多环芳烃(PAHs)的长距离迁移促进了它们向海洋环境的释放,对海洋生物构成严重威胁.研究表明PAHs对双壳类动物有显著的免疫毒性作用,但确切的免疫毒性机制尚不清楚.本文旨在研究在环境条件下暴露于0.4、2和10μg/L的苯并(a)芘(B[a]P)对衣藻免疫力的影响。以及潜在的分子机制。多种生物标志物,包括吞噬率,代谢物,神经毒性,氧化应激,DNA损伤,和细胞凋亡,被用来评估这些影响。暴露于0.4、2和10μg/LB[a]P后,观察到明显的浓度依赖性免疫毒性,由血细胞指数(总血细胞计数,吞噬率,抗菌和溶菌活性)。法雷氏梭菌解毒代谢系统的分析表明,B[a]P通过代谢产生B[a]P-7,8-二醇-9,10-环氧化物(BPDE),这导致蛋白酪氨酸激酶(PTK)的表达增加。此外,神经递质(包括乙酰胆碱,γ-氨基丁酸,脑啡肽,去甲肾上腺素,多巴胺,和5-羟色胺)和相关受体暗示B[a]P可能通过神经内分泌系统影响免疫力。参与免疫调节的信号通路因子的变化表明B[a]P通过BPDE-PTK通路或神经内分泌通路干扰Ca2+和cAMP信号转导,导致免疫抑制。此外,B[a]P诱导活性氧(ROS)含量增加和DNA损伤,以及线粒体途径和死亡受体途径中关键基因的上调,导致细胞凋亡率增加。一起来看,这项研究全面调查了解毒代谢系统,神经内分泌系统,和细胞凋亡,探讨B[a]P应激下双壳类的毒性机制。
The long-distance migration of polycyclic aromatic hydrocarbons (PAHs) promotes their release into the marine environment, posing a serious threat to marine life. Studies have shown that PAHs have significant immunotoxicity effects on bivalves, but the exact mechanism of immunotoxicity remains unclear. This paper aims to investigate the effects of exposure to 0.4, 2, and 10 μg/L of benzo(a)pyrene (B[a]P) on the immunity of Chlamys farreri under environmental conditions, as well as the potential molecular mechanism. Multiple biomarkers, including phagocytosis rate, metabolites, neurotoxicity, oxidative stress, DNA damage, and apoptosis, were adopted to assess these effects. After exposure to 0.4, 2, and 10 μg/L B[a]P, obvious concentration-dependent immunotoxicity was observed, indicated by a decrease in the hemocyte index (total hemocyte count, phagocytosis rate, antibacterial and bacteriolytic activity). Analysis of the detoxification metabolic system in C. farreri revealed that B[a]P produced B[a]P-7,8-diol-9,10-epoxide (BPDE) through metabolism, which led to an increase in the expression of protein tyrosine kinase (PTK). In addition, the increased content of neurotransmitters (including acetylcholine, γ -aminobutyric acid, enkephalin, norepinephrine, dopamine, and serotonin) and related receptors implied that B[a]P might affect immunity through neuroendocrine system. The changes in signal pathway factors involved in immune regulation indicated that B[a]P interfered with Ca2+ and cAMP signal transduction via the BPDE-PTK pathway or neuroendocrine pathway, resulting in immunosuppression. Additionally, B[a]P induced the increase in reactive oxygen species (ROS) content and DNA damage, as well as an upregulation of key genes in the mitochondrial pathway and death receptor pathway, leading to the increase of apoptosis rate. Taken together, this study comprehensively investigated the detoxification metabolic system, neuroendocrine system, and cell apoptosis to explore the toxic mechanism of bivalves under B[a]P stress.