高糖对人肾系膜细胞GSH-PX和PDGF-B表达影响及茶多酚干预作用

Effect of tea polyphenols on high glucose-induced expression of GSH-PX and PDGF-B in human mesangial cells

目的探讨高糖条件下系膜细胞氧化失衡与血小板源性生长因子B(PDGFB)表达之间的关系,通过抗氧化剂茶多酚证实氧化应激在早期糖尿病中的作用。方法将培养的系膜细胞分为正常对照组、高糖组、茶多酚对照组和茶多酚干预组,分别在0、12、24、36、48h采用分光光度法检测上清液还原型谷胱甘肽过氧化物酶(GSHPX)活性,以及免疫细胞化学法和RTPCR法检测0、12、36h的PDGFBmRNA和蛋白的表达情况。结果①高糖条件下GSHPX活性下降,抗氧化能力下降,氧化失平衡;茶多酚可增加抗氧化酶GSHPX的活性。②高糖组系膜细胞PDGFBmRNA和蛋白的表达比正常对照组均增加(P<0.05);茶多酚干预组比高糖组有明显下降(P<0.05)。结论高糖能促进系膜细胞活性氧和PDGFB的表达增加,茶多酚可抑制该作用。

Purpose To explore the effects of high ambient glucose concentrati6n on the expression of PDGF-B in human mesangial cells and the intervention of tea polyphenols （TPs）. Methods The mesangial cells were cultured in the high glucose media with or without TPs for 0, 12, 24, 36, 48 hours, respectively. The activities of GSH-PX in the supernatants were detected by spectrophotometry. The mRNA and protein expression of PDGF was measured by RT-PCR and immunocytochemistry. Results ① High glucose attenuated the activity of GSH-PX in the cells, and TPs were able to enhance the activity of GSH-PX. ② The mRNA and protein expression of PDGF-B of the cells increased remarkably in high glucose medium （ P〈0.05 ）. However, TPs inhibited the expression （ P〈0.05 ）. Conclusions The ability of antioxidation of the cells declines and the balance of oxidantion/antioxidantion is destroyed under the condition of high glucose. High ambient glucose concentration contributes to an increasing of PDGF-B produced by human mesangial cells. TPs could reverse the effect of high glucose on the mesangial cells.