Qiu Wenhui, Chen Jingsi, Li Yijie, Chen Zhong, Jiang Lihui, Yang Ming, Wu Minghong
School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
Shanghai Applied Radiation Institute, Shanghai University, Shanghai 200444, China.
Ecotoxicol Environ Saf. 2016 Aug;130:93-102. doi: 10.1016/j.ecoenv.2016.04.014. Epub 2016 Apr 16.
Bisphenol A (BPA) is a well-known endocrine disrupting chemical (EDC), ubiquitous in the aquatic environment, which poses an ecotoxicological risk to the health of aquatic organisms. However, the immunotoxic effects of its long-term exposure on fish have received limited attention. We examined a number of typical immune-related parameters and oxidative stress indices in the liver and blood serum of the red common carp (Cyprinus carpio), following a 30-day exposure to five different concentrations of BPA (0.1, 1, 10, 100, and 1000μg/L). A significant increase in the hepato somatic index was observed in fish upon exposure to 1000µg/L BPA, which correlated strongly with the accumulated BPA concentrations in fish bile. Induced oxidative stress was also apparent in the exposed fish liver, based on the enhanced levels of lipid peroxidation and inhibited activities of catalase, superoxide dismutase, and glutathione peroxidase. Serum lysozyme and C-reaction protein levels increased at low concentrations of exposure; however, they were significantly suppressed upon exposure to high concentrations. A significant increase was observed in the levels of immunoglobulin M, complement component 3, and alkaline phosphatase, in both fish liver and serum at low doses of 0.1 and 1μg/L. This suggests that long-term exposure to environmentally relevant concentrations of BPA (even as low as 0.1μg/L) could significantly disturb the immune response of fish. Moreover, RXRα expression in the liver was significantly altered upon BPA exposure and the trend underlying this change correlated closely with those of the most immune-related parameters, implying the involvement of the PPARγ/RXRα signaling pathway in regulating the immune response of fish upon long-term BPA exposure. In short, our results demonstrate the susceptibility of fish immune system to long-term BPA exposure. Therefore, the immunotoxicity of EDCs in aquatic organisms should not have been underestimated.
双酚A（BPA）是一种著名的内分泌干扰化学物质（EDC），在水生环境中广泛存在，对水生生物的健康构成生态毒理学风险。然而，其长期暴露对鱼类的免疫毒性作用受到的关注有限。我们在红鲤（Cyprinus carpio）暴露于五种不同浓度（0.1、1、10、100和1000μg/L）的BPA 30天后，检测了其肝脏和血清中一些典型的免疫相关参数和氧化应激指标。暴露于1000μg/L BPA的鱼类肝脏体指数显著增加，这与鱼胆汁中积累的BPA浓度密切相关。基于脂质过氧化水平的升高以及过氧化氢酶、超氧化物歧化酶和谷胱甘肽过氧化物酶活性的抑制，暴露鱼类的肝脏中也明显出现了氧化应激。低浓度暴露时血清溶菌酶和C反应蛋白水平升高；然而，高浓度暴露时它们被显著抑制。在低剂量0.1和1μg/L时，鱼类肝脏和血清中的免疫球蛋白M、补体成分3和碱性磷酸酶水平均显著升高。这表明长期暴露于环境相关浓度的BPA（即使低至0.1μg/L）也可能显著干扰鱼类的免疫反应。此外，BPA暴露后肝脏中RXRα的表达显著改变，这种变化的趋势与大多数免疫相关参数的趋势密切相关，这意味着PPARγ/RXRα信号通路参与调节鱼类长期暴露于BPA后的免疫反应。简而言之，我们的结果证明了鱼类免疫系统对长期BPA暴露的易感性。因此，不应低估EDCs对水生生物的免疫毒性。
