Nano-zinc oxide (ZnO NPs), as widely used nanomaterials, are inevitably released into aquatic environments, posing potential threats to aquatic organisms. Mytilus galloprovincialis is a bivalve species sensitive to changes in marine ecological environments, but there has been limited research on its toxicity response to ZnO NPs. Therefore, we selected M. galloprovincialis as the research subject and exposed them to 50 µg/L ZnO NPs for 96 h and 30 days to determine the dissolution of ZnO NPs in seawater and their distribution in M. galloprovincialis. The toxicity of ZnO NPs in M. galloprovincialis was then evaluated through gene expression, tissue pathology, and cellular immune response. The results showed that ZnO NPs could enrich Zn in various tissues of the mussel, in the order of gills > hepatopancreas > adductor muscle > mantle. Seven immune-related genes including four heat shock protein genes (HSPA12A, sHSP24.1, sHSP22, TCTP) and three apoptotic genes (Ras, p63 and Bcl-2) were altered to varying degrees. There was a downward trend in lysosomal membrane stability of M. galloprovincialis after exposure to ZnO NPs for 96 h and 30 days, while ROS and apoptosis rates increased significantly. Furthermore, the seven genes, apoptosis, LMS, and ROS were dependent on exposure time, treatment, and their interaction. Histopathological damage included disorganisation of hepatopancreas epithelial cells, gill filament swelling, and contraction of blood sinuses. These results indicated that ZnO NPs exerted toxicity in M. galloprovincialis, affecting the immune system, resulting in changes in the expression of immune-related genes and ultimately leading to histopathological changes. Our research findings could contribute to systematically understand the impact of ZnO NPs on bivalves in aquatic environments and provide a theoretical basis for marine pollution assessment.

中文翻译：

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ZnO NPs 对 Mytilus galloprovincialis 免疫反应和组织病理学的毒性影响


纳米氧化锌 （ZnO NPs） 作为广泛使用的纳米材料，不可避免地会释放到水生环境中，对水生生物构成潜在威胁。Mytilus galloprovincialis 是一种对海洋生态环境变化敏感的双壳类物种，但对其对 ZnO NPs 的毒性反应的研究有限。因此，我们选择加氏牡蛎作为研究对象，将它们暴露于 50 μg/L ZnO NPs 中 96 h 和 30 d，以确定 ZnO NPs 在海水中的溶出情况及其在加罗波省牡蛎中的分布。然后通过基因表达、组织病理学和细胞免疫反应评价 ZnO NPs 在 M. galloprovincialis 中的毒性。结果表明，ZnO NPs 可在贻贝的各个组织中富集 Zn，顺序为鳃 > 肝胰腺 > 内收肌 > 外套膜。7 个免疫相关基因包括 4 个热休克蛋白基因 （HSPA12A 、 sHSP24.1 、 sHSP22 、 TCTP） 和 3 个凋亡基因 （Ras、 p63 和 Bcl-2） 发生不同程度的改变。M. galloprovincialis 暴露于 ZnO NPs 96 h 和 30 d 后溶酶体膜稳定性呈下降趋势，而 ROS 和细胞凋亡率显著增加。此外，细胞凋亡、 LMS 和 ROS 这 7 个基因依赖于暴露时间、治疗及其相互作用。组织病理学损伤包括肝胰腺上皮细胞紊乱、鳃丝肿胀和血窦收缩。这些结果表明，ZnO NPs 对 M. galloprovincialis产生毒性，影响免疫系统，导致免疫相关基因的表达发生变化，最终导致组织病理学变化。 我们的研究结果有助于系统理解 ZnO NPs 对水生环境中双壳类的影响，并为海洋污染评估提供理论依据。