Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples 80137, Italy; Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 405 30, Sweden.
Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 405 30, Sweden.
Ecotoxicol Environ Saf. 2024 Jul 1;279:116455. doi: 10.1016/j.ecoenv.2024.116455. Epub 2024 May 20.
Microplastics (MPs) pose a clear threat to aquatic organisms affecting their health. Their impact on liver homeostasis, as well as on the potential onset of nonalcoholic fatty liver disease (NAFLD), is still poorly investigated and remains almost unknown. The aim of this study was to evaluate the outcomes of subchronic exposure to polystyrene MPs (PS-MPs; 1-20 μm; 0, 25, or 250 mg/kg b.w./day) on lipid metabolism, inflammation, and oxidative balance in the liver of gilthead seabreams (Sparus aurata Linnaeus, 1758) exposed for 21 days via contaminated food. PS-MPs induced an up-regulation of mRNA levels of crucial genes associated with lipid synthesis and storage (i.e., PPARy, Srebp1, Fasn) without modifications of genes involved in lipid catabolism (i.e., PPARα, HL, Pla2) or transport and metabolism (Fabp1) in the liver. The increase of CSF1R and pro-inflammatory cytokines gene expression (i.e., TNF-α and IL-1β) was also observed in exposed fish in a dose-dependent manner. These findings were confirmed by hepatic histological evaluations reporting evidence of lipid accumulation, inflammation, and necrosis. Moreover, PS-MPs caused the impairment of the hepatic antioxidant defense system through the alteration of its enzymatic (catalase, superoxide dismutase, and glutathione reductase) and non-enzymatic (glutathione) components, resulting in the increased production of reactive oxygen species (ROS) and malondialdehyde (MDA), as biomarkers of oxidative damage. The alteration of detoxifying enzymes was inferred by the decreased Ethoxyresorufin-O-deethylase (EROD) activity and the increased activity of glutathione-S-transferase (GST) at the highest PS-MP dose. The study suggests that PS-MPs affect the liver health of gilthead seabream. The liver dysfunction and damage caused by exposure to PS-MPs result from a detrimental interplay of inflammation, oxidative damage, and antioxidant and detoxifying enzymatic systems modifications, altering the gut-liver axis homeostasis. This scenario is suggestive of the involvement of MP-induced effects in the onset and progression of hepatic lipid dysfunction in gilthead seabream.
微塑料 (MPs) 对水生生物构成明显威胁，影响其健康。它们对肝脏内稳态的影响，以及对非酒精性脂肪性肝病 (NAFLD) 的潜在影响，仍未得到充分研究，几乎不为人知。本研究旨在评估亚慢性暴露于聚苯乙烯 MPs (PS-MPs; 1-20 μm; 0、25 或 250 mg/kg bw/天) 通过受污染的食物对金头鲷 (Sparus aurata Linnaeus, 1758) 肝脏脂质代谢、炎症和氧化平衡的影响。PS-MPs 诱导与脂质合成和储存相关的关键基因的 mRNA 水平上调 (即 PPARy、Srebp1、Fasn)，而不改变脂质分解代谢 (即 PPARα、HL、Pla2) 或运输和代谢 (Fabp1) 的基因肝脏中的基因。暴露鱼中还观察到 CSF1R 和促炎细胞因子基因表达 (即 TNF-α 和 IL-1β) 的增加呈剂量依赖性。这些发现通过肝脏组织学评估得到证实，该评估报告了脂质积累、炎症和坏死的证据。此外，PS-MPs 通过改变其酶 (过氧化氢酶、超氧化物歧化酶和谷胱甘肽还原酶) 和非酶 (谷胱甘肽) 成分，破坏肝脏抗氧化防御系统，导致活性氧 (ROS) 和丙二醛 (MDA) 的产生增加，作为氧化损伤的生物标志物。通过降低 Ethoxyresorufin-O-deethylase (EROD) 活性和最高 PS-MP 剂量下谷胱甘肽-S-转移酶 (GST) 活性推断出解毒酶的改变。该研究表明 PS-MPs 会影响金头鲷的肝脏健康。暴露于 PS-MPs 导致的肝功能障碍和损伤是由炎症、氧化损伤以及抗氧化和解毒酶系统改变的有害相互作用引起的，改变了肠道-肝脏轴的平衡。这种情况表明，MP 诱导的影响可能参与了金头鲷肝脏脂质功能障碍的发生和进展。
