Macrophages infiltrated into synovium play an important role in joint destruction in inflammatory joint diseases. In this study we focused on the production of monocyte chemoattractant protein-1 (MCP-1), a recently identified monocyte chemotactic protein, by inflammatory synovium. Synovial fluid (SF) from rheumatoid arthritis (RA), osteoarthritis, gout, and traumatic arthritis contained MCP-1. MCP-1 was produced in the synovium of patients with RA and other inflammatory joint disease in in vitro culture systems; differences in the amounts produced were not significant. Synovial MCP-1 production in RA was further investigated. Levels of MCP-1 were significantly correlated with levels of IL-1β, IL-6, and IL-8 in the culture supernatants of synovia from RA. Using immunohistochemical techniques, MCP-1 was detected in the lining and sublining cells and in the vascular endothelial cells of rheumatoid synovia. Rheumatoid synovia with active inflammation were stained more intensely by anti-MCP-1 antibody than were those with weak or inactive inflammation. IL-1β and TNF-α stimulated the expression of MCP-1 mRNA and de novo MCP-1 synthesis by cultured synovial cells. These results suggest the production of MCP-1 by synovium of various inflammatory joint diseases. In rheumatoid synovium, a cytokine network involving MCP-1 and other proinflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α) contributes to the immunopathogenesis of RA.
ASJC Scopus subject areas
- Immunology and Allergy
- Pathology and Forensic Medicine