title: Nox2 and p47(phox) modulate compensatory growth of primary collateral arteries.
abstract: The role of NADPH oxidase (Nox) in both the promotion and impairment of compensatory collateral growth remains controversial because the specific Nox and reactive oxygen species involved are unclear. The aim of this study was to identify the primary Nox and reactive oxygen species associated with early stage compensatory collateral growth in young, healthy animals. Ligation of the feed arteries that form primary collateral pathways in rat mesentery and mouse hindlimb was used to assess the role of Nox during collateral growth. Changes in mesenteric collateral artery Nox mRNA expression determined by real-time PCR at 1, 3, and 7 days relative to same-animal control arteries suggested a role for Nox subunits Nox2 and p47(phox). Administration of apocynin or Nox2ds-tat suppressed collateral growth in both rat and mouse models, suggesting the Nox2/p47(phox) interaction was involved. Functional significance of p47(phox) expression was assessed by evaluation of collateral growth in rats administered p47(phox) small interfering RNA and in p47(phox-/-) mice. Diameter measurements of collateral mesenteric and gracilis arteries at 7 and 14 days, respectively, indicated no significant collateral growth compared with control rats or C57BL/6 mice. Chronic polyethylene glycol-conjugated catalase administration significantly suppressed collateral development in rats and mice, implying a requirement for H2O2. Taken together, these results suggest that Nox2, modulated at least in part by p47(phox), mediates early stage compensatory collateral development via a process dependent upon peroxide generation. These results have important implications for the use of antioxidants and the development of therapies for peripheral arterial disease.
authors.affiliation: Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana;
authors.forename: Matthew R
authors.initials: MR
authors.lastname: DiStasi
authors.affiliation: Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana; and Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Unthank
authors.affiliation: Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana; and Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana sjmiller@iupui.edu.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Miller
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001158:Arteries / Q000254:growth & development* / Q000502:physiology; D003097:Collateral Circulation / Q000187:drug effects / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D023421:Models, Animal; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000172:deficiency / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D011921:Rats, Inbred WKY; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000098:Acetophenones; D000975:Antioxidants; D008562:Membrane Glycoproteins; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; C056165:acetovanillone; D006861:Hydrogen Peroxide; C488842:Cybb protein, mouse; C500593:Cybb protein, rat; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1
keywords: NADPH oxidase; Nox2; collateral artery; hydrogen peroxide; p47phox