Exploring optimal protocols for generating and preserving glucose-responsive insulin-secreting progenitor cells derived from human pluripotent stem cells.

Human pluripotent stem cells (hPSCs) represent an unlimited source of β-like cells for both disease modeling and cellular therapy for diabetes. Numerous protocols have been published describing the differentiation of hPSCs into β-like cells that secret insulin in response to a glucose challenge. However, among the most widely used protocols it is not clear which yield the most functional cells with reproducible glucose-stimulated insulin-secretion (GSIS). Moreover, the technical challenges in culturing and differentiating hPSCs is a barrier for many researchers. In this study, we performed a side-by-side functional comparison based on three widely used methods to generate insulin expressing cells and identified optimal stages and conditions for cryopreserving and reconstituting stem cell (SC)-derived islets with a robust GSIS. Despite the fact that each protocol yields SC-islets consisting of insulin and glucagon-expressing cells, the SC-islets obtained from the two more recent revised protocols were more functional as measured by robust and reproducible GSIS. Moreover, we demonstrate that pancreatic progenitors and differentiated endocrine cells that have been cryopreserved for up to 10 months, can be reconstituted into glucose responsive SC-islets. These findings should enable the use of human PSC-derived β-like cells technologies even by groups with minimal PSC culture experience.