RHAMM induces progression of rheumatoid arthritis by enhancing the functions of fibroblast-like synoviocytes.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic and refractory autoimmune joint disease. Fibroblast-like synoviocytes (FLS) produce inflammatory cytokines and are involved in the migration and invasion of panuus tissue, which leads to the destruction of joints in RA. Receptor for hyaluronan mediated motility (RHAMM), is known to be one of the important receptors for hyaluronic acid. It has the ability to regulate migration of fibrocytes and infiltration of inflammatory cells. Here,we explored the mechanisms of RHAMM in RAFs.

METHODS: Quantitative PCR and western blot were performed to test the expression of RHAMM in synoviocytes of RA patients and osteoarthritis (OA) controls. Collagen antibody-induced arthritis (CAIA) was used to investigate the RHAMM expression in mouse synovial issues. RHAMM siRNA was used to detect the function of RHAMM in FLS.

RESULTS: RA-FLS has a significantly higher expression of RHAMM than OA-FLS. Expression of RHAMM in joint synovial tissue was markedly increased in the CAIA mice compared with the controls. RHAMM silencing using SiRNA was not only decreased the production of IL-6 and IL-8, but also inhibited the migration and invasion of RA-FLS.

CONCLUSIONS: RHAMM has an important role in the FLS induced modulation of inflammation and destruction of joints in RA.