title: Cytokines induce nitric oxide production in mouse osteoblasts.
abstract: MC3T3-E1 mouse clonal osteogenic cells were incubated with interferon-gamma, interleukin-1 beta, tumor necrosis factor-alpha, and E. coli lipopolysaccharide. TNF alpha, IL-1 beta, and LPS caused a dose- and time-dependent increase of nitrite (NO2-), the stable metabolite of nitric oxide (NO), in conditioned media over 48 hours, while IFN gamma had a minimal effect. Different combinations of the same factors caused a synergistic enhancement of NO2- accumulation, except for IL-1 beta with LPS. The earliest detectable NO2- production was at 6-9 hours, with continued accumulation over 48 hours. NO2- production was inhibited dose-dependently by three arginine analogs known to be specific inhibitors of NO synthase, as well as by actinomycin D, cycloheximide, and dexamethasone; EGTA or indomethacin had a small inhibitory effect. It is concluded that osteoblast-like cells can be induced by proinflammatory cytokines and bacterial endotoxin to produce NO, which can play an important role in bone pathophysiology.
authors.affiliation: Harvard School of Dental Medicine, Department of Periodontology, Boston, MA 02115.
authors.forename: P D
authors.initials: PD
authors.lastname: Damoulis
authors.forename: P V
authors.initials: PV
authors.lastname: Hauschka
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D002460:Cell Line; D002470:Cell Survival; D002956:Citrulline / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D016207:Cytokines / Q000494:pharmacology*; D003609:Dactinomycin / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D004926:Escherichia coli; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000096:biosynthesis*; D009573:Nitrites / Q000032:analysis; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D016207:Cytokines; D007375:Interleukin-1; D008070:Lipopolysaccharides; D009573:Nitrites; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D003609:Dactinomycin; D002956:Citrulline; D009569:Nitric Oxide; D004533:Egtazic Acid; D003907:Dexamethasone; D007371:Interferon-gamma; D001120:Arginine; D003513:Cycloheximide; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin