高糖刺激INS-1细胞DNase I表达升高对细胞凋亡的影响

Effects of high glucose simulated DNase I increase on INS-1 cell apoptosis

目的:探讨脱氧核糖核酸酶I(DNase I)在高糖引起的胰岛β细胞凋亡过程中的作用。方法:实验分3组,正常组、高糖组和高糖+DNase I siRNA组。其中正常组给予含有11.1mmol/L葡萄糖浓度的培养基外,其余2组均给予葡萄糖浓度为30mmol/L的培养基。通过转染外源性DNase I siRNA,敲降高糖培养的INS-1细胞内DNase I的表达。采用Western blot检测DNase I、caspase-3蛋白表达,流式细胞仪观察细胞凋亡的变化。结果:与正常组相比,高糖可以显著增加INS-1细胞DNase I和caspase-3的蛋白表达水平(P<0.05);与高糖组相比,高糖+siRNA组DNase I敲降后显著降低高糖所引起的细胞内DNase I蛋白表达水平(P<0.05),同时也显著降低高糖所引起的细胞内caspase-3的蛋白表达水平(P<0.05)。流式细胞仪结果显示,高糖明显导致细胞凋亡率升高(16.7%),而敲降DNase I后则明显减少细胞凋亡的发生(9.9%)。结论:高糖可以诱导细胞内DNase I的表达升高,从而介导胰岛β细胞的凋亡,该研究可能为胰岛β细胞凋亡的机制研究提供新的证据。

Objective：To investigate the effects of DNase Ⅰ in the process of 13cell apoptosis in high glucose environment.Methods：INS-1 cell was simulated by 30 mmol/L glucose,and were divided into three groups： normal group,high glucose group,and high glucose plus siRNA group.The Normal group was cultured in the medium with 11.1mmol/L glucose concentration,and the other 2 group was cultured in the 30mmol/L glucose. DNase Ⅰ level was knocked down by siRNA in high glucose plus siRNA group,cell apoptosis rate was evaluated by flow cytometry and the protein level of DNase Ⅰ and caspase-3 was observed by Western blot.Results：Compared with normal group, high glucose can increase the DNase Ⅰ and caspase-3 expression in high glucose group.However,DNase I knocked down can significantly lower the caspase-3 expression.The flow cytometry results showed that high glucose can cause INS-1 cell apoptosis rate increase （16.7%）,however when DNase Ⅰ was knocked down, the apoptosis rate （9.9%）can be greatly reduced.Conclusion：High glucose can cause INS-1 cell apoptosis by increase the expression of DNase Ⅰ.