title: Role of NAD(P)H:quinone oxidoreductase in the progression of neuronal cell death in vitro and following cerebral ischaemia in vivo.
abstract: A direct involvement of the antioxidant enzyme NAD(P)H:quinone oxidoreductase (NQO1) in neuroprotection has not yet been shown. The aim of this study was to examine changes, localization and role of NQO1 after different neuronal injury paradigms. In primary cultures of rat cortex the activity of NQO1 was measured after treatment with ethylcholine aziridinium (AF64A; 40 micro m), inducing mainly apoptotic cell death, or oxygen-glucose deprivation (OGD; 120 min), which combines features of apoptotic and necrotic cell death. After treatment with AF64A a significant NQO1 activation started after 24 h. Sixty minutes after OGD a significant early induction of the enzyme was observed, followed by a second increase 24 h later. Enzyme activity was preferentially localized in glial cells in control and injured cultures, however, expression also occurred in injured neuronal cells. Inhibition of the NQO1 activity by dicoumarol, cibacron blue or chrysin (1-100 nM) protected the cells both after exposure to AF64A or OGD as assessed by the decreased release of lactate dehydrogenase. Comparable results were obtained in vivo using a mouse model of focal cerebral ischaemia. Dicoumarol treatment (30 nmol intracerebroventricular) reduced the infarct volume by 29% (p = 0.005) 48 h after the insult. After chemical induction of NQO1 activity by t-butylhydroquinone in vitro neuronal damage was exaggerated. Our data suggest that the activity of NQO1 is a deteriorating rather than a protective factor in neuronal cell death.
authors.affiliation: Department of Experimental Neurology, Medical Faculty Charité, Humboldt-University Berlin, Dorotheenstrasse 94, D-10098 Berlin, Germany.
authors.forename: Krisztian J
authors.initials: KJ
authors.lastname: Kapinya
authors.forename: Ulrike
authors.initials: U
authors.lastname: Harms
authors.forename: Christoph
authors.initials: C
authors.lastname: Harms
authors.forename: Katharina
authors.initials: K
authors.lastname: Blei
authors.forename: Juri
authors.initials: J
authors.lastname: Katchanov
authors.forename: Ulrich
authors.initials: U
authors.lastname: Dirnagl
authors.forename: Heide
authors.initials: H
authors.lastname: Hörtnagl
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001388:Aziridines / Q000494:pharmacology; D002545:Brain Ischemia / Q000201:enzymology* / Q000473:pathology / Q000517:prevention & control; D002478:Cells, Cultured; D002794:Choline / Q000031:analogs & derivatives* / Q000494:pharmacology; D001728:Dicumarol / Q000494:pharmacology; D004195:Disease Models, Animal; D018450:Disease Progression; D004357:Drug Synergism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006873:Hydroquinones / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009252:NADPH Dehydrogenase; D009474:Neurons / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001388:Aziridines; D004791:Enzyme Inhibitors; D006873:Hydroquinones; D001728:Dicumarol; C044894:ethylcholine aziridinium; C018855:2-tert-butylhydroquinone; D016660:NAD(P)H Dehydrogenase (Quinone); C491732:Nqo1 protein, mouse; D009252:NADPH Dehydrogenase; D002794:Choline