title: Interaction of endothelial nitric oxide synthase with mitochondria regulates oxidative stress and function in fetal pulmonary artery endothelial cells.
abstract: An increase in oxygen tension at birth is one of the key signals that initiate pulmonary vasodilation in the fetal lung. We investigated the hypothesis that targeting endothelial nitric oxide synthase (eNOS) to the mitochondrial outer membrane regulates reactive oxygen species (ROS) formation in the fetal pulmonary artery endothelial cells (PAEC) during this transition. We isolated PAEC and pulmonary arteries from 137-day gestation fetal lambs (term = 144 days). We exposed PAEC to a simulated transition from fetal to (3% O2) to normoxic (21%) or hyperoxic (95% O2) postnatal Po2 or to the nitric oxide synthase (NOS) agonist ATP. We assessed the effect of O2 and ATP on eNOS interactions with the mitochondrial outer membrane protein porin and with the chaperone hsp90. We also investigated the effect of decoy peptides that blocked eNOS interactions with porin or hsp90 on PAEC angiogenesis and vasodilator function of pulmonary arteries. Transition of fetal PAEC from 3 to 21% O2 but not to 95% O2 or exposure to ATP increased eNOS association with hsp90 and porin. Decoy peptides that blocked eNOS interactions decreased NO release, increased O2 consumption and mitochondrial ROS levels, and impaired PAEC angiogenesis. Decoy peptides also inhibited the relaxation responses of pulmonary artery rings and dilation of resistance size pulmonary arteries to ATP. The mitochondrial-antioxidant mito-ubiquinone restored the response to ATP in decoy peptide-treated pulmonary arteries. These data indicate that targeting eNOS to mitochondria decreases endothelial oxidative stress and facilitates vasodilation in fetal pulmonary circulation at birth.
authors: Department of Pediatrics, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin; and gkonduri@mcw.edu.
authors: Girija G
authors: GG
authors: Konduri
authors: Department of Pediatrics, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors: Adeleye J
authors: AJ
authors: Afolayan
authors: Department of Pediatrics, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors: Annie
authors: A
authors: Eis
authors: Department of Surgery, Division of Pediatric Surgery, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin.
authors: Kirkwood A
authors: KA
authors: Pritchard
authors: Department of Pediatrics, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors: Ru-Jeng
authors: RJ
authors: Teng
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D005333:Fetus / Q000166:cytology / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism; D011651:Pulmonary Artery / Q000166:cytology / Q000378:metabolism*; D012756:Sheep; D014664:Vasodilation / Q000502:physiology
chemical_list: D018841:HSP90 Heat-Shock Proteins; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D010100:Oxygen
keywords: antioxidants; fetal lung; mitochondrial superoxide; pulmonary circulation; vasodilation