Inhibitory effect of calcium on non-heme iron absorption may be related to translocation of DMT-1 at the apical membrane of enterocytes

Ben A V Thompson, Paul A Sharp, Ruan Elliott, Susan J Fairweather-Tait

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Many studies show that calcium reduces iron absorption from single meals, but the underlying mechanism is not known. We tested the hypothesis that calcium alters the expression and/or functionality of iron transport proteins. Differentiated Caco-2 cells were treated with ferric ammonium citrate and calcium chloride, and ferritin, DMT-1, and ferroportin were quantified in whole-cell lysate and cell-membrane fractions. Calcium attenuated the iron-induced increase in cell ferritin levels in a dose-dependent manner; a significant decrease was seen at calcium concentrations of 1.25 and 2.5 mM but was only evident after a 16-24 h incubation period. Calcium and iron treatments decreased DMT-1 protein in Caco-2 cell membranes, although total DMT-1 in whole cell lysates was unchanged by either iron or calcium. No change was seen in ferroportin expression. Our data suggest that calcium reduces iron bioavailability by decreasing DMT-1 expression at the apical cell membrane, thereby downregulating iron transport into the cell.
Original languageEnglish
Pages (from-to)8414-8417
Number of pages4
JournalJournal of Agricultural and Food Chemistry
Volume58
Issue number14
DOIs
Publication statusPublished - 28 Jul 2010

Keywords

  • Biological Transport
  • Caco-2 Cells
  • Calcium
  • Cation Transport Proteins
  • Cell Membrane
  • Down-Regulation
  • Enterocytes
  • Humans
  • Intestinal Absorption
  • Iron
  • Protein Transport

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