title: Rhodnius prolixus: modulation of antioxidant defenses by Trypanosoma rangeli.
abstract: Trypanosoma rangeli is a protozoan parasite of insects and mammals that is challenged by the constant action of reactive oxygen species, generated either by its own metabolism or through the host immune response. The aim of this work was to investigate whether T. rangeli is able to modify the redox state of its insect vector, Rhodnius prolixus, through the modulation of such antioxidant enzymes as superoxide dismutase (SOD), catalase, and GPx present in the midgut of the insect. We verified that in R. prolixus fed with blood infected with T. rangeli there is an increase in SOD activity in the anterior and posterior midguts. However, the activities of enzymes related to hydrogen peroxide and hydroperoxides metabolism, such as catalase and GPx, were decreased in relation to the insect control group, which was only fed blood. These changes in the redox state of the vector led to an increase in lipid peroxidation and thiol oxidation levels in the anterior and posterior midgut tissues. We also verified that the addition of 1 mM GSH in the blood meal of the infected insects increased the proliferation of these parasites by 50%. These results suggest that there is an increase in oxidative stress in the insect gut during T. rangeli infection, and this condition could contribute to the control of the proliferation of these parasites.
authors.affiliation: Institute of Medical Biochemistry, Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590 Rio de Janeiro, RJ, Brazil; Institute of National Science and Technology of Structural Biology and Bioimage (INCTBEB), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590 Rio de Janeiro, RJ, Brazil.
authors.forename: Daniela
authors.initials: D
authors.lastname: Cosentino-Gomes
authors.affiliation: Institute of Medical Biochemistry, Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590 Rio de Janeiro, RJ, Brazil; Institute of National Science and Technology of Structural Biology and Bioimage (INCTBEB), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590 Rio de Janeiro, RJ, Brazil. Electronic address: rocco@bioqmed.ufrj.br.
authors.forename: Nathália
authors.initials: N
authors.lastname: Rocco-Machado
authors.affiliation: Institute of Medical Biochemistry, Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590 Rio de Janeiro, RJ, Brazil; Institute of National Science and Technology of Structural Biology and Bioimage (INCTBEB), CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590 Rio de Janeiro, RJ, Brazil. Electronic address: meyer@bioqmed.ufrj.br.
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Meyer-Fernandes
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007303:Insect Vectors / Q000201:enzymology / Q000469:parasitology*; D015227:Lipid Peroxidation; D010084:Oxidation-Reduction; D012239:Rhodnius / Q000201:enzymology / Q000469:parasitology*; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D057509:Trypanosoma rangeli / Q000502:physiology*
chemical_list: D013438:Sulfhydryl Compounds; D006861:Hydrogen Peroxide; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase
keywords: Antioxidant enzymes; Parasite–host interaction; Reactive oxygen species; Rhodnius prolixus; Trypanosoma rangeli