Efficient generation of mature hepatocyte-like cells from human iPSCs

A huge number of publications reported the production of immature hepatocyte-like cells by sequential addition of multiple inductive factors; however, little comparative analyses were performed. The purpose of this study is to identify the optimal induction system using human induced pluripotent stem cells (iPSCs). Initially, based on the published outcomes, functional screen was performed to select the three promising step-wise differentiation protocols. Then, cellular morphology, hepatocyte marker gene expressions, and secreted protein production of cells derived from the each specific protocol were characterized at final maturation stage. Through these efforts, we identified a highly efficient protocol for deriving hepatocyte-like cells. In combination with our recently developed 3-D culture systems (organ bud generation method), mature hepatocytes will be derived from human iPSCs with markedly increased efficiency in an artificially reconstituted human liver by way of liver bud transplantation.