Suberoylanilide Hydroxamic Acid, an Inhibitor of Histone Deacetylase, Induces Apoptosis in Rheumatoid Arthritis Fibroblast-Like Synoviocytes.

Here, we explored the effects of suberoylanilide hydroxamic acid (SAHA) on the viability and apoptosis of rheumatoid arthritis of fibroblast-like synoviocytes (rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS)). FLS obtained from RA patients were treated with SAHA. SAHA significantly inhibited the viability of RA FLS in a concentration-dependent manner up to 5 μM. SAHA-treated FLS showed a significant increase in the percentage of apoptosis and the expression and activity of caspase-3 and higher intracellular ROS levels. N-acetyl-l-cysteine (NAC) pretreatment significantly attenuated SAHA-induced apoptosis, decreasing the percentage of apoptosis by about 60 %. A significant decline in phosphorylated IκBα and nuclear factor kappa B (NF-κB) p65 and concomitant increase in total IκBα were shown in SAHA-treated FLS. Additionally, the levels of anti-apoptotic Bcl-2 proteins (Bcl-xL and Mcl-1) were significantly reduced by SAHA. Collectively, SAHA induces apoptosis of RA FLS, at least partially, through generation of ROS and suppression of NF-κB activation and Bcl-xL and Mcl-1 expression.