Molecular Control of Vascular Function by Oxidant Stress

描述(由申请人提供) 已经很明显的是，各种病理生理状态与血管内活性氧的产生显著增加有关。我们在过去十年的工作表明，膜结合的NAD(P)H氧化酶是这些分子的主要来源。该酶激活的一个主要刺激因素是血管紧张素II，我们发现NAD(P)H氧化酶产生的超氧化物在高血压的发生发展中起着至关重要的作用。在下一个资助期，我们计划寻求与这些基本结果相关的三个新方向。在项目1中，Griendling博士和他的同事将详细研究血管平滑肌NAD(P)H氧化酶如何产生氧自由基和过氧化氢。在过去的资助期间，格里恩德林博士和她的合作者克隆了一类新的NAD(P)H氧化酶亚基，称为NOx蛋白，并证明了NOX1在血管细胞中表达。利用培养细胞和转基因小鼠，将研究NOX1与其他NAD(P)H氧化酶亚基的相互作用，并研究NOX1在体内血管自由基氧产生中的重要性。在项目2中，哈里森博士将研究调节细胞外超氧化物歧化酶(EcSOD)表达的因素。初步数据表明，ECSOD在血管紧张素II对高血压的调节中起着至关重要的作用，在血管氧化应激条件下，该酶的表达增加。哈里森博士将研究在这些情况下导致EcSOD增加的因素，并将研究缺乏EcSOD的小鼠发生高血压加重的机制。泰勒博士是上一个项目的负责人，他此前曾证明，即使在循环中血管紧张素II水平受到抑制的状态下，血管紧张素II也在高血压患者的动脉粥样硬化恶化中发挥了关键作用。泰勒博士将使用转基因“敲入”技术来确定局部产生的血管紧张素II在动脉粥样硬化发病机制中的功能意义。这项工作将是重要的，因为它将提供关于项目1和2中要研究的事件如何在体内病理生理状态下启动的信息。这些项目将得到两个核心的支持，这两个核心将提供检测活性氧物种和相关组织的组织分析方面的专门知识。总体而言，这些研究将促进我们对氧化应激在血管疾病发病机制中的基本分子机制的理解。

DESCRIPTION (provided by applicant) It has become apparent that a variety of pathophysiological states are associated with a marked increase in the vascular production of reactive oxygen species. Our work over the past decade has shown that a membrane bound NAD(P)H oxidase is a predominant source of these molecules. A major stimulus for activation of this enzyme is angiotensin II, and we have found that production of superoxide by the NAD(P)H oxidase is crucial for the development of hypertension in response to this octapeptide. In the next funding period, we plan to pursue three new directions related to these fundamental findings. In project 1, Dr. Griendling and co-workers will examine in detail how the vascular smooth muscle NAD(P)H oxidase functions to produce free radical oxygen- and H2O2. During the past funding period, Dr. Griendling and her collaborators cloned a new class of NAD(P)H oxidase subunits, termed the nox proteins, and have shown that nox1 is expressed in vascular cells. Using both cultured cells and genetically altered mice, the interactions of nox1 with other NAD(P)H oxidase subunits will be investigated and the importance of nox1 for vascular free radical oxygen production in vivo will be examined. In project 2, Dr. Harrison will study factors that modulate expression of the extracellular superoxide dismutase (ecSOD). Preliminary data indicate that the ecSOD plays a crucial role in modulation of hypertension in response to angiotensin II and that the expression of this enzyme is increased in conditions of vascular oxidative stress. Dr. Harrison will examine factors responsible for the increase in ecSOD in these conditions, and will investigate mechanisms underlying the augmented hypertension that occurs in mice lacking ecSOD. Dr. Taylor, the director of the last project, has previously shown that angiotensin II plays a crucial role in exacerbating atherosclerosis in the setting of hypertension, even in states where circulating levels of angiotensin II are suppressed. Dr. Taylor will use transgenic "knock-in" technology to define the functional significance of locally produced angiotensin II in the pathogenesis of atherosclerosis. This work will be important because it will provide information about how the events to be studied in projects 1 and 2 are initiated in pathophysiological states in vivo. These projects will be supported by two Cores that will provide expertise with detection of reactive oxygen species and histological analyses of relevant tissues. Overall, these studies will promote our understanding of the fundamental molecular mechanisms responsible for oxidant stress in the pathogenesis of vascular disease.