Crosstalk between Helicobacter pylori and gastric epithelial cells is impaired by docosahexaenoic acid.

Marta Correia (1, 2) , Valérie Michel (2) , Hugo Osório (1) , Meriem El Ghachi (3) , Mathilde Bonis (3) , Ivo G Boneca (3) , Hilde de Reuse (2) , António A Matos (4) , Pascal Lenormand (5) , Raquel Seruca (1) , Ceu Figueiredo (1) , Jose Carlos Machado (1) , Eliette Touati (2)

1 Universidade do Porto = University of Porto
2 Pathogenèse de Helicobacter
3 BGPB - Biologie et Génétique de la Paroi bactérienne - Biology and Genetics of Bacterial Cell Wall
4 Centro Hospitalar de Lisboa Central E.P.E
5 Protéomique (Plate-Forme)

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.

Mots clés: Antibacterial factors; Docosahexanoic acid DHA; Helicobacter Infections/microbiology

Domaines: Microbiologie et Parasitologie; Biologie cellulaire

Marta Correia, Valérie Michel, Hugo Osório, Meriem El Ghachi, Mathilde Bonis, et al.. Crosstalk between Helicobacter pylori and gastric epithelial cells is impaired by docosahexaenoic acid.. PLoS ONE, 2013, 8 (4), pp.e60657. ⟨10.1371/journal.pone.0060657⟩. ⟨pasteur-01441046⟩