Nanoplastic Exposure at Environmental Concentrations Disrupts Hepatic Lipid Metabolism through Oxidative Stress Induction and Endoplasmic Reticulum Homeostasis Perturbation

• Published in: Environmental science & technology 2023-09, Vol.57 (38), p.14127-14137
• Main Authors: Wang, Weiyu, Mao, Xuan, Zhang, Rui, Zhou, Xiao-Xia, Liu, Yujiao, Zhou, Hongyu, Jia, Jianbo, Yan, Bing
• Format: Article
• Language: English
• Subjects: Animal tissues; Aquatic organisms; ecotoxicology; Ecotoxicology and Public Health; Endoplasmic reticulum; Environmental effects; environmental science; Fatty liver; Food safety; Homeostasis; Inflammation; Inflammatory response; Lipid metabolism; Lipids; Liver; liver function; Metabolism; muscles; nanoplastics; Oreochromis niloticus; Oxidative metabolism; Oxidative stress; particle size; Perturbation; Plastic pollution; Polystyrene; Polystyrene resins; polystyrenes; Proteins; Steatosis; Tilapia; Toxicity
• ISSN: 0013-936X; 1520-5851; 1520-5851
• DOI: 10.1021/acs.est.3c02769

In this study, we investigated the mechanism underlying the perturbation of hepatic lipid metabolism in response to micro/nanoplastic (MP/NP) exposure at environmentally relevant concentrations. Polystyrene (PS) MPs/NPs with different sizes (0.1, 0.5, and 5.0 μm) were studied for their effects on the homeostasis and function of Nile tilapia (Oreochromis niloticus) liver. Results showed that PS MPs/NPs were readily internalized and accumulated in various internal organs/tissues, especially in fish liver and muscle. Smaller-sized NPs caused more severe toxicity than larger MPs, including hepatic steatosis, inflammatory response, and disturbed liver function. Mechanistically, PS NPs with a particle size of 100 nm perturbed protein homeostasis in the endoplasmic reticulum (ER) by inhibiting the expression of chaperone proteins and genes involved in ER-associated degradation. This led to the activation of the PERK-eIF2α pathway, which caused dysfunction of hepatic lipid metabolism. Induction of oxidative stress and activation of the Nrf2/Keap1 pathway were also involved in the PS NP-induced hepatic lipid accumulation. These findings highlight the potential adverse effects of environmental MPs/NPs on aquatic organisms, raising concerns about their ecotoxicity and food safety.