title: Inhibition of CLC-2 chloride channel expression interrupts expansion of fetal lung cysts.
abstract: Normal lung morphogenesis is dependent on chloride-driven fluid transport. The molecular identity of essential fetal lung chloride channel(s) has not been elucidated. CLC-2 is a chloride channel, which is expressed on the apical surface of the developing respiratory epithelium. CLC-2-like pH-dependent chloride secretion exists in fetal airway cells. We used a 14-day fetal rat lung submersion culture model to examine the role of CLC-2 in lung development. In this model, the excised fetal lung continues to grow, secrete fluid, and become progressively cystic in morphology (26). We inhibited CLC-2 expression in these explants, using antisense oligonucleotides, and found that lung cyst morphology was disrupted. In addition, transepithelial voltage (V(t)) of lung explants transfected with antisense CLC-2 was inhibited with V(t) = -1.5 +/- 0.2 mV (means + SE) compared with -3.7 +/- 0.3 mV (means + SE) for mock-transfected controls and -3.3 +/- 0.3 mV (means + SE) for nonsense oligodeoxynucleotide-transfected controls. This suggests that CLC-2 is important for fetal lung fluid production and that it may play a role in normal lung morphogenesis.
authors.affiliation: Department of Pediatrics, University of Maryland at Baltimore, Baltimore, MD 21201, USA. cblaisdell@peds.umaryland.edu
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Blaisdell
authors.forename: Marcelo M
authors.initials: MM
authors.lastname: Morales
authors.forename: Ana Carolina Oliveira
authors.initials: AC
authors.lastname: Andrade
authors.forename: Penelope
authors.initials: P
authors.lastname: Bamford
authors.forename: Michael
authors.initials: M
authors.lastname: Wasicko
authors.forename: Paul
authors.initials: P
authors.lastname: Welling
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000378:metabolism; D000090007:CLC-2 Chloride Channels; D002478:Cells, Cultured; D018118:Chloride Channels / Q000235:genetics* / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008168:Lung / Q000166:cytology / Q000196:embryology* / Q000502:physiology*; D016376:Oligonucleotides, Antisense; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling; D014162:Transfection
chemical_list: D000090007:CLC-2 Chloride Channels; D018118:Chloride Channels; D002712:Chlorides; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger