title: With-No-Lysine Kinase 4 Mediates Alveolar Fluid Regulation in Hyperoxia-Induced Lung Injury.
abstract: OBJECTIVE
  To investigate mechanisms involved in the regulation of epithelial ion channels and alveolar fluid clearance in hyperoxia-induced lung injury.
  
  
  METHODS
  Laboratory animal experiments.
  
  
  METHODS
  Animal care facility procedure room in a medical center.
  
  
  METHODS
  Wild-type, STE20/SPS1-related proline/alanine-rich kinase knockout (SPAK(-/-)), and with-no-lysine kinase 4 knockin (WNK4(D561A/+)) mice.
  
  
  METHODS
  Mice were exposed to room air or 95% hyperoxia for 60 hours.
  
  
  RESULTS
  Exposure to hyperoxia for 60 hours increased the lung expression of with-no-lysine kinase 4 and led to STE20/SPS1-related proline/alanine-rich kinase and sodium-potassium-chloride cotransporter phosphorylation, which resulted in the suppression of alveolar fluid clearance and increase of lung edema. WNK4(D561A/+) mice at the baseline presented an abundance of epithelium sodium channel and high levels of STE20/SPS1-related proline/alanine-rich kinase and sodium-potassium-chloride cotransporter phosphorylation. Compared with the wild-type group, hyperoxia caused greater epithelium sodium channel expression in WNK4(D561A/+) mice, but no significant difference in STE20/SPS1-related proline/alanine-rich kinase and sodium-potassium-chloride cotransporter phosphorylation. The functional inactivation of sodium-potassium-chloride cotransporter by gene knockout in SPAK(-/-) mice yielded a lower severity of lung injury and longer animal survival, whereas constitutive expression of with-no-lysine kinase 4 exacerbated the hyperoxia-induced lung injury. Pharmacologic inhibition of sodium-potassium-chloride cotransporter by inhaled furosemide improved animal survival in WNK4(D561A/+) mice. By contrast, inhibition of epithelium sodium channel exacerbated the hyperoxia-induced lung injury and animal death.
  
  
  CONCLUSIONS
  With-no-lysine kinase 4 plays a crucial role in the regulation of epithelial ion channels and alveolar fluid clearance, mainly via phosphorylation and activation of STE20/SPS1-related proline/alanine-rich kinase and sodium-potassium-chloride cotransporter.
authors.affiliation: 1Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan. 2Graduate Institute of Aerospace and Undersea Medicine, National Defense Medical Center, Taipei, Taiwan. 3Department of Critical Care Medicine, Landseed Hospital, Taoyuan, Taiwan. 4Division of Pulmonary and Critical care, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. 5Division of Nephrology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. 6Department of Nephrology, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Hsueh-Ju
authors.initials: HJ
authors.lastname: Lin
authors.forename: Chin-Pyng
authors.initials: CP
authors.lastname: Wu
authors.forename: Chung-Kan
authors.initials: CK
authors.lastname: Peng
authors.forename: Shih-Hua
authors.initials: SH
authors.lastname: Lin
authors.forename: Shinich
authors.initials: S
authors.lastname: Uchida
authors.forename: Sung-Sen
authors.initials: SS
authors.lastname: Yang
authors.forename: Kun-Lun
authors.initials: KL
authors.lastname: Huang
mesh_terms: D000818:Animals; D018496:Hyperoxia / Q000150:complications / Q000201:enzymology* / Q000235:genetics / Q000503:physiopathology*; D055370:Lung Injury / Q000201:enzymology* / Q000209:etiology / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D051379:Mice; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*
chemical_list: C499024:Prkwnk4 protein, mouse; C116037:PAS domain kinases; D017346:Protein Serine-Threonine Kinases