title: Nimesulide reduces interleukin-1beta-induced cyclooxygenase-2 gene expression in human synovial fibroblasts.
abstract: OBJECTIVE
  To characterize the effects of nimesulide (NIM) on basal and induced cyclo-oxygenase-2 (COX-2) gene expression in human synovial fibroblasts (HSF) and to define the intracellular mechanisms that mediate the changes in COX-2 expression and synthesis in response to the drug.
  
  
  METHODS
  HSF were incubated with NIM and NS-398 (0, 0.03, 0.3, 3 microg/ml) in the absence or presence of the COX-2 inducers interleukin-1beta (IL-1beta) or endotoxin (LPS). Treated cells were analysed for COX-2 mRNA and protein by Northern and Western blotting analysis, respectively. Putative transcriptional, post-transcriptional, and signaling effects of NIM on basal and induced-COX-2 expression were investigated by human COX-2 promoter studies, calcium studies, reactive oxygen species (ROS) evaluations, electrophoretic mobility shift analysis (EMSA) and half-life studies of COX-2 mRNA.
  
  
  RESULTS
  NIM inhibited IL-1beta-induced COX-2 expression and protein at sub and therapeutic concentrations (0.03-0.3 microg/ml) while the non-specific NSAID, naproxen, did not. Both drugs suppressed PGE2 release by about 95%. NIM had no effect on (1) IL-1beta-induced increases in NF-kappaB or c/EBP signaling, or (2) human COX-2 promoter activity. Stability of induced COX-2 mRNA was unaffected by NIM treatments. Pre-treatment of cells with O(2)radical scavengers (e.g. PDTC) or with Ca(++)channel blockers (e.g. verapamil) had a modest effect on IL-1beta-induced COX-2 expression. NIM blocked ionomycin+thapsigargin and H(2)O(2)-induced increases in COX-2 protein synthesis.
  
  
  CONCLUSIONS
  NIM inhibits cytokine-induced COX-2 expression and protein at sub and therapeutic concentrations. At least part of this activity may be the result of NIM inhibition of calcium and/or free radical generation induced by cytokines.
authors.affiliation: Osteoarthritis Research Unit, Centre hospitalier de l'Université de Montréal (CHUM), Hôpital Notre-Dame, Montréal, Québec, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Fahmi
authors.forename: Y
authors.initials: Y
authors.lastname: He
authors.forename: M
authors.initials: M
authors.lastname: Zhang
authors.forename: J
authors.initials: J
authors.lastname: Martel-Pelletier
authors.forename: J P
authors.initials: JP
authors.lastname: Pelletier
authors.forename: J A
authors.initials: JA
authors.lastname: Di Battista
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000378:metabolism; D051546:Cyclooxygenase 2; D005347:Fibroblasts / Q000187:drug effects*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007375:Interleukin-1 / Q000502:physiology*; D007527:Isoenzymes / Q000096:biosynthesis / Q000187:drug effects*; D008565:Membrane Proteins; D010003:Osteoarthritis / Q000188:drug therapy / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000187:drug effects*; D013449:Sulfonamides / Q000494:pharmacology*; D013582:Synovial Fluid / Q000187:drug effects / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D007375:Interleukin-1; D007527:Isoenzymes; D008565:Membrane Proteins; D013449:Sulfonamides; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; C012655:nimesulide