Fig. 2.

Silencing of MTSS1 inhibited osteogenic differentiation of stromal progenitor cells. The knockdown of MTSS1 was verified using qRT-PCR in primary BMSCs isolated from 6-week-old mice (A) and ST2 cells (E) after infection of MTSS1 shRNA expression lentivirus or transfection of MTSS1 siRNAs. BMSCs or ST2 cells underexpressing MTSS1 were induced to allow osteogenic differentiation. The effects of MTSS1 silencing (BMSCs: B–D; ST2: F–H) on osteoblast differentiation were examined. Alizarin red staining and/or ALP staining were performed in differentiated osteoblasts 14 days and 21 days, respectively, after osteogenic treatment (B, F). The mRNA (C, G) and protein (D, H) levels of osteogenic factors were measured 72 h after osteogenic treatment. The effect of MTSS1 silencing on cell growth rate of ST2 cells was measured using a CCK-8 kit (I). Values represent mean ± SD, n = 3 in (A, C−E, G, H); n=8 in (I). Student’s t test was conducted in (A, C, D). One-way ANOVA was conducted in (E, G, H, I) followed by Tukey test for post hoc comparisons. *Significant vs. control LV or control siRNA, p < 0.05