title: Reevaluating the role of Acanthamoeba proteases in tissue invasion: observation of cytopathogenic mechanisms on MDCK cell monolayers and hamster corneal cells.
abstract: The morphological analysis of the cytopathic effect on MDCK cell monolayers and hamster cornea and qualitative and quantitative analyses of conditioned medium and proteases were evaluated and compared between two strains of Acanthamoeba genotype T4. Further than highlighting the biological differences found between both strains, the most important observation in this study was the fact that proteases both in total extracts and in conditioned medium are apparently not determinant in tissue destruction. An interestingly finding was that no lysis of corneal tissue was observed as it was previously suggested. These results, together with previous studies, allow us to conclude that the invasion and disruption of corneal tissue is performed by the penetration of the amoebae through cell junctions, either by the action of proteases promoting cellular separation but not by their destruction and/or a mechanical effect exerted by amoebae. Therefore, contact-dependent mechanisms in Acanthamoeba pathogenesis are more relevant than it has been previously considered. This is supported because the phagocytosis of recently detached cells as well as those attached to the corneal epithelium leads to the modification of the cellular architecture facilitating the migration and destruction of deeper layers of the corneal epithelium.
authors.affiliation: UIICSE Faculty of Superior Studies Iztacala, Medicine, UNAM, Los Reyes Iztacala, 54090 Tlalnepantla, MEX, Mexico. maritzaomanam@yahoo.com.mx
authors.forename: Maritza
authors.initials: M
authors.lastname: Omaña-Molina
authors.forename: Arturo
authors.initials: A
authors.lastname: González-Robles
authors.forename: Lizbeth
authors.initials: L
authors.lastname: Iliana Salazar-Villatoro
authors.forename: Jacob
authors.initials: J
authors.lastname: Lorenzo-Morales
authors.forename: Ana Ruth
authors.initials: AR
authors.lastname: Cristóbal-Ramos
authors.forename: Verónica Ivonne
authors.initials: VI
authors.lastname: Hernández-Ramírez
authors.forename: Patricia
authors.initials: P
authors.lastname: Talamás-Rohana
authors.forename: Adolfo René
authors.initials: AR
authors.lastname: Méndez Cruz
authors.forename: Adolfo
authors.initials: A
authors.lastname: Martínez-Palomo
mesh_terms: D000048:Acanthamoeba / Q000201:enzymology / Q000472:pathogenicity / Q000648:ultrastructure; D000562:Amebiasis / Q000201:enzymology / Q000473:pathology; D000818:Animals; D006224:Cricetinae; D004285:Dogs; D019573:Epithelium, Corneal / Q000378:metabolism / Q000469:parasitology / Q000648:ultrastructure; D007365:Intercellular Junctions / Q000378:metabolism / Q000469:parasitology / Q000648:ultrastructure; D061985:Madin Darby Canine Kidney Cells; D008297:Male; D008647:Mesocricetus; D010447:Peptide Hydrolases / Q000378:metabolism*; D015800:Protozoan Proteins / Q000378:metabolism*
chemical_list: D015800:Protozoan Proteins; D010447:Peptide Hydrolases