title: Evidence for decreased lipofibroblast expression in hypoplastic rat lungs with congenital diaphragmatic hernia.
abstract: OBJECTIVE
  Pulmonary hypoplasia (PH) is a serious condition in newborns with congenital diaphragmatic hernia (CDH). Lipid-containing interstitial fibroblasts (LIFs) play an essential role in fetal lung maturation by stimulating alveolarization and lipid homeostasis. In rodents, LIFs are first evident during the canalicular phase of lung development with a significant increase over the last 4 days of gestation. Adipocyte differentiation-related protein (ADRP), a functional lipogenic molecular marker characterizing LIFs, is highly expressed in fetal lungs during this critical time period. We hypothesized that LIF expression in hypoplastic rat lungs is decreased in the nitrofen-induced CDH model, which is accompanied by reduced alveolar ADRP expression and lipid content.
  
  
  METHODS
  On embryonic day 9.5 (E9.5), time-mated rats received either nitrofen or vehicle. Fetuses were sacrificed on selected time points E18.5 and E21.5, and dissected lungs were divided into controls and CDH-associated PH. Pulmonary gene expression levels of ADRP were determined by quantitative real-time polymerase chain reaction. ADRP immunohistochemistry and oil red O staining were used to assess pulmonary protein expression and lipid content. Immunofluorescence double staining for alpha smooth muscle actin, which is known to be absent in LIFs, and lipid droplets was performed to evaluate the pulmonary expression of this specific subset of fibroblasts.
  
  
  RESULTS
  Relative mRNA expression of ADRP was significantly reduced in lungs of CDH-associated PH on E18.5 and E21.5 compared to controls. ADRP immunoreactivity and lipid staining were markedly diminished in alveolar mesenchymal cells of CDH-associated PH on E18.5 and E21.5 compared to controls. Confocal laser scanning microscopy demonstrated markedly decreased LIF expression in alveolar interstitium of CDH-associated PH on E18.5 and E21.5 compared to controls.
  
  
  CONCLUSIONS
  Decreased pulmonary LIF expression during late gestation suggests impaired LIF functioning in the nitrofen-induced CDH model, which may cause disruption in fetal alveolarization and lipid homeostasis, and thus contribute to the development of PH.
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin 12, Ireland, florian.friedmacher@gmx.de.
authors.forename: Florian
authors.initials: F
authors.lastname: Friedmacher
authors.forename: Naho
authors.initials: N
authors.lastname: Fujiwara
authors.forename: Alejandro Daniel
authors.initials: AD
authors.lastname: Hofmann
authors.forename: Hiromizu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Jan-Hendrik
authors.initials: JH
authors.lastname: Gosemann
authors.forename: Prem
authors.initials: P
authors.lastname: Puri
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D047109:Fetal Development / Q000235:genetics; D005347:Fibroblasts / Q000378:metabolism*; D015870:Gene Expression / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D065630:Hernias, Diaphragmatic, Congenital / Q000235:genetics*; D008168:Lung / Q000002:abnormalities* / Q000196:embryology* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics*; D038081:Organogenesis / Q000235:genetics; D000070780:Perilipin-2; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods
chemical_list: D008565:Membrane Proteins; D000070780:Perilipin-2; C000602984:Plin2 protein, rat