Hepcidin inhibits apical iron uptake in intestinal cells

Am J Physiol Gastrointest Liver Physiol. 2008 Jan;294(1):G192-8. doi: 10.1152/ajpgi.00122.2007. Epub 2007 Oct 25.

Abstract

Hepcidin (Hepc) is considered a key mediator in iron trafficking. Although the mechanism of Hepc action in macrophages is fairly well established, much less is known about its action in intestinal cells, one of the main targets of Hepc. The current study investigated the effects of physiologically generated Hepc on iron transport in Caco-2 cell monolayers and rat duodenal segments compared with the effects on the J774 macrophage cell line. Addition of Hepc to Caco-2 cells or rat duodenal segments strongly inhibited apical (55)Fe uptake without apparent effects on the transfer of (55)Fe from the cells to the basolateral medium. Concurrently, the levels of divalent metal transporter 1 (DMT1) mRNA and protein in Caco-2 cells decreased while the mRNA and protein levels of the iron export transporter ferroportin did not change. Plasma membrane localization of ferroportin was studied by selective biotinylation of apical and basolateral membrane domains; Hepc induced rapid internalization of ferroportin in J774 cells but not in Caco-2 cells These results indicate that the effect of Hepc is cell dependent: in macrophages it inhibits iron export by inducing ferroportin degradation, whereas in enterocytes it inhibits apical iron uptake by inhibiting DMT1 transcription. Our results highlight the crucial role of Hepc in the control of intestinal iron absorption.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimicrobial Cationic Peptides / genetics
  • Antimicrobial Cationic Peptides / metabolism*
  • Caco-2 Cells
  • Cation Transport Proteins / genetics
  • Cation Transport Proteins / metabolism
  • Cell Membrane / metabolism
  • Culture Media, Conditioned / metabolism
  • Duodenum / metabolism*
  • Enterocytes / metabolism*
  • Hepcidins
  • Humans
  • Intestinal Absorption*
  • Iron / metabolism*
  • Iron Radioisotopes
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism*
  • Macrophages / metabolism*
  • Male
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Inbred F344
  • Time Factors
  • Transcription, Genetic
  • Transfection

Substances

  • Antimicrobial Cationic Peptides
  • Cation Transport Proteins
  • Culture Media, Conditioned
  • HAMP protein, human
  • Hamp protein, rat
  • Hepcidins
  • Iron Radioisotopes
  • RNA, Messenger
  • metal transporting protein 1
  • solute carrier family 11- (proton-coupled divalent metal ion transporters), member 2
  • Iron