| Background and Purpose: The basic characteristics of mesenchymal stem cells (MSCs) was self-renewal and the multiple differentiative potentials, which is a "hot spot" on the study of stem cells. MSCs can be found in various locations in the body, including bone marrow, adipose tissue, and peripheral blood. Compared with tranditional neural stem cells, embryonic stem cells and haematopoietic stem cells, MSCs have more advantages. MSCs was available in body tissue and easy to culture and to proliferate. MSCs had hardly rejection when transplanting and had lesser genovariation when culturing in vitro. At prensent, the main source of MSCs is bone marrow. However, With the development of MSCs, it was found that the source of bone mesenchymal stem cells is rare. This study is designed to explore HUMSCs, which is a new kind of MSCs. The successful isolation of HUMSCs from umbilical card tissue and study on its biological characteristics will lay the foundation of directional diffrentiation of HUMSCs.Methods: The umbilical cords from full term section patients were collected in sterile condition immediately upon delivery and were washed with sterile saline. The umbilical cords was cut into pieces of 2~4cm. Blood clot in umbilical cords were rinsed out and veins and arteries were removed. Tissue fagments were trypsinized by collagenaseⅡand centrifugate. Then pellets were resuspended in DMEM/F12 medium including fetal bovine serum and penicillin in culture flask. Once adherent cells reached approximately 80~90% confluence, they were re-fed and passaged. We obsevred the cells'morphological changes under inverted phase contrast microscope and their photos were taken. Immunofluorescence and flow cytometry were employed to identify the phenotype of those cells, and the ability of proliferation was observed by means of growth curve.Results: Adherent cells could be found after incubation in 24 hours in vitro,which were small and have no evident nucleus with different appearance in morphology, and most undigestive tissue suspended on culture medium. As time went on, adherent cells were constantly increasing. After 4 days, some adherent cells took on bipolar, flat or long-shuttle shape. Eight days later, the increasing adherent cells looked likes fibroblast cells and grew in whirlpool way. Those cells reached 80% confluence in about 14 days. The passaged cells were gradually purified, and maintained their biological characteristic after at least 20 passages in vitro. It could be found from the growth curve of P3 and P7 and P14 of HUMSCs that their ability of proliferation of had no difference. The phenotype analysis showed that the expressions of CD29, CD73 and CD105 were positive in HUMSCs, and their rates were 99.2%, 99.5% and 98.9% respectively. In contrast,They expressed low level of CD34, CD45 and HLA-DR, and the positive rates were 0.1%, 0.5% and 0.2% respectively. Futhermore, the phenotype analysis showed no significant dieffrence between P3,P7and P10 of HUMSCs.Conclusions: The umbilical cords tissue is disposal after delivery, which is rich, convient to obtain and eliminate the ethical or social concerns. HUMSCs could be harvested by collagenase digesting method to umbilical cords, which had a fibroblast-like appearance and strong ability of proliferation. Surface phenotype analysis indicated that HUMSCs are new member of MSCs family and immunogenicity is low. Therefore, HUMSCs might be an ideal and potential source of cells for tissue engineering. Background and Purpose MSCs was capable of multiple differentiation potential and could differentiate into several types of mature cell, including osteogenic cells, cartilage cells, adipocytes, cardiomyocytes and endotheliocyte. HUMSCs also could be induced to differentiate into neural stem cells, neuron and astroglia-like cells because of its flexibility. The induced efficiency of HUMSCs was distinct under different conditions. The positive rate of neuron-associated protein was higher than gliocyte-associated protein after induced. So the present study was designed to induce HUMSCs to differentiate into neuroepithelium-like cells especially oligodendrocyte-like cells in vitro. This research of inducing differentiation would be possible to provide the source of ideal candidate stem cells for transplantation therapy of nervous system diseases, such as demyelinating disease of central nervous system.Methods: HUMSCs were induced with bFGF, EGF plus N2-supplement and insulin in DMEM/F12. After 24 hours, the medium changed for long-term induction by adding DMEM/F12, N2-supplement and IGF-I. Morphologic change of inducing cells was observed everyday and their pictures were taken. In the same time, immunohistochemistry technique was applied to identify the surface maker of differentiated cells, Such as Nestin,β-TubulinⅢ, GFAP, A2B5, O4, MBP and Olig2, which is respectively the maker of neural stem cell, neuron, astrocyte, oligodendrocyte progentor, preoligodendrocyte, mature oligodendrocyte.Results: Combination of IGF-1 medium with several growth factors synergistically promoted HUMSCs to differentiate into neuroepithelium-like cells. The induced cells not only underwent morphologic changes, but also expressed Nestin,β-TubulinⅢ,GFAP,MBP,A2B5,O4 and Olig2. Moreover, Fluorescence intensity of induced cells was changed with induction time because of different constituents. The borderline between neuron and mature oligodendrocyte occurred on the eighth day after induction. That was to say, the proportion of neuron was relative large first 8 days, and the proportion of oligodendrocyte was relative large after 8 days.Conclusions: HUMSCs was differentiated into neural precursor cell at first. then HUMSCs differentiated into neuroepithelium-like cells including neural, oligodendrocyte and astrocyte-like cells under the condition of combination IGF-1 medium with several growth factors. Meanwhile, the mature of oligodendrocyte experienced a progressive process from early progenitor cells period to late progenitor cells period, then gradually maturity.
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