乙酸与蛋氨酸互作效应对奶牛乳腺上皮细胞内乳蛋白合成的影响

Effect of interaction between acetic acid and methionine on milk protein synthesis in bovine mammary epithelial cells

试验旨在研究乙酸与蛋氨酸(Met)互作效应对奶牛乳腺上皮细胞(BMECs)内乳蛋白合成相关基因及蛋白表达的影响。采用2×6双因素完全随机试验设计,因素一为乙酸的浓度,设6个水平,分别为0、4、6、8、10和12 mmol/L;因素二为Met浓度,设2个水平,分别为0.13 mmol/L、0.52 mmol/L。将第三代BMECs随机分为12个处理组,每组6个重复,按试验要求培养48 h,测定各项指标。结果显示:Met浓度为0.13 mmol/L或0.52 mmol/L时,随乙酸浓度的增加,BMECs内CSN3、JACK2、STAT5的表达均有上调,CSN1S1明显下降。Met浓度为0.52 mmol/L时,8、10、12 mmol/L乙酸组CSN3、JACK2、STAT5、CSN1S1的表达明显提高,乙酸为8 mmol/L时,CSN3和JACK2、STAT5表达明显提高,乙酸浓度为0时,CSN1S1表达明显提高,乙酸浓度为6、8、10、12 mmol/L时,mTOR和4EBP1表达明显提高。在Met浓度为0.13 mmol/L或0.52 mmol/L时,随着乙酸浓度升高JACK2/STAT5信号通路基因表达、mTOR及其下游相关因子的磷酸化水平先提高后降低。研究表明,Met与乙酸互作效应对BMECs内乳蛋白合成具有显著影响,以Met浓度为0.52 mmol/L、乙酸浓度为6 mmol/L组合促进效果较好。

The experiment was to investigate the effect of the interaction between acetic acid and methionine(Met) on expression and mechanism of milk protein synthesis-related genes and proteins in cow mammary epithelial cells(BMECs).The experiment adopts a 2×6 two-factor completely randomized experimental design. The first factor was the concentration of acetic acid, which were set six levels of 0, 4, 6, 8, 10 and 12 mmol/L. The second factor was the Met concentration, which were set to two levels of 0.13 and 0.52 mmol/L. The third-generation BMECs were randomly divided into 12 treatment groups, with six replicates in each group, and each index was measured after 48 h of culture according to experimental requirements. The results showed that when the Met concentration was 0.13 mmol/L or 0.52 mmol/L, with the increase of acetic acid concentration, the expressions of CSN3、JACK2、STAT5 in BMECs were all up-regulated, and CSN1S1 was significantly decreased. When acetic acid was 8, 10, 12 mmol/L, the expression of CSN3、JACK2、STAT5、CSN1S1 was significantly increased when acetic acid was 8 mmol/L, the expressions of CSN3 and JACK2/STAT5 were significantly increased, and when acetic acid was 0, the expression of CSN1S1 was significantly increased, when the acetate concentration was 6, 8, 10, 12 mmol/L, the expressions of mTOR and 4EBP1 were significantly increased. When the Met concentration was 0.13 mmol/L or 0.52 mmol/L, the gene expression of JACK2/STAT5 signaling pathway, the expression of mTOR and its downstream related factors increased with the increase of acetate concentration.Phosphorylation levels first increased and then decreased. The experiment indicates that the interaction between Met and acetic acid has a significant effect on the synthesis of milk protein in BMECs, and the combination of Met concentration of 0.52 mmol/L and acetic acid concentration of 6 mmol/L has better promotion effect.