Signaling Mechanisms of FGF2-induced Cardioprotection

描述(申请人提供)：本提案的总体目标是研究成纤维细胞生长因子2介导的心肌保护的潜在分子靶点(S)。最初的研究结果表明，一氧化氮(NO)、蛋白激酶C(PKC)和丝裂原活化蛋白激酶(MAPK)信号在FGF2诱导的心脏保护中是必需的。然而，这些信号通路介导FGF2诱导的抗心肌功能障碍和心肌梗死的心脏保护作用的下游靶点仍有待阐明。因此，我们将采用药理学、电生理学、亚蛋白质组学和综合生理学的多学科方法来确定与FGF2诱导的心肌保护相关的信号通路的已知或新底物。该提案将评估已知的与FGF2活性或心脏保护相关的激酶下游底物的参与，并通过亚蛋白质组学分析确定FGF2诱导的心脏保护的新靶点。该研究计划将蛋白质和细胞水平的基本信息与整个器官/动物水平的信息结合起来。这些研究还将使我们能够直接将心肌梗死和缺血后心功能的恢复与FGF2的生物活性及其蛋白激酶通路的特定下游靶点联系起来。为了确定ATP敏感钾通道在FGF2诱导的心肌保护中的作用，我们将采用药理学、电生理学和分子生物学的方法。类似的技术将被用来确定FGF2在肌浆网(SR)蛋白和收缩装置水平上调节钙稳态的重要性，最终影响缺血后的心功能。随着初步数据表明线粒体、SR和收缩装置是FGF2诱导的心肌保护的靶标，这些细胞器的候选和新的底物将通过磷酸蛋白质组学(免疫印迹和2-D Gel/MS)技术进行询问。这项提议的结果将为FGF2诱导的心脏保护提供新的见解，并可能最终导致FGF2作为治疗缺血性心脏病的药物或遗传学发展。

DESCRIPTION (provided by applicant): The overall goal of this proposal is to investigate the molecular target(s) underlying FGF2-mediated cardioprotection. Findings from the original proposal indicate that nitric oxide (NO), protein kinase C (PKC), and mitogen-activated protein kinase (MAPK) signaling are necessary for FGF2-induced cardioprotection. Yet, the downstream targets by which these signaling pathways mediate FGF2- induced cardioprotection against myocardial dysfunction and infarction remain to be elucidated. Therefore, we will undertake a pharmacological-, electrophysiological-, subproteomic- and integrative physiological-based multidisciplinary approach to identify known or novel substrates of the signaling pathways associated with FGF2-induced cardioprotection. The proposal will evaluate the involvement of known downstream substrates of kinases that have been affiliated with FGF2 activity or with cardioprotection, and identify novel targets of FGF2-induced cardioprotection by subproteomic analysis. The research plan will integrate basic information at the protein and cellular level with information at the whole organ/animal level. These studies will also enable us to directly relate changes in myocardial infarction and post-ischemic recovery of ventricular function to the biological activity of FGF2 and to specific downstream targets of its protein kinase pathways. To ascertain the involvement of ATP-sensitive potassium (KATP) channels in FGF2-induced cardioprotection, we will employ pharmacologic, electrophysiological, and molecular methods. Similar techniques will be used to determine the importance of FGF2 in regulating calcium homeostasis at the level of sarco(endo)plasmic reticulum (SR) proteins and contractile apparatus, ultimately influencing post- ischemic cardiac function. With preliminary data implicating the mitochondria, SR, and contractile apparatus as targets of FGF2-induced cardioprotection, candidate and novel substrates of these organelles will be interrogated via phosphoproteomic (immunoblotting and 2-D gel/MS) techniques. Results of this proposal will provide new insights into FGF2-induced cardioprotection and may eventually lead to the pharmacologic or genetic development of FGF2 as a therapy against ischemic heart disease.