不同膳食脂肪酸对肝细胞SREBP-1c表达及脂代谢的影响  

Effect of different dietary fatty acids on expression of sterol-regulatory elementary binding protein-1c and lipid metabolism in hepatic cells

作　　者：田晓媛[1] 张乾勇[1] 冉莉[1] 糜漫天[1] 

机构地区：[1]第三军医大学军事预防医学院营养与食品卫生学教研室,重庆市医学营养研究中心,重庆市营养与食品安全重点实验室,重庆400038

出　　处：《第三军医大学学报》2012年第1期66-69,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金(30972469)~~

摘　　要：目的探讨不同膳食脂肪酸构成对肝细胞脂代谢及固醇调节元件结合蛋白-1c(sterol-regulatory elementarybinding protein-1c,SREBP-1c)表达的影响。方法以HepG2肝细胞为研究对象,分为空白对照组、二十碳五烯酸(EPA)组、棕榈酸(PA)组、EPA和亚油酸(LA)1∶1混合组、PA和油酸(OA)1∶1混合组,EPA、PA单独处理组终浓度为150μmol/L,混合处理组各组分浓度为75μmol/L,总浓度为150μmol/L,处理细胞24 h。采用油红O染色观察细胞内脂滴的变化,测定甘油三酯(TG)含量来评价细胞内脂质含量;采用RT-PCR、Western blot法检测SREBP-1c mRNA及蛋白的表达。结果 PA组、PA和OA 1∶1混合组SREBP-1c mRNA及蛋白的表达上调,EPA和LA 1∶1混合组、EPA组SREBP-1c mRNA及蛋白的表达下调,与对照组相比差异显著(P<0.05)。与对照组相比,EPA和LA 1∶1混合组、EPA组肝细胞内TG含量显著减少(P<0.05);PA和OA 1∶1混合组、PA组肝细胞内TG含量显著增加(P<0.05)。结论 PA、OA上调肝细胞SREBP-1c的表达并促进细胞内TG的合成,可能促进肝细胞脂肪变性;而EPA、LA下调肝细胞SREBP-1c的表达并显著降低肝细胞内TG含量,减轻肝细胞脂肪变性。Objective To study the effect of different dietary fatty acid compositions on expression of sterol-regulatory elementary binding protein-1 c （ SREBP-1 c） and lipid metabolism in hepatic cells. Methods HepG2 cells were divided into control group, eicosapntemacnioc acid （EPA） group, palmitic acid （PA） group, 1：1 EPA and linoleic acid （LA） mixture group, 1：1 PA and oleie acid （OA） mixture group. The final concentration of EPA and LA was 150 ~mol/L in EPA group and PA group respectively, and 75 txmol/L in EPA and LA mixture group and PA and OA mixture group respectively. The total concentration was 150 ~mol/L 24 h after the HepG2 cells were treated. Changes of lipid droplet and its level in HepG2 cells were observed with oil red staining. Expression level of SREBP-1 e mRNA and protein was measured by RT-PCR and Western ＇blotting respectively. ,Results The expression level of SREBP-1 c mRNA and protein was significantly higher !nPA group andl： 1 PA and OA mixture group, and significantly lower in EPA group and 1：1 EPA and LA mixture group than in control group （ P 〈 0.05 ）. The lipid level in hepatic cells was significantly lower in EPA group and 1 ： 1 EPA and LA mixture group than in control group （ P 〈 0.05 ） , and significantly higher in PA group and 1 ： 1 PA and OA mixture group （P 〈 0.05 ）. Conclusion PA and OA up-regulate the expression of SREBP-1 c and promote the synthesis of lipid by promoting the fatty and LA down-regulate the expression of SREBP-1 c and decrease the tion in hepatic cells. degeneration in hepatic cells, while EPA lipid level by reducing the fatty degenera-

关 键 词：脂肪酸 脂代谢 SREBP-1C 肝细胞 

分 类 号：R151.2[医药卫生—营养与食品卫生学] Q493.5[医药卫生—公共卫生与预防医学]