title: Imbalance of caveolin-1 and eNOS expression in the pulmonary vasculature of experimental diaphragmatic hernia.
abstract: BACKGROUND
  Caveolin-1 (Cav-1) exerts major regulatory functions on intracellular signaling pathways originating at the plasma membrane. Cav-1 is a key regulator in adverse lung remodeling and the development of pulmonary hypertension (PH) regulating vasomotor tone through its ability to reduce nitric oxide (NO) production. This low-output endothelial NO synthase (eNOS) derived NO maintains normal pulmonary vascular homeostasis. Cav-1 deficiency leads to increased bioavailability of NO, which has been linked to increased nitrosative stress. Inhibition of eNOS reduced oxidant production and reversed PH, supporting the concept that Cav-1 regulation of eNOS activity is crucial to endothelial homeostasis in lungs. We designed this study to investigate the hypothesis that expression of Cav-1 is downregulated while eNOS expression is upregulated by the pulmonary endothelium in the nitrofen-induced congenital diaphragmatic hernia (CDH).
  
  
  METHODS
  Pregnant rats were exposed to nitrofen or vehicle on day 9.5 (D9.5). Fetuses were sacrificed on D21 and divided into nitrofen and control groups. Quantitative real-time polymerase chain reaction, Western blotting, and confocal immunofluorescence were performed to determine pulmonary gene expression levels and protein expression of Cav-1 and eNOS.
  
  
  RESULTS
  Pulmonary Cav-1 gene expression levels were significantly decreased, while eNOS gene expression was significantly increased in nitrofen-induced CDH(+). Western blotting and confocal microscopy revealed decreased pulmonary Cav-1 protein expression, while eNOS protein expression was increased in CDH(+) compared to controls.
  
  
  CONCLUSIONS
  The striking evidence of markedly decreased gene and protein expression of Cav-1 with concurrently increased eNOS gene and protein expression in the pulmonary vasculature suggests that activation of eNOS secondary to Cav-1 deficiency may play an important role in the pathogenesis of PH in the nitrofen-induced CDH.
authors: National Children's Research Centre, Our Lady's Children's Hospital, Gate 5, Dublin, Ireland.
authors: Alejandro
authors: A
authors: Hofmann
authors: Jan-Hendrik
authors: JH
authors: Gosemann
authors: Toshiaki
authors: T
authors: Takahashi
authors: Florian
authors: F
authors: Friedmacher
authors: Johannes W
authors: JW
authors: Duess
authors: Prem
authors: P
authors: Puri
mesh_terms: D000015:Abnormalities, Multiple / Q000139:chemically induced; D000818:Animals; D051242:Caveolin 1 / Q000096:biosynthesis*; D015536:Down-Regulation; D004789:Enzyme Activation / Q000235:genetics; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D018507:Gene Expression Regulation, Developmental; D006540:Herbicides / Q000494:pharmacology; D065630:Hernias, Diaphragmatic, Congenital / Q000139:chemically induced* / Q000235:genetics; D006976:Hypertension, Pulmonary / Q000139:chemically induced; D008168:Lung / Q000002:abnormalities / Q000098:blood supply* / Q000378:metabolism; D008171:Lung Diseases / Q000139:chemically induced; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000096:biosynthesis* / Q000378:metabolism; D010647:Phenyl Ethers / Q000494:pharmacology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D015854:Up-Regulation
chemical_list: D051242:Caveolin 1; D006540:Herbicides; D010647:Phenyl Ethers; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; C007350:nitrofen
keywords: caveolin-1; congenital diaphragmatic hernia; eNOS; nitrofen; pulmonary hypertension