油酸和亚油酸对山羊乳腺细胞甘油三酯含量及乳脂合成相关基因表达的影响

为探讨外源添加油酸和亚油酸对体外培养的奶山羊乳腺上皮细胞甘油三酯(TG)含量和乳脂肪合成相关基因表达的影响,试验以奶山羊乳腺上皮细胞为研究对象,分别用0、50、100、200μmol/L油酸和0、20、40、80μmol/L的亚油酸处理细胞24h,检测细胞内TG的含量;采用实时荧光定量PCR法检测细胞内乳脂合成相关基因mRNA水平的变化。结果显示,100、200μmol/L的油酸和40、80μmol/L亚油酸均显著促进细胞内TG的合成(P<0.05)。实时荧光定量PCR结果表明,添加100、200μmol/L油酸可显著上调二酰甘油酰基转移酶2(DGAT2)、乙酰辅酶A羧化酶(ACC)及脂肪酸合成酶(FASN)基因的表达(P<0.05),显著抑制硬脂酰辅酶A去饱和酶1(SCD1)基因的表达(P<0.05),而对过氧化物酶体增殖物激活受体γ(PPARγ)基因的表达无显著影响(P>0.05)。添加20μmol/L亚油酸可显著抑制ACC和FASN基因的表达(P<0.05);亚油酸浓度为40和80μmol/L时可显著上调DGAT2基因的表达(P<0.05),抑制SCD1和SREBP1基因的表达(P<0.05),对ACC、FASN和PPARγ基因表达均无显著影响(P>0.05)。综上所述,100～200μmol/L油酸和40～80μmol/L亚油酸对奶山羊乳腺上皮细胞乳脂肪合成具有较好的促进效果。

Effects of Oleic Acid and Linoleic Acid on Triglyceride Content and Gene Expression Involved in Milk Fat Synthesis in Goat Mammary Epithelial Cells

The aim of this study was to investigate the effects of oleic acid and linoleic acid on triglyceride (TG) content and the expression of genes involved in milk fat synthesis in dairy goat mammary epithelial cells in vitro.The goat mammary epithelial cells were used as the research object,and different concentrations of oleic acid (0,50,100,200 μmol/L) and linoleic acid (0,20,40,80 μmol/L) were added in culture medium for a 24 h cultivation.The intracellular TG content was measured by using triglyceride determination kit,and gene expressions were detected by Real-time quantitative PCR.The results showed that 100,200 μmol/L oleic acid and 40,80 μmol/L linoleic acid significantly increased TG content (P<0.05).The expression of DGAT2,ACC and FASN genes were significantly up-regulated by addition of 100 and 200 μmol/L oleic acid (P<0.05),while the SCD1 gene expression was significantly inhibited by oleic acid (P<0.05).However,oleic acid had no significant effect on the expression of PPARγ gene (P>0.05).The results of linoleic acid addition showed that 20 μmol/L linoleic acid could significantly inhibit the expressions of ACC and FASN genes (P<0.05).40 and 80 μmol/L linoleic acid could significantly promote the expression of DGAT2 gene (P<0.05),inhibit the expression of SCD1 and SREBP1 genes (P<0.05),and had no significant effect on the expression of ACC,FASN and PPARγ genes (P>0.05).In conclusion,100 to 200 μmol/L oleic acid and 40 to 80 μmol/L linoleic acid were optimal levels considering its improvement effects on milk fat synthesis in dairy goat mammary epithelial cells.