环状RNA及其在生态毒理学研究中的应用进展

环状RNA（circular RNAs,circRNAs）是一类共价闭合环状非编码RNA,具有进化上保守、结构上稳定、组织特异性表达等特点。CircRNAs可作为miRNAs海绵影响其对基因的调控,还可与RNA结合蛋白（RNA binding proteins,RBPs）相互作用,也有研究表明某些circRNAs还具有被翻译成蛋白质的潜能。CircRNAs已被证实对某些疾病具有特异性、稳定性和调节功能,如癌症、糖尿病、心血管疾病、神经退行性疾病等,其可作为潜在的诊断、预后生物标志物和治疗靶点。最近,有研究发现circRNAs参与了环境化学污染物诱导的毒性效应发生及发展的过程。目前,生态毒理学研究中评价环境化学污染物和毒效应之间关系的毒性终点通常会受遗传多态性和表观遗传学影响,考虑到经环境化学污染物暴露后生物体内circRNAs差异性表达的现象,或许在生态毒理学研究中circRNAs也有作为生物标志物的可能性。基于此,对circRNAs的生物合成与降解、生物学功能、分析方法及其目前在生态毒理学研究中的应用展开综述,并对其作为分子生物标志物在环境污染物暴露早期诊断和生态风险评价中的应用进行了展望,以期为生态毒理学研究和环境风险评价提供参考。     

多溴二苯醚的环境暴露与生态毒理研究进展

多溴二苯醚(PBDEs)是一类具有生态风险的新型环境有机污染物.作为阻燃剂,PBDEs已经被愈来愈广泛地添加到工业产品中,并因此对大气、水体、沉积物和土壤等环境介质及相关生态系统产生日益广泛的污染.鉴于这一环境新问题的产生,本文基于有限的资料,初步探讨了PBDEs的人为来源和环境暴露途径,大致给出了PBDEs在不同生物和人体不同组织器官中可能的存在及含量水平;在扼要介绍其基本性质的基础上,从甲状腺、神经系统和生殖发育毒性等三个方面分析了PBDEs对动物和人体可能产生的毒性效应与生态影响,以及PBDEs在生态系统中可能具有的生物积累和生物放大风险;并对今后研究PBDEs的环境暴露与生态效应以及人体健康影响等方面的工作重点进行了展望.     

环境污染物对水生生物产生氧化压力的分子生物标志物

为了能够建立一种简单、快速、准确的环境污染监测预警体系,人们进行了广泛的研究,其中有关环境污染物对分子生物标志物的影响已成为研究热点。生物体内的氧自由基和其它活性氧分子（ROS）对组织和细胞成分造成的伤害,称之为氧化压力,环境中的有毒物质能够对生物体产生不同程度的氧化压力。生物体内的强氧化剂或体外因素（如环境污染物）引起的强氧化物与抗氧化防御系统之间的平衡能够用于评估环境压力对生物体产生影响的程度,尤其适合于评估不同种化学物质引起氧化损伤的程度。这些抗氧化防御系统及其对氧化压力的敏感性在环境毒物学研究中占有非常重要的地位,大量研究结果表明：过渡金属、多环芳烃、有机氯和有机磷农药、多氯联苯、二氧芑和其它异型物质都能够对生物体产生氧化压力。这些有毒物质能够引起各种有害影响,如对膜脂、DNA和蛋白产生损伤;改变抗氧化酶的活性等。总结了这种氧化压力的研究进展情况,并讨论了这些分子生物标志物在水生生物中的应用。     

RNA‑seq技术在水生生物生态毒理学中的应用进展

水域是地球环境的重要组成部分,也是最易受污染的生态系统之一。水生态系统中不同营养级别的水生生物可通过摄食、接触等多种途径摄入水体中的污染物。因此,监测水域污染物对水生生物和生态系统的影响,解析污染物对不同水生生物的毒性机制,筛选敏感、有效的生物标志物对生态毒理学研究和环境风险评价具有重要意义。RNA测序（RNA sequencing,RNA?seq）技术因所需样品量少,且不需参考序列,可在整体水平上鉴定基因差异表达,成为水生生物生态毒理学研究的最佳方法之一。基于此,介绍了RNA?seq技术的基本流程与数据分析过程,对该技术在不同生态位的水生生物（如鱼类、两栖类、贝类、甲壳类等）生态毒理学中的应用展开综述,并对RNA?seq技术面临的不足、挑战及发展趋势进行探讨,以期为该技术在水生生物生态毒理学研究中的应用,尤其是水生态环境中污染物胁迫水生生物机制的阐明及污染水域生态环境恢复提供参考。     

污染胁迫下的蚯蚓蛋白质组学研究进展

随着蛋白质组学的发展和每年有大量环境污染物进入土壤环境中,污染胁迫模式动物的相关生物标志物受到日益关注。蚯蚓,作为土壤中最大的无脊椎动物,是研究和评价土壤生态污染良好的模式动物。研究蚯蚓的蛋白质组学,对于寻找环境生态污染相关生物标志物和阐明生态毒理学机制有着十分重要的现实意义。目前已知的污染胁迫下蚯蚓蛋白质组学研究,提供了几个特定污染物胁迫蚯蚓的蛋白表达谱。这些蛋白涉及许多生物学过程,例如信号传导、糖酵解、能量代谢、分子伴侣和转录调节,提示了相关污染物可能的生态毒理学机制,有望成为潜在的生物标志物,用于有毒污染物的监测,但其特异性需要进一步试验的验证。对蚯蚓受污染胁迫的蛋白质组表达谱及潜在生物标志物进行简要综述。     

Pelagic food webs: Responses to environmental processes and effects on the environment

Changes in both the environment and environmental research have led to the development of new protocols and approaches. These new approaches consider both the effects of changes in the global environment on living organisms (i.e. the responses of ecosystems to environmental processes) and the feedback responses of these organisms and ecosystems (i.e. the effects of living organisms on the environment). The present paper focuses on pelagic food webs in aquatic ecosystems. We examine three major effects of global environmental changes on aquatic organisms: (i) the release of pollutants and biological agents in lakes and nearshore marine waters; (ii) the loss of biodiversity and the collapse of commercially exploited resources that were heretofore renewable. We develop detailed examples of the effects of human activities on marine organisms (i.e. the effects of nutrient supply on the structure of pelagic food webs in marine systems. Finally, we examine (iii) the food-web-controlled exchanges of CO₂ between the atmosphere and the ocean, as a feedback effect of pelagic ecosystems on the global environment with respect to the ongoing climate change.     

Transcriptome profiling in crustaceans as a tool for ecotoxicogenomics

Chemicals released into the environment have the potential to affect various species and it is important to evaluate such chemical effect on ecosystems, including aquatic organisms. Among aquatic organisms, Daphnia magna has been used extensively for acute toxicity or reproductive toxicity tests. Although these types of tests can provide information on hazardous concentrations of chemicals, they provide no information on their mode of action. Recent advances in toxicogenomics, the integration of genomics with toxicology, have the potential to afford a better understanding of the responses of aquatic organisms to pollutants. In a previous study, we developed an oligonucleotide-based DNA microarray with high reproducibility using a Daphnia expressed sequence tag (EST) database. In this study, we increased the number of genes on the array and used it for a careful ecotoxicogenomic assessment of Daphnia magna. The DNA microarray was used to evaluate gene expression profiles of neonate daphnids exposed to beta-naphthoflavone (bNF). Exposure to this chemical resulted in a characteristic gene expression pattern. As the number of the genes on an array was increased, the number of genes that were found to respond to the chemicals was also increased, which made the classification of the toxic chemicals easier and more accurate. This newly developed DNA microarray can be useful for a obtaining a better mechanistic understanding of chemical toxicity effects on a common freshwater organism.     

微塑料污染对浮游生物影响研究进展

微塑料作为一种新型的环境污染物,大量存在于水环境中,给水生生物带来了极大的危害。浮游生物是水生食物链的基础,是水生生态系统物质循环和能量流动的重要环节;同时,浮游生物也是对各种环境污染物最敏感的类群。了解微塑料对浮游生物的影响是评价其生态风险的重要依据。本文介绍了环境中微塑料来源、特征及水生态系统微塑料污染现状,阐述了微塑料对水生生物的直接和间接危害,并重点聚焦于浮游植物和浮游动物,从个体、种群和群落的层次详细总结了微塑料的影响及其作用机制。最后,本文指出当前针对浮游生物微观基因和蛋白质组学,以及宏观种群和群落响应等方面的研究还非常缺乏,为今后开展微塑料危害研究提供参考。     

Non-traditional targets of endocrine disrupting chemicals: the roots of hormone signaling

The topic of endocrine disruption and the broad range of physiologicaleffects caused by endocrine disrupting chemicals (EDCs) canonly be meaningfully framed within an ecological and evolutionarycontext. Environmental pollutants and EDCs operate by disruptingthe "chemical communication" that coordinates signaling withinan organism. Here we discuss how EDCs are also able to disruptthe chemical communication between plants and soil bacterianecessary for initiating nitrogen-fixing symbiosis. We alsoexamine, through examples of pollutant-related impacts on awide range of invertebrates, the need for identifying emergingtargets of EDCs. We suggest broadening the defined field ofendocrine disruption to encompass the effects of synthetic chemicalsthat interfere with signaling and communication, not only withinan organism, but also between organisms and linking ecosystems.The ecological consequences of failing to recognize novel targetsof chemical pollutants and EDCs may be a net loss of biologicaldiversity and a further imbalance of the global nitrogen cycle.     

Environmental proteomics and metallomics

Monitoring environmental pollution using biomarkers requires detailed knowledge about the markers, and many only allow a partial assessment of pollution. New proteomic methods (environmental proteomics) can identify proteins that, after validation, might be useful as alternative biomarkers, although this approach also has its limitations, derived mainly from their application to non-model organisms. Initial studies using environmental proteomics were carried out in animals exposed to model pollutants, and led to the concept of protein expression signatures. Experiments have been carried out in model organisms (yeast, Arabidopsis, rat cells, or mice) exposed to model contaminants. Over the last few years, proteomics has been applied to organisms from ecosystems with different pollution levels, forming the basis of an environmental branch in proteomics. Another focus is connected with the presence of metals bound to biomolecules, which adds an additional dimension to metal-biomolecule and metalloprotein characterization - the field of metallomics. The metallomic approach considers the metallome: a whole individual metal or metalloid species within a cell or tissue. A metallomic analytical approach (MAA) is proposed as a new tool to study and identify metalloproteins.     

Pollution biomarkers in estuarine animals: critical review and new perspectives

In this review, recent developments in monitoring toxicological responses in estuarine animals are analyzed, considering the biomarker responses to different classes of pollutants. The estuarine environment imposes stressful conditions to the organisms that inhabit it, and this situation can alter their sensitivity to many pollutants. The specificity of some biomarkers like metallothionein tissue concentration is discussed in virtue of its dependence on salinity, which is highly variable in estuaries. Examples of cholinesterase activity measurements are also provided and criteria to select sensitive enzymes to detect pesticides and toxins are discussed. Regarding non-specific biomarkers, toxic responses in terms of antioxidant defenses and/or oxidative damage are also considered in this review, focusing on invertebrate species. In addition, the presence of an antioxidant gradient along the body of the estuarine polychaete Laeonereis acuta (Nereididae) and its relationship to different strategies, which deal with the generation of oxidative stress, is reviewed. Also, unusual antioxidant defenses against environmental pro-oxidants are discussed, including the mucus secreted by L. acuta. Disruption of osmoregulation by pollutants is of paramount importance in several estuarine species. In some cases such as in the estuarine crab Chasmagnathus granulatus, there is a trade off between bioavailability of toxicants (e.g. metals) and their interaction with key enzymes such as Na(+)-K(+)-ATPase and carbonic anhydrase. Thus, the metal effect on osmoregulation is also discussed in the present review. Finally, field case studies with fish species like the croaker Micropogonias furnieri (Scianidae) are used to illustrate the application of DNA damage and immunosuppressive responses as potential biomarkers of complex mixture of pollutants.     

Endocrine disruptors in marine organisms: approaches and perspectives

Organic pollutants exhibiting endocrine disrupting activity (Endocrine Disruptors--EDs) are prevalent over a wide range in the aquatic ecosystems; most EDs are resistant to environmental degradation and are considered ubiquitous contaminants. The actual potency of EDs is low compared to that of natural hormones, but environmental concentrations may still be sufficiently high to produce detrimental biological effects. Most information on the biological effects and mechanisms of action of EDs has been focused on vertebrates. Here we summarize recent progress in studies on selected aspects of endocrine disruption in marine organisms that are still poorly understood and that certainly deserve further research in the near future. This review, divided in four sections, focuses mainly on invertebrates (effects of EDs and mechanisms of action) and presents data on top predators (large pelagic fish and cetaceans), a group of vertebrates that are particularly at risk due to their position in the food chain. The first section deals with basic pathways of steroid biosynthesis and metabolism as a target for endocrine disruption in invertebrates. In the second section, data on the effects and alternative mechanisms of action of estrogenic compounds in mussel immunocytes are presented, addressing to the importance of investigating full range responses to estrogenic chemicals in ecologically relevant invertebrate species. In the third section we review the potential use of vitellogenin (Vtg)-like proteins as a biomarker of endocrine disruption in marine bivalve molluscs, used worldwide as sentinels in marine biomonitoring programmes. Finally, we summarize the results of a recent survey on ED accumulation and effects on marine fish and mammals, utilizing both classical biomarkers of endocrine disruption in vertebrates and non-lethal techniques, such as non-destructive biomarkers, indicating the toxicological risk for top predator species in the Mediterranean. Overall, the reviewed data underline the potential to identify specific types of responses to specific groups of chemicals such as EDs in order to develop suitable biomarkers that could be useful as diagnostic tools for endocrine disruption in marine invertebrates and vertebrates.     

Potential Indicators of Stress Response Identified by Expressed Sequence Tag Analysis of Hemocytes and Embryos from the American Oyster, Crassostrea virginica

A pilot program was initiated to identify genes from the American oyster, Crassostrea virginica, that are potentially involved in the stress response for use as bioindicators of exposure to environmental pollutants and to toxic and infectious agents. A PCR-based method was used to construct cDNA libraries from pooled embryos and the hemocytes of a single individual. A total of 998 randomly selected clones (expressed sequence tags, ESTs) were sequenced. Approximately 40% of the ESTs are novel sequences. Several potential biomarkers identified include an antimicrobial peptide, recognition molecules (lectin receptors), proteinases and proteinase inhibitors, and a novel metallothionein. Diversity analysis shows that 363 and 286 unique genes were identified from the hemocyte and embryo libraries, respectively, indicating that full-scale EST collection is a valuable approach for the discovery of new genes of potential significance in the molluscan stress response. Received May 11, 2001; accepted July 16, 2001     

Biomarker/bioindicator response profiles of organisms can help differentiate between sources of anthropogenic stressors in aquatic ecosystems

Aquatic ecosystems can be chronically stressed by multiple environmental factors which originate from a variety of point and non-point sources. In addition, these stressors may vary both spatially and temporally, and, combined with synergestic and cumulative interactions of these stressors, complicate the interpretation and evaluation of stress responses in organisms. To help identify and differentiate between sources of anthropogenic stressors in aquatic systems, a diagnostic approach based on exposure-response profiles in sentinel organisms was developed from the known effects of various anthropogenic activities on biological systems. To generate these exposure-effects profiles, biomarkers of exposure were plotted against bioindicators of corresponding effects for several major anthropogenic activities including petrochemical, pulp and paper, domestic sewage, mining operations, land-development, and agricultural activities. Biomarkers of exposure to environmental stressors varied widely depending on the type of anthropogenic activity involved. Bioindicator effects, however, including histopathological lesions, bioenergetic status, growth, reproductive impairment, and community-level endpoints were similar among several of the major anthropogenic activities because responses at these higher levels are less specific to stressors than are biomarkers. This approach appears useful for helping to identify and diagnose sources of stress in environments impacted by multiple stressors. By identifying the types and sources of environmental stressors impacting key components of biological systems, aquatic ecosystems can be more effectively protected, regulated, and managed to help improve and maintain environmental quality and ecosystem fitness.     

Identifying and Predicting Biological Risks Associated With Manufactured Nanoparticles in Aquatic Ecosystems

Nanotechnology has great potential for revolutionizing the treatment of disease, optimizing manufacturing processes and consumer products, and remediating polluted environments. Increased use and disposal of products containing nanoparticles will inevitably result in their accumulation in aquatic ecosystems via direct input and runoff from contaminated soils. Aquatic organisms are particularly susceptible to pollutants due to their large, fragile respiratory epithelium. This potential toxicity can be exacerbated by common stressors, such as changes in water temperature, salinity, pH, and oxygen levels, and must be considered in environmental risk assessments. The unique properties of manufactured nanoparticles present serious problems for risk assessment strategies, and there is a concern in the regulatory community that standard toxicological methods may be inadequate to address these compounds. Our capacity to detect and quantify nanoparticles is extremely limited, especially in complex biological, soil, or water samples. The distinctive chemistry and physical structure of each nanomaterial will determine its bioavailability, and these parameters can be altered over time or with changes in water chemistry. The use of advanced analytical techniques, such as functional genomics, proteomics, and metabolomics, can provide a global assessment of the biological response to a novel chemical and will be important in determining the potential toxicity of nanoparticles. Industry should adopt a proactive approach to identifying potential risks to aquatic ecosystems so that the benefits of nanotechnology can be fully realized.     

Quantitative analyses of relationships between ecotoxicological effects and combined pollution

In 1939, Bliss first defined the toxicity of poisons applied jointly by antagonism, synergism, addition and dependent action? He thought that this kind of joint effects were only subject to their natural chemi-cal properties[1]. With the increasing categories and quantities of contaminants released into the environ-ment since the 1970s[2,3], effects of combined contamination and the interactions between pollutants have been increasingly seen as a source of concern[4—7]. Besides the regularly …     

模拟水生态系统及其在环境研究中的应用

随着70年代污染生态毒理学的发展,微宇宙作为评价化学品的环境影响的有力工具日益受到重视。由于从点源和非点源释放的化学物质可经直接或间接途径进入水生态系统,水生微宇宙在环境研究中的应用发展很快。早期的研究工作侧重于化学污染物在水环境的归宿。自70年代末以来,研究注意力逐渐集中于有毒物质在水生态系统内不同生物学组织水平上的生态学效应。本文分下列4个方面进行述评:(1)关于模拟生态系统的若干基本概念;(2)应用于环境研究的不同类型水生微宇宙;(3)尚有争议的若干问题;(4)水生微宇宙技术应用的新动向和展望。     

Recent developments in biodegradation of industrial pollutants by white rot fungi and their enzyme system

Increasing discharge and improper management of liquid and solid industrial wastes have created a great concern among industrialists and the scientific community over their economic treatment and safe disposal. White rot fungi (WRF) are versatile and robust organisms having enormous potential for oxidative bioremediation of a variety of toxic chemical pollutants due to high tolerance to toxic substances in the environment. WRF are capable of mineralizing a wide variety of toxic xenobiotics due to non-specific nature of their extracellular lignin mineralizing enzymes (LMEs). In recent years, a lot of work has been done on the development and optimization of bioremediation processes using WRF, with emphasis on the study of their enzyme systems involved in biodegradation of industrial pollutants. Many new strains have been identified and their LMEs isolated, purified and characterized. In this review, we have tried to cover the latest developments on enzyme systems of WRF, their low molecular mass mediators and their potential use for bioremediation of industrial pollutants.     

内分泌干扰物的生物学检测和评价方法

内分泌干扰物(endocrine disrupters,EDs)是近年来环境科学研究的热点之一。EDs不仅对陆生动物和人类具有潜在的危害,还可以通过不同途径到达水环境中,影响水生动物的生长和繁殖等。因此,建立EDs快速、灵敏的检测和评价方法非常必要。此外,生物检测方法还能在一定程度上反映化学污染物对生物体的毒害效应。本文就研究EDs的离体和在体实验方法进行了介绍,并从个体、组织细胞、生化与分子(蛋白质、酶、RNA、激素)等不同水平上,重点综述了鱼类生物标志物在检测和评价EDs方面的研究进展。