title: Cortical spreading depression preconditioning mediates neuroprotection against ischemic stroke by inducing AMP-activated protein kinase-dependent autophagy in a rat cerebral ischemic/reperfusion injury model.
abstract: Cortical spreading depression (CSD), based on its similarities with peri-infarct depolarization, is an ideal model for investigating transformation from the ischemic penumbra to infarct core. However, the underlying mechanisms remain unclear. To our knowledge, this is the first study to use a middle cerebral artery occlusion ischemic-reperfusion (I/R) injury model to determine whether AMP-activated protein kinase (AMPK)-dependent autophagy contributes to the neuroprotection of CSD preconditioning in rat cortex. In this study, we topically applied a pledget soaked in 1 mol/L KCl solution on rat cortex for 2 h to elicite CSD or 1 mol/L NaCl solution as a control. The results demonstrated that CSD preconditioning significantly decreased the infarct volume, neurological deficits and neuronal apoptosis in the cortical penumbra of middle cerebral artery occlusion rats, which was inhibited by the autophagy inhibitor 3-methyladenine (3-MA, 200 nmol). Furthermore, CSD increased the protein levels of the autophagy markers LC3-II, Beclin-1 and the p-AMPK (Thr172)/AMPK ratio at 12 h and decreased P62 and p-P70S6K (Thr389). Moreover, the AMPK inhibitor Compound C (20 mg/kg) down-regulated the LC3-II, p-AMPK (Thr172)/AMPK and ULK1 levels, up-regulated the P62 and p-P70S6K (Thr389) levels induced by CSD. The neuroprotection of CSD is likely a result of AMPK-mediated autophagy activity and autophagy-induced neuronal cells apoptosis inhibition. These novel findings support a central role for AMPK and autophagy in CSD-induced ischemic tolerance. AMPK-mediated autophagy may represent a new target for stroke.
authors.affiliation: Institute of Neuroscience Center and Neurology Department, The First Affiliated Hospital of Jilin University, Changchun, Jilin, China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Shen
authors.affiliation: Institute of Neuroscience Center and Neurology Department, The First Affiliated Hospital of Jilin University, Changchun, Jilin, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Hou
authors.affiliation: Institute of Neuroscience Center and Neurology Department, The First Affiliated Hospital of Jilin University, Changchun, Jilin, China.
authors.forename: Mingqin
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Institute of Neuroscience Center and Neurology Department, The First Affiliated Hospital of Jilin University, Changchun, Jilin, China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Zhao
authors.affiliation: Institute of Neuroscience Center and Neurology Department, The First Affiliated Hospital of Jilin University, Changchun, Jilin, China.|Department of Anesthesia, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Ouyang
authors.affiliation: Institute of Neuroscience Center and Neurology Department, The First Affiliated Hospital of Jilin University, Changchun, Jilin, China.
authors.forename: Jiachun
authors.initials: J
authors.lastname: Feng
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001343:Autophagy; D001522:Behavior, Animal; D002545:Brain Ischemia / Q000378:metabolism / Q000473:pathology* / Q000523:psychology; D002544:Cerebral Infarction / Q000473:pathology; D013181:Cortical Spreading Depression / Q000187:drug effects / Q000502:physiology*; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology; D019194:Ischemic Preconditioning; D008297:Male; D009422:Nervous System Diseases / Q000209:etiology / Q000473:pathology / Q000523:psychology; D000066829:Neuroprotection; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D020521:Stroke / Q000378:metabolism / Q000473:pathology*
chemical_list: C025946:3-methyladenine; D011189:Potassium Chloride; D055372:AMP-Activated Protein Kinases; D000225:Adenine
keywords: 
  AMPK
  ; acute stroke; autophagy; cortical spreading depression; neuroprotection