生物有效性的细胞异质性解析与原位损伤机制的研究

With the intensive developments induced by rapid industrialization and extensive urbanization, increasing amounts of anthropogenic contaminants have been continuously discharged into aquatic environments. While using traditional methods, which are mostly based on the chemical analysis alone of extracted samples from environmental and biological matrixes, it is difficult to accurately determine the bioavailability of contaminants and then reflect their cell-based effects as well as subsequent toxicity risks. Therefore in this proposal, understanding the degrees of contamination and pollution characteristics regarding of entirely environmental matrix and biological samples in the selected study sites and successfully culturing the primary cells from critical tissues in aquatic organisms of ecological niche, the field exposure were performed to analyze the subcellular distributions of contaminants and adverse effects of chemicals combined with cell-based in vitro assays and in situ tests. Further, the dynamic exchanges, translocation and mobilization of contaminants such as metals were then clarified among the "various particles, pore water and cells in exposed organisms" interfaces of matrix through measuring relevant dynamic parameters and resultant induced fluxes during experimental procedures. Moreover, coupled with chemical analysis to quantify the mitochondria components within culture wells of primary cells and molecular approaches to assess the expression of responsive genes in field exposure, the mechanisms of associated toxicity were elaborated and the interactive relationships were then obtained between contaminant bioavailability and in-situ stress. Simultaneously, the assays of cell-based evaluation and monitoring are proposing to be established considering the consistency of framework as protocols among cell culture, field tests and exposure effects. Overall, the outcomes acquired in this study support full-scale considerations of environmental prevention and retrieval and thus provide robust tool to scientifically extrapolate the environmental quality guidelines (EQGs), further improving accuracy and ecological relevance towards future pollution monitoring as powerful tools and more comprehensive risk assessments in complex scenarios.

快速工业化与持续城市化导致大量污染物进入环境，传统生物有效性的确定表征主要基于环境介质与生物体的化学提取分析，未能深入准确地反映污染物的细胞效应与毒性风险。本项目在弄清研究区域环境介质与生物体污染特征、以及生态位指示生物关键组织细胞成功培养的基础上，以培养细胞现场测试与生物原位暴露为主要手段，研究重金属等污染物在细胞器层面的亚细胞分布与毒理效应；通过测定相关通量参数在环境介质中的变化，明确污染物在固/液/生物体/细胞间的动态迁移；结合培养细胞体外试验中线粒体组分的特征响应以及生物原位暴露中重要功能基因的表达分析，阐明原位损伤机制并在细胞异质性组分水平下解析生物有效性；同时在“培养细胞－现场测试－暴露效应”一致性的原则下，建立基于细胞效应的污染评价方法与监测体系；研究成果可更好的为环境污染防治、修复与环境质量基准推导提供科学依据，并为未来污染监测以及综合风险评价生态相关性的提高提供科技支撑。

矿山开采、冶炼加工等领域广泛的工业化与大规模城市化导致大量不同种类污染物由岩石土壤圈进入水圈与生物圈，严重危害生态环境和人体健康，因此极需深入评价污染物的健康风险，而污染物在圈层间的动态迁移及其生物有效性的变化是评价其毒性效应与健康风险的重要基石。目前尚未对结合污染物在圈层界面间的迁移以及与生物有效性密切相关的敏感组织培养细胞毒理效应开展相关研究。本项目主要完成了以下内容：1）采集不同深度的沉积物样品，在分析不同环境介质的理化性质与不同结合形态污染特征（SEM与AVS）的基础上，开展确定具有不同污染梯度的试验站位以及风险评估方法的研究；2）稀土在不同生态位的典型生物体（鱼、虾、蟹与贝类等）中的含量、地化与分馏特征，以及与相应生态位营养关系响应的研究；3）环境中微塑料等新型颗粒态污染物对重金属等常规溶解态污染物的吸附特征、不同层面的毒理效应与现实环境风险评估中生物有效性的校正研究；4）自然水体中，不同结合态稀土的地化行为、分馏特征与指示生物浓缩系数关系间的研究，明晰稀土在流域水体中的动态迁移变化过程与影响生物有效性的因素及程度；5）采集的目标生物经驯养后解剖目标组织，消毒、润洗等预处理后转入细胞培养装置，观察细胞形态并测定其生理特性，通过细胞实验，阐明目标受试物的毒理效应与机制；6）设计集成被动采样与同步暴露的试验，明确目标物在试验体系中的迁移变化动态过程与细胞异质性效应之间的关系，在“培养细胞－现场测试－原位暴露－效应鉴别”基础上建立细胞测试与评价方法并阐明原位效应的细胞作用机制。本项目的研究结果为搭建细胞模型确定水环境污染物的毒理效应与生物有效性提供了理论指导，同时为确定流域稀土在不同圈层的动态迁移与细胞水平的生物有效性测试方法提供憨实基础，从而更准确深入的评估流域稀土风险、污染综合整治和环境生态修复等提供科技支撑和决策依据。