The present study sought to investigate the effect of arginine on the involvement of toll-like receptors (TLRs) in skin wound-induced intestinal barrier dysfunction in gilthead seabream (Sparus aurata L.). Two replicates of fish (n = 8) were fed a commercial diet (CON, total 2.75% arginine), CON diet enriched with 1% arginine (ARG1, total 3.65% arginine) and 2% arginine (ARG2, total 4.53% arginine) for 30 days. Half of the fish were sampled, whereas the others were injured and sampled 7 days post-wounding. The intestinal histology results showed that a more intense infiltration of mixed leucocytes was evident in the wounded fish, which was remarkably reduced in fish that were fed the ARG1 diet. Serum IgM levels were significantly higher in the ARG1 group than levels in the CON group at 7 days post-wounding. Compared with the fish in the CON group after wounding, dietary administration of 1% arginine markedly downregulated the gene expression of TLRs (TLR2 and TLR5), MyD88, and proinflammatory cytokines (CSF1R, IL-1β, and TNFα), but significantly enhanced the gene expression of IκBα, the anti-inflammatory cytokine TGF-β1, and tight junction proteins (tricellulin and occludin) in wounded fish. Furthermore, the ARG2 diet demonstrated no additional benefits on intestinal cells, compared to both the ARG1 and the CON diets, and it even appeared to induce negative effects. In summary, dietary administration of 1% arginine significantly inhibited intestinal inflammatory response and tight junction disruption in skin-wounded gilthead seabream by modulating TLR signalling in the intestine.

本研究试图研究精氨酸对长尾鲷（Sparus aurata）皮肤伤口诱导的肠屏障功能障碍中toll样受体（TLRs）参与的影响L.）。两次重复喂鱼（n = 8），以商业日粮（CON，精氨酸总量为2.75％），富含1％精氨酸（ARG1，精氨酸总量为3.65％）和2％精氨酸（ARG2，精氨酸总量为4.53％）的CON饲料喂养30天。一半的鱼被取样，而其余的则在受伤后7天取样并取样。肠道组织学结果表明，在受伤的鱼中混合白细胞有更强的浸润，在喂食ARG1日粮的鱼中明显减少。伤后7天，ARG1组的血清IgM水平显着高于CON组。与受伤后的CON组的鱼相比，饮食中添加1％的精氨酸可以显着下调TLRs（TLR2和TLR5），MyD88和促炎细胞因子的基因表达（CSF1R，IL-1β和TNFα），但显着增强了伤鱼中IκBα的基因表达，抗炎细胞因子TGF-β1和紧密连接蛋白（tricellulin和occludin）。此外，与ARG1和CON饮食相比，ARG2饮食对肠道细胞没有其他好处，甚至似乎会引起负面影响。总之，通过调节肠道中的TLR信号，饮食中添加1％的精氨酸可以显着抑制肠道炎症反应和皮肤受伤的金头鲷的紧密连接破坏。