基于chymase/AngⅡ途径探讨解毒通络法对大鼠心肌纤维化的影响

Myocardial fibrosis is an important pathological process of almost all cardiovascular disease, such as hypertensive cardiopathy, myocarditis, coronary heart disease and so on, which often accompanied with myocardial interstitial remodeling and heart function decay, so it is important to preventing myocardial fibrosis for decreasing mortality of heart disease. Chymase, produced by mast cells, can take part in the myocardial fibrosis through producing angiotensinⅡ(AngⅡ) directly or indirectly. Professor Ren think that "Du shang xue luo" is the pathogenesis of myocardial fibrosis and it can be prevented by Jiedu tongluo. It has been founded that Jiedu tongluo can reverse hypertensive left ventricular hypertrophy, reduce the myocardial collagen I and Ⅲ and suppress or reduce myocardial fibrosis of rat induced by AngⅡ. This research will focus on the mechanism of preventing effects of Jiedu Tongluo on myocardial fibrosis in rats by inhibiting chymase/AngⅡ pathway. Both animal experiment and cell culture methods will adapted. For animal experiment, the myocardial fibrosis model of rats were produced by isoprenaline subcutaneous injection, and for in vitro, the myofibroblasts and mast cells of rats will be co-cultured, both will treated by Jiedu tongluo. The results of this research will provide important proof of Jiedu tongluo preventing myocardial fibrosis in its clinical application.

心肌纤维化（Myocardial fibrosis，MF）为多种心血管疾病（如高血压性心脏病、心肌炎、冠心病等）共有的重要病理过程，每伴随心肌间质网络重构（remodeling）和心脏功能减退，抑制MF对于降低心血管疾病的致死风险具有重要意义。肥大细胞产生的心脏糜酶（chymase）可通过刺激血管紧张素Ⅱ（Angiotensin Ⅱ, AngⅡ）生成直接或间接多种机制参与MF形成。已故国医大师任继学教授提出“毒伤血络”为MF的病机，而解毒通络法能逆转左室肥厚、降低心肌I、Ⅲ型胶原产生、减少AngⅡ诱导的大鼠MF。本项目在既往工作的基础上，以盐酸异丙肾上腺素皮下注射法复制大鼠MF模型，探讨解毒通络法防治大鼠心肌纤维化的效果，并基于chymase/AngⅡ途径推测其机制，并通过大鼠心脏肥大细胞与心肌成纤维细胞共培养的方法，从体外细胞学角度探讨解毒通络法抑制MF的机制。

心肌纤维化为多种心血管疾病（如高血压性心脏病、心肌炎、冠心病等）共有的重要病理过程，每伴随心肌间质网络重构（remodeling）和心脏功能减退，抑制心肌纤维化对于降低心血管疾病的致死风险具有重要意义。肥大细胞产生的心脏糜酶可通过AngⅡ生成直接或间接多种机制参与心肌纤维化形成。已故国医大师任继学教授提出“毒伤血络”为心肌纤维化的病机，而解毒通络法能逆转左室肥厚、降低心肌I、Ⅲ型胶原产生、减少AngⅡ诱导的大鼠心肌纤维化。本项目在既往工作的基础上，以盐酸异丙肾上腺素皮下注射法复制大鼠心肌纤维化模型结合大鼠心肌成纤维细胞体外培养方法，探讨解毒通络法防治大鼠心肌纤维化的效果，并基于chymase/AngⅡ途径推测其机制。.研究结果显示，解毒通络方能明显减轻大鼠心肌纤维化程度，抑制心肌组织及心肌成纤维细胞胶原等ECM合成与分泌，降低心肌纤维化指数，延缓心肌纤维化进程。进一步分析结果显示，解毒通络方能抑制心肌纤维化大鼠心肌组织Ang II浓度；减少心肌组织肥大细胞数量，抑制其糜酶表达和分泌，并降低其活性；抑制心肌组织中ACE的合成，同时促进ACE2的合成。同时，解毒通络方还能抑制心肌纤维化大鼠心肌组织及成纤维细胞TGF-β、tTG、Vimentin、α-SMA的转录和翻译。.通过研究，我们认为，解毒通络方可有效的延缓和抑制心肌纤维化进程，其机制是通过抑制AEC并激活ACE2表达和抑制糜酶活性和表达2种途径减少心肌组织ANG II的生成，进而抑制Ang II途径诱导的心肌纤维化进程。