Mechanisms inducing differentiation of adult islet progenitor-like cells into functional islet-like organoids.

Abstract

Introduction: Adult pancreatic tissue contains cell populations with latent regenerative potential, but the processes governing their expansion and differentiation into endocrine lineages remain unclear.

Methods: Adult human pancreatic cells obtained from donor tissue were isolated and expanded and analyzed for lineage potential using single-cell RNA sequencing, flow cytometry, and functional assays. A CD9⁺ PROCR⁺ RGS16⁺ subpopulation, termed islet progenitor-like cells (IPCs), was evaluated for proliferative capacity and differentiation potential.

Results: IPCs exhibited robust proliferative capacity and, upon differentiation, formed insulin- and glucagon-secreting organoids. Treatment of IPCs with the small molecule ISX9 induced expression of key transcription factors RFX6 and NEUROD1 through calcium-dependent chromatin remodeling mediated by NFAT recruitment of p300 and displacement of histone deacetylases (HDAC1-3). Pharmacologic inhibition of HDACs further enhanced IPC maturation and glucose-stimulated insulin secretion.

Discussion: These findings define the molecular and epigenetic mechanisms driving the expansion and differentiation of adult IPCs into functional islet-like organoids, providing a foundation for future regenerative approaches using adult pancreatic tissue as a renewable source for endocrine cell replacement.