title: Induction of cyclooxygenase-1 in cultured synovial cells isolated from rheumatoid arthritis patients.
abstract: OBJECTIVE
  The aim of this study was to confirm the involvement of cyclooxygenase (COX)-1 in rheumatoid arthritis (RA).
  
  
  METHODS
  Synovial cells isolated from arthritic patients were cultured primarily and consecutively for 8 passages.
  
  
  METHODS
  The cultured synovial cells were incubated with 10 ng/ml of interleukin-1alpha (IL-1alpha) for 6 h.
  
  
  METHODS
  The effects of either COX-1 or COX-2 selective inhibitor on prostaglandin E2 (PGE2) production was estimated by enzyme-linked immunosorbent assay (ELISA) and the expression of COX-1 and COX-2 were determined by Western blotting and immunocytochemistry.
  
  
  RESULTS
  IL-1alpha-induced PGE2 production in synovial cells isolated from RA in primary culture was inhibited by mofezolac, a selective inhibitor of COX-1, as well as NS-398, a specific inhibitor of COX-2. The similar inhibitory patterns were obtained in the RA-derived synovial cells within 3 passages. However, COX activity in the RA-derived synovial cells after 5 passages was inhibited by NS-398, but not by mofezolac. In contrast, COX activity in primary and consecutively cultured synovial cells isolated from osteoarthritis (OA) or normal arthritis was inhibited by NS-398, but not by mofezolac. Western blot and immunocytochemical analyses of COX-1 and COX-2 in the synovial cells isolated from RA patients within 3 passages showed an induction in both COX-1 and COX-2 expression by IL-1alpha. The induction of both COX-1 and COX-2 was inhibited by dexamethasone.
  
  
  CONCLUSIONS
  These experiments demonstrate COX-1 induction in synovial cells isolated from RA patients, suggesting that COX-1 is involved in the progression of RA.
authors.affiliation: Department of Cellular Physiological Chemistry, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Onodera
authors.forename: Y
authors.initials: Y
authors.lastname: Horiuchi
authors.forename: K
authors.initials: K
authors.lastname: Nakahama
authors.forename: T
authors.initials: T
authors.lastname: Muneta
authors.forename: Y
authors.initials: Y
authors.lastname: Mano
authors.forename: I
authors.initials: I
authors.lastname: Morita
mesh_terms: D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D015153:Blotting, Western; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D051545:Cyclooxygenase 1; D003907:Dexamethasone / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000378:metabolism; D007527:Isoenzymes / Q000096:biosynthesis* / Q000378:metabolism; D007555:Isoxazoles / Q000494:pharmacology; D008565:Membrane Proteins; D009578:Nitrobenzenes / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013449:Sulfonamides / Q000494:pharmacology; D013583:Synovial Membrane / Q000166:cytology / Q000201:enzymology*; D013997:Time Factors
chemical_list: D017077:Culture Media, Conditioned; D007375:Interleukin-1; D007527:Isoenzymes; D007555:Isoxazoles; D008565:Membrane Proteins; D009578:Nitrobenzenes; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D003907:Dexamethasone; D051545:Cyclooxygenase 1; C496511:PTGS1 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone; C054999:mofezolac