Effects of remote ischemic preconditioning and myocardial ischemia on microRNA-1 expression in the rat heart in vivo

Shock. 2014 Sep;42(3):234-8. doi: 10.1097/SHK.0000000000000201.

Abstract

Remote ischemic preconditioning (RIPC) is an easily applicable method for protecting the heart against a subsequent ischemia and reperfusion (I/R) injury. However, the exact molecular mechanisms underlying RIPC are unknown. We examined the involvement of microRNAs (miRNAs) and in particular the expression of miRNA-1 (miR-1) in RIPC and myocardial ischemia. Remote ischemic preconditioning was conducted by four cycles of 5-min bilateral hind-limb ischemia in male Wistar rats. Cardiac ischemia was induced by ligation of the left anterior descending coronary artery for 35 min followed by 2 or 6 h of reperfusion. MicroRNA expression was analyzed by Taqman miRNA arrays and quantitative polymerase chain reaction assays. Luciferase assays were performed to validate the miR-1 target gene brain-derived neurotrophic factor (BDNF). Brain-derived neurotrophic factor mRNA and protein levels were analyzed by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. Remote ischemic preconditioning led to a differential expression of miRNAs. The most abundant cardiac miRNA, miR-1, was downregulated by RIPC without following ischemia as well as after I/R and RIPC followed by I/R after 2 h of reperfusion. After 6 h of reperfusion, RIPC led to an upregulation of miR-1, whereas ischemia had no effect on miR-1 expression. Luciferase assays confirmed the interaction of miR-1 with BDNF, a protein that has been shown to exert cardioprotective effects. Brain-derived neurotrophic factor protein levels in rat hearts measured by enzyme-linked immunosorbent assay were not significantly altered after 2 or 6 h of reperfusion in all intervention groups. Remote ischemic preconditioning leads to changes in the expression levels of the most abundant cardiac miRNA, miR-1. MicroRNA 1 levels did not correlate with protein levels of BDNF, a known miR-1 target, in vivo. Further studies are needed to explore the biological significance of changes in miR-1 expression levels and the potential interaction with BDNF in RIPC-induced cardioprotection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain-Derived Neurotrophic Factor / genetics
  • Brain-Derived Neurotrophic Factor / metabolism
  • Computational Biology
  • Disease Models, Animal
  • Gene Expression Profiling
  • Gene Expression Regulation
  • Genes, Reporter
  • HEK293 Cells
  • Hemodynamics
  • Hindlimb / blood supply*
  • Humans
  • Ischemic Preconditioning / methods*
  • Luciferases / biosynthesis
  • Luciferases / genetics
  • Male
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Myocardial Reperfusion Injury / genetics
  • Myocardial Reperfusion Injury / metabolism
  • Myocardial Reperfusion Injury / pathology
  • Myocardial Reperfusion Injury / physiopathology
  • Myocardial Reperfusion Injury / prevention & control*
  • Myocardium / metabolism*
  • Myocardium / pathology
  • RNA, Messenger / metabolism
  • Rats, Wistar
  • Time Factors
  • Transfection

Substances

  • Brain-Derived Neurotrophic Factor
  • MIRN1 microRNA, rat
  • MicroRNAs
  • RNA, Messenger
  • Luciferases