1
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Kunke M, Knöfler H, Dahlke E, Zanon Rodriguez L, Böttner M, Larionov A, Saudenova M, Ohrenschall GM, Westermann M, Porubsky S, Bernardes JP, Häsler R, Magnin JL, Koepsell H, Jouret F, Theilig F. Targeted deletion of von-Hippel-Lindau in the proximal tubule conditions the kidney against early diabetic kidney disease. Cell Death Dis 2023; 14:562. [PMID: 37626062 PMCID: PMC10457389 DOI: 10.1038/s41419-023-06074-7] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 08/01/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023]
Abstract
Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease. Glomerular hyperfiltration and albuminuria subject the proximal tubule (PT) to a subsequent elevation of workload, growth, and hypoxia. Hypoxia plays an ambiguous role in the development and progression of DKD and shall be clarified in our study. PT-von-Hippel-Lindau (Vhl)-deleted mouse model in combination with streptozotocin (STZ)-induced type I diabetes mellitus (DM) was phenotyped. In contrary to PT-Vhl-deleted STZ-induced type 1 DM mice, proteinuria and glomerular hyperfiltration occurred in diabetic control mice the latter due to higher nitric oxide synthase 1 and sodium and glucose transporter expression. PT Vhl deletion and DKD share common alterations in gene expression profiles, including glomerular and tubular morphology, and tubular transport and metabolism. Compared to diabetic control mice, the most significantly altered in PT Vhl-deleted STZ-induced type 1 DM mice were Ldc-1, regulating cellular oxygen consumption rate, and Zbtb16, inhibiting autophagy. Alignment of altered genes in heat maps uncovered that Vhl deletion prior to STZ-induced DM preconditioned the kidney against DKD. HIF-1α stabilization leading to histone modification and chromatin remodeling resets most genes altered upon DKD towards the control level. These data demonstrate that PT HIF-1α stabilization is a hallmark of early DKD and that targeting hypoxia prior to the onset of type 1 DM normalizes renal cell homeostasis and prevents DKD development.
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Affiliation(s)
- Madlen Kunke
- Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
| | - Hannah Knöfler
- Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
| | - Eileen Dahlke
- Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
| | | | - Martina Böttner
- Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
| | - Alexey Larionov
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | | | | | | | | | - Joana P Bernardes
- Department of Dermatology and Allergy, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Robert Häsler
- Department of Dermatology and Allergy, University Hospital Schleswig-Holstein, Kiel, Germany
| | | | - Hermann Koepsell
- Institute of Anatomy and Cell Biology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - François Jouret
- Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA), Cardiovascular Sciences, University of Liège (ULiège), Liège, Belgium
- Division of Nephrology, CHU of Liège, University of Liège (CHU ULiège), Liège, Belgium
| | - Franziska Theilig
- Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany.
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland.
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2
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Hugendieck G, Lettau M, Andreas S, Neumann S, Reinhardt N, Arnold P, Theilig F, Bastian L, Rogmans C, Weimer JP, Flörkemeier I, Wesch D, Arnold N, Maass N, Janssen O, Bauerschlag D, Hedemann N. Chemotherapy-induced release of ADAM17 bearing EV as a potential resistance mechanism in ovarian cancer. J Extracell Vesicles 2023; 12:e12338. [PMID: 37408115 PMCID: PMC10323107 DOI: 10.1002/jev2.12338] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 06/11/2023] [Indexed: 07/07/2023] Open
Abstract
Ovarian cancer (OvCa) is the gynaecological disorder with the poorest prognosis due to the fast development of chemoresistance. We sought to connect chemoresistance and cancer cell-derived extracellular vesicles (EV). The mechanisms of how chemoresistance is sustained by EV remained elusive. One potentially contributing factor is A Disintegrin and Metalloprotease 17 (ADAM17)-itself being able to promote chemoresistance and inducing tumour cell proliferation and survival via the Epidermal Growth Factor Receptor (EGFR) pathway by shedding several of its ligands including Amphiregulin (AREG). We now demonstrate that upon chemotherapeutic treatment, proteolytically active ADAM17 is released in association with EV from OvCa cells. In terms of function, we show that patient-derived EV induce AREG shedding and restore chemoresistance in ADAM17-deficient cells. Confirming that ADAM17-containing EV transmit chemoresistance in OvCa, we propose that ADAM17 levels (also on EV) might serve as an indicator for tumour progression and the chemosensitivity status of a given patient.
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Affiliation(s)
- Gerrit Hugendieck
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Marcus Lettau
- Institute of Immunology, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
- Department of Hematology, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Svenja Andreas
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Sabrina Neumann
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Natalie Reinhardt
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Philipp Arnold
- Institute of Functional and Clinical Anatomy, Friedrich-Alexander-Universität, Erlangen, Germany
| | - Franziska Theilig
- Institute of Anatomy, Department of Medicine, Christian-Albrechts-University, Kiel, Germany
| | - Lorenz Bastian
- Department of Medicine II, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Christoph Rogmans
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Jörg P Weimer
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Inken Flörkemeier
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Daniela Wesch
- Institute of Immunology, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Norbert Arnold
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Nicolai Maass
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Ottmar Janssen
- Institute of Immunology, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Dirk Bauerschlag
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Nina Hedemann
- Department of Gynaecology and Obstetrics, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
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3
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Bülck C, Nyström EE, Koudelka T, Mannbar-Frahm M, Andresen G, Radhouani M, Tran F, Scharfenberg F, Schrell F, Armbrust F, Dahlke E, Zhao B, Vervaeke A, Theilig F, Rosenstiel P, Starkl P, Rosshart SP, Fickenscher H, Tholey A, Hansson GC, Becker-Pauly C. Proteolytic processing of galectin-3 by meprin metalloproteases is crucial for host-microbiome homeostasis. Sci Adv 2023; 9:eadf4055. [PMID: 37000885 PMCID: PMC10065446 DOI: 10.1126/sciadv.adf4055] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 03/02/2023] [Indexed: 06/19/2023]
Abstract
The metalloproteases meprin α and meprin β are highly expressed in the healthy gut but significantly decreased in inflammatory bowel disease, implicating a protective role in mucosal homeostasis. In the colon, meprin α and meprin β form covalently linked heterodimers tethering meprin α to the plasma membrane, therefore presenting dual proteolytic activity in a unique enzyme complex. To unravel its function, we applied N-terminomics and identified galectin-3 as the major intestinal substrate for meprin α/β heterodimers. Galectin-3-deficient and meprin α/β double knockout mice show similar alterations in their microbiome in comparison to wild-type mice. We further demonstrate that meprin α/β heterodimers differentially process galectin-3 upon bacterial infection, in germ-free, conventionally housed (specific pathogen-free), or wildling mice, which in turn regulates the bacterial agglutination properties of galectin-3. Thus, the constitutive cleavage of galectin-3 by meprin α/β heterodimers may play a key role in colon host-microbiome homeostasis.
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Affiliation(s)
- Cynthia Bülck
- Institute of Biochemistry, University of Kiel, 24118 Kiel, Germany
| | | | - Tomas Koudelka
- Institute of Experimental Medicine, University of Kiel, 24188 Kiel, Germany
| | - Michael Mannbar-Frahm
- Institute of Infection Medicine, University of Kiel and University Medical Center Schleswig-Holstein, 24015 Kiel, Germany
| | - Gerrit Andresen
- Institute of Infection Medicine, University of Kiel and University Medical Center Schleswig-Holstein, 24015 Kiel, Germany
| | - Mariem Radhouani
- Division of Infection Biology, Department of Medicine I, Medical University of Vienna, 1090 Vienna, Austria
| | - Florian Tran
- Institute of Clinical Molecular Biology, Kiel University and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| | | | | | - Fred Armbrust
- Institute of Biochemistry, University of Kiel, 24118 Kiel, Germany
| | - Eileen Dahlke
- Institute of Anatomy, University of Kiel, 24118 Kiel, Germany
| | - Bei Zhao
- Department of Microbiome Research, Friedrich-Alexander-University Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Alex Vervaeke
- Division of Infection Biology, Department of Medicine I, Medical University of Vienna, 1090 Vienna, Austria
| | | | - Philip Rosenstiel
- Institute of Clinical Molecular Biology, Kiel University and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| | - Philipp Starkl
- Division of Infection Biology, Department of Medicine I, Medical University of Vienna, 1090 Vienna, Austria
| | - Stephan P. Rosshart
- Department of Microbiome Research, Friedrich-Alexander-University Erlangen-Nürnberg, 91054 Erlangen, Germany
- Department of Medicine II (Gastroenterology, Hepatology, Endocrinology, and Infectious Diseases), Medical Center–University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Helmut Fickenscher
- Institute of Infection Medicine, University of Kiel and University Medical Center Schleswig-Holstein, 24015 Kiel, Germany
| | - Andreas Tholey
- Institute of Experimental Medicine, University of Kiel, 24188 Kiel, Germany
| | - Gunnar C. Hansson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
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4
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Dahlke E, Anan Y, Klie LM, Hartkopf AE, Theilig F. Megalin Orchestrates FcRn Endocytosis and Trafficking. Cells 2022; 12:cells12010053. [PMID: 36611847 PMCID: PMC9818419 DOI: 10.3390/cells12010053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/09/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
The neonatal Fc receptor (FcRn) is highly expressed in the renal proximal tubule and is important for the reclamation of albumin by cellular transcytosis to prevent its loss in the urine. The initial event of this transcellular transport mechanism is the endocytosis of albumin by the apical scavenger receptors megalin and cubilin. An interaction of megalin and FcRn was postulated, however, evidence is still missing. Similarly, the intracellular trafficking of FcRn remains unknown and shall be identified in our study. Using a Venus-based bimolecular fluorescence complementation system, we detected an interaction between megalin and FcRn in the endosomal compartment, which significantly increased with the induction of endocytosis using albumin or lactoglobulin as a ligand. The interaction between megalin and FcRn occurred at a neutral and acidic pH between the extracellular domains of both proteins. Amnionless, another transmembrane acceptor of cubilin, revealed no interaction with FcRn. With the induction of endocytosis by albumin or lactoglobulin, super resolution microscopy demonstrated a redistribution of megalin and FcRn into clathrin vesicles and early endosomes. This trafficking into clathrin vesicles was impaired in megalin-deficient cells upon albumin-induced endocytosis, supporting the role of megalin in FcRn redistribution. Our results indicate that megalin and FcRn specifically bind and interact within their extracellular domains. The availability of megalin is necessary for the redistribution of FcRn. Megalin, therefore, orchestrates FcRn endocytosis and intracellular trafficking as an early event intranscytosis.
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5
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Rinschen MM, Harder JL, Carter-Timofte ME, Zanon Rodriguez L, Mirabelli C, Demir F, Kurmasheva N, Ramakrishnan SK, Kunke M, Tan Y, Billing A, Dahlke E, Larionov AA, Bechtel-Walz W, Aukschun U, Grabbe M, Nielsen R, Christensen EI, Kretzler M, Huber TB, Wobus CE, Olagnier D, Siuzdak G, Grahammer F, Theilig F. VPS34-dependent control of apical membrane function of proximal tubule cells and nutrient recovery by the kidney. Sci Signal 2022; 15:eabo7940. [PMID: 36445937 PMCID: PMC10350314 DOI: 10.1126/scisignal.abo7940] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The lipid kinase VPS34 orchestrates autophagy, endocytosis, and metabolism and is implicated in cancer and metabolic disease. The proximal tubule in the kidney is a key metabolic organ that controls reabsorption of nutrients such as fatty acids, amino acids, sugars, and proteins. Here, by combining metabolomics, proteomics, and phosphoproteomics analyses with functional and superresolution imaging assays of mice with an inducible deficiency in proximal tubular cells, we revealed that VPS34 controlled the metabolome of the proximal tubule. In addition to inhibiting pinocytosis and autophagy, VPS34 depletion induced membrane exocytosis and reduced the abundance of the retromer complex necessary for proper membrane recycling and lipid retention, leading to a loss of fuel and biomass. Integration of omics data into a kidney cell metabolomic model demonstrated that VPS34 deficiency increased β-oxidation, reduced gluconeogenesis, and enhanced the use of glutamine for energy consumption. Furthermore, the omics datasets revealed that VPS34 depletion triggered an antiviral response that included a decrease in the abundance of apically localized virus receptors such as ACE2. VPS34 inhibition abrogated SARS-CoV-2 infection in human kidney organoids and cultured proximal tubule cells in a glutamine-dependent manner. Thus, our results demonstrate that VPS34 adjusts endocytosis, nutrient transport, autophagy, and antiviral responses in proximal tubule cells in the kidney.
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Affiliation(s)
- Markus M Rinschen
- Scripps Center for Metabolomics, Scripps Research, La Jolla, CA 92037, USA
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
- Department II of Internal Medicine and Center for Molecular Medicine, University of Cologne, 50937 Cologne, Germany
- Aarhus Institute for Advanced Studies, Aarhus University, 8000 Aarhus, Denmark
| | - Jennifer L Harder
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | | | | | - Carmen Mirabelli
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Fatih Demir
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | | | | | - Madlen Kunke
- Department of Anatomy, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Yifan Tan
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Anja Billing
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Eileen Dahlke
- Department of Anatomy, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Alexey A Larionov
- Department of Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Wibke Bechtel-Walz
- IV Department of Medicine and Faculty of Medicine, University Medical Center Freiburg, 79110 Freiburg, Germany
| | - Ute Aukschun
- IV Department of Medicine and Faculty of Medicine, University Medical Center Freiburg, 79110 Freiburg, Germany
| | - Marlen Grabbe
- IV Department of Medicine and Faculty of Medicine, University Medical Center Freiburg, 79110 Freiburg, Germany
| | - Rikke Nielsen
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | | | - Matthias Kretzler
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Christiane E Wobus
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - David Olagnier
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Gary Siuzdak
- Scripps Center for Metabolomics, Scripps Research, La Jolla, CA 92037, USA
| | - Florian Grahammer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Franziska Theilig
- Department of Anatomy, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
- Department of Medicine, University of Fribourg, 1700 Fribourg, Switzerland
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6
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Saudenova M, Promnitz J, Ohrenschall G, Himmerkus N, Böttner M, Kunke M, Bleich M, Theilig F. Behind every smile there's teeth: Cathepsin B's function in health and disease with a kidney view. Biochim Biophys Acta Mol Cell Res 2022; 1869:119190. [PMID: 34968578 DOI: 10.1016/j.bbamcr.2021.119190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
Cathepsin B (CatB) is a very abundant lysosomal protease with endo- and carboxydipeptidase activities and even ligase features. In this review, we will provide a general characterization of CatB and describe structure, structure-derived properties and location-dependent proteolytic actions. We depict CatB action within lysosome and its important roles in lysosomal biogenesis, lysosomal homeostasis and autophagy rendering this protease a key player in orchestrating lysosomal functions. Lysosomal leakage and subsequent escape of CatB into the cytosol lead to harmful actions, e.g. the role in activating the NLPR3 inflammasome, affecting immune responses and cell death. The second focus of this review addresses CatB functions in the kidney, i.e. the glomerulus, the proximal tubule and collecting duct with strong emphasis of its role in pathology of the respective segment. Finally, observations regarding CatB functions that need to be considered in cell culture will be discussed. In conclusion, CatB a physiologically important molecule may, upon aberrant expression in different cellular context, become a harmful player effectively showing its teeth behind its smile.
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Affiliation(s)
- Makhabbat Saudenova
- Institute of Anatomy, Department of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Jessica Promnitz
- Institute of Anatomy, Department of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Gerrit Ohrenschall
- Institute of Anatomy, Department of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Nina Himmerkus
- Institute of Physiology, Department of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Martina Böttner
- Institute of Anatomy, Department of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Madlen Kunke
- Institute of Anatomy, Department of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Markus Bleich
- Institute of Physiology, Department of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Franziska Theilig
- Institute of Anatomy, Department of Medicine, Christian-Albrechts-University Kiel, Germany.
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7
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Issler N, Afonso S, Weissman I, Jordan K, Cebrian-Serrano A, Meindl K, Dahlke E, Tziridis K, Yan G, Robles-López JM, Tabernero L, Patel V, Kesselheim A, Klootwijk ED, Stanescu HC, Dumitriu S, Iancu D, Tekman M, Mozere M, Jaureguiberry G, Outtandy P, Russell C, Forst AL, Sterner C, Heinl ES, Othmen H, Tegtmeier I, Reichold M, Schiessl IM, Limm K, Oefner P, Witzgall R, Fu L, Theilig F, Schilling A, Shuster Biton E, Kalfon L, Fedida A, Arnon-Sheleg E, Ben Izhak O, Magen D, Anikster Y, Schulze H, Ziegler C, Lowe M, Davies B, Böckenhauer D, Kleta R, Falik Zaccai TC, Warth R. A Founder Mutation in EHD1 Presents with Tubular Proteinuria and Deafness. J Am Soc Nephrol 2022; 33:732-745. [PMID: 35149593 PMCID: PMC8970462 DOI: 10.1681/asn.2021101312] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 12/17/2021] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The endocytic reabsorption of proteins in the proximal tubule requires a complex machinery and defects can lead to tubular proteinuria. The precise mechanisms of endocytosis and processing of receptors and cargo are incompletely understood. EHD1 belongs to a family of proteins presumably involved in the scission of intracellular vesicles and in ciliogenesis. However, the relevance of EHD1 in human tissues, in particular in the kidney, was unknown. METHODS Genetic techniques were used in patients with tubular proteinuria and deafness to identify the disease-causing gene. Diagnostic and functional studies were performed in patients and disease models to investigate the pathophysiology. RESULTS We identified six individuals (5-33 years) with proteinuria and a high-frequency hearing deficit associated with the homozygous missense variant c.1192C>T (p.R398W) in EHD1. Proteinuria (0.7-2.1 g/d) consisted predominantly of low molecular weight proteins, reflecting impaired renal proximal tubular endocytosis of filtered proteins. Ehd1 knockout and Ehd1R398W/R398W knockin mice also showed a high-frequency hearing deficit and impaired receptor-mediated endocytosis in proximal tubules, and a zebrafish model showed impaired ability to reabsorb low molecular weight dextran. Interestingly, ciliogenesis appeared unaffected in patients and mouse models. In silico structural analysis predicted a destabilizing effect of the R398W variant and possible inference with nucleotide binding leading to impaired EHD1 oligomerization and membrane remodeling ability. CONCLUSIONS A homozygous missense variant of EHD1 causes a previously unrecognized autosomal recessive disorder characterized by sensorineural deafness and tubular proteinuria. Recessive EHD1 variants should be considered in individuals with hearing impairment, especially if tubular proteinuria is noted.
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Affiliation(s)
- Naomi Issler
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Sara Afonso
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Irith Weissman
- Pediatric Nephrology, Galilee Medical Center, Nahraia, Israel
| | - Katrin Jordan
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | | | - Katrin Meindl
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Eileen Dahlke
- Institute of Anatomy, University of Kiel, Kiel, Germany
| | - Konstantin Tziridis
- Ear, Nose, and Throat Clinic, University Hospital Erlangen, Erlangen, Germany
| | - Guanhua Yan
- Division of Molecular and Cellular Function, University of Manchester, United Kingdom
| | - José M. Robles-López
- Division of Molecular and Cellular Function, University of Manchester, United Kingdom
| | - Lydia Tabernero
- Division of Molecular and Cellular Function, University of Manchester, United Kingdom
| | - Vaksha Patel
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Anne Kesselheim
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Enriko D. Klootwijk
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Horia C. Stanescu
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Simona Dumitriu
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Daniela Iancu
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Mehmet Tekman
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Monika Mozere
- Department of Renal Medicine, University College London, London, United Kingdom
| | | | - Priya Outtandy
- Department of Renal Medicine, University College London, London, United Kingdom
| | | | - Anna-Lena Forst
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | | | | | - Helga Othmen
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Ines Tegtmeier
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Markus Reichold
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | | | - Katharina Limm
- Institute of Functional Genomics, University of Regensburg, Regensburg, Germany
| | - Peter Oefner
- Institute of Functional Genomics, University of Regensburg, Regensburg, Germany
| | - Ralph Witzgall
- Molecular and Cellular Anatomy, University of Regensburg, Regensburg, Germany
| | - Lifei Fu
- Structural Biology, University of Regensburg, Regensburg, Germany
| | | | - Achim Schilling
- Ear, Nose, and Throat Clinic, University Hospital Erlangen, Erlangen, Germany
| | | | - Limor Kalfon
- Institute of Human Genetics, Galilee Medical Center, Nahraia, Israel
| | - Ayalla Fedida
- Institute of Human Genetics, Galilee Medical Center, Nahraia, Israel
| | | | - Ofer Ben Izhak
- Department of Pathology, Rambam Health Care Campus, Technion Faculty of Medicine, Haifa, Israel
| | - Daniella Magen
- Pediatric Nephrology Institute, Rambam Health Care Campus, Technion Faculty of Medicine, Haifa, Israel
| | | | - Holger Schulze
- Ear, Nose, and Throat Clinic, University Hospital Erlangen, Erlangen, Germany
| | | | - Martin Lowe
- Division of Molecular and Cellular Function, University of Manchester, United Kingdom
| | - Benjamin Davies
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Detlef Böckenhauer
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Robert Kleta
- Department of Renal Medicine, University College London, London, United Kingdom
| | - Tzipora C. Falik Zaccai
- The Azrieli Faculty of Medicine, Bar Ilan, Safed, Israel
- Institute of Human Genetics, Galilee Medical Center, Nahraia, Israel
| | - Richard Warth
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
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8
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Khbouz B, Rowart P, Poma L, Dahlke E, Bottner M, Stokes M, Bolen G, Rahmouni S, Theilig F, Jouret F. The genetic deletion of the Dual Specificity Phosphatase 3 (DUSP3) attenuates kidney damage and inflammation following ischaemia/reperfusion injury in mouse. Acta Physiol (Oxf) 2022; 234:e13735. [PMID: 34704357 DOI: 10.1111/apha.13735] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 12/16/2022]
Abstract
AIM Dual Specificity Phosphatase 3 (DUSP3) regulates the innate immune response, with a putative role in angiogenesis. Modulating inflammation and perfusion contributes to renal conditioning against ischaemia/reperfusion (I/R). We postulate that the functional loss of DUSP3 is associated with kidney resistance to I/R. METHODS Ten C57BL/6 male WT and Dusp3-/- mice underwent right nephrectomy and left renal I/R (30 min/48 hours). Renal injury was assessed based on serum levels of urea (BUN) and Jablonski score. The expression of CD31 and VEGF vascular markers was quantified by RT-qPCR and immuno-staining. Renal resistivity index (RRI) was measured in vivo by Doppler ultrasound. Comparative phosphoproteomics was conducted using IMAC enrichment of phosphopeptides. Inflammatory markers were quantified at both mRNA and protein levels in ischaemic vs non-ischaemic kidneys in WT vs Dusp3-/- . RESULTS At baseline, we located DUSP3 in renal glomeruli and endothelial cells. CD31-positive vascular network was significantly larger in Dusp3-/- kidneys compared to WT, with a lower RRI in Dusp3-/- mice. Following I/R, BUN and Jablonski score were significantly lower in Dusp3-/- vs WT mice. Phosphoproteomics highlighted a down-regulation of inflammatory pathways and up-regulation of phospho-sites involved in cell metabolism and VEGF-related angiogenesis in Dusp3-/- vs WT ischaemic kidneys. Dusp3-/- ischaemic kidneys showed decreased mRNA levels of CD11b, TNF-α, KIM-1, IL-6, IL-1β and caspase-3 compared to controls. The numbers of PCNA-, F4-80- and CD11b-positive cells were reduced in Dusp3-/- vs WT kidneys post-I/R. CONCLUSION Genetic inactivation of Dusp3 is associated with kidney conditioning against I/R, possibly due to attenuated inflammation and improved perfusion.
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Affiliation(s)
- Badr Khbouz
- Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) Cardiovascular Sciences University of Liège (ULiège) Liège Belgium
| | - Pascal Rowart
- Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) Cardiovascular Sciences University of Liège (ULiège) Liège Belgium
- Department of Pharmacology and Chemical Biology School of Medicine University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Laurence Poma
- Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) Cardiovascular Sciences University of Liège (ULiège) Liège Belgium
| | - Eileen Dahlke
- Institute of Anatomy Christian Albrechts‐University Kiel Germany
| | - Martina Bottner
- Institute of Anatomy Christian Albrechts‐University Kiel Germany
| | - Matthew Stokes
- Cell Signaling Technology, Inc. Danvers Massachusetts USA
| | - Géraldine Bolen
- Department of Clinical Sciences Fundamental and Applied Research for Animals & Health (FARAH) Veterinary Faculty University of Liège (ULiège) Liège Belgium
| | - Souad Rahmouni
- Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) Medical Genomics University of Liège (ULiège) Liège Belgium
| | - Franziska Theilig
- Institute of Anatomy Christian Albrechts‐University Kiel Germany
- Institute of Anatomy Department of Medicine University of Fribourg Fribourg Switzerland
| | - François Jouret
- Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) Cardiovascular Sciences University of Liège (ULiège) Liège Belgium
- Division of Nephrology CHU of Liège University of Liège (CHU ULiège) Liège Belgium
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9
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Khbouz B, Rowart P, Poma L, Bottner M, Bolen G, Rahmouni S, Theilig F, Jouret F. MO329THE GENETIC DELETION OF THE DUAL SPECIFICITY PHOSPHATASE 3 (DUSP3) ATTENUATES KIDNEY DAMAGE FOLLOWING ISCHEMIA/REPERFUSION INJURY IN MOUSE. Nephrol Dial Transplant 2021. [DOI: 10.1093/ndt/gfab084.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background and Aims
Dual Specificity Phosphatase 3 (DUSP3) is a positive regulator of the innate immune response in case of sepsis, but its role in the ischemic damage is unknown. Here, we study (i) whether and where DUSP3 is expressed in the renal parenchyma, and (ii) whether its genetic deletion in Dusp3 systemic knock-out (Dusp3-/-) mice attenuates the I/R-associated inflammation and injury.
Method
Experiment 1: Ten C57BL/6 male WT and Dusp3-/- mice underwent right nephrectomy and left renal ischemia for 30 minutes followed by a reperfusion of 48 hours. Blood and kidneys were collected. Renal function was assessed upon I/R biomarkers, i.e. blood urea nitrogen (BUN) and creatinine (SCr). Expressions of inflammatory and immune markers were comparatively quantified at both mRNA (real-time qPCR) and protein (immuno-blotting and –staining) levels in ischemic vs. non-ischemic kidneys in Dusp3 WT vs. KO mice.
Experiment 2: Ten C57BL/6 male WT and Dusp3-/- mice were anesthetized. Renal Doppler ultrasound was performed to assess the renal resistivity index (RRI). The expression of CD31 and VEGF vascular markers was quantified by the means of real-time qPCR and and immuno-staining (FiJi software).
Results
Experiment 1: An immuno-reactive signal for DUSP3 was detected in the glomeruli (in co-localization with nephrin) and in Meca-32-positive endothelial cells of both outer and inner medulla of mouse non-ischemic WT kidneys. No significant immunoreactivity for DUSP3 was detected in Dusp3-/- kidneys. Following renal I/R, the mRNA level of Dusp3 was increased 1.8-fold compared to baseline (p<0.001). Immunoblot quantifications showed a 77-fold increased expression of DUSP3 post renal I/R. Serum levels of I/R biomarkers were significantly lower in Dusp3-/- compared to WT mice following renal I/R (BUN: 78.4±33.7 vs. 258.9±162.9mg/dL; SCr: 0.1±0.07 vs. 0.8±0.9 mg/dL; p<0.01). At mRNA levels, Dusp3-/- ischemic kidneys showed a significantly decreased expression level of CD11b, TNF-α, KIM-1, IL-6, IL-1β and caspase-3 compared to controls. The numbers of PCNA-, F4-80- and CD11b-positive cells were significantly reduced in Dusp3-/- vs WT renal parenchyma post I/R.
Experiment 2: The RRI non-invasively measured by ultrasound was lower in Dusp3-/- group compared to controls (0.56± 0.03 vs. 0.66±0.02; p<0.001). The Dusp3-/- non-ischemic kidneys were characterized by a 1.8-fold increased surface of CD31-positive cells compared to WT kidneys (p<0.001). At mRNA levels, the Dusp3-/- kidneys showed significantly increased basal levels of CD31 and VEGF compared to controls.
Conclusion
The genetic deletion of DUSP3 is associated with (i) increased renal vascular density, (ii) decreased RRI and (iii) nephroprotection against renal I/R injury.
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Affiliation(s)
- Badr Khbouz
- GIGA Cardiovascular sciences, Liege University , Nephrology unit , Liege, Belgium
| | - Pascal Rowart
- GIGA Cardiovascular sciences, Liege University , Nephrology unit , Liege, Belgium
| | - Laurence Poma
- GIGA Cardiovascular sciences, Liege University , Nephrology unit , Liege, Belgium
| | | | - Géraldine Bolen
- University of Liège, FARAH, department of Clinical Sciences, Liège, Belgium
| | | | | | - François Jouret
- GIGA Cardiovascular sciences, Liege University , Nephrology unit , Liege, Belgium
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10
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Riebeling T, Jamal K, Wilson R, Kolbrink B, von Samson-Himmelstjerna FA, Moerke C, Ramos Garcia L, Dahlke E, Michels F, Lühder F, Schunk D, Doldi P, Tyczynski B, Kribben A, Flüh C, Theilig F, Kunzendorf U, Meier P, Krautwald S. Primidone blocks RIPK1-driven cell death and inflammation. Cell Death Differ 2021; 28:1610-1626. [PMID: 33273695 PMCID: PMC7712602 DOI: 10.1038/s41418-020-00690-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [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: 09/16/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 12/21/2022] Open
Abstract
The receptor-interacting serine/threonine protein kinase 1 (RIPK1) is a key mediator of regulated cell death and inflammation. Recent studies suggest that RIPK1 inhibition would fundamentally improve the therapy of RIPK1-dependent organ damage in stroke, myocardial infarction, kidney failure, and systemic inflammatory response syndrome. Additionally, it could ameliorate or prevent multi-organ failure induced by cytokine release in the context of hyperinflammation, as seen in COVID-19 patients. Therefore, we searched for a RIPK1 inhibitor and present the aromatic antiepileptic and FDA-approved drug primidone (Liskantin®) as a potent inhibitor of RIPK1 activation in vitro and in a murine model of TNFα-induced shock, which mimics the hyperinflammatory state of cytokine release syndrome. Furthermore, we detected for the first time RIPK1 activation in the respiratory tract epithelium of hospitalized patients who tested positive for SARS-CoV-2 infection. Our data provide a strong rationale for evaluating the drug primidone in conditions of hyperinflammation in humans.
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Affiliation(s)
- Theresa Riebeling
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, 24105, Kiel, Germany
| | - Kunzah Jamal
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, Fulham Road, London, SW3 6JB, UK
- DDR Biology, Bioscience, Oncology R&D, AstraZeneca, Cambridge, UK
| | - Rebecca Wilson
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, Fulham Road, London, SW3 6JB, UK
| | - Benedikt Kolbrink
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, 24105, Kiel, Germany
| | | | - Caroline Moerke
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, 24105, Kiel, Germany
| | - Laura Ramos Garcia
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, Fulham Road, London, SW3 6JB, UK
| | - Eileen Dahlke
- Institute of Anatomy, Christian-Albrechts-University Kiel, 24118, Kiel, Germany
| | - Friederike Michels
- Department of Neurosurgery, University Hospital Schleswig-Holstein, 24105, Kiel, Germany
| | - Fred Lühder
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Domagoj Schunk
- Department of Emergency Medicine, University Hospital Schleswig-Holstein, 24105, Kiel, Germany
| | - Philipp Doldi
- Medizinische Klinik und Poliklinik I, Ludwig-Maximilians-University Munich, 81377, Munich, Germany
| | - Bartosz Tyczynski
- Department of Nephrology, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Andreas Kribben
- Department of Nephrology, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Charlotte Flüh
- Department of Neurosurgery, University Hospital Schleswig-Holstein, 24105, Kiel, Germany
| | - Franziska Theilig
- Institute of Anatomy, Christian-Albrechts-University Kiel, 24118, Kiel, Germany
| | - Ulrich Kunzendorf
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, 24105, Kiel, Germany
| | - Pascal Meier
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, Fulham Road, London, SW3 6JB, UK
| | - Stefan Krautwald
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, 24105, Kiel, Germany.
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11
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Mazzoli A, Sardi C, Breasson L, Theilig F, Becattini B, Solinas G. JNK1 ablation improves pancreatic β-cell mass and function in db/db diabetic mice without affecting insulin sensitivity and adipose tissue inflammation. FASEB Bioadv 2021; 3:94-107. [PMID: 33615154 PMCID: PMC7876705 DOI: 10.1096/fba.2020-00081] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/12/2020] [Accepted: 12/16/2020] [Indexed: 12/15/2022] Open
Abstract
The cJun N‐terminal Kinases (JNK) emerged as a major link between obesity and insulin resistance, but their role in the loss of pancreatic β‐cell mass and function driving the progression from insulin resistance to type‐2 diabetes and in the complications of diabetes was not investigated to the same extent. Furthermore, it was shown that pan‐JNK inhibition exacerbates kidney damage in the db/db model of obesity‐driven diabetes. Here we investigate the role of JNK1 in the db/db model of obesity‐driven type‐2 diabetes. Mice with systemic ablation of JNK1 (JNK1−/−) were backcrossed for more than 10 generations in db/+ C57BL/KS mice to generate db/db‐JNK1−/− mice and db/db control mice. To define the role of JNK1 in the loss of β‐cell mass and function occurring during obesity‐driven diabetes we performed comprehensive metabolic phenotyping, evaluated steatosis and metabolic inflammation, performed morphometric and cellular composition analysis of pancreatic islets, and evaluated kidney function in db/db‐JNK1−/− mice and db/db controls. db/db‐JNK1−/− mice and db/db control mice developed insulin resistance, fatty liver, and metabolic inflammation to a similar extent. However, db/db‐JNK1−/− mice displayed better glucose tolerance and improved insulin levels during glucose tolerance test, higher pancreatic insulin content, and larger pancreatic islets with more β‐cells than db/db mice. Finally, albuminuria, kidney histopathology, kidney inflammation and oxidative stress in db/db‐JNK1−/− mice and in db/db mice were similar. Our data indicate that selective JNK1 ablation improves glucose tolerance in db/db mice by reducing the loss of functional β‐cells occurring in the db/db mouse model of obesity‐driven diabetes, without significantly affecting metabolic inflammation, steatosis, and insulin sensitivity. Furthermore, we have found that, differently from what previously reported for pan‐JNK inhibitors, selective JNK1 ablation does not exacerbate kidney dysfunction in db/db mice. We conclude that selective JNK1 inactivation may have a superior therapeutic index than pan‐JNK inhibition in obesity‐driven diabetes.
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Affiliation(s)
- Arianna Mazzoli
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
| | - Claudia Sardi
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
| | - Ludovic Breasson
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
| | - Franziska Theilig
- Institute of Anatomy Christian Albrechts-University Kiel Kiel Germany
| | - Barbara Becattini
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
| | - Giovanni Solinas
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
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12
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Nazıroğlu M, Çiğ B, Yazğan Y, Schwaerzer GK, Theilig F, Pecze L. Albumin evokes Ca 2+-induced cell oxidative stress and apoptosis through TRPM2 channel in renal collecting duct cells reduced by curcumin. Sci Rep 2019; 9:12403. [PMID: 31455864 PMCID: PMC6711968 DOI: 10.1038/s41598-019-48716-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 07/16/2019] [Indexed: 12/14/2022] Open
Abstract
In proteinuric nephropathies of chronic kidney disease, the epithelial cells of the nephron including the collecting duct are exposed to high concentrations of luminal albumin. Albumin is taken up from collecting duct cells by endocytosis causing excessive reactive oxygen species (ROS) production and a proinflammatory response. Curcumin used in the traditional medicine possesses anti-inflammatory and antioxidant effects. ROS and ADP-ribose (ADPR) activate the cation channel TRPM2. We hypothesize, that albumin-induced cell stress and proinflammatory response are mediated by Ca2+ and can be reduced by curcumin. The cortical collecting duct (CCD) cells mpkCCDc14 exhibit spontaneous and inducible Ca2+ oscillations, which can be blocked by pre-treatment with curcumin. Curcumin accumulates in plasma membrane and intracellular vesicles, where it interferes with TRPM2 and decreases the influx of Ca2+. Albumin reduces cell viability and increases apoptosis, NF-κB activation, and mitochondrial membrane depolarization via Ca2+-dependent signaling, which results in increased ROS production. Albumin-induced cell stress is diminished by the inhibition of TRPM2 after administration of curcumin and ADPR (PARP1) inhibitors. Curcumin did not reduce the Ca2+ elevation induced by thapsigargin in Ca2+-free medium, but it reduced the function of store-operated Ca2+ channels and ATP-evoked Ca2+ response. In conclusion, albumin-induced oxidative stress is mediated by Ca2+-dependent signaling via TRPM2 and leads to cell damage and a proinflammatory response, strengthening the role of CCD cells in the progression of chronic kidney disease.
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Affiliation(s)
- Mustafa Nazıroğlu
- Neuroscience Research Center, Suleyman Demirel University, Isparta, Turkey. .,Department of Biophysics, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey. .,Department of Neuroscience, Health Science Institute, Suleyman Demirel University, Isparta, Turkey.
| | - Bilal Çiğ
- Department of Biophysics, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey.,Department of Neuroscience, Health Science Institute, Suleyman Demirel University, Isparta, Turkey
| | - Yener Yazğan
- Department of Biophysics, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey.,Department of Neuroscience, Health Science Institute, Suleyman Demirel University, Isparta, Turkey
| | | | - Franziska Theilig
- Institute of Anatomy, Christian-Albrechts-University of Kiel, Kiel, Germany. .,Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland.
| | - László Pecze
- Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland.,Independent Scientist, Neuchhatel, Switzerland
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13
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Larionov A, Dahlke E, Kunke M, Zanon Rodriguez L, Schiessl IM, Magnin JL, Kern U, Alli AA, Mollet G, Schilling O, Castrop H, Theilig F. Cathepsin B increases ENaC activity leading to hypertension early in nephrotic syndrome. J Cell Mol Med 2019; 23:6543-6553. [PMID: 31368174 PMCID: PMC6787568 DOI: 10.1111/jcmm.14387] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/04/2019] [Accepted: 05/06/2019] [Indexed: 11/28/2022] Open
Abstract
The NPHS2 gene, encoding the slit diaphragm protein podocin, accounts for genetic and sporadic forms of nephrotic syndrome (NS). Patients with NS often present symptoms of volume retention, such as oedema formation or hypertension. The primary dysregulation in sodium handling involves an inappropriate activation of the epithelial sodium channel, ENaC. Plasma proteases in a proteinuria‐dependent fashion have been made responsible; however, referring to the timeline of symptoms occurring and underlying mechanisms, contradictory results have been published. Characterizing the mouse model of podocyte inactivation of NPHS2 (Nphs2∆pod) with respect to volume handling and proteinuria revealed that sodium retention, hypertension and gross proteinuria appeared sequentially in a chronological order. Detailed analysis of Nphs2∆pod during early sodium retention, revealed increased expression of full‐length ENaC subunits and αENaC cleavage product with concomitant increase in ENaC activity as tested by amiloride application, and augmented collecting duct Na+/K+‐ATPase expression. Urinary proteolytic activity was increased and several proteases were identified by mass spectrometry including cathepsin B, which was found to process αENaC. Renal expression levels of precursor and active cathepsin B were increased and could be localized to glomeruli and intercalated cells. Inhibition of cathepsin B prevented hypertension. With the appearance of gross proteinuria, plasmin occurs in the urine and additional cleavage of γENaC is encountered. In conclusion, characterizing the volume handling of Nphs2∆pod revealed early sodium retention occurring independent to aberrantly filtered plasma proteases. As an underlying mechanism cathepsin B induced αENaC processing leading to augmented channel activity and hypertension was identified.
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Affiliation(s)
- Alexey Larionov
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Eileen Dahlke
- Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
| | - Madlen Kunke
- Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
| | | | - Ina M Schiessl
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | | | - Ursula Kern
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
| | - Geraldine Mollet
- Laboratory of Hereditary Kidney Diseases, INSERM UMR 1163, Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - Oliver Schilling
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Center for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Hayo Castrop
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Franziska Theilig
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland.,Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
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14
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Eisele N, Klossner R, Escher G, Rudloff S, Larionov A, Theilig F, Mohaupt MG, Mistry HD, Gennari‐Moser C. Physiological and Molecular Responses to Altered Sodium Intake in Rat Pregnancy. J Am Heart Assoc 2018; 7:e008363. [PMID: 30371243 PMCID: PMC6201473 DOI: 10.1161/jaha.117.008363] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 06/07/2018] [Indexed: 11/21/2022]
Abstract
Background In pregnancy, a high plasma volume maintains uteroplacental perfusion and prevents placental ischemia, a condition linked to elevated maternal blood pressure ( BP ). Reducing BP by increasing Na+ intake via plasma volume expansion appears contra-intuitive. We hypothesize that an appropriate Na+ intake in pregnancy reduces maternal BP and adapts the renin-angiotensin system in a pregnancy-specific manner. Methods and Results BP was measured by implanted telemetry in Sprague-Dawley rats before and throughout pregnancy. Pregnant and nonpregnant animals received either a normal-salt (0.4%; NS ), high-salt (8%; HS ), or low-salt (0.01%; LS ) diet, or HS (days 1-14) followed by LS (days 14-20) diet ( HS / LS ). Before delivery (day 20), animals were euthanized and organs collected. Food, water, and Na+ intake were monitored in metabolic cages, and urinary creatinine and Na+ were analyzed. Na+ intake and retention increased in pregnancy ( NS , LS ), leading to a positive Na+ balance ( NS , LS ). BP was stable during LS , but reduced in HS conditions in pregnancy. The renin-angiotensin system was adapted as expected. Activating cleavage of α- and γ-subunits of the renal epithelial Na+ channel and expression of-full length medullary β-subunits, accentuated further in all LS conditions, were upregulated in pregnancy. Conclusions Pregnancy led to Na+ retention adapted to dietary changes. HS exposure paradoxically reduced BP . Na+ uptake while only modestly linked to the renin-angiotensin system is enhanced in the presence of posttranslational renal epithelial Na+ channel modifications. This suggests (1) storage of Na+ in pregnancy upon HS exposure, bridging periods of LS availability; and (2) that potentially non-renin-angiotensin-related mechanisms participate in EN aC activation and consecutive Na+ retention.
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Affiliation(s)
- Nicole Eisele
- Department of Nephrology and HypertensionUniversity of BernSwitzerland
- Department of BioMedical ResearchUniversity of BernSwitzerland
| | - Rahel Klossner
- Department of BioMedical ResearchUniversity of BernSwitzerland
- Teaching Hospital Internal Medicine LindenhofgruppeBerneSwitzerland
| | - Geneviève Escher
- Department of Nephrology and HypertensionUniversity of BernSwitzerland
- Department of BioMedical ResearchUniversity of BernSwitzerland
| | - Stefan Rudloff
- Department of Nephrology and HypertensionUniversity of BernSwitzerland
- Department of BioMedical ResearchUniversity of BernSwitzerland
| | - Alexey Larionov
- Division of Internal MedicineUniversity of FribourgSwitzerland
| | | | - Markus G. Mohaupt
- Department of BioMedical ResearchUniversity of BernSwitzerland
- Teaching Hospital Internal Medicine LindenhofgruppeBerneSwitzerland
| | - Hiten D. Mistry
- Department of BioMedical ResearchUniversity of BernSwitzerland
- Division of Child Health, Obstetrics and GynaecologySchool of MedicineCity Hospital NottinghamNottinghamUnited Kingdom
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15
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Abstract
Distal sodium transport is a final step in the regulation of blood pressure. As such, understanding how the two main sodium transport proteins, the thiazide-sensitive sodium chloride cotransporter (NCC) and the epithelial sodium channel (ENaC), are regulated is paramount. Both are expressed in the late distal nephron; however, no evidence has suggested that these two sodium transport proteins interact. Recently, we established that these two sodium transport proteins functionally interact in the second part of the distal nephron (DCT2). Given their co-localization within the DCT2, we hypothesized that NCC and ENaC interactions might be modulated by aldosterone (Aldo). Aldo treatment increased NCC and αENaC colocalization (electron microscopy) and interaction (coimmunoprecipitation). Finally, with co-expression of the Aldo-induced protein serum- and glucocorticoid-inducible kinase 1 (SGK1), NCC and αENaC interactions were increased. These data demonstrate that Aldo promotes increased interaction of NCC and ENaC, within the DCT2 revealing a novel method of regulation for distal sodium reabsorption.
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Affiliation(s)
- Brandi M Wynne
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, GA, 30322, USA. .,Center for Cell and Molecular Signaling, Emory University, Atlanta, GA, 30322, USA.
| | - Abinash C Mistry
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Otor Al-Khalili
- Department of Physiology, Emory University, Atlanta, GA, 30322, USA
| | - Rickta Mallick
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Franziska Theilig
- Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Douglas C Eaton
- Department of Physiology, Emory University, Atlanta, GA, 30322, USA.,Center for Cell and Molecular Signaling, Emory University, Atlanta, GA, 30322, USA
| | - Robert S Hoover
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, GA, 30322, USA.,Department of Physiology, Emory University, Atlanta, GA, 30322, USA.,Research Service, Atlanta Veteran's Administration Medical Center, Decatur, GA, 30033, USA
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16
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Grahammer F, Ramakrishnan SK, Rinschen MM, Larionov AA, Syed M, Khatib H, Roerden M, Sass JO, Helmstaedter M, Osenberg D, Kühne L, Kretz O, Wanner N, Jouret F, Benzing T, Artunc F, Huber TB, Theilig F. mTOR Regulates Endocytosis and Nutrient Transport in Proximal Tubular Cells. J Am Soc Nephrol 2016; 28:230-241. [PMID: 27297946 DOI: 10.1681/asn.2015111224] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 05/14/2016] [Indexed: 01/03/2023] Open
Abstract
Renal proximal tubular cells constantly recycle nutrients to ensure minimal loss of vital substrates into the urine. Although most of the transport mechanisms have been discovered at the molecular level, little is known about the factors regulating these processes. Here, we show that mTORC1 and mTORC2 specifically and synergistically regulate PTC endocytosis and transport processes. Using a conditional mouse genetic approach to disable nonredundant subunits of mTORC1, mTORC2, or both, we showed that mice lacking mTORC1 or mTORC1/mTORC2 but not mTORC2 alone develop a Fanconi-like syndrome of glucosuria, phosphaturia, aminoaciduria, low molecular weight proteinuria, and albuminuria. Interestingly, proteomics and phosphoproteomics of freshly isolated kidney cortex identified either reduced expression or loss of phosphorylation at critical residues of different classes of specific transport proteins. Functionally, this resulted in reduced nutrient transport and a profound perturbation of the endocytic machinery, despite preserved absolute expression of the main scavenger receptors, MEGALIN and CUBILIN. Our findings highlight a novel mTOR-dependent regulatory network for nutrient transport in renal proximal tubular cells.
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Affiliation(s)
- Florian Grahammer
- Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Suresh K Ramakrishnan
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Alexey A Larionov
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Maryam Syed
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Hazim Khatib
- Department of Medical IV, Sektion Nieren- und Hochdruckkrankheiten, University of Tübingen, Tübingen, Germany
| | - Malte Roerden
- Department of Medical IV, Sektion Nieren- und Hochdruckkrankheiten, University of Tübingen, Tübingen, Germany
| | - Jörn Oliver Sass
- Bioanalytics and Biochemistry, Department of Natural Sciences, Bonn Rhein Sieg University of Applied Sciences, Rheinbach, Germany.,Division of Clinical Chemistry and Biochemistry and Children's Research Centre, University Children's Hospital Zürich, Zurich, Switzerland
| | - Martin Helmstaedter
- Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Dorothea Osenberg
- Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lucas Kühne
- Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Oliver Kretz
- Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nicola Wanner
- Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Francois Jouret
- Groupe Interdisciplinaire de Génoprotéomique Appliquée, Cardiovascular Sciences, University of Liège, Liege, Belgium; and
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Ferruh Artunc
- Department of Medical IV, Sektion Nieren- und Hochdruckkrankheiten, University of Tübingen, Tübingen, Germany
| | - Tobias B Huber
- Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; .,BIOSS, Centre for Biological Signalling Studies and.,FRIAS, Freiburg Institute for Advanced Studies and ZBSA, Center for Biological System Analysis, Albert Ludwigs University of Freiburg, Freiburg, Germany
| | - Franziska Theilig
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland;
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17
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Schießl IM, Hammer A, Kattler V, Gess B, Theilig F, Witzgall R, Castrop H. Intravital Imaging Reveals Angiotensin II-Induced Transcytosis of Albumin by Podocytes. J Am Soc Nephrol 2015; 27:731-44. [PMID: 26116357 DOI: 10.1681/asn.2014111125] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 05/11/2015] [Indexed: 11/03/2022] Open
Abstract
Albuminuria is a hallmark of kidney disease of various etiologies and usually caused by deterioration of glomerular filtration barrier integrity. We recently showed that angiotensin II (Ang II) acutely increases albumin filtration in the healthy kidney. Here, we used intravital microscopy to assess the effects of Ang II on podocyte function in rats. Acute infusion of 30, 60, or 80 ng/kg per minute Ang II enhanced the endocytosis of albumin by activation of the type 1 Ang II receptor and resulted in an average (±SEM) of 3.7±2.2, 72.3±18.6 (P<0.001), and 239.4±34.6 µm(3) (P<0.001) albumin-containing vesicles per glomerulus, respectively, compared with none at baseline or 10 ng/kg per minute Ang II. Immunostaining of Ang II-infused kidneys confirmed the presence of albumin-containing vesicles, which colocalized with megalin, in podocin-positive cells. Furthermore, podocyte endocytosis of albumin was markedly reduced in the presence of gentamicin, a competitive inhibitor of megalin-dependent endocytosis. Ang II infusion increased the concentration of albumin in the subpodocyte space, a potential source for endocytic protein uptake, and gentamicin further increased this concentration. Some endocytic vesicles were acidified and colocalized with LysoTracker. Most vesicles migrated from the capillary to the apical aspect of the podocyte and were eventually released into the urinary space. This transcytosis accounted for approximately 10% of total albumin filtration. In summary, the transcellular transport of proteins across the podocyte constitutes a new pathway of glomerular protein filtration. Ang II enhances the endocytosis and transcytosis of plasma albumin by podocytes, which may eventually impair podocyte function.
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Affiliation(s)
| | | | | | | | - Franziska Theilig
- Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Ralph Witzgall
- Molecular and Cellular Anatomy, University of Regensburg, Regensburg, Germany; and
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18
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Theilig F, Wu Q. ANP-induced signaling cascade and its implications in renal pathophysiology. Am J Physiol Renal Physiol 2015; 308:F1047-55. [PMID: 25651559 DOI: 10.1152/ajprenal.00164.2014] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 01/22/2015] [Indexed: 01/06/2023] Open
Abstract
The balance between vasoconstrictor/sodium-retaining and vasodilator/natriuretic systems is essential for maintaining body fluid and electrolyte homeostasis. Natriuretic peptides, such as atrial natriuretic peptide (ANP), belong to the vasodilator/natriuretic system. ANP is produced by the conversion of pro-ANP into ANP, which is achieved by a proteolytical cleavage executed by corin. In the kidney, ANP binds to the natriuretic peptide receptor-A (NPR-A) and enhances its guanylyl cyclase activity, thereby increasing intracellular cyclic guanosine monophosphate production to promote natriuretic and renoprotective responses. In the glomerulus, ANP increases glomerular permeability and filtration rate and antagonizes the deleterious effects of the renin-angiotensin-aldosterone system activation. Along the nephron, natriuretic and diuretic actions of ANP are mediated by inhibiting the basolaterally expressed Na(+)-K(+)-ATPase, reducing apical sodium, potassium, and protein organic cation transporter in the proximal tubule, and decreasing Na(+)-K(+)-2Cl(-) cotransporter activity and renal concentration efficiency in the thick ascending limb. In the medullary collecting duct, ANP reduces sodium reabsorption by inhibiting the cyclic nucleotide-gated cation channels, the epithelial sodium channel, and the heteromeric channel transient receptor potential-vanilloid 4 and -polycystin 2 and diminishes vasopressin-induced water reabsorption. Long-term ANP treatment may lead to NPR-A desensitization and ANP resistance, resulting in augmented sodium and water reabsorption. In mice, corin deficiency impairs sodium excretion and causes salt-sensitive hypertension. Characteristics of ANP resistance and corin deficiency are also encountered in patients with edema-associated diseases, highlighting the importance of ANP signaling in salt-water balance and renal pathophysiology.
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Affiliation(s)
- Franziska Theilig
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland; and
| | - Qingyu Wu
- Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Ohio
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19
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Pohl M, Shan Q, Petsch T, Styp-Rekowska B, Matthey P, Bleich M, Bachmann S, Theilig F. Short-term functional adaptation of aquaporin-1 surface expression in the proximal tubule, a component of glomerulotubular balance. J Am Soc Nephrol 2014; 26:1269-78. [PMID: 25270072 DOI: 10.1681/asn.2014020148] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 07/22/2014] [Indexed: 11/03/2022] Open
Abstract
Transepithelial water flow across the renal proximal tubule is mediated predominantly by aquaporin-1 (AQP1). Along this nephron segment, luminal delivery and transepithelial reabsorption are directly coupled, a phenomenon called glomerulotubular balance. We hypothesized that the surface expression of AQP1 is regulated by fluid shear stress, contributing to this effect. Consistent with this finding, we found that the abundance of AQP1 in brush border apical and basolateral membranes was augmented >2-fold by increasing luminal perfusion rates in isolated, microperfused proximal tubules for 15 minutes. Mouse kidneys with diminished endocytosis caused by a conditional deletion of megalin or the chloride channel ClC-5 had constitutively enhanced AQP1 abundance in the proximal tubule brush border membrane. In AQP1-transfected, cultured proximal tubule cells, fluid shear stress or the addition of cyclic nucleotides enhanced AQP1 surface expression and concomitantly diminished its ubiquitination. These effects were also associated with an elevated osmotic water permeability. In sum, we have shown that luminal surface expression of AQP1 in the proximal tubule brush border membrane is regulated in response to flow. Cellular trafficking, endocytosis, an intact endosomal compartment, and controlled protein stability are the likely prerequisites for AQP1 activation by enhanced tubular fluid shear stress, serving to maintain glomerulotubular balance.
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Affiliation(s)
- Marcus Pohl
- Institute of Anatomy, Charité Universitätsmedizin, Berlin, Germany
| | - Qixian Shan
- Institute of Physiology, Kiel University, Kiel, Germany
| | - Thomas Petsch
- Institute of Anatomy, Charité Universitätsmedizin, Berlin, Germany
| | | | - Patricia Matthey
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Markus Bleich
- Institute of Physiology, Kiel University, Kiel, Germany
| | | | - Franziska Theilig
- Institute of Anatomy, Charité Universitätsmedizin, Berlin, Germany; Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
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20
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Rajapakse A, Heim Y, Scolari B, Matthey P, Uldry D, Theilig F. Signaling pathways regulating renal proximal tubular endocytosis under proteinuric conditions. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.912.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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21
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Abstract
Severe sepsis is often accompanied by acute renal failure with renal tubular dysfunction. Albuminuria is a common finding in septic patients and we studied whether it was due to an impairment of proximal tubular endocytosis of filtered albumin. We studied the regulation of megalin and cubilin, the two critical multiligand receptors responsible for albumin absorption, during severe experimental endotoxemia. Lipopolysaccharide (LPS) caused a time- and dose-dependent suppression of megalin and cubilin expression that was paralleled by a decrease in plasma albumin levels and an increase in the urine concentration of albumin in mice. Incubation of rat renal cortical slices with LPS also reduced the mRNA expression of megalin and cubilin. Further, LPS suppressed megalin and cubilin mRNA expression in murine primary proximal tubule cells and decreased the uptake of FITC albumin in these cells. In addition, the increase in urine levels of albumin in response to ischemia/reperfusion-induced acute renal failure was paralleled by a decrease in the expression of megalin and cubilin. Thus, our data indicate that the expression of megalin and cubilin is decreased during experimental endotoxemia and in response to renal ischemia/reperfusion injury. This downregulation may contribute, in part, to an increase in urine levels of albumin during acute renal failure.
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Affiliation(s)
- Andrea Schreiber
- Institute of Physiology, University of Regensburg, Regensburg, Germany
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22
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Theilig F, Enke AK, Scolari B, Polzin D, Bachmann S, Koesters R. Tubular deficiency of von Hippel-Lindau attenuates renal disease progression in anti-GBM glomerulonephritis. Am J Pathol 2011; 179:2177-88. [PMID: 21925138 DOI: 10.1016/j.ajpath.2011.07.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 06/14/2011] [Accepted: 07/06/2011] [Indexed: 01/05/2023]
Abstract
In many kidney diseases, the original insult primarily involves the glomerulus and may then pass onto the tubulointerstitium. Several hypotheses link glomerular disease to tubular injury; perhaps the foremost hypothesis involves chronic tubular hypoxia. The reported effects of hypoxia and consecutive stabilization of hypoxia-inducible factors (HIFs), however, are controversial. Hypoxia induces interstitial fibrosis but also has beneficial effects on renal disease progression when HIF is activated pharmacologically. To analyze the impact of HIF on tubulointerstitial disease development in primary glomerular disease, transgenic von Hippel Lindau (VHL)-knockout mice were generated and null expression was induced before the onset of autoimmune IgG-mediated anti-glomerular basement membrane glomerulonephritis (GN). Tubular VHL knockout and, thus, local HIF-α stabilization increased renal production of vascular endothelial growth factor, tumor growth factor-β(1), and platelet-derived growth factor-B, resulting in augmented formation of capillaries and interstitial matrix, and conversion of fibroblasts to myofibroblasts. Within the glomerular disease, VHL knockout reduced the glomerular damage and attenuated tubulointerstitial injury. Likewise, proteinuria, plasma urea concentration, and tubulointerstitial matrix were decreased in VHL knockout with GN. These findings shown that tubular HIF-α stabilization in glomerular disease is beneficial for disease outcome. In comparison with VHL knockout alone, GN is a much stronger activator of fibrosis such that stimuli other than hypoxia may be considered important for renal disease progression.
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Affiliation(s)
- Franziska Theilig
- Institute of Anatomy, University of Fribourg, Switzerland; Institute of Anatomy, Charité-Universitätsmedizin, Berlin, Germany.
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23
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Pohl M, Kaminski H, Castrop H, Bader M, Himmerkus N, Bleich M, Bachmann S, Theilig F. Intrarenal renin angiotensin system revisited: role of megalin-dependent endocytosis along the proximal nephron. J Biol Chem 2010; 285:41935-46. [PMID: 20966072 PMCID: PMC3009920 DOI: 10.1074/jbc.m110.150284] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 10/14/2010] [Indexed: 12/16/2022] Open
Abstract
The existence of a local renin angiotensin system (RAS) of the kidney has been established. Angiotensinogen (AGT), renin, angiotensin-converting enzyme (ACE), angiotensin receptors, and high concentrations of luminal angiotensin II have been found in the proximal tubule. Although functional data have documented the relevance of a local RAS, the dualism between biosynthesis and endocytotic uptake of its components and their cellular processing has been incompletely understood. To resolve this, we have selectively analyzed their distribution, endocytosis, transcytosis, and biosynthesis in the proximal tubule. The presence of immunoreactive AGT, restricted to the early proximal tubule, was due to its retrieval from the ultrafiltrate and storage in endosomal and lysosomal compartments. Cellular uptake was demonstrated by autoradiography of radiolabeled AGT and depended on intact endocytosis. AGT was identified as a ligand of the multiple ligand-binding repeats of megalin. AGT biosynthesis was restricted to the proximal straight tubule, revealing substantial AGT mRNA expression. Transgenic AGT overexpression under the control of an endogenous promoter was also restricted to the late proximal tubule. Proximal handling of renin largely followed the patterns of AGT, whereas its local biosynthesis was not significant. Transcytotic transport of AGT in a proximal cell line revealed a 5% recovery rate after 1 h. ACE was expressed along late proximal brush-border membrane, whereas ACE2 was present along the entire segment. Surface expression of ACE and ACE2 differed as a function of endocytosis. Our data on the localization and cellular processing of RAS components provide new aspects of the functional concept of a "self-contained" renal RAS.
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Affiliation(s)
- Marcus Pohl
- From the Institute of Anatomy, Charité Universitätsmedizin, 10115 Berlin, Germany
| | - Henriette Kaminski
- From the Institute of Anatomy, Charité Universitätsmedizin, 10115 Berlin, Germany
| | - Hayo Castrop
- the Institute of Physiology, University Regensburg, 93053 Regensburg, Germany
| | - Michael Bader
- the Max-Delbrück-Center for Molecular Medicine, 13092 Berlin, Germany, and
| | | | | | - Sebastian Bachmann
- From the Institute of Anatomy, Charité Universitätsmedizin, 10115 Berlin, Germany
| | - Franziska Theilig
- From the Institute of Anatomy, Charité Universitätsmedizin, 10115 Berlin, Germany
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24
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Koesters R, Kaissling B, Lehir M, Picard N, Theilig F, Gebhardt R, Glick AB, Hähnel B, Hosser H, Gröne HJ, Kriz W. Tubular overexpression of transforming growth factor-beta1 induces autophagy and fibrosis but not mesenchymal transition of renal epithelial cells. Am J Pathol 2010; 177:632-43. [PMID: 20616344 PMCID: PMC2913362 DOI: 10.2353/ajpath.2010.091012] [Citation(s) in RCA: 232] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/21/2010] [Indexed: 01/05/2023]
Abstract
We recently showed in a tetracycline-controlled transgenic mouse model that overexpression of transforming growth factor (TGF)-beta1 in renal tubules induces widespread peritubular fibrosis and focal degeneration of nephrons. In the present study we have analyzed the mechanisms underlying these phenomena. The initial response to tubular cell-derived TGF-beta1 consisted of a robust proliferation of peritubular cells and deposition of collagen. On sustained expression, nephrons degenerated in a focal pattern. This process started with tubular dedifferentiation and proceeded to total decomposition of tubular cells by autophagy. The final outcome was empty collapsed remnants of tubular basement membrane embedded into a dense collagenous fibrous tissue. The corresponding glomeruli survived as atubular remnants. Thus, TGF-beta1 driven autophagy may represent a novel mechanism of tubular decomposition. The fibrosis seen in between intact tubules and in areas of tubular decomposition resulted from myofibroblasts that were derived from local fibroblasts. No evidence was found for a transition of tubular cells into myofibroblasts. Neither tracing of injured tubules in electron micrographs nor genetic tagging of tubular epithelial cells revealed cells transgressing the tubular basement membrane. In conclusion, overexpression of TGF-beta1 in renal tubules in vivo induces interstitial proliferation, tubular autophagy, and fibrosis, but not epithelial-to-mesenchymal transition.
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Affiliation(s)
- Robert Koesters
- Institute of Human Genetics, University of Heidelberg, Heidelberg, Germany
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25
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Carota I, Theilig F, Oppermann M, Kongsuphol P, Rosenauer A, Schreiber R, Jensen BL, Walter S, Kunzelmann K, Castrop H. Localization and functional characterization of the human NKCC2 isoforms. Acta Physiol (Oxf) 2010; 199:327-38. [PMID: 20146722 DOI: 10.1111/j.1748-1716.2010.02099.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM Salt reabsorption across the apical membrane of cells in the thick ascending limb (TAL) of Henle is primarily mediated by the bumetanide-sensitive Na(+)/K(+)/2Cl(-) cotransporter NKCC2. Three full-length splice variants of NKCC2 (NKCC2B, NKCC2A and NKCC2F) have been described. The NKCC2 isoforms have specific localizations and transport characteristics, as assessed for rabbit, rat and mouse. In the present study, we aimed to address the localization and transport characteristics of the human NKCC2 isoforms. METHODS RT-PCR, in situ hybridization and uptake studies in Xenopus oocytes were performed to characterize human NKCC2 isoforms. RESULTS All three classical NKCC2 isoforms were detected in the human kidney; in addition, we found splice variants with tandem duplicates of the variable exon 4. Contrary to rodents, in which NKCC2F is the most abundant NKCC2 isoform, NKCC2A was the dominant isoform in humans; similarly, isoform-specific in situ hybridization showed high expression levels of human NKCC2A along the TAL. Compared to NKCC2B and NKCC2F, human NKCC2A had the lowest Cl(-) affinity as determined by (86)Rb(+) uptake studies in oocytes. All NKCC2 isoforms were more efficiently inhibited by bumetanide than by furosemide. A sequence analysis of the amino acids encoded by exon 4 variants revealed high similarities between human and rodent NKCC2 isoforms, suggesting that differences in ion transport characteristics between species may be related to sequence variations outside the highly conserved sequence encoded by exon 4. CONCLUSION The human NKCC2 is an example of how differential splicing forms the basis for a diversification of transporter protein function.
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Affiliation(s)
- I Carota
- Institute of Physiology, University of Regensburg, Germany
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26
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Abstract
Chronic kidney disease is characterized by the decline in renal excretory, homeostatic and endocrine functions. In most instances, the primary event is glomerular injury. With ongoing progression and glomerular extracapillary proliferation, tubulointerstitial damage occurs with consequent nephron loss and development of fibrotic lesions, finally resulting in terminal renal failure. Renal tubulointerstitial damage is the final common pathway in all forms of renal disease leading to CKD. Recent research has focused on how glomerular injury spreads to the tubulointerstitium. Presently, four possible mechanisms are being discussed: (1) obstruction of the urinary pole; (2) proteinuria-induced overload of the proximal tubule; (3) chronic hypoxia and (4) inflammation induced by a glomerulotubular feedback loop. Fibrosis is hypothesized to account for further deterioration of renal functions. As to the role of fibrosis, conflicting results have been published and new data question the damaging character of fibrosis.
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Affiliation(s)
- Franziska Theilig
- Charité - Universitätsmedizin Berlin, Institut für Vegetative Anatomie, 10115 Berlin, Germany.
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27
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Stoessel A, Himmerkus N, Bleich M, Bachmann S, Theilig F. Connexin 37 is localized in renal epithelia and responds to changes in dietary salt intake. Am J Physiol Renal Physiol 2010; 298:F216-23. [PMID: 19828678 DOI: 10.1152/ajprenal.00295.2009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Connexins are the main components of gap junction channels, which are important for intercellular communication. In the kidney, several members of the connexin (Cx) family have been identified. Renal vascular expression and hemodynamic impacts have so far been shown for Cx37, Cx40, and Cx43. Additionally, Cx30, Cx30.3, and Cx43 have been identified to be part of tubular epithelial gap junctions and/or hemichannels. However, the localization and role of other Cx family members in renal epithelial structures remain undetermined. We aimed to localize Cx37 in the kidney to obtain information on its epithelial expression and potential functions. Immunohistochemistry in rodent kidney showed characteristic punctate patterns in the vasculature and along the nephron. Strong basolateral expression was found in the thick ascending limb and distal convoluted tubule. Weaker abundances were found in the proximal tubule and the collecting duct also at the basolateral side. In situ hybridization and real-time PCR of isolated nephron segments confirmed this distribution at the mRNA level. Ultrastructurally, Cx37 immunostaining was confined to basolateral cell interdigitations and infoldings. As a functional approach, rats were fed low- or high-salt diets. Compared with control and high-salt diets, rats treated with low-salt diet showed significantly increased Cx37 mRNA and protein levels. This may be indicative of an adaptive tubular response to changes in sodium reabsorption. In summary, renal epithelia express Cx37 in their basolateral membranes. Here, the formation of Cx37 gap junctions may be involved in cellular communication and adjustments of vectorial epithelial transport.
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MESH Headings
- Animals
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Connexins/metabolism
- Dose-Response Relationship, Drug
- Epithelium/drug effects
- Epithelium/metabolism
- Kidney/cytology
- Kidney/drug effects
- Kidney/metabolism
- Kidney Tubules, Collecting/drug effects
- Kidney Tubules, Collecting/metabolism
- Kidney Tubules, Distal/cytology
- Kidney Tubules, Distal/drug effects
- Kidney Tubules, Distal/metabolism
- Kidney Tubules, Proximal/cytology
- Kidney Tubules, Proximal/drug effects
- Kidney Tubules, Proximal/metabolism
- Loop of Henle/cytology
- Loop of Henle/drug effects
- Loop of Henle/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Models, Animal
- Rats
- Rats, Sprague-Dawley
- Sodium Chloride, Dietary/pharmacology
- Gap Junction alpha-4 Protein
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Affiliation(s)
- Adelina Stoessel
- Institute of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
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28
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Hakroush S, Moeller MJ, Theilig F, Kaissling B, Sijmonsma TP, Jugold M, Akeson AL, Traykova-Brauch M, Hosser H, Hähnel B, Gröne HJ, Koesters R, Kriz W. Effects of increased renal tubular vascular endothelial growth factor (VEGF) on fibrosis, cyst formation, and glomerular disease. Am J Pathol 2009; 175:1883-95. [PMID: 19834063 DOI: 10.2353/ajpath.2009.080792] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The role of vascular endothelial growth factor (VEGF) in renal fibrosis, tubular cyst formation, and glomerular diseases is incompletely understood. We studied a new conditional transgenic mouse system [Pax8-rtTA/(tetO)(7)VEGF], which allows increased tubular VEGF production in adult mice. The following pathology was observed. The interstitial changes consisted of a ubiquitous proliferation of peritubular capillaries and fibroblasts, followed by deposition of matrix leading to a unique kind of fibrosis, ie, healthy tubules amid a capillary-rich dense fibrotic tissue. In tubular segments with high expression of VEGF, cysts developed that were surrounded by a dense network of peritubular capillaries. The glomerular effects consisted of a proliferative enlargement of glomerular capillaries, followed by mesangial proliferation. This resulted in enlarged glomeruli with loss of the characteristic lobular structure. Capillaries became randomly embedded into mesangial nodules, losing their filtration surface. Serum VEGF levels were increased, whereas endogenous VEGF production by podocytes was down-regulated. Taken together, this study shows that systemic VEGF interferes with the intraglomerular cross-talk between podocytes and the endocapillary compartment. It suppresses VEGF secretion by podocytes but cannot compensate for the deficit. VEGF from podocytes induces a directional effect, attracting the capillaries to the lobular surface, a relevant mechanism to optimize filtration surface. Systemic VEGF lacks this effect, leading to severe deterioration in glomerular architecture, similar to that seen in diabetic nephropathy.
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Affiliation(s)
- Samy Hakroush
- Centrum für Biomedizin und Medizintechnik Mannheim, University of Heidelberg, Germany
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Kastner C, Pohl M, Sendeski M, Stange G, Wagner CA, Jensen B, Patzak A, Bachmann S, Theilig F. Effects of receptor-mediated endocytosis and tubular protein composition on volume retention in experimental glomerulonephritis. Am J Physiol Renal Physiol 2009; 296:F902-11. [PMID: 19193726 DOI: 10.1152/ajprenal.90451.2008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Human glomerulonephritis (GN) is characterized by sustained proteinuria, sodium retention, hypertension, and edema formation. Increasing quantities of filtered protein enter the renal tubule, where they may alter epithelial transport functions. Exaggerated endocytosis and consequent protein overload may affect proximal tubules, but intrinsic malfunction of distal epithelia has also been reported. A straightforward assignment to a particular tubule segment causing salt retention in GN is still controversial. We hypothesized that 1) trafficking and surface expression of major transporters and channels involved in volume regulation were altered in GN, and 2) proximal tubular endocytosis may influence locally as well as downstream expressed tubular transporters and channels. Effects of anti-glomerular basement membrane GN were studied in controls and megalin-deficient mice with blunted proximal endocytosis. Mice displayed salt retention and elevated systolic blood pressure when proteinuria had reached 10-15 mg/24 h. Surface expression of proximal Na(+)-coupled transporters and water channels was in part [Na(+)-P(i) cotransporter IIa (NaPi-IIa) and aquaporin-1 (AQP1)] increased by megalin deficiency alone, but unchanged (Na(+)/H(+) exchanger 3) or reduced (NaPi-IIa and AQP1) in GN irrespective of the endocytosis defect. In distal epithelia, significant increases in proteolytic cleavage products of alpha-epithelial Na(+) channel (ENaC) and gamma-ENaC were observed, suggesting enhanced tubular sodium reabsorption. The effects of glomerular proteinuria dominated over those of blunted proximal endocytosis in contributing to ENaC cleavage. Our data indicate that ENaC-mediated sodium entry may be the rate-limiting step in proteinuric sodium retention. Enhanced proteolytic cleavage of ENaC points to a novel mechanism of channel activation which may involve the action of filtered plasma proteases.
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Affiliation(s)
- Christian Kastner
- Charité-Universitätsmedizin Berlin, Institut für Vegetative Anatomie, Philippstr. 12, 10115 Berlin, Germany
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30
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Kim SM, Theilig F, Qin Y, Cai T, Mizel D, Faulhaber-Walter R, Hirai H, Bachmann S, Briggs JP, Notkins AL, Schnermann J. Dense-core vesicle proteins IA-2 and IA-2{beta} affect renin synthesis and secretion through the {beta}-adrenergic pathway. Am J Physiol Renal Physiol 2008; 296:F382-9. [PMID: 19019914 DOI: 10.1152/ajprenal.90543.2008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
IA-2 and IA-2beta, major autoantigens in type 1 diabetes, are transmembrane proteins in dense-core vesicles, and their expression influences the secretion of hormones and neurotransmitters. The present experiments were performed to examine whether IA-2 and IA-2beta modulate the release of renin from dense-core vesicles of juxtaglomerular granular cells in the kidney. Plasma renin concentration (PRC; ng angiotensin I.ml(-1).h(-1)) was significantly reduced in mice with null mutations in IA-2, IA-2beta, or both IA-2 and IA-2beta compared with wild-type mice (876 +/- 113, 962 +/- 130, and 596 +/- 82 vs. 1,367 +/- 93; P < 0.01, P < 0.02, and P < 0.001). Renin mRNA levels were reduced to 26.4 +/- 5.1, 39 +/- 5.4, and 35.3 +/- 5.5% of wild-type in IA-2-/-, IA-2beta-/-, and IA-2/IA-2beta-/- mice. Plasma aldosterone levels were not significantly different among genotypes. The regulation of PRC by furosemide and salt intake, and of aldosterone by salt intake, was maintained in all genotypes. IA-2 and IA-2beta expression did not colocalize with renin but showed overlapping immunoreactivity with tyrosine hydroxylase. While propranolol reduced PRC in wild-type mice, it had no effect on PRC in IA-2/ IA-2beta-/- mice. Renal tyrosine hydroxylase mRNA and immunoreactivity were reduced in IA-2/IA-2beta-/- mice as was the urinary excretion of catecholamines. We conclude that IA-2 and IA-2beta are required to maintain normal levels of renin expression and renin release, most likely by permitting normal rates of catecholamine release from sympathetic nerve terminals.
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Affiliation(s)
- Soo Mi Kim
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bldg. 10, Rm. 4D51, 10 Center Dr.-MSC 1370, Bethesda, MD 20892, USA
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31
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Stoessel A, Paliege A, Theilig F, Addabbo F, Ratliff B, Waschke J, Patschan D, Goligorsky MS, Bachmann S. Indolent course of tubulointerstitial disease in a mouse model of subpressor, low-dose nitric oxide synthase inhibition. Am J Physiol Renal Physiol 2008; 295:F717-25. [PMID: 18596080 DOI: 10.1152/ajprenal.00071.2008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Deficiency of nitric oxide (NO) represents a consistent manifestation of endothelial dysfunction (ECD), and the accumulation of asymmetric dimethylarginine occurs early in renal disease. Here, we confirmed in vitro and in vivo the previous finding that a fragment of collagen XVIII, endostatin, was upregulated by chronic inhibition of NO production and sought to support a hypothesis that primary ECD contributes to nephrosclerosis in the absence of other profibrotic factors. To emulate more closely the indolent course of ECD, the study was expanded to an in vivo model with N(G)-monomethyl-L-arginine (L-NMMA; mimics effects of asymmetric dimethylarginine) administered to mice in the drinking water at subpressor doses of 0.3 and 0.8 mg/ml for 3-6 mo. This resulted in subtle but significant morphological alterations detected in kidneys of mice chronically treated with L-NMMA: 1) consistent perivascular expansion of interstitial matrix components at the inner stripe of the outer medulla and 2) collagen XVIII/endostatin abundance. Ultrastructural abnormalities were detected in L-NMMA-treated mice: 1) increased activity of the interstitial fibroblasts; 2) occasional detachment of endothelial cells from the basement membrane; 3) splitting of the vascular basement membrane; 4) focal fibrosis; and 5) accumulation of lipofuscin by interstitial fibroblasts. Preembedding labeling of microvasculature with anti-CD31 antibodies showed infiltrating leukocytes and agglomerating platelets attaching to the visibly intact or denuded capillaries. Collectively, the data indicate that the mouse model of subpressor chronic administration of L-NMMA is not a robust one (endothelial pathology visible only ultrastructurally), and yet it closely resembles the natural progression of endothelial dysfunction, microvascular abnormalities, and associated tubulointerstitial scarring.
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Affiliation(s)
- Adelina Stoessel
- Department of Anatomy, Charité Universitätsmedizin Berlin, Berlin, Germany
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32
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Paliege A, Mutig K, Theilig F, Goligorsky M, Bachmann S. Activation of Na,K,2Cl‐cotransporter stimulates outer medullary connective tissue expression. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.1179.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Michael Goligorsky
- Renal Research InstituteDivision of NephrologyNew York Medical CollegeValhallaNY
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33
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Stoessel A, Paliege A, Theilig F, Addabbo F, Goligorsky M, Bachmann S. Long‐term effects of low‐dose NOS inhibition in mouse renal medulla. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.1179.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Francesco Addabbo
- Renal Research InstituteDivision of NephrologyNew York Medical CollegeValhallaNY
| | - Michael Goligorsky
- Renal Research InstituteDivision of NephrologyNew York Medical CollegeValhallaNY
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34
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Theilig F, Goranova I, Hirsch JR, Wieske M, Ünsal S, Bachmann S, Veh RW, Derst C. Cellular Localization of THIK-1 (K 2P13.1) and THIK-2 (K 2P12.1) K + Channels in the Mammalian Kidney. Cell Physiol Biochem 2008; 21:63-74. [DOI: 10.1159/000113748] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2007] [Indexed: 11/19/2022] Open
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35
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Theilig F, Kriz W, Jerichow T, Schrade P, Hähnel B, Willnow T, Le Hir M, Bachmann S. Abrogation of Protein Uptake through Megalin-Deficient Proximal Tubules Does Not Safeguard against Tubulointerstitial Injury. J Am Soc Nephrol 2007; 18:1824-34. [PMID: 17460141 DOI: 10.1681/asn.2006111266] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Sustained proteinuria and tubulointerstitial damage have been closely linked with progressive renal failure. Upon excess protein endocytosis, tubular epithelial cells are thought to produce mediators that promote inflammation, tubular degeneration, and fibrosis. This concept was tested in a transgenic mouse model with megalin deficiency. Application of an anti-glomerular basement membrane serum to transgenic megalin-deficient mice [Cre(+)/GN] and megalin-positive littermates [Cre(-)/GN] produced the typical glomerulonephritis (GN) with heavy proteinuria in both groups. Tubulointerstitial damages correlated closely with glomerular damages in pooled Cre(+)/GN and Cre(-)/GN mice. Owing to a mosaic pattern of megalin expression in the mutant mice, Cre(+)/GN kidneys permitted side-by-side analysis of megalin-deficient and megalin-positive tubules in the same kidney. Protein endocytosis was found only in megalin-positive cells. TGF-beta, intercellular adhesion molecule, vascular cellular adhesion molecule, endothelin-1, and cell proliferation were high in megalin-positive cells, whereas apoptosis, heat-shock protein 25, and osteopontin were enhanced in megalin-deficient cells. No fibrotic changes were associated with either phenotype. Tubular degeneration with interstitial inflammation was found only in nephrons with extensive crescentic lesions at the glomerulotubular junction. In sum, enhanced protein endocytosis indeed led to an upregulation of profibrotic mediators in a megalin-dependent way; however, there was no evidence that endocytosis played a pathogenetic role in the development of the tubulointerstitial disease.
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Affiliation(s)
- Franziska Theilig
- Institut für Vegetative Anatomie, Charité Universitätsmedizin Berlin, Philippstrasse 12, 10115 Berlin
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36
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Quaschning T, Voss F, Relle K, Kalk P, Vignon-Zellweger N, Pfab T, Bauer C, Theilig F, Bachmann S, Kraemer-Guth A, Wanner C, Theuring F, Galle J, Hocher B. Lack of Endothelial Nitric Oxide Synthase Promotes Endothelin-Induced Hypertension: Lessons from Endothelin-1 Transgenic/Endothelial Nitric Oxide Synthase Knockout Mice. J Am Soc Nephrol 2007; 18:730-40. [PMID: 17287431 DOI: 10.1681/asn.2006050541] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Endothelin-1 (ET-1) is one of the most potent biologic vasoconstrictors. Nevertheless, transgenic mice that overexpress ET-1 exhibit normal BP. It was hypothesized that vascular effects of ET-1 may be antagonized by an increase of the endothelial counterpart of ET-1, nitric oxide (NO), which is produced by the endothelial NO synthase (eNOS). Therefore, cross-bred animals of ET transgenic mice (ET+/+) and eNOS knockout (eNOS-/-) mice and were generated, and BP and endothelial function were evaluated in these animals. Endothelium-dependent and -independent vascular function was assessed as relaxation/contraction of isolated preconstricted aortic rings. The tissue ET and NO system was determined in aortic rings by quantitative real-time PCR and Western blotting. Systolic BP was similar in ET+/+ and wild-type (WT) mice but was significantly elevated in eNOS-/- mice (117 +/- 4 mmHg versus 94 +/- 6 mmHg in WT mice; P < 0.001) and even more elevated in ET+/+ eNOS-/- cross-bred mice (130 +/- 4 mmHg; P < 0.05 versus eNOS-/-). Maximum endothelium-dependent relaxation was enhanced in ET+/+ mice (103 +/- 6 versus 87 +/- 4% of preconstriction in WT littermates; P < 0.05) and was completely blunted in eNOS-/- (-3 +/- 4%) and ET+/+ eNOS-/- mice (-4 +/- 4%), respectively. Endothelium-independent relaxation was comparable among all groups. Quantitative real-time PCR as well as Western blotting revealed an upregulation of the aortic ET(A) and ET(B) receptors in ET+/+ eNOS-/-, whereas eNOS was absent in aortic rings of eNOS-/- and ET+/+ eNOS-/- mice. ET-1 aortic tissue concentrations were similar in WT mice and ET+/+ eNOS-/- mice most probably as a result of an enhanced clearance of ET-1 by the upregulated ET(B) receptor. These data show for the first time that in transgenic mice that overexpress human ET-1, additional knockout of eNOS results in a further enhancement of BP as compared with eNOS-/- mice. The human ET+/+ eNOS-/- mice therefore represent a novel model of hypertension as a result of an imbalance between the vascular ET-1 and NO systems.
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Affiliation(s)
- Thomas Quaschning
- Department of Nephrology, University Hospital of Freiburg, Freiburg, Germany
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37
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Merle U, Theilig F, Fein E, Gehrke S, Kallinowski B, Riedel HD, Bachmann S, Stremmel W, Kulaksiz H. Localization of the iron-regulatory proteins hemojuvelin and transferrin receptor 2 to the basolateral membrane domain of hepatocytes. Histochem Cell Biol 2006; 127:221-6. [PMID: 16932966 DOI: 10.1007/s00418-006-0229-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2006] [Indexed: 02/07/2023]
Abstract
The newly discovered proteins hemojuvelin (Hjv) and transferrin receptor type 2 (TfR2) are involved in iron metabolism. Mutations in the Hjv and TfR2 gene cause hemochromatosis. We investigated the expression and cellular localization of Hjv and TfR2 in rat and human liver. The expression of Hjv and TfR2 was shown on mRNA and protein level by RT-PCR and immunoblot experiments. Their cellular localization was studied by immunofluorescence with antibodies raised against Hjv and TfR2. Hjv and TfR2 are present in human and rat liver and in primary human hepatocytes. Antisera raised against Hjv identified immunoreactive proteins with an apparent size of 44 and 46 kDa in immunoblot experiments of rat and human liver extracts, which are in accordance with the putative membrane-bound and cleaved soluble forms of this protein, respectively. TfR2 was detected as a 105 kDa protein corresponding to the predicted size of glycosylated TfR2 monomers. In immunofluorescence experiments, Hjv and TfR2 were found in rat liver only in hepatocytes. At the subcellular level, both proteins were predominantly localized to the basolateral membrane domain of hepatocytes. The localization of Hjv and TfR2 at the same membrane domain renders a functional interaction of these two proteins in iron homeostasis possible.
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Affiliation(s)
- Uta Merle
- Department of Gastroenterology, University Hospital, Heidelberg, Germany
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38
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Oppermann M, Mizel D, Huang G, Li C, Deng C, Theilig F, Bachmann S, Briggs J, Schnermann J, Castrop H. Macula densa control of renin secretion and preglomerular resistance in mice with selective deletion of the B isoform of the Na,K,2Cl co-transporter. J Am Soc Nephrol 2006; 17:2143-52. [PMID: 16807402 DOI: 10.1681/asn.2006040384] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Na,K,2Cl co-transporter (NKCC2), the primary NaCl uptake pathway in the thick ascending limb of Henle, is expressed in three different full-length splice variants, called NKCC2F, NKCC2A, and NKCC2B. These variants, derived by differential splicing of the variable exon 4, show a distinct distribution pattern along the loop of Henle, but the functional significance of this organization is unclear. By introduction of premature stop codons into exon 4B, specific for the B isoform, mice with an exclusive NKCC2B deficiency were generated. Relative expression levels and distribution patterns of NKCC2A and NKCC2F were not altered in the NKCC2B-deficient mice. NKCC2B-deficient mice did not display a salt-losing phenotype; basal plasma renin and aldosterone levels were not different from those of wild-type mice. Ambient urine osmolarities, however, were slightly but significantly reduced. Distal Cl concentration was significantly elevated and loop of Henle Cl absorption was reduced in microperfused superficial loops of Henle of NKCC2B-deficient mice. Because of the presence of NKCC2A in the macula densa, maximum tubuloglomerular feedback responses were normal, but tubuloglomerular feedback function curves were right-shifted, indicating reduced sensitivity in the subnormal flow range. Plasma renin concentration in NKCC2B-deficient mice was reduced under conditions of salt loading compared with that in wild-type mice. This study shows the feasibility of generating mice with specific deletions of single splice variants. The mild phenotype of mice that are deficient in the B isoform of NKCC2 indicates a limited role for NKCC2B for overall salt retrieval. Nevertheless, the high-affinity NKCC2B contributes to salt absorption and macula densa function in the low NaCl concentration range.
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Affiliation(s)
- Mona Oppermann
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1370, USA
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39
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Theilig F, Debiec H, Nafz B, Ronco P, Nüsing R, Seyberth HW, Pavenstädt H, Bouby N, Bachmann S. Renal cortical regulation of COX-1 and functionally related products in early renovascular hypertension (rat). Am J Physiol Renal Physiol 2006; 291:F987-94. [PMID: 16788145 DOI: 10.1152/ajprenal.00099.2006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Renal volume regulation is modulated by the action of cyclooxygenases (COX) and the resulting generation of prostanoids. Epithelial expression of COX isoforms in the cortex directs COX-1 to the distal convolutions and cortical collecting duct, and COX-2 to the thick ascending limb. Partly colocalized are prostaglandin E synthase (PGES), the downstream enzyme for renal prostaglandin E(2) (PGE(2)) generation, and the EP receptors type 1 and 3. COX-1 and related components were studied in two kidney-one clip (2K1C) Goldblatt hypertensive rats with combined chronic ANG II or bradykinin B(2) receptor blockade using candesartan (cand) or the B(2) antagonist Hoechst 140 (Hoe). Rats (untreated sham, 2K1C, sham + cand, 2K1C + cand, sham + Hoe, 2K1C + Hoe) were treated to map expression of parameters controlling PGE(2) synthesis. In 2K1C, cortical COX isoforms did not change uniformly. COX-2 changed in parallel with NO synthase 1 (NOS1) expression with a raise in the clipped, but a decrease in the nonclipped side. By contrast, COX-1 and PGES were uniformly downregulated in both kidneys, along with reduced urinary PGE(2) levels, and showed no clear relations with the NO status. ANG II receptor blockade confirmed negative regulation of COX-2 by ANG II but blunted the decrease in COX-1 selectively in nonclipped kidneys. B(2) receptor blockade reduced COX-2 induction in 2K1C but had no clear effect on COX-1. We suggest that in 2K1C, COX-1 and PGES expression may fail to oppose the effects of renovascular hypertension through reduced prostaglandin signaling in late distal tubule and cortical collecting duct.
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MESH Headings
- Adrenergic beta-Antagonists/pharmacology
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Animals
- Benzimidazoles/pharmacology
- Biphenyl Compounds
- Blood Pressure/physiology
- Bradykinin/analogs & derivatives
- Bradykinin/pharmacology
- Cyclic GMP/metabolism
- Cyclooxygenase 1/genetics
- Cyclooxygenase 1/metabolism
- Cyclooxygenase 2/genetics
- Cyclooxygenase 2/metabolism
- Dinoprostone/urine
- Disease Models, Animal
- Hypertension, Renovascular/metabolism
- Hypertension, Renovascular/physiopathology
- Kidney Cortex/enzymology
- Kidney Tubules, Collecting/enzymology
- Kidney Tubules, Distal/enzymology
- Loop of Henle/enzymology
- Male
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Nitric Oxide/metabolism
- Nitric Oxide Synthase/metabolism
- Nitric Oxide Synthase Type I
- Rats
- Rats, Sprague-Dawley
- Receptors, Prostaglandin E/genetics
- Receptors, Prostaglandin E/metabolism
- Receptors, Prostaglandin E, EP1 Subtype
- Receptors, Prostaglandin E, EP3 Subtype
- Surgical Instruments
- Tetrazoles/pharmacology
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Affiliation(s)
- F Theilig
- Charité Universitätsmedizin Berlin, Institut für Vegetative Anatomie, Philippstr. 12, 10115 Berlin, Germany
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40
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Castrop H, Oppermann M, Weiss Y, Huang Y, Mizel D, Lu H, Germain S, Schweda F, Theilig F, Bachmann S, Briggs J, Kurtz A, Schnermann J. Reporter gene recombination in juxtaglomerular granular and collecting duct cells by human renin promoter-Cre recombinase transgene. Physiol Genomics 2006; 25:277-85. [PMID: 16418317 DOI: 10.1152/physiolgenomics.00302.2005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To assess the feasibility of using the renin promoter for expressing Cre recombinase in juxtaglomerular (JG) cells only, we generated five independent transgenic mouse lines (designated hRen-Cre) expressing Cre recombinase under control of a 12.2-kb human renin promoter. In the kidneys of adult mice Cre mRNA (RT-PCR) was found in the renal cortex, with Cre protein (immunohistochemistry) being localized in afferent arterioles and to a lower degree in interlobular arteries. Cre mRNA levels were regulated in a renin-typical fashion by changes in oral salt intake, water restriction, or isoproterenol infusion, indicating the presence of key regulatory elements within 12.2 kb of the 5′-flanking region of the human renin gene. hRen-Cre mice were interbred with both the ROSA26-EGFP and ROSA26-lacZ reporter strains to assess renin promoter activity from Cre-mediated excision of a floxed stop cassette and subsequent enhanced green fluorescent protein (EGFP) and β-galactosidase (β-gal) detection. In adult mice, β-gal staining and EGFP were observed in afferent arterioles and interlobular arteries, overlapping with Cre protein expression. In addition, intense β-gal staining was found in cortical and medullary collecting ducts where Cre expression was minimal. In embryonic kidneys, β-gal staining was detected in the developing collecting duct system beginning at embryonic day 12, showing substantial activity of the human renin promoter in the branching ureteric bud. Our data indicate that besides its well-known activity in JG cells and renal vessels the human renin promoter is transiently active in the collecting duct system during kidney development, complicating the use of this approach for JG cell-specific excision of floxed targets.
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Affiliation(s)
- H Castrop
- Institute of Physiology, University of Regensburg, Germany.
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41
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Castrop H, Oppermann M, Weiss Y, Huang Y, Mizel D, Theilig F, Bachmann S, Briggs J, Kurtz A, Schnermann J. TRANSGENIC MICE EXPRESSING CRE RECOMBINASE UNDER THE CONTROL OF THE HUMAN RENIN PROMOTER. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a344-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Hayo Castrop
- Institute of PhysiologyUniversity of Regensburg31 UniversitaetsstrasseRegensburg93053Germany
| | | | - Yvonne Weiss
- Institute of PhysiologyUniversity of Regensburg31 UniversitaetsstrasseRegensburg93053Germany
| | | | | | - Franziska Theilig
- Institute of AnatomyCharite Universitaetsmedizin12 PhilippstrasseBerlin10115Germany
| | - Sebastian Bachmann
- Institute of AnatomyCharite Universitaetsmedizin12 PhilippstrasseBerlin10115Germany
| | | | - Armin Kurtz
- Institute of PhysiologyUniversity of Regensburg31 UniversitaetsstrasseRegensburg93053Germany
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42
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Pfab T, Thöne-Reineke C, Theilig F, Lange I, Witt H, Maser-Gluth C, Bader M, Stasch JP, Ruiz P, Bachmann S, Yanagisawa M, Hocher B. Diabetic Endothelin B Receptor–Deficient Rats Develop Severe Hypertension and Progressive Renal Failure. J Am Soc Nephrol 2006; 17:1082-9. [PMID: 16495378 DOI: 10.1681/asn.2005080833] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The endothelin (ET) system has been implicated in the pathogenesis of diabetic nephropathy. The role of the ET-B receptor (ETBR) is still unclear. The effect of ETBR deficiency on the progression of diabetic nephropathy in a streptozotocin model was analyzed in four groups: (1) Homozygous ETBR-deficient (ETBRd) diabetic rats, (2) ETBRd rats, (3) diabetic controls, and (4) wild-type controls. BP and kidney function were measured for 10 wk, followed by biochemical and histologic analysis of the kidneys. The study demonstrates that ETBRd diabetic rats on a normal-sodium diet develop severe hypertension, albuminuria, and a mild reduction of creatinine clearance. The strong BP rise seems not to be caused by activation of the renin-angiotensin-aldosterone system or by suppression of the nitric oxide system. Elevated plasma ET-1, possibly reflecting a reduced ETBR-dependent clearance, seems to cause the severe hypertension via the ETA receptor. The results do not support the hypothesis that a reduction of ETBR activity inhibits the progression of diabetic nephropathy. The study demonstrates for the first time that the combination of diabetes and ETBR deficiency causes severe low-renin hypertension with progressive renal failure.
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MESH Headings
- Animals
- Blood Pressure
- Creatinine/blood
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Experimental/physiopathology
- Diabetic Nephropathies/etiology
- Disease Models, Animal
- Endothelin-1/blood
- Hypertension/etiology
- Hypertension/pathology
- Hypertension/physiopathology
- Kidney/pathology
- Kidney/physiopathology
- Kidney Failure, Chronic/etiology
- Kidney Failure, Chronic/pathology
- Kidney Failure, Chronic/physiopathology
- Myocardium/pathology
- Rats
- Rats, Mutant Strains
- Receptor, Endothelin A/physiology
- Receptor, Endothelin B/deficiency
- Receptor, Endothelin B/genetics
- Receptor, Endothelin B/physiology
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Affiliation(s)
- Thiemo Pfab
- Center for Cardiovascular Research/Institute of Pharmacology, Charité Mitte, Hessische Strasse 3-4, 10115 Berlin, Germany
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Kulaksiz H, Theilig F, Bachmann S, Gehrke SG, Rost D, Janetzko A, Cetin Y, Stremmel W. The iron-regulatory peptide hormone hepcidin: expression and cellular localization in the mammalian kidney. J Endocrinol 2005; 184:361-70. [PMID: 15684344 DOI: 10.1677/joe.1.05729] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
It is generally accepted that iron homeostasis is mainly controlled in the gastrointestinal tract by absorption of dietary iron. However, recent studies have shown that the kidneys are also involved in iron metabolism. Since the iron-regulatory and antimicrobial peptide hormone hepcidin was originally isolated from human urine we have investigated the expression as well as the zonal and cellular localization of hepcidin in the mammalian kidney and developed an ELISA assay to analyze hepcidin concentrations in serum and urine. The expression of hepcidin was shown by RT-PCR and immunoblot experiments; its cellular localization was studied by immunocytochemistry in human, mouse and rat kidney, which revealed similar patterns of immunoreactivity. Hepcidin expression was absent from the proximal tubule and descending and ascending thin limbs. There was strong expression in the thick ascending limb of the cortex and in connecting tubules. Moderate expression was noted in the thick ascending limb and collecting ducts of the medulla and in collecting ducts of the papilla. Importantly, the cells of the macula densa were unstained. At the cellular level, hepcidin was localized to the apical cell pole of the renal epithelial cells. Based on its presence in urine, hepcidin may be released apically into the urine. Enhanced levels of hepcidin were determined in patients with chronic renal insuffciency (156.8 ng/ml, controls 104.2 ng/ml) indicating that the kidneys may metabolize and/or eliminate the circulating peptide. From the expression of hepcidin in the mammalian kidney, we have concluded that the iron-regulatory hormone is an intrinsic renal peptide which is not only eliminated by the kidney but is also synthesized in the kidney tubular system. Localization of hepcidin in the kidney implicates an iron-regulatory role of this peptide hormone in the renal tubular system, possibly in connection with the iron transporter divalent metal transporter-1.
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Affiliation(s)
- H Kulaksiz
- Department of Internal Medicine, Division of Gastroenterology, Im Neuenheimer Feld 410, University Hospital Heidelberg, D-69121 Heidelberg, Germany.
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Castrop H, Huang Y, Hashimoto S, Mizel D, Hansen P, Theilig F, Bachmann S, Deng C, Briggs J, Schnermann J. Impairment of tubuloglomerular feedback regulation of GFR in ecto-5'-nucleotidase/CD73-deficient mice. J Clin Invest 2004; 114:634-42. [PMID: 15343381 PMCID: PMC514589 DOI: 10.1172/jci21851] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2004] [Accepted: 06/15/2004] [Indexed: 11/17/2022] Open
Abstract
Adenosine coordinates organ metabolism and blood supply, and it modulates immune responses. In the kidney it mediates the vascular response elicited by changes in NaCl concentration in the macula densa region of the nephron, thereby serving as an important regulator of GFR. To determine whether adenosine formation depends on extracellular nucleotide hydrolysis, we studied NaCl-dependent GFR regulation (tubuloglomerular feedback) in mice with targeted deletion of ecto-5'-nucleotidase/CD73 (e-5'NT/CD73), the enzyme responsible for adenosine formation from AMP. e-5'NT/CD73(-/-) mice were viable and showed no gross anatomical abnormalities. Blood pressure, blood and urine chemistry, and renal blood flow were not different between e-5'NT/CD73(+/+) and e-5'NT/CD73(-/-) mice. e-5'NT/CD73(-/-) mice had a significantly reduced fall in stop flow pressure and superficial nephron glomerular filtration rate in response to a saturating increase of tubular perfusion flow. Furthermore, whereas tubuloglomerular feedback responses did not change significantly during prolonged loop of Henle perfusion in e-5'NT/CD73(+/+) mice, a complete disappearance of the residual feedback response was noted in e-5'NT/CD73(-/-) mice over 10 minutes of perfusion. The contractile response of isolated afferent arterioles to adenosine was normal in e-5'NT/CD73(-/-) mice. We conclude that the generation of adenosine at the glomerular pole depends to a major extent on e-5'NT/CD73-mediated dephosphorylation of 5'-AMP, presumably generated from released ATP.
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Affiliation(s)
- Hayo Castrop
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, USA
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Henn V, Edemir B, Stefan E, Wiesner B, Lorenz D, Theilig F, Schmitt R, Vossebein L, Tamma G, Beyermann M, Krause E, Herberg FW, Valenti G, Bachmann S, Rosenthal W, Klussmann E. Identification of a novel A-kinase anchoring protein 18 isoform and evidence for its role in the vasopressin-induced aquaporin-2 shuttle in renal principal cells. J Biol Chem 2004; 279:26654-65. [PMID: 15037626 DOI: 10.1074/jbc.m312835200] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Arginine vasopressin (AVP) increases the water permeability of renal collecting duct principal cells by inducing the fusion of vesicles containing the water channel aquaporin-2 (AQP2) with the plasma membrane (AQP2 shuttle). This event is initiated by activation of vasopressin V2 receptors, followed by an elevation of cAMP and the activation of protein kinase A (PKA). The tethering of PKA to subcellular compartments by protein kinase A anchoring proteins (AKAPs) is a prerequisite for the AQP2 shuttle. During the search for AKAP(s) involved in the shuttle, a new splice variant of AKAP18, AKAP18delta, was identified. AKAP18delta functions as an AKAP in vitro and in vivo. In the kidney, it is mainly expressed in principal cells of the inner medullary collecting duct, closely resembling the distribution of AQP2. It is present in both the soluble and particulate fractions derived from renal inner medullary tissue. Within the particulate fraction, AKAP18delta was identified on the same intracellular vesicles as AQP2 and PKA. AVP not only recruited AQP2, but also AKAP18delta to the plasma membrane. The elevation of cAMP caused the dissociation of AKAP18delta and PKA. The data suggest that AKAP18delta is involved in the AQP2 shuttle.
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Affiliation(s)
- Volker Henn
- Forschungsinstitut fur Molekulare Pharmakologie, Campus Berlin-Buch, Robert-Rossle-Strasse 10, 13125 Berlin, Germany
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46
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Câmpean V, Theilig F, Paliege A, Breyer M, Bachmann S. Key enzymes for renal prostaglandin synthesis: site-specific expression in rodent kidney (rat, mouse). Am J Physiol Renal Physiol 2003; 285:F19-32. [PMID: 12657565 DOI: 10.1152/ajprenal.00443.2002] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prostanoids derived from endogenous cylooxygenase (COX)-mediated arachidonic acid metabolism play important roles in the maintenance of renal blood flow and salt and water homeostasis. The relative importance of COX-1 and COX-2 isoforms is under active investigation. We have performed a comprehensive histochemical analysis by comparing rat and mouse kidneys for cellular and subcellular localization of COX-1 and -2 and microsomal-type PGE synthase (PGES), the rate-limiting biosynthetic enzyme in PGE2 synthesis. A choice of different sera was compared, and the results were confirmed by antigen-retrieval techniques, in situ hybridization, RT-PCR, and the use of COX knockout mice. In the glomerulus, significant COX-1 expression was detected in a subset of mesangial cells. Along the renal tubule, the known COX-2 expression in cTAL and macula densa was paralleled by PGES staining. In the terminal distal convoluted tubule, connecting tubule, and cortical and medullary collecting ducts, a significant COX-1 signal was colocalized with PGES; COX-2 was not found in these sites. Intercalated cells were generally negative. Cortical fibroblasts were COX-1 and PGES positive in mice, whereas in rats only PGES could be reliably detected. Lipid-laden interstitial cells of the inner medulla were COX-1, -2, and PGES positive. Vascular smooth muscle cells were not stained. The present data support prominent functions of renal prostanoids, predominantly PGE2, by defining expression sites of the key enzymes for their biosynthesis in the rat and mouse. Results define the renal cell types involved in prostaglandin autacoid functions within spatially restricted sites such as the juxtaglomerular apparatus, mesangium, distal convolutions and collecting duct, and in compartments of the renal interstitium.
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Affiliation(s)
- Valentina Câmpean
- Anatomisches Institut, Charité, Humboldt Universität, Berlin, Germany
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Theilig F, Câmpean V, Paliege A, Breyer M, Briggs JP, Schnermann J, Bachmann S. Epithelial COX-2 expression is not regulated by nitric oxide in rodent renal cortex. Hypertension 2002; 39:848-53. [PMID: 11967238 DOI: 10.1161/01.hyp.0000013082.99285.35] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the adult rodent kidney cortex, cyclooxygenase-2 (COX-2), NO synthase (NOS1), and renin synthesis change in parallel on alterations in distal tubular NaCl concentration, and their products in part may mutually determine synthesis and activity of these enzymes. Epithelial NO synthesis has been postulated to exert a stimulatory role on COX-2 expression. Changes in COX-2 and NOS1 may be assessed histochemically by determining changes in the number of positive cells. In rat, macula densa and adjacent cells may co-express COX-2 and NOS1, whereas cell groups of the upstream thick ascending limb (cTAL) express COX-2 alone. We have tested whether the stimulation of COX-2 expression by short- and long-term unilateral renal artery stenosis, low salt, and furosemide treatment depends on co-expression of NOS1. These conditions produced significant respective increases (40% to 351%, P<0.05) in the number of COX-2 immunoreactive cells, regardless of whether NOS1 was present or not, suggesting that co-expression of NOS1 is not necessary to produce these changes. Under high-salt conditions, analogous though inverse changes were recorded (-62% to -73%, P<0.05). In mice with genetic deletion of NOS1, low- and high-salt diets caused similar changes of COX-2 immunoreactivity (106% and -52%, P<0.05) than those seen in wild-type mice (43% and -78%, P<0.05). We conclude that alterations of distal tubular NaCl concentration and presumably NaCl transport induce changes in epithelial COX-2 expression that does not depend on presence of co-expressed NOS1. It therefore seems unlikely that NO is part of a signal transduction chain between tubular chloride sensing and the modulating effects of prostaglandins in tubulo-vascular information transfer.
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Affiliation(s)
- Franziska Theilig
- Anatomisches Institut, Charité, Humboldt Universität, Berlin, Germany
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Theilig F, Bostanjoglo M, Pavenstädt H, Grupp C, Holland G, Slosarek I, Gressner AM, Russwurm M, Koesling D, Bachmann S. Cellular distribution and function of soluble guanylyl cyclase in rat kidney and liver. J Am Soc Nephrol 2001; 12:2209-2220. [PMID: 11675397 DOI: 10.1681/asn.v12112209] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Soluble guanylyl cyclase (sGC) catalyzes the biosynthesis of cGMP in response to binding of L-arginine-derived nitric oxide (NO). Functionally, the NO-sGC-cGMP signaling pathway in kidney and liver has been associated with regional hemodynamics and the regulation of glomerular parameters. The distribution of the ubiquitous sGC isoform alpha 1 beta 1 sGC was studied with a novel, highly specific antibody against the beta 1 subunit. In parallel, the presence of mRNA encoding both subunits was investigated by using in situ hybridization and reverse transcription-PCR assays. The NO-induced, sGC-dependent accumulation of cGMP in cytosolic extracts of tissues and cells was measured in vitro. Renal glomerular arterioles, including the renin-producing granular cells, mesangium, and descending vasa recta, as well as cortical and medullary interstitial fibroblasts, expressed sGC. Stimulation of isolated mesangial cells, renal fibroblasts, and hepatic Ito cells with a NO donor resulted in markedly increased cytosolic cGMP levels. This assessment of sGC expression and activity in vascular and interstitial cells of kidney and liver may have implications for understanding the role of local cGMP signaling cascades.
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Affiliation(s)
- Franziska Theilig
- Department of Anatomy, Charité, Humboldt University, Berlin, Germany
| | | | | | - Clemens Grupp
- Department of Nephrology, University of Göttingen, Göttingen, Germany
| | - Gudrun Holland
- Department of Anatomy, Charité, Humboldt University, Berlin, Germany
| | - Ilka Slosarek
- Department of Anatomy, Charité, Humboldt University, Berlin, Germany
| | - Axel M Gressner
- Department of Clinical Chemistry, Rheinisch-Westfälische Technische Hochschule Aachen, Aachen, Germany
| | | | - Doris Koesling
- Department of Pharmacology, Ruhr University, Bochum, Germany
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Bachmann S, Theilig F. Juxtaglomerular apparatus, nitric oxide, and macula densa signaling. Adv Nephrol Necker Hosp 2001; 30:95-107. [PMID: 11068637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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