Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agriculture University, Wuhan, 430070, China; Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Reuse, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
South China Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Guangzhou, 510655, China.
Environ Pollut. 2019 Jul;250:990-997. doi: 10.1016/j.envpol.2019.03.126. Epub 2019 Apr 3.
In the present study, to assess the immunotoxicity of cypermethrin (CYP) in fish, Chinese rare minnows (Gobiocypris rarus) were exposed to environmentally relevant concentrations (0.15, 0.5, and 1.5 μg/L) of CYP for 28 d and subjected to pathogen challenge trials for 2 d. After 28 d of CYP exposure, the levels of Immunoglobulin M (IgM), Alkaline phosphatase (ALP), and C-reactive protein (CRP) were significantly decreased (p < 0.05) after treatment with 1.5 μg/L CYP. Moreover, an induction of inflammatory cytokine transcripts (tnfa, il-6, il-8, and il-12) was observed (p < 0.05) after treatment with 1.5 μg/L CYP. After challenge with Pseudomonas fluorescens (P. fluorescens), plasma lysozyme (LYS) activity at 24 and 48 hours post-injection (hpi) was significantly decreased in the 0.5 and 1.5 μg/L CYP treatment groups (p < 0.05). Moreover, liver Complement component 3 (C3) and CRP contents at 24 hpi were significantly decreased in the 1.5 μg/L CYP treatment group (p < 0.05), whereas significant decreases in liver C3 and IgM contents were observed at 48 hpi (p < 0.05). Inhibition of expression of Toll-like receptor-nuclear factor kappa B (TLR-NF-kB) signaling pathway-related genes was observed in the CYP treatment groups and resulted in significant down-regulation of inflammatory cytokines (il-1β and il-12) in the 1.5 μg/L CYP treatment group at 48 hpi (p < 0.05). Interestingly, the mortality in the 0.5 and 1.5 μg/L CYP treatments was significantly increased at 48 hpi (p < 0.05). These results indicated that environmentally relevant concentrations of CYP suppressed the Chinese rare minnow immune system and reduced immune defense against bacterial infection, thereby causing subsequent mortality. Meanwhile, our results demonstrated that a subsequent host resistance challenge is an effective method for determining the immunotoxicity of chemicals (e.g., CYP).
在本研究中，为了评估氯氰菊酯（CYP）对鱼类的免疫毒性，采用 0.15、0.5 和 1.5μg/L 的 CYP 对稀有鲫（Gobiocypris rarus）进行了 28d 的暴露，并进行了 2d 的病原体挑战试验。暴露于 CYP 28d 后，1.5μg/L CYP 处理后免疫球蛋白 M（IgM）、碱性磷酸酶（ALP）和 C 反应蛋白（CRP）水平显著降低（p<0.05）。此外，在 1.5μg/L CYP 处理后观察到炎症细胞因子转录物（tnfa、il-6、il-8 和 il-12）的诱导（p<0.05）。用荧光假单胞菌（P. fluorescens）进行攻毒后，在 0.5 和 1.5μg/L CYP 处理组中，注射后 24 和 48 小时的血浆溶菌酶（LYS）活性显著降低（p<0.05）。此外，在 1.5μg/L CYP 处理组中，24 小时攻毒时肝补体成分 3（C3）和 CRP 含量显著降低（p<0.05），而在 48 小时攻毒时肝 C3 和 IgM 含量显著降低（p<0.05）。在 CYP 处理组中观察到 Toll 样受体-核因子 kappa B（TLR-NF-kB）信号通路相关基因的表达抑制，并导致在 1.5μg/L CYP 处理组中在 48 小时攻毒时炎症细胞因子（il-1β 和 il-12）的显著下调（p<0.05）。有趣的是，在 0.5 和 1.5μg/L CYP 处理组中，在 48 小时攻毒时死亡率显著增加（p<0.05）。这些结果表明，环境相关浓度的 CYP 抑制了稀有鲫的免疫系统，降低了鱼类对细菌感染的免疫防御能力，从而导致随后的死亡率。同时，我们的结果表明，随后的宿主抗性挑战是确定化学物质（如 CYP）免疫毒性的有效方法。
