National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.
Environ Sci Pollut Res Int. 2010 Mar;17(3):571-81. doi: 10.1007/s11356-009-0112-x. Epub 2009 Mar 4.
BACKGROUND, AIM AND SCOPE: For reliable environmental risk assessment of pollutants, knowledge on the effects at different levels of biological organisation is needed. During the early days of biomarker research in environmental studies approximately two decades ago, biochemical biomarkers were considered as the most promising tool for such purposes. Among these, three enzymes have often been studied: catalase (CAT), glutathione S-transferase (GST) and cholinesterase (ChE). However, despite their intensive research, their measurements in invertebrates have not been commonly applied in environmental risk assessment (ERA) or for regulatory purposes.
In the present review, we summarise our past experiences in biochemical biomarker research in two crustacean species: water flea Daphnia magna and terrestrial isopod Porcellio scaber. This is to orientate their use and to provide recommendations for the use of novel biomarkers in environmental studies, such as proteomic or genomic responses.
We assessed the intrinsic properties of biochemical biomarkers CAT, GST and ChE in the D. magna and the isopod P. scaber. It was found that they are not in agreement with the expectations that were previously given for their use in environmental studies. To advance their use in environmental risk assessment, we suggest that based on their properties, their role should be more specifically defined. ERA includes several distinct steps, among them hazard identification, effect assessment and finally risk characterisation, each of which requires a different type of toxicity data. We recommend that the use of biochemical markers is most appropriate for hazard identification because this is a procedure whose purpose is to characterise the potential hazard of the substance in question and is more flexible in terms of using different tools. Furthermore, our results imply that biochemical markers are not always more sensitive than whole-organism responses, as was anticipated. Their sensitivity depends on the mode of action, duration of exposure and test species. Therefore, we suggest that combining both a battery of biomarkers from different levels of biological organisation and an array of biomarkers within a single level could identify hazard adequately.
The lesson learnt from biochemical biomarkers in environmental studies utilizing crustacean model species is that, for successful application of each group of biomarkers, their intrinsic properties are needed to be known before an (eco)toxicity study is designed. We suggest that a substantial body of experience obtained with biochemical biomarkers should be exploited to new emerging biomarkers in environmental studies in order to facilitate their application.
The future of biomarkers lies in a combination of traditional biochemical and new-generation biomarkers. The latter are not only a potential replacement for existing biomarkers but will also provide new knowledge which might encourage renewed research and development of traditional biomarkers. For research purposes, complete ecotoxicity information should include contributions from molecular fingerprint of an organism, as well as whole organism, population and ecosystem responses. Still, the type of biomarkers used for routine purposes will depend on their reproducibility, their ease of use, robustness, affordability of the methodology and the type of chemicals, organisms and ecosystem of interest.
背景、目的和范围：为了对污染物进行可靠的环境风险评估，需要了解不同层次生物组织的影响。大约二十年前，在环境研究中的生物标志物研究早期，生物化学标志物被认为是此类目的最有前途的工具。其中，经常研究三种酶：过氧化氢酶（CAT）、谷胱甘肽 S-转移酶（GST）和胆碱酯酶（ChE）。然而，尽管它们经过了广泛的研究，但在无脊椎动物中的测量尚未普遍应用于环境风险评估（ERA）或监管目的。
在本综述中，我们总结了我们在两种甲壳类动物（水蚤 Daphnia magna 和陆生等足目 Porcellio scaber）中的生物化学标志物生化标志物研究的过去经验。这是为了指导它们的使用，并为环境研究中使用新型生物标志物（如蛋白质组学或基因组学反应）提供建议。
我们评估了 CAT、GST 和 ChE 生化标志物在水蚤 D. magna 和等足目 P. scaber 中的固有特性。结果发现，它们与先前在环境研究中使用它们的预期不一致。为了推进它们在环境风险评估中的应用，我们建议根据它们的特性，更具体地定义它们的作用。ERA 包括几个不同的步骤，其中包括危害识别、效应评估和最后风险特征描述，每个步骤都需要不同类型的毒性数据。我们建议使用生化标志物最适合危害识别，因为这是一个旨在描述所讨论物质的潜在危害的程序，并且在使用不同工具方面更加灵活。此外，我们的结果表明，生化标志物并不总是比整体生物反应更敏感，这是预期的。它们的敏感性取决于作用模式、暴露时间和测试物种。因此，我们建议，通过组合来自不同生物组织层次的一系列生物标志物和单个层次内的一系列生物标志物，可以充分识别危害。
从利用甲壳类模式生物进行环境研究的生化标志物中吸取的教训是，在设计（生态）毒性研究之前，需要了解每组生物标志物的固有特性，才能成功应用。我们建议，应该利用在环境研究中使用生化标志物获得的大量经验来促进新出现的生物标志物的应用。
生物标志物的未来在于传统生化和新一代生物标志物的结合。后者不仅是现有生物标志物的潜在替代品，还将提供新的知识，这可能鼓励对传统生物标志物进行新的研究和开发。出于研究目的，完整的生态毒性信息应包括生物体的分子指纹以及整个生物体、种群和生态系统的反应。然而，用于常规目的的生物标志物类型将取决于其可重复性、易用性、稳健性、方法的可负担性以及感兴趣的化学品、生物体和生态系统的类型。
