葡萄糖、促炎症因子和生长因子影响胰岛自身抗原的表达

Effects of glucose,cytokine,and growth factor on the expression of autoantigen of pancreas

目的:探讨葡萄糖、细胞因子TNF-α,IFN-γ和生长因子IGF-1,EGF,FGF对胰岛细胞自身抗原IA-2表达水平及胰岛功能的影响。方法:以不同浓度的葡萄糖(3,7,11和30mmol/L)、IFN-γ(10ng/ml)、TNF-α(100ng/ml)及IGF-1,EFG,FGF-10(10ng/ml),分别刺激胰岛细胞系RIN5F24h和48h,用RT-PCR方法检测各组RIN5F细胞中IA-2的mRNA表达水平,用放射免疫法检测上清中胰岛素的浓度,3-(4,5-二甲基)-5-(3-羧甲基苯环)-2-(4-硫基苯)-2H-四唑盐复合物(MTS)法检测细胞生长速率。结果:RT-PCR结果显示以不同浓度葡萄糖(3,7,11和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、IFN-γ可抑制IA-2mRNA的水平(P<0.05),IGF-1、FGF使IA2的表达增加(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后差异有显著性(P<0.05)。IGF-1,bFGF作用于RIN5F细胞系48h,上清中胰岛素较基础值显著增加(P<0.05)。MTS结果显示IGF-1使胰岛细胞增殖速率显著增加(P<0.01)。结论:葡萄糖、TNF-α、IFN-γ和一些生长因子可改变胰岛自身抗原的表达,参与1型糖尿病的发病。

Objective：To explore the effects of glucose,cytokine（TNF-γ,IFN-γ） and growth factor（IGF-1,EGF,FGF） on the level of IA-2 mRNA and the function of pancreas. Methods： Glucose of different levels （3,7,11,30 mmol/L）, IFN-γ （ 10 ng/ml） ,TNF-α （100 ng/ml） and GF-1 ,EGF,FGF（ 10 ng/ml）were used to stimulate insulinoma cell line for 24 and 48 hours. The level of IA-2 mRNA was detected with RT-PCR method. Insulin concentrations of supernatant of different groups were measured with radioimmunoassay. Cell proliferations were measured by MTS one-solution kits. Results：The levels of IA2 mRNA in RIN5F cell line were increased and were stimulated by glucose in time-dependent manner. TNF-α could significantly suppress the expression of IA2 mRNA after 48 hours, while IFN-3, significantly decreased it after 24 and 48 hours （P 〈 0.05）. IGF-1,FGF could increase the expression of IA-2 and the concentration of insulin （P 〈 0.05）.The insulin level of supernatant of RIN5F cell line was decreased by TNF-α and IFN-γ. The proliferation of RIN5F cell was increased stimulated by IGF-1 （P 〈 0.01）.Conclusion：Glucose, proinflammation （TNF-α , IFN-γ,） and growth factor （IGF-1 ,FGF）can influence the expression of islet autoantigen which may play a role in the pathogenesis of type 1 diabetes.