School of Basic Medical Sciences, Binzhou Medical University, Yantai, 264003, China.
School of Basic Medical Sciences, Binzhou Medical University, Yantai, 264003, China.
Environ Pollut. 2021 Jul 1;280:116974. doi: 10.1016/j.envpol.2021.116974. Epub 2021 Mar 19.
With the widespread use of plastics and nanotechnology products, nanoplastics (NPs) have become a potential threat to human health. It is of great practical significance to study and evaluate the distribution of NPs in mice as mammal models and their entry, transport, and cytotoxicity in human cell lines. In this study, we detected the tissue distribution of fluorescent polystyrene nanoplastics (PS-NPs) in mice and assessed their endocytosis, transport pathways, and cytotoxic effects in GES-1 cells. We found that PS-NPs were clearly visible in gastric, intestine, and liver tissues of mice and in GES-1 cells treated with PS-NPs. Entry of PS-NPs into GES-1 cells decreased with the inhibition of caveolae-mediated endocytosis (nystatin), clathrin-mediated endocytosis (chlorpromazine HCl), micropinocytosis (ethyl-isopropyl amiloride), RhoA (CCG-1423), and F-actin polymerization (lantrunculin A). Rac1 inhibitors (NSC 23766) had no significant effect on PS-NPs entering GES-1 cells. F-actin levels significantly decreased in CCG-1423-pretreated GES-1 cells exposed to PS-NPs. GES-1 cell ultrastructural features indicated that internalized PS-NPs can be encapsulated in vesicles, autophagosomes, lysosomes, and lysosomal residues. RhoA, F-actin, RAB7, and LAMP1 levels in PS-NPs-treated GES-1 cells were remarkably up-regulated and the Rab5 level was significantly down-regulated compared to levels in untreated cells. PS-NPs treatment decreased cell proliferation rates and increased cell apoptosis. The formation of autophagosomes and autolysosomes and levels of LC3II increased with the length of PS-NPs treatment. The results indicated that cells regulated endocytosis in response to PS-NPs through the RhoA/F-actin signaling pathway and internalized PS-NPs in the cytoplasm, autophagosomes, or lysosomes produced cytotoxicity. These results illustrate the potential threat of NPs pollution to human health.
随着塑料和纳米技术产品的广泛使用，纳米塑料（NPs）已成为人类健康的潜在威胁。研究和评估哺乳动物模型中小鼠体内 NPs 的分布及其在人细胞系中的内吞作用、转运和细胞毒性具有重要的实际意义。在本研究中，我们检测了荧光聚苯乙烯纳米塑料（PS-NPs）在小鼠体内的组织分布，并评估了其在 GES-1 细胞中的内吞作用、转运途径和细胞毒性。我们发现 PS-NPs 在小鼠的胃、肠和肝脏组织以及用 PS-NPs 处理的 GES-1 细胞中清晰可见。PS-NPs 进入 GES-1 细胞的能力随着小窝蛋白介导的内吞作用（制霉菌素）、网格蛋白介导的内吞作用（盐酸氯丙嗪）、微饮作用（乙基异丙基氨甲酰）、RhoA（CCG-1423）和 F-肌动蛋白聚合（拉仑丁 A）的抑制而降低。Rac1 抑制剂（NSC 23766）对 PS-NPs 进入 GES-1 细胞没有显著影响。在用 CCG-1423 预处理的 GES-1 细胞中，F-肌动蛋白水平显著降低，暴露于 PS-NPs 后。GES-1 细胞的超微结构特征表明，内化的 PS-NPs 可以被囊泡、自噬体、溶酶体和溶酶体残留物包裹。与未处理的细胞相比，用 PS-NPs 处理的 GES-1 细胞中的 RhoA、F-肌动蛋白、RAB7 和 LAMP1 水平显著上调，Rab5 水平显著下调。PS-NPs 处理降低了细胞增殖率并增加了细胞凋亡。自噬体和自溶酶体的形成以及 LC3II 的水平随着 PS-NPs 处理时间的延长而增加。结果表明，细胞通过 RhoA/F-肌动蛋白信号通路调节内吞作用以应对 PS-NPs，并将内化的 PS-NPs 转运到细胞质、自噬体或溶酶体中产生细胞毒性。这些结果说明了 NPs 污染对人类健康的潜在威胁。
