title: Nogo-B Receptor Modulates Pulmonary Artery Smooth Muscle Cell Function in Developing Lungs.
abstract: Nogo-B and its receptor (NgBR) are involved in blood vessel growth in developing lungs, but their role in pulmonary artery smooth muscle cell (PASMC) growth is unknown. We hypothesized that NgBR regulates growth of PASMCs by modulating the function of endoplasmic reticulum (ER) and formation of reactive oxygen species (ROS). In utero constriction of the ductus arteriosus created pulmonary hypertension in fetal lambs (hypertensive fetal lamb [HTFL]). PASMCs isolated 8 days after surgery were assessed for the alteration of protein levels by immunoblots and ROS formation by dihydroethidium and Cell ROX deep red fluorescence. NgBR small interfering RNA and plasmid DNA were used to manipulate NgBR levels. Proliferation and wound healing were assessed by cell counts and scratch recovery assay, respectively. Acute ER stress was induced by tunicamycin. Differences of mitogen-activated protein kinase and Akt pathway activation in HTFL versus control PASMCs were evaluated. Results showed that HTFL PASMCs had decreased NgBR levels and increased proliferation, wound healing, ER stress, and ROS formation compared with controls. Knockdown of NgBR in control PASMCs generated a phenotype similar to HTFL, and overexpression in HTFL restored the defective phenotype to control. Decreased NgBR levels were associated with increased ROS formation in HTFL PASMCs. Subsequently, scavenging ROS decreased proliferation and wound healing. Mechanistically, ROS formation decreases NgBR expression, which induces ER stress. This leads to extracellular signal-regulated kinase pathway activation and PASMC phenotype alteration. Our data suggest that decreased NgBR expression in pulmonary hypertension of the newborn contributes to increased PASMC proliferation and oxidative stress, which lead to the pathogenesis of lung injury.
authors.affiliation: Departments of 1 Pediatrics.
authors.forename: Kent S
authors.initials: KS
authors.lastname: Tadokoro
authors.affiliation: 2 Surgery, and.|3 Pathology.|4 Children's Research Institute and Cardiovascular Research Center, and.
authors.forename: Ujala
authors.initials: U
authors.lastname: Rana
authors.affiliation: Departments of 1 Pediatrics.|4 Children's Research Institute and Cardiovascular Research Center, and.
authors.forename: Xigang
authors.initials: X
authors.lastname: Jing
authors.affiliation: Departments of 1 Pediatrics.|4 Children's Research Institute and Cardiovascular Research Center, and.|5 Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: G Ganesh
authors.initials: GG
authors.lastname: Konduri
authors.affiliation: 2 Surgery, and.|3 Pathology.|4 Children's Research Institute and Cardiovascular Research Center, and.
authors.forename: Qing R
authors.initials: QR
authors.lastname: Miao
authors.affiliation: Departments of 1 Pediatrics.|4 Children's Research Institute and Cardiovascular Research Center, and.|5 Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Ru-Jeng
authors.initials: RJ
authors.lastname: Teng
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D002465:Cell Movement; D049109:Cell Proliferation; D059865:Endoplasmic Reticulum Stress; D005333:Fetus / Q000473:pathology; D055785:Gene Knockdown Techniques; D006976:Hypertension, Pulmonary / Q000378:metabolism / Q000473:pathology; D008168:Lung / Q000196:embryology* / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation; D011650:Pulmonary Alveoli / Q000378:metabolism / Q000473:pathology; D011651:Pulmonary Artery / Q000473:pathology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012756:Sheep; D013482:Superoxide Dismutase / Q000378:metabolism; D014945:Wound Healing
chemical_list: D017382:Reactive Oxygen Species; D011956:Receptors, Cell Surface; D002374:Catalase; D013482:Superoxide Dismutase; D020928:Mitogen-Activated Protein Kinases
keywords: endoplasmic reticulum stress; extracellular signal–regulated kinase pathway; persistent pulmonary hypertension of the newborn; pulmonary artery smooth muscle cell; reactive oxygen species