钠依赖二羧酸转运蛋白3和葡萄糖对肾小管上皮细胞琥珀酸转运的影响

目的　探讨钠离子依赖的二羧酸转运蛋白 3(NaDC3)对细胞能量代谢的作用以及NaDC3不同表达和不同葡萄糖浓度对肾小管上皮细胞琥珀酸转运的影响。方法　应用Westernblot明确正义转染、反义转染、空质粒转染 (pcDNA3)及未转染的人近曲肾小管上皮细胞 (HKC)中细胞hNaDC3蛋白表达的差异 ,用毛细管电泳技术测定不同时间点或同一时间不同葡萄糖浓度时细胞摄取缓冲液中琥珀酸的量。结果　正义转染细胞hNaDC3蛋白表达增强 ,约是未转染HKC细胞的 1 5倍 ,缓冲液中琥珀酸含量下降较快 ,琥珀酸摄取增快。反义转染细胞hNaDC3蛋白表达下降 ,约是未转染HKC细胞的 2 / 3,但两者缓冲液中琥珀酸含量下降差异无统计学意义 (P >0 0 5 )。空质粒转染对hNaDC3蛋白表达和琥珀酸摄取无明显影响。随葡萄糖浓度增加 ,缓冲液中琥珀酸含量下降增快。结论　hNaDC3蛋白过表达可加速三羧酸循环中间代谢产物的转运 ,葡萄糖对hNaDC3底物的转运有促进作用

The effects of human Na+-dependent high-affinity dicarboxylate cotransporter 3 and glucose on the transport of succinate in human proximal tubular epithelial cells

Objective To investigate the effects of Na +-dependent high-affinity dicarboxylate cotransporter 3(NaDC3) and glucose on the transport of succinate in human proximal tubular epithelial cells (HKC) . Methods Western blot was used to detect the expression of hNaDC3 protein in the pcDNA3-hNaDC3, pcDNA3-AhNaDC3 and pcDNA3, transfected HKC, and normal HKC cell. Analysis of succinate contents in the intaking-buffer at the various time points and in the variouse concentrations of glucose were determined by capillary zone electrophoresis. Results The cell transfected with pcDNA3- hNaDC3 was found to have over-expression of hNaDC3 protein for about 1.5 times that of the normal HKC, while succinate content in intaking-buffer was decreased. Although the cells transfected with pcDNA3-AhNaDC3 showed lower expression of hNaDC3 protein, being about 0.6 times that of normal HKC cells, the decrease of succinate in intaking buffer was not obviously effected. There were no differences in hNaDC3 protein content and succinate intaking between the cells transfected with pcDNA3 and normal HKC cells. With the increase in glucose concentration, the decrease of succinate in intaking-buffer was accelerated. Conlusion The results suggested that the overexpression of hNaDC3 protein can cause the succinate-intake more quickly in HKC.