赖氨酸二肽对奶牛乳腺mTOR信号通路元件基因表达的影响  

Effects of Lysine Dipeptides on Gene Expression of mTOR Signal Pathway Elements in Gland Explants of Bovine Mammary

作　　者：周苗苗[1] 崔景香[1] 

机构地区：[1]山东潍坊科技学院动物科学研究所,山东寿光262700

出　　处：《西北农业学报》2017年第7期963-967,共5页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：潍坊市科技发展计划(2015GX077)~~

摘　　要：为研究赖氨酸二肽对奶牛乳腺组织中哺乳动物雷帕霉素靶蛋白(mTOR)信号通路的影响,在体外培养的奶牛乳腺组织培养液中分别添加赖氨酸—赖氨酸、赖氨酸—亮氨酸和赖氨酸—组氨酸二肽,等量取代培养液中φ=5%、5%和15%的游离赖氨酸(赖氨酸总质量浓度为210 mg/L);在此基础上,在赖氨酸组和赖氨酸—赖氨酸二肽5%取代组分别添加终浓度为0和100 nmol/L的mTOR抑制剂雷帕霉素。试验结束后收集乳腺组织用于αs1酪蛋白、mTOR、4E-BP1和S6K1的基因表达检测。结果发现,与游离氨基酸相比,添加3种赖氨酸二肽显著增加αs1酪蛋白、mTOR、4E-BP1和S6K1基因的表达;添加雷帕霉素抑制上述基因的表达,赖氨酸—赖氨酸二肽可以降低雷帕霉素的抑制作用。结果表明,除作为合成底物外,赖氨酸二肽还可能通过调控mTOR信号通路促进乳蛋白的合成。The study was to investigate the effects of lysine（Lys） dipeptides on gene expression of mammalian target of rapamycin（mTOR） signal pathway elements in gland explants of bovine mammary.Mammary gland tissues were obtained from Chinese Holstein dairy cows and cultured in Dulbecco＇s modified Eagle＇s medium-F12 with the lactogenic hormones（prolactin,hydrocortisone and insulin）.Firstly,the free Lys in culture medium was equivalent substituted with Lys-Lys,Lys-leucine（Leu）,Lys-histidine（His） at ratio of φ=5%,5%,10%,respectively.Then,rapamycin,the mTOR inhibitor,was added in the Lys group and Lys-Lys group at concentration of 0 and 100nmol/L,respectively.After 48 h,mammary gland tissues were harvested for casein alpha s1,mTOR,4E-BP1 andS6K1 gene expression analysis by real-time PCR.The Lys dipeptides significantly enhanced the gene expression of casein alpha s1,mTOR,4E-BP1 and compared S6K1 with equivalent free Lys.The addition of rapamycin inhibited the gene expression of casein alpha s1,mTOR,4E-BP1 and S6K1,and Lys-Lys dipeptide decreased the inhibitory effect.The results indicated that,as the synthetic substrates,the Lys dipeptides may also promote the synthesis of milk protein by modulating the mTOR signal pathway.

关 键 词：赖氨酸二肽 αs1酪蛋白 MTOR 奶牛乳腺组织 

分 类 号：S823[农业科学—畜牧学]