Signaling Mechanisms of FGF2-induced Cardioprotection

描述（由申请人提供）：本提案的总体目标是研究fgf2介导的心脏保护的分子靶点。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）信号对于fgf2诱导的心脏保护是必要的。然而，这些信号通路介导FGF2诱导的抗心肌功能障碍和梗死的心脏保护的下游靶点仍有待阐明。因此，我们将采用基于药理学、电生理学、亚蛋白质组学和综合生理学的多学科方法来识别与fgf2诱导的心脏保护相关的信号通路的已知或新的底物。该提案将评估与FGF2活性或心脏保护相关的已知下游激酶底物的参与，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/动物水平的信息相结合。这些研究还将使我们能够直接将心肌梗死和缺血性心室功能恢复的变化与FGF2的生物活性及其蛋白激酶途径的特定下游靶点联系起来。为了确定atp敏感钾（KATP）通道在fgf2诱导的心脏保护中的作用，我们将采用药理学、电生理学和分子方法。类似的技术将用于确定FGF2在调节sarco（endo）质网（SR）蛋白和收缩器官水平钙稳态中的重要性，最终影响缺血后心功能。由于初步数据表明线粒体、SR和收缩装置是fgf2诱导的心脏保护的靶点，这些细胞器的候选底物和新底物将通过磷酸化蛋白质组学（免疫印迹和二维凝胶/质谱）技术进行研究。这一建议的结果将为FGF2诱导的心脏保护提供新的见解，并可能最终导致FGF2作为缺血性心脏病治疗的药理学或遗传学发展。

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.