title: [Role of Toll-like receptor 4 in hyperoxia-exposed microglia injury].
abstract: OBJECTIVE
  To explore the role of Toll-like receptor 4 (TLR4) in the injury of microglia exposed to hyperoxia.
  
  
  METHODS
  N9 microglia (TLR4 wild type) and EOC20 microglia (TLR4 knock-out type) were exposed to 950 mL/L high oxygen respectively for different time periods to establish the high oxygen cell injury model. Expression of TLR4  mRNA and protein levels were detected by RT-PCR and Western blotting,  respectively. After intervention with the antioxidant NAC (N-acetyl-L-cysteine,  N-acetyl half pathway of ammonia),  we detected the activity of reactive oxygen species (ROS),  NF-κB and the expression of TNF-α in cellular supernatant of N9 and EOC20 microglia exposed to hyperoxia for 2,  6 h.
  
  
  RESULTS
  Expression of TLR4 mRNA in N9 microglia exposed to hyperoxia increased in a time-dependent manner,  meanwhile,  activity of ROS,  NF-κB and expression of TNF-α in microglia exposed to hyperoxia significantly increased (P<0.05),  while decreased (P<0.05) after intervention with the antioxidant NAC. The activity of ROS,  NF-κB and the expression of TNF-α were lower in EOC20 microglia than in N9 microglia after exposed to hyperoxia for different time periods (P<0.05).
  
  
  CONCLUSIONS
  TLR4 involves in the regulation of forming ROS and the release of inflammatory markers on microglia after exposed to hyperoxia.
authors.affiliation: Department of Anesthesiology, Chongqing Medical University, Chongqing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Pu
authors.initials: P
authors.lastname: Jiang
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D018496:Hyperoxia / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D008813:Mice, Inbred ICR; D017628:Microglia / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D017382:Reactive Oxygen Species / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D016328:NF-kappa B; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D000111:Acetylcysteine