Centro de Investigação de Tecnologias Agro-Ambientais e Biológicas (CITAB), Departamento de Biologia e Ambiente (DeBA), Escola de Ciências da Vida e Ambiente (ECVA), Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Vila Real, Portugal.
Aquat Toxicol. 2013 Mar 15;128-129:183-9. doi: 10.1016/j.aquatox.2012.12.018. Epub 2012 Dec 28.
Copper (Cu) is an essential micronutrient that, when present in high concentrations, becomes toxic to aquatic organisms. It is known that Cu toxicity may induce apoptotic cell death. However, the precise mechanism and the pathways that are activated, in fish, are still unclear. Thus, this study aimed to assess which apoptotic pathways are triggered by Cu, in zebrafish (Danio rerio) gill, the main target of waterborne pollutants. Fish where exposed to 12.5 and 100 μg/L of Cu during 6, 12, 24 and 48 h. Fish gills were collected to TUNEL assay and mRNA expression analysis of selected genes by real time PCR. An approach to different apoptosis pathways was done selecting p53, caspase-8, caspase-9 and apoptosis inducing factor (AIF) genes. The higher incidence of TUNEL-positive cells, in gill epithelia of the exposed fish, proved that Cu induced apoptosis. The results suggest that different apoptosis pathways are triggered by Cu at different time points of the exposure period, as the increase in transcripts was sequential, instead of simultaneous. Apoptosis seems to be initiated via intrinsic pathway (caspase-9), through p53 activation; then followed by the extrinsic pathway (caspase-8) and finally by the caspase-independent pathway (AIF). A possible model for Cu-induce apoptosis pathways is proposed.
铜（Cu）是一种必需的微量元素，当其浓度过高时，会对水生生物产生毒性。已知铜毒性可能诱导细胞凋亡。然而，在鱼类中，确切的机制和被激活的途径仍不清楚。因此，本研究旨在评估铜在斑马鱼（Danio rerio）鳃中引发哪些凋亡途径，鳃是水污染物的主要靶标。鱼在 12.5 和 100 μg/L 的铜中暴露 6、12、24 和 48 小时。收集鱼鳃进行 TUNEL 测定，并通过实时 PCR 分析选定基因的 mRNA 表达。通过选择 p53、caspase-8、caspase-9 和凋亡诱导因子（AIF）基因，研究了不同的凋亡途径。暴露鱼类鳃上皮中 TUNEL 阳性细胞的发生率较高，证明铜诱导了细胞凋亡。结果表明，不同的凋亡途径在暴露期的不同时间点被铜触发，因为转录物的增加是顺序的，而不是同时的。凋亡似乎是通过 p53 激活的内在途径（caspase-9）引发的；然后是外在途径（caspase-8），最后是无 caspase 途径（AIF）。提出了一种可能的铜诱导凋亡途径模型。
