title: Reactive oxygen species mediate Jak2/Stat3 activation and IL-8 expression in pulmonary epithelial cells stimulated with lipid-associated membrane proteins from Mycoplasma pneumoniae.
abstract: OBJECTIVE
  To investigate the involvement of reactive oxygen species (ROS) in the activation of Janus kinase2 (Jak2)/signal transducers and activators of transcription3 (Stat3), and IL-8 expression in pulmonary epithelial cells stimulated with lipid-associated membrane proteins (LAMP) from Mycoplasma pneumoniae using a known antioxidant, N-acetylcysteine (NAC).
  
  
  METHODS
  Pulmonary epithelial A549 cells were treated with or without NAC in the presence or absence of LAMP. Intracellular ROS levels were detected by fluorescent analysis for fluorescent dichlorofluorescein. mRNA expression of IL-8 was analyzed by reverse transcription-polymerase chain reaction. IL-8 protein in the medium was determined by enzyme-linked immunosorbent assay. Activation of Jak2/Stat3 was determined by the increases in phospho-specific forms of Jak2/Stat3 compared to total forms of Jak2/Stat3 by western blotting. Stat3-DNA binding activity was assessed by electrophoretic mobility shift assay.
  
  
  RESULTS
  LAMP increased the level of ROS, phosphorylation of Jak2/Stat3, Stat3-DNA binding activity, and IL-8 expression in A549 cells, which were inhibited by NAC dose-dependently.
  
  
  CONCLUSIONS
  LAMP of M. pneumoniae induces the production of ROS, Jak2/Stat3 activation, and IL-8 induction in A549 cells. Antioxidants such as NAC may be beneficial for preventing pulmonary inflammation caused by M. pneumoniae.
authors.affiliation: Department of Food and Nutrition, Brain Korea 21 Project, College of Human Ecology, Yonsei University, Seoul, Korea.
authors.forename: Sang Yong
authors.initials: SY
authors.lastname: Choi
authors.forename: Joo Weon
authors.initials: JW
authors.lastname: Lim
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimizu
authors.forename: Koichi
authors.initials: K
authors.lastname: Kuwano
authors.forename: Jung Mogg
authors.initials: JM
authors.lastname: Kim
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Kim
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D001426:Bacterial Proteins / Q000494:pharmacology*; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics*; D053614:Janus Kinase 2 / Q000502:physiology*; D008168:Lung / Q000378:metabolism*; D008565:Membrane Proteins / Q000494:pharmacology*; D009177:Mycoplasma pneumoniae / Q000472:pathogenicity*; D016328:NF-kappa B / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000502:physiology*; D051193:Toll-Like Receptors / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D016209:Interleukin-8; D008565:Membrane Proteins; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D051193:Toll-Like Receptors; D004247:DNA; C507924:JAK2 protein, human; D053614:Janus Kinase 2; D000111:Acetylcysteine