title: Entamoeba histolytica disturbs the tight junction complex in human enteric T84 cell layers.
abstract: Entamoeba (E.) histolytica trophozoites initiate amebiasis through invasion into the enteric mucosa. It was our aim to understand the molecular interactions between amebic trophozoites and enterocytes during the early steps of invasion. Trophozoites of E. histolytica strain HM1:IMSS were seeded on the apical side of enteric T84 cell layers, which were established on filters in two-compartment culture chambers. Cocultures were analyzed for paracellular permeability by measurement of transepithelial electrical resistance (TER) and for the tight junction proteins ZO-1, ZO-2, occludin, and cingulin by immunocytochemistry and immunoprecipitation. On direct contact with the apical side of the enteric cells, trophozoites caused an increase in paracellular permeability as evidenced by a decrease of TER associated with an increase in [(3)H]mannitol flux. Immunoprecipitation of cocultures revealed dephosphorylation of ZO-2, loss of ZO-1 from ZO-2, and degradation of ZO-1 but less so of ZO-2 and none of occludin or E-cadherin. In conclusion, trophozoite-associated increase in paracellular permeability of enteric cell layers is ascribed to disturbance of the molecular organization of tight junction proteins.
authors.affiliation: Laboratory of Experimental Cancerology, Department of Radiotherapy and Nuclear Medicine, Ghent University Hospital, B-9000 Gent, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Leroy
authors.forename: T
authors.initials: T
authors.lastname: Lauwaet
authors.forename: G
authors.initials: G
authors.lastname: De Bruyne
authors.forename: M
authors.initials: M
authors.lastname: Cornelissen
authors.forename: M
authors.initials: M
authors.lastname: Mareel
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism; D002463:Cell Membrane Permeability; D016764:Cell Polarity; D015194:Diffusion Chambers, Culture; D004553:Electric Conductivity; D004748:Entamoeba histolytica / Q000254:growth & development / Q000502:physiology*; D020895:Enterocytes / Q000378:metabolism / Q000469:parasitology* / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D006801:Humans; D037102:Lectins / Q000378:metabolism; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism; D008840:Microfilament Proteins; D062793:Occludin; D010750:Phosphoproteins / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D019108:Tight Junctions / Q000502:physiology*; D014407:Tumor Cells, Cultured; D062826:Zonula Occludens-1 Protein; D062827:Zonula Occludens-2 Protein
chemical_list: D000911:Antibodies, Monoclonal; C061407:CGN protein, human; D015820:Cadherins; D037102:Lectins; D008565:Membrane Proteins; D008840:Microfilament Proteins; C568985:OCLN protein, human; D062793:Occludin; D010750:Phosphoproteins; C569042:TJP1 protein, human; C569046:TJP2 protein, human; D062826:Zonula Occludens-1 Protein; D062827:Zonula Occludens-2 Protein