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