中文摘要：

目的：观察内脂素（visfatin）对人单核细胞株THP-1源性巨噬细胞ATP结合盒转运蛋白A1（ABCA1）表达的影响,探讨visfatin诱导THP-1源性泡沫细胞形成的机制. 方法：THP-1单核细胞诱导分化为巨噬细胞,予不同浓度和时间的visfatin进行干预,分别运用油红O染色观察细胞浆脂滴变化,反转录聚合酶链反应（RT-PCR）法和蛋白免疫印迹（Western blotting）法检测各组细胞ABCA1 mRNA和蛋白表达,酶荧光学法检测细胞内总胆固醇（TC）和游离胆固醇（FC）含量,TC与FC之差为胆固醇酯（CE）含量.结果：与对照组比较,visfatin干预组细胞浆脂滴明显增多,细胞内FC和CE含量增加（均P＜0.05）.Visfatin呈浓度和时间依赖性地下调ABCA1 mRNA和蛋白表达（P＜0.05）.结论：Visfatin下调THP-1源性巨噬细胞ABCA1的表达,使细胞内FC流出减少,CE合成增加,从而诱导泡沫细胞的形成.

英文摘要：

AIM： To explore the mechanism of foam cell formation by investigating the expression of ATP bind- ing cassette transporter A1 （ ABCA1 ） in human acute monocytic leukemia cell line（ THP - 1 ） - derived maerophages treated with visfatin. METHODS： THP - 1 monocytes were induced into macrophages by exposure of the cells to phorbol myristate acetate（ PMA, 160 nmol/L） for 48 h. The macrophages were then treated with visfatin at different concentrations and for different time points. The lipid droplets in cytoplasm of the macrophages were observed by oil red O staining. The expression of ABCA1 at mRNA and protein levels was determined by reverse transcriptase polymerase chain reaction（ RT- PCR） and Western blotting, respectively. The contents of intracellnlar total cholesterol（TC） and free cholesterol（FC） was measured by enzyme fluorescence analysis. The content of cholesterol ester（CE） was calculated according to the difference between TC and FC. RESULTS： Compared with control group, the lipid droplets and the content of FC and CE were increased in visfatin -treated macrophages. The expression of ABCA1 at mRNA and protein levels was down -regulated by visfatin in a concentration - and time - dependent manner（ P 〈 0. 05 ）. CONCLUSION ： The down - regulation of ABCA1 expression is induced by visfatin through reducing FC efflux and increasing CE synthesis. This may induce the formation of THP - 1 - derived foam cells.