DIABETES AND ANESTHETIC PRECONDITIONING

这项建议的目的是阐明糖尿病损害麻醉诱导的机制。 减少围手术期心血管并发症和死亡率的预适应(ARC) 在高危患者中。越来越多的证据表明内皮型一氧化氮合酶(ENOS)- 对线粒体产生NO和下游效应！功能与三磷酸腺苷调节 钾通道(Karp)是ARC的关键介体。目前的提议将检验这一假设 糖尿病和高血糖损害心脏ARC信号转导机制 涉及HSP90、四氢生物蝶呤(BH4)的eNOS敏感通路，不对称 二甲基精氨酸(ADMA)、KATP通道和线粒体；这一途径可以有利地 通过针对NO*信号和线粒体的药理和遗传策略进行调节 功能(线粒体基因组开关)。在具体目标1中，我们将评估以下假设 ARC通过促进eNOS偶联(产生NO-而不是超氧阴离子)增强NO信号 通过减少ADMA的生产，增加BH4的可用性，以及 增强了HSP90和eNOS之间的相互作用。我们认为ARC可以改善线粒体 心肌缺血后的生物能量学(ATP产生、呼吸、线粒体膜电位) 和再灌流，并以NO*依赖的方式增强KATP通道活性，反之， 这些有益的影响被糖尿病和高血糖所消除。在《特定目标2》中，我们将 解决以ARC信号转导通路的特定组件为靶的假设 改善eNOS功能和增强线粒体生物能量学的药理学和遗传学策略 将在糖尿病期间恢复ARC保护。该提案将利用一种新的2型糖尿病模型 在大鼠中，我们能够选择性地切换线粒体基因组，以便进一步剖析 ARC受损期间的线粒体。令人兴奋的初步数据表明，糖尿病大鼠的ARC已恢复 线粒体基因组转换后。这些实验将提供新的机制信息 内皮型一氧化氮合酶调节、线粒体功能、糖尿病和高血糖对麻醉诱导的调节作用 通过蛋白质-蛋白质相互作用保护心脏；蛋白质磷酸化/酪氨酸硝化； 改变辅因子的可用性和ROS的形成；并通过使用新型的KATP通道活性降低 体内和在工程心脏组织中的遗传学和药理学方法，离体心和细胞 体外培养。这一结果还将为糖尿病患者的干预提供新的治疗目标。 外行描述：糖尿病患者心血管并发症的风险增加 在麻醉和手术后。这项拟议的研究将定义糖尿病的发病机制 削弱麻醉剂的心脏保护作用，并将找到治疗糖尿病和 高血糖症。

The objective of this proposal is to elucidate the mechanisms whereby diabetes impairs anestheticinduced preconditioning (ARC) with the goal of reducing perioperative cardiovascular morbidity and mortality in high-risk patients. A growing body of evidence implicates endothelial nitric oxide synthase (eNOS)- derived NO- and downstream effects on mitochondria! function and adenosine triphosphate-regulated potassium (KArp) channels as critical mediators of ARC. The current proposal will test the hypothesis that diabetes and hyperglycemia impair ARC signal transduction mechanisms in the heart through an eNOS-sensitive pathway involving HSP90, tetrahydrobiopterin (BH4), asymmetric dimethylarginine (ADMA), KATp channels, and mitochondria; and that this pathway can be favorably modulated with pharmacological and genetic strategies targeted at NO* signaling and mitochondrial function (mitochondrial genome switch). During Specific Aim 1, we will evaluate the hypotheses that ARC enhances NO signaling by promoting eNOS coupling (production of NO- and not superoxide anion) through mechanisms that involve decreased production of ADMA, increased availability of BH4, and enhanced interactions between HSP90 and eNOS. We propose that ARC improves mitochondrial bioenergetics (ATP production, respiration, mitochondrial membrane potential) after myocardial ischemia and reperfusion, and enhances KATP channel activity in an NO* dependent fashion, and conversely, that these beneficial effects are abolished by diabetes and hyperglycemia. During Specific Aim 2, we will address the hypotheses that targeting specific components of ARC signal transduction pathways by using pharmacological and genetic strategies to improve eNOS function and enhance mitochondrial bioenergetics will restore ARC protection during diabetes. The proposal will exploit a novel model of type 2 diabetes in the rat in which we are able to selectively switch the mitochondrial genome in order to further dissect the role of mitochondria during impaired ARC. Exciting preliminary data indicate that ARC is restored in diabetic rats after mitochondrial genome switch. These experiments will provide novel mechanistic information on the role of eNOS regulation, mitochondrial function, diabetes, and hyperglycemia to modulate anestheticinduced cardioprotection through protein-protein interactions; protein phosphorylation/tyrosine nitration; altered co-factor availability and ROS formation; and through decreased KATP channel activity using novel genetic and pharmalogical approaches in vivo and in engineered heart tissue, isolated hearts, and cells in vitro. The results will also suggest new therapeutic targets for intervention in patients with diabetes. Lay description: Individuals with diabetes are at increased risk for cardiovascular complications following anesthesia and surgery. The proposed research will define the mechanisms whereby diabetes impairs the cardioprotective effects of anesthetics and will identify new potential treatments for diabetes and hyperglycemia.