Fig. 1.

The identification and cell viability assay of MSCs. a Primary culture MSCs. b The 3rd passage MSCs with homogeneous fibroblast-like morphology. Scale bars are 20 μm. c Flow cytometry analysis of MSCs. Flow cytometry histograms demonstrate the typical expression pattern of surface antigens. The filled areas indicate the cells stained with PE-conjugated antibodies against CD 44, CD 73, CD 90, CD SCA-1 and FITC-conjugated antibodies against CD11b and CD45, whereas the empty areas indicate the isotype-matched monoclonal antibody control. d Cytotoxicity Assay of MSCs. Cells were treated with various concentrations of 5-azacytidine for 24 h, then cell viability was measured with MTT and cell numbers were counted. Relative levels of cell viability were expressed as percentage of the untreated control