| First Author | Zhou J | Year | 2015 |
| Journal | Biochim Biophys Acta | Volume | 1853 |
| Issue | 2 | Pages | 370-376 |
| PubMed ID | 25447540 | Mgi Jnum | J:234391 |
| Mgi Id | MGI:5789872 | Doi | 10.1016/j.bbamcr.2014.11.003 |
| Citation | Zhou J, et al. (2015) Mitogen-activated protein kinase p38 induces HDAC4 degradation in hypertrophic chondrocytes. Biochim Biophys Acta 1853(2):370-6 |
| abstractText | Histone deacetylase 4 (HDAC4) is a critical negative regulator for chondrocyte hypertrophy by binding to and inhibiting Runx2, a critical transcription factor for chondrocyte hypertrophy. It is unclear how HDAC4 expression and stability are regulated during growth plate development. We report here that inhibition of mitogen-activated protein kinase (MAPK) p38 by dominant negative p38 or p38 inhibitor prevents HDAC4 degradation. Mutation of a potential caspase-2 and 3 cleavage site Asp289 stabilizes HDAC4 in chondrocytes. In contrast, constitutively active MAPK kinase 6 (constitutive activator of p38) transgenic mice exhibit decreased HDAC4 content in vivo. We also observed that p38 stimulates caspase-3 activity in chondrocytes. Inhibition of p38 or caspases reduced HDAC4 degradation. HDAC4 inhibited Runx2 promoter activity in a dose-dependent manner and caspase inhibitors further enhanced this inhibition by preventing HDAC4 degradation. Overall, these results demonstrate that p38 promotes HDAC4 degradation by increasing caspase-mediated cleavage, which releases Runx2 from a repressive influence of HDAC4 and promotes the chondrocyte hypertrophy and bone formation. |
