title: Spatiotemporal alterations in Sprouty-2 expression and tyrosine phosphorylation in nitrofen-induced pulmonary hypoplasia.
abstract: OBJECTIVE
  Pulmonary hypoplasia (PH) is a life-threatening condition of newborns presenting with congenital diaphragmatic hernia (CDH). Sprouty-2 functions as a key regulator of fibroblast growth factor receptor (FGFR) signalling in developing foetal lungs. It has been reported that FGFR-mediated alveolarization is disrupted in nitrofen-induced PH. Sprouty-2 knockouts show severe defects in lung morphogenesis similar to nitrofen-induced PH. Upon FGFR stimulation, Sprouty-2 is tyrosine-phosphorylated, which is essential for its physiological function during foetal lung development. We hypothesized that Sprouty-2 expression and tyrosine phosphorylation are altered in nitrofen-induced PH.
  
  
  METHODS
  Time-pregnant rats received either nitrofen or vehicle on gestation day 9 (D9). Foetal lungs were dissected on D18 and D21. Pulmonary Sprouty-2 gene and protein expression levels were analyzed by qRT-PCR, Western blotting and immunohistochemical staining.
  
  
  RESULTS
  Relative mRNA expression of Sprouty-2 was significantly decreased in hypoplastic lungs without CDH (0.1050±0.01 vs. 0.3125±0.01; P<.0001) and with CDH (0.1671±0.01 vs. 0.3125±0.01; P<.0001) compared to controls on D18. Protein levels of Sprouty-2 were markedly decreased in hypoplastic lungs on D18 with decreased tyrosine phosphorylation levels on D18 and D21 detected at the molecular weight of Sprouty-2 consistent with Sprouty-2 tyrosine phosphorylation. Sprouty-2 immunoreactivity was markedly decreased in hypoplastic lungs on D18 and D21.
  
  
  CONCLUSIONS
  Spatiotemporal alterations in pulmonary Sprouty-2 expression and tyrosine phosphorylation during the late stages of foetal lung development may interfere with FGFR-mediated alveolarization in nitrofen-induced PH.
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland.
authors.forename: Florian
authors.initials: F
authors.lastname: Friedmacher
authors.forename: Jan-Hendrik
authors.initials: JH
authors.lastname: Gosemann
authors.forename: Naho
authors.initials: N
authors.lastname: Fujiwara
authors.forename: Luis A J
authors.initials: LA
authors.lastname: Alvarez
authors.forename: Nicolae
authors.initials: N
authors.lastname: Corcionivoschi
authors.forename: Prem
authors.initials: P
authors.lastname: Puri
mesh_terms: D000015:Abnormalities, Multiple / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D005865:Gestational Age; D006548:Hernia, Diaphragmatic / Q000139:chemically induced / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D065630:Hernias, Diaphragmatic, Congenital; D008168:Lung / Q000002:abnormalities* / Q000196:embryology* / Q000378:metabolism; D008171:Lung Diseases / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D010647:Phenyl Ethers / Q000633:toxicity; D019000:Phosphotyrosine / Q000032:analysis; D011247:Pregnancy; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000473:pathology; D012333:RNA, Messenger / Q000096:biosynthesis; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017468:Receptors, Fibroblast Growth Factor / Q000502:physiology; D013047:Specific Pathogen-Free Organisms
chemical_list: D009419:Nerve Tissue Proteins; D010647:Phenyl Ethers; D012333:RNA, Messenger; D017468:Receptors, Fibroblast Growth Factor; C404992:Spry2 protein, rat; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases; C007350:nitrofen
keywords: Foetal lung development; Nitrofen; Pulmonary hypoplasia; Sprouty-2; Tyrosine phosphorylation