title: Crosstalk between Helicobacter pylori and gastric epithelial cells is impaired by docosahexaenoic acid.
abstract: H. pylori colonizes half of the world's population leading to gastritis, ulcers and gastric cancer. H. pylori strains resistant to antibiotics are increasing which raises the need for alternative therapeutic approaches. Docosahexaenoic acid (DHA) has been shown to decrease H. pylori growth and its associated-inflammation through mechanisms poorly characterized. We aimed to explore DHA action on H. pylori-mediated inflammation and adhesion to gastric epithelial cells (AGS) and also to identify bacterial structures affected by DHA. H. pylori growth and metabolism was assessed in liquid cultures. Bacterial adhesion to AGS cells was visualized by transmission electron microscopy and quantified by an Enzyme Linked Immunosorbent Assay. Inflammatory proteins were assessed by immunoblotting in infected AGS cells, previously treated with DHA. Bacterial total and outer membrane protein composition was analyzed by 2-dimensional gel electrophoresis. Concentrations of 100 µM of DHA decreased H. pylori growth, whereas concentrations higher than 250 µM irreversibly inhibited bacteria survival. DHA reduced ATP production and adhesion to AGS cells. AGS cells infected with DHA pre-treated H. pylori showed a 3-fold reduction in Interleukin-8 (IL-8) production and a decrease of COX2 and iNOS. 2D electrophoresis analysis revealed that DHA changed the expression of H. pylori outer membrane proteins associated with stress response and metabolism and modified bacterial lipopolysaccharide phenotype. As conclusions our results show that DHA anti-H. pylori effects are associated with changes of bacteria morphology and metabolism, and with alteration of outer membrane proteins composition, that ultimately reduce the adhesion of bacteria and the burden of H. pylori-related inflammation.
authors.affiliation: Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Dr. Roberto Frias s/n, Porto, Portugal.
authors.forename: Marta
authors.initials: M
authors.lastname: Correia
authors.forename: Valérie
authors.initials: V
authors.lastname: Michel
authors.forename: Hugo
authors.initials: H
authors.lastname: Osório
authors.forename: Meriem
authors.initials: M
authors.lastname: El Ghachi
authors.forename: Mathilde
authors.initials: M
authors.lastname: Bonis
authors.forename: Ivo G
authors.initials: IG
authors.lastname: Boneca
authors.forename: Hilde
authors.initials: H
authors.lastname: De Reuse
authors.forename: António A
authors.initials: AA
authors.lastname: Matos
authors.forename: Pascal
authors.initials: P
authors.lastname: Lenormand
authors.forename: Raquel
authors.initials: R
authors.lastname: Seruca
authors.forename: Ceu
authors.initials: C
authors.lastname: Figueiredo
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Machado
authors.forename: Eliette
authors.initials: E
authors.lastname: Touati
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001422:Bacterial Adhesion / Q000187:drug effects; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism; D004281:Docosahexaenoic Acids / Q000494:pharmacology* / Q000627:therapeutic use; D004847:Epithelial Cells / Q000187:drug effects / Q000382:microbiology*; D016480:Helicobacter pylori / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D007249:Inflammation / Q000188:drug therapy / Q000382:microbiology; D013270:Stomach / Q000166:cytology*
chemical_list: D000893:Anti-Inflammatory Agents; D001425:Bacterial Outer Membrane Proteins; D004281:Docosahexaenoic Acids