养心定悸胶囊对心肌缺血再灌注损伤大鼠心肌细胞自噬和凋亡的影响

Effect of Yangxin Dingji Capsule on autophagy and apoptosis of myocardial cells in rats with myocardial ischemia-reperfusion injury

目的:探讨养心定悸胶囊对心肌缺血再灌注损伤(MIRI)大鼠心肌细胞自噬和凋亡的影响。方法:将30只成年雄性SD大鼠随机分为5组(假手术组、模型组与低、中、高剂量养心定悸组),每组6只。使用ELISA试剂盒检测各组大鼠血清中心肌损伤标志物含量,Tunel法检测各组大鼠心肌组织细胞凋亡情况,Western blot法检测各组大鼠心肌组织凋亡和自噬相关蛋白表达情况。结果:与模型组比较,养心定悸胶囊低、中、高剂量组大鼠血清肌钙蛋白I(cTnI)、肌酸激酶(CK)和乳酸脱氢酶(LDH)水平下降,差异均有统计学意义(P<0.05),高剂量组降低最明显;养心定悸胶囊各剂量组大鼠心肌细胞凋亡数量减少,心肌细胞B淋巴细胞瘤-2基因(Bcl-2)、磷酸化磷脂酰肌醇3激酶(p-PI3K)和磷酸化丝氨酸/苏氨酸激酶(p-Akt)、磷酸化哺乳动物雷帕霉素靶蛋白(p-mTOR)表达水平明显升高,差异均有统计学意义(P<0.05),激活型半胱氨酸蛋白酶-3(cleaved Caspase-3)、激活型半胱氨酸蛋白酶-9(cleaved Caspase-9)和Bcl-2基因关联X(Bax)蛋白、微管相关蛋白轻链(LC3II/I)和自噬效应蛋白(Beclin1)表达水平降低,差异均有统计学意义(P<0.05),并呈剂量依赖性。结论:养心定悸胶囊通过抑制心肌细胞凋亡和自噬对MIRI大鼠的心肌发挥保护作用,这一作用可能与PI3K/Akt/mTOR通路相关。

Objective:To investigate the effect of Yangxin Dingji Capsule on autophagy and apoptosis of myocardial cells in rats with myocardial ischemia-reperfusion injury(MIRI).Methods:Thirty adult male SD rats were randomly divided into 5 groups(sham-operated group,model group,low dose of Yangxin Dingji Capsule group,medium dose of Yangxin Dingji Capsule group and high dose of Yangxin Dingji Capsule group),with 6 rats in each group.The serum levels of myocardial injury markers were detected by ELISA kit.Tunel method was used to detect the apoptosis of myocardial tissue in each group.Western blot was used to detect the expression of apoptosis and autophagy-related proteins in myocardial tissue in each group.Results:Compared with model group,the levels of serum troponin I(cTnI),creatine kinase(CK)and lactate dehydrogenase(LDH)in rats in low,medium and high dose of Yangxin Dingji Capsule group were decreased,and the differences were statistically significant(P<0.05).The reduction was most pronounced in the high dose group.The number of apoptosis of myocardial cells decreased in each dose group of Yangxin Dingji Capsule.The expression levels of cardiomyocyte B-lymphocytoma-2 gene(Bcl-2),phosphorylated phosphatidylinositol 3 kinase(p-PI3K),phosphorylated serine/threonine kinase(p-Akt)and phosphorylated mammalian target of rapamycin(p-mTOR)were significantly increased in cardiomyocytes(P<0.05).The expression levels of cleaved Caspase-3,cleaved Caspase-9,Bcl-2 gene-associated X(Bax)protein,microtubule-associated protein light chain(LC3II/I)and autophagy effector protein(Beclin1)were decreased in a dose-dependent manner(P<0.05).Conclusion:Yangxin Dingji Capsule can protect the myocardium of MIRI rats by inhibiting cardiomyocyte apoptosis and autophagy,which may be related to PI3K/Akt/mTOR pathway.