低氧环境下多环芳烃在海水青鳉早期生活阶段的代谢转化及二者复合效应的作用机制研究

Aquatic systems are impacted by a wide array of natural and anthropogenic stressors, including chemical and physical factors. Often laboratory studies focus on characterizing the impacts of a single factor, but there has been significantly less progress made toward determining how these factors may act in concert with one another. Polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants, and its environmental concentration is increasing in China in recent years. Environmental Hypoxia is a significant problem in many estuaries and marine coastal regions around the world, and global climate change may exacerbate the problem. In addition to their co-occurrence in the environment, both of PAHs and hypoxia can cause significant effects on fish and other marine organisms. The potential effects of interactions between PAHs and hypoxia are not be ignored, however the mechanism by which hypoxia interferes with the PAHs toxicity remains unknown. Therefore, it is very important and meaningful to clarify their impacts jointly and mechanism. The PAHs, phenanthrene and alkyl-phenanthrene are selected in this study because their effects on fish development have been demonstrated, and because they are often among the most prevalent PAHs at contaminated sites. Marine medaka (Oryzias melastigma), known as a good potential marine model fish, are used as the test fish. The main works are followed: to determine or look for the interactions between hypoxia and the PAHs used in these experiments; to detect the influence of hypoxia on the changes of PAHs metabolites in fish; to discuss the role of CYP1A inhibition in PAHs/hypoxia interactions; to explore To explore the relationship among PAHs metabolites, expression of AHR/HIF1a inducible genes and development toxicity. This study is expected to reveal the mechanisms related to AHR/HIF1a crosstalk and metabolic transformation in the embryotoxic interactions between hypoxia and PAHs in marine fish. Hopefully, the results of these experiments underscore the importance of consideration of the interactive effects of physical and chemical stressors when assessing risk to wildlife populations inhabiting polluted areas.

河口及近岸低氧已在全球蔓延，季节性低氧多发鱼类产卵和发育期。我国近岸PAHs污染呈加重趋势，PAHs升高可诱导低氧产生，二者共同作用的生态风险不容忽视。低氧和PAHs都可对鱼类发育产生显著影响，二者在作用机制上具有相似性，但相互作用的复合效应及机制尚不清楚，现有PAHs风险评估可能低估了其实际风险。本研究将以近岸低氧为背景，以不同类型PAHs（菲和烷基菲）为研究对象，以海水青鳉为受试鱼种，采用化学和生物学手段，研究低氧与PAHs相互作用对鱼类发育的复合效应；通过分析低氧对鱼类吸收、转化和代谢PAHs的影响，阐述代谢过程和代谢物改变在复合效应中的作用；探讨HIF-1α与AHR相互作用方式；以差异表达蛋白、关键基因表达和代谢物等信息相结合的方式，揭示低氧与PAHs相互作用的分子机制。结果可深化对环境要素与污染物复合生态影响的认识，为科学评估低氧对近岸污染海域鱼类种群繁衍的影响提供重要科学依据。

河口及近岸低氧已在全球蔓延，季节性低氧多发鱼类产卵和发育期。我国近岸PAHs污染呈加重趋势，PAHs升高可诱导低氧产生，二者共同作用的生态风险不容忽视。本课题组利用在PAHs代谢转化过程研究领域的优势和基础，开展了广泛的国内外合作研究。不仅按计划完成了研究目标，还开展了低氧与PAHs早期复合暴露对海水青鳉鱼类后期生长、发育和繁殖的研究工作。评估了低氧环境下PAHs在鱼类体内的代谢过程及变化；揭示了低氧与PAHs二者复合作用下PAHs的毒性；发现了不同方式的低氧均可对海水青鳉产生长期影响；通过LC-MS/MS等技术解析了鱼类体内主要代谢产物；利用转录组学技术，揭示了低氧与PAHs混合物复合效应的潜在作用途径和机制，研究成果为科学评估近岸低氧与PAHs等复合污染所产生的生态风险提供了重要的科学依据。研究成果在Environmental Pollution 、Aquatic toxicology、Biogeoscience等杂志发表6篇。课题参与研究团队培养博士研究生2名、硕士研究生2名，获省部级奖项1项；获批专利2项；截止目前为止，已累计到账经费90万，支出经费90万，所有课题经费均按相关规定，按预算执行。