Thrombin could not change phenotypic and functional features of MSCs. Human bone marrow MSCs were cultured in the presence of thrombin (4 U/ml) for one week, followed by cell collection for phenotypic and functional analysis. A: Flow cytometry analysis on the surface markers. The positivity of the indicated antigens on the parent and thrombin-treated MSCs is provided. B: Alkaline phosphatase and Oil-red O staining after the parent and thrombin-treated MSCs were induced for differentiation under the specific conditions. Bar: 50 μm. C: Graded doses of MSCs, treated with or without thrombin, were seeded into 96-well culture plate, irradiated and co-cultured for 72 hours with allogeneic peripheral blood mononuclear cells in the presence of PHA. MTT assay was used to reveal the viable lymphocytes. X-axis: the number ratios of MSCs versus mononuclear cells are provided. Lymphocyte: cells cultured in the presence of PHA and absence of MSCs. The results are representative of three individual experiments. MSCs, Mesenchymal stem cells; MTT, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide; PHA, Phytohemagglutinin.