人参皂苷Rg1诱导人肝HL-7702细胞糖皮质激素受体报告基因表达的作用

目的探讨人参皂苷Rg1(ginsenoside Rg1,G-Rg1)对人肝HL-7702细胞糖皮质激素受体(GR)的调节作用。方法将含有糖皮质激素受体反应元件(GRE)的荧光素酶报告基因的表达质粒载体pGRE-tk-LUC与内参照基因载体质粒pRL-SV40,通过脂质体介导瞬时转染至人肝HL-7702细胞中,利用双荧光素酶报告基因检测系统,观察报告基因的表达变化;利用Western blotting方法检测药物对细胞GR蛋白表达的影响。结果G-Rg1与地塞米松均可诱导pGRF-tk-LUC报告基因表达,且呈剂量依赖性,而且这种诱导作用可以被糖皮质激素受体阻断剂RU486(Mifepristone)所阻断,G-Rg1对细胞GR蛋白表达有显著的抑制作用。结论G-Rg1在体外能够表现出一些类似糖皮质激素样的生物活性,可能是GR的配体。

Inducement of ginsenoside Rg1, on receptor report gene expression in HL-7702 of glucocorticoid cells

Objective To investigate the effect of ginsenoside Rg1 (G-Rg1) on regulation of glucocorticoid receptor (GR) in HL-7702 cells. Methods HL-7702 Cells were transiently cotransfected by Lipofect AMINETM2000 with pGRE-tk-LUC reporter plasmid and pRL-SV40 plasmid. The effects of G-Rg1 and Dexamethasone on luciferase activity expression were detected by Dual-Luciferase Reporter Assays, the protein expression of GR in HL-7702 cells was analyzed by Western blotting assay, respectively. Results A dose-dependent induction of the reporter gene was observed in response to Dex or G-Rg1, and the inductive effect was blocked by treatment with the antiglucocorticoid RU486 (Mifepristone). G-Rg1 also down-regulated the GR protein expression in HL-7702 cells. ConclusionThese results strongly indicate that G-Rg1, which may be a ligand of GR, has some glucocorticoid-like effect in vitro.