title: Severe global cerebral ischemia-induced programmed necrosis of hippocampal CA1 neurons in rat is prevented by 3-methyladenine: a widely used inhibitor of autophagy.
abstract: The true programmed mechanisms of delayed neuronal death induced by global cerebral ischemia/reperfusion injury remain incompletely characterized. Autophagic cell death and programmed necrosis are 2 kinds of programmed cell death distinct from apoptosis. Here, we studied the death mechanisms of hippocampal cornu ammonis 1 neuronal death after a 20-minute severe global ischemia/reperfusion injury in young adult rats and the effects of 3-methyladenine (3-MA), a widely used inhibitor of autophagy. The morphological changes detected by electron microscopy, together with the activation of autophagy, transferase-mediated UTP nick end-labeling-positive neurons, and delayed death, demonstrated that cornu ammonis 1 neuronal death induced in this paradigm was programmed necrosis. No significant activation of caspase-3 after injury was detected by Western blot and immunohistochemistry. Treatment with 3-MA provided time-dependent protection against cornu ammonis 1 neuronal death at 7 days of reperfusion when it was administered before ischemia; administration 60 minutes after reperfusion was not beneficial. The redistribution of the lysosomal enzyme cathepsin B after injury was inhibited by 3-MA administered before ischemia, suggesting that this might be another important mechanism for the protective effect of 3-MA in ischemic neuronal injury.
authors.affiliation: Department of Neurology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Jin-Ye
authors.initials: JY
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xia
authors.forename: Ke-Tan
authors.initials: KT
authors.lastname: Chu
authors.forename: Jie
authors.initials: J
authors.lastname: Pan
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Sun
authors.forename: Bin
authors.initials: B
authors.lastname: Zeng
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Zhu
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Ben-Yan
authors.initials: BY
authors.lastname: Luo
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001343:Autophagy / Q000187:drug effects; D015153:Blotting, Western; D002545:Brain Ischemia / Q000473:pathology* / Q000517:prevention & control*; D056547:CA1 Region, Hippocampal / Q000473:pathology*; D053148:Caspase 3 / Q000378:metabolism; D002401:Cathepsin B / Q000378:metabolism; D002452:Cell Count; D016923:Cell Death / Q000187:drug effects; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008297:Male; D046529:Microscopy, Electron, Transmission; D009336:Necrosis / Q000473:pathology / Q000517:prevention & control; D009474:Neurons / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: C025946:3-methyladenine; D053148:Caspase 3; D002401:Cathepsin B; D000225:Adenine