, Volume 35, Issue 4, pp 1500–1506 | Cite as

Bacterial Cell Wall Constituents Induce Hepcidin Expression in Macrophages Through MyD88 Signaling



Hepcidin is a key regulator of iron recycling by macrophages that is synthesized mainly by hepatocytes but also by macrophages. However, very little is known about the molecular regulation of hepcidin in macrophages. In the present study, we investigated hepcidin regulation in the RAW264.7 macrophage cell line and in murine peritoneal macrophages stimulated with different Toll-like receptor (TLR) ligands. We found that TLR-2 and TLR-4 ligands activated hepcidin expression in RAW264.7 cells and in wild-type murine peritoneal macrophages, but not in murine peritoneal macrophages isolated from TLR2−/−, TLR-4-deficient or MyD88−/− mice. IL-6 production by RAW264.7 cells stimulated with lipopolysaccharide (LPS, TLR4 ligand) was enhanced by high amounts of iron present in the culture medium. We conclude that hepcidin expression in macrophages is regulated mainly through TLR2 and TLR4 receptors via the MyD88-dependent signaling pathway and that autocrine regulation of iron accumulation in macrophages by hepcidin may affect the levels of proinflammatory cytokine production.


hepcidin iron macrophages inflammation TLR MyD88 hypoferremia 



We acknowledge the help of Dr. Peter P. Liu from the Heart and Stroke/Richard Lewar Centre of Excellence, University of Toronto, Canada with the MyD88−/− mouse. This work was supported by a grant from the Canadian Institutes of Health Research (CIHR, grant no. MOP44045). AL is the recipient of a Ph.D. scholarship from the Natural Sciences and Engineering Research Council of Canada (NSERC). MMS is the recipient of a research scholarship (Senior) from the FRSQ (Fonds de la recherche en santé du Québec).


AL designed and performed experiments, collected, and analyzed the data, and wrote the manuscript; and MMS designed the experiments, analyzed the data, and critically reviewed the manuscript.

Conflict of interest

The authors declare no competing financial interests.


  1. 1.
    Schaible, U.E., and S.H.E. Kaufmann. 2004. Iron and microbial infection. Nat Rev Micro 2: 946–953.CrossRefGoogle Scholar
  2. 2.
    T. Nevitt, War-Fe-re: iron at the core of fungal virulence and host immunity. Biometals 24: 547-58.Google Scholar
  3. 3.
    Collins, H.L. 2008. Withholding iron as a cellular defence mechanism—friend or foe? European Journal of Immunology 38: 1803–6.PubMedCrossRefGoogle Scholar
  4. 4.
    Ganz, T., and E. Nemeth. 2009. Iron sequestration and anemia of inflammation. Sem Hemat 46: 387–393.CrossRefGoogle Scholar
  5. 5.
    Ganz, T. 2005. Hepcidin—a regulator of intestinal iron absorption and iron recycling by macrophages. Best Practice & Research. Clinical Haematology 18: 171–82.CrossRefGoogle Scholar
  6. 6.
    Nemeth, E., M.S. Tuttle, J. Powelson, M.B. Vaughn, A. Donovan, D.M. Ward, T. Ganz, and J. Kaplan. 2004. Hepcidin regulates cellular iron efflux by binding to ferroportin and inducing its internalization. Science 306: 2090–3.PubMedCrossRefGoogle Scholar
  7. 7.
    Constante, M., W. Jiang, D. Wang, V.-A. Raymond, M. Bilodeau, and M.M. Santos. 2006. Distinct requirements for Hfe in basal and induced hepcidin levels in iron overload and inflammation. American Journal of Physiology. Gastrointestinal and Liver Physiology 291: G229–237.PubMedCrossRefGoogle Scholar
  8. 8.
    Nicolas, G., C. Chauvet, L. Viatte, J.L. Danan, X. Bigard, I. Devaux, C. Beaumont, A. Kahn, and S. Vaulont. 2002. The gene encoding the iron regulatory peptide hepcidin is regulated by anemia, hypoxia, and inflammation. The Journal of Clinical Investigation 110: 1037–44.PubMedGoogle Scholar
  9. 9.
    Weiss, G., and L.T. Goodnough. 2005. Anemia of chronic disease. The New England Journal of Medicine 352: 1011–1023.PubMedCrossRefGoogle Scholar
  10. 10.
    Nguyen, N.B., K.D. Callaghan, A.J. Ghio, D.J. Haile, and F. Yang. 2006. Hepcidin expression and iron transport in alveolar macrophages. American Journal of Physiology. Lung Cellular and Molecular Physiology 291: L417–L425.PubMedCrossRefGoogle Scholar
  11. 11.
    Sow, F.B., W.C. Florence, A.R. Satoskar, L.S. Schlesinger, B.S. Zwilling, and W.P. Lafuse. 2007. Expression and localization of hepcidin in macrophages: a role in host defense against tuberculosis. Journal of Leukocyte Biology 82: 934–45.PubMedCrossRefGoogle Scholar
  12. 12.
    Theurl, I., M. Theurl, M. Seifert, S. Mair, M. Nairz, H. Rumpold, H. Zoller, R. Bellmann-Weiler, H. Niederegger, H. Talasz, and G. Weiss. 2008. Autocrine formation of hepcidin induces iron retention in human monocytes. Blood 111: 2392–2399.PubMedCrossRefGoogle Scholar
  13. 13.
    Kumar, H., T. Kawai, and S. Akira. 2011. Pathogen recognition by the innate immune system. International Reviews of Immunology 30: 16–34.PubMedCrossRefGoogle Scholar
  14. 14.
    Akira, S., S. Uematsu, and O. Takeuchi. 2006. Pathogen recognition and innate immunity. Cell 124: 783–801.PubMedCrossRefGoogle Scholar
  15. 15.
    Lee, P., H. Peng, T. Gelbart, L. Wang, and E. Beutler. 2005. Regulation of hepcidin transcription by interleukin-1 and interleukin-6. Proc Natl Acad Sci USA 102: 1906–10.PubMedCrossRefGoogle Scholar
  16. 16.
    Akira, S., K. Hoshino, and T. Kaisho. 2000. The role of Toll-like receptors and MyD88 in innate immune responses. Journal of Endotoxin Research 6: 383–7.PubMedGoogle Scholar
  17. 17.
    Miranda, C.J., H. Makui, N.C. Andrews, and M.M. Santos. 2004. Contributions of beta2-microglobulin-dependent molecules and lymphocytes to iron regulation: insights from HfeRag1(−/−) and beta2mRag1(−/−) double knock-out mice. Blood 103: 2847–9.PubMedCrossRefGoogle Scholar
  18. 18.
    Yu, Y., and D.R. Richardson. 2011. Cellular iron depletion stimulates the JNK and p38 MAPK signaling transduction pathways, dissociation of ASK1-thioredoxin, and activation of ASK1. Journal of Biological Chemistry 286: 15413–15427.PubMedCrossRefGoogle Scholar
  19. 19.
    Coppola, G., S.-H. Choi, M.M. Santos, C.J. Miranda, D. Tentler, E.M. Wexler, M. Pandolfo, and D.H. Geschwind. 2006. Gene expression profiling in frataxin deficient mice: microarray evidence for significant expression changes without detectable neurodegeneration. Neurobiology of Disease 22: 302–311.PubMedCrossRefGoogle Scholar
  20. 20.
    Jiang, W., M. Constante, and M.M. Santos. 2008. Anemia upregulates lipocalin 2 in the liver and serum. Blood Cells, Molecules & Diseases 41: 169–174.CrossRefGoogle Scholar
  21. 21.
    Constante, M., D. Wang, V.A. Raymond, M. Bilodeau, and M.M. Santos. 2007. Repression of repulsive guidance molecule C during inflammation is independent of Hfe and involves tumor necrosis factor-alpha. American Journal of Pathology 170: 497–504.PubMedCrossRefGoogle Scholar
  22. 22.
    Nhu, Q.M., N. Cuesta, and S.N. Vogel. 2006. Transcriptional regulation of lipopolysaccharide (LPS)-induced Toll-like receptor (TLR) expression in murine macrophages: role of interferon regulatory factors 1 (IRF-1) and 2 (IRF-2). Journal of Endotoxin Research 12: 285–295.PubMedGoogle Scholar
  23. 23.
    Qureshi, S.T., L. Larivière, G. Leveque, S. Clermont, K.J. Moore, P. Gros, and D. Malo. 1999. Endotoxin-tolerant mice have mutations in toll-like receptor 4 (Tlr4). The Journal of Experimental Medicine 189: 615–625.PubMedCrossRefGoogle Scholar
  24. 24.
    Poltorak, A., X. He, I. Smirnova, M.-Y. Liu, C.V. Huffel, X. Du, D. Birdwell, E. Alejos, M. Silva, C. Galanos, M. Freudenberg, P. Ricciardi-Castagnoli, B. Layton, and B. Beutler. 1998. Defective LPS signaling in C3H/HeJ and C57BL/10ScCr mice: mutations in Tlr4 gene. Science 282: 2085–2088.PubMedCrossRefGoogle Scholar
  25. 25.
    Nemeth, E., S. Rivera, V. Gabayan, C. Keller, S. Taudorf, B.K. Pedersen, and T. Ganz. 2004. IL-6 mediates hypoferremia of inflammation by inducing the synthesis of the iron regulatory hormone hepcidin. The Journal of Clinical Investigation 113: 1271–6.PubMedGoogle Scholar
  26. 26.
    Peyssonnaux, C., A.S. Zinkernagel, V. Datta, X. Lauth, R.S. Johnson, and V. Nizet. 2006. TLR4-dependent hepcidin expression by myeloid cells in response to bacterial pathogens. Blood 107: 3727–32.PubMedCrossRefGoogle Scholar
  27. 27.
    Nemeth, E., E.V. Valore, M. Territo, G. Schiller, A. Lichtenstein, and T. Ganz. 2003. Hepcidin, a putative mediator of anemia of inflammation, is a type II acute-phase protein. Blood 101: 2461–3.PubMedCrossRefGoogle Scholar
  28. 28.
    Lee, P., H. Peng, T. Gelbart, and E. Beutler. 2004. The IL-6- and lipopolysaccharide-induced transcription of hepcidin in HFE-, transferrin receptor 2-, and beta 2-microglobulin-deficient hepatocytes. Proc Natl Acad Sci USA 101: 9263–5.PubMedCrossRefGoogle Scholar
  29. 29.
    Chaston, T., B. Chung, M. Mascarenhas, J. Marks, B. Patel, S.K. Srai, and P. Sharp. 2008. Evidence for differential effects of hepcidin in macrophages and intestinal epithelial cells. Gut 57: 374–382.PubMedCrossRefGoogle Scholar
  30. 30.
    Krause, A., S. Neitz, H.-J. Magert, A. Schulz, W.-G. Forssmann, P. Schulz-Knappe, and K. Adermann. 2000. LEAP-1, a novel highly disulfide-bonded human peptide, exhibits antimicrobial activity. FEBS Letters 480: 147–150.PubMedCrossRefGoogle Scholar
  31. 31.
    Barthe, C., A. Hocquellet, and B. Garbay. 2011. Bacteriostatic activity of the proregion of human hepcidin. Protein and Peptide Letters 18: 36–40.PubMedCrossRefGoogle Scholar
  32. 32.
    Levy, J.E., L.K. Montross, and N.C. Andrews. 2000. Genes that modify the hemochromatosis phenotype in mice. The Journal of Clinical Investigation 105: 1209–16.PubMedCrossRefGoogle Scholar
  33. 33.
    Allen, K.J., L.C. Gurrin, C.C. Constantine, N.J. Osborne, M.B. Delatycki, A.J. Nicoll, C.E. McLaren, M. Bahlo, A.E. Nisselle, C.D. Vulpe, G.J. Anderson, M.C. Southey, G.G. Giles, D.R. English, J.L. Hopper, J.K. Olynyk, L.W. Powell, and D.M. Gertig. 2008. Iron-overload-related disease in HFE hereditary hemochromatosis. The New England Journal of Medicine 358: 221–230.PubMedCrossRefGoogle Scholar
  34. 34.
    Wang, L., L. Harrington, E. Trebicka, H.N. Shi, J.C. Kagan, C.C. Hong, H.Y. Lin, J.L. Babitt, and B.J. Cherayil. 2009. Selective modulation of TLR4-activated inflammatory responses by altered iron homeostasis in mice. The Journal of Clinical Investigation 119: 3322–8.PubMedGoogle Scholar
  35. 35.
    Wang, L., E.E. Johnson, H.N. Shi, W.A. Walker, M. Wessling-Resnick, and B.J. Cherayil. 2008. Attenuated inflammatory responses in hemochromatosis reveal a role for iron in the regulation of macrophage cytokine translation. Journal of Immunology 181: 2723–2731.Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  1. 1.Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM)Hôpital Notre-DameMontréalCanada
  2. 2.Institut du cancer de MontréalMontrealCanada
  3. 3.Département de MédecineUniversité de MontréalMontréalCanada
  4. 4.Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM)MontréalCanada

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