The effect of S1P or LL-37 on the properties of MSCs. (A) Flow cytometry analysis of the expression of MSC surface proteins (CD29, CD73, and CD105) using hCB-MSCs after treatment with 0.2 μM S1P or 2.5 μg/mL LL-37 for the indicated amount of time. (B) Cell proliferation analysis of hCB-MSCs exposed to the indicated dose and duration of S1P (left panel) or LL-37 (right panel). (C) hCB-MSCs after treatment with 0.2 μM S1P or 2.5 μg/mL LL-37 for 1 day were differentiated by culture in osteogenic (upper panel), adipogenic (middle panel), or chondrogenic (lower panel) induction media. Osteogenesis, adipogenesis, and chondrogenesis were determined using Alizarin Red S, Oil Red O, and Alcian Blue staining, respectively. (D) Real-time quantitative polymerase chain reaction (RQ-PCR) analysis of the induction of osteogenic, adipogenic, and chondrogenic genes in hCB-MSCs. The relative expression level of the indicated genes is represented as the fold-change compared to the value of MSCs cultured under noninducing medium and are shown as mean±SD of three independent experiments. *P<0.05, **P<0.01 compared to N.T. (one-way ANOVA with Bonferroni post-test). NT, non-treated.