Fig. 6

Effects of SB431542 on the TGF-β and BMP signaling in hGMSCs. a Western blotting analysis of phosphorylation protein levels of SMAD2, SMAD3, ERK1/2, JNK, and P38 with or without SB431542 (1 μM) at the indicated time points (0, 15, 30, 60, 120, 180, 300 min). GAPDH was used as a protein loading control. b mRNA expression of BMP4 and BMP6 were analyzed by qRT-PCR during osteogenic differentiation of hGMSCs treatment with or without SB431542 (1 μM) at a serious time points (0, 3, 6, 9, 12 day). The relative mRNA expression is normalized to β-ACTIN. Student’s t test. c, d Alizarin Red staining of hGMSCs (c) with quantification (d) after 21 days in osteogenic induction medium with both SB and noggin or SB alone. Osteogenic induction medium treatment as control. One-way ANOVA with Tukey’s multiple comparison test. n = 3. Data are means ± SEM. ns, no statistically significant difference p > 0.05, *p < 0.05, **p < 0.001, ***p < 0.001. Scale bars, 500 μm. SB, 1 μM SB431542; N, Noggin; OI, osteogenic induction medium; P, phosphorylation; min, minutes