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: 6926479
• 负责人: JAY YANG
• 金额: $ 40.08万
• 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/6926479
• 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+过载是缺血性心脏病中心肌细胞损伤和心脏功能障碍的主要原因。通过间隙连接耦合抑制剂和连接素（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间隙连接偶联受到几种激酶（包括丝裂原激活蛋白（MAP）激酶）的调节。 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.支持我们假设的关键数据包括：1} BMK1磷酸化并与CX43磷酸化并导致间隙连接未偶联，2）Cx43磷酸化在心脏特异性转基因小鼠中增加，表达了upstream kinase mek5（Ca-mek5）的构造形式（CA-MEK1），该小Cain cain cain cain cain cain cain cain cain cain cain trempertife camek cam knection trempertial caent cam ca。在Langendorff模型中，IR损伤后，泵功能的恢复深刻加速。我们将研究BMK1和CX43磷酸化在缺血后心脏功能障碍中的作用，并具有以下特定目的：AIM 1：定义BMK1在CX43磷酸化中的作用以及随后的CX43 GAP差距连接。 AIM 2：定义BMK1在CX43磷酸化中的作用以及CX43磷酸化对IR诱导的Ca2+过载，随后的Calpain活性和线粒体功能障碍的作用。 AIM 3：确定IR损伤，体内BMK1和随后的CX43磷酸化的作用，AIM 4：研究BMK1-CX43信号传导在化学预处理中的作用。基于广泛的实验方法应该使我们能够结论IR损伤中BMK1-CX43信号的重要性。这种调查的远程目标是发现一种新的减少IR损伤的治疗策略。