过氧化体增殖物激活型受体γ对巨噬细胞脂质蓄积及CD36表达的影响

Effect of Peroxisome Proliferator-Activated Receptor-γ on Cholesterol Accumulation and CD36 Expression in THP-1 Macrophages

目的观察过氧化体增殖物激活型受体γ激动剂和拮抗剂对THP-1巨噬细胞胆固醇蓄积及CD36表达的影响。方法实验分对照组、氧化型低密度脂蛋白组、Ciglitazone处理组和GW9662处理组,后两组用50 mg/L氧化型低密度脂蛋白分别与过氧化体增殖物激活型受体γ激动剂Ciglitazone(10μmol/L)及拮抗剂GW9662(10μmol/L)共同孵育24 h,高效液相色谱分析法检测细胞总胆固醇蓄积情况,RT-PCR和Western blot分别检测THP-1巨噬细胞CD36 mRNA和蛋白的表达。结果与对照组(76.28±10.36 mg/g)相比,氧化型低密度脂蛋白(121.63±13.32 mg/g)能使细胞总胆固醇含量显著增加,而Ciglitazone能使氧化型低密度脂蛋白处理的细胞总胆固醇含量进一步增加(136.23±14.78 mg/g),GW9662能使氧化型低密度脂蛋白处理的细胞总胆固醇含量减少(98.52±11.45 mg/g)。过氧化体增殖物激活型受体γ拮抗剂GW9662使巨噬细胞CD36 mRNA和蛋白的表达下调及胆固醇蓄积减少,过氧化体增殖物激活型受体γ激动剂Ciglitazone使巨噬细胞CD36 mRNA和蛋白的表达上调及胆固醇蓄积增多。结论过氧化体增殖物激活型受体γ拮抗剂使THP-1巨噬细胞胆固醇蓄积减少及氧化型低密度脂蛋白诱导的CD36表达下调。

Aim To investigate the effects of peroxisome proliferator-activated receptor-γ（PPARγ） on cholesterol accumulation and CD36 expression in THP-1 macrophages. Methods Mononuclear cells were induced to differentiate into THP-1 macrophages by phorbol myristate acetate（160 nmol/L） co-incubation for 24 h.THP-1 macrophages were co-incubated with 50 mg/L oxidize low-density lipoprotein（ox-LDL） and PPARγ agonist Ciglitazone（10 μmol/L;C）and PPARγ antagonist GW9662（10 μmol/L;D）for 24 h,and the cells mixed with（B） and without（A） ox-LDL were as the control groups.Cellular total cholesterol was determined by high performance liquid chromatography analysis.CD36 mRNA and protein levels were determined by reverse transcription-polymerase chain reaction（RT-PCR） and Western blot respectively. Results High performance liquid chromatography analysis demonstrated the amount of cellular total cholesterol were 76.28±10.36（A）,121.63±13.32（B）,136.23±14.78（C）,98.52±11.45（D） mg per gram protein.PPARγ antagonist GW9662 inhibited CD36 mRNA and protein synthesis.Ciglitazone increased CD36 mRNA and protein synthesis.The ratios of CD36/GAPDH were 0.78（A）,0.94（B）,1.12（C）,0.52（D） respectively.Western blot results conform to RT-PCR outcomes. Conclusion Antagonist of PPARγ may decrease cholesterol accumulation and downregulate ox-LDL-induced CD36 expression in THP-1 macrophages.