The role of p38 mitogen‐activated protein kinase in IL‐6 and IL‐8 production from the TNF‐α‐ or IL‐1β‐stimulated rheumatoid synovial fibroblasts

Abstract
We examined the role of p38 mitogen-activated protein (MAP) kinase in the tumor necrosis factor α (TNF-α)- or interleukin-1β (IL-1β)-induced production of interleukin-6 (IL-6) and interleukin-8 (IL-8) in fresh rheumatoid synovial fibroblast (RSF) cultures concomitantly with the induction of p38 MAP kinase activity. Pretreatment of RSF with a specific p38 MAP kinase inhibitor, SB203580, blocked the induction of IL-6 and IL-8 without affecting nuclear translocation of nuclear factor κB (NF-κB) or IL-6 and IL-8 mRNA levels. These findings suggest that p38 MAP kinase inhibitor may have synergistic, rather than additive, effect for the treatment of rheumatoid arthritis.