Figure 5.

Polyhormonal feature and insulin granules of differentiated human pancreatic duct-derived cells (HDDCs). (A): MAFA-transfected HDDCs showed gene expression of SST and PP, but not GCG (n = 3–5). (B–D): Immunostaining for SST (B) and PP (D) on β-like HDDCs confirmed the quantitative polymerase chain reaction data (n = 3). (C): β-Like HDDCs coexpressed INS and PP as shown by immunofluorescence. Only 10.3% ± 3.3% of the cells showed exclusive expression pattern (arrow). (E): Enzyme-linked immunosorbent assay showing negligible quantities of human SST secreted by β-HDDCs compared with control group (CTL + JP). (F–H): Electron microscopic images of both mature (F, G) and immature granules (H) in differentiated HDDCs. (I): Increased signal of intrinsic light backscattering induced by insulin content on HDDCs after MAFA overexpression compared with undifferentiated cells (CTL + JP condition in small box). Scale bars = 500 nm (F–H), 100 µm (B–D), 10 µm (I), and 50 µm (I, small box). Abbreviations: CTL + JP, control HDDCs incubated with transfection reagent only (jetPEI); DAPI, 4′,6-diamidino-2-phenylindole; GCG, glucagon; INS, insulin; MAFA, V-Maf musculoaponeurotic fibrosarcoma oncogene homolog A; PP, pancreatic polypeptide; SST, somatostatin.