title: Maintenance of intracellular hypoxia and adequate heat shock response are essential requirements for pathogenicity and virulence of Entamoeba histolytica.
abstract: Adhesion to cells, cytotoxicity and proteolysis are functions required for virulence and pathogenicity of Entamoeba histolytica. However, there was no correlation between these in vitro functions and the early elimination of non-pathogenic E. dispar and non-virulent E. histolytica (nvEh) in experimental amoebic liver abscesses developed in hamsters. Thus, additional functions may be involved in amoebic pathogenicity and virulence. In the present study, an integral experimental assessment, including innovative technologies for analyses of amoebal pathophysiology, cell biology, biochemistry and transcriptomics, was carried out to elucidate whether other cellular processes are involved in amoebal pathogenicity and virulence. In comparison with virulent E. histolytica, the data indicated that the main reasons for the early clearance of nvEh from hamster liver are decreased intracellular H2 O2 detoxification rate and deficient heat shock protein expression, whereas for E. dispar, it is a relatively lower capacity for O2 reduction. Therefore, maintenance of an intracellular hypoxic environment combined with the induction of an adequate parasite response to oxidative stress are essential requirements for Entamoeba survival in the liver, and therefore for pathogenicity.
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico, D.F. 04510, Mexico.|Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México, D.F. 11340, Mexico.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Santos
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico, D.F. 04510, Mexico.
authors.forename: Mario
authors.initials: M
authors.lastname: Nequiz
authors.affiliation: Unité Biologie Cellulaire du Parasitisme, Institut Pasteur, Paris, F-75015, France.|INSERM, U786, Paris, F-75015, France.
authors.forename: Nora Adriana
authors.initials: NA
authors.lastname: Hernández-Cuevas
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico, D.F. 04510, Mexico.
authors.forename: Kahory
authors.initials: K
authors.lastname: Hernández
authors.affiliation: Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico, D.F. 14080, Mexico.
authors.forename: Erika
authors.initials: E
authors.lastname: Pineda
authors.affiliation: Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico, D.F. 14080, Mexico.
authors.forename: Rusely
authors.initials: R
authors.lastname: Encalada
authors.affiliation: Unité Biologie Cellulaire du Parasitisme, Institut Pasteur, Paris, F-75015, France.|INSERM, U786, Paris, F-75015, France.
authors.forename: Nancy
authors.initials: N
authors.lastname: Guillén
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico, D.F. 04510, Mexico.
authors.forename: Erika
authors.initials: E
authors.lastname: Luis-García
authors.affiliation: Laboratorio Nacional de Microscopía Avanzada, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos, 62250, Mexico.
authors.forename: Andrés
authors.initials: A
authors.lastname: Saralegui
authors.affiliation: Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico, D.F. 14080, Mexico.
authors.forename: Emma
authors.initials: E
authors.lastname: Saavedra
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico, D.F. 04510, Mexico.
authors.forename: Ruy
authors.initials: R
authors.lastname: Pérez-Tamayo
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico, D.F. 04510, Mexico.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Olivos-García
mesh_terms: D000818:Animals; D002470:Cell Survival; D006224:Cricetinae; D004748:Entamoeba histolytica / Q000472:pathogenicity*; D018869:Heat-Shock Response; D054884:Host-Pathogen Interactions; D008099:Liver / Q000469:parasitology / Q000473:pathology; D018384:Oxidative Stress; D014774:Virulence