title: Increased oxidative stress in the nucleus caused by Nox4 mediates oxidation of HDAC4 and cardiac hypertrophy.
abstract: BACKGROUND
  Oxidation of cysteine residues in class II histone deacetylases (HDACs), including HDAC4, causes nuclear exit, thereby inducing cardiac hypertrophy. The cellular source of reactive oxygen species responsible for oxidation of HDAC4 remains unknown.
  
  
  OBJECTIVE
  We investigated whether nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4), a major nicotinamide adenine dinucleotide phosphate oxidase, mediates cysteine oxidation of HDAC4.
  
  
  RESULTS
  Phenylephrine (100 μmol/L), an α1 adrenergic agonist, induced upregulation of Nox4 (1.5-fold; P<0.05) within 5 minutes, accompanied by increases in O(2)(-) (3.5-fold; P<0.01) from the nuclear membrane and nuclear exit of HDAC4 in cardiomyocytes. Knockdown of Nox4, but not Nox2, attenuated O(2)(-) production in the nucleus and prevented phenylephrine-induced oxidation and nuclear exit of HDAC4. After continuous infusion of phenylephrine (20 mg/kg per day) for 14 days, wild-type and cardiac-specific Nox4 knockout mice exhibited similar aortic pressures. Left ventricular weight/tibial length (5.7±0.2 versus 6.4±0.2 mg/mm; P<0.05) and cardiomyocytes cross-sectional area (223±13 versus 258±12 μm(2); P<0.05) were significantly smaller in cardiac-specific Nox4 knockout than in wild-type mice. Nuclear O(2)(-)production in the heart was significantly lower in cardiac-specific Nox4 knockout than in wild-type mice (4116±314 versus 7057±1710 relative light unit; P<0.05), and cysteine oxidation of HDAC4 was decreased. HDAC4 oxidation and cardiac hypertrophy were also attenuated in cardiac-specific Nox4 knockout mice 2 weeks after transverse aortic constriction.
  
  
  CONCLUSIONS
  Nox4 plays an essential role in mediating cysteine oxidation and nuclear exit of HDAC4, thereby mediating cardiac hypertrophy in response to phenylephrine and pressure overload.
authors.affiliation: Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ 07103, USA.
authors.forename: Shouji
authors.initials: S
authors.lastname: Matsushima
authors.forename: Junya
authors.initials: J
authors.lastname: Kuroda
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ago
authors.forename: Peiyong
authors.initials: P
authors.lastname: Zhai
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Park
authors.forename: Lai-Hua
authors.initials: LH
authors.lastname: Xie
authors.forename: Bin
authors.initials: B
authors.lastname: Tian
authors.forename: Junichi
authors.initials: J
authors.lastname: Sadoshima
mesh_terms: D000818:Animals; D001024:Aortic Valve Stenosis / Q000378:metabolism; D006332:Cardiomegaly / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D048429:Cell Size; D003545:Cysteine / Q000378:metabolism; D004789:Enzyme Activation; D004790:Enzyme Induction / Q000187:drug effects; D006655:Histone Deacetylases / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D009685:Nuclear Envelope / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010656:Phenylephrine / Q000494:pharmacology; D021381:Protein Transport / Q000502:physiology; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000502:physiology
chemical_list: D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; D011993:Recombinant Fusion Proteins; D010656:Phenylephrine; C488842:Cybb protein, mouse; C500593:Cybb protein, rat; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C422943:Nox4 protein, mouse; C498911:Nox4 protein, rat; C559944:HDAC4 protein, rat; C498618:Hdac5 protein, mouse; D006655:Histone Deacetylases; D003545:Cysteine