title: Cobalt induces hypoxia-inducible factor-1alpha expression in airway smooth muscle cells by a reactive oxygen species- and PI3K-dependent mechanism.
abstract: Cobalt can mimic hypoxia and has been implicated as a cause of lung defects. However, the effect of cobalt on airway smooth muscle (ASM) cells has not been analyzed in detail. In this article, we use primary cultures of ASM cells from rabbit trachea and show that exposure to cobalt chloride causes a rapid increase of the intracellular levels of hypoxia-inducible factor-1alpha, which is detected predominantly inside the nucleus. With the use of specific inhibitors, we demonstrate that induction of hypoxia-inducible factor-1alpha by cobalt depends on active protein synthesis but not transcription. Furthermore, wortmannin, LY294002, and N-acetyl-L-cysteine inhibit the effect of cobalt, suggesting that it involves the phosphatidylinositol 3 kinase pathway and production of reactive oxygen species. Interestingly, cobalt chloride attenuates the contractile response of rabbit airways induced by potassium chloride, but not by acetylcholine, suggesting a link between the cellular response to hypoxic stimuli and the contractile properties of ASM cells.
authors.affiliation: Laboratory of Physiology, Department of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Chachami
authors.forename: George
authors.initials: G
authors.lastname: Simos
authors.forename: Apostolia
authors.initials: A
authors.lastname: Hatziefthimiou
authors.forename: Sophia
authors.initials: S
authors.lastname: Bonanou
authors.forename: Paschalis-Adam
authors.initials: PA
authors.lastname: Molyvdas
authors.forename: Efrosyni
authors.initials: E
authors.lastname: Paraskeva
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D003035:Cobalt / Q000378:metabolism / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000860:Hypoxia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008297:Male; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009025:Morpholines / Q000494:pharmacology; D009130:Muscle, Smooth / Q000166:cytology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D017382:Reactive Oxygen Species; D013997:Time Factors; D014132:Trachea / Q000166:cytology / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D002867:Chromones; D004791:Enzyme Inhibitors; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009025:Morpholines; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D003609:Dactinomycin; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D003035:Cobalt; D011189:Potassium Chloride; D003513:Cycloheximide; D019869:Phosphatidylinositol 3-Kinases; C018021:cobaltous chloride; D000111:Acetylcysteine; D000077191:Wortmannin