Histone deacetylases (HDACs) modulate the acetylation level of histone and non-histone proteins to regulate chromatin structure and gene expression. Histone deacetylase 5 (HDAC5) undergoes signal-dependent translocation between the nucleus and cytoplasm, which is regulated in part by calcium/calmodulin-dependent kinase (CaMK)-mediatedphosphorylation. HDAC5 and its intracellular translocation are key effectors of multiple pathways that regulate neuronal cell apoptosis []. HDAC5 has been identified as a inflammatory mediator in rheumatoid arthritis, as its expression is suppressed by inflammatory cytokines which leads to activation of fibroblast-like synoviocytes [, ].
