title: Transforming growth factor Beta1 induction of tissue inhibitor of metalloproteinases 3 in articular chondrocytes is mediated by reactive oxygen species.
abstract: Transforming growth factor beta1 (TGF-beta1) stimulates cartilage extracellular matrix synthesis but, in excess, evokes synovial inflammation, hyperplasia, and osteophyte formation in arthritic joints. TGF-beta1 induces tissue inhibitor of metalloproteinases 3 (TIMP-3), an inhibitor of cartilage-damaging matrix metalloproteianases and aggrecanases. We investigated the role of reactive oxygen species (ROS) in TIMP-3 induction by TGF-beta1. In primary human and bovine chondrocytes, ROS scavenger and antioxidant N-acetylcysteine (NAC) inhibited TGF-beta1-induced TIMP-3 mRNA and protein increases. Ebselen and ascorbate also reduced this induction. TGF-beta1 time-dependently induced ROS production that was suppressed by NAC. Hydrogen peroxide, a ROS, induced TIMP-3 RNA. The TIMP-3 increase induced by TGF-beta1 was partly Smad2-dependent. TGF-beta1-stimulated Smad2 phosphorylation was inhibited by NAC. Reduced glutathione and L-cysteine also blocked Smad2 and TIMP-3 induction by TGF-beta1, whereas a nonthiol, N-acetylalanine, did not. Smad2 was not activated by H2O2. Smad2 phosphorylation was independent, and TIMP-3 expression was dependent, on new protein synthesis. TGF-beta-stimulated ERK and JNK phosphorylation was also inhibited by NAC. However, inhibitory actions of NAC were not mediated by ERK activation. Thus, ROS mediate TGF-beta1-induced TIMP-3 gene expression. Blocking TGF-beta1-induced gene expression by modulating cellular redox status with thiols can be potentially beneficial for treating arthritic and other disorders caused by excessive TGF-beta1.
authors.affiliation: Department of Medicine, Notre-Dame Hospital, Montreal, Quebec, Canada.
authors.forename: Wen Qing
authors.initials: WQ
authors.lastname: Li
authors.forename: Hamid Yaqoob
authors.initials: HY
authors.lastname: Qureshi
authors.forename: Abdelhamid
authors.initials: A
authors.lastname: Liacini
authors.forename: Faramaze
authors.initials: F
authors.lastname: Dehnade
authors.forename: Muhammad
authors.initials: M
authors.lastname: Zafarullah
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D001393:Azoles / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D002358:Cartilage, Articular / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism*; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000378:metabolism; D015536:Down-Regulation; D005609:Free Radicals; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D054833:Isoindoles; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D048670:MAP Kinase Kinase 4; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D016566:Organoselenium Compounds / Q000494:pharmacology; D010084:Oxidation-Reduction; D010766:Phosphorylation; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species; D015398:Signal Transduction; D051899:Smad2 Protein; D013045:Species Specificity; D013997:Time Factors; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D053773:Transforming Growth Factor beta1
chemical_list: D001393:Azoles; D016895:Culture Media, Serum-Free; D004268:DNA-Binding Proteins; D005609:Free Radicals; D006133:Growth Substances; D054833:Isoindoles; D016376:Oligonucleotides, Antisense; D016566:Organoselenium Compounds; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C497782:SMAD2 protein, human; D051899:Smad2 Protein; C508960:TGFB1 protein, human; D019717:Tissue Inhibitor of Metalloproteinase-3; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C042986:ebselen; D012313:RNA; D003513:Cycloheximide; D006861:Hydrogen Peroxide; D048031:JNK Mitogen-Activated Protein Kinases; D048052:Mitogen-Activated Protein Kinase 3; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D001205:Ascorbic Acid; D000111:Acetylcysteine