title: Inhibition of micro-ribonucleic acid-320 attenuates neurologic injuries after spinal cord ischemia.
abstract: OBJECTIVE
  Micro ribonucleic acids (miRNAs) are involved in a wide range of biological functions, in multiple tissues, including the central nervous system. We investigated a novel neuroprotective strategy of down-regulation of miR-320 in the spinal cord under the condition of transient ischemia.
  
  
  METHODS
  Spinal cord ischemia was induced in rats by cross-clamping the descending aorta for 14 minutes. Lentivirus vectors containing antisense oligonucleotides of rat miR-320 (antagomiR-320) were transfected into the experimental rats by means of intrathecal injection, 5 days before spinal cord ischemia. Control lentivirus vectors, or the vehicle, were given to the control animals. Hind-limb motor function was assessed during 48 hours after ischemia, using the Motor Deficit Index (MDI), and histologic examination was performed. In parallel experiments, expressions of miR-320, and the phosphorylation state of heat-shock protein 20 (phospho-Hsp20) in the spinal cord were evaluated by quantitative real-time polymerase chain reaction and western blot analysis.
  
  
  RESULTS
  The time courses of expressions of miR-320 and phospho-Hsp20 in the spinal cord, after the transient ischemia, indicated that expression of phospho-Hsp20 was negatively correlated with expression of miR-320. Transfection of antagomiR-320 significantly reduced expression of miR-320 in the spinal cord and dramatically up-regulated expression of phospho-Hsp20. Compared with controls, inhibition of miR-320 markedly improved hind-limb motor function, as evidenced by lower MDI scores, at 6, 12, 24, and 48 hours after reperfusion, and increased the number of intact motor neurons in the lumbar spinal cord.
  
  
  CONCLUSIONS
  Inhibition of miR-320 induces neuroprotection in the spinal cord, against ischemia-reperfusion injury, possibly via up-regulation of phospho-Hsp20.
authors.affiliation: Department of Anesthesiology, Fourth Affiliated Hospital, China Medical University, Shenyang, People's Republic of China.
authors.forename: Fang
authors.initials: F
authors.lastname: He
authors.affiliation: Department of Cardiac Surgery, First Affiliated Hospital, China Medical University, Shenyang, People's Republic of China.
authors.forename: Enyi
authors.initials: E
authors.lastname: Shi
authors.affiliation: Department of Anesthesiology, First Affiliated Hospital, China Medical University, Shenyang, People's Republic of China.
authors.forename: Lihui
authors.initials: L
authors.lastname: Yan
authors.affiliation: Department of Anesthesiology, First Affiliated Hospital, China Medical University, Shenyang, People's Republic of China.
authors.forename: Juchen
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, First Affiliated Hospital, China Medical University, Shenyang, People's Republic of China. Electronic address: jiangsophie@hotmail.com.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Jiang
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D050886:HSP20 Heat-Shock Proteins / Q000378:metabolism; D006614:Hindlimb; D016086:Lentivirus / Q000235:genetics; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009043:Motor Activity; D009046:Motor Neurons / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000294:innervation*; D009422:Nervous System Diseases / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D016376:Oligonucleotides, Antisense / Q000235:genetics* / Q000378:metabolism; D010766:Phosphorylation; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D013116:Spinal Cord / Q000378:metabolism* / Q000503:physiopathology; D020760:Spinal Cord Ischemia / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D014162:Transfection
chemical_list: D050886:HSP20 Heat-Shock Proteins; C000602002:MIRN320 microRNA, rat; D035683:MicroRNAs; D009124:Muscle Proteins; D016376:Oligonucleotides, Antisense; C087458:Hspb6 protein, rat
keywords: ischemia; miRNA; spinal cord