Effects of Exendine-4 on The Differentiation of Insulin Producing Cells from Rat Adipose-Derived Mesenchymal Stem Cells

To evaluate the effect of Exendine-4 (EX-4), a Glucagon-like peptide 1 (GLP-1) receptor agonist, on the differentiation of insulin-secreting cells (IPCs) from rat adipose-derived mesenchymal stem cells(ADMSCs). In this experimental study, ADMSCs were isolated from rat adipose tissue and exposed to induction media with or without EX-4. After induction, the existence of IPCs was confirmed by morphology analysis, expression pattern analysis of islet-specific genes (Pdx-1, Glut-2 and Insulin) and insulin synthesis and secretion. IPCs induced in presence of EX-4 were morphologically similar to pancreatic islet-like cells. Expression of Pdx-1, Glut-2 and Insulin genes in EX-4 treated cells was significantly higher than the cells exposed to differentiation media without EX-4. Compared to EX-4 untreated ADMSCs, insulin release from EX-4 treated ADMSCs showed a nearly 2.5 fold (P<0.05) increase when exposed to a high glucose (25 mM) medium. The percentage of insulin positive cells in the EX-4 treated group was approximately 4-fold higher than in the EX-4 untreated ADMSCs. The present study has demonstrated that EX-4 enhances the differentiation of ADMSCs into IPCs. Improvement of this method may help the formation of an unlimited source of cells for transplantation.