Metal/Metal Oxide Nanomaterials and Oxidative Stress- Are there Harmful Health Effects in Fish for Environmental Exposures?

摘要纳米技术产业对全球经济的价值高达数十亿美元。然而，在纳米级(至少一个维度小于100纳米的颗粒)表现出的独特性质(例如表面反应性)并被用于这些行业，可能会导致有毒性质，而且有越来越多的实验证据证明这一点。从机理的角度来看，产生活性氧簇(ROS)和诱导氧化应激的能力越来越被认为是解释金属/金属氧化物纳米系统中与颗粒相关的一些毒性效应的范例。在这项提案中，我们将让鱼类模型暴露于一些最广泛使用和具有商业重要性的纳米材料[银(Ag)和氧化铈(CeO2)]中，包括对环境现实的情景，以调查氧化应激对健康的有害影响。通过使用高度浓缩的稳定同位素标记NMS、先进的成像方法(例如相干反斯托克拉曼散射)和开发新的生物传感器斑马鱼模型，这项工作将得到极大的加强，因为能够在复杂的环境介质和环境水平的生物水平上检测、量化和表征NMS。将开发具有方便的反应系统来检测氧化应激的生物传感器斑马鱼。在斑马鱼模型中，ROS触发了一种电泳性反应元件(EpRE)报告--通常存在于保护细胞免受氧化损伤的基因的启动子序列中--这将诱导一种绿色荧光蛋白(GFP)，可以通过成像检测到。开发这种新型生物传感器鱼的遗传方法已经在埃克塞特成功地应用于其他污染物。该模型将能够实时识别氧化反应的目标组织。转录组学--测量数千个基因的反应--将被用来确定响应(绿色发光)组织对选定的NM暴露的作用机制(分子途径)。对转基因斑马鱼的研究结果将告知新墨西哥州在英国天然水中接触一种原产于英国河流(鲤鱼)的鱼类，以与西南水务公司合作评估慢性健康。将对水中的颗粒进行详细的表征，以了解颗粒的命运和行为，量化剂量并帮助解释生物效应分析。该项目将以跨学科团队的重要记录和出版物为基础，将广泛的基础设施和技术能力以及行业伙伴关系结合在一起，以促进对具有商业重要性的NMS在现实环境条件下造成危害的潜力的了解。这项工作将为保护淡水水环境和纳米技术产业的可持续发展支持NM风险评估。产生的所有数据都将发表在同行评议的文献和主要期刊上，并通过公共论坛和联络小组向利益攸关方(如公共、监管机构、行业)传播，合作伙伴与这些利益攸关方有广泛的现有联系。建议的项目与NERC关于生物多样性、自然资源和环境的可持续利用、污染和人类健康的科学主题直接相关，也与欧共体的欧洲水框架指令直接相关--以加深我们对污染和废物的环境风险和危害的理解。该项目进一步支持了NERC使命的目标，即促进与理解和利用生物系统有关的创新的、跨学科的高质量研究。

SummaryThe nanotechnology industry is worth $ billions to the global economy. Unique properties (e.g. surface reactivity) exhibited at the nanoscale (particles with at least one dimension less than 100nm) and exploited for use in these industries, however, can result in toxic properties and there is increasing experimental evidence for this. From a mechanistic perspective the ability to generate reactive oxygen species (ROS) and induce oxidative stress is increasingly being recognized as a paradigm to explain some of the toxic effects related to the particle for metal/metal oxide NMs. In this proposal we will undertake exposures of fish models to some of the most widely used and commercially important nanomaterials [silver (Ag) and cerium oxide (CeO2)] including for environmentally realistic scenarios to investigate for harmful health effects via oxidative stress. This work will be enhanced greatly by the ability to detect, quantify and characterise NMs in complex environmental media and organisms at ambient levels, through the use of labelling NMs with highly enriched stable isotopes, advanced imaging methods (e.g. Coherent Antistoke Raman Scattering) and the development of a novel biosensor zebrafish model.A biosensor zebrafish will be developed with a convenient response system for detecting oxidative stress. In the zebrafish model ROS triggers an electrophile responsive element (EpRE) reporter - normally found in the 'starter' (promoter) sequences of genes involved in protecting the cell from oxidative damage - and this will induce a green fluorescent protein (GFP) that can be detected via imaging. The genetic approach to develop this new biosensor fish has been applied successfully at Exeter for other pollutants. The model will enable identification of the target tissues for oxidative responses in real time. Transcriptomics - measuring the responses of many thousands of genes - will be used to identify the effect mechanisms (molecular pathways) in the responsive (green glowing) tissues for selected NM exposures. Findings from the studies with transgenic zebrafish will inform a NM exposure in a UK natural water with a fish species native to UK rivers (carp) to assess for chronic health in a partnership with South West Water. Detailed characterisation of the particles in the water will be undertaken to inform on particle fate and behaviour and to quantify dose and help interpret biological effects analysis. This project will build upon significant track records and publications of the interdisciplinary team, bringing together extensive infrastructure and technological capability, and industry partnerships, to advance understanding on the potential for commercially important NMs to induce harm under realistic environmental conditions. The work will support NM risk assessment for both protection of the freshwater aquatic environment and sustainable development of the nanotech industry. All data generated will be published in the peer reviewed literature, in leading journals, and disseminated via public fora and liaison groups to stakeholders (e.g. public, regulators, industry), which the partners have extensive existing links. The project proposed is directly relevant to NERC's science themes for Biodiversity, Sustainable use of natural resources and Environment, Pollution and Human health, and also to the EC European Water framework Directive - to develop our understanding of the environmental risks and hazards of pollution and wastes. The project furthermore supports the objectives of the NERC's mission to promote innovative, interdisciplinary high quality research that relates to the understanding and exploitation of biological systems.