衰竭心肌细胞骨架机械信号传递通路对细胞电重构及离子通道谱表达的影响及机制研究

Cardiac electrical remodeling due to ion channel function abnormality is the electrophysiological mechanism of arrhythmiainin in heart failure. At present, the comprehensive knowledge of effect of cytoskeleton on ion channels regulate during heart failure induced by mechanical stimulation d is insufficiency. The research using pressure and overload heart failure SD rat and neonatal rat myocardial cells cultured by stretch stimulation as the research object. using the patch-clamp, proteomics, molecular biology techniques. ① On the whole level , observation of QTC, change of cellular membrane ion channel expression after mechanical stimulation, and the responses of give the mechanical stimulation sensitivity of receptor blockers and microtubule intervention agent on QTC and cell membrane ion channel expression influence. ② On the cell and molecular level, observation of mechanical stretch stimulation of myocardial cells after mechanical stimulation of sensitive receptor blockers and cytoskeletal intervention agents under the action of APD, membrane ionic currents and ion channel gene profiling, proteingram changes. in order to prove that the cytoskeletal machinery transmission system participating in heart failure of electrical remodeling, and to elucidate molecular mechanism of electric remodeling of ionic channel changes. ③ Meanwhile, on the whole level and cell level observation the effects of beta blockers to mechanical stimulation of the myocardial cells APD, ion current, ion channel gene profiling, protein profiling. laying the theoretical foundation the development of a new generation of antiarrhythmic drugs which improved APD based on, multiple ion channels as targets

离子通道功能异常所致电重构是心力衰竭恶性心律失常的电生理基础，目前缺乏对心衰始动因素机械刺激传递通路-细胞骨架对离子通道调节的全面认识。本研究以超负荷心衰SD大鼠、牵张刺激培养乳鼠心肌细胞为研究对象，采用膜片钳、蛋白质组、分子生物学技术:①整体水平上观察机械刺激后QTC、膜离子通道的变化，及给予机械刺激敏感性受体阻滞剂和微管干预剂后对QTC和膜离子通道表达的影响；②细胞、分子水平上观察机械牵张刺激的心肌细胞在机械刺激敏感受体阻滞剂和细胞骨架干预剂的作用下APD、膜离子流及离子通道基因谱、蛋白谱的变化，以期证明细胞骨架机械传递系统参与心力衰竭的电重构并阐明其电重构的离子通道变化分子机制；③从整体、细胞水平观察β受体阻滞剂对机械牵张的心肌细胞APD、离子流、离子通道基因谱、蛋白谱表达的影响，为基于开发改善多种离子通道为作用靶点的新一代抗心律失常药奠定理论基础，进而改善心衰心律失常的治疗。

离子通道表达或功能异常所致电重构是心力衰竭恶性心律失常的电生理基础，细胞骨架是心肌细胞内机械信号通路的重要环节。目前缺乏对细胞骨架介导的机械信号通路对离子通道谱调节的全面认识。我们假设，机械刺激作为心力衰竭的始动因素，通过细胞骨架介导作用于心肌细胞，引起后者电生理特征的异常改变，参与心力衰竭心律失常的发生。1.本研究通过腹主动脉-腔静脉造瘘术建立容量超负荷心力衰竭大鼠模型、采用升主动脉缩窄术建立压力超负荷心力衰竭大鼠模型；2.给予机械信号通路干预剂（机械敏感性离子通道阻滞剂链霉素、微管解聚剂秋水仙素、微管稳定剂紫杉醇），证明了机械信号传递通路对心力衰竭心脏电生理改变（体表心电图QT间期）及衰竭心肌细胞膜离子通道谱重构具有调节作用；3.明确倍他乐克对心力衰竭大鼠心脏结构、心功能的影响，以及倍他乐克对衰竭心肌细胞膜离子通道谱重构具有调节作用；4.检测衰竭心肌细胞内线粒体膜蛋白质谱的表达及芪苈强心胶囊干预后的改变，提示芪苈强心胶囊的治疗机制之一可能是通过调节心肌线粒体能量代谢、氧化应激相关蛋白。本研究结果为阐明机械刺激诱导心肌细胞肥大以及电重构等病理生理过程的机制提供理论依据，同时以期为开发基于机械信号通路来调节衰竭细胞离子通道谱重构的新型抗心律失常药物奠定基础。