The mechanism of neuronal injury and repair after focal cerebral ischemia / 中国病理生理杂志

ABSTRACT

AIM: To explore the mechanism of neuronal injury and repair by investigating the expression of caspase-3 and apurinic/apyrimidinic endonuclease (APE/Ref-1) after focal cerebral ischemia. METHODS: A model of middle cerebral artery occlusion in rats was performed . The expression of caspase-3P 20 and APE/Ref-1 was examined by immunohistochemistry staining, TUNEL was applied to detected DNA damage, and double labeling with TUNEL and APE/Ref-1 was used to determine the relationship between APE/Ref-1 and DNA damage. RESULTS: The active subunit P 20 of caspase-3 was predominantly expressed within ischemic penumbra. The peak time of caspase-3P 20 positive cells preceded the appearance of TUNEL. With aggravation of cerebral ischemia, APE/Ref-1 immunoreactive cells in penumbra were significantly decreased. CONCLUSION: The activation of caspase enzymatic cascade following cerebral ischemia leads to degradation in DNA, meanwhile, decrease in DNA repair molecules or the failure of DNA repair may deteriorate the course.