维生素D对过氧化氢诱导MIN6细胞凋亡的保护作用

目的探讨维生素D(vitamin D,VitD)对过氧化氢(hydrogen peroxide,H 2O 2)诱导小鼠胰岛β细胞株MIN6细胞凋亡的保护作用及机制。方法VitD预处理后,用H 2O 2处理MIN6细胞,分别运用CCK-8法、Hoechst 33258荧光染色法、流式细胞术检测MIN6细胞增殖、形态及凋亡百分率。Western blot检测增殖与凋亡相关基因Bax、Bcl-2、Caspase-3以及Cleaved caspase-3的表达。结果H 2O 2呈时间和剂量依赖性抑制MIN6细胞增殖,诱导细胞凋亡,降低Bcl-2表达、增加Bax及Cleaved caspase-3表达,Bcl-2/Bax比值降低,Cleaved caspase-3/caspase-3比值增加;当用VitD预处理后,Bcl-2表达增加,Bax、Cleaved caspase-3表达降低,Bcl-2/Bax比值增加,Cleaved caspase-3/caspase-3比值降低,MIN6细胞活力增加。结论VitD预处理后,通过增加抗凋亡Bcl-2表达,降低促凋亡Bax和Cleaved caspase-3表达,减少由H 2O 2诱导的小鼠胰岛β细胞株MIN6细胞凋亡。

The protective effect of 1,25-dihydroxyvitamin-D_3 on hydrogen peroxide-induced MIN6 cell apoptosis

Aim To investigate the role and mechanism of VitD in protecting apoptosis of mouse isletβcell line MIN6 cells induced by H 2O 2.Methods MIN6 cells were treated with H 2O 2 after the pretreatment of VitD.The proliferation,morphological changes and apoptotic percentage of MIN6 cells were determined by CCK-8,Hoechst 33258 fluorescence staining and flow cytometry respectively.The expressions of apoptosis-related genes Bcl-2,Bax,Caspase-3 and Cleaved caspase-3 were detected by Western blot.Results H 2O 2 inhibited proliferation and induced apoptosis of MIN6 cells through up-regulation of Bax and cleaved caspase-3,down-regulation of Bcl-2,decrease of Bcl-2/Bax ratio,and increase of cleaved caspase-3/caspase-3 ratio.After pretreatment of VitD,MIN6 cell viability was restored by increasing Bcl-2 expression,decreasing Bax and cleaved caspase-3 expression,increasing Bcl-2/Bax ratio,and decreasing cleaved caspase-3/caspase-3 ratio.Conclusions VitD protects MIN6 against H 2O 2-induced apoptosis through decreasing pro-apoptotic gene Bax and cleaved caspase-3,and increasing anti-apoptotic gene Bcl-2 expression.