title: Induction of heat shock proteins (HSPs) by sodium arsenite in cultured astrocytes and reduction of hydrogen peroxide-induced cell death.
abstract: Induction of heat shock proteins (HSPs) protects cells from oxidative injury. Here Hsp72, Hsp27 and heme oxygenase-1 (HO-1) were induced in cultured rat astrocytes, and protection against oxidative stress was investigated. Astrocytes were treated with sodium arsenite (20-50 micro m) for 1 h, which was non-toxic to cells, 24 h later they were exposed to 400 micro m H2O2 for 1 h, and cell death was evaluated at different time points. Arsenite triggered strong induction of HSPs, which was prevented by 1 micro g/mL cycloheximide (CXH). H2O2 caused cell loss and increased cell death with features of apoptosis, i.e. TdT-mediated dUTP nick-end labelling (TUNEL) reaction and caspase-3 activation. These features were abrogated by pre-treatment with arsenite, which prevented cell loss and significantly reduced the number of dead cells. The protective effect of arsenite was not detected in the presence of CHX. Pre-treatment with arsenite increased protein kinase B (Akt) and extracellular signal regulated kinase 1/2 (ERK1/2) phosphorylation after H2O2. However, while Akt phosphorylation was prevented by CHX, Erk1/2 phosphorylation was further enhanced by CHX. The results show that transient arsenite pre-treatment induces Hsp72, HO-1 and, to a lesser extent, Hsp27; it reduces H2O2-induced astrocyte death; and it causes selective activation of Akt following H2O2. It is suggested that HSP expression at the time of H2O2 exposure protects astrocytes from oxidative injury and apoptotic cell death by means of pro-survival Akt.
authors.affiliation: Departament de Farmacologia i Toxicologia, IIBB-CSIC, IDIBAPS, Barcelona, Spain.
authors.forename: Bernard
authors.initials: B
authors.lastname: Fauconneau
authors.forename: Valérie
authors.initials: V
authors.lastname: Petegnief
authors.forename: Coral
authors.initials: C
authors.lastname: Sanfeliu
authors.forename: Alain
authors.initials: A
authors.lastname: Piriou
authors.forename: Anna M
authors.initials: AM
authors.lastname: Planas
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D018053:Arsenites / Q000494:pharmacology*; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D055551:HSP27 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D051547:Heme Oxygenase-1; D006861:Hydrogen Peroxide / Q000633:toxicity*; D020287:In Situ Nick-End Labeling; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D017670:Sodium Compounds / Q000494:pharmacology*
chemical_list: D018053:Arsenites; D055551:HSP27 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C486114:Hspb1 protein, rat; D009363:Neoplasm Proteins; D016877:Oxidants; D011500:Protein Synthesis Inhibitors; D011518:Proto-Oncogene Proteins; D017670:Sodium Compounds; C017947:sodium arsenite; D006861:Hydrogen Peroxide; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C494920:Akt1 protein, rat; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases