葡萄糖及细胞因子对胰岛素瘤相关蛋白-2表达水平的影响

目的探讨葡萄糖、肿瘤坏死因子(TNF)-α、干扰素(IFN)-γ对胰岛细胞自身抗原胰岛素瘤相关蛋白(IA)-2表达水平及胰岛素分泌水平的影响。方法以不同浓度的葡萄糖(3、7、11、30mmol/L)、10ng/mlIFN-γ及100ng/mlTNF-α分别刺激胰岛细胞系RIN5F24h和48h,用反转录聚合酶链反应(RT-PCR)方法检测各组RIN5F细胞中IA-2的mRNA表达水平,并用放射免疫法检测上清中胰岛素的浓度。结果RT-PCR结果显示以不同浓度葡萄糖(3、7、11、30mmol/L)分别刺激RIN5F细胞系后IA-2mRNA水平呈浓度依赖性和时间依赖性增加;TNF-α可抑制IA-2mRNA的水平,并且作用48h后IA-2表达水平显著降低(P<0.05);IFN-γ作用24h及48h均可显著抑制IA-2的表达(P<0.05)。TNF-α或IFN-γ刺激RIN5F细胞系后,上清中胰岛素水平均较基础值降低,并且作用48h后差异有统计学意义(P<0.05)。结论葡萄糖可使IA-2的mRNA水平呈剂量依赖性和时间依赖性增加,TNF-α、IFN-γ可抑制IA-2的mRNA表达和胰岛素分泌浓度。

Glucose and cytokines to influence insulinoma-associated protein-2 expression

Objective To explore the effect of glucose and cytokine(TNF-α,IFN-γ)to the level of insulinoma associated protein-2(IA-2) mRNA and insulin concentration. Methods Glucose of different concentrations(3,7,11,30 mmol/L),10 ng/ml IFN-γ and 100 ng/mL TNF-α were used to stimulate insulinoma cell line for 24 and 48 hours.The levels of IA-2 mRNA were detected with RT-PCR method. Insulin concentrations of supernatant of different groups were measured with radioimmunoassay. Results The levels of IA-2 mRNA in RIN5F cell line were increased in concentration-depending and time-depending way after stimulated with glucose. TNF-α could significantly suppress the expression of IA-2 mRNA after stimulated for 48 hours,while IFN-γ significantly decreased it both for 24 hours and 48 hours (P<0.05). The insulin level of supernatant of RIN5F cell line was decreased after stimulated with TNF-α or IFN-γ. Conclusion Glucose can increase the mRNA level of IA-2 in dose-dependent and time-dependent manner. TNF-α and IFN-γ depress the mRNA level of IA-2 and insulin concentration.