Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS-UP), Universidade do Porto, Rua de Jorge Viterbo Ferreira n° 228, 4050-313 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.
Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal.
Gen Comp Endocrinol. 2021 Feb 1;302:113690. doi: 10.1016/j.ygcen.2020.113690. Epub 2020 Dec 7.
Methionine ability to enhance fish immune status and inflammatory response by the modulation of methionine-related pathways has been verified in several fish species. However, no attention has been given to the role of methionine as an immune-modulatory additive in rainbow trout (Oncorhynchus mykiss). Hence, this study was designed to evaluate the effect of short-term feeding a diet supplemented with dl-methionine on the rainbow trout immune status. For this purpose, two diets were formulated: a control (CTRL) diet including the AA profile required to meet the ideal pattern estimated for rainbow trout; and an experimental diet (MET) identical to the CTRL but supplemented with dl-methionine two fold above its requirement level. After 2 and 4 weeks, fish haematological profile, peripheral cell populations, plasma and skin mucus humoral immune parameters as well as head-kidney gene expression were analysed. Results showed that methionine was able to improve peripheral neutrophil numbers after 4 weeks of feeding while reducing the expression of pro-inflammatory genes (i.e. IL1β and IL8). Also, indications of fish physiological ability to regulate polyamine biosynthesis were found by the reduced expression of the spermine synthase enzyme (SMS). Together, these results point to some level of enhancement of the cellular-related innate immune status by dietary dl-methionine supplementation after a short-term feeding period, which could be used as a prophylactic strategy for rainbow trout health management.
蛋氨酸通过调节蛋氨酸相关途径来增强鱼类免疫状态和炎症反应的能力已在几种鱼类中得到验证。然而，蛋氨酸作为一种免疫调节添加剂在虹鳟（Oncorhynchus mykiss）中的作用尚未得到关注。因此，本研究旨在评估短期饲喂添加 dl-蛋氨酸的饮食对虹鳟免疫状态的影响。为此，设计了两种饮食：一种对照（CTRL）饮食，其中包含满足虹鳟理想模式估计所需的 AA 谱；另一种实验饮食（MET）与 CTRL 相同，但 dl-蛋氨酸的含量是其需求水平的两倍。在 2 周和 4 周后，分析了鱼类的血液学特征、外周细胞群、血浆和皮肤黏液体液免疫参数以及头肾基因表达。结果表明，蛋氨酸能够在饲喂 4 周后提高外周中性粒细胞的数量，同时降低促炎基因（即 IL1β 和 IL8）的表达。此外，通过降低精脒合酶（SMS）的表达，发现了鱼类调节多胺生物合成的生理能力的迹象。综上所述，这些结果表明，短期饲喂 dl-蛋氨酸补充剂后，细胞相关固有免疫状态得到一定程度的增强，可作为虹鳟健康管理的预防策略。
