Characterization of human stem cell-derived hepatocytes

Chronic liver diseases represent a primary worldwide health concern. Liver transplantation is the only practical cure for severe and chronic diseases, but due to the lack of human livers donor an insufficient number. The alternative is the cell-based transplantation of hepatocytes or hepatocyte-like cells derived from human stem cells. We aim to produce a physiologically relevant human liver model from human stem cells and to scale-up their production to be utilised in disease modelling and drug testing. Wnt/ β-catenin signalling pathway involved in hepatoblast proliferation and differentiation during liver development and regeneration. Here we showed that inhibition of GSK3β to stabilise β-catenin during hESC- derived hepatoblast differentiation resulted in high level of β-catenin with the early appearance of truncated form, improvement of HLCs morphology and upregulation of HNF4α and albumin expression. Although hESC can differentiate into almost any cell type including hepatocytes, their genetic instability in cultures limited their utilisation in regeneration medicine and cell-based transplantation therapy. Adult liver stem/ hepatic progenitor cells (HPCs) on the other hand upon activation following severe liver injury can differentiate into both hepatocytes and biliary epithelial cells. EpCAM+ progenitor cells isolated from human livers presented their expandability with the maintenance of progenitor characteristics and capacity to differentiate into hepatocytes in 3D culture (organoids). Differentiation of organoids- resulted in a loss of hepatic progenitor cell markers expression while the expression of differentiated hepatocyte-specific genes increased. Differentiated organoids showed low albumin expression compared to primary human hepatocytes; suggesting that the differentiation may have arisen from a limited population of cells or the organoids- derived hepatocytes were not fully mature. FACS sorting using a combination of specific markers (EPCAM, CD133 and CD24) produced a more homogeneous cell population that differentiated more effectively into hepatocytes compared to EpCAM+ cells. The acellular rat liver scaffolds obtained by decellularisation using detergents was naturally directed the cultured HPCs and NPCs to their in localisation and improved the albumin expression in the differentiated HPC providing an applicable model for drug testing and bio-engineered liver transplantation. Generating functional hepatocytes from human liver progenitor cells could provide an unlimited supply of hepatocytes; replacing the animal use in drug screening, testing new chemical entities and modelling human liver diseases