Role of PI3K p110ß in the differentiation of human embryonic stem cells into islet-like cells.

To investigate the effects of the PI3K inhibitors on the differentiation of insulin-producing cells derived from human embryonic stem cells. Here, we report that human embryonic stem cells induced by phosphatidylinositol-3-kinase (PI3K) p110ß inhibitors could produce more mature islet-like cells. Findings were validated by immunofluorescence analysis, quantitative real-time PCR, insulin secretion in vitro and cell transplantation for the diabetic SCID mice. Immunofluorescence analysis revealed that unihormonal insulin-positive cells were predominant in cultures with rare polyhormonal cells. Real-time PCR data showed that islet-like cells expressed key markers of pancreatic endocrine hormones and mature pancreatic ß cells including MAFA. Furthermore, this study showed that the expression of most pancreatic endocrine hormones was similar between groups treated with the LY294002 (nonselective PI3K inhibitor) and TGX-221 (PI3K isoform selective inhibitors of class 1ß) derivatives. However, the level of insulin mRNA in TGX-221-treated cells was significantly higher than that in LY294002-treated cells. In addition, islet-like cells displayed glucose-stimulated insulin secretion in vitro. After transplantation, islet-like cells improved glycaemic control and ameliorated the survival outcome in diabetic mice. This study demonstrated an important role for PI3K p110ß in regulating the differentiation and maturation of islet-like cells derived from human embryonic stem cells.