title: MicroRNA-200c contributes to injury from transient focal cerebral ischemia by targeting Reelin.
abstract: OBJECTIVE
  MicroRNA (miR)-200c increases rapidly in the brain after transient cerebral ischemia but its role in poststroke brain injury is unclear. Reelin, a regulator of neuronal migration and synaptogenesis, is a predicted target of miR-200c. We hypothesized that miR-200c contributes to injury from transient cerebral ischemia by targeting reelin.
  
  
  METHODS
  Brain infarct volume, neurological score and levels of miR-200c, reelin mRNA, and reelin protein were assessed in mice subjected to 1 hour of middle cerebral artery occlusion with or without intracerebroventricular infusion of miR-200c antagomir, mimic, or mismatch control. Direct targeting of reelin by miR-200c was assessed in vitro by dual luciferase assay and immunoblot.
  
  
  RESULTS
  Pretreatment with miR-200c antagomir decreased post-middle cerebral artery occlusion brain levels of miR-200c, resulting in a significant reduction in infarct volume and neurological deficit. Changes in brain levels of miR-200c inversely correlated with reelin protein expression. Direct targeting of the Reln 3' untranslated region by miR-200c was verified with dual luciferase assay. Inhibition of miR-200c resulted in an increase in cell survival subsequent to in vitro oxidative injury. This effect was blocked by knockdown of reelin mRNA, whereas application of reelin protein afforded protection.
  
  
  CONCLUSIONS
  These findings suggest that the poststroke increase in miR-200c contributes to brain cell death by inhibiting reelin expression, and that reducing poststroke miR-200c is a potential target to mitigate stroke-induced brain injury.
authors.affiliation: From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.).
authors.forename: Creed M
authors.initials: CM
authors.lastname: Stary
authors.affiliation: From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.).
authors.forename: Lijun
authors.initials: L
authors.lastname: Xu
authors.affiliation: From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.).
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Sun
authors.affiliation: From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.).
authors.forename: Yi-Bing
authors.initials: YB
authors.lastname: Ouyang
authors.affiliation: From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.).
authors.forename: Robin E
authors.initials: RE
authors.lastname: White
authors.affiliation: From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.).
authors.forename: Jason
authors.initials: J
authors.lastname: Leong
authors.affiliation: From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.).
authors.forename: John
authors.initials: J
authors.lastname: Li
authors.affiliation: From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.).
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Xiong
authors.affiliation: From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.). rgiffard@stanford.edu.
authors.forename: Rona G
authors.initials: RG
authors.lastname: Giffard
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology; D015816:Cell Adhesion Molecules, Neuronal / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D002478:Cells, Cultured; D016326:Extracellular Matrix Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D018390:Gene Targeting; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000008:administration & dosage* / Q000096:biosynthesis*; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000096:biosynthesis*
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; C533896:MIRN200 microRNA, human; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; D000091042:Reelin Protein; C000717127:RELN protein, human; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases
keywords: infarction, middle cerebral artery; microRNAs; reperfusion injury; stroke