National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Key Laboratory for Lake Pollution Control, State Environmental Protection Scientific Observation and Research Station for Lake Dongtinghu (SEPSORSLD), State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou 310015, China.
Comp Biochem Physiol C Toxicol Pharmacol. 2024 Mar;277:109824. doi: 10.1016/j.cbpc.2023.109824. Epub 2023 Dec 26.
Microcystins (MCs) are the most widespread, frequently found, and seriously toxic cyanobacterial toxins in aquatic environments. Microcystin-leucine-arginine (MCLR) and microcystin-arginine-arginine (MCRR) are the most studied MCs. Normally, their levels are low and they coexist in the environment; however, they may also interact with each other. The developmental toxicity of MCLR in the presence of MCRR in the early life stage of zebrafish (from 2 to 120 h post fertilization) was investigated for the first time in this study. Our findings revealed that MCRR treatment marginally elevated thyroxine (T4) and 3,5,3'-triiodothyronine (T3) levels, whereas MCLR treatment alone resulted in a significant increase in T3 and T4 levels, indicating a cooperative effect. Furthermore, clear changes in the expression levels of genes involved in growth and development, accompanied by growth inhibition, were observed after co-treatment with MCRR and MCLR. In addition, zebrafish larvae subjected to MCRR and/or MCLR treatment showed increased levels of superoxide dismutase, glutathione, and malondialdehyde, and decreased levels of catalase in the MCRR + MCLR group, indicating oxidative stress and lipid peroxidation. Thus, we investigated the synergistic developmental toxicity of MCRR and MCLR during the early life stages of zebrafish development.
微囊藻毒素（MCs）是水生环境中分布最广泛、最常见且毒性最强的蓝藻毒素。微囊藻氨酸-亮氨酸-精氨酸（MCLR）和微囊藻氨酸-精氨酸-精氨酸（MCRR）是研究最多的 MCs。通常情况下，它们的含量很低，并且在环境中共存，但也可能相互作用。本研究首次研究了在斑马鱼早期生命阶段（受精后 2 至 120 小时）存在 MCRR 的情况下，MCLR 的发育毒性。我们的研究结果表明，MCRR 处理轻微升高了甲状腺素（T4）和 3,5,3'-三碘甲状腺原氨酸（T3）水平，而单独的 MCLR 处理导致 T3 和 T4 水平显著升高，表明存在协同作用。此外，在 MCRR 和 MCLR 共同处理后，观察到参与生长和发育的基因表达水平发生明显变化，伴随着生长抑制。此外，暴露于 MCRR 和/或 MCLR 的斑马鱼幼虫的超氧化物歧化酶、谷胱甘肽和丙二醛水平升高，而 MCRR + MCLR 组中的过氧化氢酶水平降低，表明存在氧化应激和脂质过氧化。因此，我们研究了 MCRR 和 MCLR 在斑马鱼发育早期阶段的协同发育毒性。
