Plastics are one of the most pervasive materials on Earth, to which humans are exposed daily. Polystyrene (PS) is a common plastic packaging material. However, the impact of PS on human health remains poorly understood. Therefore, this study aimed to identify intestinal damage induced by PS nanoplastics (PS-NPs) in zebrafish larvae which have a high homology with humans. Four days post fertilization (dpf), zebrafish larvae were exposed to 0-, 10-, and 50-ppm PS-NPs for 48 h Initially, to ascertain if 100 nm PS-NPs could accumulate in the gastrointestinal (GI) tract of zebrafish larvae, the larvae were exposed to red fluorescence-labeled PS-NPs, and at 6 dpf, the larvae were examined using a fluorescence microscope. Analysis of the fluorescence intensity revealed that the GI tract of larvae exposed to 50-ppm exhibited a significantly stronger fluorescence intensity than the other groups. Nonfluorescent PS-NPs were then used in further studies. Scanning electron microscopy (SEM) confirmed the spherical shape of the PS-NPs. Fourier-transform infrared spectroscopy (FT-IR) analysis revealed chemical alterations in the PS-NPs before and after exposure to larvae. The polydispersity index (PDI) value derived using a Zetasizer indicated a stable dispersion of PS-NPs in egg water. Whole-mount apoptotic signal analysis via TUNEL assay showed increased apoptosis in zebrafish larval intestines exposed to 50-ppm PS-NPs. Damage to the intestinal tissue was assessed by Alcian blue (AB) and hematoxylin and eosin (H&E) staining. AB staining revealed increased mucin levels in the zebrafish larval intestines. Thin larval intestinal walls with a decrease in the density of intestinal epithelial cells were revealed by H&E staining. The differentially expressed genes (DEGs) induced by PS-NPs were identified and analyzed. In conclusion, exposure to PS-NPs may damage the intestinal barrier of zebrafish larvae due to increased intestinal permeability, and the gene network may change in larvae exposed to PS-NPs.

中文翻译：

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聚苯乙烯纳米塑料通过斑马鱼幼虫（Danio Rerio）炎症和细胞凋亡诱导肠道屏障破坏


塑料是地球上最普遍的材料之一，人类每天都会接触到它。聚苯乙烯（PS）是一种常见的塑料包装材料。然而，PS 对人类健康的影响仍然知之甚少。因此，本研究旨在鉴定与人类具有高度同源性的PS纳米塑料（PS-NPs）在斑马鱼幼虫中引起的肠道损伤。受精后四天 (dpf)，将斑马鱼幼虫暴露于 0、10 和 50 ppm PS-NP 48 小时。最初，以确定 100 nm PS-NP 是否可以在斑马鱼的胃肠道 (GI) 中积聚幼虫，将幼虫暴露于红色荧光标记的 PS-NP，并在 6 dpf 时，使用荧光显微镜检查幼虫。荧光强度分析表明，暴露于 50 ppm 的幼虫胃肠道的荧光强度明显强于其他组。然后将非荧光 PS-NP 用于进一步的研究。扫描电子显微镜 (SEM) 证实了 PS-NP 的球形形状。傅里叶变换红外光谱 (FT-IR) 分析揭示了 PS-NP 在接触幼虫之前和之后发生了化学变化。使用 Zetasizer 得出的多分散指数 (PDI) 值表明 PS-NP 在蛋水中稳定分散。通过 TUNEL 检测进行的整体细胞凋亡信号分析显示，暴露于 50 ppm PS-NP 的斑马鱼幼虫肠道细胞凋亡增加。通过阿新蓝 (AB) 和苏木精和伊红 (H&E) 染色评估肠道组织的损伤。 AB 染色显示斑马鱼幼虫肠道中的粘蛋白水平增加。 H&E 染色显示幼虫肠壁薄且肠上皮细胞密度降低。 鉴定并分析了 PS-NP 诱导的差异表达基因 (DEG)。总之，暴露于PS-NPs可能会由于肠道通透性增加而损害斑马鱼幼虫的肠道屏障，并且暴露于PS-NPs的幼虫的基因网络可能发生变化。