Visfatin诱导THP-1源性泡沫细胞形成的机制研究

目的观察内脂素(visfatin)对人单核细胞株(THP-1)源性巨噬细胞胆固醇代谢相关基因ATP结合盒转运蛋白A1(ABCA1)和酰基辅酶A:胆固醇酰基转移酶1(ACAT1)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,随机分组,给予不同浓度和不同作用时间的visfatin进行干预,分别运用油红O染色观察细胞质脂滴变化,反转录聚合酶链反应(RT-PCR)法和蛋白免疫印迹(Western blot)法检测各组细胞ABCA1及ACAT1 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干预组细胞质脂滴明显增多,细胞内FC和CE含量增加(均P<0.05),CE与TC的比值明显增加(>50%),ABCA1 mRNA和蛋白表达水平降低(均P<0.05),ACAT1 mRNA和蛋白表达水平升高(均P<0.05)。相关分析显示,visfatin呈浓度和时间依赖性下调ABCA1 mRNA和蛋白的表达,上调ACAT1 mRNA和蛋白的表达。结论 visfatin下调巨噬细胞ABCA1的表达,上调ACAT1的表达,使细胞内FC流出减少,CE合成增加,从而诱导THP-1源性泡沫细胞的形成,这可能为visfatin致动脉粥样硬化发病机制的研究提供一个新的理论依据。

Mechanism of THP-1-derived Foam Cell Formation Induced by Visfatin

Objective To investigate the expression of ATP binding cassette transporter A1(ABCA1)and acyl-CoA:cholesterol acyltransferase 1(ACAT1)in macrophages induced by visfatin,and the mechanism of THP-1-derived foam cell formation.Methods THP-1 monocytes were induced into macrophages by 160 nmol/L phorbol myristate acetate(PMA)for 48 h,and the macrophages were exposed to visfatin with different concentrations and durations.Lipid droplets in cytoplasm were observed by Oil Red O staining.The expression levels of ABC...