急性缺氧诱导小鼠心肌细胞微小RNA-34a升高和凋亡实验研究

Experimental study of microRNA-34a elevation and apoptosis in mouse cardiomyocytes induced by acute hypoxia

目的:探讨急性缺氧对心肌细胞miR-34a表达、蛋白磷酸酶1核靶向亚基(PNUTS)蛋白和凋亡的影响。方法:原代培养小鼠乳鼠心肌细胞,缺氧24 h造模,使用antimiR-34a纳米颗粒干预。将其随机分为三组:对照组、缺氧组、缺氧+antimiR-34a纳米颗粒组。采用实时荧光定量聚合酶链反应(qRT-PCR)测miR-34a表达,Western blot检测PNUTS蛋白表达,流式细胞术测凋亡率。结果:与对照组相比,缺氧24 h后miR-34a表达明显增高(P<0.05),PNUTS水平降低(P<0.05),凋亡率升高(P<0.05);与缺氧组相比,缺氧+antimiR-34a纳米颗粒组的miR-34a表达下降(P<0.05),PNUTS水平升高(P<0.05),凋亡率下降(P<0.05)。结论:急性缺氧上调小鼠心肌细胞miR-34a基因表达,下调其下游PNUTS蛋白表达,同时上调凋亡率;antimiR-34a纳米颗粒抑制急性缺氧诱导的小鼠心肌细胞miR-34a升高,PNUTS降低以及细胞凋亡。

Objective:To investigate the effects of acute hypoxia on miR-34a expression,PNUTS protein and apoptosis in mouse cardiomyocytes.Methods:Primary cultured mouse mammary heart myocytes were cultured and modeled with hypoxia for 24 hours and intervened with antimiR-34a nanoparticles.They were randomly divided into three groups:control group,hypoxia group,and hypoxia+antimiR-34a nanoparticles group.The expression of miR-34a was measured by qRT-PCR,and the expression of PNUTS protein was detected by Western blot.Apoptosis rate was measured by flow cytometry.Results:Compared with the control group,miR-34a expression was significantly increased(P<0.05),PNUTS level was decreased(P<0.05),and apoptosis rate was increased(P<0.05)after 24 hours of hypoxia.Compared with the hypoxia group,miR-34a expression was decreased(P<0.05),PNUTS level was increased(P<0.05)in the hypoxia+antimiR-34a nanoparticles group,and apoptosis rate was decreased(P<0.05).Conclusion:Acute hypoxia up-regulates miR-34a expression,down-regulates its downstream PNUTS protein expression,and increases apoptosis rate in mouse cardiomyocytes.AntimiR-34a nanoparticles inhibit the increase of miR-34a,the decrease of PNUTS and the apoptosis of mouse cardiomyocytes induced by acute hypoxia.