Transcriptional and Behavioral Responses of Zebrafish Larvae to Microcystin-LR Exposure.
Transcriptional and Behavioral Responses of Zebrafish Larvae to Microcystin-LR Exposure.
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DOI：
10.3390/ijms18020365
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发表时间：
2017-02-09
影响因子：
5.6
通讯作者：
Papamarcaki T
中科院分区：
文献类型：
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作者：
Tzima E;Serifi I;Tsikari I;Alzualde A;Leonardos I;Papamarcaki T
微囊藻毒素是由蓝藻产生的一类环状七肽类毒素。该家族中毒性最强的变体之一是微囊藻毒素-LR（MclA），它是蛋白磷酸酶2A（PP 2A）的有效抑制剂，并诱导细胞骨架改变。在这项研究中，斑马鱼幼虫暴露于500 μg/L的Mexylamine四天，与对照组相比，PP 2A活性降低了40%，表明毒素的早期影响。使用微阵列分析的MCLR暴露的幼虫的基因表达谱显示，角蛋白96（krt 96）是最下调的基因，与MCLR对细胞骨架结构的良好记录的影响一致。此外，我们的分析揭示了所有编码视网膜视觉周期酶的基因的上调，包括rpe 65 a（视网膜色素上皮特异性蛋白65 a），这对幼虫的视觉至关重要。定量实时PCR（qPCR）分析证实了微阵列数据，显示rpe 65 a在50 μg/L和500 μg/L MtdR下以剂量依赖性方式显著上调。与微阵列数据一致，MCLR处理的幼虫表现出行为改变，如对突然黑暗的反应减弱和黑暗中的活动减退。我们的工作揭示了新的分子靶点，并提供了进一步的见解，在早期发展过程中的分子机制的毒性。
Microcystins are cyclic heptapeptides that constitute a diverse group of toxins produced by cyanobacteria. One of the most toxic variants of this family is microcystin-LR (MCLR) which is a potent inhibitor of protein phosphatase 2A (PP2A) and induces cytoskeleton alterations. In this study, zebrafish larvae exposed to 500 μg/L of MCLR for four days exhibited a 40% reduction of PP2A activity compared to the controls, indicating early effects of the toxin. Gene expression profiling of the MCLR-exposed larvae using microarray analysis revealed that keratin 96 (krt96) was the most downregulated gene, consistent with the well-documented effects of MCLR on cytoskeleton structure. In addition, our analysis revealed upregulation in all genes encoding for the enzymes of the retinal visual cycle, including rpe65a (retinal pigment epithelium-specific protein 65a), which is critical for the larval vision. Quantitative real-time PCR (qPCR) analysis confirmed the microarray data, showing that rpe65a was significantly upregulated at 50 μg/L and 500 μg/L MCLR in a dose-dependent manner. Consistent with the microarray data, MCLR-treated larvae displayed behavioral alterations such as weakening response to the sudden darkness and hypoactivity in the dark. Our work reveals new molecular targets for MCLR and provides further insights into the molecular mechanisms of MCLR toxicity during early development.