryonic stem cell (hESC), line ESI-017. We identified a highly scalable, perivascular progenitor cell line that we termed PC-A, which expressed surface markers common to mesenchymal stromal cells. PC-A cells were not osteogenic or adipogenic under standard differentiation conditions and showed minimal angiogenic support function in vitro. PC-A cells were capable of further differentiation to perivascular progenitors with limited differentiation capacity, having osteogenic potential (PC-O) or angiogenic support function (PC-M), while lacking adipogenic potential. Importantly, PC-M cells expressed surface markers associated with pericytes. Moreover, PC-M cells had pericyte-like functionality being capable of co-localizing with human umbilical vein endothelial cells (HUVECs) and enhancing tube stability up to 6 days in vitro. We have thus identified a self-renewing perivascular progenitor cell line that lacks osteogenic, adipogenic and angiogenic potential but is capable of differentiation toward progenitor cell lines with either osteogenic potential or pericyte-like angiogenic function. The hESC-derived perivascular progenitors described here have potential applications in vascular research, drug development and cell therapy. PMID:27109637

  6. Occurring of In Vitro Functional Vasculogenic Pericytes from Human Circulating Early Endothelial Precursor Cell Culture

    PubMed Central

    Bianchi, Francesca; Galletti, Margherita; Galiè, Nazzareno; Ventura, Carlo

    2015-01-01

    Pericytes are periendothelial cells of the microcirculation which contribute to tissue homeostasis and hemostasis by regulating microvascular morphogenesis and stability. Because of their multipotential ex vivo differentiation capabilities, pericytes are becoming very interesting in regenerative medicine field. Several studies address this issue by attempting to isolate pericyte/mesenchymal-like cells from peripheral blood; however the origin of these cells and their culture conditions are still debated. Here we showed that early Endothelial Progenitor Cells (EPCs) expressing CD45+/CD146+/CD31+ can be a source of cells with pericyte/mesenchymal phenotype and function, identified as human Progenitor Perivascular Cells (hPPCs). We provided evidence that hPPCs have an immunophenotype consistent with Mesenchymal Stem Cells (MSCs) from human adipose tissue (hASCs) and fetal membranes of term placenta (FM-hMSCs). In addition, hPPCs can be subcultured and exhibit expression of pluripotent genes (OCT-4, KLF-4, and NANOG) as well as a remarkable vasculogenic potential. Our findings could be helpful to develop innovative cell-based therapies for future clinical applications with distinct therapeutic purposes. PMID:26064139

  7. Cultured pericytes from human brain show phenotypic and functional differences associated with differential CD90 expression.

    PubMed

    Park, Thomas I-H; Feisst, Vaughan; Brooks, Anna E S; Rustenhoven, Justin; Monzo, Hector J; Feng, Sheryl X; Mee, Edward W; Bergin, Peter S; Oldfield, Robyn; Graham, E Scott; Curtis, Maurice A; Faull, Richard L M; Dunbar, P Rod; Dragunow, Mike

    2016-01-01

    The human brain is a highly vascular organ in which the blood-brain barrier (BBB) tightly regulates molecules entering the brain. Pericytes are an integral cell type of the BBB, regulating vascular integrity, neuroinflammation, angiogenesis and wound repair. Despite their importance, identifying pericytes amongst other perivascular cell types and deciphering their specific role in the neurovasculature remains a challenge. Using primary adult human brain cultures and fluorescent-activated cell sorting, we identified two CD73(+)CD45(-) mesenchymal populations that showed either high or low CD90 expression. CD90 is known to be present on neurons in the brain and peripheral blood vessels. We found in the human brain, that CD90 immunostaining localised to the neurovasculature and often associated with pericytes. In vitro, CD90(+) cells exhibited higher basal proliferation, lower expression of markers αSMA and CD140b, produced less extracellular matrix (ECM) proteins, and exhibited lesser pro-inflammatory responses when compared to the CD90(-) population. Thus, CD90 distinguishes two interrelated, yet functionally distinct pericyte populations in the adult human brain that may have discrete roles in neurovascular function, immune response and scar formation. PMID:27215737

  8. Astrocytes and pericytes differentially modulate blood–brain barrier characteristics during development and hypoxic insult

    PubMed Central

    Al Ahmad, Abraham; Taboada, Carole Bürgi; Gassmann, Max; Ogunshola, Omolara O

    2011-01-01

    Understanding regulation of blood–brain barrier (BBB) is crucial to reduce/prevent its disruption during injury. As high brain complexity makes interpretation of in vivo data challenging, BBB studies are frequently performed using simplified in vitro models. However, many models fail to address the three-dimensional (3D) cellular interactions that occur in vivo, an important feature that may explain discrepancies in translation of in vitro data to the in vivo situation. We have designed and characterized an innovative 3D model that reproduces morphological and functional characteristics of the BBB in vivo and used it to investigate cellular interactions and contribution of astrocytes and pericytes to BBB development. Our model shows that both astrocytes and pericytes significantly suppress endothelial proliferation. In contrast, differential effects on tubulogenesis were observed with astrocytes reducing the number of tubes formed but increasing diameters and length, whereas pericytes had the opposite effect. Pericytes also induce proper localization of barrier proteins, lumen polarization, and functional activity of ATP-binding cassette (ABC) transporters similar to astrocytes, but the presence of both cells is required to maintain optimal barrier characteristics during hypoxic exposure. This model is simple, dynamic, and convenient to study many aspects of BBB function and represents an exciting new tool to address open questions of BBB regulation. PMID:20827262

  9. Pericytes contribute to airway remodeling in a mouse model of chronic allergic asthma

    PubMed Central

    Folestad, Erika; Rowley, Jessica E.; Noll, Elisa M.; Walker, Simone A.; Lloyd, Clare M.; Rankin, Sara M.; Pietras, Kristian; Eriksson, Ulf; Fuxe, Jonas

    2015-01-01

    Myofibroblast accumulation, subepithelial fibrosis, and vascular remodeling are complicating features of chronic asthma, but the mechanisms are not clear. Platelet-derived growth factors (PDGFs) regulate the fate and function of various mesenchymal cells and have been implicated as mediators of lung fibrosis. However, it is not known whether PDGF-BB signaling via PDGFRβ, which is critical for the recruitment of pericytes to blood vessels, plays a role in airway remodeling in chronic asthma. In the present study, we used a selective PDGFRβ inhibitor (CP-673451) to investigate the role of PDGFRβ signaling in the development of airway remodeling and lung dysfunction in an established mouse model of house dust mite-induced chronic allergic asthma. Unexpectedly, we found that pharmacological inhibition of PDGFRβ signaling in the context of chronic aeroallergen exposure led to exacerbated lung dysfunction and airway smooth muscle thickening. Further studies revealed that the inflammatory response to aeroallergen challenge in mice was associated with decreased PDGF-BB expression and the loss of pericytes from the airway microvasculature. In parallel, cells positive for pericyte markers accumulated in the subepithelial region of chronically inflamed airways. This process was exacerbated in animals treated with CP-673451. The results indicate that perturbed PDGF-BB/PDGFRβ signaling and pericyte accumulation in the airway wall may contribute to airway remodeling in chronic allergic asthma. PMID:25637607

  10. Hemoglobin induced NO/cGMP suppression Deteriorate Microcirculation via Pericyte Phenotype Transformation after Subarachnoid Hemorrhage in Rats

    PubMed Central

    Li, Qiang; Chen, Yujie; Li, Bo; Luo, Chunxia; Zuo, Shilun; Liu, Xin; Zhang, John H.; Ruan, Huaizhen; Feng, Hua

    2016-01-01

    Subarachnoid hemorrhage (SAH) usually results from ruptured aneurysm, but how leaked hemoglobin regulates the microcirculation in the pathophysiology of early brain injury after SAH is still unclear. In the present study, we sought to investigate the role and possible mechanism of hemoglobin induced pericyte phenotype transformation in the regulation of microcirculation after SAH. Endovascular perforation SAH rat model, brain slices and cultured pericytes were used, and intervened with endothelial nitric oxide synthase (eNOS) antagonist L-NNA and its agonist scutellarin, hemoglobin, DETA/NO (nitric oxide(NO) donor), PITO (NO scavenger), 8-Br-cGMP (cGMP analog). We found modulating eNOS regulated pericyte α-SMA phenotype transformation, microcirculation, and neurological function in SAH rats. Modulating eNOS also affected eNOS expression, eNOS activity and NO availability after SAH. In addition, we showed hemoglobins penetrated into brain parenchyma after SAH. And hemoglobins significantly reduced the microvessel diameters at pericyte sites, due to the effects of hemoglobin inducing α-SMA expressions in cultured pericytes and brain slices via inhibiting NO/cGMP pathway. In conclusion, pericyte α-SMA phenotype mediates acute microvessel constriction after SAH possibly by hemoglobin suppressing NO/cGMP signaling pathway. Therefore, by targeting the eNOS and pericyte α-SMA phenotype, our present data may shed new light on the management of SAH patients. PMID:26911739

  11. Sulforaphane inhibits advanced glycation end product-induced pericyte damage by reducing expression of receptor for advanced glycation end products.

    PubMed

    Maeda, Sayaka; Matsui, Takanori; Ojima, Ayako; Takeuchi, Masayoshi; Yamagishi, Sho-Ichi

    2014-09-01

    Advanced glycation end products (AGEs) not only inhibit DNA synthesis but also play a role in diabetic retinopathy by evoking apoptosis and inflammation in retinal pericytes via interaction with a receptor for AGE (RAGE). Similarly, sulforaphane, which is a naturally occurring isothiocyanate that is found in widely consumed cruciferous vegetables, protects against oxidative stress-induced tissue damage. Therefore, we hypothesized that sulforaphane could inhibit AGE-induced pericytes injury through its antioxidative properties. Advanced glycation end product stimulated superoxide generation as well as RAGE gene and protein expression in bovine-cultured retinal pericytes, and these effects were prevented by the treatment with sulforaphane. Antibodies directed against RAGE also blocked AGE-evoked reactive oxygen species generation in pericytes. Sulforaphane and antibodies directed against RAGE significantly inhibited the AGE-induced decrease in DNA synthesis, apoptotic cell death, and up-regulation of monocyte chemoattractant protein 1 messenger RNA levels in pericytes. For the first time, the present study demonstrates that sulforaphane could inhibit DNA synthesis, apoptotic cell death, and inflammatory reactions in AGE-exposed pericytes, partly by suppressing RAGE expression via its antioxidative properties. Blockade of the AGE-RAGE axis in pericytes by sulforaphane might be a novel therapeutic target for the treatment of diabetic retinopathy. PMID:25241332

  12. T-type calcium channel Cav3.2 deficient mice show elevated anxiety, impaired memory and reduced sensitivity to psychostimulants.

    PubMed

    Gangarossa, Giuseppe; Laffray, Sophie; Bourinet, Emmanuel; Valjent, Emmanuel

    2014-01-01

    The fine-tuning of neuronal excitability relies on a tight control of Ca(2+) homeostasis. The low voltage-activated (LVA) T-type calcium channels (Cav3.1, Cav3.2 and Cav3.3 isoforms) play a critical role in regulating these processes. Despite their wide expression throughout the central nervous system, the implication of T-type Cav3.2 isoform in brain functions is still poorly characterized. Here, we investigate the effect of genetic ablation of this isoform in affective disorders, including anxiety, cognitive functions as well as sensitivity to drugs of abuse. Using a wide range of behavioral assays we show that genetic ablation of the cacna1h gene results in an anxiety-like phenotype, whereas novelty-induced locomotor activity is unaffected. Deletion of the T-type channel Cav3.2 also triggers impairment of hippocampus-dependent recognition memories. Acute and sensitized hyperlocomotion induced by d-amphetamine and cocaine are dramatically reduced in T-type Cav3.2 deficient mice. In addition, the administration of the T-type blocker TTA-A2 prevented the expression of locomotor sensitization observed in wildtype mice. In conclusion, our data reveal that physiological activity of this specific Ca(2+) channel is required for affective and cognitive behaviors. Moreover, our work highlights the interest of T-type channel blockers as therapeutic strategies to reverse drug-associated alterations. PMID:24672455

  13. Hepatic Sirt1 deficiency in mice impairs mTorc2/Akt signaling and results in hyperglycemia, oxidative damage, and insulin resistance

    PubMed Central

    Wang, Rui-Hong; Kim, Hyun-Seok; Xiao, Cuiying; Xu, Xiaoling; Gavrilova, Oksana; Deng, Chu-Xia

    2011-01-01

    Insulin resistance is a major risk factor for type 2 diabetes mellitus. The protein encoded by the sirtuin 1 (Sirt1) gene, which is a mouse homolog of yeast Sir2, is implicated in the regulation of glucose metabolism and insulin sensitivity; however, the underlying mechanism remains elusive. Here, using mice with a liver-specific null mutation of Sirt1, we have identified a signaling pathway involving Sirt1, Rictor (a component of mTOR complex 2 [mTorc2]), Akt, and Foxo1 that regulates gluconeogenesis. We found that Sirt1 positively regulates transcription of the gene encoding Rictor, triggering a cascade of phosphorylation of Akt at S473 and Foxo1 at S253 and resulting in decreased transcription of the gluconeogenic genes glucose-6-phosphatase (G6pase) and phosphoenolpyruvate carboxykinase (Pepck). Liver-specific Sirt1 deficiency caused hepatic glucose overproduction, chronic hyperglycemia, and increased ROS production. This oxidative stress disrupted mTorc2 and impaired mTorc2/Akt signaling in other insulin-sensitive organs, leading to insulin resistance that could be largely reversed with antioxidant treatment. These data delineate a pathway through which Sirt1 maintains insulin sensitivity and suggest that treatment with antioxidants might provide protection against progressive insulin resistance in older human populations. PMID:21965330

  14. Age-dependent acceleration of ischemic injury in endothelial nitric oxide synthase-deficient mice: potential role of impaired VEGF receptor 2 expression.

    PubMed

    Qian, Hu Sheng; de Resende, Micheline Monterio; Beausejour, Christian; Huw, Ling-Yuh; Liu, Perry; Rubanyi, Gabor M; Kauser, Katalin

    2006-04-01

    Morbidity and mortality of peripheral arterial occlusive disease significantly increases with age, often exhibiting more severe disease pathology and decreased treatment effectiveness. Therapeutic angiogenesis with angiogenic growth factors may represent a valuable treatment option for the severely ill, older adult patient population. Aging is considered an independent cardiovascular risk factor, but pathomechanistically it is not well understood. Diminished endothelial nitric oxide (EDNO) production has been considered as a major contributor to the aging process. To investigate the effect of age on postischemic revascularization independent of changes in EDNO, we used endothelial nitric oxide synthase-deficient (ecNOS-KO) mice. We found an age-dependent acceleration in ischemic injury following unilateral femoral artery ligation in these animals compared to C57BL/J6 mice. Postischemic revascularization, quantified by measuring von Willebrand factor expression, was significantly impaired, suggesting that factors other than progressive EDNO deterioration are also involved in the age-dependent severe disease phenotype. Ischemia led to an increase in the expression of vascular endothelial growth factor receptor-2, KDR, in younger ecNOS-KO; however, this increase in KDR expression was absent in the older animals. Lack of increased KDR expression may provide a mechanistic explanation for the severe ischemic injury and perhaps can be used as a clinical marker to identify severe, vascular endothelial growth factor refractory patient population. PMID:16680073

  15. T-type calcium channel Cav3.2 deficient mice show elevated anxiety, impaired memory and reduced sensitivity to psychostimulants

    PubMed Central

    Gangarossa, Giuseppe; Laffray, Sophie; Bourinet, Emmanuel; Valjent, Emmanuel

    2014-01-01

    The fine-tuning of neuronal excitability relies on a tight control of Ca2+ homeostasis. The low voltage-activated (LVA) T-type calcium channels (Cav3.1, Cav3.2 and Cav3.3 isoforms) play a critical role in regulating these processes. Despite their wide expression throughout the central nervous system, the implication of T-type Cav3.2 isoform in brain functions is still poorly characterized. Here, we investigate the effect of genetic ablation of this isoform in affective disorders, including anxiety, cognitive functions as well as sensitivity to drugs of abuse. Using a wide range of behavioral assays we show that genetic ablation of the cacna1h gene results in an anxiety-like phenotype, whereas novelty-induced locomotor activity is unaffected. Deletion of the T-type channel Cav3.2 also triggers impairment of hippocampus-dependent recognition memories. Acute and sensitized hyperlocomotion induced by d-amphetamine and cocaine are dramatically reduced in T-type Cav3.2 deficient mice. In addition, the administration of the T-type blocker TTA-A2 prevented the expression of locomotor sensitization observed in wildtype mice. In conclusion, our data reveal that physiological activity of this specific Ca2+ channel is required for affective and cognitive behaviors. Moreover, our work highlights the interest of T-type channel blockers as therapeutic strategies to reverse drug-associated alterations. PMID:24672455

  16. SENP1-Mediated Desumoylation of DBC1 Inhibits Apoptosis Induced by High Glucose in Bovine Retinal Pericytes

    PubMed Central

    Gao, Jian; Chen, Xia; Gu, Qing; Liu, Xiaoxiao; Xu, Xun

    2016-01-01

    Pericyte loss is an early characteristic change in diabetic retinopathy, but its precise molecular mechanisms have not been elucidated. This study investigated the role of SENP1 in pericyte loss in diabetic retinopathy. We demonstrated that a high concentration of glucose inhibited the expression of the Sentrin/SUMO-specific protease 1 (SENP1), which resulted in an increase in DBC1 sumoylation in bovine retinal pericytes (BRPCs). Furthermore, SENP1 overexpression attenuated hyperemia-induced apoptosis of BPRCs, and SENP1 knockdown aggravated this effect. We also provide evidence that DBC1 sumoylation/desumoylation is involved in the SENP1-regulated apoptosis of BRPCs under high glucose conditions. Understanding the role of SENP1 in the pathogenesis of high glucose induced pericyte loss could help elucidate important targets for future pharmacological interventions. PMID:27110392

  17. PKC/MAPK signaling suppression by retinal pericyte conditioned medium prevents retinal endothelial cell proliferation.

    PubMed

    Kondo, Tetsu; Hosoya, Ken-Ichi; Hori, Satoko; Tomi, Masatoshi; Ohtsuki, Sumio; Terasaki, Tetsuya

    2005-05-01

    Little is known about the regulation mechanism of endothelial cell proliferation by retinal pericytes. The purpose of this study was to elucidate the suppression mechanism of retinal capillary endothelial cell growth by soluble factors derived from retinal pericytes. Conditioned medium of retinal pericytes (rPCT1-CM) suppressed ischemia-induced retinal neovascularization. The growth and DNA synthesis of TR-iBRB2 cells, a conditionally immortalized rat retinal capillary endothelial cell line, were suppressed in a concentration-dependent manner by concentrated rPCT1-CM. The number of human cultured endothelial cells was also reduced by rPCT1-CM. These results provide the first evidence that CM from the cultivation of pericytes alone can inhibit retinal neovascularization in vivo and in vitro. Although the growth reduction of TR-iBRB2 cells was only partly reversed by treatment of rPCT1-CM with antibodies to transforming growth factor-beta1, it was completely lost by heat-treatment of rPCT1-CM, suggesting that anti-angiogenic factors are soluble proteins. The levels of expression of G1/S-phase-related proteins, such as cyclin D1, cyclin-dependent kinase (cdk)4, cdk6, and proliferating cell nuclear antigen, were reduced and a cdk inhibitor, p21(Cip1), was induced in rPCT1-CM-treated TR-iBRB2 cells. Moreover, phosphorylated p44/42 mitogen-activated protein kinase (p44/42 MAPK) in TR-iBRB2 cells was reduced by rPCT1-CM treatment and phosphorylated protein kinase C (PKC)alpha/betaII, which is upstream of p44/42 MAPK, was also suppressed. In conclusion, CM from retinal pericytes suppresses PKC-p44/42 MAPK signaling, inhibits endothelial cell growth, and prevents retinal neovascularization. Anti-angiogenic factors derived from retinal pericytes are likely to play a critical role in the regulation of retinal endothelial cell growth. PMID:15499572

  18. NG2 proteoglycan-dependent recruitment of tumor macrophages promotes pericyte-endothelial cell interactions required for brain tumor vascularization

    PubMed Central

    Yotsumoto, Fusanori; You, Weon-Kyoo; Cejudo-Martin, Pilar; Kucharova, Karolina; Sakimura, Kenji; Stallcup, William B

    2015-01-01

    Early stage growth of intracranial B16F10 tumors is reduced by 87% in myeloid-specific NG2 null (Mac-NG2ko) mice and by 77% in pericyte-specific NG2 null (PC-NG2ko) mice, demonstrating the importance of the NG2 proteoglycan in each of these stromal compartments. In both genotypes, loss of pericyte-endothelial cell interaction results in numerous structural defects in tumor blood vessels, including decreased formation of endothelial cell junctions and decreased assembly of the vascular basal lamina. All vascular deficits are larger in Mac-NG2ko mice than in PC-NG2ko mice, correlating with the greater decrease in pericyte-endothelial cell interaction in Mac-NG2ko animals. Accordingly, tumor vessels in Mac-NG2ko mice have a smaller diameter, lower degree of patency, and higher degree of leakiness than tumor vessels in PC-NG2ko mice, leading to less efficient tumor blood flow and to increased intratumoral hypoxia. While reduced pericyte interaction with endothelial cells in PC-NG2ko mice is caused by loss of NG2-dependent pericyte activation of β1 integrin signaling in endothelial cells, reduced pericyte-endothelial cell interaction in Mac-NG2ko mice is due to a 90% reduction in NG2-dependent macrophage recruitment to tumors. The absence of a macrophage-derived signal(s) in Mac-NG2ko mice results in the loss of pericyte ability to associate with endothelial cells, possibly due to reduced expression of N-cadherin by both pericytes and endothelial cells. PMID:26137396

  19. Constitutional Nephrin Deficiency in Conditionally Immortalized Human Podocytes Induced Epithelial-Mesenchymal Transition, Supported by β-Catenin/NF-kappa B Activation: A Consequence of Cell Junction Impairment?

    PubMed

    Ghiggeri, Gian Marco; Gigante, Maddalena; Di Donato, Armando

    2013-01-01

    The kidney glomerular podocytes are the cellular target of many chronic nephropathies both determined and acquired genetically. Mutations that affected the expression and/or the function of nephrin, a key component of the slit-diaphragm, are often causes of these pathologies. Recent findings showed that murine podocytes could undergo epithelial-mesenchymal transformation (EMT), suggesting new hypotheses about the pathogenesis of glomerular fibrosis. Here, we show that also human podocytes can undergo EMT, but more importantly nephrin ablation itself can trigger this phenotypic transformation. In fact, a model of human podocyte with engineered nephrin deficiency constitutionally expressed high levels of α-SMA, vimentin, fibronectin, and other hallmarks of EMT. Since it is known that cell contact abrogation is one of the triggers of EMT, we reasoned that nephrin loss could account for such cell junction disruption and cause the EMT. Therefore, we demonstrated that also normal podocytes could spontaneously undergo EMT if grown in Ca(2+)-free medium, which is known to impair cell contacts. The analysis of the main intracellular signal transduction pathways evidenced some major anomalies consequent with the nephrin abrogation. The most intriguing was the activation of β-catenin pathway, which plays a critical role in podocyte ontogenesis as well as in the nephrin expression and EMT regulation. Also other important signaling proteins, like NF-κB, p53, and retinoblastoma protein (RB), showed important activity modifications. Interestingly, most of the above indicated signaling pathway alterations were again reproducible by cell junction rupture, induced by Ca(2+) deprivation. Finally, immunofluorescence analysis on kidney sections of patients with NS of Finnish type confirmed the constitutive expression of α-SMA. PMID:24392227

  20. Deficiency in a Very-Long-Chain Fatty Acid β-Ketoacyl-Coenzyme A Synthase of Tomato Impairs Microgametogenesis and Causes Floral Organ Fusion1[W

    PubMed Central

    Smirnova, Anna; Leide, Jana; Riederer, Markus

    2013-01-01

    Previously, it was shown that β-ketoacyl-coenzyme A synthase ECERIFERUM6 (CER6) is necessary for the biosynthesis of very-long-chain fatty acids with chain lengths beyond C28 in tomato (Solanum lycopersicum) fruits and C26 in Arabidopsis (Arabidopsis thaliana) leaves and the pollen coat. CER6 loss of function in Arabidopsis resulted in conditional male sterility, since pollen coat lipids are responsible for contact-mediated pollen hydration. In tomato, on the contrary, pollen hydration does not rely on pollen coat lipids. Nevertheless, mutation in SlCER6 impairs fertility and floral morphology. Here, the contribution of SlCER6 to the sexual reproduction and flower development of tomato was addressed. Cytological analysis and cross-pollination experiments revealed that the slcer6 mutant has male sterility caused by (1) hampered pollen dispersal and (2) abnormal tapetum development. SlCER6 loss of function provokes a decrease of n- and iso-alkanes with chain lengths of C27 or greater and of anteiso-alkanes with chain lengths of C28 or greater in flower cuticular waxes, but it has no impact on flower cuticle ultrastructure and cutin content. Expression analysis confirmed high transcription levels of SlCER6 in the anther and the petal, preferentially in sites subject to epidermal fusion. Hence, wax deficiency was proposed to be the primary reason for the flower fusion phenomenon in tomato. The SlCER6 substrate specificity was revisited. It might be involved in elongation of not only linear but also branched very-long-chain fatty acids, leading to production of the corresponding alkanes. SlCER6 implements a function in the sexual reproduction of tomato that is different from the one in Arabidopsis: SlCER6 is essential for the regulation of timely tapetum degradation and, consequently, microgametogenesis. PMID:23144186

  1. Constitutional Nephrin Deficiency in Conditionally Immortalized Human Podocytes Induced Epithelial-Mesenchymal Transition, Supported by β-Catenin/NF-kappa B Activation: A Consequence of Cell Junction Impairment?

    PubMed Central

    Ghiggeri, Gian Marco

    2013-01-01

    The kidney glomerular podocytes are the cellular target of many chronic nephropathies both determined and acquired genetically. Mutations that affected the expression and/or the function of nephrin, a key component of the slit-diaphragm, are often causes of these pathologies. Recent findings showed that murine podocytes could undergo epithelial-mesenchymal transformation (EMT), suggesting new hypotheses about the pathogenesis of glomerular fibrosis. Here, we show that also human podocytes can undergo EMT, but more importantly nephrin ablation itself can trigger this phenotypic transformation. In fact, a model of human podocyte with engineered nephrin deficiency constitutionally expressed high levels of α-SMA, vimentin, fibronectin, and other hallmarks of EMT. Since it is known that cell contact abrogation is one of the triggers of EMT, we reasoned that nephrin loss could account for such cell junction disruption and cause the EMT. Therefore, we demonstrated that also normal podocytes could spontaneously undergo EMT if grown in Ca2+-free medium, which is known to impair cell contacts. The analysis of the main intracellular signal transduction pathways evidenced some major anomalies consequent with the nephrin abrogation. The most intriguing was the activation of β-catenin pathway, which plays a critical role in podocyte ontogenesis as well as in the nephrin expression and EMT regulation. Also other important signaling proteins, like NF-κB, p53, and retinoblastoma protein (RB), showed important activity modifications. Interestingly, most of the above indicated signaling pathway alterations were again reproducible by cell junction rupture, induced by Ca2+ deprivation. Finally, immunofluorescence analysis on kidney sections of patients with NS of Finnish type confirmed the constitutive expression of α-SMA. PMID:24392227

  2. Impaired Lysosomal Integral Membrane Protein 2-dependent Peroxiredoxin 6 Delivery to Lamellar Bodies Accounts for Altered Alveolar Phospholipid Content in Adaptor Protein-3-deficient pearl Mice.

    PubMed

    Kook, Seunghyi; Wang, Ping; Young, Lisa R; Schwake, Michael; Saftig, Paul; Weng, Xialian; Meng, Ying; Neculai, Dante; Marks, Michael S; Gonzales, Linda; Beers, Michael F; Guttentag, Susan

    2016-04-15

    The Hermansky Pudlak syndromes (HPS) constitute a family of disorders characterized by oculocutaneous albinism and bleeding diathesis, often associated with lethal lung fibrosis. HPS results from mutations in genes of membrane trafficking complexes that facilitate delivery of cargo to lysosome-related organelles. Among the affected lysosome-related organelles are lamellar bodies (LB) within alveolar type 2 cells (AT2) in which surfactant components are assembled, modified, and stored. AT2 from HPS patients and mouse models of HPS exhibit enlarged LB with increased phospholipid content, but the mechanism underlying these defects is unknown. We now show that AT2 in the pearl mouse model of HPS type 2 lacking the adaptor protein 3 complex (AP-3) fails to accumulate the soluble enzyme peroxiredoxin 6 (PRDX6) in LB. This defect reflects impaired AP-3-dependent trafficking of PRDX6 to LB, because pearl mouse AT2 cells harbor a normal total PRDX6 content. AP-3-dependent targeting of PRDX6 to LB requires the transmembrane protein LIMP-2/SCARB2, a known AP-3-dependent cargo protein that functions as a carrier for lysosomal proteins in other cell types. Depletion of LB PRDX6 in AP-3- or LIMP-2/SCARB2-deficient mice correlates with phospholipid accumulation in lamellar bodies and with defective intraluminal degradation of LB disaturated phosphatidylcholine. Furthermore, AP-3-dependent LB targeting is facilitated by protein/protein interaction between LIMP-2/SCARB2 and PRDX6 in vitro and in vivo Our data provide the first evidence for an AP-3-dependent cargo protein required for the maturation of LB in AT2 and suggest that the loss of PRDX6 activity contributes to the pathogenic changes in LB phospholipid homeostasis found HPS2 patients. PMID:26907692

  3. CD70-deficiency impairs effector CD8 T cell generation and viral clearance but is dispensable for the recall response to LCMV

    PubMed Central

    Munitic, Ivana; Kuka, Mirela; Allam, Atef; Scoville, Jonathan P.; Ashwell, Jonathan D.

    2012-01-01

    CD27 interactions with its ligand, CD70, are thought to be necessary for optimal primary and memory adaptive immune responses to a variety of pathogens. Thus far all studies addressing the function of the CD27-CD70 axis have been performed either in mice lacking CD27, overexpressing CD70, or in which these receptors were blocked or mimicked by antibodies or recombinant soluble CD70. Because these methods have in some cases led to divergent results, we generated CD70-deficient mice to directly assess its role in vivo. We find that lack of CD70-mediated stimulation during primary responses to LCMV lowered the magnitude of CD8 antigen-specific T cell response, resulting in impaired viral clearance, without affecting CD4 T cell responses. Unexpectedly, CD70-CD27 costimulation was not needed for memory CD8 T cell generation or the ability to mount a recall response to LCMV. Adoptive transfers of wild type (WT) memory T cells into CD70−/− or WT hosts also showed no need for CD70-mediated stimulation during the course of the recall response. Moreover, CD70-expression by CD8 T cells could not rescue endogenous CD70−/− cells from defective expansion, arguing against a role for CD70-mediated T:T help in this model. Therefore, CD70 appears to be an important factor in the initiation of a robust and effective primary response but dispensable for CD8 T cell memory responses. PMID:23269247

  4. Endothelial cells are progenitors of cardiac pericytes and vascular smooth muscle cells

    PubMed Central

    Chen, Qi; Zhang, Hui; Liu, Yang; Adams, Susanne; Eilken, Hanna; Stehling, Martin; Corada, Monica; Dejana, Elisabetta; Zhou, Bin; Adams, Ralf H.

    2016-01-01

    Mural cells of the vessel wall, namely pericytes and vascular smooth muscle cells, are essential for vascular integrity. The developmental sources of these cells and molecular mechanisms controlling their progenitors in the heart are only partially understood. Here we show that endocardial endothelial cells are progenitors of pericytes and vascular smooth muscle cells in the murine embryonic heart. Endocardial cells undergo endothelial–mesenchymal transition and convert into primitive mesenchymal progenitors expressing the platelet-derived growth factor receptors, PDGFRα and PDGFRβ. These progenitors migrate into the myocardium, differentiate and assemble the wall of coronary vessels, which requires canonical Wnt signalling involving Frizzled4, β-catenin and endothelial cell-derived Wnt ligands. Our findings identify a novel and unexpected population of progenitors for coronary mural cells with potential relevance for heart function and disease conditions. PMID:27516371

  5. Endothelial cells are progenitors of cardiac pericytes and vascular smooth muscle cells.

    PubMed

    Chen, Qi; Zhang, Hui; Liu, Yang; Adams, Susanne; Eilken, Hanna; Stehling, Martin; Corada, Monica; Dejana, Elisabetta; Zhou, Bin; Adams, Ralf H

    2016-01-01

    Mural cells of the vessel wall, namely pericytes and vascular smooth muscle cells, are essential for vascular integrity. The developmental sources of these cells and molecular mechanisms controlling their progenitors in the heart are only partially understood. Here we show that endocardial endothelial cells are progenitors of pericytes and vascular smooth muscle cells in the murine embryonic heart. Endocardial cells undergo endothelial-mesenchymal transition and convert into primitive mesenchymal progenitors expressing the platelet-derived growth factor receptors, PDGFRα and PDGFRβ. These progenitors migrate into the myocardium, differentiate and assemble the wall of coronary vessels, which requires canonical Wnt signalling involving Frizzled4, β-catenin and endothelial cell-derived Wnt ligands. Our findings identify a novel and unexpected population of progenitors for coronary mural cells with potential relevance for heart function and disease conditions. PMID:27516371

  6. Role of Lung Pericytes and Resident Fibroblasts in the Pathogenesis of Pulmonary Fibrosis

    PubMed Central

    Hung, Chi; Linn, Geoffrey; Chow, Yu-Hua; Kobayashi, Akio; Mittelsteadt, Kristen; Altemeier, William A.; Gharib, Sina A.

    2013-01-01

    Rationale: The origin of cells that make pathologic fibrillar collagen matrix in lung disease has been controversial. Recent studies suggest mesenchymal cells may contribute directly to fibrosis. Objectives: To characterize discrete populations of mesenchymal cells in the normal mouse lung and to map their fate after bleomycin-induced lung injury. Methods: We mapped the fate of Foxd1-expressing embryonic progenitors and their progeny during lung development, adult homeostasis, and after fibrosing injury in Foxd1-Cre; Rs26-tdTomato-R mice. We studied collagen-I(α)1–producing cells in normal and diseased lungs using Coll-GFPTg mice. Measurements and Main Results: Foxd1-expressing embryonic progenitors enter lung buds before 13.5 days post-conception, expand, and form an extensive lineage of mesenchymal cells that have characteristics of pericytes. A collagen-I(α)1–expressing mesenchymal population of distinct lineage is also found in adult lung, with features of a resident fibroblast. In contrast to resident fibroblasts, Foxd1 progenitor–derived pericytes are enriched in transcripts for innate immunity, vascular development, WNT signaling pathway, and cell migration. Foxd1 progenitor–derived pericytes expand after bleomycin lung injury, and activate expression of collagen-I(α)1 and the myofibroblast marker αSMA in fibrotic foci. In addition, our studies suggest a distinct lineage of collagen-I(α)1–expressing resident fibroblasts that also expands after lung injury is a second major source of myofibroblasts. Conclusions: We conclude that the lung contains an extensive population of Foxd1 progenitor–derived pericytes that are an important lung myofibroblast precursor population. PMID:23924232

  7. Occludin controls HIV transcription in brain pericytes via regulation of SIRT-1 activation.

    PubMed

    Castro, Victor; Bertrand, Luc; Luethen, Mareen; Dabrowski, Sebastian; Lombardi, Jorge; Morgan, Laura; Sharova, Natalia; Stevenson, Mario; Blasig, Ingolf E; Toborek, Michal

    2016-03-01

    HIV invades the brain early after infection; however, its interactions with the cells of the blood-brain barrier (BBB) remain poorly understood. Our goal was to evaluate the role of occludin, one of the tight junction proteins that regulate BBB functions in HIV infection of BBB pericytes. We provide evidence that occludin levels largely control the metabolic responses of human pericytes to HIV. Occludin in BBB pericytes decreased by 10% during the first 48 h after HIV infection, correlating with increased nuclear translocation of the gene repressor C-terminal-binding protein (CtBP)-1 and NFκB-p65 activation. These changes were associated with decreased expression and activation of the class III histone deacetylase sirtuin (SIRT)-1. Occludin levels recovered 96 h after infection, restoring SIRT-1 and reducing HIV transcription to 20% of its highest values. We characterized occludin biochemically as a novel NADH oxidase that controls the expression and activation of SIRT-1. The inverse correlation between occludin and HIV transcription was then replicated in human primary macrophages and differentiated monocytic U937 cells, in which occludin silencing resulted in 75 and 250% increased viral transcription, respectively. Our work shows that occludin has previously unsuspected metabolic properties and is a target of HIV infection, opening the possibility of designing novel pharmacological approaches to control HIV transcription. PMID:26601824

  8. Severe but Not Moderate Vitamin B12 Deficiency Impairs Lipid Profile, Induces Adiposity, and Leads to Adverse Gestational Outcome in Female C57BL/6 Mice.

    PubMed

    Ghosh, Shampa; Sinha, Jitendra Kumar; Putcha, Uday Kumar; Raghunath, Manchala

    2016-01-01

    Vitamin B12 deficiency is widely prevalent in women of childbearing age, especially in developing countries. In the present study, through dietary restriction, we have established mouse models of severe and moderate vitamin B12 deficiencies to elucidate the impact on body composition, biochemical parameters, and reproductive performance. Female weanling C57BL/6 mice were fed for 4 weeks: (a) control AIN-76A diet, (b) vitamin B12-restricted AIN-76A diet with pectin as dietary fiber (severe deficiency group, as pectin inhibits vitamin B12 absorption), or (c) vitamin B12-restricted AIN-76A diet with cellulose as dietary fiber (moderate deficiency group as cellulose does not interfere with vitamin B12 absorption). After confirming deficiency, the mice were mated with male colony mice and maintained on their respective diets throughout pregnancy, lactation, and thereafter till 12 weeks. Severe vitamin B12 deficiency increased body fat% significantly, induced adiposity and altered lipid profile. Pregnant dams of both the deficient groups developed anemia. Severe vitamin B12 deficiency decreased the percentage of conception and litter size, pups were small-for-gestational-age and had significantly lower body weight at birth as well as weaning. Most of the offspring born to severely deficient dams died within 24 h of birth. Stress markers and adipocytokines were elevated in severe deficiency with concomitant decrease in antioxidant defense. The results show that severe but not moderate vitamin B12 restriction had profound impact on the physiology of C57BL/6 mice. Oxidative and corticosteroid stress, inflammation and poor antioxidant defense seem to be the probable underlying mechanisms mediating the deleterious effects. PMID:26835453

  9. Severe but Not Moderate Vitamin B12 Deficiency Impairs Lipid Profile, Induces Adiposity, and Leads to Adverse Gestational Outcome in Female C57BL/6 Mice

    PubMed Central

    Ghosh, Shampa; Sinha, Jitendra Kumar; Putcha, Uday Kumar; Raghunath, Manchala

    2016-01-01

    Vitamin B12 deficiency is widely prevalent in women of childbearing age, especially in developing countries. In the present study, through dietary restriction, we have established mouse models of severe and moderate vitamin B12 deficiencies to elucidate the impact on body composition, biochemical parameters, and reproductive performance. Female weanling C57BL/6 mice were fed for 4 weeks: (a) control AIN-76A diet, (b) vitamin B12-restricted AIN-76A diet with pectin as dietary fiber (severe deficiency group, as pectin inhibits vitamin B12 absorption), or (c) vitamin B12-restricted AIN-76A diet with cellulose as dietary fiber (moderate deficiency group as cellulose does not interfere with vitamin B12 absorption). After confirming deficiency, the mice were mated with male colony mice and maintained on their respective diets throughout pregnancy, lactation, and thereafter till 12 weeks. Severe vitamin B12 deficiency increased body fat% significantly, induced adiposity and altered lipid profile. Pregnant dams of both the deficient groups developed anemia. Severe vitamin B12 deficiency decreased the percentage of conception and litter size, pups were small-for-gestational-age and had significantly lower body weight at birth as well as weaning. Most of the offspring born to severely deficient dams died within 24 h of birth. Stress markers and adipocytokines were elevated in severe deficiency with concomitant decrease in antioxidant defense. The results show that severe but not moderate vitamin B12 restriction had profound impact on the physiology of C57BL/6 mice. Oxidative and corticosteroid stress, inflammation and poor antioxidant defense seem to be the probable underlying mechanisms mediating the deleterious effects. PMID:26835453

  10. In vitro modeling of endothelial interaction with macrophages and pericytes demonstrates Notch signaling function in the vascular microenvironment.

    PubMed

    Tattersall, Ian W; Du, Jing; Cong, Zhuangzhuang; Cho, Bennet S; Klein, Alyssa M; Dieck, Chelsea L; Chaudhri, Reyhaan A; Cuervo, Henar; Herts, James H; Kitajewski, Jan

    2016-04-01

    Angiogenesis is regulated by complex interactions between endothelial cells and support cells of the vascular microenvironment, such as tissue myeloid cells and vascular mural cells. Multicellular interactions during angiogenesis are difficult to study in animals and challenging in a reductive setting. We incorporated stromal cells into an established bead-based capillary sprouting assay to develop assays that faithfully reproduce major steps of vessel sprouting and maturation. We observed that macrophages enhance angiogenesis, increasing the number and length of endothelial sprouts, a property we have dubbed "angiotrophism." We found that polarizing macrophages toward a pro-inflammatory profile further increased their angiotrophic stimulation of vessel sprouting, and this increase was dependent on macrophage Notch signaling. To study endothelial/pericyte interactions, we added vascular pericytes directly to the bead-bound endothelial monolayer. These pericytes formed close associations with the endothelial sprouts, causing increased sprout number and vessel caliber. We found that Jagged1 expression and Notch signaling are essential for the growth of both endothelial cells and pericytes and may function in their interaction. We observed that combining endothelial cells with both macrophages and pericytes in the same sprouting assay has multiplicative effects on sprouting. These results significantly improve bead-capillary sprouting assays and provide an enhanced method for modeling interactions between the endothelium and the vascular microenvironment. Achieving this in a reductive in vitro setting represents a significant step toward a better understanding of the cellular elements that contribute to the formation of mature vasculature. PMID:26965898

  11. Development of spontaneous neuropathy in NF-κBp50-deficient mice by calcineurin-signal involving impaired NF-κB activation

    PubMed Central

    Nakamura-Yanagidaira, Tomoko; Takahashi, Yasuko; Sano, Kenji; Murata, Toshinori

    2011-01-01

    Purpose The transcriptional regulator, nuclear factor-kappa B (NF-κB)/Rel family are involved in neuronal cell death and survival. Previously, we reported that NF-κBp50-deficient (p50-deficient) mice exhibit many features resembling human normal tension glaucoma (NTG). The developmental mechanism of human NTG is not clearly understood, and a radical curative treatment has yet to be established. Our aim is to elucidate the signal cascade which mediates the spontaneous optic neuropathy in p50-deficient mice as a model of NTG. Methods To demonstrate the expression and activation of pro-apoptotic factors, which mediate the death of retinal ganglion cells (RGCs) in p50-deficient mice, western blot (WB) and luciferase reporter assays with retinas from p50-deficient and wild type mice, and cultured RGC-5 cells were performed. Furthermore, we tested the neuroprotective effects of chemical reagents (memantine, lomerizine, and tacrolimus) against N-methyl-D-aspartate (NMDA)-susceptible RGC damage according to in vitro experiments with RGC-5 cells. To elucidate the NF-κB-mediated death signaling, the effects of chemical reagents on spontaneous optic neuropathy were examined by histopathological studies. Results WB experiments and luciferase reporter assays showed that NF-κB-inducible BCL2-associated X protein (Bax) and a pro-apoptotic factor, activated caspase 3 were expressed in the retina of p50-deficient mice as well as NMDA-treated RGC-5 cells. Further, the constitutivelyactivecleaved forms of calcineurin (CaN), which havebeen reported to lead to apoptosis, were detected in the retina of p50-deficient mice as well as NMDA-treated RGC-5 cells. Pre-treatment with tacrolimus markedlyprotected RGC-5 cells from NMDA-induced neurotoxicity, and then both spontaneous RGC death and degenerative changes to the optic nerve in p50-deficient mice were significantlyreduced by the chronic administration of tacrolimus. The experiments with cultured RGC-5 cells supported the results

  12. Inflammation-induced endothelial cell-derived extracellular vesicles modulate the cellular status of pericytes.

    PubMed

    Yamamoto, Seiji; Niida, Shumpei; Azuma, Erika; Yanagibashi, Tsutomu; Muramatsu, Masashi; Huang, Ting Ting; Sagara, Hiroshi; Higaki, Sayuri; Ikutani, Masashi; Nagai, Yoshinori; Takatsu, Kiyoshi; Miyazaki, Kenji; Hamashima, Takeru; Mori, Hisashi; Matsuda, Naoyuki; Ishii, Yoko; Sasahara, Masakiyo

    2015-01-01

    Emerging lines of evidence have shown that extracellular vesicles (EVs) mediate cell-to-cell communication by exporting encapsulated materials, such as microRNAs (miRNAs), to target cells. Endothelial cell-derived EVs (E-EVs) are upregulated in circulating blood in different pathological conditions; however, the characteristics and the role of these E-EVs are not yet well understood. In vitro studies were conducted to determine the role of inflammation-induced E-EVs in the cell-to-cell communication between vascular endothelial cells and pericytes/vSMCs. Stimulation with inflammatory cytokines and endotoxin immediately induced release of shedding type E-EVs from the vascular endothelial cells, and flow cytometry showed that the induction was dose dependent. MiRNA array analyses revealed that group of miRNAs were specifically increased in the inflammation-induced E-EVs. E-EVs added to the culture media of cerebrovascular pericytes were incorporated into the cells. The E-EV-supplemented cells showed highly induced mRNA and protein expression of VEGF-B, which was assumed to be a downstream target of the miRNA that was increased within the E-EVs after inflammatory stimulation. The results suggest that E-EVs mediate inflammation-induced endothelial cell-pericyte/vSMC communication, and the miRNAs encapsulated within the E-EVs may play a role in regulating target cell function. E-EVs may be new therapeutic targets for the treatment of inflammatory diseases. PMID:25687367

  13. Valve Interstitial Cells Act in a Pericyte Manner Promoting Angiogensis and Invasion by Valve Endothelial Cells.

    PubMed

    Arevalos, C Alexander; Berg, Jonathan M; Nguyen, Jacqueline M V; Godfrey, Elizabeth L; Iriondo, Claudia; Grande-Allen, K Jane

    2016-09-01

    Neovascularization is an understudied aspect of calcific aortic valve disease (CAVD). Within diseased valves, cells along the neovessels' periphery stain for pericyte markers, but it is unclear whether valvular interstitial cells (VICs) can demonstrate a pericyte-like phenotype. This investigation examined the perivascular potential of VICs to regulate valve endothelial cell (VEC) organization and explored the role of Angiopoeitin1-Tie2 signaling in this process. Porcine VECs and VICs were fluorescently tracked and co-cultured in Matrigel over 7 days. VICs regulated early VEC network organization in a ROCK-dependent manner, then guided later VEC network contraction through chemoattraction. Unlike vascular control cells, the valve cell cultures ultimately formed invasive spheroids with 3D angiogenic-like sprouts. VECs co-cultured with VICs displayed significantly more invasion than VECs alone; with VICs generally leading and wrapping around VEC invasive sprouts. Lastly, Angiopoietin1-Tie2 signaling was found to regulate valve cell organization during VEC/VIC spheroid formation and invasion. VICs demonstrated pericyte-like behaviors toward VECs throughout sustained co-culture. The change from a vasculogenic network to an invasive sprouting spheroid suggests that both cell types undergo phenotypic changes during long-term culture in the model angiogenic environment. Valve cells organizing into spheroids and undergoing 3D invasion of Matrigel demonstrated several typical angiogenic-like phenotypes dependent on basal levels of Angiopoeitin1-Tie2 signaling and ROCK activation. These results suggest that the ectopic sustained angiogenic environment during the early stages of valve disease promotes organized activity by both VECs and VICs, contributing to neovessel formation and the progression of CAVD. PMID:26905695

  14. Expansion and Characterization of Neonatal Cardiac Pericytes Provides a Novel Cellular Option for Tissue Engineering in Congenital Heart Disease

    PubMed Central

    Avolio, Elisa; Rodriguez-Arabaolaza, Iker; Spencer, Helen L; Riu, Federica; Mangialardi, Giuseppe; Slater, Sadie C; Rowlinson, Jonathan; Alvino, Valeria V; Idowu, Oluwasomidotun O; Soyombo, Stephanie; Oikawa, Atsuhiko; Swim, Megan M; Kong, Cherrie H T; Cheng, Hongwei; Jia, Huidong; Ghorbel, Mohamed T; Hancox, Jules C; Orchard, Clive H; Angelini, Gianni; Emanueli, Costanza; Caputo, Massimo; Madeddu, Paolo

    2015-01-01

    Background Living grafts produced by combining autologous heart-resident stem/progenitor cells and tissue engineering could provide a new therapeutic option for definitive correction of congenital heart disease. The aim of the study was to investigate the antigenic profile, expansion/differentiation capacity, paracrine activity, and pro-angiogenic potential of cardiac pericytes and to assess their engrafting capacity in clinically certified prosthetic grafts. Methods and Results CD34pos cells, negative for the endothelial markers CD31 and CD146, were identified by immunohistochemistry in cardiac leftovers from infants and children undergoing palliative repair of congenital cardiac defects. Following isolation by immunomagnetic bead-sorting and culture on plastic in EGM-2 medium supplemented with growth factors and serum, CD34pos/CD31neg cells gave rise to a clonogenic, highly proliferative (>20 million at P5), spindle-shape cell population. The following populations were shown to expresses pericyte/mesenchymal and stemness markers. After exposure to differentiation media, the expanded cardiac pericytes acquired markers of vascular smooth muscle cells, but failed to differentiate into endothelial cells or cardiomyocytes. However, in Matrigel, cardiac pericytes form networks and enhance the network capacity of endothelial cells. Moreover, they produce collagen-1 and release chemo-attractants that stimulate the migration of c-Kitpos cardiac stem cells. Cardiac pericytes were then seeded onto clinically approved xenograft scaffolds and cultured in a bioreactor. After 3 weeks, fluorescent microscopy showed that cardiac pericytes had penetrated into and colonized the graft. Conclusions These findings open new avenues for cellular functionalization of prosthetic grafts to be applied in reconstructive surgery of congenital heart disease. PMID:26080813

  15. A Triple Culture Model of the Blood-Brain Barrier Using Porcine Brain Endothelial cells, Astrocytes and Pericytes

    PubMed Central

    Thomsen, Louiza Bohn; Burkhart, Annette; Moos, Torben

    2015-01-01

    In vitro blood-brain barrier (BBB) models based on primary brain endothelial cells (BECs) cultured as monoculture or in co-culture with primary astrocytes and pericytes are useful for studying many properties of the BBB. The BECs retain their expression of tight junction proteins and efflux transporters leading to high trans-endothelial electric resistance (TEER) and low passive paracellular permeability. The BECs, astrocytes and pericytes are often isolated from small rodents. Larger species as cows and pigs however, reveal a higher yield, are readily available and have a closer resemblance to humans, which make them favorable high-throughput sources for cellular isolation. The aim of the present study has been to determine if the preferable combination of purely porcine cells isolated from the 6 months old domestic pigs, i.e. porcine brain endothelial cells (PBECs) in co-culture with porcine astrocytes and pericytes, would compare with PBECs co-cultured with astrocytes and pericytes isolated from newborn rats with respect to TEER value and low passive permeability. The astrocytes and pericytes were grown both as contact and non-contact co-cultures as well as in triple culture to examine their effects on the PBECs for barrier formation as revealed by TEER, passive permeability, and expression patterns of tight junction proteins, efflux transporters and the transferrin receptor. This syngenic porcine in vitro BBB model is comparable to triple cultures using PBECs, rat astrocytes and rat pericytes with respect to TEER formation, low passive permeability, and expression of hallmark proteins signifying the brain endothelium (tight junction proteins claudin 5 and occludin, the efflux transporters P-glycoprotein (PgP) and breast cancer related protein (BCRP), and the transferrin receptor). PMID:26241648

  16. LRP-6 is a coreceptor for multiple fibrogenic signaling pathways in pericytes and myofibroblasts that are inhibited by DKK-1

    PubMed Central

    Ren, Shuyu; Johnson, Bryce G.; Kida, Yujiro; Ip, Colin; Davidson, Kathryn C.; Lin, Shuei-Liong; Kobayashi, Akio; Lang, Richard A.; Hadjantonakis, Anna-Katerina; Moon, Randall T.; Duffield, Jeremy S.

    2013-01-01

    Fibrosis of vital organs is a major public health problem with limited therapeutic options. Mesenchymal cells including microvascular mural cells (pericytes) are major progenitors of scar-forming myofibroblasts in kidney and other organs. Here we show pericytes in healthy kidneys have active WNT/β-catenin signaling responses that are markedly up-regulated following kidney injury. Dickkopf-related protein 1 (DKK-1), a ligand for the WNT coreceptors low-density lipoprotein receptor-related proteins 5 and 6 (LRP-5 and LRP-6) and an inhibitor of WNT/β-catenin signaling, effectively inhibits pericyte activation, detachment, and transition to myofibroblasts in vivo in response to kidney injury, resulting in attenuated fibrogenesis, capillary rarefaction, and inflammation. DKK-1 blocks activation and proliferation of established myofibroblasts in vitro and blocks pericyte proliferation to PDGF, pericyte migration, gene activation, and cytoskeletal reorganization to TGF-β or connective tissue growth factor. These effects are largely independent of inhibition of downstream β-catenin signaling. DKK-1 acts predominantly by inhibiting PDGF-, TGF-β–, and connective tissue growth factor-activated MAPK and JNK signaling cascades, acting via LRP-6 with associated WNT ligand. Biochemically, LRP-6 interacts closely with PDGF receptor β and TGF-β receptor 1 at the cell membrane, suggesting that it may have roles in pathways other than WNT/β-catenin. In summary, DKK-1 blocks many of the changes in pericytes required for myofibroblast transition and attenuates established myofibroblast proliferation/activation by mechanisms dependent on LRP-6 and WNT ligands but not the downstream β-catenin pathway. PMID:23302695

  17. Blood-Brain Barrier Impairment in an Animal Model of MPS III B

    PubMed Central

    Garbuzova-Davis, Svitlana; Louis, Michael K.; Haller, Edward M.; Derasari, Hiranya M.; Rawls, Ashley E.; Sanberg, Paul R.

    2011-01-01

    Background Sanfilippo syndrome type B (MPS III B) is caused by a deficiency of α-N-acetylglucosaminidase enzyme, leading to accumulation of heparan sulfate within lysosomes and eventual progressive cerebral and systemic multiple organ abnormalities. However, little is known about the competence of the blood-brain barrier (BBB) in MPS III B. BBB dysfunction in this devastating disorder could contribute to neuropathological disease manifestations. Methodology/Principal Findings In the present study, we investigated structural (electron microscope) and functional (vascular leakage) integrity of the BBB in a mouse model of MPS III B at different stages of disease, focusing on brain structures known to experience neuropathological changes. Major findings of our study were: (1) endothelial cell damage in capillary ultrastructure, compromising the BBB and resulting in vascular leakage, (2) formation of numerous large vacuoles in endothelial cells and perivascular cells (pericytes and perivascular macrophages) in the large majority of vessels, (3) edematous space around microvessels, (4) microaneurysm adjacent to a ruptured endothelium, (6) Evans Blue and albumin microvascular leakage in various brain structures, (7) GM3 ganglioside accumulation in endothelium of the brain microvasculature. Conclusions/Significance These new findings of BBB structural and function impairment in MPS III B mice even at early disease stage may have implications for disease pathogenesis and should be considered in current and future development of treatments for MPS III B. PMID:21408219

  18. Regional Blood Flow in the Normal and Ischemic Brain Is Controlled by Arteriolar Smooth Muscle Cell Contractility and Not by Capillary Pericytes.

    PubMed

    Hill, Robert A; Tong, Lei; Yuan, Peng; Murikinati, Sasidhar; Gupta, Shobhana; Grutzendler, Jaime

    2015-07-01

    The precise regulation of cerebral blood flow is critical for normal brain function, and its disruption underlies many neuropathologies. The extent to which smooth muscle-covered arterioles or pericyte-covered capillaries control vasomotion during neurovascular coupling remains controversial. We found that capillary pericytes in mice and humans do not express smooth muscle actin and are morphologically and functionally distinct from adjacent precapillary smooth muscle cells (SMCs). Using optical imaging we investigated blood flow regulation at various sites on the vascular tree in living mice. Optogenetic, whisker stimulation, or cortical spreading depolarization caused microvascular diameter or flow changes in SMC but not pericyte-covered microvessels. During early stages of brain ischemia, transient SMC but not pericyte constrictions were a major cause of hypoperfusion leading to thrombosis and distal microvascular occlusions. Thus, capillary pericytes are not contractile, and regulation of cerebral blood flow in physiological and pathological conditions is mediated by arteriolar SMCs. PMID:26119027

  19. Adipose derived pericytes rescue fractures from a failure of healing - non-union.

    PubMed

    Tawonsawatruk, T; West, C C; Murray, I R; Soo, C; Péault, B; Simpson, A H R W

    2016-01-01

    Atrophic non-union is attributed to biological failure of the fracture repair process. It occurs in up to 10% of fractures, results in significant morbidity to patients, and treatment often requires complex reconstructive procedures. We tested the ability of human bone derived marrow mesenchymal stem cells (MSC), and human adipose derived pericytes (the native ancestor of the MSC) delivered percutaneously to the fracture gap to prevent the formation of atrophic non-union in a rat model. At eight weeks, 80% of animals in the cell treatment groups showed evidence of bone healing compared to only 14% of those in the control group. Radiographic parameters showed significant improvement over the eight-week period in the cell treatment groups, and histology confirmed bone bridges at the fracture gap in the both treatment groups. The quality of bone produced and its biomechanical properties were significantly enhanced in both treatment groups. The results from this study demonstrate that MSC and pericytes have significant bone regeneration potential in an atrophic non-union model. These cells may have a role in the prevention of atrophic non-union and could enable a paradigm shift in the treatment of fractures at high risk of failing to heal and developing non-union. PMID:26997456

  20. Adipose derived pericytes rescue fractures from a failure of healing – non-union

    PubMed Central

    Tawonsawatruk, T.; West, C. C.; Murray, I. R.; Soo, C.; Péault, B.; Simpson, A. H. R. W.

    2016-01-01

    Atrophic non-union is attributed to biological failure of the fracture repair process. It occurs in up to 10% of fractures, results in significant morbidity to patients, and treatment often requires complex reconstructive procedures. We tested the ability of human bone derived marrow mesenchymal stem cells (MSC), and human adipose derived pericytes (the native ancestor of the MSC) delivered percutaneously to the fracture gap to prevent the formation of atrophic non-union in a rat model. At eight weeks, 80% of animals in the cell treatment groups showed evidence of bone healing compared to only 14% of those in the control group. Radiographic parameters showed significant improvement over the eight-week period in the cell treatment groups, and histology confirmed bone bridges at the fracture gap in the both treatment groups. The quality of bone produced and its biomechanical properties were significantly enhanced in both treatment groups. The results from this study demonstrate that MSC and pericytes have significant bone regeneration potential in an atrophic non-union model. These cells may have a role in the prevention of atrophic non-union and could enable a paradigm shift in the treatment of fractures at high risk of failing to heal and developing non-union. PMID:26997456

  1. Differential Contribution to Neuroendocrine Tumorigenesis of Parallel Egfr Signaling in Cancer Cells and Pericytes

    PubMed Central

    Nolan-Stevaux, Olivier; Truitt, Morgan C.; Pahler, Jessica C.; Olson, Peter; Guinto, Cristina; Lee, David C.; Hanahan, Douglas

    2010-01-01

    Factors associated with tumor sensitivity to epidermal growth factor receptor (EGFR) inhibitors in the context of wild-type EGFR remain elusive. This study investigates the mechanistic basis of responsiveness to EGFR inhibitors in the RIP1-Tag2 (RT2) mouse model of pancreatic neuroendocrine tumorigenesis (PNET). Upon treatment of RT2 mice with EGFR inhibitors, PNET tumors harboring wild-type, nonamplified alleles of Egfr grow at a markedly reduced rate and display a significant increase in tumor cell apoptosis, as well as reduced neovascularization. The authors identify Tgf-α and Hb-egf as key limiting mediators of separable pathological functions of Egfr in neuroendocrine tumor progression: Tgf-α mutant tumors present with an elevated apoptotic index, whereas Hb-egf mutant lesions exhibit decreased angiogenic switching and neovascularization. This study not only associates Tgf-α and Hb-egf expression with wild-type Egfr oncogenicity but also ascribes the proangiogenic activity of Egfr in this tumor model to a novel mesenchymal Hb-egf/Egfr signaling axis, whereby endothelial and pericyte-derived Hb-egf activates Egfr specifically in tumor-associated perivascular cells, leading to increased pericyte coverage of the tumor endothelium and enhanced angiogenesis. PMID:20975924

  2. Presence of retinal pericyte-reactive autoantibodies in diabetic retinopathy patients

    PubMed Central

    Zhang, Lingjun; Li, Yan; Payne, John; Srivastava, Sunil; Fan, Xingjun; Fung, John; Li, Xiaorong; Kern, Timothy S.; Lin, Feng

    2016-01-01

    The loss of retinal pericytes (RPCs) is a hallmark of early stage diabetic retinopathy (DR), but the mechanism underlying RPC death is unclear. Although it was postulated in previous studies using bovine RPCs that autoantibodies against RPCs might develop and induce RPC death, it is unknown whether autoantibodies against cell-surface antigens on human RPCs exist in DR patients, whether such autoantibodies contribute to RPC damage/loss, and if they do, through which mechanism. We screened serum samples from DR patients and controls using primary human RPCs and found that that levels of IgGs reactive to RPCs were significantly higher in the DR group than the control group. Serum samples with higher RPC-reactive IgG levels induced more severe complement-mediated RPC damage than those with lower RPC-reactive IgG levels. We also assessed levels of the complement-activation products C3a, C4a and C5a in these serum samples, and found that serum levels of C3a and C5a, but not C4a, were higher in the DR group than control group. These data provide evidence the first time showing that autoantibodies against RPCs can develop in DR patients, and that these autoantibodies could contribute to pericyte damage through complement activation. PMID:26839120

  3. 3-D Imaging Reveals Participation of Donor Islet Schwann Cells and Pericytes in Islet Transplantation and Graft Neurovascular Regeneration

    PubMed Central

    Juang, Jyuhn-Huarng; Kuo, Chien-Hung; Peng, Shih-Jung; Tang, Shiue-Cheng

    2015-01-01

    The primary cells that participate in islet transplantation are the endocrine cells. However, in the islet microenvironment, the endocrine cells are closely associated with the neurovascular tissues consisting of the Schwann cells and pericytes, which form sheaths/barriers at the islet exterior and interior borders. The two cell types have shown their plasticity in islet injury, but their roles in transplantation remain unclear. In this research, we applied 3-dimensional neurovascular histology with cell tracing to reveal the participation of Schwann cells and pericytes in mouse islet transplantation. Longitudinal studies of the grafts under the kidney capsule identify that the donor Schwann cells and pericytes re-associate with the engrafted islets at the peri-graft and perivascular domains, respectively, indicating their adaptability in transplantation. Based on the morphological proximity and cellular reactivity, we propose that the new islet microenvironment should include the peri-graft Schwann cell sheath and perivascular pericytes as an integral part of the new tissue. PMID:26137552

  4. Foxf2 Is Required for Brain Pericyte Differentiation and Development and Maintenance of the Blood-Brain Barrier.

    PubMed

    Reyahi, Azadeh; Nik, Ali M; Ghiami, Mozhgan; Gritli-Linde, Amel; Pontén, Fredrik; Johansson, Bengt R; Carlsson, Peter

    2015-07-01

    Pericytes are critical for cerebrovascular maturation and development of the blood-brain barrier (BBB), but their role in maintenance of the adult BBB, and how CNS pericytes differ from those of other tissues, is less well understood. We show that the forkhead transcription factor Foxf2 is specifically expressed in pericytes of the brain and that Foxf2(-/-) embryos develop intracranial hemorrhage, perivascular edema, thinning of the vascular basal lamina, an increase of luminal endothelial caveolae, and a leaky BBB. Foxf2(-/-) brain pericytes were more numerous, proliferated faster, and expressed significantly less Pdgfrβ. Tgfβ-Smad2/3 signaling was attenuated, whereas phosphorylation of Smad1/5 and p38 were enhanced. Tgfβ pathway components, including Tgfβ2, Tgfβr2, Alk5, and integrins αVβ8, were reduced. Foxf2 inactivation in adults resulted in BBB breakdown, endothelial thickening, and increased trans-endothelial vesicular transport. On the basis of these results, FOXF2 emerges as an interesting candidate locus for stroke susceptibility in humans. PMID:26120030

  5. 3-D Imaging Reveals Participation of Donor Islet Schwann Cells and Pericytes in Islet Transplantation and Graft Neurovascular Regeneration.

    PubMed

    Juang, Jyuhn-Huarng; Kuo, Chien-Hung; Peng, Shih-Jung; Tang, Shiue-Cheng

    2015-02-01

    The primary cells that participate in islet transplantation are the endocrine cells. However, in the islet microenvironment, the endocrine cells are closely associated with the neurovascular tissues consisting of the Schwann cells and pericytes, which form sheaths/barriers at the islet exterior and interior borders. The two cell types have shown their plasticity in islet injury, but their roles in transplantation remain unclear. In this research, we applied 3-dimensional neurovascular histology with cell tracing to reveal the participation of Schwann cells and pericytes in mouse islet transplantation. Longitudinal studies of the grafts under the kidney capsule identify that the donor Schwann cells and pericytes re-associate with the engrafted islets at the peri-graft and perivascular domains, respectively, indicating their adaptability in transplantation. Based on the morphological proximity and cellular reactivity, we propose that the new islet microenvironment should include the peri-graft Schwann cell sheath and perivascular pericytes as an integral part of the new tissue. PMID:26137552

  6. Molecular Control of Vascular Tube Morphogenesis and Stabilization: Regulation by Extracellular Matrix, Matrix Metalloproteinases, and Endothelial Cell-Pericyte Interactions

    NASA Astrophysics Data System (ADS)

    Davis, George E.; Stratman, Amber N.; Sacharidou, Anastasia

    Recent studies have revealed a critical role for both extracellular matrices and matrix metalloproteinases in the molecular control of vascular morphogenesis and stabilization in three-dimensional (3D) tissue environments. Key interactions involve endothelial cells (ECs) and pericytes, which coassemble to affect vessel formation, remodeling, and stabilization events during development and postnatal life. EC-pericyte interactions control extracellular matrix remodeling events including vascular basement membrane matrix assembly, a necessary step for endothelial tube maturation and stabilization. ECs form tube networks in 3D extracellular matrices in a manner dependent on integrins, membrane-type metalloproteinases, and the Rho GTPases, Cdc42 and Rac1. Recent work has defined an EC lumen signaling complex of proteins composed of these proteins that controls 3D matrix-specific signaling events required for these processes. The EC tube formation process results in the creation of a network of proteolytically generated vascular guidance tunnels. These tunnels are physical matrix spaces that regulate vascular tube remodeling and represent matrix conduits into which pericytes are recruited to allow dynamic cell-cell interactions with ECs. These dynamic EC-pericyte interactions induce vascular basement membrane matrix deposition, leading to vessel maturation and stabilization.

  7. Platelet-derived growth factor-BB has neurorestorative effects and modulates the pericyte response in a partial 6-hydroxydopamine lesion mouse model of Parkinson's disease.

    PubMed

    Padel, Thomas; Özen, Ilknur; Boix, Jordi; Barbariga, Marco; Gaceb, Abderahim; Roth, Michaela; Paul, Gesine

    2016-10-01

    Parkinson's disease (PD) is a neurodegenerative disease where the degeneration of the nigrostriatal pathway leads to specific motor deficits. There is an unmet medical need for regenerative treatments that stop or reverse disease progression. Several growth factors have been investigated in clinical trials to restore the dopaminergic nigrostriatal pathway damaged in PD. Platelet-derived growth factor-BB (PDGF-BB), a molecule that recruits pericytes to stabilize microvessels, was recently investigated in a phase-1 clinical trial, showing a dose-dependent increase in dopamine transporter binding in the putamen of PD patients. Interestingly, evidence is accumulating that PD is paralleled by microvascular changes, however, whether PDGF-BB modifies pericytes in PD is not known. Using a pericyte reporter mouse strain, we investigate the functional and restorative effect of PDGF-BB in a partial 6-hydroxydopamine medial forebrain bundle lesion mouse model of PD, and whether this restorative effect is accompanied by changes in pericyte features. We demonstrate that a 2-week treatment with PDGF-BB leads to behavioural recovery using several behavioural tests, and partially restores the nigrostriatal pathway. Interestingly, we find that pericytes are activated in the striatum of PD lesioned mice and that these changes are reversed by PDGF-BB treatment. The modulation of brain pericytes may contribute to the PDGF-BB-induced neurorestorative effects, PDGF-BB allowing for vascular stabilization in PD. Pericytes might be a new cell target of interest for future regenerative therapies. PMID:27288154

  8. Genetics Home Reference: prekallikrein deficiency

    MedlinePlus

    ... a role in a process called the intrinsic coagulation pathway (also called the contact activation pathway). This ... functional plasma kallikrein, which likely impairs the intrinsic coagulation pathway. Researchers suggest that this lack (deficiency) of ...

  9. CD8+ T-cell clones deficient in the expression of the CD45 protein tyrosine phosphatase have impaired responses to T-cell receptor stimuli.

    PubMed Central

    Weaver, C T; Pingel, J T; Nelson, J O; Thomas, M L

    1991-01-01

    CD45 is a high-molecular-weight transmembrane protein tyrosine phosphatase expressed only by nucleated cells of hematopoietic origin. To examine function, mouse CD8+ cytolytic T-cell clones were derived that had a specific defect in the expression of CD45. Northern (RNA) blot analysis indicates that the CD45 deficiency is due to either a transcriptional defect or mRNA instability. The CD45-deficient cells were greatly diminished in their ability to respond to antigen. All functional parameters of T-cell receptor signalling analyzed (cytolysis of targets, proliferation, and cytokine production) were markedly diminished. A CD45+ revertant was isolated, and the ability to respond to antigen was restored. These results support a central and immediate role for this transmembrane protein tyrosine phosphatase in T-cell receptor signalling. Images PMID:1652055

  10. Impairment of blastogenic response of splenic lymphocytes from iron-deficient mice. In vitro repletion by hemin, transferrin, and ferric chloride.

    PubMed

    Kuvibidila, S R; Nauss, K M; Baliga, S B; Suskind, R M

    1983-04-01

    Splenic lymphocytes from iron deficient C57BL/6 mice gave smaller proliferative responses to T and B cell mitogens than those from either the control of pair-fed mice. The addition of hemin to the culture medium partially restored the responses to Con A and phytohemagglutinin but not to bacterial lipopolysaccharide in unfractionated spleen cells and enriched T cell fractions. The responses of lymphocytes from the control and pair-fed mice were either unchanged or decreased. Hemin restored the blastogenic response to Con A more efficiently than to phytohemagglutinin. The blastogenic responses were increased linearly with increasing doses of hemin. Ferric chloride and iron saturated mouse transferrin did not restore the response to either Con A or lipopolysaccharide. However, both transferrin and ferric chloride partially restored the response to phytohemagglutinin. The possible mechanism of selective restoration of blastogenesis by hemin, transferrin, and ferric chloride in iron-deficient T lymphocytes is discussed. PMID:6601454

  11. Pericytes support neutrophil transmigration via interleukin-8 across a porcine co-culture model of the blood-brain barrier.

    PubMed

    Pieper, Christian; Pieloch, Paulina; Galla, Hans-Joachim

    2013-08-01

    Transmigration of neutrophils across the blood-brain barrier (BBB) to an inflamed brain tissue is an important process during neuronal inflammation. The process of neutrophil activation as well as their way of rolling along the endothelium and their transmigration is quite well understood. Nevertheless, relatively little is known about the fate of neutrophils after they have transmigrated through the endothelium. The role of the other cells of the neurovascular unit in this process is also poorly understood. Here we studied the potential of pericytes to chemo-attract neutrophils under inflammatory conditions. Quantitative real time PCR, western blot analysis, and a chemotaxis assay showed that pericytes are able to chemo-attract neutrophils by interleukin-8 (IL-8) after stimulation with lipopolysaccharides (LPS), tumor necrosis factor-alpha (TNF-α), or interleukin-1beta (IL-1β). Then, a co-culture model consisting of primary porcine brain capillary endothelial cells (PBCECs) and primary porcine brain capillary pericytes (PBCPs) was used to analyze neutrophil transmigration across the BBB. As a model for inflammation, LPS was used and the effects of the cytokines TNF-α, IL-1β, and interferon-gamma (IFN-γ) were analyzed. In general, all stimulants apart from IFN-γ were able to increase transendothelial neutrophil migration. This effect was significantly reduced by a specific inhibitor of matrix metalloproteinases (MMPs)-2 and -9. MMP-2/-9 secretion is expected to decrease adhesion to pericytes and thus support the transmigration of neutrophils. Additionally, in an adhesion experiment, we showed that MMP-2/-9 inhibition significantly enhances the adhesion of neutrophils to pericytes. PMID:23769734

  12. Blood dendritic cell levels associated with impaired IL-12 production and T-cell deficiency in patients with kidney disease: implications for post-transplant viral infections.

    PubMed

    Chen, Ping; Sun, Qianmei; Huang, Yanfei; Atta, Mohamed G; Turban, Sharon; Segev, Dorry L; Marr, Kieren A; Naqvi, Fizza F; Alachkar, Nada; Kraus, Edward S; Womer, Karl L

    2014-10-01

    Reduced pretransplant blood myeloid dendritic cell (mDC) levels are associated with post-transplant BK viremia and cytomegalovirus (CMV) disease after kidney transplantation. To elucidate potential mechanisms by which mDC levels might influence these outcomes, we studied the association of mDC levels with mDC IL-12 production and T-cell level/function. Peripheral blood (PB) was studied in three groups: (i) end stage renal disease patients on hemodialysis (HD; n = 81); (ii) chronic kidney disease stage IV-V patients presenting for kidney transplant evaluation or the day of transplantation (Eval/Tx; n = 323); and (iii) healthy controls (HC; n = 22). Along with a statistically significant reduction in mDC levels, reduced CD8(+) T-cell levels were also demonstrated in the kidney disease groups compared with HC. Reduced PB mDC and monocyte-derived DC (MoDC) IL-12 production was observed after in vitro LPS stimulation in the HD versus HC groups. Finally, ELISpot assays demonstrated less robust CD3(+) INF-γ responses by MoDCs pulsed with CMV pp65 peptide from HD patients compared with HC. PB mDC level deficiency in patients with kidney disease is associated with deficient IL-12 production and T-cell level/function, which may explain the known correlation of CD8(+) T-cell lymphopenia with deficient post-transplant antiviral responses. PMID:24963818

  13. Flooding impairs Fe uptake and distribution in Citrus due to the strong down-regulation of genes involved in Strategy I responses to Fe deficiency in roots.

    PubMed

    Martínez-Cuenca, Mary-Rus; Quiñones, Ana; Primo-Millo, Eduardo; Forner-Giner, M Ángeles

    2015-01-01

    This work determines the ffects of long-term anoxia conditions--21 days--on Strategy I responses to iron (Fe) deficiency in Citrus and its impact on Fe uptake and distribution. The study was carried out in Citrus aurantium L. seedlings grown under flooding conditions (S) and in both the presence (+Fe) and absence of Fe (-Fe) in nutritive solution. The results revealed a strong down-regulation (more than 65%) of genes HA1 and FRO2 coding for enzymes proton-ATPase and Ferric-Chelate Reductase (FC-R), respectively, in -FeS plants when compared with -Fe ones. H+-extrusion and FC-R activity analyses confirmed the genetic results, indicating that flooding stress markedly repressed acidification and reduction responses to Fe deficiency (3.1- and 2.0-fold, respectively). Waterlogging reduced by half Fe concentration in +FeS roots, which led to 30% up-regulation of Fe transporter IRT1, although this effect was unable to improve Fe absorption. Consequently, flooding inhibited 57Fe uptake in +Fe and -Fe seedlings (29.8 and 66.2%, respectively) and 57Fe distribution to aerial part (30.6 and 72.3%, respectively). This evidences that the synergistic action of both enzymes H+-ATPase and FC-R is the preferential regulator of the Fe acquisition system under flooding conditions and, hence, their inactivation implies a limiting factor of citrus in their Fe-deficiency tolerance in waterlogged soils. PMID:25897804

  14. The Impact of Bdnf Gene Deficiency to the Memory Impairment and Brain Pathology of APPswe/PS1dE9 Mouse Model of Alzheimer’s Disease

    PubMed Central

    Rantamäki, Tomi; Kemppainen, Susanna; Autio, Henri; Stavén, Saara; Koivisto, Hennariikka; Kojima, Masami; Antila, Hanna; Miettinen, Pasi O.; Kärkkäinen, Elisa; Karpova, Nina; Vesa, Liisa; Lindemann, Lothar; Hoener, Marius C.; Tanila, Heikki; Castrén, Eero

    2013-01-01

    Brain-derived neurotrophic factor (BDNF) importantly regulates learning and memory and supports the survival of injured neurons. Reduced BDNF levels have been detected in the brains of Alzheimer’s disease (AD) patients but the exact role of BDNF in the pathophysiology of the disorder remains obscure. We have recently shown that reduced signaling of BDNF receptor TrkB aggravates memory impairment in APPswe/PS1dE9 (APdE9) mice, a model of AD. The present study examined the influence of Bdnf gene deficiency (heterozygous knockout) on spatial learning, spontaneous exploratory activity and motor coordination/balance in middle-aged male and female APdE9 mice. We also studied brain BDNF protein levels in APdE9 mice in different ages showing progressive amyloid pathology. Both APdE9 and Bdnf mutations impaired spatial learning in males and showed a similar trend in females. Importantly, the effect was additive, so that double mutant mice performed the worst. However, APdE9 and Bdnf mutations influenced spontaneous locomotion in contrasting ways, such that locomotor hyperactivity observed in APdE9 mice was normalized by Bdnf deficiency. Obesity associated with Bdnf deficiency did not account for the reduced hyperactivity in double mutant mice. Bdnf deficiency did not alter amyloid plaque formation in APdE9 mice. Before plaque formation (3 months), BDNF protein levels where either reduced (female) or unaltered (male) in the APdE9 mouse cortex. Unexpectedly, this was followed by an age-dependent increase in mature BDNF protein. Bdnf mRNA and phospho-TrkB levels remained unaltered in the cortical tissue samples of middle-aged APdE9 mice. Immunohistological studies revealed increased BDNF immunoreactivity around amyloid plaques indicating that the plaques may sequester BDNF protein and prevent it from activating TrkB. If similar BDNF accumulation happens in human AD brains, it would suggest that functional BDNF levels in the AD brains are even lower than reported, which could

  15. Deficiencies and Missed Opportunities to Formulate Clinical Guidelines in Australia for Withholding or Withdrawing Life-Sustaining Treatment in Severely Disabled and Impaired Infants.

    PubMed

    Bhatia, Neera; Tibballs, James

    2015-09-01

    This paper examines the few, but important legal and coronial cases concerning withdrawing or withholding life-sustaining treatment from severely disabled or critically impaired infants in Australia. Although sparse in number, the judgements should influence common clinical practices based on assessment of "best interests" but these have not yet been adopted. In particular, although courts have discounted assessment of "quality of life" as a legitimate component of determination of "best interests," this remains a prominent component of clinical guidelines. In addition, this paper highlights the lack of uniform clinical guidelines available to medical professionals and parents in Australia when making end-of-life decisions for severely ill infants. Thus, it is argued here that there is a need for an overarching prescriptive uniform framework or set of guidelines in end-of-life decision-making for impaired infants. This would encourage greater transparency, consistency, and some degree of objectivity in an area that often appears subjective. PMID:25173981

  16. Flooding Impairs Fe Uptake and Distribution in Citrus Due to the Strong Down-Regulation of Genes Involved in Strategy I Responses to Fe Deficiency in Roots

    PubMed Central

    Martínez-Cuenca, Mary-Rus; Quiñones, Ana; Primo-Millo, Eduardo; Forner-Giner, M. Ángeles

    2015-01-01

    This work determines the ffects of long-term anoxia conditions—21 days—on Strategy I responses to iron (Fe) deficiency in Citrus and its impact on Fe uptake and distribution. The study was carried out in Citrus aurantium L. seedlings grown under flooding conditions (S) and in both the presence (+Fe) and absence of Fe (-Fe) in nutritive solution. The results revealed a strong down-regulation (more than 65%) of genes HA1 and FRO2 coding for enzymes proton-ATPase and Ferric-Chelate Reductase (FC-R), respectively, in –FeS plants when compared with –Fe ones. H+-extrusion and FC-R activity analyses confirmed the genetic results, indicating that flooding stress markedly repressed acidification and reduction responses to Fe deficiency (3.1- and 2.0-fold, respectively). Waterlogging reduced by half Fe concentration in +FeS roots, which led to 30% up-regulation of Fe transporter IRT1, although this effect was unable to improve Fe absorption. Consequently, flooding inhibited 57Fe uptake in +Fe and –Fe seedlings (29.8 and 66.2%, respectively) and 57Fe distribution to aerial part (30.6 and 72.3%, respectively). This evidences that the synergistic action of both enzymes H+-ATPase and FC-R is the preferential regulator of the Fe acquisition system under flooding conditions and, hence, their inactivation implies a limiting factor of citrus in their Fe-deficiency tolerance in waterlogged soils. PMID:25897804

  17. Autoimmune Kidney Disease and Impaired Engulfment of Apoptotic Cells in Mice with Macrophage Peroxisome Proliferator-Activated Receptor γ or Retinoid X Receptor α Deficiency

    PubMed Central

    Rőszer, Tamás; Menéndez-Gutiérrez, María P.; Lefterova, Martina I.; Alameda, Daniel; Núñez, Vanessa; Lazar, Mitchell A.; Fischer, Thierry; Ricote, Mercedes

    2014-01-01

    Autoimmune glomerulonephritis is a common manifestation of systemic lupus erythematosus (SLE). In this study, we show that mice lacking macrophage expression of the heterodimeric nuclear receptors PPARγ or RXRα develop glomerulonephritis and autoantibodies to nuclear Ags, resembling the nephritis seen in SLE. These mice show deficiencies in phagocytosis and clearance of apoptotic cells, and they are unable to acquire an anti-inflammatory phenotype upon feeding of apoptotic cells, which is critical for the maintenance of self-tolerance. These results demonstrate that stimulation of PPARγ and RXRα in macrophages facilitates apoptotic cell engulfment, and they provide a potential strategy to avoid autoimmunity against dying cells and to attenuate SLE. PMID:21135166

  18. Iodine-deficiency disorders.

    PubMed

    Zimmermann, Michael B; Jooste, Pieter L; Pandav, Chandrakant S

    2008-10-01

    2 billion individuals worldwide have insufficient iodine intake, with those in south Asia and sub-Saharan Africa particularly affected. Iodine deficiency has many adverse effects on growth and development. These effects are due to inadequate production of thyroid hormone and are termed iodine-deficiency disorders. Iodine deficiency is the most common cause of preventable mental impairment worldwide. Assessment methods include urinary iodine concentration, goitre, newborn thyroid-stimulating hormone, and blood thyroglobulin. In nearly all countries, the best strategy to control iodine deficiency is iodisation of salt, which is one of the most cost-effective ways to contribute to economic and social development. When iodisation of salt is not possible, iodine supplements can be given to susceptible groups. Introduction of iodised salt to regions of chronic iodine-deficiency disorders might transiently increase the proportion of thyroid disorders, but overall the small risks of iodine excess are far outweighed by the substantial risks of iodine deficiency. International efforts to control iodine-deficiency disorders are slowing, and reaching the third of the worldwide population that remains deficient poses major challenges. PMID:18676011

  19. Distinct expression of synaptic NR2A and NR2B in the central nervous system and impaired morphine tolerance and physical dependence in mice deficient in postsynaptic density-93 protein

    PubMed Central

    Liaw, Wen-Jinn; Zhu, Xu-Guang; Yaster, Myron; Johns, Roger A; Gauda, Estelle B; Tao, Yuan-Xiang

    2008-01-01

    Postsynaptic density (PSD)-93, a neuronal scaffolding protein, binds to and clusters N-methyl-D-aspartate receptor (NMDAR) subunits NR2A and NR2B at cellular membranes in vitro. However, the roles of PSD-93 in synaptic NR2A and NR2B targeting in the central nervous system and NMDAR-dependent physiologic and pathologic processes are still unclear. We report here that PSD-93 deficiency significantly decreased the amount of NR2A and NR2B in the synaptosomal membrane fractions derived from spinal cord dorsal horn and forebrain cortex but did not change their levels in the total soluble fraction from either region. However, PSD-93 deficiency did not markedly change the amounts of NR2A and NR2B in either synaptosomal or total soluble fractions from cerebellum. In mice deficient in PSD-93, morphine dose-dependent curve failed to shift significantly rightward as it did in wild type (WT) mice after acute and chronic morphine challenge. Unlike WT mice, PSD-93 knockout mice also showed marked losses of NMDAR-dependent morphine analgesic tolerance and associated abnormal sensitivity in response to mechanical, noxious thermal, and formalin-induced inflammatory stimuli after repeated morphine injection. In addition, PSD-93 knockout mice displayed dramatic loss of jumping activity, a typical NMDAR-mediated morphine withdrawal abstinence behavior. These findings indicate that impaired NMDAR-dependent neuronal plasticity following repeated morphine injection in PSD-93 knockout mice is attributed to PSD-93 deletion-induced alterations of synaptic NR2A and NR2B expression in dorsal horn and forebrain cortex neurons. The selective effect of PSD-93 deletion on synaptic NMDAR expression in these two major pain-related regions might provide the better strategies for the prevention and treatment of opioid tolerance and physical dependence. PMID:18851757

  20. A Moderate Zinc Deficiency Does Not Impair Gene Expression of PPARα, PPARγ, and Mitochondrial Enoyl-CoA Delta Isomerase in the Liver of Growing Rats.

    PubMed

    Justus, Jennifer; Weigand, Edgar

    2014-01-01

    The aim of the study was to investigate the impact of a moderate zinc deficiency and a high intake of polyunsaturated fat on the mRNA expression of peroxisome-proliferator-activated receptor alpha (PPARα), peroxisome-proliferator-activated receptor gamma (PPARγ), and mitochondrial Δ3Δ2-enoyl-CoA isomerase (ECI) in the liver. Weanling rats were assigned to five groups (eight animals each) and fed semi-synthetic, low-carbohydrate diets containing 7 or 50 mg Zn/kg (low-Zn (LZ) or high-Zn (HZ)) and 22% cocoa butter (CB) or 22% safflower (SF) oil for four weeks. One group each was fed the LZ-CB, LZ-SF, or HZ-SF diet free choice, and one group each was fed the HZ-CB and HZ-SF diets in restricted amounts according to intake of the respective LZ diets. The LZ diets markedly lowered growth and zinc concentrations in plasma and femur. Hepatic mRNA levels of PPARα, PPARγ, and ECI were not reduced by the moderate zinc deficiency. Overall, ECI-mRNA abundance was marginally higher in the SF-fed than in the CB-fed animals. PMID:24855375

  1. A Moderate Zinc Deficiency Does Not Impair Gene Expression of PPARα, PPARγ, and Mitochondrial Enoyl-CoA Delta Isomerase in the Liver of Growing Rats

    PubMed Central

    Justus, Jennifer; Weigand, Edgar

    2014-01-01

    The aim of the study was to investigate the impact of a moderate zinc deficiency and a high intake of polyunsaturated fat on the mRNA expression of peroxisome-proliferator-activated receptor alpha (PPARα), peroxisome-proliferator-activated receptor gamma (PPARγ), and mitochondrial Δ3Δ2-enoyl-CoA isomerase (ECI) in the liver. Weanling rats were assigned to five groups (eight animals each) and fed semi-synthetic, low-carbohydrate diets containing 7 or 50 mg Zn/kg (low-Zn (LZ) or high-Zn (HZ)) and 22% cocoa butter (CB) or 22% safflower (SF) oil for four weeks. One group each was fed the LZ-CB, LZ-SF, or HZ-SF diet free choice, and one group each was fed the HZ-CB and HZ-SF diets in restricted amounts according to intake of the respective LZ diets. The LZ diets markedly lowered growth and zinc concentrations in plasma and femur. Hepatic mRNA levels of PPARα, PPARγ, and ECI were not reduced by the moderate zinc deficiency. Overall, ECI-mRNA abundance was marginally higher in the SF-fed than in the CB-fed animals. PMID:24855375

  2. Age-related impairment of bones' adaptive response to loading in mice is associated with sex-related deficiencies in osteoblasts but no change in osteocytes.

    PubMed

    Meakin, Lee B; Galea, Gabriel L; Sugiyama, Toshihiro; Lanyon, Lance E; Price, Joanna S

    2014-08-01

    Bones adjust their mass and architecture to be sufficiently robust to withstand functional loading by adapting to their strain environment. This mechanism appears less effective with age, resulting in low bone mass. In male and female young adult (17-week-old) and old (19-month-old) mice, we investigated the effect of age in vivo on bones' adaptive response to loading and in vitro in primary cultures of osteoblast-like cells derived from bone cortices. Right tibias were axially loaded on alternate days for 2 weeks. Left tibias were non-loaded controls. In a separate group, the number of sclerostin-positive osteocytes and the number of periosteal osteoblasts were analyzed 24 hours after a single loading episode. The responses to strain of the primary osteoblast-like cells derived from these mice were assessed by EGR2 expression, change in cell number and Ki67 immunofluorescence. In young male and female mice, loading increased trabecular thickness and the number of trabecular connections. Increase in the number of trabecular connections was impaired with age but trabecular thickness was not. In old mice, the loading-related increase in periosteal apposition of the cortex was less than in young ones. Age was associated with a lesser loading-related increase in osteoblast number on the periosteal surface but had no effect on loading-related reduction in the number of sclerostin-positive osteocytes. In vitro, strain-related proliferation of osteoblast-like cells was lower in cells from old than young mice. Cells from aged female mice demonstrated normal entry into the cell cycle but subsequently arrested in G2 phase, reducing strain-related increases in cell number. Thus, in both male and female mice, loading-related adaptive responses are impaired with age. This impairment is different in females and males. The deficit appears to occur in osteoblasts' proliferative responses to strain rather than earlier strain-related responses in the osteocytes. PMID:24644060

  3. Impaired Mobilization of Vascular Reparative Bone Marrow Cells in Streptozotocin-Induced Diabetes but not in Leptin Receptor-Deficient db/db Mice.

    PubMed

    Vasam, Goutham; Joshi, Shrinidh; Jarajapu, Yagna P R

    2016-01-01

    Diabetes is associated with impaired mobilization of bone marrow stem/progenitor cells that accelerate vascularization of ischemic areas. This study characterized mobilization of vascular reparative bone marrow progenitor cells in mouse models of diabetes. Age-matched control or streptozotocin (STZ)-induced diabetic, and db/db mice with lean-controls were studied. Mobilization induced by G-CSF, AMD3100 or ischemia was evaluated by flow cytometric enumeration of circulating Lin(-)Sca-1(+)cKit(+) (LSK) cells, and by colony forming unit (CFU) assay. The circulating WBCs and LSKs, and CFUs were reduced in both models with a shorter duration (10-12 weeks) of diabetes compared to their respective controls. Longer duration of STZ-diabetes (≥20 weeks) induced impairment of G-CSF- or AMD3100-mobilization (P < 0.01, n = 8). In db/db mice, mobilization by G-CSF or AMD3100 was either increased or unaffected (P < 0.05, n = 6 to 8). Proliferation, migration, and ischemia-induced mobilization, of LSK cells were impaired in both models. Leptin receptor antagonist, PESLAN-1, increased G-CSF- or AMD3100-mobilization of WBCs and LSKs, compared to the untreated. Leptin increased basal WBCs, decreased basal and AMD3100-mobilized LSK cells, and had no effect on G-CSF. These results suggest that mobilopathy is apparent in STZ-diabetes but not in db/db mice. Leptin receptor antagonism would be a promising approach for reversing diabetic bone marrow mobilopathy. PMID:27188595

  4. Impaired Mobilization of Vascular Reparative Bone Marrow Cells in Streptozotocin-Induced Diabetes but not in Leptin Receptor-Deficient db/db Mice

    PubMed Central

    Vasam, Goutham; Joshi, Shrinidh; Jarajapu, Yagna P. R.

    2016-01-01

    Diabetes is associated with impaired mobilization of bone marrow stem/progenitor cells that accelerate vascularization of ischemic areas. This study characterized mobilization of vascular reparative bone marrow progenitor cells in mouse models of diabetes. Age-matched control or streptozotocin (STZ)-induced diabetic, and db/db mice with lean-controls were studied. Mobilization induced by G-CSF, AMD3100 or ischemia was evaluated by flow cytometric enumeration of circulating Lin−Sca-1+cKit+ (LSK) cells, and by colony forming unit (CFU) assay. The circulating WBCs and LSKs, and CFUs were reduced in both models with a shorter duration (10–12 weeks) of diabetes compared to their respective controls. Longer duration of STZ-diabetes (≥20 weeks) induced impairment of G-CSF- or AMD3100-mobilization (P < 0.01, n = 8). In db/db mice, mobilization by G-CSF or AMD3100 was either increased or unaffected (P < 0.05, n = 6 to 8). Proliferation, migration, and ischemia-induced mobilization, of LSK cells were impaired in both models. Leptin receptor antagonist, PESLAN-1, increased G-CSF- or AMD3100-mobilization of WBCs and LSKs, compared to the untreated. Leptin increased basal WBCs, decreased basal and AMD3100-mobilized LSK cells, and had no effect on G-CSF. These results suggest that mobilopathy is apparent in STZ-diabetes but not in db/db mice. Leptin receptor antagonism would be a promising approach for reversing diabetic bone marrow mobilopathy. PMID:27188595

  5. Morphology and Topography of Retinal Pericytes in the Living Mouse Retina Using In Vivo Adaptive Optics Imaging and Ex Vivo Characterization

    PubMed Central

    Schallek, Jesse; Geng, Ying; Nguyen, HoanVu; Williams, David R.

    2013-01-01

    Purpose. To noninvasively image retinal pericytes in the living eye and characterize NG2-positive cell topography and morphology in the adult mouse retina. Methods. Transgenic mice expressing fluorescent pericytes (NG2, DsRed) were imaged using a two-channel, adaptive optics scanning laser ophthalmoscope (AOSLO). One channel imaged vascular perfusion with near infrared light. A second channel simultaneously imaged fluorescent retinal pericytes. Mice were also imaged using wide-field ophthalmoscopy. To confirm in vivo imaging, five eyes were enucleated and imaged in flat mount with conventional fluorescent microscopy. Cell topography was quantified relative to the optic disc. Results. We observed strong DsRed fluorescence from NG2-positive cells. AOSLO revealed fluorescent vascular mural cells enveloping all vessels in the living retina. Cells were stellate on larger venules, and showed banded morphology on arterioles. NG2-positive cells indicative of pericytes were found on the smallest capillaries of the retinal circulation. Wide-field SLO enabled quick assessment of NG2-positive distribution, but provided insufficient resolution for cell counts. Ex vivo microscopy showed relatively even topography of NG2-positive capillary pericytes at eccentricities more than 0.3 mm from the optic disc (515 ± 94 cells/mm2 of retinal area). Conclusions. We provide the first high-resolution images of retinal pericytes in the living animal. Subcellular resolution enabled morphological identification of NG2-positive cells on capillaries showing classic features and topography of retinal pericytes. This report provides foundational basis for future studies that will track and quantify pericyte topography, morphology, and function in the living retina over time, especially in the progression of microvascular disease. PMID:24150762

  6. Mild Maternal Iron Deficiency Anemia Induces Hearing Impairment Associated with Reduction of Ribbon Synapse Density and Dysregulation of VGLUT3, Myosin VIIa, and Prestin Expression in Young Guinea Pigs.

    PubMed

    Yu, Fei; Hao, Shuai; Yang, Bo; Zhao, Yue; Zhang, Wenyue; Yang, Jun

    2016-05-01

    Mild maternal iron deficiency anemia (IDA) adversely affects the development of cochlear hair cells of the young offspring, but the mechanisms underlying the association are incompletely understood. The aim of this study was to evaluate whether mild maternal IDA in guinea pigs could interrupt inner hair cell (IHC) ribbon synapse density and outer hair cell motility of the offspring. Here, we established a dietary restriction model that allows us to study quantitative changes in the number of IHC ribbon synapses and hearing impairment in response to mild maternal IDA in young guinea pig. The offspring were weaned on postnatal day (PND) 9 and then were given the iron-sufficient diet. On PND 24, pups were examined the hearing function by auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) measurements. Then, the cochleae were harvested for assessment of the number of IHC ribbon synapses by immunofluorescence, the morphology of cochlear hair cells, and spiral ganglion cells (SGCs) by scanning electron microscope and hematoxylin-eosin staining, the location, and expression of vesicular glutamate transporter (VGLUT) 3, myosin VIIa, and prestin by immunofluorescence and blotting. Here, we show that mild maternal IDA in guinea pigs induced elevated ABR threshold shifts, declined DPOAE level shifts, and reduced the number of ribbon synapses, impaired the morphology of cochlear hair cells and SGCs in offsprings. In addition, downregulation of VGLUT3 and myosin VIIa, and upregulation of prestin were observed in the cochlea of offsprings from mild maternal IDA in guinea pigs. These data indicate that mild maternal IDA in guinea pigs induced hearing impairment in offsprings, and this deficit may be attributed to the reduction of ribbon synapse density and dysregulation of VGLUT3, myosin VIIa, and prestin. PMID:26913517

  7. Deficient guanine nucleotide regulatory unit activity in cultured fibroblast membranes from patients with pseudohypoparathyroidism type I. A cause of impaired synthesis of 3',5'-cyclic AMP by intact and broken cells

    PubMed Central

    Levine, Michael A.; Eil, Charles; Downs, Robert W.; Spiegel, Allen M.

    1983-01-01

    Deficient activity of the guanine nucleotide regulatory protein (G unit), an integral component of the membrane-bound adenylate cyclase complex, has been implicated as the biochemical lesion in many patients with pseudohypoparathyroidism (PHP) type I. In addition to renal resistance to parathyroid hormone in this disorder, there is decreased responsiveness of diverse tissues to hormones that act via 3',5'-cyclic AMP (cAMP). To assess whether a deficiency of G units could account for impaired adenylate cyclase activity, we studied cAMP production in intact cultured fibroblasts and fibroblast plasma membranes from five patients with PHP in response to several activators of adenylate cyclase. The number of G units in PHP fibroblast membranes, measured by cholera toxin-dependent [32P]ADP ribosylation of G-unit peptides, as well as the G-unit activity, determined by the ability of detergent extracts to reconstitute adenylate cyclase activity in G-unit-deficient S49 CYC- membranes, were found to be markedly reduced compared with control membranes (43 and 40%, respectively), The activation of fibroblast membrane adenylate cyclase by effectors that act directly through the G unit (guanosine triphosphate, guanosine 5'-0-[3-thiotriphosphate] [GTP-γ-S], NaF) was significantly greater in control membranes than in membranes from patients with PHP. Moreover, we found that hormone (prostaglandin E1) stimulated adenylate cyclase activity was also greater in control membranes than in PHP membranes. Neither the apparent affinity of membrane adenylate cyclase for GTP-γ-S (apparent Km =5 X 10-8 M) nor the rate of enzyme activation by GTP-γ-S was significantly different in fibroblast membranes from control subjects and patients with PHP. In contrast to the notable differences in hormone and G-unit-activated adenylate cyclase shown in fibroblast membranes from PHP patients and control subjects, the intrinsic catalytic activity of membranes, as determined by forskolin

  8. Blocking TGF-β Signaling Pathway Preserves Mitochondrial Proteostasis and Reduces Early Activation of PDGFRβ+ Pericytes in Aristolochic Acid Induced Acute Kidney Injury in Wistar Male Rats

    PubMed Central

    Pozdzik, Agnieszka A.; Giordano, Laetitia; Li, Gang; Antoine, Marie-Hélène; Quellard, Nathalie; Godet, Julie; De Prez, Eric; Husson, Cécile; Declèves, Anne-Emilie; Arlt, Volker M.; Goujon, Jean-Michel; Brochériou-Spelle, Isabelle; Ledbetter, Steven R.; Caron, Nathalie; Nortier, Joëlle L.

    2016-01-01

    Background The platelet-derived growth factor receptor β (PDGFRβ)+ perivascular cell activation becomes increasingly recognized as a main source of scar-associated kidney myofibroblasts and recently emerged as a new cellular therapeutic target. Aims In this regard, we first confirmed the presence of PDGFRβ+ perivascular cells in a human case of end-stage aristolochic acid nephropathy (AAN) and thereafter we focused on the early fibrosis events of transforming growth factor β (TGFβ) inhibition in a rat model of AAN. Materials and Methods Neutralizing anti-TGFβ antibody (1D11) and its control isotype (13C4) were administered (5 mg/kg, i.p.) at Days -1, 0, 2 and 4; AA (15 mg/kg, sc) was injected daily. Results At Day 5, 1D11 significantly suppressed p-Smad2/3 signaling pathway improving renal function impairment, reduced the score of acute tubular necrosis, peritubular capillaritis, interstitial inflammation and neoangiogenesis. 1D11 markedly decreased interstitial edema, disruption of tubular basement membrane loss of brush border, cytoplasmic edema and organelle ultrastructure alterations (mitochondrial disruption and endoplasmic reticulum edema) in proximal tubular epithelial cells. Moreover, 1D11 significantly inhibited p-PERK activation and attenuated dysregulation of unfolded protein response (UPR) pathways, endoplasmic reticulum and mitochondrial proteostasis in vivo and in vitro. Conclusions The early inhibition of p-Smad2/3 signaling pathway improved acute renal function impairment, partially prevented epithelial-endothelial axis activation by maintaining PTEC proteostasis and reduced early PDGFRβ+ pericytes-derived myofibroblasts accumulation. PMID:27379382

  9. Age-Related Impairment of Bones' Adaptive Response to Loading in Mice Is Associated With Sex-Related Deficiencies in Osteoblasts but No Change in Osteocytes†

    PubMed Central

    Meakin, Lee B; Galea, Gabriel L; Sugiyama, Toshihiro; Lanyon, Lance E; Price, Joanna S

    2014-01-01

    Bones adjust their mass and architecture to be sufficiently robust to withstand functional loading by adapting to their strain environment. This mechanism appears less effective with age, resulting in low bone mass. In male and female young adult (17-week-old) and old (19-month-old) mice, we investigated the effect of age in vivo on bones' adaptive response to loading and in vitro in primary cultures of osteoblast-like cells derived from bone cortices. Right tibias were axially loaded on alternate days for 2 weeks. Left tibias were non-loaded controls. In a separate group, the number of sclerostin-positive osteocytes and the number of periosteal osteoblasts were analyzed 24 hours after a single loading episode. The responses to strain of the primary osteoblast-like cells derived from these mice were assessed by EGR2 expression, change in cell number and Ki67 immunofluorescence. In young male and female mice, loading increased trabecular thickness and the number of trabecular connections. Increase in the number of trabecular connections was impaired with age but trabecular thickness was not. In old mice, the loading-related increase in periosteal apposition of the cortex was less than in young ones. Age was associated with a lesser loading-related increase in osteoblast number on the periosteal surface but had no effect on loading-related reduction in the number of sclerostin-positive osteocytes. In vitro, strain-related proliferation of osteoblast-like cells was lower in cells from old than young mice. Cells from aged female mice demonstrated normal entry into the cell cycle but subsequently arrested in G2 phase, reducing strain-related increases in cell number. Thus, in both male and female mice, loading-related adaptive responses are impaired with age. This impairment is different in females and males. The deficit appears to occur in osteoblasts' proliferative responses to strain rather than earlier strain-related responses in the osteocytes. © 2014 The Authors

  10. Deficiency of dietary niacin impaired gill immunity and antioxidant capacity, and changes its tight junction proteins via regulating NF-κB, TOR, Nrf2 and MLCK signaling pathways in young grass carp (Ctenopharyngodon idella).

    PubMed

    Li, Shun-Quan; Feng, Lin; Jiang, Wei-Dan; Liu, Yang; Jiang, Jun; Wu, Pei; Kuang, Sheng-Yao; Tang, Ling; Tang, Wu-Neng; Zhang, Yong-An; Zhou, Xiao-Qiu

    2016-08-01

    To investigate the effects of dietary niacin on gill immunity, tight junction proteins, antioxidant system and related signaling molecules mRNA expression, young grass carp (Ctenopharyngodon idella) were fed six diets containing graded levels of niacin (3.95-55.01 mg/kg diet) for 8 weeks. The study indicated that niacin deficiency decreased lysozyme and acid phosphatase activities, and complement 3 content, and caused oxidative damage that might be partly due to the decreased copper, zinc superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and glutathione-S-transferase activities and reduced glutathione content in fish gills (P < 0.05). Moreover, the relative mRNA levels of antimicrobial peptides (liver expressed antimicrobial peptide 2 and Hepcidin), anti-inflammatory cytokines (interleukin 10 and transforming growth factor β1), tight junction proteins (Occludin, zonula occludens 1, Claudin-15 and -3), signaling molecules (inhibitor of κBα (IκBα), target of rapamycin (TOR), ribosomal protein S6 kinase 1 (S6K1) and NF-E2-related factor 2 (Nrf2)) and antioxidant enzymes were significantly decreased (P < 0.05) in niacin-deficient diet group. Conversely, the mRNA levels of pro-inflammatory cytokines (tumor necrosis factor α, interleukin 8, interferon γ2, and interleukin 1β), signaling molecules (nuclear factor kappa B p65, IκB kinase α, IκB kinase β, IκB kinase γ, Kelch-like-ECH-associated protein 1b, myosin light chain kinase and p38 mitogen-activated protein kinase (p38 MAPK) were significantly increased (P < 0.05) in fish gills fed niacin-deficient diet. Interestingly, the varying niacin levels of 3.95-55.01 mg/kg diet had no effect on the mRNA level of Kelch-like-ECH-associated protein 1a, Claudin-c and -12 in fish gills (P > 0.05). In conclusion, niacin deficiency decreased gill immunity, impaired gill antioxidant system, as well as regulated mRNA expression of gill tight junction proteins and related signaling

  11. Low-density Lipoprotein Receptor Deficiency Causes Impaired Osteoclastogenesis and Increased Bone Mass in Mice because of Defect in Osteoclastic Cell-Cell Fusion*

    PubMed Central

    Okayasu, Mari; Nakayachi, Mai; Hayashida, Chiyomi; Ito, Junta; Kaneda, Toshio; Masuhara, Masaaki; Suda, Naoto; Sato, Takuya; Hakeda, Yoshiyuki

    2012-01-01

    Osteoporosis is associated with both atherosclerosis and vascular calcification attributed to hyperlipidemia. However, the cellular and molecular mechanisms explaining the parallel progression of these diseases remain unclear. Here, we used low-density lipoprotein receptor knockout (LDLR−/−) mice to elucidate the role of LDLR in regulating the differentiation of osteoclasts, which are responsible for bone resorption. Culturing wild-type osteoclast precursors in medium containing LDL-depleted serum decreased receptor activator of NF-κB ligand (RANKL)-induced osteoclast formation, and this defect was additively rescued by simultaneous treatment with native and oxidized LDLs. Osteoclast precursors constitutively expressed LDLR in a RANKL-independent manner. Osteoclast formation from LDLR−/− osteoclast precursors was delayed, and the multinucleated cells formed in culture were smaller and contained fewer nuclei than wild-type cells, implying impaired cell-cell fusion. Despite these findings, RANK signaling, including the activation of Erk and Akt, was normal in LDLR−/− preosteoclasts, and RANKL-induced expression of NFATc1 (a master regulator of osteoclastogenesis), cathepsin K, and tartrate-resistant acid phosphatase was equivalent in LDLR-null and wild-type cells. In contrast, the amounts of the osteoclast fusion-related proteins v-ATPase V0 subunit d2 and dendritic cell-specific transmembrane protein in LDLR−/− plasma membranes were reduced when compared with the wild type, suggesting a correlation with impaired cell-cell fusion, which occurs on the plasma membrane. LDLR−/− mice consistently exhibited increased bone mass in vivo. This change was accompanied by decreases in bone resorption parameters, with no changes in bone formation parameters. These findings provide a novel mechanism for osteoclast differentiation and improve the understanding of the correlation between osteoclast formation and lipids. PMID:22500026

  12. Molecular Signaling Pathways Controlling Vascular Tube Morphogenesis and Pericyte-Induced Tube Maturation in 3D Extracellular Matrices.

    PubMed

    Bowers, S L K; Norden, P R; Davis, G E

    2016-01-01

    During capillary network formation, ECs establish interconnecting tubes with defined lumens that reside within vascular guidance tunnels (physical spaces generated during EC tubulogenesis). Pericytes are recruited to EC tubes within these tunnels and capillary basement membrane deposition occurs to facilitate tube maturation. Here, we discuss molecular mechanisms controlling EC tubulogenesis demonstrating the involvement of integrins, MT1-MMP, extracellular matrix, Cdc42, Rac1, Rac2, k-Ras, Rap1b, and key downstream effectors including Pak2, Pak4, IQGAP1, MRCKβ, and Rasip1. These molecules activate kinase cascades controlling EC tube formation, in conjunction with growth factor receptor signaling, which involve PKCɛ, Src family, Raf, Mek, and Erk kinases. These molecules and signaling cascades stimulate EC lumen and tube formation by: regulating MT-MMP-dependent lumen expansion and vascular guidance tunnel formation; generation of intracellular vacuoles/vesicles to create EC apical membranes; and establishing cytoskeletal polarity with acetylated tubulin distributed subapically (and F-actin basally) to facilitate vacuole trafficking/fusion in a polarized, perinuclear region. Using defined serum-free models, we have demonstrated that human EC tubulogenesis and EC-pericyte tube coassembly requires five exogenously applied growth factors which are SCF, IL-3, SDF-1α, FGF-2, and insulin (Factors). Also, we have demonstrated that EC-derived PDGF-BB and HB-EGF are necessary for pericytes to proliferate, recruit to tubes, and induce basement membrane assembly. Finally, we have shown that VEGF fails to directly stimulate EC tubulogenesis. In contrast, it acts as an upstream EC primer of downstream "Factor"-induced tubulogenic and EC-pericyte tube coassembly by upregulating c-Kit, IL-3Rα, and CXCR4 as well as PDGF-BB and HB-EGF expression. PMID:27451100

  13. Zinc deficiency and eating disorders.

    PubMed

    Humphries, L; Vivian, B; Stuart, M; McClain, C J

    1989-12-01

    Decreased food intake, a cyclic pattern of eating, and weight loss are major manifestations of zinc deficiency. In this study, zinc status was evaluated in 62 patients with bulimia and 24 patients with anorexia nervosa. Forty percent of patients with bulimia and 54% of those with anorexia nervosa had biochemical evidence of zinc deficiency. The authors suggest that for a variety of reasons, such as lower dietary intake of zinc, impaired zinc absorption, vomiting, diarrhea, and binging on low-zinc foods, patients with eating disorders may develop zinc deficiency. This acquired zinc deficiency could then add to the chronicity of altered eating behavior in those patients. PMID:2600063

  14. Sourcing of an Alternative Pericyte-Like Cell Type from Peripheral Blood in Clinically Relevant Numbers for Therapeutic Angiogenic Applications

    PubMed Central

    Blocki, Anna; Wang, Yingting; Koch, Maria; Goralczyk, Anna; Beyer, Sebastian; Agarwal, Nikita; Lee, Michelle; Moonshi, Shehzahdi; Dewavrin, Jean-Yves; Peh, Priscilla; Schwarz, Herbert; Bhakoo, Kishore; Raghunath, Michael

    2015-01-01

    Autologous cells hold great potential for personalized cell therapy, reducing immunological and risk of infections. However, low cell counts at harvest with subsequently long expansion times with associated cell function loss currently impede the advancement of autologous cell therapy approaches. Here, we aimed to source clinically relevant numbers of proangiogenic cells from an easy accessible cell source, namely peripheral blood. Using macromolecular crowding (MMC) as a biotechnological platform, we derived a novel cell type from peripheral blood that is generated within 5 days in large numbers (10–40 million cells per 100 ml of blood). This blood-derived angiogenic cell (BDAC) type is of monocytic origin, but exhibits pericyte markers PDGFR-β and NG2 and demonstrates strong angiogenic activity, hitherto ascribed only to MSC-like pericytes. Our findings suggest that BDACs represent an alternative pericyte-like cell population of hematopoietic origin that is involved in promoting early stages of microvasculature formation. As a proof of principle of BDAC efficacy in an ischemic disease model, BDAC injection rescued affected tissues in a murine hind limb ischemia model by accelerating and enhancing revascularization. Derived from a renewable tissue that is easy to collect, BDACs overcome current short-comings of autologous cell therapy, in particular for tissue repair strategies. PMID:25582709

  15. Preservation of peritubular capillary endothelial integrity and increasing pericytes may be critical to recovery from postischemic acute kidney injury

    PubMed Central

    Kwon, Osun; Hong, Seok-Min; Sutton, Timothy A.; Temm, Constance J.

    2008-01-01

    Decreased renal blood flow following an ischemic insult contributes to a reduction in glomerular filtration. However, little is known about the underlying cellular or subcellular mechanisms mediating reduced renal blood flow in human ischemic acute kidney injury (AKI) or acute renal failure (ARF). To examine renal vascular injury following ischemia, intraoperative graft biopsies were performed after reperfusion in 21 cadaveric renal allografts. Confocal fluorescence microscopy was utilized to examine vascular smooth muscle and endothelial cell integrity as well as peritubular interstitial pericytes in the biopsies. The reperfused, transplanted kidneys exhibited postischemic injury to the renal vasculature, as demonstrated by disorganization/disarray of the actin cytoskeleton in vascular smooth muscle cells and disappearance of von Willebrand factor from vascular endothelial cells. Damage to peritubular capillary endothelial cells was more severe in subjects destined to have sustained ARF than in those with rapid recovery of their graft function. In addition, peritubular pericytes/myofibroblasts were more pronounced in recipients destined to recover than those with sustained ARF. Taken together, these data suggest damage to the renal vasculature occurs after ischemia-reperfusion in human kidneys. Preservation of peritubular capillary endothelial integrity and increasing pericytes may be critical to recovery from postischemic AKI. PMID:18562634

  16. Mesenchymal Tumors Can Derive from Ng2/Cspg4-Expressing Pericytes with β-Catenin Modulating the Neoplastic Phenotype.

    PubMed

    Sato, Shingo; Tang, Yuning J; Wei, Qingxia; Hirata, Makoto; Weng, Angela; Han, Ilkyu; Okawa, Atsushi; Takeda, Shu; Whetstone, Heather; Nadesan, Puvindran; Kirsch, David G; Wunder, Jay S; Alman, Benjamin A

    2016-07-26

    The cell of origin for most mesenchymal tumors is unclear. One cell type that contributes to this lineages is the pericyte, a cell expressing Ng2/Cspg4. Using lineage tracing, we demonstrated that bone and soft tissue sarcomas driven by the deletion of the Trp53 tumor suppressor, or desmoid tumors driven by a mutation in Apc, can derive from cells expressing Ng2/Cspg4. Deletion of the Trp53 tumor suppressor gene in these cells resulted in the bone and soft tissue sarcomas that closely resemble human sarcomas, while stabilizing β-catenin in this same cell type caused desmoid tumors. Comparing expression between Ng2/Cspg4-expressing pericytes lacking Trp53 and sarcomas that arose from deletion of Trp53 showed inhibition of β-catenin signaling in the sarcomas. Activation of β-catenin inhibited the formation and growth of sarcomas. Thus, pericytes can be a cell of origin for mesenchymal tumors, and β-catenin dysregulation plays an important role in the neoplastic phenotype. PMID:27425618

  17. Restimulation-induced apoptosis of T cells is impaired in patients with X-linked lymphoproliferative disease caused by SAP deficiency

    PubMed Central

    Snow, Andrew L.; Marsh, Rebecca A.; Krummey, Scott M.; Roehrs, Philip; Young, Lisa R.; Zhang, Kejian; van Hoff, Jack; Dhar, Deepali; Nichols, Kim E.; Filipovich, Alexandra H.; Su, Helen C.; Bleesing, Jack J.; Lenardo, Michael J.

    2009-01-01

    X-linked lymphoproliferative disease (XLP) is a rare congenital immunodeficiency that leads to an extreme, usually fatal increase in the number of lymphocytes upon infection with EBV. It is most commonly defined molecularly by loss of expression of SLAM-associated protein (SAP). Despite this, there is little understanding of how SAP deficiency causes lymphocytosis following EBV infection. Here we show that T cells from individuals with XLP are specifically resistant to apoptosis mediated by TCR restimulation, a process that normally constrains T cell expansion during immune responses. Expression of SAP and the SLAM family receptor NK, T, and B cell antigen (NTB-A) were required for TCR-induced upregulation of key pro-apoptotic molecules and subsequent apoptosis. Further, SAP/NTB-A signaling augmented the strength of the proximal TCR signal to achieve the threshold required for restimulation-induced cell death (RICD). Strikingly, TCR ligation in activated T cells triggered increased recruitment of SAP to NTB-A, dissociation of the phosphatase SHP-1, and colocalization of NTB-A with CD3 aggregates. In contrast, NTB-A and SHP-1 contributed to RICD resistance in XLP T cells. Our results reveal what we believe to be novel roles for NTB-A and SAP in regulating T cell homeostasis through apoptosis and provide mechanistic insight into the pathogenesis of lymphoproliferative disease in XLP. PMID:19759517

  18. Therapeutic inhibition of TRF1 impairs the growth of p53-deficient K-RasG12V-induced lung cancer by induction of telomeric DNA damage

    PubMed Central

    García-Beccaria, María; Martínez, Paula; Méndez-Pertuz, Marinela; Martínez, Sonia; Blanco-Aparicio, Carmen; Cañamero, Marta; Mulero, Francisca; Ambrogio, Chiara; Flores, Juana M; Megias, Diego; Barbacid, Mariano; Pastor, Joaquín; Blasco, Maria A

    2015-01-01

    Telomeres are considered anti-cancer targets, as telomere maintenance above a minimum length is necessary for cancer growth. Telomerase abrogation in cancer-prone mouse models, however, only decreased tumor growth after several mouse generations when telomeres reach a critically short length, and this effect was lost upon p53 mutation. Here, we address whether induction of telomere uncapping by inhibition of the TRF1 shelterin protein can effectively block cancer growth independently of telomere length. We show that genetic Trf1 ablation impairs the growth of p53-null K-RasG12V-induced lung carcinomas and increases mouse survival independently of telomere length. This is accompanied by induction of telomeric DNA damage, apoptosis, decreased proliferation, and G2 arrest. Long-term whole-body Trf1 deletion in adult mice did not impact on mouse survival and viability, although some mice showed a moderately decreased cellularity in bone marrow and blood. Importantly, inhibition of TRF1 binding to telomeres by small molecules blocks the growth of already established lung carcinomas without affecting mouse survival or tissue function. Thus, induction of acute telomere uncapping emerges as a potential new therapeutic target for lung cancer. PMID:25971796

  19. Cognitive impairment in Gdi1-deficient mice is associated with altered synaptic vesicle pools and short-term synaptic plasticity, and can be corrected by appropriate learning training

    PubMed Central

    Bianchi, Veronica; Farisello, Pasqualina; Baldelli, Pietro; Meskenaite, Virginia; Milanese, Marco; Vecellio, Matteo; Mühlemann, Sven; Lipp, Hans Peter; Bonanno, Giambattista; Benfenati, Fabio; Toniolo, Daniela; D'Adamo, Patrizia

    2009-01-01

    The GDI1 gene, responsible in human for X-linked non-specific mental retardation, encodes αGDI, a regulatory protein common to all GTPases of the Rab family. Its alteration, leading to membrane accumulation of different Rab GTPases, may affect multiple steps in neuronal intracellular traffic. Using electron microscopy and electrophysiology, we now report that lack of αGDI impairs several steps in synaptic vesicle (SV) biogenesis and recycling in the hippocampus. Alteration of the SV reserve pool (RP) and a 50% reduction in the total number of SV in adult synapses may be dependent on a defective endosomal-dependent recycling and may lead to the observed alterations in short-term plasticity. As predicted by the synaptic characteristics of the mutant mice, the short-term memory deficit, observed when using fear-conditioning protocols with short intervals between trials, disappeared when the Gdi1 mutants were allowed to have longer intervals between sessions. Likewise, previously observed deficits in radial maze learning could be corrected by providing less challenging pre-training. This implies that an intact RP of SVs is necessary for memory processing under challenging conditions in mice. The possibility to correct the learning deficit in mice may have clinical implication for future studies in human. PMID:18829665

  20. Impaired Intestinal Calcium Absorption in Protein 4.1R-deficient Mice Due to Altered Expression of Plasma Membrane Calcium ATPase 1b (PMCA1b)*

    PubMed Central

    Liu, Congrong; Weng, Haibao; Chen, Lixiang; Yang, Shaomin; Wang, Hua; Debnath, Gargi; Guo, Xinhua; Wu, Liancheng; Mohandas, Narla; An, Xiuli

    2013-01-01

    Protein 4.1R was first identified in the erythrocyte membrane skeleton. It is now known that the protein is expressed in a variety of epithelial cell lines and in the epithelia of many tissues, including the small intestine. However, the physiological function of 4.1R in the epithelial cells of the small intestine has not so far been explored. Here, we show that 4.1R knock-out mice exhibited a significantly impaired small intestinal calcium absorption that resulted in secondary hyperparathyroidism as evidenced by increased serum 1,25-(OH)2-vitamin D3 and parathyroid hormone levels, decreased serum calcium levels, hyperplasia of the parathyroid, and demineralization of the bones. 4.1R is located on the basolateral membrane of enterocytes, where it co-localizes with PMCA1b (plasma membrane calcium ATPase 1b). Expression of PMCA1b in enterocytes was decreased in 4.1−/− mice. 4.1R directly associated with PMCA1b, and the association involved the membrane-binding domain of 4.1R and the second intracellular loop and C terminus of PMCA1b. Our findings have enabled us to define a functional role for 4.1R in small intestinal calcium absorption through regulation of membrane expression of PMCA1b. PMID:23460639

  1. Deficiency of the 65 kDa isoform of glutamic acid decarboxylase impairs extinction of cued but not contextual fear memory.

    PubMed

    Sangha, Susan; Narayanan, Rajeevan T; Bergado-Acosta, Jorge R; Stork, Oliver; Seidenbecher, Thomas; Pape, Hans-Christian

    2009-12-16

    Extinction procedures are clinically relevant for reducing pathological fear, and the mechanisms of fear regulation are a subject of intense research. The amygdala, hippocampus, and prefrontal cortex (PFC) have all been suggested to be key brain areas in extinction of conditioned fear. GABA has particularly been implicated in extinction learning, and the 65 kDa isoform of glutamic acid decarboxylase (GAD65) may be important in elevating GABA levels in response to environmental signals. Extinction of conditioned fear was examined in Gad65(-/-) mice while recording local field potentials from the amygdala, hippocampus, and PFC simultaneously while monitoring behavior. Gad65(-/-) mice showed generalization of cued fear, as reported previously, and impaired extinction of cued fear, such that fear remained high across extinction training. This endurance in cued fear was associated with theta frequency synchronization between the amygdala and hippocampus. Extinction of contextual fear, however, was unaltered in Gad65(-/-) mice when compared with wild-type littermates. The data imply that GAD65 plays a critical role in regulating cued fear responses during extinction learning and that, during this process, GABAergic signaling is involved in modulating synchronized activity between the amygdala and hippocampus. In view of the more pronounced effect on cued versus contextual fear extinction, these influences may rely more on GABAergic mechanisms in the amygdala. PMID:20016086

  2. Sympathetic nerve-derived ATP regulates renal medullary vasa recta diameter via pericyte cells: a role for regulating medullary blood flow?

    PubMed

    Crawford, C; Wildman, S S P; Kelly, M C; Kennedy-Lydon, T M; Peppiatt-Wildman, C M

    2013-01-01

    Pericyte cells are now known to be a novel locus of blood flow control, being able to regulate capillary diameter via their unique morphology and expression of contractile proteins. We have previously shown that exogenous ATP causes constriction of vasa recta via renal pericytes, acting at a variety of membrane bound P2 receptors on descending vasa recta (DVR), and therefore may be able to regulate medullary blood flow (MBF). Regulation of MBF is essential for appropriate urine concentration and providing essential oxygen and nutrients to this region of high, and variable, metabolic demand. Various sources of endogenous ATP have been proposed, including from epithelial, endothelial, and red blood cells in response to stimuli such as mechanical stimulation, local acidosis, hypoxia, and exposure to various hormones. Extensive sympathetic innervation of the nephron has previously been shown, however the innervation reported has focused around the proximal and distal tubules, and ascending loop of Henle. We hypothesize that sympathetic nerves are an additional source of ATP acting at renal pericytes and therefore regulate MBF. Using a rat live kidney slice model in combination with video imaging and confocal microscopy techniques we firstly show sympathetic nerves in close proximity to vasa recta pericytes in both the outer and inner medulla. Secondly, we demonstrate pharmacological stimulation of sympathetic nerves in situ (by tyramine) evokes pericyte-mediated vasoconstriction of vasa recta capillaries; inhibited by the application of the P2 receptor antagonist suramin. Lastly, tyramine-evoked vasoconstriction of vasa recta by pericytes is significantly less than ATP-evoked vasoconstriction. Sympathetic innervation may provide an additional level of functional regulation in the renal medulla that is highly localized. It now needs to be determined under which physiological/pathophysiological circumstances that sympathetic innervation of renal pericytes is important

  3. Loss of hepatocyte EGFR has no effect alone but exacerbates carbon tetrachloride-induced liver injury and impairs regeneration in hepatocyte Met-deficient mice

    PubMed Central

    Zhang, Xiuqi; Stevenson, Mary C.; Threadgill, David W.; Russell, William E.

    2014-01-01

    The role(s) of the epidermal growth factor receptor (EGFR) in hepatocytes is unknown. We generated a murine hepatocyte specific-EGFR knockout (KO) model to evaluate how loss of hepatocellular EGFR expression affects processes such as EGF clearance, circulating EGF concentrations, and liver regeneration following 70% resection or CCl4-induced centrilobular injury. We were able to disrupt EGFR expression effectively in hepatocytes and showed that the ability of EGF and heregulin (HRG) to phosphorylate EGFR and ERBB3, respectively, required EGFR. Loss of hepatocellular EGFR impaired clearance of exogenous EGF from the portal circulation but paradoxically resulted in reduced circulating levels of endogenous EGF. This was associated with decreased submandibular salivary gland production of EGF. EGFR disruption did not result in increased expression of other ERBB proteins or Met, except in neonatal mice. Liver regeneration following 70% hepatectomy revealed a mild phenotype, with no change in cyclin D1 expression and slight differences in cyclin A expression compared with controls. Peak 5-bromo-2′-deoxyuridine labeling was shifted from 36 to 48 h. Centrilobular damage and regenerative response induced by carbon tetrachloride (CCl4) were identical in the KO and wild-type mice. In contrast, loss of Met increased CCl4-induced necrosis and delayed regeneration. Although loss of hepatocellular EGFR alone did not have an effect in this model, EGFR-Met double KOs displayed enhanced necrosis and delayed liver regeneration compared with Met KOs alone. This suggests that EGFR and Met may partially compensate for the loss of the other, although other compensatory mechanisms can be envisioned. PMID:25414100

  4. Human sunlight-induced basal-cell-carcinoma-associated dendritic cells are deficient in T cell co-stimulatory molecules and are impaired as antigen-presenting cells.

    PubMed Central

    Nestle, F. O.; Burg, G.; Fäh, J.; Wrone-Smith, T.; Nickoloff, B. J.

    1997-01-01

    Immune surveillance of skin cancer involves the stimulation of effector T cells by tumor-derived antigens and antigen-presenting cells (APCs). An effective APC must not only display processed antigen in the context of MHC molecules but also express co-stimulatory molecules that are required to fully activate T cells. One of the most common cutaneous neoplasms is basal cell carcinoma. To investigate expression of the co-stimulatory molecules CD80 (B7-1) and CD86 (B7-2) on tumor-associated dendritic cells (TADCs), cryosections from basal cell carcinomas were immunostained. In basal cell carcinomas, only 1 to 2% of intratumor and 5 to 10% of peritumor APCs expressed CD80 or CD86. In contrast, biopsies of immunological/inflammatory dermatoses revealed that 38 to 73% of APCs expressed CD80 and CD86. To further evaluate their phenotype and function, TADCs were isolated from tissue samples of basal cell carcinomas; they were non-adherent to plastic, displayed a typical dendritic morphology, and expressed high levels of major histocompatibility class II molecules on their surface. When TADCs were compared with dendritic cells from blood for presentation of superantigens (staphylococcal enterotoxins A and B) to resting autologous T cells, TADCs were consistently weaker stimulators of T cell proliferation than blood dendritic cells. When analyzed by flow cytometry, TADCs expressed high levels of HLA-DR, but only 5 to 10% co-expressed CD80 or CD86. A 3-day culture in granulocyte/macrophage colony-stimulating factor-containing medium partially reconstituted the TADC expression of CD80 and CD86 as well as their immunostimulatory capacity. Thus, in this common skin cancer, although there are prominent collections of HLA-DR-positive APCs in and around tumor cells, the TADCs are deficient in important co-stimulatory molecules as well as being weak stimulators of T cell proliferation. The paucity of co-stimulatory molecule expression and functional activity of TADCs may explain why

  5. Flesh Quality Loss in Response to Dietary Isoleucine Deficiency and Excess in Fish: A Link to Impaired Nrf2-Dependent Antioxidant Defense in Muscle

    PubMed Central

    Gan, Lu; Jiang, Wei-Dan; Wu, Pei; Liu, Yang; Jiang, Jun; Li, Shu-Hong; Tang, Ling; Kuang, Sheng-Yao; Feng, Lin; Zhou, Xiao-Qiu

    2014-01-01

    The present study explored the impact of dietary isoleucine (Ile) on fish growth and flesh quality and revealed a possible role of muscle antioxidant defense in flesh quality in relation to dietary Ile. Grass carp (weighing 256.8±3.5 g) were fed diets containing six graded levels of Ile (3.8, 6.6, 9.3, 12.5, 15.2 and 18.5 g/kg) for eight weeks. The results indicated that compared with Ile deficiency (3.8 g/kg diets) and excess (18.5 g/kg diets) groups, 9.3–15.2 g Ile/kg diet supplementations promoted fish growth and muscle fat deposition, whereas 6.6–15.2 g Ile/kg diets supplementation enhanced muscle nutrients (protein and total EAAs) deposition. Furthermore, muscle shear force, pH value, and hydroxyproline concentration were improved by 9.3–12.5, 9.3 and 9.3 g Ile/kg diet supplementations, respectively. However, muscle cooking loss, lactate content, and activities of cathepsin B and L were decreased by 6.6–15.2, 9.3–12.5, 9.3–12.5 and 9.3–15.2 g Ile/kg diet supplementations, respectively. Additionally, 6.6–15.2 and 6.6–12.5 g Ile/kg diet supplementations attenuated malondialdehyde and protein carbonyl contents, respectively. The activities of copper/zinc superoxide dismutase (Cu/Zn-SOD) and glutathione peroxidase (GPx), and glutathione content were enhanced by 6.6–9.3, 6.6–12.5 and 6.6–15.2 g Ile/kg diet supplementations, respectively. Moreover, the relative mRNA expressions of antioxidant enzymes, including Cu/Zn-SOD (6.6–12.5 g/kg diets) and GPx (12.5 g/kg diets), as well as antioxidant-related signaling molecules, including NF-E2-related factor 2 (Nrf2) (6.6–12.5 g/kg diets), target of rapamycin (6.6–12.5 g/kg diets), ribosomal S6 protein kinase 1 (9.3–12.5 g/kg diets) and casein kinase 2 (6.6–12.5 g/kg diets), were up-regulated when Ile diet supplementations were administered at these levels, respectively, whereas the relative mRNA expression of Kelch-like ECH-associated protein 1 was down-regulated with 9.3 g Ile/kg diet

  6. Natural killer cell deficiency

    PubMed Central

    Orange, Jordan S.

    2013-01-01

    Natural killer (NK) cells are part of the innate immune defense against infection and cancer, and are especially useful in combating certain viral pathogens. The utility of NK cells in human health has been underscored by a growing number of individuals who are deficient in NK cells and/or their functions. This can be in the context of a broader genetically-defined congenital immunodeficiency of which there are over forty presently known to impair NK cells. The abnormality of NK cells, however, in certain cases represents the majority immunological defect. In aggregate, these conditions are termed NK cell deficiency. Recent advances have added clarity to this diagnosis and identified defects in three different genes that can cause NK cell deficiency as well as some of the underlying biology. Appropriate consideration of these diagnoses and patients raises the potential for rational therapeutic options and further innovation. PMID:23993353

  7. Arginase-1 deficiency.

    PubMed

    Sin, Yuan Yan; Baron, Garrett; Schulze, Andreas; Funk, Colin D

    2015-12-01

    Arginase-1 (ARG1) deficiency is a rare autosomal recessive disorder that affects the liver-based urea cycle, leading to impaired ureagenesis. This genetic disorder is caused by 40+ mutations found fairly uniformly spread throughout the ARG1 gene, resulting in partial or complete loss of enzyme function, which catalyzes the hydrolysis of arginine to ornithine and urea. ARG1-deficient patients exhibit hyperargininemia with spastic paraparesis, progressive neurological and intellectual impairment, persistent growth retardation, and infrequent episodes of hyperammonemia, a clinical pattern that differs strikingly from other urea cycle disorders. This review briefly highlights the current understanding of the etiology and pathophysiology of ARG1 deficiency derived from clinical case reports and therapeutic strategies stretching over several decades and reports on several exciting new developments regarding the pathophysiology of the disorder using ARG1 global and inducible knockout mouse models. Gene transfer studies in these mice are revealing potential therapeutic options that can be exploited in the future. However, caution is advised in extrapolating results since the lethal disease phenotype in mice is much more severe than in humans indicating that the mouse models may not precisely recapitulate human disease etiology. Finally, some of the functions and implications of ARG1 in non-urea cycle activities are considered. Lingering questions and future areas to be addressed relating to the clinical manifestations of ARG1 deficiency in liver and brain are also presented. Hopefully, this review will spark invigorated research efforts that lead to treatments with better clinical outcomes. PMID:26467175

  8. IL-17 Promotes Neutrophil-Mediated Immunity by Activating Microvascular Pericytes and Not Endothelium.

    PubMed

    Liu, Rebecca; Lauridsen, Holly M; Amezquita, Robert A; Pierce, Richard W; Jane-Wit, Dan; Fang, Caodi; Pellowe, Amanda S; Kirkiles-Smith, Nancy C; Gonzalez, Anjelica L; Pober, Jordan S

    2016-09-15

    A classical hallmark of acute inflammation is neutrophil infiltration of tissues, a multistep process that involves sequential cell-cell interactions of circulating leukocytes with IL-1- or TNF-activated microvascular endothelial cells (ECs) and pericytes (PCs) that form the wall of the postcapillary venules. The initial infiltrating cells accumulate perivascularly in close proximity to PCs. IL-17, a proinflammatory cytokine that acts on target cells via a heterodimeric receptor formed by IL-17RA and IL-17RC subunits, also promotes neutrophilic inflammation but its effects on vascular cells are less clear. We report that both cultured human ECs and PCs strongly express IL-17RC and, although neither cell type expresses much IL-17RA, PCs express significantly more than ECs. IL-17, alone or synergistically with TNF, significantly alters inflammatory gene expression in cultured human PCs but not ECs. RNA sequencing analysis identifies many IL-17-induced transcripts in PCs encoding proteins known to stimulate neutrophil-mediated immunity. Conditioned media from IL-17-activated PCs, but not ECs, induce pertussis toxin-sensitive neutrophil polarization, likely mediated by PC-secreted chemokines, and they also stimulate neutrophil production of proinflammatory molecules, including TNF, IL-1α, IL-1β, and IL-8. Furthermore, IL-17-activated PCs, but not ECs, can prolong neutrophil survival by producing G-CSF and GM-CSF, delaying the mitochondrial outer membrane permeabilization and caspase-9 activation. Importantly, neutrophils exhibit enhanced phagocytic capacity after activation by conditioned media from IL-17-treated PCs. We conclude that PCs, not ECs, are the major target of IL-17 within the microvessel wall and that IL-17-activated PCs can modulate neutrophil functions within the perivascular tissue space. PMID:27534549

  9. NG2 proteoglycan as a pericyte target for anticancer therapy by tumor vessel infarction with retargeted tissue factor

    PubMed Central

    Brand, Caroline; Schliemann, Christoph; Ring, Janine; Kessler, Torsten; Bäumer, Sebastian; Angenendt, Linus; Mantke, Verena; Ross, Rebecca; Hintelmann, Heike; Spieker, Tilmann; Wardelmann, Eva; Mesters, Rolf M.; Berdel, Wolfgang E.; Schwöppe, Christian

    2016-01-01

    tTF-TAA and tTF-LTL are fusion proteins consisting of the extracellular domain of tissue factor (TF) and the peptides TAASGVRSMH and LTLRWVGLMS, respectively. These peptides represent ligands of NG2, a surface proteoglycan expressed on angiogenic pericytes and some tumor cells. Here we have expressed the model compound tTF-NGR, tTF-TAA, and tTF-LTL with different lengths in the TF domain in E. coli and used these fusion proteins for functional studies in anticancer therapy. We aimed to retarget TF to tumor vessels leading to tumor vessel infarction with two barriers of selectivity, a) the leaky endothelial lining in tumor vessels with the target NG2 being expressed on pericytes on the abluminal side of the endothelial cell barrier and b) the preferential expression of NG2 on angiogenic vessels such as in tumors. Chromatography-purified tTF-TAA showed identical Factor X (FX)-activating procoagulatory activity as the model compound tTF-NGR with Km values of approx. 0.15 nM in Michaelis-Menten kinetics. The procoagulatory activity of tTF-LTL varied with the chosen length of the TF part of the fusion protein. Flow cytometry revealed specific binding of tTF-TAA to NG2-expressing pericytes and tumor cells with low affinity and dissociation KD in the high nM range. In vivo and ex vivo fluorescence imaging of tumor xenograft-carrying animals and of the explanted tumors showed reduction of tumor blood flow upon tTF-TAA application. Therapeutic experiments showed a reproducible antitumor activity of tTF-TAA against NG2-expressing A549-tumor xenografts, however, with a rather small therapeutic window (active/toxic dose in mg/kg body weight). PMID:26735180

  10. NG2 proteoglycan as a pericyte target for anticancer therapy by tumor vessel infarction with retargeted tissue factor.

    PubMed

    Brand, Caroline; Schliemann, Christoph; Ring, Janine; Kessler, Torsten; Bäumer, Sebastian; Angenendt, Linus; Mantke, Verena; Ross, Rebecca; Hintelmann, Heike; Spieker, Tilmann; Wardelmann, Eva; Mesters, Rolf M; Berdel, Wolfgang E; Schwöppe, Christian

    2016-02-01

    tTF-TAA and tTF-LTL are fusion proteins consisting of the extracellular domain of tissue factor (TF) and the peptides TAASGVRSMH and LTLRWVGLMS, respectively. These peptides represent ligands of NG2, a surface proteoglycan expressed on angiogenic pericytes and some tumor cells. Here we have expressed the model compound tTF-NGR, tTF-TAA, and tTF-LTL with different lengths in the TF domain in E. coli and used these fusion proteins for functional studies in anticancer therapy. We aimed to retarget TF to tumor vessels leading to tumor vessel infarction with two barriers of selectivity, a) the leaky endothelial lining in tumor vessels with the target NG2 being expressed on pericytes on the abluminal side of the endothelial cell barrier and b) the preferential expression of NG2 on angiogenic vessels such as in tumors. Chromatography-purified tTF-TAA showed identical Factor X (FX)-activating procoagulatory activity as the model compound tTF-NGR with Km values of approx. 0.15 nM in Michaelis-Menten kinetics. The procoagulatory activity of tTF-LTL varied with the chosen length of the TF part of the fusion protein. Flow cytometry revealed specific binding of tTF-TAA to NG2-expressing pericytes and tumor cells with low affinity and dissociation KD in the high nM range. In vivo and ex vivo fluorescence imaging of tumor xenograft-carrying animals and of the explanted tumors showed reduction of tumor blood flow upon tTF-TAA application. Therapeutic experiments showed a reproducible antitumor activity of tTF-TAA against NG2-expressing A549-tumor xenografts, however, with a rather small therapeutic window (active/toxic dose in mg/kg body weight). PMID:26735180

  11. Adult Human Glia, Pericytes and Meningeal Fibroblasts Respond Similarly to IFNy but Not to TGFβ1 or M-CSF

    PubMed Central

    Smith, Amy M.; Graham, E. Scott; Feng, Sheryl Xia; Oldfield, Robyn L.; Bergin, Peter M.; Mee, Edward W.; Faull, Richard L. M.; Curtis, Maurice A.; Dragunow, Mike

    2013-01-01

    The chemokine Interferon gamma-induced protein 10 (IP-10) and human leukocyte antigen (HLA) are widely used indicators of glial activation and neuroinflammation and are up-regulated in many brain disorders. These inflammatory mediators have been widely studied in rodent models of brain disorders, but less work has been undertaken using human brain cells. In this study we investigate the regulation of HLA and IP-10, as well as other cytokines and chemokines, in microglia, astrocytes, pericytes, and meningeal fibroblasts derived from biopsy and autopsy adult human brain, using immunocytochemistry and a Cytometric Bead Array. Interferonγ (IFNγ) increased microglial HLA expression, but contrary to data in rodents, the anti-inflammatory cytokine transforming growth factor β1 (TGFβ1) did not inhibit this increase in HLA, nor did TGFβ1 affect basal microglial HLA expression or IFNγ-induced astrocytic HLA expression. In contrast, IFNγ-induced and basal microglial HLA expression, but not IFNγ-induced astrocytic HLA expression, were strongly inhibited by macrophage colony stimulating factor (M-CSF). IFNγ also strongly induced HLA expression in pericytes and meningeal fibroblasts, which do not basally express HLA, and this induction was completely blocked by TGFβ1, but not affected by M-CSF. In contrast, TGFβ1 did not block the IFNγ-induced increase in IP-10 in pericytes and meningeal fibroblasts. These results show that IFNγ, TGFβ1 and M-CSF have species- and cell type-specific effects on human brain cells that may have implications for their roles in adult human brain inflammation. PMID:24339874

  12. Diversified Expression of NG2/CSPG4 Isoforms in Glioblastoma and Human Foetal Brain Identifies Pericyte Subsets

    PubMed Central

    Rizzi, Marco; Errede, Mariella; Wälchli, Thomas; Mucignat, Maria Teresa; Frei, Karl; Roncali, Luisa; Perris, Roberto; Virgintino, Daniela

    2013-01-01

    NG2/CSPG4 is a complex surface-associated proteoglycan (PG) recognized to be a widely expressed membrane component of glioblastoma (WHO grade IV) cells and angiogenic pericytes. To determine the precise expression pattern of NG2/CSPG4 on glioblastoma cells and pericytes, we generated a panel of >60 mouse monoclonal antibodies (mAbs) directed against the ectodomain of human NG2/CSPG4, partially characterized the mAbs, and performed a high-resolution distributional mapping of the PG in human foetal, adult and glioblastoma-affected brains. The reactivity pattern initially observed on reference tumour cell lines indicated that the mAbs recognized 48 immunologically distinct NG2/CSPG4 isoforms, and a total of 14 mAbs was found to identify NG2/CSPG4 isoforms in foetal and neoplastic cerebral sections. These were consistently absent in the adult brain, but exhibited a complementary expression pattern in angiogenic vessels of both tumour and foetal tissues. Considering the extreme pleomorphism of tumour areas, and with the aim of subsequently analysing the distributional pattern of the NG2/CSPG4 isoforms on similar histological vessel typologies, a preliminary study was carried out with endothelial cell and pericyte markers, and with selected vascular basement membrane (VBM) components. On both tumour areas characterized by 'glomeruloid' and 'garland vessels', which showed a remarkably similar cellular and molecular organization, and on developing brain vessels, spatially separated, phenotypically diversified pericyte subsets with a polarized expression of key surface components, including NG2/CSPG4, were disclosed. Interestingly, the majority of the immunolocalized NG2/CSPG4 isoforms present in glioblastoma tissue were present in foetal brain, except for one isoform that seemed to be exclusive of tumour cells, being absent in foetal brain. The results highlight an unprecedented, complex pattern of NG2/CSPG4 isoform expression in foetal and neoplastic CNS, discriminating

  13. Two- and three-dimensional co-culture models of soft tissue healing: pericyte-endothelial cell interaction.

    PubMed

    Jennewein, Martina; Bubel, Monika; Guthörl, Silke; Metzger, Wolfgang; Weigert, Martin; Pohlemann, Tim; Oberringer, Martin

    2016-08-01

    The demographic change in western countries towards an older population is being shadowed by an increased appearance of chronic diseases influencing soft tissue healing in a negative manner. Although various promising therapeutic approaches are available for treating chronic wounds, no in vitro model exists that successfully allows the analysis of interacting cells and of the effect of therapeutic drugs within a wound. Granulation tissue assures wound stability, neo-angiogenesis and revascularization finally leading to functional soft tissue repair. As one of the first steps in developing a model for human granulation tissue, we examined microvascular endothelial cells and pericytes in conventional 2D and in 3D spheroid co-cultures. We determined which parameters could be used in a standardized manner and whether the cultures were responsive to hypoxia and to erythropoietin supplementation. The read-out parameters of cell migration, cell density, rate of apoptotic cells, spatial cell distribution in the spheroid and spheroid volume were shown to be excellent analytic measures. In addition, quantification of hypoxia-related genes identified a total of 13 genes that were up-regulated in spheroids after hypoxia. As these parameters delivered reliable results in the present approach and as the general morphological distribution of pericytes and endothelial cells within the spheroid occurred in a typical manner, we believe that this basic in vitro model will serve for the future study of diverse aspects of soft tissue healing. PMID:27026609

  14. Direct Cell-Cell Contact between Mesenchymal Stem Cells and Endothelial Progenitor Cells Induces a Pericyte-Like Phenotype In Vitro

    PubMed Central

    Richards, R. Geoff; Nerlich, Michael; Alini, Mauro

    2014-01-01

    Tissue engineering techniques for the regeneration of large bone defects require sufficient vascularisation of the applied constructs to ensure a sufficient supply of oxygen and nutrients. In our previous work, prevascularised 3D scaffolds have been successfully established by coculture of bone marrow derived stem cells (MSCs) and endothelial progenitor cells (EPCs). We identified stabilising pericytes (PCs) as part of newly formed capillary-like structures. In the present study, we report preliminary data on the interactions between MSCs and EPCs, leading to the differentiation of pericyte-like cells. MSCs and EPCs were seeded in transwell cultures, direct cocultures, and single cultures. Cells were cultured for 10 days in IMDM 10% FCS or IMDM 5% FCS 5% platelet lysate medium. Gene expression of PC markers, CD146, NG2, αSMA, and PDGFR-β, was analysed using RT-PCR at days 0, 3, 7, and 10. The upregulation of CD146, NG2, and αSMA in MSCs in direct coculture with EPCs advocates the MSCs' differentiation towards a pericyte-like phenotype in vitro. These results suggest that pericyte-like cells derive from MSCs and that cell-cell contact with EPCs is an important factor for this differentiation process. These findings emphasise the concept of coculture strategies to promote angiogenesis for cell-based tissue engineered bone grafts. PMID:24563864

  15. Zinc and its deficiency diseases.

    PubMed

    Evans, G W

    1986-01-01

    The pervasive role of zinc in the metabolic function of the body results from its function as a cofactor of a multitude of enzymes. Zinc is found in every tissue in the body, and because zinc metalloenzymes are found in every known class of enzymes, the metal has a function in every conceivable type of biochemical pathway. Symptoms resulting from zinc deficiency are as diverse as the enzymes with which the metal is associated. If chronic, severe, and untreated, zinc deficiency can be fatal. Less drastic symptoms include infections, hypogonadism, weight loss, emotional disturbance, dermatitis, alopecia, impaired taste acuity, night blindness, poor appetite, delayed wound healing, and elevated blood ammonia levels. Many symptoms of zinc deficiency result from poor diet consumption, but often the most severe symptoms result from other factors including excessive alcohol use, liver diseases, malabsorption syndromes, renal disease, enteral or parenteral alimentation, administration of sulfhydryl-containing drugs, and sickle cell disease. The most severe symptoms of zinc deficiency occur in young children affected with the autosomal-recessive trait, acrodermatitis enteropathica. This disease results in decreased synthesis of picolinic acid which causes an impaired ability to utilize zinc from common food. Because simple laboratory analyses are often not reliable in determining zinc nutriture of a patient, those symptoms caused by suspected zinc deficiency are best verified by the oral administration of zinc dipicolinate. This zinc compound is efficacious and safe and would provide an accurate means of identifying symptoms that do result from zinc deficiency. PMID:3514057

  16. Molybdenum cofactor deficiency.

    PubMed

    Atwal, Paldeep S; Scaglia, Fernando

    2016-01-01

    Molybdenum cofactor deficiency (MoCD) is a severe autosomal recessive inborn error of metabolism first described in 1978. It is characterized by a neonatal presentation of intractable seizures, feeding difficulties, severe developmental delay, microcephaly with brain atrophy and coarse facial features. MoCD results in deficiency of the molybdenum cofactor dependent enzymes sulfite oxidase, xanthine dehydrogenase, aldehyde oxidase and mitochondrial amidoxime reducing component. The resultant accumulation of sulfite, taurine, S-sulfocysteine and thiosulfate contributes to the severe neurological impairment. Recently, initial evidence has demonstrated early treatment with cyclic PMP can turn MoCD type A from a previously neonatal lethal condition with only palliative options, to near normal neurological outcomes in affected patients. We review MoCD and focus on describing the currently published evidence of this exciting new therapeutic option for MoCD type A caused by pathogenic variants in MOCD1. PMID:26653176

  17. Disialotransferrin developmental deficiency syndrome.

    PubMed Central

    Kristiansson, B; Andersson, M; Tonnby, B; Hagberg, B

    1989-01-01

    Seven mentally deficient children and adolescents (three pairs of siblings and one singleton) were studied. A peculiar external appearance, a characteristic neurohepatosubcutaneous tissue impairment syndrome and, as a biological marker, an abnormal sialic acid transferrin pattern were characteristic features. All seven seemed odd from birth and prone to acute cerebral dysfunction during catabolic states. Abnormal lower neurone, cerebellar, and retinal functions dominated from later childhood. The disialotransferrin pattern found in serum and cerebrospinal fluid is thought to be the biological marker of a newly discovered inborn error of glycoprotein metabolism with autosomal recessive inheritance. Images Fig 1 Fig 2 p74-b PMID:2466439

  18. Blocking SDF-1α/CXCR4 downregulates PDGF-B and inhibits bone marrow-derived pericyte differentiation and tumor vascular expansion in Ewing tumors.

    PubMed

    Hamdan, Randala; Zhou, Zhichao; Kleinerman, Eugenie S

    2014-02-01

    Bone marrow cells (BMC) are critical to the expansion of the tumor vessel network that supports Ewing sarcoma growth. BMCs migrate to the tumor and differentiate into endothelial cells and pericytes. We recently demonstrated that stromal-derived growth factor 1α (SDF-1α) regulates platelet-derived growth factor B (PDGF-B) and that this pathway plays a critical role in bone marrow-derived pericyte differentiation in vitro. We investigated the role of SDF-1α/PDGF-B in the tumor microenvironment in vivo in promoting bone marrow-derived pericyte differentiation in Ewing tumors. The CXCR4 antagonist AMD 3100 was used to disrupt the SDF-1α/CXCR4 axis in vivo in two xenograft Ewing tumor models. BMCs from GFP(+) transgenic mice were transplanted into lethally irradiated nude mice to track BMC migration to the tumor site. Following BMC engraftment, tumor-bearing mice received daily subcutaneous injections of either PBS or AMD 3100 for 3 weeks. Tumors were resected and tumor sections were analyzed by immunohistochemistry. AMD 3100 inhibited BMC differentiation into desmin(+) and NG2(+) pericytes, affected the morphology of the tumor vasculature, decreased perfusion, and increased tumor cell apoptosis. We observed smaller vessels with tiny lumens and a decrease in the microvessel density. AMD 3100 also inhibited PDGF-B protein expression in vitro and in vivo. SDF-1α in the tumor microenvironment plays a critical role in promoting pericyte formation and Ewing sarcoma tumor neovascularization by regulating PDGF-B expression. Interfering with this pathway affects tumor vascular morphology and expansion. PMID:24282276

  19. RHOA SIGNAL TRANSDUCTION: EFFECTS OF MATERNAL COPPER DEFICIENCY ON PROGENY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Maternal copper deficiency during pregnancy and lactation impairs development of the cardiovascular system.Maternal copper deficiency induces reduction in CCO activity in neonatal cardiac mitochondria, pointing to developmental alterations. Effects of maternal copper deficiency on RhoA s...

  20. Iodine deficiency disorders (IDD) and their eradication.

    PubMed

    Hetzel, B S

    1983-11-12

    Disorders resulting from severe iodine deficiency affect more than 400 million people in Asia alone. These disorders include stillbirths, abortions, and congenital anomalies; endemic cretinism, characterised most commonly by mental deficiency, deaf mutism, and spastic diplegia and lesser degrees of neurological defect related to fetal iodine deficiency; and impaired mental function in children and adults with goitre associated with subnormal concentrations of circulating thyroxine. Use of the term iodine deficiency disorders, instead of "goitre", would help to bridge the serious gap between knowledge and its application. Iodised salt and iodised oil (by injection or by mouth) are suitable for the correction of iodine deficiency on a mass scale. A single dose of iodised oil can correct severe iodine deficiency for 3-5 years. Iodised oil offers a satisfactory immediate measure for primary care services until an iodised salt programme can be implemented. The complete eradication of iodine deficiency is therefore feasible within 5-10 years. PMID:6138653

  1. Immature Dental Pulp Stem Cells Showed Renotropic and Pericyte-Like Properties in Acute Renal Failure in Rats.

    PubMed

    Barros, Michele A; Martins, João Flávio Panattoni; Maria, Durvanei Augusto; Wenceslau, Crisitiane Valverde; De Souza, Dener Madeiro; Kerkis, Alexandre; Câmara, Niels Olsen S; Balieiro, Julio Cesar C; Kerkis, Irina

    2015-10-01

    Acute renal failure (ARF) is a common renal disease that can lead to high mortality. Recovery from ARF occurs with the replacement of necrotic tubular cells by functional tubular epithelial cells and the normalization of microvascular endothelial cell function in the peritubular capillaries. Conventional therapeutic techniques are often ineffective against ARF. Hence, stem cell therapies, which act through multiple trophic and regenerative mechanisms, are encouraging. We investigated the homing of human immature dental pulp stem cells (IDPSCs) after endovenous (EV) or intraperitoneal (IP) injection, in immunocompetent Wistar rats with ARF induced by intramuscular injection of glycerol, without the use of immunosuppression. The cells, which had been cryopreserved for 6 years, were CD105(+), CD73(+), CD44(+), and partly, STRO-1(+) and CD146(+), and presented unaltered mesoderm differentiation potential. The presence of these cells in the tubular region of the kidney and in the peritubular capillaries was demonstrated. These cells accelerate tubular epithelial cell regeneration through significant increase of Ki-67-immunoreactive cells in damaged kidney. Flow cytometry analysis confirmed that IDPSCs home to the kidneys (EV 34.10% and IP 33.25%); a lower percentage of cells was found in the liver (EV 19.05% and IP 9.10%), in the muscles (EV 6.30% and IP 1.35%), and in the lungs (EV 2.0% and IP 1.85%). After infusion into rat, these cells express pericyte markers, such as CD146(+), STRO-1(+), and vascular endothelial growth factor (VEGF(+)). We found that IDPSCs demonstrate renotropic and pericyte-like properties and contributed to restore renal tubule structure in an experimental rat ARF model. PMID:26858898

  2. Immature Dental Pulp Stem Cells Showed Renotropic and Pericyte-Like Properties in Acute Renal Failure in Rats

    PubMed Central

    Barros, Michele A.; Martins, João Flávio Panattoni; Maria, Durvanei Augusto; Wenceslau, Crisitiane Valverde; De Souza, Dener Madeiro; Kerkis, Alexandre; Câmara, Niels Olsen S.; Balieiro, Julio Cesar C.; Kerkis, Irina

    2015-01-01

    Acute renal failure (ARF) is a common renal disease that can lead to high mortality. Recovery from ARF occurs with the replacement of necrotic tubular cells by functional tubular epithelial cells and the normalization of microvascular endothelial cell function in the peritubular capillaries. Conventional therapeutic techniques are often ineffective against ARF. Hence, stem cell therapies, which act through multiple trophic and regenerative mechanisms, are encouraging. We investigated the homing of human immature dental pulp stem cells (IDPSCs) after endovenous (EV) or intraperitoneal (IP) injection, in immunocompetent Wistar rats with ARF induced by intramuscular injection of glycerol, without the use of immunosuppression. The cells, which had been cryopreserved for 6 years, were CD105+, CD73+, CD44+, and partly, STRO-1+ and CD146+, and presented unaltered mesoderm differentiation potential. The presence of these cells in the tubular region of the kidney and in the peritubular capillaries was demonstrated. These cells accelerate tubular epithelial cell regeneration through significant increase of Ki-67-immunoreactive cells in damaged kidney. Flow cytometry analysis confirmed that IDPSCs home to the kidneys (EV 34.10% and IP 33.25%); a lower percentage of cells was found in the liver (EV 19.05% and IP 9.10%), in the muscles (EV 6.30% and IP 1.35%), and in the lungs (EV 2.0% and IP 1.85%). After infusion into rat, these cells express pericyte markers, such as CD146+, STRO-1+, and vascular endothelial growth factor (VEGF+). We found that IDPSCs demonstrate renotropic and pericyte-like properties and contributed to restore renal tubule structure in an experimental rat ARF model. PMID:26858898

  3. Tissue-Specific Cultured Human Pericytes: Perivascular Cells from Smooth Muscle Tissue Have Restricted Mesodermal Differentiation Ability.

    PubMed

    Pierantozzi, Enrico; Vezzani, Bianca; Badin, Margherita; Curina, Carlo; Severi, Filiberto Maria; Petraglia, Felice; Randazzo, Davide; Rossi, Daniela; Sorrentino, Vincenzo

    2016-05-01

    Microvascular pericytes (PCs) are considered the adult counterpart of the embryonic mesoangioblasts, which represent a multipotent cell population that resides in the dorsal aorta of the developing embryo. Although PCs have been isolated from several adult organs and tissues, it is still controversial whether PCs from different tissues exhibit distinct differentiation potentials. To address this point, we investigated the differentiation potentials of isogenic human cultured PCs isolated from skeletal (sk-hPCs) and smooth muscle tissues (sm-hPCs). We found that both sk-hPCs and sm-hPCs expressed known pericytic markers and did not express endothelial, hematopoietic, and myogenic markers. Both sk-hPCs and sm-hPCs were able to differentiate into smooth muscle cells. In contrast, sk-hPCs, but not sm-hPCs, differentiated in skeletal muscle cells and osteocytes. Given the reported ability of the Notch pathway to regulate skeletal muscle and osteogenic differentiation, sk-hPCs and sm-hPCs were treated with N-[N-(3,5- difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), a known inhibitor of Notch signaling. DAPT treatment, as assessed by histological and molecular analysis, enhanced myogenic differentiation and abolished osteogenic potential of sk-hPCs. In contrast, DAPT treatment did not affect either myogenic or osteogenic differentiation of sm-hPCs. In summary, these results indicate that, despite being isolated from the same anatomical niche, cultured PCs from skeletal muscle and smooth muscle tissues display distinct differentiation abilities. PMID:26956507

  4. Myricetin inhibits advanced glycation end product (AGE)-induced migration of retinal pericytes through phosphorylation of ERK1/2, FAK-1, and paxillin in vitro and in vivo.

    PubMed

    Kim, Young Sook; Kim, Junghyun; Kim, Ki Mo; Jung, Dong Ho; Choi, Sojin; Kim, Chan-Sik; Kim, Jin Sook

    2015-02-15

    Advanced glycation end products (AGE) have been implicated in the development of diabetic retinopathy. Characterization of the early stages of diabetic retinopathy is retinal pericytes loss, which is the result of pericytes migration. In this study, we investigated the pathological mechanisms of AGE on the migration of retinal pericytes and confirmed the inhibitory effect of myricetin on migration in vitro and in vivo. Migration assays of bovine retinal pericytes (BRP) were induced using AGE-BSA and phosphorylation of Src, ERK1/2, focal adhesion kinase (FAK-1) and paxillin were determined using immunoblot analysis. Sprague-Dawley rats (6 weeks old) were injected intravitreally with AGE-BSA and morphological and immunohistochemical analysis of p-FAK-1 and p-paxillin were performed in the rat retina. Immunoblot analysis and siRNA transfection were used to study the molecular mechanism of myricetin on BRP migration. AGE-BSA increased BRP migration in a dose-dependent manner via receptor for AGEs (RAGE)-dependent activation of the Src kinase-ERK1/2 pathway. AGE-BSA-induced migration was inhibited by an ERK1/2 specific inhibitor (PD98059), but not by p38 and Jun N-terminal kinase inhibitors. AGE-BSA increased FAK-1 and paxillin phosphorylation in a dose- and time-dependent manner. These increases were attenuated by PD98059 and ERK1/2 siRNA. Phosphorylation of FAK-1 and paxillin was increased in response to AGE-BSA-induced migration of rat retinal pericytes. Myricetin strongly inhibited ERK1/2 phosphorylation and significantly suppressed pericytes migration in AGE-BSA-injected rats. Our results demonstrate that AGE-BSA participated in the pathophysiology of retinal pericytes migration likely through the RAGE-Src-ERK1/2-FAK-1-paxillin signaling pathway. Furthermore, myricetin suppressed phosphorylation of ERK 1/2-FAK-1-paxillin and inhibited pericytes migration. PMID:25450667

  5. High Glucose-Induced Mitochondrial Respiration and Reactive Oxygen Species in Mouse Cerebral Pericytes is Reversed by Pharmacological Inhibition of Mitochondrial Carbonic Anhydrases: Implications for Cerebral Microvascular Disease in Diabetes

    PubMed Central

    Shah, Gul N.; Morofuji, Yoichi; Banks, William A.; Price, Tulin O.

    2013-01-01

    Hyperglycemia-induced oxidative stress leads to diabetes-associated damage to the microvasculature of the brain. Pericytes in close proximity to endothelial cells in the brain microvessels are vital to the integrity of the blood-brain barrier and are especially susceptible to oxidative stress. According to our recently published results, streptozotocin-diabetic mouse brain exhibits oxidative stress and loose pericytes by twelve weeks of diabetes, and cerebral pericytes cultured in high glucose media suffer intracellular oxidative stress and apoptosis. Oxidative stress in diabetes is hypothesized to be caused by reactive oxygen species (ROS) produced during hyperglycemia-induced enhanced oxidative metabolism of glucose (respiration). To test this hypothesis, we investigated the effect of high glucose on respiration rate and ROS production in mouse cerebral pericytes. Previously, we showed that pharmacological inhibition of mitochondrial carbonic anhydrases protects the brain from oxidative stress and pericyte loss. The high glucose-induced intracellular oxidative stress and apoptosis of pericytes in culture were also reversed by inhibition of mitochondrial carbonic anhydrases. Therefore, we extended our current study to determine the effect of these inhibitors on high glucose-induced increases in pericyte respiration and ROS. We now report that both the respiration and ROS are significantly increased in pericytes challenged with high glucose. Furthermore, inhibition of mitochondrial carbonic anhydrases significantly slowed down both the rate of respiration and ROS production. These data provide new evidence that pharmacological inhibitors of mitochondrial carbonic anhydrases, already in clinical use, may prove beneficial in protecting the brain from oxidative stress caused by ROS produced as a consequence of hyperglycemia-induced enhanced respiration. PMID:24076121

  6. Alpha-1 Antitrypsin Deficiency

    MedlinePlus

    ... Liver Disease Information > Alpha-1 Antitrypsin Deficiency Alpha-1 Antitrypsin Deficiency Explore this section to learn more about alpha-1 antitrypsin deficiency, including a description of the disorder ...

  7. Pacemaker role of pericytes in generating synchronized spontaneous Ca2+ transients in the myenteric microvasculature of the guinea-pig gastric antrum.

    PubMed

    Hashitani, Hikaru; Mitsui, Retsu; Masaki, Shota; Van Helden, Dirk F

    2015-11-01

    Properties of spontaneous Ca(2+) transients in the myenteric microvasculature of the guinea-pig stomach were investigated. Specifically, we explored the spatio-temporal origin of Ca(2+) transients and the role of voltage-dependent Ca(2+) channels (VDCCs) in their intercellular synchrony using fluorescence Ca(2+) imaging and immunohistochemistry. The microvasculature generated spontaneous Ca(2+) transients that were independent of both Ca(2+) transients in interstitial cells of Cajal (ICC) and neural activity. Spontaneous Ca(2+) transients were highly synchronous along the length of microvasculature, and appeared to be initiated in pericytes and spread to arteriolar smooth muscle cells (SMCs). In most cases, the generation or synchrony of Ca(2+) transients was not affected by blockers of L-type VDCCs. In nifedipine-treated preparations, synchronous spontaneous Ca(2+) transients were readily blocked by Ni(2+), mibefradil or ML216, blockers for T-type VDCCs. These blockers also suppressed the known T-type VDCC dependent component of ICC Ca(2+) transients or slow waves. Spontaneous Ca(2+) transients were also suppressed by caffeine, tetracaine or cyclopiazonic acid (CPA). After the blockade of both L- and T-type VDCCs, asynchronous Ca(2+) transients were generated in pericytes on precapillary arterioles and/or capillaries but not in arteriolar SMCs, and were abolished by CPA or nominally Ca(2+) free solution. Together these data indicate that pericytes in the myenteric microvasculature may act as the origin of synchronous spontaneous Ca(2+) transients. Pericyte Ca(2+) transients arise from Ca(2+) release from the sarco-endoplasmic reticulum and the opening of T-type Ca(2+) VDCCs is required for their synchrony and propagation to arteriolar SMCs. PMID:26153078

  8. Involvement of Matrix Metalloproteinase-9 in Amyloid-β 1–42–Induced Shedding of the Pericyte Proteoglycan NG2

    PubMed Central

    Schultz, Nina; Nielsen, Henrietta M.; Minthon, Lennart; Wennström, Malin

    2014-01-01

    Abstract Deposition of amyloid-β (Aβ) 1–42, the major component of senile plaques characteristic of Alzheimer disease, affects brain microvascular integrity and causes blood-brain barrier dysfunction, increased angiogenesis, and pericyte degeneration. To understand the cellular events underlying Aβ1–42 effects on microvascular alterations, we investigated whether different aggregation forms of Aβ1–42 affect shedding of the pericyte proteoglycan NG2 and whether they affect proteolytic cleavage mediated by matrix metalloproteinase (MMP)-9. We found decreased levels of soluble NG2, total MMP-9, and MMP-9 activity in pericyte culture supernatants in response to fibril-enriched preparations of Aβ1–42. Conversely, oligomer-enriched preparations of Aβ1–42 increased soluble NG2 levels in the supernatants. This increase was ablated by the MMP-9/MMP-2 inhibitor SB-3CT. There was also a trend toward increased MMP-9 activity observed after oligomeric Aβ1–42 exposure. Our results, demonstrating an Aβ1–42 aggregation-dependent effect on levels of NG2 and MMP-9, support previous studies showing an impact of Aβ1–42 on vascular integrity and thereby add to our understanding of mechanisms behind the microvascular changes commonly found in patients with Alzheimer disease. PMID:24918635

  9. Angiomotin like-1 is a novel component of the N-cadherin complex affecting endothelial/pericyte interaction in normal and tumor angiogenesis

    PubMed Central

    Zheng, Yujuan; Zhang, Yuanyuan; Barutello, Giuseppina; Chiu, Kungchun; Arigoni, Maddalena; Giampietro, Costanza; Cavallo, Federica; Holmgren, Lars

    2016-01-01

    Transmission of mechanical force via cell junctions is an important component that molds cells into shapes consistent with proper organ function. Of particular interest are the cadherin transmembrane proteins, which play an essential role in connecting cell junctions to the intra-cellular cytoskeleton. Understanding how these biomechanical complexes orchestrate intrinsic and extrinsic forces is important for our understanding of the underlying mechanisms driving morphogenesis. We have previously identified the Amot protein family, which are scaffold proteins that integrate polarity, junctional, and cytoskeletal cues to modulate cellular shape in endothelial as well as epithelial cells. In this report, we show that AmotL1 is a novel partner of the N-cadherin protein complex. We studied the role of AmotL1 in normal retinal as well as tumor angiogenesis using inducible endothelial-specific knock-out mice. We show that AmotL1 is essential for normal establishment of vascular networks in the post-natal mouse retina as well as in a transgenic breast cancer model. The observed phenotypes were consistent with a non-autonomous pericyte defect. We show that AmotL1 forms a complex with N-cadherin present on both endothelial cells and pericytes. We propose that AmotL1 is an essential effector of the N-cadherin mediated endothelial/pericyte junctional complex. PMID:27464479

  10. Response of endothelial cells and pericytes to hypoxia and erythropoietin in a co-culture assay dedicated to soft tissue repair.

    PubMed

    Schneider, Gerrit; Bubel, Monika; Pohlemann, Tim; Oberringer, Martin

    2015-09-01

    The increasing mean life expectancy of the citizens of the western world countries leads to an increase of the age-related diseases, among them soft tissue defects exhibiting inadequate healing. In order to develop new therapeutic strategies to support disturbed soft tissue repair, there is a strong need of sophisticated in vitro assays. A new assay combining scratch wounding with co-cultures of primary human microvascular endothelial cells (HDMEC) and pericytes (HPC) focuses on basic characteristics of cell interaction against the background of soft tissue repair. The cell parameters proliferation, migration and differentiation, and the release of monocyte chemoattractant protein-1 (MCP-1) were analysed in response to hypoxia (pO2 < 5 mmHg) and to erythropoietin (EPO; 50 IU/ml), a glycoprotein hormone having shown promising effects in soft tissue repair. As basic characteristics of the assay, direct cell contact in co-culture led to a weakened proliferation of both cell types, an increase of the percentage of myofibroblast-like pericytes and to a higher release of MCP-1. Hypoxia caused a proliferation decrease of HPC in co-culture, which was slightly attenuated by EPO. Hypoxia also reduced the MCP-1 release of co-cultured cells, when EPO had been added. In addition, EPO had a rather positive effect on HPC migration under hypoxia. These in vitro results allow new insights into the interaction of pericytes with endothelial cells in the context of soft tissue repair. PMID:26026617

  11. Taste - impaired

    MedlinePlus

    ... treat cancer Swollen or inflamed gums ( gingivitis ) Vitamin B12 or zinc deficiency ... pubmed/20187599 . Travers JB, Travers SP, Christian JM. Physiology of the oral cavity In: Flint PW, Haughey ...

  12. Anemia and iron deficiency in heart failure.

    PubMed

    Gil, Victor M; Ferreira, Jorge S

    2014-01-01

    Heart failure is a common problem and a major cause of mortality, morbidity and impaired quality of life. Anemia is a frequent comorbidity in heart failure and further worsens prognosis and disability. Regardless of anemia status, iron deficiency is a common and usually unidentified problem in patients with heart failure. This article reviews the mechanisms, impact on outcomes and treatment of anemia and iron deficiency in patients with heart failure. PMID:24216080

  13. PGK deficiency.

    PubMed

    Beutler, Ernest

    2007-01-01

    Phosphoglycerate kinase (PGK) deficiency is one of the relatively uncommon causes of hereditary non-spherocytic haemolytic anaemia (HNSHA). The gene encoding the erythrocyte enzyme PGK1, is X-linked. Mutations of this gene may cause chronic haemolysis with or without mental retardation and they may cause myopathies, often with episodes of myoglobinuria, or a combination of these clinical manifestations. Twenty-six families have been described and in 20 of these the mutations are known. The reason for different clinical manifestations of mutations of the same gene remains unknown. PMID:17222195

  14. Evidence for pericyte origin of TSC-associated renal angiomyolipomas and implications for angiotensin receptor inhibition therapy

    PubMed Central

    Siroky, Brian J.; Yin, Hong; Dixon, Bradley P.; Reichert, Ryan J.; Hellmann, Anna R.; Ramkumar, Thiruvamoor; Tsuchihashi, Zenta; Bunni, Marlene; Dillon, Joshua; Bell, P. Darwin; Sampson, Julian R.

    2014-01-01

    Nearly all patients with tuberous sclerosis complex (TSC) develop renal angiomyolipomas, although the tumor cell of origin is unknown. We observed decreased renal angiomyolipoma development in patients with TSC2- polycystic kidney disease 1 deletion syndrome and hypertension that were treated from an early age with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers compared with patients who did not receive this therapy. TSC-associated renal angiomyolipomas expressed ANG II type 1 receptors, platelet-derived growth factor receptor-β, desmin, α-smooth muscle actin, and VEGF receptor 2 but did not express the adipocyte marker S100 or the endothelial marker CD31. Sera of TSC patients exhibited increased vascular mural cell-secreted peptides, such as VEGF-A, VEGF-D, soluble VEGF receptor 2, and collagen type IV. These findings suggest that angiomyolipomas may arise from renal pericytes. ANG II treatment of angiomyolipoma cells in vitro resulted in an exaggerated intracellular Ca2+ response and increased proliferation, which were blocked by the ANG II type 2 receptor antagonist valsartan. Blockade of ANG II signaling may have preventative therapeutic potential for angiomyolipomas. PMID:24920756

  15. Changes in integrity of the gill during histidine deficiency or excess due to depression of cellular anti-oxidative ability, induction of apoptosis, inflammation and impair of cell-cell tight junctions related to Nrf2, TOR and NF-κB signaling in fish.

    PubMed

    Jiang, Wei-Dan; Feng, Lin; Qu, Biao; Wu, Pei; Kuang, Sheng-Yao; Jiang, Jun; Tang, Ling; Tang, Wu-Neng; Zhang, Yong-An; Zhou, Xiao-Qiu; Liu, Yang

    2016-09-01

    This study firstly explored the possible effects of dietary histidine on structural integrity and the related signaling factor gene expression in the gills of fish. Young grass carp (Ctenopharyngodon idella) were fed with six diets containing gradual levels of histidine for 8 weeks. The results firstly demonstrated that histidine deficiency caused increases in reactive oxygen species (ROS) contents, and severe oxidative damage (lipid peroxidation and protein oxidation) in the gills of fish, which was partially due to the decreased glutathione (GSH) content and antioxidant enzyme activities [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR)]. Further investigations indicated that histidine deficiency caused depressions of those antioxidant enzyme activities are related to the down-regulation of corresponding antioxidant enzyme genes and the related signaling factor Nrf2 mRNA levels. Meanwhile, histidine deficiency induced DNA fragmentation via up-regulation of caspase-3, caspase-8 and caspase-9 expressions that referring to the down-regulation of TOR and S6K mRNA levels. Furthermore, His deficiency down-regulated claudin-b, claudin-c, claudin-3, claudin-12, claudin-15, occludin and ZO-1 transcription in fish gills. These effects were partially related to the up-regulation of pro-inflammatory cytokines, interleukin 1β (IL-1β), interleukin 8 (IL-8), tumor necrosis factor-α (TNF-α) and related signaling factor nuclear factor κB P65 (NF-κB P65) mRNA levels, and the down-regulation of anti-inflammatory cytokines, interleukin 10 (IL-10), transforming growth factor β1 (TGF-β1) and related signaling factor IκBα mRNA levels. Excessive histidine exhibited negative effects that were similar to histidine deficiency, whereas the optimal histidine levels reversed those negative effects. Taken together, our results showed that histidine deficiency or excess impaired the structural

  16. Health consequences of iodine deficiency.

    PubMed

    Kapil, Umesh

    2007-12-01

    Iodine Deficiency Disorders (IDD) are one of the biggest worldwide public health problem of today. Their effect is hidden and profoundly affects the quality of human life. Iodine deficiency occurs when the soil is poor in iodine, causing a low concentration in food products and insufficient iodine intake in the population. When iodine requirements are not met, the thyroid may no longer be able to synthesize sufficient amounts of thyroid hormone. The resulting low-level of thyroid hormones in the blood is the principal factor responsible for the series of functional and developmental abnormalities, collectively referred to as IDD. Iodine deficiency is a significant cause of mental developmental problems in children, including implications on reproductive functions and lowering of IQ levels in school-aged children. The consequence of iodine deficiency during pregnancy is impaired synthesis of thyroid hormones by the mother and the foetus. An insufficient supply of thyroid hormones to the developing brain may result in mental retardation. Brain damage and irreversible mental retardation are the most important disorders induced by iodine deficiency. Daily consumption of salt fortified with iodine is a proven effective strategy for prevention of IDD. PMID:21748117

  17. Soybean β-Conglycinin Prevents Age-Related Hearing Impairment

    PubMed Central

    Tanigawa, Tohru; Shibata, Rei; Kondo, Kazuhisa; Katahira, Nobuyuki; Kambara, Takahiro; Inoue, Yoko; Nonoyama, Hiroshi; Horibe, Yuichiro; Ueda, Hiromi; Murohara, Toyoaki

    2015-01-01

    Obesity-related complications are associated with the development of age-related hearing impairment. β-Conglycinin (β-CG), one of the main storage proteins in soy, offers multiple health benefits, including anti-obesity and anti-atherosclerotic effects. Here, to elucidate the potential therapeutic application of β-CG, we investigated the effect of β-CG on age-related hearing impairment. Male wild-type mice (age 6 months) were randomly divided into β-CG-fed and control groups. Six months later, the body weight was significantly lower in β-CG-fed mice than in the controls. Consumption of β-CG rescued the hearing impairment observed in control mice. Cochlear blood flow also increased in β-CG-fed mice, as did the expression of eNOS in the stria vascularis (SV), which protects vasculature. β-CG consumption also ameliorated oxidative status as assessed by 4-HNE staining. In the SV, lipofuscin granules of marginal cells and vacuolar degeneration of microvascular pericytes were decreased in β-CG-fed mice, as shown by transmission electron microscopy. β-CG consumption prevented loss of spiral ganglion cells and reduced the frequencies of lipofuscin granules, nuclear invaginations, and myelin vacuolation. Our observations indicate that β-CG ameliorates age-related hearing impairment by preserving cochlear blood flow and suppressing oxidative stress. PMID:26348726

  18. Genetics Home Reference: X-linked creatine deficiency

    MedlinePlus

    ... gene mutations impair the ability of the transporter protein to bring creatine into cells, resulting in a creatine shortage ... E, Uldry J. Creatine deficiency syndromes and the importance of creatine synthesis in the brain. Amino Acids. 2011 May;40( ...

  19. The impaired intestinal mucosal immune system by valine deficiency for young grass carp (Ctenopharyngodon idella) is associated with decreasing immune status and regulating tight junction proteins transcript abundance in the intestine.

    PubMed

    Luo, Jian-Bo; Feng, Lin; Jiang, Wei-Dan; Liu, Yang; Wu, Pei; Jiang, Jun; Kuang, Sheng-Yao; Tang, Ling; Zhang, Yong-An; Zhou, Xiao-Qiu

    2014-09-01

    This study investigated the effects of dietary valine on the growth, intestinal immune response, tight junction proteins transcript abundance and gene expression of immune-related signaling molecules in the intestine of young grass carp (Ctenopharyngodon idella). Six iso-nitrogenous diets containing graded levels of valine (4.3-19.1 g kg(-)(1) diet) were fed to the fish for 8 weeks. The results showed that percentage weight gain (PWG), feed intake and feed efficiency of fish were the lowest in fish fed the valine-deficient diet (P < 0.05). In addition, valine deficiency decreased lysozyme, acid phosphatase activities and complement 3 content in the intestine (P < 0.05), down-regulated mRNA levels of interleukin 10, transforming growth factor β1, IκBα and target of rapamycin (TOR) (P < 0.05), and up-regulated tumor necrosis factor α, interleukin 8 and nuclear factor κB P65 (NF-κB P65) gene expression (P < 0.05). Additionally, valine deficiency significantly decreased transcript of Occludin, Claudin b, Claudin c, Claudin 3, and ZO-1 (P < 0.05), and improved Claudin 15 expression in the fish intestine (P < 0.05). However, valine did not have a significant effect on expression of Claudin 12 in the intestine of grass carp (P > 0.05). In conclusion, valine deficiency decreased fish growth and intestinal immune status, as well as regulated gene expression of tight junction proteins, NF-κB P65, IκBα and TOR in the fish intestine. Based on the quadratic regression analysis of lysozyme activity or PWG, the dietary valine requirement of young grass carp (268-679 g) were established to be 14.47 g kg(-1) diet (4.82 g 100 g(-1) CP) or 14.00 g kg(-1) diet (4.77 g 100 g(-1) CP), respectively. PMID:25014314

  20. [Physiopathology of iodine deficiency].

    PubMed

    Pinchera, A; Rago, T; Vitti, P

    1998-01-01

    The process of goitrogenesis is likely to be the consequence of an increased TSH stimulation linked to an initial reduction of circulating thyroid hormone caused by iodine deficiency (ID). Other growth factors associated to TSH may have a role in the pathogenesis of goiter. Natural history of goiter is the evolution towards nodularity and functional autonomy. This phenomenon is due to the heterogeneity of thyroid follicular cells, some of which, with an intrinsic elevated growth rate, under the stimulation of ID progress to nodule formation and hyperfunction. In multinodular goiter TSH receptor mutations activating adenylate cyclase-cAMP pathway were found. In a recent epidemiological survey it was shown that nodular goiter increased with the age, being about 1% in schoolchildren and 23% in the adults (56-75 years). Also nodular autonomy and hyperthyroidism were more frequent in the 36-75 year age group. Severe ID is also cause of endemic cretinism. In Europe minor neuropsychological impairments and cognitive deficits were described in areas of moderate ID. The exposure to a mild ID during fetal life causes minor neuropsychological damage. In conclusion, ID is responsible of goiter and its evolution towards nodularity and functional autonomy. Severe ID is also cause of endemic cretinism, while cognitive deficits and minor neuropsychological impairments were found in mild to moderate ID. PMID:10052165

  1. Zinc: physiology, deficiency, and parenteral nutrition.

    PubMed

    Livingstone, Callum

    2015-06-01

    The essential trace element zinc (Zn) has a large number of physiologic roles, in particular being required for growth and functioning of the immune system. Adaptive mechanisms enable the body to maintain normal total body Zn status over a wide range of intakes, but deficiency can occur because of reduced absorption or increased gastrointestinal losses. Deficiency impairs physiologic processes, leading to clinical consequences that include failure to thrive, skin rash, and impaired wound healing. Mild deficiency that is not clinically overt may still cause nonspecific consequences, such as susceptibility to infection and poor growth. The plasma Zn concentration has poor sensitivity and specificity as a test of deficiency. Consequently, diagnosis of deficiency requires a combination of clinical assessment and biochemical tests. Patients receiving parenteral nutrition (PN) are susceptible to Zn deficiency and its consequences. Nutrition support teams should have a strategy for assessing Zn status and optimizing this by appropriate supplementation. Nutrition guidelines recommend generous Zn provision from the start of PN. This review covers the physiology of Zn, the consequences of its deficiency, and the assessment of its status, before discussing its role in PN. PMID:25681484

  2. Nature and nurture in vitamin B12 deficiency.

    PubMed

    Zschocke, J; Schindler, S; Hoffmann, G F; Albani, M

    2002-07-01

    We report on a child in whom severe nutritional vitamin B12 deficiency was exacerbated by a genetic impairment of the folate cycle, causing reduced CSF concentrations of the methyl group donor 5-methyltetrahydrofolate. Some patients with vitamin B12 deficiency may benefit from high dose folic acid supplementation, even if plasma concentrations are high. PMID:12089131

  3. Iodine Deficiency in Australia: Be Alarmed. Opinions & Perspectives

    ERIC Educational Resources Information Center

    McElduff, Aidan; Beange, Helen

    2004-01-01

    Iodine deficiency, the leading preventable cause of intellectual impairment in the world (World Health Organization, 1999), has reappeared in Australia. Recently, we identified the re-emergence of iodine deficiency in Sydney (Gunton, Hams, Fiegert & McElduff, 1999). This has been confirmed locally (Li, Ma, Boyages & Eastman, 2001) and…

  4. Chronic zinc deficiency alters chick gut microbiota composition and function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc (Zn) deficiency is a prevalent micronutrient insufficiency. Although the gut is a vital organ for Zn utilization, and Zn deficiency is associated with impaired intestinal permeability and a global decrease in gastrointestinal health, alterations in the gut microbial ecology of the host under co...

  5. Hearing Impairments

    NASA Astrophysics Data System (ADS)

    Cavender, Anna; Ladner, Richard E.

    For many people with hearing impairments, the degree of hearing loss is only a small aspect of their disability and does not necessarily determine the types of accessibility solutions or accommodations that may be required. For some people, the ability to adjust the audio volume may be sufficient. For others, translation to a signed language may be more appropriate. For still others, access to text alternatives may be the best solution. Because of these differences, it is important for researchers in Web accessibility to understand that people with hearing impairmen