title: Molecular imaging of inflammation and platelet adhesion in advanced atherosclerosis effects of antioxidant therapy with NADPH oxidase inhibition.
abstract: BACKGROUND
  In atherosclerosis, local generation of reactive oxygen species amplifies the inflammatory response and contributes to plaque vulnerability. We used molecular imaging to test whether inhibition of NADPH oxidase with apocynin would reduce endothelial inflammatory activation and endothelial-platelet interactions, thereby interrupting progression to high-risk plaque phenotype.
  
  
  RESULTS
  Mice deficient for both the low-density lipoprotein receptor and Apobec-1 were studied at 30 weeks of age and again after 10 weeks with or without apocynin treatment (10 or 50 mg/kg per day orally). In vivo molecular imaging of vascular cell adhesion molecule-1 (VCAM 1) P-selectin, and platelet glycoprotein-1bα (GPIbα) in the thoracic aorta was performed with targeted contrast-enhanced ultrasound molecular imaging. Arterial elastic modulus and pulse wave transit time were assessed using ultrahigh frequency ultrasound and invasive hemodynamic measurements. Plaque size and composition were assessed by histology. Molecular imaging in nontreated mice detected a 2-fold increase in P-selectin expression, VCAM-1 expression, and platelet adhesion between 30 and 40 weeks of age. Apocynin reduced all of these endothelial events in a dose-dependent fashion (25% and 50% reduction in signal at 40 weeks for low- and high-dose apocynin). Apocynin also decreased aortic elastic modulus and increased the pulse transit time. On histology, apocynin reduced total monocyte accumulation in a dose-dependent manner as well as platelet adhesion, although total plaque area was reduced in only the high-dose apocynin treatment group.
  
  
  CONCLUSIONS
  Inhibition of NADPH oxidase in advanced atherosclerosis reduces endothelial activation and platelet adhesion, which are likely responsible for the arrest of plaque growth and improvement of vascular mechanical properties.
authors.affiliation: Division of Cardiovascular Medicine, Oregon Health & Science University, Portland, OR 97239, USA.
authors.forename: Yani
authors.initials: Y
authors.lastname: Liu
authors.forename: Brian P
authors.initials: BP
authors.lastname: Davidson
authors.forename: Qi
authors.initials: Q
authors.lastname: Yue
authors.forename: Todd
authors.initials: T
authors.lastname: Belcik
authors.forename: Aris
authors.initials: A
authors.lastname: Xie
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Inaba
authors.forename: Owen J T
authors.initials: OJ
authors.lastname: McCarty
authors.forename: Garth W
authors.initials: GW
authors.lastname: Tormoen
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Zaverio M
authors.initials: ZM
authors.lastname: Ruggeri
authors.forename: Beat A
authors.initials: BA
authors.lastname: Kaufmann
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Lindner
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D050197:Atherosclerosis / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D007249:Inflammation / Q000175:diagnosis* / Q000188:drug therapy / Q000201:enzymology; D051379:Mice; D008810:Mice, Inbred C57BL; D057054:Molecular Imaging / Q000379:methods*; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors*; D010973:Platelet Adhesiveness / Q000187:drug effects / Q000502:physiology*
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D019255:NADPH Oxidases