title: Molecular mechanisms underlying the probiotic effects of Escherichia coli Nissle 1917 involve ZO-2 and PKCzeta redistribution resulting in tight junction and epithelial barrier repair.
abstract: The probiotic Escherichia coli strain Nissle 1917 (EcN) has been used for decades in human medicine in Central Europe for the treatment and prevention of intestinal disorders and diseases. However, the molecular mechanisms underlying its beneficial effects are only partially understood. To identify molecular responses induced by EcN that might contribute to its probiotic properties polarized T84 cells were investigated employing DNA microarrays, quantitative RT-PCR, Western blotting, immunofluorescence and specific protein kinase C (PKC) inhibitors. Polarized T84 epithelial cell monolayers were used as a model to monitor barrier disruption by infection with the enteropathogenic E. coli (EPEC) strain E2348/69. Co-incubation of EPEC with EcN or addition of EcN following EPEC infection abolished barrier disruption and, moreover, restored barrier integrity as monitored by transepithelial resistance. DNA-microarray analysis of T84 cells incubated with EcN identified 300+ genes exhibiting altered expression. EcN altered the expression, distribution of zonula occludens-2 (ZO-2) protein and of distinct PKC isotypes. ZO-2 expression was enhanced in parallel to its redistribution towards the cell boundaries. This study provides evidence that EcN induces an overriding signalling effect leading to restoration of a disrupted epithelial barrier. This is transmitted via silencing of PKCzeta and the redistribution of ZO-2. We suggest that these properties contribute to the reported efficacy in the treatment of inflammatory bowel diseases and in part rationalize the probiotic nature of EcN.
authors.affiliation: Institut für Infektiologie, Zentrum für Molekularbiologie der Entzündung (ZMBE), Westfälische Wilhelms-Universität/Universitätsklinikum Münster, von-Esmarch-Str. 56, D-48149 Münster, Germany.
authors.forename: Agata A
authors.initials: AA
authors.lastname: Zyrek
authors.forename: Christoph
authors.initials: C
authors.lastname: Cichon
authors.forename: Simone
authors.initials: S
authors.lastname: Helms
authors.forename: Corinne
authors.initials: C
authors.lastname: Enders
authors.forename: Ulrich
authors.initials: U
authors.lastname: Sonnenborn
authors.forename: M Alexander
authors.initials: MA
authors.lastname: Schmidt
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000502:physiology; D004847:Epithelial Cells / Q000378:metabolism* / Q000382:microbiology; D004926:Escherichia coli / Q000254:growth & development*; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D019936:Probiotics; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D019108:Tight Junctions / Q000378:metabolism / Q000382:microbiology; D062827:Zonula Occludens-2 Protein; D000099221:Protein Kinase C zeta
chemical_list: D008565:Membrane Proteins; D011493:Protein Kinase C; D062827:Zonula Occludens-2 Protein; D000099221:Protein Kinase C zeta; C569046:TJP2 protein, human