title: Inhibition of myocardial reperfusion injury by ischemic postconditioning requires sirtuin 3-mediated deacetylation of cyclophilin D.
abstract: BACKGROUND
  How ischemic postconditioning can inhibit opening of the mitochondrial permeability transition pore (PTP) and subsequent cardiac myocytes death at reperfusion remains unknown. Recent studies have suggested that de-acetylation of cyclophilin D (CyPD) by sirtuin 3 (SIRT3) can modulate its binding to the PTP.
  
  
  OBJECTIVE
  The aim of the present study was to examine whether ischemic postconditioning (PostC) might activate SIRT3 and consequently prevent lethal myocardial reperfusion injury through a deacetylation of CyPD.
  
  
  RESULTS
  Using hypoxia-reoxygenation (H/R) in H9C2 cells, we showed that SIRT3 overexpression prevented CyPD acetylation, limited PTP opening and reduced cell death by 24%. In vitro modification of the CyPD acetylation status in MEFs by site-directed mutagenesis altered capacity of PTP opening by calcium. Calcium Retention Capacity (CRC) was significantly decreased with CyPD-KQ that mimics acetylated protein compared with CyPD WT (871 ± 266 vs 1193 ± 263 nmoles Ca(2+)/mg protein respectively). Cells expressing non-acetylable CyPD mutant (CyPD-KR) displayed 20% decrease in cell death compared to cells expressing CyPD WT after H/R. Correspondingly, in mice we showed that cardiac ischemic postconditioning could not reduce infarct size and CyPD acetylation in SIRT3 KO mice, and was unable to restore CRC in mitochondria as it is observed in WT mice.
  
  
  CONCLUSIONS
  Our study suggests that the increased acetylation of CyPD following myocardial ischemia-reperfusion facilitates PTP opening and subsequent cell death. Therefore ischemic postconditioning might prevent lethal reperfusion injury through an increased SIRT3 activity and subsequent attenuation of CyPD acetylation at reperfusion.
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France; Hospices Civils de Lyon, Hôpital Louis Pradel, Service d'Explorations Fonctionnelles Cardiovasculaires & CIC de Lyon, F-69394 Lyon, France.
authors: T
authors: T
authors: Bochaton
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France.
authors: C
authors: C
authors: Crola-Da-Silva
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France.
authors: B
authors: B
authors: Pillot
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France.
authors: C
authors: C
authors: Villedieu
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France.
authors: L
authors: L
authors: Ferreras
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France.
authors: M R
authors: MR
authors: Alam
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France; Hospices Civils de Lyon, Hôpital Louis Pradel, Service d'Explorations Fonctionnelles Cardiovasculaires & CIC de Lyon, F-69394 Lyon, France.
authors: H
authors: H
authors: Thibault
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France.
authors: M
authors: M
authors: Strina
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France.
authors: A
authors: A
authors: Gharib
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France; Hospices Civils de Lyon, Hôpital Louis Pradel, Service d'Explorations Fonctionnelles Cardiovasculaires & CIC de Lyon, F-69394 Lyon, France.
authors: M
authors: M
authors: Ovize
authors: INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, F-69373 Lyon, France. Electronic address: delphine.baetz@univ-lyon1.fr.
authors: D
authors: D
authors: Baetz
mesh_terms: D000107:Acetylation; D000818:Animals; D016923:Cell Death; D015687:Cell Hypoxia; D000081406:Peptidyl-Prolyl Isomerase F; D021983:Cyclophilins / Q000378:metabolism*; D057775:Ischemic Postconditioning; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D018345:Mice, Knockout; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D015428:Myocardial Reperfusion Injury / Q000378:metabolism*; D010100:Oxygen / Q000494:pharmacology; D051381:Rats; D056566:Sirtuin 3 / Q000378:metabolism*
chemical_list: D000081406:Peptidyl-Prolyl Isomerase F; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; C000631446:PPIF protein, mouse; D056566:Sirtuin 3; D021983:Cyclophilins; D010100:Oxygen
keywords: Cyclophilin D; Ischemia–reperfusion; Post-conditioning; Sirtuin 3; Survival