G6PD IN OXIDATIVE STRESS ASSOCATED WITH ATHEROSCLEROSIS

葡萄糖-6-磷酸脱氢酶(G6PD)在氧化应激调节中起重要作用，其在血管疾病中的作用可能在G6PD基因缺陷的黑人中得到突出。项目2的假设是G6PD在为超氧阴离子(O2-)的产生提供底物方面起着重要作用。在动脉粥样硬化形成过程中，由细胞因子激活的血管细胞中的NAD(P)H氧化酶。对这两种物质的高要求都增加了O2-的产生。和一氧化氮(NO.)对于内皮细胞和诱导型NO。动脉粥样硬化斑块中的合成酶将增加对NADPH的需求和流量，从而增强G6PD的重要性，G6PD是供应NADPH的戊糖分流中的限速酶。我们还将研究G6PD的这种促氧化作用与其通过GSH还原酶和硫氧还蛋白还原酶提供NADPH以维持还原型谷胱甘肽(GSH)和蛋白质硫醇之间的相互关系。这些特定的目标将解决G6PD在动脉粥样硬化发展过程中对氧化应激的调节。这将在目标1中通过研究载脂蛋白缺陷小鼠动脉粥样硬化斑块的发展来完成，该小鼠也是G6PD缺陷小鼠。在目标2中，我们将测量细胞因子激活的培养的人主动脉内皮细胞中黏附分子的表达，这是导致单核/巨噬细胞来源的泡沫细胞形成的动脉粥样硬化的初始步骤的模型。在体内和体外模型中，我们将确定G6PD对O2-的调节的相对重要性。生产和硫醇还原。在目标3中，我们将研究G6PD在氧化应激中的作用，氧化应激可能会降低NO的生物活性。在动脉粥样硬化小鼠和兔主动脉的血管平滑肌中，以及在G6PD缺乏的黑人的血小板中。这将通过研究肌浆网钙ATPase的翻译后氧化修饰来实现，我们的团队已经证明，这一修饰介导了NO引起的细胞内钙的减少。通过研究G6PD在这些血管疾病模型中调节氧化应激的作用，我们将确定G6PD缺陷可能影响黑人动脉粥样硬化性心血管疾病的潜在影响和机制。

Glucose-6 phosphate dehydrogenase (G6PD) plays an important role in the regulation of oxidative stress, and its role in vascular disease may be highlighted in blacks with a genetic deficiency in G6PD. The hypothesis of Project 2 is that G6PD takes on importance in providing substrate for the production of superoxide anion (O2-.) by NAD(P)H oxidase in vascular cells activated by cytokines during atherogenesis. Heightened requirements for both increased production of O2-. and nitric oxide (NO.) for both the endothelial and inducible NO. synthases in the atherosclerotic plaque will increase the demand for, and flux of, NADPH, enhancing the importance of G6PD, the rate-limiting enzyme in the pentose shunt that supplies NADPH. We will also investigate the inter- relationship between this proposed pro-oxidant role of G6PD with its anti-oxidant role in providing NADPH for maintaining reduced glutathione (GSH) and protein thiols via GSH reductase and thioredoxin reductase. The specific aims will address the modulation of oxidative stress by G6PD during the development of atherosclerosis. This will be done in Aim 1 by studying the development of atherosclerotic plaques in apolipoprotein deficient mice made deficient also in G6PD. In Aim 2 we will measure the expression of adhesion molecules in cytokine-activated cultured human aortic endothelial cells, a model of the initial steps of atherogenesis that leads to formation of monocyte/macrophage-derived foam cells. In both t he in vivo and in vitro models, we will determine the relative importance of the modulation by G6PD of O2-. production and thiol reduction. In Aim 3, we will examine the role of G6PD in the oxidative stress that may decrease the biological activity of NO. in the vascular smooth muscle of the atherosclerotic mouse and rabbit aorta and in platelets from blacks with G6PD deficiency. This will be done by studying post-translational oxidative modifications in the sarcoplasmic reticulum Ca2+ ATPase, which our group has shown mediates the reduction of intracellular Ca2+ caused by NO. By examining the role of G6PD in modulating oxidative stress in these models of vascular disease, we will ascertain the potential impact and mechanisms by which a deficiency in G6PD may influence atherosclerotic cardiovascular disease in blacks.