title: Production of nitric oxide in the synovial membrane of rheumatoid and osteoarthritis patients.
abstract: We have demonstrated spontaneous nitric oxide (NO) production by primary synovial cultures from rheumatoid (RA) and osteoarthritis patients. Increased NO production followed addition of staphylococcal enterotoxin B. Immunochemical double staining with specific anti-human inducible NO synthase (iNOS) and nonspecific esterase (NSE), or anti-CD68 (markers for tissue macrophages) showed that although many lining layer cells in RA synovium expressed iNOS, most (approximately 90%) were NSE- and CD68-, with only a minor population (approximately 10%) which were iNOS+, CD68+/NSE+. These data demonstrate the capacity for high output of NO by human synovial tissue and show that, although human macrophages can express high levels of iNOS, the majority of cells expressing iNOS are fibroblasts. We also report that synoviocytes, and macrophage cell lines, cultured with the NO donor, S-nitroso-acetyl penicillamine, produced high concentrations of tumor necrosis factor (TNF)-alpha. These results suggest that NO may mediate pathology in RA through the induction of TNF-alpha production.
authors.affiliation: Department of Immunology, University of Glasgow, United Kingdom.
authors.forename: I B
authors.initials: IB
authors.lastname: McInnes
authors.forename: B P
authors.initials: BP
authors.lastname: Leung
authors.forename: M
authors.initials: M
authors.lastname: Field
authors.forename: X Q
authors.initials: XQ
authors.lastname: Wei
authors.forename: F P
authors.initials: FP
authors.lastname: Huang
authors.forename: R D
authors.initials: RD
authors.lastname: Sturrock
authors.forename: A
authors.initials: A
authors.lastname: Kinninmonth
authors.forename: J
authors.initials: J
authors.lastname: Weidner
authors.forename: R
authors.initials: R
authors.lastname: Mumford
authors.forename: F Y
authors.initials: FY
authors.lastname: Liew
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D001178:Arthroplasty; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D008875:Middle Aged; D009569:Nitric Oxide / Q000096:biosynthesis*; D010003:Osteoarthritis / Q000378:metabolism*; D013583:Synovial Membrane / Q000166:cytology / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide