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Kiermayer C, Northrup E, Schrewe A, Walch A, de Angelis MH, Schoensiegel F, Zischka H, Prehn C, Adamski J, Bekeredjian R, Ivandic B, Kupatt C, Brielmeier M. Heart-Specific Knockout of the Mitochondrial Thioredoxin Reductase (Txnrd2) Induces Metabolic and Contractile Dysfunction in the Aging Myocardium. J Am Heart Assoc 2015; 4:e002153. [PMID: 26199228 PMCID: PMC4608093 DOI: 10.1161/jaha.115.002153] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 05/19/2015] [Indexed: 01/19/2023]
Abstract
BACKGROUND Ubiquitous deletion of thioredoxin reductase 2 (Txnrd2) in mice is embryonically lethal and associated with abnormal heart development, while constitutive, heart-specific Txnrd2 inactivation leads to dilated cardiomyopathy and perinatal death. The significance of Txnrd2 in aging cardiomyocytes, however, has not yet been examined. METHODS AND RESULTS The tamoxifen-inducible heart-specific αMHC-MerCreMer transgene was used to inactivate loxP-flanked Txnrd2 alleles in adult mice. Hearts and isolated mitochondria from aged knockout mice were morphologically and functionally analyzed. Echocardiography revealed a significant increase in left ventricular end-systolic diameters in knockouts. Fractional shortening and ejection fraction were decreased compared with controls. Ultrastructural analysis of cardiomyocytes of aged mice showed mitochondrial degeneration and accumulation of autophagic bodies. A dysregulated autophagic activity was supported by higher levels of lysosome-associated membrane protein 1 (LAMP1), microtubule-associated protein 1A/1B-light chain 3-I (LC3-I), and p62 in knockout hearts. Isolated Txnrd2-deficient mitochondria used less oxygen and tended to produce more reactive oxygen species. Chronic hypoxia inducible factor 1, α subunit stabilization and altered transcriptional and metabolic signatures indicated that energy metabolism is deregulated. CONCLUSIONS These results imply a novel role of Txnrd2 in sustaining heart function during aging and suggest that Txnrd2 may be a modifier of heart failure.
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MESH Headings
- Age Factors
- Animals
- Autophagy
- Blood Pressure
- Disease Models, Animal
- Energy Metabolism
- Gene Expression Profiling/methods
- Gene Expression Regulation
- Genetic Predisposition to Disease
- Heart Failure/enzymology
- Heart Failure/genetics
- Heart Failure/pathology
- Heart Failure/physiopathology
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Lysosomal Membrane Proteins/genetics
- Lysosomal Membrane Proteins/metabolism
- Metabolomics/methods
- Mice, Knockout
- Microtubule-Associated Proteins/genetics
- Microtubule-Associated Proteins/metabolism
- Mitochondria, Heart/enzymology
- Mitochondria, Heart/ultrastructure
- Myocardial Contraction
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/ultrastructure
- Oxidative Stress
- Phenotype
- RNA, Messenger/metabolism
- Reactive Oxygen Species/metabolism
- Stroke Volume
- Thioredoxin Reductase 2/deficiency
- Thioredoxin Reductase 2/genetics
- Time Factors
- Ventricular Dysfunction, Left/enzymology
- Ventricular Dysfunction, Left/genetics
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Function, Left
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Affiliation(s)
- Claudia Kiermayer
- Research Unit Comparative Medicine, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Emily Northrup
- Research Unit Comparative Medicine, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Anja Schrewe
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Axel Walch
- Reserach Unit Analytical Pathology, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Martin Hrabe de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
- Chair of Experimental Genetics, Technische Universität MünchenMunich, Germany
| | - Frank Schoensiegel
- Department of Internal Medicine III, University of HeidelbergHeidelberg, Germany
| | - Hans Zischka
- Institute of molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Cornelia Prehn
- Institute of Experimental Genetics, Genome Analysis Center, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
| | - Jerzy Adamski
- Institute of Experimental Genetics, Genome Analysis Center, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
- Chair of Experimental Genetics, Technische Universität MünchenMunich, Germany
| | - Raffi Bekeredjian
- Department of Internal Medicine III, University of HeidelbergHeidelberg, Germany
| | - Boris Ivandic
- Department of Internal Medicine III, University of HeidelbergHeidelberg, Germany
| | - Christian Kupatt
- I. Medizinische Klinik und Poliklinik, Klinikum Rechts der Isar, TU MunichMunich, Germany
- German Center for Cardiovascular Research (DZHK) partner site Munich Heart AllianceMunich, Germany
| | - Markus Brielmeier
- Research Unit Comparative Medicine, Helmholtz Zentrum München, German Research Center for Environmental HealthNeuherberg, Germany
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Rowshanravan B, Woodcock SA, Botella JA, Kiermayer C, Schneuwly S, Hughes DA. RasGAP mediates neuronal survival in Drosophila through direct regulation of Rab5-dependent endocytosis. J Cell Sci 2014; 127:2849-61. [PMID: 24816559 DOI: 10.1242/jcs.139329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The GTPase Ras can either promote or inhibit cell survival. Inactivating mutations in Drosophila RasGAP (encoded by vap), a Ras GTPase-activating protein, lead to age-related brain degeneration. Genetic interactions implicate the epidermal growth factor receptor (EGFR)-Ras pathway in promoting neurodegeneration but the mechanism is not known. Here, we show that the Src homology 2 (SH2) domains of RasGAP are essential for its neuroprotective function. By using affinity purification and mass spectrometry, we identify a complex containing RasGAP together with Sprint, which is a Ras effector and putative activator of the endocytic GTPase Rab5. Formation of the RasGAP-Sprint complex requires the SH2 domains of RasGAP and tyrosine phosphorylation of Sprint. RasGAP and Sprint colocalize with Rab5-positive early endosomes but not with Rab7-positive late endosomes. We demonstrate a key role for this interaction in neurodegeneration: mutation of Sprint (or Rab5) suppresses neuronal cell death caused by the loss of RasGAP. These results indicate that the long-term survival of adult neurons in Drosophila is crucially dependent on the activities of two GTPases, Ras and Rab5, regulated by the interplay of RasGAP and Sprint.
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Affiliation(s)
- Behzad Rowshanravan
- The Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Simon A Woodcock
- The Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - José A Botella
- Lehrstuhl für Entwicklungsbiologie, Universität Regensburg, 93040 Regensburg, Germany
| | - Claudia Kiermayer
- Research Unit Comparative Medicine, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Stephan Schneuwly
- Lehrstuhl für Entwicklungsbiologie, Universität Regensburg, 93040 Regensburg, Germany
| | - David A Hughes
- The Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
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Horstkotte J, Perisic T, Schneider M, Lange P, Schroeder M, Kiermayer C, Hinkel R, Ziegler T, Mandal PK, David R, Schulz S, Schmitt S, Widder J, Sinowatz F, Becker BF, Bauersachs J, Naebauer M, Franz WM, Jeremias I, Brielmeier M, Zischka H, Conrad M, Kupatt C. Mitochondrial thioredoxin reductase is essential for early postischemic myocardial protection. Circulation 2011; 124:2892-902. [PMID: 22144571 DOI: 10.1161/circulationaha.111.059253] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Excessive formation of reactive oxygen species contributes to tissue injury and functional deterioration after myocardial ischemia/reperfusion. Especially, mitochondrial reactive oxygen species are capable of opening the mitochondrial permeability transition pore, a harmful event in cardiac ischemia/reperfusion. Thioredoxins are key players in the cardiac defense against oxidative stress. Mutations in the mitochondrial thioredoxin reductase (thioredoxin reductase-2, Txnrd2) gene have been recently identified to cause dilated cardiomyopathy in patients. Here, we investigated whether mitochondrial thioredoxin reductase is protective against myocardial ischemia/reperfusion injury. METHODS AND RESULTS In mice, α-MHC-restricted Cre-mediated Txnrd2 deficiency, induced by tamoxifen (Txnrd2-/-ic), aggravated systolic dysfunction and cardiomyocyte cell death after ischemia (90 minutes) and reperfusion (24 hours). Txnrd2-/-ic was accompanied by a loss of mitochondrial integrity and function, which was resolved on pretreatment with the reactive oxygen species scavenger N-acetylcysteine and the mitochondrial permeability transition pore blocker cyclosporin A. Likewise, Txnrd2 deletion in embryonic endothelial precursor cells and embryonic stem cell-derived cardiomyocytes, as well as introduction of Txnrd2-shRNA into adult HL-1 cardiomyocytes, increased cell death on hypoxia and reoxygenation, unless N-acetylcysteine was coadministered. CONCLUSIONS We report that Txnrd2 exerts a crucial function during postischemic reperfusion via thiol regeneration. The efficacy of cyclosporin A in cardiac Txnrd2 deficiency may indicate a role for Txnrd2 in reducing mitochondrial reactive oxygen species, thereby preventing opening of the mitochondrial permeability transition pore.
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Affiliation(s)
- Jan Horstkotte
- Medizinische Klinik und Poliklinik I, Munich Heart Alliance, Klinikum Grosshadern of the Ludwig Maximilians-University, Munich, Germany
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Kiermayer C, Hoehne-Hückstädt UM, Brielmeier M, Brütting M, Ellegast R, Schmidt J. Musculoskeletal load in and highly repetitive actions of animal facility washroom employees. J Am Assoc Lab Anim Sci 2011; 50:665-674. [PMID: 22330713 PMCID: PMC3189670] [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] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 03/15/2011] [Accepted: 05/17/2011] [Indexed: 05/31/2023]
Abstract
Regular work tasks in the washroom of laboratory animal facilities include cleaning of cages and bottles and handling of chow and bedding. These operations largely are carried out by hand. We quantitatively determined the musculoskeletal load on the trunk and upper limbs of washroom employees in an animal facility with a holding capacity of 35,000 rodent cages by using a computer-assisted, quantitative, recording, and long-term analysis (CUELA) system, which volunteers wore during routine work. Parallel video recording allowed exact assignment of each movement of body and limbs to the data recorded by the sensors. For the most part, trunk movements were unassociated with risk of injury. Evaluation of upper limb movements by CUELA indicated elevated burden on shoulder, elbows, and wrists due to the high repetitiveness and range of movements and postures. However, after additional work factors like low effort and the presence of micropauses were taken into account, workers were not at risk for the development of musculoskeletal disorders of the upper limbs. Handling bottles, chow, and bedding and maneuvering trolleys that entailed greater musculoskeletal loads did not yield evidence of overstraining, because the actions typically were executed alternately and were of short duration during daily shifts. The results represent quantitative information on the musculoskeletal load of regular washroom operations in a laboratory animal facility. These data provide the basis for ergonomic redesign of operations and implementation of automation for highly repetitive movements.
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Affiliation(s)
- Claudia Kiermayer
- Department of Comparative Medicine, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.
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5
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Geisberger R, Kiermayer C, Hömig C, Conrad M, Schmidt J, Zimber-Strobl U, Brielmeier M. B- and T-cell-specific inactivation of thioredoxin reductase 2 does not impair lymphocyte development and maintenance. Biol Chem 2007; 388:1083-90. [DOI: 10.1515/bc.2007.131] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Thioredoxin reductases (Txnrds) are a group of selenoenzymes participating in cellular redox regulation. Three Txnrd isoforms are known, each of which exhibits distinct cellular localisation and tissue-specific expression pattern. Txnrd1 is found in the cytoplasm, expression of Txnrd2 is restricted to mitochondria and Txnrd3 shows testis-specific expression. Recently, it was shown that Txnrd2 strongly affects the development of blood cells, since mouse embryos deficient for Txnrd2 are severely anaemic, show increased apoptosis in foetal liver and possess haematopoietic liver stem cells of reduced capacity to proliferate in vitro. However, because Txnrd2-deficient mice die at embryonic day 13.5, it was not known how this enzyme affects blood cell function in the adult animal. In the present study we show that conditional Txnrd2 knockouts generated using CD4- and CD19Cre transgenic mice lack Txnrd2 expression in CD4-- and CD19-positive T- and B-lymphocytes, respectively. However, the development and differentiation of both cell types in thymus and bone marrow was not significantly impaired. In addition, B-cell proliferation and activation in response to CD40 and IL-4 was unaltered in Txnrd2-deficient B-cells.
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Kiermayer C, Conrad M, Schneider M, Schmidt J, Brielmeier M. Optimization of spatiotemporal gene inactivation in mouse heart by oral application of tamoxifen citrate. Genesis 2007; 45:11-6. [PMID: 17216603 DOI: 10.1002/dvg.20244] [Citation(s) in RCA: 50] [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: 11/06/2022]
Abstract
Inducible and tissue-specific gene inactivation in mice has become a powerful tool to bypass embryonic and postnatal lethality of knockout mice. The most frequently used inducible system is based on Cre recombinase fused to either one or two mutated estrogen receptor ligand binding domains, thus rendering Cre function tamoxifen-dependent. To achieve Cre-mediated inactivation of a given gene, 4-OH tamoxifen (4-OHT) dissolved either in alcohol and/or oil is usually administered by repeated intraperitoneal (i.p.) injections. Since this procedure imposes considerable stress on mice, we compared the effect of tamoxifen citrate, mixed into a standard mouse diet at different concentrations, with that of i.p. administration of 4-OHT on Cre-mediated, heart-specific inactivation of thioredoxin reductase 2. Here we show that tamoxifen citrate in the chow was equally effective as 4-OHT given i.p. Oral tamoxifen administration is thus a convenient and cost-saving way for gene induction, and, most importantly, it reduces stress and avoids adverse effects in mice.
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Affiliation(s)
- Claudia Kiermayer
- Department of Comparative Medicine, GSF Research Center for Environment and Health, Neuherberg, Germany
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Kiermayer C, Michalke B, Schmidt J, Brielmeier M. Effect of selenium on thioredoxin reductase activity in Txnrd1 or Txnrd2 hemizygous mice. Biol Chem 2007; 388:1091-7. [DOI: 10.1515/bc.2007.133] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Botella JA, Kretzschmar D, Kiermayer C, Feldmann P, Hughes DA, Schneuwly S. Deregulation of the Egfr/Ras signaling pathway induces age-related brain degeneration in the Drosophila mutant vap. Mol Biol Cell 2003. [PMID: 12529440 DOI: 10.1091/mbc.e02--05--0297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Ras signaling has been shown to play an important role in promoting cell survival in many different tissues. Here we show that upregulation of Ras activity in adult Drosophila neurons induces neuronal cell death, as evident from the phenotype of vacuolar peduncle (vap) mutants defective in the Drosophila RasGAP gene, which encodes a Ras GTPase-activating protein. These mutants show age-related brain degeneration that is dependent on activation of the EGF receptor signaling pathway in adult neurons, leading to autophagic cell death (cell death type 2). These results provide the first evidence for a requirement of Egf receptor activity in differentiated adult Drosophila neurons and show that a delicate balance of Ras activity is essential for the survival of adult neurons.
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Affiliation(s)
- José A Botella
- Lehrstuhl für Entwicklungsbiologie, Universität Regensburg, 93040 Regensburg, Germany.
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Botella JA, Kretzschmar D, Kiermayer C, Feldmann P, Hughes DA, Schneuwly S. Deregulation of the Egfr/Ras signaling pathway induces age-related brain degeneration in the Drosophila mutant vap. Mol Biol Cell 2003; 14:241-50. [PMID: 12529440 PMCID: PMC140241 DOI: 10.1091/mbc.e02-05-0297] [Citation(s) in RCA: 27] [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: 01/27/2023] Open
Abstract
Ras signaling has been shown to play an important role in promoting cell survival in many different tissues. Here we show that upregulation of Ras activity in adult Drosophila neurons induces neuronal cell death, as evident from the phenotype of vacuolar peduncle (vap) mutants defective in the Drosophila RasGAP gene, which encodes a Ras GTPase-activating protein. These mutants show age-related brain degeneration that is dependent on activation of the EGF receptor signaling pathway in adult neurons, leading to autophagic cell death (cell death type 2). These results provide the first evidence for a requirement of Egf receptor activity in differentiated adult Drosophila neurons and show that a delicate balance of Ras activity is essential for the survival of adult neurons.
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Affiliation(s)
- José A Botella
- Lehrstuhl für Entwicklungsbiologie, Universität Regensburg, 93040 Regensburg, Germany.
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