title: Identification of specific miRNAs targeting proteins of the apical junctional complex that simulate the probiotic effect of E. coli Nissle 1917 on T84 epithelial cells.
abstract: In the intestine, dysregulation of miRNA is associated with inflammation, disruption of the gastrointestinal barrier, and the onset of gastrointestinal disorders. This study identifies miRNAs involved in the maintenance of intercellular junctions and barrier integrity. For the functional identification of barrier affecting miRNAs, we took advantage of the barrier-enforcing effects of the probiotic bacterium Escherichia coli Nissle 1917 (EcN) which can be monitored by enhanced transepithelial resistance (TER). miRNA-profiling of T84 monolayers prior and after co-incubation with EcN revealed for the first time differentially regulated miRNAs (miR-203, miR-483-3p, miR-595) targeting tight junction (TJ) proteins. Using real-time PCR, Western blotting and specific miRNA mimics, we showed that these miRNAs are involved in the regulation of barrier function by modulating the expression of regulatory and structural components of tight junctional complexes. Furthermore, specific inhibitors directed at these miRNA abrogated the disturbance of tight junctions induced by enteropathogenic E. coli (EPEC). The half-maximal inhibitory concentration (IC(50)) was determined to 340 nM by monitoring inhibitor kinetics. In summary, we conclude that specific miRNAs effect regulatory as well as structural proteins of the junctional complex which in turn are involved in the barrier enhancing effect of EcN. Hence, we suggest that the application of miRNAs might be refined and further developed as a novel supportive strategy for the treatment of gastrointestinal disorders.
authors.affiliation: Institut für Infektiologie - Zentrum für Molekularbiologie der Entzündung, Westfälische Wilhelms-Universität Münster, Münster, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Veltman
authors.forename: Stephanie
authors.initials: S
authors.lastname: Hummel
authors.forename: Christoph
authors.initials: C
authors.lastname: Cichon
authors.forename: Ulrich
authors.initials: U
authors.lastname: Sonnenborn
authors.forename: Marcus Alexander
authors.initials: MA
authors.lastname: Schmidt
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D004926:Escherichia coli; D007365:Intercellular Junctions / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000378:metabolism*; D019936:Probiotics / Q000494:pharmacology*; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology
chemical_list: D008565:Membrane Proteins; D035683:MicroRNAs