Biology of Human Liver Stem Cells

摘要: Although until recently the existence of liver stem cell was questioned, now race is on to obtain and characterize human for clinical therapeutic use gene replacement, repopulation, drug development, bioartificial support systems. Experimental models have identified cells at different stages in hepatocyte lineage, including mature hepatocytes, bipotential ductular (so-called oval cells), as well blood-derived periductular cells, possible progenitor (LPCs). In liver, many cholestatic diseases, associated with loss bile ducts proliferation “ductular proliferative cells” an appearance similar are seen. The origin these not clear; possibilities considered canals Hering, duct metaplasia blood-borne that locate liver. Specific markers been identified, but OV-6, a marker by monoclonal antibody cytokeratin rat ducts, has shown identify presumptive LPC. Other seen CD34 c-kit, shared hematopoietic indeed, after bone marrow transplantation, donor can be found recipient albeit rarely. Cells from injured or normal expressing c-kit selected, cultured vitro, express biliary phenotype; give rise hepatic epithelial endothelial phenotype also identified. addition, CD34-, - mesenchymal multipotential adult cell) differentiate into hepatocytes. Human fetal hepatoblasts may serve source LPCs. A number factors control differentiation precursor Jagged/Notch signaling. Much further work required before potential realized.