微塑料,被认为是新兴的污染物,通常被观察到在环境中带电,可能对各种生物产生毒性作用。然而,聚苯乙烯(PS)的跨代生殖毒性和潜在机制,特别是羧基修饰的PS(PS-COOH)和氨基修饰的PS(PS-NH2),在很大程度上仍未被探索。在这项研究中,秀丽隐杆线虫的亲代(P0)受到环境浓度(0.1-100μg/L)的PS,PS-COOH,和PS-NH2,随后的世代(F1-F4)在正常条件下培养。与PS或PS-COOH相比,以10-100μg/L的浓度暴露于PS-NH2表现出更明显的生殖毒性,导致小窝大小减小,卵射血率,受精卵的数量,和每个性腺的细胞尸体。同样,母体暴露于100μg/L的PS-NH2在秀丽隐杆线虫中引起更严重的跨代生殖效应。在随后的世代中观察到H3对赖氨酸4二甲基化(H3K4me2)和H3对赖氨酸9三甲基化(H3K9me3)水平的显着增加,与父母暴露于PS后set-30和met-2的跨代上调同时,PS-COOH,PS-NH2相关分析表明,这些基因的表达与生殖能力之间存在显着关联。分子对接研究表明,PS-NH2对SET-30和MET-2表现出更高的亲和力。进一步的分析表明,在集合30(gk315)和met-2(n4256)突变体中不存在对繁殖的跨代效应,强调set-30和met-2在调解跨代效应中的关键作用。这项研究提供了与带负电和带正电的微塑料相关的环境风险的新见解。
Microplastics, recognized as emerging contaminants, are commonly observed to be charged in the environment, potentially exerting toxic effects on various organisms. However, the transgenerational reproductive toxicity and underlying mechanisms of polystyrene (PS), particularly carboxyl-modified PS (PS-COOH) and amino-modified PS (PS-NH2), remain largely unexplored. In this study, the parental generation (P0) of Caenorhabditis elegans was subjected to environmental concentrations (0.1-100 μg/L) of PS, PS-COOH, and PS-NH2, with subsequent generations (F1-F4) cultured under normal conditions. Exposure to PS-NH2 at concentrations of 10-100 μg/L exhibited more pronounced reproductive toxicity compared to PS or PS-COOH, resulting in decreased brood size, egg ejection rate, number of fertilized eggs, and cell corpses per gonad. Similarly, maternal exposure to 100 μg/L of PS-NH2 induced more severe transgenerational reproductive effects in C. elegans. Significant increases in H3 on lysine 4 dimethylation (H3K4me2) and H3 on lysine 9 trimethylation (H3K9me3) levels were observed in the subsequent generation, concurrent with the transgenerational upregulation of set-30 and met-2 following parental exposure to PS, PS-COOH, and PS-NH2. Correlation analyses revealed significant associations between the expression of these genes with the reproductive ability. Molecular docking studies suggested that PS-NH2 exhibited higher affinity for SET-30 and MET-2. Further analysis demonstrated that transgenerational effects on reproduction were absent in set-30(gk315) and met-2(n4256) mutants, highlighting the pivotal role of set-30 and met-2 in mediating the transgenerational effect. This study provides novel insights into the environmental risks associated with negatively and positively charged microplastics.