title: Glucose and NADPH oxidase drive neuronal superoxide formation in stroke.
abstract: OBJECTIVE
  Hyperglycemia has been recognized for decades to be an exacerbating factor in ischemic stroke, but the mechanism of this effect remains unresolved. Here, we evaluated superoxide production by neuronal nicotinamide adenine dinucleotide phosphate (NADPH) oxidase as a possible link between glucose metabolism and neuronal death in ischemia-reperfusion.
  
  
  METHODS
  Superoxide production was measured by the ethidium method in cultured neurons treated with oxygen-glucose deprivation and in mice treated with forebrain ischemia-reperfusion. The role of NADPH oxidase was examined using genetic disruption of its p47(phox) subunit and with the pharmacological inhibitor apocynin.
  
  
  RESULTS
  In neuron cultures, postischemic superoxide production and cell death were completely prevented by removing glucose from the medium, by inactivating NADPH oxidase, or by inhibiting the hexose monophosphate shunt that generates NADPH from glucose. In murine stroke, neuronal superoxide production and death were decreased by the glucose antimetabolite 2-deoxyglucose and increased by high blood glucose concentrations. Inactivating NADPH oxidase with either apocynin or deletion of the p47(phox) subunit blocked neuronal superoxide production and negated the deleterious effects of hyperglycemia.
  
  
  CONCLUSIONS
  These findings identify glucose as the requisite electron donor for reperfusion-induced neuronal superoxide production and establish a previously unrecognized mechanism by which hyperglycemia can exacerbate ischemic brain injury.
authors.affiliation: Department of Neurology, University of California, San Francisco, CA, USA.
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Suh
authors.forename: Byung Seop
authors.initials: BS
authors.lastname: Shin
authors.forename: Hualong
authors.initials: H
authors.lastname: Ma
authors.forename: Michaël
authors.initials: M
authors.lastname: Van Hoecke
authors.forename: Angela M
authors.initials: AM
authors.lastname: Brennan
authors.forename: Midori A
authors.initials: MA
authors.lastname: Yenari
authors.forename: Raymond A
authors.initials: RA
authors.lastname: Swanson
mesh_terms: D000818:Animals; D016923:Cell Death / Q000502:physiology; D002478:Cells, Cultured; D005947:Glucose / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009474:Neurons / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D020521:Stroke / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D013481:Superoxides / Q000378:metabolism*
chemical_list: D013481:Superoxides; D005947:Glucose