Aluminium triggers oxidative stress and antioxidant response in the microalgae Scenedesmus sp
Aluminium triggers oxidative stress and antioxidant response in the microalgae Scenedesmus sp
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DOI：
10.1016/j.jplph.2020.153114
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发表时间：
2020-03-01
影响因子：
4.3
通讯作者：
Hernandez, Luis E.
中科院分区：
文献类型：
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作者：
Ameri, Maryam;Baron-Sola, Angel;Hernandez, Luis E.
铝水污染是一个日益严重的环境问题，对水生初级生产者的毒性反应进行综合分析势在必行。我们研究了栅藻的抗氧化反应。微藻对铝诱导的氧化应激。在改良的Bold Basal培养液(pH 5.0)中暴露铝(0，10和100mM)72小时后，我们观察到细胞聚集和亚细胞结构的改变，强烈的脂质过氧化和氧化应激诱导(用荧光探针2‘，7’-二氯二氢荧光素二醋酸酯检测)与细胞内铝的积累平行。同时，铝毒害导致细胞壁结构中重要的常量营养元素如钙的耗竭。对铝处理的栅藻细胞抗氧化酶活性的分析表明，过氧化氢酶、抗坏血酸过氧化物酶以及不同的超氧化物歧化酶同工酶受到抑制，尤其是在最高铝剂量(100 MU M)下，细胞积累了最高浓度的铝。另一方面，谷胱甘肽还原酶活性在该铝浓度下增加。Western-blotting后的免疫检测证实，只有抗坏血酸过氧化物酶的抑制明显是由于酶水平的下降。然而，在铝胁迫下，过氧化氢酶的抑制和谷胱甘肽还原酶活性的激活似乎分别与蛋白质表达减少或增加的翻译后蛋白质功能修饰有关。我们的结果可能有助于了解淡水微藻中铝的毒性机制，进而有助于选择适合水生态系统铝污染的生物标志物。
Aluminium (Al) water pollution is an increasing environmental problem and comprehensive analysis of toxic responses of aquatic primary producer organisms is imperative. We characterized the antioxidant response of Scenedesmus sp. microalga to Al-induced oxidative stress. After 72 h of exposure to Al (0, 10, and 100 mu M) in a modified Bold Basal Medium (pH 5.0), we observed cell aggregation and alterations in the subcellular structure, strong lipid peroxidation and oxidative stress induction (detected with the fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate) in parallel with Al accumulation in cells. At the same time, Al toxicity caused depletion of important macronutrients like Ca, which is important for cell-wall structure. Analysis of antioxidant enzymatic activities in Al-treated Scenedesmus cells revealed that catalase, ascorbate peroxidase, as well as different isoforms of superoxide dismutase were inhibited especially at the highest Al dose (100 mu M), cells that accumulated the highest concentration of Al. On the other hand, glutathione reductase activity increased at that Al concentration. Immunodetection after Western-blotting confirmed that only ascorbate peroxidase inhibition was apparently due to a decrease in enzyme levels. However, the inhibition of catalase and activation of glutathione reductase activities seemed related with post-translational modifications in protein function as protein expression decreased or increased, respectively under Al stress. Our results may help to understand toxic mechanisms triggered by Al in freshwater microalgae, which in turn could aid to select suitable biomarkers of Al contamination in aquatic ecosystems.