线粒体氧化应激在纳米塑料致刺参毒性中的作用研究

As a new contaminant, nanoplastics (NPs) have attracted extensive attention in recent years. NPs exposure in maricultural environment has posed a potential threat to the healthful breeding of aquatic animals. Sea cucumber Apostichopus japonicus, a typical benthonic animal with the characteristics of sedimental filter-feeding, is an important mariculture species in China. It has great capacity of enriching pollutants and relatively higher sensibility. However, study on the biological effect and toxicity mechanism of NPs to sea cucumber has not been reported so far. This project will be carried out by using molecular ecotoxicology approaches. Firstly, the toxic effect of sea cucumber exposure to NPs is investigated from the viewpoints of tissue pathology, oxidative damage and energy metabolism, which contributes to the establishment of toxic animal models; and then structure and dysfunction of mitochondrion and changing patterns of mitochondrial pathway are evaluated, to demonstrate the role of mitochondrial oxidative stress in the toxic effect of sea cucumber exposure to NPs, and to preliminarily reveal the mechanism of toxication. The present study will provide scientific basis for the ecological risk assessment of NPs pollution and their potential impacts on the seafood quality and safety.

纳米塑料作为一种新型污染物近年来受到广泛关注，海水养殖环境中暴露的纳米塑料对水产动物的健康养殖构成潜在威胁。刺参是我国重要的海水养殖品种，属典型的沉积物滤食特征的底栖动物，对污染物的富集能力强且敏感性较高。然而目前，有关纳米塑料对刺参的生物效应及其致毒机理尚未见报道。本项目拟采用分子生态毒理学方法，首先从组织病理、氧化胁迫和能量代谢等方面研究纳米塑料暴露诱发刺参的毒性效应，并构建毒性动物模型；然后通过研究纳米塑料胁迫条件下刺参线粒体结构和功能紊乱，以及线粒体凋亡途径变化，阐明线粒体氧化应激在纳米塑料致刺参毒性中的作用，初步揭示纳米塑料对刺参的致毒机理，为纳米塑料污染的生态风险评估及其对水产品质量安全的潜在影响提供科学依据。

纳米塑料作为一种新型污染物近年来受到广泛关注，海水养殖环境中暴露的纳米塑料对水产动物的健康养殖构成潜在威胁。刺参是我国重要的海水养殖对象，属典型的沉积物滤食特征的底栖动物，对污染物的富集能力强且敏感性较高。然而目前，有关纳米塑料对刺参的生物效应及其致毒机理鲜有报道。本项目采用分子生态毒理学方法结合IBR混合标志物模型发现，纳米塑料暴露对刺参生长、抗氧化能力和免疫应答的毒性显著高于微米级塑料，并且耐氨氮和抗病能力更低。不同官能团纳米塑料在刺参体组织中的积累量和毒性效应因粒径不同而存在显著差异。纳米塑料不仅诱导了刺参肠道和呼吸树的氧化应激，而且导致其能量代谢障碍和线粒体功能异常。随着纳米塑料暴露浓度的不断升高，刺参原代细胞结构损伤加剧，细胞凋亡率显著增加，线粒体膜通透性转运孔开放活性显著增强，膜电位呈明显下降趋势，同时线粒体呼吸链复合酶Ⅰ-Ⅴ活性显著降低，活性氧含量升高，ATP含量显著减少，说明纳米塑料影响了刺参线粒体结构和功能。高剂量的纳米塑料暴露造成了刺参细胞DNA损伤，并通过细胞色素C释放激活线粒体介导的凋亡通路，进而引起细胞凋亡。以上研究结果，阐明了线粒体氧化应激在纳米塑料致刺参毒性中的作用，初步揭示了纳米塑料对刺参的致毒机理，为纳米塑料污染的生态风险评估及其对水产品质量安全的潜在影响提供科学依据。