Alpha-亚麻酸对HepG2细胞脂肪酸合成关键基因的影响

The effects of Alpha-linolenic acid on the related key gene expressions of fatty acid synthesis in HepG2 cells

目的探讨不同剂量Alpha-亚麻酸(ALA)对硬脂酸培养后的HepG2细胞脂肪酸合成基因表达的影响。方法 HepG2细胞分为对照组(NC)以及含有0.5 mmol/L硬脂酸的培养液培养高脂组(HF),培养36 h后应用实时定量PCR检测脂肪酸合成关键基因SREBP1C、FAS及ACC表达;基因表达存在显著差异后分别用10%、20%、50%、70%、100%ALA替代硬脂酸培养36 h,实时定量PCR和免疫印迹法检测上述基因mRNA水平及蛋白表达。结果硬脂酸处理后HepG2细胞SREBP1C、FAS及ACC基因显著升高(P<0.001),ALA替代组SREBP1C基因mRNA表达水平均显著低于高脂组(P<0.001),0.5 mmol/L ALA组及0.35 mmol/L ALA组FAS显著低于高脂组(P<0.001),各替代组ACC基因mRNA水平与高脂组无统计学差异;替代组SREBP1C及FAS蛋白表达水平显著低于高脂组,而ACC蛋白表达量与高脂组无明显差异。结论硬脂酸促进HepG2细胞脂肪酸合成,ALA通过抑制SREBP1C及FAS基因表达来减弱脂肪酸合成。

Objective To investigate the effects of different doses Alpha-Linolenic acid （ ALA ） on the expressions of fatty acid synthesis-related genes in HepG2 cells.Methods HepG2 cells were divided into two groups, normal control group （NC） and high fat group （HF） in which cells were firstly cultured for 36h in the medium contained 0.5mmol/L stearic acid.Real-time quantitative PCR was taken to detect mRNA expression of genes SREBP1C, FAS and ACC which are related to fatty synthesis.While there are significant differences in fatty synthesis, 10%, 20%, 50%, 70% and 100%ALA took the place of stearic acid, 36h later, real-time quantitative PCR and Western blotting were taken to detect mRNA and protein expression of genes related to fatty synthesis.Results SREBP1C mRNA expression of ALA substitution groups were significantly lower than the high-fat group （ P 〈0.001） .The FAS of 0.5 mmol/L ALA group and 0.35 mmol/L ALA group were significantly lower than the high-fat group （P 〈0.001）.ACC genes mRNA level was not significantly different from high-fat group.SREBP1C and FAS protein expression were significantly lower than the high-fat group, but ACC showed no significant difference.Conclusions Saturated fatty acids promote hepatocyte fatty acid synthesis, ALA abates fatty acid synthesis by inhibiting FAS and SREBP1C gene expression.