Dietary arginine and citrulline supplementation modulates the immune condition and inflammatory response of European seabass
Dietary arginine and citrulline supplementation modulates the immune condition and inflammatory response of European seabass
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DOI：
10.1016/j.fsi.2020.07.060
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发表时间：
2020-11-01
影响因子：
4.7
通讯作者：
Costas, Benjamin
中科院分区：
文献类型：
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作者：
Azeredo, Rita;Machado, Marina;Costas, Benjamin
本研究旨在探讨饲料中添加精氨酸和瓜氨酸对长尾双线鳕免疫状况和炎症反应的调节作用。研制了四种饲料：对照饲料(CTRL)，以满足所建立的必需氨基酸组成。在此基础上，在其他三种日粮中分别添加两种不同水平的L精氨酸(分别为0.5%和1%，精氨酸1%和精氨酸2%)和L-瓜氨酸0.5%(CIT)。在受控条件下，给鱼喂食这些饲料2到4周。在4周结束时，所有饲料处理组的鱼都被注入淡水鱼假单胞菌，并在4、24、48小时后取材，免疫状态表现为淋巴细胞随时间的下降，而在投喂ARG1和ARG2的鱼中，过氧化物酶活性随着时间的推移而下降，在4周时，投喂ARG1的鱼的过氧化物酶活性低于投喂CTRL的鱼。在喂ARG1和CIT的鱼中，几个基因的上调更为明显，尽管CIT饮食处理下调了促炎细胞因子的表达。免疫刺激后，投喂ARG1组的中性粒细胞和单核细胞循环数明显减少。另一方面，17个选定的免疫和炎症反应基因的表达几乎不受饮食处理的影响。根据分析的参数，结果表明，饮食中补充精氨酸/瓜氨酸在调节免疫防御方面发挥了积极作用，似乎转化为受抑制的免疫谱系，主要是在细胞反应水平上。观察到的由补充瓜氨酸引起的变化在一定程度上与精氨酸引起的变化相似，这表明瓜氨酸可能被巨噬细胞用作精氨酸前体，然后参与了类似的免疫损伤主导机制。
The present study was designed to determine the modulatory effects of arginine and citrulline dietary supplementation on the immune condition and inflammatory response of European seabass, Dicentrarchus labrax. Four diets were manufactured: a control diet (CTRL) was formulated to meet the indispensable amino acids profile established for seabass. Based on this formulation, three other diets were supplemented with L-arginine at two different levels (0.5% and 1%, ARG1 and ARG2, respectively) and L-citrulline at 0.5% (CIT). Fish were fed these diets for 2 or 4 weeks under controlled conditions. At the end of 4 weeks, fish from all dietary treatments were intraperitoneally-injected with Photobacterium damselae piscicida and sampled after 4, 24 our 48 h. Immune status was characterized by a lymphocyte time-dependent decrease regardless of dietary treatment, whereas peroxidase values dropped in time in fish fed ARG1 and ARG2 and was lower at 4 weeks in fish fed ARG1 than in fish fed CTRL. Up-regulation of several genes was more evident in ARG1-and CIT-fed fish, though pro-inflammatory cytokines were down-regulated by CIT dietary treatment. Following immune stimulation, seabass fed ARG1 showed a decrease in neutrophils and monocytes circulating numbers. On the other hand, expression of 17 selected immune and inflammatory responses genes was barely affected by dietary treatments. Based on the analyzed parameters, results suggest an active role of dietary arginine/citrulline supplementation in modulating immune defences that seem to translate into a suppressed immune repertoire, mostly at the cell response level. The observed changes due to citrulline dietary supplementation were in part similar to those caused by arginine, suggesting that citrulline might have been used by macrophages as an arginine precursor and then engaged in similar immune-impairment leading mechanisms.