Abstract：
Aquatic environments serve as critical repositories for pollutants and have significantly accumulated micro- and nanoplastics (MNPs) due to the extensive production and application of plastic products. While the disease resistance and immunity of fish are closely linked to the condition of their aquatic habitats, the specific effects of nanoplastics (NPs) and microplastics (MPs) within these environments on fish immune functions are still not fully understood. The present study utilized zebrafish (Danio rerio) embryos and larvae as model organisms to examine the impacts of polystyrene NPs (100 nm) and MPs (5 μm) on fish immune responses. Our findings reveal that NPs and MPs tend to accumulate on the surfaces of embryos and within the intestines of larvae, triggering oxidative stress and significantly increasing susceptibility to Edwardsiella piscicida infection in zebrafish larvae. Transmission electron microscopy examined that both NPs and MPs inflicted damage to the kidney, an essential immune organ, with NPs predominantly inducing endoplasmic reticulum stress and MPs causing lipid accumulation. Transcriptomic analysis further demonstrated that both NPs and MPs significantly suppress the expression of key innate immune pathways, notably the C-type lectin receptor signaling pathway and the cytosolic DNA-sensing pathway. Within these pathways, the immune factor interleukin-1 beta (il1b) was consistently downregulated in both exposure groups. Furthermore, exposure to E. piscicida resulted in restricted upregulation of il1b mRNA and protein levels, likely contributing to diminished disease resistance in zebrafish larvae exposed to MNPs. Our findings suggest that NPs and MPs similarly impair the innate immune function of zebrafish larvae and weaken their disease resistance, highlighting the significant environmental threat posed by these pollutants.
摘要：
水生环境是污染物的关键储存库，并且由于塑料制品的广泛生产和应用，已经大量积累了微米和纳米塑料（MNPs）。虽然鱼类的抗病性和免疫力与其水生栖息地的状况密切相关，纳米塑料（NPs）和微塑料（MPs）在这些环境中对鱼类免疫功能的具体影响仍未完全了解。本研究利用斑马鱼（Daniorerio）胚胎和幼虫作为模型生物，研究了聚苯乙烯NP（100nm）和MPs（5μm）对鱼类免疫反应的影响。我们的研究结果表明，NP和MP倾向于在胚胎表面和幼虫的肠道内积累，在斑马鱼幼虫中引发氧化应激并显着增加对皮西氏菌感染的敏感性。透射电子显微镜检查，NP和MP都对肾脏造成了损害，一个重要的免疫器官，NP主要诱导内质网应激和MPs引起脂质积累。转录组学分析进一步证明，NP和MPs均显著抑制关键先天免疫途径的表达，特别是C型凝集素受体信号通路和胞质DNA传感通路。在这些途径中，在两个暴露组中,免疫因子白细胞介素-1β(il1b)持续下调.此外，暴露于皮西氏菌导致il1bmRNA和蛋白质水平的限制性上调，可能导致暴露于MNPs的斑马鱼幼虫的抗病性降低。我们的发现表明，NP和MPs同样损害斑马鱼幼虫的先天免疫功能，并削弱其抗病性，强调这些污染物对环境的威胁。
