Long-Term Culture of Genome-Stable Bipotent Stem Cells from Adult Human Liver

TLDR

The human liver has great replication potential, yet no in vitro culture system can sustain hepatocyte replication or function, although mouse Lgr5⁺ liver stem cells have been expanded as organoids and differentiated into functional hepatocytes. The study establishes culture conditions that enable long‑term expansion of adult bile‑duct derived bipotent progenitor cells from human liver. The expanded cells are chromosomally stable with very low mutation rates, differentiate into functional hepatocytes in vitro and after transplantation, and organoids from α1‑antitrypsin deficiency and Alagille syndrome patients recapitulate disease pathology, thereby enabling disease modeling, toxicology studies, regenerative medicine, and gene therapy.

Abstract

Despite the enormous replication potential of the human liver, there are currently no culture systems available that sustain hepatocyte replication and/or function in vitro. We have shown previously that single mouse Lgr5+ liver stem cells can be expanded as epithelial organoids in vitro and can be differentiated into functional hepatocytes in vitro and in vivo. We now describe conditions allowing long-term expansion of adult bile duct-derived bipotent progenitor cells from human liver. The expanded cells are highly stable at the chromosome and structural level, while single base changes occur at very low rates. The cells can readily be converted into functional hepatocytes in vitro and upon transplantation in vivo. Organoids from α1-antitrypsin deficiency and Alagille syndrome patients mirror the in vivo pathology. Clonal long-term expansion of primary adult liver stem cells opens up experimental avenues for disease modeling, toxicology studies, regenerative medicine, and gene therapy.