Trichostatin A, an Inhibitor of Histone Deacetylase, Inhibits the Viability and Invasiveness of Hypoxic Rheumatoid Arthritis Fibroblast-Like Synoviocytes via PI3K/Akt Signaling.

This study was undertaken to explore the effects of trichostatin A (TSA), an inhibitor of histone deacetylase, on the viability, apoptosis, and invasiveness of hypoxic rheumatoid arthritis fibroblast-like synoviocytes (RA FLSs). RA FLSs were exposed to hypoxia for 24 h in the presence or absence of 2 μM TSA and tested for cell viability, apoptosis, invasion, and gene expression. The involvement of the phosphatidylinositol-3-kinase (PI3K)/Akt pathway was checked. TSA significantly inhibited the viability and induced apoptosis of hypoxic RA FLSs, compared to vehicle control. TSA blocked hypoxia-induced invasion of RA FLSs during Matrigel invasion assays and reduced the expression of matrix metalloproteinases (MMP-2 and MMP-9) and PI3K and phosphorylation of Akt. Overexpression of constitutively active Akt reversed TSA-mediated suppression of invasiveness and downregulation of MMP-2 and MMP-9. Our results indicate the antisurvival and antiinvasive activities of TSA in hypoxic RA FLSs, which is associated with inactivation of PI3K/Akt signaling.