Mitogen-activated protein kinase p38 induces HDAC4 degradation in hypertrophic chondrocytes

作者：Zhou, Jingming; Li, Pengcui; Chen, Qian; Wei, Xiaochun; Zhao, Ting; Wang, Zhengke; Wei, Lei^*

来源：Biochimica et Biophysica Acta-Molecular Cell Research, 2015, 1853(2): 370-376.

DOI：10.1016/j.bbamcr.2014.11.003

• HDAC4
• p38
• Caspase
• Inhibition
• Degradation

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.

• 出版日期2015-2
• 单位山西医科大学第二医院