International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China.
State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China; Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China.
Mar Environ Res. 2023 Nov;192:106214. doi: 10.1016/j.marenvres.2023.106214. Epub 2023 Oct 14.
Numerous studies have shown that microplastics can interact with other pollutants in the environment to produce synergistic effects, leading to more serious impacts. To date, there is little consensus on the combined effects of microfibers (MFs) and polychlorinated biphenyls (PCBs, Aroclor 1254), two legacy and alarming environmental pollutants. There is an urgent need to assess the impact of combined exposures on bivalve immune defences. In this study, we assessed the immune response of the mussels (Mytilus coruscus) hemocyte to MFs and PCBs alone and in combination by using flow cytometry. M. coruscus were exposed to MFs (1000 pieces/L) and PCBs (PCBs) (100 ng/L and 1000 ng/L) alone or in combination for 14 consecutive days and recovered for 7 days. The hemocyte of M. coruscus was collected on day 7, 14 and 21. MF exposure alone had no effect on the hemocyte. The total hemocyte count (THC), esterase (EA), lysosomal contents (LC), mitochondrial number (MN) and mitochondrial membrane potential (MMP) of mussels showed a decreasing trend with increasing PCB concentrations, both individually and in combination; The decreases in EA, MN and MMP were associated with the induction of reactive oxygen species (ROS). Hemocyte mortality (HM) was associated with a decrease in THC. Combined exposure to MFs and PCBs would exacerbate the effects on hemocyte immunity. These new findings improve our understanding of the toxic effects of MFs and organic chemical pollutants, and demonstrate the potential mechanism of PCBs to bivalves through changes in hemolymph immunity-related indicators.
大量研究表明，微塑料可以与环境中的其他污染物相互作用，产生协同效应，导致更严重的影响。迄今为止，对于微纤维（MFs）和多氯联苯（PCBs，Aroclor 1254）这两种遗留的、令人警觉的环境污染物的联合效应，人们尚未达成共识。迫切需要评估联合暴露对双壳类动物免疫防御的影响。在这项研究中，我们通过流式细胞术评估了贻贝（Mytilus coruscus）血细胞对单独和联合暴露于微纤维（MFs）和 PCBs 时的免疫反应。贻贝连续 14 天暴露于微纤维（1000 个/L）和 PCBs（100ng/L 和 1000ng/L）中，然后恢复 7 天。在第 7、14 和 21 天采集贻贝的血细胞。单独暴露于 MF 对血细胞没有影响。贻贝的总血细胞计数（THC）、酯酶（EA）、溶酶体含量（LC）、线粒体数量（MN）和线粒体膜电位（MMP）均呈下降趋势，无论是单独还是联合暴露于 PCB 时，均呈下降趋势；EA、MN 和 MMP 的减少与活性氧（ROS）的诱导有关。血细胞死亡率（HM）与 THC 的减少有关。MFs 和 PCBs 的联合暴露会加剧对血细胞免疫的影响。这些新发现提高了我们对 MF 和有机化学污染物毒性作用的认识，并通过血液免疫相关指标的变化，展示了 PCBs 对双壳类动物的潜在作用机制。
