Pluripotent stem cell SOX9 and INS reporters facilitate differentiation into insulin-producing cells

Differentiation of human pluripotent stem cells into insulin-producing stem cell-derived beta cells harbors great potential for research and therapy of diabetes. The SOX9 gene plays a crucial role during development of the pancreas and particularly in the development of insulin-producing cells as SOX9+ cells form the source for NEUROG3+ endocrine progenitor cells. For the purpose of easy monitoring of differentiation efficiencies into pancreatic progenitors and insulin-producing cells, we generated new reporter lines by knocking in a P2A-H-2Kk-F2A-GFP2 reporter genes into the SOX9 locus and a P2A-mCherry reporter gene into the INS locus mediated by CRISPR/CAS9-technology. The knock-ins enable co-expression of the endogenous genes and reporter genes, report the endogenous gene expression and enable the purification of pancreatic progenitors and insulin-producing cells using FACS or MACS. Using these cell lines we established a new differentiation protocol geared towards SOX9+ cells to efficiently drive human pluripotent stem cells into glucose-responsive beta cells.