激活乙醛脱氢酶2的表达可减轻过氧化氢诱导的心肌细胞损伤

Activation of aldehyde dehydrogenase 2 alleviates H_2O_2-induced injury in cardiomyocytes

目的探讨线粒体乙醛脱氢酶2(ALDH2)在过氧化氢(H_2O_2)诱导的心肌细胞氧化应激损伤中的变化。方法正常体外培养的H9C2心肌细胞,取对数生长期细胞建立H_2O_2氧化应激损伤模型,分为正常对照组、正常+ALDH2激动剂Alda-1组、H_2O_2损伤组、H_2O_2+ALDH2激动剂Alda-1组、H_2O_2+ALDH2抑制剂Daidzin组;MTT比色法测定各组心肌细胞活力,DHE荧光染色检测各组心肌细胞氧化应激水平,分光光度法和Western blotting法分别检测ALDH2活性及蛋白水平变化。结果与正常对照组相比,正常+ALDH2激动剂Alda-1组心肌细胞活力、氧化应激水平、ALDH2活性水平和蛋白表达均无明显变化(P>0.05);H_2O_2损伤组心肌细胞活力明显下降,DHE荧光染色显示氧化应激水平明显升高,ALDH2活性和蛋白表达降低(P<0.05);给予Alda-1激动ALDH2后,与H_2O_2损伤组相比,心肌细胞活力升高,氧化应激水平下降,ALDH2活性和蛋白表达均明显升高(P<0.05);给予Daidzin阻断ALDH2后,与H_2O_2损伤组相比,心肌细胞活力、氧化应激水平、ALDH2活性水平和蛋白表达均无明显变化(P<0.05)。结论 H_2O_2直接诱导H9C2心肌细胞ALDH2活性及蛋白表达下降;提高心肌ALDH2表达可减轻H_2O_2诱导的氧化应激损伤。

Objective To investigate the changes of aldehyde dehydrogenase 2（ALDH2） expression in H2O2 inducedcardiomyocytes oxidative stress injury. Methods Cultured H9 C2 cardiomyocytes were exposed to H2O2-induced oxidative stress and the effects of the ALDH2 agonist Alda-1 and ALDH2 inhibitor Daidzin were tested on the stress level of the exposed cells. MTT colorimetric assay was used to assess the cell viability after the treatments. The oxidative stress level in the myocardial cells was detected using DHE fluorescence staining, and the activity and protein level of ALDH2 were detected with spectrophotometry and Western blotting. Results Compared with normal control cells, Alda-1 treatment did not significantly affect the cell viability, oxidative stress level, or ALDH2 activity and protein level. H2O2 exposure significantly lowered the cell activity and ALDH2 activity and protein expression and increased the oxidative stress level; Alda-1 treatment obvious antagonized the effects of H2O2. Blocking ALDH2 with Daidzin produced similar effects to H2O2 exposure on the viability, oxidative stress level, and ALDH2 activity and expression in the myocardial cells. Conclusion H2O2 exposure lowers the activity and reduces the protein expression of ALDH2 in cardiomyocyte H9 C2 cells, and activation of ALDH2 can alleviate H2O2-induced oxidative stress in the cells.