title: Peroxynitrite production by TNF-alpha and IL-1beta: implication for suppression of osteoblastic differentiation.
abstract: To determine the roles of nitric oxide (NO) and its metabolite, peroxynitrite (ONOO(-)), on osteoblastic activation, we investigated the effects of a NO donor [ethanamine, 2, 2'-(hydroxynitrosohydrazono)bis- (dNO)], an O(-2) donor (pyrogallol), and an ONOO(-) scavenger (urate) on alkaline phosphatase (ALPase) activity and osteocalcin gene expression, which are indexes of osteoblastic differentiation. dNO elevated ALPase activity in the osteogenic MC3T3-E1 cell line. The combination of dNO and pyrogallol reduced both ALPase activity and osteocalcin gene expression. Because both indexes were recovered by urate, ONOO(-), unlike NO itself, inhibited the osteoblastic differentiation. Furthermore, treatment with a combination of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) was found to yield ONOO(-) as well as NO and O(-2). The reductions in ALPase activity and osteocalcin gene expression were also restored by urate. We conclude that ONOO(-) produced by TNF-alpha and IL-1beta, but not NO per se, would overcome the stimulatory effect of NO on osteoblastic activity and inhibit osteoblastic differentiation.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-8865, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hikiji
authors.forename: W S
authors.initials: WS
authors.lastname: Shin
authors.forename: T
authors.initials: T
authors.lastname: Koizumi
authors.forename: T
authors.initials: T
authors.lastname: Takato
authors.forename: T
authors.initials: T
authors.lastname: Susami
authors.forename: Y
authors.initials: Y
authors.lastname: Koizumi
authors.forename: Y
authors.initials: Y
authors.lastname: Okai-Matsuo
authors.forename: T
authors.initials: T
authors.lastname: Toyo-Oka
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D004357:Drug Synergism; D016166:Free Radical Scavengers; D015870:Gene Expression; D007375:Interleukin-1 / Q000494:pharmacology*; D051379:Mice; D009566:Nitrates / Q000032:analysis / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010006:Osteoblasts / Q000502:physiology*; D015675:Osteocalcin / Q000235:genetics; D011748:Pyrogallol / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D013482:Superoxide Dismutase / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D016166:Free Radical Scavengers; D007375:Interleukin-1; D009566:Nitrates; D020030:Nitric Oxide Donors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D011748:Pyrogallol; D015675:Osteocalcin; D013481:Superoxides; C039642:peroxynitric acid; D013482:Superoxide Dismutase; D000469:Alkaline Phosphatase