过氧化氢酶对高糖诱导NIT-1胰岛β细胞Pax6基因表达下降的影响

Effects of Catalase on Decrease of Pax6 Expression Induced by Hyperglycemia

目的探讨过氧化氢酶(catalase)对高糖诱导的NIT-1胰岛β细胞成对同源异形盒转录因子6(Pax6)基因表达下降的影响。方法体外培养NIT-1胰岛β细胞24h,分4个处理组:低糖组(NG),低糖+过氧化氢酶组(NG+C),高糖组(HG),高糖+过氧化氢酶组(HG+C),用2,7二氯氢化荧光素二酯(H2DCF-DA)染色检测活性氧簇(ROS)的水平,RT-PCR半定量检测Pax6mRNA表达。结果HG组ROS水平(1.10±0.24)明显高于NG组(0.95±0.26),P<0.05;HG+C组ROS水平(0.94±0.26)低于HG组,P<0.05;HG组Pax6mRNA表达(0.64±0.09)低于NG组(0.93±0.12),P<0.05;HG+C组Pax6mRNA表达(0.74±0.11)高于HG组,但差异无统计学意义,P>0.05。结论高糖可使NIT-1胰岛β细胞内ROS产生增加,胰岛β细胞特异性转录因子Pax6基因表达下降,给予ROS的抗氧化剂过氧化氢酶后,Pax6基因表达有所恢复,但差异无统计学意义。

[Objective] To observe the effect of catalase on the decrease of Pax6 expression induced by hyperglycemia in NIT-1 cells. [Methods] NIT-1 cells were divided into four groups： normal glucose concentration without or with catalase （NG, NG＋C）; high glucose concentration without or with catalase （HG, HG＋C）. In vitro the cells were cultured in the different medium as mentioned above for 24 hours. Then the cells were used for 2＇,7＇- dichlorodihydrofluorescein diacetate （H2DCF-DA） staining to detect the level of reactive oxygen species（ROS） and evaluate the expression of Pax6 mRNA by RT-PCR.[Results] The levels of ROS in HG group （1.10±0.24） were higher than those of in NG group （0.95±0.26,P〈 0.05）, but the levels of ROS in HG＋C group （0.94±0.26, P〈 0.05） were lower as compared with HG group. On the contrary, the expression of Pax6 in HG group （0.64±0.09） was lower than in NG group （0.93±0.12, P〈 0.05）. The mRNA level of Pax6 in HG＋C group （0.74±0.11, P 〉0.05） was higher than in HG group without statistical significance. [ Conclusion ] The hyperglycemia could induce the increase of ROS and decrease of Pax6 mRNA levels in NIT-1 ceils. The antioxidant could partially restore the decline of Pax6 caused by hyperglycemia, but not significant.