The effects of reduced dietary protein level on amino acid transporters and mTOR signaling pathway in pigs
The effects of reduced dietary protein level on amino acid transporters and mTOR signaling pathway in pigs
复制标题
降低日粮蛋白质水平对猪氨基酸转运蛋白和mTOR信号通路的影响
DOI：
10.1016/j.bbrc.2017.02.084
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发表时间：
2017-04-01
影响因子：
3.1
通讯作者：
Jiang, Siwen
中科院分区：
文献类型：
--
作者：
Wang, Dan;Wan, Xuebin;Jiang, Siwen
氨基酸转运体在调节mTOR信号通路中起着重要作用。本研究探讨了日粮蛋白质水平降低对氨基酸转运体和mTOR信号通路的影响。选用54头断奶仔猪，随机分成3×3析因设计，分别于10日龄、25日龄和45日龄后屠宰，每期18头，随机分为3组，分别饲喂3种不同蛋白质水平的日粮：20%粗蛋白(CP)日粮(推荐常规高蛋白)、17%CP日粮(中蛋白)和14%CP日粮(低蛋白LP)。结果表明，降低饲料蛋白质水平可以降低背最长肌的重量。定量PCR芯片分析显示，饲喂25d后，LP组氨基酸转运蛋白SLC38A2、SLC1A7、SLC7A1、SLC7A5、SLC16A10和SLC3A2的mRNA表达显著高于MP组和HP组(P<0.05)，mTOR和S6K1的磷酸化水平低于MP组和HP组(P<0.05)。体外实验进一步证实，随着C2C12成肌细胞中氨基酸浓度的降低，SLC7A1、SLC7A5、SLC3A2、SLC38A2和SLC36A1的mRNA水平升高，mTOR和S6K1的磷酸化水平降低。这些结果表明，低脂饲料诱导了氨基酸转运蛋白的高表达和mTOR活性的抑制，从而抑制了蛋白质合成和背最长肌的生长。(C)2017 Elsevier Inc.保留所有权利。
Amino acid transporter plays an important role in regulating mTOR signaling pathway. This study investigated the effects of reduced dietary protein levels on amino acid transporters and mTOR signaling pathway. A total of 54 weaning pigs were randomly allocated into a 3 x 3 factorial design, followed by slaughtering the pigs separately after 10-, 25- and 45-day feeding, with 18 pigs from each feeding period divided into three subgroups for treatment with three different protein-level diets: 20% crude protein (CP) diet (normal recommended, high protein, HP), 17% CP diet (medium protein, MP) and 14% CP diet (low protein, LP). The results indicated that reduced dietary protein level decreased the weight of longissimus dorsi. Additionally, quantitative PCR chip analysis showed that mRNA expression of amino acid transporters SLC38A2, SLC1A7, SLC7A1, SLC7A5, SLC16A10 and SLC3A2 in the LP group were significantly (P < 0.05) higher than those in the MP or HP group, and the phosphorylation of mTOR and S6K1 decreased in the LP group after 25-day feeding. Furthermore, the vitro experimental results further confirmed that the mRNA levels for SLC7A1, SLC7A5, SLC3A2, SLC38A2 and SLC36A1 were increased and the phosphorylation of mTOR and S6K1 was decreased when the concentration of amino acids in C2C12 myoblasts was reduced. All these results indicated that the LP diet induced a high expression of amino acid transporters and the inhibition of the mTOR activity, which resulting in restriction on protein synthesis and longissimus dorsi growth. (C) 2017 Elsevier Inc. All rights reserved.