Figure 4. ERRγ promotes maturation of human iPSC-derived β-like cells.

(A) Schematic protocol for iPSC-derived β-like cell generation (ED, endoderm; PP, pancreatic progenitors; iβL, iPSC-derived β-like cells; iβeta, ERRγ-expressing iPSC-derived β-like cells). Growth factors and small molecules were added at each stage. Vitamin C, GABA and 13.6 mM glucose were in the base media for all stages. (B) Relative expression of human insulin during iPSC differentiation (C) Human insulin reporter-driven GFP expression (left panel) and phase contrast image (right) of day 22 iβL cells. (D) Intracellular (left) and extracellular (right) c-peptide concentrations of iβL cells after adenoviral infection: Ad-EGFP infected, iβL^GFP cells, open bars; Ad-ERRγ infected, iβeta cells, red bars. (E) Induced c-peptide secretion in iβL cells, iβL^GFP cells, iβeta cells, and human islets. (F) Functional annotation of upregulated gene categories in iβeta cells identified by Gene Ontology (GO). (G) Heatmap of expression changes in known β cell maker genes (left) and metabolic genes (right) in iβL^GFP and iβeta cells (log2 ratio relative to undifferentiated iPSC). Data represent the mean ±s.e.m. *p<0.05 Student’s unpaired t-test. See also Figure S5.