| Background and Purpose Orthotopic liver transplantation is the most clinically effective method of treating acute liver failure,liver diseases of terminal stage ,and metabolic liver disorders.however,due to shortage of organs,a large number of patients die before a liver can be procured for transplantation.At the same time,the need for long-term immunodepression restricts wider application of orthotopic liver transplantation.Artificial liver was first proposed 40 year ago,nowadays it has been used in clinic and plays a role in improving syndromes of terminal liver disorders and prolonging survival time of patients with liver failure.Because non-bioartificial liver support system may not substitute for biochemical function of the liver,Matsamura mentioned the notion of bioartificial liver support system (BLSS) in 1987.As an effective support therapeutic means of liver function failure and a necessary auxiliary therapeutic measure of liver transplantation,BLSS has already achieved better results in preclinical researches,but still have a lot of questions to be resolved.One of these questions is that how to obtain hepatocytes which are the key part of BLSS.There are two types of stem cells in bone marrow,one is hematopoietic stem cells(HSCs) ,the other is mesenchymal stem cells (MSCs) .MSCs are pluripotent cells andcan differentiate into non-hematopoietic cell types under certain conditions,such asosteoblasts, chondroblasts,adipocytes, skeletal myoblasts,neurocytes,and neuroglialcells.Human MSCs are heterogeneous in that they contain three morphologically distinctkinds of cellsrspindle-shaped cells,large flattened cells and extremely small round cells.These small round cells are a subpopulation of MSCs and appear to be the earliest progenitors in the cultures and have the greatest potential for multilineage differentiation. Fibroblast growth factor-4(FGF-4)is a polypeptide that stimulates growth of stromal cells and induces differentiation of stromal cells in vitro. As a signal molecule in vivo,it is very important for stromal cells differentiation during embryonic development. Hepatocyte growth factor (HGF) is a potential hepatocyte mitogen,its receptor is c-Met protein.lt plays an important role in the development and regeneration of the liver.HGF and c-met jointly regulate the formation of the liver in vitro,and in vivo they play a crucial role in embryogenesis.The ability to identify and exploit a clonal subpopulation of human marrow mesenchymal stem cells could have important clinical implications,as generating large numbers of differentiated and therefore fully functional human hepatocytes has enormous potential. Other important areas where progress has been limited due to lack of sufficient numbers of good quality primary human hepatocyte include hepatocyte transplantation for the treatment of metabolic disorders or fulminant liver failure,and evaluation of drug toxicology and pharmacokinetics drugs.Moreover,because MSCs come from patients own bone marrow,so no histocompatibility barrier of host against donor, and no opportunity of immune based reactivity of donor against host,exists.The aim of this study is to observe FGF-4 and/or HGF induce(s) differentiation of CD45HLA-DR" cells in human bone marrow MSCs into functional hepatocyte-like cells,and to discuss the possibility of obtaining hepatocyte-like cells in vitro.Moreover,it will be decided which growth factor is appropriate in inducing differentiation of human CD45HLA-DR' cells and bone marrow mononuclear cells into hepatocyte-like cells by transmission electron microscopy, immunocytochemistry,and functional tests. Accordingly these differentiation cells will offer cell source for cell engineering.Methods Bone marrow mononuclear cells (BMMNCs) were collected from the iliac crest of 20 patients (15-50 years of age) who have no hematologic diseases.they were precultured in the growth liquidsfincluding 90% DMEM (low glucose), 10% FBS, l00u/ml Penicillin ,100 μ g/ml Streptomycin ]at cell density of 5.0x10-5/ml.Me...
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