Lysine Stimulates Protein Synthesis by Promoting the Expression of ATB0,+ and Activating the mTOR Pathway in Bovine Mammary Epithelial Cells
Lysine Stimulates Protein Synthesis by Promoting the Expression of ATB0,+ and Activating the mTOR Pathway in Bovine Mammary Epithelial Cells
复制标题
赖氨酸通过促进 ATB0 的表达并激活牛乳腺上皮细胞中的 mTOR 通路来刺激蛋白质合成
DOI：
10.1093/jn/nxy140
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发表时间：
2018-09-01
影响因子：
4.2
通讯作者：
Liu, Hongyun
中科院分区：
文献类型：
--
作者：
Lin, Xiujuan;Li, Shanshan;Liu, Hongyun
背景：L赖氨酸(Lys)是乳腺发育和产奶的重要膳食营养素。目的：探讨赖氨酸对牛乳上皮细胞蛋白质合成的影响及其摄取分解机制。方法：将牛乳腺上皮细胞分别加入0、0.5、1.0、1.5、2.0、5.0和10.0mmolLys/L中培养，检测细胞活力，或在0~2.0mmolLys/L中加入L-[环-H-3(5)]苯丙氨酸，研究赖氨酸对牛乳腺上皮细胞蛋白质代谢的影响。或在含[U-C-14]L-赖氨酸的Krebs缓冲液中培养，以定量测定赖氨酸的代谢。在一些实验中，BMEC在单独的或含有1.0mmolLys/L和2-氨基双环[2.2.1]庚烷-2-羧酸的条件培养液中培养24 h，以分析氨基酸转运体B(0+)(ATB(0，+))、哺乳动物雷帕霉素靶标(MTOR)和Janus kinase2(JAK2)-信号转导和转录激活因子5(STAT5)途径的表达。结果：加入1.0 mmolLys/L可使细胞存活率提高17~47%，蛋白质合成增加7~23%。而与0、0.5、2.0mmolLys/L组相比，4-浓度可显著抑制细胞蛋白质降解(均P
Background: L-lysine (Lys) is a critical dietary nutrient for mammary gland development and milk production. However, the specific pathways of Lys utilization and how milk protein synthesis is affected in bovine mammary epithelial cells (BMECs) are poorly understood.Objective: We aimed to investigate the effects of Lys on milk protein synthesis and the mechanism of Lys uptake and catabolism in BMECs.Methods: BMECs were cultured in 0, 0.5, 1.0, 1.5, 2.0, 5.0, and 10.0 mmol Lys/L to detect cell viability, or cultured in 0-2.0 mmol Lys/L with L-[ring-H-3(5)] phenylalanine to study the effect of Lys on protein turnover, or cultured in Krebs buffer with [U-C-14] L-Lys to quantify Lys metabolism. In some experiments, BMECs were cultured in a conditioned medium alone or including 1.0 mmol Lys/L and 2-amino-endo-bicyclo [2.2.1] heptane-2-carboxylic acid (BCH) for 24 h to analyze the expression of amino acid transporter B (0+) (ATB(0,+)), mammalian target of rapamycin (mTOR), and Janus kinase 2 (JAK2)-signal transducer and activator of transcription 5 (STAT5) pathways.Results: Including 1.0 mmol Lys/L in cultures increased cell viability by 17-47% and protein synthesis by 7-23%, whereas protein degradation was inhibited by 4-64% compared with BMECs cultured with 0, 0.5, or 2.0 mmol Lys/L (all P