The aim of this study was to characterize an in vitro modulating effect of three commensal Lactobacillus strains on cellular differentiation of non-transformed crypt-like rat small intestinal cell line IEC-18. IEC-18 was grown on extracellular matrix, with or without presence of Lactobacillus strains. Gene expression of IEC-18 bacterial detection system - such as Toll-like receptors TLR-2, TLR-4, signal adapter MyD88, cytoplasmic NOD2 receptor, inflammatory cytokines IL-18, IL-1beta, chemokine IL-8 and enzyme caspase-1 - was evaluated using real-time PCR. Expression and localization of TLR-2, TLR-4, IL-18 and caspase-1 proteins was demonstrated by Western blotting and immunofluorescent staining. Secretion of IL-18 to apical and basolateral surfaces was assayed by ELISA. Our results suggested that L. casei LOCK0919 accelerated differentiation of IEC-18 by stimulating TLR-2, TLR-4, MyD88, IL-18, caspase-1 mRNAs and proteins. L. casei LOCK0919 increased expression and transfer of villin and beta-catenin from cytoplasm to cell membrane. Presence of L. rhamnosus LOCK0900 resulted in detachment of IEC-18 layer from extracellular matrix leading to induction of IL-1beta, of TLR-2 and IL-8 mRNAs and stimulation of MyD88, caspase-1 and cytosolic receptor NOD2 mRNAs. L. rhamnosus LOCK0908 was not recognized by TLR-2 or TLR-4 receptors. Lactobacilli-IEC-18 crosstalk enhanced immune and barrier mucosal functions.

• MeSH
• beta-katenin biosyntéza   MeSH
• buněčná diferenciace účinky léků   MeSH
• cytokiny biosyntéza   MeSH
• epitelové buňky účinky léků   MeSH
• interleukin-18 biosyntéza   MeSH
• kaspasa 1 biosyntéza   MeSH
• krysa rodu rattus MeSH
• Lacticaseibacillus rhamnosus * MeSH
• Lactobacillus casei * MeSH
• messenger RNA biosyntéza   MeSH
• mikrofilamentové proteiny biosyntéza   MeSH
• probiotika farmakologie   MeSH
• regulace genové exprese účinky léků   MeSH
• střevní sliznice cytologie   účinky léků   MeSH
• subcelulární frakce metabolismus   MeSH
• toll-like receptory biosyntéza   účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The toxic modes of action of non-dioxin-like polychlorinated biphenyls (PCBs) in liver cells are still only partially understood. Several recent studies have indicated that PCBs may interfere with cell membrane protein functions. Therefore, we analyzed in the present study the effects of di-ortho-substituted 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) on proteins involved in the formation of adherens junctions in a model of rat liver progenitor cells - WB-F344 cell line. PCB 153, at micromolar concentrations, induced a gradual degradation of E-cadherin, beta-catenin or plakoglobin (gamma-catenin) proteins. This effect was not due to changes in gene expression, as PCB 153 had no effect on mRNA levels of the above mentioned proteins. Moreover, apart from the reduction of total beta-catenin pool, PCB 153 also decreased levels of the active beta-catenin form, dephosphorylated at residues Ser37 and Thr41, which is the key co-activator of Wnt-induced TCF/LEF-dependent gene expression. Therefore, we also evaluated the impact of PCB 153 on expression of Axin2, a known transcriptional target of canonical Wnt signaling. PCB 153 reduced basal Axin2 mRNA levels and it inhibited induction of Axin2 expression by recombinant mouse Wnt3a. Nevertheless, PCB 153 had no effect on phosphorylation of glycogen synthase kinase-3beta (GSK-3beta), which is supposed to target beta-catenin for its proteasomal degradation. This suggested that GSK-3beta activity is not modulated by PCB 153 and, consequently, not involved in the observed PCB 153-induced decrease of both total and active beta-catenin levels. Protein levels of E-cadherin and beta-catenin were partially restored with lysosomal inhibitor leupeptin, thus suggesting a possible role of lysosomes in the observed degradation of adherens junction proteins. Taken together, the present data suggest that PCB 153 may interfere with functions of adherens junction proteins involved in both cell-to-cell communication and intracellular signaling. Such mechanisms might be involved in the effects of non-dioxin-like PCBs contributing to liver tumor promotion.

• MeSH
• adhezní spoje metabolismus   účinky léků   MeSH
• beta-katenin antagonisté a inhibitory   biosyntéza   genetika   MeSH
• buněčné linie MeSH
• epitelové buňky cytologie   metabolismus   účinky léků   MeSH
• fosforylace účinky léků   MeSH
• gama-katenin biosyntéza   genetika   metabolismus   MeSH
• genetická transkripce účinky léků   MeSH
• inhibitory cysteinových proteinas farmakologie   MeSH
• játra cytologie   metabolismus   účinky léků   MeSH
• kadheriny biosyntéza   genetika   metabolismus   MeSH
• kinasa 3 glykogensynthasy metabolismus   MeSH
• kmenové buňky cytologie   metabolismus   účinky léků   MeSH
• krysa rodu rattus MeSH
• leupeptiny farmakologie   MeSH
• lyzozomy metabolismus   MeSH
• messenger RNA biosyntéza   genetika   MeSH
• polychlorované bifenyly toxicita   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• represorové proteiny biosyntéza   genetika   metabolismus   MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH