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Tatsumi Y, Yano M, Wakusawa S, Miyajima H, Ishikawa T, Imashuku S, Takano A, Nihei W, Kato A, Kato K, Hayashi H, Yoshioka K, Hayashi K. A Revised Classification of Primary Iron Overload Syndromes. J Clin Transl Hepatol 2024; 12:346-356. [PMID: 38638373 PMCID: PMC11022062 DOI: 10.14218/jcth.2023.00290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 11/02/2023] [Accepted: 12/11/2023] [Indexed: 04/20/2024] Open
Abstract
Background and Aims The clinical introduction of hepcidin25 (Hep25) has led to a more detailed understanding of its relationship with ferroportin (FP) and divalent metal transporter1 in primary iron overload syndromes (PIOSs). In 2012, we proposed a classification of PIOSs based on the Hep25/FP system, which consists of prehepatic aceruloplasminemia, hepatic hemochromatosis (HC), and posthepatic FP disease (FP-D). However, in consideration of accumulated evidence on PIOSs, we aimed to renew the classification. Methods We reviewed the 2012 classification and retrospectively renewed it according to new information on PIOSs. Results Iron-loading anemia was included in PIOSs as a prehepatic form because of the newly discovered erythroferrone-induced suppression of Hep25, and the state of traditional FP-D was remodeled as the BIOIRON proposal. The key molecules responsible for prehepatic PIOSs are low transferrin saturation in aceruloplasminemia and increased erythroferrone production by erythroblasts in iron-loading anemia. Hepatic PIOSs comprise four genotypes of HC, in each of which the synthesis of Hep25 is inappropriately reduced in the liver. Hepatic Hep25 synthesis is adequate in posthepatic PIOSs; however, two mutant FP molecules may resist Hep25 differently, resulting in SLC40A1-HC and FP-D, respectively. PIOS phenotypes are diagnosed using laboratory tests, including circulating Hep25, followed by suitable treatments. Direct sequencing of the candidate genes may be outsourced to gene centers when needed. Laboratory kits for the prevalent mutations, such as C282Y, may be the first choice for a genetic analysis of HC in Caucasians. Conclusions The revised classification may be useful worldwide.
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Affiliation(s)
- Yasuaki Tatsumi
- Department of Medical Biochemistry, Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Japan
| | - Motoyoshi Yano
- Department of Gastroenterology, Yokkaichi Municipal Hospital, Yokkaichi, Japan
| | - Shinya Wakusawa
- Department of Medical Technology, Shubun University, Ichinomiya, Japan
| | - Hiroaki Miyajima
- Department of Medicine and Neurology, Tenryu Kohseikai Clinic, Hamamatsu, Japan
| | - Tetsuya Ishikawa
- Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinsaku Imashuku
- Department of Laboratory Medicine, Uji-Tokushukai Medical Center, Uji, Japan
| | - Atsuko Takano
- Department of Medicine, Saiseikai Takaoka Hospital, Takaoka, Japan
| | - Wataru Nihei
- Department of Medicine, Aichi-Gakuin University School of Pharmacy, Nagoya, Japan
| | - Ayako Kato
- Department of Medicine, Aichi-Gakuin University School of Pharmacy, Nagoya, Japan
| | - Koichi Kato
- Department of Medicine, Aichi-Gakuin University School of Pharmacy, Nagoya, Japan
| | - Hisao Hayashi
- Department of Medicine, Aichi-Gakuin University School of Pharmacy, Nagoya, Japan
| | - Kentaro Yoshioka
- Department of Gastroenterology, FNPS Meijo Hospital, Nagoya, Japan
| | - Kazuhiko Hayashi
- Department of Gastroenterology, FNPS Meijo Hospital, Nagoya, Japan
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Guellec J, Elbahnsi A, Le Tertre M, Uguen K, Gourlaouen I, Férec C, Ka C, Callebaut I, Le Gac G. Molecular model of the ferroportin intracellular gate and implications for the human iron transport cycle and hemochromatosis type 4A. FASEB J 2019; 33:14625-14635. [PMID: 31690120 DOI: 10.1096/fj.201901857r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ferroportin 1 (FPN1) is a major facilitator superfamily transporter that is essential for proper maintenance of human iron homeostasis at the systemic and cellular level. FPN1 dysfunction leads to the progressive accumulation of iron in reticuloendothelial cells, causing hemochromatosis type 4A (or ferroportin disease), an autosomal dominant disorder that displays large phenotypic heterogeneity. Although crystal structures have unveiled the outward- and inward-facing conformations of the bacterial homolog Bdellovibrio bacteriovorus Fpn (or Bd2019) and calcium has recently been identified as an essential cofactor, our molecular understanding of the iron transport mechanism remains incomplete. Here, we used a combination of molecular modeling, molecular dynamics simulations, and Ala site-directed mutagenesis, followed by complementary in vitro functional analyses, to explore the structural architecture of the human FPN1 intracellular gate. We reveal an interdomain network that involves 5 key amino acids and is likely very important for stability of the iron exporter facing the extracellular milieu. We also identify inter- and intradomain interactions that rely on the 2 Asp84 and Asn174 critical residues and do not exist in the bacterial homolog. These interactions are thought to play an important role in the modulation of conformational changes during the transport cycle. We interpret these results in the context of hemochromatosis type 4A, reinforcing the idea that different categories of loss-of-function mutations exist. Our findings provide an unprecedented view of the human FPN1 outward-facing structure and the particular function of the so-called "gating residues" in the mechanism of iron export.-Guellec, J., Elbahnsi, A., Le Tertre, M., Uguen, K., Gourlaouen, I., Férec, C., Ka, C., Callebaut, I., Le Gac, G. Molecular model of the ferroportin intracellular gate and implications for the human iron transport cycle and hemochromatosis type 4A.
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Affiliation(s)
- Julie Guellec
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Association Gaetan Saleun, Brest, France
| | - Ahmad Elbahnsi
- Muséum National d'Histoire Naturelle, UMR Centre National de la Recherche Scientifique (CNRS) 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, Paris, France
| | - Marlène Le Tertre
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and
| | - Kévin Uguen
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and
| | - Isabelle Gourlaouen
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France
| | - Claude Férec
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Association Gaetan Saleun, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and
| | - Chandran Ka
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and.,Laboratory of Excellence Laboratory of Excellence (GR-Ex), Paris, France
| | - Isabelle Callebaut
- Muséum National d'Histoire Naturelle, UMR Centre National de la Recherche Scientifique (CNRS) 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, Paris, France
| | - Gérald Le Gac
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and.,Laboratory of Excellence Laboratory of Excellence (GR-Ex), Paris, France
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Vlasveld LT, Janssen R, Bardou-Jacquet E, Venselaar H, Hamdi-Roze H, Drakesmith H, Swinkels DW. Twenty Years of Ferroportin Disease: A Review or An Update of Published Clinical, Biochemical, Molecular, and Functional Features. Pharmaceuticals (Basel) 2019; 12:ph12030132. [PMID: 31505869 PMCID: PMC6789780 DOI: 10.3390/ph12030132] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/14/2019] [Accepted: 08/20/2019] [Indexed: 12/14/2022] Open
Abstract
Iron overloading disorders linked to mutations in ferroportin have diverse phenotypes in vivo, and the effects of mutations on ferroportin in vitro range from loss of function (LOF) to gain of function (GOF) with hepcidin resistance. We reviewed 359 patients with 60 ferroportin variants. Overall, macrophage iron overload and low/normal transferrin saturation (TSAT) segregated with mutations that caused LOF, while GOF mutations were linked to high TSAT and parenchymal iron accumulation. However, the pathogenicity of individual variants is difficult to establish due to the lack of sufficiently reported data, large inter-assay variability of functional studies, and the uncertainty associated with the performance of available in silico prediction models. Since the phenotypes of hepcidin-resistant GOF variants are indistinguishable from the other types of hereditary hemochromatosis (HH), these variants may be categorized as ferroportin-associated HH, while the entity ferroportin disease may be confined to patients with LOF variants. To further improve the management of ferroportin disease, we advocate for a global registry, with standardized clinical analysis and validation of the functional tests preferably performed in human-derived enterocytic and macrophagic cell lines. Moreover, studies are warranted to unravel the definite structure of ferroportin and the indispensable residues that are essential for functionality.
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Affiliation(s)
- L Tom Vlasveld
- Department of Internal Medicine, Haaglanden MC-Bronovo, 2597AX The Hague, The Netherlands
| | - Roel Janssen
- Department of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Edouard Bardou-Jacquet
- Liver Diseases Department, French Reference Centre for Rare Iron Overload Diseases of Genetic Origin, University Hospital Pontchaillou, 35033 Rennes, France
| | - Hanka Venselaar
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud, University Medical Center, P.O. Box 9191, 6500 HB Nijmegen, The Netherlands
| | - Houda Hamdi-Roze
- Molecular Genetics Department, French Reference Centre for Rare Iron Overload Diseases of Genetic Origin, University Hospital Pontchaillou, 35033 Rennes, France
| | - Hal Drakesmith
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX39DS, UK
| | - Dorine W Swinkels
- Department of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
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Lv T, Zhang W, Xu A, Li Y, Zhou D, Zhang B, Li X, Zhao X, Wang Y, Wang X, Duan W, Wang Q, Xu H, Zheng J, Zhao R, Zhu L, Dong Y, Lu L, Chen Y, Long J, Zheng S, Wang W, You H, Jia J, Ou X, Huang J. Non- HFE mutations in haemochromatosis in China: combination of heterozygous mutations involving HJV signal peptide variants. J Med Genet 2018; 55:650-660. [PMID: 30166352 DOI: 10.1136/jmedgenet-2018-105348] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 06/22/2018] [Accepted: 07/08/2018] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Hereditary haemochromatosis (HH) caused by a homozygous p.C282Y mutation in haemochromatosis (HFE) gene has been well documented. However, less is known about the causative non-HFE mutation. We aimed to assess mutation patterns of haemochromatosis-related genes in Chinese patients with primary iron overload. METHODS Patients were preanalysed for mutations in the classic HH-related genes: HFE, HJV, HAMP, TFR2 and SLC40A1. Whole exome sequencing was conducted for cases with variants in HJV signal peptide region. Representative variants were analysed for biological function. RESULTS None of the cases analysed harboured the HFE p.C282Y; however, 21 of 22 primary iron-overload cases harboured at least one non-synonymous variant in the non-HFE genes. Specifically, p.E3D or p.Q6H variants in the HJV signal peptide region were identified in nine cases (40.9%). In two of three probands with the HJV p.E3D, exome sequencing identified accompanying variants in BMP/SMAD pathway genes, including TMPRSS6 p.T331M and BMP4 p.R269Q, and interestingly, SUGP2 p.R639Q was identified in all the three cases. Pedigree analysis showed a similar pattern of combination of heterozygous mutations in cases with HJV p.E3D or p.Q6H, with SUGP2 p.R639Q or HJV p.C321X being common mutation. In vitro siRNA interference of SUGP2 showed a novel role of downregulating the BMP/SMAD pathway. Site-directed mutagenesis of HJV p.Q6H/p.C321X in cell lines resulted in loss of membrane localisation of mutant HJV, and downregulation of p-SMAD1/5 and HAMP. CONCLUSION Compound heterozygous mutations of HJV or combined heterozygous mutations of BMP/SMAD pathway genes, marked by HJV variants in the signal peptide region, may represent a novel aetiological factor for HH.
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Affiliation(s)
- Tingxia Lv
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Experimental Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Wei Zhang
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Anjian Xu
- Experimental Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Yanmeng Li
- Experimental Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Donghu Zhou
- Experimental Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Bei Zhang
- Experimental Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Xiaojin Li
- Experimental Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Xinyan Zhao
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Yu Wang
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Xiaoming Wang
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Weijia Duan
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Qianyi Wang
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Hexiang Xu
- Department of Infectious Diseases, The Third Affiliated Hospital of Anhui Medical University, The First People's Hospital of Hefei, Hefei, China
| | - JiShun Zheng
- Department of Infectious Diseases, The Third Affiliated Hospital of Anhui Medical University, The First People's Hospital of Hefei, Hefei, China
| | - Rongrong Zhao
- Department of Infectious Diseases, The First Hospital of Lanzhou University, Lanzhou, China
| | - Longdong Zhu
- Department of Infectious Diseases, The First Hospital of Lanzhou University, Lanzhou, China
| | - Yuwei Dong
- Department of Gastroenterology, School of Medicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Lungen Lu
- Department of Gastroenterology, School of Medicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yongpeng Chen
- Department of Infectious Diseases, Institute of Hepatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jiang Long
- Department of Oncology Minimally Invasive Interventional Radiology, Beijing You-An Hospital, Capital Medical University, Shanghai, China
| | - Sujun Zheng
- Artificial Liver Center, Beijing You-An Hospital, Capital Medical University, Beijing, China
| | - Wei Wang
- Department of Clinical Laboratory, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Hong You
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Jidong Jia
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Xiaojuan Ou
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
| | - Jian Huang
- Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Experimental Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Rare Liver Disease, Capital Medical University, Beijing, China.,Liver Research Center, National Clinical Research Center for Digestive Diseases, Beijing, China
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