title: MicroRNA-155-enhanced autophagy in human gastric epithelial cell in response to Helicobacter pylori.
abstract: OBJECTIVE
  MicroRNAs (miRNAs) are a class of small noncoding RNAs acting as posttranscriptional gene expression regulators in many physiological and pathological conditions. MiR-155 is one kind of miRNAs that plays an important role in causing various diseases. However, the precise molecular mechanism of the ectopic expression of miR-155 in Helicobacter pylori infection remains poorly understood. Autophagy has recently been identified as an effective way to control the intracellular bacterium survival. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-H. pylori response.
  
  
  METHODS
  Totally 86 H. pylori-positive patients together with 10 H. pylori-negative, healthy control subjects were included in the study. Correlation between immunohistochemical grades and miR-155 expression were determined. Molecular mechanism of miR-155 on regulation of autophagy and elimination of intracellular H. pylori were determined using the GES-1 cell model.
  
  
  RESULTS
  We found that overexpression of miR-155 by transfecting miR-155 mimics could significantly decrease the survival of intracellular H. pylori, and this process was through induction of autophagy. Furthermore, there was a significant correlation between miR-155 and immunohistochemical grades in H. pylori-positive patients, and miR-155 expression were decreased in the intestinal metaplasia group.
  
  
  CONCLUSIONS
  The results have indicated that the miR-155 expression level plays a key role in immunity response against H. pylori and this might provide potential targets for the future treatment of H. pylori-related diseases.
authors.affiliation: Department of Gastroenterology, 309 Hospital of Chinese Peoples Liberation Army, Beijing, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wu
authors.forename: Chaohui
authors.initials: C
authors.lastname: Zhu
authors.forename: Yi
authors.initials: Y
authors.lastname: Yao
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Jiugang
authors.initials: J
authors.lastname: Song
authors.forename: Junshan
authors.initials: J
authors.lastname: Zhai
mesh_terms: D001343:Autophagy / Q000235:genetics; D016022:Case-Control Studies; D002460:Cell Line; D004847:Epithelial Cells / Q000382:microbiology / Q000473:pathology; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000235:genetics* / Q000382:microbiology / Q000473:pathology*; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*
chemical_list: C524942:MIRN155 microRNA, human; D035683:MicroRNAs
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