Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
Sci Total Environ. 2024 May 20;926:172125. doi: 10.1016/j.scitotenv.2024.172125. Epub 2024 Mar 31.
Despite both microplastics (MPs) and harmful algae blooms (HABs) may pose a severe threat to the immunity of marine bivalves, the toxification mechanism underlying is far from being fully understood. In addition, owing to the prevalence and sudden occurrence characteristics of MPs and HABs, respectively, bivalves with MP-exposure experience may face acute challenge of harmful algae under realistic scenarios. However, little is known about the impacts and underlying mechanisms of MP-exposure experience on the susceptibility of immunity to HABs in bivalve mollusks. Taking polystyrene MPs and diarrhetic shellfish toxin-producing Prorocentrum lima as representatives, the impacts of MP-exposure on immunity vulnerability to HABs were investigated in the thick-shell mussel, Mytilus coruscus. Our results revealed evident immunotoxicity of MPs and P. lima to the mussel, as evidenced by significantly impaired total count, phagocytic activity, and cell viability of haemocytes, which may result from the induction of oxidative stress, aggravation of haemocyte apoptosis, and shortage in cellular energy supply. Moreover, marked disruptions of immunity, antioxidant system, apoptosis regulation, and metabolism upon MPs and P. lima exposure were illustrated by gene expression and comparative metabolomic analyses. Furthermore, the mussels that experienced MP-exposure were shown to be more vulnerable to P. lima, indicated by greater degree of deleterious effects on abovementioned parameters detected. In general, our findings emphasize the threat of MPs and HABs to bivalve species, which deserves close attention and more investigation.
尽管微塑料（MPs）和有害藻类水华（HABs）都可能对海洋双壳类动物的免疫力构成严重威胁，但它们的毒害机制还远未完全了解。此外，由于 MPs 和 HABs 的普遍存在和突发特性，暴露于 MPs 中的贝类在现实场景下可能会面临有害藻类的急性挑战。然而，对于暴露于 MPs 经验对贝类免疫力易感性对 HABs 的影响及其潜在机制知之甚少。本研究以聚苯乙烯 MPs 和产腹泻性贝类毒素的赤潮甲藻（Prorocentrum lima）为代表，研究了 MPs 暴露对厚壳贻贝（Mytilus coruscus）对 HABs 易感性的影响。研究结果表明 MPs 和 P. lima 对贻贝具有明显的免疫毒性，表现为血细胞总数、吞噬活性和细胞活力显著受损，这可能是由于氧化应激的诱导、血细胞凋亡的加剧和细胞能量供应的短缺所致。此外，通过基因表达和比较代谢组学分析，还说明了 MPs 和 P. lima 暴露对贻贝的免疫、抗氧化系统、凋亡调控和代谢的显著破坏。此外，暴露于 MPs 的贻贝对 P. lima 更为敏感，表现在上述参数检测到的有害影响程度更大。总之，本研究结果强调了 MPs 和 HABs 对双壳类物种的威胁，值得密切关注和进一步研究。
