积雪草苷促进ROCK/JNK通路介导的自噬减轻小鼠压力负荷性心肌肥厚

Asiaticoside alleviates stress-induced cardiac hypertrophy in mice by promoting autophagy through ROCK/JNK pathway

目的探讨积雪草苷(asiaticoside,ASI)改善主动脉缩窄(TAC)所致心肌肥厚的作用及机制。方法将100只雄性6周龄C57/BL小鼠随机分为假手术组(sham组)、TAC组、ASI+TAC组、ASI+Y-33075(ROCK抑制剂)+TAC组。各组以普通饲料喂养,TAC组、ASI+TAC组和ASI+Y-33075+TAC组以结扎小鼠主动脉弓方式建立TAC模型。自模型建立第1天起,ASI+TAC组腹腔注射ASI[10 mg/(kg·d)],ASI+Y-33075+TAC组同时给予腹腔注射ASI[10 mg/(kg·d)]以及Y-33075[10 mg/(kg·d)],连续给药30 d。检测小鼠血清结缔组织生长因子(CTGF)、心房钠尿肽(ANP)、脑钠尿肽(BNP)水平,超声检测心脏左室射血分数等心功能指标,HE、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,LC3Ⅱ/Ⅰ免疫荧光染色检测各组小鼠心肌组织自噬水平,Western blot检测心肌组织ROCK、JNK及自噬相关蛋白Atg5、Beclin 1、LC3Ⅱ/Ⅰ表达。结果与sham组比较,TAC组射血分数(ejection fraction,EF)值降低,心肌肥厚程度增加,血清ANP、BNP、CTGF水平升高,ROCK、JNK、Atg5、Beclin 1、LC3Ⅱ/Ⅰ表达水平降低(均P<0.05);与TAC组比较,ASI+TAC组EF值增加,心肌肥厚程度降低,血清ANP、BNP、CTGF水平降低,ROCK、JNK、Atg5、Beclin 1、LC3-Ⅰ/Ⅱ表达增高(均P<0.05);与ASI+TAC组比较,ASI+Y-33075+TAC组EF值降低,心肌肥厚程度增加,血清ANP、BNP、CTGF水平升高,ROCK、JNK、Atg5、Beclin 1、LC3Ⅱ/Ⅰ表达水平表达降低(均P<0.05)。结论ASI通过激活ROCK/JNK信号上调自噬减轻TAC引起的心肌损伤。

Objective To investigate the effect and mechanism of asiaticoside(ASI)on cardiac hypertrophy induced by transverse aortic constriction(TAC).Methods A total of 100 male 6-week-old C57/BL mice were randomly divided into sham group,TAC group,ASI+TAC group,and ASI+Y-33075+TAC group.All mice were fed with ordinary diet.TAC model was established by ligating the aortic arch of mice in TAC group,ASI+TAC group,and ASI+Y-33075+TAC group.From the first day of TAC establishment,the mice were intraperitoneally injected with ASI[10 mg/(kg·d)]in ASI+TAC group,and ASI[10 mg/(kg·d)]and Y-33075[10 mg/(kg·d)]in ASI+Y-33075+TAC group for 30 d.The levels of serum connective tissue growth factor(CTGF),atrial natriuretic peptide(ANP)and brain natriuretic peptide(BNP)in mice were detected.The left ventricular ejection fraction and other cardiac function indexes were detected by ultrasound.The myocardial structure and the tissue fibrosis degree of mice in each group were detected by HE,Sirius red and Masson staining.The autophagy level of mice in each group was detected by LC3Ⅱ/Ⅰimmunofluorescence staining.The expression of ROCK,JNK,autophagy-related proteins Atg5,Beclin 1 and LC3Ⅱ/Ⅰin myocardial tissue was detected by Western blot.Results Compared with sham group,the EF value was decreased in TAC group,the degree of myocardial hypertrophy was increased,the levels of ANP,BNP and CTGF were increased,and the expression levels of ROCK,JNK,Atg5,Beclin 1 and LC3Ⅱ/Ⅰwere decreased(all P<0.05).Compared with TAC group,the ejection fraction(EF)value was increased in ASI+TAC group,the degree of myocardial hypertrophy was decreased,the levels of serum ANP,BNP and CTGF were decreased,and the expression of ROCK,JNK,Atg5,Beclin 1 and LC3Ⅱ/Ⅰwas increased(all P<0.05).Compared with ASI+TAC group,the EF value was decreased in ASI+Y-33075+TAC group,the degree of myocardial hypertrophy was increased,the levels of serum ANP,BNP and CTGF were increased,and the expression levels of ROCK,JNK,Atg5,Beclin 1 and LC3Ⅱ/Ⅰwere decreased(all P<0.05).Conclusion ASI attenuates myocardial injury induced by TAC by activating ROCK/JNK signal and promoting autophagy.