Nox2 oxidase activity accounts for the oxidative stress and vasomotor dysfunction in mouse cerebral arteries following ischemic stroke

PLoS One. 2011;6(12):e28393. doi: 10.1371/journal.pone.0028393. Epub 2011 Dec 2.


Background and purpose: Post-ischemic oxidative stress and vasomotor dysfunction in cerebral arteries may increase the likelihood of cognitive impairment and secondary stroke. However, the underlying mechanisms of post-stroke vascular abnormalities, as distinct from those causing primary brain injury, are poorly understood. We tested whether augmented superoxide-dependent dysfunction occurs in the mouse cerebral circulation following ischemia-reperfusion, and evaluated the role of Nox2 oxidase.

Methods: Cerebral ischemia was induced in male C57Bl6/J wild-type (WT) and Nox2-deficient (Nox2(-/-)) mice by middle cerebral artery occlusion (MCAO; 0.5 h), followed by reperfusion (23.5 h). Superoxide production by MCA was measured by L-012-enhanced chemiluminescence. Nitric oxide (NO) function was assessed in cannulated and pressurized MCA via the vasoconstrictor response to N(ω)-nitro-L-arginine methyl ester (L-NAME; 100 µmol/L). Expression of Nox2, the nitration marker 3-nitrotyrosine, and leukocyte marker CD45 was assessed in cerebral arteries by Western blotting.

Results: Following ischemia-reperfusion, superoxide production was markedly increased in the MCA of WT, but not Nox2(-/-) mice. In WT mice, L-NAME-induced constriction was reduced by ∼50% in ischemic MCA, whereas ischemia-reperfusion had no effect on responses to L-NAME in vessels from Nox2(-/-) mice. In ischemic MCA from WT mice, expression of Nox2 and 3-nitrotyrosine were ∼1.4-fold higher than in the contralateral MCA, or in ischemic or contralateral vessels from Nox2(-/-) mice. Vascular CD45 levels were unchanged by ischemia-reperfusion.

Conclusions: Excessive superoxide production, impaired NO function and nitrosative stress occur in mouse cerebral arteries after ischemia-reperfusion. These abnormalities appear to be exclusively due to increased activity of vascular Nox2 oxidase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cerebral Arteries / metabolism*
  • Cerebrovascular Circulation
  • Crosses, Genetic
  • Ischemia
  • Leukocyte Common Antigens / biosynthesis
  • Male
  • Membrane Glycoproteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Middle Cerebral Artery / metabolism
  • Middle Cerebral Artery / pathology
  • Models, Biological
  • NADPH Oxidase 2
  • NADPH Oxidases / metabolism*
  • Oxidative Stress
  • Reperfusion Injury
  • Stroke / metabolism*
  • Superoxides / metabolism
  • Tyrosine / analogs & derivatives
  • Tyrosine / chemistry


  • Membrane Glycoproteins
  • Superoxides
  • 3-nitrotyrosine
  • Tyrosine
  • Cybb protein, mouse
  • NADPH Oxidase 2
  • NADPH Oxidases
  • Leukocyte Common Antigens