【摘要】 目的 探讨微小核糖核酸-34a(miR-34a)靶向沉默信息调节因子-1(SIRT1)促进THP-1人巨噬细胞的脂质蓄积并降低胆固醇流出的作用。方法 体外培养THP-1细胞，分别将miR-NC、miR-34a inhibitor和miR-34a mimic转染到THP-1细胞，同时用佛波酯（160 nmol/L）孵育细胞24 h，诱导其分化成巨噬细胞；检测THP-1巨噬细胞中miR-34a和SIRT1 mRNA的表达，用红油O染色观察细胞内脂质蓄积情况，用高效液相色谱检测THP-1巨噬细胞内胆固醇水平，用闪烁计数法观察细胞内胆固醇的流出情况，同时检测THP-1巨噬细胞中SIRT1和肝脏X受体（LXR）蛋白含量。结果 通过转染miR-34a inhibitor降低miR-34a后，THP-1巨噬细胞中红色脂滴明显减少，通过转染miR-34a mimic增加miR-34a后，THP-1巨噬细胞中可见大量的红色脂滴。通过转染miR-34a inhibitor降低miR-34a后，THP-1巨噬细胞中SIRT1mRNA表达、胆固醇流出率、SIRT1和LXR含量增加，THP-1巨噬细胞中总胆固醇（TC）、胆固醇酯（CE）和游离胆固醇（FC）含量降低（P<0.05）；通过转染miR-34a mimic增加miR-34a后，THP-1巨噬细胞中SIRT1 mRNA表达、胆固醇流出率、SIRT1和LXR含量降低，THP-1巨噬细胞中TC、CE和FC含量增加（P<0.05）。结论 通过转染促进miR-34a表达后，可以靶向抑制SIRT1，促进THP-1人巨噬细胞的脂质蓄积并降低胆固醇流出。更多还原

【Abstract】 Objective To investigate the effect of microRNA-34a(miR-34a) in promoting lipid accumulation and reducing cholesterol efflux through targeting silent information regulator-1(SIRT1) in THP-1 human macrophages. Methods THP-1 cells were cultured in vitro, and miR-NC, miR-34a inhibitor, and miR-34a mimic were transfected into THP-1. At the same time, THP-1 cells were incubated with phorbol ester(160 nmol/L) for 24 h to induce them to differentiate into macrophages. The mRNA expressions of miR-34a and SIRT1 were detected,and intracellular lipid accumulation was observed by using red oil O staining in THP-1 macrophages. The level of cholesterol was detected by using high performance liquid chromatography(HPLC), and cholesterol efflux was observed by using scintillation counting in THP-1 macrophages. Meanwhile the protein content of SIRT1 and Liver X receptor(LXR) were detected in THP-1 macrophages. Results After miR-34a was reduced by transfection with miR-34a inhibitor, the red lipid droplets decreased significantly in THP-1 macrophages. After miR-34a was increased by transfection with miR-34a mimic, a large amount of red lipid droplets could be observed in THP-1macrophages. After miR-34a was reduced by transfection with miR-34a inhibitor, SIRT1 mRNA expression,cholesterol efflux rate, and content of SIRT1 and LXR increased, and content of total cholesterol(TC), cholesterol ester(CE) and free cholesterol(FC) decreased in THP-1 macrophages(P<0.05). After miR-34a was increased by transfection of miR-34a mimic, SIRT1 mRNA expression, cholesterol efflux rate, and content of SIRT1 and LXR in decreased, and content of TC, CE and FC increased in THP-1 macrophages(P<0.05). Conclusion MiR-34a, after promoting its expression through transfection, can target to inhibit SIRT1, promote lipid accumulation and reduce cholesterol efflux in THP-1 macrophages.更多还原