Fig. 7.

Induction of IL-6 but not IL-1Ra expression by TLR3 activation is dependent on the p38 MAPK signaling. Human FLS were pre-treated with SB203580 (5 μM) for 1 h. Subsequently, the cells were stimulated with poly(I:C) for 30 min and the relative levels of p38 MAPK expression and phosphorylation in the different groups of FLS were measured by Western blot assays (a). Human FLS were pre-treated with SB203580 (5 μM) for 1 h and stimulated by poly(I:C) for 8 h or 24 h. The cell viability was measured by CCK-8 assay (b). The concentrations of IL-1Ra (c), IFN-β (d), and IL-6 (e) in the culture supernatants were determined with ELISA. Results are presented as mean ± SEM (n = 5 per group) from 3 separate experiments. * p < 0.05 versus the group with poly(I:C) and vehicle. IL, interleukin; IL-1Ra, IL-1 receptor antagonist.