H9C2大鼠胚胎心肌细胞缺氧/复氧损伤对端粒酶逆转录酶的表达变化

Changes of telomerase reverse transcriptase expression induced by hypoxia/reoxidation injury in rat H9C2 cardiomyocytes

目的探讨H9C2大鼠胚胎心肌细胞株不同时间缺氧/复氧损伤对端粒酶逆转录酶的表达变化。方法利用H9C2大鼠胚胎心肌细胞株建立缺氧复氧损伤模型,实验分组及处理;正常对照组,缺氧3 h组,缺氧6 h组,缺氧12 h组。缺氧损伤结束后更换为正常培养基进行复氧培养。复氧3 h后进行相关检测,采用CCK-8法测定细胞活力,测定细胞上清液中乳酸脱氢酶(LDH)的含量,Western blot法检测细胞总蛋白中端粒酶逆转录酶(TERT)的表达量。结果随着缺氧处理3、6和12 h后,与对照组相比细胞株的存活率明显下降(P<0.05),其LDH含量明显升高,各个时点与对照组相比,细胞株的TERT蛋白含量明显增高(P<0.05)。其中在缺氧6 h TERT蛋白含量最高(P<0.05)。结论在缺氧3~6 h期间,随着缺氧时间的延长,心肌细胞TERT表达增高,但随着缺氧时间持续延长到12 h,心肌细胞TERT表达降低,导致心肌损伤增加。

Objective To investigate the expression of telomerase reverse transcriptase(telomerase)in H9C2 rat cardiomyocytes after hypoxia/reoxidation injury at different time points.Methods The rat embryonic cardiomyocyte cell line H9C2 was used to establish rat models with myocardial hypoxia/reoxygenation injury,which were randomly divided into the control group and experimental groups(hypoxia for 3 h,6 h and 12 h respectively).The activity of the cells was determined by CCK-8 assay,the content of lactic dehydrogenase(LDH)in the culture medium was measured,and the expression of TERT in the total protein was detected by Western blot assay.Results Compared with the control group,after hypoxia treatment for 3 h,6 h and 12 h,the survival rate of the cell line decreased significantly(P<0.05)and the serum level of LDH increased significantly(P<0.05).In addition,the expression of TERT of experimental groups was significantly increased than that of the control group at each time point.Among them,the highest expression of TERT protein was at 6 h after hypoxia.Conclusion After hypoxia treatments for 3 h,6 h and 12 h respectively,the expression of TERT in the cardiomyocytes increased with prolonged incubation time of hypoxia,but the expression of the TERT in the cardiac muscle decreased after hypoxia treatment for 12 h,and it would enhance myocardial injury.