5-氮杂-2′-脱氧胞苷联合曲古霉素 A 对高糖诱导下胰岛 β 细胞的增殖及 PDX-1 甲基化的影响

Effects of 5-aza-2′-deoxycytidine combined with trichostatin A on cell proliferation and PDX-1 methylation on high glucose-induced toxicity in pancreatic β cells

目的：探讨高糖诱导下应用5-氮杂-2~′-脱氧胞苷（5-Aza-d C）和曲古霉素A（TSA）对胰岛β细胞NIT-1细胞株增殖及PDX-1启动子区甲基化及其表达的影响。方法：胰岛β细胞株予33.3 mmol/L葡萄糖浓度处理后随机分为：空白对照（NC）组、高糖诱导（HG）组、5-Aza-d C干预组、TSA干预组、5-Aza-d C＋TSA联合干预组,检测细胞增殖情况、胰岛素释放水平、PDX-1启动子区甲基化状态及其表达水平的变化。结果：5-Aza-d C和TSA单独或联合干预可增加NIT-1细胞增殖率和胰岛素分泌量,降低PDX-1启动子区甲基化产物,增加PDX-1 m RNA相对表达量,并且联合组比单药组效果更加明显（均P〈0.05）。结论：5-Aza-d C和TSA可以激活高糖诱导下失表达的PDX-1,进而恢复胰岛β细胞功能,两药联合具有协同效应。

Objective To investigate the effects of 5-aza-2~′-deoxycytidine（5-Aza-d C） alone or combined with trichostatin A（TSA） on cell proliferation, promoter methylation and m RNA expression level of PDX-1 gene in pancreatic β cells induced by high glucose toxicity. Method NIT-1 cells were treated in vitro by high glucose（33.3 mmol / L）, then divided into five groups, control group, HG grpup, 5-Aza-d C treatment group,TSA interfere group and 5-Aza-d C ＋ TSA group. Proliferation of NIT-1 cells, insulin secretion, promoter methylation and m RNA expression of PDX-1 gene were detected respectively. Results 5-Aza-d C and TSA alone or in combination could promote cell proliferation and recover insulin secretion in NIT-1 cells, could also reduce PDX-1 gene methylation and enhance expression of PDX-1 m RNA. Compared with single-treatment group,combined group was significantly different（all P〈0.05）. Conclusion 5-Aza-d C and TSA could activate the expression of PDX-1 and, then recover insulin secretion in NIT-1 cells induced by high glucose. Combination of them had synergistic effect.