Unit for Environmental Sciences and Management, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa.
Unit for Environmental Sciences and Management, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa; South African Research Chair for Nanotechnology for Water, Department of Applied Chemistry, University of Johannesburg, South Africa.
Aquat Toxicol. 2019 Oct;215:105287. doi: 10.1016/j.aquatox.2019.105287. Epub 2019 Aug 29.
Gold nanoparticles are used as drug delivery vectors based on the assumption that they have low toxicity. Literature has, however, produced conflicting results over the last few years. As such, this study aimed to investigate the toxicological effects of nanogold (nAu) on several indicators that range from subcellular to whole-organism level. Gene regulation, changes in oxidative stress biomarkers and swimming performance were assessed in Danio rerio (zebrafish) following exposures to nAu. Adult zebrafish were exposed in vivo to nAu for 96 h and swimming performance measured post-exposure. Liver tissue was collected for DNA microarray and Real-Time Polymerase Chain Reactions (RT-PCR) analyses to determine changes in gene expression (catalase, superoxide dismutase and metallothioneins) and protein biomarker analyses (catalase, superoxide dismutase, acetylcholine esterase, malondialdehyde, cellular energy allocation and metallothionein) were performed on whole-body samples. Swimming behaviour was assessed in 1.1 L Tecniplast™ tanks for a period of six hours and videos were analysed using Noldus EthoVision software. Critical swimming speed was measured in a Loligo® swimming tunnel. The DNA microarray revealed that fish exposed to 20 mg/L differed most from the control group. At 20 mg/L there was a significant increase in gene expression for all genes analysed but this didn't translate to significant responses in protein biomarker levels except for an increase in protein carbonyl formation. The behaviour results demonstrated significant changes in distance moved, swimming speed, acceleration bouts, zone alterations and time spent within the top zone - responses that are usually observed in fish responding to toxicological stress. Furthermore, the critical swimming speed of exposed fish was decreased significantly compared to the control. Since swimming performance and social interaction among zebrafish is essential to their survival, whole-organism behaviour that suggests a toxicological response after exposure to nAu is in agreement with the genetic responses measured in this study.
金纳米颗粒被用作药物输送载体，基于它们毒性低的假设。然而，近年来文献中产生了相互矛盾的结果。因此，本研究旨在调查纳米金（nAu）对从亚细胞到整体水平的几种指标的毒理学影响。在暴露于 nAu 后，评估了 Danio rerio（斑马鱼）的基因调控、氧化应激生物标志物变化和游泳性能。成年斑马鱼进行体内暴露，暴露时间为 96 小时，并在暴露后测量游泳性能。收集肝组织进行 DNA 微阵列和实时聚合酶链反应（RT-PCR）分析，以确定基因表达（过氧化氢酶、超氧化物歧化酶和金属硫蛋白）的变化，以及对全身体样本进行蛋白质生物标志物分析（过氧化氢酶、超氧化物歧化酶、乙酰胆碱酯酶、丙二醛、细胞能量分配和金属硫蛋白）。游泳行为在 1.1 L Tecniplast™ 罐中进行了六个小时的评估，并使用 Noldus EthoVision 软件对视频进行了分析。临界游泳速度在 Loligo®游泳隧道中进行测量。DNA 微阵列显示，暴露于 20 mg/L 的鱼类与对照组差异最大。在 20 mg/L 时，所有分析基因的基因表达均显著增加，但这并未转化为蛋白质生物标志物水平的显著反应，除了蛋白质羰基形成增加外。行为结果表明，距离移动、游泳速度、加速回合、区域改变和在顶部区域花费的时间有显著变化 - 这些通常是鱼类对毒理学应激做出反应时观察到的反应。此外，暴露鱼类的临界游泳速度与对照组相比显著降低。由于游泳性能和斑马鱼之间的社会互动对其生存至关重要，因此在暴露于 nAu 后观察到的整体动物行为与本研究中测量的遗传反应一致。
