G蛋白偶联受体激酶2在老年心脏缺血性心衰发生发展中的作用及分子机制研究

Aging play a vital role in the development and progress of post-ischemia heart failure. Previous studies indicated aging increase myocardial apoptotic death, which may be the major cause of post-ischemia heart failure. However, what mediates the pro-apoptotic effect of aging remains unknown. G protein–coupled receptor (GPCR) kinase 2 (GRK2), a critical regulator of cardiac GPCRs, has been shown to be a key regulator of cardiac apoptosis and contractile function. In addition, our most recent experiments indicated GRK2 is up-regulated in the heart from aged mouse compared with the young mouse. the current proposal test a hypothesis that aging result in the up-regulation of GRK2, which in turn activates the downstream apoptotic pathway. To determine the mechanisms leading to GRK2 upregulation in the aged heart, micro-array and real time RT PCR will be utilized to detect DNA methylation, micro RNA and long non-coding RNA(lncRNA) level in the cardiac tissue of the young and old mouse. To clarify the molecular mechanisms through which upregulated GRK2 stimulate cardiomyocyte apoptosis, effect of aging and GRK2 knockout/overexpression upon Akt,MAPKs,Bcl-2/Bcl-xl and GSK3βexpression/activity will be determined. The study will be helpful to clarify the mechanism of aging-related heart failure. Furthermore, it will also contribute to the development of the new treatment on the aging-related heart failure.

衰老导致心肌凋亡增加是其引发或加重缺血后心衰的主要原因。但衰老通过什么机制诱发心肌凋亡，目前尚不明确。已知G蛋白偶联受体激酶2（GRK2）参与缺血后心衰的发生，申请者最新预实验结果表明衰老引起心脏GRK2表达上调。据此提出假说：衰老引起GRK2上调，激活下游凋亡通路而加重缺血后心衰。本研究拟采用老年大鼠缺血性心衰模型，使用基因芯片和real time RT PCR等方法对DNA甲基化、小RNA(micro RNA)和长链非编码RNA(lncRNA)进行检测，力求阐明衰老心脏GRK2表达增加的分子机制；检测老年或GRK2基因敲除/过表达对心肌Akt、MAPKs、Bcl-2家族以及GSK3β表达与活性的影响,以期揭示老年心脏GRK2高表达刺激心肌细胞凋亡加重心衰的下游通路。本项目有助于阐明GRK2在老年心衰中的关键作用,同时为以干预GRK2上\下游通路而保护老年心衰的临床治疗提供实验依据。

衰老导致心肌凋亡增加是其引发或加重缺血后心衰的主要原因。但衰老通过什么机制诱发心肌凋亡，目前尚不明确。已知G蛋白偶联受体激酶2（GRK2）参与缺血后心衰的发生，申请者最新预实验结果表明衰老引起心脏GRK2表达上调。据此提出假说：衰老引起GRK2上调，激活下游凋亡通路而加重缺血后心衰。本研究拟采用老年大鼠缺血性心衰模型，使用基因芯片和real time RT PCR等方法对DNA甲基化、小RNA(micro RNA)和长链非编码RNA(lncRNA)进行检测，力求阐明衰老心脏GRK2表达增加的分子机制；检测老年或GRK2基因敲除/过表达对心肌Akt、MAPKs、Bcl-2家族以及GSK3β表达与活性的影响,以期揭示老年心脏GRK2高表达刺激心肌细胞凋亡加重心衰的下游通路。本项目有助于阐明GRK2在老年心衰中的关键作用,同时为以干预GRK2上\下游通路而保护老年心衰的临床治疗提供实验依据。