H. pylori related proinflammatory cytokines contribute to the induction of miR-146a in human gastric epithelial cells

Mol Biol Rep. 2012 Apr;39(4):4655-61. doi: 10.1007/s11033-011-1257-5. Epub 2011 Sep 23.

Abstract

MicroRNAs have been implicated as a central regulator of the immune system. We have previously reported that Helicobacter pylori (H. pylori) was able to increase the expression of miR-146a, and miR-146a may negatively regulate H. pylori-induced inflammation, but the exact mechanism of how H. pylori contribute the induction of miR-146a is not clear. Here, we attempted to assess the role of H. pylori related proinflammatory cytokines including interleukin (IL)-8, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β, and cytotoxin-associated gene A (CagA) virulence factor on the induction of miR-146a. We found that IL-8, TNF-α, and IL-1β could contribute to the induction of miR-146a in gastric epithelial cell HGC-27 in NF-κB-dependent manner, while the induction of miR-146a upon H. pylori stimulation was independent of above proinflammatory cytokines. Furthermore, overexpression of miR-146a reduced H. pylori-induced IL-8, TNF-α, and IL-1β. However, CagA had no effect on the miR-146a induction. Taken together, our study suggest that proinflammatory cytokines IL-8, TNF-α, and IL-1β could contribute to the induction of miR-146a during H. pylori infection, while CagA is not necessarily required for miR-146a induction. miR-146a may function as novel negative regulators to modulate the inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Bacterial / metabolism
  • Bacterial Proteins / metabolism
  • Cell Line, Tumor
  • Cytokines / metabolism*
  • Epithelial Cells / immunology
  • Epithelial Cells / metabolism*
  • Epithelial Cells / microbiology*
  • Epithelial Cells / pathology
  • Gene Expression Regulation, Neoplastic
  • Helicobacter Infections / genetics
  • Helicobacter Infections / immunology
  • Helicobacter Infections / microbiology
  • Helicobacter pylori / physiology*
  • Humans
  • Inflammation Mediators / metabolism*
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • NF-kappa B / metabolism
  • Signal Transduction
  • Stomach / pathology*
  • Up-Regulation / genetics

Substances

  • Antigens, Bacterial
  • Bacterial Proteins
  • Cytokines
  • Inflammation Mediators
  • MIRN146 microRNA, human
  • MicroRNAs
  • NF-kappa B
  • cagA protein, Helicobacter pylori