KLF9通过增加氧化应激对心肌细胞缺血损伤的影响

Effect of KLF9 on myocardial ischemic injury by increasing oxidative stress

目的探讨Kruppel样转录因子9(KLF9)通过增加氧化应激对心肌细胞缺血损伤的影响。方法将心肌细胞H9c2分为以下两组,正常组:将心肌细胞H9c2放于10%胎牛血清的DMEM、100 U/ml的青霉素和链霉素中培养;缺血组:用无血清代替培养基,添加至10μg/ml转铁蛋白和10μg/ml胰岛素中培养。通过逆转录聚合酶链式反应(Rt-PCR)检测KLF9的mRNA水平,采用免疫印迹(Western blotting)检测KLF9蛋白的表达,对乳酸脱氢酶(LDH)的活性进行测定,MTT法检测心肌细胞活力,应用缺口末端标记法(TUNEL)检测细胞凋亡情况,对活性氧(ROS)进行测定。结果心肌细胞中KLF9 mRNA的表达水平较正常组比较明显增加(P<0.05);心肌细胞中KLF9蛋白水平较正常组比较明显升高(P<0.05);缺血组的心肌细胞LDH的释放能力明显高于正常组(P<0.05),在转染siKLF9#1和siKLF9#2后的缺血组LDH的释放能力较siCtrl中的缺血组相比明显减弱(P均<0.05);缺血组的心肌细胞活力的明显高于正常组(P<0.05),在转染siKLF9#1和siKLF9#2后的缺血组细胞活力较siCtrl中的缺血组相比明显降低(P均<0.05);缺血组的心肌细胞凋亡能力的明显低于正常组(P<0.05),在转染siKLF9#1和siKLF9#2后的缺血组细胞凋亡能力较siCtrl中的缺血组相比明显降低(P均<0.05);缺血组的心肌细胞ROS水平明显低于正常组(P<0.05),在转染siKLF9#1和siKLF9#2后的缺血组细胞ROS水平较siCtrl中的缺血组相比明显降低(P均<0.05)。结论KLF9可增加ROS的水平加重心肌细胞缺血性损伤,靶向KLF9可能有助于维持心肌细胞的活力,减少心肌梗死期间心肌细胞的损伤。

Objective To explore the effect of Kruppel-like transcription factor 9(KLF9)on ischemic myocardial injury by increasing oxidative stress.Methods The cardiomyocyte H9c2 was divided into the following groups,the normal group:the cardiomyocyte H9c2 was cultured in 10%fetal bovine serum in DMEM,100 U/ml penicillin and streptomycin;ischemia group:serum-free instead of medium,Added to 10μg/ml transferrin and 10μg/ml insulin culture.The mRNA level of KLF9(Kruppel-like transcription factor 9)was detected by reverse transcription polymerase chain reaction(Rt-PCR),the expression of KLF9 protein was detected by Western blotting,and the activity of lactate dehydrogenase(LDH)was tested.Determination,MTT method was used to detect cardiomyocyte viability,TUNEL was used to detect cell apoptosis,and reactive oxygen species(ROS)was measured.Results The expression of KLF9 mRNA in cardiomyocytes was significantly higher than that in the normal group(P<0.05).The level of KLF9 protein in cardiomyocytes was significantly higher than that in the normal group(P<0.05).The release of LDH in the ischemic group.The ability was significantly higher than that of the normal group(P<0.05).The release ability of LDH in the ischemic group after siKLF9#1 and siKLF9#2 was significantly weaker than that in the siht group(both P<0.05).The viability of cardiomyocytes in the blood group was significantly higher than that in the normal group(P<0.05).The viability of the ischemic group after transfection of siKLF9#1 and siKLF9#2 was significantly lower than that in the ischemic group in siCtrl(both P<0.05).The ability of cardiomyocyte apoptosis in the ischemic group was significantly lower than that in the normal group(P<0.05),and the apoptosis ability of the ischemic group after transfection of siKLF9#1 and siKLF9#2 was lower than that in the siCtrl group.Compared with the significant decrease(all P<0.05),the ROS level of myocardial cells in the ischemic group was significantly lower than that in the normal group(P<0.05),and the ROS level in the ischemic group after transfection of siKLF9#1 and siKLF9#2 was higher than that of siCtrl.There was a significant decrease in the ischemic group(both P<0.05).Conclusion KLF9 can increase the level of ROS and aggravate myocardial ischemic injury.Targeting KLF9 may help maintain the viability of cardiomyocytes and reduce myocardial cell damage during myocardial infarction.