GP2-enriched pancreatic progenitors give rise to functional beta cells in vivo and eliminate the risk of teratoma formation.

Human pluripotent stem cell (hPSC)-derived pancreatic progenitors (PPs) can be differentiated into beta-like cells in vitro and in vivo and therefore have therapeutic potential for type 1 diabetes (T1D) treatment. However, the purity of PPs varies across different hPSC lines, differentiation protocols, and laboratories. The uncommitted cells may give rise to non-pancreatic endodermal, mesodermal, or ectodermal derivatives in vivo, hampering the safety of hPSC-derived PPs for clinical applications and their differentiation efficiency in research settings. Recently, proteomics and transcriptomics analyses identified glycoprotein 2 (GP2) as a PP-specific cell surface marker. The GP2-enriched PPs generate higher percentages of beta-like cells in vitro, but their potential in vivo remains to be elucidated. Here, we demonstrate that the GP2-enriched-PPs give rise to all pancreatic cells in vivo, including functional beta-like cells. Remarkably, GP2 enrichment eliminates the risk of teratomas, which establishes GP2 sorting as an effective method for PP purification and safe pancreatic differentiation.

Sufu- and Spop-mediated downregulation of Hedgehog signaling promotes beta cell differentiation through organ-specific niche signals.

Human embryonic stem cell-derived beta cells offer a promising cell-based therapy for diabetes. However, efficient stem cell to beta cell differentiation has proven difficult, possibly due to the lack of cross-talk with the appropriate mesenchymal niche. To define organ-specific niche signals, we isolated pancreatic and gastrointestinal stromal cells, and analyzed their gene expression during development. Our genetic studies reveal the importance of tightly regulated Hedgehog signaling in the pancreatic mesenchyme: inactivation of mesenchymal signaling leads to annular pancreas, whereas stroma-specific activation of signaling via loss of Hedgehog regulators, Sufu and Spop, impairs pancreatic growth and beta cell genesis. Genetic rescue and transcriptome analyses show that these Sufu and Spop knockout defects occur through Gli2-mediated activation of gastrointestinal stromal signals such as Wnt ligands. Importantly, inhibition of Wnt signaling in organoid and human stem cell cultures significantly promotes insulin-producing cell generation, altogether revealing the requirement for organ-specific regulation of stromal niche signals.

Stem Cells, Self-Renewal, and Lineage Commitment in the Endocrine System.

The endocrine system coordinates a wide array of body functions mainly through secretion of hormones and their actions on target tissues. Over the last decades, a collective effort between developmental biologists, geneticists, and stem cell biologists has generated a wealth of knowledge related to the contribution of stem/progenitor cells to both organogenesis and self-renewal of endocrine organs. This review provides an up-to-date and comprehensive overview of the role of tissue stem cells in the development and self-renewal of endocrine organs. Pathways governing crucial steps in both development and stemness maintenance, and that are known to be frequently altered in a wide array of endocrine disorders, including cancer, are also described. Crucially, this plethora of information is being channeled into the development of potential new cell-based treatment modalities for endocrine-related illnesses, some of which have made it through clinical trials.

Efficient Differentiation of Pluripotent Stem Cells to NKX6-1+ Pancreatic Progenitors.

Pluripotent stem cells have the ability to self renew and differentiate to multiple lineages, making them an attractive source for the generation of pancreatic progenitor cells that can be used for the study of and future treatment of diabetes. This article outlines a four-stage differentiation protocol designed to generate pancreatic progenitor cells from human embryonic stem cells (hESCs). This protocol can be applied to a number of human pluripotent stem cell (hPSC) lines. The approach taken to generate pancreatic progenitor cells is to differentiate hESCs to accurately model key stages of pancreatic development. This begins with the induction of the definitive endoderm, which is achieved by culturing the cells in the presence of Activin A, basic Fibroblast Growth Factor (bFGF) and CHIR990210. Further differentiation and patterning with Fibroblast Growth Factor 10 (FGF10) and Dorsomorphin generates cells resembling the posterior foregut. The addition of Retinoic Acid, NOGGIN, SANT-1 and FGF10 differentiates posterior foregut cells into cells characteristic of pancreatic endoderm. Finally, the combination of Epidermal Growth Factor (EGF), Nicotinamide and NOGGIN leads to the efficient generation of PDX1+/NKX6-1+ cells. Flow cytometry is performed to confirm the expression of specific markers at key stages of pancreatic development. The PDX1+/NKX6-1+ pancreatic progenitors at the end of stage 4 are capable of generating mature ß cells upon transplantation into immunodeficient mice and can be further differentiated to generate insulin-producing cells in vitro. Thus, the efficient generation of PDX1+/NKX6-1+ pancreatic progenitors, as demonstrated in this protocol, is of great importance as it provides a platform to study human pancreatic development in vitro and provides a source of cells with the potential of differentiating to ß cells that could eventually be used for the treatment of diabetes.

Glycoprotein 2 is a specific cell surface marker of human pancreatic progenitors.

PDX1+/NKX6-1+ pancreatic progenitors (PPs) give rise to endocrine cells both in vitro and in vivo. This cell population can be successfully differentiated from human pluripotent stem cells (hPSCs) and hold the potential to generate an unlimited supply of ß cells for diabetes treatment. However, the efficiency of PP generation in vitro is highly variable, negatively impacting reproducibility and validation of in vitro and in vivo studies, and consequently, translation to the clinic. Here, we report the use of a proteomics approach to phenotypically characterize hPSC-derived PPs and distinguish these cells from non-PP populations during differentiation. Our analysis identifies the pancreatic secretory granule membrane major glycoprotein 2 (GP2) as a PP-specific cell surface marker. Remarkably, GP2 is co-expressed with NKX6-1 and PTF1A in human developing pancreata, indicating that it marks the multipotent pancreatic progenitors in vivo. Finally, we show that isolated hPSC-derived GP2+ cells generate ß-like cells (C-PEPTIDE+/NKX6-1+) more efficiently compared to GP2- and unsorted populations, underlining the potential therapeutic applications of GP2.Pancreatic progenitors (PPs) can be derived from human pluripotent stem cells in vitro but efficiency of differentiation varies, making it hard to sort for insulin-producing cells. Here, the authors use a proteomic approach to identify the secretory granule membrane glycoprotein 2 as a marker for PDX1+/NKX6-1+ PPs.