运动预处理对心肌缺血再灌注损伤大鼠自噬相关蛋白表达及心肌细胞凋亡的影响

目的 研究运动预处理对心肌缺血再灌注损伤大鼠心肌自噬相关蛋白Beclin 1、微管相关蛋白1轻链3 (LC3)表达及细胞凋亡的影响,探讨其心肌保护相关作用机制。方法 36只雄性Sprague-Dawley大鼠随机分为假手术组(n= 12)、模型组(n= 12)和运动预处理组(n = 12)。运动预处理组造模前给予4周运动预处理训练。结扎左冠状动脉前降支30 min再灌注。再灌注1 h后,Western blotting检测心肌缺血区Beclin 1、LC3蛋白表达;TUNEL染色观察心肌缺血区细胞凋亡情况,计算心肌细胞凋亡指数。结果 与模型组相比,运动预处理组心肌缺血区LC3-Ⅰ蛋白表达上升,Beclin 1、LC3-Ⅱ蛋白表达下降,LC3-Ⅱ/LC3-Ⅰ下降(P< 0.05),心肌缺血区凋亡细胞指数减少(P< 0.05)。结论 运动预处理能上调心肌缺血再灌注损伤大鼠心肌缺血区LC3-Ⅰ表达,下调Beclin 1、LC3-Ⅱ表达,抑制心肌细胞凋亡。

Effects of Exercise Preconditioning on Expression of Autophagy-related Proteins and Apoptosis after Myocardial Ischemia-reperfusion Injury in Rats

Objective To study the effect of exercise preconditioning on the expression of autophagy-related protein Beclin 1 and microtubule-associated protein 1 light chain 3 (LC3), and apoptosis after myocardial ischemia-reperfusion injury in rats, to explore the mechanism of myocardial protection by exercise preconditioning.Methods A total of 36 male Sprague-Dawley rats were randomly divided into sham operation group, model group and exercise preconditioning group, with twelve rats in each group. The exercise preconditioning group received electric treadmill training for four weeks before modeling. The model of myocardial ischemia-reperfusion was made by ligation of the left anterior descending coronary artery 30 minutes and reperfusion. One hour after reperfusion, the expression of Beclin 1 and LC3 protein in myocardium was detected by Western blotting, and apoptosis of myocardial cells was observed by TUNEL staining, then the apoptotic index was calculated.Results Compared with the model group, the level of LC3-I protein in the myocardial ischemic area increased, the levels of Beclin 1 and LC3-II decreased, the ratio of LC3-II/LC3-I decreased (P < 0.05); and the apoptotic index decreased in the preconditioning group ( P < 0.05). Conclusion Exercise preconditioning could up-regulate LC3-I in ischemic area, down-regulate the expression of Beclin 1 and LC3-II, and inhibit cardiomyocyte apoptosis after ischemia-reperfusion.