Fig. 2.

Inhibition of HDAC6 reduces the secretion of MMP-1, MMP-3, and IL-6 by fibroblast-like synoviocytes (FLS). a RA-FLS were activated with IL-1β (10 ng/mL) in the presence of HDAC6 inhibitor M808 and tubastatin A. The expression of HDAC6, total and acetylated cortactin, and total and acetylated α-tubulin were examined by Western blotting. A representative blot from three independent experiments is shown. Acetylated cortactin and acetylated tubulin relative to the respective total protein were shown (n = 3). Data represent the mean ± SEM. Groups were compared using a t-test. *p < 0.05 vs. FLS treated with IL-1β only. b FLS from RA patients (n = 6) were pre-treated for 1 h with M808 and then stimulated with IL-1β (10 ng/mL) for 24 h. The production of IL-6, MMP-1, and MMP-3 was measured in an ELISA. Data represent the mean ± SEM. Groups were compared using a t-test. *p < 0.05 vs. FLS treated with IL-1β only. AU, arbitrary unit; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; IL, interleukin; MMP, metalloproteinases; Tuba A, tubastatin A