title: MicroRNA-21 Mediates Isoflurane-induced Cardioprotection against Ischemia-Reperfusion Injury via Akt/Nitric Oxide Synthase/Mitochondrial Permeability Transition Pore Pathway.
abstract: BACKGROUND
  The role of microRNA-21 in isoflurane-induced cardioprotection is unknown. The authors addressed this issue by using microRNA-21 knockout mice and explored the underlying mechanisms.
  
  
  METHODS
  C57BL/6 and microRNA-21 knockout mice were echocardiographically examined. Mouse hearts underwent 30 min of ischemia followed by 2 h of reperfusion in vivo or ex vivo in the presence or absence of 1.0 minimum alveolar concentration of isoflurane administered before ischemia. Cardiac Akt, endothelial nitric oxide synthase (eNOS), and neuronal nitric oxide synthase (nNOS) proteins were determined by Western blot analysis. Opening of the mitochondrial permeability transition pore (mPTP) in cardiomyocytes was induced by photoexcitation-generated oxidative stress and detected by rapid dissipation of tetramethylrhodamine ethyl ester fluorescence using a confocal microscope.
  
  
  RESULTS
  Genetic disruption of miR-21 gene did not alter phenotype of the left ventricle, baseline cardiac function, area at risk, and the ratios of phosphorylated-Akt/Akt, phosphorylated-eNOS/eNOS, and phosphorylated-nNOS/nNOS. Isoflurane decreased infarct size from 54 ± 10% in control to 36 ± 10% (P < 0.05, n = 8 mice per group), improved cardiac function after reperfusion, and increased the ratios of phosphorylated-Akt/AKT, phosphorylated-eNOS/eNOS, and phosphorylated-nNOS/nNOS in C57BL/6 mice subjected to ischemia-reperfusion injury. These beneficial effects of isoflurane were lost in microRNA-21 knockout mice. There were no significant differences in time of the mPTP opening induced by photoexcitation-generated oxidative stress in cardiomyocytes isolated between C57BL/6 and microRNA-21 knockout mice. Isoflurane significantly delayed mPTP opening in cardiomyocytes from C57BL/6 but not from microRNA-21 knockout mice.
  
  
  CONCLUSIONS
  Isoflurane protects mouse hearts from ischemia-reperfusion injury by a microRNA-21-dependent mechanism. The Akt/NOS/mPTP pathway is involved in the microRNA-21-mediated protective effect of isoflurane.
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Shigang
authors.initials: S
authors.lastname: Qiao
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Olson
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Mark
authors.initials: M
authors.lastname: Paterson
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Yasheng
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Ivan
authors.initials: I
authors.lastname: Zaja
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Matthias L
authors.initials: ML
authors.lastname: Riess
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Judy R
authors.initials: JR
authors.lastname: Kersten
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Mingyu
authors.initials: M
authors.lastname: Liang
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: David C
authors.initials: DC
authors.lastname: Warltier
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Zeljko J
authors.initials: ZJ
authors.lastname: Bosnjak
authors.affiliation: Department of Anesthesiology (S.Q., J.M.O., M.P., Y.Y., I.Z., Y.L., J.R.K., D.C.W., Z.J.B., Z.D.G.), Department of Physiology (J.M.O., M.L., Z.J.B.), and Department of Pharmacology and Toxicology (J.R.K., D.C.W.), Medical College of Wisconsin, Milwaukee, Wisconsin, and Department of Anesthesiology (M.L.R.), TVHS VA Medical Center and Vanderbilt University, Nashville, Tennessee.
authors.forename: Zhi-Dong
authors.initials: ZD
authors.lastname: Ge
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000008:administration & dosage; D002478:Cells, Cultured; D007530:Isoflurane / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D035683:MicroRNAs / Q000502:physiology*; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism*; D000083162:Mitochondrial Permeability Transition Pore; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000517:prevention & control; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D009924:Organ Culture Techniques; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
chemical_list: D002316:Cardiotonic Agents; C531950:MIRN21 microRNA, mouse; D035683:MicroRNAs; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D007530:Isoflurane; D019001:Nitric Oxide Synthase; D051057:Proto-Oncogene Proteins c-akt