Engineered nanoceria alleviates thermally induced oxidative stress in free-living Breviolum minutum (Symbiodiniaceae, formerly Clade B)
Engineered nanoceria alleviates thermally induced oxidative stress in free-living Breviolum minutum (Symbiodiniaceae, formerly Clade B)
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DOI：
10.3389/fmars.2022.960173
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发表时间：
2022-08
期刊：
影响因子：
4.6
通讯作者：
L. Roger;Joseph A. Russo;Robert E. Jinkerson;J. P. Giraldo;Nastassja A. Lewinski
中科院分区：
文献类型：
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作者：
L. Roger;Joseph A. Russo;Robert E. Jinkerson;J. P. Giraldo;Nastassja A. Lewinski
刺胞动物宿主和甲藻伙伴之间共生共生的崩溃（即白化）与硝基氧化爆发（热应激的症状）引起的类似免疫反应途径有关。活性氧（ROS）/活性氮引起的压力是有氧系统常见的问题。在这项研究中，我们测试了工程聚丙烯酸）涂覆的二氧化铈纳米粒子（CeO2，nanoceria）对自由生活的共生藻（Breviolum minutum）的抗氧化作用，共生藻是一种与造礁珊瑚和海葵形成共生关系的甲藻。结果表明，流体动力学直径约为 4 nm 的聚丙烯酸包被的 CeO2 在 30 分钟内被微小芽孢杆菌内化，随后定位在细胞质中。随着时间的推移，接触 Nanoceria 不会抑制细胞生长，经过处理的培养物在 25 天的接触中显示出类似的生长趋势。有氧活动和热应激在 34°C 下保持 1 小时（比对照高出 6°C）会导致细胞内 ROS 浓度随时间增加。观察到纳米陶瓷具有明显的 ROS 清除作用，热应激期间细胞内 ROS 水平降低了 5 倍。一氧化氮 (NO) 浓度随热应激下降约 17%，表明一氧化氮清除酶或蛋白质在应激发生后 1 小时内快速参与。纳米陶瓷的存在似乎不会影响 NO 浓度。此外，非共生海葵（Exaiptasia diaphana、ex Aiptasia pallida）成功地被负载纳米细胞的微小芽孢杆菌感染，表明接种可以作为一种递送方法。纳米藻被共生藻吸收并减少活性氧产生的能力可以作为减少珊瑚白化的潜在缓解策略。
The breakdown of symbiotic mutualism between cnidarian hosts and dinoflagellate algae partners (i.e., bleaching) has been linked to an immune-like response pathway brought on by a nitro-oxidative burst, a symptom of thermal stress. Stress induced by reactive oxygen species (ROS)/reactive nitrogen species is a problem common to aerobic systems. In this study, we tested the antioxidant effects of engineered poly(acrylic acid)-coated cerium dioxide nanoparticles (CeO2, nanoceria) on free-living Symbiodiniaceae (Breviolum minutum), a dinoflagellate alga that forms symbiotic relationships with reef-building corals and anemones. Results show that poly(acrylic acid)-coated CeO2 with hydrodynamic diameters of ~4 nm are internalized by B. minutum in under 30 min and subsequently localized in the cytosol. Nanoceria exposure does not inhibit cell growth over time, with the treated cultures showing a similar growth trend over the 25-day exposure. Aerobic activity and thermal stress when held at 34°C for 1 h (+6°C above control) led to increased intracellular ROS concentration with time. A clear ROS scavenging effect of the nanoceria was observed, with a 5-fold decrease in intracellular ROS levels during thermal stress. The nitric oxide (NO) concentration decreased by ~17% with thermal stress, suggesting the rapid involvement of NO scavenging enzymes or proteins within 1 h of stress onset. The presence of nanoceria did not appear to influence NO concentration. Furthermore, aposymbiotic anemones (Exaiptasia diaphana, ex Aiptasia pallida) were successfully infected with nanoceria-loaded B. minutum, demonstrating that inoculation could serve as a delivery method. The ability of nanoceria to be taken up by Symbiodiniaceae and reduce ROS production could be leveraged as a potential mitigation strategy to reduce coral bleaching.