Laboratory of Marine Biology and Ecology, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen 361102, China.
Laboratory of Marine Biology and Ecology, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
Ecotoxicol Environ Saf. 2022 Aug;241:113843. doi: 10.1016/j.ecoenv.2022.113843. Epub 2022 Jul 6.
Microplastics (MPs), due to their impacts on the ecosystem and their integration into the food web either through trophic transfer or ingestion directly from the ambient environment, are an emerging class of environmental contaminants posing a great threat to marine organisms. Most reports on the toxic effects of MPs exclusively focus on bioaccumulation, oxidative stress, pathological damage, and metabolic disturbance in fish. However, the collected information on fish immunity in response to MPs is poorly defined. In particular, little is known regarding mucosal immunity and the role of mucins. In this study, marine medaka (Oryzias melastigma) larvae were exposed to 6.0 µm beads of polystyrene microplastics (PS-MPs) at three environmentally relevant concentrations (10 particles/L, 10 particles/L, and 10 particles/L) for 14 days. The experiment was carried out to explore the developmental and behavioural indices, the transcriptional profiles of mucins, pro-inflammatory, immune, metabolism and antioxidant responses related genes, as well as the accumulation of PS-MPs in larvae. The results revealed that PS-MPs were observed in the gastrointestinal tract, with a concentration- and exposure time-dependent manner. No significant difference in the larval mortality was found between the treatment groups and the control, whereas the body length of larvae demonstrated a significant reduction at 10 particles/L on 14 days post-hatching. The swimming behaviour of the larvae became hyperactive under exposure to 10 and 10 particles/L PS-MPs. In addition, PS-MP exposure significantly up-regulated the mucin gene transcriptional levels of muc7-like and muc13-like, however down-regulated the mucin gene expression levels of heg1, muc2, muc5AC-like and muc13. The immune- and inflammation and metabolism-relevant genes (jak, stat-3, il-6, il-1β, tnf-а, ccl-11, nf-κb, and sod) were significantly induced by PS-MPs at 10 and 10 particles/L compared to the control. Taken together, this study suggests that PS-MPs induced inflammation response and might obstruct the immune functions and retarded the growth of the marine medaka larvae even at environmentally relevant concentrations.
微塑料（MPs）由于其对生态系统的影响以及通过营养转移或直接从环境中摄取而整合到食物网中，是一类新兴的环境污染物，对海洋生物构成了巨大威胁。大多数关于 MPs 毒性影响的报告都专门关注鱼类的生物积累、氧化应激、病理损伤和代谢紊乱。然而，关于鱼类对 MPs 反应的免疫信息收集得很差。特别是，关于黏膜免疫和粘蛋白的作用知之甚少。在这项研究中，用聚苯乙烯微塑料（PS-MPs）的 6.0μm 珠粒在三个环境相关浓度（10 个/升、10 个/升和 10 个/升）下暴露海洋斑马鱼（Oryzias melastigma）幼鱼 14 天。该实验旨在探讨发育和行为指标、粘蛋白、促炎、免疫、代谢和抗氧化反应相关基因的转录谱，以及 PS-MPs 在幼鱼中的积累。结果表明，PS-MPs 在胃肠道中被观察到，呈浓度和暴露时间依赖性。处理组与对照组之间幼鱼死亡率没有显著差异，而孵化后 14 天，10 个/升组的幼鱼体长显著减小。暴露于 10 个/升和 10 个/升 PS-MPs 下，幼鱼的游泳行为变得更加活跃。此外，PS-MP 暴露显著上调了 muc7-like 和 muc13-like 的粘蛋白基因转录水平，而下调了 heg1、muc2、muc5AC-like 和 muc13 的粘蛋白基因表达水平。与对照组相比，10 个/升和 10 个/升 PS-MPs 显著诱导了免疫和炎症以及代谢相关基因（jak、stat-3、il-6、il-1β、tnf-α、ccl-11、nf-κb 和 sod）的表达。综上所述，本研究表明，PS-MPs 诱导了炎症反应，即使在环境相关浓度下，也可能阻碍海洋斑马鱼幼鱼的免疫功能并阻碍其生长。
