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Thévenod F, Herbrechter R, Schlabs C, Pethe A, Lee WK, Wolff NA, Roussa E. Role of the SLC22A17/lipocalin-2 receptor in renal endocytosis of proteins/metalloproteins: a focus on iron- and cadmium-binding proteins. Am J Physiol Renal Physiol 2023; 325:F564-F577. [PMID: 37589051 DOI: 10.1152/ajprenal.00020.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 08/15/2023] [Accepted: 08/15/2023] [Indexed: 08/18/2023] Open
Abstract
The transmembrane protein SLC22A17 [or the neutrophil gelatinase-associated lipocalin/lipocalin-2 (LCN2)/24p3 receptor] is an atypical member of the SLC22 family of organic anion and cation transporters: it does not carry typical substrates of SLC22 transporters but mediates receptor-mediated endocytosis (RME) of LCN2. One important task of the kidney is the prevention of urinary loss of proteins filtered by the glomerulus by bulk reabsorption of multiple ligands via megalin:cubilin:amnionless-mediated endocytosis in the proximal tubule (PT). Accordingly, overflow, glomerular, or PT damage, as in Fanconi syndrome, results in proteinuria. Strikingly, up to 20% of filtered proteins escape the PT under physiological conditions and are reabsorbed by the distal nephron. The renal distal tubule and collecting duct express SLC22A17, which mediates RME of filtered proteins that evade the PT but with limited capacity to prevent proteinuria under pathological conditions. The kidney also prevents excretion of filtered essential and nonessential transition metals, such as iron or cadmium, respectively, that are largely bound to proteins with high affinity, e.g., LCN2, transferrin, or metallothionein, or low affinity, e.g., microglobulins or albumin. Hence, increased uptake of transition metals may cause nephrotoxicity. Here, we assess the literature on SLC22A17 structure, topology, tissue distribution, regulation, and assumed functions, emphasizing renal SLC22A17, which has relevance for physiology, pathology, and nephrotoxicity due to the accumulation of proteins complexed with transition metals, e.g., cadmium or iron. Other putative renal functions of SLC22A17, such as its contribution to osmotic stress adaptation, protection against urinary tract infection, or renal carcinogenesis, are discussed.
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Affiliation(s)
- Frank Thévenod
- Institute for Physiology, Pathophysiology and Toxicology, Center for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany
- Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, Bielefeld, Germany
| | - Robin Herbrechter
- Institute for Physiology, Pathophysiology and Toxicology, Center for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany
| | - Carolin Schlabs
- Institute for Physiology, Pathophysiology and Toxicology, Center for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany
| | - Abhishek Pethe
- Department of Molecular Embryology, Faculty of Medicine, Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Wing-Kee Lee
- Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, Bielefeld, Germany
| | - Natascha A Wolff
- Institute for Physiology, Pathophysiology and Toxicology, Center for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany
| | - Eleni Roussa
- Department of Molecular Embryology, Faculty of Medicine, Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg im Breisgau, Germany
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Schellhorn S, Brücher D, Wolff NA, Schröer K, Sallard E, Mese K, Zhang W, Ehrke-Schulz E, Thévenod F, Plückthun A, Ehrhardt A. Targeting Oncolytic Adenoviruses to Cancer Cells Using a Designed Ankyrin Repeat Protein Lipocalin-2 Fusion Protein. Hum Gene Ther 2023; 34:203-216. [PMID: 36802735 DOI: 10.1089/hum.2022.215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
Oncolytic viruses are a promising technology to attack cancer cells and to recruit immune cells to the tumor site. Since the Lipocalin-2 receptor (LCN2R) is expressed on most cancer cells, we used its ligand LCN2 to target oncolytic adenoviruses (Ads) to cancer cells. Therefore, we fused a Designed Ankyrin Repeat Protein (DARPin) adapter binding the knob of Ad type 5 (knob5) to LCN2 to retarget the virus toward LCN2R with the aim of analyzing the basic characteristics of this novel targeting approach. The adapter was tested in vitro with Chinese Hamster Ovary (CHO) cells stably expressing the LCN2R and on 20 cancer cell lines (CCLs) using an Ad5 vector encoding luciferase and green fluorescent protein. Luciferase assays with the LCN2 adapter (LA) showed 10-fold higher infection compared with blocking adapter (BA) in CHO cells expressing LCN2R and in cells not expressing the LCN2R. Most CCLs showed an increased viral uptake of LA-bound virus compared with BA-bound virus and for five CCLs viral uptake was comparable to unmodified Ad5. Flow cytometry and hexon immunostainings also revealed increased uptake of LA-bound Ads compared with BA-bound Ads in most tested CCLs. Virus spread was studied in 3D cell culture models and nine CCLs showed increased and earlier fluorescence signals for LA-bound virus compared with BA-bound virus. Mechanistically, we show that the LA increases viral uptake only in the absence of its ligand Enterobactin (Ent) and independently of iron. Altogether, we characterized a novel DARPin-based system resulting in enhanced uptake demonstrating potential for future oncolytic virotherapy.
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Affiliation(s)
- Sebastian Schellhorn
- Virology and Microbiology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - Dominik Brücher
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Natascha A Wolff
- Institute of Physiology, Pathophysiology, and Toxicology, Center for Biomedical Training and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - Katrin Schröer
- Virology and Microbiology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - Erwan Sallard
- Virology and Microbiology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - Kemal Mese
- Virology and Microbiology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - Wenli Zhang
- Virology and Microbiology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - Eric Ehrke-Schulz
- Virology and Microbiology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
| | - Frank Thévenod
- Institute of Physiology, Pathophysiology, and Toxicology, Center for Biomedical Training and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Anja Ehrhardt
- Virology and Microbiology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
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Cirovic A, Denic A, Clarke BL, Vassallo R, Cirovic A, Landry GM. A hypoxia-driven occurrence of chronic kidney disease and osteoporosis in COPD individuals: New insights into environmental cadmium exposure. Toxicology 2022; 482:153355. [DOI: 10.1016/j.tox.2022.153355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 11/07/2022]
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Halcrow PW, Lakpa KL, Khan N, Afghah Z, Miller N, Datta G, Chen X, Geiger JD. HIV-1 gp120-Induced Endolysosome de-Acidification Leads to Efflux of Endolysosome Iron, and Increases in Mitochondrial Iron and Reactive Oxygen Species. J Neuroimmune Pharmacol 2022; 17:181-194. [PMID: 33834418 PMCID: PMC8497638 DOI: 10.1007/s11481-021-09995-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/31/2021] [Indexed: 12/29/2022]
Abstract
The HIV-1 coat protein gp120 continues to be implicated in the pathogenesis of HIV-1 associated neurocognitive disorder (HAND); a condition known to affect ~50% of people living with HIV-1 (PLWH). Autopsy brain tissues of HAND individuals display morphological changes to mitochondria and endolysosomes, and HIV-1 gp120 causes mitochondrial dysfunction including increased levels of reactive oxygen species (ROS) and de-acidification of endolysosomes. Ferrous iron is linked directly to ROS production, ferrous iron is contained in and released from endolysosomes, and PLWH have elevated iron and ROS levels. Based on those findings, we tested the hypothesis that HIV-1 gp120-induced endolysosome de-acidification and subsequent iron efflux from endolysosomes is responsible for increased levels of ROS. In U87MG glioblastoma cells, HIV-1 gp120 de-acidified endolysosomes, reduced endolysosome iron levels, increased levels of cytosolic and mitochondrial iron, and increased levels of cytosolic and mitochondrial ROS. These effects were all attenuated significantly by the endolysosome-specific iron chelator deferoxamine, by inhibitors of endolysosome-resident two-pore channels and divalent metal transporter-1 (DMT-1), and by inhibitors of mitochondria-resident DMT-1 and mitochondrial permeability transition pores. These results suggest that oxidative stress commonly observed with HIV-1 gp120 is downstream of its ability to de-acidify endolysosomes, to increase the release of iron from endolysosomes, and to increase the uptake of iron into mitochondria. Thus, endolysosomes might represent early and upstream targets for therapeutic strategies against HAND.
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Affiliation(s)
| | | | - Nabab Khan
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA
| | - Zahra Afghah
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA
| | - Nicole Miller
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA
| | - Gaurav Datta
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA
| | - Xuesong Chen
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA
| | - Jonathan D. Geiger
- Address correspondence to: Jonathan D. Geiger, Ph.D., Chester Fritz Distinguished Professor, Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 504 Hamline Street, Room #110, Grand Forks, North Dakota 58203, (701) 777-2183 (P), (701) 777-0387 (F),
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Wu K, Fei L, Wang X, Lei Y, Liu Y, Xu W, Chen J, Zhu E, Zhong M, Huang M, Jiang X, Yin F, Yan Z, Zhao X, Tang C, Patzak A, Liu X, Zheng Z. ZIP14 is involved in iron deposition and triggers ferroptosis in diabetic nephropathy. Metallomics 2022; 14:6596292. [PMID: 35641158 DOI: 10.1093/mtomcs/mfac034] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 05/25/2022] [Indexed: 11/12/2022]
Abstract
Ferroptosis is caused by lipid peroxidation and iron accumulation and can cause cell death. Abnormally expressed iron transporters are involved in ferroptosis in a variety of diseases. ZRT/IRT-like protein 14 (ZIP14) is a transport protein that can mediate cellular uptake of iron, zinc and manganese. Herein, we have tested the hypothesis that the divalent metal transporter ZIP14 is involved in the initiation of ferroptosis in diabetic nephropathy (DN). DN was induced in eight-week old male rats by streptozotocin (STZ) before analysis of the degree of renal tubular injury. In addition, an in vitro model of DN in HK2 cells was used. We showed that ZIP14 was upregulated and Fe2+ levels increased both in vivo and in vitro. Expression of glutathione peroxidase 4 (GPX4) and the level of glutathione (GSH) were reduced, whereas that of malondialdehyde (MDA) increased. Ferrostatin-1(Fer-1) treatment reduced the expression of ZIP14 and the levels of Fe2+ and MDA, which is consistent with ferroptosis. Fer-1 improved kidney function in DN rats. This was characterized by urine levels of protein-to-creatinine ratio, α 1-microglobulin and N-acetyl-β-D-glucosaminidase. Our study demonstrates a novel role for ZIP14 in diabetic kidney injury mediated by ferroptosis, and suggests a potential new therapeutic approach for the treatment of diabetic nephropathy.
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Affiliation(s)
- Keping Wu
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China.,Department of Nephrology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Lingyan Fei
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China.,Institute of Translation Physiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin.,Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xiaohua Wang
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Yan Lei
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Yu Liu
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Wenqian Xu
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Jiasi Chen
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Enyi Zhu
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Ming Zhong
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Mingcheng Huang
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Xi Jiang
- Department of Clinical Laboratory, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Fei Yin
- Department of Thoracic Surgery, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Zhijun Yan
- Department of Anesthesia, The First Affiliated Hospital of Nanhua University, Hunan, China
| | - Xinying Zhao
- Department of Hematology, Guangzhou Women and Children's Medical center, Guangzhou Medical University, Guangzhou, China
| | - Chun Tang
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Andreas Patzak
- Institute of Translation Physiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin
| | - Xiaoping Liu
- Department of Hematology, Guangzhou Women and Children's Medical center, Guangzhou Medical University, Guangzhou, China
| | - Zhihua Zheng
- Department of Nephrology, Kidney and Urology Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
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6
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OUP accepted manuscript. Nutr Rev 2022; 80:1974-1984. [DOI: 10.1093/nutrit/nuac011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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7
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Wareing M, Smith CP. Iron Is Filtered by the Kidney and Is Reabsorbed by the Proximal Tubule. Front Physiol 2021; 12:740716. [PMID: 34658926 PMCID: PMC8514780 DOI: 10.3389/fphys.2021.740716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 08/30/2021] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to determine the iron (Fe) concentration profile within the lumen of the S2 renal proximal convoluted tubule (PCT) and to resolve whether this nephron segment transported Fe. To do this, we performed in vivo renal micropuncture on Wistar rats, collected PCT tubular fluid from superficial nephrons, and measured Fe concentration. The Fe concentration profile along the S2 PCT suggested significant Fe reabsorption. Proximal tubules were also microperfused in vivo with physiological solutions containing Fe and Zn, Cu, Mn, or Cd. PCTs perfused with 12μmol.l−1 55FeCl3 reabsorbed 105.2±12.7 fmol.mm−1.min−1 Fe, 435±52pmol.mm-1.min−1 Na, and 2.7±0.2nl.mm−1.min−1 water (mean ± SEM; n=19). Addition of ascorbate (1mmol.l−1) to the perfusate did not significantly alter Fe, Na, or water reabsorption. Supplementing the control perfusate with 60μmol.l−1 FeSO4 significantly decreased 55Fe uptake. Recalculating for the altered molar activity following addition of unlabeled Fe revealed a three-fold increase in Fe flux. Addition to the perfusate 12μmol.l−1 CuSO4, MnSO4, CdSO4, or ZnSO4 did not affect Fe, Na, or water flux. In conclusion, (1) in vivo, S2 PCTs of rat reabsorb Fe and (2) Fe is reabsorbed along the PCT via a pathway that is insensitive to Cu, Mn, Cd, or Zn. Together, these data demonstrate for the first time the hitherto speculated process of renal Fe filtration and subsequent tubular Fe reabsorption in a living mammal.
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Affiliation(s)
- Mark Wareing
- School of Medical Sciences, The University of Manchester, Manchester, United Kingdom
| | - Craig P Smith
- School of Medical Sciences, The University of Manchester, Manchester, United Kingdom
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Probst S, Fels J, Scharner B, Wolff NA, Roussa E, van Swelm RPL, Lee WK, Thévenod F. Role of hepcidin in oxidative stress and cell death of cultured mouse renal collecting duct cells: protection against iron and sensitization to cadmium. Arch Toxicol 2021; 95:2719-2735. [PMID: 34181029 PMCID: PMC8298330 DOI: 10.1007/s00204-021-03106-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 06/17/2021] [Indexed: 11/05/2022]
Abstract
The liver hormone hepcidin regulates systemic iron homeostasis. Hepcidin is also expressed by the kidney, but exclusively in distal nephron segments. Several studies suggest hepcidin protects against kidney damage involving Fe2+ overload. The nephrotoxic non-essential metal ion Cd2+ can displace Fe2+ from cellular biomolecules, causing oxidative stress and cell death. The role of hepcidin in Fe2+ and Cd2+ toxicity was assessed in mouse renal cortical [mCCD(cl.1)] and inner medullary [mIMCD3] collecting duct cell lines. Cells were exposed to equipotent Cd2+ (0.5-5 μmol/l) and/or Fe2+ (50-100 μmol/l) for 4-24 h. Hepcidin (Hamp1) was transiently silenced by RNAi or overexpressed by plasmid transfection. Hepcidin or catalase expression were evaluated by RT-PCR, qPCR, immunoblotting or immunofluorescence microscopy, and cell fate by MTT, apoptosis and necrosis assays. Reactive oxygen species (ROS) were detected using CellROX™ Green and catalase activity by fluorometry. Hepcidin upregulation protected against Fe2+-induced mIMCD3 cell death by increasing catalase activity and reducing ROS, but exacerbated Cd2+-induced catalase dysfunction, increasing ROS and cell death. Opposite effects were observed with Hamp1 siRNA. Similar to Hamp1 silencing, increased intracellular Fe2+ prevented Cd2+ damage, ROS formation and catalase disruption whereas chelation of intracellular Fe2+ with desferrioxamine augmented Cd2+ damage, corresponding to hepcidin upregulation. Comparable effects were observed in mCCD(cl.1) cells, indicating equivalent functions of renal hepcidin in different collecting duct segments. In conclusion, hepcidin likely binds Fe2+, but not Cd2+. Because Fe2+ and Cd2+ compete for functional binding sites in proteins, hepcidin affects their free metal ion pools and differentially impacts downstream processes and cell fate.
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Affiliation(s)
- Stephanie Probst
- Faculty of Health, Institute of Physiology, Pathophysiology and Toxicology and ZBAF (Centre for Biomedical Education and Research), School of Medicine, Witten/Herdecke University, Stockumer Str 12 (Thyssenhaus), 58453, Witten, Germany
| | - Johannes Fels
- Faculty of Health, Institute of Physiology, Pathophysiology and Toxicology and ZBAF (Centre for Biomedical Education and Research), School of Medicine, Witten/Herdecke University, Stockumer Str 12 (Thyssenhaus), 58453, Witten, Germany
| | - Bettina Scharner
- Faculty of Health, Institute of Physiology, Pathophysiology and Toxicology and ZBAF (Centre for Biomedical Education and Research), School of Medicine, Witten/Herdecke University, Stockumer Str 12 (Thyssenhaus), 58453, Witten, Germany
| | - Natascha A Wolff
- Faculty of Health, Institute of Physiology, Pathophysiology and Toxicology and ZBAF (Centre for Biomedical Education and Research), School of Medicine, Witten/Herdecke University, Stockumer Str 12 (Thyssenhaus), 58453, Witten, Germany
| | - Eleni Roussa
- Department of Molecular Embryology, Faculty of Medicine, Institute of Anatomy and Cell Biology, University of Freiburg, Albertstr. 17, 79104, Freiburg, Germany
| | - Rachel P L van Swelm
- Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
| | - Wing-Kee Lee
- Faculty of Health, Institute of Physiology, Pathophysiology and Toxicology and ZBAF (Centre for Biomedical Education and Research), School of Medicine, Witten/Herdecke University, Stockumer Str 12 (Thyssenhaus), 58453, Witten, Germany
- AG Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, Morgenbreede 1, 33615, Bielefeld, Germany
| | - Frank Thévenod
- Faculty of Health, Institute of Physiology, Pathophysiology and Toxicology and ZBAF (Centre for Biomedical Education and Research), School of Medicine, Witten/Herdecke University, Stockumer Str 12 (Thyssenhaus), 58453, Witten, Germany.
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Zavala-Guevara IP, Ortega-Romero MS, Narváez-Morales J, Jacobo-Estrada TL, Lee WK, Arreola-Mendoza L, Thévenod F, Barbier OC. Increased Endocytosis of Cadmium-Metallothionein through the 24p3 Receptor in an In Vivo Model with Reduced Proximal Tubular Activity. Int J Mol Sci 2021; 22:7262. [PMID: 34298880 PMCID: PMC8303618 DOI: 10.3390/ijms22147262] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/08/2021] [Accepted: 06/24/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The proximal tubule (PT) is the major target of cadmium (Cd2+) nephrotoxicity. Current dogma postulates that Cd2+ complexed to metallothionein (MT) (CdMT) is taken up through receptor-mediated endocytosis (RME) via the PT receptor megalin:cubilin, which is the predominant pathway for reuptake of filtered proteins in the kidney. Nevertheless, there is evidence that the distal parts of the nephron are also sensitive to damage induced by Cd2+. In rodent kidneys, another receptor for protein endocytosis, the 24p3 receptor (24p3R), is exclusively expressed in the apical membranes of distal tubules (DT) and collecting ducts (CD). Cell culture studies have demonstrated that RME and toxicity of CdMT and other (metal ion)-protein complexes in DT and CD cells is mediated by 24p3R. In this study, we evaluated the uptake of labeled CdMT complex through 24p3R after acute kidney injury (AKI) induced by gentamicin (GM) administration that disrupts PT function. Subcutaneous administration of GM at 10 mg/kg/day for seven days did not alter the structural and functional integrity of the kidney's filtration barrier. However, because of PT injury, the concentration of the renal biomarker Kim-1 increased. When CdMT complex coupled to FITC was administered intravenously, both uptake of the CdMT complex and 24p3R expression in DT increased and also colocalized after PT injury induced by GM. Although megalin decreased in PT after GM administration, urinary protein excretion was not changed, which suggests that the increased levels of 24p3R in the distal nephron could be acting as a compensatory mechanism for protein uptake. Altogether, these results suggest that PT damage increases the uptake of the CdMT complex through 24p3R in DT (and possibly CD) and compensate for protein losses associated with AKI.
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Affiliation(s)
- Itzel Pamela Zavala-Guevara
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México CP 07360, Mexico; (I.P.Z.-G.); (M.S.O.-R.); (J.N.-M.)
| | - Manolo Sibael Ortega-Romero
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México CP 07360, Mexico; (I.P.Z.-G.); (M.S.O.-R.); (J.N.-M.)
| | - Juana Narváez-Morales
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México CP 07360, Mexico; (I.P.Z.-G.); (M.S.O.-R.); (J.N.-M.)
| | - Tania Libertad Jacobo-Estrada
- Departamento de Biociencias e Ingeniería, Centro Interdisciplinario de Investigaciones y Estudios Sobre Medio Ambiente y Desarrollo, Instituto Politécnico Nacional, 30 de Junio de 1520 s/n, Col. Barrio la Laguna Ticomán, México CP 07340, Mexico;
| | - Wing-Kee Lee
- Department of Physiology, Pathophysiology and Toxicology and ZBAF (Center for Biomedical Education and Research), Faculty of Health-School of Medicine, Witten/Herdecke University, 58448 Witten, Germany; (W.-K.L.); (F.T.)
- Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, 33615 Bielefeld, Germany
| | - Laura Arreola-Mendoza
- Departamento de Biociencias e Ingeniería, Centro Interdisciplinario de Investigaciones y Estudios Sobre Medio Ambiente y Desarrollo, Instituto Politécnico Nacional, 30 de Junio de 1520 s/n, Col. Barrio la Laguna Ticomán, México CP 07340, Mexico;
| | - Frank Thévenod
- Department of Physiology, Pathophysiology and Toxicology and ZBAF (Center for Biomedical Education and Research), Faculty of Health-School of Medicine, Witten/Herdecke University, 58448 Witten, Germany; (W.-K.L.); (F.T.)
| | - Olivier Christophe Barbier
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México CP 07360, Mexico; (I.P.Z.-G.); (M.S.O.-R.); (J.N.-M.)
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Sun L, Lin X, Pornprasert S, Lü X, Ran B, Lin Y. L-type calcium channel blockers decrease the iron overload-mediated oxidative stress in renal epithelial cells by reducing iron accumulation. Eur J Pharmacol 2020; 886:173513. [PMID: 32898550 DOI: 10.1016/j.ejphar.2020.173513] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 08/06/2020] [Accepted: 08/26/2020] [Indexed: 11/26/2022]
Abstract
Iron-mediated oxidative stress has been recognized as one of the leading causes of chronic kidney injury. The effect of L-type calcium channel (LTCC) blocker on iron overload has been shown in cardiomyocytes, liver cells, and nerve cells. So far, few studies have examined whether blockers improve kidney iron-mediated oxidative stress. Yet, the precise mechanism through which blockers regulate kidney iron transport still remains unclear. In the present work, treatment with nifedipine or verapamil decreased oxidative stress and reduced the cell apoptosis-induced by ferric ammonium citrate (P < 0.05), decreased cellular iron contents, and prevented the rising of iron level-induced by ferric ammonium citrate (P > 0.05) in HK-2 and HEK293 cells. Besides, nifedipine and verapamil treatments increased the expression of divalent metal transporter 1, divalent metal transporter ZIP14, and ferroportin1 in HK-2 cells and increased ferroportin1 expression in HEK293 cells. In summary, LTCC blockers alleviate iron overload-induced oxidative stress in renal epithelial cells by blocking the iron uptake and enhancing cellular iron transport and/or iron export, thus synergistically reducing the cellular iron accumulation. Consequently, LTCC blockers may be used as a novel treatment for the prevention of primary or secondary iron overload-kidney injury.
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Affiliation(s)
- Linfeng Sun
- Department of Physiology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, China
| | - Xiaoding Lin
- Class 2 of Grade 2017, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Sakorn Pornprasert
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Xiaomei Lü
- Department of Neurology, Chongqing Medical University Affiliated Children's Hospital, Chongqing, 400014, China
| | - Bing Ran
- Department of Physiology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, China.
| | - Yan Lin
- Department of Physiology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, China; Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, 50200, Thailand; Institute for Cancer Medicine, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, 646000, China.
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11
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Bednarz A, Lipiński P, Starzyński RR, Tomczyk M, Kraszewska I, Herman S, Kowalski K, Gruca E, Jończy A, Mazgaj R, Szudzik M, Rajfur Z, Baster Z, Józkowicz A, Lenartowicz M. Exacerbation of Neonatal Hemolysis and Impaired Renal Iron Handling in Heme Oxygenase 1-Deficient Mice. Int J Mol Sci 2020; 21:ijms21207754. [PMID: 33092142 PMCID: PMC7589678 DOI: 10.3390/ijms21207754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 01/03/2023] Open
Abstract
In most mammals, neonatal intravascular hemolysis is a benign and moderate disorder that usually does not lead to anemia. During the neonatal period, kidneys play a key role in detoxification and recirculation of iron species released from red blood cells (RBC) and filtered out by glomeruli to the primary urine. Activity of heme oxygenase 1 (HO1), a heme-degrading enzyme localized in epithelial cells of proximal tubules, seems to be of critical importance for both processes. We show that, in HO1 knockout mouse newborns, hemolysis was prolonged despite a transient state and exacerbated, which led to temporal deterioration of RBC status. In neonates lacking HO1, functioning of renal molecular machinery responsible for iron reabsorption from the primary urine (megalin/cubilin complex) and its transfer to the blood (ferroportin) was either shifted in time or impaired, respectively. Those abnormalities resulted in iron loss from the body (excreted in urine) and in iron retention in the renal epithelium. We postulate that, as a consequence of these abnormalities, a tight systemic iron balance of HO1 knockout neonates may be temporarily affected.
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Affiliation(s)
- Aleksandra Bednarz
- Department of Genetics and Evolution, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland; (A.B.); (S.H.); (K.K.); (E.G.)
| | - Paweł Lipiński
- Department of Molecular Biology, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzębiec, 05-552 Magdalenka, Poland; (P.L.); (R.R.S.); (A.J.); (R.M.); (M.S.)
| | - Rafał R. Starzyński
- Department of Molecular Biology, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzębiec, 05-552 Magdalenka, Poland; (P.L.); (R.R.S.); (A.J.); (R.M.); (M.S.)
| | - Mateusz Tomczyk
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland; (M.T.); (I.K.); (A.J.)
| | - Izabela Kraszewska
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland; (M.T.); (I.K.); (A.J.)
| | - Sylwia Herman
- Department of Genetics and Evolution, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland; (A.B.); (S.H.); (K.K.); (E.G.)
| | - Kacper Kowalski
- Department of Genetics and Evolution, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland; (A.B.); (S.H.); (K.K.); (E.G.)
| | - Ewelina Gruca
- Department of Genetics and Evolution, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland; (A.B.); (S.H.); (K.K.); (E.G.)
| | - Aneta Jończy
- Department of Molecular Biology, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzębiec, 05-552 Magdalenka, Poland; (P.L.); (R.R.S.); (A.J.); (R.M.); (M.S.)
| | - Rafał Mazgaj
- Department of Molecular Biology, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzębiec, 05-552 Magdalenka, Poland; (P.L.); (R.R.S.); (A.J.); (R.M.); (M.S.)
| | - Mateusz Szudzik
- Department of Molecular Biology, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzębiec, 05-552 Magdalenka, Poland; (P.L.); (R.R.S.); (A.J.); (R.M.); (M.S.)
| | - Zenon Rajfur
- Department of Molecular and Interfacial Biophysics, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland; (Z.R.); (Z.B.)
| | - Zbigniew Baster
- Department of Molecular and Interfacial Biophysics, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland; (Z.R.); (Z.B.)
| | - Alicja Józkowicz
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland; (M.T.); (I.K.); (A.J.)
| | - Małgorzata Lenartowicz
- Department of Genetics and Evolution, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland; (A.B.); (S.H.); (K.K.); (E.G.)
- Correspondence:
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12
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Thévenod F, Lee WK, Garrick MD. Iron and Cadmium Entry Into Renal Mitochondria: Physiological and Toxicological Implications. Front Cell Dev Biol 2020; 8:848. [PMID: 32984336 PMCID: PMC7492674 DOI: 10.3389/fcell.2020.00848] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/07/2020] [Indexed: 12/15/2022] Open
Abstract
Regulation of body fluid homeostasis is a major renal function, occurring largely through epithelial solute transport in various nephron segments driven by Na+/K+-ATPase activity. Energy demands are greatest in the proximal tubule and thick ascending limb where mitochondrial ATP production occurs through oxidative phosphorylation. Mitochondria contain 20-80% of the cell's iron, copper, and manganese that are imported for their redox properties, primarily for electron transport. Redox reactions, however, also lead to reactive, toxic compounds, hence careful control of redox-active metal import into mitochondria is necessary. Current dogma claims the outer mitochondrial membrane (OMM) is freely permeable to metal ions, while the inner mitochondrial membrane (IMM) is selectively permeable. Yet we recently showed iron and manganese import at the OMM involves divalent metal transporter 1 (DMT1), an H+-coupled metal ion transporter. Thus, iron import is not only regulated by IMM mitoferrins, but also depends on the OMM to intermembrane space H+ gradient. We discuss how these mitochondrial transport processes contribute to renal injury in systemic (e.g., hemochromatosis) and local (e.g., hemoglobinuria) iron overload. Furthermore, the environmental toxicant cadmium selectively damages kidney mitochondria by "ionic mimicry" utilizing iron and calcium transporters, such as OMM DMT1 or IMM calcium uniporter, and by disrupting the electron transport chain. Consequently, unraveling mitochondrial metal ion transport may help develop new strategies to prevent kidney injury induced by metals.
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Affiliation(s)
- Frank Thévenod
- Faculty of Health, Centre for Biomedical Education and Research, Institute of Physiology, Pathophysiology and Toxicology, Witten/Herdecke University, Witten, Germany
| | - Wing-Kee Lee
- Faculty of Health, Centre for Biomedical Education and Research, Institute of Physiology, Pathophysiology and Toxicology, Witten/Herdecke University, Witten, Germany
| | - Michael D Garrick
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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13
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Cell organelles as targets of mammalian cadmium toxicity. Arch Toxicol 2020; 94:1017-1049. [PMID: 32206829 DOI: 10.1007/s00204-020-02692-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 02/25/2020] [Indexed: 02/07/2023]
Abstract
Ever increasing environmental presence of cadmium as a consequence of industrial activities is considered a health hazard and is closely linked to deteriorating global health status. General animal and human cadmium exposure ranges from ingestion of foodstuffs sourced from heavily polluted hotspots and cigarette smoke to widespread contamination of air and water, including cadmium-containing microplastics found in household water. Cadmium is promiscuous in its effects and exerts numerous cellular perturbations based on direct interactions with macromolecules and its capacity to mimic or displace essential physiological ions, such as iron and zinc. Cell organelles use lipid membranes to form complex tightly-regulated, compartmentalized networks with specialized functions, which are fundamental to life. Interorganellar communication is crucial for orchestrating correct cell behavior, such as adaptive stress responses, and can be mediated by the release of signaling molecules, exchange of organelle contents, mechanical force generated through organelle shape changes or direct membrane contact sites. In this review, cadmium effects on organellar structure and function will be critically discussed with particular consideration to disruption of organelle physiology in vertebrates.
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14
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Pan S, Qian ZM, Cui S, Zhao D, Lan W, Wang X, Chen X. Local hepcidin increased intracellular iron overload via the degradation of ferroportin in the kidney. Biochem Biophys Res Commun 2019; 522:322-327. [PMID: 31761321 DOI: 10.1016/j.bbrc.2019.11.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 11/10/2019] [Indexed: 02/09/2023]
Abstract
BACKGROUND Hepcidin is a key regulator of iron homeostasis. Some studies showed that exogenous hepcidin decreased the expression of divalent metal transporter (DMT1) rather than ferroportin(FPN1) to regulate renal iron metabolism. This study explored the effects of hepcidin synthesized by the kidney and its mechanism of iron regulation. METHODS In the in vivo experiments, mice were divided into a unilateral ureter obstruction (UUO) model group and a sham operation group, and mice in the UUO model group were sacrificed on days 1, 3, 5 and 7. The expression of renal hepcidin, FPN1, DMT1 and the retention of renal iron were studied. In the in vitro experiments, we overexpressed hepcidin in HK-2 cells. Then we tested the expression of renal hepcidin, FPN1, DMT1 and observed the production of intracellular ferrous ions. RESULTS Renal hepcidin expression was consistently higher in the UUO group than in the sham group from the first day. The expression of FPN1 gradually decreased, and the expression of DMT1 gradually increased in the UUO model. Intracellular ferrous ions significantly increased on the first day of the UUO model. In hepcidin overexpressed HK-2 cells, the expression of FPN1 was decreased, while the expression of DMT1 has no significant change. In addition, production of intracellular ferrous ions increased. CONCLUSION local hepcidin can regulate iron metabolism in the kidney by adjusting the expression of FPN1.
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Affiliation(s)
- Sai Pan
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, Beijing Key Laboratory of Kidney Disease, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, People's Republic of China
| | - Zhong-Ming Qian
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, Shanghai, 201203, People's Republic of China
| | - Shaoyuan Cui
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, Beijing Key Laboratory of Kidney Disease, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, People's Republic of China
| | - Delong Zhao
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, Beijing Key Laboratory of Kidney Disease, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, People's Republic of China
| | - Weiren Lan
- The Second Affiliated Hospital of Army Medical University, Chongqing, People's Republic of China
| | - Xu Wang
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, Beijing Key Laboratory of Kidney Disease, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, People's Republic of China
| | - Xiangmei Chen
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, Beijing Key Laboratory of Kidney Disease, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, People's Republic of China.
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15
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Balla J, Balla G, Zarjou A. Ferritin in Kidney and Vascular Related Diseases: Novel Roles for an Old Player. Pharmaceuticals (Basel) 2019; 12:E96. [PMID: 31234273 PMCID: PMC6630272 DOI: 10.3390/ph12020096] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/14/2019] [Accepted: 06/19/2019] [Indexed: 12/12/2022] Open
Abstract
Iron is at the forefront of a number of pivotal biological processes due to its ability to readily accept and donate electrons. However, this property may also catalyze the generation of free radicals with ensuing cellular and tissue toxicity. Accordingly, throughout evolution numerous pathways and proteins have evolved to minimize the potential hazardous effects of iron cations and yet allow for readily available iron cations in a wide variety of fundamental metabolic processes. One of the extensively studied proteins in the context of systemic and cellular iron metabolisms is ferritin. While clinicians utilize serum ferritin to monitor body iron stores and inflammation, it is important to note that the vast majority of ferritin is located intracellularly. Intracellular ferritin is made of two different subunits (heavy and light chain) and plays an imperative role as a safe iron depot. In the past couple of decades our understanding of ferritin biology has remarkably improved. Additionally, a significant body of evidence has emerged describing the significance of the kidney in iron trafficking and homeostasis. Here, we briefly discuss some of the most important findings that relate to the role of iron and ferritin heavy chain in the context of kidney-related diseases and, in particular, vascular calcification, which is a frequent complication of chronic kidney disease.
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Affiliation(s)
- József Balla
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, H-4032 Debrecen, Hungary.
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary.
| | - György Balla
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, H-4032 Debrecen, Hungary.
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary.
| | - Abolfazl Zarjou
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
- Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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16
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Smith CP, Lee WK, Haley M, Poulsen SB, Thévenod F, Fenton RA. Proximal tubule transferrin uptake is modulated by cellular iron and mediated by apical membrane megalin-cubilin complex and transferrin receptor 1. J Biol Chem 2019; 294:7025-7036. [PMID: 30833328 PMCID: PMC6497946 DOI: 10.1074/jbc.ra118.006390] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/27/2019] [Indexed: 01/12/2023] Open
Abstract
Receptor-mediated endocytosis is responsible for reabsorption of transferrin (Tf) in renal proximal tubules (PTs). Although the role of the megalin-cubilin receptor complex (MCRC) in this process is unequivocal, modalities independent of this complex are evident but as yet undefined. Here, using immunostaining and Tf-flux assays, FACS analysis, and fluorescence imaging, we report localization of Tf receptor 1 (TfR1), the cognate Tf receptor mediating cellular holo-Tf (hTf) acquisition, to the apical brush border of the PT, with expression gradually declining along the PT in mouse and rat kidneys. In functional studies, hTf uptake across the apical membrane of cultured PT epithelial cell (PTEC) monolayers increased in response to decreased cellular iron after desferrioxamine (DFO) treatment. We also found that apical hTf uptake under basal conditions is receptor-associated protein (RAP)-sensitive and therefore mediated by the MCRC but becomes RAP-insensitive under DFO treatment, with concomitantly decreased megalin and cubilin expression levels and increased TfR1 expression. Thus, as well as the MCRC, TfR1 mediates hTf uptake across the PT apical brush border, but in conditions of decreased cellular iron, hTf uptake is predominated by augmented apical TfR1. In conclusion, both the MCRC and TfR1 mediate hTf uptake across apical brush border membranes of PTECs and reciprocally respond to decreased cellular iron. Our findings have implications for renal health, whole-body iron homeostasis, and pathologies arising from disrupted iron balance.
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Affiliation(s)
- Craig P Smith
- From the School of Medical Sciences, The University of Manchester, Manchester M13 9PT, United Kingdom,
| | - Wing-Kee Lee
- Physiology, Pathophysiology and Toxicology, University of Witten/Herdecke, D-58453 Witten, Germany, and
| | - Matthew Haley
- From the School of Medical Sciences, The University of Manchester, Manchester M13 9PT, United Kingdom
| | - Søren B Poulsen
- Department of Biomedicine, Aarhus University, Aarhus, 8000 Denmark
| | - Frank Thévenod
- Physiology, Pathophysiology and Toxicology, University of Witten/Herdecke, D-58453 Witten, Germany, and
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, 8000 Denmark
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17
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Channels, transporters and receptors for cadmium and cadmium complexes in eukaryotic cells: myths and facts. Biometals 2019; 32:469-489. [DOI: 10.1007/s10534-019-00176-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 01/21/2019] [Indexed: 12/21/2022]
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18
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Weiss A, Spektor L, A. Cohen L, Lifshitz L, Magid Gold I, Zhang DL, Truman-Rosentsvit M, Leichtmann-Bardoogo Y, Nyska A, Addadi S, Rouault TA, Meyron-Holtz EG. Orchestrated regulation of iron trafficking proteins in the kidney during iron overload facilitates systemic iron retention. PLoS One 2018; 13:e0204471. [PMID: 30321179 PMCID: PMC6188744 DOI: 10.1371/journal.pone.0204471] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/07/2018] [Indexed: 01/24/2023] Open
Abstract
The exact route of iron through the kidney and its regulation during iron overload are not completely elucidated. Under physiologic conditions, non-transferrin and transferrin bound iron passes the glomerular filter and is reabsorbed through kidney epithelial cells, so that hardly any iron is found in the urine. To study the route of iron reabsorption through the kidney, we analyzed the location and regulation of iron metabolism related proteins in kidneys of mice with iron overload, elicited by iron dextran injections. Transferrin Receptor 1 was decreased as expected, following iron overload. In contrast, the multi-ligand hetero-dimeric receptor-complex megalin/cubilin, which also mediates the internalization of transferrin, was highly up-regulated. Moreover, with increasing iron, intracellular ferritin distribution shifted in renal epithelium from an apical location to a punctate distribution throughout the epithelial cells. In addition, in contrast to many other tissues, the iron exporter ferroportin was not reduced by iron overload in the kidney. Iron accumulated mainly in interstitial macrophages, and more prominently in the medulla than in the cortex. This suggests that despite the reduction of Transferrin Receptor 1, alternative pathways may effectively mediate re-absorption of iron that cycles through the kidney during parenterally induced iron-overload. The most iron consuming process of the body, erythropoiesis, is regulated by the renal erythropoietin producing cells in kidney interstitium. We propose, that the efficient re-absorption of iron by the kidney, also during iron overload enables these cells to sense systemic iron and regulate its usage based on the systemic iron state.
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Affiliation(s)
- Avital Weiss
- Laboratory for Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Lior Spektor
- Laboratory for Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Lyora A. Cohen
- Laboratory for Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Lena Lifshitz
- Laboratory for Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Inbar Magid Gold
- Laboratory for Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - De-Liang Zhang
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Marianna Truman-Rosentsvit
- Laboratory for Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yael Leichtmann-Bardoogo
- Laboratory for Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Abraham Nyska
- Sackler School of Medicine, Tel Aviv University, and Consultant in Toxicologic Pathology, Timrat, Israel
| | | | - Tracey A. Rouault
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Esther G. Meyron-Holtz
- Laboratory for Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
- * E-mail:
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19
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van Raaij S, Masereeuw R, Swinkels D, van Swelm R. Inhibition of Nrf2 alters cell stress induced by chronic iron exposure in human proximal tubular epithelial cells. Toxicol Lett 2018; 295:179-186. [DOI: 10.1016/j.toxlet.2018.06.1218] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/18/2018] [Accepted: 06/26/2018] [Indexed: 01/19/2023]
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20
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Tubular iron deposition and iron handling proteins in human healthy kidney and chronic kidney disease. Sci Rep 2018; 8:9353. [PMID: 29921869 PMCID: PMC6008459 DOI: 10.1038/s41598-018-27107-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 05/23/2018] [Indexed: 02/07/2023] Open
Abstract
Iron is suggested to play a detrimental role in the progression of chronic kidney disease (CKD). The kidney recycles iron back into the circulation. However, the localization of proteins relevant for physiological tubular iron handling and their potential role in CKD remain unclear. We examined associations between iron deposition, expression of iron handling proteins and tubular injury in kidney biopsies from CKD patients and healthy controls using immunohistochemistry. Iron was deposited in proximal (PT) and distal tubules (DT) in 33% of CKD biopsies, predominantly in pathologies with glomerular dysfunction, but absent in controls. In healthy kidney, PT contained proteins required for iron recycling including putative iron importers ZIP8, ZIP14, DMT1, iron storage proteins L- and H-ferritin and iron exporter ferroportin, while DT only contained ZIP8, ZIP14, and DMT1. In CKD, iron deposition associated with increased intensity of iron importers (ZIP14, ZIP8), storage proteins (L-, H-ferritin), and/or decreased ferroportin abundance. This demonstrates that tubular iron accumulation may result from increased iron uptake and/or inadequate iron export. Iron deposition associated with oxidative injury as indicated by heme oxygenase-1 abundance. In conclusion, iron deposition is relatively common in CKD, and may result from altered molecular iron handling and may contribute to renal injury.
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21
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Satarug S. Dietary Cadmium Intake and Its Effects on Kidneys. TOXICS 2018; 6:E15. [PMID: 29534455 PMCID: PMC5874788 DOI: 10.3390/toxics6010015] [Citation(s) in RCA: 172] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/08/2018] [Accepted: 03/09/2018] [Indexed: 12/11/2022]
Abstract
Cadmium (Cd) is a food-chain contaminant that has high rates of soil-to-plant transference. This phenomenon makes dietary Cd intake unavoidable. Although long-term Cd intake impacts many organ systems, the kidney has long been considered to be a critical target of its toxicity. This review addresses how measurements of Cd intake levels and its effects on kidneys have traditionally been made. These measurements underpin the derivation of our current toxicity threshold limit and tolerable intake levels for Cd. The metal transporters that mediate absorption of Cd in the gastrointestinal tract are summarized together with glomerular filtration of Cd and its sequestration by the kidneys. The contribution of age differences, gender, and smoking status to Cd accumulation in lungs, liver, and kidneys are highlighted. The basis for use of urinary Cd excretion to reflect body burden is discussed together with the use of urinary N-acetyl-β-d-glucosaminidase (NAG) and β2-microglobulin (β2-MG) levels to quantify its toxicity. The associations of Cd with the development of chronic kidney disease and hypertension, reduced weight gain, and zinc reabsorption are highlighted. In addition, the review addresses how urinary Cd threshold levels have been derived from human population data and their utility as a warning sign of impending kidney malfunction.
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Affiliation(s)
- Soisungwan Satarug
- Centre for Kidney Disease Research and Translational Research Institute, The University of Queensland Diamantina Institute and Centre for Health Services Research, Woolloongabba, Brisbane 4102, Australia.
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Lee WK, Probst S, Santoyo-Sánchez MP, Al-Hamdani W, Diebels I, von Sivers JK, Kerek E, Prenner EJ, Thévenod F. Initial autophagic protection switches to disruption of autophagic flux by lysosomal instability during cadmium stress accrual in renal NRK-52E cells. Arch Toxicol 2017; 91:3225-3245. [PMID: 28321485 DOI: 10.1007/s00204-017-1942-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 02/23/2017] [Indexed: 02/07/2023]
Abstract
The renal proximal tubule (PT) is the major target of cadmium (Cd2+) toxicity where Cd2+ causes stress and apoptosis. Autophagy is induced by cell stress, e.g., endoplasmic reticulum (ER) stress, and may contribute to cell survival or death. The role of autophagy in Cd2+-induced nephrotoxicity remains unsettled due to contradictory results and lack of evidence for autophagic machinery damage by Cd2+. Cd2+-induced autophagy in rat kidney PT cell line NRK-52E and its role in cell death was investigated. Increased LC3-II and decreased p62 as autophagy markers indicate rapid induction of autophagic flux by Cd2+ (5-10 µM) after 1 h, accompanied by ER stress (increased p-PERK, p-eIF2α, CHOP). Cd2+ exposure exceeding 3 h results in p62/LC3-II accumulation, but diminished effect of lysosomal inhibitors (bafilomycin A1, pepstatin A +E-64d) on p62/LC3-II levels, indicating decreased autophagic flux and cargo degradation. At 24 h exposure, Cd2+ (5-25 µM) activates intrinsic apoptotic pathways (Bax/Bcl-2, PARP-1), which is not evident earlier (≤6 h) although cell viability by MTT assay is decreased. Autophagy inducer rapamycin (100 nM) does not overcome autophagy inhibition or Cd2+-induced cell viability loss. The autophagosome-lysosome fusion inhibitor liensinine (5 μM) increases CHOP and Bax/Bcl-2-dependent apoptosis by low Cd2+ stress, but not by high Cd2+. Lysosomal instability by Cd2+ (5 μM; 6 h) is indicated by increases in cellular sphingomyelin and membrane fluidity and decreases in cathepsins and LAMP1. The data suggest dual and temporal impact of Cd2+ on autophagy: Low Cd2+ stress rapidly activates autophagy counteracting damage but Cd2+ stress accrual disrupts autophagic flux and lysosomal stability, possibly resulting in lysosomal cell death.
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Affiliation(s)
- W-K Lee
- Department of Physiology, Pathophysiology and Toxicology, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany.
| | - S Probst
- Department of Physiology, Pathophysiology and Toxicology, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - M P Santoyo-Sánchez
- Department of Physiology, Pathophysiology and Toxicology, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany
- Department of Toxicology, Cinvestav-IPN, México D.F., Mexico
| | - W Al-Hamdani
- Department of Physiology, Pathophysiology and Toxicology, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - I Diebels
- Department of Physiology, Pathophysiology and Toxicology, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - J-K von Sivers
- Department of Physiology, Pathophysiology and Toxicology, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - E Kerek
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - E J Prenner
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - F Thévenod
- Department of Physiology, Pathophysiology and Toxicology, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany.
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Hashimoto H, Kawabe T, Fukuda T, Kusakabe M. A Novel Ataxic Mutant Mouse Line Having Sensory Neuropathy Shows Heavy Iron Deposition in Kidney. NEURODEGENER DIS 2017; 17:181-198. [DOI: 10.1159/000457126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 01/20/2017] [Indexed: 01/11/2023] Open
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Yu SS, Jiang LR, Ling Y, Qian ZM, Zhou YF, Li J, Ke Y. Nifedipine Increases Iron Content in WKPT-0293 Cl.2 Cells via Up-Regulating Iron Influx Proteins. Front Pharmacol 2017; 8:60. [PMID: 28243203 PMCID: PMC5303744 DOI: 10.3389/fphar.2017.00060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 01/30/2017] [Indexed: 12/25/2022] Open
Abstract
Nifedipine was reported to enhance urinary iron excretion in iron overloaded mice. However, it remains unknown how nifedipine stimulates urinary iron excretion in the kidney. We speculated that nifedipine might inhibit the TfR1/ DMT1 (transferrin receptor 1/divalent metal transporter1)-mediated iron uptake by proximal tubule cells in addition to blocking L-type Ca2+ channels, leading to an increase in iron in lumen-fluid and then urinary iron excretion. To test this hypothesis, we investigated the effects of nifedipine on iron content and expression of TfR1, DMT1 and ferroportin1 (Fpn1) in WKPT-0293 Cl.2 cells of the S1 segment of the proximal tubule in rats, using a graphite furnace atomic absorption spectrophotometer and Western blot analysis, respectively. We demonstrated for the first time that nifedipine significantly enhanced iron content as well as TfR1 and DMT1 expression and had no effect on Fpn1 levels in the cells. We also found that ferric ammonium citrate decreased TfR1 levels, increased Fpn1 expression and had no effect on DMT1 content, while co-treatment with nifedipine and FAC increase TfR1 and DMT1 expression and also had no effect on Fpn1 levels. These findings suggest that the nifedipine-induced increase in cell iron may mainly be due to the corresponding increase in TfR1 and DMT1 expression and also imply that the effects of nifedipine on iron transport in proximal tubule cells can not explain the increase in urinary iron excretion.
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Affiliation(s)
- Shuang-Shuang Yu
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy Pudong, China
| | - Li-Rong Jiang
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy Pudong, China
| | - Yan Ling
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy Pudong, China
| | - Zhong-Ming Qian
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy Pudong, China
| | - Yu-Fu Zhou
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy Pudong, China
| | - Juan Li
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy Pudong, China
| | - Ya Ke
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong Hong Kong, Hong Kong
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Milto IV, Suhodolo IV, Prokopieva VD, Klimenteva TK. Molecular and Cellular Bases of Iron Metabolism in Humans. BIOCHEMISTRY (MOSCOW) 2017; 81:549-64. [PMID: 27301283 DOI: 10.1134/s0006297916060018] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Iron is a microelement with the most completely studied biological functions. Its wide dissemination in nature and involvement in key metabolic pathways determine the great importance of this metal for uni- and multicellular organisms. The biological role of iron is characterized by its indispensability in cell respiration and various biochemical processes providing normal functioning of cells and organs of the human body. Iron also plays an important role in the generation of free radicals, which under different conditions can be useful or damaging to biomolecules and cells. In the literature, there are many reviews devoted to iron metabolism and its regulation in pro- and eukaryotes. Significant progress has been achieved recently in understanding molecular bases of iron metabolism. The purpose of this review is to systematize available data on mechanisms of iron assimilation, distribution, and elimination from the human body, as well as on its biological importance and on the major iron-containing proteins. The review summarizes recent ideas about iron metabolism. Special attention is paid to mechanisms of iron absorption in the small intestine and to interrelationships of cellular and extracellular pools of this metal in the human body.
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Affiliation(s)
- I V Milto
- Siberian State Medical University, Tomsk, 634050, Russia.
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Satarug S, Vesey DA, Gobe GC. Kidney Cadmium Toxicity, Diabetes and High Blood Pressure: The Perfect Storm. TOHOKU J EXP MED 2017; 241:65-87. [DOI: 10.1620/tjem.241.65] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Soisungwan Satarug
- Centre for Kidney Disease Research, Translational Research Institute and The University of Queensland Diamantina Institute
| | - David A. Vesey
- Centre for Kidney Disease Research, Translational Research Institute and The University of Queensland Diamantina Institute
| | - Glenda C. Gobe
- Centre for Kidney Disease Research, Translational Research Institute and The University of Queensland Diamantina Institute
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Hephaestin and ceruloplasmin facilitate iron metabolism in the mouse kidney. Sci Rep 2016; 6:39470. [PMID: 27991585 PMCID: PMC5171654 DOI: 10.1038/srep39470] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 11/21/2016] [Indexed: 12/12/2022] Open
Abstract
Multicopper ferroxidases (MCFs) play an important role in cellular iron homeostasis. However, the role of MCFs in renal metabolism remains unclear. We used Hephaestin (Heph) and Ceruloplasmin (Cp) single or double (Heph/Cp) knockout (KO) mice to study the roles of MCFs in the kidney. Renal iron levels and the expression of iron metabolism genes were examined. The non-heme iron content both in the renal cortex and medulla of Heph/Cp KO mice was significantly increased. Perls' Prussian blue staining showed iron accumulation on the apical side of renal tubular cells in Heph/Cp KO mice. A significant increase in ferritin protein expression was also observed in the renal medulla and cortex of Heph/Cp KO mice. Both DMT1 and TfR1 protein expression were significantly decreased in the renal medulla of Heph/Cp KO mice, while the expression of DMT1 protein was significantly increased in the renal cortex of these animals. Significant increase in proteinuria and total urinary iron was observed in the double knockout mice, and this was associated with compromised structural integrity. These results suggest that KO of both the HEPH and CP genes leads to kidney iron deposition and toxicity, MCFs could protect kidney against a damage from iron excess.
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Thévenod F, Wolff NA. Iron transport in the kidney: implications for physiology and cadmium nephrotoxicity. Metallomics 2016; 8:17-42. [PMID: 26485516 DOI: 10.1039/c5mt00215j] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The kidney has recently emerged as an organ with a significant role in systemic iron (Fe) homeostasis. Substantial amounts of Fe are filtered by the kidney, which have to be reabsorbed to prevent Fe deficiency. Accordingly Fe transporters and receptors for protein-bound Fe are expressed in the nephron that may also function as entry pathways for toxic metals, such as cadmium (Cd), by way of "ionic and molecular mimicry". Similarities, but also differences in handling of Cd by these transport routes offer rationales for the propensity of the kidney to develop Cd toxicity. This critical review provides a comprehensive update on Fe transport by the kidney and its relevance for physiology and Cd nephrotoxicity. Based on quantitative considerations, we have also estimated the in vivo relevance of the described transport pathways for physiology and toxicology. Under physiological conditions all segments of the kidney tubules are likely to utilize Fe for cellular Fe requiring processes for metabolic purposes and also to contribute to reabsorption of free and bound forms of Fe into the circulation. But Cd entering tubule cells disrupts metabolic pathways and is unable to exit. Furthermore, our quantitative analyses contest established models linking chronic Cd nephrotoxicity to proximal tubular uptake of metallothionein-bound Cd. Hence, Fe transport by the kidney may be beneficial by preventing losses from the body. But increased uptake of Fe or Cd that cannot exit tubule cells may lead to kidney injury, and Fe deficiency may facilitate renal Cd uptake.
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Affiliation(s)
- Frank Thévenod
- Institute of Physiology, Pathophysiology & Toxicology, Center for Biomedical Training and Research (ZBAF), University of Witten/Herdecke, Stockumer Str. 12, 58453 Witten, Germany.
| | - Natascha A Wolff
- Institute of Physiology, Pathophysiology & Toxicology, Center for Biomedical Training and Research (ZBAF), University of Witten/Herdecke, Stockumer Str. 12, 58453 Witten, Germany.
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Alvarado-Díaz CP, Núñez MT, Devoto L, González-Ramos R. Endometrial expression and in vitro modulation of the iron transporter divalent metal transporter-1: implications for endometriosis. Fertil Steril 2016; 106:393-401. [PMID: 27117373 DOI: 10.1016/j.fertnstert.2016.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/31/2016] [Accepted: 04/01/2016] [Indexed: 01/13/2023]
Abstract
OBJECTIVE To evaluate divalent metal transporter-1 (DMT1) expression in healthy women's and endometriosis patients' endometrium and to analyze DMT1 and ferritin light chain (Fn-L) expression modulation by iron overload and IL-1β in endometrial stromal cells (ESCs). DESIGN Observational and experimental study. SETTING University hospital research laboratory. PATIENT(S) Thirty-one healthy women and 24 endometriosis patients. INTERVENTION(S) Menstrual, proliferative, and secretory endometrial biopsies. Isolated ESCs from seven endometrial biopsies incubated with IL-1β or FeSO4 overload for 24 hours. MAIN OUTCOME MEASURE(S) Divalent metal transporter-1 endometrial protein expression assessed by immunohistochemistry and Western blot. Divalent metal transporter-1 and Fn-L proteins expression in stimulated ESCs evaluated by Western blot. RESULT(S) Divalent metal transporter-1 is expressed throughout the menstrual cycle in human endometrium. Four endometrial DMT1 variants were identified accordingly to their molecular weight: DMT-80, -65, -55, and -50. Endometrial expression of DMT-80 and -55 is higher in endometriosis patients than in healthy women. In ESCs, iron overload induces an overexpression of DMT-80, DMT-50, and Fn-L, whereas IL-1β increases DMT-80 and -50 expressions and decreases Fn-L expression. CONCLUSION(S) Divalent metal transporter-1 overexpression in endometriosis patients' endometrium can increase iron influx to endometrial cells, inducing oxidative stress-mediated proinflammatory signaling. In turn, endometriosis-related conditions, as iron overload and inflammation (IL-1β), enhance endometriosis patients endometrial DMT1 expression, creating a vicious circle on DMT-1-modulated pathways.
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Affiliation(s)
- Carlos Patricio Alvarado-Díaz
- Instituto de Investigaciones Materno Infantil, Departamento de Obstetricia y Ginecología, Hospital San Borja-Arriarán, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Marco Tulio Núñez
- Instituto de Dinámica Celular y Biotecnología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Luigi Devoto
- Instituto de Investigaciones Materno Infantil, Departamento de Obstetricia y Ginecología, Hospital San Borja-Arriarán, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Reinaldo González-Ramos
- Instituto de Investigaciones Materno Infantil, Departamento de Obstetricia y Ginecología, Hospital San Borja-Arriarán, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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30
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Wolff NA, Garrick LM, Zhao L, Garrick MD, Thévenod F. Mitochondria represent another locale for the divalent metal transporter 1 (DMT1). Channels (Austin) 2015; 8:458-66. [PMID: 25483589 DOI: 10.4161/19336950.2014.956564] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The divalent metal transporter (DMT1) is well known for its roles in duodenal iron absorption across the apical enterocyte membrane, in iron efflux from the endosome during transferrin-dependent cellular iron acquisition, as well as in uptake of non-transferrin bound iron in many cells. Recently, using multiple approaches, we have obtained evidence that the mitochondrial outer membrane is another subcellular locale of DMT1 expression. While iron is of vital importance for mitochondrial energy metabolism, its delivery is likely to be tightly controlled due to iron's damaging redox properties. Here we provide additional support for a role of DMT1 in mitochondrial iron acquisition by immunofluorescence colocalization with mitochondrial markers in cells and isolated mitochondria, as well as flow cytometric quantification of DMT1-positive mitochondria from an inducible expression system. Physiological consequences of mitochondrial DMT1 expression are discussed also in consideration of other DMT1 substrates, such as manganese, relevant to mitochondrial antioxidant defense.
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Key Words
- AIF, apoptosis-inducing factor
- BSA, bovine serum albumin
- CHO, Chinese hamster ovary
- COXII, cytochrome C oxidase subunit II
- DMT1, divalent metal transporter 1
- HEK293, human embryonic kidney cells
- IRE, iron responsive element
- Lamp1, lysosome-associated membrane protein 1
- MRB, Mitochondrial Resuspending Buffer
- OMM, outer mitochondrial membrane
- PBS, phosphate-buffered saline
- Tf, transferrin
- Tom6/Tom20, translocase of the outer mitochondrial membrane 6 kDa subunit homolog/20 kDa subunit, respectively
- VDAC1, voltage-dependent anion-selective channel protein 1
- divalent metal transporter 1 (DMT1)
- flow cytometry
- immunofluorescence microscopy
- iron transport
- mitochondrial outer membrane
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Affiliation(s)
- Natascha A Wolff
- a Institute of Physiology; Pathophysiology & Toxicology ; University of Witten/Herdecke ; Witten , Germany
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Castiglione A, Benatti A, Girasoli L, Caserta E, Montino S, Pagliaro M, Bovo R, Martini A. Cochlear implantation outcomes in older adults. HEARING BALANCE AND COMMUNICATION 2015. [DOI: 10.3109/13625187.2015.1030885] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Sudden sensorineural hearing loss and polymorphisms in iron homeostasis genes: new insights from a case-control study. BIOMED RESEARCH INTERNATIONAL 2015; 2015:834736. [PMID: 25789325 PMCID: PMC4348611 DOI: 10.1155/2015/834736] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 12/15/2014] [Accepted: 01/06/2015] [Indexed: 12/19/2022]
Abstract
Background. Even if various pathophysiological events have been proposed as explanations, the putative cause of sudden hearing loss remains unclear. Objectives. To investigate and to reveal associations (if any) between the main iron-related gene variants and idiopathic sudden sensorineural hearing loss. Study Design. Case-control study. Materials and Methods. A total of 200 sudden sensorineural hearing loss patients (median age 63.65 years; range 10-92) were compared with 400 healthy control subjects. The following genetic variants were investigated: the polymorphism c.-8CG in the promoter of the ferroportin gene (FPN1; SLC40A1), the two isoforms C1 and C2 (p.P570S) of the transferrin protein (TF), the amino acidic substitutions p.H63D and p.C282Y in the hereditary hemochromatosis protein (HFE), and the polymorphism c.-582AG in the promoter of the HEPC gene, which encodes the protein hepcidin (HAMP). Results. The homozygous genotype c.-8GG of the SLC40A1 gene revealed an OR for ISSNHL risk of 4.27 (CI 95%, 2.65-6.89; P = 0.001), being overrepresented among cases. Conclusions. Our study indicates that the homozygous genotype FPN1 -8GG was significantly associated with increased risk of developing sudden hearing loss. These findings suggest new research should be conducted in the field of iron homeostasis in the inner ear.
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Kayaaltı Z, Akyüzlü DK, Söylemezoğlu T. Evaluation of the effect of divalent metal transporter 1 gene polymorphism on blood iron, lead and cadmium levels. ENVIRONMENTAL RESEARCH 2015; 137:8-13. [PMID: 25483413 DOI: 10.1016/j.envres.2014.11.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 10/30/2014] [Accepted: 11/03/2014] [Indexed: 06/04/2023]
Abstract
Divalent metal transporter 1 (DMT1), a member of the proton-coupled metal ion transporter family, mediates transport of ferrous iron from the lumen of the intestine into the enterocyte and export of iron from endocytic vesicles. It has an affinity not only for iron but also for other divalent cations including manganese, cobalt, nickel, cadmium, lead, copper, and zinc. DMT1 is encoded by the SLC11a2 gene that is located on chromosome 12q13 in humans and express four major mammalian isoforms (1A/+IRE, 1A/-IRE, 2/+IRE and 2/-IRE). Mutations or polymorphisms of DMT1 gene may have an impact on human health by disturbing metal trafficking. To study the possible association of DMT1 gene with the blood levels of some divalent cations such as iron, lead and cadmium, a single nucleotide polymorphism (SNP) (IVS4+44C/A) in DMT1 gene was investigated in 486 unrelated and healthy individuals in a Turkish population by method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The genotype frequencies were found as 49.8% homozygote typical (CC), 38.3% heterozygote (CA) and 11.9% homozygote atypical (AA). Metal levels were analyzed by dual atomic absorption spectrometer system and the average levels of iron, lead and cadmium in the blood samples were 446.01 ± 81.87 ppm, 35.59 ± 17.72 ppb and 1.25 ± 0.87 ppb, respectively. Individuals with the CC genotype had higher blood iron, lead and cadmium levels than those with AA and CA genotypes. Highly statistically significant associations were detected between IVS4+44 C/A polymorphism in the DMT1 gene and iron and lead levels (p=0.001 and p=0.036, respectively), but no association was found with cadmium level (p=0.344). This study suggested that DMT1 IVS4+44 C/A polymorphism is associated with inter-individual variations in blood iron, lead and cadmium levels.
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Affiliation(s)
- Zeliha Kayaaltı
- Institute of Forensic Sciences, Ankara University, Dikimevi 06590, Ankara, Turkey.
| | - Dilek Kaya Akyüzlü
- Institute of Forensic Sciences, Ankara University, Dikimevi 06590, Ankara, Turkey
| | - Tülin Söylemezoğlu
- Institute of Forensic Sciences, Ankara University, Dikimevi 06590, Ankara, Turkey
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Haldar S, Tripathi A, Qian J, Beserra A, Suda S, McElwee M, Turner J, Hopfer U, Singh N. Prion protein promotes kidney iron uptake via its ferrireductase activity. J Biol Chem 2015; 290:5512-22. [PMID: 25572394 DOI: 10.1074/jbc.m114.607507] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Brain iron-dyshomeostasis is an important cause of neurotoxicity in prion disorders, a group of neurodegenerative conditions associated with the conversion of prion protein (PrP(C)) from its normal conformation to an aggregated, PrP-scrapie (PrP(Sc)) isoform. Alteration of iron homeostasis is believed to result from impaired function of PrP(C) in neuronal iron uptake via its ferrireductase activity. However, unequivocal evidence supporting the ferrireductase activity of PrP(C) is lacking. Kidney provides a relevant model for this evaluation because PrP(C) is expressed in the kidney, and ∼370 μg of iron are reabsorbed daily from the glomerular filtrate by kidney proximal tubule cells (PT), requiring ferrireductase activity. Here, we report that PrP(C) promotes the uptake of transferrin (Tf) and non-Tf-bound iron (NTBI) by the kidney in vivo and mainly NTBI by PT cells in vitro. Thus, uptake of (59)Fe administered by gastric gavage, intravenously, or intraperitoneally was significantly lower in PrP-knock-out (PrP(-/-)) mouse kidney relative to PrP(+/+) controls. Selective in vivo radiolabeling of plasma NTBI with (59)Fe revealed similar results. Expression of exogenous PrP(C) in immortalized PT cells showed localization on the plasma membrane and intracellular vesicles and increased transepithelial transport of (59)Fe-NTBI and to a smaller extent (59)Fe-Tf from the apical to the basolateral domain. Notably, the ferrireductase-deficient mutant of PrP (PrP(Δ51-89)) lacked this activity. Furthermore, excess NTBI and hemin caused aggregation of PrP(C) to a detergent-insoluble form, limiting iron uptake. Together, these observations suggest that PrP(C) promotes retrieval of iron from the glomerular filtrate via its ferrireductase activity and modulates kidney iron metabolism.
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Affiliation(s)
| | | | - Juan Qian
- From the Departments of Pathology and
| | | | | | | | - Jerrold Turner
- the Department of Pathology, University of Chicago, Chicago, Illinois 60637
| | - Ulrich Hopfer
- Physiology and Biophysics, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio 44106 and
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Gastrointestinal absorption of uranium compounds--a review. Regul Toxicol Pharmacol 2014; 71:125-33. [PMID: 25263405 DOI: 10.1016/j.yrtph.2014.08.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/14/2014] [Accepted: 08/21/2014] [Indexed: 01/18/2023]
Abstract
Uranium occurs naturally in soil and rocks, and therefore where it is present in water-soluble form it also occurs naturally in groundwater as well as in drinking water obtained from groundwater. Animal studies suggest that the toxicity of uranium is mainly due to its damage to kidney tubular cells following exposure to soluble uranium compounds. The assessments of the absorption of uranium via the gastrointestinal tract vary, and this has consequences for regulation, in particular the derivation of e.g. drinking water limit values. Absorption rates vary according to the nature and solubility of the compound in which uranium is presented to the test animals and depending on the animal species used in the test. No differences for sex have been observed for absorption in either animals or humans. However, human biomonitoring data do show that boys excrete significantly more uranium than girls. In animal studies neonates took up more uranium than adults or older children. Nutritional status, and in particular the iron content of the diet, have a marked influence on absorption, and higher uranium levels in food intake also appear to increase the absorption rate. If the pointers to an absorption mechanism competing with iron are correct, these mechanisms could also explain the relatively high concentration and chemical toxicity of uranium in the kidneys. It is here (and in the duodenum) that divalent metal transporter 1 (DMT1), which is primarily responsible for the passage of iron (or uranium?) through the cell membranes, is most strongly expressed.
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Abstract
Iron is essential for the normal physiological function of all organisms. In humans it is required for a plethora of biochemical roles including the transport of oxygen in the blood and energy production in the mitochondria. However, iron is also highly cytotoxic when present at high levels as it readily participates in oxidation-reduction reactions that lead to the generation of reactive oxygen species. One unique feature of iron biology is the lack of excretory mechanisms to remove excess iron from the body. Therefore, the concerted action of several genes and proteins working together to regulate the movement of iron across cell membranes, its storage in peripheral tissues and its physiological utilization in the body is essential for maintaining iron homeostasis. Humans are exposed to iron in a number of chemical forms (haem or non-haem; ferric or ferrous). This chapter will describe how humans acquire iron from their diet; the subsequent delivery of iron to its sites of utilization and storage; and how iron is recycled from effete erythrocytes for re-use in metabolism. Mutations in a number of the genes controlling iron metabolism have been identified and study of the pathological consequences of these mutations has allowed us to gain a greater understanding of how the body senses changes in iron status and coordinates its transport, storage and utilization to maintain homeostasis.
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Affiliation(s)
- Paul Sharp
- Diabetes & Nutritional Sciences Division, King's College London, School of Medicine Franklin Wilkins Building, 150 Stamford Street London SE1 9NH UK
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Wolff NA, Ghio AJ, Garrick LM, Garrick MD, Zhao L, Fenton RA, Thévenod F. Evidence for mitochondrial localization of divalent metal transporter 1 (DMT1). FASEB J 2014; 28:2134-45. [PMID: 24448823 DOI: 10.1096/fj.13-240564] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In mammalian cells, mitochondria receive most incoming iron, yet no entry pathway for iron at the outer mitochondrial membrane (OMM) has been characterized. Our results show that the divalent metal transporter 1 (DMT1) occurs in the OMM. Immunoblots detected DMT1 in mitochondria from a pneumocyte cell model in their OMM. Using the split-ubiquitin yeast 2-hybrid system, we found that cytochrome c oxidase subunit II (COXII) and the translocase of OMM 6-kDa subunit (Tom6) homologue interact with DMT1. COXII coimmunoprecipitates with DMT1. There are 4 DMT1 isoforms that differ at the N and C termini. Using HEK293 cells that inducibly express all of the 4 ends of DMT1, we found all of them in the OMM, as detected by immunoblots after cell fractionation, and in isolated mitochondria, as detected by immunofluorescence. Immunoblot analysis of purified cell fractions from rat renal cortex confirmed and extended these results to the kidney, which expressed high levels of DMT1. Immunogold labeling detected DMT1 colocalization in mitochondria with the voltage-dependent anion-selective channel protein-1, which is expressed in the OMM. We suggest that DMT1 not only exports iron from endosomes, but also serves to import the metal into the mitochondria.
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Affiliation(s)
- Natascha A Wolff
- 1Department of Physiology and Pathophysiology and ZBAF, University of Witten/Herdecke, Stockumer Strasse 12, D-58453 Witten, Germany. F.T.,
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Pereira DIA, Mergler BI, Faria N, Bruggraber SFA, Aslam MF, Poots LK, Prassmayer L, Lönnerdal B, Brown AP, Powell JJ. Caco-2 cell acquisition of dietary iron(III) invokes a nanoparticulate endocytic pathway. PLoS One 2013; 8:e81250. [PMID: 24278403 PMCID: PMC3836913 DOI: 10.1371/journal.pone.0081250] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/10/2013] [Indexed: 12/19/2022] Open
Abstract
Dietary non-heme iron contains ferrous [Fe(II)] and ferric [Fe(III)] iron fractions and the latter should hydrolyze, forming Fe(III) oxo-hydroxide particles, on passing from the acidic stomach to less acidic duodenum. Using conditions to mimic the in vivo hydrolytic environment we confirmed the formation of nanodisperse fine ferrihydrite-like particles. Synthetic analogues of these (~ 10 nm hydrodynamic diameter) were readily adherent to the cell membrane of differentiated Caco-2 cells and internalization was visualized using transmission electron microscopy. Moreover, Caco-2 exposure to these nanoparticles led to ferritin formation (i.e., iron utilization) by the cells, which, unlike for soluble forms of iron, was reduced (p=0.02) by inhibition of clathrin-mediated endocytosis. Simulated lysosomal digestion indicated that the nanoparticles are readily dissolved under mildly acidic conditions with the lysosomal ligand, citrate. This was confirmed in cell culture as monensin inhibited Caco-2 utilization of iron from this source in a dose dependent fashion (p<0.05) whilet soluble iron was again unaffected. Our findings reveal the possibility of an endocytic pathway for acquisition of dietary Fe(III) by the small intestinal epithelium, which would complement the established DMT-1 pathway for soluble Fe(II).
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Affiliation(s)
- Dora I. A. Pereira
- Medical Research Council Human Nutrition Research (MRC HNR), Elsie Widdowson Laboratory, Cambridge, United Kingdom
| | - Bianca I. Mergler
- Medical Research Council Human Nutrition Research (MRC HNR), Elsie Widdowson Laboratory, Cambridge, United Kingdom
| | - Nuno Faria
- Medical Research Council Human Nutrition Research (MRC HNR), Elsie Widdowson Laboratory, Cambridge, United Kingdom
| | - Sylvaine F. A. Bruggraber
- Medical Research Council Human Nutrition Research (MRC HNR), Elsie Widdowson Laboratory, Cambridge, United Kingdom
| | - Mohamad F. Aslam
- Medical Research Council Human Nutrition Research (MRC HNR), Elsie Widdowson Laboratory, Cambridge, United Kingdom
| | - Lynsey K. Poots
- Medical Research Council Human Nutrition Research (MRC HNR), Elsie Widdowson Laboratory, Cambridge, United Kingdom
| | - Laura Prassmayer
- Medical Research Council Human Nutrition Research (MRC HNR), Elsie Widdowson Laboratory, Cambridge, United Kingdom
| | - Bo Lönnerdal
- Department of Nutrition, University of California Davis, Davis, California, United States of America
| | - Andy P. Brown
- Institute for Materials Research, School of Process, Environmental and Materials Engineering, University of Leeds, Leeds, United Kingdom
| | - Jonathan J. Powell
- Medical Research Council Human Nutrition Research (MRC HNR), Elsie Widdowson Laboratory, Cambridge, United Kingdom
- * E-mail:
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Veuthey T, Hoffmann D, Vaidya VS, Wessling-Resnick M. Impaired renal function and development in Belgrade rats. Am J Physiol Renal Physiol 2013; 306:F333-43. [PMID: 24226520 DOI: 10.1152/ajprenal.00285.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Belgrade rats carry a disabling mutation in the iron transporter divalent metal transporter 1 (DMT1). Although DMT1 plays a major role in intestinal iron absorption, the transporter is also highly expressed in the kidney, where its function remains unknown. The goal of this study was to characterize renal physiology of Belgrade rats. Male Belgrade rats died prematurely with ∼50% survival at 20 wk of age. Necropsy results indicated marked glomerular nephritis and chronic end-stage renal disease. By 15 wk of age, Belgrade rats displayed altered renal morphology associated with sclerosis and fibrosis. Creatinine clearance was significantly lower compared with heterozygote littermates. Urinary biomarkers of kidney injury, including albumin, fibrinogen, and kidney injury molecule-1, were significantly elevated. Pilot morphological studies suggest that nephrogenesis is delayed in Belgrade rat pups due to their low iron status and fetal growth restriction. Such defects in renal development most likely underlie the compromised renal metabolism observed in adult b/b rats. Belgrade rat kidney nonheme iron levels were not different from controls but urinary iron and transferrin levels were higher. These results further implicate an important role for the transporter in kidney function not only in iron reabsorption but also in glomerular filtration of the serum protein.
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Affiliation(s)
- Tania Veuthey
- Dept. of Genetics & Complex Diseases, Harvard School of Public Health, 665 Huntington Ave., Boston, MA 02115.
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Zarjou A, Bolisetty S, Joseph R, Traylor A, Apostolov EO, Arosio P, Balla J, Verlander J, Darshan D, Kuhn LC, Agarwal A. Proximal tubule H-ferritin mediates iron trafficking in acute kidney injury. J Clin Invest 2013; 123:4423-34. [PMID: 24018561 DOI: 10.1172/jci67867] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 07/18/2013] [Indexed: 12/30/2022] Open
Abstract
Ferritin plays a central role in iron metabolism and is made of 24 subunits of 2 types: heavy chain and light chain. The ferritin heavy chain (FtH) has ferroxidase activity that is required for iron incorporation and limiting toxicity. The purpose of this study was to investigate the role of FtH in acute kidney injury (AKI) and renal iron handling by using proximal tubule-specific FtH-knockout mice (FtH(PT-/-) mice). FtH(PT-/-) mice had significant mortality, worse structural and functional renal injury, and increased levels of apoptosis in rhabdomyolysis and cisplatin-induced AKI, despite significantly higher expression of heme oxygenase-1, an antioxidant and cytoprotective enzyme. While expression of divalent metal transporter-1 was unaffected, expression of ferroportin (FPN) was significantly lower under both basal and rhabdomyolysis-induced AKI in FtH(PT-/-) mice. Apical localization of FPN was disrupted after AKI to a diffuse cytosolic and basolateral pattern. FtH, regardless of iron content and ferroxidase activity, induced FPN. Interestingly, urinary levels of the iron acceptor proteins neutrophil gelatinase-associated lipocalin, hemopexin, and transferrin were increased in FtH(PT-/-) mice after AKI. These results underscore the protective role of FtH and reveal the critical role of proximal tubule FtH in iron trafficking in AKI.
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Langelueddecke C, Roussa E, Fenton RA, Thévenod F. Expression and function of the lipocalin-2 (24p3/NGAL) receptor in rodent and human intestinal epithelia. PLoS One 2013; 8:e71586. [PMID: 23940770 PMCID: PMC3734285 DOI: 10.1371/journal.pone.0071586] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 07/08/2013] [Indexed: 02/06/2023] Open
Abstract
The lipocalin 2//NGAL/24p3 receptor (NGAL-R/24p3-R) is expressed in rodent distal nephron where it mediates protein endocytosis. The mechanisms of apical endocytosis and transcytosis of proteins and peptides in the intestine are poorly understood. In the present study, the expression and localization of rodent 24p3-R (r24p3-R) and human NGAL-R (hNGAL-R) was investigated in intestinal segments by immunofluorescence and confocal laser scanning microscopy, immunohistochemistry and immunoblotting. r24p3-R/hNGAL-R was also studied in human Caco-2 BBE cells and CHO cells transiently transfected with r24p3-R by immunofluorescence microscopy, RT-PCR and immunoblotting of plasma membrane enriched vesicles (PM). To assay function, endocytosis/transcytosis of putative ligands phytochelatin (PC3), metallothionein (MT) and transferrin (Tf) was assayed by measuring internalization of fluorescence-labelled ligands in Caco-2 BBE cells grown on plastic or as monolayers on Transwell inserts. The binding affinity of Alexa 488-PC3 to colon-like Caco-2 BBE PM was quantified by microscale thermophoresis (MST). r24p3-R/hNGAL-R expression was detected apically in all intestinal segments but showed the highest expression in ileum and colon. Colon-like, but not duodenum-like, Caco-2 BBE cells expressed hNGAL-R on their surface. Colon-like Caco-2 BBE cells or r24p3-R transfected CHO cells internalized fluorescence-labelled PC3 or MT with half-maximal saturation at submicromolar concentrations. Uptake of PC3 and MT (0.7 µM) by Caco-2 BBE cells was partially blocked by hNGAL (500 pM) and an EC50 of 18.6 ± 12.2 nM was determined for binding of Alexa 488-PC3 to PM vesicles by MST. Transwell experiments showed rapid (0.5-2 h) apical uptake and basolateral delivery of fluorescent PC3/MT/Tf (0.7 µM). Apical uptake of ligands was significantly blocked by 500 pM hNGAL. hNGAL-R dependent uptake was more prominent with MT but transcytosis efficiency was reduced compared to PC3 and Tf. Hence, r24p3-R/hNGAL-R may represent a high-affinity multi-ligand receptor for apical internalization and transcytosis of intact proteins/peptides by the lower intestine.
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Affiliation(s)
- Christian Langelueddecke
- Institute of Physiology & Pathophysiology, ZBAF, University of Witten, Herdecke, Witten, Germany
| | - Eleni Roussa
- Anatomy and Cell Biology II, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Robert A. Fenton
- Department of Biomedicine and InterPrET Center, Aarhus University, Aarhus C, Denmark
| | - Frank Thévenod
- Institute of Physiology & Pathophysiology, ZBAF, University of Witten, Herdecke, Witten, Germany
- * E-mail:
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Effect of iron restriction on renal damage and mineralocorticoid receptor signaling in a rat model of chronic kidney disease. J Hypertens 2013; 30:2192-201. [PMID: 22922699 DOI: 10.1097/hjh.0b013e3283581a64] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Iron is associated with the pathogenesis of chronic kidney disease (CKD). Activation of mineralocorticoid receptor signaling is implicated in CKD; however, a link between iron and mineralocorticoid receptor signaling in CKD remains unknown. We have previously shown that long-term dietary iron restriction leads to increased sodium and decreased potassium excretions in the rat urine. Herein, we investigated the effect of iron restriction on renal damage and mineralocorticoid receptor signaling in a rat model of CKD. METHODS CKD was induced by 5/6 nephrectomy in Sprague-Dawley rats. CKD rats were divided into untreated and dietary iron-restricted groups. RESULTS CKD rats exhibited proteinuria, glomerulosclerosis, tubulointerstitinal damage, and podocyte injury. In contrast, these changes were attenuated by 16 weeks of iron-restricted diet. Consistent with these findings, iron restriction suppressed increased gene expression of collagen type III, transforming growth factor-β, CD68, and tumor necrosis factor-α in the CKD kidney. Importantly, increased expression of nuclear mineralocorticoid receptor and SGK1, a key downstream effector of mineralocorticoid receptor signaling, in the CKD kidney was markedly attenuated by iron restriction. Of interest, expression of cellular iron transport proteins, transferrin receptor 1, and divalent metal transporter 1 was increased in the CKD renal tubules, along with increased iron accumulation, superoxide production, and urinary iron excretion. CKD rats also developed hypertension, although iron restriction suppressed the development of hypertension. CONCLUSION Taken together, these data uncover a novel effect of iron restriction on renal damage and hypertension through the inhibition of renal mineralocorticoid receptor signaling.
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Lee WK, Chakraborty PK, Roussa E, Wolff NA, Thévenod F. ERK1/2-dependent bestrophin-3 expression prevents ER-stress-induced cell death in renal epithelial cells by reducing CHOP. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1864-76. [DOI: 10.1016/j.bbamcr.2012.06.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 06/04/2012] [Accepted: 06/05/2012] [Indexed: 01/14/2023]
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Illing AC, Shawki A, Cunningham CL, Mackenzie B. Substrate profile and metal-ion selectivity of human divalent metal-ion transporter-1. J Biol Chem 2012; 287:30485-96. [PMID: 22736759 PMCID: PMC3436370 DOI: 10.1074/jbc.m112.364208] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 06/18/2012] [Indexed: 12/13/2022] Open
Abstract
Divalent metal-ion transporter-1 (DMT1) is a H(+)-coupled metal-ion transporter that plays essential roles in iron homeostasis. DMT1 exhibits reactivity (based on evoked currents) with a broad range of metal ions; however, direct measurement of transport is lacking for many of its potential substrates. We performed a comprehensive substrate-profile analysis for human DMT1 expressed in RNA-injected Xenopus oocytes by using radiotracer assays and the continuous measurement of transport by fluorescence with the metal-sensitive PhenGreen SK fluorophore. We provide validation for the use of PhenGreen SK fluorescence quenching as a reporter of cellular metal-ion uptake. We determined metal-ion selectivity under fixed conditions using the voltage clamp. Radiotracer and continuous measurement of transport by fluorescence assays revealed that DMT1 mediates the transport of several metal ions that were ranked in selectivity by using the ratio I(max)/K(0.5) (determined from evoked currents at -70 mV): Cd(2+) > Fe(2+) > Co(2+), Mn(2+) ≫ Zn(2+), Ni(2+), VO(2+). DMT1 expression did not stimulate the transport of Cr(2+), Cr(3+), Cu(+), Cu(2+), Fe(3+), Ga(3+), Hg(2+), or VO(+). (55)Fe(2+) transport was competitively inhibited by Co(2+) and Mn(2+). Zn(2+) only weakly inhibited (55)Fe(2+) transport. Our data reveal that DMT1 selects Fe(2+) over its other physiological substrates and provides a basis for predicting the contribution of DMT1 to intestinal, nasal, and pulmonary absorption of metal ions and their cellular uptake in other tissues. Whereas DMT1 is a likely route of entry for the toxic heavy metal cadmium, and may serve the metabolism of cobalt, manganese, and vanadium, we predict that DMT1 should contribute little if at all to the absorption or uptake of zinc. The conclusion in previous reports that copper is a substrate of DMT1 is not supported.
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Affiliation(s)
| | - Ali Shawki
- From the Department of Molecular and Cellular Physiology and
- the Systems Biology and Physiology Program, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | | | - Bryan Mackenzie
- From the Department of Molecular and Cellular Physiology and
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Fujishiro H, Yano Y, Takada Y, Tanihara M, Himeno S. Roles of ZIP8, ZIP14, and DMT1 in transport of cadmium and manganese in mouse kidney proximal tubule cells. Metallomics 2012; 4:700-8. [PMID: 22534978 DOI: 10.1039/c2mt20024d] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Chronic exposure to cadmium causes preferential accumulation of cadmium in the kidney, leading to nephrotoxicity. In the process of renal cadmium accumulation, the cadmium bound to a low-molecular-weight metal-binding protein, metallothionein, has been considered to play an important role in reabsorption by epithelial cells of proximal tubules in the kidney. However, the role and mechanism of the transport of Cd(2+) ions in proximal tubule cells remain unclear. Zinc transporters such as Zrt, Irt-related protein 8 (ZIP8) and ZIP14, and divalent metal transporter 1 (DMT1) have been reported to have affinities for Cd(2+) and Mn(2+). To examine the roles of these metal transporters in the absorption of luminal Cd(2+) and Mn(2+) into proximal tubule cells, we utilized a cell culture system, in which apical and basolateral transport of metals can be separately examined. The uptake of Cd(2+) and Mn(2+) from the apical side of proximal tubule cells was inhibited by simultaneous addition of Mn(2+) and Cd(2+), respectively. The knockdown of ZIP8, ZIP14 or DMT1 by siRNA transfection significantly reduced the uptake of Cd(2+) and Mn(2+) from the apical membrane. The excretion of Cd(2+) and Mn(2+) was detected predominantly in the apical side of the proximal tubule cells. In situ hybridization of these transporters revealed that ZIP8 and ZIP14 are highly expressed in the proximal tubules of the outer stripe of the outer medulla. These results suggest that ZIP8 and ZIP14 expressed in the S3 segment of proximal tubules play significant roles in the absorption of Cd(2+) and Mn(2+) in the kidney.
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Affiliation(s)
- Hitomi Fujishiro
- Laboratory of Molecular Nutrition and Toxicology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima 770-8514, Japan
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Shawki A, Knight PB, Maliken BD, Niespodzany EJ, Mackenzie B. H(+)-coupled divalent metal-ion transporter-1: functional properties, physiological roles and therapeutics. CURRENT TOPICS IN MEMBRANES 2012. [PMID: 23177986 DOI: 10.1016/b978-0-12-394316-3.00005-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Divalent metal-ion transporter-1 (DMT1) is a widely expressed, iron-preferring membrane transport protein. Animal models establish that DMT1 plays indispensable roles in intestinal nonheme-iron absorption and iron acquisition by erythroid precursor cells. Rare mutations in human DMT1 result in severe microcytic-hypochromic anemia. When we express DMT1 in RNA-injected Xenopus oocytes, we observe rheogenic Fe(2+) transport that is driven by the proton electrochemical potential gradient. In that same preparation, DMT1 also transports cadmium and manganese but not copper. Whether manganese metabolism relies upon DMT1 remains unclear but DMT1 contributes to the effects of overexposure to cadmium and manganese in some tissues. There exist at least four DMT1 isoforms that arise from variant transcription of the SLC11A2 gene. Whereas these isoforms display identical functional properties, N- and C-terminal variations contain cues that direct the cell-specific targeting of DMT1 isoforms to discrete subcellular compartments (plasma membrane, endosomes, and lysosomes). An iron-responsive element (IRE) in the mRNA 3'-untranslated region permits the regulation of some isoforms by iron status, and additional mechanisms by which DMT1 is regulated are emerging. Natural-resistance-associated macrophage protein-1 (NRAMP1)-the only other member of the mammalian SLC11 gene family-contributes to antimicrobial function by extruding from the phagolysosome divalent metal ions (e.g. Mn(2+)) that may be essential cofactors for bacteria-derived enzymes or required for bacterial growth. The principal or only intestinal nonheme-iron transporter, DMT1 is a validated therapeutic target in hereditary hemochromatosis (HHC) and other iron-overload disorders.
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Affiliation(s)
- Ali Shawki
- Department of Molecular & Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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Langelueddecke C, Roussa E, Fenton RA, Wolff NA, Lee WK, Thévenod F. Lipocalin-2 (24p3/neutrophil gelatinase-associated lipocalin (NGAL)) receptor is expressed in distal nephron and mediates protein endocytosis. J Biol Chem 2011; 287:159-169. [PMID: 22084236 DOI: 10.1074/jbc.m111.308296] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In the kidney, bulk reabsorption of filtered proteins occurs in the proximal tubule via receptor-mediated endocytosis (RME) through the multiligand receptor complex megalin-cubilin. Other mechanisms and nephron sites for RME of proteins are unclear. Recently, the secreted protein 24p3 (lipocalin-2, neutrophil gelatinase-associated lipocalin (NGAL)), which is expressed in the distal nephron, has been identified as a sensitive biomarker of kidney damage. A high-affinity receptor for 24p3 (24p3R) that is involved in endocytotic iron delivery has also been cloned. We investigated the localization of 24p3R in rodent kidney and its role in RME of protein-metal complexes and albumin. Immunostaining of kidney tissue showed expression of 24p3R in apical membranes of distal tubules and collecting ducts, but not of proximal tubule. The differential expression of 24p3R in these nephron segments was confirmed in the respective cell lines. CHO cells transiently transfected with 24p3R or distal tubule cells internalized submicromolar concentrations of fluorescence-coupled proteins transferrin, albumin, or metallothionein (MT) as well as the toxic cadmium-MT (Cd2+(7)-MT) complex, which caused cell death. Uptake of MT or transferrin and Cd2+(7)-MT toxicity were prevented by picomolar concentrations of 24p3. An EC50 of 123±50 nM was determined for binding of MT to 24p3R by microscale thermophoresis. Hence, 24p3R binds proteins filtered by the kidney with high affinity and may contribute to RME of proteins, including 24p3, and to Cd2+(7)-MT toxicity in distal nephron segments.
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Affiliation(s)
- Christian Langelueddecke
- Institute of Physiology and Pathophysiology, Centre for Biomedical Training and Research (ZBAF), University of Witten/Herdecke, 58453 Witten, Germany
| | - Eleni Roussa
- Institute of Anatomy and Cell Biology II, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Natascha A Wolff
- Institute of Physiology and Pathophysiology, Centre for Biomedical Training and Research (ZBAF), University of Witten/Herdecke, 58453 Witten, Germany
| | - Wing-Kee Lee
- Institute of Physiology and Pathophysiology, Centre for Biomedical Training and Research (ZBAF), University of Witten/Herdecke, 58453 Witten, Germany
| | - Frank Thévenod
- Institute of Physiology and Pathophysiology, Centre for Biomedical Training and Research (ZBAF), University of Witten/Herdecke, 58453 Witten, Germany.
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Wolff NA, Lee WK, Thévenod F. Role of Arf1 in endosomal trafficking of protein-metal complexes and cadmium-metallothionein-1 toxicity in kidney proximal tubule cells. Toxicol Lett 2011; 203:210-8. [PMID: 21421027 DOI: 10.1016/j.toxlet.2011.03.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2010] [Revised: 03/06/2011] [Accepted: 03/07/2011] [Indexed: 11/26/2022]
Abstract
Cadmium (Cd) is nephrotoxic. Circulating Cd-metallothionein complexes (CdMT) are filtered by the kidney, reabsorbed by proximal tubule cells (PTC) via receptor-mediated endocytosis, and trafficked to lysosomes which results in apoptosis. ADP-ribosylation factors (Arfs) regulate vesicular trafficking. Arf1 is traditionally associated with the secretory pathway, but has been recently found involved in endocytotic trafficking in PTC. Hence, the role of Arf1 was investigated in MT-1 and transferrin (Tf) endocytosis, and in CdMT-1-induced cell death in a PTC line by overexpressing Arf1-wildtype (WT) or dominant-negative mutant Arf1-T31N. Endogenous Arf1 distribution in PTC was punctate throughout the cytosol, but was not detected in the plasma membrane. Arf1 colocalized with markers for sorting to late endosomes (Rab7, CLC6). Arf1 weakly overlapped with the late endosomal/lysosomal marker CLC7, but not with markers for early (Rab5, CLC5) and recycling endosomes (Rab11). Arf1-T31N significantly attenuated CdMT-1 toxicity by ∼60% when compared to Arf1-WT. However, overexpression of Arf1-T31N did not prevent internalization of Alexa Fluor 546-coupled Tf or MT-1 which accumulated in an EEA1-positive early endocytotic compartment, but not in Arf1-WT overexpressing cells. We conclude that Arf1 is involved in trafficking of protein-metal complexes, including CdMT, to late endosomes/lysosomes in renal PTC.
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Affiliation(s)
- Natascha A Wolff
- Institute of Physiology & Pathophysiology, University of Witten/Herdecke, Stockumer Strasse 12, D-58453 Witten, Germany
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