Figure 2

Induced differentiation, flow cytometric and immunosuppressive ability analysis of human umbilical cord mesenchymal stem cells expanded in serum-free medium. After differentiation induction, (a) osteogenesis was confirmed by Alizarin Red (×40), (b) adipogenesis was stained by Oil Red O (×200) and (c) chondrogenesis was analyzed by Toluidine Blue (×100). (d) Serum-free medium (SFM)-expanded human umbilical cord mesenchymal stem cells (hUC-MSCs) at the 10th passage were labeled with antibodies against human antigens CD14-PE, CD19-PE, CD34-FITC, CD45-PE, CD73-PE, CD90-PE, CD105-PE, HLA-ABC-FITC, HLA-DR-PE and Nestin-PE. (e) Expression of hTERT in hUC-MSCs. Graph shows the level of hTERT transcripts of hUC-MSCs cultured in serum-containing medium (SCM) and SFM (n = 5). Values presented as ratio of positive control (HeLa cells). Immunosuppressive ability of hUC-MSCs was evaluated by co-culturing with human peripheral blood mononuclear cells (hPBMCs). (f) Proliferation of hPBMCs was quantified based the measurement of BrdU incorporation during DNA synthesis. (g) Level of interferon gamma (IFN-γ) in the supernatant was determined by ELISA.