脐血源性神经球分化为类雪旺细胞的研究

Umbilical cord blood cell-derived neurospheres differentiating into Schwann-like cells

目的 研究脐血间充质干细胞（CB-MSC）向雪旺细胞谱系分化的生物表型和特征.方法诱导CB-MSC为悬浮的神经球,然后用胶质生长因子诱导分化为类雪旺细胞.分化的CB-MSC表现出和雪旺细胞类似的形态学的改变.通过免疫化学染色和Western blotting鉴定这些细胞雪旺细胞标志的表达情况;通过分化的CB-MSC与背根神经节神经元共培养观察其促进其轴突生长的作用.结果 未分化的CB-MSC很少表达nestin、GFAP和S-100.在CB-MSC诱导成神经球以后,82.38%±3.70%的细胞表达nestin,而GFAP和S-100仍然阴性.接种于分化液36 h后细胞表达nestin、GFAP、S-100,阳性率分别为43.78%±3.21%、35.42%±1.82%和29.49%±2.54%.相比未分化CB-MSC,分化的CB-MSC中神经轴突的形成率和轴突的长度明显增加,差异有统计学意义（P＜0.05）.结论CB-MSC可以通过诱导转变为神经球,神经球可以诱导成雪旺细胞的形态,表型和功能类似雪旺细胞,可做为一种替代骨髓间充质干细胞的细胞来源,对于治疗神经系统疾病具有潜在的应用价值.

Objective To investigate the phenotypic and biological characteristics of human umbilical cord blood mesenchymal stem cells （CB-MSCs） differentiating into a Schwann cell lineage.Methods Initially, we induced human CB-MSC into floating neurospheres,and then, neurospheres were induced to differentiating into Schwann-like cells using glia growth factors.Differentiated CB-MSCs showed morphological changes eing similar to those of Schwann cells.Expression of the Schwann cell markers was determined by immunocytochemical staining and Western blotting.Furthermore,differentiated CB-MSCs were co-cultured with dorsal root ganglia neurons to promote the neurite outgrowth.Results The stained nestin,GFAP and S-100 of the undifferentiated CB-MSCs were barely expressed. When CB-MSCs were induced into neurospheres,the nestin positive cells were （82.38±3.70）%,but the expressions of GFAP and S-100 were still negative.After inoculated 36 h,the positive rates of nestin, GFAP,S-100 were （43.78±3.21）%,（35.42±1.82）% and （29.49±2.54）%,respectively.Compared to those of the undifferentiated group,differentiated axons of CB-MSC were significantly longer and the numbers of them were obviously larger （P〈0.05）.Conclusion CB-MSCs could be onverted into neurospheres and then induced into Schwann-like cells in terms of morphology,phenotype and functional capacities.CB-MSCs can be used as an alternative source for bone marrow derived-MSCs,suggesting their potential values in the treatment of neurological diseases.