| Backgrounds and aimsStem cells is a kind of archaeocyte which can self-replication and proliferation differentiation .It's origin cells of formatting various kinds tissue and organ of life bodies.According to developmental stage ,stem cells were divided into embryonic stem cells and adult stem cells.the studies and application of embryonic stem cells were resticted due to ethics and law. so,people more interest in studies of adult stem cells.At present, Plasticity of adult stem cells is hot spot domain of studies. Committed tissue stem/progenitor cells possess multipotent differentiation. They not only differentiated into cell tapes of same embryonic layer,but also tran- differentiated into cell tapes of differtent embryonic layer.In 1999, American scientist found that muscle tissue stem cells of mouse tran- differentiated into blood cells.After that ,reseacher proved that nerve stem cells obtaining from fetus brain tissue cound differential into blood cells, hemotopoietic stem cells and mesenchymal stem cells could produce skeletal muscle myocardium > hepatocyte,nerve glial cells and neuron-like cells.Studies proved that there are abundand hemotopoietic/progenitor stem cells in umbilical cord blood .It's the third source of hemotopoietic/progenitor stem cells besides bone marrow and peripheral blood .Proliferation and self-renew abilities were similar or surpass that in bone marrow. Umbilical cord blood were discovered also containing multipotency stem cells,called mesenchymal stem cells, which cound differential into endothelium, blood vessel and nerve tissue.Achivement of stem cells in biology and medical domain provided a new thought fortherapeutic of hepatic disease . Inducing differentiation of adult stem cells could supply cells for hepatocyte transplantation or bioartificial liver , and treatment on acute/chronic liver function failure or hepatic metabolic diseases .There are lots of studies on inducing differentiation of marrow stem cells into hepatocyte in vitro and in vivo at present .but rarely on human umbilical cord blood stem cells. Based on situation of reseach, We intend to investigate wether or not human umbilical cord blood stem cells could be induced to differentiate into hepatocyte-like cells in vitro and explore conditions of differentiation. In addition, we aim to study the mechanism of differentiation by analyzing the effect of two growth factor and expression of its corresponding receptors. Materials and MethodsHuman umbilical cord blood samples were obtained sterilely by punture umbilical vein,citrate phosphate dextrose as anticoagulant .MNC were isolated by lymphocyte separation medium(density 1.077g/ml), analysed vital force and pure degree by hematoxylin and trypan blue.MSC were obtained by adhere cultivation. MNC and MSC were purified and expanded with DMEM medium containing 10% FBS. The surface antigen expression of MNC and MSC were detected by flow cytometry.MNC and MSC were induced with DMEM medium, containing 2%FBS, lxITS(insulin/transferring/selenium),and HGF alone, FGF4 alone, HGF + FGF4 or no growth factor respectively. The markers of hepatic linear cells were examined before induction ,and 7, 14, 21 and 28 day after induction by RT-PCR, immunocyte chemistry and PAS (periodic acid-schiff) in every group. C-met and FGFR2 mRNA was examined before induction ,and 14, 28 day after induction by RT-PCR in HGF+FGF4 and no growth factor groups. Results1 Both vital force and pure degree of MNC seperated by gradient centrifugation were above 95 percent .averagely accounted for 0.96+0.12% of CD34+ cells2 The MSC began to be adherent from the 24th hour after seperation and to be fusiformshape clonal manner, flow cytometry showed that MSC expressed strongly CD29 andCD44 ,but did not express CD34.3 The MNC and MSC were detected weakly expression of C-met and FGFR2,but did not detect expression of a -fetoprotein ,albumin,CK18,hepatocyte antigen,glycogen.4 a -fetoprotein mRNA and protain were detected expression on day of 7 after induction.albumin mRNA an...
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