Thioredoxin and Endothelial Cell Function

硫氧还蛋白和内皮细胞功能

• 批准号: 7676147
• 负责人: WANG MIN
• 金额: $ 41.38万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7676147
• 关键词: Antioxidants; Aorta; Apolipoprotein E; Apoptosis; Apoptotic; Arterial Fatty Streak; Arteries; Atherosclerosis; Binding; Biochemistry; Biological Availability; Blood Vessels; Blood flow; Breeding; Catalytic Domain; Cause of Death; Cell physiology; Cells; Cessation of life; Complex; Coronary artery; Data; Development; Embryo; Endothelial Cells; Endothelium; Environment; Enzymes; Figs - dietary; Fluorescence Resonance Energy Transfer; Fractionation; Functional disorder; Generations; Genetic; Hydrogen Peroxide; In Vitro; Inflammation; Inflammatory; Knock-out; Knockout Mice; Lead; MAP3K5 gene; Mediating; Mediator of activation protein; Mitochondria; Mus; Myocardial Infarction; Organelles; Oxidases; Oxidation-Reduction; Oxidative Stress; Oxidoreductase; Pathway interactions; Patients; Peroxidases; Plasma; Play; Process; Production; Proteins; Reactive Oxygen Species; Regulation; Role; Signal Transduction; Stimulus; Stress; Superoxide Dismutase; Superoxides; System; TNF gene; Testing; Thioredoxin; Transgenic Mice; Transgenic Organisms; United States; Vascular Endothelium; Vasodilation; Viral Vector; Work; base; catalase; cellular targeting; cytokine; improved; in vivo; in vivo Model; mouse model; mutant; novel therapeutic intervention; overexpression; oxidation; prevent; protective effect; protein protein interaction; response

DESCRIPTION (provided by applicant): Myocardial infarction due to atherosclerosis of coronary arteries remains the leading cause of death in the United States. It has become clear that changes of cellular/systemic redox state, resulting in increases in inflammation (e.g., TNF) and reactive oxygen species (ROS), represent a common pathogenic mechanism for atherosclerosis. The vascular cell that primarily limits the inflammatory and atherosclerotic process is the endothelial cell (EC). ROS-induced reduction in NO bioavailability and increase of EC apoptosis results in a proatherogenic state. Increasing evidence supports that ROS generated from mitochondria in vasculature significantly contribute to EC dysfunction and atherosclerotic progression. Furthermore, recent data suggest that mitochondria normally produce the strongest reducing environment among all cellular organelles, and mitochondria are especially vulnerable to oxidation in response to stress stimuli including proinflammatory cytokines. A key system regulating mitochondria redox is mitochondria-specific thioredoxin (Trx2) system, consisting of Trx2, Trx2 reductase (TrxR2) and Trx2-depndent peroxidase (Prx3). Little is known for the role of mitochondrial Trx2 system in vasculature. Our data suggest that mitochondrial Trx2 may play critical roles in maintaining mitochondria reduced state, preventing ROS-induced EC dysfunction. Specifically, we have used both EC-specific transgenic and knockout mice, and demonstrated a critical role of Trx2 in regulating endothelium functions by increasing NO bioactivity. We also show that Trx2 inhibits the activity of proapoptotic protein kinase ASK1 through protein-protein interactions, protecting EC from TNF and ROS- induced apoptosis. We propose that Trx2 prevents ROS-induced EC dysfunction through two distinct and cooperative pathways: Trx2 maintains a reduced state of mitochondria in EC, reducing ROS generation leading and increasing NO bioactivity; Trx2 protects ROS-induced EC apoptosis by directly binding to ASK1. We further hypothesize that increased NO bioactivity and decreased apoptotic responses prevent EC dysfunction and atherosclerotic development. To explore these hypotheses, we propose the following specific aims: 1) Determine the mechanisms by which Trx2 preserves NO bioactivity and EC function. 2) Determine the mechanisms by which Trx2 inhibits mitochondrial ASK1-mediated apoptosis. 3) Determine the role of Trx2 in preventing EC dysfunction and atherosclerosis development/progression in a mouse model. This proposal uses both in vitro and in vivo models to determine the roles of Trx2 in protection against ROS- induced EC dysfunction and atherosclerosis development/progression. These studies, if successful, will facilitate the development of new therapeutic approaches to control atherosclerosis progression and myocardial infarction. Project Narrative: Myocardial infarction due to narrowing of arteries manifesting as decreased blood flow remains the leading cause of death in the United States. We will study the effects of a antioxidant protein thioredoxin, on vascular endothelium. Our work may lead to better tests and treatments for atherosclerosis patients.

描述（由申请人提供）：冠状动脉粥样硬化引起的心肌梗塞仍然是美国的首要死因。很明显，细胞/全身氧化还原状态的变化导致炎症（例如 TNF）和活性氧（ROS）的增加，代表了动脉粥样硬化的常见致病机制。主要限制炎症和动脉粥样硬化过程的血管细胞是内皮细胞（EC）。 ROS 诱导的 NO 生物利用度降低和 EC 细胞凋亡增加导致促动脉粥样硬化状态。越来越多的证据表明，脉管系统中线粒体产生的 ROS 显着导致 EC 功能障碍和动脉粥样硬化进展。此外，最近的数据表明，线粒体通常会在所有细胞器中产生最强的还原环境，并且线粒体特别容易因应激刺激（包括促炎细胞因子）而被氧化。调节线粒体氧化还原的关键系统是线粒体特异性硫氧还蛋白（Trx2）系统，由Trx2、Trx2还原酶（TrxR2）和Trx2依赖的过氧化物酶（Prx3）组成。对于线粒体 Trx2 系统在脉管系统中的作用知之甚少。我们的数据表明线粒体 Trx2 可能在维持线粒体还原状态、防止 ROS 诱导的 EC 功能障碍方面发挥关键作用。具体来说，我们使用了 EC 特异性转基因和基因敲除小鼠，并证明了 Trx2 通过增加 NO 生物活性来调节内皮功能的关键作用。我们还表明，Trx2 通过蛋白质-蛋白质相互作用抑制促凋亡蛋白激酶 ASK1 的活性，保护 EC 免受 TNF 和 ROS 诱导的细胞凋亡。我们认为Trx2通过两种不同且协同的途径来预防ROS诱导的EC功能障碍：Trx2维持EC中线粒体的还原状态，减少ROS的产生并增加NO的生物活性； Trx2 通过直接结合 ASK1 来保护 ROS 诱导的 EC 细胞凋亡。我们进一步假设，NO 生物活性的增加和细胞凋亡反应的减少可以防止 EC 功能障碍和动脉粥样硬化的发展。为了探索这些假设，我们提出以下具体目标：1）确定 Trx2 保留 NO 生物活性和 EC 功能的机制。 2)确定Trx2抑制线粒体ASK1介导的细胞凋亡的机制。 3) 确定 Trx2 在预防小鼠模型中 EC 功能障碍和动脉粥样硬化发展/进展中的作用。该提案使用体外和体内模型来确定 Trx2 在防止 ROS 诱导的 EC 功能障碍和动脉粥样硬化发展/进展中的作用。这些研究如果成功，将有助于开发新的治疗方法来控制动脉粥样硬化进展和心肌梗塞。项目叙述：由于动脉狭窄（表现为血流量减少）引起的心肌梗塞仍然是美国的主要原因。我们将研究抗氧化蛋白硫氧还蛋白对血管内皮的影响。我们的工作可能会为动脉粥样硬化患者带来更好的测试和治疗。