title: [Anti-apoptosis and expression of microRNA-21 in rat myocardium during early ischemia-reperfusion injury].
abstract: OBJECTIVE
  To observe the expression and anti-apoptosis of microRNA-21(miR-21) in rat myocardium during early ischemia-reperfusion injury (I/R).
  
  
  METHODS
  Sprague-Dawley rats were randomly divided into 5 groups: a control group (transfected with rAAV9-ZsGreen by coronary injection), a miR-21group (transfected rAAV9-ZsGreen-premiR- 21 by coronary injection), a sham group (open-chest only), an I/R group (I/R), and an I/ R+miR-21 (I/R after transfected rAAV9-ZsGreen-pre-miR-21 by coronary injection). Realtime PCR was used to assess the expression level of miR-21. Immunohistochemistry and Western blot were used to determine the expression of Bcl-2, Bax, caspase-3 and Bcl-2/Bax.
  
  
  RESULTS
  MiR-21 was increased by 4.43 times in the miR-21 group (P<0.001). MiR-21 was downregulated in the ischemia zone after I/R compared with the sham group (P<0.05), but that in the non-ischemia zone was significantly increased compared with the sham group (P<0.01). MiR- 21 expression was decreased in the I/R group compared with that in the sham group at 1 h, 2 h and 6 h after I/R (P<0.05), and it was up-regulated in the I/R+miR-21 group at the same time point compared with the I/R group (P<0.01). The expression of Bcl-2, Bax, and caspase-3 was upregulated and Bcl-2/Bax was decreased in the ischemia zone in the I/R group and I/R+miR-21 group than the sham group(P<0.05). Compared with the I/R group, the expression of Bcl-2 and caspase-3 was down-regulated and Bcl-2/Bax was increased in the ischemia zone in the I/ R+miR-21 group (P<0.05).
  
  
  CONCLUSIONS
  MiR-21 expression is down-regulated and cell apoptosis is increased in rat myocardium during early ischemia-reperfusion injury. Myocardial cell apoptosis may be alleviated by miR-21 over-expression.
authors.affiliation: Department of Cardiology, Third Xiangya Hospital, Central South University, Changsha 410013,China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Yang
authors.forename: Kan
authors.initials: K
authors.lastname: Yang
authors.forename: Anying
authors.initials: A
authors.lastname: Li
authors.forename: Wenpeng
authors.initials: W
authors.lastname: Tan
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D000229:Dependovirus / Q000235:genetics; D005822:Genetic Vectors; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D017202:Myocardial Ischemia / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism*; D014162:Transfection
chemical_list: D035683:MicroRNAs; C546082:mirn21 microRNA, rat