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Objective:Immunoregulation study of umbilical mesenchymal stem cell (UCMSCs) on allogeneic umbilical cord blood(UCB) CD4+T lymphocytes,which proliferation,apoptosis and the differentiation to CD4+CD25+ regulatory T cell (Treg) in vitro. Methods:Establishing on direct contact or transwell co-culture system,adopt in different proportion of UCMCs with phytohaemag-glutinin (PHA)-activated UCB CD4+T lymphocytes were co-cultured. The proliferation of lymphocyte,percent of CD4+CD25+/CD4+and Foxp3 expression, regulatory T cell marker gene were measured. Apoptosis of CD4+T lymphocytes were observed in the direct contact or transwell coculture system of UCMSCs with desamethason( DXM)-stimulated UCB CD4+T lymphocytes. Results: The UCB CD4+T lymphocytes cocultured with UCMSCs with PHA-activating for 3 days,compared with the UCMSCs free control group,the amount of cells was reduced noticeably(P<0. 05) and the percent of CD4+CD25+in CD4+T lymphocytes and Foxp3 expression significantly in-creased(P<0. 01) in a dose dependent way(P<0. 05). The UCB CD4+T lymphocytes cocultured with UCMSCs with DXM-inducing for 7 days,the apoptosis rate was significantly lower than that of the control group without UCMSCs (P<0. 01). These effects were partially attenuated in transwell coculture but could not be eliminated. Conclusion: UCMSCs are negative effect on UCB CD4+T lymphocytes-mediated immunity effects,and mainly manifested in the regulation on cell proliferate ability and differentiation rather than promoting apoptosis.
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Objective To compare the hepatic differentiation potential of human umbilical cord mesenchymal stem cells (UC-MSCs) with bone marrow mesenchymal stem cells (BM-MSCs).Methods UC-MSCs and BM-MSCs derived from passage 3 were induced by IMDM supplemented with 20 μg/L HGF and 20 mg/L α-FGF.The medium was changed twice a week.The concentrations of albumin and urea nitrogen from cultural medium were measured to compare the differentiation ability of the two cells.We also examined the expression of hepatic related genes by real-time RT-PCR.Results UC-MSCs manifested significandy stronger proliferation potential than BM-MSCs.Both UC-MSCs and BM-MSCs could be induced into hepatocyte-like cells.The morphology of UC-MSCs tended to be more mature than BM-MSCs and they had more cytoplasmic granules.After 4 weeks,the levels of albumin and urea nitrogen from the cultural medium of the UC-MSCs group were significantly higher than the BM-MSCs group (P ＜ 0.05).Real-time PCR showed the expressions of four liver related genes CK18,G6P,HGF and ALB in the UC-MSCs group were significantly higher than the BM-MSCs group (P ＜ 0.05).Conclusion UC-MSCs had higher hepatic differentiation potential than BM-MSCs.Thus,UC-MSCs are more suitable than BM-MSCs for tissue engineering in the treatment of end-stage liver diseases.