Increased mitochondrial DNA oxidative damage after transient middle cerebral artery occlusion in mice

Neurosci Res. 2007 Aug;58(4):349-55. doi: 10.1016/j.neures.2007.04.005. Epub 2007 Apr 19.


Oxidative stress and DNA oxidation play important roles in the induction of ischemic neuronal cell death. However, the subcellular source of oxidized DNA detected by 8-hydroxy-2'-deoxyguanosine (8-OHdG) after ischemia has not been clarified although it is known to increase in the brain after ischemia. One-hour transient ischemia of the middle cerebral artery was induced in mice utilizing an intraluminal filament. The occurrence of superoxide anion as an ethidium (Et) signal, 8-OHdG, cytochrome c release and neuronal cell death were examined using immunohistological and biochemical techniques in sham-operated control (0h) and 1, 3, 6, 24, or 96h after reperfusion. Et signals were prominent in the cortical neurons of ipsilateral hemisphere 3h after reperfusion. Strong 8-OHdG immunoreactivity was observed 3-6h after reperfusion. Immunoassays after cell fractionation revealed a significant increase of 8-OHdG in mitochondria 6h after reperfusion. Immunohistochemistry revealed that the 8-OHdG immunoreactivity colocalized with a neuronal marker, microfilament 200 and a mitochondrial marker, cytochrome oxidase subunit I. Cytochrome c rose in cytoplasm at 6h and TUNEL-positive neurons noted 6-24h after ischemia. The present results suggest the possibility that the mitochondrial damage including mitochondrial DNA oxidation might be responsible for the induction of ischemic neuronal cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cytochromes c / metabolism
  • DNA Damage*
  • DNA, Mitochondrial / metabolism*
  • Deoxyadenosines / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Functional Laterality
  • In Situ Nick-End Labeling / methods
  • Indoles
  • Infarction, Middle Cerebral Artery / physiopathology*
  • Mice
  • Neurofilament Proteins / metabolism
  • Oxidative Stress / physiology*
  • Phosphopyruvate Hydratase / metabolism
  • Reactive Oxygen Species / metabolism
  • Reperfusion
  • Time Factors


  • 8-hydroxy-2'-deoxyadenosine
  • DNA, Mitochondrial
  • Deoxyadenosines
  • Indoles
  • Neurofilament Proteins
  • Reactive Oxygen Species
  • neurofilament protein H
  • DAPI
  • Cytochromes c
  • Phosphopyruvate Hydratase