| BackgroundIn .the last few years, as seeds cells of biological medicine tissue engineering technique and therapeutic cloning technique, stem cell brought the new hope to dream about human health and longevial, became the hot spot of biological medicine research. Stem cells were divided into embryo stem cells (ESCs) and adult stem cells (ASCs) according to the stage differentiation. Up to now, problems of the cell differentiation mechanism and immunological rejection of xenogenic resource ESCs meeted during clinical application were still not resolved. Although the ESCs obtained from therapeutic cloning technique could resolve the immunological rejection, but the technique was very complicated, and the functions of the ESCs were much different from the function cell that differentiated completely. ASCs resided in adult tissue, had characteristics of abundance resource, powerful plasticity, recent to mature cell and multiple differentiation potentiality, could conduct individualize treatment, had not immunological rejection problem, so that it was the seeds cells for clinical application prevalently. Stem cells had been discovered in many adult tissues such as adult marrow, cartilage, tooth pulp, blood, nerve, muscle, fat, skin, limbus of cornea, liver, islands of pancreas. The multiple differentiation potentiality of ASCs had been confirmed. ASCs could trans-differentiate different type special cells, even retro-differentiate furthermore initial stem cells.Marrow mesenchymal stem cells (MMSCs) was a kind of stem cell that obtained easily, had the potential capability to differentiate to mesoblastema and neuroepidermal, even endoblastic layer tissue cells, such as muscle cell (myocyte), skeletogenous cell, cartilage cell, fibroblast, skin cell, nerve cell and lipocyte. A great quantity researches showed that MMSCs or hematopoietic stem cells (HSCs) could differentiate to hepatocyte of experimental rat that This work was supported by the 863 program of China (Research of human hepatocyte amplification differentiation and humanized blood cell No.2001AA216161)was induced with liver pathological changes, reconstruct liver and restore the liver function of disease rat to normal in vivo. At the same time, many researchers differentiated rat bone marrow cell or adult multi-potentiality stem cells (MPSCs) of rat bone marrow to hepatocyte-like cell under different condition in vitro. MSCs had advantages of collection repeatedly and auto-transplantation or application but did not appeared immunological rejection. When MSCs could be induced differentiation into mature hepatocytes in vitro, it would be provided a great deal of cells for liver cell transplantation and bioartificial liver.There were many patients with liver disease in China. Cell replacement or gene transfer therapy was a new and prospective hepatology therapeutical strategy for the pathological position of liver cirrhosis, hepatic necrosis and heritage liver diseases. The donor cell of cell therapy for liver diseases should have such as characteristics: obtained, cultured, proliferated or established easily; could differentiate directional special hepatocytes or biliary tract epithelial cells; survived for long time after transplanting in vivo; could not induce immunological rejection and had not harmful to host; objective gene could transfection the donor cell high performance if using for gene therapy. MMSCs had many of above characteristics, so that attracted the height attention of liver diseases researchers. Using human autogenic MMSCs trans-differentiated to hepatocyte would provide alterative for the cell therapy of liver diseases.Although comparatively large advancement had been gained in ASCs research, but there were many problems needed to be resolved in clinical application. Many experimental results obtained from the experimental animal in vivo, many were side population research, and these were not confirmed on clonal cell level. It was unclear that whether coincidence of the characteristics of human and animal ASCs or the results...
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