Percorrer por autor "Gomes, P."
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- Carcinogenic liver fluke Opisthorchis viverrini oxysterols detected by LC-MS/MS survey of soluble fraction parasite extractPublication . Vale, N.; Gouveia, M.J.; Botelho, M.; Sripa, B.; Suttiprapa, S.; Rinaldi, G.; Gomes, P.; Brindley, P.J.; Correia da Costa, J.M.Liquid chromatography in tandem mass spectrometry (LC-MS/MS) has emerged as an informative tool to investigate oxysterols (oxidized derivatives of cholesterol) in helminth parasite associated cancers. Here, we used LC-MS/MS to investigate in soluble extracts of the adult developmental stage of Opisthorchis viverrini from experimentally infected hamsters. Using comparisons with known bile acids and the metabolites of estrogens, the LC-MS data indicated the existence of novel oxysterol derivatives in O. viverrini. Most of these derivatives were ramified at C-17, in similar fashion to bile acids and their conjugated salts. Several were compatible with the presence of an estrogen core, and/or hydroxylation of the steroid aromatic ring A, hydroxylation of both C-2 and C-3 of the steroid ring and further oxidation into an estradiol-2,3-quinone.
- Tumour-like phenotypes in urothelial cells after exposure to antigens from eggs of Schistosoma haematobium: an oestrogen-DNA adducts mediated pathway?Publication . Botelho, Mónica C.; Vale, N.; Gouveia, M.J.; Rinaldi, G.; Santos, J.; Santos, L.L.; Gomes, P.; Brindley, P.J.; Correia da Costa, José ManuelChronic infection with the blood fluke, Schistosoma haematobium, is associated with squamous cell carcinoma of the bladder. Previously, it has been shown that soluble extracts of mixed sex adult S. haematobium worms (SWAP) are tumourigenic, both in vitro and in vivo. In addition, oestrogen-related molecules in SWAP of S. haematobium down-regulate oestrogen receptors (ERs) alpha and beta in oestrogen responsive cells. Moreover, schistosome oestrogens occur in sera of persons with schistosomiasis haematobia and repress transcription of ERs in urothelial cells. Given that eggs of S. haematobium are the developmental stage directly responsible for urogenital disease during schistosomiasis haematobia, we suspected that soluble antigens from S. haematobium eggs exhibit similar or more potent tumorigenic capacity. Here we investigated the tumorigenic potential of soluble egg antigens (Sh-SEA) of S. haematobium and the endocrine system in favouring parasitism by schistosomes. The findings confirmed that 6.25μg/ml of Sh-SEA was enough to stimulate cell proliferation, reduce apoptosis and increase oxidative stress of Sh-SEA-exposed urothelial cells. In addition, genotoxic effects of Sh-SEA on these cells were determined by using alkaline single-cell gel electrophoresis (Comet). Furthermore, Liquid Chromatography Diode Array Detection Electron Spray Ionisation Mass Spectrometry indicated the presence of catechol-oestrogens in S. haematobium SEA. A prospective oestrogen-DNA adduct mediated pathway in S. haematobium egg induced bladder cancer is also discussed.
- Urinary Estrogen Metabolites and Self-Reported Infertility in Women Infected with Schistosoma haematobiumPublication . Santos, J.; Gouveia, M.J.; Vale, N.; Delgado, M. de L.; Gonçalves, A.; da Silva, J.M.; Oliveira, C.; Xavier, P.; Gomes, P.; Santos, L.L.; Lopes, C.; Barros, A.; Rinaldi, G.; Brindley, P.J.; da Costa, J.M.; Sousa, M.; Botelho, M.C.Schistosomiasis is a neglected tropical disease, endemic in 76 countries, that afflicts more than 240 million people. The impact of schistosomiasis on infertility may be underestimated according to recent literature. Extracts of Schistosoma haematobium include estrogen-like metabolites termed catechol-estrogens that down regulate estrogen receptors alpha and beta in estrogen responsive cells. In addition, schistosome derived catechol-estrogens induce genotoxicity that result in estrogen-DNA adducts. These catechol estrogens and the catechol-estrogen-DNA adducts can be isolated from sera of people infected with S. haematobium. The aim of this study was to study infertility in females infected with S. haematobium and its association with the presence of schistosome-derived catechol-estrogens.