Abstract:

Objective To investigate the therapeutic effect of allogeneic transplantation of rat bone marrow mesenchymal stem cell (BMSCs) on experimental autoimmune encephalomylitis (EAE) in mice. Methods Rat BMSCs were obtained by a whole-bone marrow adherent culture method and identified with flow cytometry for cellular immune phenotypes. The obtained rat BMSCs were induced to differentiate into osteoblasts. The female C57BL/6 mice were randomly divided into three groups: control group, PBS group and rat BMSCs group. The EAE was induced by myelin oligodendrocyte glycoprotein( MOG) _35-55 with fully emulsified Freund’s adjuvant and immunization by subcutaneous multi-point injection. The mice were treated with rat BMSCs by intraperitoneal injection 38 and 48 days after immunization. Neurological function scores were performed to evaluate the neurological function. Twelve days after the second treatment the spinal cord，spleen and peripheral blood were taken. HE staining and Luxol fast blue staining were used to observe inflammatory cell infiltration and demyelination in the spinal cord. Single-cell suspension was prepared and stimulated with 10mg/L concanavalin A (ConA) and MOG _35-55for 3 days. The splenocytes proliferation was observed. The peripheral blood interferon-γ（IFN-γ）、interleukin-17（IL-17）cytokines were evaluated by ELISA. Results Flow cytometry results showed that P3 cells of rat BMSCs expressed CD29, CD90 and CD106, but not expressed CD45. The obtained cells were induced to osteogenic cells. The neural function was less seriously damaged in the rat BMSCs group than the PBS group. HE staining indicated that the infiltration of inflammatory cells in rat BMSCs group was less than that in PBS group (P<0.05). Luxol fast blue staining displayed that the demyelination of rat BMSCs group was less than the PBS group at the same time point (P<0.05). After stimulation with ConA and MOG _35-55, the splenocytes proliferation of PBS group and rat BMSCs group was increased, while that of rat BMSCs group was lower than PBS group. Compared with PBS group, rat BMSCs group had decreased peripheral blood IFN-γ、IL-17 levels (P<0.05). Conclusion Rat BMSCs can be effectively isolated and purified by the whole bone marrow adherent culture method, and rat bone marrow mesenchymal stem cells have therapeutic effects on mouse EAE.

Key words: Bone marrow mesenchymal stem cell, Allograft, Experimental autoimmune encephalomylitis, Splenocyte proliferation, Cytokine；Flow cytometry, Luxol fast blue staining, Mouse