Generation of pancreatic insulin-producing cells from rhesus monkey induced pluripotent stem cells

Aims/hypothesis The generation of induced pluripotent stem cells (iPSCs) provides a promising possibility for type 1 diabetes therapy. However, the generation of insulinproducing cells from iPSCs and evaluation of their efficacy and safety should be achieved in large animals before clinically applying iPSC-derived cells in humans. Here we try to generate insulin-producing cells from rhesus monkey (RM) iPSCs. Methods Based on the knowledge of embryonic pancreatic development, we developed a four-stage protocol to generate insulin-producing cells from RM iPSCs. We established a quantitative method using flow cytometry to analyse the differentiation efficiency. In addition, to evaluate the differentiation competence and function of RM iPSC-derived cells, transplantation of stage 3 and 4 cells into immunodeficient mice was performed. Results RM iPSCs were sequentially induced to definitive endoderm (DE), pancreatic progenitors (PP), endocrine precursors (EP) and insulin-producing cells. PDX1 ⁺ PP cells were obtained efficiently from RM iPSCs (over 85% efficiency). The TGF-β inhibitor SB431542 promoted the generation of NGN3 ⁺ EP cells, which can generate insulin-producing cells in vivo upon transplantation. Finally, after this fourstage differentiation in vitro, insulin-producing cells that could secrete insulin in response to glucose stimulation were obtained. When transplanted into mouse models for diabetes, these insulin-producing cells could decrease blood glucose levels in approximately 50% of the mice. Conclusions/interpretation We demonstrate for the first time that RM iPSCs can be differentiated into functional insulin-producing cells, which will provide the basis for investigating the efficacy and safety of autologous iPSCderived insulin-producing cells in a rhesus monkey model for type 1 diabetes therapy.