骨髓间充质干细胞对海藻酸钙胶珠内神经干细胞增殖与分化的作用

Effects of Bone Marrow Mesenchymal Stem Cells on the Proliferation and Differentiation of Neural Stem Cells Growing in Calcium Alginate Beads

神经干细胞(neural stem cells,NSCs)移植治疗神经损伤被认为是具有潜在应用价值的手段,但其来源困难;骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)以其所具有的诸多优点,为神经损伤的治疗提供了一个新的思路。而BMSCs是否是通过作用于内源性的NSCs来促进神经修复,仍存在着争议。今采用海藻酸钙胶珠将NSCs包囊培养至一定大小的神经球后,再与BMSCs进行共培养,考察BMSCs对生长在海藻酸钙胶珠内的NSCs增殖与分化的作用,探讨BMSCs移植治疗神经疾病与损伤的作用机理。共培养过程中观察神经球结构的变化;共培养结束后计算NSCs的增殖倍数,对增殖条件下共培养的NSCs表型和多向分化潜能进行免疫荧光染色鉴定;对分化条件下共培养的NSCs向不同神经细胞分化的能力进行流式细胞仪检测。结果表明,BMSCs可使生长于支架内的NSCs迁出细胞球,对NSCs的增殖没有明显影响;但能够明显影响NSCs的分化,使其向少突胶质细胞分化的能力增加3倍,向星形胶质细胞分化的能力减弱1倍,而向神经元细胞分化的能力没有明显变化。BMSCs有可能是通过分泌某些因子增加了NSCs迁移及向少突胶质细胞分化的能力,从而促进神经损伤的修复。

Neural stem cells （NSCs） transplantation is believed to be effective in the treatment of nerve injuries; however, they are limited and difficult to be isolated from brain. The bone marrow mesenchymal stem cells （BMSCs） possessing some advantages can be used as a new cell source for repairing nerve injuries. However, it is still not clear that isn＇t the BMSCs effect on NSCs is the mechanism of promoting nerve repair. Therefore, in our research, the neurospheres of NSCs encapsulated in calcium alginate beads （Ca-Alg-Bs） were cocultured with BMSCs to investigate the effects of BMSCs on the proliferation and differentiation of NSCs growing in Ca-Alg-Bs and to explore the mechanism of recover neural diseases by BMSCs transplantation. During the coculture period, the neurosphere structure was observed, and when the coculture ended, the NSC expansion fold was measured; the phenotype and multi-differentiation potentials of NSCs in the proliferation medium were assayed by immunofluorescent staining. At the same time the differentiating capacity of NSCs into neurocytes in the differentiation medium was analyzed with flow cytometry. The results show that the NSCs in beads could migrate out of the neurospheres by contacting with BMSCs indirectly, and the BMSCs effect NSCs proliferation slightly, while influence NSCs differentiation obviously; so that the oligodendrocyte proportion increases 3 times and the astrocyte proportion decreases 1 fold, but the neuron proportion remains unchanged. The BMSCs probably secret some factors to encourage NSCs to migrate and differentiate into oligodendrocytes and subsequently accelerate the nerve recovery.