| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Departamento de Biología, Facultad de Ciencias, 2 Millennium Institute for Advanced Studies in Cell Biology and Biotechnology, and 3 Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile
Despite important advances in the understanding of copper secretion and excretion, the molecular components of intestinal copper absorption remain a mystery. DMT1, also known as Nramp2 and DCT1, is the transporter responsible for intestinal iron uptake. Electrophysiological evidence suggests that DMT1 can also be a copper transporter. Thus we examined the potential role of DMT1 as a copper transporter in intestinal Caco-2 cells. Treatment of cells with a DMT1 antisense oligonucleotide resulted in 80 and 48% inhibition of iron and copper uptake, respectively. Cells incorporated considerable amounts of copper as Cu1+, whereas Cu2+ transport was about 10-fold lower. Cu1+ inhibited apical Fe2+ transport. Fe2+, but not Fe3+, effectively inhibited Cu1+ uptake. The iron content of the cells influenced both copper and iron uptake. Cells with low iron content transported fourfold more iron and threefold more copper than cells with high iron content. These results demonstrate that DMT1 is a physiologically relevant Cu1+ transporter in intestinal cells, indicating that intestinal absorption of copper and iron are intertwined.
Nramp2; iron; copper; absorption; metals; antisense
This article has been cited by other articles:
|
|
 |
|
  M. Gonzalez, A. Reyes-Jara, M. Suazo, W. J Jo, and C. Vulpe Expression of copper-related genes in response to copper load Am. J. Clinical Nutrition, September 1, 2008; 88(3): 830S - 834S. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Lonnerdal Intestinal regulation of copper homeostasis: a developmental perspective Am. J. Clinical Nutrition, September 1, 2008; 88(3): 846S - 850S. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Moriya, Y.-H. Ho, A. Grana, L. Nguyen, A. Alvarez, R. Jamil, M. L. Ackland, A. Michalczyk, P. Hamer, D. Ramos, et al. Copper is taken up efficiently from albumin and {alpha}2-macroglobulin by cultured human cells by more than one mechanism Am J Physiol Cell Physiol, September 1, 2008; 295(3): C708 - C721. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. D. San Martin, C. Garri, F. Pizarro, T. Walter, E. C. Theil, and M. T. Nunez Caco-2 Intestinal Epithelial Cells Absorb Soybean Ferritin by {micro}2 (AP2)-Dependent Endocytosis J. Nutr., April 1, 2008; 138(4): 659 - 666. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Lutsenko, N. L. Barnes, M. Y. Bartee, and O. Y. Dmitriev Function and Regulation of Human Copper-Transporting ATPases Physiol Rev, July 1, 2007; 87(3): 1011 - 1046. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Nyasae, R. Bustos, L. Braiterman, B. Eipper, and A. Hubbard Dynamics of endogenous ATP7A (Menkes protein) in intestinal epithelial cells: copper-dependent redistribution between two intracellular sites Am J Physiol Gastrointest Liver Physiol, April 1, 2007; 292(4): G1181 - G1194. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P Bressler, L. Olivi, J. H. Cheong, Y. Kim, A. Maerten, and D. Bannon Metal transporters in intestine and brain: their involvement in metal-associated neurotoxicities Human and Experimental Toxicology, March 1, 2007; 26(3): 221 - 229. [Abstract] [PDF]
|
|
|
|
|
|
M. Moriya and M. C. Linder Vesicular transport and apotransferrin in intestinal iron absorption, as shown in the Caco-2 cell model Am J Physiol Gastrointest Liver Physiol, February 1, 2006; 290(2): G301 - G309. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W.S. Chong, P.C. Kwan, L.Y. Chan, P.Y. Chiu, T.K. Cheung, and T.K. Lau Expression of divalent metal transporter 1 (DMT1) isoforms in first trimester human placenta and embryonic tissues Hum. Reprod., December 1, 2005; 20(12): 3532 - 3538. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. F. Collins, C. A. Franck, K. V. Kowdley, and F. K. Ghishan Identification of differentially expressed genes in response to dietary iron deprivation in rat duodenum Am J Physiol Gastrointest Liver Physiol, May 1, 2005; 288(5): G964 - G971. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. F. Eisses, Y. Chi, and J. H. Kaplan Stable Plasma Membrane Levels of hCTR1 Mediate Cellular Copper Uptake J. Biol. Chem., March 11, 2005; 280(10): 9635 - 9639. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Arredondo, V. Cambiazo, L. Tapia, M. Gonzalez-Aguero, M. T. Nunez, R. Uauy, and M. Gonzalez Copper overload affects copper and iron metabolism in Hep-G2 cells Am J Physiol Gastrointest Liver Physiol, July 1, 2004; 287(1): G27 - G32. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
