Mitochondrial Modulation of Endothelial Phenotype

血管内皮细胞是正常血管内稳态的重要组成部分。众所周知，正常的 动脉粥样硬化及其危险因素如血管内皮细胞功能紊乱 高胆固醇血症、糖尿病和高血压。这可能是多种机制造成的损害 内皮功能，然而，氧化应激以产生活性氧物种(ROS)的形式出现 尤其重要的是。现在人们也普遍认识到，ROS作为信号分子参与了 血管损伤反应，但在动脉粥样硬化中，ROS信号变得失调，并参与 内皮功能障碍。尽管如此，内皮细胞中ROS信号的机制仍然存在 默默无闻。这一建议是基于一个中心假设，即线粒体是一种重要的 氧化还原敏感信号的组成部分，因此是内皮细胞的关键决定因素 细胞表型。因此，这项应用的目的是确定线粒体在 调节内皮细胞表型并阐明其作用机制。为了实现这一目标，我们 首先，我们将对内皮细胞表型如何调节线粒体功能进行详细研究 如质子动力(Delta-MuH+)、线粒体ROS和解偶联蛋白的表达。使用这个 我们开发的知识和试剂，然后我们将操纵特定的线粒体功能(Delta-MuH+， UCPs)，并确定对内皮功能的影响，已知涉及 ROS，如一氧化氮生物活性、细胞增殖和迁移、黏附分子表达等。 由于细胞不能完美地模拟活体内的事件，我们还将使用 我们将UCP-2基因缺失的小鼠和可诱导内皮细胞特异性过度表达的UCP-2小鼠进行比较。 然后，我们将继续确定体内UCP-2操纵内皮细胞表型的意义 静息状态和对动脉损伤形式的应激反应。成功完成这些研究 将提供氧化还原介导的内皮细胞表型调控的机制信息，并为我们提供 为设计新的治疗策略提供必要的洞察力，重点是改善血管内稳态 动脉粥样硬化的背景及其危险因素。

The endothelium is an important component of normal vascular homeostasis. It is known that normal endothelial function is disturbed in the setting of atherosclerosis and its risk factors such as hypercholesterolemia, diabetes, and hypertension. It is likely that multiple mechanisms contribute to impaired endothelial function, however, oxidant stress in the form of reactive oxygen species (ROS) production appear particularly important. It is also now widely appreciated that ROS act as signaling molecules that contribute to the vascular injury response, but in atherosclerosis ROS signaling becomes dysregulated and contributes to endothelial dysfunction. Despite this knowledge, the mechanisms of ROS signaling in the endothelium remain obscure. This proposal is based upon the central hypothesis that mitochondria are an important component of redox-sensitive signaling and, as a consequence, are a key determinant of endothelial cell phenotype. The objective of this application, therefore, is to determine the role of the mitochondrion in modulating endothelial cell phenotype and elucidate any operative mechanisms. To accomplish this goal, we first will undertake a detailed examination of how endothelial cell phenotype modulates mitochondrial functions such as protonmotive force (delta-muH+), mitochondrial ROS, and uncoupling protein expression. Using this knowledge and reagents we have developed, we will then manipulate specific mitochondrial functions (delta-muH+, UCPs) in cultured endothelial cells and determine the implications for endothelial functions known to involve ROS, such as nitric oxide bioactivity, cell proliferation and migration, and adhesion molecule expression. Because cells imperfectly model events in vivo, we will also manipulate mitochondrial function in vivo using UCP-2 null mice and mice we will develop with inducible endothelial cell-specific over-expression of UCP-2. We will then go on to determine the implications of UCP-2 manipulation endothelial phenotype in vivo both in the resting state and in response to stress in the form of arterial injury. Successful completion of these studies will provide mechanistic information on redox-mediated control of endothelial cell phenotype and afford us the necessary insight to design new therapeutic strategies that focus on improving vascular homeostasis in the setting of atherosclerosis and its risk factors.