Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
Ecotoxicol Environ Saf. 2020 Jun 15;196:110532. doi: 10.1016/j.ecoenv.2020.110532. Epub 2020 Apr 1.
A major uptake route of nanoparticles (NPs) occurs via the gastrointestinal (GI) tract. When GI tract cells are exposed, NPs cytotoxic effects are observed that subsequently adversely affect the GI tract morphology and have consequences for the whole organism. The aim of this study was to understand the mechanism of effects caused by ZnO-NPs compared to Zn ions on the earthworm Eisenia andrei. The following aspects of individually exposed earthworms were investigated: 1) qualitative structural alterations in the gut epithelium and chloragogen cells of the GI tract, 2) quantitative changes within chloragogen tissues after 48 h of exposure (using morphometric analysis), and 3) the ADP/ATP ratio in homogenized tissue of the whole organism after 21 days of exposure to contaminated soil (contamination phase) followed by 14 days of elimination in clean soil (decontamination phase) to identify possible recovery. Both ZnO-NPs and Zn ions adversely affect the gut epithelium and chloragogen tissue of earthworms after 48 h of exposure to contaminated soil. Morphometric measurements revealed that the proportions of debris vesicles in the chloragocytes were significantly lower in worms exposed to ZnO-NPs than in worms exposed to Zn ions. Moreover, numerous spherite granules were observed in the chloragocytes of ionic Zn-treated worms, but not the ZnO-NPs-treated worms, suggesting differential regulation of these Zn forms. The Zn cytotoxic effect was not reflected in ADP/ATP ratio measurements. Our study provides new insights into nano-specific effects that are distinctive from ion regulation inside the GI tract and furthers our understanding of the relationship between effects at the cellular and whole-body levels.
纳米颗粒（NPs）的主要摄取途径是通过胃肠道（GI）。当 GI 道细胞暴露于 NPs 时，会观察到其细胞毒性作用，这些作用随后会对 GI 道形态产生不利影响，并对整个生物体产生后果。本研究的目的是了解 ZnO-NPs 与 Zn 离子对蚯蚓 Eisenia andrei 产生影响的机制。分别暴露的蚯蚓有以下几个方面的研究：1）GI 道肠上皮和胆绿素细胞的定性结构改变，2）暴露 48 小时后胆绿素组织内的定量变化（使用形态计量分析），以及 3）暴露于污染土壤后的 21 天（污染期）后整个生物体匀浆组织中的 ADP/ATP 比，随后在清洁土壤中进行 14 天的消除（消除期），以确定是否有恢复的可能。在暴露于污染土壤 48 小时后，ZnO-NPs 和 Zn 离子均对蚯蚓的肠上皮和胆绿素组织产生不利影响。形态计量测量显示，暴露于 ZnO-NPs 的蚯蚓的胆绿素细胞中的碎片囊泡比例明显低于暴露于 Zn 离子的蚯蚓。此外，在离子 Zn 处理的蚯蚓的胆绿素细胞中观察到大量的球形颗粒，但在 ZnO-NPs 处理的蚯蚓中没有观察到，这表明这些 Zn 形式的调节存在差异。Zn 的细胞毒性作用没有反映在 ADP/ATP 比值的测量中。我们的研究提供了有关纳米特异性效应的新见解，这些效应与 GI 道内的离子调节不同，并进一步加深了我们对细胞和整体水平上的作用关系的理解。
