The role of mitochondrial protein thiol modification in endothelial dysfunction

描述（由申请人提供）：现在出现的peption作为一个网站在血管细胞能够调节细胞质中的氧化还原细胞信号事件。这种情况发生的机制尚不清楚，这是本建议的重点。我们最近的研究表明，通过Keap 1/Nrf-2系统诱导内源性细胞内抗氧化剂是由线粒体蛋白巯基的翻译后修饰调节的。这一点很重要，因为已知血管系统中内源性抗氧化蛋白（如血红素加氧酶-1）的缺乏与动脉粥样硬化病变的发展增加相关，而过度表达具有保护作用。有趣的是，我们已经表明，线粒体蛋白硫醇修饰导致内皮细胞功能障碍的内源性抗氧化剂途径的抑制。此外，线粒体巯基修饰导致响应于乙酰胆碱的主动脉环的内皮依赖性血管舒张的衰减。我们的初步数据还表明，线粒体巯基修饰导致生物能途径从线粒体氧化磷酸化向效率较低的糖酵解途径转变，可能导致生物能缺乏。总之，这些发现导致了这样的假设，即线粒体蛋白巯基和氧化还原状态的调节将改变血管内皮细胞功能。这将通过追求以下具体目标来测试：1：确定线粒体蛋白硫醇和氧化还原状态在内皮细胞（EC）对氧化应激的易感性中的作用; 2：确定线粒体硫醇修饰和改变的氧化还原状态在血管内皮功能障碍中的作用;以及3：确定动脉粥样硬化小鼠模型中线粒体氧化应激增加期间线粒体蛋白巯基修饰在内皮细胞功能障碍中的机制作用。从这些特定目标的实现中获得的信息将使我们深入了解线粒体，特别是线粒体蛋白硫醇，在确定与动脉粥样硬化相关的内皮细胞功能障碍中的作用。 公共卫生相关性：氧化损伤是炎症相关疾病发展的早期事件。细胞中的线粒体通常是氧化损伤的目标，并且这种损伤的一些最敏感的位点是含有反应性蛋白硫醇的蛋白质上的氨基酸残基。该项目测试了线粒体蛋白硫醇在动脉粥样硬化中受损并导致血管功能障碍的假设。

DESCRIPTION (provided by applicant): The mitochondrion is now emerging as a site in vascular cells capable of regulating redox cell signaling events in the cytosol. The mechanisms through which this occurs are not well understood and are the focus of this proposal. Our recent studies suggest that the induction of the endogenous intracellular antioxidants through the Keap1/Nrf-2 system is modulated by post-translational modification of mitochondrial protein thiols. This is important because it is known that deficiencies of endogenous antioxidant proteins, such as heme oxygenase-1, in the vasculature are associated with increased development of atherosclerotic lesions, while over-expression is protective. Interestingly, we have shown that modification of mitochondrial protein thiols leads to endothelial cell dysfunction by inhibition of the endogenous antioxidant pathway. In addition, mitochondrial thiol modification results in the attenuation of the endothelium-dependent vasorelaxation of aortic rings in response to acetylcholine. Our preliminary data also demonstrate that mitochondrial thiol modification causes a switch in bioenergetic pathways away from mitochondrial oxidative phosphorylation and toward the less efficient glycolytic pathway, potentially contributing to a bioenergetic deficiency. Taken together these findings have led to the hypothesis that modulation of mitochondrial protein thiol and redox status will alter vascular endothelial cell function. This will be tested by pursuit of the following specific aims: 1: Determine the role of mitochondrial protein thiols and redox status in the susceptibility of endothelial cells (EC) to oxidative stress; 2: Determine the role of mitochondrial thiol modification and altered redox status in vascular endothelial dysfunction; and 3: Determine the mechanistic role of mitochondrial protein thiol modification in endothelial cell dysfunction during increased mitochondrial oxidative stress in atherosclerotic mouse models. The information gained from the accomplishment of these specific aims will give insight into the role of the mitochondrion, particularly mitochondrial protein thiols, in determining endothelial cell dysfunction associated with atherosclerosis. PUBLIC HEALTH RELEVANCE: Oxidative damage is an early event in the development of diseases associated with inflammation. Mitochondria are in cells are often a target for oxidative damage, and some of the most sensitive sites for this damage are the amino acid residues on proteins that contain reactive protein thiols. This project tests the hypothesis that mitochondrial protein thiols are damaged in atherosclerosis and contribute to vascular dysfunction.