Mechanisms for Arsenic-Induced Vascular Disease

砷诱发血管疾病的机制

基本信息

批准号：
7363862
负责人：
Aaron Barchowsky
金额：
$ 32.82万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-12-14 至 2012-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7363862
关键词：
Adult Affect Age Animal Model Antibodies Antioxidants Arsenic Atherosclerosis Biological Assay Blood Vessels CD31 Antigens Cardiac Cardiovascular Diseases Cardiovascular system Cells Chemoprevention Chronic Coupled Diabetes Mellitus Discontinuous Capillary Disease Dose Electrons Endothelial Cells Endothelium Equilibrium Event Exposure to Family member Fibrosis Functional disorder Generations Genetic Models Glucose Guanosine Triphosphate Phosphohydrolases Health Hepatic Human Hypertension Knowledge Labyrinth fenestration Light Link Lipids Liver Liver Fibrosis Maintenance Measures Mediating Microelectrodes Microscopic Modeling Molecular Monoclonal Antibodies Mus NADPH Oxidase Nitrogen Nutrient Oxidants Oxygen Pathogenesis Pathway interactions Peripheral Personal Satisfaction Pertussis Toxin Phenotype Porosity Portal Hypertension Proteins Public Health Publishing Reactive Oxygen Species Regulation Risk Role Signal Transduction Small Interfering RNA Stress Vascular Diseases Vascular Endothelial Growth Factor Receptor Vascular Endothelial Growth Factors Vascular remodeling Vascularization Week atherogenesis drinking water in vivo inhibitor/antagonist laminin-1 link protein liver metabolism molecular pathology novel receptor function response rho sensor superoxide-generating NADPH oxidase targeted delivery tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): Chronic exposure to trivalent arsenic (As III) is well known to cause cardiovascular diseases. In the human liver, As (III) promotes vascular remodeling, portal fibrosis, and hypertension, but the molecular pathophysiology of these As III-induced vascular changes is unknown. In general, the pathogenesis of As III induced vascular diseases has been understudied, in part, due to a lack of relevant animal models sensitive to chronic low dose As III effects. Our preliminary results show that exposure of intact adult mice to as low as 10 ppb of As III in their drinking water caused defenestration and capillarization of liver sinusoidal endothelium (LSEC). Furthermore, we also show that primary, short term cultures of murine or human LSEC are useful in revealing functional roles for As (III)-stimulated NADPH oxidase (NOX) generation of reactive oxygen species in the early signaling events affecting phenotype (e.g. fenestration) of this important target cell. The objective of the proposed studies is to use these in vivo and ex vivo models to investigate the mechanisms through which As (III) initiates LSEC remodeling and the molecular pathology of As (III)-induced vascular diseases. The global hypothesis for these studies states that As (III) acts at the level of g-protein coupled cell signaling to promote NOX oxidant generation that disrupts maintenance of LSEC fenestrations and suppression of capillarization. Accordingly, the specific aims of this proposal are to determine: I. the molecular mechanism by which As (III) causes liver sinusoidal capillarization and remodeling in intact mice. Wildtype and NOX deficient (p47phox -/-) mice will be exposed to As (III) (10-50 ppb) for 2 weeks and morphometric (light and electron microscopic level) determinants of SEC defenestration and capillarization will be quantified. Pharmacologically (antibodies to vascular endothelial cell growth factor receptor or Pertussis toxin) modified mice will be used to assess the contribution VEGF receptor and Gi-protein linked signaling to As III-induced vascular changes. II. the role of NOX generated superoxide in mediating As III-induced phenotypic conversion of primary murine and human LSEC. LSEC isolated from human liver or wildtype and p47phox -/- mice will be exposed to As (III) ex vivo to demonstrate mechanisms through which an imbalance of reactive oxygen and nitrogen species generation mediates AsIII-dysregulation of VEGF receptor maintained LSEC fenestration. III. if an imbalance in LSEC GT Pase activity mediates As (III) stimulated remodeling of the LSEC. Targeted delivery of RhoA or Rac1-GTPase siRNA and selective GT Pase activity assays will be used to dissect the roles of Rho family members in As (III)-stimulated LSEC capillarization.

描述（由申请人提供）：众所周知，长期暴露于三价砷（AS III）会引起心血管疾病。在人肝脏中，AS（III）促进了血管重塑，门户纤维化和高血压，但是这些分子病理生理学作为III诱导的血管变化尚不清楚。通常，AS III诱导的血管疾病的发病机理部分研究了，部分原因是缺乏对慢性低剂量为III效应的相关动物模型。我们的初步结果表明，完整的成年小鼠在饮用水中暴露于10 ppb的AS III低至10 ppb，导致肝窦内皮（LSEC）的分裂和毛细管化。此外，我们还表明，鼠或人LSEC的一级短期培养物可用于揭示AS（III）刺激的NADPH氧化酶（NOX）在早期信号事件中产生活性氧的功能作用，从而影响了该重要靶细胞的表型（例如，f膜片）。拟议的研究的目的是使用这些体内和离体模型来研究（III）启动LSEC重塑和AS（III）诱导的血管疾病的分子病理的机制。这些研究的全球假设指出，AS（iii）作用于G蛋白偶联细胞信号传导水平，以促进NOX氧化剂产生，从而破坏LSEC燃烧的维持和抑制毛细管化。因此，该提案的具体目的是确定：I。（III）在完整小鼠中引起肝正正弦毛细管和重塑的分子机制。野生型和NOX缺乏（P47phox - / - ）小鼠将暴露于AS（iii）（10-50 ppb）2周，并且将量化SEC脱肌和毛细管化的形态计量学（光和电子显微镜水平）的决定因素。在药理学上（对血管内皮细胞生长因子受体或百日咳毒素的抗体）修饰的小鼠将用于评估贡献VEGF受体和GI-蛋白链接的信号传导与III诱导的血管变化。 ii。 NOX的作用在III诱导的原代鼠和人LSEC的表型转化中产生了超氧化物。从人肝脏或野生型和p47phox - / - 小鼠中分离出的LSEC将暴露于（iii）离体以证明机制，通过这种机制，通过这种机制，反应性氧和氮物种产生的失衡会介导vegf受体维持Lsec Fenestration的ASIII-dyiatiatiation。 iii。如果LSEC GT PASE活性的失衡会介导（III）刺激LSEC的重塑。靶向递送RHOA或RAC1-GTPase siRNA和选择性GT PASE活性测定将用于剖析AS（III）刺激的LSEC毛细管化中Rho家族成员的作用。