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Prajapati M, Conboy HL, Hojyo S, Fukada T, Budnik B, Bartnikas TB. Biliary excretion of excess iron in mice requires hepatocyte iron import by Slc39a14. J Biol Chem 2021; 297:100835. [PMID: 34051234 PMCID: PMC8214222 DOI: 10.1016/j.jbc.2021.100835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/13/2021] [Accepted: 05/25/2021] [Indexed: 12/19/2022] Open
Abstract
Iron is essential for erythropoiesis and other biological processes, but is toxic in excess. Dietary absorption of iron is a highly regulated process and is a major determinant of body iron levels. Iron excretion, however, is considered a passive, unregulated process, and the underlying pathways are unknown. Here we investigated the role of metal transporters SLC39A14 and SLC30A10 in biliary iron excretion. While SLC39A14 imports manganese into the liver and other organs under physiological conditions, it imports iron under conditions of iron excess. SLC30A10 exports manganese from hepatocytes into the bile. We hypothesized that biliary excretion of excess iron would be impaired by SLC39A14 and SLC30A10 deficiency. We therefore analyzed biliary iron excretion in Slc39a14-and Slc30a10-deficient mice raised on iron-sufficient and -rich diets. Bile was collected surgically from the mice, then analyzed with nonheme iron assays, mass spectrometry, ELISAs, and an electrophoretic assay for iron-loaded ferritin. Our results support a model in which biliary excretion of excess iron requires iron import into hepatocytes by SLC39A14, followed by iron export into the bile predominantly as ferritin, with iron export occurring independently of SLC30A10. To our knowledge, this is the first report of a molecular determinant of mammalian iron excretion and can serve as basis for future investigations into mechanisms of iron excretion and relevance to iron homeostasis.
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Affiliation(s)
- Milankumar Prajapati
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Heather L Conboy
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Shintaro Hojyo
- Division of Molecular Psychoimmunology, Institute for Genetic Medicine, Graduate School of Medicine, Hokkaido University, Hokkaido, Japan
| | - Toshiyuki Fukada
- Department of Molecular and Cellular Physiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Bogdan Budnik
- Mass Spectrometry and Proteomics Resource Laboratory, Faculty of Arts and Sciences, Division of Science, Harvard University, Cambridge, Massachusetts, USA
| | - Thomas B Bartnikas
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA.
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La Carpia F, Wojczyk BS, Annavajhala MK, Rebbaa A, Culp-Hill R, D’Alessandro A, Freedberg DE, Uhlemann AC, Hod EA. Transfusional iron overload and intravenous iron infusions modify the mouse gut microbiota similarly to dietary iron. NPJ Biofilms Microbiomes 2019; 5:26. [PMID: 31583109 PMCID: PMC6760189 DOI: 10.1038/s41522-019-0097-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 08/12/2019] [Indexed: 01/19/2023] Open
Abstract
Iron is essential for both microorganisms and their hosts. Although effects of dietary iron on gut microbiota have been described, the effect of systemic iron administration has yet to be explored. Here, we show that dietary iron, intravenous iron administration, and chronic transfusion in mice increase the availability of iron in the gut. These iron interventions have consistent and reproducible effects on the murine gut microbiota; specifically, relative abundance of the Parabacteroides and Lactobacillus genera negatively correlate with increased iron stores, whereas members of the Clostridia class positively correlate with iron stores regardless of the route of iron administration. Iron levels also affected microbial metabolites, in general, and indoles, in particular, circulating in host plasma and in stool pellets. Taken together, these results suggest that by shifting the balance of the microbiota, clinical interventions that affect iron status have the potential to alter biologically relevant microbial metabolites in the host.
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Affiliation(s)
- Francesca La Carpia
- Department of Pathology and Cell biology, Columbia University Irving Medical Center, New York, NY USA
| | - Boguslaw S. Wojczyk
- Department of Pathology and Cell biology, Columbia University Irving Medical Center, New York, NY USA
| | - Medini K. Annavajhala
- Department of Medicine, Columbia University, Irving Medical Center-New York Presbyterian Hospital, New York, NY USA
- Columbia Medicine Microbiome and Pathogen Genomic core, Columbia University Irving Medical Center, New York, NY USA
| | - Abdelhadi Rebbaa
- Department of Pathology and Cell biology, Columbia University Irving Medical Center, New York, NY USA
| | - Rachel Culp-Hill
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver-Anschutz Medical Campus, Aurora, Colorado USA
| | - Angelo D’Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver-Anschutz Medical Campus, Aurora, Colorado USA
| | - Daniel E. Freedberg
- Department of Medicine, Columbia University, Irving Medical Center-New York Presbyterian Hospital, New York, NY USA
| | - Anne-Catrin Uhlemann
- Department of Medicine, Columbia University, Irving Medical Center-New York Presbyterian Hospital, New York, NY USA
| | - Eldad A. Hod
- Department of Pathology and Cell biology, Columbia University Irving Medical Center, New York, NY USA
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Mercadante CJ, Prajapati M, Parmar JH, Conboy HL, Dash ME, Pettiglio MA, Herrera C, Bu JT, Stopa EG, Mendes P, Bartnikas TB. Gastrointestinal iron excretion and reversal of iron excess in a mouse model of inherited iron excess. Haematologica 2018; 104:678-689. [PMID: 30409795 PMCID: PMC6442972 DOI: 10.3324/haematol.2018.198382] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 11/07/2018] [Indexed: 12/13/2022] Open
Abstract
The current paradigm in the field of mammalian iron biology states that body iron levels are determined by dietary iron absorption, not by iron excretion. Iron absorption is a highly regulated process influenced by iron levels and other factors. Iron excretion is believed to occur at a basal rate irrespective of iron levels and is associated with processes such as turnover of intestinal epithelium, blood loss, and exfoliation of dead skin. Here we explore iron excretion in a mouse model of iron excess due to inherited transferrin deficiency. Iron excess in this model is attributed to impaired regulation of iron absorption leading to excessive dietary iron uptake. Pharmacological correction of transferrin deficiency not only normalized iron absorption rates and halted progression of iron excess but also reversed body iron excess. Transferrin treatment did not alter the half-life of 59Fe in mutant mice. 59Fe-based studies indicated that most iron was excreted via the gastrointestinal tract and suggested that iron-loaded mutant mice had increased rates of iron excretion. Direct measurement of urinary iron levels agreed with 59Fe-based predictions that urinary iron levels were increased in untreated mutant mice. Fecal ferritin levels were also increased in mutant mice relative to wild-type mice. Overall, these data suggest that mice have a significant capacity for iron excretion. We propose that further investigation into iron excretion is warranted in this and other models of perturbed iron homeostasis, as pharmacological targeting of iron excretion may represent a novel means of treatment for diseases of iron excess.
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Affiliation(s)
| | - Milankumar Prajapati
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI
| | - Jignesh H Parmar
- Center for Quantitative Medicine and Department of Cell Biology, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Heather L Conboy
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI
| | - Miriam E Dash
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI
| | - Michael A Pettiglio
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI
| | - Carolina Herrera
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI
| | - Julia T Bu
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI
| | - Edward G Stopa
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI
| | - Pedro Mendes
- Center for Quantitative Medicine and Department of Cell Biology, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Thomas B Bartnikas
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI
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Egorova KS, Ananikov VP. Welche Katalysatormetalle sind harmlos, welche giftig? Vergleich der Toxizitäten von Ni-, Cu-, Fe-, Pd-, Pt-, Rh- und Au-Salzen. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603777] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Ksenia S. Egorova
- N. D. Zelinsky Institute of Organic Chemistry; Russian Academy of Sciences; Leninsky prospect 47 Moscow 119991 Russland
| | - Valentine P. Ananikov
- N. D. Zelinsky Institute of Organic Chemistry; Russian Academy of Sciences; Leninsky prospect 47 Moscow 119991 Russland
- Department of Chemistry; Saint Petersburg State University; Stary Petergof 198504 Russland
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Egorova KS, Ananikov VP. Which Metals are Green for Catalysis? Comparison of the Toxicities of Ni, Cu, Fe, Pd, Pt, Rh, and Au Salts. Angew Chem Int Ed Engl 2016; 55:12150-62. [PMID: 27532248 DOI: 10.1002/anie.201603777] [Citation(s) in RCA: 249] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Indexed: 01/01/2023]
Abstract
Environmental profiles for the selected metals were compiled on the basis of available data on their biological activities. Analysis of the profiles suggests that the concept of toxic heavy metals and safe nontoxic alternatives based on lighter metals should be re-evaluated. Comparison of the toxicological data indicates that palladium, platinum, and gold compounds, often considered heavy and toxic, may in fact be not so dangerous, whereas complexes of nickel and copper, typically assumed to be green and sustainable alternatives, may possess significant toxicities, which is also greatly affected by the solubility in water and biological fluids. It appears that the development of new catalysts and novel applications should not rely on the existing assumptions concerning toxicity/nontoxicity. Overall, the available experimental data seem insufficient for accurate evaluation of biological activity of these metals and its modulation by the ligands. Without dedicated experimental measurements for particular metal/ligand frameworks, toxicity should not be used as a "selling point" when describing new catalysts.
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Affiliation(s)
- Ksenia S Egorova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect 47, Moscow, 119991, Russia
| | - Valentine P Ananikov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect 47, Moscow, 119991, Russia. .,Department of Chemistry, Saint Petersburg State University, Stary Petergof, 198504, Russia.
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Iron metabolism and related genetic diseases: A cleared land, keeping mysteries. J Hepatol 2016; 64:505-515. [PMID: 26596411 DOI: 10.1016/j.jhep.2015.11.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/06/2015] [Accepted: 11/09/2015] [Indexed: 12/14/2022]
Abstract
Body iron has a very close relationship with the liver. Physiologically, the liver synthesizes transferrin, in charge of blood iron transport; ceruloplasmin, acting through its ferroxidase activity; and hepcidin, the master regulator of systemic iron. It also stores iron inside ferritin and serves as an iron reservoir, both protecting the cell from free iron toxicity and ensuring iron delivery to the body whenever needed. The liver is first in line for receiving iron from the gut and the spleen, and is, therefore, highly exposed to iron overload when plasma iron is in excess, especially through its high affinity for plasma non-transferrin bound iron. The liver is strongly involved when iron excess is related either to hepcidin deficiency, as in HFE, hemojuvelin, hepcidin, and transferrin receptor 2 related haemochromatosis, or to hepcidin resistance, as in type B ferroportin disease. It is less involved in the usual (type A) form of ferroportin disease which targets primarily the macrophagic system. Hereditary aceruloplasminemia raises important pathophysiological issues in light of its peculiar organ iron distribution.
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Brissot P, Troadec MB, Loréal O. Intestinal absorption of iron in HFE-1 hemochromatosis: local or systemic process? J Hepatol 2004; 40:702-9. [PMID: 15030990 DOI: 10.1016/j.jhep.2004.01.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Pierre Brissot
- Service des Maladies du Foie and Inserm Unit U-522, University Hospital Pontchaillou, Rennes, France.
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Brissot P, Loréal O. Role of non-transferrin-bound iron in the pathogenesis of iron overload and toxicity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 509:45-53. [PMID: 12572988 DOI: 10.1007/978-1-4615-0593-8_3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Pierre Brissot
- Service des Maladies du Foie et INSERM U-522, Pontchaillou University Hospital, Rennes, France
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Iancu TC, Shiloh H, Raja KB, Simpson RJ, Peters TJ, Perl DP, Hsu A, Good PF. The hypotransferrinaemic mouse: ultrastructural and laser microprobe analysis observations. J Pathol 1995; 177:83-94. [PMID: 7472784 DOI: 10.1002/path.1711770113] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Homozygote hypotransferrinaemic mice (hpx/hpx) have cytopathological features similar to those of human congenital atransferrinaemia, genetic haemochromatosis, and neonatal haemochromatosis. These conditions all have in common high levels of cytotoxic non-transferrin-bound serum iron. This study describes the ultrastructural features of iron overload in liver, pancreas, heart, and small intestine of 2- and 12-month-old hypotransferrinaemic mice. Electron microscopic studies of unstained sections showed early parenchymal cell siderosis, with accumulation of numerous ferritin particles and clusters in the cytosol, as well as ferritin and haemosiderin in lysosomes (siderosomes). In the 12-month-old animals, iron was also found in Kupffer cells and macrophages in other tissues. In addition, there were conspicuous iron-containing compounds in the bile canaliculi, and marked iron deposition in the pancreas and heart. Laser microprobe mass analysis (LAMMA) enabled localization and relative quantitation of iron deposition in subcellular compartments providing in situ documentation of iron accumulation in siderosomes and contributed in assessing total cytosolic iron in various cell types. Moreover, it demonstrated the importance and magnitude of the biliary route for iron excretion in these animals.
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Affiliation(s)
- T C Iancu
- Paediatric Research Unit, Carmel Hospital, Haifa, Israel
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