Optimization Of The Directed Differentiation System Of Human Pluripotent Stem Cells Into Hepatocyte-like Cells

In recent years,the incidence of many liver diseases is increasing gradually,which seriously affects health.Currently,liver transplantation and hepatocyte transplantation are effective methods for the treatment of end-stage liver disease,but the lack of liver donors makes the application of these two methods face great challenges.So,the development of regenerative sources of hepatocytes is an urgent issue.Human pluripotent stem cells are ideal cell sources for the generation of hepatocyte-like cells(HLCs)due to their ability to self-renew and differentiate into multiple cell types.Although much progress has been made in the field of generating HLCs from pluripotent stem cells,there are still many problems.For example,the high heterogeneity of HLCs and the large consumption of growth factors and xenogeneic animal products during differentiation make it difficult to meet the requirements of clinical and mass production,in addition,the function and maturity of hepatocytes need to be improved.In this study,we expanded and purified definitive endoderm,an intermediate stage in the process of differentiating human embryonic stem cells into hepatocytes,to construct endodermal progenitor cell lines(EPCs),which were further differentiated into hepatocytes.This approach minimizes the heterogeneity of differentiated cells and reduces the risk of tumorigenesis after transplantation.In addition,through chemical screening,we established a chemical-based EPCs expansion and differentiation system independent of growth factors.The HLCs derived from new system were morphologically similar to hepatocytes differentiated from growth factor-based system,expressing high levels of liver specific markers and displaying biological functions such as glycogen synthesis and lipid metabolism.In conclusion,this study optimized and established a new system for endoderm progenitor cells,which provides the basis for large-scale production of hepatocytes,provides a platform for the study of the process and mechanism of liver development,and helps promote the clinical application of HLCs.