title: Expression of three essential antioxidants of Helicobacter pylori in clinical isolates.
abstract: OBJECTIVE
  Helicobacter pylori maintains long-term persistence in the host and combats oxidative stress via many antioxidant proteins, which are expected to be relevant to bacterial-associated gastric diseases. We aimed to investigate the expression of three essential antioxidants in H. pylori strains isolated from patients with different clinical outcomes.
  
  
  METHODS
  Forty H. pylori strains were isolated from endoscopic biopsy specimens of gastric mucosa from 13 patients with gastric cancer, 13 with peptic ulcer, and 14 with gastritis. The expression of thioredoxin 1 (Trx1), arginase (RocF), and alkyl hydroperoxide reductase (AhpC) in H. pylori was measured by real-time PCR. Comparisons among multiple sample sets were analyzed using a one-way ANOVA test. Pearson's correlation test was used to assess relationships among multiple continuous variables.
  
  
  RESULTS
  Trx1 expression of H. pylori in gastric cancer and peptic ulcer tissues was higher than that in tissues with gastritis. RocF expression of H. pylori in gastric cancer tissues was higher than that in tissues exhibiting peptic ulcer and gastritis. However, we did not find any differences in AhpC expression in samples from patients with different clinical outcomes. The expression of Trx1 and RocF had a positive, linear correlation. The expression of Trx1 and AhpC had a positive correlation without a linear trend. We found no correlation between the expression of RocF and AhpC.
  
  
  CONCLUSIONS
  Our observations indicate that the expression of Trx1 and RocF in H. pylori might be related to gastric carcinogenesis. In H. pylori, the expression of members of the antioxidant system may be correlated and relevant to gastric cancer.
authors.affiliation: Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Yan-yan
authors.initials: YY
authors.lastname: Shi
authors.forename: Mo
authors.initials: M
authors.lastname: Chen
authors.forename: Yue-xia
authors.initials: YX
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Shi-gang
authors.initials: SG
authors.lastname: Ding
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001119:Arginase / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D005753:Gastric Mucosa / Q000382:microbiology*; D016481:Helicobacter Infections / Q000378:metabolism / Q000382:microbiology*; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D010544:Peroxidases / Q000378:metabolism*; D013879:Thioredoxins / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D001426:Bacterial Proteins; D013879:Thioredoxins; D010544:Peroxidases; C508531:ahpC protein, Helicobacter pylori; C402431:RocF protein, Helicobacter pylori; D001119:Arginase
keywords: Antioxidant; Gastric cancer; Helicobacter pylori; Oxidative stress