本文研究了不同比例n-6/n-3多不饱和脂肪酸对HepG2细胞影响，通过体外培养细胞60 μM不同比例LA/ALA 培养24 h，通过反转录PCR研究不同比例LA/ALA对HepG2细胞SREBP-1、FAS、HMG-CR、LDLr和ApoB蛋白等脂代谢相关基因及蛋白表达量的影响。结果表明在组1（LA）、组2（10:1 LA/ALA）、组3（5:1 LA/ALA）、组4（1:1 LA/ALA）、组5（1:5 LA/ALA）、组6（1:10 LA/ALA）和组7（ALA）7组比例中，1:1 LA/ALA比例处理细胞效果最佳，此比例脂肪酸通过下调HepG2细胞SREBP-1和FAS基因的表达来降低细胞TG的含量；下调HMG-CR基因的表达，上调LDLr基因的表达来降低细胞TC和LDL-C含量；通过上调SR-B1基因表达增加胆固醇逆转运，从而实现对HepG2脂代谢的有效调控。此多不饱和脂肪酸体外营养评价模型，为n-6/n-3多不饱和脂肪酸最佳营养比例推荐及食用植物油中多不饱和脂肪酸比例营养评估提供理论依据。

Using RT-PCR, the variation in lipid metabolism of HepG2 cells caused by different ratios of n-6/n-3 polyunsaturated fatty acids was studied. HepG2 cells were treated in vitro with different ratios of linoleic acid(LA)/ α- linolenic acid(ALA) at a concentration of 60 μM for 24 h, and RT-PCR was performed to analyze the expression of proteins associated with lipid metabolism, such as ApoB, SREBP-1, FAS, HMG-CR, and LDLr. The results showed that the LA/ALA ratio of 1:1 was the optimum ratio among seven test groups studied. At this ratio, downregulation of the SREBP-1 and FAS genes to decrease TG, downregulation of HMG-CR and upregulation of LDLr to reduce TC and LDL-C, and upregulation of SR-B1 to enhance the reverse transport of cholesterol to regulate lipid metabolism were observed. This in vitro model could be used to provide a theoretical basis for evaluating the nutritional value of polyunsaturated fatty acids in vegetable oils.

国家自然科学基金资助项目（31401525）；中国博士后基金项目（2015M571666）；山东省博士后基金项目（145635）