title: Stimulation of cyclooxygenase-2-activity by nitric oxide-derived species in rat chondrocyte: lack of contribution to loss of cartilage anabolism.
abstract: Cross-talk between inducible nitric oxide synthase (NOS II) and cyclooxygenase-2 (COX-2) was investigated in rat chondrocytes. In monolayers, interleukin-1beta (IL-1beta) induced COX-2 and NOS II expression in a dose- and time-dependent manner, to produce high prostaglandin E(2) (PGE(2)) and nitrite (NO(2)(-)) levels in an apparently coordinated fashion. COX-2 mRNA was induced earlier (30 min. versus 4 hr) and less markedly (4-fold versus 12-fold at 24 hr) than NOS II, and was poorly affected by the translational inhibitor cycloheximide (CHX). IL-1beta did not stabilize COX-2 mRNA in contrast to CHX. Indomethacin and NS-398 lacked any effect on NO(2)(-) levels whereas L-NMMA and SMT reduced PGE(2) levels at concentration inhibiting NO(2)(-) production from 50 to 90%, even when added at a time allowing a complete expression of both enzymes (8 hr). Basal COX activity was unaffected by NO donors. The SOD mimetic, CuDips inhibited COX-2 activity by more than 75% whereas catalase did not. Inhibition of COX-2 by CuDips was not sensitive to catalase, consistent with a superoxide-mediated effect. In tridimensional culture, IL-1beta inhibited radiolabelled sodium sulphate incorporation while stimulating COX-2 and NOS II activities. Cartilage injury was corrected by L-NMMA or CuDips but not by NSAIDs, consistent with a peroxynitrite-mediated effect. These results show that in chondrocytes: (i) COX2 and NOS II genes are induced sequentially and distinctly by IL-1beta; (ii) COX-1 and COX-2 activity are affected differently by NO-derived species; (iii) peroxynitrite accounts likely for stimulation of COX-2 activity and inhibition of proteoglycan synthesis induced by IL-1beta.
authors: Laboratoire de Pharmacologie et UMR CNRS-UHP 7561, Faculté de Médecine de Nancy, Avenue de la Forêt de Haye, BP184, F-54505, Vandoeuvre-lès-Nancy, France.
authors: E
authors: E
authors: Nédélec
authors: A
authors: A
authors: Abid
authors: C
authors: C
authors: Cipolletta
authors: N
authors: N
authors: Presle
authors: B
authors: B
authors: Terlain
authors: P
authors: P
authors: Netter
authors: J
authors: J
authors: Jouzeau
mesh_terms: D000818:Animals; D002356:Cartilage / Q000166:cytology / Q000378:metabolism; D019902:Chondrocytes / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007213:Indomethacin / Q000494:pharmacology; D007375:Interleukin-1 / Q000378:metabolism / Q000494:pharmacology*; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D009573:Nitrites / Q000378:metabolism; D009578:Nitrobenzenes / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D011509:Proteoglycans / Q000096:biosynthesis / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013449:Sulfonamides / Q000494:pharmacology; D013890:Thiourea / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D007375:Interleukin-1; D007527:Isoenzymes; D009573:Nitrites; D009578:Nitrobenzenes; D011509:Proteoglycans; D013449:Sulfonamides; C120262:methylthioisourea; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D019323:omega-N-Methylarginine; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D013890:Thiourea; D007213:Indomethacin