title: Targeting NADPH oxidase decreases oxidative stress in the transgenic sickle cell mouse penis.
abstract: BACKGROUND
  Sickle cell disease (SCD) is a state of chronic vasculopathy characterized by endothelial dysfunction and increased oxidative stress, but the sources and mechanisms responsible for reactive oxygen species (ROS) production in the penis are unknown.
  
  
  OBJECTIVE
  We evaluated whether SCD activates NADPH oxidase, induces endothelial nitric oxide synthase (eNOS) uncoupling, and decreases antioxidants in the SCD mouse penis. We further tested the hypothesis that targeting NADPH oxidase decreases oxidative stress in the SCD mouse penis.
  
  
  METHODS
  SCD transgenic (sickle) mice were used as an animal model of SCD. Hemizygous (hemi) mice served as controls. Mice received an NADPH oxidase inhibitor apocynin (10 mM in drinking water) or vehicle. Penes were excised at baseline for molecular studies. Markers of oxidative stress (4-hydroxy-2-nonenal [HNE]), sources of ROS (eNOS uncoupling and NADPH oxidase subunits p67(phox) , p47(phox) , and gp91(phox) ), and enzymatic antioxidants (superoxide dismutase [SOD]1, SOD2, catalase, and glutathione peroxidase-1 [GPx1]) were measured by Western blot in penes.
  
  
  METHODS
  Sources of ROS, oxidative stress, and enzymatic antioxidants in the SCD penis.
  
  
  RESULTS
  Relative to hemi mice, SCD increased (P<0.05) protein expression of NADPH oxidase subunits p67(phox) , p47(phox) , and gp91(phox) , 4-HNE-modified proteins, induced eNOS uncoupling, and reduced Gpx1 expression in the penis. Apocynin treatment of sickle mice reversed (P<0.05) the abnormalities in protein expressions of p47(phox) , gp91(phox) (but not p67(phox) ) and 4-HNE, but only slightly (P>0.05) prevented eNOS uncoupling in the penis. Apocynin treatment of hemi mice did not affect any of these parameters.
  
  
  CONCLUSIONS
  NADPH oxidase and eNOS uncoupling are sources of oxidative stress in the SCD penis; decreased GPx1 further contributes to oxidative stress. Inhibition of NADPH oxidase upregulation decreases oxidative stress, implying a major role for NADPH oxidase as a ROS source and a potential target for improving vascular function in the SCD mouse penis.
authors.affiliation: Department of Urology, The Johns Hopkins University, Baltimore, MD 21287, USA. bmusicki@jhmi.edu
authors.forename: Biljana
authors.initials: B
authors.lastname: Musicki
authors.forename: Tongyun
authors.initials: T
authors.lastname: Liu
authors.forename: Sena F
authors.initials: SF
authors.lastname: Sezen
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Burnett
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D000447:Aldehydes / Q000378:metabolism; D000755:Anemia, Sickle Cell / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010413:Penis / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000098:Acetophenones; D000447:Aldehydes; D000975:Antioxidants; D010750:Phosphoproteins; D017382:Reactive Oxygen Species; C079789:neutrophil cytosol factor 67K; C056165:acetovanillone; D052250:Nitric Oxide Synthase Type III; D019255:NADPH Oxidases; C027576:4-hydroxy-2-nonenal