Acquisition of dietary copper: a role for anion transporters in intestinal apical copper uptake.
Acquisition of dietary copper: a role for anion transporters in intestinal apical copper uptake.
复制标题
膳食铜的获取：阴离子转运蛋白在肠道顶端铜吸收中的作用。
DOI：
10.1152/ajpcell.00054.2010
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Kaplan,JackH
中科院分区：
文献类型：
--
作者：
Zimnicka,AdrianaM;Ivy,Kristin;Kaplan,JackH
Copper is an essential micronutrient in humans and is required for a wide range of physiological processes, including neurotransmitter biosynthesis, oxidative metabolism, protection against reactive oxygen species, and angiogenesis. The first step in the acquisition of dietary copper is absorption from the intestinal lumen. The major human high-affinity copper uptake protein, human copper transporter hCTR1, was recently shown to be at the basolateral or blood side of both intestinal and renal epithelial cell lines and thus does not play a direct role in this initial step. We sought to functionally identify the major transport pathways available for the absorption of dietary copper across the apical intestinal membrane using Caco2 cells, a well-established model for human enterocytes. The initial rate of apical copper uptake into confluent monolayers of Caco2 cells is greatly elevated if amino acids and serum proteins are removed from the growth media. Uptake from buffered saline solutions at neutral pH (but not at lower pH) is inhibited by eitherd- orl-histidine, unaltered by the removal of sodium ions, and inhibited by ∼90% when chloride ions are replaced by gluconate or sulfate. Chloride-dependent copper uptake occurs with Cu(II) or Cu(I), although Cu(I) uptake is not inhibited by histidine, nor by silver ions. A well-characterized inhibitor of anion exchange systems, DIDS, inhibited apical copper uptake by 60–70%, while the addition of Mn(II) or Fe(II), competitive substrates for the divalent metal transporter DMT1, had no effect on copper uptake. We propose that anion exchangers play an unexpected role in copper absorption, utilizing copper-chloride complexes as pseudo-substrates. This pathway is also observed in mouse embryonic fibroblasts, human embryonic kidney cells, and Cos-7 cells. The special environment of low pH, low concentration of protein, and protonation of amino acids in the early intestinal lumen make this pathway especially important in dietary copper acquisition.
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DOI：
10.1152/ajpgi.00236.2003
发表时间：
2003-12
期刊：
American journal of physiology. Gastrointestinal and liver physiology
影响因子：
--
作者：
Jie Xu;Sharon L. Barone;S. Petrovic;Zhaohui Wang;U. Seidler;B. Riederer;K. Ramaswamy;P. Dudeja;G. Shull;M. Soleimani
通讯作者：
Jie Xu;Sharon L. Barone;S. Petrovic;Zhaohui Wang;U. Seidler;B. Riederer;K. Ramaswamy;P. Dudeja;G. Shull;M. Soleimani
大鼠十二指肠顶膜囊泡中的 Cl-HCO3 交换和阴离子电导。
DOI：
10.1152/ajpgi.1989.257.4.g661
发表时间：
1989
期刊：
The American journal of physiology
影响因子：
--
作者：
C. Brown;C. Dunk;L. Turnberg
通讯作者：
L. Turnberg
穿过人类红细胞膜的锌摄取的阴离子机制。
DOI：
--
发表时间：
1990
期刊：
Journal of Physiology
影响因子：
--
作者：
V. Kalfakakou;T. Simons
通讯作者：
T. Simons
DOI：
10.1152/ajpgi.00338.2001
发表时间：
2002-03-01
影响因子：
4.5
作者：
Wang, ZH;Petrovic, S;Soleimani, M
通讯作者：
Soleimani, M
人红细胞中通过阴离子交换剂吸收氯化物（或碳酸氢盐）依赖性铜。
DOI：
10.1152/ajpcell.1990.259.4.c570
发表时间：
1990
期刊：
The American journal of physiology
影响因子：
--
作者：
J. Alda;R. Garay
通讯作者：
R. Garay