乙酸和β-羟丁酸对体外培养牛肝细胞脂代谢部分关键酶表达的影响

Effects of acetic acid and β-hydroxybutyrate on the expression of key enzyme genes involved to fatty acid metabolism in bovine hepatocytes cultured in vitro

本研究以体外原代培养的奶牛肝细胞为模型,添加不同浓度的乙酸(AcOH)和β-羟丁酸(BHBA),探讨其对奶牛肝细胞脂肪酸代谢关键酶基因表达的影响。添加不同浓度乙酸和β-羟丁酸,培养24h后,提取细胞总RNA。应用实时荧光定量PCR方法,检测脂代谢关键酶长链脂酰辅酶A合成酶1(ACSL1)、柠檬酸合成酶(CS)和乙酰辅酶A羧化酶α(ACCα)mRNA丰度的变化。结果显示,适当浓度的AcOH能够促进肝细胞脂肪酸活化及氧化途径关键酶ACSL1和CS的转录,而高浓度AcOH能够抑制脂肪酸从头合成途径关键酶ACCα的转录;高浓度BHBA能够抑制肝细胞ACSL1、CS和ACCα的转录。说明血液中适当浓度的AcOH能够促进肝脏脂肪酸氧化并抑制脂肪酸从头合成,高浓度BHBA能够抑制肝脏脂氧化和合成,影响乳脂前体物的供应,进而影响乳脂合成。

The objective of this study was to investigate the effects of acetic acid （AcOH） and β-hydroxybutyrate （BHBA） on the transcription levels of key enzymes involved to fatty acid metabolism in the bovine hepatocytes cul- tured in vitro. The total RNA was isolated from hepatocytes, which were treated with different concentrations of AcOH or BHBA after 24 h. The mRNA expression levels of the key lipid metabolism genes,including long-chain ac- yl-CoA synthetase-1 （ACSL1）, citrate synthase （CS） and acetyl coenzyme A carboxylase a （ACCα）, were determined using fluorescent quantitative real time PCR. The results showed that appropriate concentration of AcOH can pro- mote the transcription of ACSL1 and CS. However, high concentration of AcOH could inhibit ACCatranscription, which inhibit the de nove synthesis of fatty acid. Furthermore, high concentration of BHBA showed inhibition effects on the ACSL1 ,CS and ACCα transcription. In summary,the results of this study indicate that appropriate concentra- tion of AcOH promotes lipid oxidation and inhibits the de hove synthesis of fatty acid. Furthermore,high concentra- tion of BHBA inhibits lipid synthesis and oxidation,thereby affecting the supply of milk fat precursors, which affects the milk fat synthesis.