title: Prenatal retinoic acid increases lipofibroblast expression in hypoplastic rat lungs with experimental congenital diaphragmatic hernia.
abstract: OBJECTIVE
  Prenatal administration of all-trans retinoic acid (ATRA) has been shown to stimulate alveolarization in nitrofen-induced pulmonary hypoplasia (PH) associated with congenital diaphragmatic hernia (CDH). Lipid-containing interstitial lipofibroblasts (LIFs), characterized by adipocyte differentiation-related protein (ADRP), play a critical role in alveolar development by coordinating lipid homeostasis. Previous studies have demonstrated that ATRA positively affects LIF expression in developing lungs. We hypothesized that pulmonary LIF expression is increased after prenatal ATRA treatment in the nitrofen model of CDH-associated PH.
  
  
  METHODS
  Timed-pregnant rats were treated with nitrofen or vehicle on E9.5, followed by injection of ATRA or placebo on E18.5, E19.5, and E20.5. Fetal lungs were dissected on E21.5 and divided into Control+Placebo, Control+ATRA, Nitrofen+Placebo, and Nitrofen+ATRA. Pulmonary gene expression levels of ADRP were analyzed by quantitative real-time polymerase chain reaction, and LIF expression was investigated by ADRP immunohistochemistry, oil-red-O-, and immunofluorescence-double-staining.
  
  
  RESULTS
  Relative mRNA expression of pulmonary ADRP was significantly increased in Nitrofen+ATRA compared to Nitrofen+Placebo (0.31±0.02 vs. 0.08±0.01; P<0.0001). ADRP immunoreactivity and oil-red-O-staining were markedly increased in alveolar interstitium of Nitrofen+ATRA compared to Nitrofen+Placebo. Immunofluorescence-double-staining confirmed markedly increased LIF expression in alveolar walls of Nitrofen+ATRA compared to Nitrofen+Placebo.
  
  
  CONCLUSIONS
  Increased LIF expression after prenatal treatment with ATRA in nitrofen-induced PH suggests that ATRA may have a therapeutic potential in attenuating CDH-associated PH by stimulating alveolar development.
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland; Department of Pediatric and Adolescent Surgery, Medical University Graz, Graz, Austria.
authors.forename: Florian
authors.initials: F
authors.lastname: Friedmacher
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland.
authors.forename: Naho
authors.initials: N
authors.lastname: Fujiwara
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland.
authors.forename: Alejandro D
authors.initials: AD
authors.lastname: Hofmann
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland.
authors.forename: Hiromizu
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland.
authors.forename: Luis A J
authors.initials: LA
authors.lastname: Alvarez
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland.
authors.forename: Jan-Hendrik
authors.initials: JH
authors.lastname: Gosemann
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland; Conway Institute of Biomolecular and Biomedical Research, School of Medicine and Medical Science, University College Dublin, Dublin, Ireland. Electronic address: prem.puri@ncrc.ie.
authors.forename: Prem
authors.initials: P
authors.lastname: Puri
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D065630:Hernias, Diaphragmatic, Congenital / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D007150:Immunohistochemistry; D008168:Lung / Q000002:abnormalities* / Q000378:metabolism; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D038081:Organogenesis / Q000187:drug effects; D000070780:Perilipin-2; 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; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014212:Tretinoin / Q000494:pharmacology*; D015854:Up-Regulation
chemical_list: D008565:Membrane Proteins; D000070780:Perilipin-2; D010647:Phenyl Ethers; C000602984:Plin2 protein, rat; D012333:RNA, Messenger; D014212:Tretinoin; C007350:nitrofen
keywords: Adipocyte differentiation-related protein; Congenital diaphragmatic hernia; Lipofibroblast; Pulmonary hypoplasia; Retinoic acid