Diagnosing Toxicant Specific Disruption of Sexual Development in Wild Fish using Metabolomics

环境监测对于确定污染和气候变化等人为应激源是否正在损害生活在我们水环境中的动物非常重要。也许令人惊讶的是，英国一些河流中多达一半的水来自污水处理厂的污水，这可能会影响当地的野生动物。几年前，我们发现生活在英国许多河流中的鱼类的生殖系统因暴露于污水处理厂污水中含有的化学物质而受损，这些化学物质扰乱了人体的性激素系统。尽管科学家现在有了确定鱼类生殖系统是否受到损害的工具，但这些工具通常涉及杀死鱼类和检查解剖组织，这对于广泛的影响监测方案来说并不理想。此外，现有的工具没有提供太多造成损害的污染物类型的信息。这些信息对环境监管机构非常有用，可以用来帮助追踪污染物(S)的来源(S)，并帮助制定策略，在这些化学物质损害鱼类和其他动物之前将其从水中去除。这项研究项目的目的是开发和应用一种新技术(称为代谢组学)，通过测量鱼类血液和组织中的大量小分子(称为代谢物)来评估鱼类的健康。这些测量是如此详细，以至于它们可以准确地提供鱼类生殖系统的哪些部分(或“新陈代谢途径”)受损的信息。这种方法现在也被成功地用于医院评估人类疾病，我们将使用它来寻找野生鱼类的独特模式或“特征”，以确定它们是否受到损害，如果是的话，是由河流中的什么类型的污染物造成的。为了实现这一点，我们首先需要在实验室中将鱼类(蟑螂，我们在其中表现出广泛的性干扰)暴露在被怀疑与野生鱼类繁殖中断有关的单一污染物中，并测量每种化学物质造成的损害。这些实验将包括鱼的短期和长期曝光，其中一些将持续两年，以准确模拟真实的环境场景。然后，我们将训练计算机识别污染物引起的损害的特定模式，这些计算机将在野生鱼中搜索这些模式，就像它们可以通过搜索基因指纹来匹配在犯罪现场收集的指纹一样。代谢组学的另一个优势是，与大多数现有的环境监测方法不同，它可以快速进行，只需从鱼身上提取极少量的血液，然后将血液释放回河流中。最后一个好处是，对血液中某些代谢物的测量，特别是那些被称为性类固醇的代谢物，可以告诉我们许多关于鱼的生殖健康的信息，即这些分子测量与整个鱼的整体健康状况之间有密切的关系。代谢组学中使用的工具更多地与化学实验室联系在一起，包括核磁共振光谱和质谱学。此外，由于将产生大量数据，还需要数学专家。我们的多学科团队拥有化学、生物、毒理学和数学方面的专业知识，并汇集了来自伯明翰大学和埃克塞特大学以及环境局、一家自来水公司和一家质谱学公司的科学家。最终，这项研究的结果将为最终用户开发一套更合适的方法和实用工具(称为“生物标记物”)，有助于环境影响评估和监管当局对排放的监管。这将提供更多关于我们河流健康的知识，从而保护我们的水产资源和生物多样性。

Environmental monitoring is important for determining if man-made stressors, such as pollution and climate change, are damaging animals that live in our aquatic environment. Perhaps surprisingly, up to half of the water flowing in some UK rivers originates from the effluent of sewage treatment plants and this can affect the native wildlife. Several years ago we found that the reproductive systems in fish living in many UK rivers had been damaged by exposure to chemicals contained in the sewage treatment plant effluents that disrupt the body's sex hormone systems. Although scientists now have tools for determining if fish reproductive systems have been damaged, these generally involve killing the fish and examining dissected tissues, which is not ideal for extensive impact monitoring programmes. Also, the existing tools do not provide much information on the types of pollutants that are causing the damage.Such information would be very useful to environmental regulators,and could be used to help trace the source(s) of pollutant(s) and to help design strategies to remove these chemicals from the water before they damage fish and other animals. The aim of this research project is to develop and apply a new technology (called 'metabolomics') for assessing the health of fish by measuring large numbers of small molecules (called metabolites) in their blood and tissues. These measurements are so detailed that they can provide information on exactly which parts (or 'metabolic pathways') of the fish's reproductive system are damaged. This approach is now also being used successfully in hospitals to assess human diseases, and we will use it to look for unique patterns or 'signatures' in wild fish that would determine if they are damaged and if so by what types of pollutants in the river. To achieve this we will first need to expose fish (the roach, in which we have shown widespread sexual disruption) in the laboratory to single pollutants that are suspected to be involved with disruption of reproduction in wild fish, and measure the damage caused by each of these chemicals. These experiments will include short and long exposures of the fish, some of which will last for two years to accurately mimic real environmental scenarios. Then we will 'train' computers to recognize the specific patterns of pollutant-induced damage, and those computers will search for these patterns in the wild fish in much the same way they can search through genetic fingerprints to match those collected at a crime scene. Another advantage of 'metabolomics' is that unlike most existing environmental monitoring methods, it can be conducted rapidly using only a minute volume of blood taken from the fish, which can then be released back into the river. The final advantage is that the measurements of certain metabolites in the blood, particularly those called 'sex steroids', can tell us a lot about the fish's reproductive health, i.e., there is a close relationship between these molecular measurements and the overall fitness of the whole fish. The tools used in 'metabolomics' are more commonly associated with chemistry labs and include nuclear magnetic resonance spectroscopy and mass spectrometry. Also, because of the immense amount of data that will be produced, experts in mathematics will also be needed. Our multi-disciplinary team has expertise in chemistry, biology, toxicology and mathematics, and brings together scientists from the Universities of Birmingham and Exeter, as well as the Environment Agency, a Water company and a Mass Spectrometry company. Ultimately the results of this study will enable development of a more appropriate methodology and practical set of tools (called 'biomarkers') for end-users, which can contribute to environmental impact assessments and the regulation of discharges by the regulatory authorities. This will provide a more informed knowledge of the health of our rivers thus protecting our aquatic resources and biodiversity.