Microplastics and bisphenol A co-exposure causes oxidative damage and induces ion regulation disorders in the gills of Portunus trituberculatus

Microplastics have been established as a novel environmental contaminant, while bisphenol A represents a common endocrine-disrupting chemical. However, the combined toxicity of both pollutants on the gills of marine crustaceans remains underexplored. This study investigated the possible risks associated with co-exposure to MPs and BPA on the gills of Portunus trituberculatus. Crabs were exposed to 100 μg/L BPA, 10 mg/L MPs, and a combination of 100 μg/L BPA + 10 mg/L MPs for 21 days. Histological analysis revealed that both MPs and BPA significantly compromised gill architecture. Transcriptomic analysis identified 1766 differentially expressed transcripts under varying exposure conditions, which were implicated in biological processes associated with oxidative stress, ion regulation, and apoptosis. The presence of MPs, BPA, and their co-exposure resulted in a reduction of sodium/potassium-transporting ATPase subunit beta-1 expression levels, ATPase activities, ATP content, and ion concentrations in the gills when compared to the control group. Notably, MPs, BPA and their combined treatment induced ROS and HO accumulation, and the upregulation of catalase and superoxide dismutase activities, which could potentially impact cell apoptosis. These results suggest that MPs and BPA may adversely affect oxidative damage, ion content, ion regulatory proteins, ion transport ATPase activity, apoptosis and their related gene expression in the gills of P. trituberculatus. Besides, integrated biomarker response values indicated that co-treatment resulted in greater gill toxicity. This comprehensive understanding highlights the imperative for preemptive measures to mitigate the adverse effects of environmental pollutants on ecological health, while providing valuable insights into the relevant molecular pathways.