目的 探讨瑞舒伐他汀(RSV)对急性心肌梗死大鼠心肌细胞自噬及凋亡的调节作用及可能机制.方法 采用简单随机抽样方法将SD大鼠分为假手术大鼠组(Sham组);急性心梗模型大鼠组(AMI组);RSV治疗急性心梗模型大鼠组(RSV组,剂量为5 mg· kg-1·d-1);RSV治疗急性心梗模型大鼠,同时给予AMPK抑制剂Compound C处理(RSV+ CC组),每组8只.H9c2大鼠心肌细胞,分为正常细胞组(control),缺氧细胞组(Hypoxia),缺氧+RSV干预组(Hypoxia+ RSV),缺氧+RSV+ Compound C组(Hypoxia+ RSV+ CC);缺氧+AICAR(AMPK激活剂)组(Hypoxia+AICAR);大鼠造模干预6周后行血流动力学检查,取出心脏,HE染色观察心肌病理学变化;RT-PCR及Western印迹分别检测不同组别大鼠心肌组织及细胞Beclin1、p62、BAX、Bcl-2 mRNA表达;Western印迹检测各组心肌组织mTOR及AMPK蛋白表达及磷酸化情况.结果 本研究成功制备急性心梗大鼠模型,相比AMI组,RSV干预组大鼠心肌组织炎症减轻,LVMI显著降低,LVSP显著上升,LVEDP显著降低,HR显著降低,dP/dTmax及-dP/dTmax绝对值显著升高;Beclin1、Bcl-2 mRNA表达水平分别从0.43上升到2.01和0.30上升到0.72、p62、BAX mRNA表达水平降低一半,AMPK磷酸化水平显著上调,mTOR磷酸化水平显著降低(P<0.05);上述变化在RSV+ CC组中受到AMPK抑制剂的拮抗.体外细胞实验结果显示,RSV干预后心肌细胞Beclin1、Bcl-2 mRNA及蛋白相对表达水平上调3倍左右,p62、BAXmRNA及蛋白相对表达水平显著降低一半以上;上述变化与AMPK激活剂处理组一致,并受到Compound C的拮抗.结论 RSV可通过AMPK/mTOR途径有效地促进心肌梗死后大鼠心脏细胞自噬,减少凋亡.
Objective To investigate the effects of rosuvastatin (RSV)on autophagy and apoptosis of myocardial cells in rats with acute myocardial infarction.Methods SD rats were divided into control (Sham group),acute myocardial infarction model rats (AMI group),AMI rats treated by RSV with the dose of 5 mg · kg-1 · d-1(RSV group),AMI rats treated by RSV and AMPK inhibitor Compound C at the same time (RSV +CC group)(n =8) based on simple random sampling methods.Rat myocardial cell line H9c2 was divided into control group,Hypoxia group,Hypoxia + RSV group,Hypoxia + RSV + Compound C group,Hypoxia + AICAR (AMPK activator) group.After 6 weeks,the rats were examined by hemodynamics,and pathological observation of myocardial tissue by HE staining was also carried out.RT-PCR/Western blot were used to detect the expression of Beclin1,p62,BAX and Bcl-2 mRNA or protein of different groups in vivo and in vitro.Western blot was used to detect the expression of mTOR and AMPK protein and phosphorylation in cardiac tissue of each group.Results In this study,the rat model of acute myocardial infarction was successfully prepared.Compared with the AMI group,the myocardium inflammation in the RSV group was alleviated,the LVMI decreased significantly,LVSP increased significantly,LVEDP decreased significantly,HR decreased significantly,the absolute value of dP/dTmax and-dP/dTmax increased significantly.The levels of Beclinl and Bcl-2 mRNA were significantly upregulated from 0.43 to 2.01 and 0.30 to 0.72,the expression of p62 and BAX mRNA decreased in half,the phosphorylation level of AMPK was significantly up-regulated,and the level of mTOR phosphorylation significantly reduced (P <0.05).These changes were antagonized by AMPK inhibitors in RSV + CC group.In vitro experiments showed that,after RSV intervening,the levels of Beclinl and Bcl-2 mRNA and protein in the myocardial cells of Hypoxia group significantly increased in triple,while the expressions of p62 and BAX mRNA and protein significantly decreased above a half.The above changes were consistent with those of the AMPK activator group and were antagonized by Compound C.Conclusion RSV can effectively promote autophagy and decrease apoptosis in rat heart after myocardial infarction through AMPK/mTOR pathway.