Pharmacological Induction of a Progenitor State for the Efficient Expansion of Primary Human Hepatocytes

Transplantation of genetically corrected hepatocytes is an attractive alternative to liver transplantation but is hampered by the low amplification potential of these cells in vitro. Here, we describe a method for generating proliferative hepatic progenitor cells (iHPC) from human hepatocytes as an expandable cell source for liver therapy. Dedifferentiation of primary hepatocytes to iHPC was achieved in less than 7 days by culturing the cells in medium with a cocktail of growth factors and small molecules. In culture, iHPC expressed a combination of endoderm hepatic progenitor and mesenchymal stem cell markers and proliferated vigorously, allowing for their expansion by at least 104 times. RNA sequencing of iHPC demonstrated that they displayed far more subtle changes in both transcriptome and transposcriptome, compared to hepatocyte-derived iPSC. Finally, transplantation of iHPC into the liver of immuno-deficient mice showed iHPC differentiation potential in vivo, without triggering detectable tumor development. Transcriptome profiling of human primary hepatocytes from two different pediatric donors, reprogramming timepoints to induced pluripotent stem cells (iPSC) from one donor, two iPSC clones and differentiation timepoints to hepatocyte-like cells (HLC).