Tumor-necrosis factor-alpha induces retinoic acid-inducible gene-I in rheumatoid fibroblast-like synoviocytes

Department of Vascular Biology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
Immunology letters (Impact Factor: 2.37). 02/2009; 122(1):89-93. DOI: 10.1016/j.imlet.2008.12.005
Source: PubMed

ABSTRACT Tumor-necrosis factor-alpha (TNF-alpha) is a potent proinflammtory cytokine and a key molecule in the pathogenesis of rheumatoid arthritis (RA). Retinoic acid-inducible gene-I (RIG-I) is a DExH box protein, which is known to play a role in the inflammatory and immune reactions. We previously reported about potential involvement of RIG-I in synovial inflammation in RA. In the present study, we demonstrated the expression of RIG-I in fibroblast-like synoviocytes stimulated with TNF-alpha. RNA interference against interferon (IFN)-beta abolished the TNF-alpha-induced RIG-I expression. In addition, knockdown of RIG-I partially inhibited the TNF-alpha-induced expression of CC chemokine ligand (CCL) 5, a chemokine with chemotactic activity toward lymphocytes and monocytes. These findings suggest that the TNF-alpha/IFN-beta/RIG-I/CCL5 pathway may be involved in the pathogenesis of synovial inflammation in RA.

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