蛋氨酸对奶牛乳腺上皮细胞内乳蛋白和乳糖合成的调节作用  

Regulating Effects of Methionine on Milk Protein and Lactose Synthesis inBovine Mammary Epithelial Cells

作　　者：赵艳丽[1] 闫素梅[1] 郭晓宇[1] 史彬林[1] 陈璐[1] ZHAO Yanli;YAN Sumei;GUO Xiaoyu;SHI Binlin;CHEN Lu(Inner Mongolia Key Laboratory of Animal Nutrition and Feed Science,College of Animal Sciences,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学动物科学学院,内蒙古自治区高校动物营养与饲料科学重点实验室,呼和浩特010018

出　　处：《动物营养学报》2021年第4期2073-2082,共10页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：内蒙古自治区高校科研项目(NJZY19055);内蒙古农业大学高水平人才引进科研启动基金项目(NDYB⁃2017);国家奶业“973计划”项目(2011CB1008003)。

摘　　要：本试验旨在研究蛋氨酸(Met)对泌乳奶牛乳腺上皮细胞(BMECs)内乳糖含量及乳蛋白和乳糖合成相关基因和蛋白表达的影响,探讨Met对乳蛋白和乳糖合成的影响机理。将第3代BMECs随机分为6个组,每个组6个重复。Met终浓度分别为0.13、0.26、0.39、0.52、0.65和0.78 mmol/L,37℃、5%CO2培养48 h后测定BMECs活力、ATP含量、乳蛋白和乳糖合成相关基因和蛋白表达及细胞液中乳糖含量。结果表明:与0.13和0.78 mmol/L组相比,0.39~0.65 mmol/L组细胞活力显著增加(P<0.05),0.26~0.52 mmol/L组的葡萄糖转运蛋白1和α-乳清白蛋白的基因相对表达量显著下降(P<0.05),0.39 mmol/L组乳糖含量显著增加(P<0.05)。与0.13~0.26 mmol/L组相比,0.39~0.52 mmol/L组信号转导和转录因子5、真核起始因子4E基因相对表达量及哺乳动物雷帕霉素靶蛋白、核糖体蛋白S6激酶1磷酸化水平显著增加(P<0.05)。0.52 mmol/L组ATP含量、β-酪蛋白、κ-酪蛋白和酪氨酸激酶2基因相对表达量显著高于其他组(P<0.05),但腺苷酸活化蛋白激酶磷酸化水平显著低于其他组(P<0.05)。0.26~0.52 mmol/L组的哺乳动物雷帕霉素靶蛋白基因相对表达量显著高于0.65~0.78 mmol/L组(P<0.05)。综合乳蛋白和乳糖合成的多项指标,0.39~0.52 mmol/L的Met对BMECs乳蛋白基因和蛋白表达及乳糖的合成促进效果较好。This study was to detect the effects of methionine(Met)on lactose content,gene expression and protein expression of milk protein and lactose synthesis in bovine mammary epithelial cells(BMECs)to inves⁃tigate the mechenism of Met regulating milk protein and lactose synthesis.The third generation of BMECs were divided into six groups with six replicates and cultured in medium with 0.13,0.26,0.39,0.52,0.65 and 0.78 mmol/L Met,respectively.After culturn at 37℃,5%CO2 for 48 h,cell viability,ATP content,the relative expression levels of genes involved in milk protein and lactose synthesis,and lactose content were de⁃tected.The results showed that compared with 0.13 and 0.78 mmol/L groups,the cell viability in 0.39 to 0.65 mmol/L groups was significantly increased(P<0.05),the relative expression levels of glucose transport⁃er 1(GLUT1)andα⁃whey albumin(LALBA)genes were significantly decreased in 0.26 to 0.52 mmol/L groups(P<0.05),and latose content was significantly increased in 0.39 mmol/L group(P<0.05).Conpared with 0.13 to 0.26 mmol/L groups,the relative expression levels of signal transduction and transcription factor 5(STAT5)and eukaryotic initiation factor 4E(eIF4E)genes and the phosphoralation levels of mammalian target of rapamycin(mTOR)and ribosomal protein S6 kinase 1(S6K1)in 0.39 to 0.52 mmol/L groups were significantly increased(P<0.05).Compared with the other groups,the ATP content,relative expression levels ofβ⁃casein(CSN2),κ⁃casein(CSN3)and tyrosine kinase 2(JACK2)genes in 0.52 mmol/L group were significantly increased(P<0.05),but AMP⁃activated protein kinase(AMPK)phosphoralation level was sig⁃nificantly decreased(P<0.05).The relative expression level of mTOR was significantly greater in 0.26 to 0.52 mmol/L groups than that in 0.65 to 0.78 mmol/L groups(P<0.05).These results demonstrate that the optimal Met concentrations are 0.39 to 0.52 mmo/L for protein and gene expression of milk protein and lactose synthesis in BMECs.

关 键 词：奶牛 乳腺上皮细胞 蛋氨酸 乳蛋白 乳糖 

分 类 号：S823[农业科学—畜牧学]