Histidine-rich protein Hpn from Helicobacter pylori forms amyloid-like fibrils in vitro and inhibits the proliferation of gastric epithelial AGS cells

Biochim Biophys Acta. 2011 Aug;1813(8):1422-7. doi: 10.1016/j.bbamcr.2011.04.005. Epub 2011 Apr 22.

Abstract

Helicobacter pylori causes various gastric diseases, such as gastritis, peptic ulcerations, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Hpn is a histidine-rich protein abundant in this bacterium and forms oligomers in physiologically relevant conditions. In this present study, Hpn oligomers were found to develop amyloid-like fibrils as confirmed by negative stain transition electron microscopy, thioflavin T and Congo red binding assays. The amyloid-like fibrils of Hpn inhibit the proliferation of gastric epithelial AGS cells through cell cycle arrest in the G2/M phase, which may be closely related to the disruption of mitochondrial bioenergetics as reflected by the significant depletion of intracellular ATP levels and the mitochondrial membrane potential. The collective data presented here shed some light on the pathologic mechanisms of H. pylori infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / physiology*
  • Bacterial Proteins / ultrastructure
  • Cell Line
  • Cell Proliferation
  • Epithelial Cells / microbiology
  • Epithelial Cells / pathology
  • Gastric Mucosa / microbiology*
  • Gastric Mucosa / pathology*
  • Helicobacter Infections / etiology
  • Helicobacter pylori / pathogenicity*
  • Helicobacter pylori / physiology*
  • Humans
  • Membrane Potential, Mitochondrial
  • Microscopy, Electron, Transmission
  • Protein Multimerization
  • Proteins / chemistry*
  • Proteins / physiology*
  • Proteins / ultrastructure

Substances

  • Bacterial Proteins
  • Proteins
  • histidine-rich proteins
  • Adenosine Triphosphate