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)

In the present study, turpentine oil was injected in the hind limb muscle of the rat to stimulate an acute-phase response (APR). The changes in the gene expression of cytokines and proteins known to be involved in the iron regulatory pathway were then studied in the liver and in extra-hepatic tissue. In addition to the strong upregulation of interleukin-6 (IL-6) and IL-1 beta observed in the inflamed muscle, an upregulation of the genes for IL1-beta and tumor necrosis factor-alpha, but not IL-6, were detectable in the liver. Hepatic Hepc gene expression increased to a maximum at 6 h after the onset of APR. An upregulation of transferrin, transferrin receptor 1 (TfR1), TfR2, ferritin-H, iron responsive element binding protein-1 (IRP1), IRP2 and divalent metal transporter gene expression was also found. Hemojuvelin (Hjv)-, ferroportin 1-, Dcytb-, hemochromatosis-gene- and hephaestin gene expression was downregulated. Hepcidin (Hepc) gene expression was not only detectable in extra-hepatic tissues such as heart, small intestine, colon, spleen and kidney but it was also upregulated under acute-phase conditions, with the Hjv gene being regulated antagonistically. Fpn-1 gene expression was downregulated significantly in heart, colon and spleen. Most of the genes of the known proteins involved in iron metabolism are expressed not only in the liver but also in extra-hepatic tissues. Under acute-phase conditions, acute-phase cytokines (eg IL-6) may modulate the gene expression of such proteins not only in the liver but also in other organs.
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PMID:Changes of gene expression of iron regulatory proteins during turpentine oil-induced acute-phase response in the rat. 1741 67

Rigorous regulation of iron absorption is required to meet the requirements of the body and to limit excess iron accumulation that can produce oxidative stress. Regulation of iron absorption is controlled by hepcidin and probably by the crypt program. Hepcidin is a humoral mediator of iron absorption that interacts with the basolateral transporter, ferroportin. High levels of hepcidin reduce iron absorption by targeting ferroportin to lysosomes for destruction. It is also proposed that ferroportin is expressed on the apical membrane and coordinates with ferroportin-hepcidin derived from the basal surface to modulate the uptake phase of iron absorption. The crypt program suggests that as crypt cells differentiate and migrate into the absorptive zone they absorb iron from the diet at levels inverse to the amount of iron taken up from transferrin. Under most circumstances, intestinal iron absorption is controlled at multiple levels that lead to hepcidin/ferroportin modulation of the enterocyte labile iron pool (LIP). It is likely that transcription of iron transport proteins involved in the apical and basolateral transport of iron are differentially regulated by separate LIPs. Iron-responsive protein (IRP) 1 and IRP2 do not appear to play a significant role in the expression of iron transport proteins, although IRP2 regulates L- and H-ferritin expression. Despite the importance of hepcidin, there is evidence of hepcidin-independent regulation of iron absorption possibly involving haemojuvelin (HJV) and neogenin, which may be up-regulated during ineffective erythropoiesis.
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PMID:The relevance of the intestinal crypt and enterocyte in regulating iron absorption. 1747 33

Patients with chronic hepatitis C frequently have serum and hepatic iron overload, but the mechanism is unknown. Recently identified hepcidin, exclusively synthesized in the liver, is thought to be a key regulator for iron homeostasis and is induced by infection and inflammation. This study was conducted to determine the hepatic hepcidin expression levels in patients with various liver diseases. We investigated hepcidin mRNA levels of liver samples by real-time detection-polymerase chain reaction; 56 were hepatitis C virus (HCV) positive, 34 were hepatitis B virus (HBV) positive, and 42 were negative for HCV and HBV (3 cases of auto-immune hepatitis, 7 alcoholic liver disease, 13 primary biliary cirrhosis, 9 nonalcoholic fatty liver disease, and 10 normal liver). We analyzed the relation of hepcidin to clinical, hematological, histological, and etiological findings. Hepcidin expression levels were strongly correlated with serum ferritin (P < 0.0001) and the degree of iron deposit in liver tissues (P < 0.0001). Hepcidin was also correlated with hematological parameters (vs. hemoglobin, P = 0.0073; vs. serum iron, P = 0.0012; vs. transferrin saturation, P < 0.0001) and transaminase levels (P = 0.0013). The hepcidin-to-ferritin ratio was significantly lower in HCV(+) patients than in HBV(+) patients (P = 0.0129) or control subjects (P = 0.0080). In conclusion, hepcidin expression levels in chronic liver diseases were strongly correlated with either the serum ferritin concentration or degree of iron deposits in the liver. When adjusted by either serum ferritin values or hepatic iron scores, hepcidin indices were significantly lower in HCV(+) patients than in HBV(+) patients, suggesting that hepcidin may play a pivotal role in the pathogenesis of iron overload in patients with chronic hepatitis C.
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PMID:Hepcidin expression in the liver: relatively low level in patients with chronic hepatitis C. 1751 61

Since the discovery of the HFE gene of hereditary haemochromatosis in 1996 several new genetic defects have been identified, enabling explanation of the cause and variety of this disease. To date, at least 5 major types of hereditary haemochromatosis have been recognised. All these genes encode for proteins that are involved in metabolic pathways relevant to hepcidin synthesis in the liver. Hepcidin is a small protein that regulates the activity of the iron exporting protein ferroportin in the basolateral membrane of duodenal cells and the cell membrane of macrophages and thereby controls serum iron concentration. Plasma hepcidin concentration is elevated in body iron excess and by inflammatory stimuli, and is lowered in erythroid iron demand, hypoxia and most types of hereditary haemochromatosis. It is the clinician's task to diagnose hereditary haemochromatosis before irreversible tissue damage arises and at the same time to differentiate between ongoing iron accumulation and increasingly prevalent disorders with elevated serum ferritin such as the metabolic syndrome.
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PMID:[Hereditary haemochromatosis: novel genes, novel diseases and hepcidin]. 1755 64

Hepcidin has been proposed as an important factor in the pathogenesis of the anaemia of chronic disease (ACD). The aim of this study was to assess the relationship between anaemia and inflammatory activity in patients with solid tumours. Patients were classified as having iron deficiency anaemia (IDA) (hypoferremia and hypoferretinemia), ACD (hypoferremia, normal or increased serum ferritin) and anaemia related to cancer (ARC) (no abnormalities in iron status). Serum pro-hepcidin, IL-6, C-reactive protein (CRP) and iron status parameters were measured using commercial kits. CRP and IL-6 levels were significantly higher in patients with ACD when compared to IDA, ARC and non anaemic patients (P < 0.005). Serum pro-hepcidin levels were not different among all studied groups (P = 0.138). A negative correlation was observed between haemoglobin and serum ferritin, CRP and IL-6 levels only in group of ACD. Serum pro-hepcidin concentrations were not correlated with degree of anaemia or iron metabolism parameters. According to our results the inflammatory activity represented by high levels of IL-6 and CRP are involved in the pathogenesis of ACD, probably due to the action of inflammation on iron metabolism, but not in ARC. It was not possible to demonstrate a significant effect of pro-hepcidin on the anaemia in cancer patients.
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PMID:Anaemia in patients with cancer: role of inflammatory activity on iron metabolism and severity of anaemia. 1787 9

Hepcidin is a key regulator of iron metabolism. In this study, we examined whether measurement of hepcidin is useful in assessing recombinant human erythropoietin (rHuEPO) responsiveness in regular hemodialysis (HD) patients in a cross-sectional fashion. We examined the association between serum prohepcidin, a prohormone of hepcidin, and rHuEPO dosage and the rHuEPO/hemoglobin (Hb) ratio in 75 HD patients. We also semiquantatively measured the peak intensity of serum hepcidin-25, the major form of mature hepcidin, in 24 HD patients by using surface-enhanced laser desorption ionization time of flight time mass spectrometry, and compared those between rHuEPO-hyporesponsive (rHuEPO 192 +/- 10 [126-252] IU/kg/week, n = 15) and responsive patients (rHuEPO 40 +/- 9 [0-81] U/kg/week, n = 9). A significant but weak relationship was found between serum prohepcidin and rHuEPO dosage (r = 0.24, p < 0.05) and rHuEPO/Hb ratio (r = 0.22, p = 0.06). However, prohepcidin did not become an indicator of hematopoietic parameters by multiple regression analysis. Serum hepcidin-25 intensity was significantly and positively correlated with ferritin (r = 0.51, p < 0.01) but not with log-transformed C-reactive protein. There was no difference in the intensities of serum hepcidin-25 between rHuEPO-hyporesponsive and responsive patients (64 +/- 10 vs. 52 +/- 16 AU, p = NS). It follows from these findings that the assessment of serum hepcidin using currently available assays was not valid in predicting rHuEPO responsiveness in chronic HD patients.
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PMID:Association of prohepcidin and hepcidin-25 with erythropoietin response and ferritin in hemodialysis patients. 1794 20

Hepcidin is a principal iron regulatory hormone and its expression is stimulated by cytokines. The aim of this study was to determine serum levels of the prohormone form of hepcidin, pro-hepcidin, in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). The study included 72 RA and 28 SLE patients and 33 healthy controls (HC). Serum iron status, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 and pro-hepcidin levels were determined. Pro-hepcidin levels in the RA group was higher than SLE and HC groups (p < 0.05, p < 0.001, respectively). Pro-hepcidin levels did not correlate with disease activity scores, cytokine levels and serum iron status in the RA and SLE groups, while it correlated with TNF-alpha, IL-6 and ferritin levels in the HC group (r = 0.459, p < 0.01, r = 0.374, p < 0.05, r = -0.603, p < 0.01, respectively). Pro-hepcidin levels show extremely wide variations within the groups as do iron status and cytokines. Despite these wide variations correlation analysis do not reveal anything.
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PMID:Serum pro-hepcidin levels in rheumatoid arthritis and systemic lupus erythematosus. 1827 47

Meeting the iron requirements of infants and children is difficult, and supplementation or fortification of food with iron is often recommended. Although iron supplementation of infants and children with iron deficiency and iron-deficiency anemia may be beneficial, recent studies suggest that this may not be the case for those with adequate iron status, and adverse effects have been noted. The recent discoveries of proteins and peptides regulating iron absorption have enhanced our knowledge of iron metabolism in infants and children. Iron is taken up in the small intestine by divalent metal transporter-1 and is either stored by ferritin inside the mucosal cell or transported to the systemic circulation by ferroportin, while being oxidized by hephaestin to be incorporated into transferrin. Hepcidin, a small peptide synthesized by the liver, can sense iron stores and regulates iron transport by inhibition of ferroportin. However, regulation of iron transporters is immature in infants, possibly explaining the adverse effects of iron supplementation. Interactions among iron, vitamin A, zinc, and copper need to be considered when evaluating the effects of iron supplementation on infants and children.
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PMID:Iron metabolism in infants and children. 1829 87

The aim of our study was to assess possible relations between prohepcidin, iron status and inflammatory markers in hemodialysis (HD) patients, as well as its association with resistance to recombinant human erythropoietin (rhEPO) therapy. Fifty HD patients and 25 healthy controls were enrolled in the study. Among HD patients, 25 were non-responders and 25 were responders to rhEPO therapy. Complete blood cell count, reticulocyte count, and circulating levels of ferritin, iron, transferrin saturation, C-reactive protein (CRP), soluble interleukin (IL)-2 receptor (s-IL2R), soluble transferrin receptor (s-TfR), IL-6 and prohepcidin were measured in all patients and controls. HD patients showed higher circulating levels of ferritin, s-TfR, CRP, IL-6, s-IL2R and prohepcidin, and lower levels of transferrin compared to healthy controls. Higher levels of s-TfR, CRP and lower levels prohepcidin were observed among non-responders compared to responders. Prohepcidin levels correlated negatively with s-TfR and reticulocyte count. The weekly rhEPO/kg dose was found to be positively correlated with CRP, hemoglobin and s-TfR. In conclusion, our data show that a close interaction exists between inflammation, iron status and prohepcidin serum levels that ultimately regulate intracellular iron availability. Prohepcidin and s-TfR, together with CRP, may prove to be good markers of resistance to rhEPO therapy in HD patients.
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PMID:Role of prohepcidin, inflammatory markers and iron status in resistance to rhEPO therapy in hemodialysis patients. 1835 52

Anemia of inflammation in patients with acute or chronic acute-phase activation is a common clinical problem. Hepcidin is a peptide shown to be the principal regulator of the absorption and systemic distribution of iron. Main inducers of hepcidin are iron overload, hypoxia and inflammation, where the latter has been linked to hepcidin via increased interleukin-6 (IL-6). This article addresses the impact and time course of postoperative acute-phase reaction in humans following heart surgery on prohepcidin, hepcidin, hematological markers and IL-6 concentrations. Serum concentrations of prohepcidin, hepcidin, IL-6 and hematological iron parameters were studied in five male patients without infection before and after heart surgery. This study, which is the first to report the impact on serum hepcidin and serum prohepcidin concentrations in patients following surgery, clearly demonstrates the induction of hypoferremia due to the postoperative acute-phase reaction. Significant changes were seen for serum iron concentration, transferrin saturation, total iron binding capacity and hemoglobin concentration. A significant increase in ferritin concentration was seen 96-144 h postoperatively. Additionally, there were significant alterations in both serum hepcidin after 96-144 h and serum prohepcidin after 48 h compared with preoperative values. Serum prohepcidin decreased, whereas serum hepcidin increased. In conclusion, changes in serum prohepcidin were followed by an increase in serum hepcidin. This speaks in favor of a chain of action where proteolytic trimming of serum prohepcidin results in increased serum hepcidin. However, hypoferremia appeared prior to the changes in serum prohepcidin and serum hepcidin.
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PMID:Hepcidin, interleukin-6 and hematological iron markers in males before and after heart surgery. 1849 62


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