中文摘要：

目的：研究单核／巨噬细胞分化成为泡沫细胞过程中ghrelin对人酰基辅酶A：胆固醇酰基转移酶1（ACAT-1）表达以及细胞内胆固醇酯的影响。方法：体外培养人源单核细胞系（THP-1），由佛波酯（PMA）作用使其分化为巨噬细胞，后者可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。巨噬细胞加入不同浓度的ghrelin预孵2h后再加入ox—LDL，油红O染色法观察细胞内脂滴含量，运用RT—PCR法检测ACAT-1mRNA水平，Westernblotting法检测ACAT-1蛋白表达，采用酶法，通过荧光分光光度计检测细胞内胆固醇酯含量。结果：Ghrelin可明显减少THP-1源性泡沫细胞内脂滴的形成，显著降低细胞内胆固醇酯含量，并能显著降低单核／巨噬细胞泡沫化过程中ACAT—1mRNA水平和蛋白表达，且此干预作用呈浓度依赖性。结论：Ghrelin可能通过ACAT-1转录翻译水平的下调延缓动脉粥样硬化的发生。

英文摘要：

AIM： To investigate the effects of ghrelin on the expression of acyl coenzyme A：cholesterol acyl- transferases - 1 （ ACAT - 1 ） during the formation of foam cells. METHODS ： The human monocytic leukemia cell line THP - 1 was used in the study. The differentiation of THP - 1 ceils into macrophages was induced by phorbol 12 - myristate 13 - acetate （PMA）. Macrophages were incubated with oxidized LDL （ ox - LDL） to generate foam cells. Ghrelin of different concentrations were used during the formation of foam cells. The ACAT - 1 protein and mRNA levels were detected by Western blotting and RT - PCR. The variance of cholesterol content was measured by zymochemistry via - fluorospectropho- tometer. RESULTS ： Ghrelin reduced the content of cholesterol ester in foam ceils obviously. ACAT - 1 protein and mRNA levels were also decreased. Ghrelin reduced ACAT - 1 protein mass and mRNA level in a dose - dependent manner. CONCLUSION： Ghrelin might retard the formation of atherosclerosis via down - regulating the expression of ACAT - 1.