Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy.
Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy; Department of Physical, Earth and Environmental Sciences, University of Siena, 53100, Siena, Italy.
Mar Environ Res. 2020 Sep;160:104978. doi: 10.1016/j.marenvres.2020.104978. Epub 2020 Apr 3.
Marine pollution due to disused industrial activities is a major threat to ecosystems and human health, for example through the effects of re-suspension of toxic substances that are present in contaminated sediments. Here, we examined the effects of different re-suspension patterns of polluted sediments from the site of national interest Bagnoli-Coroglio, on the immune system of the sea urchin Paracentrotus lividus. An indoor experiment was set up exposing sea urchins for 34 days to such sediments and evaluating the effects of two patterns of water turbulence, mimicking natural storms at sea. One group of animals experienced an "aggregated" pattern of turbulence, consisting in two events, each lasting 2 days, separated by only 3 calm days, while a second group experienced two events of turbulence separated by 17 calm days (spaced pattern). At different times from the beginning of the experiment, coelomic fluid was collected from the animals and immune cells were examined for cell count and morphology, oxidative stress variables, and expression of genes involved in metal detoxification, stress response and inflammation. Our results highlighted that the aggregated pattern of turbulence was more noxious for sea urchins. Indeed, their immune system was altered, over the exposure time, as indicated by the increase of red amoebocytes number. Moreover, despite of an increase of the antioxidant power, animals from this group displayed a very significant ROS over-production at the end of the experiment. Conversely, animals in the spaced condition activated a different immune response, mainly having phagocytes as actors, and were able to partially recover from the received stress at the end of the experiment. No changes in the expression of genes related to antioxidant and anti-inflammatory responses were observed in both groups. By contrast, a down-regulation of various metallothioneins (4, 6, 7 and 8) in the group subjected to aggregated pattern was observed, while metallothionein 8 was up-regulated in the animals from the group exposed to the spaced pattern of turbulence. This work provides the first evidence of how sea urchins can respond to different re-suspension patterns of polluted sediments by modulating their immune system functions. The present data are relevant in relation to the possible environmental restoration of the study site, whose priorities include the assessment of the effects of marine pollution on local organisms, among which P. lividus represents a key benthic species.
由于废弃的工业活动造成的海洋污染是对生态系统和人类健康的主要威胁，例如通过重新悬浮存在于受污染沉积物中的有毒物质来实现。在这里，我们研究了来自国家利益区巴尼奥利-科罗廖（Bagnoli-Coroglio）的受污染沉积物的不同再悬浮模式对海胆 Paracentrotus lividus 免疫系统的影响。我们设计了一项室内实验，让海胆暴露在这些沉积物中 34 天，并评估了两种模拟海上自然风暴的水湍流模式的影响。一组动物经历了一种“聚集”的湍流模式，该模式由两个事件组成，每个事件持续 2 天，仅间隔 3 天的平静期，而第二组动物则经历了两个事件的湍流，间隔 17 天（间隔模式）。从实验开始的不同时间，从动物体内收集体腔液，并检查免疫细胞的细胞计数和形态、氧化应激变量以及参与金属解毒、应激反应和炎症的基因的表达。我们的结果表明，聚集的湍流模式对海胆更为有害。事实上，它们的免疫系统在暴露过程中发生了改变，如红血细胞数量的增加所表明的那样。此外，尽管抗氧化能力增加，但该组动物在实验结束时表现出非常显著的 ROS 过度产生。相反，处于间隔条件下的动物激活了不同的免疫反应，主要由吞噬细胞作为作用者，并能够在实验结束时部分从所受到的压力中恢复。在这两个组中都没有观察到与抗氧化和抗炎反应相关的基因表达的变化。相反，在经历聚集模式的动物中观察到各种金属硫蛋白（4、6、7 和 8）的下调，而在经历间隔模式的动物中金属硫蛋白 8 被上调。这项工作首次提供了证据，证明海胆如何通过调节其免疫系统功能来应对受污染沉积物的不同再悬浮模式。目前的数据与研究地点的可能环境恢复有关，其中包括评估海洋污染对当地生物的影响，其中 P. lividus 是一种关键的底栖物种。
