Fig. 4: Ablation of PP5 enhances osteoblast differentiation and promotes osteogenesis of MSCs

Alizarin red staining on day 14 revealed significantly higher osteoblast differentiation of MSCs in PP5 KO mice (a, d, e, and f) compared to WT mice at the same cellular density (b and c). ImageJ analysis quantified the relative Alizarin red staining optical density (f) based on three independent experiments. The gene expression profile of MSCs showed that in KO the mRNA expression of PP5 was significantly lower (g), whereas the expression of Runx2, Opn, and Ocn were significantly higher (h–j) relative to WT. Slightly lower expression of PPARγ was observed between in KO MSCs compared with WT cells, but failed to reach significance (k). Western blot analysis indicated a dramatic increase in Runx2 in PP5 KO MSCs (l and m). In addition, while total PPARγdid not differ between KO and WT cells, the expression of Phospho- PPARγ (pSER112) was higher in the KO cells (l and m). Values are presented as mean ± SE. *P < 0.05, **P < 0.01, and ***P < 0.005 using Student’s t-test. n = 3