Duodenal HFE expression and hepcidin levels determine body iron homeostasis: modulation by genetic diversity and dietary iron availability

HFE affects the interaction of transferrin bound iron with transferrin receptors (TfR) thereby modulating iron uptake. To study genetically determined differences in HFE expression we examined individual HFE levels in C57BL/Sv129 mice and assessed their relationship to the regulation of iron homeostasis in the duodenum and the liver, and their regulation by diet. We found an up to 14-fold variation in inter-individual expression of HFE mRNA in the duodenum. Mice with high duodenal HFE mRNA expression presented with significantly higher levels of TfR and DMT-1 mRNAs and an increased IRP-1 binding affinity as compared to mice with low HFE levels. Duodenal HFE expression was positively associated with serum iron and liver HFE levels. Dietary iron supplementation decreased HFE in the duodenum but not in the liver. This was paralleled by reduced amounts of DMT-1 and FP-1 in the duodenum while the expression of DMT-1, FP-1, and hepcidin in the liver were increased with dietary iron overload. Duodenal and liver HFE levels are regulated by divergent penetration of as yet unelucidated modifier genes and to a much lesser extent by dietary iron. These measures control duodenal iron transport and liver iron homeostasis by modulating HFE expression either directly or via stimulation of iron sensitive regulatory molecules, such as hepcidin, which then exert their effects on body iron homeostasis.Susanne Ludwiczek and Igor Theurl contributed equally to the work     

Ferroportin-1 is a 'nuclear'-negative acute-phase protein in rat liver: a comparison with other iron-transport proteins

Liver is the central organ of iron metabolism. During acute-phase-response (APR), serum iron concentration rapidly decreases. The current study aimed to compare expression and localization of iron transport protein ferroportin-1 (Fpn-1) and of other iron import proteins after experimental tissue damage induced by injecting turpentine oil in the hind limbs of rats and mice. Serum and spleen iron concentration decreased with an increase in total liver, cytoplasmic and nuclear iron concentration. In liver, mRNA amount of Fpn-1, Fpn-1a, Fpn-1b, HFE, hemojuvelin (HJV) and hephaestin (heph) genes showed a rapid decrease. Hepcidin, divalent metal transporter-1 (DMT-1), transferrin (Tf) and Tf-receptor-1 (TfR1), TfR-2 (TfR2) gene expression was increased. Western blot analysis of liver tissue lysate confirmed the changes observed at mRNA level. In spleen, a rapid decrease in gene expression of Fpn-1, Fpn-1a, Fpn-1b, DMT-1, Tf, TfR1 and TfR2, and an increase in hepcidin was observed. Immunohistochemistry of DMT-1 and TfR2 were mainly detected in the nucleus of rat liver and spleen, whereas TfR1 was clearly localized in the plasma membrane. Fpn-1 was mostly found in the nuclei of liver cells, whereas in spleen, the protein was mainly detected in the cell membrane. Western blot analysis of liver fractions confirmed immunohistochemical results. In livers of wild-type mice, gene expression of Fpn-1, Fpn-1a and Fpn-1b was downregulated, whereas hepcidin gene expression was increased. In contrast, these changes were less pronounced in IL-6ko-mice. Cytokine (IL-6, IL-1b and TNF-a) treatment of rat hepatocytes showed a downregulation of Fpn-1, Fpn-1a and Fpn-1b, and upregulation of hepcidin gene expression. Moreover, western blot analysis of cell lysate of IL-6-treated hepatocytes detected, as expected, an increase of a2-macroglobulin (positive acute-phase protein), whereas albumin (negative acute-phase protein) and Fpn-1 were downregulated. Our results demonstrate that liver behaves as a 'sponge' for iron under acute-phase conditions, and Fpn-1 behaves as a negative acute-phase protein in rat hepatocytes mainly, but not exclusively, because of the effect of IL-6. These changes could explain iron retention in the cytoplasm and in the nucleus of hepatocytes during APR.     

Age-dependent and iron-independent expression of two mRNA isoforms of divalent metal transporter 1 in rat brain

The DMT1(Nramp2/DCT1) is a newly discovered proton-coupled metal-ion transport protein. The cellular localization and functional characterization of DMT1 suggest that it might play a role in physiological iron transport in the brain. In the study, we evaluated effects of dietary iron and age on iron content and DMT1 expression in four brain regions: cortex, hippocampus, striatum, substantia nigra. Total iron content in all regions was significantly lower in the low-iron diet rats and higher in the high-iron diet rats than that in the control animals, showing that dietary iron treatment for 6-weeks can alter brain iron levels. Contrary to our expectation, there was no significant alternation in DMT1(+IRE) and (-IRE) mRNA expression and protein content in all brain regions examined in spite of the existence of the altered iron levels in these regions after 6-weeks' diet treatment although TfR mRNA expression and protein level were affected significantly, as was expected. The data demonstrates that expression of DMT1(+IRE) and (-IRE) was not regulated by iron in these regions of adult rats. The lack of response of DMT1 to iron status in the brain suggests that the IRE of brain DMT1 mRNA might be not really iron-responsive and that DMT1-mediated iron transport might be not the rate-limiting step in brain iron uptake in adult rats. Our findings also showed that development can significantly affect brain iron and DMT1(+IRE) and (-IRE) expression but the effect varies in different brain regions, indicating a regionally specific regulation in the brain.     

脂多糖对小鼠铁代谢相关基因mRNA水平表达的影响

目的 探讨脂多糖（LPS）对小鼠肝脏和脾脏铁代谢相关基因mRNA水平表达的影响。 方法 10只2月龄雄性小鼠腹腔注射LPS（0.5 μg/g）, 6h后处死并取血液、肝脏和脾脏组织进行血常规测定,使用试剂盒检测血清铁和总铁结合力;使用半定量RT-PCR检测小鼠肝脏和脾脏铁代谢相关基因（HP）、膜铁转运蛋白１(Fpn1)和转铁蛋白受体1(TfR1)以及脾脏白细胞介素-6(IL-6)的mRNA变化。 结果 注射LPS 6h后可造成小鼠脾脏IL-6表达增加,肝脏HP表达增加（P ＜0.05）,肝脏和脾脏Fpn1表达减少,而肝脏TfR1表达亦减少,血清铁下降和适度贫血（Ｐ ＜0.05）。 结论 LPS可通过影响肝脏和脾脏铁相关基因HP、Fpn1和TfR1的mRNA表达而影响血清铁状态。     

高铁对大鼠大脑皮层二价金属转运蛋白1表达的影响

目的 探讨在脑铁代谢中发挥重要生理作用的二价金属转运蛋白1(DMT1)的表达及其调控机制.方法 大鼠(n=6)侧脑室注射右旋糖酐铁3d和7d后,采用铁组织化学法检测脑内铁含量的变化,免疫组织化学技术检测大脑皮层中DMT1的两种亚型,即DMT1(+IRE)和DMT1(-IRE)蛋白表达的变化.结果 铁组织化学染色结果显示,大鼠侧脑室注射右旋糖酐铁500μg/(只·d)7d后,大脑皮层中二价铁和三价铁均显著增高.同时,免疫组织化学结果表明,与对照组相比,脑内达高铁状态时大脑皮层DMT1(+IRE)蛋白表达显著升高,而DMT1(-IRE)蛋白表达无显著变化.结论 在大鼠大脑皮层中,DMT1(+IRE)蛋白对铁水平的升高更为敏感,其表达与脑铁水平(尤其是二价铁)呈正相关.高铁对脑内不同区域内不同亚型DMT1表达的影响存在特异性.     

CHOP‐mediated hepcidin suppression modulates hepatic iron load

The liver is the central regulator of iron metabolism and accordingly, chronic liver diseases often lead to systemic iron overload due to diminished expression of the iron‐regulatory hormone hepcidin. To study the largely unknown regulation of iron metabolism in the context of hepatic disease, we used two established models of chronic liver injury, ie repeated carbon tetrachloride (CCl₄) or thioacetamide (TAA) injections. To determine the impact of CCAAT/enhancer‐binding protein (C/EBP)‐homologous protein (CHOP) on hepcidin production, the effect of a single TAA injection was determined in wild‐type and CHOP knockout mice. Furthermore, CHOP and hepcidin expression was assessed in control subjects and patients with alcoholic liver disease. Both chronic injury models developed a distinct iron overload in macrophages. TAA‐, but not CCl₄‐ injected mice displayed additional iron accumulation in hepatocytes, resulting in a significant hepatic and systemic iron overload which was due to suppressed hepcidin levels. C/EBPα signalling, a known hepcidin inducer, was markedly inhibited in TAA mice, due to lower C/EBPα levels and overexpression of CHOP, a C/EBPα inhibitor. A single TAA injection resulted in a long‐lasting (> 6 days) suppression of hepcidin levels and CHOP knockouts (compared to wild‐types) displayed significantly attenuated hepcidin down‐regulation in response to acute TAA administration. CHOP mRNA levels increased 5‐fold in alcoholic liver disease patients versus controls (p < 0.005) and negatively correlated with hepcidin expression. Our results establish CHOP as an important regulator of hepatic hepcidin expression in chronic liver disease. The differences in iron metabolism between the two widely used fibrosis models likely reflect the differential regulation of hepcidin expression in human liver disease. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Expression and localization of hepcidin in macrophages: a role in host defense against tuberculosis

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.     

Kupffer cells modulate iron homeostasis in mice via regulation of hepcidin expression

Hepcidin, a small cationic liver derived peptide, is a master regulator of body iron homeostasis. Cytokines and iron availability have so far been identified as regulators of hepcidin expression. Herein, we investigated the functional role of Kupffer cells for hepcidin expression because of their vicinity to the hepatocytes and their importance for iron recycling via erythrophagocytosis. We investigated C57Bl6 mice and littermates, in which Kupffer cells were eliminated in vivo upon intravenous injection of liposome-encapsulated clodronate. Primary cultures of hepatocytes and Kupffer cells were used to study direct regulatory effects ex vivo. The in vivo depletion of Kupffer cells resulted in a significant increase in liver hepcidin expression, which was paralleled by a significant reduction in serum iron levels. The same pattern of regulation by Kupffer cell depletion was observed upon injection of bacterial lipopolysaccharide into mice and in primary (Hfe -/-) and in secondary iron-overloaded mice. Accordingly, the messenger ribonucleic acid (mRNA) concentrations of the hepcidin iron-sensing molecule hemojuvelin were not significantly changed upon Kupffer cell depletion. When primary hepatocytes were cocultivated with Kupffer cells or stimulated with a Kupffer cell-conditioned medium ex vivo, a significant reduction in hepatocyte hepcidin mRNA expression was observed. Our data suggest that Kupffer cells control body iron homeostasis by exerting negative regulatory signals toward hepcidin expression, which may be primarily referred to the secretion of yet unidentified hepcidin-suppressing molecules by Kupffer cells.     

Hepcidin knockout mice spontaneously develop chronic pancreatitis owing to cytoplasmic iron overload in acinar cells

Iron is both an essential and a potentially toxic element, and its systemic homeostasis is controlled by the iron hormone hepcidin. Hepcidin binds to the cellular iron exporter ferroportin, causes its degradation, and thereby diminishes iron uptake from the intestine and the release of iron from macrophages. Given that hepcidin‐resistant ferroportin mutant mice show exocrine pancreas dysfunction, we analysed pancreata of aging hepcidin knockout (KO) mice. Hepcidin and Hfe KO mice were compared with wild‐type (WT) mice kept on standard or iron‐rich diets. Twelve‐month‐old hepcidin KO mice were subjected to daily minihepcidin PR73 treatment for 1 week. Six‐month‐old hepcidin KO mice showed cytoplasmic acinar iron overload and mild pancreatitis, together with elevated expression of the iron uptake mediators DMT1 and Zip14. Acinar atrophy, massive macrophage infiltration, fatty changes and pancreas fibrosis were noted in 1‐year‐old hepcidin KO mice. As an underlying mechanism, 6‐month‐old hepcidin KO mice showed increased pancreatic oxidative stress, with elevated DNA damage, apoptosis and activated nuclear factor‐κB (NF‐κB) signalling. Neither iron overload nor pancreatic damage was observed in WT mice fed iron‐rich diet or in Hfe KO mice. Minihepcidin application to hepcidin KO mice led to an improvement in general health status and to iron redistribution from acinar cells to macrophages. It also resulted in decreased NF‐κB activation and reduced DNA damage. In conclusion, loss of hepcidin signalling in mice leads to iron overload‐induced chronic pancreatitis that is not seen in situations with less severe iron accumulation. The observed tissue injury can be reversed by hepcidin supplementation. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

铁调素在小鼠脑内的表达及其对膜铁转运蛋白1和二价金属离子转运体1表达的影响

目的 探讨铁调素(hepcidin)在小鼠脑内的表达及其对膜铁转运蛋白1(ferroportir 1)和二价金属离子转运体1(DMT1)表达的调节作用.方法 应用RT-PCR技术检测铁调素在正常小鼠各脑区的表达分布,并观察了脑室内注射铁调素对DMT1、膜铁转运蛋白1表达的影响 结果 铁调素在小鼠脑内有广泛表达,且不同脑区表达程度不同,脉络丛部分表达较高.结论 侧脑室内注射铁调素后,能够显著影响DMT1、膜铁转运蛋白1表达,且具有明显的区域特异性.     

Effects of Intracerebroventricular Injection of Iron Dextran on the Iron Concentration and Divalent Metal Transporter 1 Expression in the Caudate Putamen and Substantia Nigra of Rats

The cellular localization of DMT1 and its functional characterization suggest that DMT1 may play an important role in the physiological brain iron transport. But the regulation of DMT1 expression by iron in the brain is still not clearly understood. In this study, both the contents of ferric and ferrous iron as well as DMT1 expression were evaluated in CPu and SN after ICV of 500 μg iron dextran/rat/day for 3 or 7 days. It was found that the iron levels in CPu and SN were not altered obviously until ICV for 7 days. Immunohistochemistry results indicated that the expression of DMT1 (?IRE) in CPu and SN was not altered significantly after 3 days of ICV. Whereas the expression of DMT1 (?IRE) decreased significantly after 7 days of ICV when ferrous iron was increased significantly. Contrary to that of DMT1 (?IRE) in the same regions, there were no significant alterations in DMT1 (+IRE) expression in CPu and SN in spite of the existence of the altered iron levels, compared with that of control groups. The results demonstrate that DMT1 (?IRE) expression was correlated probably with brain iron levels; especially, its regulation was correlated with ferrous iron (not ferric iron) in CPu and SN in adult rats, compared with those of saline‐injected control rats. The effect of ferrous iron on the expression of DMT1 (?IRE) in the brain also suggests that it might play a major physiological role in brain iron uptake and transport, but further studies are needed to clarify these issues. Anat Rec, 2009. © 2008 Wiley‐Liss, Inc.     

A bone morphogenetic protein (BMP)-responsive element in the hepcidin promoter controls HFE2-mediated hepatic hepcidin expression and its response to IL-6 in cultured cells

The precise regulation of the iron-regulatory hormone hepcidin is essential to maintain body iron homeostasis: Hepcidin deficiency induces iron overload, and hepcidin excess results in anaemia. Mutations in the gene HFE2 cause severe iron overload and are associated with low hepcidin expression. Recent data suggest that HFE2 is a bone morphogenetic protein (BMP) co-receptor, and that the decreased hepcidin mRNA expression because of HFE2 dysfunction is a result of impaired BMP signalling ability. In this study, we identify a critical BMP-responsive element (BMP-RE) at position -84/-79 of the hepcidin promoter. We show that this element mediates HFE2-dependent basal hepcidin mRNA expression under control conditions. Unexpectedly, the mutation of the same BMP-RE element also severely impairs hepcidin activation in response to IL-6. These data uncover a missing link in the HFE2-mediated control of hepcidin expression and suggest that the BMP-RE controls hepcidin promoter activity mediated by HFE2 and inflammatory stimuli.     

Iron metabolism: State of the art

Iron homeostasis relies on the amount of its absorption by the intestine and its release from storage sites, the macrophages. Iron homeostasis is also dependent on the amount of iron used for the erythropoiesis. Hepcidin, which is synthesized predominantly by the liver, is the main regulator of iron metabolism. Hepcidin reduces serum iron by inhibiting the iron exporter, ferroportin expressed both tissues, the intestine and the macrophages. In addition, in the enterocytes, hepcidin inhibits the iron influx by acting on the apical transporter, DMT1. A defect of hepcidin expression leading to the appearance of a parenchymal iron overload may be genetic or secondary to dyserythropoiesis. The exploration of genetic hemochromatosis has revealed the involvement of several genes, including the recently described BMP6. Non-transfusional secondary hemochromatosis is due to hepcidin repression by cytokines, in particular the erythroferone factor that is produced directly by the erythroid precursors. Iron overload is correlated with the appearance of a free form of iron called NTBI. The influx of NTBI seems to be mediated by ZIP14 transporter in the liver and by calcium channels in the cardiomyocytes. Beside the liver, hepcidin is expressed at lesser extent in several extrahepatic tissues where it plays its ancestral role of antimicrobial peptide. In the kidney, hepcidin modulates defense barriers against urinary tract infections. In the heart, hepcidin maintains tissue iron homeostasis by an autocrine regulation of ferroprotine expression on the surface of cardiomyocytes. In conclusion, hepcidin remains a promising therapeutic tool in various iron pathologies.     

NF-κB参与枸橼酸铁铵过载诱导的人肝细胞hepcidin基因表达

目的:研究核因子κB(NF-κB)在枸橼酸铁铵过载诱导人肝细胞铁调素(hepcidin)基因表达中的调控作用。方法:依据前期不同浓度枸橼酸铁铵抑制人肝细胞HH4增殖实验结果,选取0.1、1、5和10 mmol/L枸橼酸铁铵处理人肝细胞HH4 48 h,半定量PCR法检测胞内hepcidin的表达水平;利用染色质免疫共沉淀(Ch IP)、电泳迁移率实验(EMSA)和双萤光素酶报告基因检测系统,并结合胞内NF-κB活性抑制实验,确定NF-κB对人hepcidin转录活性的影响。结果:5 mmol/L和10 mmol/L浓度的枸橼酸铁铵处理细胞后,hepcidin表达水平显著增强;Ch IP和EMSA实验证实NF-κB能够与hepcidin基因启动子结合;重组萤光素酶报告质粒TOPFlash-p Hepcidin相对萤光素酶活性明显高于对照组;与重组质粒TOPFlash-p Hepcidin相比,突变重组萤光素酶报告质粒TOPFlash-p Hepcidin-mut相对萤光素酶活性显著降低;NF-κB抑制剂BAY 11-7082显著降低了hepcidin基因的表达。结论:NF-κB参与了铁过载诱导的人hepcidin基因表达。这为进一步深入研究肝细胞铁过载模式下多因子协同调控hepcidin基因表达的具体分子机理奠定了基础。     

Hepcidin messenger RNA expression in human lymphocytes

Hepcidin regulates intracellular iron levels by interacting with and promoting the degradation of ferroportin, a membrane protein and the only known cellular iron exporter. Studies of hepcidin expression and regulation have focused on its effects in innate immunity and as a regulator of systemic iron metabolism. In the present study we characterized the expression of hepcidin messenger RNA (mRNA) in human peripheral blood mononuclear cells (PBMCs) with a focus on peripheral blood lymphocytes (PBLs). We found that (1) all human PBMCs analyzed express basal hepcidin mRNA levels; (2) hepcidin mRNA expression increases after T‐lymphocyte activation; (3) expression by PBLs increases in response to challenge by holotransferrin (Fe‐TF) and by ferric citrate in vitro; (4) the Fe‐TF‐mediated up‐regulation of hepcidin decreases ferroportin expression at the cytoplasmic membrane of PBLs; and (5) silencing of tumour necrosis factor‐α (TNF‐α) abrogates the effect of Fe‐TF. In summary, we show that hepcidin expression determines intracellular iron levels by regulating the expression of ferroportin, as described in other cells, and that inappropriately low expression of hepcidin impairs normal lymphocyte proliferation. The results establish hepcidin as a new player in lymphocyte biology.     

Transferrin Receptor Expression in Normal, Iron-deficient and Iron-overloaded Rats

The distribution of transferrin receptor (TfR) positive cells and their staining intensity were examined in the liver, duodenum, pancreas, spleen, kidney and brain of iron deficient, iron-overloaded and normal Wistar rats to elucidate the regulatory effects of iron on TfR expression in vivo. Iron deficiency was produced by an iron deficient food and water regimen, and iron overload by repeated intraperitoneal injections of ferric nitrilotriacetate (Fe³-NTA) for 12 weeks. In iron deficient rats, levels of hemoglobin (Hb= 5.9 ± 0.7) and serum iron (Sl = 29.9 ± 4.4) were lower, and total iron binding capacity (TIBC = 624.4 ± 72.7) was higher than in normal rats (Hb = 15.6 ± 0.9, Sl = 206.5 # 20.5, TIBC = 416.0 ± 56.0), and Wee versa for SI (217.7 ± 15.5) and TIBC (307.1 ± M45.4) in iron-overloaded rats. In normal rats, TfR positive granules were observed in hepatocytes and Kupffer cells of the liver, absorptive epithelium of the duodenum, acinar and Langerhans islet cells of the pancreas, macrophages and red pulp erythro-blasts of the spleen, and distal convoluted tubular epithelium of the kidney. Although the tissue distribution pattern of TfR positive cells was similar in normal, iron deficient and iron overloaded rats, the staining intensity and number of TfR positive cells were obviously higher in iron deficient, and lower in iron overloaded rats. We conclude that TfR expression is negatively regulated by the tissue concentration of iron. Acta Pathol Jpn 39: 759-764, 1989.     

Iron overload and heart fibrosis in mice deficient for both beta2-microglobulin and Rag1

Genetic causes of hereditary hemochromatosis (HH) include mutations in the HFE gene, a ss2-microglobulin (ss2m)-associated major histocompatibility complex class I-like protein. Accordingly, mutant ss2m(-/-) mice have increased intestinal iron absorption and develop parenchymal iron overload in the liver. In humans, other genetic and environmental factors have been suggested to influence the pathology and severity of HH. Previously, an association has been reported between low numbers of lymphocytes and the severity of clinical expression of the iron overload in HH. In the present study, the effect of a total absence of lymphocytes on iron overload was investigated by crossing ss2m(-/-) mice (which develop iron overload resembling human disease) with mice deficient in recombinase activator gene 1 (Rag1), which is required for normal B and T lymphocyte development. Iron overload was more severe in ss2mRag1 double-deficient mice than in each of the single deficient mice, with iron accumulation in parenchymal cells of the liver, in acinar cells of the pancreas, and in heart myocytes. With increasing age ss2mRag1(-/-) mice develop extensive heart fibrosis, which could be prevented by reconstitution with normal hematopoietic cells. Thus, the development of iron-mediated cellular damage is substantially enhanced when a Rag1 mutation, which causes a lack of mature lymphocytes, is introduced into ss2m(-/-) mice. Mice deficient in ss2m and Rag1 thus offer a new experimental model of iron-related cardiomyopathy.     

Chlamydophila pneumoniae changes iron homeostasis in infected tissues

Many bacteria, including Chlamydophila pneumoniae (C. pneumoniae), are dependent on iron (Fe) for their growth. However, it is not known whether bacterial infections affect gastrointestinal uptake and uptake of trace elements in infected tissues. A human C. pneumoniae strain adapted to C57BL/6J mice was used to study hepcidin gene expression in the liver and divalent metal transporter 1 (DMT1) content in the liver and intestine and whether Fe is concomitantly changed in serum, liver, and intestine. The copper/zinc (Cu/Zn) ratio in the serum was used as a marker for infection. Bacterial DNA, mRNA, and hepcidin were measured by real-time PCR, DMT1 by Western blot, and trace elements by ICP-MS on days 2, 5, and 8 of the infection. C. pneumoniae DNA was found in the liver on all days but the number of viable bacteria peaked on day 8. Hepcidin expression increased on days 2 and 5, whereas DMT1 content in the liver increased on day 8. Fe decreased in serum, increased in the liver but was not changed in the intestine during the disease. In the serum, the Cu/Zn ratio peaked on day 5. The peak of viable bacteria in the liver was associated with increased DMT1 and Fe contents and increased hepcidin expression, but this did not affect intestinal Fe uptake. Thus, growth of C. pneumoniae in tissues parallels a redistribution of Fe to those tissues resulting in a changed body homeostasis of Fe.