Jiang Jun, Shi Dan, Zhou Xiao-Qiu, Hu Yi, Feng Lin, Liu Yang, Jiang Wei-Dan, Zhao Ye
College of Animal Science and Technology, Sichuan Agricultural University, Ya'an 625014, China; Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an 625014, China.
College of Animal Science and Technology, Sichuan Agricultural University, Ya'an 625014, China; Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China.
Fish Shellfish Immunol. 2015 Feb;42(2):457-64. doi: 10.1016/j.fsi.2014.11.030. Epub 2014 Nov 27.
The present study was designed to assess the possible protective effects of arginine (Arg) against lipopolysaccharide (LPS) induced inflammatory response in juvenile Jian carp (Cyprinus carpio var. Jian) in vivo and in enterocytes in vitro. Firstly, inflammatory response was established by exposing enterocytes to different concentrations of LPS for 24 h. Secondly, the protective effects of Arg against subsequent LPS exposure were studied in enterocytes. Finally, we investigated whether dietary Arg supplementation could attenuate immune challenge induced by LPS in vivo. The result indicated that 10 mg/L LPS could induced inflammatory response in enterocytes. Cells exposed to LPS (10-30 mg/L) alone for 24 h resulted in a significant increase in lactate dehydrogenase release (LDH) (P < 0.05). The cell viability, protein content, alkaline phosphatase activity were decreased by LPS (P < 0.05). Moreover, LPS exposure significantly increased TNF-α, IL-1β, and IL-6 mRNA expression in vitro (P < 0.05). However, pre-treatment with Arg remarkably prevented the increase of TNF-α, IL-1β, and IL-6 by inhibiting the excessive activation of TLR4-Myd88 signaling pathway through down-regulating TLR4, Myd88, NFκB p65, and MAPK p38 mRNA expression (P < 0.05). Interestingly, the experiment in vivo showed that Arg pre-supplementation could attenuate immune challenge induced by LPS via TLR4-Myd88 signaling pathway, and thus protect fish against LPS-induced inflammatory response. In conclusion, all of these results indicated pre-supplementation with Arg decreased LPS induced immune damage and regulated TLR4-Myd88 signaling pathway in juvenile Jian carp in vivo and in enterocytes in vitro.
本研究旨在评估精氨酸（Arg）对体内幼年建鲤（Cyprinus carpio var. Jian）和体外肠细胞中脂多糖（LPS）诱导的炎症反应的可能保护作用。首先，通过将肠细胞暴露于不同浓度的LPS 24小时来建立炎症反应。其次，研究了Arg对随后LPS暴露的保护作用。最后，我们研究了日粮中添加Arg是否能减轻体内LPS诱导的免疫挑战。结果表明，10 mg/L LPS可诱导肠细胞产生炎症反应。单独暴露于LPS（10 - 30 mg/L）24小时的细胞导致乳酸脱氢酶释放（LDH）显著增加（P < 0.05）。LPS使细胞活力、蛋白质含量、碱性磷酸酶活性降低（P < 0.05）。此外，LPS暴露显著增加了体外TNF-α、IL-1β和IL-6 mRNA表达（P < 0.05）。然而，Arg预处理通过下调TLR4、Myd88、NFκB p65和MAPK p38 mRNA表达抑制TLR4-Myd88信号通路的过度激活，从而显著阻止了TNF-α、IL-1β和IL-6的增加（P < 0.05）。有趣的是，体内实验表明，预先补充Arg可通过TLR4-Myd88信号通路减轻LPS诱导的免疫挑战，从而保护鱼类免受LPS诱导的炎症反应。总之，所有这些结果表明，预先补充Arg可减少LPS诱导的免疫损伤，并在体内幼年建鲤和体外肠细胞中调节TLR4-Myd88信号通路。
