In Vivo Mechanisms of Vascular Dysfunction in Obesity with Insulin Resistance

肥胖伴胰岛素抵抗导致血管功能障碍的体内机制

基本信息

批准号：
8018461
负责人：
Rosario G Scalia
金额：
$ 31.86万
依托单位：
TEMPLE UNIV OF THE COMMONWEALTH
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-09-30 至 2014-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8018461
关键词：
Affect American Heart Association Angiotensin II Angiotensin II Receptor Animal Model Anti-Inflammatory Agents Antisense DNA Applications Grants Atherosclerosis Attenuated Binding Biochemistry Biological Markers Blood Pressure Blood Vessels Calcium Calpain Cardiovascular Diseases Cardiovascular system Cell Adhesion Molecules Cells Data Development Diabetic Angiopathies Direct Costs Disease Dose E-Selectin Electrodes Electrophoretic Mobility Shift Assay Endothelial Cells Endothelium Expectancy Facilities and Administrative Costs Functional disorder Funding Goals Health Human Hyperglycemia Immunofluorescence Immunologic Immunohistochemistry In Vitro Incidence Inflammatory Injury Insulin Resistance Intercellular adhesion molecule 1 Knockout Mice Knowledge Laboratories Laboratory Study Leukocytes Link Literature Measurement Measures Mediating Mediator of activation protein Metabolic syndrome Microscopy Molecular Molecular Target Monoclonal Antibodies Mus Nitric Oxide Obesity Obesity associated cardiovascular disease Organ Peptide Hydrolases Peroxidases Pharmaceutical Preparations Phosphotransferases Physiology Play Population Process Quality of life Rattus Receptor, Angiotensin, Type 1 Renin-Angiotensin System Research Reverse Transcriptase Polymerase Chain Reaction Rodent Role Signal Pathway Signal Transduction Superoxides System Techniques Technology Therapeutic Therapeutic Intervention Tissues United States Up-Regulation Vascular Cell Adhesion Molecule-1 Vascular Diseases Vascular Endothelium Western Blotting Work cost effective design economic cost economic implication fighting improved in vivo inhibitor/antagonist intravital microscopy leukocyte activation neutrophil novel novel therapeutics pandemic disease prevent public health relevance receptor response social implication stem tool vascular inflammation

项目摘要

DESCRIPTION (provided by applicant): This grant proposal is designed to study novel cellular and molecular mechanisms of vascular dysfunction in obesity with insulin resistance, two major components of the metabolic syndrome. Specifically, we will study the role that the calcium-dependent protease calpain plays in the inflammatory signaling of angiotensin II (AngII), and in the tissue protective action of AngII receptor blocking therapy in vivo. Our main hypothesis is that in states of obesity-associated insulin resistance, elevated AngII signaling synergizes with neutrophil-derived myeloperoxidase (MPO) to cause vascular dysfunction via activation of calpain in the vascular endothelium. The results of the integrative studies proposed here may uncover novel mechanisms of vascular complications in the metabolic syndrome. They will also provide an in depth understanding of the pleiotropic actions of AngII receptor blocking therapy in such disease state. Evidence has been accumulating in the literature to indicate that AngII, the key effector of the renin- angiotensin system (RAS), induces vascular inflammation, and that obesity-associated insulin resistance upregulates the RAS and AngII signaling. Despite intense research, the cellular and molecular mechanisms of the inflammatory action of AngII remain largely unknown, which limits therapeutic interventions in the ever-growing obese, insulin resistant U.S. population. Recently, our laboratory has found evidence of increased calpain activity with endothelial dysfunction and leukocyte activation in obese, insulin resistant laboratory rodents. Others have now linked the calpain system to the metabolic syndrome in humans. Preliminary data provided in the present application demonstrate a role for calpain in the inflammatory signaling of AngII, which gives rise to several, unresolved scientific questions. The answering of such questions will ultimately allow us to develop new, effective therapeutic tools to fight vascular disease in humans. To implement this research we will use the Zucker Obese rat, a relevant animal model of obesity-associated insulin resistance, and selected knockout mouse technology. In vivo studies will clarify whether (1) inhibition of AngII signaling prevents calpain activation and actions in the vascular endothelium; (2) circulating neutrophils are mechanistically important to sustain endothelial calpain activation in response to AngII; (3) neutrophil-derived MPO is a key molecular determinant of the AngII/calpain inflammatory signaling cascade; (4) IkB/NFkB plays a mechanistic role in the endothelial dysfunction of calpain. We will utilize the following biochemistry and physiology techniques: western blot analysis, immunohistochemistry and immunofluorescence, quantitative reverse transcriptase-polymerase chain reaction, antisense DNA technology, cells and tissue isolation techniques, intravital microscopy, in vivo measurements of nitric oxide and superoxide. We expect that the results of our research will improve the life quality and expectancy of the obese, insulin resistant U.S. population, in addition to lowering the overall economic cost of managing cardiovascular complications. PUBLIC HEALTH RELEVANCE: The research proposed in this application intends to provide new biological markers and therapeutic strategies to fight the vascular complications of obesity and insulin resistance. According to the American Heart Association, cardiovascular disease (CDV) remains the No. 1 killer in the United States. The estimated direct and indirect cost of CVD for 2006 is $403.1 billion. We have identified a novel signaling pathway, the calpain system, which helps explain a) how angiotensin II damage the vasculature of body organs, and b) why medications that block the renin-angiotensin system protect the cardiovascular system. We expect that the results of our research will improve life quality and expectancy of the obese, insulin resistant U.S. population, in addition to lowering the overall economic cost of managing cardiovascular disease.

描述（由申请人提供）：本拨款提案旨在研究肥胖伴胰岛素抵抗（代谢综合征的两个主要组成部分）血管功能障碍的新细胞和分子机制。具体来说，我们将研究钙依赖性蛋白酶钙蛋白酶在血管紧张素 II (AngII) 炎症信号传导中的作用，以及在体内 AngII 受体阻断疗法的组织保护作用中的作用。我们的主要假设是，在肥胖相关的胰岛素抵抗状态下，升高的 AngII 信号传导与中性粒细胞衍生的髓过氧化物酶 (MPO) 协同作用，通过激活血管内皮中的钙蛋白酶而导致血管功能障碍。这里提出的综合研究的结果可能会揭示代谢综合征血管并发症的新机制。他们还将深入了解 AngII 受体阻断疗法在此类疾病状态下的多效作用。文献中越来越多的证据表明，肾素-血管紧张素系统 (RAS) 的关键效应物 AngII 会诱导血管炎症，而肥胖相关的胰岛素抵抗会上调 RAS 和 AngII 信号传导。尽管进行了大量研究，但 AngII 炎症作用的细胞和分子机制仍然很大程度上未知，这限制了对日益增长的肥胖、胰岛素抵抗的美国人群的治疗干预。最近，我们的实验室在肥胖、胰岛素抵抗的实验室啮齿动物中发现了钙蛋白酶活性增加、内皮功能障碍和白细胞活化的证据。其他人现在已将钙蛋白酶系统与人类代谢综合征联系起来。本申请中提供的初步数据证明了钙蛋白酶在AngII的炎症信号传导中的作用，这引起了几个未解决的科学问题。这些问题的回答最终将使我们能够开发出新的、有效的治疗工具来对抗人类血管疾病。为了实施这项研究，我们将使用 Zucker 肥胖大鼠（一种与肥胖相关的胰岛素抵抗的相关动物模型）和选定的基因敲除小鼠技术。体内研究将阐明 (1) AngII 信号传导的抑制是否会阻止钙蛋白酶在血管内皮中的激活和作用； (2) 循环中性粒细胞对于维持内皮钙蛋白酶响应 AngII 的激活具有重要的机制； (3) 中性粒细胞来源的 MPO 是 AngII/钙蛋白酶炎症信号级联的关键分子决定因素； (4)IkB/NFkB在钙蛋白酶的内皮功能障碍中发挥机制作用。我们将利用以下生物化学和生理学技术：蛋白质印迹分析、免疫组织化学和免疫荧光、定量逆转录酶-聚合酶链反应、反义DNA技术、细胞和组织分离技术、活体显微镜、一氧化氮和超氧化物的体内测量。我们期望我们的研究结果除了降低管理心血管并发症的总体经济成本之外，还将改善肥胖、胰岛素抵抗的美国人群的生活质量和预期。公共健康相关性：本申请中提出的研究旨在提供新的生物标志物和治疗策略，以对抗肥胖和胰岛素抵抗的血管并发症。据美国心脏协会称，心血管疾病（CDV）仍然是美国第一大杀手。 2006 年 CVD 的直接和间接成本估计为 4031 亿美元。我们发现了一种新的信号传导途径，即钙蛋白酶系统，它有助于解释 a) 血管紧张素 II 如何损害身体器官的脉管系统，以及 b) 为什么阻断肾素-血管紧张素系统的药物可以保护心血管系统。我们期望我们的研究结果除了降低管理心血管疾病的总体经济成本之外，还将改善肥胖、胰岛素抵抗的美国人群的生活质量和预期。