Regulation of iron uptake in primary culture rat hepatocytes: the role of acute-phase cytokines

Shock. 2014 Apr;41(4):337-45. doi: 10.1097/SHK.0000000000000107.


Decreased serum and increased hepatic iron uptake is the hallmark of acute-phase (AP) response. Iron uptake is controlled by iron transport proteins such as transferrin receptors (TfRs) and lipocalin 2 (LCN-2). The current study aimed to understand the regulation of iron uptake in primary culture hepatocytes in the presence/absence of AP mediators. Rat hepatocytes were stimulated with different concentrations of iron alone (0.01, 0.1, 0.5 mM) and AP cytokines (interleukin 6 [IL-6], IL-1β, tumor necrosis factor α) in the presence/absence of iron (FeCl3: 0.1 mM). Hepatocytes were harvested at different time points (0, 6, 12, 24 h). Total mRNA and proteins were extracted for reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. A significant iron uptake was detected with 0.1 mM iron administration with a maximum (133.37 ± 4.82 µg/g of protein) at 24 h compared with control and other iron concentrations. This uptake was further enhanced in the presence of AP cytokines with a maximum iron uptake (481 ± 25.81 µg/g of protein) after concomitant administration of IL-6 + iron to cultured hepatocytes. Concomitantly, gene expression of LCN-2 and ferritin subunits (light- and heavy-chain ferritin subunits) was upregulated by iron or/and AP cytokines with a maximum at 24 h both at mRNA and protein levels. In contrast, a decreased TfR1 level was detected by IL-6 and iron alone, whereas combination of iron and AP cytokines (mainly IL-6) abrogated the downregulation of TfR1. An increase in LCN-2 release into the supernatant of cultured hepatocytes was observed after addition of iron/AP cytokines into the medium. This increase in secretion was further enhanced by combination of IL-6 + iron. In conclusion, iron uptake is tightly controlled by already present iron concentration in the culture. This uptake can be further enhanced by AP cytokines, mainly by IL-6.

MeSH terms

  • Acute-Phase Reaction / metabolism*
  • Animals
  • Apoferritins / biosynthesis
  • Cells, Cultured
  • Cytokines / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Combinations
  • Hepatocytes / drug effects
  • Hepatocytes / metabolism*
  • Interleukin-6 / pharmacology
  • Iron / administration & dosage
  • Iron / pharmacokinetics*
  • Iron / pharmacology
  • L-Lactate Dehydrogenase / metabolism
  • Lipocalin-2
  • Lipocalins / metabolism
  • Male
  • RNA, Messenger / genetics
  • Rats
  • Rats, Wistar
  • Receptors, Transferrin / biosynthesis
  • Up-Regulation / drug effects


  • Cytokines
  • Drug Combinations
  • Interleukin-6
  • Lcn2 protein, rat
  • Lipocalin-2
  • Lipocalins
  • RNA, Messenger
  • Receptors, Transferrin
  • Tfrc protein, rat
  • Apoferritins
  • Iron
  • L-Lactate Dehydrogenase