脂联素对巨噬细胞源性泡沫细胞内胆固醇含量的影响

Effects of adiponectin on cholesterol in THP-1 derived foam cells

目的通过研究脂联素对细胞内胆固醇的影响,探讨其抗动脉粥样硬化作用的可能机制。方法以人急性单核细胞白血病细胞株(THP-1细胞株)来源的泡沫细胞模型为研究对象,用不同浓度的脂联素(1mg/L,5mg/L和10mg/L)进行体外干预。采用油红O观察泡沫细胞形成,用胆固醇氧化酶法检测细胞内胆固醇含量的变化,用荧光显微镜观察巨噬细胞对Dil标记的氧化低密度脂蛋白(Dil-Ox-LDL)的摄取率。结果脂联素(1mg/L,5mg/L和10mg/L)干预对巨噬细胞内总胆固醇(TC)无显著影响,却能促进胆固醇酯(CE)转化为游离胆固醇(FC),CE/TC比值明显降低(P<0.05);同时观察到脂联素(10mg/L)干预后可抑制巨噬细胞对Dil-Ox-LDL的摄取。结论脂联素能减少巨噬细胞对Ox-LDL的摄取和促进巨噬细胞内胆固醇酯的水解,这可能是脂联素抑制胆固醇沉着从而发挥抗动脉粥样硬化作用的机制之一。

Objective To investigate the effect of adiponectin on cholesterol in THP-1 derived foam cells,and to explore its anti-athe-rosclerotic mechanism.Methods THP-1 derived foam cells were incubated with Ox-LDL and adiponectin（1 mg/L,5 mg/L and 10 mg/L）＋Ox-LDL in vitro,respectively.Oil red O staining was used to observe the cellular lipid droplets in lipid-loaded cells.The cholesterol oxidase was employed to determine the content of cellular cholesterol.The uptake of Dil-Ox-LDL in THP-1 cells was assayed by fluorescence microscopy.Results Adiponectin（1 mg/L,5 mg/L and 10 mg/L）enhanced the transformation from cholesterol ester to free cholesterol,and adiponectin（10 mg/L）suppressed the uptake of Dil-Ox-LDL.Conclusion Adiponectin could inhibit intracellular cholesterol deposit in foam cells by suppressing the uptake of Ox-LDL and enhancing the hydrolysis of intracellular cholesterol ester.