title: Hypoxia, hypoxia-inducible factor-1α and vascular endothelial growth factor in a murine model of Schistosoma mansoni infection.
abstract: Schistosomiasis mansoni is a chronic parasitic disease where much of the symptomatology is attributed to granuloma formation, an immunopathological reaction against Schistosoma eggs. To more clearly understand the immunopathology of schistosomiasis, the tissue microenvironment generated by S. mansoni infected mice was investigated. Using the hypoxia marker pimonidazole, we provide immunohistochemical evidence that hypoxia occurred in inflammatory cells infiltrated around the eggs and cells surrounding granulomas in the liver, intestine, spleen and lungs of infected mice. Hypoxia-inducible factor-1α (HIF-1α) was mainly expressed in inflammatory cells surrounding the eggs and in hepatocytes surrounding cellular and fibrocellular granulomas in infected mouse liver. HIF-1α expression was also verified in granulomas in the other tissues tested (intestine, spleen and lungs). Vascular endothelial growth factor (VEGF) expression was observed in the extracellular space surrounding inflammatory cells in liver granuloma. The VEGF expression pattern verified in infected mouse liver was very similar to that observed in the other tissues tested. A strong positive correlation occurred between pimonidazole binding and HIF-1α and VEGF expression in the tissues tested, except for lung. This work is the first evidence that infection by a helminth parasite, S. mansoni, produces a hypoxic tissue microenvironment and induces HIF-1α and VEGF expression.
authors.affiliation: Department of Animal Biology, Biology Institute, Universidade Estadual de Campinas, Caixa Postal 6109, Cep 13083-970, Campinas, SP, Brazil.
authors.forename: Alexandra Paiva
authors.initials: AP
authors.lastname: Araújo
authors.forename: Tarsila Ferraz
authors.initials: TF
authors.lastname: Frezza
authors.forename: Silmara Marques
authors.initials: SM
authors.lastname: Allegretti
authors.forename: Selma
authors.initials: S
authors.lastname: Giorgio
mesh_terms: D000818:Animals; D015687:Cell Hypoxia / Q000502:physiology*; D004195:Disease Models, Animal; D005260:Female; D006099:Granuloma / Q000378:metabolism / Q000473:pathology; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000096:biosynthesis*; D007150:Immunohistochemistry; D051379:Mice; D012555:Schistosomiasis mansoni / Q000378:metabolism* / Q000473:pathology*; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis*
chemical_list: C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D042461:Vascular Endothelial Growth Factor A