Fig. 4.

Knockdown of adenosine uridine-rich elements binding proteins does not cause changes in the expression of inflammatory mediators. a Rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) (n = 3) were left untransfected or were transfected for 72 h with 20 nM control non-targeting siRNA (siCtrl) or 20 nM specific siRNA targeting AUF1 (siAUF1), BRF1 (siBRF1), BRF2 (siBRF2), KHSRP (siKHSRP) and HuR (siHuR). Knockdown efficiency was verified at the mRNA level by qPCR. Data are presented as fold expression of mRNA compared to siCtrl transfected cells:*p < 0.05, **p < 0.01, ratio t test. b RA FLS (n = 3) were transfected as in a and further left untreated or treated with ITF2357, prior to stimulation with IL-1β for 8 h. IL6, IL8, CXCL2 and PTGS2 expression were determined by qPCR. Data are presented as fold expression of mRNA compared to siCtrl-treated IL-1β stimulated cells: *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, one-way analysis of variance followed by Fisher’s least significant difference test