title: Caco-2 cell monolayer integrity and effect of probiotic Escherichia coli Nissle 1917 components.
abstract: OBJECTIVE
  Different probiotic strains used in clinical trials have shown prophylactic properties in different inflammatory diseases of the gastrointestinal tract. This study was aimed to investigate the influence of Escherichia coli strain Nissle 1917 (EcN) components on the integrity of the Caco-2 cell monolayer (human adenocarcinoma cell line).
  
  
  METHODS
  The effect of supernatant of EcN suspension and lipopolysaccharide (LPS) isolated from EcN (in concentrations from 0.001 to 1 000 µg/ml) on paracellular transport of 14C-mannitol marker through epithelial cell monolayer was estimated.
  
  
  RESULTS
  Both LPS and EcN supernatant exerted almost the same effect; whereas no effect was shown using high concentrations (100 and 1 000 µg/ml), low concentrations (0.001, 0.1 and 1 µg/ml) significantly decreased permeability of 14C-mannitol. Concentration (0.001 µg/ml) decreased 14C-mannitol permeability approximately about 20% (LPS) and 30% (EcN supernatant). To elucidate the observed changes in monolayer permeability ("tighter monolayer") induced by concentrations of LPS or supernatant, media able to open epithelial intercellular junctions were used. The effects of Ca2+-free transport medium and of medium containing 5, 10, 20, 50, and 100% of Ca2+ on the 14C-mannitol transport in the presence of the lowest (0.001 µg/ml) and high (100 µg/ml) concentrations of LPS were studied. Using Ca2+-free medium both concentrations of LPS significantly decreased apparent permeability coefficient (Papp) of 14C-mannitol indicating that changes of 14C-mannitol permeability are independent of dimensions of paracellular spaces.
  
  
  CONCLUSIONS
  The decrease of 14C-mannitol permeability caused by EcN LPS indicates the ability of components of probiotic EcN strain to restore disrupted epithelial barrier.
authors.affiliation: Institute of Experimental Biopharmaceutics, Joint Research Centre of PRO.MED.CS Praha a.s. and the Czech Academy of Sciences, Czech Republic. Stetinova@uebf.cas.cz
authors.forename: Vera
authors.initials: V
authors.lastname: Stetinova
authors.forename: Libuse
authors.initials: L
authors.lastname: Smetanova
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Kvetina
authors.forename: Zbynek
authors.initials: Z
authors.lastname: Svoboda
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Zidek
authors.forename: Helena
authors.initials: H
authors.lastname: Tlaskalova-Hogenova
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D018938:Caco-2 Cells; D002250:Carbon Radioisotopes; D002463:Cell Membrane Permeability / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008353:Mannitol / Q000378:metabolism; D019936:Probiotics / Q000494:pharmacology*
chemical_list: D002250:Carbon Radioisotopes; D008070:Lipopolysaccharides; D008353:Mannitol