title: Excessive autophagy contributes to neuron death in cerebral ischemia.
abstract: OBJECTIVE
  To determine the extent to which autophagy contributes to neuronal death in cerebral hypoxia and ischemia.
  
  
  METHODS
  We performed immunocytochemistry, western blot, cell viability assay, and electron microscopy to analyze autophagy activities in vitro and in vivo.
  
  
  RESULTS
  In both primary cortical neurons and SH-SY5Y cells exposed to oxygen and glucose deprivation (OGD)for 6 h and reperfusion (RP) for 24, 48, and 72 h, respectively, an increase of autophagy was observed as determined by the increased ratio of LC3-II to LC3-I and Beclin-1 (BECN1) expression. Using Fluoro-Jade C and monodansylcadaverine double-staining, and electron microscopy we found the increment in autophagy after OGD/RP was accompanied by increased autophagic cell death, and this increased cell death was inhibited by the specific autophagy inhibitor, 3-methyladenine. The presence of large autolysosomes and numerous autophagosomes in cortical neurons were confirmed by electron microscopy. Autophagy activities were increased dramatically in the ischemic brains 3-7 days postinjury from a rat model of neonatal cerebral hypoxia/ischemia as shown by increased punctate LC3 staining and BECN1 expression.
  
  
  CONCLUSIONS
  Excessive activation of autophagy contributes to neuronal death in cerebral ischemia.
authors.affiliation: Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Ruoyang
authors.initials: R
authors.lastname: Shi
authors.forename: Jiequn
authors.initials: J
authors.lastname: Weng
authors.forename: Ling
authors.initials: L
authors.lastname: Zhao
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: Li
authors.forename: Tian-Ming
authors.initials: TM
authors.lastname: Gao
authors.forename: Jiming
authors.initials: J
authors.lastname: Kong
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001343:Autophagy / Q000502:physiology*; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology*; D016923:Cell Death / Q000502:physiology; D002478:Cells, Cultured; D005260:Female; D009474:Neurons / Q000378:metabolism* / Q000473:pathology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley