Department of Animal and Aquaculture Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, 1430 Ås, Norway.
Department of Preclinical Sciences and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1430 Ås, Norway.
Int J Mol Sci. 2021 Jan 21;22(3):1028. doi: 10.3390/ijms22031028.
Ensuring salmon health and welfare is crucial to maximize production in recirculation aquaculture systems. Healthy and robust mucosal surfaces of the skin and intestine are essential to achieve this goal because they are the first immunological defenses and are constantly exposed to multistressor conditions, such as infectious diseases, suboptimal nutrition, and environmental and handling stress. In this work, Atlantic salmon, split from a single cohort, were subjected to acute hypoxia stress or 15-min crowding stress and observed over a 24-h recovery period. Samples were collected from fish at 0, 1, 3, 6, 12 and 24 h post-stress to analyze plasma-circulating markers of endocrine function (cortisol), oxidative stress (glutathione peroxidase) and immune function (interleukin 10 (IL-10), annexin A1). In addition, mucosal barrier function parameters were measured in the skin mucus (Muc-like protein and lysozyme) and distal intestine (simple folds, goblet cell size and goblet cell area). The results showed that both acute stress models induced increases of circulating cortisol in plasma (1 h post-stress), which then returned to baseline values (initial control) at 24 h post-stress. Moreover, the hypoxia stress was mostly related to increased oxidative stress and IL-10 production, whereas the crowding stress was associated with a higher production of Muc-like protein and lysozyme in the skin mucus. Interestingly, in the distal intestine, smaller goblet cells were detected immediately and one hour after post-hypoxia stress, which could be related to rapid release of the cellular content to protect this organ. Finally, the correlation of different markers in the hypoxic stress model showed that the circulating levels of cortisol and IL-10 were directly proportional, while the availability of Muc-like proteins was inversely proportional to the size of the goblet cells. On the other hand, in the crowding stress model, a proportional relationship was established between plasma cortisol levels and skin mucus lysozyme. Our results suggest key differences in energy partitioning between the two acute stress models and support the need for further investigation into the interplay of multistressor conditions and strategies to modulate immunological aspects of mucosal surfaces.
确保鲑鱼的健康和福利对于最大化循环水产养殖系统的产量至关重要。健康和强壮的皮肤和肠道黏膜表面对于实现这一目标至关重要，因为它们是第一道免疫防线，并且经常暴露于多种应激条件下，如传染病、营养不足以及环境和处理应激。在这项工作中，从单个批次中分离出的大西洋鲑鱼受到急性缺氧应激或 15 分钟的拥挤应激，并在 24 小时的恢复期内进行观察。在应激后 0、1、3、6、12 和 24 小时采集鱼类样本，以分析血浆循环内分泌功能标志物（皮质醇）、氧化应激标志物（谷胱甘肽过氧化物酶）和免疫功能标志物（白细胞介素 10（IL-10）、膜联蛋白 A1）。此外，还测量了皮肤黏液（Muc-样蛋白和溶菌酶）和远端肠道（简单褶皱、杯状细胞大小和杯状细胞面积）中的黏膜屏障功能参数。结果表明，两种急性应激模型均导致血浆中循环皮质醇升高（应激后 1 小时），然后在应激后 24 小时恢复到基线值（初始对照）。此外，缺氧应激主要与氧化应激和 IL-10 产生增加有关，而拥挤应激与皮肤黏液中 Muc-样蛋白和溶菌酶产量增加有关。有趣的是，在缺氧应激后立即和 1 小时，在远端肠道中检测到较小的杯状细胞，这可能与为了保护该器官而迅速释放细胞内容物有关。最后，在缺氧应激模型中不同标志物的相关性表明，循环皮质醇和 IL-10 水平呈直接比例关系，而 Muc-样蛋白的可用性与杯状细胞的大小呈反比。另一方面，在拥挤应激模型中，血浆皮质醇水平与皮肤黏液溶菌酶之间建立了比例关系。我们的研究结果表明，两种急性应激模型之间的能量分配存在关键差异，并支持进一步研究多种应激条件的相互作用以及调节黏膜表面免疫方面的策略的必要性。
