title: Impaired Endothelial Nitric Oxide Synthase Homodimer Formation Triggers Development of Transplant Vasculopathy - Insights from a Murine Aortic Transplantation Model.
abstract: Transplant vasculopathy (TV) represents a major obstacle to long-term graft survival and correlates with severity of ischemia reperfusion injury (IRI). Donor administration of the nitric oxide synthases (NOS) co-factor tetrahydrobiopterin has been shown to prevent IRI. Herein, we analysed whether tetrahydrobiopterin is also involved in TV development. Using a fully allogeneic mismatched (BALB/c to C57BL/6) murine aortic transplantation model grafts subjected to long cold ischemia time developed severe TV with intimal hyperplasia (α-smooth muscle actin positive cells in the neointima) and endothelial activation (increased P-selectin expression). Donor pretreatment with tetrahydrobiopterin significantly minimised these changes resulting in only marginal TV development. Severe TV observed in the non-treated group was associated with increased protein oxidation and increased occurrence of endothelial NOS monomers in the aortic grafts already during graft procurement. Tetrahydrobiopterin supplementation of the donor prevented all these early oxidative changes in the graft. Non-treated allogeneic grafts without cold ischemia time and syngeneic grafts did not develop any TV. We identified early protein oxidation and impaired endothelial NOS homodimer formation as plausible mechanistic explanation for the crucial role of IRI in triggering TV in transplanted aortic grafts. Therefore, targeting endothelial NOS in the donor represents a promising strategy to minimise TV.
authors.affiliation: Centre of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Rupert
authors.initials: R
authors.lastname: Oberhuber
authors.affiliation: Centre of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Gregor
authors.initials: G
authors.lastname: Riede
authors.affiliation: Centre of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Benno
authors.initials: B
authors.lastname: Cardini
authors.affiliation: Cardiac Surgery Research Laboratory, University Clinic for Cardiac Surgery, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Bernhard
authors.affiliation: Cardiac Surgery Research Laboratory, Department of Surgery, Vienna Medical University, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Messner
authors.affiliation: Division of Biological Chemistry, Biocenter, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Katrin
authors.initials: K
authors.lastname: Watschinger
authors.affiliation: Institute of Pathology, Academic Teaching Hospital Feldkirch, Feldkirch, Austria.
authors.forename: Christina
authors.initials: C
authors.lastname: Steger
authors.affiliation: Centre of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Medical University Innsbruck, Innsbruck, Austria.|Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation (VCA) Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Gerald
authors.initials: G
authors.lastname: Brandacher
authors.affiliation: Centre of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Medical University Innsbruck, Innsbruck, Austria.|Department of General-, Visceral- and Transplantation Surgery, Charité, Campus Virchow Klinikum, Berlin, Germany.
authors.forename: Johann
authors.initials: J
authors.lastname: Pratschke
authors.affiliation: Division of Biological Chemistry, Biocenter, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Golderer
authors.affiliation: Division of Biological Chemistry, Biocenter, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Ernst R
authors.initials: ER
authors.lastname: Werner
authors.affiliation: Centre of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Manuel
authors.initials: M
authors.lastname: Maglione
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001011:Aorta / Q000473:pathology / Q000502:physiology* / Q000637:transplantation*; D001708:Biopterins / Q000031:analogs & derivatives / Q000494:pharmacology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D019281:Dimerization; D004195:Disease Models, Animal; D007249:Inflammation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009130:Muscle, Smooth / Q000378:metabolism; D058426:Neointima / Q000473:pathology; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D019007:P-Selectin / Q000378:metabolism; D015427:Reperfusion Injury; D000097382:CD68 Molecule
chemical_list: D000199:Actins; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D001708:Biopterins; D052250:Nitric Oxide Synthase Type III; D010100:Oxygen; D019007:P-Selectin; C081026:CD68 protein, mouse; D000097382:CD68 Molecule; C496315:Nos3 protein, mouse; C003402:sapropterin