Decreased expression of the vitamin C transporter SVCT1 by ascorbic acid in a human intestinal epithelial cell line
Decreased expression of the vitamin C transporter SVCT1 by ascorbic acid in a human intestinal epithelial cell line
复制标题
DOI：
10.1079/bjn2001492
复制
发表时间：
2002-02-01
影响因子：
3.6
通讯作者：
Sharp, P
中科院分区：
文献类型：
--
作者：
MacDonald, L;Thumser, AE;Sharp, P
维生素C（抗坏血酸）是一种必需的营养素，参与许多细胞过程。然而，与大多数哺乳动物不同，人类无法合成维生素C，因此必须从饮食中获得。维生素C的吸收是通过最近从大鼠和人类肾脏中克隆的两种转运蛋白SVCT 1和SVCT 2实现的。SVCT 1被认为是肠道中的主要转运蛋白。维生素C补充剂越来越普遍，从而导致饮食负荷增加，因此本研究的目的是研究高剂量抗坏血酸对SVCT 1表达的影响。使用小肠肠细胞的Caco-2 TC 7细胞模型，我们测量了抗坏血酸（4.5 mg/ml培养基）对L-[C-14]抗坏血酸摄入和SVCT 1表达的影响（通过逆转录-聚合酶链反应测定）。Caco-2 TC 7细胞经抗坏血酸处理24 h后，其抗坏血酸摄取量显著下降（-50%，P
Vitamin C (ascorbic acid) is an essential nutrient that is involved in a number of cellular processes. However, unlike most mammals, man is unable to synthesize vitamin C and it must therefore be acquired from the diet. Absorption of vitamin C is achieved by two transporters, SVCT1 and SVCT2, recently cloned from rat and human kidney. SVCT1 is thought to be the predominant transporter in the intestine. Vitamin C supplements are increasingly common, thus contributing to an increased dietary load, and therefore the aim of the present study was to investigate the effect of high doses of ascorbic acid on SVCT1 expression. Using the Caco-2 TC7 cell model of small intestinal enterocytes, we measured the effects of ascorbic acid (4.5 mg/ml culture medium) on L-[C-14]ascorbic acid uptake and SVCT1 expression (determined by reverse transcription-polymerase chain reaction). Ascorbic acid uptake was decreased significantly in Caco-2 TC7 cells exposed to ascorbate for 24 h (- 50 %, P