title: Decreased endothelial nitric oxide synthase expression and function contribute to impaired mitochondrial biogenesis and oxidative stress in fetal lambs with persistent pulmonary hypertension.
abstract: Impaired vasodilation in persistent pulmonary hypertension of the newborn (PPHN) is characterized by mitochondrial dysfunction. We investigated the hypothesis that a decreased endothelial nitric oxide synthase level leads to impaired mitochondrial biogenesis and function in a lamb model of PPHN induced by prenatal ductus arteriosus constriction. We ventilated PPHN lambs with 100% O2 alone or with inhaled nitric oxide (iNO). We treated pulmonary artery endothelial cells (PAECs) from normal and PPHN lambs with detaNONOate, an NO donor. We observed decreased mitochondrial (mt) DNA copy number, electron transport chain (ETC) complex subunit levels, and ATP levels in PAECs and lung tissue of PPHN fetal lambs at baseline compared with gestation matched controls. Phosphorylation of AMP-activated kinase (AMPK) and levels of peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC-1α) and sirtuin-1, which facilitate mitochondrial biogenesis, were decreased in PPHN. Ventilation with 100% O2 was associated with larger decreases in ETC subunits in the lungs of PPHN lambs compared with unventilated PPHN lambs. iNO administration, which facilitated weaning of FiO2 , partly restored mtDNA copy number, ETC subunit levels, and ATP levels. DetaNONOate increased eNOS phosphorylation and its interaction with heat shock protein 90 (HSP90); increased levels of superoxide dismutase 2 (SOD2) mRNA, protein, and activity; and decreased the mitochondrial superoxide levels in PPHN-PAECs. Knockdown of eNOS decreased ETC protein levels in control PAECs. We conclude that ventilation with 100% O2 amplifies oxidative stress and mitochondrial dysfunction in PPHN, which are partly improved by iNO and weaning of oxygen.
authors.affiliation: Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and aafolaya@mcw.edu.
authors.forename: Adeleye J
authors.initials: AJ
authors.lastname: Afolayan
authors.affiliation: Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Annie
authors.initials: A
authors.lastname: Eis
authors.affiliation: Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Maxwell
authors.initials: M
authors.lastname: Alexander
authors.affiliation: Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Teresa
authors.initials: T
authors.lastname: Michalkiewicz
authors.affiliation: Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Ru-Jeng
authors.initials: RJ
authors.lastname: Teng
authors.affiliation: Department of Pediatrics, University of Buffalo, Buffalo, New York.
authors.forename: Satyan
authors.initials: S
authors.lastname: Lakshminrusimha
authors.affiliation: Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Girija G
authors.initials: GG
authors.lastname: Konduri
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D042783:Endothelial Cells / Q000378:metabolism*; D005260:Female; D005333:Fetus / Q000276:immunology / Q000378:metabolism; D006976:Hypertension, Pulmonary / Q000378:metabolism*; D008928:Mitochondria / Q000276:immunology / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D018384:Oxidative Stress; D047492:Peroxisome Proliferator-Activated Receptors / Q000276:immunology; D010547:Persistent Fetal Circulation Syndrome / Q000378:metabolism*; D011247:Pregnancy; D012756:Sheep
chemical_list: D047492:Peroxisome Proliferator-Activated Receptors; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III
keywords: SOD2; biogenesis; eNOS; mitochondria; oxidative stress