title: Nitric oxide and cyclic GMP increase the expression of matrix metalloproteinase-9 in vascular smooth muscle.
abstract: Interactions and possible cross talk between inducible nitricoxide synthase (iNOS), cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9), were studied in rat aortic vascular smooth muscle cells stimulated with bacterial lipopolysaccharide (LPS), interferon-gamma (IFN-gamma), and phorbol 12-myristate13-acetate (PMA). The expression and activity of iNOS, COX-2, and MMP-9 were characterized at the transcriptional, protein, and enzyme activity levels. The NOS inhibitor Nomega-nitro-L-arginine methyl ester (L-NAME) was used to investigate the effects of NO on COX-2 and MMP-9 at the transcriptional level. The measurements of mRNAs for these enzymes using real-time polymerase chain reaction (PCR) showed that COX-2 mRNA was up-regulated 2.3-fold, whereas MMP-9 mRNA up-regulation was 11.7-fold in the presence of LPS, IFN-gamma, and PMA. Real-time PCR results indicated that L-NAME exerted an inhibitory effect on COX-2 and MMP-9 mRNA synthesis. Both superoxide dismutase (SOD) and the SOD mimetic Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride (MnTMPyP) did not modify significantly the up-regulation of these enzymes, indicating that neither superoxide nor peroxynitrite are involved in this mechanism. Furthermore, NO-mediated up-regulation of MMP-9 was cGMP-dependent since 1H-[1,2,4] oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase, blocked, in a concentration-dependent manner, the increased expression of MMP-9, an effect reversed by 8-bromo-cGMP, a soluble analog of cGMP. Our findings suggest that NO and cGMP are necessary to up-regulate the expression of MMP-9.
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Canada.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Marcet-Palacios
authors.forename: Kathryn
authors.initials: K
authors.lastname: Graham
authors.forename: Carol
authors.initials: C
authors.lastname: Cass
authors.forename: A Dean
authors.initials: AD
authors.lastname: Befus
authors.forename: Irvin
authors.initials: I
authors.lastname: Mayers
authors.forename: Marek W
authors.initials: MW
authors.lastname: Radomski
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000494:pharmacology*; D051546:Cyclooxygenase 2; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis* / Q000235:genetics; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000201:enzymology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D010069:Oxadiazoles / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000235:genetics; D011810:Quinoxalines / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects; D051381:Rats; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D007527:Isoenzymes; D008070:Lipopolysaccharides; D010069:Oxadiazoles; D011810:Quinoxalines; D012333:RNA, Messenger; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D013482:Superoxide Dismutase; D020780:Matrix Metalloproteinase 9; D006152:Cyclic GMP; D019331:NG-Nitroarginine Methyl Ester