Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Trans-Boundary Eco-security, Yunnan University, Kunming, 650091, People's Republic of China; Yunnan International Joint Research Center for Hydro-Ecology Science & Engineering, Yunnan University, Kunming, 650091, People's Republic of China.
Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Trans-Boundary Eco-security, Yunnan University, Kunming, 650091, People's Republic of China; Yunnan International Joint Research Center for Hydro-Ecology Science & Engineering, Yunnan University, Kunming, 650091, People's Republic of China.
Chemosphere. 2022 Nov;307(Pt 2):135887. doi: 10.1016/j.chemosphere.2022.135887. Epub 2022 Aug 3.
Microplastic exposure leads to various toxic effects in Daphnia magna; however, the effects of microplastics on the metabolic processes in D. magna and the corresponding molecular toxicity mechanisms remain unclear. In the present study, the effects of acute exposure to polyethylene microplastics with different particle sizes (20 μm [MPs-20] and 30 μm [MPs-30]) on metabolites in D. magna and the mechanisms of toxicity were investigated by combining metabolomics and traditional toxicology techniques. Exposure to both MPs-20 and MPs-30 resulted in significant accumulation of microplastics in the gut of D. magna and significantly reduced D. magna survival and heart rate. Metabolomics analysis revealed that MPs-20 and MPs-30 induced significant changes in up to 88 and 91 differential metabolites, respectively, and collectively induced significant changes in 75 metabolites in D. magna. Among lipid metabolites, MPs-20 specifically downregulated phosphatidylcholine and upregulated phosphatidylethanolamine, which mainly affected phospholipid metabolism, whereas MPs-30 specifically downregulated amino acid metabolites l-glutamine, l-glutamate and malic acid, which mainly interfered with energy metabolism. The results of this study provide novel insights into the mechanism of effects of microplastics on metabolic processes in D. magna.
微塑料暴露会对大型溞（Daphnia magna）造成各种毒性影响；然而，微塑料对大型溞代谢过程的影响及其相应的分子毒性机制尚不清楚。在本研究中，通过结合代谢组学和传统毒理学技术，研究了不同粒径（20μm [MPs-20]和 30μm [MPs-30]）的聚乙烯微塑料急性暴露对大型溞代谢物的影响及其毒性机制。暴露于 MPs-20 和 MPs-30 都会导致微塑料在大型溞肠道中大量积累，并显著降低大型溞的存活率和心率。代谢组学分析显示，MPs-20 和 MPs-30 分别诱导了多达 88 个和 91 个差异代谢物的显著变化，总共诱导了大型溞中 75 个代谢物的显著变化。在脂质代谢物中，MPs-20 特异性地下调了磷脂酰胆碱并上调了磷脂酰乙醇胺，主要影响了磷脂代谢，而 MPs-30 特异性地下调了氨基酸代谢物 l-谷氨酰胺、l-谷氨酸和苹果酸，主要干扰了能量代谢。本研究的结果为微塑料对大型溞代谢过程影响的机制提供了新的见解。
