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，长期接触三价砷（As III）会导致心血管疾病。在人类肝脏中，As (III) 促进血管重塑、门静脉纤维化和高血压，但这些 As III 诱导的血管变化的分子病理生理学尚不清楚。一般来说，As III 诱发的血管疾病的发病机制尚未得到充分研究，部分原因是缺乏对慢性低剂量 As III 效应敏感的相关动物模型。我们的初步结果表明，完整成年小鼠的饮用水中暴露于低至 10 ppb 的 As III 会导致肝窦内皮 (LSEC) 开窗和毛细血管化。此外，我们还表明，鼠或人 LSEC 的原代短期培养物有助于揭示 As (III) 刺激的 NADPH 氧化酶 (NOX) 生成活性氧在影响表型的早期信号事件（例如开窗）中的功能作用这个重要的靶细胞。本研究的目的是利用这些体内和离体模型来研究 As (III) 启动 LSEC 重塑的机制以及 As (III) 诱导的血管疾病的分子病理学。这些研究的总体假设表明，As (III) 在 g 蛋白偶联细胞信号传导水平上发挥作用，促进 NOX 氧化剂的生成，从而破坏 LSEC 开窗的维持和毛细血管化的抑制。因此，本提案的具体目标是确定： I. As (III) 在完整小鼠中引起肝窦毛细血管化和重塑的分子机制。野生型和 NOX 缺陷 (p47phox -/-) 小鼠将暴露于 As (III) (10-50 ppb) 2 周，并对 SEC 开窗和毛细血管化的形态测定（光和电子显微镜水平）决定因素进行量化。药理学（针对血管内皮细胞生长因子受体或百日咳毒素的抗体）修饰小鼠将用于评估 VEGF 受体和 Gi 蛋白相关信号传导对 As III 诱导的血管变化的贡献。二. NOX 产生的超氧化物在介导 As III 诱导的原代小鼠和人类 LSEC 表型转化中的作用。从人肝脏或野生型和 p47phox -/- 小鼠中分离的 LSEC 将离体暴露于 As (III)，以证明活性氧和氮物质生成的不平衡介导 VEGF 受体的 AsIII 失调维持 LSEC 开窗的机制。三．如果 LSEC GT Pase 活性不平衡介导 As (III) 刺激的 LSEC 重塑。 RhoA 或 Rac1-GTPase siRNA 的靶向递送和选择性 GT Pase 活性测定将用于剖析 Rho 家族成员在 As (III) 刺激的 LSEC 毛细血管化中的作用。