Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, USA.
Biol Reprod. 2011 Jun;84(6):1139-47. doi: 10.1095/biolreprod.110.088153. Epub 2011 Feb 3.
Nutrients are primary requirements for development of conceptuses (embryo and extraembryonic membranes), including protein synthesis. We have shown that arginine (Arg), leucine (Leu), and glucose stimulate protein synthesis through phosphorylation of MTOR signaling molecules, thereby increasing proliferation of ovine trophectoderm cells. This study determined whether Arg, Leu, glutamine (Gln), and glucose influence gene expression and protein synthesis in explant cultures of ovine conceptuses recovered from ewes on Day 16 of pregnancy. Conceptuses were deprived of select nutrients and then cultured with either Arg, Leu, Gln, or glucose for 18 h, after which they were analyzed for abundance of MTOR, RPS6K, RPS6, EIF4EBP1 (also known as 4EBP1), IFNT, NOS2, NOS3, GCH1, and ODC1 mRNAs and proteins. Levels of MTOR, RPS6K, RPS6, and EIF4EBP1 mRNAs were not affected by treatment with any of the select nutrients. Similarly, expression of IFNT, NOS2, NOS3, and ODC1 mRNAs were not different. Interestingly, GCH1 mRNA levels increased in response to Arg treatment. Importantly, Arg, Leu, Gln, and glucose increased the abundance of phosphorylated MTOR, RPS6K, RPS6, and EIF4EBP1 proteins as well as NOS and ODC1 proteins, but only Arg increased the abundance of IFNT protein. These findings indicate that Arg, Leu, Gln, and glucose stimulate translation of mRNAs to increase synthesis of proteins through phosphorylation and activation of components of the MTOR signaling pathway. Increases in abundance of IFNT protein (the pregnancy recognition signal), NOS2, NOS3 and GCH1 for conversion of Arg to nitric oxide, and ODC1 for synthesis of polyamines are all important for growth and development of the ovine conceptus during pregnancy.
营养素是胚胎(胚胎和胚胎外膜)发育的主要需求,包括蛋白质合成。我们已经表明,精氨酸(Arg)、亮氨酸(Leu)和葡萄糖通过 MTOR 信号分子的磷酸化刺激蛋白质合成,从而增加绵羊滋养层细胞的增殖。本研究旨在确定 Arg、Leu、谷氨酰胺(Gln)和葡萄糖是否会影响妊娠第 16 天从母羊中回收的绵羊胚胎外植体培养物中的基因表达和蛋白质合成。胚胎被剥夺了选择的营养物质,然后用 Arg、Leu、Gln 或葡萄糖培养 18 小时,之后分析 MTOR、RPS6K、RPS6、EIF4EBP1(也称为 4EBP1)、IFNT、NOS2、NOS3、GCH1 和 ODC1 mRNA 和蛋白质的丰度。任何选择的营养物质处理都不会影响 MTOR、RPS6K、RPS6 和 EIF4EBP1 mRNA 的水平。同样,IFNT、NOS2、NOS3 和 ODC1 mRNA 的表达也没有差异。有趣的是,Arg 处理会增加 GCH1 mRNA 的水平。重要的是,Arg、Leu、Gln 和葡萄糖增加了磷酸化 MTOR、RPS6K、RPS6 和 EIF4EBP1 蛋白以及 NOS 和 ODC1 蛋白的丰度,但只有 Arg 增加了 IFNT 蛋白的丰度。这些发现表明,Arg、Leu、Gln 和葡萄糖通过磷酸化和激活 MTOR 信号通路的成分来刺激 mRNA 的翻译,从而增加蛋白质的合成。IFNT 蛋白(妊娠识别信号)、NOS2、NOS3 和 GCH1 用于将 Arg 转化为一氧化氮以及 ODC1 用于合成多胺的丰度增加,对妊娠期间绵羊胚胎的生长和发育都很重要。