炎症对脂肪酸负荷的HepG2细胞FAT/CD36表达的影响  

Effects of inflammation on FAT/CD36 expressions in HepG2 cells loaded with fatty acids

作　　者：殷鹭[1] 赵蕾[1] 李青[1] 黄爱龙[1] 陈压西[1] 阮雄中[1] 

机构地区：[1]重庆医科大学脂糖代谢性疾病重庆市重点实验室、脂质研究中心,重庆400016

出　　处：《重庆医科大学学报》2013年第4期341-345,共5页Journal of Chongqing Medical University

基　　金：国家自然科学基金资助项目(编号:30871159、81070631、81270493)

摘　　要：目的:观察炎症是否干扰脂肪酸负荷的人肝癌细胞系HepG2细胞脂肪酸转运蛋白/CD36(fatty acid transporter/CD36,FAT/CD36)的表达及脂质代谢。方法:分别给予不同浓度软脂酸(0.00、0.04、0.08、0.16、0.32 mmol/L)处理HepG2细胞24 h。采用Western blot和real-time PCR的方法检测HepG2细胞FAT/CD36的蛋白及mRNA的表达水平,再用油红O的方法观察细胞的脂质积聚情况。然后进一步选取0.04 mmol/L的软脂酸联合炎症因子[25 ng/ml的肿瘤坏死因子-α(tumor necrosis factor,TNF-α)或20 ng/ml的白细胞介素-6(interleukin-6,IL-6)]处理HepG2细胞24 h后,观察细胞FAT/CD36的蛋白表达情况,再用油红O和酶法检测细胞内的甘油三酯(triglyceride,TG)水平,ELISA检测细胞内游离脂肪酸(free fatty acid,FFA)含量。结果:软脂酸呈浓度依赖性上调HepG2细胞FAT/CD36的蛋白(r=0.873,P=0.000)和mRNA表达(r=0.884,P=0.000)及细胞内脂质积聚。炎症因子TNF-α和IL-6能明显刺激脂肪酸负荷的HepG2细胞FAT/CD36的蛋白表达进一步增加(P值分别为0.001和0.000)。油红O染色显示炎症因子TNF-α和IL-6能明显促进HepG2细胞的脂质积聚,胞内TG定量检测也显示炎症因子能促进HepG2细胞的脂质积聚,其中软脂酸联合TNF-α组与对照组及软脂酸组相比,P值分别为0.009和0.037,软脂酸联合IL-6组与对照组及软脂酸组相比,P值均为0.000。胞内FFA定量检测结果与油红O染色和TG检测结果一致,也显示炎症因子能促进HepG2细胞的脂质积聚,其中软脂酸联合TNF-α组与对照组及软脂酸组相比,P值分别为0.001和0.002,软脂酸联合IL-6组与对照组及软脂酸组相比,P值均为0.000。结论:炎症因子可以上调HepG2细胞FAT/CD36的表达并加重细胞内的脂质积聚。Objective：To investigate the effects of inflammatory cytokines on expressions of fatty acid transporter/CD36（FAT/CD36） in HepG2 cells loaded with fatty acids.Methods：HepG2 cells were cultured and treated with palmitate at concentrations of 0.00,0.04,0.08,0.16,0.32 mmol/L for 24 h.Protein and mRNA expressions of FAT/CD36 were detected by Western blot and real-time PCR,respectively.Intracellular lipid droplet formation was determined by Oil red O staining.Then the HepG2 cells were cultured and treated with palmitate at concentration of 0.04 mmol/L combined with tumor necrosis factor-α（TNF-α）（25 ng/ml） or interleukin-6（IL6）（20 ng/ml） for 24 h.Effects of inflammatory cytokines on the protein and mRNA levels of FAT/CD36 in HepG2 cells were also investigated.Oil red O staining was used to determine the intracellular lipid droplet formation.Intracellular triglyceride（TG） and free fatty acid（FFA） were measured by enzymic assay and ELISA,respectively.Results：Palmitate loading dose-dependently increased the protein and mRNA expressions of FAT/CD36 and intracellular lipid levels（r=0.873,P=0.000;r=0.884,P=0.000）.Inflammatory cytokines further increased the protein and mRNA expressions of FAT/CD36 in HepG2 cells loaded with palmitate（P=0.001,P= 0.000）.Oil red O staining and intracellular TG and FFA quantitative detection all showed that inflammatory cytokines can promote lipid accumulation of HepG2 cells.Based on intracellular TG quantitative detection：palmitate ＋ TNF-α group vs.control group,P= 0.009,P=0.037;palmitate ＋ IL-6 group vs.control group and palmitate group,all P=0.000.Based on intracellular FFA quantitative detection：palmitate ＋ TNF-α group vs.control group and palmitate group,P=0.001,P=0.002;palmitate ＋ IL-6 group vs.control group and palmitate group,all P=0.000.Conclusions：Inflammatory cytokines up-regulate the expression of FAT/CD36 in HepG2 cells loaded with fatty acids and exacerbate the intracellular lipid accumulation.

关 键 词：炎症 软脂酸 脂肪酸转运蛋白 CD36 HEPG2细胞 脂质积聚 

分 类 号：R589.2[医药卫生—内分泌]