title: Expression of Sproutys and SPREDs is decreased during lung branching morphogenesis in nitrofen-induced pulmonary hypoplasia.
abstract: OBJECTIVE
  Pulmonary hypoplasia (PH) is a life-threatening condition associated with congenital diaphragmatic hernia (CDH), characterized by defective lung development. Sproutys and Sprouty-related proteins (SPREDs) play a key role in lung branching morphogenesis through modification of epithelial-mesenchymal interactions. During the pseudoglandular stage, Sproutys are highly expressed in distal airway epithelium, while SPREDs within the surrounding mesenchyme. Sprouty2/4 knockouts show severe defects in branching morphogenesis with reduced number of distal airways. SPRED-1 and SPRED-2 are strongly expressed in regions of new airway formation, highlighting their important function in branching pattern. We hypothesized that expression of Sprouty2, Sprouty4, SPRED-1 and SPRED-2 is decreased during lung branching morphogenesis in nitrofen-induced PH.
  
  
  METHODS
  Timed-pregnant rats received either nitrofen or vehicle on E9.5. On E15.5 (n = 16), fetal lungs were micro-dissected and divided into controls and PH, while on E18.5 (n = 24) groups were: control, PH without CDH [CDH(-)], and PH with CDH [CDH(+)]. Pulmonary gene expression levels of Sprouty2, Sprouty4, SPRED-1 and SPRED-2 were analyzed by qRT-PCR. Immunohistochemistry was performed to evaluate protein expression/distribution.
  
  
  RESULTS
  On E18.5, relative mRNA expression levels of Sprouty2, Sprouty4, SPRED-1 and SPRED-2 were significantly decreased in CDH(-) and CDH(+) groups compared to controls (P < 0.05). Immunoreactivity of Sprouty2, Sprouty4, SPRED-1 and SPRED-2 was markedly diminished on E18.5 in nitrofen-induced PH.
  
  
  CONCLUSIONS
  Decreased expression of Sproutys and SPREDs during the terminal pseudoglandular stage may disrupt lung branching morphogenesis by interfering with epithelial-mesenchymal interactions contributing to PH.
authors: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin 12, Ireland.
authors: Florian
authors: F
authors: Friedmacher
authors: Jan-Hendrik
authors: JH
authors: Gosemann
authors: Naho
authors: N
authors: Fujiwara
authors: Hiromizu
authors: H
authors: Takahashi
authors: Alejandro
authors: A
authors: Hofmann
authors: Prem
authors: P
authors: Puri
mesh_terms: D000015:Abnormalities, Multiple / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005346:Fibroblast Growth Factors / Q000037:antagonists & inhibitors; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D008168:Lung / Q000002:abnormalities* / Q000196:embryology / Q000378:metabolism; D008171:Lung Diseases / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D020935:MAP Kinase Signaling System; D009024:Morphogenesis / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D010647:Phenyl Ethers / Q000633:toxicity; D011247:Pregnancy; D011270:Pregnancy, Animal; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D009419:Nerve Tissue Proteins; D010647:Phenyl Ethers; D012333:RNA, Messenger; D012097:Repressor Proteins; C499021:Spred1 protein, rat; C433764:Spred2 protein, mouse; C404992:Spry2 protein, rat; C499037:Spry4 protein, mouse; D005346:Fibroblast Growth Factors; C007350:nitrofen
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