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

纳米技术产业对全球经济的价值高达数十亿美元。然而，在纳米尺度（至少一个维度小于100纳米的颗粒）上展示的独特性质（例如表面反应性）和用于这些工业的开发可能导致毒性，并且有越来越多的实验证据表明这一点。从机制的角度来看，产生活性氧（ROS）和诱导氧化应激的能力越来越被认为是解释金属/金属氧化物纳米材料颗粒相关毒性效应的一个范例[NMs]。在这个项目中，我们将进行鱼类模型暴露于一些最广泛使用和商业上重要的NMs，银（Ag）和氧化铈（CeO2），并调查环境现实情况，以确定氧化应激对健康的潜在有害影响。通过使用高富集稳定同位素标记的纳米粒子，先进的成像方法（例如相干反斯托克拉曼散射）和开发一种新型生物传感器斑马鱼模型，在复杂的环境介质和生物体中检测、量化和表征纳米粒子的能力将大大增强这项工作。生物传感器斑马鱼将开发一个方便的响应系统来检测氧化应激。在斑马鱼模型中，ROS触发亲电反应元件（EpRE）报告因子——通常在保护细胞免受氧化损伤的基因的“启动子”（启动子）序列中发现——这将诱导一种可以通过成像检测到的绿色荧光蛋白（GFP）。利用遗传方法开发这种新型生物传感器鱼已经在埃克塞特大学成功应用于其他污染物。该模型将能够实时识别氧化反应的目标组织。转录组学——测量成千上万个基因的反应——将被用于确定对选定的纳米照射有反应的（发出绿色光的）组织中的作用机制（分子途径）。转基因斑马鱼的研究结果将为与西南水务公司合作，在天然水中与英国河流中的一种鱼类（鲤鱼）接触NM提供信息，以评估其慢性健康状况。将对水中颗粒进行详细的特征描述，以了解颗粒的命运和行为，并帮助了解它们是否可被鱼类吸收。该项目将以跨学科团队的重要记录和出版物为基础，汇集广泛的基础设施和技术能力，以及行业合作伙伴关系，以促进对商业上重要的纳米材料在现实环境条件下造成危害的潜力的理解。这项工作将支持纳米风险评估，以保护淡水水生环境和纳米技术产业的可持续发展。所产生的所有数据将发表在同行评议文献和主要期刊上，并通过公共论坛和联络小组传播给与合作伙伴有广泛现有联系的利益攸关方（如公众、监管机构、行业）。拟议的项目与NERC的生物多样性、自然资源和环境的可持续利用、污染和人类健康等科学主题直接相关，也与欧共体《欧洲水框架指令》有关，以增进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NERC的使命目标，即促进与生物系统的理解和利用有关的创新，跨学科的高质量研究。

The 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 nanomaterials [NMs]. In this project we will undertake exposures of fish models to some of the most widely used and commercially important NMs, silver (Ag) and cerium oxide (CeO2), and investigate environmentally realistic scenarios to identify potentially 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 NMs that are labelled 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 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 help inform on their availability for uptake into fish. This project will build upon the 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), with 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 NERC's mission to promote innovative, interdisciplinary high quality research that relates to the understanding and exploitation of biological systems.