Three-dimensional differentiation of embryonic stem cells into islet-like insulin-producing clusters

The production of mature pancreatic cells that function similarly to primary islets is the premise of cell therapy for diabetes. Here, we describe a novel approach to generating more mature insulin-producing cells from embryonic stem (ES) cells. A three-dimensional (3D) ES cell pancreatic differentiation system was developed and used to direct the ES cell differentiation into glucose-responsive, insulin-secreting cells. Using mouse ES cells as a model, we demonstrate that more mature insulin-producing cells can be generated from ES cells in 3D cultures. The 3D differentiated pancreatic endocrine cells can assemble into an islet-like tissue structure that displays greater similarities in phenotype and gene expression profile to adult mouse pancreatic islets, that is, with β cells in the core and non-β cells forming the mantel, leading to a significant improvement of the maturity of the insulin-producing cells. Our findings show that nearly 50-60% of the cells in 3D formed cell clusters express insulin. More importantly, those cells exhibit a high level of glucose-responsive insulin and C-peptide syntheses and release. A high level of expression of glucose transporter-2 was also detected in these cells. Compared to two-dimensional ES cell-derived insulin-producing cells, the insulin release from 3D ES cell-derived insulin-producing cells showed a nearly fivefold (p< 0.05) increase when exposed to a high glucose (27.7mM) medium. This 3D culture model provides an excellent system to study pancreatic endocrine morphogenesis and tissue organization. This study also demonstrates the feasibility of producing clinically relevant β cells from ES cells in a 3D environment.