低密度脂蛋白受体/报告基因系统建立及中药降脂药物的筛选

为了从中药中筛选降脂药物，本文构建了低密度脂蛋白受体／荧光素酶(LDLR／Luc)报告基因系统。将LDLR／Luc报告质粒转染至HepG2细胞，并优化细胞接种密度、细胞培养时间以及检测底物浓度等条件，获得较高荧光素酶活性；进一步选择普伐他汀作为阳性对照药物，可明显提高LDIR／Luc转录活性，表明成功地建立了靶向ldlr转录活性的报告基因筛选体系。应用该体系对500余种中药提取物进行了筛选，决明子、泽泻、穿龙薯蓣等提取物显示阳性，与过去报道采用动物模型研究的结果一致。

Construction of LDLR/Luc Reporter System and Screening of Cholesterol-lowering Drug from Traditional Chinese Medicine

In order to screen cholesterol-lowering drug from Traditional Chinese Medicine, LDLR/Lucifrase(Luc) reporter system was constructed. The LDLR/Luc reporter plasmid was transfected into HepG2 cells and the luciferase expression under the control LDLR promoter/enhancer region were obtained by the optimization of various conditions including cell density, incubated time of transfected cells and substrate volume in the assay system. As a positive control in the screening model we used paravastatin, which is known cholesterol-lowering drug, we show that the LDLR promoter activity was strongly elevated by paravastatin. These results indicated that a screening model in vitro targeting the transactivity of ldlr was established. The model was used to screen cholesterol-lowering drug from about 500 Traditional Chinese Medicine (TCM), in which Semen cassiae, Rhizoma alismatis and Dioscorea nipponica Makino exhibit positive signal, consistent with previous studies in animal model.