黄芪甲苷激活ROCK/JNK介导自噬减轻异丙肾上腺素诱导的小鼠心肌纤维化

Alleviation of isoproterenol-induced myocardial fibrosis in mice by autophagy regulated by AstragalosideⅣthrough activating ROCK/JNK pathway

目的探讨黄芪甲苷(AS-Ⅳ)激活ROCK/JNK调控自噬,改善异丙肾上腺素(ISO)诱导的小鼠心肌纤维化(MF)的作用及机制。方法将小鼠随机分为对照组、ISO诱导心肌纤维化组(MF组)、黄芪甲苷组、黄芪甲苷与Y33075(ROCK抑制剂)联合组(黄芪甲苷+Y-33075组),重复给药持续30 d后,检测小鼠血清LDH、BNP、CTGF水平,超声检测心功能指标,天狼猩红、Masson染色检测各组小鼠心肌结构及组织纤维化程度,DHE检测各组小鼠心肌组织氧化应激(ROS)水平,蛋白印迹法检测心肌组织ROCK、JNK、Atg5、Beclin 1、LC3Ⅰ/Ⅱ表达。结果与黄芪甲苷组比较,黄芪甲苷+Y-33075组的EF值降低,心肌纤维化程度增加,血清LDH、BNP、CTGF水平升高,心肌组织ROS水平增高,ROCK、JNK、Atg5、Beclin 1、LC3Ⅰ/Ⅱ表达水平表达降低(P<0.05),表明Y-33075能够阻断黄芪甲苷对心肌纤维化的保护作用,并抑制黄芪甲苷对ROCK和JNK的调控。结论黄芪甲苷通过激活ROCK/JNK信号促进自噬减轻小鼠心肌纤维化。

Objective To investigate the effect and mechanism of astragalosideⅣ(AS-Ⅳ)activating ROCK/JNK to regulate autophagy in improving isoproterenol(ISO)induced myocardial fibrosis(MF)in mice.Methods The mice were randomly divided into control operation group(Control group),ISO induced myocardial fibrosis group(MF group),AS-Ⅳtreatment group(AS-Ⅳgroup)and combination group of astragaloside IV and Y-33075(ROCK inhibitor)(astragaloside IV+Y-33075 group).After repeated administration for 30 days.The serum levels of LDH,BNP,CTGF in each group were detected.The cardiac function was detected by ultrasound.Myocardial structure and tissue fibrosis degree in each group were detected by Sirius Red and Masson staining.Oxidative stress(ROS)levels in myocardial tissue of each group were detected by DHE staining and the expression of ROCK,JNK,Atg5,Beclin 1,and LC3Ⅰ/Ⅱin myocardial tissue were detected by Western blotting.Results Compared with AS-Ⅳgroup,the EF value of AS-Ⅳ+Y-33075 group decreased and the degree of myocardial fibrosis increased(P<0.05).The serum level of LDH,BNP,CTGF increased and the level of ROS in myocardial tissue increased while the expression of ROCK,JNK,Atg5,Beclin 1,LC3Ⅰ/Ⅱdecreased(P<0.05).Y-33075 could block the protective effect of AS-Ⅳon myocardial injury induced by MF and inhibit the regulation of AS-Ⅳon ROCK and JNK.Conclusion AS-Ⅳcould attenuate myocardial fibrosis in mice by activating ROCK/JNK signal and promoting autophagy.