中文摘要：

目的探讨Ghrelin对人单核细胞系（THP-1）源性泡沫细胞ATP结合盒转运子G1（ABCG1）表达的调控作用及其可能途径。方法体外培养THP-1,由佛波酯（PMA）作用使其分化为巨噬细胞,继而在氧化低密度脂蛋白（ox-LDL）存在条件下进一步转变为泡沫细胞,油红O染色法鉴定泡沫细胞形成。运用RT-PCR法和Western印迹法分别检测Ghrelin干预后及封闭过氧化物酶体增生物激活受体γ（PPARγ）后ABCG1 mRNA与蛋白表达。采用酶法,通过荧光分光光度计检测胆固醇含量及胆固醇流出率。结果 Ghrelin可明显减少细胞内脂滴的形成,增加胆固醇流出,并能显著增加单核/巨噬细胞泡沫化过程中ABCG1 mRNA水平和蛋白表达,此作用呈浓度依赖性。封闭PPARγ后,Ghrelin抑制泡沫细胞形成的效应被阻断,且PPARγ拮抗剂浓度越高,该阻断作用越明显。结论 Ghrelin可能通过上调ABCG1转录翻译水平延缓动脉粥样硬化的发生,且该效应可能通过PPARγ途径发挥作用。

英文摘要：

Objective To investigate the effects of Ghrelin on the expression of ATP binding cassette transporter G1 （ABCG1） in THP-1 derived foam cells and its possible mechanism. Methods Human monocytic leukemia cell line （THP-1） was chosen. The differentiation of THP-1 cells into macrophages was induced by phorbol myristate acetate （PMA）. Macrophages were then incubated with oxidized LDL （ox-LDL） to generate foam cells. Ghrelin and antagonist of PPARγ were treated during foam cells formation. The ABCG1 protein and mRNA levels were detected by Western blotting and RT-PCR. The effect of variance of cholesterol content was measured by zymochemistry via-fluorospectrophotometer. Results Ghrelin increased the cholesterol efflux obviously. ABCG1 protein and mRNA levels were also decreased. The antagonist of peroxisome proliferator-activated receptorγ （PPARγ） inhibited the effects of Ghrelin on ABCG1 expression in dose-dependent manner. Conclusions Ghrelin might interfere atherosclerosis by up-regulating the expression of ABCG1 via PPARγ pathway.