title: NAD(P)H oxidase activity of Nox4 in chondrocytes is both inducible and involved in collagenase expression.
abstract: Reactive oxygen species (ROS) are regulators of redox-sensitive cell signaling pathways. In osteoarthritis, human interleukin-1beta is implicated in cartilage destruction through an ROS-dependent matrix metalloproteinase production. To determine the molecular source of ROS production in the human IL-1beta (hIL-1beta)-sensitive chondrocyte immortalized cell line C-20/A4, transfected cells were constructed that overexpress NAD(P)H oxidases. First, RT-PCR analysis showed that the C-20/A4 cell line expressed Nox2, Nox4, p22( phox ), and p67( phox ), but not p47( phox ). It was found that ROS production by C-20/A4 chondrocytes does not depend on PMA and ionomycin activation. This indicates that Nox2 was not involved in the production of ROS. In C- 20/A4 cells that overexpress Nox4, hIL-1beta stimulated ROS production three times more than the normal production of C-20/A4 cells. Moreover, there was a fourfold increase in the production of collagenase (MMP-1) by chondrocytes that overexpress Nox4. Interestingly, MMP-1 production in cells that overexpress Nox2 was not sensitive to hIL-1beta. These data suggest that under hIL-1beta stimulation, C-20/A4 chondrocytes produce MMP-1 through a Nox4-mediated, ROS-dependent pathway.
authors.affiliation: GREPI EA 2938 UJF, Lab Enzymology/DBPC, Universitary Hospital A. Michallon, Grenoble, France [corrected] LGrange@chu-grenoble.fr
authors.forename: Laurent
authors.initials: L
authors.lastname: Grange
authors.forename: Minh Vu Chuong
authors.initials: MV
authors.lastname: Nguyen
authors.forename: Bernard
authors.initials: B
authors.lastname: Lardy
authors.forename: Madiha
authors.initials: M
authors.lastname: Derouazi
authors.forename: Yannick
authors.initials: Y
authors.lastname: Campion
authors.forename: Candice
authors.initials: C
authors.lastname: Trocme
authors.forename: Marie-Helene
authors.initials: MH
authors.lastname: Paclet
authors.forename: Philippe
authors.initials: P
authors.lastname: Gaudin
authors.forename: Francoise
authors.initials: F
authors.lastname: Morel
mesh_terms: D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt / Q000494:pharmacology; D002461:Cell Line, Transformed; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism*; D017364:Collagenases / Q000378:metabolism*; D016166:Free Radical Scavengers / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D053583:Interleukin-1beta / Q000494:pharmacology; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics* / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014162:Transfection
chemical_list: D016166:Free Radical Scavengers; D053583:Interleukin-1beta; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; D020033:Protein Isoforms; D017382:Reactive Oxygen Species; C079789:neutrophil cytosol factor 67K; D013481:Superoxides; D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; D006861:Hydrogen Peroxide; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human; C086986:CYBA protein, human; D017364:Collagenases; D020781:Matrix Metalloproteinase 1