title: Duration of gestation and mode of delivery affect the genes of transepithelial sodium transport in pulmonary adaptation.
abstract: BACKGROUND
  Respiratory distress due to inadequate lung liquid clearance is a significant problem in infants delivered late preterm or early term, especially by elective cesarean delivery (CD). Lung liquid clearance depends on epithelial ion transport and in animals is induced by glucocorticoids.
  
  
  OBJECTIVE
  In newborn late preterm and term infants to study airway epithelial gene expressions of epithelial sodium channel (ENaC), and the serum and glucocorticoid-inducible kinase 1 (SGK1), and their association with cortisol, mode of delivery, and gestational age (GA).
  
  
  METHODS
  Infants were delivered at 35(0/7)-41(6/7) weeks. Cortisol in umbilical cord plasma was analyzed with liquid chromatography-tandem mass spectrometry. ENaC and SGK1 mRNAs in airway epithelial cells obtained within 3 h and at 1 day postnatally were quantified with real-time PCR.
  
  
  RESULTS
  ENaC and SGK1 mRNAs were significantly lower in late preterm and early term infants than in those ≥ 39(0/7) weeks. Significant correlations existed between both ENaC and SGK1 and cord cortisol and GA. In term infants, SGK1 mRNA at 1.5 h was higher after vaginal delivery than elective CD.
  
  
  CONCLUSIONS
  In late preterm and early term infants, low expression of ENaC and SGK1 may parallel insufficient lung liquid clearance predisposing to respiratory distress. Lower SGK1 expression after term CD could translate into insufficient sodium and lung liquid absorption. The findings demonstrate a central role for cortisol in regulation of ENaC and potentially perinatal sodium and lung liquid clearance.
authors.affiliation: Children's Hospital, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Janér
authors.forename: Olli M
authors.initials: OM
authors.lastname: Pitkänen
authors.forename: Liina
authors.initials: L
authors.lastname: Süvari
authors.forename: Ursula
authors.initials: U
authors.lastname: Turpeinen
authors.forename: Anniina
authors.initials: A
authors.lastname: Palojärvi
authors.forename: Sture
authors.initials: S
authors.lastname: Andersson
authors.forename: Otto
authors.initials: O
authors.lastname: Helve
mesh_terms: D000222:Adaptation, Physiological; D001692:Biological Transport; D002585:Cesarean Section / Q000009:adverse effects*; D004847:Epithelial Cells / Q000378:metabolism; D053503:Epithelial Sodium Channels / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D017874:Immediate-Early Proteins / Q000378:metabolism*; D007231:Infant, Newborn; D008168:Lung / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008297:Male; D011247:Pregnancy; D011379:Prognosis; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012127:Respiratory Distress Syndrome, Newborn / Q000209:etiology / Q000378:metabolism; D000099184:Serum-Glucocorticoid Regulated Kinases
chemical_list: D053503:Epithelial Sodium Channels; D006854:Hydrocortisone; D017874:Immediate-Early Proteins; D017346:Protein Serine-Threonine Kinases; D000099184:Serum-Glucocorticoid Regulated Kinases