Investigating the gene regulatory programs directing stem cell differentiation can provide new insights into cell fate decision. Recently, we have developed an expandable pancreatic progenitor (ePP) platform, but the detailed characterization is lacking. Here, we perform systems-level characterization of the ePP-islet system. We not only define the dynamic and coordinated transcriptomic and chromatin landscapes of pancreatic differentiation but also infer the sophisticated gene regulatory networks that govern ePP self-renewal, control endocrine cell fate bifurcation, and regulate islet function. In addition, we identify the essential roles of the NKX2.2-CLEC16A/endosomal pathway axis. Unexpectedly, we have developed an authentic human stem cell-based model with autoimmune-like characteristics for type 1 diabetes by CLEC16A knockout and further identified effective pharmacological rescuers for CLEC16A deficiency. Notably, this study provides rich information and highlights the ePP-islet system as a powerful platform for uncovering the molecular mechanisms of cell fate decision, paving the way for therapeutic applications.
Chen et al. (Sun,) studied this question.