Effect of Adenosine A2 receptor activation on the mitochondrial death pathway

腺苷A2受体激活对线粒体死亡途径的影响

• 批准号: 7261330
• 负责人: ZHELONG XU
• 金额: $ 35.44万
• 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/7261330
• 关键词: Effect; Adenosine; A2; receptor; activation

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）：最近的大量研究已将再灌注时的线粒体死亡途径与坏死和细胞凋亡联系起来。因此，防止线粒体死亡途径是再灌注时成功心脏保护的先决条件。尽管有人提出再灌注时腺苷 A2 受体激活可以保护心脏，但其机制仍不清楚。该提案的目的是确定 A2 受体激活对线粒体死亡途径的影响，并阐明 A2 受体激活影响下的信号传导机制。我们假设再灌注时 NECA 刺激 A2 受体激活，通过涉及 eNOS、NO、PKG、锌和 GSK-3 的信号级联阻断线粒体死亡途径。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多种技术来测试这些假设。目标 1 将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。目标 2 将通过定义 PKA、酪氨酸激酶和 HSP90 在 eNOS 激活中的作用来确定 A2 受体激活产生 NO 的机制。目标 3 将确定 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 基因来定义 PKG 的作用。目标 4 将确定 PKG 激活的下游靶标，从而导致 A2 受体激活对线粒体死亡途径产生预防作用。为了实现这一目标，我们将描述细胞内游离锌、线粒体 KATP 通道和 GSK-3 的作用。该提案的成功实施将为研究再灌注时A2受体激活对缺血/再灌注损伤的保护作用背后的信号机制带来重要的新见解，并对治疗急性心肌梗死患者具有重要的临床意义。