title: Integrated biological responses and tissue-specific expression of p53 and ras genes in marine mussels following exposure to benzo(α)pyrene and C60 fullerenes, either alone or in combination.
abstract: We used the marine bivalve (Mytilus galloprovincialis) to assess a range of biological or biomarker responses following exposure to a model-engineered nanoparticle, C60fullerene, either alone or in combination with a model polycyclic aromatic hydrocarbon, benzo(α)pyrene [B(α)P]. An integrated biomarker approach was used that included: (i) determination of 'clearance rates' (a physiological indicator at individual level), (ii) histopathological alterations (at tissue level), (iii) DNA strand breaks using the comet assay (at cellular level) and (iv) transcriptional alterations of p53 (anti-oncogene) and ras (oncogene) determined by real-time quantitative polymerase chain reaction (at the molecular/genetic level). In addition, total glutathione in the digestive gland was measured as a proxy for oxidative stress. Here, we report that mussels showed no significant changes in 'clearance rates' after 1 day exposure, however significant increases in 'clearance rates' were found following exposure for 3 days. Histopathology on selected organs (i.e. gills, digestive glands, adductor muscles and mantles) showed increased occurrence of abnormalities in all tissues types, although not all the exposed organisms showed these abnormalities. Significantly, increased levels of DNA strand breaks were found after exposure for 3-days in most individuals tested. In addition, a significant induction for p53 and ras expression was observed in a tissue and chemical-specific pattern, although large amounts of inter-individual variability, compared with other biomarkers, were clearly apparent. Overall, biological responses at different levels showed variable sensitivity, with DNA strand breaks and gene expression alterations exhibiting higher sensitivities. Furthermore, the observed genotoxic responses were reversible after a recovery period, suggesting the ability of mussels to cope with the toxicants C60and/or B(α)P under our experimental conditions. Overall, in this comprehensive study, we have demonstrated mussels as a suitable model marine invertebrate species to study the potential detrimental effects induced by possible genotoxicants and toxicants, either alone or in combinations at different levels of biological organisation (i.e. molecular to individual levels).
authors.affiliation: School of Biological Sciences and.|Present address: Institute of Marine Biology, Ocean College, Zhejiang University, People's Republic of China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Di
authors.affiliation: School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth, PL4 8AA, UK.
authors.forename: Yann
authors.initials: Y
authors.lastname: Aminot
authors.affiliation: Marine Biological Association of the United Kingdom (MBA), Citadel Hill, Plymouth, PL1 2PB, UK and.
authors.forename: Declan C
authors.initials: DC
authors.lastname: Schroeder
authors.affiliation: School of Biological Sciences and.|School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth, PL4 8AA, UK.|Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK.
authors.forename: James W
authors.initials: JW
authors.lastname: Readman
authors.affiliation: School of Biological Sciences and a.jha@plymouth.ac.uk.
authors.forename: Awadhesh N
authors.initials: AN
authors.lastname: Jha
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000494:pharmacology / Q000633:toxicity; D049872:Bivalvia / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D020552:Comet Assay; D004247:DNA / Q000187:drug effects; D004249:DNA Damage; D037741:Fullerenes / Q000494:pharmacology / Q000633:toxicity*; D005786:Gene Expression Regulation; D005978:Glutathione / Q000032:analysis / Q000187:drug effects; D023421:Models, Animal; D009928:Organ Specificity; D018384:Oxidative Stress / Q000187:drug effects; D016159:Tumor Suppressor Protein p53 / Q000187:drug effects* / Q000235:genetics; D018631:ras Proteins / Q000187:drug effects* / Q000235:genetics
chemical_list: D037741:Fullerenes; D016159:Tumor Suppressor Protein p53; D001564:Benzo(a)pyrene; D004247:DNA; D018631:ras Proteins; D005978:Glutathione; C069837:fullerene C60