Pancreatic islet differentiation of human embryonic stem cells by microRNA overexpression.

Development of stem cell-based therapies for the treatment of type 1 diabetes would provide a renewable supply of human β-cells. Human embryonic stem cells (ESCs) are considered to be one of the stem cell populations with sufficient proliferative capacity to achieve this goal. Currently, differentiation protocols directing ESCs toward a pancreatic fate employ a variety of expensive cytokines and inhibitors. With the known significance of microRNAs in islet development, we present a novel and cost-effective strategy in which miR-375 overexpression promotes pancreatic endocrine differentiation in hESCs in the absence of any extrinsic factors. miR-375 has been shown to be a key regulator of pancreatic development and function in zebrafish, mouse and human. In this study, hESCs were transduced with lentiviral vectors containing human miR-375 precursor and aggregated to form human embryoid bodies (hEBs) for up to 21 days. Morphological assessment, immunocytochemistry and DTZ staining confirmed that miR-375-induced hEBs have similar characteristics to those of mature islets. In addition, the dynamic expression profile of endodermal marker Foxa2 and endocrine-specific genes, including HNF4α, Pdx1, Pax6, Nkx6.1, Glut2 and insulin, were detected by quantitative real-time PCR. Finally, insulin release upon glucose stimulation was detected in our differentiated clusters. The data presented here demonstrate the feasibility of using microRNAs to direct differentiation into the pancreatic lineage. Copyright © 2013 John Wiley & Sons, Ltd.