糖尿病大鼠心肌组织中自噬相关基因Atg7和Atg12-Atg5表达降低

摘要

Objective To investigate the protein expression of Atg7 and Atg12-Atg5 in myocardium of streptozotocin (STZ)diabetic rats.Methods The diabetic model was made in rats by injection of STZ.The rats were divided into control group(NC)and diabetes model group(DM).The left ventricular weight index of rats was detected at the time of 10,20,30,40,60,80,100 d after model initiated.The protein expression of Atg7 and Atg12-Atg5 in myocardium of rats was assayed by western blot.The myocardial ultrastructure and autophagosome were observed by electron microscope. Results Compared with rats in NC group at the same period,the left ventricular weight index in DM group increased since the day of 40th.The protein expression of Atg7 and Atg12-Atg5 in myocardium of diabetic rats increased a little at 20 d(It had not a statistical significance),but reduced significantly at 80 d(P<0.01).The changes in the myocardial ultrastructure and decrease in autophagosome were both obvious in diabetic rats at 80 d.Conclusions With the develop-ment of diabetes mellitus,the autophagy level in myocardium of STZ diabetic rats finally is reduced.%目的 探讨链脲佐菌素(STZ)糖尿病大鼠心肌组织中自噬相关基因的蛋白表达情况.方法 将大鼠分为对照组(NC)、糖尿病模型组(DM,采用尾静脉注射STZ制备糖尿病模型).在造模后10、20、30、40、60、80和100 d时,检测大鼠的左心质量指数;Western blot 检测Atg7和Atg12-Atg5蛋白表达;透射电镜观察心肌超微结构和自噬小体.结果 与对照组相比,DM组的左心质量指数在40 d开始增加;Atg7和Atg12-Atg5蛋白表达20 d时稍增多,在80 d时蛋白表达显著降低(P<0.01);超微结构改变和自噬小体明显减少.结论 随着病情发展,DM组大鼠心肌组织中自噬现象最终表现为减少.