title: A deficiency of apoptosis inducing factor (AIF) in Harlequin mouse heart mitochondria paradoxically reduces ROS generation during ischemia-reperfusion.
abstract: OBJECTIVE
  AIF (apoptosis inducing factor) is a flavin and NADH containing protein located within mitochondria required for optimal function of the respiratory chain. AIF may function as an antioxidant within mitochondria, yet when released from mitochondria it activates caspase-independent cell death. The Harlequin (Hq) mouse has a markedly reduced content of AIF, providing an experimental model to query if the main role of AIF in the exacerbation of cell death is enhanced mitochondrial generation of reactive oxygen species (ROS) or the activation of cell death programs. We asked if the ROS generation is altered in Hq heart mitochondria at baseline or following ischemia-reperfusion (IR).
  
  
  METHODS
  Buffer perfused mouse hearts underwent 30 min ischemia and 30 min reperfusion. Mitochondrial function including oxidative phosphorylation and H2O2 generation was measured. Immunoblotting was used to determine the contents of AIF and PAR [poly(ADP-ribose)] in cell fractions.
  
  
  RESULTS
  There were no differences in the release of H2O2 between wild type (WT) and Hq heart mitochondria at baseline. IR increased H2O2 generation from WT but not from Hq mitochondria compared to corresponding time controls. The complex I activity was decreased in WT but not in Hq mice following IR. The relocation of AIF from mitochondria to nucleus was increased in WT but not in Hq mice. IR activated PARP-1 only in WT mice. Cell injury was decreased in the Hq mouse heart following in vitro IR.
  
  
  CONCLUSIONS
  A deficiency of AIF within mitochondria does not increase ROS production during IR, indicating that AIF functions less as an antioxidant within mitochondria. The decreased cardiac injury in Hq mouse heart accompanied by less AIF translocation to the nucleus suggests that AIF relocation, rather than the AIF content within mitochondria, contributes to cardiac injury during IR.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA.
authors.forename: Qun
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA.
authors.forename: Karol
authors.initials: K
authors.lastname: Szczepanek
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Thompson
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA ; Department of Biochemistry and Molecular Biology, Virginia Commonwealth University Richmond, VA, USA ; McGuire Department of Veterans Affairs Medical Center Richmond, VA, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Lesnefsky
keywords: apoptosis; electron transport chain; poly(ADP-ribose); reactive oxygen species
references.citation: Antioxid Redox Signal. 2011 Jun 15;14(12):2545-79
references.pmid: 20868295
references.citation: J Biol Chem. 2009 Nov 13;284(46):31616-24
references.pmid: 19762472
references.citation: Am J Physiol. 1997 Sep;273(3 Pt 2):H1544-54
references.pmid: 9321848
references.citation: J Biol Chem. 2011 Aug 26;286(34):29610-20
references.pmid: 21715323
references.citation: J Cardiovasc Pharmacol. 2012 Jan;59(1):101-8
references.pmid: 21964159
references.citation: Cardiovasc Drug Rev. 2007 Fall;25(3):235-60
references.pmid: 17919258
references.citation: J Mol Cell Cardiol. 1980 Jun;12(6):639-45
references.pmid: 7452739
references.citation: Circ Res. 2003 Aug 22;93(4):292-301
references.pmid: 12933700
references.citation: EMBO J. 2005 Apr 6;24(7):1375-86
references.pmid: 15775970
references.citation: ASN Neuro. 2009 Nov 18;1(5):
references.pmid: 19863494
references.citation: Am J Physiol Cell Physiol. 2007 Jan;292(1):C137-47
references.pmid: 16971498
references.citation: Am J Physiol Heart Circ Physiol. 2006 Aug;291(2):H714-23
references.pmid: 16582021
references.citation: Am J Physiol Cell Physiol. 2014 Jun 15;306(12):C1142-53
references.pmid: 24696146
references.citation: Biochem Biophys Res Commun. 2011 Dec 2;415(4):533-8
references.pmid: 22057010
references.citation: Apoptosis. 2012 Oct;17(10):1027-38
references.pmid: 22865232
references.citation: J Aging Res. 2012;2012:753949
references.pmid: 22619720
references.citation: Cardiovasc Res. 2004 Feb 15;61(3):372-85
references.pmid: 14962470
references.citation: Cell Metab. 2013 Aug 6;18(2):239-50
references.pmid: 23931755
references.citation: EMBO J. 2004 Nov 24;23(23):4679-89
references.pmid: 15526035
references.citation: Circ Res. 2004 Jan 9;94(1):53-9
references.pmid: 14656928
references.citation: Free Radic Res Commun. 1991;12-13 Pt 2:681-9
references.pmid: 2060840
references.citation: J Biol Chem. 1980 Apr 25;255(8):3278-84
references.pmid: 6245075
references.citation: Circulation. 2011 Dec 20;124(25):2892-902
references.pmid: 22144571
references.citation: J Am Heart Assoc. 2013 Apr 18;2(2):e000159
references.pmid: 23598272
references.citation: Nature. 2002 Sep 26;419(6905):367-74
references.pmid: 12353028
references.citation: Circ Res. 2005 Jun 24;96(12):e92-e101
references.pmid: 15933268
references.citation: Biochem J. 2006 Mar 15;394(Pt 3):627-34
references.pmid: 16371007
references.citation: Cardiovasc Res. 2008 Nov 1;80(2):280-9
references.pmid: 18596060
references.citation: Science. 2002 Jul 12;297(5579):259-63
references.pmid: 12114629
references.citation: J Biol Chem. 2011 Sep 23;286(38):33669-77
references.pmid: 21832082
references.citation: Cell Health Cytoskelet. 2012 Feb 1;2012(4):11-27
references.pmid: 22593641
references.citation: J Biochem. 2007 Sep;142(3):365-76
references.pmid: 17646173
references.citation: Cardiovasc Res. 2008 Jan 15;77(2):334-43
references.pmid: 18006487
references.citation: Proc Natl Acad Sci U S A. 2006 Nov 28;103(48):18314-9
references.pmid: 17116881
references.citation: J Neurochem. 2009 Jul;110(2):687-96
references.pmid: 19457082
references.citation: Physiol Rev. 2008 Apr;88(2):581-609
references.pmid: 18391174
references.citation: Transl Res. 2009 May;153(5):224-31
references.pmid: 19375683
references.citation: Exp Neurol. 2009 May;217(1):210-8
references.pmid: 19268668
references.citation: Cell Death Differ. 2012 Feb;19(2):245-56
references.pmid: 21738214
references.citation: Am J Physiol Cell Physiol. 2008 Feb;294(2):C460-6
references.pmid: 18077608
references.citation: J Mol Cell Cardiol. 2001 Jun;33(6):1065-89
references.pmid: 11444914
references.citation: Am J Pathol. 2001 Apr;158(4):1271-8
references.pmid: 11290545
references.citation: J Pharmacol Exp Ther. 2006 Dec;319(3):1405-12
references.pmid: 16990510
references.citation: Mol Cell Biol. 2005 Dec;25(23):10261-72
references.pmid: 16287843
references.citation: J Biol Chem. 2008 Sep 5;283(36):24801-15
references.pmid: 18611857
references.citation: Am J Physiol. 1983 Jun;244(6):H743-8
references.pmid: 6305212
references.citation: J Physiol. 2003 Oct 15;552(Pt 2):335-44
references.pmid: 14561818
references.citation: Cell. 2007 Nov 2;131(3):476-91
references.pmid: 17981116
references.citation: J Biol Chem. 1991 Nov 5;266(31):20998-1003
references.pmid: 1657942
references.citation: J Biol Chem. 2003 Sep 19;278(38):36027-31
references.pmid: 12840017
references.citation: Free Radic Biol Med. 2009 Apr 1;46(7):939-47
references.pmid: 19280713
references.citation: Free Radic Biol Med. 2010 Mar 15;48(6):791-7
references.pmid: 20043986
references.citation: Biochem Biophys Res Commun. 2006 May 12;343(3):873-8
references.pmid: 16564501