Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto, ON, Canada M1C 1A4.
Chemosphere. 2013 Sep;93(2):331-7. doi: 10.1016/j.chemosphere.2013.04.085. Epub 2013 Jun 2.
Metal and metalloid contamination constitutes a major concern in aquatic ecosystems. Thus it is important to find rapid and reliable indicators of metal stress to aquatic organisms. In this study, we tested the use of (1)H nuclear magnetic resonance (NMR) - based metabolomics to examine the response of Daphnia magna neonates after a 48h exposure to sub-lethal concentrations of arsenic (49μgL(-1)), copper (12.4μgL(-1)) or lithium (1150μgL(-1)). Metabolomic responses for all conditions were compared to a control using principal component analysis (PCA) and metabolites that contributed to the variation between the exposures and the control condition were identified and quantified. The PCA showed that copper and lithium exposures result in statistically significant metabolite variations from the control. Contributing to this variation was a number of amino acids such as: phenylalanine, leucine, lysine, glutamine, glycine, alanine, methionine and glutamine as well as the nucleobase uracil and osmolyte glycerophosphocholine. The similarities in metabolome changes suggest that lithium has an analogous mode of toxicity to that of copper, and may be impairing energy production and ionoregulation. The PCA also showed that arsenic exposure resulted in a metabolic shift in comparison to the control population but this change was not statistically significant. However, significant changes in specific metabolites such as alanine and lysine were observed, suggesting that energy metabolism is indeed disrupted. This research demonstrates that (1)H NMR-based metabolomics is a viable platform for discerning metabolomic changes and mode of toxicity of D. magna in response to metal stressors in the environment.
金属和类金属污染物是水生生态系统的主要关注点。因此，找到快速可靠的金属胁迫水生生物的指标非常重要。在这项研究中，我们测试了（1）H 核磁共振（NMR）代谢组学用于检测在亚致死浓度的砷（49μgL（-1））、铜（12.4μgL（-1））或锂（1150μgL（-1））暴露 48 小时后，大型溞幼虫的代谢组响应。使用主成分分析（PCA）比较了所有条件下的代谢组响应，并鉴定和量化了对暴露和对照条件之间的差异有贡献的代谢物。PCA 表明，铜和锂暴露导致与对照相比存在统计学上显著的代谢物变化。促成这种变化的是一些氨基酸，如苯丙氨酸、亮氨酸、赖氨酸、谷氨酰胺、甘氨酸、丙氨酸、蛋氨酸和谷氨酰胺以及核苷碱基尿嘧啶和渗透调节剂甘油磷酸胆碱。代谢组变化的相似性表明，锂具有类似于铜的毒性模式，可能会损害能量产生和离子调节。PCA 还表明，与对照种群相比，砷暴露导致代谢发生转变，但这种变化没有统计学意义。然而，观察到特定代谢物如丙氨酸和赖氨酸的显著变化，表明能量代谢确实受到干扰。这项研究表明，（1）H NMR 代谢组学是一种可行的平台，可用于辨别大型溞对环境中金属胁迫的代谢组变化和毒性模式。
