title: Role of protease-activated receptor-2 on cell death and DNA fragmentation in Helicobacter pylori-infected gastric epithelial cells.
abstract: BACKGROUND
  Helicobacter pylori (H. pylori) infection is associated with chronic gastritis, peptic ulceration and gastric carcinoma. Protease-activated receptor-2 (PAR-2), which is activated by trypsin, induced the activation of mitogen-activated protein kinases (MAPK), cell proliferation and apoptosis in several cells. Previously, we found that H. pylori induces the expression of PAR-2, which mediates the expression of adhesion molecules integrins in gastric epithelial cells. In the present study, the role of PAR-2 on H. pylori-induced cell death was investigated by determining cell viability, DNA fragmentation, and the activation of MAPK in gastric epithelial AGS cells.
  
  
  METHODS
  AGS cells were cultured in the presence of H. pylori transfected with PAR-2 antisense (AS) oligonucleotide (ODN) or treated with a soybean trypsin inhibitor (SBTI). Viable cells and DNA fragmentation were determined by trypan blue exclusion assay and the amount of oligonucleosome-bound DNA, respectively. The activation of MAPK such as extracellular signal-regulated kinases (ERK), p38, and c-Jun N-terminal kinases (JNK), was assessed by Western blotting for phospho-specific forms of MAPK.
  
  
  RESULTS
  H. pylori-induced cell death and DNA fragmentation augmented in the cells transfected with PAR-2 AS ODN or treated with SBTI. The activation of MAPK, induced by H. pylori, were suppressed by transfection with PAR-2 AS ODN or treatment with SBTI.
  
  
  CONCLUSIONS
  PAR-2, whose expression is induced by H. pylori, may prevent cell death and DNA fragmentation with the activation of MAPK in gastric epithelial cells.
authors.affiliation: Department of Food and Nutrition, Brain Korea 21 Project, College of Human Ecology, Yonsei University, Seoul 120-749, Korea.
authors.forename: Joo Weon
authors.initials: JW
authors.lastname: Lim
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Kim
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D016923:Cell Death / Q000502:physiology*; D002478:Cells, Cultured; D053938:DNA Fragmentation; D017931:DNA Primers; D004789:Enzyme Activation; D005753:Gastric Mucosa / Q000201:enzymology / Q000382:microbiology / Q000473:pathology*; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D044464:Receptor, PAR-2 / Q000502:physiology*; D014361:Trypsin Inhibitors / Q000494:pharmacology
chemical_list: D017931:DNA Primers; D044464:Receptor, PAR-2; D014361:Trypsin Inhibitors; D020928:Mitogen-Activated Protein Kinases