title: Diphenyleneiodonium inhibits the activation of mitogen-activated protein kinases and the expression of monocyte chemoattractant protein-1 in Helicobacter pylori-infected gastric epithelial AGS cells.
abstract: OBJECTIVE
  To investigate whether NADPH oxidase induces MCP-1 expression and the activation of mitogen-activated protein kinases (MAPKs) in H. pylori-infected gastric epithelial cells.
  
  
  METHODS
  H. pylori in Korean isolates, human gastric epithelial AGS cells
  
  
  METHODS
  AGS cells pretreated with or without an NADPH oxidase inhibitor diphenyleneiodonium (DPI) are cultured in the presence of H. pylori at a bacterium/cell ratio of 300:1.
  
  
  METHODS
  Reactive oxygen species (ROS) and MCP-1 were determined by confocal microscopy and enzyme-linked immonosorbent assay. NADPH oxidase activity was measured by lucigenin assay. mRNA expression of MCP-1 was analyzed by reverse transcription-polymerase chain reaction. Levels of MAPKs were assessed by Western blot analysis.
  
  
  RESULTS
  H. pylori induced increase in ROS, NADPH oxidase activity, MCP-1 expression, and the activation of MAPKs including extracellular signal-regulated kinases, p38, and jun N-terminal kinases in AGS cells, which was inhibited by DPI.
  
  
  CONCLUSIONS
  Inhibiting NADPH oxidase by DPI suppresses H. pylori-induced activation of MAPKs and MCP-1 expression in AGS cells.
authors.affiliation: Department of Pharmacology, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, 120-752, Korea.
authors.forename: Soon Ok
authors.initials: SO
authors.lastname: Cho
authors.forename: Joo Weon
authors.initials: JW
authors.lastname: Lim
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Kim
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Kim
mesh_terms: D002460:Cell Line; D018932:Chemokine CCL2 / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000166:cytology*; D005753:Gastric Mucosa / Q000378:metabolism*; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D007249:Inflammation; D007723:Korea; D020935:MAP Kinase Signaling System; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009861:Onium Compounds / Q000494:pharmacology; D017382:Reactive Oxygen Species
chemical_list: D018932:Chemokine CCL2; D016207:Cytokines; D009861:Onium Compounds; D017382:Reactive Oxygen Species; C007517:diphenyleneiodonium; D019255:NADPH Oxidases