title: The oxygen reduction pathway and heat shock stress response are both required for Entamoeba histolytica pathogenicity.
abstract: Several species belonging to the genus Entamoeba can colonize the mouth or the human gut; however, only Entamoeba histolytica is pathogenic to the host, causing the disease amoebiasis. This illness is responsible for one hundred thousand human deaths per year worldwide, affecting mainly underdeveloped countries. Throughout its entire life cycle and invasion of human tissues, the parasite is constantly subjected to stress conditions. Under in vitro culture, this microaerophilic parasite can tolerate up to 5 % oxygen concentrations; however, during tissue invasion the parasite has to cope with the higher oxygen content found in well-perfused tissues (4-14 %) and with reactive oxygen and nitrogen species derived from both host and parasite. In this work, the role of the amoebic oxygen reduction pathway (ORP) and heat shock response (HSP) are analyzed in relation to E. histolytica pathogenicity. The data suggest that in contrast with non-pathogenic E. dispar, the higher level of ORP and HSPs displayed by E. histolytica enables its survival in tissues by diminishing and detoxifying intracellular oxidants and repairing damaged proteins to allow metabolic fluxes, replication and immune evasion.
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México D.F., 04510, Mexico. olivosa@yahoo.com.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Olivos-García
authors.affiliation: Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, México 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, México D.F., 04510, Mexico.
authors.forename: Mario
authors.initials: M
authors.lastname: Nequiz
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México D.F., 04510, Mexico.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Santos
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México D.F., 04510, Mexico.
authors.forename: Erika Rubí
authors.initials: ER
authors.lastname: Luis-García
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México D.F., 04510, Mexico.
authors.forename: Marco
authors.initials: M
authors.lastname: Gudiño
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México D.F., 04510, Mexico.
authors.forename: Ruy
authors.initials: R
authors.lastname: Pérez-Tamayo
mesh_terms: D004748:Entamoeba histolytica / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D006360:Heat-Shock Proteins; D010100:Oxygen
keywords: Entamoeba histolytica; Heat shock; Oxidative stress; Pathogenicity