title: Endogenous production of reactive oxygen species is required for stimulation of human articular chondrocyte matrix metalloproteinase production by fibronectin fragments.
abstract: The objective of the present study was to determine if reactive oxygen species (ROS) are required as secondary messengers for fibronectin fragment-stimulated matrix metalloproteinase (MMP) production in human articular chondrocytes. Cultured cells were stimulated with 25 microg/ml of the alpha5beta1 integrin-binding 110-kDa fibronectin fragment (FN-f) in the presence and absence of various antioxidants including Mn(III) tetrakis(4-benzoic acid)porphyrin (MnTBAP). FN-f stimulation significantly increased intracellular levels of ROS in articular chondrocytes. Pretreatment of cells with 250 microM MnTBAP or 40 mM N-acetyl-L-cysteine, but not inhibitors of nitric oxide synthase, completely prevented FN-f-stimulated MMP-3, -10, and -13 production. MnTBAP also blocked FN-f-induced phosphorylation of the MAP kinases and NF-kappaB-associated proteins and blocked activation of an NF-kappaB promoter-reporter construct. Overexpression of catalase, superoxide dismutase, or glutathione peroxidase also inhibited FN-f-stimulated MMP-13 production. Preincubation of chondrocytes with rotenone, an inhibitor of the mitochondrial electron transport chain, or nordihydroguaiaretic acid (NDGA), a selective 5-lipoxygenase inhibitor, partially prevented FN-f-stimulated MMP-13 production and decreased MAP kinase and NF-kappaB phosphorylation. These results show that increased production of ROS but not nitric oxide as obligatory secondary messengers in the chondrocyte FN-f signaling pathway leads to the increased production of MMPs, including MMP-13.
authors: Department of Biochemistry, Section of Rheumatology, Rush Medical College, Chicago, IL, USA.
authors: Marcello
authors: M
authors: Del Carlo
authors: Daniel
authors: D
authors: Schwartz
authors: Elizabeth A
authors: EA
authors: Erickson
authors: Richard F
authors: RF
authors: Loeser
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002358:Cartilage, Articular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D005353:Fibronectins / Q000494:pharmacology*; D006801:Humans; D053509:Matrix Metalloproteinase 13 / Q000378:metabolism*; D018613:Microscopy, Confocal; D010446:Peptide Fragments / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D005353:Fibronectins; D010446:Peptide Fragments; D017382:Reactive Oxygen Species; C507079:MMP13 protein, human; D053509:Matrix Metalloproteinase 13