Adenosine A2 receptor activation--mitochondrial death

腺苷A2受体激活——线粒体死亡

• 批准号: 7139769
• 负责人: ZHELONG XU
• 金额: $ 35.86万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7139769
• 关键词: apoptosis; biological signal transduction; cGMP dependent protein kinase; cardiac myocytes; cardiovascular disorder prevention; cardiovascular pharmacology; chemoprevention; enzyme activity; gene targeting; heat shock proteins; kinase inhibitor; laboratory mouse; mitochondrial disease /disorder; myocardial infarction; myocardial ischemia /hypoxia; nitric oxide; nitric oxide synthase; potassium channel; purinergic receptor; receptor expression; reperfusion; serine threonine protein kinase; zinc

DESCRIPTION (provided by applicant): A large number of recent studies have associated a mitochondrial death pathway at reperfusion with both necrosis and apoptosis. Preventing the mitochondrial death pathway, therefore, is a prerequisite for successful cardioprotection at reperfusion. Although adenosine A2 receptor activation at reperfusion has been proposed to protect the heart, its mechanisms are still not clear. The objective of this proposal is to determine the effects of A2 receptor activation on the mitochondrial death pathway and to elucidate the signaling mechanisms underling the effects of A2 receptor activation. We hypothesize that stimulation of A2 receptor activation by NECA at reperfusion interdicts the mitochondrial death pathway through a signal cascade involving eNOS, NO, PKG, zinc, and GSK-3. We will test these hypotheses by using diverse techniques of cell biology, molecular biology, physiology, pharmacology, and gene targeting. Aim 1 will determine the effects of A2 receptor activation at reperfusion on the mitochondrial death pathway by measuring mitochondrial function, infarct size, and indexes of apoptosis. Aim 2 will determine the mechanisms by which A2 receptor activation produces NO by defining the roles of PKA, tyrosine kinase, and HSP90 in activation of eNOS. Aim 3 will determine the role of PKG in the protective action of A2 receptor activation. We will define the role of PKG by overexpressing or knocking out the PKG gene. Aim 4 will ascertain the downstream targets of PKG activation that lead to the preventive effects of A2 receptor activation on the mitochondrial death pathway. Towards this goal we will characterize the roles of intracellular free zinc, mitochondrial KATP channels, and GSK-3. The successful execution of this proposal should produce important new insights into the signaling mechanisms underlying the protective effects of A2 receptor activation at reperfusion against ischemia/reperfusion injury, and have great clinical significance for treating patients with acute myocardial infarction.

描述（由申请人提供）：大量近期研究将再灌注时的线粒体死亡途径与坏死和凋亡相关联。因此，阻止线粒体死亡途径是再灌注时成功的心脏保护的先决条件。尽管腺苷A2受体在再灌注时的激活被认为可以保护心脏，但其机制仍不清楚。本提案的目的是确定A2受体激活对线粒体死亡途径的影响，并阐明A2受体激活影响的信号传导机制。我们推测，刺激A2受体激活NECA在再灌注阻断线粒体死亡途径，通过涉及eNOS，NO，PKG，锌，GSK-3的信号级联。我们将通过使用细胞生物学、分子生物学、生理学、药理学和基因靶向的各种技术来测试这些假设。目的1通过测量线粒体功能、梗死面积和细胞凋亡指数来确定再灌注时A2受体激活对线粒体死亡途径的影响。目的2通过研究PKA、酪氨酸激酶和HSP 90在eNOS激活中的作用，探讨A2受体激活产生NO的机制。目的3：研究PKG在A2受体激活的保护作用中的作用。我们将通过过表达或敲除PKG基因来确定PKG的作用。目的4确定PKG激活的下游靶点，从而导致A2受体激活对线粒体死亡途径的预防作用。为了实现这一目标，我们将表征细胞内游离锌，线粒体KATP通道和GSK-3的作用。该方案的成功实施将对再灌注时A2受体激活对缺血/再灌注损伤的保护作用的信号转导机制产生重要的新见解，并对急性心肌梗死患者的治疗具有重要的临床意义。