Fig. 4. Knockdown of SRY-related high-mobility-group box 4 (SOX4) partially reversed the effect of insulin-like growth factor-1 (IGF-1) on inducing rat bone marrow mesenchymal stem cell (BMSC) osteogenic differentiation. (A) SOX4 mRNA expression in BMSCs was assessed by reverse transcription-quantitative polymerase chain reaction. (B) SOX4 protein level in BMSCs was determined by Western blot. (C) Alkaline phosphatase (ALP) activity of cells was measured by ALP staining. (D) Calcification level of cells was measured by Alizarin Red staining. (E) Runt related protein 2 (RUNX2), osteocalcin (OCN), and osterix (OSX) protein levels in BMSCs were assessed by Western blot. The cellular experiments were independently repeated three times. Data were expressed as the mean±SD. One-way ANOVA was adopted for comparisons among groups, followed by Tukey’s test. GAPDH: glyceraldehyde-3-phosphate dehydrogenase, si: small interfering. *p<0.05, ***p<0.001.