title: Downregulation of KCNQ5 expression in the rat pulmonary vasculature of nitrofen-induced congenital diaphragmatic hernia.
abstract: OBJECTIVE
  Pulmonary hypertension (PH) is a common complication of congenital diaphragmatic hernia (CDH). Voltage-gated potassium channels KCNQ1, KCNQ4, and KCNQ5 are expressed by rodent pulmonary artery smooth muscle cells, contributing to their vascular tone. We hypothesized that KCNQ1, KCNQ4, and KCNQ5 expression is altered in the pulmonary vasculature of nitrofen-induced CDH rats.
  
  
  METHODS
  After ethical approval (REC913b), time-pregnant rats received nitrofen or vehicle on gestational day (D)9. D21 fetuses were divided into CDH and control group (n=22). QRT-PCR and western blotting were performed to determine gene and protein expression of KCNQ1, KCNQ4, and KCNQ5. Confocal microscopy was used to detect these proteins in the pulmonary vasculature.
  
  
  RESULTS
  Relative mRNA level of KCNQ5 (p=0.025) was significantly downregulated in CDH lungs compared to controls. KCNQ1 (p=0.052) and KCNQ4 (p=0.574) expression was not altered. Western blotting confirmed the decreased pulmonary KCNQ5 protein expression in CDH lungs. Confocal-microscopy detected a markedly diminished KCNQ5 expression in pulmonary vasculature of CDH fetuses.
  
  
  CONCLUSIONS
  Downregulated pulmonary expression of KCNQ5 in CDH lungs suggests that this potassium channel may play an important role in the development of PH in this model. KCNQ5 channel activator drugs may be a potential therapeutic target for the treatment of PH in CDH.
  
  
  METHODS
  2b (Centre for Evidence-Based Medicine, Oxford).
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital Crumlin, Gate 5, Dublin 12, Dublin, Ireland.
authors.forename: Julia
authors.initials: J
authors.lastname: Zimmer
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital Crumlin, Gate 5, Dublin 12, Dublin, Ireland.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Department of Pediatric Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
authors.forename: Alejandro D
authors.initials: AD
authors.lastname: Hofmann
authors.affiliation: National Children's Research Centre, Our Lady's Children's Hospital Crumlin, Gate 5, Dublin 12, Dublin, Ireland; School of Medicine and Medical Science and Conway Institute of Biomedical Research, University College Dublin, Belfield, Dublin 4, Dublin, Ireland. Electronic address: prem.puri@ncrc.ie.
authors.forename: Prem
authors.initials: P
authors.lastname: Puri
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D016022:Case-Control Studies; D015536:Down-Regulation; D005260:Female; D065630:Hernias, Diaphragmatic, Congenital / Q000139:chemically induced / Q000150:complications* / Q000378:metabolism; D006976:Hypertension, Pulmonary / Q000209:etiology* / Q000378:metabolism; D051656:KCNQ Potassium Channels / Q000378:metabolism*; D051657:KCNQ1 Potassium Channel / Q000378:metabolism*; D010647:Phenyl Ethers; D011247:Pregnancy; D011651:Pulmonary Artery / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D015415:Biomarkers; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; C496911:Kcnq1 protein, rat; C492166:Kcnq4 protein, rat; C501028:Kcnq5 protein, rat; D010647:Phenyl Ethers; C007350:nitrofen
keywords: Congenital diaphragmatic hernia; KCNQ5; Nitrofen; Pulmonary hypertension; Voltage-gated potassium channels