title: Heat shock induces IkappaB-alpha and prevents stress-induced endothelial cell apoptosis.
abstract: OBJECTIVE
  To determine whether prior heat shock would attenuate endothelial cell apoptosis and whether any effect of preemptive heat shock is mediated through a nuclear factor kappa B and inhibitor kappa B alpha mechanism.
  
  
  METHODS
  A randomized, controlled in vitro study.
  
  
  METHODS
  A laboratory in a large, academic medical center.
  
  
  METHODS
  Cultured primary porcine endothelial cells were treated with increasing doses of sodium arsenite (40-160 micromol/L), after which the interval until subsequent apoptotic (lipopolysaccharide-arsenite) challenge was varied (4-16 hours). The degree of cell death and apoptosis were determined using neutral red uptake and staining with annexin V and propidium iodide, respectively. Inducible heat shock protein 70 and inhibitor kappa B alpha levels in treated cells were determined by Western blot analysis. Lipopolysaccharide-induced nuclear factor kappa B activity was assessed using an electrophoretic mobility shift assay.
  
  
  RESULTS
  Prior arsenite treatment decreased cell death by apoptosis in a time- and dose-dependent manner. Specifically, a higher sodium arsenite concentration and shorter intervals afforded better protection (P=.01, 160 micromol/L at 4 hours). Protection against apoptosis correlated with increased heat shock protein 70 and inhibitor kappa B alpha levels and decreased nuclear factor kappa B binding activity.
  
  
  CONCLUSIONS
  Arsenite, an inducer of the heat shock response, decreased stress-induced endothelial cell apoptosis. The mechanism of this protection may include decreased nuclear factor kappa B activity or increased inducible heat shock protein 70 levels. Heat shock protein 70 may serve as a molecular marker to determine not only the phenotypic state of the cell but also the durability of protection afforded by heat shock. These data support the hypothesis that stress-induced changes in transcription factor activity and protein expression can regulate the induction of apoptosis.
authors.affiliation: Department of Surgery, Washington University School of Medicine, St Louis, Mo, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: DeMeester
authors.forename: T G
authors.initials: TG
authors.lastname: Buchman
authors.forename: Y
authors.initials: Y
authors.lastname: Qiu
authors.forename: A K
authors.initials: AK
authors.lastname: Jacob
authors.forename: K
authors.initials: K
authors.lastname: Dunnigan
authors.forename: R S
authors.initials: RS
authors.lastname: Hotchkiss
authors.forename: I
authors.initials: I
authors.lastname: Karl
authors.forename: J P
authors.initials: JP
authors.lastname: Cobb
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D018053:Arsenites / Q000494:pharmacology; D015153:Blotting, Western; D004586:Electrophoresis; D004727:Endothelium / Q000166:cytology; D018840:HSP70 Heat-Shock Proteins / Q000502:physiology*; D018869:Heat-Shock Response; D016328:NF-kappa B / Q000502:physiology*; D017670:Sodium Compounds / Q000494:pharmacology; D013439:Sulfhydryl Reagents; D013552:Swine
chemical_list: D018053:Arsenites; D018840:HSP70 Heat-Shock Proteins; D016328:NF-kappa B; D017670:Sodium Compounds; D013439:Sulfhydryl Reagents; C017947:sodium arsenite