[Polystyrene nanoplastics disrupt macrophage cholesterol metabolism by adsorbing apolipoprotein E]

This study aimed to investigate the potential health hazards and molecular mechanisms of nanoplastic (NP) pollutants. Polystyrene nanoplastics (PS-NPs), which are prevalent in the environment and can enter the human body, have been closely associated with the risk of cardiovascular diseases, yet their impact on cholesterol metabolism remains unclear. In this study, proteomic analysis revealed that PS-NPs specifically adsorbed 1 676 proteins following their interaction with macrophages. Bioinformatic analysis indicated that these adsorbed proteins were significantly enriched in the cholesterol metabolism pathway, with apolipoprotein E (APOE) being the most prominently adsorbed. Further molecular docking and molecular dynamics simulations demonstrated that polystyrene molecules could inhibit the interaction between APOE and cholesterol by competitively binding to key amino acid residues (e.g., LEU-202 and TRP-228) of APOE. Cell experiments confirmed that exposure to 100 μg/mL PS-NPs for 24 h significantly induced lipid accumulation in macrophages. This study reveals, from a molecular interaction perspective, a novel mechanism by which PS-NPs disrupt lipid metabolism by interfering with APOE function. It provides key evidence for elucidating the toxicological mechanism through which PS-NPs promote atherosclerosis and holds significant scientific importance for assessing their health risks.