Exendin-4通过下调Wnt5a基因表达促进胰岛β细胞瘤INS-1细胞增殖

Exendin-4 promotes proliferation of pancreatic β cell line INS-1 via down-regulating the expression of Wnt5a gene

目的:研究Exendin-4调控胰岛β细胞瘤INS-1细胞增殖的机制。方法:使用Exendin-4刺激INS-1细胞,通过Ed U标记染色法检测INS-1细胞增殖率变化,并采用实时半定量PCR法和蛋白质印迹法检测INS-1细胞Wnt5a基因和蛋白的表达。siRNA瞬时转染沉默INS-1细胞Wnt5a基因,通过Ed U标记观察细胞增殖率变化。重组Wnt5a蛋白与Exendin-4共刺激INS-1后Ed U标记观察细胞增殖率变化。结果:Wnt5a在INS-1细胞中基础表达丰度高,Exendin-4显著降低INS-1细胞Wnt5a基因mRNA及蛋白表达水平。siRNA-Wnt5a瞬时转染降低INS-1细胞增殖率。重组Wnt5a蛋白呈浓度依赖性拮抗Exendin-4对INS-1细胞的促增殖效应。结论:Exendin-4通过下调Wnt5a基因表达促进INS-1细胞增殖。

To investigate the mechanism of Exendin-4regulating proliferation of pancreaticβcell line INS-1.Methods:After stimulation of Exendin-4,the proliferation rate of INS-1cells was detected by EdU method.The expression of Wnt5a gene was detected by real-time semi-quantitative PCR and Western-blotting.The proliferation rate of INS-1cells was evaluated by EdU method after Wnt5a gene was silenced by siRNA.Cocultured with Exendin-4and recombinant Wnt5a protein,the proliferation rate was observed by EdU labelling method.Results:The baseline expression of Wnt5a in INS-1reached a considerably high level,and Exendin-4significantly decreased the expression of Wnt5a gene in INS-1cells at both mRNA and protein level.Transient transfection of siRNA-Wnt5a into INS-1cells decreased the proliferation rate of cells.Recombinant Wnt5a protein antagonized the pro-proliferative effect of Exendin-4on INS-1cells in a dose-dependent manner.Conclusion:Exendin-4promotes INS-1proliferation via down-regulating the expression of Wnt5a gene.