Preconditioning against a source of reperfusion oxidants

针对再灌注氧化剂源的预处理

• 批准号: 6890948
• 负责人: Terry L. Vanden Hoek
• 金额: $ 38.13万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6890948
• 关键词: NAD(P)H dehydrogenase; antioxidants; bioenergetics; calcium flux; cardiac myocytes; cardiovascular injury; cytoprotection; enzyme activity; enzyme induction /repression; enzyme inhibitors; free radical oxygen; laboratory mouse; mitochondria; oxidative stress; potassium channel; reperfusion; superoxides; tissue /cell culture

DESCRIPTION (provided by applicant): This revised proposal extends a current K08 award to study a novel target of myocardial preconditioning, and builds on 5 years of studies in chick cardiomyocytes that demonstrate (a) significant oxidant injury at reperfusion following ischemia, (b) hypoxic preconditioning (PC) which attenuates this injury, and (c) a burst of reactive oxygen species (ROS) at reperfusion which originate from an NAD(P)H oxidase. We propose to advance these studies in a recently established murine cardiomyocyte system to further establish a mechanism by which PC attenuates reperfusion oxidants generated by this oxidase. These murine cardiomyocytes also exhibit hypoxic preconditioning against reperfusion ROS and allow for study of transgenic mouse cardiomyocytes. The central hypothesis of this proposal is that classical PC, by opening mitochondrial KATP channels, increases NO generation at reperfusion and thereby inhibits NAD(P)H oxidase activity, superoxide generation, and subsequent reperfusion injury. We propose two specific aims, testing whether: (1) PC or mitochondrial KATP channel openers given at reperfiision increase transient calcium release from the mitochondria, activate constitutive nitric oxide synthase (cNOS), and thereby attenuates reperfusion ROS and its associated injury, and whether this protection can be abrogated by addition of ¿-NADPH and ¿-NADH and (2) Alterations of NAD(P)H oxidase, using murine cardiomyocytes from NAD(P)H knockout mice, will attenuate reperfusion ROS and confer preconditioning-like protection, which will not be effected by inhibitors of mitochondrial KATP channels or NOS. This work will clarify how PC blocks an important source of ROS, and could improve postresuscitation care following cardiac arrest and other ischemia/reperfusion diseases such as myocardial infarction and stroke.

描述（由适用提供）：该修订的提案扩大了当前的K08奖励，以研究心肌预处理的新颖目标，并建立在雏鸡心肌细胞中的5年研究中，这些研究证明了（a）在缺血后融合时（pc）造成的（PC）造成的（roseferfective this Rectivice forsegen）的氧化物造成严重的氧化物损伤（c）。起源于NAD（P）H氧化酶。我们建议在最近建立的鼠心肌细胞系统中推进这些研究，以进一步建立一种机制，PC通过该机制减弱了该氧化酶产生的再灌注氧化剂。这些鼠心肌细胞还表现出针对再灌注ROS的缺氧预处理，并允许研究转基因小鼠心肌细胞。 该提案的中心假设是，经典的PC通过打开线粒体KATP通道，在再灌注时不会增加产生，从而抑制NAD（P）H氧化物活性，超氧化物的产生和随后的再灌注损伤。 We propose two specific aims, testing whether: (1) PC or mitochondrial KATP channel openers given at reperfision increase transient calcium release from the mitochondria, activate constitutive nitric oxide synthase (cNOS), and thereby attenuates reperfusion ROS and its associated injury, and whether this protection can be acrogated by addition of ¿ -NADPH and ¿ -NADH and (2) Alterations of NAD（P）H氧化酶，使用NAD（P）H基因敲除小鼠的鼠心肌细胞，将减弱再灌注ROS和会议预处理样保护，这不会受到线粒体KATP通道或NOS的抑制剂的影响。这项工作将阐明PC如何阻止ROS的重要来源，并可以在心脏骤停后改善后引起护理以及其他缺血/再灌注疾病，例如心肌梗塞和中风。