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Gehrer CM, Mitterstiller AM, Grubwieser P, Meyron-Holtz EG, Weiss G, Nairz M. Advances in Ferritin Physiology and Possible Implications in Bacterial Infection. Int J Mol Sci 2023; 24:4659. [PMID: 36902088 PMCID: PMC10003477 DOI: 10.3390/ijms24054659] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/17/2023] [Accepted: 02/25/2023] [Indexed: 03/04/2023] Open
Abstract
Due to its advantageous redox properties, iron plays an important role in the metabolism of nearly all life. However, these properties are not only a boon but also the bane of such life forms. Since labile iron results in the generation of reactive oxygen species by Fenton chemistry, iron is stored in a relatively safe form inside of ferritin. Despite the fact that the iron storage protein ferritin has been extensively researched, many of its physiological functions are hitherto unresolved. However, research regarding ferritin's functions is gaining momentum. For example, recent major discoveries on its secretion and distribution mechanisms have been made as well as the paradigm-changing finding of intracellular compartmentalization of ferritin via interaction with nuclear receptor coactivator 4 (NCOA4). In this review, we discuss established knowledge as well as these new findings and the implications they may have for host-pathogen interaction during bacterial infection.
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Affiliation(s)
- Clemens M. Gehrer
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Anna-Maria Mitterstiller
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Philipp Grubwieser
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Esther G. Meyron-Holtz
- Laboratory of Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Günter Weiss
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Manfred Nairz
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
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Brändle K, Bergmann TC, Raic A, Li Y, Million N, Rehbock C, Barcikowski S, Lee-Thedieck C. Iron Nanoparticle Composite Hydrogels for Studying Effects of Iron Ion Release on Red Blood Cell In Vitro Production. ACS APPLIED BIO MATERIALS 2020; 3:4766-4778. [PMID: 35021724 DOI: 10.1021/acsabm.0c00297] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Growing numbers of complex surgical interventions increase the need for blood transfusions, which cannot be fulfilled by the number of donors. Therefore, the interest in producing erythrocytes from their precursors-the hematopoietic stem and progenitor cells (HSPCs)-in laboratories is rising. To enable this, in vitro systems are needed, which allow analysis of the effects of essential factors such as iron on erythroid development. For this purpose, iron ion-releasing systems based on poly(ethylene glycol) (PEG)-iron nanocomposites are developed to assess if gradual iron release improves iron bioavailability during in vitro erythroid differentiation. The nanocomposites are synthesized using surfactant-free pulsed laser ablation of iron directly in the PEG solution. The iron concentrations released from the material are sufficient to influence in vitro erythropoiesis. In this way, the production of erythroid cells cultured on flat PEG-iron nanocomposite hydrogel pads can be enhanced. In contrast, erythroid differentiation is not enhanced in the biomimetic macroporous 3D composite scaffolds, possibly because of local iron overload within the pores of the system. In conclusion, the developed iron nanoparticle-PEG composite hydrogel allows constant iron ion release and thus paves the way (i) to understand the role of iron during erythropoiesis and (ii) toward the development of biomaterials with a controlled iron release for directing erythropoiesis in culture.
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Affiliation(s)
- Katharina Brändle
- Institute of Functional Interfaces, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen 76344, Germany.,Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hannover 30419, Germany
| | - Timna C Bergmann
- Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hannover 30419, Germany
| | - Annamarija Raic
- Institute of Functional Interfaces, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen 76344, Germany.,Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hannover 30419, Germany
| | - Yaya Li
- Technical Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstr. 5-7, Essen 45141, Germany
| | - Nina Million
- Technical Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstr. 5-7, Essen 45141, Germany
| | - Christoph Rehbock
- Technical Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstr. 5-7, Essen 45141, Germany
| | - Stephan Barcikowski
- Technical Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstr. 5-7, Essen 45141, Germany
| | - Cornelia Lee-Thedieck
- Institute of Cell Biology and Biophysics, Leibniz University Hannover, Hannover 30419, Germany
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Abstract
PURPOSE OF REVIEW Terminal differentiation of erythropoietic progenitors requires the rapid accumulation of large amounts of iron, which is transported to the mitochondria, where it is incorporated into heme. Ferritin is the sole site of iron storage present in the cytosol. Yet the role of iron accumulation into ferritin in the context of red cell development had not been clearly defined. Early studies indicated that at the onset of terminal differentiation, iron initially accumulates in ferritin and precedes heme synthesis. Whether this accumulation is physiologically important for red cell development was unclear until recent studies defined an obligatory pathway of iron flux through ferritin. RECENT FINDINGS The iron chaperone functions of poly rC-binding protein 1 (PCBP1) and the autophagic cargo receptor for ferritin, nuclear co-activator 4 (NCOA4) are required for the flux of iron through ferritin in developing red cells. In the absence of these functions, iron delivery to mitochondria for heme synthesis is impaired. SUMMARY The regulated trafficking of iron through ferritin is important for maintaining a consistent flow of iron to mitochondria without releasing potentially damaging redox-active species in the cell. Other components of the iron trafficking machinery are likely to be important in red cell development.
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Yeo JH, Colonne CK, Tasneem N, Cosgriff MP, Fraser ST. The iron islands: Erythroblastic islands and iron metabolism. Biochim Biophys Acta Gen Subj 2018; 1863:466-471. [PMID: 30468802 DOI: 10.1016/j.bbagen.2018.10.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/05/2018] [Accepted: 10/30/2018] [Indexed: 11/17/2022]
Abstract
BACKGROUND A healthy human can produce over 1 × 1015 blood cells throughout their life. This remarkable amount of biomass requires a concomitantly vast amount of iron to generate functional haemoglobin and functional erythrocytes. SCOPE OF THE REVIEW Erythroblasts form multicellular clusters with macrophages in the foetal liver, bone marrow and spleen termed erythroblastic islands. How the central erythroblastic island macrophage co-ordinates the supply of iron to the developing erythroblasts will be a central focus of this review. MAJOR CONCLUSION Despite being studied for over 60 years, the mechanisms by which the erythroblastic island niche serves to control erythroid cell iron metabolism are poorly resolved. GENERAL SIGNIFICANCE Over 2 billion people suffer from some form of anaemia. Iron deficiency anaemia is the most prevalent form of anaemia. Therefore, understanding the processes by which iron is trafficked to, and metabolised in developing erythrocytes, is crucially important.
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Affiliation(s)
- Jia Hao Yeo
- Discipline of Anatomy & Histology, School of Medical sciences, Faculty of Medicine, The University of Sydney, Camperdown, Australia.
| | - Chanukya K Colonne
- Discipline of Physiology, School of Medical sciences, Faculty of Medicine, The University of Sydney, Camperdown, Australia
| | - Nuren Tasneem
- Discipline of Physiology, School of Medical sciences, Faculty of Medicine, The University of Sydney, Camperdown, Australia
| | - Matthew P Cosgriff
- Discipline of Anatomy & Histology, School of Medical sciences, Faculty of Medicine, The University of Sydney, Camperdown, Australia
| | - Stuart T Fraser
- Discipline of Anatomy & Histology, School of Medical sciences, Faculty of Medicine, The University of Sydney, Camperdown, Australia; Discipline of Physiology, School of Medical sciences, Faculty of Medicine, The University of Sydney, Camperdown, Australia; Australian Institute for Nanoscience and Nanotechnology, The University of Sydney, Camperdown, Australia.
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5
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Santana-Codina N, Mancias JD. The Role of NCOA4-Mediated Ferritinophagy in Health and Disease. Pharmaceuticals (Basel) 2018; 11:E114. [PMID: 30360520 PMCID: PMC6316710 DOI: 10.3390/ph11040114] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/17/2018] [Accepted: 10/19/2018] [Indexed: 12/26/2022] Open
Abstract
Nuclear receptor coactivator 4 (NCOA4) is a selective cargo receptor that mediates the autophagic degradation of ferritin ("ferritinophagy"), the cytosolic iron storage complex. NCOA4-mediated ferritinophagy maintains intracellular iron homeostasis by facilitating ferritin iron storage or release according to demand. Ferritinophagy is involved in iron-dependent physiological processes such as erythropoiesis, where NCOA4 mediates ferritin iron release for mitochondrial heme synthesis. Recently, ferritinophagy has been shown to regulate ferroptosis, a newly described form of iron-dependent cell death mediated by excess lipid peroxidation. Dysregulation of iron metabolism and ferroptosis have been described in neurodegeneration, cancer, and infection, but little is known about the role of ferritinophagy in the pathogenesis of these diseases. Here, we will review the biochemical regulation of NCOA4, its contribution to physiological processes and its role in disease. Finally, we will discuss the potential of activating or inhibiting ferritinophagy and ferroptosis for therapeutic purposes.
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Affiliation(s)
- Naiara Santana-Codina
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Institute of Medicine, Room 221, 4 Blackfan Circle, Boston, MA 02215, USA.
| | - Joseph D Mancias
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Institute of Medicine, Room 221, 4 Blackfan Circle, Boston, MA 02215, USA.
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Ferreira LG, Endrighi M, Lisenko KG, de Oliveira MRD, Damasceno MR, Claudino JA, Gutierres PG, Peconick AP, Saad FMDOB, Zangeronimo MG. Oat beta-glucan as a dietary supplement for dogs. PLoS One 2018; 13:e0201133. [PMID: 30063762 PMCID: PMC6067736 DOI: 10.1371/journal.pone.0201133] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 07/08/2018] [Indexed: 11/26/2022] Open
Abstract
The aim of this study was to evaluate the effects of oat beta-glucan supplementation on metabolic, physiological, immunological and nutritional variables in adult dogs. Fourteen dogs were fed a control diet or a diet supplemented with 1% beta-glucan during 71 days. Serum concentrations of glucose, total cholesterol and lipoprotein fractions, as well as plasma concentrations of peptide YY and ghrelin, were determined. In addition, coefficient of total tract apparent macronutrient digestibility (CTTAD), food intake and fecal output, score, and pH were evaluated. For evaluation of immunological variables, serum concentrations of interleukin-4 and interferon gamma were determined on days 0, 57 and 71, which corresponded to blood collection prior to beta-glucan supplementation, and at 7 and 14 days post first and second dose of vaccination (Pneumodog®, Merial, Campinas, Brazil), respectively. Animals fed the supplemented diet showed (P<0.05) lower serum concentrations of total cholesterol and low and very low density lipoproteins, lower coefficients of total tract apparent digestibility of dry matter, organic matter, mineral matter and ether extract, higher fecal output and lower fecal consistency, as well as a tendency (P = 0.07) of decreasing the coefficient of total tract apparent digestibility of crude protein. Moreover, the supplemented diet resulted in lower number of red blood cells, hematocrit percentage and hemoglobin concentration 21 days post-vaccination as well as lower serum concentration of interleukin-4 seven days post-vaccination (P<0.05). It is concluded that oat beta-glucan extract can be used as a dietary supplement for dogs at a dose of 10 g/kg of food, being effective in reducing blood concentrations of total cholesterol, LDL-c and VLDL-c as well as CTTAD of nutrients, demonstrating a potential to be used in the feeding of obese animals. In addition, by reducing the predominance of a Th2 response, oat beta-glucan can positively modulate the vaccine response of animals.
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Affiliation(s)
- Lívia Geraldi Ferreira
- Veterinary Medicine Department, Federal University of Lavras, Lavras, Minas Gerais, Brazil
| | - Mariangela Endrighi
- Veterinary Medicine Department, Federal University of Lavras, Lavras, Minas Gerais, Brazil
| | | | | | | | | | | | - Ana Paula Peconick
- Veterinary Medicine Department, Federal University of Lavras, Lavras, Minas Gerais, Brazil
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Ryu MS, Duck KA, Philpott CC. Ferritin iron regulators, PCBP1 and NCOA4, respond to cellular iron status in developing red cells. Blood Cells Mol Dis 2017; 69:75-81. [PMID: 29032941 DOI: 10.1016/j.bcmd.2017.09.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 09/23/2017] [Indexed: 10/18/2022]
Abstract
Developing red blood cells exhibit multiple, redundant systems for regulating and coordinating the uptake of iron, the synthesis of heme, and the formation of hemoglobin during terminal differentiation. We recently described the roles of poly rC-binding protein (PCBP1) and nuclear coactivator 4 (NCOA4) in mediating the flux of iron through ferritin in developing erythroid cells, with PCBP1, an iron chaperone, delivering iron to ferritin and NCOA4, an autophagic cargo receptor, directing ferritin to the lysosome for degradation and iron release. Ferritin iron flux is critical, as mice lacking these factors develop microcytic anemia. Here we report that these processes are regulated by cellular iron levels in a murine model of ex vivo terminal differentiation. PCBP1 delivers iron to ferritin via a direct protein-protein interaction. This interaction is developmentally regulated, enhanced by iron deprivation, and inhibited by iron excess, both in developing cells and in vitro. NCOA4 activity also exhibited developmental regulation and regulation by cellular iron levels. Excess iron uptake during differentiation triggered lysosomal degradation of NCOA4, which was dependent on the E3 ubiquitin ligase HERC2. Thus, developing red blood cells express a series of proteins that both mediate and regulate the flux of iron to the mitochondria.
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Affiliation(s)
- Moon-Suhn Ryu
- Genetics and Metabolism Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kari A Duck
- Genetics and Metabolism Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Caroline C Philpott
- Genetics and Metabolism Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
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8
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Ryu MS, Zhang D, Protchenko O, Shakoury-Elizeh M, Philpott CC. PCBP1 and NCOA4 regulate erythroid iron storage and heme biosynthesis. J Clin Invest 2017; 127:1786-1797. [PMID: 28375153 DOI: 10.1172/jci90519] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/02/2017] [Indexed: 01/03/2023] Open
Abstract
Developing erythrocytes take up exceptionally large amounts of iron, which must be transferred to mitochondria for incorporation into heme. This massive iron flux must be precisely controlled to permit the coordinated synthesis of heme and hemoglobin while avoiding the toxic effects of chemically reactive iron. In cultured animal cells, iron chaperones poly rC-binding protein 1 (PCBP1) and PCBP2 deliver iron to ferritin, the sole cytosolic iron storage protein, and nuclear receptor coactivator 4 (NCOA4) mediates the autophagic turnover of ferritin. The roles of PCBP, ferritin, and NCOA4 in erythroid development remain unclear. Here, we show that PCBP1, NCOA4, and ferritin are critical for murine red cell development. Using a cultured cell model of erythroid differentiation, depletion of PCBP1 or NCOA4 impaired iron trafficking through ferritin, which resulted in reduced heme synthesis, reduced hemoglobin formation, and perturbation of erythroid regulatory systems. Mice lacking Pcbp1 exhibited microcytic anemia and activation of compensatory erythropoiesis via the regulators erythropoietin and erythroferrone. Ex vivo differentiation of erythroid precursors from Pcbp1-deficient mice confirmed defects in ferritin iron flux and heme synthesis. These studies demonstrate the importance of ferritin for the vectorial transfer of imported iron to mitochondria in developing red cells and of PCBP1 and NCOA4 in mediating iron flux through ferritin.
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9
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Szunyogova E, Zhou H, Maxwell GK, Powis RA, Francesco M, Gillingwater TH, Parson SH. Survival Motor Neuron (SMN) protein is required for normal mouse liver development. Sci Rep 2016; 6:34635. [PMID: 27698380 PMCID: PMC5048144 DOI: 10.1038/srep34635] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 09/12/2016] [Indexed: 01/15/2023] Open
Abstract
Spinal Muscular Atrophy (SMA) is caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene. Decreased levels of, cell-ubiquitous, SMN protein is associated with a range of systemic pathologies reported in severe patients. Despite high levels of SMN protein in normal liver, there is no comprehensive study of liver pathology in SMA. We describe failed liver development in response to reduced SMN levels, in a mouse model of severe SMA. The SMA liver is dark red, small and has: iron deposition; immature sinusoids congested with blood; persistent erythropoietic elements and increased immature red blood cells; increased and persistent megakaryocytes which release high levels of platelets found as clot-like accumulations in the heart. Myelopoiesis in contrast, was unaffected. Further analysis revealed significant molecular changes in SMA liver, consistent with the morphological findings. Antisense treatment from birth with PMO25, increased lifespan and ameliorated all morphological defects in liver by postnatal day 21. Defects in the liver are evident at birth, prior to motor system pathology, and impair essential liver function in SMA. Liver is a key recipient of SMA therapies, and systemically delivered antisense treatment, completely rescued liver pathology. Liver therefore, represents an important therapeutic target in SMA.
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Affiliation(s)
- Eva Szunyogova
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
- Euan MacDonald Center for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Haiyan Zhou
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, London, United Kingdom
| | - Gillian K. Maxwell
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Rachael A. Powis
- Euan MacDonald Center for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, United Kingdom
- Center for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Muntoni Francesco
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, London, United Kingdom
| | - Thomas H. Gillingwater
- Euan MacDonald Center for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, United Kingdom
- Center for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Simon H. Parson
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
- Euan MacDonald Center for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, United Kingdom
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10
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Hamdi A, Roshan TM, Kahawita TM, Mason AB, Sheftel AD, Ponka P. Erythroid cell mitochondria receive endosomal iron by a "kiss-and-run" mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2859-2867. [PMID: 27627839 DOI: 10.1016/j.bbamcr.2016.09.008] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/24/2016] [Accepted: 09/08/2016] [Indexed: 12/11/2022]
Abstract
In erythroid cells, more than 90% of transferrin-derived iron enters mitochondria where ferrochelatase inserts Fe2+ into protoporphyrin IX. However, the path of iron from endosomes to mitochondrial ferrochelatase remains elusive. The prevailing opinion is that, after its export from endosomes, the redox-active metal spreads into the cytosol and mysteriously finds its way into mitochondria through passive diffusion. In contrast, this study supports the hypothesis that the highly efficient transport of iron toward ferrochelatase in erythroid cells requires a direct interaction between transferrin-endosomes and mitochondria (the "kiss-and-run" hypothesis). Using a novel method (flow sub-cytometry), we analyze lysates of reticulocytes after labeling these organelles with different fluorophores. We have identified a double-labeled population definitively representing endosomes interacting with mitochondria, as demonstrated by confocal microscopy. Moreover, we conclude that this endosome-mitochondrion association is reversible, since a "chase" with unlabeled holotransferrin causes a time-dependent decrease in the size of the double-labeled population. Importantly, the dissociation of endosomes from mitochondria does not occur in the absence of holotransferrin. Additionally, mutated recombinant holotransferrin, that cannot release iron, significantly decreases the uptake of 59Fe by reticulocytes and diminishes 59Fe incorporation into heme. This suggests that endosomes, which are unable to provide iron to mitochondria, cause a "traffic jam" leading to decreased endocytosis of holotransferrin. Altogether, our results suggest that a molecular mechanism exists to coordinate the iron status of endosomal transferrin with its trafficking. Besides its contribution to the field of iron metabolism, this study provides evidence for a new intracellular trafficking pathway of organelles.
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Affiliation(s)
- Amel Hamdi
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada; Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Tariq M Roshan
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Tanya M Kahawita
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada; Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Anne B Mason
- Department of Biochemistry, University of Vermont, Burlington, VT, USA
| | - Alex D Sheftel
- Spartan Bioscience Inc., Ottawa, Ontario, Canada; High Impact Editing, Ottawa, Ontario, Canada
| | - Prem Ponka
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada; Department of Physiology, McGill University, Montreal, Quebec, Canada.
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Noguchi-Sasaki M, Sasaki Y, Matsuo-Tezuka Y, Yasuno H, Kurasawa M, Yorozu K, Shimonaka Y. Reduction of a marker of oxidative stress with enhancement of iron utilization by erythropoiesis activation following epoetin beta pegol administration in iron-loaded db/db mice. Int J Hematol 2016; 103:262-73. [PMID: 26739261 DOI: 10.1007/s12185-015-1929-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 12/09/2015] [Accepted: 12/11/2015] [Indexed: 01/01/2023]
Abstract
UNLABELLED Iron, an essential element for various biological processes, can induce oxidative stress. We hypothesized that iron utilization for erythropoiesis, stimulated by epoetin beta pegol (C.E.R.A.), a long-acting erythropoiesis-stimulating agent, contributes to the reduction of iron-induced oxidative stress. We first investigated the sensitivity of several biomarkers to detect oxidative stress in mice by altering the amount of total body iron; we then investigated whether C.E.R.A. ameliorated oxidative stress through enhanced iron utilization. We treated db/db mice with intravenous iron-dextran and evaluated several biomarkers of iron-induced oxidative stress. In mice loaded with 5 mg/head iron, hepatic iron content was elevated and the oxidative stress marker d-ROMs (serum derivatives of reactive oxygen metabolites) was increased, whereas urinary 8-hydroxy-2'-deoxyguanosine and serum malondialdehyde were not, indicating that d-ROMs is a sensitive marker of iron-induced oxidative stress. To investigate whether C.E.R.A. ameliorated oxidative stress, db/db mice were intravenously administered iron-dextran or dextran only, followed by C.E.R.A. Hemoglobin level increased, while hepatic iron content decreased after C.E.R.A. TREATMENT Serum d-ROMs decreased after C.E.R.A. treatment in the iron-dextran-treated group. Our results suggest that C.E.R.A. promotes iron utilization for erythropoiesis through mobilization of hepatic iron storage, leading to a decrease in serum oxidative stress markers in iron-loaded db/db mice.
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Affiliation(s)
- Mariko Noguchi-Sasaki
- Product Research Department, Chugai Pharmaceutical Co., Ltd., 200 Kajiwara, Kamakura, Kanagawa, 247-8530, Japan.
| | - Yusuke Sasaki
- Product Research Department, Chugai Pharmaceutical Co., Ltd., 200 Kajiwara, Kamakura, Kanagawa, 247-8530, Japan
| | - Yukari Matsuo-Tezuka
- Product Research Department, Chugai Pharmaceutical Co., Ltd., 200 Kajiwara, Kamakura, Kanagawa, 247-8530, Japan
| | - Hideyuki Yasuno
- Product Research Department, Chugai Pharmaceutical Co., Ltd., 200 Kajiwara, Kamakura, Kanagawa, 247-8530, Japan
| | - Mitsue Kurasawa
- Product Research Department, Chugai Pharmaceutical Co., Ltd., 200 Kajiwara, Kamakura, Kanagawa, 247-8530, Japan
| | - Keigo Yorozu
- Product Research Department, Chugai Pharmaceutical Co., Ltd., 200 Kajiwara, Kamakura, Kanagawa, 247-8530, Japan
| | - Yasushi Shimonaka
- Product Research Department, Chugai Pharmaceutical Co., Ltd., 200 Kajiwara, Kamakura, Kanagawa, 247-8530, Japan
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12
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Biasiotto G, Di Lorenzo D, Archetti S, Zanella I. Iron and Neurodegeneration: Is Ferritinophagy the Link? Mol Neurobiol 2015; 53:5542-74. [PMID: 26468157 DOI: 10.1007/s12035-015-9473-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/01/2015] [Indexed: 12/12/2022]
Abstract
Mounting evidence indicates that the lysosome-autophagy pathway plays a critical role in iron release from ferritin, the main iron storage cellular protein, hence in the distribution of iron to the cells. The recent identification of nuclear receptor co-activator 4 as the receptor for ferritin delivery to selective autophagy sheds further light on the understanding of the mechanisms underlying this pathway. The emerging view is that iron release from ferritin through the lysosomes is a general mechanism in normal and tumour cells of different tissue origins, but it has not yet been investigated in brain cells. Defects in the lysosome-autophagy pathway are often involved in the pathogenesis of neurodegenerative disorders, and brain iron homeostasis disruption is a hallmark of many of these diseases. However, in most cases, it has not been established whether iron dysregulation is directly involved in the pathogenesis of the diseases or if it is a secondary effect derived from other pathogenic mechanisms. The recent evidence of the crucial involvement of autophagy in cellular iron handling offers new perspectives about the role of iron in neurodegeneration, suggesting that autophagy dysregulation could cause iron dyshomeostasis. In this review, we recapitulate our current knowledge on the routes through which iron is released from ferritin, focusing on the most recent advances. We summarise the current evidence concerning lysosome-autophagy pathway dysfunctions and those of iron metabolism and discuss their potential interconnections in several neurodegenerative disorders, such as Alzheimer's, Parkinson's and Huntington's diseases; amyotrophic lateral sclerosis; and frontotemporal lobar dementia.
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Affiliation(s)
- Giorgio Biasiotto
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Diego Di Lorenzo
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Silvana Archetti
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Isabella Zanella
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy.
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13
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Mancias JD, Pontano Vaites L, Nissim S, Biancur DE, Kim AJ, Wang X, Liu Y, Goessling W, Kimmelman AC, Harper JW. Ferritinophagy via NCOA4 is required for erythropoiesis and is regulated by iron dependent HERC2-mediated proteolysis. eLife 2015; 4. [PMID: 26436293 PMCID: PMC4592949 DOI: 10.7554/elife.10308] [Citation(s) in RCA: 311] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/05/2015] [Indexed: 12/27/2022] Open
Abstract
NCOA4 is a selective cargo receptor for the autophagic turnover of ferritin, a process critical for regulation of intracellular iron bioavailability. However, how ferritinophagy flux is controlled and the roles of NCOA4 in iron-dependent processes are poorly understood. Through analysis of the NCOA4-FTH1 interaction, we demonstrate that direct association via a key surface arginine in FTH1 and a C-terminal element in NCOA4 is required for delivery of ferritin to the lysosome via autophagosomes. Moreover, NCOA4 abundance is under dual control via autophagy and the ubiquitin proteasome system. Ubiquitin-dependent NCOA4 turnover is promoted by excess iron and involves an iron-dependent interaction between NCOA4 and the HERC2 ubiquitin ligase. In zebrafish and cultured cells, NCOA4 plays an essential role in erythroid differentiation. This work reveals the molecular nature of the NCOA4-ferritin complex and explains how intracellular iron levels modulate NCOA4-mediated ferritinophagy in cells and in an iron-dependent physiological setting. DOI:http://dx.doi.org/10.7554/eLife.10308.001 The cells of nearly all organisms need iron as this metal plays an important role in a wide range of biological processes. However, iron can also trigger the formation of harmful molecules that can damage cells. It is therefore crucial that the amount of iron in cells is tightly controlled and that any extra iron is safely stored away. Most of the iron in the body is stored within a protein called ferritin, which is then broken down to release iron as it is needed, in a process known as ferritinophagy. Cells use several systems to break down proteins, one of which, called autophagy, has been linked to ferritinophagy. During autophagy, a bubble-like structure called an autophagosome engulfs proteins that need to be removed and delivers them to a compartment in the cell where they can be broken down. In 2014, researchers showed that a protein called NCOA4 on the surface of autophagosomes targets ferritin for destruction. When iron levels are high in the cell, the amount of NCOA4 on the autophagosomes is low. This leads to fewer ferritin molecules being broken down. In contrast, low iron levels lead to an increase of NCOA4 on autophagosomes, which promotes ferritinophagy and increases the amount of iron in the cell. Now, Mancias, Vaites et al—including several of the researchers involved in the 2014 work—investigate the role of NCOA4 in ferritinophagy in more detail. Biochemical experiments revealed that a region of NCOA4 directly interacts with a particular subunit of ferritin and this interaction is necessary to deliver ferritin to autophagosomes. Mancias, Vaites et al. then used laboratory grown-cells to investigate why the amount of NCOA4 changes in response to the amount of iron in the cell. The experiments show the amount of NCOA4 varies depending on whether it interacts with another protein called HERC2, which targets proteins for destruction by a structure called the proteasome. HERC2 only binds to NCOA4 when iron levels are high, which leads to NCOA4 being broken down by the proteasome. When iron levels are low, HERC2 does not interact with NCOA4. The presence of more NCOA4 then leads to more ferritinophagy, and so increases the amount of iron in the cell. Mancias, Vaites et al. also found that red blood cells, which depend highly on iron, do not develop properly in zebrafish that have lower amounts of the NCOA4 protein. Further work is needed to see whether NCOA4 is also important for the development of other cells and tissues. DOI:http://dx.doi.org/10.7554/eLife.10308.002
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Affiliation(s)
- Joseph D Mancias
- Department of Cell Biology, Harvard Medical School, Boston, United States.,Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, United States.,Department of Radiation Oncology, Harvard Medical School, Boston, United States
| | | | - Sahar Nissim
- Gastroenterology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, United States.,Genetics Division, Brigham and Women's Hospital, Boston, United States.,Dana-Farber Cancer Institute, Boston, United States
| | - Douglas E Biancur
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, United States
| | - Andrew J Kim
- Gastroenterology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
| | - Xiaoxu Wang
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, United States
| | - Yu Liu
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Wolfram Goessling
- Gastroenterology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, United States.,Genetics Division, Brigham and Women's Hospital, Boston, United States.,Dana-Farber Cancer Institute, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Alec C Kimmelman
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, United States
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, United States
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14
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Epoetin beta pegol (C.E.R.A.) promotes utilization of iron for erythropoiesis through intensive suppression of serum hepcidin levels in mice. Int J Hematol 2014; 99:561-9. [DOI: 10.1007/s12185-014-1554-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 02/19/2014] [Accepted: 02/20/2014] [Indexed: 02/08/2023]
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15
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Al-Qenaei A, Yiakouvaki A, Reelfs O, Santambrogio P, Levi S, Hall ND, Tyrrell RM, Pourzand C. Role of intracellular labile iron, ferritin, and antioxidant defence in resistance of chronically adapted Jurkat T cells to hydrogen peroxide. Free Radic Biol Med 2014; 68:87-100. [PMID: 24333634 PMCID: PMC4046229 DOI: 10.1016/j.freeradbiomed.2013.12.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 11/14/2013] [Accepted: 12/06/2013] [Indexed: 02/07/2023]
Abstract
To examine the role of intracellular labile iron pool (LIP), ferritin (Ft), and antioxidant defence in cellular resistance to oxidative stress on chronic adaptation, a new H2O2-resistant Jurkat T cell line "HJ16" was developed by gradual adaptation of parental "J16" cells to high concentrations of H2O2. Compared to J16 cells, HJ16 cells exhibited much higher resistance to H2O2-induced oxidative damage and necrotic cell death (up to 3mM) and had enhanced antioxidant defence in the form of significantly higher intracellular glutathione and mitochondrial ferritin (FtMt) levels as well as higher glutathione-peroxidase (GPx) activity. In contrast, the level of the Ft H-subunit (FtH) in the H2O2-adapted cell line was found to be 7-fold lower than in the parental J16 cell line. While H2O2 concentrations higher than 0.1mM fully depleted the glutathione content of J16 cells, in HJ16 cells the same treatments decreased the cellular glutathione content to only half of the original value. In HJ16 cells, H2O2 concentrations higher than 0.1mM increased the level of FtMt up to 4-fold of their control values but had no effect on the FtMt levels in J16 cells. Furthermore, while the basal cytosolic level of LIP was similar in both cell lines, H2O2 treatment substantially increased the cytosolic LIP levels in J16 but not in HJ16 cells. H2O2 treatment also substantially decreased the FtH levels in J16 cells (up to 70% of the control value). In contrast in HJ16 cells, FtH levels were not affected by H2O2 treatment. These results indicate that chronic adaptation of J16 cells to high concentrations of H2O2 has provoked a series of novel and specific cellular adaptive responses that contribute to higher resistance of HJ16 cells to oxidative damage and cell death. These include increased cellular antioxidant defence in the form of higher glutathione and FtMt levels, higher GPx activity, and lower FtH levels. Further adaptive responses include the significantly reduced cellular response to oxidant-mediated glutathione depletion, FtH modulation, and labile iron release and a significant increase in FtMt levels following H2O2 treatment.
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Affiliation(s)
| | - Anthie Yiakouvaki
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK
| | - Olivier Reelfs
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK
| | | | - Sonia Levi
- San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
| | - Nick D Hall
- Bath Institute for Rheumatic Diseases, Bath, UK
| | - Rex M Tyrrell
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK
| | - Charareh Pourzand
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK.
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16
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Linder MC. Mobilization of stored iron in mammals: a review. Nutrients 2013; 5:4022-50. [PMID: 24152745 PMCID: PMC3820057 DOI: 10.3390/nu5104022] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 09/04/2013] [Accepted: 09/12/2013] [Indexed: 12/16/2022] Open
Abstract
From the nutritional standpoint, several aspects of the biochemistry and physiology of iron are unique. In stark contrast to most other elements, most of the iron in mammals is in the blood attached to red blood cell hemoglobin and transporting oxygen to cells for oxidative phosphorylation and other purposes. Controlled and uncontrolled blood loss thus has a major impact on iron availability. Also, in contrast to most other nutrients, iron is poorly absorbed and poorly excreted. Moreover, amounts absorbed (~1 mg/day in adults) are much less than the total iron (~20 mg/day) cycling into and out of hemoglobin, involving bone marrow erythropoiesis and reticuloendothelial cell degradation of aged red cells. In the face of uncertainties in iron bioavailability, the mammalian organism has evolved a complex system to retain and store iron not immediately in use, and to make that iron available when and where it is needed. Iron is stored innocuously in the large hollow protein, ferritin, particularly in cells of the liver, spleen and bone marrow. Our current understanding of the molecular, cellular and physiological mechanisms by which this stored iron in ferritin is mobilized and distributed-within the cell or to other organs-is the subject of this review.
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Affiliation(s)
- Maria C Linder
- Department of Chemistry and Biochemistry, California State University, Fullerton, CA 92834-6866, USA.
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17
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Zhang Y, Zhang R, Zou J, Hu X, Wang S, Zhang L, Bao Z. Identification and characterization of four ferritin subunits involved in immune defense of the Yesso scallop (Patinopecten yessoensis). FISH & SHELLFISH IMMUNOLOGY 2013; 34:1178-1187. [PMID: 23428517 DOI: 10.1016/j.fsi.2013.01.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 01/21/2013] [Accepted: 01/27/2013] [Indexed: 06/01/2023]
Abstract
As a primary iron storage protein, ferritin plays a vital role in iron homeostasis and innate immunity. In this study, four ferritin subunits (PyFer1, PyFer2, PyFer3, and PyFer4) were cloned from the Yesso scallop, Patinopecten yessoensis, by rapid amplification of cDNA ends (RACE) following in silico transcriptome analysis. The full-length cDNAs of the four ferritins are 895, 920, 891, and 1400 bp in length, respectively, and each contains a putative iron response element (IRE) in its 5' UTR. Meanwhile, multiple A+U-destabilizing elements (TATT or ATTTA) are present in the 3' UTRs of PyFer2 and PyFer4. The open reading frames of the four ferritins are 522, 516, 516, and 519 bp, encoding 173, 171, 171, and 172 amino acids, respectively. These proteins have typical ferritin structures, with four long α-helices, one short α-helix and an L-loop. All of the predicted proteins possess both the ferroxidase center of mammalian H ferritins (E25, Y32, E59, E60, H63, E105, and Q139) and the iron nucleation site of mammalian L ferritins (H116, D129, and E132), and the recombinant proteins possess apparent ferroxidase activity. Quantitative real-time PCR analysis revealed that the expression of the four PyFers was significantly elevated at the D-shaped stage and was relatively high in the adult mantle and hepatopancreas. Furthermore, the four PyFers were significantly up-regulated by iron or bacterial challenge, and all four purified recombinant PyFers were able to inhibit the growth of the scallop pathogen Vibrio anguillarum. These results suggest that these PyFers are likely to play important roles in many fundamental biological processes in P. yessoensis, including immune defense, iron homeostasis, and shell development.
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Affiliation(s)
- Yueyue Zhang
- Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
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18
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Baati T, Njim L, Neffati F, Kerkeni A, Bouttemi M, Gref R, Najjar MF, Zakhama A, Couvreur P, Serre C, Horcajada P. In depth analysis of the in vivo toxicity of nanoparticles of porous iron(iii) metal–organic frameworks. Chem Sci 2013. [DOI: 10.1039/c3sc22116d] [Citation(s) in RCA: 253] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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19
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Cardiac protection by preconditioning is generated via an iron-signal created by proteasomal degradation of iron proteins. PLoS One 2012; 7:e48947. [PMID: 23155431 PMCID: PMC3498359 DOI: 10.1371/journal.pone.0048947] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 10/02/2012] [Indexed: 11/25/2022] Open
Abstract
Ischemia associated injury of the myocardium is caused by oxidative damage during reperfusion. Myocardial protection by ischemic preconditioning (IPC) was shown to be mediated by a transient ‘iron-signal’ that leads to the accumulation of apoferritin and sequestration of reactive iron released during the ischemia. Here we identified the source of this ‘iron signal’ and evaluated its role in the mechanisms of cardiac protection by hypoxic preconditioning. Rat hearts were retrogradely perfused and the effect of proteasomal and lysosomal protease inhibitors on ferritin levels were measured. The iron-signal was abolished, ferritin levels were not increased and cardiac protection was diminished by inhibition of the proteasome prior to IPC. Similarly, double amounts of ferritin and better recovery after ex vivo ischemia-and-reperfusion (I/R) were found in hearts from in vivo hypoxia pre-conditioned animals. IPC followed by normoxic perfusion for 30 min (‘delay’) prior to I/R caused a reduced ferritin accumulation at the end of the ischemia phase and reduced protection. Full restoration of the IPC-mediated cardiac protection was achieved by employing lysosomal inhibitors during the ‘delay’. In conclusion, proteasomal protein degradation of iron-proteins causes the generation of the ‘iron-signal’ by IPC, ensuing de-novo apoferritin synthesis and thus, sequestering reactive iron. Lysosomal proteases are involved in subsequent ferritin breakdown as revealed by the use of specific pathway inhibitors during the ‘delay’. We suggest that proteasomal iron-protein degradation is a stress response causing an expeditious cytosolic iron release thus, altering iron homeostasis to protect the myocardium during I/R, while lysosomal ferritin degradation is part of housekeeping iron homeostasis.
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20
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Should we reconsider iron administration based on prevailing ferritin and hepcidin concentrations? Clin Exp Nephrol 2012; 16:819-26. [PMID: 23053592 PMCID: PMC3521641 DOI: 10.1007/s10157-012-0694-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 08/29/2012] [Indexed: 12/21/2022]
Abstract
The results of recent randomized, controlled trials in patients with chronic kidney disease and anemia have suggested that hyporesponsiveness to erythropoiesis stimulating agents (ESA) is a significant predictor of poor patient outcomes. Functional iron deficiency (FID) is the most common cause of suboptimal ESA response, and intravenous iron administration (IVFe) efficiently raises hemoglobin (Hb) concentrations even under the condition of FID. Consequently, renal anemia correction has conceptually shifted from ‘higher Hb values with high ESA doses’ to ‘prevention of ESA hyporesponsiveness with IVFe’. The discovery of hepcidin has profoundly changed our understanding of the place of FID in renal anemia therapy. Hepcidin reduces the abundance of iron transport proteins which facilitate iron absorption from the gut and iron mobilization from macrophages. Serum hepcidin is mainly modulated by iron stores, as is serum ferritin. High hepcidin or ferritin levels block intestinal iron absorption and iron recycling in macrophages and decrease iron availability for erythropoiesis, leading to FID. Iron administration, especially IVFe, increases hepcidin levels and concomitantly inhibits iron supply to erythroid cells. This in turn could lead to a vicious circle, exacerbating FID and increasing iron demand. Therefore, physicians should be cautious with unrestricted IVFe to chronic kidney disease patients with FID.
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21
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Sheftel AD, Mason AB, Ponka P. The long history of iron in the Universe and in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1820:161-87. [PMID: 21856378 PMCID: PMC3258305 DOI: 10.1016/j.bbagen.2011.08.002] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 07/19/2011] [Accepted: 08/01/2011] [Indexed: 12/21/2022]
Abstract
BACKGROUND Not long after the Big Bang, iron began to play a central role in the Universe and soon became mired in the tangle of biochemistry that is the prima essentia of life. Since life's addiction to iron transcends the oxygenation of the Earth's atmosphere, living things must be protected from the potentially dangerous mix of iron and oxygen. The human being possesses grams of this potentially toxic transition metal, which is shuttling through his oxygen-rich humor. Since long before the birth of modern medicine, the blood-vibrant red from a massive abundance of hemoglobin iron-has been a focus for health experts. SCOPE OF REVIEW We describe the current understanding of iron metabolism, highlight the many important discoveries that accreted this knowledge, and describe the perils of dysfunctional iron handling. GENERAL SIGNIFICANCE Isaac Newton famously penned, "If I have seen further than others, it is by standing upon the shoulders of giants". We hope that this review will inspire future scientists to develop intellectual pursuits by understanding the research and ideas from many remarkable thinkers of the past. MAJOR CONCLUSIONS The history of iron research is a long, rich story with early beginnings, and is far from being finished. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders.
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Affiliation(s)
- Alex D. Sheftel
- University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON K1Y 4W7, Canada
| | - Anne B. Mason
- Department of Biochemistry, College of Medicine, University of Vermont, 89 Beaumont Avenue, Burlington, VT 05405-0068, USA
| | - Prem Ponka
- Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Côte-Ste.-Catherine Rd., Montréal, QC H3T 1E2, and Departments of Physiology and Medicine, McGill University, Montréal, QC, Canada
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22
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Chen C, Paw BH. Cellular and mitochondrial iron homeostasis in vertebrates. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1459-67. [PMID: 22285816 DOI: 10.1016/j.bbamcr.2012.01.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 01/07/2012] [Accepted: 01/07/2012] [Indexed: 02/08/2023]
Abstract
Iron plays an essential role in cellular metabolism and biological processes. However, due to its intrinsic redox activity, free iron is a potentially toxic molecule in cellular biochemistry. Thus, organisms have developed sophisticated ways to import, sequester, and utilize iron. The transferrin cycle is a well-studied iron uptake pathway that is important for most vertebrate cells. Circulating iron can also be imported into cells by mechanisms that are independent of transferrin. Once imported into erythroid cells, iron is predominantly consumed by the mitochondria for the biosynthesis of heme and iron sulfur clusters. This review focuses on canonical transferrin-mediated and the newly discovered, non-transferrin mediated iron uptake pathways, as well as, mitochondrial iron homeostasis in higher eukaryotes. This article is part of a Special Issue entitled: Cell Biology of Metals.
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Affiliation(s)
- Caiyong Chen
- Department of Medicine, Hematology Division, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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23
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Aroun A, Zhong JL, Tyrrell RM, Pourzand C. Iron, oxidative stress and the example of solar ultraviolet A radiation. Photochem Photobiol Sci 2012; 11:118-34. [DOI: 10.1039/c1pp05204g] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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24
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Kurz T, Eaton JW, Brunk UT. The role of lysosomes in iron metabolism and recycling. Int J Biochem Cell Biol 2011; 43:1686-97. [PMID: 21907822 DOI: 10.1016/j.biocel.2011.08.016] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 08/25/2011] [Accepted: 08/26/2011] [Indexed: 02/07/2023]
Abstract
Iron is the most abundant transition metal in the earth's crust. It cycles easily between ferric (oxidized; Fe(III)) and ferrous (reduced; Fe(II)) and readily forms complexes with oxygen, making this metal a central player in respiration and related redox processes. However, 'loose' iron, not within heme or iron-sulfur cluster proteins, can be destructively redox-active, causing damage to almost all cellular components, killing both cells and organisms. This may explain why iron is so carefully handled by aerobic organisms. Iron uptake from the environment is carefully limited and carried out by specialized iron transport mechanisms. One reason that iron uptake is tightly controlled is that most organisms and cells cannot efficiently excrete excess iron. When even small amounts of intracellular free iron occur, most of it is safely stored in a non-redox-active form in ferritins. Within nucleated cells, iron is constantly being recycled from aged iron-rich organelles such as mitochondria and used for construction of new organelles. Much of this recycling occurs within the lysosome, an acidic digestive organelle. Because of this, most lysosomes contain relatively large amounts of redox-active iron and are therefore unusually susceptible to oxidant-mediated destabilization or rupture. In many cell types, iron transit through the lysosomal compartment can be remarkably brisk. However, conditions adversely affecting lysosomal iron handling (or oxidant stress) can contribute to a variety of acute and chronic diseases. These considerations make normal and abnormal lysosomal handling of iron central to the understanding and, perhaps, therapy of a wide range of diseases.
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Affiliation(s)
- Tino Kurz
- Division of Pharmacology, Faculty of Health Sciences, Linköping University, 581 85 Linköping, Sweden.
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25
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Kurz T, Gustafsson B, Brunk UT. Cell sensitivity to oxidative stress is influenced by ferritin autophagy. Free Radic Biol Med 2011; 50:1647-58. [PMID: 21419217 DOI: 10.1016/j.freeradbiomed.2011.03.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 02/24/2011] [Accepted: 03/08/2011] [Indexed: 12/19/2022]
Abstract
To test the consequences of lysosomal degradation of differently iron-loaded ferritin molecules and to mimic ferritin autophagy under iron-overload and normal conditions, J774 cells were allowed to endocytose heavily iron loaded ferritin, probably with some adventitious iron (Fe-Ft), or iron-free apo-ferritin (apo-Ft). When cells subsequently were exposed to a bolus dose of hydrogen peroxide, apo-Ft prevented lysosomal membrane permeabilization (LMP), whereas Fe-Ft enhanced LMP. A 4-h pulse of Fe-Ft initially increased oxidative stress-mediated LMP that was reversed after another 3h under standard culture conditions, suggesting that lysosomal iron is rapidly exported from lysosomes, with resulting upregulation of apo-ferritin that supposedly is autophagocytosed, thereby preventing LMP by binding intralysosomal redox-active iron. The obtained data suggest that upregulation of the stress protein ferritin is a rapid adaptive mechanism that counteracts LMP and ensuing apoptosis during oxidative stress. In addition, prolonged iron starvation was found to induce apoptotic cell death that, interestingly, was preceded by LMP, suggesting that LMP is a more general phenomenon in apoptosis than so far recognized. The findings provide new insights into aging and neurodegenerative diseases that are associated with enhanced amounts of cellular iron and show that lysosomal iron loading sensitizes to oxidative stress.
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Affiliation(s)
- Tino Kurz
- Division of Pharmacology, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
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26
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A possible role for secreted ferritin in tissue iron distribution. J Neural Transm (Vienna) 2011; 118:337-47. [PMID: 21298454 DOI: 10.1007/s00702-011-0582-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 01/09/2011] [Indexed: 01/19/2023]
Abstract
Ferritin is known as a well-conserved iron detoxification and storage protein that is found in the cytosol of many prokaryotic and eukaryotic organisms. In insects and worms, ferritin has evolved into a classically secreted protein that transports iron systemically. Mammalian ferritins are found intracellularly in the cytosol, as well as in the nucleus, the endo-lysosomal compartment and the mitochondria. Extracellular ferritin is found in fluids such as serum and synovial and cerebrospinal fluids. We recently characterized the biophysical properties, secretion mechanism and cellular origin of mouse serum ferritin, which is actively secreted by a non-classical pathway involving lysosomal processing. Here, we review the data to support a hypothesis that intracellular and extracellular ferritin may play a role in intra- and intercellular redistribution of iron.
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27
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Abstract
Iron is essential for all life, yet can be dangerous under certain conditions. Iron storage by the 24-subunit protein ferritin renders excess amounts of the metal non-reactive and, consequentially, ferritin is crucial for life. Although the mechanism detailing the storage of iron in ferritin has been well characterized, little is known about the fate of ferritin-stored iron and whether it can be released and reutilized for metabolic use within a single cell. Virtually nothing is known about the use of ferritin-derived iron in non-erythroid cells. We therefore attempted to answer the question of whether iron from ferritin can be used for haem synthesis in the murine macrophage cell line RAW 264.7 cells. Cells treated with ALA (5-aminolaevulinic acid; a precursor of haem synthesis) show increased haem production as determined by enhanced incorporation of transferrin-bound 59Fe into haem. However, the present study shows that, upon the addition of ALA, 59Fe from ferritin cannot be incorporated into haem. Additionally, little 59Fe is liberated from ferritin when haem synthesis is increased upon addition of ALA. In conclusion, ferritin in cultivated macrophages is not a significant source of iron for the cell's own metabolic functions.
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28
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Zhang HL, Li YQ, Zhang MZ, Zhao YD. Real-time observation of the effect of iron on receptor-mediated endocytosis of transferrin conjugated with quantum dots. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:045003. [PMID: 20799798 DOI: 10.1117/1.3465595] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The optical properties of antiphotobleaching and the advantage of long-term fluorescence observation of quantum dots are fully adopted to study the effects of iron on the endocytosis of transferrin. Quantum dots are labeled for transferrin and endocytosis of transferrin in HeLa cells is observed under the normal state, iron overloading, and an iron-deficient state. In these three states, the fluorescence undergoes a gradual process of first dark, then light, and finally dark, indicating the endocytosis of transferrin. The fluorescence intensity analysis shows that a platform emerges when fluorescence changes to a certain degree in the three states. Experienced a same period of time after platform, the fluorescence strength of cells in the normal state is 1.2 times the first value, and the iron-deficiency state is 1.4 times, but the iron overloading state was 0.85 times. We also find that the average fluorescence intensity in cells detected by the spectrophotometer in the iron-deficiency state is almost 7 times than that in a high iron state. All this proves that iron overloading would slow the process, but iron deficiency would accelerate endocytosis. We advance a direct observational method that may contribute to further study of the relationship of iron and transferrin.
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Affiliation(s)
- Hai-Li Zhang
- Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Wuhan, Hubei, China
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Darshan D, Vanoaica L, Richman L, Beermann F, Kühn LC. Conditional deletion of ferritin H in mice induces loss of iron storage and liver damage. Hepatology 2009; 50:852-60. [PMID: 19492434 DOI: 10.1002/hep.23058] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
UNLABELLED Ferritin plays a central role in iron metabolism by acting both as iron storage and a detoxifying protein. We generated a ferritin H allele with loxP sites and studied the conditional ferritin H deletion in adult mice. Ten days after Mx-Cre induced deletion, ferritin H messenger RNA (mRNA) was below 5% in the liver, spleen, and bone marrow of deleted mice compared to control littermates. Mice lost their cellular iron stores indicating the requirement of ferritin H in iron deposition. Serum iron and transferrin saturation were slightly increased and correlated with a two-fold increased liver hepcidin 1 mRNA and a reduced duodenal DcytB mRNA level. Under a normal iron regimen, deleted mice survived for 2 years without visible disadvantage. Mice fed on a high iron diet prior to ferritin H deletion suffered from severe liver damage. Similarly, ferritin H deleted mouse embryonic fibroblasts showed rapid cell death after exposure to iron salt in the medium. This was reversed by wild-type ferritin H but not by a ferritin H mutant lacking ferroxidase activity. Cell death was preceded by an increase in cytoplasmic free iron, reactive oxygen species, and mitochondrial depolarization. CONCLUSION Our results provide evidence that the iron storage function of ferritin plays a major role in preventing iron-mediated cell and tissue damage.
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Affiliation(s)
- Deepak Darshan
- Ecole Polytechnique Fédérale de Lausanne, ISREC - Swiss Institute for Experimental Cancer Research, Lausanne, Switzerland
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Hower V, Mendes P, Torti FM, Laubenbacher R, Akman S, Shulaev V, Torti SV. A general map of iron metabolism and tissue-specific subnetworks. MOLECULAR BIOSYSTEMS 2009; 5:422-43. [PMID: 19381358 PMCID: PMC2680238 DOI: 10.1039/b816714c] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Iron is required for survival of mammalian cells. Recently, understanding of iron metabolism and trafficking has increased dramatically, revealing a complex, interacting network largely unknown just a few years ago. This provides an excellent model for systems biology development and analysis. The first step in such an analysis is the construction of a structural network of iron metabolism, which we present here. This network was created using CellDesigner version 3.5.2 and includes reactions occurring in mammalian cells of numerous tissue types. The iron metabolic network contains 151 chemical species and 107 reactions and transport steps. Starting from this general model, we construct iron networks for specific tissues and cells that are fundamental to maintaining body iron homeostasis. We include subnetworks for cells of the intestine and liver, tissues important in iron uptake and storage, respectively, as well as the reticulocyte and macrophage, key cells in iron utilization and recycling. The addition of kinetic information to our structural network will permit the simulation of iron metabolism in different tissues as well as in health and disease.
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Affiliation(s)
- Valerie Hower
- Department of Cancer Biology, Wake Forest University School of Medicine, Medical Center Blvd, Winston Salem, NC 27157, USA
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Ferritins: a family of molecules for iron storage, antioxidation and more. Biochim Biophys Acta Gen Subj 2008; 1790:589-99. [PMID: 18929623 DOI: 10.1016/j.bbagen.2008.09.004] [Citation(s) in RCA: 609] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 08/28/2008] [Accepted: 09/09/2008] [Indexed: 01/19/2023]
Abstract
Ferritins are characterized by highly conserved three-dimensional structures similar to spherical shells, designed to accommodate large amounts of iron in a safe, soluble and bioavailable form. They can have different architectures with 12 or 24 equivalent or non-equivalent subunits, all surrounding a large cavity. All ferritins readily interact with Fe(II) to induce its oxidation and deposition in the cavity in a mineral form, in a reaction that is catalyzed by a ferroxidase center. This is an anti-oxidant activity that consumes Fe(II) and peroxides, the reagents that produce toxic free radicals in the Fenton reaction. The mechanism of ferritin iron incorporation has been characterized in detail, while that of iron release and recycling has been less thoroughly studied. Generally ferritin expression is regulated by iron and by oxidative damage, and in vertebrates it has a central role in the control of cellular iron homeostasis. Ferritin is mostly cytosolic but is found also in mammalian mitochondria and nuclei, in plant plastids and is secreted in insects. In vertebrates the cytosolic ferritins are composed of H and L subunit types and their assembly in a tissues specific ratio that permits flexibility to adapt to cell needs. The H-ferritin can translocate to the nuclei in some cell types to protect DNA from iron toxicity, or can be actively secreted, accomplishing various functions. The mitochondrial ferritin is found in mammals, it has a restricted tissue distribution and it seems to protect the mitochondria from iron toxicity and oxidative damage. The various functions attributed to the cytosolic, nuclear, secretory and mitochondrial ferritins are discussed.
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Heart protection by ischemic preconditioning: a novel pathway initiated by iron and mediated by ferritin. J Mol Cell Cardiol 2008; 45:839-45. [PMID: 18817783 DOI: 10.1016/j.yjmcc.2008.08.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2008] [Revised: 08/11/2008] [Accepted: 08/22/2008] [Indexed: 12/20/2022]
Abstract
Ischemic preconditioning is a well-known procedure transiently protecting the heart against injury associated with prolonged ischemia, through mechanism/s only partly understood. The aim of this study was to test whether preconditioning-induced protection of the heart involves an iron-based mechanism, including the generation of an iron signal followed by accumulation of ferritin. In isolated rat hearts perfused in the Langendorff configuration, we measured heart contractility, ferritin levels, ferritin-iron content, and mRNA levels of ferritin subunits. Ischemic preconditioning caused rapid accumulation of ferritin, reaching 359% of the baseline value (set at 100%). This was accompanied by a parallel decline in ferritin-bound iron: from 2191+/-548 down to 760+/-34 Fe atoms/ferritin molecule, p<0.05. Ferritin levels remained high during the subsequent period of prolonged ischemia, and returned to nearly the baseline value during the reperfusion phase. Selective iron chelators (acetyl hydroxamate or Zn-desferrioxamine) abrogated the functional protection and suppressed ferritin accumulation, thus demonstrating the essentiality of an iron signal in the preconditioning-induced protective mechanism. Moreover, introduction of an iron-containing ternary complex, known to import iron into cells, caused a three-fold accumulation of ferritin and simulated the preconditioning-induced functional protection against prolonged myocardial ischemia. The ischemic preconditioning-and-ischemia-induced increase in ferritin levels correlated well with the accumulation of ferritin L-subunit mRNA: 5.44+/-0.47 vs 1.23+/-0.15 (units) in the baseline, p<0.05, suggesting that transcriptional control of ferritin L-subunit synthesis had been activated. Ischemic preconditioning initiates de novo synthesis of ferritin in the heart; the extra ferritin is proposed to serve a 'sink' for redox-active iron, thus protecting the heart from iron-mediated oxidative damage associated with ischemia-reperfusion injury. The present results substantiate a novel iron-based mechanism of ischemic preconditioning and could pave the way for the development of new modalities of heart protection.
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Abstract
Although most cellular iron is firmly bound (e.g. in haemoglobin), some, the labile iron pool (LIP), is bound to low-affinity ligands. The LIP is regarded as the crossroads of cellular iron traffic. Using multi-parameter flow-cytometry of cells treated with the metal-sensitive sensor calcein and the cell-permeable chelator deferiprone, we studied LIP in various human erythroid cell populations in peripheral blood, bone marrow and culture. Erythroid maturation was found to be associated with a decrease in the LIP. In the peripheral blood, nucleated erythrocytes (normoblasts) had 5.8-fold and 8.8-fold greater LIP than reticulocytes and erythrocytes respectively. Early reticulocytes had 2.5-fold more LIP than late reticulocytes. In the bone-marrow and in culture, LIP decreased by c. 30-fold as early erythroid precursors matured to late precursors. Adding holo-transferrin to iron-depleted cultures elevated LIP by 3.9-fold. We also show that in beta-thalassaemia, a disease associated with iron-overload, erythrocytes and reticulocytes in the blood and erythroid precursors in culture have a significantly greater LIP than their normal counterparts. In conclusion, the LIP in erythroid cells is altered under physiological (maturation) and pathological (thalassaemia) conditions. The methodology presented might be useful for evaluating the LIP in various diseases and for studying the efficacy of iron-chelators.
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Affiliation(s)
- Eugenia Prus
- Department of Haematology, Hadassah-Hebrew University Medical Centre, Jerusalem, Israel
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Kurz T, Terman A, Gustafsson B, Brunk UT. Lysosomes in iron metabolism, ageing and apoptosis. Histochem Cell Biol 2008; 129:389-406. [PMID: 18259769 PMCID: PMC2668650 DOI: 10.1007/s00418-008-0394-y] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2008] [Indexed: 12/19/2022]
Abstract
The lysosomal compartment is essential for a variety of cellular functions, including the normal turnover of most long-lived proteins and all organelles. The compartment consists of numerous acidic vesicles (pH approximately 4 to 5) that constantly fuse and divide. It receives a large number of hydrolases ( approximately 50) from the trans-Golgi network, and substrates from both the cells' outside (heterophagy) and inside (autophagy). Many macromolecules contain iron that gives rise to an iron-rich environment in lysosomes that recently have degraded such macromolecules. Iron-rich lysosomes are sensitive to oxidative stress, while 'resting' lysosomes, which have not recently participated in autophagic events, are not. The magnitude of oxidative stress determines the degree of lysosomal destabilization and, consequently, whether arrested growth, reparative autophagy, apoptosis, or necrosis will follow. Heterophagy is the first step in the process by which immunocompetent cells modify antigens and produce antibodies, while exocytosis of lysosomal enzymes may promote tumor invasion, angiogenesis, and metastasis. Apart from being an essential turnover process, autophagy is also a mechanism by which cells will be able to sustain temporary starvation and rid themselves of intracellular organisms that have invaded, although some pathogens have evolved mechanisms to prevent their destruction. Mutated lysosomal enzymes are the underlying cause of a number of lysosomal storage diseases involving the accumulation of materials that would be the substrate for the corresponding hydrolases, were they not defective. The normal, low-level diffusion of hydrogen peroxide into iron-rich lysosomes causes the slow formation of lipofuscin in long-lived postmitotic cells, where it occupies a substantial part of the lysosomal compartment at the end of the life span. This seems to result in the diversion of newly produced lysosomal enzymes away from autophagosomes, leading to the accumulation of malfunctioning mitochondria and proteins with consequent cellular dysfunction. If autophagy were a perfect turnover process, postmitotic ageing and several age-related neurodegenerative diseases would, perhaps, not take place.
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Affiliation(s)
- Tino Kurz
- Division of Pharmacology, Faculty of Health Sciences, Linköping University, Linköping, Sweden
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35
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Leimberg JM, Prus E, Link G, Fibach E, Konijn AM. Iron-chelator complexes as iron sources for early developing human erythroid precursors. Transl Res 2008; 151:88-96. [PMID: 18201676 DOI: 10.1016/j.trsl.2007.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Revised: 11/29/2007] [Accepted: 12/04/2007] [Indexed: 11/24/2022]
Abstract
Developing erythroid cells are dependent on transferrin (Tf) to acquire iron in amounts sufficient for hemoglobin production. Previously, we showed that although these cells cannot grow in culture in the absence of Tf, ferritin (Ft) can substitute Tf to some extent and support the development of hemoglobin-containing cells. In the current study, we investigated the ability of various iron sources to replace Tf in cultures of normal human erythroid precursors. The results showed that whereas Ft and hemin supported erythroid cell proliferation and hemoglobinization in Tf-free cultures to some extent, ferric amonium citrate and iron complexed with several chelators had little or no effect. Although salicylaldehyde-isonicotinoyl-hydrazone, which is a tridentate lipid-soluble chelator, complexed with iron increased both cytosolic and mitochondrial labile iron pools, it failed to support heme synthesis and did not decrease the surface Tf receptors, suggesting that its iron is not recognized by the cells. Moreover, this iron-chelator complex did not support erythroid precursor proliferation and hemoglobinization. Thus, although under normal conditions, Tf is the major route of iron uptake, Ft and hemin, but not iron-chelator complexes, may serve as alternative iron sources under Tf-poor conditions.
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Affiliation(s)
- Joseph M Leimberg
- Department of Human Nutrition and Metabolism, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
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36
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Lysosomes and oxidative stress in aging and apoptosis. Biochim Biophys Acta Gen Subj 2008; 1780:1291-303. [PMID: 18255041 DOI: 10.1016/j.bbagen.2008.01.009] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 01/13/2008] [Accepted: 01/15/2008] [Indexed: 12/19/2022]
Abstract
The lysosomal compartment consists of numerous acidic vesicles (pH approximately 4-5) that constantly fuse and divide. It receives a large number of hydrolases from the trans-Golgi network, while their substrates arrive from both the cell's outside (heterophagy) and inside (autophagy). Many macromolecules under degradation inside lysosomes contain iron that, when released in labile form, makes lysosomes sensitive to oxidative stress. The magnitude of generated lysosomal destabilization determines if reparative autophagy, apoptosis, or necrosis will follow. Apart from being an essential turnover process, autophagy is also a mechanism for cells to repair inflicted damage, and to survive temporary starvation. The inevitable diffusion of hydrogen peroxide into iron-rich lysosomes causes the slow oxidative formation of lipofuscin in long-lived postmitotic cells, where it finally occupies a substantial part of the volume of the lysosomal compartment. This seems to result in a misdirection of lysosomal enzymes away from autophagosomes, resulting in depressed autophagy and the accumulation of malfunctioning mitochondria and proteins with consequent cellular dysfunction. This scenario might put aging into the category of autophagy disorders.
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37
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Leimberg MJ, Prus E, Konijn AM, Fibach E. Macrophages function as a ferritin iron source for cultured human erythroid precursors. J Cell Biochem 2008; 103:1211-8. [PMID: 17902167 DOI: 10.1002/jcb.21499] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Iron is essential for the survival as well as the proliferation and maturation of developing erythroid precursors (EP) into hemoglobin-containing red blood cells. The transferrin-transferrin receptor pathway is the main route for erythroid iron uptake. Using a two-phase culture system, we have previously shown that placental ferritin as well as macrophages derived from peripheral blood monocytes could partially replace transferrin and support EP growth in a transferrin-free medium. We now demonstrate that in the absence of transferrin, ferritin synthesized and secreted by macrophages can serve as an iron source for EP. Macrophages trigger an increase in both the cytosolic and the mitochondrial labile iron pools, in heme and in hemoglobin synthesis, along with a decrease in surface transferrin receptors. Inhibiting macrophage exocytosis, binding extracellular ferritin with specific antibodies, inhibiting EP receptor-mediated endocytosis or acidification of EP lysosomes, all resulted in a decreased EP growth when co-cultured with macrophages under transferrin-free conditions. The results suggest that iron taken up by macrophages is incorporated mainly into their ferritin, which is subsequently secreted by exocytosis. Nearby EP are able to take up this ferritin probably through clathrin-dependent, receptor-mediated endocytosis into endosomes, which following acidification and proteolysis release the iron from the ferritin, making it available for regulatory and synthetic purposes. Thus, macrophages support EP development under transferrin-free conditions by delivering essential iron in the form of metabolizable ferritin.
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Affiliation(s)
- Moshe J Leimberg
- Department of Human Nutrition and Metabolism, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
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38
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Kurz T, Terman A, Brunk UT. Autophagy, ageing and apoptosis: the role of oxidative stress and lysosomal iron. Arch Biochem Biophys 2007; 462:220-30. [PMID: 17306211 DOI: 10.1016/j.abb.2007.01.013] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 01/10/2007] [Accepted: 01/14/2007] [Indexed: 01/10/2023]
Abstract
As an outcome of normal autophagic degradation of ferruginous materials, such as ferritin and mitochondrial metalloproteins, the lysosomal compartment is rich in labile iron and, therefore, sensitive to the mild oxidative stress that cells naturally experience because of their constant production of hydrogen peroxide. Diffusion of hydrogen peroxide into the lysosomes results in Fenton-type reactions with the formation of hydroxyl radicals and ensuing peroxidation of lysosomal contents with formation of lipofuscin that amasses in long-lived postmitotic cells. Lipofuscin is a non-degradable polymeric substance that forms at a rate that is inversely related to the average lifespan across species and is built up of aldehyde-linked protein residues. The normal accumulation of lipofuscin in lysosomes seems to reduce autophagic capacity of senescent postmitotic cells--probably because lipofuscin-loaded lysosomes continue to receive newly formed lysosomal enzymes, which results in lack of such enzymes for autophagy. The result is an insufficient and declining rate of autophagic turnover of worn-out and damaged cellular components that consequently accumulate in a way that upsets normal metabolism. In the event of a more substantial oxidative stress, enhanced formation of hydroxyl radicals within lysosomes jeopardizes the membrane stability of particularly iron-rich lysosomes, specifically of autophagolysosomes that have recently participated in the degradation of iron-rich materials. For some time, the rupture of a limited number of lysosomes has been recognized as an early upstream event in many cases of apoptosis, particularly oxidative stress-induced apoptosis, while necrosis results from a major lysosomal break. Consequently, the regulation of the lysosomal content of redox-active iron seems to be essential for the survival of cells both in the short- and the long-term.
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Affiliation(s)
- Tino Kurz
- Division of Pharmacology, Faculty of Health Sciences, Linköping University, Linköping, Sweden
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39
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Danzeisen R, Achsel T, Bederke U, Cozzolino M, Crosio C, Ferri A, Frenzel M, Gralla EB, Huber L, Ludolph A, Nencini M, Rotilio G, Valentine JS, Carrì MT. Superoxide dismutase 1 modulates expression of transferrin receptor. J Biol Inorg Chem 2006; 11:489-98. [PMID: 16680451 DOI: 10.1007/s00775-006-0099-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Accepted: 03/01/2006] [Indexed: 10/24/2022]
Abstract
Copper-zinc superoxide dismutase (SOD1) plays a protective role against the toxicity of superoxide, and studies in Saccharomyces cerevisiae and in Drosophila have suggested an additional role for SOD1 in iron metabolism. We have studied the effect of the modulation of SOD1 levels on iron metabolism in a cultured human glial cell line and in a mouse motoneuronal cell line. We observed that levels of the transferrin receptor and the iron regulatory protein 1 were modulated in response to altered intracellular levels of superoxide dismutase activity, carried either by wild-type SOD1 or by an SOD-active amyotrophic lateral sclerosis (ALS) mutant enzyme, G93A-SOD1, but not by a superoxide dismutase inactive ALS mutant, H46R-SOD1. Ferritin expression was also increased by wild-type SOD1 overexpression, but not by mutant SOD1s. We propose that changes in superoxide levels due to alteration of SOD1 activity affect iron metabolism in glial and neuronal cells from higher eukaryotes and that this may be relevant to diseases of the nervous system.
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Affiliation(s)
- Ruth Danzeisen
- Department of Neurology, University of Ulm, Ulm, Germany
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40
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Iwasaki K, Mackenzie EL, Hailemariam K, Sakamoto K, Tsuji Y. Hemin-mediated regulation of an antioxidant-responsive element of the human ferritin H gene and role of Ref-1 during erythroid differentiation of K562 cells. Mol Cell Biol 2006; 26:2845-56. [PMID: 16537925 PMCID: PMC1430308 DOI: 10.1128/mcb.26.7.2845-2856.2006] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An effective utilization of intracellular iron is a prerequisite for erythroid differentiation and hemoglobinization. Ferritin, consisting of 24 subunits of H and L, plays a crucial role in iron homeostasis. Here, we have found that the H subunit of the ferritin gene is activated at the transcriptional level during hemin-induced differentiation of K562 human erythroleukemic cells. Transfection of various 5' regions of the human ferritin H gene fused to a luciferase reporter into K562 cells demonstrated that hemin activates ferritin H transcription through an antioxidant-responsive element (ARE) that is responsible for induction of a battery of phase II detoxification genes by oxidative stress. Gel retardation and chromatin immunoprecipitation assays demonstrated that hemin induced binding of cJun, JunD, FosB, and Nrf2 b-zip transcription factors to AP1 motifs of the ferritin H ARE, despite no significant change in expression levels or nuclear localization of these transcription factors. A Gal4-luciferase reporter assay did not show activation of these b-zip transcription factors after hemin treatment; however, redox factor 1 (Ref-1), which increases DNA binding of Jun/Fos family members via reduction of a conserved cysteine in their DNA binding domains, showed induced nuclear translocation after hemin treatment in K562 cells. Consistently, Ref-1 enhanced Nrf2 binding to the ARE and ferritin H transcription. Hemin also activated ARE sequences of other phase II genes, such as GSTpi and NQO1. Collectively, these results suggest that hemin activates the transcription of the ferritin H gene during K562 erythroid differentiation by Ref-1-mediated activation of these b-zip transcription factors to the ARE.
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Affiliation(s)
- Kenta Iwasaki
- Department of Environmental and Molecular Toxicology, North Carolina State University, Campus Box 7633, Raleigh, North Carolina 27695, USA
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Kidane TZ, Sauble E, Linder MC. Release of iron from ferritin requires lysosomal activity. Am J Physiol Cell Physiol 2006; 291:C445-55. [PMID: 16611735 DOI: 10.1152/ajpcell.00505.2005] [Citation(s) in RCA: 187] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
How ferritin-Fe becomes available for cell functions is unknown. Our previous studies with rat hepatoma cells indicated ferritin had to be degraded to release its Fe. In these studies, we investigated whether this occurs in other cell types and whether lysosomes are required. Release of ferritin-Fe was induced with desferoxamine (DFO) in (59)Fe-preloaded hepatoma, Caco2, and erythroid K562 cells and measured by rocket immunoelectrophoresis and autoradiography. The half-lives for ferritin-(59)Fe and protein were parallel (23, 16, and 11 h for the hepatic, Caco2, and K562 cells, respectively). Co-treatment with 180 microM Fe, leupeptin, chymostatin, or chloroquine markedly decreased rates of ferritin-Fe release and ferritin degradation. Lactacystin had no effect except for a small one in erythroid cells. Fractionation of hepatoma cell lysates on iodixanol gradients showed rapid depletion of cytosolic ferritin by DFO treatment but no accumulation in lysosomes. We conclude that regardless of cell type, release of Fe from ferritin occurs mainly through lysosomal proteolysis.
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Affiliation(s)
- Theodros Z Kidane
- Department of Chemistry and Biochemistry, California State University, Fullerton, CA 91834-6866, USA
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42
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Watanabe H, Tatarazako N, Oda S, Nishide H, Uchiyama I, Morita M, Iguchi T. Analysis of expressed sequence tags of the water flea Daphnia magna. Genome 2005; 48:606-9. [PMID: 16094427 DOI: 10.1139/g05-038] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To study gene expression in the water flea Daphnia magna we constructed a cDNA library and characterized the expressed sequence tags (ESTs) of 7210 clones. The EST sequences clustered into 2958 nonredundant groups. BLAST analyses of both protein and DNA databases showed that 1218 (41%) of the unique sequences shared significant similarities to known nucleotide or amino acid sequences, whereas the remaining 1740 (59%) showed no significant similarities to other genes. Clustering analysis revealed particularly high expression of genes related to ATP synthesis, structural proteins, and proteases. The cDNA clones and EST sequence information should be useful for future functional analysis of daphnid biology and investigation of the links between ecology and genomics.
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Affiliation(s)
- Hajime Watanabe
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Japan
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43
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Leimberg JM, Konijn AM, Fibach E. Macrophages promote development of human erythroid precursors in transferrin-free culture medium. ACTA ACUST UNITED AC 2005; 10:73-6. [PMID: 16019451 DOI: 10.1080/10245330412331269876] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Iron is mandatory for cell growth and development. Erythroid precursors need iron to a greater degree for hemoglobinization. Culturing erythroid precursors under serum and transferrin-free conditions resulted in their death, whereas under the same conditions, but in the presence of macrophages erythroid cell growth and development was evident as measured by hemoglobin (Hb)-specific cytochemical staining, flow cytometric immuno-staining of glycophorin A and Hb quantitation by a spectrophotometric method as well as by high performance liquid chromatography. Thus, macrophages support erythroid cell growth in the absence of transferrin, most likely by providing iron.
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Affiliation(s)
- J M Leimberg
- Department of Human Nutrition and Metabolism, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
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44
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Abstract
Ferritins are spherical, cage-like proteins with nanocavities formed by multiple polypeptide subunits (four-helix bundles) that manage iron/oxygen chemistry. Catalytic coupling yields diferric oxo/hydroxo complexes at ferroxidase sites in maxi-ferritin subunits (24 subunits, 480 kDa; plants, animals, microorganisms). Oxidation occurs at the cavity surface of mini-ferritins/Dps proteins (12 subunits, 240 kDa; bacteria). Oxidation products are concentrated as minerals in the nanocavity for iron-protein cofactor synthesis (maxi-ferritins) or DNA protection (mini-ferritins). The protein cage and nanocavity characterize all ferritins, although amino acid sequences diverge, especially in bacteria. Catalytic oxidation/di-iron coupling in the protein cage (maxi-ferritins, 480 kDa; plants, bacteria and animal cell-specific isoforms) or on the cavity surface (mini-ferritins/Dps proteins, 280 kDa; bacteria) initiates mineralization. Gated pores (eight or four), symmetrically arranged, control iron flow. The multiple ferritin functions combine pore, channel, and catalytic functions in compact protein structures required for life and disease response.
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Affiliation(s)
- Xiaofeng Liu
- Center for BioIron at CHORI (Children's Hospital Oakland Research Institute), Oakland, CA 94609, USA
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45
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Leimberg JM, Konijn AM, Fibach E. Developing human erythroid cells grown in transferrin-free medium utilize iron originating from extracellular ferritin. Am J Hematol 2003; 73:211-2. [PMID: 12827660 DOI: 10.1002/ajh.10355] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In addition to transferrin, ferritin can also function as a source of iron for heme synthesis (Gelvin D, et al. Blood 1996;88:3200-3207; Meyron-Holtz EG, et al. Blood 1999;94:3205-3211). In the present study we investigate the effect of external ferritin on the proliferation and hemoglobinization of human erythroid precursors grown in transferrin-free cultures.
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Affiliation(s)
- J M Leimberg
- Department of Human Nutrition and Metabolism, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
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46
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Abstract
Iron and oxygen are central to terrestrial life. Aqueous iron and oxygen chemistry will produce a ferric ion trillions of times less soluble than cell iron concentrations, along with radical forms of oxygen that are toxic. In the physiological environment, many proteins have evolved to transport iron or modulate the redox chemistry of iron that transforms oxygen in useful biochemical reactions. Only one protein, ferritin, evolved to concentrate iron to levels needed in aerobic metabolism. Reversible formation and dissolution of a solid nanomineral-hydrated, iron oxide is the main function of ferritin, which additionally detoxifies excess iron and possibly dioxygen and reactive oxygen. Ferritin is a large multifunctional, multisubunit protein with eight Fe transport pores, 12 mineral nucleation sites and up to 24 oxidase sites that produce mineral precursors from ferrous iron and oxygen. Regulation of ferritin synthesis in animals uses both DNA and mRNA controls and genes encoding two types of related subunits with: 1) catalytically active (H) or 2) inactive (L) oxidase sites. Ferritin with varying H/L ratios is related to cell-specific iron and oxygen homeostasis. H-ferritin oxidase activity accelerates rates of iron mineralization in ferritins and, in animals, ferritin produces H(2)O(2) as a byproduct. Properties of ferritin mRNA and ferritin protein pore structure are new targets for manipulating iron homeostasis. Recent observations of the high bioavailability of iron in soybean ferritin and efficient utilization of soybean and ferritin iron by iron-deficient animals, and of soybean iron by humans with borderline deficiency, indicate a role for ferritin in managing global iron deficiency in humans.
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Affiliation(s)
- Elizabeth C Theil
- Children's Hospital and Research Center at Oakland, Oakland, CA 94609, USA.
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47
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Petrat F, de Groot H, Sustmann R, Rauen U. The chelatable iron pool in living cells: a methodically defined quantity. Biol Chem 2002; 383:489-502. [PMID: 12033438 DOI: 10.1515/bc.2002.051] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A very small, predominantly cytosolic pool of iron ions plays the central role in the cellular iron metabolism. It links the cellular iron uptake with the insertion of the metal in iron storage proteins and other essential iron-containing molecules. Furthermore, this transit ('labile') pool is essentially involved in the pathogenesis of a number of diseases. Due to its high physiological and pathophysiological significance, numerous methods for its characterization have been developed during the last five decades. Most of these methods, however, influence the size and nature of the transit iron pool artificially, as they are not applicable to viable biological material. Recently, fluorescence spectroscopic methods for measurements within viable cells have become available. Although these methods avoid the artifacts of previous methods, studies using fluorescent iron indicators revealed that the 'intracellular transit iron pool', which is methodically assessed as 'chelatable iron', is substantially defined by the method and/or the iron-chelating indicator applied for its detection, since the iron ions are bound to a large number of different ligands in different metabolic compartments. A more comprehensive characterization of the nature and the role of the thus not uniform cellular transit iron pool therefore requires parallel employment of different indicator molecules, which clearly differ in their intracellular distribution and their physico-chemical characteristics.
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Affiliation(s)
- Frank Petrat
- Institut für Physiologische Chemie, Universitätsklinikum Essen, Germany
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48
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Agrawal R, Sharma PK, Rao GS. Release of iron from ferritin by metabolites of benzene and superoxide radical generating agents. Toxicology 2001; 168:223-30. [PMID: 11684319 DOI: 10.1016/s0300-483x(01)00412-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The release of iron from ferritin in the presence of benzene metabolites, viz. phenol (P), catechol (CT), hydroquinone (HQ) and superoxide radical generating compounds, viz. pyrogallol (PL), phloroglucinol (PG), phenylhydrazine (PH) or phenylenediamine (PD) was studied in acetate buffer, pH 5.6. Monitoring the formation of the iron-ferrozine complex quantitated the release of iron from ferritin. The presence of P (125 microM) did not result in the release of iron from ferritin, whereas the same concentration of CT, HQ, PL, PH or PD resulted in the release of significant amounts of iron from ferritin and a marginal amount of iron in the presence of PG, CT, HQ, PL, PH or PD concentration and time-dependent increase in iron release from ferritin were observed although the increase was not linear as a function of time and concentration of the compounds studied. The presence of superoxide dismutase inhibited significantly the release of iron from ferritin by CT, HQ, PL, PH or PD. The iron released from ferritin by CT, HQ, PL, PH or PD enhanced lipid peroxidation in rat brain homogenate and released aldehydic products from bleomycin-dependent degradation of DNA and also caused single strand nicks to pUC18 DNA. These studies indicate that CT and HQ, the two principal polyphenolic metabolites of benzene and PL, PH or PD, the superoxide radical generating compounds were capable of reducing ferric iron from ferritin and also mobilizing and releasing iron from ferritin core. The release of iron from ferritin by these compounds is a result of direct reduction of ferritin iron by electron transfer and also reduction via superoxide radical. The release of iron from ferritin by CT and HQ may have toxicological implications in relation to benzene toxicity. The release of iron by superoxide radical generating agents suggests that oxidative stress may play a role as this could lead to disruption of intracellular iron homeostasis.
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Affiliation(s)
- R Agrawal
- Industrial Toxicology Research Centre, PO Box 80, M.G. Marg, Lucknow 226 001, India
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49
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Fibach E. Cell culture and animal models to screen for promising fetal hemoglobin-stimulating compounds. Semin Hematol 2001; 38:374-81. [PMID: 11605173 DOI: 10.1016/s0037-1963(01)90032-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Sickle cell anemia (SCA) and the thalassemias are globally the most common class of inherited single-gene disorders. Current treatment options are limited, especially in developing countries. More practical and cheaper therapies are urgently needed. Since high fetal hemoglobin (HbF) levels ameliorate the clinical symptoms of these diseases, one current approach is to use pharmacological agents to reactivate the gamma-globin genes and stimulate the production of HbF. Several in vitro and in vivo experimental models developed for this purpose are the subject of this review. The models include in vitro established erythroid-like cell lines and primary cultures (both in semisolid and liquid media) of erythroid progenitor cells obtained from normal donors and patients with SCA and beta-thalassemia, as well as in vivo models in genetically modified (transgenic) and unmodified animals. These experimental systems are useful for large-scale screening of compounds for HbF-stimulating potential, for determining the mechanism of action of potent compounds at the cellular and molecular levels, and for studying the pharmacology, pharmacokinetics, and toxicology of the drugs. These models are essential to find, test, and develop new drugs that will be effective and safe for clinical use in adults and children.
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Affiliation(s)
- E Fibach
- Department of Hematology, Hadassah University Hospital, Ein-Kerem, Jerusalem, Israel
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Kuriyama-Matsumura K, Sato H, Suzuki M, Bannai S. Effects of hyperoxia and iron on iron regulatory protein-1 activity and the ferritin synthesis in mouse peritoneal macrophages. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1544:370-7. [PMID: 11341946 DOI: 10.1016/s0167-4838(00)00251-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Ferritin is an intracellular iron storage protein and its translation is inhibited by binding of iron regulatory proteins (IRPs) to the iron-responsive element (IRE) located in the 5' untranslated region of its mRNA. In this paper, we have investigated the effect of hyperoxia and iron on the binding activity of IRP-1 and the ferritin synthesis in mouse peritoneal macrophages. The binding activity of IRP-1 was increased and the ferritin synthesis was suppressed when the macrophages were cultured under hyperoxia, and the reverse occurred under hypoxia. Iron diminished the IRP-1-binding activity and the enhanced synthesis of ferritin. However, this effect was arrested under hyperoxia. Consistently, hypoxia-induced loss of binding activity of IRP-1 and the enhanced synthesis of ferritin were blocked in the presence of an iron chelator deferoxamine. These alterations of the binding activity of IRP-1 in response to oxygen and iron were not reproduced in the cell-free extract. The data suggest that in the macrophages oxygen and iron inversely act on the binding activity of IRP-1 and the ferritin synthesis, and that intracellular mechanism(s) to sense iron and/or oxygen is required for these actions.
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Affiliation(s)
- K Kuriyama-Matsumura
- Department of Biochemistry, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki 305-8575, Tsukuba, Japan
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