2,093 research outputs found
Hepatocarcinoma with tumor thrombus occupying the right atrium and portal vein in a patient with hereditary hemochromatosis and liver cirrhosis
We present the case of a 46-year old patient with Child-Pugh class C cirrhosis with MEDL-Score 16, and hepatocellular carcinoma invading the inferior vena cava and the right atrium. The etiology of cirrhosis is type 1 hereditary hemochromatosis with positive HFE C282Y/C282Y and H63D/H63D mutations. A systematic review of the literature was performed and only 30 cases of hepatocellular carcinoma with tumor thrombosis extending into the right atrium have been described. To our knowledge, this is the first case that evidences the presence in hereditary hemochromatosis of hepatocellular carcinoma with atypical invasion into the right atrium. Screening of patients with a family history of hereditary hemochromatosis allows detection of the disease in the asymptomatic phase, allowing initiation of early therapy and improved prognosis
Profound Morphological Changes in the Erythrocytes and Fibrin Networks of Patients with Hemochromatosis or with Hyperferritinemia, and Their Normalization by Iron Chelators and Other Agents
It is well-known that individuals with increased iron levels are more prone to thrombotic diseases, mainly due to the presence of unliganded iron, and thereby the increased production of hydroxyl radicals. It is also known that erythrocytes (RBCs) may play an important role during thrombotic events. Therefore the purpose of the current study was to assess whether RBCs had an altered morphology in individuals with hereditary hemochromatosis (HH), as well as some who displayed hyperferritinemia (HF). Using scanning electron microscopy, we also assessed means by which the RBC and fibrin morphology might be normalized. An important objective was to test the hypothesis that the altered RBC morphology was due to the presence of excess unliganded iron by removing it through chelation. Very striking differences were observed, in that the erythrocytes from HH and HF individuals were distorted and had a much greater axial ratio compared to that accompanying the discoid appearance seen in the normal samples. The response to thrombin, and the appearance of a platelet-rich plasma smear, were also markedly different. These differences could largely be reversed by the iron chelator desferal and to some degree by the iron chelator clioquinol, or by the free radical trapping agents salicylate or selenite (that may themselves also be iron chelators). These findings are consistent with the view that the aberrant morphology of the HH and HF erythrocytes is caused, at least in part, by unliganded (‘free’) iron, whether derived directly via raised ferritin levels or otherwise, and that lowering it or affecting the consequences of its action may be of therapeutic benefit. The findings also bear on the question of the extent to which accepting blood donations from HH individuals may be desirable or otherwise
Novel loci affecting iron homeostasis and their effects in individuals at risk for hemochromatosis
Variation in body iron is associated with or causes diseases, including anaemia and iron overload. Here, we analyse genetic association data on biochemical markers of iron status from 11 European-population studies, with replication in eight additional cohorts (total up to 48,972 subjects). We find 11 genome-wide-significant (
Minihepcidins are rationally designed small peptides that mimic hepcidin activity in mice and may be useful for the treatment of iron overload
Iron overload is the hallmark of hereditary hemochromatosis and a complication of iron-loading anemias such as β-thalassemia. Treatment can be burdensome and have significant side effects, and new therapeutic options are needed. Iron overload in hereditary hemochromatosis and β-thalassemia intermedia is caused by hepcidin deficiency. Although transgenic hepcidin replacement in mouse models of these diseases prevents iron overload or decreases its potential toxicity, natural hepcidin is prohibitively expensive for human application and has unfavorable pharmacologic properties. Here, we report the rational design of hepcidin agonists based on the mutagenesis of hepcidin and the hepcidin-binding region of ferroportin and computer modeling of their docking. We identified specific hydrophobic/aromatic residues required for hepcidin-ferroportin binding and obtained evidence in vitro that a thiol-disulfide interaction between ferroportin C326 and the hepcidin disulfide cage may stabilize binding. Guided by this model, we showed that 7–9 N-terminal amino acids of hepcidin, including a single thiol cysteine, comprised the minimal structure that retained hepcidin activity, as shown by the induction of ferroportin degradation in reporter cells. Further modifications to increase resistance to proteolysis and oral bioavailability yielded minihepcidins that, after parenteral or oral administration to mice, lowered serum iron levels comparably to those after parenteral native hepcidin. Moreover, liver iron concentrations were lower in mice chronically treated with minihepcidins than those in mice treated with solvent alone. Minihepcidins may be useful for the treatment of iron overload disorders
HFE variants and the expression of iron-related proteins in breast cancer-associated lymphocytes and macrophages
Disponível em: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5264664/The association of HFE (High Iron FE) major variants with breast cancer risk and behavior has been a matter of discussion for a long time. However, their impact on the expression of iron-related proteins in the breast cancer tissue has never been addressed. In the present study, hepcidin, ferroportin 1, transferrin receptor 1 (TfR1), and ferritin expressions, as well as tissue iron deposition were evaluated in a collection of samples from breast cancers patients and analyzed according to the patients’ HFE genotype. Within the group of patients with invasive carcinoma, those carrying the p.Cys282Tyr variant in heterozygosity presented a higher expression of hepcidin in lymphocytes and macrophages than wild-type or p.His63Asp carriers. An increased expression of TfR1 was also observed in all the cell types analyzed but only in p.Cys282Tyr/p.His63Asp compound heterozygous patients. A differential impact of the two HFE variants was further noticed with the observation of a significantly higher percentage of p.Cys282Tyr heterozygous patients presenting tissue iron deposition in comparison to p.His63Asp heterozygous. In the present cohort, no significant associations were found between HFE variants and classical clinicopathological markers of breast cancer behavior and prognosis. Although limited by a low sampling size, our results provide a new possible explanation for the previously reported impact of HFE major variants on breast cancer progression, i.e., not by influencing systemic iron homeostasis but rather by differentially modulating the local cellular expression of iron-related proteins and tissue iron deposition.OM is a recipient of the PhD grant SFRH/BD/2011/78184 from Fundação para a Ciência e Tecnologia (FCT). The authors also acknowledge financial support from ICBAS/AI&NSUMIB and by national funds through FCT and Ministério da Educação e Ciência (MEC) and when applicable co-funded by FEDER funds within the partnership agreement PT2020 related with the research unit number 4293.info:eu-repo/semantics/publishedVersio
Transferrin receptor 2 (TfR2) and HFE mutational analysis in non‐C282Y iron overload: identification of a novel TfR2 mutation
Blood. 2002 Aug 1;100(3):1075-7.
Transferrin receptor 2 (TfR2) and HFE mutational analysis in non-C282Y iron overload: identification of a novel TfR2 mutation.
Mattman A, Huntsman D, Lockitch G, Langlois S, Buskard N, Ralston D, Butterfield Y, Rodrigues P, Jones S, Porto G, Marra M, De Sousa M, Vatcher G.
SourceGenes, Elements, and Metabolism Program, Children and Women's Hospital of British Columbia, Vancouver, British Columbia, Canada.
Abstract
Hereditary hemochromatosis (HH) is classically associated with a Cys282Tyr (C282Y) mutation of the HFE gene. Non-C282Y HH is a heterogeneous group accounting for 15% of HH in Northern Europe. Pathogenic mutations of the transferrin receptor 2 (TfR2) gene have been identified in 4 Italian pedigrees with the latter syndrome. The goal of this study was to perform a mutational analysis of the TfR2 and HFE genes in a cohort of non-C282Y iron overload patients of mixed ethnic backgrounds. Several sequence variants were identified within the TfR2 gene, including a homozygous missense change in exon 17, c2069 A-->C, which changes a glutamine to a proline residue at position 690. This putative mutation was found in a severely affected Portuguese man and 2 family members with the same genotype. In summary, pathologic TfR2 mutations are present outside of Italy, accounting for a small proportion of non-C282Y HH
Haptoglobin type neither influences iron accumulation in normal subjects nor predicts clinical presentation in HFE C282Y haemochromatosis: phenotype and genotype analysis
In the UK, 90% of patients with hereditary haemochromatosis (HH) are homozygous for HFE C282Y, as are one in 150 people in the general population. However, only a minority of these will develop clinical haemochromatosis. Iron loss modifies iron accumulation but so may other genetic factors. Haptoglobin (Hp) exists as three major types (Hp 1-1, Hp 2-1 or Hp 2-2) and binds free plasma haemoglobin. In men, Hp 2-2 has been shown to be associated with increased macrophage iron accumulation and serum ferritin concentration. Furthermore, the frequency of Hp 2-2 was shown to be increased in patients with HH. We determined Hp types by phenotyping and genotyping 265 blood donor control subjects and 173 subjects who were homozygous for HFE C282Y. The latter group included 66 blood donors lacking clinical features suggestive of haemochromatosis and without a known family history, and 68 patients presenting clinically with haemochromatosis. Hp 2-2 frequencies did not differ in control subjects and C282Y homozygotes. Hp 2-2 was not a risk factor for disease development in HH. To investigate the relationship between iron accumulation and haptoglobin type, we determined transferrin saturation and serum ferritin concentration in 192 male, first-time blood donors aged 20-40 years who lacked both HFE C282Y and H63D. Transferrin saturation and serum ferritin concentrations did not vary with Hp type
Bases moleculares de la hemocromatosis hereditaria
La hemocromatosis hereditaria es la enfermedad más relevante dentro de las enfermedades hereditarias debido a su alta prevalencia. Se trata de una enfermedad del metabolismo del hierro que está afectada una correcta eliminación de este por el organismo y que es regulada, principalmente, por la hormona hepcidina y la proteína del gen HFE.
El hierro es una molécula necesaria para el organismo pero a su vez, si no se controlan los niveles de almacenamiento, puede causar graves problemas de sobrecarga en órganos pudiendo llegar a causar cirrosis, hepatocarcinoma, miocardiopatía, artritis o diabetes mellitus; se trata de patologías crónicas que a largo plazo podrían causar un desenlace fatal en los enfermos.
Sobre las bases moleculares que codifican esta enfermedad engloban a los procesos de absorción y transporte del hierro que no funcionarán correctamente debido a las mutaciones causadas por las distintas variantes de la enfermedad, pero, principalmente, por las ocasionadas al gen HFE. Las distintas mutaciones ocasionarán acumulación de hierro en los órganos con mayor o menor intensidad y con diferente progreso de la enfermedad.
Aunque esta sea la enfermedad hereditaria más común en la población la mayoría de los casos de esta enfermedad permanecen sin diagnosticar ya que la mayoría de las mutaciones no presentan síntomas hasta una edad adulta-madura. Por ello, es clave el diagnóstico que se realiza basándose en la técnica de la PCR y la realización de tratamientos como flebotomías o la búsqueda de incorporación de otros nuevos, como inyecciones de hepcidinaUniversidad de Sevilla. Grado en Farmaci
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