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Huang G, Wallace DF, Powell EE, Rahman T, Clark PJ, Subramaniam VN. Gene Variants Implicated in Steatotic Liver Disease: Opportunities for Diagnostics and Therapeutics. Biomedicines 2023; 11:2809. [PMID: 37893185 PMCID: PMC10604560 DOI: 10.3390/biomedicines11102809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/05/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) describes a steatotic (or fatty) liver occurring as a consequence of a combination of metabolic, environmental, and genetic factors, in the absence of significant alcohol consumption and other liver diseases. NAFLD is a spectrum of conditions. Steatosis in the absence of inflammation is relatively benign, but the disease can progress into more severe forms like non-alcoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma. NAFLD onset and progression are complex, as it is affected by many risk factors. The interaction between genetic predisposition and other factors partially explains the large variability of NAFLD phenotype and natural history. Numerous genes and variants have been identified through large-scale genome-wide association studies (GWAS) that are associated with NAFLD and one or more subtypes of the disease. Among them, the largest effect size and most consistent association have been patatin-like phospholipase domain-containing protein 3 (PNPLA3), transmembrane 6 superfamily member 2 (TM6SF2), and membrane-bound O-acyltransferase domain containing 7 (MBOAT7) genes. Extensive in vitro and in vivo studies have been conducted on these variants to validate these associations. The focus of this review is to highlight the genetics underpinning the molecular mechanisms driving the onset and progression of NAFLD and how they could potentially be used to improve genetic-based diagnostic testing of the disease and develop personalized, targeted therapeutics.
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Affiliation(s)
- Gary Huang
- Hepatogenomics Research Group, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia;
- Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia;
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
| | - Daniel F. Wallace
- Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia;
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
- Metallogenomics Laboratory, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
| | - Elizabeth E. Powell
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia;
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, QLD 4102, Australia
- Centre for Liver Disease Research, Translational Research Institute, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4101, Australia
| | - Tony Rahman
- Department of Gastroenterology and Hepatology, Prince Charles Hospital, Brisbane, QLD 4032, Australia;
| | - Paul J. Clark
- Mater Adult Hospital, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4101, Australia;
| | - V. Nathan Subramaniam
- Hepatogenomics Research Group, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia;
- Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia;
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
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Goncalves Monteiro D, Rishi G, Gorman DM, Burnet G, Aliyanto R, Rosengren KJ, Frazer DM, Subramaniam VN, Clark RJ. Engineering Peptide Inhibitors of the HFE-Transferrin Receptor 1 Complex. Molecules 2022; 27:molecules27196581. [PMID: 36235117 PMCID: PMC9570809 DOI: 10.3390/molecules27196581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/22/2022] [Accepted: 09/28/2022] [Indexed: 11/05/2022]
Abstract
The protein HFE (homeostatic iron regulator) is a key regulator of iron metabolism, and mutations in HFE underlie the most frequent form of hereditary haemochromatosis (HH-type I). Studies have shown that HFE interacts with transferrin receptor 1 (TFR1), a homodimeric type II transmembrane glycoprotein that is responsible for the cellular uptake of iron via iron-loaded transferrin (holo-transferrin) binding. It has been hypothesised that the HFE/TFR1 interaction serves as a sensor to the level of iron-loaded transferrin in circulation by means of a competition mechanism between HFE and iron-loaded transferrin association with TFR1. To investigate this, a series of peptides based on the helical binding interface between HFE and TFR1 were generated and shown to significantly interfere with the HFE/TFR1 interaction in an in vitro proximity ligation assay. The helical conformation of one of these peptides, corresponding to the α1 and α2 helices of HFE, was stabilised by the introduction of sidechain lactam “staples”, but this did not result in an increase in the ability of the peptide to disrupt the HFE/TFR1 interaction. These peptides inhibitors of the protein–protein interaction between HFE and TFR1 are potentially useful tools for the analysis of the functional role of HFE in the regulation of hepcidin expression.
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Affiliation(s)
| | - Gautam Rishi
- Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
| | - Declan M. Gorman
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Guillaume Burnet
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Randy Aliyanto
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - K. Johan Rosengren
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David M. Frazer
- The QIMR Berghofer Medical Research Institute, 300 Herston Rd, Brisbane, QLD 4006, Australia
| | - V. Nathan Subramaniam
- Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
- Correspondence: (V.N.S.); (R.J.C.)
| | - Richard J. Clark
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Correspondence: (V.N.S.); (R.J.C.)
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Rishi G, Huang G, Subramaniam VN. Cancer: The role of iron and ferroptosis. Int J Biochem Cell Biol 2021; 141:106094. [PMID: 34628027 DOI: 10.1016/j.biocel.2021.106094] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 09/25/2021] [Accepted: 10/05/2021] [Indexed: 02/09/2023]
Abstract
Iron is an essential element for virtually all living things. Body iron levels are tightly controlled as both increased iron levels and iron deficiency are associated with many clinical conditions. Increased iron levels are associated with a worse prognosis in some cancers, so understanding the role of iron in cancer development has thus been an active area of research. Regulated forms of cell death are important in development and disease pathogenesis. In this Medicine in Focus review article, we discuss the role of iron in cancer, and ferroptosis, a new form of iron-regulated cell death triggered by increased iron and peroxidation of lipids. We also review the pathogenesis of cancer, potential therapeutics for targeting the increased requirement of iron, as well as how ferroptosis activation may have a role in treatment of cancers.
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Affiliation(s)
- Gautam Rishi
- Hepatogenomics Research Group, Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Qld 4059, Australia
| | - Gary Huang
- Hepatogenomics Research Group, Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Qld 4059, Australia
| | - V Nathan Subramaniam
- Hepatogenomics Research Group, Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Qld 4059, Australia.
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Baas FS, Rishi G, Swinkels DW, Subramaniam VN. Genetic Diagnosis in Hereditary Hemochromatosis: Discovering and Understanding the Biological Relevance of Variants. Clin Chem 2021; 67:1324-1341. [PMID: 34402502 DOI: 10.1093/clinchem/hvab130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/23/2021] [Indexed: 11/13/2022]
Abstract
BACKGROUND Hereditary hemochromatosis (HH) is a genetic disease, leading to iron accumulation and possible organ damage. Patients are usually homozygous for p. Cys282Tyr in the homeostatic iron regulator gene but may have mutations in other genes involved in the regulation of iron. Next-generation sequencing is increasingly being utilized for the diagnosis of patients, leading to the discovery of novel genetic variants. The clinical significance of these variants is often unknown. CONTENT Determining the pathogenicity of such variants of unknown significance is important for diagnostics and genetic counseling. Predictions can be made using in silico computational tools and population data, but additional evidence is required for a conclusive pathogenicity classification. Genetic disease models, such as in vitro models using cellular overexpression, induced pluripotent stem cells or organoids, and in vivo models using mice or zebrafish all have their own challenges and opportunities when used to model HH and other iron disorders. Recent developments in gene-editing technologies are transforming the field of genetic disease modeling. SUMMARY In summary, this review addresses methods and developments regarding the discovery and classification of genetic variants, from in silico tools to in vitro and in vivo models, and presents them in the context of HH. It also explores recent gene-editing developments and how they can be applied to the discussed models of genetic disease.
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Affiliation(s)
- Floor S Baas
- Translational Metabolic Laboratory (TML 831), Radboudumc, Nijmegen, the Netherlands.,Hepatogenomics Research Group, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Gautam Rishi
- Hepatogenomics Research Group, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Dorine W Swinkels
- Translational Metabolic Laboratory (TML 831), Radboudumc, Nijmegen, the Netherlands
| | - V Nathan Subramaniam
- Hepatogenomics Research Group, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD, Australia
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Milanese C, Gabriels S, Barnhoorn S, Cerri S, Ulusoy A, Gornati SV, Wallace DF, Blandini F, Di Monte DA, Subramaniam VN, Mastroberardino PG. Gender biased neuroprotective effect of Transferrin Receptor 2 deletion in multiple models of Parkinson's disease. Cell Death Differ 2021; 28:1720-1732. [PMID: 33323945 PMCID: PMC8166951 DOI: 10.1038/s41418-020-00698-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 11/16/2020] [Accepted: 11/24/2020] [Indexed: 01/28/2023] Open
Abstract
Alterations in the metabolism of iron and its accumulation in the substantia nigra pars compacta accompany the pathogenesis of Parkinson's disease (PD). Changes in iron homeostasis also occur during aging, which constitutes a PD major risk factor. As such, mitigation of iron overload via chelation strategies has been considered a plausible disease modifying approach. Iron chelation, however, is imperfect because of general undesired side effects and lack of specificity; more effective approaches would rely on targeting distinctive pathways responsible for iron overload in brain regions relevant to PD and, in particular, the substantia nigra. We have previously demonstrated that the Transferrin/Transferrin Receptor 2 (TfR2) iron import mechanism functions in nigral dopaminergic neurons, is perturbed in PD models and patients, and therefore constitutes a potential therapeutic target to halt iron accumulation. To validate this hypothesis, we generated mice with targeted deletion of TfR2 in dopaminergic neurons. In these animals, we modeled PD with multiple approaches, based either on neurotoxin exposure or alpha-synuclein proteotoxic mechanisms. We found that TfR2 deletion can provide neuroprotection against dopaminergic degeneration, and against PD- and aging-related iron overload. The effects, however, were significantly more pronounced in females rather than in males. Our data indicate that the TfR2 iron import pathway represents an amenable strategy to hamper PD progression. Data also suggest, however, that therapeutic strategies targeting TfR2 should consider a potential sexual dimorphism in neuroprotective response.
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Affiliation(s)
- Chiara Milanese
- Department of Molecular Genetics, Rotterdam, the Netherlands ,grid.7678.e0000 0004 1757 7797IFOM-The FIRC Institute of Molecular Oncology, Milan, Italy
| | - Sylvia Gabriels
- Department of Molecular Genetics, Rotterdam, the Netherlands
| | | | | | - Ayse Ulusoy
- grid.424247.30000 0004 0438 0426German Centre for Neurodegenerative Diseases (DZNE), 53175 Bonn, Germany
| | - S. V. Gornati
- grid.5645.2000000040459992XDepartment of Neuroscience Erasmus MC, Rotterdam, the Netherlands
| | - Daniel F. Wallace
- grid.1024.70000000089150953School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, QLD Australia
| | - Fabio Blandini
- IRCCS Mondino Foundation, 27100 Pavia, Italy ,grid.8982.b0000 0004 1762 5736Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Donato A. Di Monte
- grid.424247.30000 0004 0438 0426German Centre for Neurodegenerative Diseases (DZNE), 53175 Bonn, Germany
| | - V. Nathan Subramaniam
- grid.1024.70000000089150953School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, QLD Australia
| | - Pier G. Mastroberardino
- Department of Molecular Genetics, Rotterdam, the Netherlands ,grid.7678.e0000 0004 1757 7797IFOM-The FIRC Institute of Molecular Oncology, Milan, Italy ,grid.158820.60000 0004 1757 2611Department of Life, Health, and Environmental Sciences, University of L’Aquila, L’Aquila, Italy
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Hawula ZJ, Davis RA, Wallace DF, Rishi G, Subramaniam VN. In vitro identification and characterisation of iron chelating catechol-containing natural products and derivatives. Biometals 2021; 34:855-866. [PMID: 33913062 DOI: 10.1007/s10534-021-00312-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 04/20/2021] [Indexed: 12/18/2022]
Abstract
Iron is an essential component for multiple biological processes. Its regulation within the body is thus tightly controlled. Dysregulation of iron levels within the body can result in several disorders associated with either excess iron accumulation, including haemochromatosis and thalassaemia, or iron deficiency. In cases of excess body iron, therapy involves depleting body iron levels either by venesection, typically for haemochromatosis, or using iron chelators for thalassemia. However, the current chelation options for people with iron overload are limited, with only three iron chelators approved for clinical use. This presents an opportunity for improved therapeutics to be identified and developed. The aim of this study was to examine multiple compounds from within the Davis open access natural product-based library (512 compounds) for their ability to chelate iron. In silico analysis of this library initially identified nine catechol-containing compounds and two closely related compounds. These compounds were subsequently screened using an in vitro DNA breakage assay and their ability to chelate biological iron was also examined in an iron-loaded hepatocyte cellular assay. Toxicity was assessed in hepatocyte and breast cancer cell lines. One compound, RAD362 [N-(3-aminopropyl)-3,4-dihydroxybenzamide] was able to protect against DNA damage, likely through the prevention of free radicals generated via the Fenton reaction; RAD362 treatment resulted in decreased ferritin protein levels in iron-loaded hepatocytes. Lastly, RAD362 resulted in significantly less cell death than the commonly used iron chelator deferoxamine. This is the first study to identify compound RAD362 as an iron chelator and potential therapeutic.
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Affiliation(s)
- Zachary J Hawula
- Faculty of Health, School of Biomedical Sciences, Queensland University of Technology (QUT), 60 Musk Avenue, Kelvin Grove, Brisbane, QLD, 4059, Australia
| | - Rohan A Davis
- Griffith Institute for Drug Discovery, Environment and Science, Griffith University, Brisbane, QLD, Australia
| | - Daniel F Wallace
- Faculty of Health, School of Biomedical Sciences, Queensland University of Technology (QUT), 60 Musk Avenue, Kelvin Grove, Brisbane, QLD, 4059, Australia
| | - Gautam Rishi
- Faculty of Health, School of Biomedical Sciences, Queensland University of Technology (QUT), 60 Musk Avenue, Kelvin Grove, Brisbane, QLD, 4059, Australia.
| | - V Nathan Subramaniam
- Faculty of Health, School of Biomedical Sciences, Queensland University of Technology (QUT), 60 Musk Avenue, Kelvin Grove, Brisbane, QLD, 4059, Australia.
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Abstract
Iron, the most common metal in the earth, is also an essential component for almost all living organisms. While these organisms require iron for many biological processes, too much or too little iron itself poses many issues; this is most easily recognized in human beings. The control of body iron levels is thus an important metabolic process which is regulated essentially by controlling the expression, activity and levels of the iron transporter ferroportin. Ferroportin is the only known iron exporter. The function and activity of ferroportin is influenced by its interaction with the iron-regulatory peptide hepcidin, which itself is regulated by many factors. Here we review the current state of understanding of the mechanisms that regulate ferroportin and its function.
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Affiliation(s)
- Gautam Rishi
- Hepatogenomics Research Group, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - V Nathan Subramaniam
- Hepatogenomics Research Group, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, QLD, Australia
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Secondes ES, Wallace DF, Rishi G, McLaren GD, McLaren CE, Chen WP, Ramm LE, Powell LW, Ramm GA, Barton JC, Subramaniam VN. Increased frequency of GNPAT p.D519G in compound HFE p.C282Y/p.H63D heterozygotes with elevated serum ferritin levels. Blood Cells Mol Dis 2020; 85:102463. [PMID: 32652459 DOI: 10.1016/j.bcmd.2020.102463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/30/2020] [Accepted: 06/30/2020] [Indexed: 12/12/2022]
Abstract
Glyceronephosphate O-acyltransferase (GNPAT) p.D519G (rs11558492) was identified as a genetic modifier correlated with more severe iron overload in hemochromatosis through whole-exome sequencing of HFE p.C282Y homozygotes with extreme iron phenotypes. We studied the prevalence of p.D519G in HFE p.C282Y/p.H63D compound heterozygotes, a genotype associated with iron overload in some patients. Cases were Australian participants with elevated serum ferritin (SF) levels ≥300μg/L (males) and ≥200μg/L (females); subjects whose SF levels were below these cut-offs were designated as controls. Samples were genotyped for GNPAT p.D519G. We compared the allele frequency of the present subjects, with/without elevated SF, to p.D519G frequency in public datasets. GNPAT p.D519G was more prevalent in our cohort of p.C282Y/p.H63D compound heterozygotes with elevated SF (37%) than European public datasets: 1000G 21%, gnomAD 20% and ESP 21%. We conclude that GNPAT p.D519G is associated with elevated SF in Australian HFE p.C282Y/p.H63D compound heterozygotes.
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Affiliation(s)
- Eriza S Secondes
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
| | - Daniel F Wallace
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
| | - Gautam Rishi
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
| | - Gordon D McLaren
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, CA, USA; Department of Veterans Affairs Long Beach Healthcare System, Long Beach, CA, USA.
| | | | - Wen-Pin Chen
- Chao Family Comprehensive Cancer Center, University of California, Irvine, CA.
| | - Louise E Ramm
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
| | - Lawrie W Powell
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
| | - Grant A Ramm
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
| | - James C Barton
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA, Southern Iron Disorders Center, Birmingham, AL, USA
| | - V Nathan Subramaniam
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Queensland, Australia; QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
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Hawula ZJ, Wallace DF, Subramaniam VN, Rishi G. Therapeutic Advances in Regulating the Hepcidin/Ferroportin Axis. Pharmaceuticals (Basel) 2019; 12:ph12040170. [PMID: 31775259 PMCID: PMC6958404 DOI: 10.3390/ph12040170] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/15/2019] [Accepted: 11/19/2019] [Indexed: 12/15/2022] Open
Abstract
The interaction between hepcidin and ferroportin is the key mechanism involved in regulation of systemic iron homeostasis. This axis can be affected by multiple stimuli including plasma iron levels, inflammation and erythropoietic demand. Genetic defects or prolonged inflammatory stimuli results in dysregulation of this axis, which can lead to several disorders including hereditary hemochromatosis and anaemia of chronic disease. An imbalance in iron homeostasis is increasingly being associated with worse disease outcomes in many clinical conditions including multiple cancers and neurological disorders. Currently, there are limited treatment options for regulating iron levels in patients and thus significant efforts are being made to uncover approaches to regulate hepcidin and ferroportin expression. These approaches either target these molecules directly or regulatory steps which mediate hepcidin or ferroportin expression. This review examines the current status of hepcidin and ferroportin agonists and antagonists, as well as inducers and inhibitors of these proteins and their regulatory pathways.
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Affiliation(s)
- Zachary J. Hawula
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia; (Z.J.H.); (D.F.W.)
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia
| | - Daniel F. Wallace
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia; (Z.J.H.); (D.F.W.)
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia
| | - V. Nathan Subramaniam
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia; (Z.J.H.); (D.F.W.)
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia
- Correspondence: (V.N.S.); (G.R.)
| | - Gautam Rishi
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia; (Z.J.H.); (D.F.W.)
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia
- Correspondence: (V.N.S.); (G.R.)
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Zhang X, Karunathilaka N, Senanayake S, Subramaniam VN, Chan W, Kostner K, Fraser J, Atherton JJ, Punyadeera C. The potential prognostic utility of salivary galectin-3 concentrations in heart failure. Clin Res Cardiol 2019; 109:685-692. [PMID: 31598750 DOI: 10.1007/s00392-019-01557-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/24/2019] [Indexed: 01/10/2023]
Abstract
BACKGROUND Patients with HF are at a higher risk of rehospitalisation and, as such, significant costs to our healthcare system. A non-invasive method to collect body fluids and measure Gal-3 could improve the current management of HF. In this study, we investigated the potential prognostic utility of salivary Galectin-3 (Gal-3) in patients with heart failure (HF). METHODS We collected saliva samples from patients with HF (n = 105) either at hospital discharge or during routine clinical visits. Gal-3 concentrations in saliva samples were measured by ELISA. The Kaplan-Meier survival curve analysis and Cox proportional regression model were used to determine the potential prognostic utility of salivary Gal-3 concentrations. RESULTS The primary end point was either cardiovascular death or hospitalisation. Salivary Gal-3 concentrations were significantly higher (p < 0.05) in patients with HF who subsequently experienced the primary endpoint compared to those who did not. HF patients with salivary Gal-3 concentrations > 172.58 ng/mL had a significantly (p < 0.05) higher cumulative risk of the primary endpoint compared to those with lower salivary Gal-3 concentrations. In patients with HF, salivary Gal-3 concentration was a predictor of the primary endpoint even after adjusting for other covariates. CONCLUSIONS In our pilot study, HF patients with salivary Gal-3 concentrations of > 172.58 ng/mL demonstrated a higher cumulative risk of the primary outcome compared to those with lower Gal-3 levels, even after adjusting for other variables. Confirming our findings in a larger multi-centre clinical trial in the future would enable salivary Gal-3 measurements to form part of routine management for patients with HF.
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Affiliation(s)
- Xi Zhang
- Saliva and Liquid Biopsy Translational Research Team, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, GPO Box 2434, Brisbane, QLD, 4001, Australia
| | - Nuwan Karunathilaka
- Saliva and Liquid Biopsy Translational Research Team, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, GPO Box 2434, Brisbane, QLD, 4001, Australia
| | - Sameera Senanayake
- Australian Centre For Health Services Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - V Nathan Subramaniam
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Wandy Chan
- Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia
| | - Karam Kostner
- Department of Cardiology, Mater Adult Hospital, Brisbane, QLD, Australia
| | - John Fraser
- Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia
| | - John J Atherton
- Cardiology Department, Royal Brisbane and Women's Hospital and University of Queensland School of Medicine, Brisbane, QLD, Australia
| | - Chamindie Punyadeera
- Saliva and Liquid Biopsy Translational Research Team, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, GPO Box 2434, Brisbane, QLD, 4001, Australia.
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Abstract
Since its discovery in 2001, there have been a number of important discoveries and findings that have increased our knowledge about the functioning of hepcidin. Hepcidin, the master iron regulator has been shown to be regulated by a number of physiological stimuli and their associated signaling pathways. This chapter will summarize our current understanding of how these physiological stimuli and downstream signaling molecules are involved in hepcidin modulation and ultimately contribute to the regulation of systemic or local iron homeostasis. The signaling pathways and molecules described here have been shown to primarily affect hepcidin at a transcriptional level, but these transcriptional changes correlate with changes in systemic iron levels as well, supporting the functional effects of hepcidin regulation by these signaling pathways.
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Affiliation(s)
- Gautam Rishi
- The Liver Disease and Iron Disorders Research Group, Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - V Nathan Subramaniam
- The Liver Disease and Iron Disorders Research Group, Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD, Australia.
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12
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Barton JC, McLaren CE, Chen WP, Ramm GA, Anderson GJ, Powell LW, Subramaniam VN, Adams PC, Phatak PD, Gurrin LC, Phillips JD, Parker CJ, Emond MJ, McLaren GD. Cirrhosis in Hemochromatosis: Independent Risk Factors in 368 HFE p.C282Y Homozygotes. Ann Hepatol 2018; 17:871-879. [PMID: 30145563 PMCID: PMC6368858 DOI: 10.5604/01.3001.0012.3169] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
INTRODUCTION AND AIM We sought to identify independent risk factors for cirrhosis in HFE p.C282Y homozygotes in a cross-sectional study. MATERIAL AND METHODS We evaluated 368 p.C282Y homozygotes who underwent liver biopsy and compared characteristics of those with and without cirrhosis. We performed multivariable logistic regression on cirrhosis with: age; sex; race/ethnicity; diabetes; blood pints/units donated voluntarily; erythrocyte pints/units received; iron supplement use; alcohol intake, g/d; body mass index, kg/m2; swollen/tender 2nd/3rd metacarpophalangeal joints; elevated alanine aminotransferase; elevated aspartate aminotransferase; steatosis/fatty liver; iron removed by phlebotomy, g; and GNPAT p.D519G positivity. RESULTS Mean age of 368 participants (73.6% men) was 47 ± 13 (standard deviation) y. Cirrhosis was diagnosed in 86 participants (23.4%). Participants with cirrhosis had significantly greater mean age, proportion of men, diabetes prevalence, mean daily alcohol intake, prevalence of swollen/ tender 2nd/3rd metacarpophalangeal joints, mean serum ferritin, elevated alanine aminotransferase, elevated aspartate aminotransferase, and mean iron removed; and significantly fewer mean blood pints/units donated. GNPAT p.D519G positivity was detected in 82 of 188 participants (43.6%). In a multivariable model for cirrhosis, there were four significant positive associations: age (10-y intervals) (odds ratio 2.2 [95% confidence interval 1.5, 3.3]); diabetes (3.3; [1.1, 9.7]); alcohol intake (14 g alcohol drinks/d) (1.5 [1.2, 1.8]); and iron removed, g (1.3 [1.2, 1.4]). There was no statistical evidence of two-way interactions between these variables. CONCLUSION In conclusion, cirrhosis in HFE p.C282Y homozygotes is significantly associated with age, diabetes, daily alcohol intake, and iron removed by phlebotomy, taking into account the effect of other variables.
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Affiliation(s)
- James C. Barton
- Southern Iron Disorders Center, Birmingham, AL, USA
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Wen-pin Chen
- Chao Family Comprehensive Cancer Center, lrvine, CA, USA
| | - Grant A. Ramm
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Gregory J. Anderson
- Faculty of Medicine, The University of Queensland, Herston, QLD, Australia
- School of Chemistry and Molecular Bioscience, University of Queensland, Brisbane St. Lucia, QLD, Australia
| | - Lawrie W Powell
- Faculty of Medicine, The University of Queensland, Herston, QLD, Australia
- School of Chemistry and Molecular Bioscience, University of Queensland, Brisbane St. Lucia, QLD, Australia
- Royal Brisbane & Women’s Hospital, Herston, QLD, Australia
| | - V. Nathan Subramaniam
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Paul C. Adams
- Department of Medicine, London Health Sciences Centre, London, ONT, Canada
| | | | - Lyle C. Gurrin
- Melbourne School of Population and Global Health, The University of Melbourne, Victoria, Australia
| | - John D. Phillips
- Departments of Medicine and Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Charles J. Parker
- Division of Hematology and Hematologic Malignancies, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Mary J. Emond
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - Gordon D. McLaren
- Department of Veterans Affairs Long Beach Healthcare System, Long Beach, CA, USA
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, CA, USA
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13
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Rishi G, Secondes ES, Nathan Subramaniam V. Hemochromatosis: Evaluation of the dietary iron model and regulation of hepcidin. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2550-2556. [PMID: 29752985 DOI: 10.1016/j.bbadis.2018.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 04/20/2018] [Accepted: 05/07/2018] [Indexed: 12/22/2022]
Abstract
Our knowledge of iron homeostasis has increased steadily over the last two decades; much of this has been made possible through the study of animal models of iron-related disease. Analysis of transgenic mice with deletions or perturbations in genes known to be involved in systemic or local regulation of iron metabolism has been particularly informative. The effect of these genes on iron accumulation and hepcidin regulation is traditionally compared with wildtype mice fed a high iron diet, most often a 2% carbonyl iron diet. Recent studies have indicated that a very high iron diet could be detrimental to the health of the mice and could potentially affect homeostasis of other metals, for example zinc and copper. We analyzed mice fed a diet containing either 0.25%, 0.5%, 1% or 2% carbonyl iron for two weeks and compared them with mice on a control diet. Our results indicate that a 0.25% carbonyl iron diet is sufficient to induce maximal hepatic hepcidin response. Importantly these results also demonstrate that in a chronic setting of iron administration, the amount of excess hepatic iron may not further influence hepcidin regulation and that expression of hepcidin plateaus at lower hepatic iron levels. These studies provide further insights into the regulation of this important hormone.
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Affiliation(s)
- Gautam Rishi
- The Liver Disease and Iron Disorders Research Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Eriza S Secondes
- The Liver Disease and Iron Disorders Research Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - V Nathan Subramaniam
- The Liver Disease and Iron Disorders Research Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
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14
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Britton L, Bridle K, Reiling J, Santrampurwala N, Wockner L, Ching H, Stuart K, Subramaniam VN, Jeffrey G, St Pierre T, House M, Gummer J, Trengove R, Olynyk J, Crawford D, Adams L. Hepatic iron concentration correlates with insulin sensitivity in nonalcoholic fatty liver disease. Hepatol Commun 2018; 2:644-653. [PMID: 29881816 PMCID: PMC5983226 DOI: 10.1002/hep4.1190] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/23/2018] [Accepted: 04/01/2018] [Indexed: 01/01/2023] Open
Abstract
Rodent and cell‐culture models support a role for iron‐related adipokine dysregulation and insulin resistance in the pathogenesis of nonalcoholic fatty liver disease (NAFLD); however, substantial human data are lacking. We examined the relationship between measures of iron status, adipokines, and insulin resistance in patients with NAFLD in the presence and absence of venesection. This study forms part of the Impact of Iron on Insulin Resistance and Liver Histology in Nonalcoholic Steatohepatitis (IIRON2) study, a prospective randomized controlled trial of venesection for adults with NAFLD. Paired serum samples at baseline and 6 months (end of treatment) in controls (n = 28) and patients who had venesection (n = 23) were assayed for adiponectin, leptin, resistin, retinol binding protein‐4, tumor necrosis factor α, and interleukin‐6, using a Quantibody, customized, multiplexed enzyme‐linked immunosorbent assay array. Hepatic iron concentration (HIC) was determined using MR FerriScan. Unexpectedly, analysis revealed a significant positive correlation between baseline serum adiponectin concentration and HIC, which strengthened after correction for age, sex, and body mass index (rho = 0.36; P = 0.007). In addition, there were significant inverse correlations between HIC and measures of insulin resistance (adipose tissue insulin resistance (Adipo‐IR), serum insulin, serum glucose, homeostasis model assessment of insulin resistance, hemoglobin A1c, and hepatic steatosis), whereas a positive correlation was noted with the insulin sensitivity index. Changes in serum adipokines over 6 months did not differ between the control and venesection groups. Conclusion: HIC positively correlates with serum adiponectin and insulin sensitivity in patients with NAFLD. Further study is required to establish causality and mechanistic explanations for these associations and their relevance in the pathogenesis of insulin resistance and NAFLD. (Hepatology Communications 2018;2:644‐653)
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Affiliation(s)
- Laurence Britton
- Gallipoli Medical Research Institute Greenslopes Private Hospital Greenslopes Australia.,University of Queensland Herston Australia.,Department of Gastroenterology Princess Alexandra Hospital Woolloongabba Australia.,QIMR Berghofer Medical Research Institute Brisbane Australia
| | - Kim Bridle
- Gallipoli Medical Research Institute Greenslopes Private Hospital Greenslopes Australia.,University of Queensland Herston Australia
| | - Janske Reiling
- Gallipoli Medical Research Institute Greenslopes Private Hospital Greenslopes Australia.,University of Queensland Herston Australia.,Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism Maastricht University Maastricht the Netherlands
| | - Nishreen Santrampurwala
- Gallipoli Medical Research Institute Greenslopes Private Hospital Greenslopes Australia.,University of Queensland Herston Australia.,QIMR Berghofer Medical Research Institute Brisbane Australia
| | - Leesa Wockner
- QIMR Berghofer Medical Research Institute Brisbane Australia
| | - Helena Ching
- Medical School, Faculty of Health Sciences University of Western Australia Crawley Australia
| | - Katherine Stuart
- Gallipoli Medical Research Institute Greenslopes Private Hospital Greenslopes Australia.,Department of Gastroenterology Princess Alexandra Hospital Woolloongabba Australia
| | - V Nathan Subramaniam
- QIMR Berghofer Medical Research Institute Brisbane Australia.,Institute of Health and Biomedical Innovation and School of Biomedical Sciences Queensland University of Technology Kelvin Grove Australia
| | - Gary Jeffrey
- Medical School, Faculty of Health Sciences University of Western Australia Crawley Australia.,Department of Hepatology Sir Charles Gairdner Hospital Perth Australia
| | - Tim St Pierre
- School of Physics University of Western Australia Crawley Australia
| | - Michael House
- School of Physics University of Western Australia Crawley Australia
| | - Joel Gummer
- Separation Science and Metabolomics Laboratory (Metabolomics Australia, Western Australia node) Murdoch University Murdoch Australia
| | - Robert Trengove
- Separation Science and Metabolomics Laboratory (Metabolomics Australia, Western Australia node) Murdoch University Murdoch Australia
| | - John Olynyk
- Department of Gastroenterology Fiona Stanley and Fremantle Hospital Group Murdoch Australia.,School of Health and Medical Sciences Edith Cowan University Joondalup Australia
| | - Darrell Crawford
- Gallipoli Medical Research Institute Greenslopes Private Hospital Greenslopes Australia.,University of Queensland Herston Australia
| | - Leon Adams
- Medical School, Faculty of Health Sciences University of Western Australia Crawley Australia.,Department of Hepatology Sir Charles Gairdner Hospital Perth Australia
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15
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McDonald CJ, Rishi G, Secondes ES, Ostini L, Wallace DF, Crawford DHG, Sia H, Clark P, Subramaniam VN. Evaluation of a bone morphogenetic protein 6 variant as a cause of iron loading. Hum Genomics 2018; 12:23. [PMID: 29695288 PMCID: PMC5918843 DOI: 10.1186/s40246-018-0155-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 04/18/2018] [Indexed: 12/13/2022] Open
Abstract
Background Atypical iron overload without variation in the five clinically associated hereditary hemochromatosis genes is now recognized; however, their etiology remains unknown. Since the identification of iron overload in the bone morphogenetic protein 6 (Bmp6) knockout mouse, the search has been on for clinically pathogenic variants in the BMP6 gene. A recent report proposes that variants in the pro-peptide region of BMP6 are the underlying cause of several cases of iron overload. We performed targeted next-generation sequencing on three cases of atypical iron overload with Asian ethnicity and identified a p.Q118dup (aka p.E112indelEQ, p.Q115dup, p.Q118_L119insQ) variant in BMP6. The purpose of this study was to characterize the molecular function of the identified BMP6 variant. Molecular characterization by immunofluorescence microscopy and Western blotting of transfected cells, bioinformatics, and population analyses was performed. Results In contrast to reports for other BMP6 pro-peptide variants in this region, our data indicates that this variant does not affect the function of the mature BMP6 protein. Conclusions Our data suggest that assignment of disease causation in clinical cases of iron overload to pro-peptide variants in BMP6 should thus be treated with caution and requires biological characterization.
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Affiliation(s)
| | - Gautam Rishi
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Queensland University of Technology (QUT), 60 Musk Avenue, Kelvin Grove, Brisbane, Queensland, 4059, Australia
| | - Eriza S Secondes
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Queensland University of Technology (QUT), 60 Musk Avenue, Kelvin Grove, Brisbane, Queensland, 4059, Australia
| | - Lesa Ostini
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Daniel F Wallace
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Queensland University of Technology (QUT), 60 Musk Avenue, Kelvin Grove, Brisbane, Queensland, 4059, Australia
| | - Darrell H G Crawford
- Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | | | - Paul Clark
- Princess Alexandra and Mater Hospitals, Brisbane, Australia
| | - V Nathan Subramaniam
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Queensland University of Technology (QUT), 60 Musk Avenue, Kelvin Grove, Brisbane, Queensland, 4059, Australia.
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16
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Britton L, Bridle K, Jaskowski LA, He J, Ng C, Ruelcke JE, Mohamed A, Reiling J, Santrampurwala N, Hill MM, Whitehead JP, Subramaniam VN, Crawford DH. Iron Inhibits the Secretion of Apolipoprotein E in Cultured Human Adipocytes. Cell Mol Gastroenterol Hepatol 2018; 6:215-217.e8. [PMID: 30105281 PMCID: PMC6085534 DOI: 10.1016/j.jcmgh.2018.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 04/02/2018] [Indexed: 12/11/2022]
Affiliation(s)
- L.J. Britton
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
- Department of Gastroenterology, Princess Alexandra Hospital, Queensland, Australia
- Mater Research, Translational Research Institute, Woolloongabba, Queensland, Australia
| | - Kim Bridle
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Lesley-Anne Jaskowski
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Jingjing He
- Mater Research, Translational Research Institute, Woolloongabba, Queensland, Australia
| | - Choaping Ng
- Mater Research, Translational Research Institute, Woolloongabba, Queensland, Australia
- School of Life Sciences, University of Lincoln, Lincoln, United Kingdom
| | - Jayde E. Ruelcke
- The University of Queensland Diamantina Institute, Faculty of Medicine, University of Queensland, Queensland, Australia
| | - Ahmed Mohamed
- The University of Queensland Diamantina Institute, Faculty of Medicine, University of Queensland, Queensland, Australia
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Janske Reiling
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
- Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands
| | - Nishreen Santrampurwala
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Michelle M. Hill
- The University of Queensland Diamantina Institute, Faculty of Medicine, University of Queensland, Queensland, Australia
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Jonathan P. Whitehead
- Mater Research, Translational Research Institute, Woolloongabba, Queensland, Australia
- School of Life Sciences, University of Lincoln, Lincoln, United Kingdom
| | - V. Nathan Subramaniam
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Kelvin Grove, Queensland, Australia
| | - Darrell H.G. Crawford
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
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17
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Cooray SD, Heerasing NM, Selkrig LA, Subramaniam VN, Hamblin PS, McDonald CJ, McLean CA, McNamara E, Leet AS, Roberts SK. Reversal of end-stage heart failure in juvenile hemochromatosis with iron chelation therapy: a case report. J Med Case Rep 2018; 12:18. [PMID: 29373985 PMCID: PMC5787235 DOI: 10.1186/s13256-017-1526-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 11/23/2017] [Indexed: 12/31/2022] Open
Abstract
Background Juvenile hemochromatosis is the most severe form of iron overloading phenotype. Although rare, it should be suspected in patients who present with hypogonadotropic hypogonadism, diabetes mellitus, or cardiomyopathy without a clear cause. Case presentation A young Serbian male presenting with end-stage heart failure was referred for extracorporeal membrane oxygenation. An endomyocardial biopsy revealed cytoplasmic iron deposits in myocytes. His condition was stabilized with biventricular assist devices and he was listed for heart transplantation. Iron chelation therapy was commenced and resulted in rapid removal of iron burden. Serial outpatient echocardiograms demonstrated myocardial recovery such that a successful biventricular assist device explant occurred 131 days after initial implant. Targeted gene sequencing revealed a loss-of-function mutation within the HJV gene, which is consistent with juvenile hemochromatosis. Conclusions This rare case of a patient with juvenile hemochromatosis associated with a HJV mutation provides histologic evidence documenting the reversal of associated end-stage heart failure, requiring emergent mechanical circulatory support, with iron chelation therapy.
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Affiliation(s)
- Shamil D Cooray
- Department of Endocrinology & Diabetes, The Alfred Hospital, Melbourne, VIC, 3004, Australia.
| | - Neel M Heerasing
- Department of Gastroenterology & Hepatology, The Alfred Hospital, Melbourne, VIC, 3004, Australia
| | - Laura A Selkrig
- Department of Advanced Heart Failure/ Transplantation, The Alfred Hospital, Melbourne, VIC, 3004, Australia
| | - V Nathan Subramaniam
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| | - P Shane Hamblin
- Department of Endocrinology & Diabetes, The Alfred Hospital, Melbourne, VIC, 3004, Australia.,Endocrinology & Diabetes Unit, Western Health, St Albans, VIC, 3021, Australia.,Department of Medicine, Monash University, Melbourne, VIC, Australia.,Department of Medicine, Melbourne Medical School - Western Precinct, The University of Melbourne, Melbourne, VIC, 3021, Australia
| | - Cameron J McDonald
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| | - Catriona A McLean
- Department of Medicine, Monash University, Melbourne, VIC, Australia.,Department of Anatomical Pathology, The Alfred Hospital, Melbourne, VIC, 3004, Australia
| | - Elissa McNamara
- Endocrinology & Diabetes Unit, Western Health, St Albans, VIC, 3021, Australia
| | - Angeline S Leet
- Department of Advanced Heart Failure/ Transplantation, The Alfred Hospital, Melbourne, VIC, 3004, Australia.,Baker Research Institute, Melbourne, VIC, 3004, Australia
| | - Stuart K Roberts
- Department of Gastroenterology & Hepatology, The Alfred Hospital, Melbourne, VIC, 3004, Australia.,Department of Medicine, Monash University, Melbourne, VIC, Australia
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18
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Wallace DF, McDonald CJ, Ostini L, Iser D, Tuckfield A, Subramaniam VN. The dynamics of hepcidin-ferroportin internalization and consequences of a novel ferroportin disease mutation. Am J Hematol 2017; 92:1052-1061. [PMID: 28681497 DOI: 10.1002/ajh.24844] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 12/31/2022]
Abstract
The hepcidin-ferroportin axis underlies the pathophysiology of many iron-associated disorders and is a key target for the development of therapeutics for treating iron-associated disorders. The aims of this study were to investigate the dynamics of hepcidin-mediated ferroportin internalization and the consequences of a novel disease-causing mutation on ferroportin function. Specific reagents for ferroportin are limited; we developed and characterized antibodies against the largest extracellular loop of ferroportin and developed a novel cell-based assay for studying hepcidin-ferroportin function. We show that hepcidin-mediated ferroportin internalization is a rapid process and could be induced using low concentrations of hepcidin. Targeted next-generation sequencing utilizing an iron metabolism gene panel developed in our group identified a novel ferroportin p.D84E variant in a patient with iron overload. Wild-type and mutant ferroportin constructs were generated, transfected into HEK293 cells and analysed using an all-in-one flow-cytometry-based assay to study the effects on hepcidin-mediated internalization and iron transport. Consistent with the classical phenotype of ferroportin disease, the p.D84E mutation results in an inability to transport iron and hepcidin insensitivity. These results validate a recently proposed 3D-structural model of ferroportin and highlight the significance of this variant in the structure and function of ferroportin. Our novel ferroportin antibody and assay will be valuable tools for investigating the regulation of hepcidin/ferroportin function and the development of novel approaches for the therapeutic modulation of iron homeostasis.
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Affiliation(s)
- Daniel F. Wallace
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences. Queensland University of Technology (QUT); Brisbane Queensland Australia
- Membrane Transport Laboratory; QIMR Berghofer Medical Research Institute; Brisbane Queensland Australia
| | - Cameron J. McDonald
- Membrane Transport Laboratory; QIMR Berghofer Medical Research Institute; Brisbane Queensland Australia
| | - Lesa Ostini
- Membrane Transport Laboratory; QIMR Berghofer Medical Research Institute; Brisbane Queensland Australia
| | - David Iser
- Department of Gastroenterology; St Vincent's Hospital; Fitzroy Victoria Australia
| | | | - V. Nathan Subramaniam
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences. Queensland University of Technology (QUT); Brisbane Queensland Australia
- Membrane Transport Laboratory; QIMR Berghofer Medical Research Institute; Brisbane Queensland Australia
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19
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Rishi G, Subramaniam VN. The liver in regulation of iron homeostasis. Am J Physiol Gastrointest Liver Physiol 2017; 313:G157-G165. [PMID: 28596277 DOI: 10.1152/ajpgi.00004.2017] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/31/2017] [Accepted: 05/31/2017] [Indexed: 01/31/2023]
Abstract
The liver is one of the largest and most functionally diverse organs in the human body. In addition to roles in detoxification of xenobiotics, digestion, synthesis of important plasma proteins, gluconeogenesis, lipid metabolism, and storage, the liver also plays a significant role in iron homeostasis. Apart from being the storage site for excess body iron, it also plays a vital role in regulating the amount of iron released into the blood by enterocytes and macrophages. Since iron is essential for many important physiological and molecular processes, it increases the importance of liver in the proper functioning of the body's metabolism. This hepatic iron-regulatory function can be attributed to the expression of many liver-specific or liver-enriched proteins, all of which play an important role in the regulation of iron homeostasis. This review focuses on these proteins and their known roles in the regulation of body iron metabolism.
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Affiliation(s)
- Gautam Rishi
- Liver Disease and Iron Disorders Research Group, Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - V Nathan Subramaniam
- Liver Disease and Iron Disorders Research Group, Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
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20
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Heritage M, Jaskowski L, Bridle K, Campbell C, Briskey D, Britton L, Fletcher L, Vitetta L, Subramaniam VN, Crawford D. Combination curcumin and vitamin E treatment attenuates diet-induced steatosis in Hfe-/- mice. World J Gastrointest Pathophysiol 2017; 8:67-76. [PMID: 28573069 PMCID: PMC5437504 DOI: 10.4291/wjgp.v8.i2.67] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 12/01/2016] [Accepted: 03/02/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the synergistic hepato-protective properties of curcumin and vitamin E in an Hfe-/- high calorie diet model of steatohepatitis.
METHODS Hfe-/- C57BL/6J mice were fed either a high calorie diet or a high calorie diet with 1 mg/g curcumin; 1.5 mg/g vitamin E; or combination of 1 mg/g curcumin + 1.5 mg/g vitamin E for 20 wk. Serum and liver tissue were collected at the completion of the experiment. Liver histology was graded by a pathologist for steatosis, inflammation and fibrosis. RNA and protein was extracted from liver tissue to examine gene and protein expression associated with fatty acid oxidation, mitochondrial biogenesis and oxidative stress pathways.
RESULTS Hfe-/- mice fed the high calorie diet developed steatohepatitis and pericentral fibrosis. Combination treatment with curcumin and vitamin E resulted in a greater reduction of percent steatosis than either vitamin E or curcumin therapy alone. Serum alanine aminotransferase and non-alcoholic fatty liver disease (NAFLD) activity score were decreased following combination therapy with curcumin and vitamin E compared with high calorie diet alone. No changes were observed in inflammatory or fibrosis markers following treatment. Epididymal fat pad weights were significantly reduced following combination therapy, however total body weight and liver weight were unchanged. Combination therapy increased the mRNA expression of AdipoR2, Ppar-α, Cpt1a, Nrf-1 and Tfb2m suggesting enhanced fatty acid oxidation and mitochondrial biogenesis. In addition, combination treatment resulted in increased catalase activity in Hfe-/- mice.
CONCLUSION Combination curcumin and vitamin E treatment decreases liver injury in this steatohepatitis model, indicating that combination therapy may be of value in NAFLD.
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21
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McLaren GD, Barton JC, Ramm GA, Emond MJ, Subramaniam VN, Phatak PD, Adams PC, Powell LW, Gurrin LC, Anderson GJ, McLaren CE. Reply. Hepatology 2017; 65:1072-1073. [PMID: 28010035 PMCID: PMC5319902 DOI: 10.1002/hep.29002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 12/12/2016] [Indexed: 12/07/2022]
Affiliation(s)
- Gordon D. McLaren
- Department of Veterans Affairs Long Beach Healthcare System, Long
Beach, CA, USA,Division of Hematology/Oncology, Department of Medicine, University
of California, Irvine, CA USA
| | | | - Grant A. Ramm
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of
Queensland, Brisbane, Australia
| | - Mary J. Emond
- Department of Biostatistics, University of Washington, Seattle, WA,
USA
| | - V. Nathan Subramaniam
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Institute of Health and Biomedical Innovation, School of Biomedical
Sciences, Queensland University of Technology, Brisbane, Australia
| | | | - Paul C. Adams
- Department of Medicine, London Health Sciences Centre, London, ON,
Canada
| | - Lawrie W. Powell
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of
Queensland, Brisbane, Australia,Royal Brisbane & Women’s Hospital, Brisbane,
Australia
| | - Lyle C. Gurrin
- Centre for MEGA Epidemiology, The University of Melbourne,
Melbourne, Australia
| | - Gregory J. Anderson
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,School of Medicine and School of Chemistry and Molecular
Bioscience, University of Queensland, Brisbane, Australia
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22
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Sternberg J, Wankell M, Nathan Subramaniam V, W. Hebbard L. The functional roles of T-cadherin in mammalian biology. AIMS Molecular Science 2017. [DOI: 10.3934/molsci.2017.1.62] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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23
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Barton JC, Chen WP, Emond MJ, Phatak PD, Subramaniam VN, Adams PC, Gurrin LC, Anderson GJ, Ramm GA, Powell LW, Allen KJ, Phillips JD, Parker CJ, McLaren GD, McLaren CE. GNPAT p.D519G is independently associated with markedly increased iron stores in HFE p.C282Y homozygotes. Blood Cells Mol Dis 2016; 63:15-20. [PMID: 27936396 DOI: 10.1016/j.bcmd.2016.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 11/08/2016] [Accepted: 11/11/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND GNPAT p.D519G positivity is significantly increased in HFE p.C282Y homozygotes with markedly increased iron stores. We sought to determine associations of p.D519G and iron-related variables with iron stores in p.C282Y homozygotes. METHODS We defined markedly increased iron stores as serum ferritin >2247pmol/L (>1000μg/L) and either hepatic iron >236μmol/g dry weight or iron >10g by induction phlebotomy (men and women). We defined normal or mildly elevated iron stores as serum ferritin <674.1pmol/L (<300μg/L) or either age≥40y with iron ≤2.5g iron by induction phlebotomy or age≥50y with ≤3.0g iron by induction phlebotomy (men only). We compared participant subgroups using univariate methods. Using multivariable logistic regression, we evaluated associations of markedly increased iron stores with these variables: age; iron supplement use (dichotomous); whole blood units donated; erythrocyte units received as transfusion; daily alcohol consumption, g; and p.D519G positivity (heterozygosity or homozygosity). RESULTS The mean age of 56 participants (94.6% men) was 55±10 (SD) y; 41 had markedly increased iron stores. Prevalences of swollen/tender 2nd/3rd metacarpophalangeal joints and elevated aspartate or alanine aminotransferase were significantly greater in participants with markedly increased iron stores. Only participants with markedly increased iron stores had cirrhosis. In multivariable analyses, p.D519G positivity was the only exposure variable significantly associated with markedly increased iron stores (odds ratio 9.9, 95% CI [1.6, 60.3], p=0.0126). CONCLUSIONS GNPAT p.D519G is strongly associated with markedly increased iron stores in p.C282Y homozygotes after correction for age, iron-related variables, and alcohol consumption.
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Affiliation(s)
- James C Barton
- Southern Iron Disorders Center, Birmingham, AL, 35209, USA; Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Wen-Pin Chen
- Chao Family Comprehensive Cancer Center, Irvine, CA 92697, USA
| | - Mary J Emond
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | | | - V Nathan Subramaniam
- QIMR Berghofer Medical Research Institute, Brisbane City, QLD 4006, Australia; Faculty of Medicine and Biomedical Sciences, The University of Queensland, Herston, QLD, 4006, Australia
| | - Paul C Adams
- Department of Medicine, London Health Sciences Centre, London, Ontario, N6A 5W9, Canada
| | - Lyle C Gurrin
- Centre for MEGA Epidemiology, The University of Melbourne, Victoria 3010, Australia
| | - Gregory J Anderson
- QIMR Berghofer Medical Research Institute, Brisbane City, QLD 4006, Australia; School of Medicine and School of Chemistry and Molecular Bioscience, University of Queensland, Brisbane, St. Lucia, QLD 4072, Australia
| | - Grant A Ramm
- QIMR Berghofer Medical Research Institute, Brisbane City, QLD 4006, Australia; Faculty of Medicine and Biomedical Sciences, The University of Queensland, Herston, QLD, 4006, Australia
| | - Lawrie W Powell
- QIMR Berghofer Medical Research Institute, Brisbane City, QLD 4006, Australia; Faculty of Medicine and Biomedical Sciences, The University of Queensland, Herston, QLD, 4006, Australia; Royal Brisbane & Women's Hospital, Herston, QLD, 4029, Australia
| | - Katrina J Allen
- Murdoch Childrens Research Institute, Parkville, Victoria 3052, Australia
| | - John D Phillips
- Departments of Medicine and Pathology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Charles J Parker
- Division of Hematology and Hematologic Malignancies, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Gordon D McLaren
- Department of Veterans Affairs Long Beach Healthcare System, Long Beach, CA 90822, USA; Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, CA 92868, USA
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24
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Britton L, Jaskowski L, Bridle K, Santrampurwala N, Reiling J, Musgrave N, Subramaniam VN, Crawford D. Heterozygous Hfe gene deletion leads to impaired glucose homeostasis, but not liver injury in mice fed a high-calorie diet. Physiol Rep 2016; 4:4/12/e12837. [PMID: 27354540 PMCID: PMC4923236 DOI: 10.14814/phy2.12837] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 05/26/2016] [Indexed: 12/30/2022] Open
Abstract
Heterozygous mutations of the Hfe gene have been proposed as cofactors in the development and progression of nonalcoholic fatty liver disease (NAFLD). Homozygous Hfe deletion previously has been shown to lead to dysregulated hepatic lipid metabolism and accentuated liver injury in a dietary mouse model of NAFLD. We sought to establish whether heterozygous deletion of Hfe is sufficient to promote liver injury when mice are exposed to a high‐calorie diet (HCD). Eight‐week‐old wild‐type and Hfe+/− mice received 8 weeks of a control diet or HCD. Liver histology and pathways of lipid and iron metabolism were analyzed. Liver histology demonstrated that mice fed a HCD had increased NAFLD activity score (NAS), steatosis, and hepatocyte ballooning. However, liver injury was unaffected by Hfe genotype. Hepatic iron concentration (HIC) was increased in Hfe+/− mice of both dietary groups. HCD resulted in a hepcidin‐independent reduction in HIC. Hfe+/− mice demonstrated raised fasting serum glucose concentrations and HOMA‐IR score, despite unaltered serum adiponectin concentrations. Downstream regulators of hepatic de novo lipogenesis (pAKT, SREBP‐1, Fas, Scd1) and fatty acid oxidation (AdipoR2, Pparα, Cpt1) were largely unaffected by genotype. In summary, heterozygous Hfe gene deletion is associated with impaired iron and glucose metabolism. However, unlike homozygous Hfe deletion, heterozygous gene deletion did not affect lipid metabolism pathways or liver injury in this model.
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Affiliation(s)
- Laurence Britton
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia The School of Medicine, University of Queensland, Herston, Queensland, Australia The Department of Gastroenterology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Lesley Jaskowski
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia The School of Medicine, University of Queensland, Herston, Queensland, Australia QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Kim Bridle
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia The School of Medicine, University of Queensland, Herston, Queensland, Australia
| | - Nishreen Santrampurwala
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia The School of Medicine, University of Queensland, Herston, Queensland, Australia QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Janske Reiling
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia The School of Medicine, University of Queensland, Herston, Queensland, Australia Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands
| | - Nick Musgrave
- Sullivan and Nicolaides Pathology, Greenslopes Private Hospital, Greenslopes, Queensland, Australia
| | | | - Darrell Crawford
- Gallipoli Medical Research Institute, Greenslopes Private Hospital, Greenslopes, Queensland, Australia The School of Medicine, University of Queensland, Herston, Queensland, Australia
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25
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McDonald CJ, Rishi G, Wallace DF, Subramaniam VN. Genetic Variants in the BMP6 Pro-Peptide May Not Cause Iron Loading and Should Be Interpreted With Caution. Gastroenterology 2016; 151:770-1. [PMID: 27591424 DOI: 10.1053/j.gastro.2016.03.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 03/25/2016] [Indexed: 12/02/2022]
Affiliation(s)
- Cameron J McDonald
- IHBI, School of Biomedical Sciences, Queensland University of Technology and QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Gautam Rishi
- IHBI, School of Biomedical Sciences, Queensland University of Technology and QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Daniel F Wallace
- IHBI, School of Biomedical Sciences, Queensland University of Technology and QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - V Nathan Subramaniam
- IHBI, School of Biomedical Sciences, Queensland University of Technology and QIMR Berghofer Medical Research Institute, Brisbane, Australia
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26
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Abstract
The mechanisms that promote liver injury in non-alcoholic fatty liver disease (NAFLD) are yet to be thoroughly elucidated. As such, effective treatment strategies are lacking and novel therapeutic targets are required. Iron has been widely implicated in the pathogenesis of NAFLD and represents a potential target for treatment. Relationships between serum ferritin concentration and NAFLD are noted in a majority of studies, although serum ferritin is an imprecise measure of iron loading. Numerous mechanisms for a pathogenic role of hepatic iron in NAFLD have been demonstrated in animal and cell culture models. However, the human data linking hepatic iron to liver injury in NAFLD is less clear, with seemingly conflicting evidence, supporting either an effect of iron in hepatocytes or within reticulo-endothelial cells. Adipose tissue has emerged as a key site at which iron may have a pathogenic role in NAFLD. Evidence for this comes indirectly from studies that have evaluated the role of adipose tissue iron with respect to insulin resistance. Adding further complexity, multiple strands of evidence support an effect of NAFLD itself on iron metabolism. In this review, we summarise the human and basic science data that has evaluated the role of iron in NAFLD pathogenesis.
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27
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Rossi E, Wallace DF, Subramaniam VN, St Pierre TG, Mews C, Jeffrey GP. Clinical expression of C282Y homozygous HFE haemochromatosis at 14 years of age. Ann Clin Biochem 2016; 43:233-6. [PMID: 16704763 DOI: 10.1258/000456306776865197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A 14-year-old boy who presented with debilitating lethargy was shown to have an elevated serum ferritin of 572 μg/L and a C282Y homozygous HFE genotype. Liver iron concentration was measured non-invasively by magnetic resonance imaging, which revealed a liver iron concentration of 59 μmol/g dry weight (children's reference range <14). The early phenotypic expression was further investigated by screening genomic DNA for the presence of co-inherited mutations in genes responsible for non- HFE haemochromatosis. Coding regions and splice sites in genes encoding hepcidin and haemojuvelin were sequenced and previously described mutations in ferroportin 1 and transferrin receptor 2 genes were screened. Although no mutations were found, the most likely cause for the early expression is the presence of novel mutations or gene(s).
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Affiliation(s)
- Enrico Rossi
- Department of Clinical Biochemistry, PathWest Nedlands, Western Australia, Australia.
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28
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Rishi G, Secondes ES, Wallace DF, Subramaniam VN. Hematopoietic deletion of transferrin receptor 2 in mice leads to a block in erythroid differentiation during iron-deficient anemia. Am J Hematol 2016; 91:812-8. [PMID: 27169626 DOI: 10.1002/ajh.24417] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 05/09/2016] [Accepted: 05/10/2016] [Indexed: 12/29/2022]
Abstract
Iron metabolism and erythropoiesis are inherently interlinked physiological processes. Regulation of iron metabolism is mediated by the iron-regulatory hormone hepcidin. Hepcidin limits the amount of iron released into the blood by binding to and causing the internalization of the iron exporter, ferroportin. A number of molecules and physiological stimuli, including erythropoiesis, are known to regulate hepcidin. An increase in erythropoietic demand decreases hepcidin, resulting in increased bioavailable iron in the blood. Transferrin receptor 2 (TFR2) is involved in the systemic regulation of iron metabolism. Patients and mice with mutations in TFR2 develop hemochromatosis due to inappropriate hepcidin levels relative to body iron. Recent studies from our laboratory and others have suggested an additional role for TFR2 in response to iron-restricted erythropoiesis. These studies used mouse models with perturbed systemic iron metabolism: anemic mice lacking matriptase-2 and Tfr2, or bone marrow transplants from iron-loaded Tfr2 null mice. We developed a novel transgenic mouse model which lacks Tfr2 in the hematopoietic compartment, enabling the delineation of the role of Tfr2 in erythroid development without interfering with its role in systemic iron metabolism. We show that in the absence of hematopoietic Tfr2 immature polychromatic erythroblasts accumulate with a concordant reduction in the percentage of mature erythroid cells in the spleen and bone marrow of anemic mice. These results demonstrate that erythroid Tfr2 is essential for an appropriate erythropoietic response in iron-deficient anemia. These findings may be of relevance in clinical situations in which an immediate and efficient erythropoietic response is required. Am. J. Hematol. 91:812-818, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Gautam Rishi
- Membrane Transport Laboratory; QIMR Berghofer Medical Research Institute; Brisbane Queensland 4006 Australia
- School of Medicine; the University of Queensland; Brisbane Queensland 4006 Australia
| | - Eriza S. Secondes
- Membrane Transport Laboratory; QIMR Berghofer Medical Research Institute; Brisbane Queensland 4006 Australia
| | - Daniel F. Wallace
- Membrane Transport Laboratory; QIMR Berghofer Medical Research Institute; Brisbane Queensland 4006 Australia
| | - V. Nathan Subramaniam
- Membrane Transport Laboratory; QIMR Berghofer Medical Research Institute; Brisbane Queensland 4006 Australia
- School of Medicine; the University of Queensland; Brisbane Queensland 4006 Australia
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29
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Briskey D, Heritage M, Jaskowski LA, Peake J, Gobe G, Subramaniam VN, Crawford D, Campbell C, Vitetta L. Probiotics modify tight-junction proteins in an animal model of nonalcoholic fatty liver disease. Therap Adv Gastroenterol 2016; 9:463-72. [PMID: 27366215 PMCID: PMC4913342 DOI: 10.1177/1756283x16645055] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND We have investigated the effects of a multispecies probiotic preparation containing a combination of probiotic bacterial genera that included Bifidobacteria, Lactobacilli and a Streptococcus in a mouse model of high-fat diet or obesity-induced liver steatosis. METHODS Three groups of C57B1/6J mice were fed either a standard chow or a high-fat diet for 20 weeks, while a third group was fed a high-fat diet for 10 weeks and then concomitantly administered probiotics for a further 10 weeks. Serum, liver and large bowel samples were collected for analysis. RESULTS The expression of the tight-junction proteins ZO-1 and ZO-2 was reduced (p < 0.05) in high-fat diet-fed mice compared to chow-fed mice. Probiotic supplementation helped to maintain tight ZO-1 and ZO-2 expression compared with the high-fat diet group (p < 0.05), but did not restore ZO-1 or ZO-2 expression compared with chow-fed mice. Mice fed a high-fat diet ± probiotics had significant steatosis development compared with chow-fed mice (p < 0.05); steatosis was less severe in the probiotics group compared with the high-fat diet group. Hepatic triglyceride concentration was higher in mice fed a high-fat diet ± probiotics compared with the chow group (p < 0.05), and was lower in the probiotics group compared with the high-fat diet group (p < 0.05). Compared with chow-fed mice, serum glucose, cholesterol concentration and the activity of alanine transaminase were higher (p < 0.05), whereas serum triglyceride concentration was lower (p < 0.05) in mice fed a high-fat diet ± probiotics. CONCLUSIONS Supplementation with a multispecies probiotic formulation helped to maintain tight-junction proteins ZO-1 and ZO-2, and reduced hepatic triglyceride concentration compared with a high-fat diet alone.
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Affiliation(s)
- David Briskey
- School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Mandy Heritage
- Gallipoli Medical Research Centre, Greenslopes Hospital, Brisbane, Australia School of Medicine, The University of Queensland, Brisbane, Australia
| | - Lesley-Anne Jaskowski
- Gallipoli Medical Research Centre, Greenslopes Hospital, Brisbane, Australia School of Medicine, The University of Queensland, Brisbane, Australia
| | - Jonathan Peake
- School of Biomedical Sciences and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Glenda Gobe
- Centre for Kidney Disease Research, School of Medicine, The University of Queensland, Translational Research Institute, Queensland, Australia
| | - V. Nathan Subramaniam
- Gallipoli Medical Research Centre, Greenslopes Hospital, Brisbane, Australia Queensland Institute of Medical Research Berghofer Medical Research Institute, Brisbane, Australia Envoi Specialist Pathologists, Brisbane, Australia
| | - Darrell Crawford
- Gallipoli Medical Research Centre, Greenslopes Hospital, Brisbane, Australia School of Medicine, The University of Queensland, Brisbane, Australia
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McLaren CE, Barton JC, Phatak PD, Emond MJ, Subramaniam VN, Gurrin LC, Adams PC, Powell LW, Ramm GA, Anderson GJ, McLaren GD. Reply. Hepatology 2016; 63:2056-7. [PMID: 26417986 PMCID: PMC4811743 DOI: 10.1002/hep.28260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Affiliation(s)
| | | | | | - Mary J. Emond
- Department of Biostatistics, University of Washington, Seattle,
WA
| | - V. Nathan Subramaniam
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of
Queensland, Brisbane, Australia
| | - Lyle C. Gurrin
- Centre for MEGA Epidemiology, The University of Melbourne,
Melbourne, Australia
| | - Paul C. Adams
- Department of Medicine, London Health Sciences Centre, London, ON,
Canada
| | - Lawrie W. Powell
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of
Queensland, Brisbane, Australia,Royal Brisbane & Women's Hospital, Brisbane,
Australia
| | - Grant A. Ramm
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of
Queensland, Brisbane, Australia
| | - Gregory J. Anderson
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,School of Medicine and School of Chemistry and Molecular
Bioscience, University of Queensland
| | - Gordon D. McLaren
- Department of Veterans Affairs Long Beach Healthcare System, Long
Beach, CA,Division of Hematology/Oncology, Department of Medicine, University
of California, Irvine, CA
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31
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McLaren CE, Barton JC, Subramaniam VN, Ramm GA, Phatak PD, Emond MJ, Gurrin LC, Adams PC, Powell LW, Anderson GJ, McLaren GD. Reply. Hepatology 2016; 63:2058-60. [PMID: 26845080 PMCID: PMC4874893 DOI: 10.1002/hep.28479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Affiliation(s)
| | | | - V. Nathan Subramaniam
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of
Queensland, Brisbane, Australia
| | - Grant A. Ramm
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of
Queensland, Brisbane, Australia
| | | | - Mary J. Emond
- Department of Biostatistics, University of Washington, Seattle,
WA
| | - Lyle C. Gurrin
- Centre for MEGA Epidemiology, The University of Melbourne,
Melbourne, Australia
| | - Paul C. Adams
- Department of Medicine, London Health Sciences Centre, London, ON,
Canada
| | - Lawrie W. Powell
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of
Queensland, Brisbane, Australia,Royal Brisbane & Women’s Hospital, Brisbane,
Australia
| | - Gregory J. Anderson
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,School of Medicine and School of Chemistry and Molecular
Bioscience, University of Queensland
| | - Gordon D. McLaren
- Department of Veterans Affairs Long Beach Healthcare System, Long
Beach, CA,Division of Hematology/Oncology, Department of Medicine, University
of California, Irvine, CA
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32
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Rishi G, Secondes ES, Wallace DF, Subramaniam VN. Normal systemic iron homeostasis in mice with macrophage-specific deletion of transferrin receptor 2. Am J Physiol Gastrointest Liver Physiol 2016; 310:G171-80. [PMID: 26608187 DOI: 10.1152/ajpgi.00291.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/23/2015] [Indexed: 01/31/2023]
Abstract
Iron is an essential element, since it is a component of many macromolecules involved in diverse physiological and cellular functions, including oxygen transport, cellular growth, and metabolism. Systemic iron homeostasis is predominantly regulated by the liver through the iron regulatory hormone hepcidin. Hepcidin expression is itself regulated by a number of proteins, including transferrin receptor 2 (TFR2). TFR2 has been shown to be expressed in the liver, bone marrow, macrophages, and peripheral blood mononuclear cells. Studies from our laboratory have shown that mice with a hepatocyte-specific deletion of Tfr2 recapitulate the hemochromatosis phenotype of the global Tfr2 knockout mice, suggesting that the hepatic expression of TFR2 is important in systemic iron homeostasis. It is unclear how TFR2 in macrophages contributes to the regulation of iron metabolism. We examined the role of TFR2 in macrophages by analysis of transgenic mice lacking Tfr2 in macrophages by crossing Tfr2(f/f) mice with LysM-Cre mice. Mice were fed an iron-rich diet or injected with lipopolysaccharide to examine the role of macrophage Tfr2 in iron- or inflammation-mediated regulation of hepcidin. Body iron homeostasis was unaffected in the knockout mice, suggesting that macrophage TFR2 is not required for the regulation of systemic iron metabolism. However, peritoneal macrophages of knockout mice had significantly lower levels of ferroportin mRNA and protein, suggesting that TFR2 may be involved in regulating ferroportin levels in macrophages. These studies further elucidate the role of TFR2 in the regulation of iron homeostasis and its role in regulation of ferroportin and thus macrophage iron homeostasis.
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Affiliation(s)
- Gautam Rishi
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia; and School of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Eriza S Secondes
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia; and
| | - Daniel F Wallace
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia; and School of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - V Nathan Subramaniam
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia; and School of Medicine, The University of Queensland, Brisbane, Queensland, Australia
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33
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Wallace DF, Subramaniam VN. The global prevalence of HFE and non-HFE hemochromatosis estimated from analysis of next-generation sequencing data. Genet Med 2015; 18:618-26. [PMID: 26633544 DOI: 10.1038/gim.2015.140] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/27/2015] [Indexed: 12/31/2022] Open
Abstract
PURPOSE The prevalence of HFE-related hereditary hemochromatosis (HH) among European populations has been well studied. There are no prevalence data for atypical forms of HH caused by mutations in HFE2, HAMP, TFR2, or SLC40A1. The purpose of this study was to estimate the population prevalence of these non-HFE forms of HH. METHODS A list of HH pathogenic variants in publically available next-generation sequence (NGS) databases was compiled and allele frequencies were determined. RESULTS Of 161 variants previously associated with HH, 43 were represented among the NGS data sets; an additional 40 unreported functional variants also were identified. The predicted prevalence of HFE HH and the p.Cys282Tyr mutation closely matched previous estimates from similar populations. Of the non-HFE forms of iron overload, TFR2-, HFE2-, and HAMP-related forms are predicted to be rare, with pathogenic allele frequencies in the range of 0.00007 to 0.0005. Significantly, SLC40A1 variants that have been previously associated with autosomal-dominant ferroportin disease were identified in several populations (pathogenic allele frequency 0.0004), being most prevalent among Africans. CONCLUSION We have, for the first time, estimated the population prevalence of non-HFE HH. This methodology could be applied to estimate the population prevalence of a wide variety of genetic disorders.Genet Med 18 6, 618-626.
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Affiliation(s)
- Daniel F Wallace
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - V Nathan Subramaniam
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
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34
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McLaren CE, Emond MJ, Subramaniam VN, Phatak PD, Barton JC, Adams PC, Powell LW, Gurrin LC, Ramm GA, Anderson GJ, McLaren GD. Reply: To PMID 25605615. Hepatology 2015; 62:1918-9. [PMID: 25914125 DOI: 10.1002/hep.27851] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
| | - Mary J Emond
- Department of Biostatistics, University of Washington, Seattle, WA
| | - V Nathan Subramaniam
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Faculty of Medicine and Biomedical Sciences, The University of Queensland Brisbane, Australia
| | | | | | - Paul C Adams
- Department of Medicine, London Health Sciences Center, London, Ontario, Canada
| | - Lawrie W Powell
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Faculty of Medicine and Biomedical Sciences, The University of Queensland Brisbane, Australia.,Royal Brisbane & Women's Hospital, Brisbane, Australia
| | - Lyle C Gurrin
- Center for MEGA Epidemiology, The University of Melbourne, Melbourne, Australia
| | - Grant A Ramm
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Faculty of Medicine and Biomedical Sciences, The University of Queensland Brisbane, Australia
| | - Gregory J Anderson
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Medicine and School of Chemistry and Molecular Bioscience, University of Queensland, St. Lucia, Australia
| | - Gordon D McLaren
- Department of Veterans Affairs Long Beach Healthcare System, Long Beach, CA.,Division of Hematology/Oncology, Department of Medicine, University of California Irvine, CA
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McDonald CJ, Ostini L, Wallace DF, Lyons A, Crawford DHG, Subramaniam VN. Next-generation sequencing: Application of a novel platform to analyze atypical iron disorders. J Hepatol 2015; 63:1288-93. [PMID: 26151776 DOI: 10.1016/j.jhep.2015.06.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 06/25/2015] [Accepted: 06/29/2015] [Indexed: 12/31/2022]
Abstract
The development of targeted next-generation sequencing (NGS) applications now promises to be a clinically viable option for the diagnosis of rare disorders. This approach is proving to have significant utility where standardized testing has failed to identify the underlying molecular basis of disease. We have developed a unique targeted NGS panel for the systematic sequence-based analysis of atypical iron disorders. We report the analysis of 39 genes associated with iron regulation in eight cases of atypical iron dysregulation, in which five cases we identified the definitive causative mutation, and a possible causative mutation in a sixth. We further provide a molecular and cellular characterization study of one of these mutations (TFR2, p.I529N) in a familial case as proof of principle. Cellular analysis of the mutant protein indicates that this amino acid substitution affects the localization of the protein, which results in its retention in the endoplasmic reticulum and thus failure to function at the cell surface. Our unique NGS panel presents a rapid and cost-efficient approach to identify the underlying genetic cause in cases of atypical iron homeostasis disorders.
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Affiliation(s)
- Cameron J McDonald
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Australia
| | - Lesa Ostini
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Australia
| | - Daniel F Wallace
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Australia; Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | | | - Darrell H G Crawford
- Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - V Nathan Subramaniam
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Australia; Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia.
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Goh JB, Wallace DF, Hong W, Subramaniam VN. Endofin, a novel BMP-SMAD regulator of the iron-regulatory hormone, hepcidin. Sci Rep 2015; 5:13986. [PMID: 26358513 PMCID: PMC4566084 DOI: 10.1038/srep13986] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/12/2015] [Indexed: 11/15/2022] Open
Abstract
BMP-SMAD signalling plays a crucial role in numerous biological processes including embryonic development and iron homeostasis. Dysregulation of the iron-regulatory hormone hepcidin is associated with many clinical iron-related disorders. We hypothesised that molecules which mediate BMP-SMAD signalling play important roles in the regulation of iron homeostasis and variants in these proteins may be potential genetic modifiers of iron-related diseases. We examined the role of endofin, a SMAD anchor, and show that knockdown of endofin in liver cells inhibits basal and BMP-induced hepcidin expression along with other BMP-regulated genes, ID1 and SMAD7. We show for the first time, the in situ interaction of endofin with SMAD proteins and significantly reduced SMAD phosphorylation with endofin knockdown, suggesting that endofin modulates hepcidin through BMP-SMAD signalling. Characterisation of naturally occurring SNPs show that mutations in the conserved FYVE domain result in mislocalisation of endofin, potentially affecting downstream signalling and modulating hepcidin expression. In conclusion, we have identified a hitherto unrecognised link, endofin, between the BMP-SMAD signalling pathway, and the regulation of hepcidin expression and iron homeostasis. This study further defines the molecular network involved in iron regulation and provides potential targets for the treatment of iron-related disorders.
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Affiliation(s)
- Justin B Goh
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Daniel F Wallace
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Wanjin Hong
- Institute of Molecular and Cell Biology, Singapore
| | - V Nathan Subramaniam
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia
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McLaren CE, Emond MJ, Subramaniam VN, Phatak PD, Barton JC, Adams PC, Goh JB, McDonald CJ, Powell LW, Gurrin LC, Allen KJ, Nickerson DA, Louie T, Ramm GA, Anderson GJ, McLaren GD. Exome sequencing in HFE C282Y homozygous men with extreme phenotypes identifies a GNPAT variant associated with severe iron overload. Hepatology 2015; 62:429-39. [PMID: 25605615 PMCID: PMC4508230 DOI: 10.1002/hep.27711] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 01/13/2015] [Indexed: 12/12/2022]
Abstract
UNLABELLED To identify polymorphisms associated with variability of iron overload severity in HFE-associated hemochromatosis, we performed exome sequencing of DNA from 35 male HFE C282Y homozygotes with either markedly increased iron stores (n = 22; cases) or with normal or mildly increased iron stores (n = 13; controls). The 35 participants, residents of the United States, Canada, and Australia, reported no or light alcohol consumption. Sequencing data included 82,068 single-nucleotide variants, and 10,337 genes were tested for a difference between cases and controls. A variant in the GNPAT gene showed the most significant association with severe iron overload (P = 3 × 10(-6) ; P = 0.033 by the likelihood ratio test after correction for multiple comparisons). Sixteen of twenty-two participants with severe iron overload had glyceronephosphate O-acyltransferase (GNPAT) polymorphism p.D519G (rs11558492; 15 heterozygotes, one homozygote). No control participant had this polymorphism. To examine functional consequences of GNPAT deficiency, we performed small interfering RNA-based knockdown of GNPAT in the human liver-derived cell line, HepG2/C3A. This knockdown resulted in a >17-fold decrease in expression of the messenger RNA encoding the iron-regulatory hormone, hepcidin. CONCLUSION GNPAT p.D519G is associated with a high-iron phenotype in HFE C282Y homozygotes and may participate in hepcidin regulation.
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Affiliation(s)
| | - Mary J. Emond
- Department of Biostatistics, University of Washington, Seattle, WA
| | - V. Nathan Subramaniam
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | | | | | - Paul C. Adams
- Department of Medicine, London Health Sciences Centre, London, ON, Canada
| | - Justin B. Goh
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | | | - Lawrie W. Powell
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia,Royal Brisbane & Women’s Hospital, Brisbane, Australia
| | - Lyle C. Gurrin
- Centre for MEGA Epidemiology, The University of Melbourne, Melbourne, Australia
| | | | | | - Tin Louie
- Department of Biostatistics, University of Washington, Seattle, WA
| | - Grant A. Ramm
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Gregory J. Anderson
- QIMR Berghofer Medical Research Institute, Brisbane, Australia,School of Medicine and School of Chemistry and Molecular Bioscience, University of Queensland
| | - Gordon D. McLaren
- Department of Veterans Affairs Long Beach Healthcare System, Long Beach, CA,Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, CA
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Wallace DF, Subramaniam VN. Analysis of IL-22 contribution to hepcidin induction and hypoferremia during the response to LPS in vivo. Int Immunol 2015; 27:281-7. [PMID: 25568302 DOI: 10.1093/intimm/dxu144] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 12/23/2014] [Indexed: 12/16/2023] Open
Abstract
The anaemia of chronic disease (ACD) results from inflammation-mediated up-regulation of the iron regulatory hormone hepcidin, with the consequent sequestration of iron limiting its availability for erythropoiesis. The inflammatory cytokine IL-6, a regulator of hepcidin, has been implicated in this process. Recent in vivo and in vitro studies indicate that IL-22 is also able to stimulate hepcidin expression. We aimed to determine if IL-22 had a role in causing the hypoferremia associated with the inflammatory response. Wild-type and Il22-knockout mice were subjected to an acute inflammatory stimulus via administration of LPS and the response of hepcidin and iron homeostasis was analysed. In the absence of IL-22, there was a response of hepcidin, resulting in a reduction in serum iron levels. However, the hypoferremic response to LPS was slightly blunted in mice lacking IL-22, suggesting that, during LPS-mediated inflammation, IL-22 may play a minor role in mediating the hypoferremic response. These results may have implications for the treatment and management of the ACD.
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Affiliation(s)
- Daniel F Wallace
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia and School of Medicine, University of Queensland, Brisbane, Queensland 4006, Australia
| | - V Nathan Subramaniam
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia and School of Medicine, University of Queensland, Brisbane, Queensland 4006, Australia
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McDonald CJ, Ostini L, Bennett N, Subramaniam N, Hooper J, Velasco G, Wallace DF, Subramaniam VN. Functional analysis of matriptase-2 mutations and domains: insights into the molecular basis of iron-refractory iron deficiency anemia. Am J Physiol Cell Physiol 2015; 308:C539-47. [DOI: 10.1152/ajpcell.00264.2014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 01/09/2015] [Indexed: 12/17/2022]
Abstract
Mutations in the TMPRSS6 gene are associated with severe iron-refractory iron deficiency anemia resulting from an overexpression of hepcidin, the key regulator of iron homeostasis. The matriptase (MT)-2 protein (encoded by the TMPRSS6 gene) regulates hepcidin expression by cleaving hemojuvelin [HJV/hemochromatosis type 2 (HFE2)], a bone morphogenetic protein (BMP) coreceptor in the hepcidin regulatory pathway. We investigated the functional consequences of five clinically associated TMPRSS6 variants and the role of MT-2 protein domains by generating epitope-tagged mutant and domain-swapped MT-2-MT-1 (encoded by the ST14 gene) chimeric constructs and expressing them in HepG2/C3A cells. We developed a novel cell culture immunofluorescence assay to assess the effect of MT-2 on cell surface HJV expression levels, compatible with HJV cleavage. The TMPRSS6 variants Y141C, I212T, G442R, and C510S were retained intracellularly and were unable to inhibit BMP6 induction of hepcidin. The R271Q variant, although it has been associated with iron-refractory iron deficiency anemia, appears to remain functional. Analysis of the chimeric constructs showed that replacement of sperm protein, enterokinase, and agrin (SEA), low-density-lipoprotein receptor class A (LDLRA), and protease (PROT) domains from MT-2 with those from MT-1 resulted in limited cell surface localization, while the complement C1r/C1s, Uegf, Bmp1 (CUB) domain chimera retained localization at the cell surface. The SEA domain chimera was able to reduce cell surface HJV expression, while the CUB, LDLRA, and PROT domain chimeras were not. These studies suggest that the SEA and LDLRA domains of MT-2 are important for trafficking to the cell surface and that the CUB, LDLRA, and PROT domains are required for cleavage of HJV.
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Affiliation(s)
- Cameron J. McDonald
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Lesa Ostini
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Nigel Bennett
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Nanthakumar Subramaniam
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - John Hooper
- Mater Research Institute-University of Queensland, Translational Research Institute, Brisbane, Queensland, Australia
| | - Gloria Velasco
- Departamento de Bioquímica y Biología Molecular, Instituto Universitario de Oncología, Universidad de Oviedo, Oviedo, Spain; and
| | - Daniel F. Wallace
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - V. Nathan Subramaniam
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- Faculty of Medicine and Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
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Bridle KR, Sobbe AL, de Guzman CE, Santrampurwala N, Jaskowski LA, Clouston AD, Campbell CM, Nathan Subramaniam V, Crawford DHG. Lack of efficacy of mTOR inhibitors and ACE pathway inhibitors as antifibrotic agents in evolving and established fibrosis in Mdr2⁻/⁻ mice. Liver Int 2015; 35:1451-63. [PMID: 24517519 DOI: 10.1111/liv.12494] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 02/04/2014] [Indexed: 02/13/2023]
Abstract
BACKGROUND & AIMS Mammalian target of rapamycin and angiotensin-converting enzyme inhibition has been shown to have antifibrotic activity in models of liver fibrosis. The aim of our study was to determine the efficacy of rapamycin, everolimus, irbesartan and captopril, alone and in combination, as antifibrotic agents in the Mdr2(-/-) model of cholestasis both in early injury and established disease. METHODS Mdr2(-/-) mice were treated for 4 weeks with vehicle, rapamycin (1 mg/kg) or everolimus (5 mg/kg) every second day or with captopril (30 mg/kg/day), irbesartan (10 mg/kg/day) or vehicle. Further groups of 3-week-old Mdr2(-/-) mice were treated with rapamycin and irbesartan in combination (1 mg/kg/day and 10 mg/kg/day) or with rapamycin (2 mg/kg/day) for 4 weeks. Liver injury and fibrosis were compared between treated and untreated animals. RESULTS There were no significant improvements in liver injury, histology, hepatic hydroxyproline or profibrogenic gene expression following treatment with rapamycin, everolimus, captopril or irbesartan at any time point studied. Likewise, there were no improvements in liver histology or profibrogenic gene expression following combination therapy or high-dose rapamycin treatment. CONCLUSIONS The antifibrotic effects of rapamycin, everolimus, captopril and irbesartan seen in other models of fibrosis were not replicated in the Mdr2(-/-) model in this study. This highlights the clear need to test specific antifibrotic agents in a number of different animal models. We believe this animal model is ideal to study usefulness of antifibrotic agents in cholestatic liver disease because of the similarity in genetics and hepatic histopathology to human cholestatic liver disease.
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Affiliation(s)
- Kim R Bridle
- The University of Queensland School of Medicine and the Gallipoli Medical Research Foundation, Greenslopes Private Hospital, Envoi Specialist Pathologists and The Queensland Institute of Medical Research, Brisbane, Qld, Australia
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Sobbe A, Bridle KR, Jaskowski L, de Guzman CE, Santrampurwala N, Clouston AD, Campbell CM, Subramaniam VN, Crawford DHG. Inconsistent hepatic antifibrotic effects with the iron chelator deferasirox. J Gastroenterol Hepatol 2015; 30:638-45. [PMID: 25168203 DOI: 10.1111/jgh.12720] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/17/2014] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND AIM Development of effective antifibrotic treatments that can be translated to clinical practice is an important challenge in contemporary hepatology. A recent report on β-thalassemia patients demonstrated that deferasirox treatment reversed or stabilized liver fibrosis independent of its iron-chelating properties. In this study, we investigated deferasirox in cell and animal models to better understand its potential antifibrotic effects. METHODS The LX-2 stellate cell line was treated with 5 μM or 50 μM deferasirox (Exjade, Novartis Pharmaceuticals Australia, North Ryde, NSW, Australia) for up to 120 h. Three-week-old multidrug resistance 2 null (Mdr2(-/-) ) mice received oral deferasirox or vehicle for 4 weeks (30 mg/kg/day). Cells and liver tissue were collected for assessment of fibrosis and fibrogenic gene expression. RESULTS In LX-2 cells treated with 50 μM deferasirox for 12 h, α1(I)procollagen expression was decreased by 25%, with maximal reductions (10-fold) seen following 24-120 h of treatment. Similarly, α-smooth muscle actin (αSMA) expression was significantly lower. Alterations in matrix remodeling genes, specifically decreased expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2, were observed. There was no significant difference in hepatic hydroxyproline content in Mdr2(-/-) mice following deferasirox administration (vehicle: 395 ± 27 μg/g vs deferasirox: 421 ± 33 μg/g). Similarly, no changes in the expression of fibrogenic genes were observed. CONCLUSION Despite reductions in α1(I)procollagen and αSMA expression and alterations in matrix degradation genes in LX-2 cells, deferasirox did not exhibit antifibrotic activity in Mdr2(-/-) mice. Given the positive outcomes seen in human trials, it may be appropriate to study deferasirox in other animal models of fibrosis and/or for a longer duration of therapy.
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Affiliation(s)
- Amy Sobbe
- School of Medicine, The University of Queensland, Gallipoli Medical Research Foundation, Greenslopes Private Hospital, Brisbane, Queensland, Australia
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Affiliation(s)
- V Nathan Subramaniam
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Daniel F Wallace
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
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Wallace DF, Secondes ES, Rishi G, Ostini L, McDonald CJ, Lane SW, Vu T, Hooper JD, Velasco G, Ramsay AJ, Lopez-Otin C, Subramaniam VN. A critical role for murine transferrin receptor 2 in erythropoiesis during iron restriction. Br J Haematol 2014; 168:891-901. [PMID: 25403101 DOI: 10.1111/bjh.13225] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 09/22/2014] [Indexed: 12/29/2022]
Abstract
Effective erythropoiesis requires an appropriate supply of iron and mechanisms regulating iron homeostasis and erythropoiesis are intrinsically linked. Iron dysregulation, typified by iron-deficiency anaemia and iron overload, is common in many clinical conditions and impacts the health of up to 30% of the world's population. The proteins transmembrane protease, serine 6 (TMPRSS6; also termed matriptase-2), HFE and transferrin receptor 2 (TFR2) play important and opposing roles in systemic iron homeostasis, by regulating expression of the iron regulatory hormone hepcidin. We have performed a systematic analysis of mice deficient in these three proteins and show that TMPRSS6 predominates over HFE and TFR2 in hepcidin regulation. The phenotype of mice lacking TMPRSS6 and TFR2 is characterized by severe anaemia and extramedullary haematopoiesis in the spleen. Stress erythropoiesis in these mice results in increased expression of the newly identified erythroid iron regulator erythroferrone, which does not appear to overcome the hepcidin overproduction mediated by loss of TMPRSS6. Extended analysis reveals that TFR2 plays an important role in erythroid cells, where it is involved in terminal erythroblast differentiation and the regulation of erythropoietin. In conclusion, we have identified an essential role for TFR2 in erythropoiesis that may provide new targets for the treatment of anaemia.
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Affiliation(s)
- Daniel F Wallace
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Qld, Australia; School of Medicine, The University of Queensland, Brisbane, Qld, Australia
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McDonald CJ, Wallace DF, Ostini L, Subramaniam VN. Parenteral vs. oral iron: influence on hepcidin signaling pathways through analysis of Hfe/Tfr2-null mice. Am J Physiol Gastrointest Liver Physiol 2014; 306:G132-9. [PMID: 24284962 DOI: 10.1152/ajpgi.00256.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Treatment for iron deficiency anemia can involve iron supplementation via dietary or parenteral routes that result in different cellular iron distributions. The effect of the administered iron on the iron regulatory system and hepcidin in the liver has not been well studied. Hepcidin, the liver-expressed central iron-regulatory peptide, is itself regulated through the bone morphogenetic protein (BMP)/SMAD signaling pathway. Specifically, Bmp6 expression is upregulated in response to iron and induces hepcidin through phosphorylation of Smad1/5/8. The hemochromatosis-associated proteins Hfe and transferrin receptor 2 (Tfr2) are known upstream regulators of hepcidin, although their precise roles are still unclear. To investigate the mechanisms of this regulation and the roles of the Hfe and Tfr2, we subjected wild-type, Hfe(-/-), Tfr2(-/-), and Hfe(-/-)/Tfr2(-/-) mice to iron loading via dietary or parenteral routes. Systematic analysis demonstrated that Tfr2 is required for effective upregulation of Bmp6 in response to hepatocyte iron, but not nonparenchymal iron. Hfe is not required for Bmp6 upregulation, regardless of iron localization, but rather, is required for efficient downstream transmission of the regulatory signal. Our results demonstrate that Hfe and Tfr2 play separate roles in the regulatory responses to iron compartmentalized in different cell types and further elucidates the regulatory mechanisms controlling iron homeostasis.
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Affiliation(s)
- Cameron J McDonald
- Membrane Transport Laboratory, QIMR Berghofer Medical Research Institute, 300 Herston Rd., Herston, Brisbane, QLD 4006, Australia.
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Wood MJ, Powell LW, Dixon JL, Subramaniam VN, Ramm GA. Transforming growth factor-β and toll-like receptor-4 polymorphisms are not associated with fibrosis in haemochromatosis. World J Gastroenterol 2013; 19:9366-9376. [PMID: 24409064 PMCID: PMC3882410 DOI: 10.3748/wjg.v19.i48.9366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 08/23/2013] [Accepted: 09/05/2013] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the role of genetic polymorphisms in the progression of hepatic fibrosis in hereditary haemochromatosis.
METHODS: A cohort of 245 well-characterised C282Y homozygous patients with haemochromatosis was studied, with all subjects having liver biopsy data and DNA available for testing. This study assessed the association of eight single nucleotide polymorphisms (SNPs) in a total of six genes including toll-like receptor 4 (TLR4), transforming growth factor-beta (TGF-β), oxoguanine DNA glycosylase, monocyte chemoattractant protein 1, chemokine C-C motif receptor 2 and interleukin-10 with liver disease severity. Genotyping was performed using high resolution melt analysis and sequencing. The results were analysed in relation to the stage of hepatic fibrosis in multivariate analysis incorporating other cofactors including alcohol consumption and hepatic iron concentration.
RESULTS: There were significant associations between the cofactors of male gender (P = 0.0001), increasing age (P = 0.006), alcohol consumption (P = 0.0001), steatosis (P = 0.03), hepatic iron concentration (P < 0.0001) and the presence of hepatic fibrosis. Of the candidate gene polymorphisms studied, none showed a significant association with hepatic fibrosis in univariate or multivariate analysis incorporating cofactors. We also specifically studied patients with hepatic iron loading above threshold levels for cirrhosis and compared the genetic polymorphisms between those with no fibrosis vs cirrhosis however there was no significant effect from any of the candidate genes studied. Importantly, in this large, well characterised cohort of patients there was no association between SNPs for TGF-β or TLR4 and the presence of fibrosis, cirrhosis or increasing fibrosis stage in multivariate analysis.
CONCLUSION: In our large, well characterised group of haemochromatosis subjects we did not demonstrate any relationship between candidate gene polymorphisms and hepatic fibrosis or cirrhosis.
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Rishi G, Crampton EM, Wallace DF, Subramaniam VN. In situ proximity ligation assays indicate that hemochromatosis proteins Hfe and transferrin receptor 2 (Tfr2) do not interact. PLoS One 2013; 8:e77267. [PMID: 24155934 PMCID: PMC3796466 DOI: 10.1371/journal.pone.0077267] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 09/02/2013] [Indexed: 01/05/2023] Open
Abstract
The hemochromatosis associated proteins HFE and Transferrin Receptor 2 (TFR2) have been shown to be important for the proper regulation of hepcidin. A number of in vitro studies using transient overexpression systems have suggested that an interaction between HFE and TFR2 is required for the regulation of hepcidin. This model of iron sensing which centers upon the requirement for an interaction between HFE and TFR2 has recently been questioned with in vivo studies in mice from our laboratory and others which suggest that Hfe and Tfr2 can regulate hepcidin independently of each other. To re-examine the postulated interaction between Hfe and Tfr2 we developed a novel expression system in which both proteins are stably co-expressed and used the proximity ligation assay to examine the interactions between Hfe, Tfr1 and Tfr2 at a cellular level. We were able to detect the previously described interaction between Hfe and Tfr1, and heterodimers between Tfr1 and Tfr2; however no interaction between Hfe and Tfr2 was observed in our system. The results from this study indicate that Hfe and Tfr2 do not interact with each other when they are stably expressed at similar levels. Furthermore, these results support in vivo studies which suggest that Hfe and Tfr2 can independently regulate hepcidin.
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Affiliation(s)
- Gautam Rishi
- The Membrane Transport Laboratory, the Queensland Institute of Medical Research, Queensland, Australia
- Liver Research Centre, School of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Emily M. Crampton
- The Membrane Transport Laboratory, the Queensland Institute of Medical Research, Queensland, Australia
| | - Daniel F. Wallace
- The Membrane Transport Laboratory, the Queensland Institute of Medical Research, Queensland, Australia
| | - V. Nathan Subramaniam
- The Membrane Transport Laboratory, the Queensland Institute of Medical Research, Queensland, Australia
- Liver Research Centre, School of Medicine, University of Queensland, Brisbane, Queensland, Australia
- * E-mail:
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McDonald CJ, Wallace DF, Crawford DHG, Subramaniam VN. Iron storage disease in Asia-Pacific populations: the importance of non-HFE mutations. J Gastroenterol Hepatol 2013; 28:1087-94. [PMID: 23577916 DOI: 10.1111/jgh.12222] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/03/2013] [Indexed: 01/24/2023]
Abstract
Hereditary hemochromatosis (HH) is a widely recognized and well-studied condition in European populations. This is largely due to the high prevalence of the C282Y mutation of HFE. Although less common than in Europe, HH cases have been reported in the Asia-Pacific region because of mutations in both HFE and non-HFE genes. Mutations in all of the currently known genes implicated in non-HFE HH (hemojuvelin, hepcidin, transferrin receptor 2, and ferroportin) have been reported in patients from the Asia-Pacific region. This review discusses the molecular basis of HH and the genes and mutations known to cause non-HFE HH with particular reference to the Asia-Pacific region. Challenges in the genetic diagnosis of non-HFE HH are also discussed and how new technologies such as next generation sequencing may be informative in the future.
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Affiliation(s)
- Cameron J McDonald
- The Membrane Transport Laboratory, The Queensland Institute of Medical Research, Brisbane, Queensland, Australia
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Tan TCH, Crawford DHG, Jaskowski LA, Murphy TL, Santrampurwala N, Crane D, Clouston AD, Subramaniam VN, Anderson GJ, Fletcher LM. A corn oil-based diet protects against combined ethanol and iron-induced liver injury in a mouse model of hemochromatosis. Alcohol Clin Exp Res 2013; 37:1619-31. [PMID: 23742171 DOI: 10.1111/acer.12155] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 02/18/2013] [Indexed: 02/06/2023]
Abstract
BACKGROUND Combined iron overload and alcohol may promote synergistic chronic liver injury and toxicity. The role of specific dietary fats in influencing the development of co-toxic alcoholic liver disease needs further evaluation and is investigated in this study. METHODS Wild-type (WT) and the iron-loaded Hfe-null (Hfe(-/-) ) mice were fed chow (CC), a AIN-93G standard control (SC), or a corn oil-modified, AIN-93G-based (CO) diet with or without the addition of 20% ethanol (EtOH) in the drinking water for 8 weeks and assessed for liver injury. RESULTS WT mice on CC, SC, and CO diets had no liver injury, although mild steatosis developed in the SC and CO groups. The addition of EtOH resulted in mild steatohepatitis in WT mice fed SC but not those on a CO diet. EtOH administration in Hfe(-/-) animals on the CC and SC diets caused marked oxidative stress, inflammatory activity, and subsinusoidal and portal-portal tract linkage fibrosis with significant up-regulation of genes involved in cellular stress signaling and fibrogenic pathways. These effects were abrogated in the CO-fed mice, despite elevated serum EtOH levels and hepatic iron concentrations, reduced hepatic glutathione and mitochondrial superoxide dismutase activities. Feeding with the CO diet led to increased hepatic glutathione peroxidase and catalase activities and attenuated alcohol-induced hepatic steatosis in the Hfe(-/-) animals. Iron and EtOH feeding markedly reduced p-STAT3 and p-AMPK protein levels, but this effect was significantly attenuated when a CO diet was consumed. CONCLUSIONS A CO-based diet is protective against combined EtOH- and iron-induced liver toxicity, likely via attenuation of hepatic steatosis and oxidative stress and may have a role in the prevention of fibrosis development in chronic liver disease.
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Affiliation(s)
- Terrence C H Tan
- School of Medicine, University of Queensland, Brisbane, Queensland, Australia; Gallipoli Medical Research Centre, Greenslopes Hospital, Brisbane, Queensland, Australia; Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Queensland, Australia
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Jeffery JM, Grigoriev I, Poser I, van der Horst A, Hamilton N, Waterhouse N, Bleier J, Subramaniam VN, Maly IV, Akhmanova A, Khanna KK. Centrobin regulates centrosome function in interphase cells by limiting pericentriolar matrix recruitment. Cell Cycle 2013; 12:899-906. [PMID: 23442802 DOI: 10.4161/cc.23879] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The amount of pericentriolar matrix at the centrosome is tightly linked to both microtubule nucleation and centriole duplication, although the exact mechanism by which pericentriolar matrix levels are regulated is unclear. Here we show that Centrobin, a centrosomal protein, is involved in regulating these levels. Interphase microtubule arrays in Centrobin-depleted cells are more focused around the centrosome and are less stable than the arrays in control cells. Centrobin-depleted cells initiate microtubule nucleation more rapidly than control cells and exhibit an increase in the number of growing microtubule ends emanating from the centrosome, while the parameters of microtubule plus end dynamics around the centrosome are not significantly altered. Finally, we show that Centrobin depletion results in the increased recruitment of pericentriolar matrix proteins to the centrosome, including γ-tubulin, AKAP450, Kendrin and PCM-1. We propose that Centrobin might regulate microtubule nucleation and organization by controlling the amount of pericentriolar matrix.
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Affiliation(s)
- Jessie M Jeffery
- Department of Cell and Molecular Biology, Queensland Institute of Medical Research, Brisbane, QLD, Australia
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Wallace DF, Crawford DHG, Subramaniam VN. Iron predicts tolerance in liver transplantation. Gastroenterology 2012; 143:862-865. [PMID: 22841725 DOI: 10.1053/j.gastro.2012.07.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Affiliation(s)
- Daniel F Wallace
- The Membrane Transport Laboratory, The Queensland Institute of Medical Research and Liver Research Centre, School of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Darrell H G Crawford
- Liver Research Centre, School of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - V Nathan Subramaniam
- The Membrane Transport Laboratory, The Queensland Institute of Medical Research and Liver Research Centre, School of Medicine, University of Queensland, Brisbane, Queensland, Australia
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