Big MAP Kinase 1-Cx 43 Signaling in Ischemia Injury

缺血损伤中的大 MAP 激酶 1-Cx 43 信​​号转导

• 批准号: 7031042
• 负责人: JAY YANG
• 金额: $ 35.62万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7031042
• 关键词: biological signal transduction; calcium flux; calpain; cytoprotection; gap junctions; genetically modified animals; immunoprecipitation; ischemic preconditioning; laboratory mouse; mitogen activated protein kinase; myocardial ischemia /hypoxia; phosphorylation; protein structure function; reperfusion; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): Ca2+ overload is a major cause of myocardial cell damage and cardiac dysfunction in ischemic heart diseases. Studies with gap junction coupling inhibitors and connexin (Cx) 43 knock out mice suggest that Cx43 is important in regulating ischemia/ reperfusion (IR)- induced cellular Ca2+ overload. Cx43 gap junction coupling is regulated by several kinases including mitogen-activated-protein (MAP) kinases. Since ischemic preconditioning improves the recovery of cardiac function after IR-injury and also activates Big- MAPK 1 (BMK1), a member of MARK, we hypothesized that activation of BMK1 induced by preconditioning phosphorylates Cx43, decreases gap junction coupling, and reduces ischemia/ reperfusion-induced cellular Ca2+ overload. Key data in support of our hypothesis include: 1} BMK1 phosphorylates and associates with Cx43, and leads to gap junction uncoupling, 2) Cx43 phosphorylation is increased in cardiac-specific transgenic mice expressing the constitutively active form of the upstream kinase MEK5 (CA-MEK5) which specifically activates BMK1, 3) CA-MEK5 transgenic hearts exhibit a profoundly accelerated recovery of pump function after IR-injury in a Langendorff model. We will study the role of BMK1 and Cx43 phosphorylation in post-ischemic cardiac dysfunction with the following specific aims: Aim 1: Define the role of BMK1 in Cx43 phosphorylation and subsequent Cx43 gap junction uncoupling. Aim 2: Define the role of BMK1 in Cx43 phosphorylation and the effect of Cx43 phosphorylation on IR- induced Ca2+ overload, subsequent calpain activity, and mitochondrial dysfunction. Aim 3: Determine the role of BMK1 and subsequent Cx43 phosphorylation in IR-injury, in vivo, and Aim 4: Investigate the role of BMK1-Cx43 signaling in chemical preconditioning. The broad-based experimental approach should allow us to conclude the importance of BMK1-Cx43 signaling in IR-injury. The long-range goal of this line of investigation is to discover a novel therapeutic strategy for reducing IR-injury.

描述（由申请人提供）：Ca2+超载是缺血性心脏病心肌细胞损伤和心功能障碍的主要原因。对间隙连接偶联抑制剂和连接蛋白（Cx） 43敲除小鼠的研究表明，Cx43在调节缺血/再灌注（IR）诱导的细胞Ca2+过载中很重要。Cx43间隙连接偶联受包括丝裂原活化蛋白（MAP）激酶在内的几种激酶的调控。由于缺血预处理改善了ir损伤后心功能的恢复，并激活了MARK成员之一的大- mapk1 (BMK1)，我们假设预处理诱导的BMK1激活使Cx43磷酸化，减少间隙连接偶联，并减少缺血/再灌注诱导的细胞Ca2+过载。支持我们假设的关键数据包括：1}BMK1磷酸化并与Cx43结合，导致间隙连接解耦；2)表达上游激酶MEK5 （CA-MEK5）组成活性形式特异性激活BMK1的心脏特异性转基因小鼠中Cx43磷酸化增加；3)在Langendorff模型中，CA-MEK5转基因心脏在损伤后表现出泵功能的加速恢复。我们将研究BMK1和Cx43磷酸化在缺血性心功能障碍中的作用，具体目的如下：目的1：确定BMK1在Cx43磷酸化和随后的Cx43间隙连接解耦中的作用。目的2：明确BMK1在Cx43磷酸化中的作用，以及Cx43磷酸化对IR诱导的Ca2+超载、随后的钙蛋白酶活性和线粒体功能障碍的影响。目的3：确定BMK1和随后的Cx43磷酸化在体内ir损伤中的作用；目的4：研究BMK1-Cx43信号传导在化学预处理中的作用。广泛的实验方法应该使我们能够得出BMK1-Cx43信号在ir损伤中的重要性。这项研究的长期目标是发现一种新的治疗策略来减少ir损伤。