Thioredoxin and Endothelial Cell Function

硫氧还蛋白和内皮细胞功能

• 批准号: 7530934
• 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/7530934
• 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; NAD(P)H oxidase; Organelles; Oxidation-Reduction; Oxidative Stress; Oxidoreductase; Pathway interactions; Patients; Peroxidase; Peroxidases; Plasma; Play; Process; Production; Protein Overexpression; 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 therapeutics; 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）：由于冠状动脉动脉动脉粥样硬化引起的心肌梗塞仍然是美国死亡的主要原因。很明显，细胞/全身氧化还原状态的变化导致炎症增加（例如TNF）和活性氧（ROS），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诱导的无生物利用度和EC凋亡增加的降低导致促进质量。越来越多的证据支持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，线粒体通常在所有细胞细胞器中产生最强的还原环境，而线粒体尤其容易受到氧化的影响，以响应包括促炎细胞因子在内的胁迫刺激。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，该系统由TRX2，TRX2还原酶（TRXR2）和TRX2-DEPNDENT过氧化物酶（PRX3）组成。线粒体TRX2系统在脉管系统中的作用鲜为人知。我们的数据表明，线粒体TRX2在维持线粒体降低状态方面可能起关键作用，从而阻止ROS诱导的EC功能障碍。具体而言，我们同时使用了EC特异性的转基因和基因敲除小鼠，并通过提高无生物活性来证明TRX2在调节内皮功能中的关键作用。我们还表明，TRX2通过蛋白质 - 蛋白质相互作用抑制了促凋亡蛋白激酶ASK1的活性，从而保护EC免受TNF和ROS诱导的凋亡。我们建议TRX2通过两种不同的合作途径来防止ROS诱导的EC功能障碍：TRX2在EC中保持了线粒体的降低，从而降低了ROS的产生，并且没有生物活性。 TRX2通过直接与Ask1结合来保护ROS诱导的EC凋亡。我们进一步假设，没有增加生物活性和降低凋亡反应会阻止EC功能障碍和动脉粥样硬化发育。为了探索这些假设，我们提出以下特定目的：1）确定TRX2保持不保留生物活性和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在小鼠模型中预防EC功能障碍和动脉粥样硬化发育/进展中的作用。该建议同时使用体外和体内模型来确定TRX2在防止诱导的EC功能障碍和动脉粥样硬化发育/进展中的作用。这些研究，如果成功的话，将有助于开发新的治疗方法，以控制动脉粥样硬化进展和心肌梗死。项目叙述：由于血流减少而表现出的动脉狭窄导致的心肌梗塞仍然是美国死亡的主要原因。我们将研究抗氧化剂蛋白硫氧还蛋白对血管内皮的影响。我们的工作可能会导致对动脉粥样硬化患者的更好的测试和治疗。