重组高密度脂蛋白激活PI3K/Akt信号通路调控心肌自噬保护心功能的分子机制研究

项目名称： 重组高密度脂蛋白激活PI3K/Akt信号通路调控心肌自噬保护心功能的分子机制研究

项目编号： No.81500316

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 医药、卫生

项目作者： 王凡

作者单位： 中国人民解放军总医院

项目金额： 18万元

中文摘要： HDL是独立的心血管保护因素，与HDL结合的S1P调节了心肌细胞的存活。自噬是细胞死亡的方式之一，PI3K/Akt信号通路是调控自噬的经典途径。随着压力负荷持续，心肌细胞过度自噬导致细胞丢失，心功能进一步恶化。目前尚未见有关S1P、心肌细胞自噬及心功能之间的研究报道。结合我们前期研究发现：包含S1P成分的重组HDL（rHDL）能够保护压力负荷HF的心功能，我们提出假设：rHDL可能通过PI3K/Akt信号通路调控心肌细胞自噬保护压力负荷HF的心功能。本研究通过体内及体外实验，观察rHDL对压力负荷HF心肌细胞自噬和心功能的影响；结合信号通路特异性抑制剂，及siRNA干扰技术，运用RT-PCR、Western blot等方法检测自噬相关蛋白和信号通路相关蛋白的表达，并确定参与其中的S1P受体亚型。从而深入探讨rHDL保护压力负荷HF心功能的分子机制，为心力衰竭的治疗提供新视角。

中文关键词： 重组高密度脂蛋白；压力负荷心力衰竭；心肌细胞自噬；PI3K/Akt；信号通路；鞘脂1-磷酸鞘氨醇

英文摘要： HDL is an independent protective factor of atherosclerotic disease. HDL connected sphingosine-1-phosphate (HDL-S1P) is documented to have amazing cardiovascular protection. HDL-S1P is reported to intervene in cardiomyocyte survival. Autophagy is one pathway of cell death. PI3K/Akt signalling pathway had been confirmed playing an important role in autophagy. During the process of happening and developing of load-induced heart failure, cardiomyocyte autophagy promotes myocardial hypertrophy transforming to myocardial dysfunction, in which cardiomyocyte loss induced by autophagy is key point. There are no related report about the correlation among S1P, autophagy and heart failure. Based on our new findings that reconstituted HDL (rHDL) with S1P can protect heart function in load-induced heart failure, we hypothesis that rHDL protect heart function possibly via PI3K/Akt signaling pathway suppressing excessive cardiomyocyte autophagy activated by load-induced heart failure. In the present study, cultured neonatal rat cardiomyocytes and adult mice are performed to prepared in vitro and in vivo, and were interfered with rHDL. RT-PCR and Western blot were performed to detect autophagy related genes and protein, p-Akt and p-mTOR. Furthermore, S1P receptors will be identified by S1P receptor siRNA. All of these will help us try to demonstrate the mechanism that rHDL via PI3K/Akt signaling pathway suppressing autophagy to protect heart function. Our work will discover a new mechanism about the cardiovascular protection of HDL and provide new possible method for improving load-induced heart failure in clinic.

英文关键词： Reconstituted HDL;Load-induced Heart Failure;Cardiomyocyte Autophagy;PI3K/Akt Signaling Pathway;Sphingosine-1-phosphate