Open AccessSoluble Fas ligand in the joints of patients with rheumatoid arthritis and osteoarthritis
Author(s) -
Hashimoto Hideo,
Tanaka Masato,
Suda Takashi,
Tomita Tetsuya,
Hayashida Kenji,
Takeuchi Eiji,
Kaneko Motoharu,
Takano Hiroshi,
Nagata Shigekazu,
Ochi Takahiro
Publication year - 1998
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/1529-0131(199804)41:4<657::aid-art12>3.0.co;2-n
Subject(s) - fas ligand , rheumatoid arthritis , synovial membrane , apoptosis , osteoarthritis , medicine , synovial fluid , immunology , arthritis , microbiology and biotechnology , pathology , chemistry , biology , programmed cell death , biochemistry , alternative medicine
Objective To investigate the expression and function of Fas ligand (FasL), which can be in a membrane‐bound or soluble form, in the joints of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Methods The concentration of soluble FasL (sFasL) in serum and synovial fluid (SF) from 24 OA and 38 RA patients was measured using an enzyme‐linked immunosorbent assay. The expression of FasL on SF lymphocytes (SFL) and peripheral blood lymphocytes (PBL) was assessed by reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis. A cytotoxic killing assay of membrane‐bound FasL and purified sFasL against cultured synovial cells was also performed. Results Soluble FasL was detected in the SF of patients with RA and OA, but not in their serum. The concentration of SF sFasL was remarkably higher in patients with severe RA than in patients with mild RA or with OA. RT‐PCR showed that SFL, but not PBL, from RA patients expressed messenger RNA for FasL. Membrane‐bound FasL induced apoptosis in cultured synovial cells from the RA and OA patients, but naturally processed human sFasL did not. Conclusion SFL from RA patients expressed FasL, and cleaved sFasL accumulated in the SF of inflamed joints. The different killing activity of membrane‐bound FasL and sFasL against synovial cells may regulate Fas‐mediated apoptosis in synovial cells.