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

• 批准号: 8007471
• 负责人: Rosario G Scalia
• 金额: $ 9.83万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-31 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8007471
• 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; 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; design; economic cost; economic implication; fighting; improved; in vivo; inhibitor/antagonist; intravital microscopy; leukocyte activation; neutrophil; novel; novel therapeutics; pandemic disease; prevent; receptor; response; social; stem; tool; vascular inflammation

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) I?B/NF?B 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. 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.

该拨款提案旨在研究血管功能障碍的新细胞和分子机制 肥胖伴有胰岛素抵抗，这是代谢综合征的两个主要组成部分。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， 以及体内 AngII 受体阻断疗法的组织保护作用。我们的主要假设是在各州 肥胖相关的胰岛素抵抗，升高的 AngII 信号传导与中性粒细胞衍生的髓过氧化物酶协同作用 (MPO) 通过激活血管内皮细胞中的钙蛋白酶引起血管功能障碍。综合结果 这里提出的研究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中的多效作用 疾病状态。文献中不断积累的证据表明，AngII，肾素的关键效应子， 血管紧张素系统（RAS），诱发血管炎症，以及肥胖相关的胰岛素抵抗 上调 RAS 和 AngII 信号传导。尽管进行了大量的研究，但其细胞和分子机制 AngII 的炎症作用仍然很大程度上未知，这限制了不断增长的治疗干预 肥胖、胰岛素抵抗的美国人群。最近，我们的实验室发现了钙蛋白酶活性增加的证据 肥胖、胰岛素抵抗的实验室啮齿动物的内皮功能障碍和白细胞活化。其他人有 现在将钙蛋白酶系统与人类代谢综合征联系起来。目前提供的初步数据 应用证明了钙蛋白酶在 AngII 炎症信号传导中的作用，AngII 产生了几种， 未解决的科学问题。回答这些问题最终将使我们能够开发出新的、有效的 对抗人类血管疾病的治疗工具。为了实施这项研究，我们将使用 Zucker Obese 大鼠，肥胖相关胰岛素抵抗的相关动物模型，以及选定的基因敲除小鼠技术。在 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的激活和作用 血管内皮； (2) 循环中性粒细胞对于维持内皮钙蛋白酶具有重要的机制 响应 AngII 的激活； (3) 中性粒细胞来源的 MPO 是 AngII/钙蛋白酶的关键分子决定因素 炎症信号级联； (4)I?B/NF?B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、体内测量 一氧化氮和超氧化物。我们期望我们的研究成果能够改善人们的生活质量 除了降低总体经济成本外，还可以提高肥胖、胰岛素抵抗的美国人口的预期 管理心血管并发症。本申请提出的研究旨在提供新的生物标志物和治疗方法 对抗肥胖和胰岛素抵抗引起的血管并发症的策略。据《美国之心》报道 协会认为，心血管疾病（CDV）仍然是美国的第一大杀手。预计直接 2006年CVD的间接成本为4031亿美元。 我们已经确定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) 血管紧张素如何 II 损害身体器官的脉管系统，b) 为什么要使用阻断肾素-血管紧张素系统的药物 保护心血管系统。 我们期望我们的研究结果将改善肥胖者的生活质量和预期，胰岛素 除了降低管理心​​血管的总体经济成本之外，还可以提高美国人口的抵抗力 疾病。