title: NADPH oxidase 4 deficiency leads to impaired wound repair and reduced dityrosine-crosslinking, but does not affect myofibroblast formation.
abstract: NADPH oxidases (NOX) mediate redox signaling by generating superoxide and/or hydrogen peroxide, which are involved in biosynthetic pathways, e.g. thyroid hormone generation, dityrosine crosslinking, as well as bacterial killing. Data investigating the role of NOX enzymes in cutaneous wound repair is limited and specifically their function in skin myofibroblast expression is unknown. The isoform NOX4 was recently shown to be a pre-requisite for the differentiation of cardiac and pulmonary myofibroblasts. In this study we investigate the role of NOX4 in wound repair using a wound model in NOX4 knockout mice (n=16) and wildtype mice (n=16). Wounds were photographed daily until complete wound closure. Mice were sacrificed at day 3, 7, 14; wound tissue was harvested. NOX4-deficient mice healed significantly slower (22 days, SD=1.9) than wild-type mice (17 days, SD=1.4, p<0.005). However, there was no difference in myofibroblast expression. Strong dityrosine formation was observed, but was significantly weaker in NOX4-/- mice (p<0.05). NOX2, HIF1α and CD31 expression was significantly weaker in NOX4-/- mice (p<0.05). In this study we show for the first time that NOX4 plays a role in cutaneous wound repair. Our data suggests that NOX4 mediates HIF1α expression and neoangiogenesis during wound repair. NOX4 deletion led to a decreased expression of NOX2, implying a role of NOX4 in phagocytic cell recruitment. NOX4 was required for effective wound contraction but not myofibroblast expression. We suggest that myofibroblast contraction in NOX4-deficient mice is less effective in contracting the wound because of insufficient dityrosine-crosslinking of the ECM, providing the first indication for a physiological function of dityrosine crosslinking in higher animals.
authors.affiliation: Division of Plastic, Reconstructive & Aesthetic Surgery, Geneva University Hospitals, Geneva, Switzerland. Electronic address: dominik@levigne.eu.
authors.forename: Dominik
authors.initials: D
authors.lastname: Lévigne
authors.affiliation: Division of Plastic, Reconstructive & Aesthetic Surgery, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: Ali
authors.initials: A
authors.lastname: Modarressi
authors.affiliation: Department of Pathology, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Krause
authors.affiliation: Division of Plastic, Reconstructive & Aesthetic Surgery, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Pittet-Cuénod
mesh_terms: D000818:Animals; D053898:Biosynthetic Pathways / Q000235:genetics; D005347:Fibroblasts; D005786:Gene Expression Regulation; D006861:Hydrogen Peroxide / Q000378:metabolism; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D058628:Myofibroblasts / Q000378:metabolism / Q000473:pathology; D000074662:NADPH Oxidase 2 / Q000235:genetics*; D000074663:NADPH Oxidase 4 / Q000172:deficiency / Q000235:genetics*; D010084:Oxidation-Reduction; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D014945:Wound Healing / Q000235:genetics*
chemical_list: C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D017382:Reactive Oxygen Species; D013481:Superoxides; D014443:Tyrosine; D006861:Hydrogen Peroxide; C007543:dityrosine; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4
keywords: CD31; Collagen crosslinking; Dityrosine crosslinking; Extracellular matrix; HIF1alpha; MPO; Mouse model; Myeloperoxidase; Myofibroblast; NADPH oxidase 4; NOX2; NOX4; Neovascularization; ROS; VPO1; Wound healing; Wound repair