Differential distribution of the Sodium-vitamin C cotransporter-1 along the proximal tubule of the mouse and human kidney
Differential distribution of the Sodium-vitamin C cotransporter-1 along the proximal tubule of the mouse and human kidney
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DOI：
10.1038/ki.2008.329
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发表时间：
2008-11-01
影响因子：
19.6
通讯作者：
Nualart, Francisco
中科院分区：
文献类型：
--
作者：
Castro, Tamara;Low, Marcela;Nualart, Francisco
维生素C通过钠-维生素C共转运蛋白的一种亚型从肾腔重吸收，该亚型介导高亲和力钠依赖性L-抗坏血酸转运。钠-维生素C协同转运蛋白-1 mRNA已在肠和肝以及肾近端小管的S3段中检测到。在此，我们发现它的分布更广泛，小鼠和人的所有三个近端小管段都表达转运蛋白，但S3段的表达最高。钠-维生素C协同转运蛋白-1的表达也被发现在肾上皮来源的LLC-PK 1细胞系。这些细胞中的抗坏血酸转运受单一动力学成分调节，该成分取决于钠浓度、pH值和温度。降低抗坏血酸浓度增加顶端表达的转运蛋白，这表明存在一个反馈系统，用于调节转运蛋白丰度在管腔膜。
Vitamin C is reabsorbed from the renal lumen by one isoform of sodium-vitamin C co-transporters that mediate high affinity sodium-dependent L-ascorbic acid transport. Sodium-vitamin C cotransporter-1 mRNA has been detected in intestine and liver and the S3 segment of the renal proximal tubule. Here, we found that its distribution was broader and all three proximal tubule segments of mouse and human expressed the transporter but the S3 segment had the highest expression. Sodium-vitamin C co-transporter-1 expression was also found in the renal epithelial-derived LLC-PK1 cell line. Ascorbic acid transport in these cells was regulated by a single kinetic component that depended on the sodium concentration, pH and temperature. Reducing ascorbate concentration increased the apical expression of the transporter suggesting the presence of a feedback system for regulation of transporter abundance at the luminal membrane.