ROLE OF P38 MAPK AND PP2C IN ISCHEMIC INJURY AND PROTECTION

首席调查员/项目主任(最后，第一中)：平，佩佩(王建民，项目3) 项目3： P38A标记和PP2CK在脑缺血损伤中的作用 保护 加州大学洛杉矶分校 项目负责人：王宜宾，博士。 联合项目负责人：Enrico Stefani，医学博士 小灵通398(05/01版)第181页 在整个应用程序的底部连续编号页码。不要使用3a、3b等后缀。 首席调查员/项目主任(最后、第一、中间)：平，佩佩(王，项目3) 项目3将从心脏角度探讨缺血性损伤和保护的中心主题 重塑和心力衰竭。心肌梗死的一个重要有害后果是诱发 病理性重塑，最近的报告显示其特征是线粒体功能障碍，包括改变 能量代谢和细胞凋亡。介导应激诱导的细胞内信号事件 病理重塑和心肌细胞凋亡涉及蛋白激酶和磷酸酶的复杂调控。在……里面 在这方面，缺血损伤有效地诱导了高度保守的Ser/Thr蛋白激酶p38Mark，它调节 线粒体能量代谢与细胞凋亡。在我们之前的研究中，靶向诱导p38在脑内的活性 心脏足以引起病理性重构和心力衰竭，而P38A的遗传失活 异构体显著保护心脏免受缺血损伤。尽管在这一领域取得了重大进展，但几乎没有 已知线粒体上的压力信号。为此，发现了一种新的蛋白磷酸酶-2C 项目3的异构体(PP2Cic)代表了对该细胞器信号转导的重要新见解。初步数据 这表明PP2dc在心脏中高表达，并定位于线粒体。此外， 结果表明，PP2CK在衰竭心脏中表达下调，提示PP2CK的过度表达 保护心肌细胞免受氧化应激所致的损伤。 这些令人兴奋的发现导致了项目3的中心假说：应激激活蛋白激酶 P38A MAPK和线粒体蛋白磷酸酶PP2CK是细胞内两个重要的信号转导元件 缺血再灌注损伤及其对心脏表型形成的调节作用 缺血损伤时线粒体功能与心肌细胞凋亡。与项目1、2和 4、心脏生物学核心和蛋白质组核心，项目3将对 单个p38亚型和PP2dc在缺血性损伤中的作用提出了四个具体目标：与项目合作 1和心脏生物学核心，Aim 1将研究p38 MAPK在调节线粒体功能和 调节对MPT的敏感性。在项目2和心脏生物学核心的合作下，Aim 2将调查 单个p38MAPK亚型在脑缺血/再灌流中调节MPT敏感性的体内作用 受伤。在与蛋白质组核心的合作下，AIM 3将利用一种功能蛋白质组方法来鉴定P38A- 心脏相关蛋白以阐明参与P38A信号转导的分子的亚蛋白质组 缺血性损伤与保护。最后，与项目1和项目4合作，目标4将充分说明新的-- 发现线粒体特异性磷酸酶PP2dc，并探讨其在应激信号和信号转导中的作用 心脏保护。这项拟议的研究将为应激蛋白在调节 线粒体在缺血损伤期间功能障碍，并可能导致心力衰竭的新治疗方法。

Principal Investigator/Program Director (Last, First. Middle): Ping, Peipei (Wang, Project 3) PROJECT 3: ROLE OF P38a MARK AND PP2CK IN ISCHEMIC INJURY AND PROTECTION UCLA Project Leader: Yibin Wang, Ph.D. Co-Project Leader: Enrico Stefani, M.D., Ph.D. PHS 398 (Rev. 05/01) Page 181 Number pages consecutively at the bottom throughout the application. Do not use suffixes such as 3a, 3b. Principal Investigator/Program Director (Last, First, Middle): Ping, Peipei (Wang, Project 3) Project 3 will address the central theme of ischemic injury and protection from a perspective of cardiac remodeling and heart failure. An important deleterious consequence of myocardial infarction is the induction of pathological remodeling, which recent reports shown is characterized by mitochondrial dysfunction, including altered energy metabolism and apoptotic cell death. The intracellular signaling events that mediate stress-induced pathological remodeling and myocyte apoptosis involve intricate regulation by protein kinases and phosphatases. In this regard, ischemic injury potently induces a highly conserved Ser/Thr protein kinase, p38 MARK, that regulates mitochondrial energy metabolism and apoptosis. In our previous studies, targeted induction of p38 activity in the heart was sufficient to induce pathological remodeling and heart failure, whereas genetic inactivation of the p38a isoform significantly protects the heart against ischemic injury. Despite significant progress in this field, very little is known regarding stress signaling at mitochondria. To this end, the discovery of a novel protein phosphatase-2C isoform (PP2Cic) by Project 3 represents important new insight into signaling at this organelle. Preliminary data indicate that PP2dc is highly expressed in the heart with targeted localization to the mitochondria. Moreover, the findings demonstrate that PP2CK is down-regulated in the failing heart and indicate that overexpression of PP2CK protects cardiac cells against oxidative stress-induced injury. These exciting findings led to the central hypothesis of Project 3: The stress-activated protein kinase p38a MAPK and the mitochondrial protein phosphatase PP2CK are two important signaling components in ischemia-reperfusion injury and they contribute to the genesis of cardiac phenotype by modulating mitochondria function and myocyte apoptosis during ischemic injury. In collaboration with Projects 1, 2, and 4, the Heart Biology Core and the Proteomic Core, Project 3 will undertake a comprehensive analysis of the role of individual p38 isoforms and PP2dc in ischemic injury. Four specific aims are proposed: In collaboration with Project 1 and the Heart Biology Core, Aim 1 will investigate the role of p38 MAPKs in regulating mitochondrial function and modulating susceptibility to MPT. In collaboration with Project 2 and the Heart Biology Core, Aim 2 will investigate the in vivo role of individual p38 MAP kinase isoforms in modulating susceptibility to MPT in ischemia/reperfusion injury. In collaboration with the Proteomic Core, Aim 3 will utilize a functional proteomic approach to identify p38a- associated proteins in the heart to elucidate the subproteome of molecules involved in p38a signaling during ischemic injury and protection. Finally, in collaboration with Projects 1 and 4, Aim 4 will fully characterize the newly- discovered mitochondria-specific phosphatase, PP2dc, and explore its role in modulation of stress signaling and cardioprotection. The proposed studies will provide novel insights into the role of stress proteins in regulation of mitochondrial dysfunction during ischemic injury and can lead to new therapeutic approaches to heart failure.