Area of Toxicology, Faculty of Pharmacy, University of Sevilla, C/Profesor García González 2, Sevilla 41012, Spain.
Toxins (Basel). 2014 Mar 13;6(3):1062-79. doi: 10.3390/toxins6031062.
The cyanobacterial toxin Cylindrospermopsin (CYN), a potent protein synthesis inhibitor, is increasingly being found in freshwater bodies infested by cyanobacterial blooms worldwide. Moreover, it has been reported to be implicated in human intoxications and animal mortality. Recently, the alteration of the activity and gene expression of some glutathione related enzymes in tilapias (Oreochromis niloticus) exposed to a single dose of CYN has been reported. However, little is known about the effects induced by repeated doses of this toxin in tilapias exposed by immersion and the potential reversion of these biochemical alterations after two different depuration periods (3 or 7 days). In the present study, tilapias were exposed by immersion to repeated doses of a CYN-containing culture of Aphanizomenon ovalisporum during 14 days, and then were subjected to depuration periods (3 or 7 days) in clean water in order to examine the potential reversion of the effects observed. The activity and relative mRNA expression by real-time polymerase chain reaction (PCR) of the antioxidant enzymes glutathione peroxidase (GPx) and soluble glutathione-S-transferases (sGST), and also the sGST protein abundance by Western blot analysis were evaluated in liver and kidney of fish. Results showed significant alterations in most of the parameters evaluated and their recovery after 3 days (GPx activity, sGST relative abundance) or 7 days (GPx gene expression, sGST activity). These findings not only confirm the oxidative stress effects produced in fish by cyanobacterial cells containing CYN, but also show the effectiveness of depuration processes in mitigating the CYN-containing culture toxic effects.
蓝藻毒素 Cylindrospermopsin（CYN）是一种有效的蛋白质合成抑制剂，在世界各地遭受蓝藻水华侵袭的淡水体中越来越多地被发现。此外，据报道，它与人类中毒和动物死亡有关。最近，有报道称，单一剂量 CYN 暴露会改变罗非鱼（Oreochromis niloticus）中一些与谷胱甘肽相关的酶的活性和基因表达。然而，对于这种毒素在罗非鱼中多次暴露引起的影响以及经过两个不同的净化期（3 天或 7 天）后这些生化变化的潜在逆转知之甚少。在本研究中，罗非鱼通过浸泡暴露于含 Aphanizomenon ovalisporum 的 CYN 培养物中重复剂量 14 天，然后在清洁水中进行净化期（3 天或 7 天），以检查观察到的影响的潜在逆转。通过实时聚合酶链反应（PCR）评估抗氧化酶谷胱甘肽过氧化物酶（GPx）和可溶性谷胱甘肽-S-转移酶（sGST）的活性和相对 mRNA 表达，以及通过 Western blot 分析评估 sGST 蛋白丰度在鱼的肝脏和肾脏中进行。结果表明，在大多数评估参数中观察到显著变化，并且在 3 天（GPx 活性，sGST 相对丰度）或 7 天（GPx 基因表达，sGST 活性）后恢复。这些发现不仅证实了含有 CYN 的蓝藻细胞在鱼类中产生的氧化应激效应，而且还表明净化过程在减轻含 CYN 培养物的毒性效应方面的有效性。
