New insights into the responding mechanism of Eriocheir sinensis hepatopancreas under nanoplastics and copper stress by transcriptome analysis.

Nanoplastics (NPs) possess adsorptive properties and can interact with pollutants such as heavy metals, raising concerns about their toxicological effects on aquatic organisms. However, systematic evaluations of the mechanisms underlying the impact of these pollutants on crustaceans are limited. To investigate the combined toxicological effects of NPs and copper (Cu), Eriocheir sinensis were exposed to 0.4 mg/L NPs (NPs group), 0.1 mg/L Cu (Cu group), 0.4 mg/L NPs + 0.1 mg/L Cu (NPs + Cu group), and a control group for 21 days. The results indicated a significant increase in the accumulation of NPs and Cu in the hepatopancreas as the exposure duration increased. Exposure to NPs and/or Cu not only induces pronounced histopathological changes in the hepatopancreas but also ultimately leads to an increase in most antioxidant enzymes and a decrease in most immune-related enzymes. Transcriptome sequencing analysis revealed that exposure to NPs and/or Cu affects the energy supply of the organism by interfering with lipid metabolism and activates the antioxidant system, which regulates the expression of glutathione S-transferase (GST) and glutathione peroxidase (GSH-Px). In addition, nuclear factor kappa-light-chain-enhancer of activated B cells 1 (NFKB1) and UDP-glucuronosyltransferase (UGT), key genes in the immune system, play a crucial role in mitigating hepatopancreatic toxicity by combined exposure to NPs and Cu. This study provides valuable insights into the mechanisms by which crustaceans in the Yangtze estuary respond to combined exposure to NPs and Cu.