title: Poly(ADP-ribose) polymerase-dependent energy depletion occurs through inhibition of glycolysis.
abstract: Excessive poly(ADP-ribose) (PAR) polymerase-1 (PARP-1) activation kills cells via a cell-death process designated "parthanatos" in which PAR induces the mitochondrial release and nuclear translocation of apoptosis-inducing factor to initiate chromatinolysis and cell death. Accompanying the formation of PAR are the reduction of cellular NAD(+) and energetic collapse, which have been thought to be caused by the consumption of cellular NAD(+) by PARP-1. Here we show that the bioenergetic collapse following PARP-1 activation is not dependent on NAD(+) depletion. Instead PARP-1 activation initiates glycolytic defects via PAR-dependent inhibition of hexokinase, which precedes the NAD(+) depletion in N-methyl-N-nitroso-N-nitroguanidine (MNNG)-treated cortical neurons. Mitochondrial defects are observed shortly after PARP-1 activation and are mediated largely through defective glycolysis, because supplementation of the mitochondrial substrates pyruvate and glutamine reverse the PARP-1-mediated mitochondrial dysfunction. Depleting neurons of NAD(+) with FK866, a highly specific noncompetitive inhibitor of nicotinamide phosphoribosyltransferase, does not alter glycolysis or mitochondrial function. Hexokinase, the first regulatory enzyme to initiate glycolysis by converting glucose to glucose-6-phosphate, contains a strong PAR-binding motif. PAR binds to hexokinase and inhibits hexokinase activity in MNNG-treated cortical neurons. Preventing PAR formation with PAR glycohydrolase prevents the PAR-dependent inhibition of hexokinase. These results indicate that bioenergetic collapse induced by overactivation of PARP-1 is caused by PAR-dependent inhibition of glycolysis through inhibition of hexokinase.
authors.affiliation: Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering,Departments of Neurology, sandrabi@jhmi.edu vdawson@jhmi.edu tdawson@jhmi.edu.
authors.forename: Shaida A
authors.initials: SA
authors.lastname: Andrabi
authors.affiliation: Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering,Departments of Neurology.
authors.forename: George K E
authors.initials: GK
authors.lastname: Umanah
authors.affiliation: Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering,Biomedical Engineering.
authors.forename: Calvin
authors.initials: C
authors.lastname: Chang
authors.affiliation: Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering,Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205; and.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Stevens
authors.affiliation: Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering,Departments of Neurology.
authors.forename: Senthilkumar S
authors.initials: SS
authors.lastname: Karuppagounder
authors.affiliation: Centre de Recherche du CHU de Québec, Université Laval, Québec, Canada G1V 4G2.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Gagné
authors.affiliation: Centre de Recherche du CHU de Québec, Université Laval, Québec, Canada G1V 4G2.
authors.forename: Guy G
authors.initials: GG
authors.lastname: Poirier
authors.affiliation: Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering,Departments of Neurology,Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205; andPhysiology, and sandrabi@jhmi.edu vdawson@jhmi.edu tdawson@jhmi.edu.
authors.forename: Valina L
authors.initials: VL
authors.lastname: Dawson
authors.affiliation: Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering,Departments of Neurology,Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205; andPharmacology and Molecular Sciences, and sandrabi@jhmi.edu vdawson@jhmi.edu tdawson@jhmi.edu.
authors.forename: Ted M
authors.initials: TM
authors.lastname: Dawson
mesh_terms: D000178:Acrylamides / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000201:enzymology*; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D005947:Glucose / Q000378:metabolism; D019298:Glucose-6-Phosphate / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects / Q000502:physiology*; D006593:Hexokinase / Q000378:metabolism; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D051379:Mice; D008928:Mitochondria / Q000201:enzymology*; D009243:NAD / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D010880:Piperidines / Q000494:pharmacology; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*
chemical_list: D000178:Acrylamides; C480543:N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide; D009419:Nerve Tissue Proteins; D010880:Piperidines; D009243:NAD; D008769:Methylnitronitrosoguanidine; D019298:Glucose-6-Phosphate; C499321:Parp1 protein, mouse; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D006593:Hexokinase; D005947:Glucose