Chen Feng, Huang Chao, Luo Zhi, Shi Xi, Liu Xu, Fan Yao-Fang, Pan Ya-Xiong
Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College, Huazhong Agricultural University, Wuhan 430070, China.
Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College, Huazhong Agricultural University, Wuhan 430070, China; Collaborative Innovation Center for Efficient and Health Production of Fisheries in Hunan Province, Changde 415000, China.
Aquat Toxicol. 2016 May;174:134-45. doi: 10.1016/j.aquatox.2016.02.022. Epub 2016 Mar 3.
Recent evidences suggested that Fe influenced Cu metabolism in vertebrates. The present study was conducted to test the hypothesis that Fe could alleviate Cu-induced change of lipid deposition in the fish species. Synechogobius hasta were exposed to 0, 0.606 and 1.212μM Cu, in combination with 0 and 1.128μM Fe, respectively. Sampling occurred on day 28 and day 56, respectively. Growth performance, hepatic lipid deposition, Fe and Cu level, and activities and mRNA expression of enzymes and genes involved in lipid metabolism were analyzed. Fe addition in water improved survival in S. hasta exposed to the highest waterborne Cu concentration on day 56. Fe addition also increased hepatic Fe content both at day 28 and day 56, and reduced hepatic Cu content. Fe exposure tended to reduce the activities and mRNA expressions of lipogenic enzymes and genes (G6PD and FAS), and up-regulated the mRNA expression of ATGL. With the same Cu concentration, Fe addition tended to down-regulate mRNA levels of SREBP-1 and PPARγ, and up-regulate PPARα mRNA level on day 28. However, on day 56, the mRNA levels of SREBP-1, PPARγ and PPARα are very variable and not related with waterborne Fe addition. Some correlative relationship was observed between the mRNA of transcriptional factors, and the activities of enzymes and the mRNA expression of genes encoding them, implying their transcription regulation of these enzymatic genes by transcriptional factors after Fe addition. Overall, Fe addition mitigated Cu-induced changes of lipid deposition in fish by down-regulation of lipogenesis and up-regulation of lipolysis. Different response patterns of these enzyme activities and gene expressions in the liver of S. hasta following waterborne Fe exposure indicated that Fe effects on Cu-induced change of lipid metabolism are time-dependent.
近期证据表明，铁会影响脊椎动物体内的铜代谢。本研究旨在验证铁可缓解铜诱导的鱼类脂质沉积变化这一假说。将矛尾复虾虎鱼分别暴露于0、0.606和1.212μM的铜中，并分别添加0和1.128μM的铁。分别在第28天和第56天进行采样。分析了生长性能、肝脏脂质沉积、铁和铜水平，以及参与脂质代谢的酶和基因的活性及mRNA表达。在第56天，添加铁提高了暴露于最高水体铜浓度下的矛尾复虾虎鱼的存活率。添加铁还在第28天和第56天增加了肝脏铁含量，并降低了肝脏铜含量。铁暴露倾向于降低脂肪生成酶和基因（G6PD和FAS）的活性及mRNA表达，并上调ATGL的mRNA表达。在相同铜浓度下，添加铁在第28天倾向于下调SREBP-1和PPARγ的mRNA水平，并上调PPARα的mRNA水平。然而，在第56天，SREBP-1、PPARγ和PPARα的mRNA水平变化很大，且与水体中铁的添加无关。观察到转录因子的mRNA与酶活性及编码这些酶的基因的mRNA表达之间存在一些相关性，这意味着添加铁后转录因子对这些酶基因有转录调控作用。总体而言，添加铁通过下调脂肪生成和上调脂肪分解减轻了铜诱导的鱼类脂质沉积变化。水体中铁暴露后，矛尾复虾虎鱼肝脏中这些酶活性和基因表达的不同反应模式表明，铁对铜诱导的脂质代谢变化的影响具有时间依赖性。
