Centre de recherche en toxicologie de l'environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-ville, Montreal, QC, H3C 3P8, Canada.
Environment and Climate Change Canada, 105 McGill Street, Montreal, QC, H2Y 2E7, Canada.
Aquat Toxicol. 2020 Apr;221:105421. doi: 10.1016/j.aquatox.2020.105421. Epub 2020 Jan 25.
Lipids play important roles in growth, reproduction, locomotion, and migration of fish. Municipal effluents, which are complex mixtures of biological and chemical compounds including flame retardants, have been shown to alter lipid metabletabolism in environmentally and experimentally exposed fish. Down-regulation of several genes coding for fatty acid metabolism enzymes has previously been reported in male northern pike (Esox lucius) collected in the St. Lawrence River (QC, Canada) downstream of a major primary wastewater treatment plant (WWTP) point of discharge. The main objective of this study was to investigate the effects of exposure to the Montreal's WWTP effluent on the lipidomic profile (i.e., fatty acids, acylcarnitines, and phospholipids) as well as the transcription of genes related to lipid metabolism in the liver of northern pike collected upstream and downstream of this WWTP effluent. Halogenated flame retardant concentrations were also determined in pike liver and used as markers of exposure to this effluent. Greater concentrations of saturated and monounsaturated lysophosphatidylcholines (LPCs) and lower concentrations of polyunsaturated LPCs were determined in the liver of pike collected downstream of the WWTP compared to those collected upstream. Lower mRNA levels of peroxisome proliferator-activated receptor alpha (pparα), a major regulator of lipid metabolism, were also measured in pike exposed to Montreal's WWTP effluent. In addition, the relative contributions (%) of LPC 18:2 and LPC14:0, compounds used as markers of obesity and inflammation, were significantly correlated with halogenated flame retardant concentrations and fish girth. Results of the present study suggest that chronic environmental exposure to a primary WWTP effluent can modulate the transcription of genes related to lipid metabolism, and hence affect the hepatic phospholipid composition of pike from the St. Lawrence River.
脂质在鱼类的生长、繁殖、运动和迁移中起着重要作用。城市废水是生物和化学化合物的复杂混合物，包括阻燃剂，已被证明会改变环境和实验暴露于鱼类中的脂质代谢。以前有报道称，在圣劳伦斯河（加拿大魁北克省）下游一个主要的一级污水处理厂（WWTP）排放点采集的雄性北方狗鱼（Esox lucius）中，几种编码脂肪酸代谢酶的基因的表达下调。本研究的主要目的是研究暴露于蒙特利尔 WWTP 废水对北方狗鱼肝中脂质组学谱（即脂肪酸、酰基肉碱和磷脂）以及与脂质代谢相关的基因转录的影响，这些鱼是在 WWTP 废水的上游和下游采集的。还测定了狗鱼肝中卤代阻燃剂的浓度，并将其用作暴露于该废水的标志物。与 WWTP 废水上游采集的狗鱼肝相比，WWTP 废水下游采集的狗鱼肝中饱和和单不饱和溶血磷脂酰胆碱（LPC）的浓度较高，多不饱和 LPC 的浓度较低。暴露于蒙特利尔 WWTP 废水中的狗鱼肝中过氧化物酶体增殖物激活受体α（pparα）的 mRNA 水平也较低，pparα 是脂质代谢的主要调节剂。此外，用作肥胖和炎症标志物的 LPC 18:2 和 LPC14:0 的相对贡献（%）与卤代阻燃剂浓度和鱼腰围呈显著相关。本研究结果表明，慢性环境暴露于一级 WWTP 废水会调节与脂质代谢相关的基因的转录，从而影响圣劳伦斯河狗鱼肝中的磷脂组成。
