title: Saccharomyces boulardii preserves the barrier function and modulates the signal transduction pathway induced in enteropathogenic Escherichia coli-infected T84 cells.
abstract: Use of the nonpathogenic yeast Saccharomyces boulardii in the treatment of infectious diarrhea has attracted growing interest. The present study designed to investigate the effect of this yeast on enteropathogenic Escherichia coli (EPEC)-associated disease demonstrates that S. boulardii abrogated the alterations induced by an EPEC strain on transepithelial resistance, [(3)H]inulin flux, and ZO-1 distribution in T84 cells. Moreover, EPEC-mediated apoptosis of epithelial cells was delayed in the presence of S. boulardii. The yeast did not modify the number of adherent bacteria but lowered by 50% the number of intracellular bacteria. Infection by EPEC induced tyrosine phosphorylation of several proteins in T84 cells, including p46 and p52 SHC isoforms, that was attenuated in the presence of S. boulardii. Similarly, EPEC-induced activation of the ERK1/2 mitogen-activated protein (MAP) kinase pathway was diminished in the presence of the yeast. Interestingly, inhibition of the ERK1/2 pathway with the specific inhibitor PD 98059 decreased EPEC internalization, suggesting that modulation of the ERK1/2 MAP pathway might account for the lowering of the number of intracellular bacteria observed in the presence of S. boulardii. Altogether, this study demonstrated that S. boulardii exerts a protective effect on epithelial cells after EPEC adhesion by modulating the signaling pathway induced by bacterial infection.
authors.affiliation: Laboratoire de Gastroentérologie et Nutrition, IFR50, Faculté de Médecine, Université de Nice-Sophia Antipolis, 06107 Nice Cedex 2, France. czerucka@unice.fr
authors.forename: D
authors.initials: D
authors.lastname: Czerucka
authors.forename: S
authors.initials: S
authors.lastname: Dahan
authors.forename: B
authors.initials: B
authors.lastname: Mograbi
authors.forename: B
authors.initials: B
authors.lastname: Rossi
authors.forename: P
authors.initials: P
authors.lastname: Rampal
mesh_terms: D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000502:physiology*; D003110:Colonic Neoplasms; D017097:Electric Impedance; D004789:Enzyme Activation; D004926:Escherichia coli / Q000254:growth & development / Q000472:pathogenicity*; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology* / Q000502:physiology*; D007444:Inulin; D020935:MAP Kinase Signaling System; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation; D012440:Saccharomyces / Q000502:physiology*; D015398:Signal Transduction; D019108:Tight Junctions / Q000648:ultrastructure; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism
chemical_list: D014443:Tyrosine; D007444:Inulin; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases