Helicobacter pylori's cholesterol uptake impacts resistance to docosahexaenoic acid.
Helicobacter pylori colonizes half of the world population and is associated with gastric cancer. We have previously demonstrated that docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid known for its anti-inflammatory and antitumor effects, directly inhibits H. pylori growth in vitro and in mice. Nevertheless, the concentration of DHA shown to reduce H. pylori mice gastric colonization was ineffective in vitro. Related to the auxotrophy of H. pylori for cholesterol, we hypothesize that other mechanisms, in addition to DHA direct antibacterial effect, must be responsible for the reduction of the infection burden. In the present study we investigated if DHA affects also H. pylori growth, by reducing the availability of membrane cholesterol in the epithelial cell for H. pylori uptake. Levels of cholesterol in gastric epithelial cells and of cholesteryl glucosides in H. pylori were determined by thin layer chromatography and gas chromatography. The consequences of epithelial cells' cholesterol depletion on H. pylori growth were assessed in liquid cultures. We show that H. pylori uptakes cholesterol from epithelial cells. In addition, DHA lowers cholesterol levels in epithelial cells, decreases its de novo synthesis, leading to a lower synthesis of cholesteryl glucosides by H. pylori. A previous exposition of H. pylori to cholesterol influences the bacterium response to the direct inhibitory effect of DHA. Overall, our results suggest that a direct effect of DHA on H. pylori survival is modulated by its access to epithelial cell cholesterol, supporting the notion that cholesterol enhances the resistance of H. pylori. The cholesterol-dependent resistance of H. pylori to antimicrobial compounds raises new important aspects for the development of new anti-bacterial strategies.
Institute of Molecular Pathology and Immunology of the University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; Faculdade de Medicina da Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; Institut Pasteur, Unité de Pathogenèse de Helicobacter, 25, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France.
Marta
M
Correia
REQUIMTE/Laboratório de Bromatologia e Hidrologia, Faculdade de Farmácia do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
Susana
S
Casal
Institute of Molecular Pathology and Immunology of the University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; Faculdade de Medicina da Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; Institute of Biomedical Sciences Abel Salazar of the University of Porto (ICBAS), 4099-003 Porto, Portugal.
João
J
Vinagre
Institute of Molecular Pathology and Immunology of the University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; Faculdade de Medicina da Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
Raquel
R
Seruca
Institute of Molecular Pathology and Immunology of the University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; Faculdade de Medicina da Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
Ceu
C
Figueiredo
Institut Pasteur, Unité de Pathogenèse de Helicobacter, 25, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France.
Eliette
E
Touati
Institute of Molecular Pathology and Immunology of the University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; Faculdade de Medicina da Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal. Electronic address: josem@ipatimup.pt.
José C
JC
Machado
D000900:Anti-Bacterial Agents / Q000378:metabolism*; D002460:Cell Line; D002784:Cholesterol / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D004281:Docosahexaenoic Acids / Q000378:metabolism*; D024881:Drug Resistance, Bacterial; D004847:Epithelial Cells / Q000737:chemistry / Q000382:microbiology*; D008401:Gas Chromatography-Mass Spectrometry; D016480:Helicobacter pylori / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D006801:Humans
D000900:Anti-Bacterial Agents; D004281:Docosahexaenoic Acids; D002784:Cholesterol
Bactericidal agents; Cholesterol; Helicobacter pylori; Mechanisms of resistance; PUFAs