ERK1/2信号通路在老龄缺血性心力衰竭中的作用及靶向干预研究

Aging is considered as a major risk factor for ischemia heart failure , to reverse the pathological and physiological cardiac remodeling process is the key factor to control the development of congestive heart failure. Recently, we have identified that the ERK1/2 signaling pathway activition in aged mice heart was significantly lower than that in youger mice suffering from myocardial infarction, but the mechanisms are not clear. Our previous studies have demonstrated that CaMEK geng transduce could activate ERK1/2 signaling pathway and result in attenuated acute myocardial ischemia-reperfusion in aged mice. So, this research will mainly explore the effects and mechanisms of ERK1/2 signal pathway in ischemic congestive heart failure of aged mice, meanwhile to select the ERK1/2 signal pathway as intervention target，to construct the double strand serotype 9 recombinant adeno-associated viral vectors containing CaMEK gene and to targetly transfect it into the heart, the research will investigate the index of ERK1/2 signal pathway activity and related proteins expression, mitochondrial function , oxidative stress, collagen protein and inflammatory factors expression, MMPs activity, myocardial pathological damage, infarct size and cardic function, et al. Meanwhile we will also investigate the targeted activation of ERK1/2 signaling pathway, prevent and cure the aging ischemic heart failure and provide the insight and molecular mechanisms of identified gene.

老龄是缺血性心力衰竭发病的高危因素，逆转心室重塑的病理生理过程是控制心衰发生的关键。我们前期研究发现ERK1/2信号通路在老龄心肌梗死后活性较年轻心肌显著下降, 但具体机制不详，CaMEK 基因转导可有效减轻老龄急性心肌缺血再灌注损伤。据此，本课题拟采用老龄小鼠缺血性心衰模型，探讨ERK1/2通路在老龄缺血性心衰中的作用及分子机制；同时，以ERK1/2信号通路为干预靶点，构建CaMEK基因的双链重组AAV-9载体，靶向转导老龄小鼠心脏，通过检测ERK1/2活性及通路中相关蛋白、线粒体功能、氧化应激、胶原表达、细胞凋亡、MMPs活性、心肌病理损害程度、心功能等指标，阐明靶向激活ERK1/2信号通路防治老龄缺血性心力衰竭的作用及分子机制，明确基因靶向干预治疗的有效性和可行性，为老龄缺血性心力衰竭的基因治疗提供新的思路和依据。

线粒体结构紊乱和功能异常是心肌衰老的关键因素，ERK1/2信号通路在线粒体质量控制中发挥重要的调节作用，然而ERK1/2是否通过调控线粒体形态和功能而参与衰老心肌缺血性损伤及心力衰竭尚不清楚。本课题研究表明，ERK1/2信号通路活化受限是衰老心肌缺血性损伤严重的重要原因之一。我们在衰老心肌缺血及缺氧损伤模型中，用亲心肌、安全、高效稳定的dsAAV9-CMV-CaMEK载体进行靶向干预后发现，该病毒载体能够有效激活心肌组织及细胞中的ERK1/2信号通路，增加线粒体融合蛋白Mfn1、降低线粒体分裂蛋白Drp1的水平，抑制心肌细胞线粒体过度分裂和氧化应激损伤，促进线粒体功能恢复，进而抑制心肌细胞凋亡和细胞坏死，最终改善小鼠心脏功能。上述结果提示，ERK1/2信号通路通过调控线粒体融合与分裂参与衰老心肌损伤的病理过程，而dsAAV9-CMV-CaMEK载体激活该信号通路后有望成为衰老心肌损伤个性化防治的良好手段之一。