Di Yanan, Aminot Yann, Schroeder Declan C, Readman James W, Jha Awadhesh N
School of Biological Sciences and.
Present address: Institute of Marine Biology, Ocean College, Zhejiang University, People's Republic of China.
Mutagenesis. 2017 Jan;32(1):77-90. doi: 10.1093/mutage/gew049. Epub 2016 Oct 10.
We used the marine bivalve (Mytilus galloprovincialis) to assess a range of biological or biomarker responses following exposure to a model-engineered nanoparticle, C fullerene, 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 C and/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).
我们使用海洋双壳贝类（地中海贻贝）来评估暴露于一种模型工程纳米颗粒C富勒烯单独或与一种模型多环芳烃苯并(α)芘[B(α)P]联合后的一系列生物学或生物标志物反应。采用了一种综合生物标志物方法，包括：(i) “清除率”的测定（个体水平的生理指标），(ii) 组织病理学改变（组织水平），(iii) 使用彗星试验测定DNA链断裂（细胞水平），以及(iv) 通过实时定量聚合酶链反应测定p53（抑癌基因）和ras（癌基因）的转录改变（分子/遗传水平）。此外，测量消化腺中的总谷胱甘肽作为氧化应激的指标。在此，我们报告贻贝在暴露1天后“清除率”没有显著变化，然而在暴露3天后发现“清除率”显著增加。对选定器官（即鳃、消化腺、闭壳肌和外套膜）的组织病理学检查显示，所有组织类型中异常情况的发生率均有所增加，尽管并非所有暴露的生物体都表现出这些异常。值得注意的是，在大多数测试个体中，暴露3天后发现DNA链断裂水平显著增加。此外，观察到p53和ras表达以组织和化学物质特异性模式显著诱导，尽管与其他生物标志物相比，个体间的差异明显更大。总体而言，不同水平的生物学反应显示出不同的敏感性，DNA链断裂和基因表达改变表现出更高的敏感性。此外，在恢复期后观察到的遗传毒性反应是可逆的，这表明贻贝在我们的实验条件下有能力应对毒物C和/或B(α)P。总体而言，在这项全面的研究中，我们证明贻贝是一种合适的海洋无脊椎动物模型物种，可用于研究单独或组合的可能遗传毒物和毒物在不同生物组织水平（即分子到个体水平）上诱导的潜在有害影响。
