title: Salicylate regulates COX-2 expression through ERK and subsequent NF-kappaB activation in osteoblasts.
abstract: The expression of cyclooxygenase-2 (COX-2) is a characteristic response to inflammation and can be inhibited with sodium salicylate. TNF-alpha plus IFN-gamma can induce extracellular signal-regulated kinase (ERK), IKK, IkappaB degradation and NF-kappaB activation. The inhibition of the ERK pathway with selective inhibitor, PD098059, blocked cytokine-induced COX-2 expression and PGE2 release. Salicylate treatment inhibited COX-2 expression induced by TNF-alpha/IFN-gamma and regulated the activation of ERK, IKK and IkappaB degradation and subsequent NF-kappaB activation in MC3T3E1 osteoblasts. As well, antioxidant-catalase, N-acetyl-cysteine or reduced glutathione-attenuated COX-2 expression in combined cytokines-treated cells. These antioxidants also inhibited the activation of ERK, IKK and NF-kappaB in MC3T3E1 osteoblasts. In addition, TNF-alpha/IFN-gamma stimulated ROS release in the osteoblasts. However salicylate had no obvious effect on ROS release in DCFDA assay. The results showed that salicylate inhibited the activation of ERK and IKK, IkappaB degradation and NF-kappaB activation independent of ROS release and suggested that salicylate exerts its anti-inflammatory action in part through inhibition of the ERK, IKK, IkappaB, NF-kappaB and resultant COX-2 expression pathway.
authors.affiliation: Department of Pharmacology, Institute of Cardiovascular Research, School of Medicine, Chonbuk National University, Chonbuk, South Korea.
authors.forename: Han-Jung
authors.initials: HJ
authors.lastname: Chae
authors.forename: Soo-Wan
authors.initials: SW
authors.lastname: Chae
authors.forename: John C
authors.initials: JC
authors.lastname: Reed
authors.forename: Hyung-Ryong
authors.initials: HR
authors.lastname: Kim
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D015153:Blotting, Western; D002460:Cell Line; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism / Q000502:physiology*; D005419:Flavonoids / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D020672:I-kappa B Proteins / Q000378:metabolism / Q000502:physiology; D007371:Interferon-gamma / Q000494:pharmacology; D007527:Isoenzymes / Q000378:metabolism*; D048369:MAP Kinase Kinase 1 / Q000037:antagonists & inhibitors / Q000502:physiology; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism / Q000502:physiology*; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D012980:Sodium Salicylate / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D020672:I-kappa B Proteins; D007527:Isoenzymes; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D048049:Extracellular Signal-Regulated MAP Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048369:MAP Kinase Kinase 1; C482127:Map2k1 protein, mouse; D015232:Dinoprostone; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D012980:Sodium Salicylate