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Protective Role of Histidine Supplementation Against Oxidative Stress Damage in the Management of Anemia of Chronic Kidney Disease. Pharmaceuticals (Basel) 2018; 11:ph11040111. [PMID: 30347874 PMCID: PMC6315830 DOI: 10.3390/ph11040111] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/16/2018] [Accepted: 10/16/2018] [Indexed: 12/19/2022] Open
Abstract
Anemia is a major health condition associated with chronic kidney disease (CKD). A key underlying cause of this disorder is iron deficiency. Although intravenous iron treatment can be beneficial in correcting CKD-associated anemia, surplus iron can be detrimental and cause complications. Excessive generation of reactive oxygen species (ROS), particularly by mitochondria, leads to tissue oxidation and damage to DNA, proteins, and lipids. Oxidative stress increase in CKD has been further implicated in the pathogenesis of vascular calcification. Iron supplementation leads to the availability of excess free iron that is toxic and generates ROS that is linked, in turn, to inflammation, endothelial dysfunction, and cardiovascular disease. Histidine is indispensable to uremic patients because of the tendency toward negative plasma histidine levels. Histidine-deficient diets predispose healthy subjects to anemia and accentuate anemia in chronic uremic patients. Histidine is essential in globin synthesis and erythropoiesis and has also been implicated in the enhancement of iron absorption from human diets. Studies have found that L-histidine exhibits antioxidant capabilities, such as scavenging free radicals and chelating divalent metal ions, hence the advocacy for its use in improving oxidative stress in CKD. The current review advances and discusses evidence for iron-induced toxicity in CKD and the mechanisms by which histidine exerts cytoprotective functions.
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Ferritin Heavy Subunit Silencing Blocks the Erythroid Commitment of K562 Cells via miR-150 up-Regulation and GATA-1 Repression. Int J Mol Sci 2017; 18:ijms18102167. [PMID: 29039805 PMCID: PMC5666848 DOI: 10.3390/ijms18102167] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/09/2017] [Accepted: 10/12/2017] [Indexed: 11/17/2022] Open
Abstract
Erythroid differentiation is a complex and multistep process during which an adequate supply of iron for hemoglobinization is required. The role of ferritin heavy subunit, in this process, has been mainly attributed to its capacity to maintain iron in a non-toxic form. We propose a new role for ferritin heavy subunit (FHC) in controlling the erythroid commitment of K562 erythro-myeloid cells. FHC knockdown induces a change in the balance of GATA transcription factors and significantly reduces the expression of a repertoire of erythroid-specific genes, including α- and γ-globins, as well as CD71 and CD235a surface markers, in the absence of differentiation stimuli. These molecular changes are also reflected at the morphological level. Moreover, the ability of FHC-silenced K562 cells to respond to the erythroid-specific inducer hemin is almost completely abolished. Interestingly, we found that this new role for FHC is largely mediated via regulation of miR-150, one of the main microRNA implicated in the cell-fate choice of common erythroid/megakaryocytic progenitors. These findings shed further insight into the biological properties of FHCand delineate a role in erythroid differentiation where this protein does not act as a mere iron metabolism-related factor but also as a critical regulator of the expression of genes of central relevance for erythropoiesis.
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Zhang L, Li L, Di Penta A, Carmona U, Yang F, Schöps R, Brandsch M, Zugaza JL, Knez M. H-Chain Ferritin: A Natural Nuclei Targeting and Bioactive Delivery Nanovector. Adv Healthc Mater 2015; 4:1305-10. [PMID: 25973730 DOI: 10.1002/adhm.201500226] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 04/22/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Lianbing Zhang
- CIC nanoGUNE; Tolosa Hiribidea 76 20018 Donostia-San Sebastián Spain
| | - Le Li
- CIC nanoGUNE; Tolosa Hiribidea 76 20018 Donostia-San Sebastián Spain
| | - Alessandra Di Penta
- Achucarro Basque Center for Neuroscience, Building 205; Bizkaia Science and Technology Park; 48170 Zamudio Spain
- ThreeRLabs, Building 804; Bizkaia Science and Technology Park; 48170 Zamudio Spain
| | - Unai Carmona
- CIC nanoGUNE; Tolosa Hiribidea 76 20018 Donostia-San Sebastián Spain
| | - Fan Yang
- CIC nanoGUNE; Tolosa Hiribidea 76 20018 Donostia-San Sebastián Spain
| | - Regina Schöps
- Institute of Chemistry; Martin-Luther-University Halle-Wittenberg; 06099 Halle Germany
| | - Matthias Brandsch
- Biozentrum; Martin-Luther-University Halle-Wittenberg; 06120 Halle Germany
| | - José L. Zugaza
- Achucarro Basque Center for Neuroscience, Building 205; Bizkaia Science and Technology Park; 48170 Zamudio Spain
- Department of Genetics; Physical Anthropology and Animal Physiology; University of the Basque Country; 48940 Leioa Spain
- IKERBASQUE; Basque Foundation for Science; Maria Diaz de Haro 3 48013 Bilbao Spain
| | - Mato Knez
- CIC nanoGUNE; Tolosa Hiribidea 76 20018 Donostia-San Sebastián Spain
- IKERBASQUE; Basque Foundation for Science; Maria Diaz de Haro 3 48013 Bilbao Spain
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Ruzzenenti P, Asperti M, Mitola S, Crescini E, Maccarinelli F, Gryzik M, Regoni M, Finazzi D, Arosio P, Poli M. The Ferritin-Heavy-Polypeptide-Like-17 (FTHL17) gene encodes a ferritin with low stability and no ferroxidase activity and with a partial nuclear localization. Biochim Biophys Acta Gen Subj 2015; 1850:1267-73. [DOI: 10.1016/j.bbagen.2015.02.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Revised: 02/13/2015] [Accepted: 02/26/2015] [Indexed: 12/12/2022]
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Vercellotti GM, Khan FB, Nguyen J, Chen C, Bruzzone CM, Bechtel H, Brown G, Nath KA, Steer CJ, Hebbel RP, Belcher JD. H-ferritin ferroxidase induces cytoprotective pathways and inhibits microvascular stasis in transgenic sickle mice. Front Pharmacol 2014; 5:79. [PMID: 24860503 PMCID: PMC4029007 DOI: 10.3389/fphar.2014.00079] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/31/2014] [Indexed: 01/17/2023] Open
Abstract
Hemolysis, oxidative stress, inflammation, vaso-occlusion, and organ infarction are hallmarks of sickle cell disease (SCD). We have previously shown that increases in heme oxygenase-1 (HO-1) activity detoxify heme and inhibit vaso-occlusion in transgenic mouse models of SCD. HO-1 releases Fe(2+) from heme, and the ferritin heavy chain (FHC) ferroxidase oxidizes Fe(2+) to catalytically inactive Fe(3+) inside ferritin. FHC overexpression has been shown to be cytoprotective. In this study, we hypothesized that overexpression of FHC and its ferroxidase activity will inhibit inflammation and microvascular stasis in transgenic SCD mice in response to plasma hemoglobin. We utilized a Sleeping Beauty (SB) transposase plasmid to deliver a human wild-type-ferritin heavy chain (wt-hFHC) transposable element by hydrodynamic tail vein injections into NY1DD SCD mice. Control SCD mice were infused with the same volume of lactated Ringer's solution (LRS) or a human triple missense FHC (ms-hFHC) plasmid with no ferroxidase activity. 8 weeks later, LRS-injected mice had ~40% microvascular stasis (% non-flowing venules) 1 h after infusion of stroma-free hemoglobin, while mice overexpressing wt-hFHC had only 5% stasis (p < 0.05), and ms-hFHC mice had 33% stasis suggesting vascular protection by ferroxidase active wt-hFHC. The wt-hFHC SCD mice had marked increases in splenic hFHC mRNA and hepatic hFHC protein, ferritin light chain (FLC), 5-aminolevulinic acid synthase (ALAS), heme content, ferroportin, nuclear factor erythroid 2-related factor 2 (Nrf2), and HO-1 activity and protein. There was also a decrease in hepatic activated nuclear factor-kappa B (NF-κB) phospho-p65 and vascular cell adhesion molecule-1 (VCAM-1). Inhibition of HO-1 activity with tin protoporphyrin demonstrated HO-1 was not essential for the protection by wt-hFHC. We conclude that wt-hFHC ferroxidase activity enhances cytoprotective Nrf2-regulated proteins including HO-1, thereby resulting in decreased NF-κB-activation, adhesion molecules, and microvascular stasis in transgenic SCD mice.
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Affiliation(s)
- Gregory M Vercellotti
- Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN USA ; Vascular Biology Center, Department of Medicine, University of Minnesota Medical School Minneapolis, MN, USA
| | - Fatima B Khan
- Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN USA ; Vascular Biology Center, Department of Medicine, University of Minnesota Medical School Minneapolis, MN, USA
| | - Julia Nguyen
- Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN USA ; Vascular Biology Center, Department of Medicine, University of Minnesota Medical School Minneapolis, MN, USA
| | - Chunsheng Chen
- Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN USA ; Vascular Biology Center, Department of Medicine, University of Minnesota Medical School Minneapolis, MN, USA
| | - Carol M Bruzzone
- Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN USA ; Vascular Biology Center, Department of Medicine, University of Minnesota Medical School Minneapolis, MN, USA
| | - Heather Bechtel
- Mercy Clinic Children's Cancer and Hematology, St. Louis, MO USA
| | - Graham Brown
- Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN USA ; Vascular Biology Center, Department of Medicine, University of Minnesota Medical School Minneapolis, MN, USA
| | - Karl A Nath
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic/Foundation Rochester, MN, USA
| | - Clifford J Steer
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Minnesota Medical School Minneapolis, MN, USA
| | - Robert P Hebbel
- Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN USA ; Vascular Biology Center, Department of Medicine, University of Minnesota Medical School Minneapolis, MN, USA
| | - John D Belcher
- Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN USA ; Vascular Biology Center, Department of Medicine, University of Minnesota Medical School Minneapolis, MN, USA
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Di Sanzo M, Gaspari M, Misaggi R, Romeo F, Falbo L, De Marco C, Agosti V, Quaresima B, Barni T, Viglietto G, Larsen MR, Cuda G, Costanzo F, Faniello MC. H Ferritin Gene Silencing in a Human Metastatic Melanoma Cell Line: A Proteomic Analysis. J Proteome Res 2011; 10:5444-53. [DOI: 10.1021/pr200705z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Maddalena Di Sanzo
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Marco Gaspari
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Roberta Misaggi
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Francesco Romeo
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Lucia Falbo
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Carmela De Marco
- Laboratorio di Oncologia Molecolare, BioGem s.c. a r.l., Ariano Irpino (AV), Italy
| | - Valter Agosti
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Barbara Quaresima
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Tullio Barni
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Giuseppe Viglietto
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Martin Røssel Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Giovanni Cuda
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Francesco Costanzo
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
| | - Maria Concetta Faniello
- Dipartimento di Medicina Sperimentale e Clinica “G. Salvatore”, Università degli Studi di Catanzaro “Magna Græcia”, viale Europa, Campus Universitario, “S. Venuta” - 88100 Catanzaro, Italy
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Danış Ö, Demir S, Günel A, Aker RG, Gülçebi M, Onat F, Ogan A. Changes in intracellular protein expression in cortex, thalamus and hippocampus in a genetic rat model of absence epilepsy. Brain Res Bull 2011; 84:381-8. [DOI: 10.1016/j.brainresbull.2011.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 01/03/2011] [Accepted: 02/01/2011] [Indexed: 11/28/2022]
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Sevcenco AM, Pinkse MWH, Wolterbeek HT, Verhaert PDEM, Hagen WR, Hagedoorn PL. Exploring the microbial metalloproteome using MIRAGE. Metallomics 2011; 3:1324-30. [DOI: 10.1039/c1mt00154j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Alkhateeb AA, Connor JR. Nuclear ferritin: A new role for ferritin in cell biology. Biochim Biophys Acta Gen Subj 2010; 1800:793-7. [DOI: 10.1016/j.bbagen.2010.03.017] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 03/19/2010] [Accepted: 03/22/2010] [Indexed: 02/08/2023]
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Abstract
Hemochromatosis is a known cause of osteoporosis, and iron overload has deleterious effects on bone. Although iron overload and its association with osteoporosis has long been recognized, the pathogenesis and exact role of iron have been undefined. Bone is an active tissue with constant remodeling capacity. Osteoblast (OB) development and maturation are under the influence of core binding factor alpha-1 (CBF-alpha1), which induces expression of OB-specific genes, including alkaline phosphatase, an important enzyme in early osteogenesis, and osteocalcin, a noncollagenous protein deposited within the osteoid. This study investigates the mechanism by which iron inhibits human OB activity, which in vivo may lead to decreased mineralization, osteopenia, and osteoporosis. We demonstrate that iron-provoked inhibition of OB activity is mediated by ferritin and its ferroxidase activity. We confirm this notion by using purified ferritin H-chain and ceruloplasmin, both known to possess ferroxidase activity that inhibited calcification, whereas a site-directed mutant of ferritin H-chain lacking ferroxidase activity failed to provide any inhibition. Furthermore, we are reporting that such suppression is not restricted to inhibition of calcification, but OB-specific genes such as alkaline phosphatase, osteocalcin, and CBF-alpha1 are all downregulated by ferritin in a dose-responsive manner. This study corroborates that iron decreases mineralization and demonstrates that this suppression is provided by iron-induced upregulation of ferritin. In addition, we conclude that inhibition of OB activity, mineralization, and specific gene expression is attributed to the ferroxidase activity of ferritin.
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Zarjou A, Jeney V, Arosio P, Poli M, Antal-Szalmás P, Agarwal A, Balla G, Balla J. Ferritin prevents calcification and osteoblastic differentiation of vascular smooth muscle cells. J Am Soc Nephrol 2009; 20:1254-63. [PMID: 19423691 DOI: 10.1681/asn.2008070788] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Vascular calcification plays a role in the pathogenesis of atherosclerosis, diabetes, and chronic kidney disease. Human aortic smooth muscle cells (HSMCs) undergo mineralization in response to elevated levels of inorganic phosphate (Pi) in an active and well-regulated process. This process involves increased activity of alkaline phosphatase and increased expression of core binding factor alpha-1, a bone-specific transcription factor, with the subsequent induction of osteocalcin. Mounting evidence suggests an essential role for the heme oxygenase 1 (HO-1)/ferritin system to maintain homeostasis of vascular function. We examined whether induction of HO-1 and ferritin alters mineralization of HSMCs provoked by high Pi. Upregulation of the HO-1/ferritin system inhibited HSMC calcification and osteoblastic differentiation. Of the products of the system, only ferritin and, to a lesser extent, biliverdin were responsible for the inhibition. Ferritin heavy chain and ceruloplasmin, which both possess ferroxidase activity, inhibited calcification; a site-directed mutant of ferritin heavy chain, which lacked ferroxidase activity, failed to inhibit calcification. In addition, osteoblastic transformation of HSMCs provoked by elevated Pi (assessed by upregulation of core binding factor alpha-1, osteocalcin, and alkaline phosphatase activity) was diminished by ferritin/ferroxidase activity. We conclude that induction of the HO-1/ferritin system prevents Pi-mediated calcification and osteoblastic differentiation of human smooth muscle cells mainly via the ferroxidase activity of ferritin.
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Affiliation(s)
- Abolfazl Zarjou
- Department of Medicine, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
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Nurminskaya MV, Talbot CJ, Nurminsky DI, Beazley KE, Linsenmayer TF. Nuclear ferritin: a ferritoid-ferritin complex in corneal epithelial cells. Invest Ophthalmol Vis Sci 2009; 50:3655-61. [PMID: 19255152 DOI: 10.1167/iovs.08-3170] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Ferritin is an iron storage protein that is generally cytoplasmic. However, in embryonic avian corneal epithelial (CE) cells, the authors previously observed that the ferritin was predominantly nuclear. They also obtained evidence that this ferritin protects DNA from oxidative damage by UV light and hydrogen peroxide and that the nuclear localization involves a tissue-specific nuclear transporter, termed ferritoid. In the present investigation, the authors have determined additional properties of the nuclear ferritoid-ferritin complexes. METHODS For biochemical characterization, a combination of molecular sieve chromatography, immunoblotting, and nuclear-cytoplasmic fractionation was used; DNA binding was analyzed by electrophoretic mobility shift assay. RESULTS The CE nuclear ferritin complex has characteristics that differentiate it from a "typical" cytoplasmic ferritin, including the presence of ferritin and ferritoid subunits; a molecular weight of approximately 260 kDa, which is approximately half that of cytoplasmic ferritin; its iron content, which is below our limits of detection; and its ability to bind to DNA. CONCLUSIONS Within CE cell nuclei, ferritin and ferritoid are coassembled into stable complex(es) present in embryonic and adult corneas. Thus, ferritoid not only serves transiently as a nuclear transporter for ferritin, it remains as a component of a unique ferritoid-ferritin nuclear complex.
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Affiliation(s)
- Maria V Nurminskaya
- Department of Anatomy and Cell Biology, Tufts University, Boston, MA 02111, USA
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Beaudoin ME, Poirel VJ, Krushel LA. Regulating amyloid precursor protein synthesis through an internal ribosomal entry site. Nucleic Acids Res 2008; 36:6835-47. [PMID: 18953033 PMCID: PMC2588504 DOI: 10.1093/nar/gkn792] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 09/14/2008] [Accepted: 10/10/2008] [Indexed: 12/31/2022] Open
Abstract
Expression of amyloid precursor protein (APP) is critical to the etiology of Alzheimer's disease (AD). Consequently, regulating APP expression is one approach to block disease progression. To this end, APP can be targeted at the levels of transcription, translation, and protein stability. Little is currently known about the translation of APP mRNA. Here, we report that endogenous APP mRNA is translated in neural cell lines via an internal ribosome entry site (IRES) located in the 5'-untranslated leader. The functional unit of the APP IRES is located within the 5' 50 nucleotides of the 5'-leader. In addition, we found that the APP IRES is positively regulated by two conditions correlated with AD, increased intracellular iron concentration and ischemia. Interestingly, the enhancement of APP IRES activity is dependent upon de novo transcription. Taken together, our data suggest that internal initiation of translation of the APP mRNA is an important mode for synthesis of APP, a mechanism which is regulated by conditions that also contribute to AD.
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Affiliation(s)
- Monique E. Beaudoin
- Neurosciences Program, Department of Biochemistry and Molecular Genetics and Department of Pharmacology, University of Colorado Denver School of Medicine, Aurora, CO 80045, USA
| | - Vincent-Joseph Poirel
- Neurosciences Program, Department of Biochemistry and Molecular Genetics and Department of Pharmacology, University of Colorado Denver School of Medicine, Aurora, CO 80045, USA
| | - Leslie A. Krushel
- Neurosciences Program, Department of Biochemistry and Molecular Genetics and Department of Pharmacology, University of Colorado Denver School of Medicine, Aurora, CO 80045, 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: 604] [Impact Index Per Article: 37.8] [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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Expression of a mutant form of the ferritin light chain gene induces neurodegeneration and iron overload in transgenic mice. J Neurosci 2008; 28:60-7. [PMID: 18171923 DOI: 10.1523/jneurosci.3962-07.2008] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Increased iron levels and iron-mediated oxidative stress play an important role in the pathogenesis of many neurodegenerative diseases. The finding that mutations in the ferritin light polypeptide (FTL) gene cause a neurodegenerative disease known as neuroferritinopathy or hereditary ferritinopathy (HF) provided a direct connection between abnormal brain iron storage and neurodegeneration. HF is characterized by a severe movement disorder and by the presence of nuclear and cytoplasmic ferritin inclusion bodies in glia and neurons throughout the CNS and in tissues of multiple organ systems. Here we report that the expression in transgenic mice of a human FTL cDNA carrying a thymidine and cytidine insertion at position 498 (FTL498-499InsTC) leads to the formation of nuclear and cytoplasmic ferritin inclusion bodies. As in HF, ferritin inclusions are seen in glia and neurons throughout the CNS as well as in cells of other organ systems. Our studies show histological, immunohistochemical, and biochemical similarities between ferritin inclusion bodies found in transgenic mice and in individuals with HF. Expression of the transgene in mice leads to a significant decrease in motor performance and a shorter life span, formation of ferritin inclusion bodies, misregulation of iron metabolism, accumulation of ubiquitinated proteins, and incorporation of elements of the proteasome into inclusions. This new transgenic mouse represents a relevant model of HF in which to study the pathways that lead to neurodegeneration in HF, to evaluate the role of iron mismanagement in neurodegenerative disorders, and to evaluate potential therapies for HF and related neurodegenerative diseases.
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Infante AA, Infante D, Chan MC, How PC, Kutschera W, Linhartová I, Müllner EW, Wiche G, Propst F. Ferritin associates with marginal band microtubules. Exp Cell Res 2007; 313:1602-14. [PMID: 17391669 DOI: 10.1016/j.yexcr.2007.02.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2006] [Revised: 02/06/2007] [Accepted: 02/08/2007] [Indexed: 10/23/2022]
Abstract
We characterized chicken erythrocyte and human platelet ferritin by biochemical studies and immunofluorescence. Erythrocyte ferritin was found to be a homopolymer of H-ferritin subunits, resistant to proteinase K digestion, heat stable, and contained iron. In mature chicken erythrocytes and human platelets, ferritin was localized at the marginal band, a ring-shaped peripheral microtubule bundle, and displayed properties of bona fide microtubule-associated proteins such as tau. Red blood cell ferritin association with the marginal band was confirmed by temperature-induced disassembly-reassembly of microtubules. During erythrocyte differentiation, ferritin co-localized with coalescing microtubules during marginal band formation. In addition, ferritin was found in the nuclei of mature erythrocytes, but was not detectable in those of bone marrow erythrocyte precursors. These results suggest that ferritin has a function in marginal band formation and possibly in protection of the marginal band from damaging effects of reactive oxygen species by sequestering iron in the mature erythrocyte. Moreover, our data suggest that ferritin and syncolin, a previously identified erythrocyte microtubule-associated protein, are identical. Nuclear ferritin might contribute to transcriptional silencing or, alternatively, constitute a ferritin reservoir.
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Affiliation(s)
- Anthony A Infante
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
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17
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Koorts AM, Viljoen M. Ferritin and ferritin isoforms I: Structure-function relationships, synthesis, degradation and secretion. Arch Physiol Biochem 2007; 113:30-54. [PMID: 17522983 DOI: 10.1080/13813450701318583] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Ferritin is the intracellular protein responsible for the sequestration, storage and release of iron. Ferritin can accumulate up to 4500 iron atoms as a ferrihydrite mineral in a protein shell and releases these iron atoms when there is an increase in the cell's need for bioavailable iron. The ferritin protein shell consists of 24 protein subunits of two types, the H-subunit and the L-subunit. These ferritin subunits perform different functions in the mineralization process of iron. The ferritin protein shell can exist as various combinations of these two subunit types, giving rise to heteropolymers or isoferritins. Isoferritins are functionally distinct and characteristic populations of isoferritins are found depending on the type of cell, the proliferation status of the cell and the presence of disease. The synthesis of ferritin is regulated both transcriptionally and translationally. Translation of ferritin subunit mRNA is increased or decreased, depending on the labile iron pool and is controlled by an iron-responsive element present in the 5'-untranslated region of the ferritin subunit mRNA. The transcription of the genes for the ferritin subunits is controlled by hormones and cytokines, which can result in a change in the pool of translatable mRNA. The levels of intracellular ferritin are determined by the balance between synthesis and degradation. Degradation of ferritin in the cytosol results in complete release of iron, while degradation in secondary lysosomes results in the formation of haemosiderin and protection against iron toxicity. The majority of ferritin is found in the cytosol. However, ferritin with slightly different properties can also be found in organelles such as nuclei and mitochondria. Most of the ferritin produced intracellularly is harnessed for the regulation of iron bioavailability; however, some of the ferritin is secreted and internalized by other cells. In addition to the regulation of iron bioavailability ferritin may contribute to the control of myelopoiesis and immunological responses.
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Affiliation(s)
- A M Koorts
- Department of Physiology, School of Medicine, University of Pretoria, Pretoria, South Africa.
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18
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Li R, Luo C, Mines M, Zhang J, Fan GH. Chemokine CXCL12 induces binding of ferritin heavy chain to the chemokine receptor CXCR4, alters CXCR4 signaling, and induces phosphorylation and nuclear translocation of ferritin heavy chain. J Biol Chem 2006; 281:37616-27. [PMID: 17056593 DOI: 10.1074/jbc.m607266200] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Chemokine receptor-initiated signaling plays critical roles in cell differentiation, proliferation, and migration. However, the regulation of chemokine receptor signaling under physiological and pathological conditions is not fully understood. In the present study, we demonstrate that the CXC chemokine receptor 4 (CXCR4) formed a complex with ferritin heavy chain (FHC) in a ligand-dependent manner. Our in vitro binding assays revealed that purified FHC associated with both the glutathione S-transferase-conjugated N-terminal and C-terminal domains of CXCR4, thereby suggesting the presence of more than one FHC binding site in the protein sequence of CXCR4. Using confocal microscopy, we observed that stimulation with CXCL12, the receptor ligand, induced colocalization of the internalized CXCR4 with FHC into internal vesicles. Furthermore, after CXCL12 treatment, FHC underwent time-dependent nuclear translocation and phosphorylation at serine residues. By contrast, a mutant form of FHC in which serine 178 was replaced by alanine (S178A) failed to undergo phosphorylation, suggesting that serine 178 is the major phosphorylation site. Compared with the wild type FHC, the FHC-S178A mutant exhibited reduced association with CXCR4 and constitutive nuclear translocation. We also found that CXCR4-mediated extracellular signal-regulated kinase 1/2 (ERK1/2) activation and chemotaxis were inhibited by overexpression of wild type FHC but not FHC-S178A mutant, and were prolonged by FHC knockdown. In addition to CXCR4, other chemokine receptor-initiated signaling appeared to be similarly regulated by FHC, because CXCR2-mediated ERK1/2 activation was also inhibited by FHC overexpression and prolonged by FHC knockdown. Altogether, our data provide strong evidence for an important role of FHC in chemokine receptor signaling and receptor-mediated cell migration.
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Affiliation(s)
- Runsheng Li
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiaotong University School of Medicine, Shanghai 200025, People's Republic of China
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19
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Theil EC, Matzapetakis M, Liu X. Ferritins: iron/oxygen biominerals in protein nanocages. J Biol Inorg Chem 2006; 11:803-10. [PMID: 16868744 DOI: 10.1007/s00775-006-0125-6] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Accepted: 06/06/2006] [Indexed: 01/09/2023]
Abstract
Ferritin protein nanocages that form iron oxy biominerals in the central nanometer cavity are nature's answer to managing iron and oxygen; gene deletions are lethal in mammals and render bacteria more vulnerable to host release of antipathogen oxidants. The multifunctional, multisubunit proteins couple iron with oxygen (maxi-ferritins) or hydrogen peroxide (mini-ferritins) at catalytic sites that are related to di-iron sites oxidases, ribonucleotide reductase, methane monooxygenase and fatty acid desaturases, and synthesize mineral precursors. Gated pores, distributed symmetrically around the ferritin cages, control removal of iron by reductants and chelators. Gene regulation of ferritin, long known to depend on iron and, in animals, on a noncoding messenger RNA (mRNA) structure linked in a combinatorial array to functionally related mRNA of iron transport, has recently been shown to be linked to an array of proteins for antioxidant responses such as thioredoxin and quinone reductases. Ferritin DNA responds more to oxygen signals, and ferritin mRNA responds more to iron signals. Ferritin genes (DNA and RNA) and protein function at the intersection of iron and oxygen chemistry in biology.
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Affiliation(s)
- Elizabeth C Theil
- CHORI (Children's Hospital Research Institute Oakland), 5700 Martin Luther King Jr. Way, Oakland, CA 94609, USA.
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20
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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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21
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Basak S, Polley S, Basu M, Chattopadhyay D, Roy S. Monomer and dimer of Chandipura virus unphosphorylated P-protein binds leader RNA differently: implications for viral RNA synthesis. J Mol Biol 2004; 339:1089-101. [PMID: 15178250 DOI: 10.1016/j.jmb.2004.03.081] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2003] [Revised: 03/20/2004] [Accepted: 03/25/2004] [Indexed: 11/30/2022]
Abstract
Interaction of the leader RNA with the unphosphorylated P-protein has been proposed to play a key role in the transcription-replication transition of Chandipura virus, a model rhabdovirus. Electrophoretic mobility shift assay with the leader RNA and the unphosphorylated P-protein demonstrated existence of two distinct complexes in vitro. Measurements of stoichiometry indicate the protein monomer/RNA ratio to be 1:1 and 2:1 for faster and slower migrating bands, respectively. We have also observed a concentration-dependent oligomerization of the unphosphorylated P-protein, in sub-micromolar to low micromolar range. Sedimentation velocity, dynamic light scattering and large zone gel filtration experiments suggest a monomer-dimer-tetramer model of association. RNA binding experiments suggest that the two complexes assembled from one molecule of the leader RNA binding to either a protein monomer or a dimer. A truncated RNA consisting of a 3' region of the leader transcript exclusively formed the 1:1 complex, whereas a RNA consisting of only the 5' region forms the 2:1 complex exclusively. RNA binding experiments at different protein concentrations suggest that binding of the RNA comprising the 3' region weakens significantly at higher P(0) concentrations, whereas in contrast the binding of the RNA comprising the 5' region becomes modestly tighter. Implications of two different types of leader RNA-P-protein complexes in viral RNA synthesis are discussed.
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Affiliation(s)
- Soumen Basak
- Department of Biochemistry and Dr B. C. Guha Centre for Genetic Engineering and Biotechnology, University College of Science, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, India
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22
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Kuo HC, Smith JJ, Lis A, Zhao L, Gonsiorek EA, Zhou X, Higgins DM, Roth JA, Garrick MD, Garrick LM. Computer-identified nuclear localization signal in exon 1A of the transporter DMT1 is essentially ineffective in nuclear targeting. J Neurosci Res 2004; 76:497-511. [PMID: 15114622 DOI: 10.1002/jnr.20112] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Divalent metal transporter 1 (DMT1; also called DCT1, Nramp2, or SLC11A2) has multiple isoforms that localize differently in many cell types. DMT1 +IRE species (encoded by mRNA with an iron-responsive element) are limited to the plasma membrane and cytosolic vesicles. In neural cells, -IRE isoforms of DMT1 (encoded by mRNA lacking an IRE) localize to the nucleus, plasma membrane, and cytosolic vesicles. In considering nuclear compartmentalization of -IRE isoforms, we hypothesized that the newly identified exon 1A in the N-terminus of this transporter might contain a nuclear localization signal. DNA constructs starting with exon 1A and ending with exons encoding alternative isoforms were made and transiently transfected into HEK293T and PC12 cells as well as rat sympathetic neurons. None of the constructs appeared in the nucleus despite the presence of exon 1A. Antibody specific for exon 1A was also used in both immunostaining and Western blots to investigate localization of exon 1A expressed both endogenously and ectopically in cells. Again, nuclear localization of DMT1 containing exon 1A was not observed. Our data suggest that exon 1A is neither sufficient nor necessary for DMT1 to appear in the nucleus.
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Affiliation(s)
- H C Kuo
- Department of Biochemistry, SUNY at Buffalo, Buffalo, New York 14214-3000, USA
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23
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Surguladze N, Thompson KM, Beard JL, Connor JR, Fried MG. Interactions and Reactions of Ferritin with DNA. J Biol Chem 2004; 279:14694-702. [PMID: 14734543 DOI: 10.1074/jbc.m313348200] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ferritin, normally considered a cytoplasmic iron-storage protein, is also found in the nuclei of some cells. There is no current agreement about its function(s) in this environment. Proposals include DNA protection, provision of iron to nuclear enzymes, and regulation of transcription initiation, but evidence for these functions is scanty. We have shown previously that H-ferritin subunits can be cross-linked to chromosomal DNA in vivo (Thompson, K. J., Fried, M. G., Ye, Z., Boyer, P., and Connor, J. R. (2002) J. Cell Sci. 115, 2165-2177). Here we describe systematic analyses of DNA binding and the covalent stability of DNA in the presence of ferritins from several different sources. Our data show that the H-subunit of human ferritin binds DNA, whereas neither the L-subunit nor the ferroxidase-deficient 222-mutant of the H-subunit has detectable binding activity. DNA binding is without significant preference for base composition, sequence, or the nature of DNA ends. H- and L-ferritins and ferritins of mixed subunit composition stimulate the conversion of superhelical plasmid DNA to the relaxed form. The sensitivity of this conversion to glycerol suggests that DNA is nicked by a free radical mechanism. The rate of nicking correlates with the iron content of the ferritin and is strongly inhibited by chelators. Ferritin-dependent nicking is characterized by a kinetic lag that is not seen in control reactions containing free iron species. These results suggest that the release of iron from ferritin is an important part of the nicking mechanism. The potential role of ferritin as a protector of the genome is discussed in the context of these results.
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Affiliation(s)
- Nodar Surguladze
- Departments of Neural and Behavioral Science and Biochemistry and Molecular Biology, the Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
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24
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Huang WH, Guo HB, Huang XY, Sun FZ. Two types of new ferritin cDNA sequences from Xenopus laevis germinal vesicle oocytes. ACTA ACUST UNITED AC 2004; 14:211-4. [PMID: 14509834 DOI: 10.1080/1042517031000098810] [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: 10/27/2022]
Abstract
Some of Xenopus ferritin cDNA family genes have already been sequenced. In this study, we report that two ferritin cDNA genes have been cloned from the Xenopus laevis germinal vesicle (GV) oocytes. The deduced proteins have different lengths with varied sequences when compared with the published Xenopus ferritins. One of them is the ferritin light chain homologous (LCH), which is reported for the first time in Xenopus and the other is the ferritin heavy chain homologous (HCH) that is first reported in Xenopus GV oocyte.
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Affiliation(s)
- Wei-Hong Huang
- Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
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25
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Millholland JM, Fitch JM, Cai CX, Gibney EP, Beazley KE, Linsenmayer TF. Ferritoid, a tissue-specific nuclear transport protein for ferritin in corneal epithelial cells. J Biol Chem 2003; 278:23963-70. [PMID: 12697769 DOI: 10.1074/jbc.m210050200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previously we reported that ferritin in corneal epithelial (CE) cells is a nuclear protein that protects DNA from UV damage. Since ferritin is normally cytoplasmic, in CE cells, a mechanism must exist that effects its nuclear localization. We have now determined that this involves a nuclear transport molecule we have termed ferritoid. Ferritoid is specific for CE cells and is developmentally regulated. Structurally, ferritoid contains multiple domains, including a functional SV40-type nuclear localization signal and a ferritin-like region of approximately 50% similarity to ferritin itself. This latter domain is likely responsible for the interaction between ferritoid and ferritin detected by co-immunoprecipitation analysis. To test functionally whether ferritoid is capable of transporting ferritin into the nucleus, we performed cotransfections of COS-1 cells with constructs for ferritoid and ferritin. Consistent with the proposed nuclear transport function for ferritoid, co-transfections with full-length constructs for ferritoid and ferritin resulted in a preferential nuclear localization of both molecules; this was not observed when the nuclear localization signal of ferritoid was deleted. Moreover, since ferritoid is structurally similar to ferritin, it may be an example of a nuclear transporter that evolved from the molecule it transports (ferritin).
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Affiliation(s)
- John M Millholland
- Department of Anatomy and Cellular Biology, Tufts University Medical School, Boston, Massachusetts 02111, USA
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26
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Thompson KJ, Fried MG, Ye Z, Boyer P, Connor JR. Regulation, mechanisms and proposed function of ferritin translocation to cell nuclei. J Cell Sci 2002; 115:2165-77. [PMID: 11973357 DOI: 10.1242/jcs.115.10.2165] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ferritin is traditionally considered a cytoplasmic iron-storage protein,but recent reports indicate that it is also found in cell nuclei. Nuclear ferritin has been proposed to be involved in both the protection of DNA and the exacerbation of iron-induced oxidative damage to DNA. We demonstrate that H-rich ferritin is present in the nucleus of human astrocytoma tumor cells. To study the mechanism and regulation of ferritin translocation to the nucleus,we developed a cell culture model using SW1088 human astrocytoma cells. Changes in cellular iron levels, cytokine treatments and hydrogen peroxide exposure affected the distribution of ferritin between the cytosol and the nucleus. Ferritin enters the nucleus via active transport through the nuclear pore and does not require NLS-bearing cytosolic factors for transport. Furthermore, H-rich ferritin is preferred over L-rich ferritin for uptake into the nucleus. Whole cell crosslinking studies revealed that ferritin is associated with DNA. Ferritin protected DNA from iron-induced oxidative damage in both in vitro and in cell culture models. These results strongly suggest a novel role for ferritin in nuclear protection. This work should lead to novel characterization of ferritin functions in the context of genomic stability and may have unparalleled biological significance in terms of the accessibility of metals to DNA. The knowledge generated as a result of these studies will also improve our understanding of iron-induced damage of nuclear constituents.
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Affiliation(s)
- Khristy J Thompson
- Department of Neuroscience and Anatomy, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, 17033, USA.
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27
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Affiliation(s)
- Frank M Torti
- Department of Cancer Biology and Biochemistry and the Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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