Fig. 4

Culturing MSCs in serum-free medium increases the secretion of EGF. MSCs, SF-MSCs, and HK-2 cells were cultured in DMEM containing 0.1% FBS for 48 h, and then the culture supernatants were collected as conditioned medium. A The concentrations of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), milk fat globule-EGF factor 8 (MFGE8), and epidermal growth factor (EGF) in each conditioned medium were measured by ELISA (n = 5 in each group). B The concentrations of heparin-binding EGF-like growth factor (HB-EGF) and transforming growth factor-alpha (TGF-α) in each conditioned medium were measured by ELISA (n = 5 in each group). Concentrations were normalized to the total protein content. Data are means ± S.D. ^#P < 0.01 (one-way ANOVA followed by Tukey–Kramer’s post-hoc test)