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

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 digested with typeⅡ collagenase into single cells. Culture medium for MSCs was used for cell culture. The morphology 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 analyzed. 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 fibroblast-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 functionally 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. Key words: Cerebral cortex; Mesenchymal stem cell; Lymphocyte transformation test