Conclusions
MS-275 critically regulates RUNX2 transactivation in VICs through both canonical and non-canonical Wnt signaling pathways.
Methods
Western blotting, real-time polymerase chain reaction, and proliferation assay were used to analyze osteogenesis marker expression, Wnt signaling, bone morphogenetic protein (BMP) signaling, and proliferation in porcine VICs treated with osteogenic (OST) medium alone or in combination with HDAC inhibitors.
Results
VICs treated with OST medium for 5 days exhibited higher RUNX2 and GSK-3β expression levels than did control cells. A class I HDAC inhibitor (MS-275 at 1 μM) reduced the RUNX2 mRNA and protein expression levels and alkaline phosphatase activity and downregulated non-canonical Wnt/GSK-3β signaling, canonical Wnt/β-catenin signaling, and BMP signaling. By contrast, a combined class IIa (MC1568) and IIb HDAC (tubacin) inhibitor (0.1 μM) increased RUNX2 expression. MS-275, MC1568, and tubacin reduced VIC proliferation; however, the extent of reduction differed. MS-275 reduced RUNX2 and osteocalcin expression in VICs treated with OST medium for an extended period (14 days). Conclusions: MS-275 critically regulates RUNX2 transactivation in VICs through both canonical and non-canonical Wnt signaling pathways.