title: [Protective effects of mitochondrial ATP-sensitive potassium channel on A549 cell apoptosis induced by hyperoxia].
abstract: OBJECTIVE
  To explore the protective effects of mitochondrial ATP-sensitive potassium channel opener diazoxide on hyperoxia-induced apoptosis of type II alveolar epithelial cells (A549 cells) and possible mechanisms.
  
  
  METHODS
  A549 cells were cultured in vitro and divided randomly into control, hyperoxia and diazoxide group. The hyperoxia group was exposed to a mixture of O2 (900 mL/L) and CO2 (50 mL/L) for 10 minutes, then cultured in a closed environment. The diazoxide group was pretreated with diazoxide of 100 μmol/L for 24 hrs before hyperxia induction. The cells were collected 12, 24 and 48 hrs after culture. The morphologic changes of A549 cells were observed under an inverted microscope. A549 cell apoptosis was detected by flow cytometry. The expression of Omi/HtrA2 in the endochylema of A549 cells was determined by immunohistochemistry.
  
  
  RESULTS
  A549 cells were damaged and the changes in morphology of the cells were serious in the hyperoxia group. The apoptosis rate of A549 cells and the expression of Omi/HtrA2 in the endochylema increased in the hyperoxia group compared with the control group (P<0.05). The growth and the morphology of A549 cells were greatly improved and the cell injuries were obviously alleviated in the diazoxide group. The expression of Omi/HtrA2 in the endochylema and the apoptosis rate of A549 cells were significantly reduced in the diazoxide group compared with the hyperoxia group (P<0.05).
  
  
  CONCLUSIONS
  Diazoxide as an opener of mitoKATP channel can reduce the expression of Omi/HtrA2 and the apoptosis rate of A549 cells, thus relieves the injury of A549 cells induced by hyperoxia.
authors.affiliation: Department of Neonatology, Affiliated Hospital of Luzhou Medical College, Luzhou, Sichuan 646000, China.
authors.forename: Xin-Yan
authors.initials: XY
authors.lastname: Zou
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Dong
authors.forename: Dan
authors.initials: D
authors.lastname: Zou
authors.forename: Qing-Ping
authors.initials: QP
authors.lastname: Li
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Lei
authors.forename: Xue-Song
authors.initials: XS
authors.lastname: Zhai
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
mesh_terms: D017209:Apoptosis; D002478:Cells, Cultured; D019610:Cytoprotection; D003981:Diazoxide / Q000494:pharmacology; D000074923:High-Temperature Requirement A Serine Peptidase 2; D006801:Humans; D018496:Hyperoxia / Q000150:complications*; D008168:Lung / Q000473:pathology*; D024101:Mitochondrial Proteins / Q000032:analysis; D015221:Potassium Channels / Q000502:physiology*; D012697:Serine Endopeptidases / Q000032:analysis
chemical_list: D024101:Mitochondrial Proteins; D015221:Potassium Channels; C117780:mitochondrial K(ATP) channel; D012697:Serine Endopeptidases; C000615914:HTRA2 protein, human; D000074923:High-Temperature Requirement A Serine Peptidase 2; D003981:Diazoxide