Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2007-9-17
pubmed:abstractText
Hepcidin is an antimicrobial peptide produced by the liver in response to inflammatory stimuli and iron overload. Hepcidin regulates iron homeostasis by mediating the degradation of the iron export protein ferroportin 1, thereby inhibiting iron absorption from the small intestine and release of iron from macrophages. Here, we examined the expression of hepcidin in macrophages infected with the intracellular pathogens Mycobacterium avium and Mycobacterium tuberculosis. Stimulation of the mouse RAW264.7 macrophage cell line and mouse bone marrow-derived macrophages with mycobacteria and IFN-gamma synergistically induced high levels of hepcidin mRNA and protein. Similar results were obtained using the human THP-1 monocytic cell line. Stimulation of macrophages with the inflammatory cytokines IL-6 and IL-beta did not induce hepcidin mRNA expression. Iron loading inhibited hepcidin mRNA expression induced by IFN-gamma and M. avium, and iron chelation increased hepcidin mRNA expression. Intracellular protein levels and secretion of hepcidin were determined by a competitive chemiluminescence ELISA. Stimulation of RAW264.7 cells with IFN-gamma and M. tuberculosis induced intracellular expression and secretion of hepcidin. Furthermore, confocal microscopy analyses showed that hepcidin localized to the mycobacteria-containing phagosomes. As hepcidin has been shown to possess direct antimicrobial activity, we investigated its activity against M. tuberculosis. We found that hepcidin inhibited M. tuberculosis growth in vitro and caused structural damage to the mycobacteria. In summary, our data show for the first time that hepcidin localizes to the phagosome of infected, IFN-gamma-activated cells and has antimycobacterial activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0741-5400
pubmed:author
pubmed:issnType
Print
pubmed:volume
82
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
934-45
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:17609338-Animals, pubmed-meshheading:17609338-Antimicrobial Cationic Peptides, pubmed-meshheading:17609338-Cell Line, pubmed-meshheading:17609338-Gene Expression Regulation, pubmed-meshheading:17609338-Homeostasis, pubmed-meshheading:17609338-Humans, pubmed-meshheading:17609338-Immunity, Innate, pubmed-meshheading:17609338-Interferon-gamma, pubmed-meshheading:17609338-Intestinal Absorption, pubmed-meshheading:17609338-Iron, pubmed-meshheading:17609338-Iron Chelating Agents, pubmed-meshheading:17609338-Iron Overload, pubmed-meshheading:17609338-Liver, pubmed-meshheading:17609338-Mice, pubmed-meshheading:17609338-Mycobacterium avium, pubmed-meshheading:17609338-Mycobacterium tuberculosis, pubmed-meshheading:17609338-Phagosomes, pubmed-meshheading:17609338-RNA, Messenger, pubmed-meshheading:17609338-Tuberculosis
pubmed:year
2007
pubmed:articleTitle
Expression and localization of hepcidin in macrophages: a role in host defense against tuberculosis.
pubmed:affiliation
Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural