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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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