高糖对肾小管细胞胆固醇转运的影响及花青素的干预研究

Effect of high glucose on cholesterol efflux in renal tubular cell and intervention of anthocyanins

目的观察高糖环境中肾小管上皮细胞胆固醇代谢变化以及花青素对其干预作用。方法体外培养人肾小管上皮细胞(HK-2),随机分为正常糖组、高糖组、甘露醇组、花青素1(C3G)干预组及花青素2(Cy)干预组。采用MTT法观察花青素对细胞活力的影响;Amplex Red荧光法和Filipin染色检测细胞内外胆固醇水平;RT-q PCR和Western blot检测三磷酸腺苷结合区转运蛋白A1(ABCA1)的表达。结果与正常糖组比较,高糖培养的肾小管上皮细胞内出现胆固醇蓄积,细胞上清中的胆固醇含量明显下降;RT-q PCR和Western blot检测发现三磷酸腺苷结合区转运蛋白A1(ABCA1)的表达高糖组均低于正常对照组,差异有统计学意义(P<0.05)。花青素1(C3G)干预组及花青素2(Cy)干预组相比较高糖组,ABCA1的蛋白和RNA表达均明显提高,胆固醇胞内蓄积明显减少。结论高糖可诱导的肾小管上皮细胞三磷酸腺苷结合区转运蛋白A1表达降低,导致胆固醇外流减少,从而造成胆固醇胞内蓄积;花青素减少胆固醇胞内蓄积部分可能是通过上调ABCA1的表达实现的。

Aim To investigate the effects of high glucose on cholesterol metabolism in renal tubular cells and the intervention of the anthocyanins. Methods HK-2 cells were grown in the DMEM medium supplemented with 10% FBS and were divided into 5 groups:normal glucose group,high glucose group,mannitol group,C3 G group and Cy group. Effect of anthocyanins on cell viability was detected with MTT,and cholesterol accumulation was detected with Amplex Red Cholesterol Assay kit and Filipin staining. Expression of ABCA1 was detected with RT-q PCR and Western Blot. Results In compared with control groups,HG significantly promoted cholesterol mass inside the cell and decreased the cholesterol concentration in the medium after treatment for 24 h or 48 h. The levels of mRNA and protein of ABCA1 were detected with RTq PCR and Western blot,and both were decreased in the presence of HG. Whereas treatment with C3 G and Cy markedly attenuated HG-induced cholesterol mass inside the cell by up-regulating the expression of ABCA1. Conclusions High glucose can reduce the expressions of the ABCA1,and then decrease cholesterol efflux and increase the cholesterol accumulation in HK-2 cells. Anthocyanins can decrease cholesterol accumulation by up-regulating the expression of ABCA1.