title: Regulation of cyclooxygenase-2 expression in human osteoblastic cells by N-acetylcysteine.
abstract: Cyclooxygenase (COX) plays a pivotal role in the inflammatory process of inflammatory arthropathies. Inflammatory cytokines induce COX-2 expression in osteoblasts of inflamed joints, followed by osteoclast activation. The inhibition of COX-2 expression could help prevent prostaglandin E2 secretion, followed by osteoclast activation for bone destruction and resorption. We examined whether the antioxidant N-acetylcysteine (NAC) inhibited COX-2 expression induced in the human osteoblastic cell line MG63 by interleukin-1beta (IL-1beta). According to Western blot and reverse transcription-polymerase chain reaction (RT-PCR) test results, NAC inhibited IL-1beta-induced COX-2 expression in protein and messenger RNA. We also demonstrated immunohistochemically that NAC inhibited NFkappaB nuclear translocation. These results suggested that NAC inhibited both COX-2 expression and NFkappaB nuclear translocation in MG63, which in turn indicated that NAC could inhibit the inflammatory process involved in bone resorption by regulating COX-2 expression at the level of transcription.
authors.affiliation: School of Allied Medical Sciences, Nagasaki University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Origuchi
authors.forename: K
authors.initials: K
authors.lastname: Migita
authors.forename: T
authors.initials: T
authors.lastname: Nakashima
authors.forename: S
authors.initials: S
authors.lastname: Honda
authors.forename: S
authors.initials: S
authors.lastname: Yamasaki
authors.forename: A
authors.initials: A
authors.lastname: Hida
authors.forename: A
authors.initials: A
authors.lastname: Kawakami
authors.forename: T
authors.initials: T
authors.lastname: Aoyagi
authors.forename: Y
authors.initials: Y
authors.lastname: Kawabe
authors.forename: K
authors.initials: K
authors.lastname: Eguchi
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D051546:Cyclooxygenase 2; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D007527:Isoenzymes / Q000235:genetics*; D008565:Membrane Proteins; D016328:NF-kappa B / Q000378:metabolism; D010006:Osteoblasts / Q000378:metabolism*; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D011817:Rabbits
chemical_list: D007375:Interleukin-1; D007527:Isoenzymes; D008565:Membrane Proteins; D016328:NF-kappa B; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D000111:Acetylcysteine