title: Glutathione Transferases Responses Induced by Microcystin-LR in the Gills and Hepatopancreas of the Clam Venerupis philippinarum.
abstract: A multi-method approach was employed to compare the responses of Glutatione Transferases (GSTs) in the gills and hepatopancreas of Venerupis philippinarum to microcystins (MCs) toxicity. In this way, using the cytosolic fraction, the enzymatic activity of GSTs, superoxide dismutase (SOD), serine/threonine protein phosphatases (PPP2) along with the gene expression levels of four GST isoforms (pi, mu, sigma1, sigma2) were investigated in both organs of the clams exposed for 24 h to 10, 50 and 100 μg L(-1) of MC-LR. Cytosolic GSTs (cGSTs) from both organs of the high dose exposed clams were purified by glutathione-agarose affinity chromatography, characterized kinetically and the changes in the expression of cGSTs of the gills identified using a proteomic approach. MC-LR caused an increase in GST enzyme activity, involved in conjugation reactions, in both gills and hepatopancreas (100 μg L(-1) exposure). SOD activity, an indicator of oxidative stress, showed signiﬁcantly elevated levels in the hepatopancreas only (50 and 100 μg L(-1) exposure). No significant changes were found in PPP2 activity, the main target of MCs, for both organs. Transcription responses revealed an up-regulation of sigma2 in the hepatopancreas at the high dose, but no significant changes were detected in the gills. Kinetic analysis evidenced differences between gills of exposed and non-exposed extracts. Using proteomics, qualitative and quantitative differences were found between the basal and inducible cGSTs. Overall, results suggest a distinct role of GST system in counteracting MCs toxicity between the gills and the hepatopancreas of V. philippinarum, revealing different roles between GST isoforms within and among both organs.
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, Porto 4050-123, Portugal. marianarcarneiro@gmail.com.
authors.forename: Mariana
authors.initials: M
authors.lastname: Carneiro
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, Porto 4050-123, Portugal. brunobuendia@gmail.com.
authors.forename: Bruno
authors.initials: B
authors.lastname: Reis
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, Porto 4050-123, Portugal. joana_passo@hotmail.com.
authors.forename: Joana
authors.initials: J
authors.lastname: Azevedo
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, Porto 4050-123, Portugal. acampos@ciimar.up.pt.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Campos
authors.affiliation: IPATIMUP-Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-465, Portugal. hosorio@ipatimup.pt.|Instituto de Investigação e Inovação em Saúde, University of Porto, Porto 4200-135, Portugal. hosorio@ipatimup.pt.|Faculty of Medicine, University of Porto, Porto 4200-319, Portugal. hosorio@ipatimup.pt.
authors.forename: Hugo
authors.initials: H
authors.lastname: Osório
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, Porto 4050-123, Portugal. vmvascon@fc.up.pt.|Department of Biology, Faculty of Sciences, Porto University, Rua do Campo Alegre, Porto 4069-007, Portugal. vmvascon@fc.up.pt.
authors.forename: Vítor
authors.initials: V
authors.lastname: Vasconcelos
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, Porto 4050-123, Portugal. jmartins@ciimar.up.pt.
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Martins
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000633:toxicity*; D049872:Bivalvia; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005880:Gills / Q000187:drug effects* / Q000201:enzymology; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism*; D043143:Hepatopancreas / Q000187:drug effects* / Q000201:enzymology; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008387:Marine Toxins / Q000633:toxicity*; D052998:Microcystins / Q000633:toxicity*; D054648:Protein Phosphatase 2 / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D001427:Bacterial Toxins; D007527:Isoenzymes; D008387:Marine Toxins; D052998:Microcystins; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D054648:Protein Phosphatase 2; C057862:cyanoginosin LR
keywords: V. philippinarum; biomarker; detoxification; enzyme activity; glutathione transferases; microcystins; proteomics; real-time PCR