基于环境浓度下全氟烷基醚磺酸盐慢性暴露对斑马鱼免疫和抗氧化功能的影响及其机理研究

As an alternative to PFOS, chlorinated polyfluorinated ether sulfonic acid (F-53B) has been frequently detected in various environmental media and even in humans in recent years, but the data on the toxicity of F-53B is scarce, which indicates the necessity and urgency of carrying out relevant research work. In the previous studies, the applicant found F-53B could cause developmental toxicity and decrease antioxidant enzyme activity in zebrafish, but the mechanisms of action are not yet clear. In this study, the concentration of F-53B in major rivers in China will be selected as the reference exposure dose and zebrafish will be chronically exposed to F-53B. The cumulative characteristics of F-53B in zebrafish were analyzed, and the effects on the growth and development of zebrafish, histopathology, oxygen radicals, nitric oxide, malondialdehyde content and major antioxidant enzyme activities were studied. Furthermore, the molecular mechanisms that influence the immune and antioxidant function of zebrafish will be interpreted by detecting changes in the expression levels of genes and proteins involved in the regulation of oxidative stress and immune responses and using computational toxicology-related techniques to determine the interaction mechanism between F-53B and target proteins. The research results provide a theoretical basis for a comprehensive evaluation of the ecological health risks of F-53B, and provide new ideas for the toxicity evaluation of other PFOS alternatives.

作为PFOS的替代品，近年来全氟烷基醚磺酸盐（F-53B）在各种环境介质甚至人体内被广泛检出，但有关F-53B的毒性数据却十分缺乏，这预示了开展相关研究工作的必要性和紧迫性。申请人前期研究发现F-53B可导致斑马鱼发育毒性和抗氧化酶活性的降低，但作用机制尚不清楚。本项目以我国主要河流中F-53B浓度为参考暴露剂量，对斑马鱼进行长期暴露，分析F-53B在斑马鱼体内的累积特征，进而研究富集于鱼体内的F-53B对斑马鱼生长发育、组织病理、氧自由基、一氧化氮、丙二醛含量及主要抗氧化酶活性的影响，并进一步通过检测参与调控氧化应激和免疫反应相关基因和蛋白的表达量变化，利用计算毒理学相关技术确定F-53B与靶标蛋白的相互作用机制，以期诠释环境浓度的F-53B长期暴露对斑马鱼免疫和抗氧化功能影响的分子机理。研究成果为全面评价F-53B的生态健康风险提供理论依据，并为其它PFOS替代品的毒性评价提供新思路。

近年来F-53B和OBS作为PFOS的替代品在不同环境介质甚至人体内被广泛检出，但是基于环境浓度下它们长期暴露产生的毒性效应及其分子机制还不清楚。本项目在前期工作基础上，从氧化应激和免疫反应的视角出发，结合分析化学、分子生物学以及计算毒理学等多种技术手段，研究了环境浓度的PFASs长期暴露对水生动物斑马鱼的生态健康风险。研究结果表明：PFASs主要在斑马鱼的血液和肝脏中富集，这与PFASs能够同鱼类血清白蛋白和肝脏脂肪酸结合蛋白结合相关，同时毒代动力学相关参数与暴露浓度具有显著相关性。与F-53B和OBS相比，慢性暴露于PFOS诱导的肝脏氧化应激更为严重，且这三种PFASs通过抑制促炎细胞因子的表达诱导了相似的抗炎反应。肠道菌群分析显示，这三种PFASs处理组中，Plesiomonas、Aeromonas、Cetobacterium、Shewanella和Vibrio的相对丰度变化趋势是相同的。PFASs暴露后肠褶皱高度降低，肠道中hepcidin、muc以及免疫相关基因mpo和saa的表达量增加，肠道紧密连接相关基因occ的表达量降低。总的来说，暴露于PFOS替代品F-53B和OBS可诱导与成年斑马鱼肠道微生物群失调相关的肝脏免疫毒性。课题的实施有助于推进此类化合物在现有环境容量下的生态健康风险评估，为政府部门监管这些PFOS替代品的处理和排放提供有力的科学依据，从而防止和减少它们对环境和人类所造成的潜在危害。

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