高糖对肾小管上皮细胞脂质代谢影响及罗格列酮的干预研究

EFFECT OF HIGH GLUCOSE ON LIPID METABOLISM IN RENAL TUBULAR CELL AND THE INTERVEN TION OF ROSIGLITAZONE

目的探讨高糖环境中肾小管上皮细胞脂质代谢变化,以及罗格列酮对其干预作用。方法体外培养HKC细胞,随机分为正常糖组、高糖组、罗格列酮干预组,采用油红染色检测细胞内脂质,免疫细胞化学和WesternBlot检测固醇调节元件结合蛋白1(sterolregulatory element binding protein-1,SREBP-1)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明显脂滴;免疫细胞化学、WesternBlot检测发现固醇调节元件结合蛋白1表达于胞浆,12、24、48、72h固醇调节元件结合蛋白1前体和成熟体表达高糖组均高于正常对照组,差异有统计学意义,其中以48h表达量最大(前体2.334±0.045,成熟体1.082±0.040),罗格列酮组相对于高糖组,前体和成熟体表达均下降,脂滴形成有所减少。结论高糖可诱导肾小管上皮细胞固醇调节元件结合蛋白1前体和成熟体表达升高,进一步导致脂质合成增多;罗格列酮减少脂质合成可能是部分通过抑制固醇调节元件结合蛋白1表达而实现。

Objective To investigate the effect of high glucose on lipid metabolism in renal tubular cells and the intervention of the rosiglitazone （RGZ） Methods The RTCS were grown in the DMEM medium supplemented with 10% FCS and were divided into 3 groups： normal glucose group, high glucose group, RGZ group. Lipid accumulation was detected with oil-red O, and the expression of sterol regulatory element binding protein-1 （SREBP-1） was detected with immunohistochemistry and Western Blot. Results Oil-red O-positive lipid droplets appeared in the cells with high glucose. Furthermore, immunohistochemistry showed that high glucose also induced the increasing expression of SREBP-1, and RGZ could inhibit it. The precursor and mature segments of SREBP-1 were detected with Western blot, and both of them were increasing with the presence of high glucose. RGZ intervention decreased the expressions of precursor and mature segments of SREBP-1. Conclusion The observations suggested that high glucose can induce the expressions of the precursor and mature segments of SREBP-1 and lipid synthesis in RTCS which may contribute to the pathogenesis of diabetic nephropathy. RGZ can lessened the lipid accumulation in RTCS through the inhibition of SREBP-1.