Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although iron plays a critical role in exercise, the regulatory mechanism of iron metabolism remains poorly understood. The aims of the present study were to investigate the effects of different intensity exercise on body iron status and the regulatory mechanism of duodenal iron absorption. Thirty female Sprague-Dawley rats (90-100 g) were randomly divided into three groups: a control group (remained sedentary, CG), a moderately exercised group (swam 1.5 h/day, MG) and a strenuously exercised group (swam with different load, SG). Serum iron status, serum ferritin and Hct were examined after 10 weeks of swimming. Western blot was performed to detect the expression of iron transport proteins: divalent metal transporter1 (DMT1) and ferroportin 1 (FPN1) in duodenal epithelium. The expression of hepcidin mRNA in liver was examined by RT-PCR. The results showed: (1) the body iron status in MG was kept at a high level compared to that of CG and SG, (2) Western blot showed DMT1 with iron responsive element (IRE) and FPN1 in duodenal epithelium which were higher in MG than that of CG and (3) the expression of hepatic hepcidin mRNA was down regulated in MG (p < 0.05). The data suggested that moderate exercise improved iron status and that was likely regulated by increased DMT1 with IRE and FPN1 expression. Hepcidin signaling pathway may involve in the regulation of duodenal iron absorption proteins.
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PMID:Molecular analysis of increased iron status in moderately exercised rats. 1631 19

Anemia of chronic disease (ACD) is frequently found in patients with chronic immune activation. Since most studies on ACD pathophysiology were performed with cell culture or animal models but not in humans, we examined 37 ACD patients suffering from autoimmune diseases or infections, 10 subjects with iron-deficiency anemia (IDA), 10 anemic patients with hereditary spherocytosis (HS), and 27 age-matched controls. Although hemoglobin concentrations were comparable between ACD and IDA patients, the latter presented with significantly higher serum erythropoietin concentrations than ACD patients. The significant negative correlation between erythropoietin and hemoglobin levels observed in IDA patients was also found in a group of anemic but not hypoferremic hereditary spherocytosis subjects, but not in ACD patients. Increased serum concentrations of the hepcidin precursor prohepcidin were paralleled by a decreased expression of the iron exporter ferroportin in circulating monocytes of ACD patients. In the latter cells, increased amounts of the iron storage protein ferritin and a reduced activity of iron-regulatory protein indicated monocyte iron accumulation. Our data indicate that hypoferremia in ACD may result from downregulation of ferroportin expression by hepcidin and cytokines with subsequent iron retention in monocytes. Together with a diminished erythropoietin formation, the impaired iron recirculation from monocytes may be central in the pathophysiology of ACD in humans.
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PMID:Dysregulated monocyte iron homeostasis and erythropoietin formation in patients with anemia of chronic disease. 1643 84

Hepcidin, a key regulator of iron metabolism, decreases intestinal absorption of iron and its release from macrophages. Iron, anemia, hypoxia, and inflammation were reported to influence hepcidin expression. To investigate regulation of the expression of hepcidin and other iron-related genes, we manipulated erythropoietic activity in mice. Erythropoiesis was inhibited by irradiation or posttransfusion polycythemia and stimulated by phenylhydrazine administration and erythropoietin. Gene expression of hepcidin and other iron-related genes (hemojuvelin, DMT1, ferroportin, transferrin receptors, ferritin) in the liver was measured by the real-time polymerase chain reaction. Hepcidin expression increased despite severe anemia when hematopoiesis was inhibited by irradiation. Suppression of erythropoiesis by posttransfusion polycythemia or irradiation also increased hepcidin mRNA levels. Compensated hemolysis induced by repeated phenylhydrazine administration did not change hepcidin expression. The decrease caused by exogenous erythropoeitin was blocked by postirradiation bone marrow suppression. The hemolysis and anemia decrease hepcidin expression only when erythropoiesis is functional; on the other hand, if erythropoiesis is blocked, even severe anemia does not lead to a decrease of hepcidin expression, which is indeed increased. We propose that hepcidin is exclusively sensitive to iron utilization for erythropoiesis and hepatocyte iron balance, and these changes are not sensed by other genes involved in the control of iron metabolism in the liver.
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PMID:Hepcidin mRNA levels in mouse liver respond to inhibition of erythropoiesis. 1649 4

In this work, we used two rat models, partial hepatectomy (PH) and CCl(4) administration, to study the changes in iron pathways in response to hepatic damage. Liver injury induced changes in the hepatic gene expression of hepcidin, hemojuvelin (Hjv), several other proteins of iron metabolism, and several cytokines such as IL-1beta, IL-6, TNF-alpha, and IFN-gamma. Hepcidin gene expression was upregulated between 4 and 8 h with a maximum up to 16 h after surgery. However, Hjv gene expression was downregulated at the same time. An early upregulation of hepcidin (3 h) and downregulation of Hjv gene expression was found after CCl(4) administration. Transferrin receptor 1 and ferritin H gene expression was upregulated, whereas ferroportin 1 gene expression was downregulated. Hepatic IL-6 gene expression was upregulated early after PH and reached maximum 8 h after the PH. In CCl(4)-induced liver injury, IL-6, IL-1beta, TNF-alpha, and IFN-gamma upregulation were found at the maximum 12 h after the administration of the toxin. Treatment of isolated rat hepatocytes with IL-6 and, to a lesser extent, with IL-1beta but not with TNF-alpha or IFN-gamma dose dependently upregulated hepcidin and downregulated Hjv gene expression. In hepatic damage, changes of the hepatic gene expression of the main proteins involved in iron metabolism may be induced by locally synthesized mediators.
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PMID:Hepcidin and hemojuvelin gene expression in rat liver damage: in vivo and in vitro studies. 1657 81

A recently isolated peptide hormone, hepcidin, is thought to be the principal regulator of iron homeostasis. Hepcidin acts by limiting intestinal iron absorption and promoting iron retention in reticuloendothelial cells. Its precursor peptide form is called pro-hepcidin. The aims of this study were to determine serum pro-hepcidin levels in healthy preterm and term newborns, and to assess possible relationships between pro-hepcidin and serum iron, serum ferritin, and transferrin. A serum sample was collected from each of 26 healthy preterm (gestational age < 37 weeks) and 16 healthy, full-term, appropriate-for-gestational age babies. The preterm babies were also divided into 2 subgroups based on gestational age. Samples were analyzed for complete blood count, serum iron and ferritin concentrations, iron-binding capacity, and transferrin and pro-hepcidin levels. Group findings were compared and correlations between pro-hepcidin and the iron parameters were tested. The respective serum pro-hepcidin levels (mean +/- SD) in the 16 healthy term and 26 healthy preterm newborns were 482 +/- 371.9 ng/mL and 496.7 +/- 443.5 ng/mL. Analysis revealed no significant correlations between serum pro-hepcidin level and serum iron, serum ferritin, or transferrin in the preterm or term newborns. Pro-hepcidin levels were not correlated with gestational age in the preterm group. The results indicate that healthy preterm and term newborns have high pro-hepcidin levels.
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PMID:Serum pro-hepcidin levels and relationships with iron parameters in healthy preterm and term newborns. 1662 70

Hepcidin, a key regulator of iron metabolism, is expressed in the liver, distributed in blood, and excreted in urine. However, to date, no reliable and practical method for measuring the bioactive form of hepcidin in serum has been developed. Here, we used surface-enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF MS) to analyze the distinctive serum proteomic patterns of patients receiving hemodialysis. In the range of 1000 to 15,000 m/z, we found 3 peptides at 2192, 2789, and 2851 m/z that showed a significant correlation with the serum ferritin levels. The molecular sizes of peptides at 2192 and 2789 m/z matched with the reported sizes of hepcidin-20 and -25, respectively, and the serum peptide at 2789 m/z was identified as hepcidin-25 by collision-induced dissociation tandem MS. By using SELDI-TOF MS, we developed a semiquantitative assay for hepcidin-25. In this assay, the level of serum hepcidin-25 correlated well with levels of serum ferritin and serum interleukin-6. Hepcidin-25 was found to accumulate in the serum of patients receiving hemodialysis; this could contribute to the pathogenesis of renal anemia by decreasing the available iron for hematopoiesis. Thus, SELDI-TOF MS would be a clinically useful tool to detect and semiquantify bioactive hepcidin in serum.
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PMID:Detection of serum hepcidin in renal failure and inflammation by using ProteinChip System. 1662 68

Patients with alcoholic liver disease frequently exhibit iron overload in association with increased hepatic fibrosis. Even moderate alcohol consumption elevates body iron stores; however, the underlying molecular mechanisms are unknown. Hepcidin, a circulatory peptide synthesized in the liver, is a key mediator of iron metabolism. Ethanol metabolism significantly down-regulated both in vitro and in vivo hepcidin mRNA and protein expression. 4-Methylpyrazole, a specific inhibitor of the alcohol-metabolizing enzymes, abolished the effects of ethanol on hepcidin. However, ethanol did not alter the expression of transferrin receptor1 and ferritin or the activation of iron regulatory RNA-binding proteins, IRP1 and IRP2. Mice maintained on 10-20% ethanol for 7 days displayed down-regulation of liver hepcidin expression without changes in liver triglycerides or histology. This was accompanied by elevated duodenal divalent metal transporter1 and ferroportin protein expression. Injection of hepcidin peptide negated the effect of ethanol on duodenal iron transporters. Ethanol down-regulated hepcidin promoter activity and the DNA binding activity of CCAAT/enhancer-binding protein alpha (C/EBPalpha) but not beta. Interestingly, the antioxidants vitamin E and N-acetylcysteine abolished both the alcohol-mediated down-regulation of C/EBPalpha binding activity and hepcidin expression in the liver and the up-regulation of duodenal divalent metal transporter 1. Collectively, these findings indicate that alcohol metabolism-mediated oxidative stress regulates hepcidin transcription via C/EBPalpha, which in turn leads to increased duodenal iron transport.
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PMID:Alcohol metabolism-mediated oxidative stress down-regulates hepcidin transcription and leads to increased duodenal iron transporter expression. 1725 19

Restless legs syndrome (RLS) is a neurological disorder characterized by a strong urge to move the legs. Sufferers of RLS often experience chronic sleep deprivation, due to the characteristic worsening of symptoms both when at rest and during the night. MRI data, autopsy studies, and a consistent decrease in CSF ferritin all suggest that early-onset RLS is associated with insufficient iron in the brain. In this study, we examined the relationship between the iron regulatory hormone hepcidin and RLS. Hepcidin serves as a hormone that signals iron release from cells by interacting with ferroportin. We measured the expression and concentration of pro-hepcidin in the brain and cerebrospinal fluid of both RLS patients and control individuals. In CSF, we found that pro-hepcidin levels were significantly decreased in early-onset RLS patient samples, but not in late-onset RLS patients, when compared to controls. Conversely, in neuromelanin cells, substantia nigra, and putamen, the concentration of pro-hepcidin in RLS samples is significantly increased compared to controls. Functionally, hepcidin binds to ferroportin to limit iron movement from cells. Therefore, we provide immunocytochemical evidence that ferroportin is expressed by the epithelial cells of the choroid plexus and the ependymal cells lining the ventricles. These data suggest that sites of action for hepcidin include signaling the ventricular system for movement between brain and CSF. At this time, it cannot be determined if the lower levels of pro-hepcidin in the CSF represent a compensatory response to the decreased levels of iron in the brain or a defective signaling mechanism in RLS. Nonetheless, these data support the mounting evidence that there is a biological basis for RLS and the underlying mechanism involves iron management.
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PMID:Is ferroportin-hepcidin signaling altered in restless legs syndrome? 1675 69

Hepcidin is a small defensin-like peptide whose production by hepatocytes is modulated in response to anemia, hypoxia, or inflammation. Hepcidin could also act as an indicator of functional iron deficiency in these patients. Cross-sectional study was performed to assess hepcidin correlations with renal function, iron status, and hsCRP in patients with chronic renal failure on conservative treatment, on hemodialyses, and in kidney transplant recipients. Iron status, complete blood count, creatinine, albumin, lipids were assessed using standard laboratory methods. GFR was estimated using MDRD formula. Hepcidin and high sensitivity CRP were measured using commercially available kits. Ferritin and hepcidin were higher in hemodialyzed patients, kidney transplant recipients, and patients with chronic renal failure over controls. In patients with chronic renal failure, hepcidin correlated significantly with total protein, albumin, creatinine, and eGRF. In kidney transplant recipients, hepcidin correlated significantly in univariate analysis, with total protein, ferritin, time after transplantation, creatinine, eGRF and tended to correlate with cholesterol. In hemodialyzed patients hepcidin, correlated significantly with triglycerides, albumin, creatinine, urea, residual renal function, and hsCRP. In healthy volunteers, hepcidin was related to triglycerides and ferritin. Multiple regression analysis in hemodialyzed patients showed that hepcidin was independently related to creatinine, triglycerides, and residual renal function. Multiple regression analysis in kidney transplant recipients showed that hepcidin was independently related only to GFR and ferritin. Elevated hepcidin in all groups of patients studied may be due to low grade inflammation, frequently encountered in this population and mainly to impaired renal function.
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PMID:Hepcidin, iron status, and renal function in chronic renal failure, kidney transplantation, and hemodialysis. 1692 40

Hepcidin plays a major role in iron homeostasis, but understanding its role has been hampered by the absence of analytical methods for quantification in blood. A commercial ELISA has been developed for serum prohepcidin, a hepcidin precursor, and there is interest in its potential use in the clinical and research arena. We investigated the association between serum prohepcidin concentration and iron absorption in healthy men, and its relationship with iron status in men carrying HFE mutations, hereditary haemochromatosis patients, and pregnant women. Iron absorption was determined in thirty healthy men (fifteen wild-type, fifteen C282Y heterozygote) using the stable isotope red cell incorporation technique. Iron status was measured in 138 healthy men (ninety-one wild-type, forty-seven C282Y heterozygote), six hereditary haemochromatosis patients, and thirteen pregnant women. Mean serum prohepcidin concentrations were 214 (SD 118) ng/ml [208 (SD 122) ng/ml in wild-type and 225 (SD 109) ng/ml in C282Y heterozygotes] in healthy men, 177 (SD 36) ng/ml in haemochromatosis patients, and 159 (SD 59) ng/ml in pregnant women. There was no relationship between serum prohepcidin concentration and serum ferritin in any subject groups, nor was it associated with efficiency of iron absorption. Serum prohepcidin is not a useful biomarker for clinical or research purposes.
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PMID:Serum prohepcidin concentration: no association with iron absorption in healthy men; and no relationship with iron status in men carrying HFE mutations, hereditary haemochromatosis patients undergoing phlebotomy treatment, or pregnant women. 1731 17


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