Nogo-B Receptor Modulates Pulmonary Artery Smooth Muscle Cell Function in Developing Lungs. Am J Respir Cell Mol Biol 2016 Jun;54(6):892-900
Date
12/15/2015Pubmed ID
26652754Pubmed Central ID
PMC4942214DOI
10.1165/rcmb.2015-0068OCScopus ID
2-s2.0-84988841193 (requires institutional sign-in at Scopus site) 8 CitationsAbstract
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.
Author List
Tadokoro KS, Rana U, Jing X, Konduri GG, Miao QR, Teng RJAuthors
Xi-Gang Jing Research Scientist I in the Pediatrics department at Medical College of WisconsinGirija Ganesh Konduri MD Chief, Professor in the Pediatrics department at Medical College of Wisconsin
Ru-Jeng Teng MD Professor in the Pediatrics department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsCatalase
Cell Movement
Cell Proliferation
Endoplasmic Reticulum Stress
Fetus
Gene Knockdown Techniques
Hypertension, Pulmonary
Lung
Mitogen-Activated Protein Kinases
Myocytes, Smooth Muscle
Phosphorylation
Pulmonary Alveoli
Pulmonary Artery
Reactive Oxygen Species
Receptors, Cell Surface
Sheep
Superoxide Dismutase
Wound Healing