scholarly journals Targeted disruption of hepcidin in the liver recapitulates the hemochromatotic phenotype

Blood ◽  
2014 ◽  
Vol 123 (23) ◽  
pp. 3646-3650 ◽  
Author(s):  
Sara Zumerle ◽  
Jacques R. R. Mathieu ◽  
Stéphanie Delga ◽  
Mylène Heinis ◽  
Lydie Viatte ◽  
...  

Key Points Liver-specific hepcidin KO mice fully recapitulate the severe iron overload phenotype observed in the total KO mice. The hepcidin produced by hepatocytes is the main regulator of body iron homeostasis.

2017 ◽  
Vol 138 (4) ◽  
pp. 183-193 ◽  
Author(s):  
Sintayehu Ambachew ◽  
Belete Biadgo

The prevalence of type 2 diabetes is increasing in epidemic proportions worldwide. Evidence suggests body iron overload is frequently linked and observed in patients with type 2 diabetes. Body iron metabolism is based on iron conservation and recycling by which only a part of the daily need is replaced by duodenal absorption. The principal liver-produced peptide called hepcidin plays a fundamental role in iron metabolism. It directly binds to ferroportin, the sole iron exporter, resulting in the internalization and degradation of ferroportin. However, inappropriate production of hepcidin has been shown to play a role in the pathogenesis of type 2 diabetes mellitus and its complications, based on the regulation and expression in iron-abundant cells. Underexpression of hepcidin results in body iron overload, which triggers the production of reactive oxygen species simultaneously thought to play a major role in diabetes pathogenesis mediated both by β-cell failure and insulin resistance. Increased hepcidin expression results in increased intracellular sequestration of iron, and is associated with the complications of type 2 diabetes. Besides, hepcidin concentrations have been linked to inflammatory cytokines, matriptase 2, and chronic hepatitis C infection, which have in turn been reported to be associated with diabetes by several approaches. Either hepcidin-targeted therapy alone or as adjunctive therapy with phlebotomy, iron chelators, or dietary iron restriction may be able to alter iron parameters in diabetic patients. Therefore, measuring hepcidin may improve differential diagnosis and the monitoring of disorders of iron metabolism.


Blood ◽  
2017 ◽  
Vol 130 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Chia-Yu Wang ◽  
Amanda B. Core ◽  
Susanna Canali ◽  
Kimberly B. Zumbrennen-Bullough ◽  
Sinan Ozer ◽  
...  

Key Points The presence of Smad1 or Smad5 in hepatocytes is sufficient to maintain iron homeostasis, whereas deficiency of both induces iron overload. Erythropoietin and erythroferrone fail to suppress hepcidin in mice with a conditional ablation of Smad1 and Smad5 in hepatocytes.


Blood ◽  
2013 ◽  
Vol 122 (9) ◽  
pp. 1658-1668 ◽  
Author(s):  
Nicole Wilkinson ◽  
Kostas Pantopoulos

Key Points IRP1 controls HIF2α mRNA translation in vivo and thereby acts as an upstream regulator of Epo expression. IRP1 deficiency leads to age-dependent erythropoietic abnormalities and misregulation of body iron metabolism via the HIF2α/Epo pathway.


2005 ◽  
Vol 43 (4) ◽  
pp. 711-719 ◽  
Author(s):  
Igor Theurl ◽  
Susanne Ludwiczek ◽  
Philipp Eller ◽  
Markus Seifert ◽  
Erika Artner ◽  
...  

Blood ◽  
2010 ◽  
Vol 115 (16) ◽  
pp. 3382-3389 ◽  
Author(s):  
Antonella Roetto ◽  
Ferdinando Di Cunto ◽  
Rosa Maria Pellegrino ◽  
Emilio Hirsch ◽  
Ornella Azzolino ◽  
...  

Abstract Transferrin receptor 2 (TFR2) is a transmembrane protein that is mutated in hemochromatosis type 3. The TFR2 gene is transcribed in 2 main isoforms: the full-length (α) and a shorter form (β). α-Tfr2 is the sensor of diferric transferrin, implicated in the modulation of hepcidin, the main regulator of iron homeostasis. The function of the putative β-Tfr2 protein is unknown. We have developed a new mouse model (KI) lacking β-Tfr2 compared with Tfr2 knockout mice (KO). Adult Tfr2 KO mice show liver iron overload and inadequate hepcidin levels relative to body iron stores, even though they increase Bmp6 production. KI mice have normal transferrin saturation, liver iron concentration, hepcidin and Bmp6 levels but show a transient anemia at young age and severe spleen iron accumulation in adult animals. Fpn1 is strikingly decreased in the spleen of these animals. These findings and the expression of β-Tfr2 in wild-type mice spleen suggest a role for β-Tfr2 in Fpn1 transcriptional control. Selective inactivation of liver α-Tfr2 in KI mice (LCKO-KI) returned the phenotype to liver iron overload. Our results strengthen the function of hepatic α-Tfr2 in hepcidin activation, suggest a role for extrahepatic Tfr2 and indicate that β-Tfr2 may specifically control spleen iron efflux.


2021 ◽  
Vol 22 (4) ◽  
pp. 2204
Author(s):  
Simon Grootendorst ◽  
Jonathan de Wilde ◽  
Birgit van Dooijeweert ◽  
Annelies van Vuren ◽  
Wouter van Solinge ◽  
...  

Rare hereditary anemias (RHA) represent a group of disorders characterized by either impaired production of erythrocytes or decreased survival (i.e., hemolysis). In RHA, the regulation of iron metabolism and erythropoiesis is often disturbed, leading to iron overload or worsening of chronic anemia due to unavailability of iron for erythropoiesis. Whereas iron overload generally is a well-recognized complication in patients requiring regular blood transfusions, it is also a significant problem in a large proportion of patients with RHA that are not transfusion dependent. This indicates that RHA share disease-specific defects in erythroid development that are linked to intrinsic defects in iron metabolism. In this review, we discuss the key regulators involved in the interplay between iron and erythropoiesis and their importance in the spectrum of RHA.


2021 ◽  
Vol 22 (10) ◽  
pp. 5202
Author(s):  
Verena Petzer ◽  
Igor Theurl ◽  
Günter Weiss ◽  
Dominik Wolf

Systemic iron overload is multifactorial in patients suffering from myelodysplastic syndrome (MDS). Disease-immanent ineffective erythropoiesis together with chronic red blood cell transfusion represent the main underlying reasons. However, like the genetic heterogeneity of MDS, iron homeostasis is also diverse in different MDS subtypes and can no longer be generalized. While a certain amount of iron and reactive oxygen species (ROS) are indispensable for proper hematological output, both are harmful if present in excess. Consequently, iron overload has been increasingly recognized as an important player in MDS, which is worth paying attention to. This review focuses on iron- and ROS-mediated effects in the bone marrow niche, their implications for hematopoiesis and their yet unclear involvement in clonal evolution. Moreover, we provide recent insights into hepcidin regulation in MDS and its interaction between erythropoiesis and inflammation. Based on Tet methylcytosine dioxygenase 2 (TET2), representing one of the most frequently mutated genes in MDS, leading to disturbances in both iron homeostasis and hematopoiesis, we highlight that different genetic alteration may have different implications and that a comprehensive workup is needed for a complete understanding and development of future therapies.


2012 ◽  
Vol 86 (5) ◽  
pp. 683-684 ◽  
Author(s):  
R. Marchan ◽  
R. Reif ◽  
J. G. Hengstler

2017 ◽  
Vol 313 (3) ◽  
pp. G157-G165 ◽  
Author(s):  
Gautam Rishi ◽  
V. Nathan Subramaniam

The liver is one of the largest and most functionally diverse organs in the human body. In addition to roles in detoxification of xenobiotics, digestion, synthesis of important plasma proteins, gluconeogenesis, lipid metabolism, and storage, the liver also plays a significant role in iron homeostasis. Apart from being the storage site for excess body iron, it also plays a vital role in regulating the amount of iron released into the blood by enterocytes and macrophages. Since iron is essential for many important physiological and molecular processes, it increases the importance of liver in the proper functioning of the body’s metabolism. This hepatic iron-regulatory function can be attributed to the expression of many liver-specific or liver-enriched proteins, all of which play an important role in the regulation of iron homeostasis. This review focuses on these proteins and their known roles in the regulation of body iron metabolism.


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