title: MicroRNAs induced during ischemic preconditioning.
abstract: OBJECTIVE
  MicroRNAs (miRNA) are single-stranded short RNA molecules that regulate gene expression by either degradation or translational repression of mRNA. Although miRNAs control a number of conditions and diseases, few neuroprotective miRNAs have been described. In this study, we investigated neuroprotective miRNAs induced early in ischemic preconditioning.
  
  
  METHODS
  Ischemic preconditioning or focal cerebral ischemia was induced in mice by transient occlusion of the middle cerebral artery for 15 or 120 minutes. We prepared RNA samples from the ischemic cortex at 3 or 24 hours after the onset of ischemia. Selective miRNAs then were synthesized and transfected into Neuro-2a cells before oxygen-glucose deprivation.
  
  
  RESULTS
  We detected a total of 360 miRNAs. Two miRNA families, miR-200 and miR-182, were selectively upregulated at 3 hours after ischemic preconditioning. Transfections of some of these were neuroprotective in in vitro ischemia. Among them, miR-200b, miR-200c, and miR-429 targeted prolyl hydroxylase 2 and had the best neuroprotective effect.
  
  
  CONCLUSIONS
  Two miRNA families, miR-200 and miR-182, were upregulated early after ischemic preconditioning and the miR-200 family was neuroprotective mainly by downregulating prolyl hydroxylase 2 levels. These miRNAs may be useful in future research and therapeutic applications.
authors.affiliation: Department of Neurology, Clinical Research Institute, Seoul National University Hospital, Seoul, South Korea.
authors.forename: Soon-Tae
authors.initials: ST
authors.lastname: Lee
authors.forename: Kon
authors.initials: K
authors.lastname: Chu
authors.forename: Keun-Hwa
authors.initials: KH
authors.lastname: Jung
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Yoon
authors.forename: Daejong
authors.initials: D
authors.lastname: Jeon
authors.forename: Kyoung-Mook
authors.initials: KM
authors.lastname: Kang
authors.forename: Ki-Ho
authors.initials: KH
authors.lastname: Park
authors.forename: Eun-Kee
authors.initials: EK
authors.lastname: Bae
authors.forename: Manho
authors.initials: M
authors.lastname: Kim
authors.forename: Sang Kun
authors.initials: SK
authors.lastname: Lee
authors.forename: Jae-Kyu
authors.initials: JK
authors.lastname: Roh
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D002540:Cerebral Cortex / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D020244:Infarction, Middle Cerebral Artery / Q000235:genetics* / Q000378:metabolism; D019194:Ischemic Preconditioning; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation / Q000235:genetics
chemical_list: D035683:MicroRNAs