Grupo de Biología y Toxicología Ambiental, Departamento de Física Matemática y de Fluidos, Facultad de Ciencias, UNED. Urbanización Monte Rozas, Avda. Esparta S/nCrta. de Las Rozas Al Escorial Km 5, 28232, Las Rozas (Madrid), Spain.
Environmental Toxicology Unit, Centro Nacional de Sanidad Ambiental (CNSA), Instituto de Salud Carlos III (ISCIII), Ctra. Majadahonda-Pozuelo Km. 2,2., Majadahonda, Madrid, 28220, Spain.
Chemosphere. 2023 Jan;312(Pt 1):137077. doi: 10.1016/j.chemosphere.2022.137077. Epub 2022 Nov 2.
Plastics pose a health hazard to living beings and the environment. Plastic degradation produces nano-sized plastic particles (NPs) that end up in terrestrial and aquatic ecosystems, including oceans, rivers, and lakes. Their presence in air, drinking water, sediments, food, and personal care products leads to a variety of exposure routes for living beings, including humans. The toxicity mechanisms of these nanomaterials (NMs) in living organisms and ecosystems are currently unknown, making it a priority to understand their effects at the molecular and cellular levels. The zebrafish (Zf) (Danio rerio) is a model organism which has a high homology with humans and has been widely used to assess the hazard of different xenobiotics. In this study, the expression changes of different genes in 120 hpf Zf embryos (Zfe) after exposure to polystyrene (PS) NPs (30 nm) at concentrations of 0.1, 0.5 and 3 ppm were investigated. The results showed that the gene encoding heat shock protein (hsp70) was down-regulated in a dose-dependent manner. The genes encoding superoxide dismutase (SOD 1 and SOD 2), apoptotic genes (cas 1 and cas 8) and interleukin 1-β (il1β) were activated at the concentration of 3 ppm PS NP, while the anti-apoptotic gene Bcl2α was inhibited at 0.5 and 3 ppm. In addition, the neurotransmitter-related gene Acetyl-Cholinesterase (ache) was significantly inhibited and the DNA repair genes (gadd45α and rad51) were also down-regulated. In contrast, the mitochondrial metabolism-related gene cox1 did not alter its expression in any of the treatments. Most of the changes in gene expression occurred at the highest concentration of NPs. Overall, the results indicated that NPs generated cellular stress that caused certain alterations in normal gene expression (oxidative stress, apoptotic and inflammatory processes, neurotoxicity and anti-apoptotic proteins), but did not cause any mortality after 120 hpf exposure at the three concentrations assayed. These results highlight the need for further studies investigating the effects, at the molecular level, of these materials in humans and other living organisms.
塑料对生物和环境构成健康危害。塑料降解会产生纳米级塑料颗粒（NPs），这些颗粒最终进入陆地和水生生态系统，包括海洋、河流和湖泊。它们存在于空气、饮用水、沉积物、食物和个人护理产品中，使生物（包括人类）有多种暴露途径。这些纳米材料（NMs）在生物体内和生态系统中的毒性机制尚不清楚，因此优先了解它们在分子和细胞水平上的影响。斑马鱼（Zf）（Danio rerio）是一种与人类高度同源的模式生物，已被广泛用于评估不同异源生物的危害。在这项研究中，研究了暴露于浓度为 0.1、0.5 和 3 ppm 的聚苯乙烯（PS）NPs（30nm）后 120 hpf Zf 胚胎（Zfe）中不同基因的表达变化。结果表明，热休克蛋白（hsp70）编码基因呈剂量依赖性下调。超氧化物歧化酶（SOD 1 和 SOD 2）、凋亡基因（cas 1 和 cas 8）和白细胞介素 1-β（il1β）编码基因在 3ppm PS NP 浓度下被激活，而抗凋亡基因 Bcl2α 在 0.5 和 3ppm 时被抑制。此外，神经递质相关基因乙酰胆碱酯酶（ache）显著受到抑制，DNA 修复基因（gadd45α 和 rad51）也下调。相比之下，线粒体代谢相关基因 cox1 在任何处理中都没有改变其表达。大多数基因表达的变化发生在 NPs 浓度最高的情况下。总的来说，这些结果表明 NPs 引起了细胞应激，导致正常基因表达发生了某些改变（氧化应激、凋亡和炎症过程、神经毒性和抗凋亡蛋白），但在三个浓度下暴露 120 hpf 后没有引起任何死亡率。这些结果强调了需要进一步研究这些材料在人类和其他生物体内的分子水平上的影响。
