PDGF receptors and signaling are required for 3D-structure formation and differentiation of human iPSCs-derived hepatic spheroids

Human iPSC-derived liver organoids (LO) or hepatic spheroids (HS) have attracted widespread interest and the numerous studies on them have recently provided various production protocols. However, the mechanism by which the 3D structures of LO and HS are formed from the 2D-cultured cells and the mechanism of the LO and HS maturation remain largely unknown. In this study, we demonstrate that PDGFRA is specifically induced in the cells that are suitable for HS formation and that PDGF receptors and signaling are required for HS formation and maturation. Additionally, in vivo, we show that the localization of PDGFRα is in complete agreement with mouse E9.5 hepatoblasts which begin to form the 3D-structural liver bud from the single layer. Our results present that PDGFRA play important roles for 3D structure formation and maturation of hepatocyte in vitro and in vivo, and provide a clue to elucidate the hepatocyte differentiation mechanism. During differentiation of hepatocyte-like cells derived from hiPSC, each sample was extracted on day8, 10, 12, and 14 in d4DE or d6DE protocol (total 8 samples).