目的 观察绞股蓝皂苷(GP)对晚期糖基化终末产物(AGEs)诱导下人肾小球系膜细胞(HMCs)中晚期糖基化终末产物受体(RAGE)表达及氧化应激水平的影响。方法 用含13% FBS的DMEM低糖培养液体外培养HMCs细胞,将细胞分为6组：对照组(DMEM培养液),AGEs组(200 mg/L),GP低、中、高剂量(25、75、150 mg/L)组和阳性对照组(氨基胍0.1 mmol/L)。培养72 h后,采用实时荧光定量PCR法检测各组细胞中RAGE mRNA的表达水平,Western blotting法检测RAGE蛋白表达水平。应用试剂盒检测各组细胞上清液中超氧化物歧化酶(SOD)、丙二醛(MDA)及细胞内微量还原型谷胱甘肽(GSH)活性。结果 AGEs显著促进HMCs中RAGE mRNA及蛋白表达(P<0.01),增强细胞氧化应激水平。GP能有效抑制RAGE mRNA及蛋白表达,增加上清液中SOD和细胞内GSH水平,降低细胞上清液中MDA水平,且呈浓度依赖效应,与AGEs组比较差异显著(P<0.01)。结论 GP下调AGEs刺激后HMCs细胞RAGE的异常高表达,同时改善细胞内氧化应激水平,其可能的机制是GP阻断了RAGE介导的AGEs-RAGE-氧化应激信号通路,表现为细胞上清液中MDA水平降低和SOD水平增加及细胞内GSH水平增加。

Objective To observe the effect of gypenosides (GP) on the expression of receptor for advanced glycated endproducts (RAGE) and the oxidative stress status of human mesangial cells (HMCs) induced by AGEs. Methods HMCs were cultured in DMEM of low glucose containing 13% fetal bovine serum in vitro, which were divided into six groups: normal control group (DMEM of low glucose containing 13% fetal bovine serum), AGEs group (AGEs 200mg/L), GP low-dose group (25 mg/L and AGEs 200 mg/L), GP mid-dose group (75 mg/L and AGEs 200 mg/L), GP high dose group: (150 mg/L and AGEs 200 mg/L), and aminoguanidine positive control group (0.1 mmol/L and AGEs 200 mg/L). The expression of RAGE mRNA levels of each group was detected using semi-quantitative RT-PCR method, protein expression levels by Western blotting after cultured 72 h. Simultaneously, the levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in cell supernatant, and intracellular glutathione trace (GSH) in cell were measured. Results AGEs could significantly promote the expression of RAGE and mRNA in HMCs (P < 0.01), and enhance cellular oxidative stress levels. GP could effectively inhibit the expression of RAGE and mRNA, increase the level of SOD in cell supernatant and GSH in cell, reduce the level of MDA in cell supernatant in a dose-dependent manner compared with the control group, the difference was significant (P < 0.05). Conclusion AGEs stimulation can induce the high expression of RAGE in HMCs and enhance the level of oxidative stress in vitro. GP can down the high expression of RAGE stimulated by AGEs, while improve the oxidative stress in cells, and its possible mechanism of GP may block AGEs-RAGE-oxidative stress signaling pathways mediated by RAGE, it shows the lower levels of MDA and SOD and higher levels of GSH in cell.

广西自然科学基金项目(2013GXNSFAA019197);桂林市科学研究与技术开发计划项目(20120121-1-1)