title: Peroxiredoxin I protects gastric mucosa from oxidative injury induced by H. pylori infection.
abstract: OBJECTIVE
  Helicobacter pylori (H. pylori) infection enhances the production of reactive oxygen species and peroxynitrite, thereby resulting in oxidative tissue damage. In this study, we examined the role of peroxiredoxin I (Prx I), a stress-induced antioxidant enzyme, in protecting gastric mucosa from H. pylori-induced gastric mucosal injury.
  
  
  METHODS
  Wild type (Prx I(+/+)) and Prx I-deficient type (Prx I(-/-)) mice were maintained for 2 to 12 months with or without infection of H. pylori, Sydney strain-1. Gastric mucosal expression of Prx I was assessed by immunoblot analysis and immunohistochemistry. The degree of gastritis was evaluated by the updated Sydney system and by mucosal levels of inflammatory cytokines (MIP-2, IL-1beta, and TNF-alpha). Oxidative DNA injury and apoptosis were analyzed by mucosal level of 8-hydroxy-2'-deoxyguanosine, and the number of apoptotic cells stained with a single-stranded DNA antibody, respectively.
  
  
  RESULTS
  H. pylori infection upregulated gastric mucosal Prx I expression in the Prx I(+/+) but not the Prx I(-/-) mice. H. pylori infection also induced more severe gastritis and a more prominent increase in MIP level, more marked oxidative DNA injury, and apoptosis in the Prx I(-/-) than the Prx I(+/+) mice. In the absence of H. pylori infection, no changes were demonstrated in gastric mucosa in either the Prx I(+/+) or the Prx I(-/-) mice.
  
  
  CONCLUSIONS
  These data suggest that H. pylori infection upregulates gastric mucosal Prx I expression, and further, that Prx I plays an important role in gastric mucosal protection against oxidative injury induced by H. pylori infection.
authors.affiliation: Department of Gastroenterology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sato
authors.forename: Akinori
authors.initials: A
authors.lastname: Yanaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shibahara
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Matsui
authors.forename: Akira
authors.initials: A
authors.lastname: Nakahara
authors.forename: Toru
authors.initials: T
authors.lastname: Yanagawa
authors.forename: Eiji
authors.initials: E
authors.lastname: Warabi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ishii
authors.forename: Ichinosuke
authors.initials: I
authors.lastname: Hyodo
mesh_terms: D000818:Animals; D005753:Gastric Mucosa / Q000382:microbiology*; D016481:Helicobacter Infections / Q000378:metabolism* / Q000517:prevention & control; D016480:Helicobacter pylori; D051379:Mice; D018384:Oxidative Stress; D054464:Peroxiredoxins / Q000502:physiology*
chemical_list: D054464:Peroxiredoxins