title: Effect of Toxoplasma gondii infection on the junctional complex of retinal pigment epithelial cells.
abstract: Ocular toxoplasmosis is the most frequent cause of uveitis, leading to partial or total loss of vision, with the retina the main affected structure. The cells of the retinal pigment epithelium (RPE) play an important role in the physiology of the retina and formation of the blood-retinal barrier. Several pathogens induce barrier dysfunction by altering tight junction (TJ) integrity. Here, we analysed the effect of infection by Toxoplasma gondii on TJ integrity in ARPE-19 cells. Loss of TJ integrity was demonstrated in T. gondii-infected ARPE-19 cells, causing increase in paracellular permeability and disturbance of the barrier function of the RPE. Confocal microscopy also revealed alteration in the TJ protein occludin induced by T. gondii infection. Disruption of junctional complex was also evidenced by scanning and transmission electron microscopy. Cell-cell contact loss was noticed in the early stages of infection by T. gondii with the visualization of small to moderate intercellular spaces. Large gaps were mostly observed with the progression of the infection. Thus, our data suggest that the alterations induced by T. gondii in the structural organization of the RPE may contribute to retinal injury evidenced by ocular toxoplasmosis.
authors.affiliation: Laboratório de Ultraestrutura Celular,Instituto Oswaldo Cruz,Fiocruz,Av. Brasil 4365,Manguinhos,Rio de Janeiro,RJ, 21040-900,Brazil.
authors.forename: Alanderson R
authors.initials: AR
authors.lastname: Nogueira
authors.affiliation: Divisão de Biologia Celular,Coordenação de Pesquisa,Instituto Nacional de Câncer,Rua André Cavalcanti 37,5° Andar,Rio de Janeiro,RJ 20230-051,Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Leve
authors.affiliation: Divisão de Biologia Celular,Coordenação de Pesquisa,Instituto Nacional de Câncer,Rua André Cavalcanti 37,5° Andar,Rio de Janeiro,RJ 20230-051,Brazil.
authors.forename: José
authors.initials: J
authors.lastname: Morgado-Diaz
authors.affiliation: Laboratório de Biologia Estrutural,Instituto Oswaldo Cruz,Fiocruz,Av. Brasil 4365,Manguinhos,Rio de Janeiro,RJ, 21040-900,Brazil.
authors.forename: Roberto Carlos
authors.initials: RC
authors.lastname: Tedesco
authors.affiliation: Laboratório de Ultraestrutura Celular,Instituto Oswaldo Cruz,Fiocruz,Av. Brasil 4365,Manguinhos,Rio de Janeiro,RJ, 21040-900,Brazil.
authors.forename: Mirian Claudia S
authors.initials: MC
authors.lastname: Pereira
mesh_terms: D000818:Animals; D001813:Blood-Retinal Barrier / Q000502:physiology* / Q000648:ultrastructure; D002478:Cells, Cultured; D017097:Electric Impedance; D005260:Female; D006801:Humans; D051379:Mice; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D055213:Retinal Pigment Epithelium / Q000469:parasitology* / Q000503:physiopathology / Q000648:ultrastructure; D019108:Tight Junctions / Q000502:physiology* / Q000648:ultrastructure; D014122:Toxoplasma / Q000502:physiology* / Q000648:ultrastructure; D014126:Toxoplasmosis, Ocular / Q000473:pathology / Q000503:physiopathology*
keywords: Toxoplasma gondii; junctional complex; retinal pigment epithelial cells