从正常大鼠大脑皮层分离培养具有间充质干细胞特性的细胞

Identification of mesenchymal stem-like cells in cerebral cortex of normal rats

目的探讨大鼠大脑皮层是否存在间充质干细胞(mesechymal stem cells,MSCs)特性的细胞.方法用Ⅱ型胶原酶消化大鼠的大脑皮层使其成为单个细胞,按MSCs培养方法培养,在显微镜下观察细胞形态,流式细胞术检测MSCs特异性表面分子的表达,在诱导培养体系中鉴定其是否具有分化为成骨细胞和脂肪细胞的功能,淋巴细胞转化试验(lymphocyte transformation test,LTT)检测其是否具有免疫抑制功能.骨髓MSCs(BM-MSCs)作为阳性对照.结果从大鼠大脑皮层中分离、培养出的成纤维样细胞形态均一,呈旋涡状生长.流式结果显示其表面高表达CD29、CD90、CD146的mRNA等,不表达CD45及CD31的mRNA,可以诱导分化成脂肪细胞及成骨细胞,可有效抑制由刀豆蛋白A刺激引起的脾脏淋巴细胞的增殖.结论本实验结果表明,大鼠大脑皮层中存在具有MSCs特性的细胞.

Objective To investigate whether the cells with the characteristic of mesenchymal stem cells(MSCs)could be found in rat cerebral cortex.Methods Rat cerebral cortex samples were diges-ted with typeⅡcollagenase into single cells.Culture medium for MSCs was used for cell culture.The mor-phology of the cells was observed under a microscope.MSC-specific surface markers were detected by flow cytometry.Differentiation potential favoring adipogenesis or osteogenesis of the subcultured cells was ana-lyzed.Lymphocyte transformation test(LTT)was performed to analyze their immunosuppressive function.Bone marrow MSCs(BM-MSCs)were used as positive control cells in all experiments.Results The fibro-blast-like cells isolated from the cerebral cortex of rats were morphologically heomeogeneous after cell culture and grew in a spiral pattern.On the surface of these cells,CD29,CD90 and CD146 were highly expressed at mRNA level,while the expression of CD45 and CD31 at mRNA level were not detected.Moreover,they could be induced to differentiate into adipocytes and osteoblasts.Results of LTT showed that they were func-tionally equivalent to BM-MSCs in inhibiting the proliferation of spleen lymphocytes induced by concanavalin A.Conclusions This study suggested that the cells with the characteristic of MSCs could be detected in rat cerebral cortex.