348-OR: Differentiation of Adult Islet Cell Precursors into ß- and α-like Cells for Islet Transplantation

Abstract

Advances in protocols to convert human embryonic and inducible pluripotent stem cells (hESCs and iPSCs) into pancreatic β cells has allowed us to generate islet cell organoids in culture for potential use in islet cell transplantation. Here, we demonstrate that dedifferentiated β cells and/or NGN-/RGS16+ islet cell precursors (ICPs) can be harvested from adult pancreatic tissue and converted into β- and α-like cells. In this study, we used ICPs derived from COBE bag pancreatic tissue remnants from organ donors to produce islet cell organoids capable of releasing both insulin and glucagon in response to high (16.7 mM) and low (2.8 mM) glucose conditions, respectively. These organoids displayed zinc-containing granule staining by dithizone and exhibited GSIS with stimulation indices comparable to human islets. ICPs produced genetic profiles similar to hESC-derived endocrine progenitor cells at stages 5-7 (S5-7). Using small molecule ISX9 and GSK/DYRK inhibitors GNF and harmine to induce and activate calcineurin (CN)/NFAT signaling, we were able to expand and differentiate ICPs into β- and α-like cells. CN/NFAT upregulated genes that promote cell cycle and proliferation (S5) and islet cell differentiation genes (S5-7). Islet cell type fate and function could be modulated by hedgehog/GLI signaling. Whereas introduction of sonic hedgehog (Shh) inhibitor SANT-1 at S5 favored production of β-like cells, Shh signaling agonists promoted differentiation to α-like cells up to S7. Overall, these results indicate that adult ICPs can be harvested from donor tissue and expanded for differentiation into functional β- and α-like cells. The capability to expand and differentiate adult ICPs could potentially provide an unlimited supply of islet organoid tissue for islet cell transplantation. Disclosure C.Darden: None. J.Kuncha: None. J.D.Mattke: None. B.Naziruddin: None. M.C.Lawrence: None. Funding Baylor Scott & White Health