Univ. Lille, IMT Lille Douai, Univ. Artois, Yncrea Hauts-de-France, ULR 4515, - LGCgE, Laboratoire de Génie Civil et géo-Environnement, F-59000, Lille, France.
Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE, Aix-en-Provence, France.
Environ Sci Pollut Res Int. 2021 Jan;28(4):3756-3765. doi: 10.1007/s11356-020-08548-z. Epub 2020 Apr 8.
The use of silver nanoparticles (AgNPs) in agriculture and many consumer products has led to a significant release of Ag in the environment. Although Ag toxicity in terrestrial organisms has been studied extensively, very little is known about the accumulation capacity and coping mechanisms of organisms in Ag-contaminated soil. In this context, we exposed Eisenia fetida earthworms to artificial OECD soil spiked with a range of concentrations of Ag (AgNPs or AgNO). The main aims were to (1) identify the location and form of accumulation of Ag in the exposed earthworms and (2) better understand the physiological mechanisms involved in Ag detoxification. The results showed that similar doses of AgNPs or AgNO did not have the same effect on E. fetida survival. The two forms of Ag added to soil exhibited substantial differences in speciation at the end of exposure, but the Ag speciation and content of Ag in earthworms were similar, suggesting that biotransformation of Ag occurred. Finally, 3D images of intact earthworms obtained by X-ray micro-computed tomography revealed that Ag accumulated preferentially in the chloragogen tissue, coelomocytes, and nephridial epithelium. Thus, E. fetida bioaccumulates Ag, but a regulation mechanism limits its impact in a very efficient manner. The location of Ag in the organism, the competition between Ag and Cu, and the speciation of internal Ag suggest a link between Ag and the thiol-rich proteins that are widely present in these tissues, most probably metallothioneins, which are key proteins in the sequestration and detoxification of metals.
纳米银（AgNPs）在农业和许多消费产品中的使用导致了大量 Ag 在环境中的释放。尽管已经对陆生生物中的 Ag 毒性进行了广泛的研究，但对于受 Ag 污染土壤中生物的积累能力和应对机制知之甚少。在这种情况下，我们将赤子爱胜蚓暴露于人工 OECD 土壤中，该土壤中添加了一系列浓度的 Ag（AgNPs 或 AgNO）。主要目的是：（1）确定暴露在 Ag 中的蚯蚓中 Ag 的积累位置和形式；（2）更好地理解 Ag 解毒所涉及的生理机制。结果表明，AgNPs 或 AgNO 的相似剂量对赤子爱胜蚓的存活没有相同的影响。添加到土壤中的两种形式的 Ag 在暴露结束时表现出明显的形态差异，但 Ag 的形态和蚯蚓中 Ag 的含量相似，表明 Ag 发生了生物转化。最后，通过 X 射线微计算机断层扫描获得的完整蚯蚓的 3D 图像显示，Ag 优先积累在胆绿素组织、体腔细胞和肾上皮中。因此，赤子爱胜蚓可以生物积累 Ag，但一种调节机制以非常有效的方式限制了其影响。Ag 在生物体中的位置、Ag 与 Cu 之间的竞争以及内部 Ag 的形态表明 Ag 与广泛存在于这些组织中的富含巯基的蛋白质之间存在联系，最有可能是金属硫蛋白，这是金属螯合和解毒的关键蛋白。
