Serum amyloid A-induced IL-6 production by rheumatoid synoviocytes

Abstract 

In this study, we investigated the role of serum amyloid A protein (SAA) in the production of interleukin-6 (IL-6) using rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS). Recombinant SAA stimulation induced the production of pro-inflammatory cytokine, IL-6, from RA-FLS. The signaling events induced by SAA included the activation of the mitogen-activated protein kineases, p38 and JNK1/2 and the activation of nuclear factor-kappa B (NF-κB). Inhibitor studies have shown SAA-induced IL-6 production to be down-regulated by NF-κB inhibition and partially inhibited by p38 or JNK inhibitors. Our findings demonstrate that SAA is a significant inducer of IL-6, which is critically involved in RA pathogenesis.

Abbreviations: FLS, fibroblast-like synoviocytes, FPRL1, N-formyl peptide receptor-like 1, IL-6, interleukin-6, MAPKs, mitogen-activated protein kineases, NF-κB, nuclear factor-kappa B, RA, rheumatoid arthritis, SAA, serum amyloid A protein

Keywords: Interleukin-6, Nuclear factor-kappa B, Rheumatoid arthritis, Serum amyloid A protein