Conversion of terminally committed mouse hepatocytes to culturable bipotent progenitor cells

A challenge for advancing approaches to liver regeneration is loss of functional differentiation capacity when hepatocyte progenitors are maintained in culture. Recent lineage-tracing studies have shown that mature hepatocytes (MHs) convert to an immature state during chronic liver injury, and we investigated whether this conversion could be recapitulated in vitro and if such converted cells could represent a source of expandable hepatocytes. We report that a cocktail of small molecules, Y-27632, A-83-01 and CHIR99021, can convert rat and mouse MHs in vitro into proliferative bipotent cells, which we term chemically induced liver progenitors (CLiPs). CLiPs can differentiate into both MHs and biliary epithelial cells that can form functional ductal structures. CLiPs in long-term culture did not lose their proliferative capacity or their hepatic differentiation ability, and rat CLiPs were shown to extensively repopulate chronically injured liver tissue. Thus our study advances the goals of liver regenerative medicine. Transcriptomic analysis for mouse CLiPs at P1 which underwent hepatic induction (Matrix 1). Transcriptomic analysis for mouse CLiPs at P11-12 which underwent hepatic induction (Matrix 2). Hepatic induction was performed for P1 mouse CLiPs or CLiPs that underwent 11-12 passages.