Elevation of activated protein C in synovial joints in rheumatoid arthritis and its correlation with matrix metalloproteinase 2.

Autor: Buisson-Legendre N; Institute of Bone and Joint Research, University of Sydney, Sydney, New South Wales, Australia. nathalie@med.usyd.edu.au, Smith S, March L, Jackson C
Jazyk: angličtina
Zdroj: Arthritis and rheumatism [Arthritis Rheum] 2004 Jul; Vol. 50 (7), pp. 2151-6.
DOI: 10.1002/art.20313
Abstrakt: Objective: To investigate the involvement of the anticoagulant serine protease activated protein C (APC) in tissue remodeling in rheumatoid arthritis (RA).
Methods: PC/APC, matrix metalloproteinase 2 (MMP-2), and MMP-9 were detected in synovial fluid by Western blotting, and their antigen levels were quantified by enzyme-linked immunosorbent assay in patients with osteoarthritis (OA) or RA. Enzymatic activity of MMP-2 was assayed using a specific fluorogenic substrate. We developed an improved assay to measure APC activity in synovial fluid utilizing a chromogenic substrate following immunoprecipitation with a specific PC/APC antibody. PC/APC and MMP-2 were localized by immunohistochemistry in RA, OA, and normal synovial tissues.
Results: Synovial fluid analysis demonstrated that APC is present in both RA and OA synovial fluid, with APC activity being markedly higher in RA (mean +/- SEM 462 +/- 112 ng/ml versus 136 +/- 42 ng/ml; P < 0.02). A correlation (r(2) = 0.61) was found between APC and MMP-2 activity levels in RA patients, but not in OA patients. Immunohistochemical studies of synovial sections showed colocalization of APC and MMP-2 in endothelial and synovial lining cells. Additionally, APC and MMP-2 coimmunoprecipitated with an anti-PC/APC antibody.
Conclusion: Our results show, for the first time, that APC and MMP-2 are coordinately up-regulated and tightly bound in RA synovial fluid and colocalized in synovia. Their association suggests that APC may modulate MMP-2 activity in RA.
Databáze: MEDLINE
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