Fig. 2. Insulin-like growth factor-1 (IGF-1) up-regulated SRY-related high-mobility-group box 4 (SOX4) expression by activating the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway. (A) Total- (t-) ERK1/2 and phosphorylated- (p-) ERK1/2 levels in bone marrow mesenchymal stem cells (BMSCs) were assessed by Western blot. (B) SOX4 mRNA expression in BMSCs was measured by reverse transcription-quantitative polymerase chain reaction. (C) SOX4 protein expression in BMSCs was determined by Western blot. The cellular experiments were independently repeated three times. Data were expressed as mean±SD. One-way ANOVA was applied for comparisons among groups, followed by Tukey’s test. GAPDH: glyceraldehyde-3-phosphate dehydrogenase, DMSO: dimethyl sulfoxide. *p<0.05, **p<0.01, ***p<0.001.