益气活血药对心肌梗死后神经重构及ERK1/2信号通路影响的研究

The incidence and mortality of myocardial infarction are on the rise, and this situation is very harmful. The focus of the study is still the pathological mechanism and prevention. This project based on the previous extensive research work, relying on the classical model of myocardial infarction and oxygen glucose deprivation model of myocardial cells, using the techniques of cardiac magnetic resonance imaging, microscopic image analysis, immunohistochemistry and cardiac electrophysiological stimulation, from the whole animal, cell and molecular level: The impact on myocardial ischemia, arrhythmia and cardiac function change could be revealed by studying the damage and reconstruction of the sympathetic nerve in the myocardial infarction area and infarct marginal zone. By studying the process of sympathetic nerve remodeling, to reveal the relationship between left ventricular remodeling, electrical remodeling and sympathetic nerve remodeling, to explore whether the sympathetic nerve reconstruction plays a leading role. By studying the expression of ERK1/2 signal transduction pathway, to reveal the change of ERK1/2 related proteins and the regulation function of the reconstruction of the sympathetic nervous after myocardial infarction. Based on the theory of qi and blood in traditional Chinese medicine and the change of index, from the change of cardiac function and structure, nerve injury and repair and electrophysiological changes, combined with the previous study of cardiac microcirculation, energy metabolismto analyse, to explore the theoretical basis of TCM “heart governing blood and vessels”.

心肌梗死的发病率和死亡率呈上升趋势，危害性大，其病理机制和防治仍是研究的重点。本项目在前期大量研究工作基础上，依托经典大鼠心肌梗死模型和心肌细胞缺氧缺糖模型，借助心脏核磁共振技术、显微图像分析、免疫组化和心脏电生理刺激等技术，从动物整体、细胞和分子水平层面，通过研究心肌梗死区和梗死边缘区的交感神经受损以及重构情况，揭示其对心肌缺血、心律失常、心功能变化的影响过程；通过研究在交感神经重构过程中，揭示其与左心室重构、电重构的关系，探究交感神经重构是否发挥着主导作用；通过研究ERK1/2信号通路的表达情况，揭示ERK1/2等相关蛋白的变化，对心肌梗死交感神经重构的调控作用；以中医气血理论为指导，基于指标变化情况，从心脏功能和结构、神经损伤和修复、电生理特性等的变化，并结合课题组前期心脏微循环、能量代谢等有关研究成果，探索阐释中医“心主血脉”的相关理论基础。

心肌梗死后交感神经的过度再生和分布的不均一性，称神经重构，会导致心室重塑及不可逆性心功能损害。对神经重构的评价和干预可能会为心肌梗死后患者的治疗和预后提供一个新方向。课题组前期研究表明，益气活血方（Yiqihuoxue Decoction, YQHX）能有效改变心肌梗死后炎症因子异常表达，防治心肌重构，改善左室功能，降低心肌梗死后心力衰竭的发生率。本研究以在体大鼠心梗模型和体外缺氧诱导心肌细胞损伤模型为基础，观察益气活血方对心梗大鼠心肌组织及缺氧心肌细胞的保护作用，发现益气活血方可显著改善心梗对心肌组织和缺氧对心肌细胞的损伤，并改善心梗后神经纤维的过度再生和分布的密度，调节神经重构相关因子的表达。其中，7天作为亚急性期，是神经重构相关因子NGF、GAP43、Sema-3A和TH蛋白表达的临界点也是中药和西药药效的临界点。还可以显著降低心梗大鼠血浆NPY的浓度及下调梗死边缘区ANP蛋白的表达，改善心肌细胞肥大情况。此外，益气活血方水提物对缺氧心肌细胞的保护，是通过抑制缺氧诱导的ERK磷酸化途径来实现的，其效果通过ERK1/2信号通路平衡了NGF和Sema-3A在缺氧心肌细胞上的表达，提示益气活血方可通过抑制神经重构相关因子在ERK1/2信号通路上的表达，保护缺氧受损的心肌细胞。但对NGF和Sema-3A的调控，可能还存在其他通路或靶点，有待于我们的进一步研究。