Abstract
Liver sinusoidal endothelial cells (LSECs) and LSEC progenitor cells (LPCs) derived from human pluripotent stem cells (PSCs) are expected as valuable cell sources for the development of cell therapy for hemophilia A, a congenital deficiency of coagulation factor VIII (FVIII), as LSECs are responsible for FVIII production. However, there is room for improvement in the efficiency of LSEC and LPC differentiation from human PSCs. In this study, we sought to optimize the method of mesoderm differentiation induction, the initial step of LSEC differentiation from human PSCs, to efficiently induce LSEC-like cells capable of secreting FVIII from human induced pluripotent stem cells (iPSCs). Following optimization of the concentration and stimulation period of CHIR99021 (glycogen synthase kinase 3β inhibitor), bone morphogenetic protein 4, fibroblast growth factor 2, and Activin A in the mesoderm induction step, approximately 65% and 54% of cells differentiated into LPCs and LSEC-like cells, respectively. Furthermore, we observed substantial FVIII protein secretion from LSEC-like cells in vitro. In conclusion, we established an efficient method for obtaining LPCs and functional LSEC-like cells from human iPSCs in vitro.