目的:观察雄性激素苯丙酸诺龙(BPN)干预下胰岛NIT-1细胞中烟酰胺磷酸核糖转移酶(Nampt)、胰岛素受体底物-2(IRS-2)和胰岛十二指肠同源盒-1(PDX-1)蛋白表达、细胞周期和胰岛素分泌的变化,探讨高浓度葡萄糖氧化应激状态下BPN对NIT-1细胞Nampt表达和胰岛素信号分子的影响。方法:应用4种不同浓度(5.6、11.1、16.7和27.6mmol·L^-1)葡萄糖培养NIT-1细胞,以10mg·L^-1 BPN干预NIT-1细胞48h,以未加BPN处理的相应浓度葡萄糖为对照组。应用Western blotting法检测各组细胞中Nampt、IRS-2和PDX-1蛋白表达水平;流式细胞术检测细胞周期;放射免疫法测定细胞胰岛素分泌水平。结果:与相应浓度葡萄糖对照组比较,各BPN处理组NIT-1细胞中Nampt、ISR-2和PDX-1蛋白表达水平增加(P〈0.05或P〈0.01);与相应对照组比较,在低糖(5.6mmol·L^-1)时,BPN能够明显解除细胞G0/G1期阻滞(P〈0.01),在高糖(27.6 mmol·L^-1)时,能够解除细胞的G2/M阻滞(P〈0.01);除正常葡萄糖浓度11.1mmol·L^-1组之外,各处理组细胞的胰岛素分泌水平均明显增加(P〈0.01)。结论:BPN能够增加胰岛NIT-1细胞中Nampt、ISR-2和PDX-1蛋白表达水平,NIT-1细胞中Nampt表达与胰岛素信号传导途径的相关分子间可能存在密切关联,雄性激素在一定条件下能够改善胰岛细胞的胰岛素抵抗状态。
Objective To study the effects of benzyl propionate nandrolone(BPN)on the nicotinamide phosphoribosyl transferase(Nampt),insulin receptor substeate-2(IRS-2)and pancreatic duodenal homeobox-1(PDX-1)expressions,cell cycle changes as well as insulin secretion in pancreatic islet cell NIT-1lines,and to explore the influence of BPN in the Nampte xpression in NIT-1cells and insulin signaling molecules in high glucose oxidation stress.Methods The NIT-1cells were cultured with different concentrations(5.6,11.1,16.7,and27.6mmol·L^-1)of glucose,then they were treated with 10mg·L^-1 BPN for 48hwith no BPN treatment as corresponding control groups.The expression levels of Nampt,IRS-2,and PDX-1were tested by Western blotting assay.The changes of cell cycle were determined by FCM and the cell insulin secretion levels were measured with radioimmunoassay.Results Compared with corresponding control groups,the expression levels of Nampt,IRS-2,and PDX-1proteins in the NIT-1cells in various BPM groups were increased(P〈0.05or P〈0.01).The G0/G1phase arrest was relieved(P〈0.01)when the cells was cultured in low glucose(5.6mmol·L^-1)condition,and the G2/M block was remitted significantly in high glucose(27.6mmol·L^-1)condition(P〈0.01),furthermore,the cell insulin secretion was promoted compared with control groups except 11.1mmol·L^-1 glucose group(P〈0.01).Conclusion BPN can promote the expression levels of Nampt,ISR-2and PDX-1proteins in NIT-1cells.There is close relationship between the Nampt expression in NIT-1cells and insulin signaling pathway and BPN prevents the cells from insulin resistance.