目的 探讨表没食子儿茶素没食子酸酯(epigallocatechin-3-gallate,EGCG)对泡沫细胞中胆固醇流出的影响及其机制.方法 人单核细胞白血病细胞诱导分化为巨噬细胞再转化为泡沫细胞,将细胞分为对照组,低、中和高剂量组,每组1.5×106个细胞,分别用0,10,30,100 μmol/L EGCG干预后,胆固醇检测试剂盒检测细胞中胆固醇含量,液体闪烁计数仪检测载脂蛋白A-I介导的泡沫细胞胆固醇流出,蛋白质印迹检测三磷酸腺苷结合盒转运体A1(ATP-binding cassette A1,ABCA1)蛋白质表达,实时荧光定量PCR检测ABCA1 mRNA的表达.结果 与对照组比较,低、中和高剂量组泡沫细胞ABCA1 mRNA和蛋白表达明显升高(P＜0.01),胆固醇流出率升高[(7.04±0.21)％、(7.75±0.17)％、(8.53±0.18)％ vs (3.37±0.16)％,P＜0.01],胆固醇含量降低[(419.33±19.75) mg/g、(352.58±14.23)mg/g、(312.62±17.45)mg/g vs (520.51±20.62) mg/g,P＜0.01],且中剂量组和高剂量组胆固醇流出率、胆固醇含量和ABCA1蛋白表达均较低剂量组变化明显(P＜0.05).结论 EGCG通过上调ABCA1的转录与表达,促进胆固醇流出,减轻细胞中胆固醇负荷.%Objective To study the effect of epigallocatechin-3 gallate (EGCG) on cholesterol efflux in foam cells and its mechanism.Methods THP-1 cells were induced to differentiate into macrophages which were then transformed to foam cells.Foam cells were divided into 0 μmol/L EGCG group,10 μmol/L EGCG group,30 μmol/L EGCG group,and 100 μmol/L EGCG group (1.5 × 106 in each group).Their cholesterol content was measured with a cholesterol test kit,apoA-I-mediated cholesterol efflux was assayed with a liquid scintillation counter,expression of ATP-binding cassette A1 (ABCA1) was detected by RT-PCR and Western blot respectively.Results The ABCA1 mRNA and protein expression levels and cholesterol efflux were significantly higher while the cholesterol content was significantly lower in 10 μmol/L EGCG group,30 μmol/L EGCG group,and 100 μmol/L EGCG group than in 0 μmol/L EGCG group (7.04％ ±0.21％,7.75％±0.17％ and 8.53％±0.18％ vs 3.37％±0.16％,P＜0.01;419.33±19.75 mg/g,352.58± 14.23 mg/g and 312.62±17.45 mg/g vs 520.51 ±20.62 mg/g,P＜0.01),and in 30 μmol/L EGCG group,100μmol/L EGCG group than in 10μmol/L EGCG group (P＜0.05).Conclusion EGCG increases cholesterol efflux and decreases cholesterol content in foam cells by upregulating the transcription and expression of ABCA1.
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