1
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Hagendorff A, Helfen A, Brandt R, Knebel F, Altiok E, Ewers A, Haghi D, Knierim J, Merke N, Romero-Dorta E, Ruf T, Sinning C, Stöbe S, Ewen S. Expert proposal to analyze the combination of aortic and mitral regurgitation in multiple valvular heart disease by comprehensive echocardiography. Clin Res Cardiol 2024; 113:393-411. [PMID: 37212864 PMCID: PMC10881739 DOI: 10.1007/s00392-023-02227-y] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 05/08/2023] [Indexed: 05/23/2023]
Abstract
The assessment of valvular pathologies in multiple valvular heart disease by echocardiography remains challenging. Data on echocardiographic assessment-especially in patients with combined aortic and mitral regurgitation-are rare in the literature. The proposed integrative approach using semi-quantitative parameters to grade the severity of regurgitation often yields inconsistent findings and results in misinterpretation. Therefore, this proposal aims to focus on a practical systematic echocardiographic analysis to understand the pathophysiology and hemodynamics in patients with combined aortic and mitral regurgitation. The quantitative approach of grading the regurgitant severity of each compound might be helpful in elucidating the scenario in combined aortic and mitral regurgitation. To this end, both the individual regurgitant fraction of each valve and the total regurgitant fraction of both valves must be determined. This work also outlines the methodological issues and limitations of the quantitative approach by echocardiography. Finally, we present a proposal that enables verifiable assessment of regurgitant fractions. The overall interpretation of echocardiographic results includes the symptomatology of patients with combined aortic and mitral regurgitation and the individual treatment options with respect to their individual risk. In summary, a reproducible, verifiable, and transparent in-depth echocardiographic investigation might ensure consistent hemodynamic plausibility of the quantitative results in patients with combined aortic and mitral regurgitation.
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Affiliation(s)
- Andreas Hagendorff
- Department of Cardiology, University of Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
| | - A Helfen
- Department of Cardiology, Kath. St. Paulus Gesellschaft, St-Marien-Hospital Lunen, Altstadtstrasse 23, 44534, Lünen, Germany
| | - R Brandt
- Department of Cardiology, Kerckhoff Heart Center, Benekestr. 2‑8, 61231, Bad Nauheim, Germany
| | - F Knebel
- Klinik Für Innere Medizin II, Kardiologie, Sana Klinikum Lichtenberg, Fanningerstrasse 32, 10365, Berlin, Germany
- Department of Cardiology, Angiology and Intensive Care Medicine, University of Berlin, German Heart Center Charité Berlin, Campus Mitte, Chariteplatz 1, 10117, Berlin, Germany
| | - E Altiok
- Department of Cardiology, University of Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - A Ewers
- Department of Cardiology and Angiology, BG University Hospital Bergmannsheil, de La Camp-Platz 1, 44789, Bochum, Germany
| | - D Haghi
- Kardiologische Praxisklinik Ludwigshafen-Akademische Lehrpraxis der Universitat Mannheim-Ludwig-Guttmann, Strasse 11, 67071, Ludwigshafen, Germany
| | - J Knierim
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Charité Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Paulinenkrankenhaus Berlin, Klinik Für Innere Medizin Und Kardiologie, Dickensweg 25‑39, 14055, Berlin, Germany
| | - N Merke
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Charité Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - E Romero-Dorta
- Department of Cardiology, Angiology and Intensive Care Medicine, University of Berlin, German Heart Center Charité Berlin, Campus Mitte, Chariteplatz 1, 10117, Berlin, Germany
| | - T Ruf
- Department of Cardiology, Center of Cardiology, Heart Valve Center, University Medical Center Mainz, University of Mainz, Langenbeckstrasse 1, 55131, Mainz, Germany
| | - C Sinning
- Department of Cardiology, University Heart and Vascular Center Hamburg, German Centre of Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lubeck, Martinistrasse 52, 20251, Hamburg, Germany
| | - S Stöbe
- Department of Cardiology, University of Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - S Ewen
- Zentrale Notaufnahme and Klinik Für Innere Medizin III, Kardiologie, Angiologie Und Internistische Intensivmedizin, Universitätsklinikum Des Saarlandes, Homburg, Germany
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Pinzi L, Conze C, Bisi N, Torre GD, Soliman A, Monteiro-Abreu N, Trushina NI, Krusenbaum A, Dolouei MK, Hellwig A, Christodoulou MS, Passarella D, Bakota L, Rastelli G, Brandt R. Quantitative live cell imaging of a tauopathy model enables the identification of a polypharmacological drug candidate that restores physiological microtubule interaction. Nat Commun 2024; 15:1679. [PMID: 38396035 PMCID: PMC10891143 DOI: 10.1038/s41467-024-45851-6] [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: 10/04/2022] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Tauopathies such as Alzheimer's disease are characterized by aggregation and increased phosphorylation of the microtubule-associated protein tau. Tau's pathological changes are closely linked to neurodegeneration, making tau a prime candidate for intervention. We developed an approach to monitor pathological changes of aggregation-prone human tau in living neurons. We identified 2-phenyloxazole (PHOX) derivatives as putative polypharmacological small molecules that interact with tau and modulate tau kinases. We found that PHOX15 inhibits tau aggregation, restores tau's physiological microtubule interaction, and reduces tau phosphorylation at disease-relevant sites. Molecular dynamics simulations highlight cryptic channel-like pockets crossing tau protofilaments and suggest that PHOX15 binding reduces the protofilament's ability to adopt a PHF-like conformation by modifying a key glycine triad. Our data demonstrate that live-cell imaging of a tauopathy model enables screening of compounds that modulate tau-microtubule interaction and allows identification of a promising polypharmacological drug candidate that simultaneously inhibits tau aggregation and reduces tau phosphorylation.
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Affiliation(s)
- Luca Pinzi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Christian Conze
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Nicolo Bisi
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Gabriele Dalla Torre
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Ahmed Soliman
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Nanci Monteiro-Abreu
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Nataliya I Trushina
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Andrea Krusenbaum
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Maryam Khodaei Dolouei
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Andrea Hellwig
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany
| | - Michael S Christodoulou
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Department of Chemistry, University of Milan, Milan, Italy
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy
| | | | - Lidia Bakota
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Giulio Rastelli
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.
| | - Roland Brandt
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany.
- Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany.
- Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany.
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Bakota L, Brandt R. Why kiss-and-hop explains that tau does not stabilize microtubules and does not interfere with axonal transport (at physiological conditions). Cytoskeleton (Hoboken) 2024; 81:47-52. [PMID: 37694806 DOI: 10.1002/cm.21787] [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: 07/10/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/12/2023]
Abstract
Tau is a microtubule-associated protein that is enriched in the axonal process of neurons. Post-translational modifications of tau have been implicated in the development of tauopathies characterized by defects in axonal transport, neuronal atrophy, and microtubule disassembly. Although tau is almost quantitatively bound to microtubules under physiological conditions, it does not significantly affect axonal transport. Furthermore, acute or chronic tau deficiency does not result in significant destabilization of neuronal microtubules, challenging the classical view that disease-related tau modifications directly cause axonal microtubule collapse. Here, we discuss how the rapid interaction kinetics of the tau-microtubule interaction, which we previously termed the kiss-and-hop interaction, explains why tau does not affect microtubule-dependent axonal transport but still allows tau to modulate microtubule polymerization. In contrast, tau modifications that slow down the kinetics of the tau-microtubule interaction and increase the residence time of tau at a microtubule interaction site can disrupt axonal transport and cause dendritic atrophy. We discuss the consequences of such a gain-of-toxicity mechanism in terms of the development of disease-modulating drugs that target the tau protein.
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Affiliation(s)
- Lidia Bakota
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, School of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
- Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany
- Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany
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Lapa DA, Acácio GL, Trigo L, Goncalves RT, Catissi G, Gato B, Brandt R. Biocellulose patch technique for fetoscopic repair of open spina bifida in twin pregnancy. Ultrasound Obstet Gynecol 2023; 62:558-564. [PMID: 37128166 DOI: 10.1002/uog.26236] [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] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/27/2023] [Accepted: 04/10/2023] [Indexed: 05/03/2023]
Abstract
OBJECTIVES Twin pregnancy is currently an exclusion criterion for prenatal repair of open spina bifida (OSB). The main objective of this study was to report on our experience of treating twin pregnancies with OSB using the skin-over-biocellulose for antenatal fetoscopic repair (SAFER) technique. We also discuss reconsideration of the current exclusion criteria for fetal OSB repair. METHODS Eight fetuses with OSB from seven twin pregnancies underwent successful prenatal repair. Six pregnancies were dichorionic diamniotic with only one twin affected, and one was monochorionic diamniotic with both twins affected. Percutaneous fetoscopy was performed under CO2 insufflation of the sac of the affected twin. Neurosurgical repair was performed using a biocellulose patch to protect the placode, with the skin sutured to hold the patch in place, with or without a myofascial flap. Neurodevelopment was assessed using the pediatric evaluation of disability inventory scale in babies older than 6 months of adjusted age, whereas the Alberta scale was used for babies younger than 6 months of adjusted age. RESULTS All 14 fetuses were liveborn and none required additional repair. Gestational age at surgery ranged from 27.3 to 31.1 weeks, and gestational age at birth ranged from 31.6 to 36.0 weeks. Four out of eight affected twins developed sepsis, but had a good recovery. No sequela of prematurity was found in any of the unaffected twins. Short-term neurodevelopment was normal in all evaluated unaffected twins (5/5) and in all but one affected twins (7/8). In the affected group, only one baby required ventriculoperitoneal shunt placement. CONCLUSIONS Prematurity is frequent after fetal surgery, and the risk is increased in twin pregnancy. Nevertheless, prenatal surgery using the SAFER technique is feasible, with low risk to both twins and their mother when performed by a highly experienced team. Long-term cognitive assessment of the unaffected twin is needed. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
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Affiliation(s)
- D A Lapa
- Fetal Therapy Program, Hospital Israelita Albert Einstein, São Paulo, Brazil
- Fetal and Neonatal Therapy, Hospital Infantil Sabará, São Paulo, Brazil
| | - G L Acácio
- Fetal and Neonatal Therapy, Hospital Infantil Sabará, São Paulo, Brazil
- Department of Obstetrics and Gynecology, University of Taubaté, São Paulo, Brazil
| | - L Trigo
- BCNatal - Fetal Medicine Research Center, Hospital Clínic and Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Obstetrics and Gynecology Department, Pourtalès Hospital, Neuchâtel, Switzerland
- Faculty of Medicine and Health Sciences, University of Barcelona
| | - R T Goncalves
- Fetal Therapy Program, Hospital Israelita Albert Einstein, São Paulo, Brazil
- Gynecology Section, Hospital Servidor Público Estadual de São Paulo, São Paulo, Brazil
| | - G Catissi
- Fetal Therapy Program, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - B Gato
- Anesthesiology Department, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - R Brandt
- Neurosurgery Department, Hospital Israelita Albert Einstein, São Paulo, Brazil
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5
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Brandt R, Götz J. Special issue on "Cytoskeletal Proteins in Health and Neurodegenerative Disease: Concepts and Methods". Brain Res Bull 2023; 198:50-52. [PMID: 37084983 DOI: 10.1016/j.brainresbull.2023.04.007] [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: 04/23/2023]
Abstract
Since 2016, when we compiled a very well-received special issue on "Cytoskeletal Proteins in Health and Neurodegenerative Disease" for Brain Research Bulletin, the field has rapidly evolved, to a large part thanks to the development and maturation of new methods including super-resolution microscopy. Being asked to create a sequel, we therefore decided to keep the main topic, but focus on emerging concepts and novel methods. As before, we compiled nine articles on the role of the neuronal cytoskeleton in both physiological and pathological conditions. Seven of the contributions present current concepts and discuss how cytoskeletal components develop and are maintained throughout a neuron's long lifespan, and also, how they may contribute to physiology and neurodegenerative diseases. Two contributions focus on novel methodological developments and how these techniques can be used to analyze the structure and function of the neuronal cytoskeleton in new ways. The compilation of the articles makes it clear that future approaches must consider the functional relationships between the individual filament systems and the influence different signal transduction mechanisms have on the cytoskeleton and vice versa, in order to adequately explore the causes and consequences of the role of cytoskeletal proteins in health and disease. We hope that this compilation will help in the design of appropriate experiments, aided by new methods, to test critical hypotheses in the field.
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Affiliation(s)
- Roland Brandt
- Department of Neurobiology Osnabrück University, Barbarastrasse 11, D-49076 Osnabrück, Germany; Center for Cellular Nanosciences Osnabrück University, Barbarastrasse 11, D-49076 Osnabrück, Germany; Institute of Cognitive Sciences, Osnabrück University, Barbarastrasse 11, D-49076 Osnabrück, Germany.
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia Campus, Brisbane, QLD 4072, Australia.
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Söhnel AC, Brandt R. Neuronal stress granules as dynamic microcompartments: current concepts and open questions. Biol Chem 2023; 404:491-498. [PMID: 36779376 DOI: 10.1515/hsz-2022-0302] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/18/2023] [Indexed: 02/14/2023]
Abstract
Stress granules are cytosolic, membraneless RNA-protein complexes that form in the cytosol in response to various stressors. Stress granules form through a process termed liquid-liquid phase separation, which increases the local concentration of RNA and protein within the granules, creates dynamic sorting stations for mRNAs and associated proteins, and modulates the availability of mRNA for protein translation. We introduce the concept that neuronal stress granules act as dynamic cytosolic microcompartments in which their components differentially cycle in and out, monitoring the cellular environment. We discuss that neuronal stress granules have distinctive features and contain substructures in which individual components interact transiently. We describe that neuronal stress granules modulate protein expression at multiple levels and affect the proteoform profile of the cytoskeletal protein tau. We argue that a better knowledge of the regulation of stress granule dynamics in neurons and the modulation of their material state is necessary to understand their function during physiological and pathological stress responses. Finally, we delineate approaches to determine the behavior and regulation of critical stress granule organizers and the physical state of stress granules in living neurons.
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Affiliation(s)
| | - Roland Brandt
- Department of Neurobiology, Osnabrück, Germany.,Center for Cellular Nanoanalytics, Osnabrück, Germany.,Institute of Cognitive Science, Osnabrück University, 49076 Osnabrück, Germany
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7
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Hagendorff A, Helfen A, Brandt R, Altiok E, Breithardt O, Haghi D, Knierim J, Lavall D, Merke N, Sinning C, Stöbe S, Tschöpe C, Knebel F, Ewen S. Expert proposal to characterize cardiac diseases with normal or preserved left ventricular ejection fraction and symptoms of heart failure by comprehensive echocardiography. Clin Res Cardiol 2023; 112:1-38. [PMID: 35660948 PMCID: PMC9849322 DOI: 10.1007/s00392-022-02041-y] [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] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/10/2022] [Indexed: 01/22/2023]
Abstract
Currently, the term "heart failure with preserved left ventricular ejection fraction (HFpEF)" is based on echocardiographic parameters and clinical symptoms combined with elevated or normal levels of natriuretic peptides. Thus, "HFpEF" as a diagnosis subsumes multiple pathophysiological entities making a uniform management plan for "HFpEF" impossible. Therefore, a more specific characterization of the underlying cardiac pathologies in patients with preserved ejection fraction and symptoms of heart failure is mandatory. The present proposal seeks to offer practical support by a standardized echocardiographic workflow to characterize specific diagnostic entities associated with "HFpEF". It focuses on morphological and functional cardiac phenotypes characterized by echocardiography in patients with normal or preserved left ventricular ejection fraction (LVEF). The proposal discusses methodological issues to clarify why and when echocardiography is helpful to improve the diagnosis. Thus, the proposal addresses a systematic echocardiographic approach using a feasible algorithm with weighting criteria for interpretation of echocardiographic parameters related to patients with preserved ejection fraction and symptoms of heart failure. The authors consciously do not use the diagnosis "HFpEF" to avoid misunderstandings. Central illustration: Scheme illustrating the characteristic echocardiographic phenotypes and their combinations in patients with "HFpEF" symptoms with respect to the respective cardiac pathology and pathophysiology as well as the underlying typical disease.
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Affiliation(s)
- A. Hagendorff
- Department of Cardiology, University of Leipzig, Liebigstraße 20, 04103 Leipzig, Germany
| | - A. Helfen
- Department of Cardiology, Kath. St. Paulus Gesellschaft, St-Marien-Hospital Lünen, Altstadtstrasse 23, 44534 Lünen, Germany
| | - R. Brandt
- Department of Cardiology, Kerckhoff Heart Center, Benekestr. 2-8, 61231 Bad Nauheim, Germany
| | - E. Altiok
- Department of Cardiology, University of Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany
| | - O. Breithardt
- Klinik für Innere Medizin-Kardiologie and Rhythmologie, Agaplesion Diakonie Kliniken Kassel, Herkulesstrasse 34, 34119 Kassel, Germany
| | - D. Haghi
- Kardiologische Praxisklinik Ludwigshafen-Akademische Lehrpraxis der Universität Mannheim-Ludwig-Guttmann, Strasse 11, 67071 Ludwigshafen, Germany
| | - J. Knierim
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ,Paulinenkrankenhaus Berlin, Klinik Für Innere Medizin Und Kardiologie, Dickensweg 25-39, 14055 Berlin, Germany
| | - D. Lavall
- Department of Cardiology, University of Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany
| | - N. Merke
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - C. Sinning
- Department of Cardiology, University Heart and Vascular Center Hamburg, German Centre of Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Martinistrasse 52, 20251 Hamburg, Germany
| | - S. Stöbe
- Department of Cardiology, University of Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany
| | - C. Tschöpe
- Berlin Institute of Health at Charité (BIH), Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ,BIH Center for Regenerative Therapies (BCRT), Augustenburger Platz 1, 13353 Berlin, Germany ,German Centre for Cardiovascular Research DZHK, Partner Site Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ,Department of Cardiology, Charité University Medicine Berlin, Campus Virchow Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - F. Knebel
- Klinik Für Innere Medizin II, Kardiologie, Sana Klinikum Lichtenberg, Fanningerstrasse 32, 10365 Berlin, Germany ,Department of Cardiology, University of Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - S. Ewen
- Zentrale Notaufnahme and Klinik Für Innere Medizin III, Kardiologie, Angiologie Und Internistische Intensivmedizin, Universitätsklinikum Des Saarlandes, Kirrberger Strasse, 66421 Homburg, Germany
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8
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Conze C, Trushina NI, Holtmannspötter M, Rierola M, Attanasio S, Bakota L, Piehler J, Brandt R. Super-resolution imaging and quantitative analysis of microtubule arrays in model neurons show that epothilone D increases the density but decreases the length and straightness of microtubules in axon-like processes. Brain Res Bull 2022; 190:234-243. [PMID: 36244582 PMCID: PMC9634454 DOI: 10.1016/j.brainresbull.2022.10.008] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 11/29/2022]
Abstract
Microtubules are essential for the development of neurons and the regulation of their structural plasticity. Microtubules also provide the structural basis for the long-distance transport of cargo. Various factors influence the organization and dynamics of neuronal microtubules, and disturbance of microtubule regulation is thought to play a central role in neurodegenerative diseases. However, imaging and quantitative assessment of the microtubule organization in the densely packed neuronal processes is challenging. The development of super-resolution techniques combined with the use of nanobodies offers new possibilities to visualize microtubules in neurites in high resolution. In combination with recently developed computational analysis tools, this allows automated quantification of neuronal microtubule organization with high precision. Here we have implemented three-dimensional DNA-PAINT (Point Accumulation in Nanoscale Topography), a single-molecule localization microscopy (SMLM) technique, which allows us to acquire 3D arrays of the microtubule lattice in axons of model neurons (neuronally differentiated PC12 cells) and dendrites of primary neurons. For the quantitative analysis of the microtubule organization, we used the open-source software package SMLM image filament extractor (SIFNE). We found that treatment with nanomolar concentrations of the microtubule-targeting drug epothilone D (EpoD) increased microtubule density in axon-like processes of model neurons and shifted the microtubule length distribution to shorter ones, with a mean microtubule length of 2.39 µm (without EpoD) and 1.98 µm (with EpoD). We also observed a significant decrease in microtubule straightness after EpoD treatment. The changes in microtubule density were consistent with live-cell imaging measurements of ensemble microtubule dynamics using a previously established Fluorescence Decay After Photoactivation (FDAP) assay. For comparison, we determined the organization of the microtubule array in dendrites of primary hippocampal neurons. We observed that dendritic microtubules have a very similar length distribution and straightness compared to microtubules in axon-like processes of a neuronal cell line. Our data show that super-resolution imaging of microtubules followed by algorithm-based image analysis represents a powerful tool to quantitatively assess changes in microtubule organization in neuronal processes, useful to determine the effect of microtubule-modulating conditions. We also provide evidence that the approach is robust and can be applied to neuronal cell lines or primary neurons, both after incorporation of labeled tubulin and by anti-tubulin antibody staining.
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Affiliation(s)
- Christian Conze
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | | | | | - Marina Rierola
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Simone Attanasio
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Lidia Bakota
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Jacob Piehler
- Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany; Division of Biophysics, Osnabrück University, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany; Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany; Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany.
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9
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Jost J, Brandt R, Altuner U, Müther M, Stummer W, Völker K, Wiewrodt R, Wiewrodt D. P08.12.B Conceptual development of an intensive supervised exercise program for brain tumor patients: summary of clinical experience. Neuro Oncol 2022. [DOI: 10.1093/neuonc/noac174.156] [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
Several studies have identified beneficial effects of physical activity on reducing cancer-related symptoms. However, the number of such studies in neuro-oncology is limited, and even today, brain tumor patients are often advised against physically strenuous exercise. Here we summarize our experience with an individualized training program in brain tumor patients over a period of more than 8 years.
Material and Methods
Patients with primary brain tumors were invited to participate in the individual training program as part of the psycho-oncological consultation. If interested and free of major comorbidity, a professional sport scientist/diploma coach individualized two 60-minute sessions/week adapted to the patients’ respective symptoms and trained them on a 1:1-basis. One session consisted of bicycle ergometry at an average workload of 75% of the max. age-adjusted heart rate (up to 95% at peak; continuous monitoring throughout entire session), the other session was progressive whole-body resistance training based on 10 separate, but standardized exercise tasks using the university’s training facilities. Both training sessions were complimented by challenging elements to improve coordination. Exercise tasks were adapted as needed, and exercise levels were enhanced over time, if possible.
Results
From 2011 to 2019, 45 patients (19 women, 26 men) aged 20-76 years (mean 49) with different tumor types (65% high-grade gliomas, 22% low-grade gliomas, 13% other) participated in the program. The majority of patients started the program following concurrent radio-chemotherapy and in parallel with adjuvant systemic therapy. On average, 41 training sessions were performed. No training-related adverse events (e.g., falls, head pain, etc.) occurred during the entire period. In a total of 1828 training sessions, two minor epileptic seizures occurred (1 speech arrest; 1 simple focal seizure, left hand affected). Both patients were familiar with the respective type of seizure before entering the program and training could be continued immediately, with reduced intensity. Seizures did not reoccur during subsequent training sessions.
Conclusion
This supervised intensive physical training program with submaximal exertion zones was feasible, safe, and highly rated by all participants. Based on these experiences and the reported well-being of the patients, we launched a prospective oligocentric study to objectify the improvements in physical performance and quality of life in patients with glioblastoma (ClinicalTrials.gov Identifier: NCT05015543).
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Affiliation(s)
- J Jost
- Muenster University Hospital , Muenster , Germany
| | - R Brandt
- Muenster University Hospital , Muenster , Germany
| | - U Altuner
- Muenster University Hospital , Muenster , Germany
| | - M Müther
- Muenster University Hospital , Muenster , Germany
| | - W Stummer
- Muenster University Hospital , Muenster , Germany
| | - K Völker
- Muenster University Hospital , Muenster , Germany
| | - R Wiewrodt
- Muenster University Hospital , Muenster , Germany
| | - D Wiewrodt
- Muenster University Hospital , Muenster , Germany
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10
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Soliman A, Bakota L, Brandt R. Microtubule-modulating Agents in the Fight Against Neurodegeneration: Will it ever Work? Curr Neuropharmacol 2022; 20:782-798. [PMID: 34852744 PMCID: PMC9878958 DOI: 10.2174/1570159x19666211201101020] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/15/2021] [Accepted: 11/15/2021] [Indexed: 11/22/2022] Open
Abstract
The microtubule skeleton plays an essential role in nerve cells as the most important structural determinant of morphology and as a highway for axonal transport processes. Many neurodegenerative diseases are characterized by changes in the structure and organization of microtubules and microtubule-regulating proteins such as the microtubule-associated protein tau, which exhibits characteristic changes in a whole class of diseases collectively referred to as tauopathies. Changes in the dynamics of microtubules appear to occur early under neurodegenerative conditions and are also likely to contribute to age-related dysfunction of neurons. Thus, modulating microtubule dynamics and correcting impaired microtubule stability can be a useful neuroprotective strategy to counteract the disruption of the microtubule system in disease and aging. In this article, we review current microtubule- directed approaches for the treatment of neurodegenerative diseases with microtubules as a drug target, tau as a drug target, and post-translational modifications as potential modifiers of the microtubule system. We discuss limitations of the approaches that can be traced back to the rather unspecific mechanism of action, which causes undesirable side effects in non-neuronal cell types or which are due to the disruption of non-microtubule-related interactions. We also develop some thoughts on how the specificity of the approaches can be improved and what further targets could be used for modulating substances.
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Affiliation(s)
- Ahmed Soliman
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Lidia Bakota
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany;,Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany;,Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany,Address correspondence to this author at the Department of Neurobiology, Osnabrück University, Osnabrück, Germany; Tel: +49 541 969 2338; E-mail:
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11
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Hashemi-Nezhad SR, Brandt R, Westmeier W, Bamblevski VP, Krivopustov MI, Kulakov BA, Sosnin AN, Wan JS, Odoj R. Monte Carlo analysis of accelerator-driven systems: Studies on spallation neutron yield and energy gain. KERNTECHNIK 2022. [DOI: 10.1515/kern-2001-0013] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The neutron yield in the interaction of protons with lead and uranium targets has been studied using the LAHET code system. The dependence of the neutron multiplicity on target dimensions and proton energy has been calculated and the dependence of the energy amplification on the proton energy has been investigated in an accelerator-driven system of a given effective multiplication coefficient. Some of the results are compared with experimental findings and with similar calculations by the DCM/CEM code of Dubna and the FLUKA code system used in CERN.
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Affiliation(s)
- S. R. Hashemi-Nezhad
- Department of High Energy Physics, School of Physics, University of Sydney , A28, NSW 2006 , Sydney Australia
| | - R. Brandt
- Institut für Physikalische, Kern- und Makromolekulare Chemie , FB 15, Philipps-Universität , Marburg , Germany
| | - W. Westmeier
- Institut für Physikalische, Kern- und Makromolekulare Chemie , FB 15, Philipps-Universität , Marburg , Germany
| | | | | | - B. A. Kulakov
- Joint Institute for Nuclear Research, JINR , Dubna , Russia
| | - A. N. Sosnin
- Joint Institute for Nuclear Research, JINR , Dubna , Russia
| | - J.-S. Wan
- Northwest Institute of Nuclear Technology , 710024 Xian , China
| | - R. Odoj
- Institut fuer Sicherheitsforschung und Reaktorsicherheit, Forschungszentrum Juelich GmbH , Juelich , Germany
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12
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Wan JS, Brandt R, Sosnin AN, Krivopustov MI. Subcritical nuclear systems and their stability against changes in the geometrical set-up. KERNTECHNIK 2022. [DOI: 10.1515/kern-2001-0014] [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: 11/15/2022]
Abstract
Abstract
A specific subcritical reactor system has been suggested and the stability of its parameters against small changes in the geometrical set-up has been estimated using the model calculation code DCM/CEM from Dubna. The dimensions of the system are 200 cm in diameter and 170 cm in length and it supplies a thermal power of 900 MW with keff =0.943, using a 20 mA proton beam of an energy of 1 GeV. Considering the thermal → electricity power and electricity → beam power conversion efficiencies, the electric power amplification is about 8. Energy deposition and neutron energy distribution in the fission core are also studied. Some properties, such as the heat production per unit volume, are rather similar to modern fast breeders. The neutron multiplication factor keff is very sensitive to small changes in the geometrical set-up within the fission core.
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Affiliation(s)
- J.-S. Wan
- Institut für Physikalische Chemie, Kernchemie und Makromolekulare Chemie, Philipps-Universität, Hans Meerweinstr ., D-35032 Marburg Germany
| | - R. Brandt
- Institut für Physikalische Chemie, Kernchemie und Makromolekulare Chemie, Philipps-Universität, Hans Meerweinstr ., D-35032 Marburg Germany
| | - A. N. Sosnin
- Northwest Institute of Nuclear Technology , P.O. Box 69 , Xian , China
| | - M. I. Krivopustov
- Joint Institute for Nuclear Research, Dubna , Moscow Region , Russia
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13
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Conze C, Rierola M, Trushina NI, Peters M, Janning D, Holzer M, Heinisch JJ, Arendt T, Bakota L, Brandt R. Caspase-cleaved tau is senescence-associated and induces a toxic gain of function by putting a brake on axonal transport. Mol Psychiatry 2022; 27:3010-3023. [PMID: 35393558 PMCID: PMC9205779 DOI: 10.1038/s41380-022-01538-2] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 03/15/2022] [Accepted: 03/21/2022] [Indexed: 01/04/2023]
Abstract
The microtubule-associated protein tau plays a central role in tauopathies such as Alzheimer's disease (AD). The exact molecular mechanisms underlying tau toxicity are unclear, but aging is irrefutably the biggest risk factor. This raises the question of how cellular senescence affects the function of tau as a microtubule regulator. Here we report that the proportion of tau that is proteolytically cleaved at the caspase-3 site (TauC3) doubles in the hippocampus of senescent mice. TauC3 is also elevated in AD patients. Through quantitative live-cell imaging, we show that TauC3 has a drastically reduced dynamics of its microtubule interaction. Single-molecule tracking of tau confirmed that TauC3 has a longer residence time on axonal microtubules. The reduced dynamics of the TauC3-microtubule interaction correlated with a decreased transport of mitochondria, a reduced processivity of APP-vesicle transport and an induction of region-specific dendritic atrophy in CA1 neurons of the hippocampus. The microtubule-targeting drug Epothilone D normalized the interaction of TauC3 with microtubules and modulated the transport of APP-vesicles dependent on the presence of overexpressed human tau. The results indicate a novel toxic gain of function, in which a post-translational modification of tau changes the dynamics of the tau-microtubule interaction and thus leads to axonal transport defects and neuronal degeneration. The data also introduce microtubule-targeting drugs as pharmacological modifiers of the tau-microtubule interaction with the potential to restore the physiological interaction of pathologically altered tau with microtubules.
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Affiliation(s)
- Christian Conze
- grid.10854.380000 0001 0672 4366Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Marina Rierola
- grid.10854.380000 0001 0672 4366Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Nataliya I. Trushina
- grid.10854.380000 0001 0672 4366Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Michael Peters
- grid.10854.380000 0001 0672 4366Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Dennis Janning
- grid.10854.380000 0001 0672 4366Department of Neurobiology, Osnabrück University, Osnabrück, Germany ,grid.10854.380000 0001 0672 4366Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany
| | - Max Holzer
- grid.9647.c0000 0004 7669 9786Center for Neuropathology and Brain Research, Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Jürgen J. Heinisch
- grid.10854.380000 0001 0672 4366Department of Genetics, Osnabrück University, Osnabrück, Germany
| | - Thomas Arendt
- grid.9647.c0000 0004 7669 9786Center for Neuropathology and Brain Research, Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Lidia Bakota
- grid.10854.380000 0001 0672 4366Department of Neurobiology, Osnabrück University, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany. .,Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany. .,Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany.
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14
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Söhnel AC, Trushina NI, Brandt R. Monitoring and Quantification of the Dynamics of Stress Granule Components in Living Cells by Fluorescence Decay After Photoactivation. Methods Mol Biol 2022; 2428:243-259. [PMID: 35171484 DOI: 10.1007/978-1-0716-1975-9_15] [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] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Stress granules (SGs) are cytosolic, nonmembranous RNA-protein (RNP) complexes that form in the cytosol of many cells under various stress conditions and can integrate responses to various stressors. Although physiological SG formation appears to be an adaptive and survival-promoting mechanism, inappropriate formation or chronic persistence of SGs has been linked to aging and various neurodegenerative diseases. The quantitative monitoring of the dynamics of SG components in living nerve cells can therefore be an important tool for identifying conditions that disrupt SG function and lead to disease-related attacks in the cells. Here, we describe a method for the quantitative determination of the distribution and shuttling dynamics of components of SGs in living model neurons by fluorescence decay after photoactivation (FDAP) measurements using a standard confocal laser scanning microscope. The method includes lipofection of photoactivatable green fluorescent protein (paGFP) fused to an SG protein of interest in a neural cell line, differentiation of the cells into a neuronal phenotype, focal activation using a blue diode (405 nm), and recording of decay curves with a 488 nm laser line. By modeling the decay measurements with FDAP functions, the approach enables estimating the residence time of the SG protein of interest, determining the proportion of the respective component in SGs, and the detection of possible changes after experimental manipulation.
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Affiliation(s)
| | | | - Roland Brandt
- Department of Neurobiology, Osnabrück University, Osnabrück, Germany.
- Center of Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany.
- Institute of Cognitive Science, Osnabrück Unversity, Osnabrück, Germany.
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15
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Hagendorff A, Helfen A, Flachskampf FA, Ewen S, Kruck S, La Rosée K, Knierim J, Voigt JU, Kreidel F, Fehske W, Brandt R, Zahn R, Knebel F. Manual zur Indikation und Durchführung spezieller echokardiographischer Anwendungen. Kardiologe 2021. [PMCID: PMC8521495 DOI: 10.1007/s12181-021-00509-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Das zweite Manual zur Indikation und Durchführung der Echokardiographie bezieht sich auf spezifische Anwendungen der Echokardiographie und besondere Fragestellungen bei speziellen Patientengruppen. Dabei stehen v. a. praktische Aspekte im Vordergrund. Methodisch etabliert sind die transösophageale Echokardiographie, die Stressechokardiographie und die Kontrastechokardiographie. Bei nahezu allen echokardiographischen Untersuchungen spielen aktuell 3‑D-Echokardiographie und Deformationsbildgebung eine Rolle. Das gesamte Spektrum der echokardiographischen Möglichkeiten wird derzeit in Notfall- und Intensivmedizin, bei der Überwachung und Führung von Katheterinterventionen, bei strukturellen Herzerkrankungen, bei herzchirurgischen Operationen, bei der Nachsorge von kardialen Unterstützungssystemen, bei kongenitalen Vitien im Erwachsenenalter und bei der Versorgung von hochinfektiösen Patienten in Pandemiezeiten angewandt. Die diagnostischen Fortschritte der konventionellen und modernen echokardiographischen Anwendungen stehen im Fokus dieses Manuals. Die 3‑D-Echokardiographie zur Charakterisierung der kardialen Morphologie und die Deformationsbildgebung zur Objektivierung der kardialen Funktion sind bei vielen Indikationen im klinischen Alltag etabliert. Die Stressechokardiographie zur Ischämie‑, Vitalitäts- und Vitiendiagnostik, die Bestimmung der koronaren Flussreserve und die Kontrastechokardiographie bei der linksventrikulären Wandbewegungsanalyse und kardialen Tumordetektion finden zunehmend klinische Anwendung. Wie für die konventionelle Echokardiographie im ersten Manual der Echokardiographie 2009 beschrieben, erfordert der Einsatz moderner echokardiographischer Verfahren die standardisierte Dokumentation und Akquisition bestimmter Bildsequenzen bei optimierter Geräteeinstellung, da korrekte und reproduzierbare Auswertungen nur bei guter Bildqualität möglich sind.
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Affiliation(s)
- Andreas Hagendorff
- Klinik und Poliklinik für Kardiologie, Universitätsklinikum Leipzig, Liebigstr. 20, 04103 Leipzig, Deutschland
| | - Andreas Helfen
- Medizinische Klinik I, Katholisches Klinikum Lünen Werne GmbH St. Marien-Hospital Lünen, Lünen, Deutschland
| | - Frank A. Flachskampf
- Department of Medical Sciences, Universität Uppsala, und Klinisk fysiologi och kardiologi, Uppsala University Hospital, Uppsala, Schweden
| | - Sebastian Ewen
- Klinik für Innere Medizin III – Kardiologie, Angiologie und Internistische Intensivmedizin, Universitätsklinikum des Saarlandes, Homburg/Saar, Deutschland
| | - Sebastian Kruck
- Cardio Centrum Ludwigsburg Bietigheim, Ludwigsburg, Deutschland
| | - Karl La Rosée
- Gemeinschaftspraxis Dr. La Rosée & Prof. Dr. Müller, Bonn, Deutschland
| | - Jan Knierim
- Klinik für Herz‑, Thorax- und Gefäßchirurgie, Deutsches Herzzentrum Berlin, Berlin, Deutschland
| | - Jens-Uwe Voigt
- Department of Cardiovascular Diseases, University Hospital Gasthuisberg und Department of Cardiovascular Sciences, Cath. University Leuven, Leuven, Belgien
| | - Felix Kreidel
- Zentrum für Kardiologie, Universitätsmedizin Mainz, Mainz, Deutschland
| | - Wolfgang Fehske
- Klinik III für Innere Medizin, Universitätsklinikum Köln – Herzzentrum, Universität zu Köln, Köln, Deutschland
| | - Roland Brandt
- Abteilung für Kardiologie, Kerckhoff Klinik GmbH, Bad Nauheim, Deutschland
| | - Ralf Zahn
- Medizinische Klinik B – Abteilung für Kardiologie, Klinikum der Stadt Ludwigshafen gGmbH, Ludwigshafen am Rhein, Deutschland
- Kommission für Klinische Kardiovaskuläre Medizin, Deutsche Gesellschaft für Kardiologie, Düsseldorf, Deutschland
| | - Fabian Knebel
- Medizinische Klinik mit Schwerpunkt Kardiologie und Angiologie, Charité – Universitätsmedizin Berlin, Campus Mitte, Berlin, Deutschland
- Sana Klinikum Lichtenberg, Berlin, Deutschland
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16
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Sosnin VN, Ochs M, Brandt R, Birkholz W. On some operational limits of accelerator-driven subcritical nuclear reactors / Über die Grenzen einiger Betriebsparameter von unterkritischen Anlagen mit Beschleunigerantrieb. KERNTECHNIK 2021. [DOI: 10.1515/kern-1996-610418] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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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17
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Hagendorff A, Knebel F, Helfen A, Stöbe S, Haghi D, Ruf T, Lavall D, Knierim J, Altiok E, Brandt R, Merke N, Ewen S. Echocardiographic assessment of mitral regurgitation: discussion of practical and methodologic aspects of severity quantification to improve diagnostic conclusiveness. Clin Res Cardiol 2021; 110:1704-1733. [PMID: 33839933 PMCID: PMC8563569 DOI: 10.1007/s00392-021-01841-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 03/08/2021] [Indexed: 12/28/2022]
Abstract
The echocardiographic assessment of mitral valve regurgitation (MR) by characterizing specific morphological features and grading its severity is still challenging. Analysis of MR etiology is necessary to clarify the underlying pathological mechanism of the valvular defect. Severity of mitral regurgitation is often quantified based on semi-quantitative parameters. However, incongruent findings and/or interpretations of regurgitation severity are frequently observed. This proposal seeks to offer practical support to overcome these obstacles by offering a standardized workflow, an easy means to identify non-severe mitral regurgitation, and by focusing on the quantitative approach with calculation of the individual regurgitant fraction. This work also indicates main methodological problems of semi-quantitative parameters when evaluating MR severity and offers appropriateness criteria for their use. It addresses the diagnostic importance of left-ventricular wall thickness, left-ventricular and left atrial volumes in relation to disease progression, and disease-related complaints to improve interpretation of echocardiographic findings. Finally, it highlights the conditions influencing the MR dynamics during echocardiographic examination. These considerations allow a reproducible, verifiable, and transparent in-depth echocardiographic evaluation of MR patients ensuring consistent haemodynamic plausibility of echocardiographic results.
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Affiliation(s)
- Andreas Hagendorff
- Department of Cardiology, Klinik und Poliklinik für Kardiologie, University of Leipzig, Liebigstraße 20, 04103, Leipzig, Germany.
| | - Fabian Knebel
- Department of Cardiology, University of Berlin, Charité Universitätsmedizin Berlin, Campus Mitte, Medizinische Klinik mit Schwerpunkt Kardiologie und Angiologie, Charitéplatz 1, 10117, Berlin, Germany
| | - Andreas Helfen
- Department of Cardiology, Katholisches Klinikum Lünen Werne GmbH, St-Marien-Hospital Lünen, Altstadtstrasse 23, 44534, Lünen, Germany
| | - Stephan Stöbe
- Department of Cardiology, Klinik und Poliklinik für Kardiologie, University of Leipzig, Liebigstraße 20, 04103, Leipzig, Germany
| | - Dariush Haghi
- Kardiologische Praxisklinik Ludwigshafen, Akademische Lehrpraxis der Universität Mannheim, Ludwig-Guttmann-Strasse 11, 67071, Ludwigshafen, Germany
| | - Tobias Ruf
- Department of Cardiology, Center of Cardiology, Heart Valve Center, University Medical Center Mainz, University of Mainz, Langenbeckstrasse 1, 55131, Mainz, Germany
| | - Daniel Lavall
- Department of Cardiology, Klinik und Poliklinik für Kardiologie, University of Leipzig, Liebigstraße 20, 04103, Leipzig, Germany
| | - Jan Knierim
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Augustenburger Platz 1, Berlin, 13353, Germany
| | - Ertunc Altiok
- Department of Cardiology, University of Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Roland Brandt
- Department of Cardiology, Kerckhoff Heart Center, Benekestr. 2-8, 61231, Bad Nauheim, Germany
| | - Nicolas Merke
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Augustenburger Platz 1, Berlin, 13353, Germany
| | - Sebastian Ewen
- Klinik für Innere Medizin III - Kardiologie, Angiologie und Internistische Intensivmedizin, Universitätsklinikum des Saarlandes, Kirrberger Str, IMED, 66421, Homburg, Germany
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18
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Brandt R, Trushina NI, Bakota L. Much More Than a Cytoskeletal Protein: Physiological and Pathological Functions of the Non-microtubule Binding Region of Tau. Front Neurol 2020; 11:590059. [PMID: 33193056 PMCID: PMC7604284 DOI: 10.3389/fneur.2020.590059] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [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: 07/31/2020] [Accepted: 09/16/2020] [Indexed: 12/21/2022] Open
Abstract
Tau protein (MAPT) is classified as a microtubule-associated protein (MAP) and is believed to regulate the axonal microtubule arrangement. It belongs to the tau/MAP2/MAP4 family of MAPs that have a similar microtubule binding region at their carboxy-terminal half. In tauopathies, such as Alzheimer's disease, tau is distributed more in the somatodendritic compartment, where it aggregates into filamentous structures, the formation of which correlates with cognitive impairments in patients. While microtubules are the dominant interaction partners of tau under physiological conditions, tau has many additional interaction partners that can contribute to its physiological and pathological role. In particular, the amino-terminal non-microtubule binding domain (N-terminal projection region, NTR) of tau interacts with many partners that are involved in membrane organization. The NTR contains intrinsically disordered regions (IDRs) that show a strong evolutionary increase in the disorder and may have been the basis for the development of new, tau-specific interactions. In this review we discuss the functional organization of the tau protein and the special features of the tau non-microtubule binding region also in the connection with the results of Tau KO models. We consider possible physiological and pathological functions of tau's non-microtubule interactions, which could indicate that interactions mediated by tau's NTR and regulated by far-reaching functional interactions of the PRR and the extreme C-terminus of tau contribute to the pathological processes.
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Affiliation(s)
- Roland Brandt
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany.,Center for Cellular Nanoanalytics, University of Osnabrück, Osnabrück, Germany.,Institute of Cognitive Science, University of Osnabrück, Osnabrück, Germany
| | | | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
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19
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Hrynchak MV, Rierola M, Golovyashkina N, Penazzi L, Pump WC, David B, Sündermann F, Brandt R, Bakota L. Chronic Presence of Oligomeric Aβ Differentially Modulates Spine Parameters in the Hippocampus and Cortex of Mice With Low APP Transgene Expression. Front Synaptic Neurosci 2020; 12:16. [PMID: 32390822 PMCID: PMC7194154 DOI: 10.3389/fnsyn.2020.00016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 12/09/2019] [Accepted: 03/25/2020] [Indexed: 01/06/2023] Open
Abstract
Alzheimer’s disease is regarded as a synaptopathy with a long presymptomatic phase. Soluble, oligomeric amyloid-β (Aβ) is thought to play a causative role in this disease, which eventually leads to cognitive decline. However, most animal studies have employed mice expressing high levels of the Aβ precursor protein (APP) transgene to drive pathology. Here, to understand how the principal neurons in different brain regions cope with moderate, chronically present levels of Aβ, we employed transgenic mice expressing equal levels of mouse and human APP carrying a combination of three familial AD (FAD)-linked mutations (Swedish, Dutch, and London), that develop plaques only in old age. We analyzed dendritic spine parameters in hippocampal and cortical brain regions after targeted expression of EGFP to allow high-resolution imaging, followed by algorithm-based evaluation of mice of both sexes from adolescence to old age. We report that Aβ species gradually accumulated throughout the life of APPSDL mice, but not the oligomeric forms, and that the amount of membrane-associated oligomers decreased at the onset of plaque formation. We observed an age-dependent loss of thin spines under most conditions as an indicator of a loss of synaptic plasticity in older mice. We further found that hippocampal pyramidal neurons respond to increased Aβ levels by lowering spine density and shifting spine morphology, which reached significance in the CA1 subfield. In contrast, the spine density in cortical pyramidal neurons of APPSDL mice was unchanged. We also observed an increase in the protein levels of PSD-95 and Arc in the hippocampus and cortex, respectively. Our data demonstrated that increased concentrations of Aβ have diverse effects on dendritic spines in the brain and suggest that hippocampal and cortical neurons have different adaptive and compensatory capacity during their lifetime. Our data also indicated that spine morphology differs between sexes in a region-specific manner.
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Affiliation(s)
- Mariya V Hrynchak
- Department of Neurobiology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Marina Rierola
- Department of Neurobiology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Nataliya Golovyashkina
- Department of Neurobiology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Lorène Penazzi
- Department of Neurobiology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Wiebke C Pump
- Department of Neurobiology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Bastian David
- Department of Neurobiology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Frederik Sündermann
- Department of Neurobiology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Center for Cellular Nanoanalytics, University of Osnabrück, Osnabrück, Germany.,Institute of Cognitive Science, University of Osnabrück, Osnabrück, Germany
| | - Lidia Bakota
- Department of Neurobiology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
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20
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Trushina NI, Mulkidjanian AY, Brandt R. The microtubule skeleton and the evolution of neuronal complexity in vertebrates. Biol Chem 2020; 400:1163-1179. [PMID: 31116700 DOI: 10.1515/hsz-2019-0149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 02/04/2019] [Accepted: 04/17/2019] [Indexed: 12/21/2022]
Abstract
The evolution of a highly developed nervous system is mirrored by the ability of individual neurons to develop increased morphological complexity. As microtubules (MTs) are crucially involved in neuronal development, we tested the hypothesis that the evolution of complexity is driven by an increasing capacity of the MT system for regulated molecular interactions as it may be implemented by a higher number of molecular players and a greater ability of the individual molecules to interact. We performed bioinformatics analysis on different classes of components of the vertebrate neuronal MT cytoskeleton. We show that the number of orthologs of tubulin structure proteins, MT-binding proteins and tubulin-sequestering proteins expanded during vertebrate evolution. We observed that protein diversity of MT-binding and tubulin-sequestering proteins increased by alternative splicing. In addition, we found that regions of the MT-binding protein tau and MAP6 displayed a clear increase in disorder extent during evolution. The data provide evidence that vertebrate evolution is paralleled by gene expansions, changes in alternative splicing and evolution of coding sequences of components of the MT system. The results suggest that in particular evolutionary changes in tubulin-structure proteins, MT-binding proteins and tubulin-sequestering proteins were prominent drivers for the development of increased neuronal complexity.
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Affiliation(s)
- Nataliya I Trushina
- Department of Neurobiology, University of Osnabrück, Barbarastraße 11, D-49076 Osnabrück, Germany
| | - Armen Y Mulkidjanian
- Department of Physics, University of Osnabrück, Barbarastraße 7, D-49076 Osnabrück, Germany.,A.N. Belozersky Institute of Physico-Chemical Biology and School of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Barbarastraße 11, D-49076 Osnabrück, Germany.,Center for Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, D-49076 Osnabrück, Germany.,Institute of Cognitive Science, University of Osnabrück, Barbarastraße 11, D-49076 Osnabrück, Germany
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21
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Ortiz-Sanz C, Gaminde-Blasco A, Valero J, Bakota L, Brandt R, Zugaza JL, Matute C, Alberdi E. Early Effects of Aβ Oligomers on Dendritic Spine Dynamics and Arborization in Hippocampal Neurons. Front Synaptic Neurosci 2020; 12:2. [PMID: 32116638 PMCID: PMC7029715 DOI: 10.3389/fnsyn.2020.00002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [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: 11/08/2019] [Accepted: 01/13/2020] [Indexed: 01/22/2023] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder that leads to impaired memory and cognitive deficits. Spine loss as well as changes in spine morphology correlates with cognitive impairment in this neurological disorder. Many studies in animal models and ex vivo cultures indicate that amyloid β-peptide (Aβ) oligomers induce synaptic damage early during the progression of the disease. Here, in order to determine the events that initiate synaptic alterations, we acutely applied oligomeric Aβ to primary hippocampal neurons and an ex vivo model of organotypic hippocampal cultures from a mouse after targeted expression of EGFP to allow high-resolution imaging and algorithm-based evaluation of spine changes. Dendritic spines were classified as thin, stubby or mushroom, based on morphology. In vivo, time-lapse imaging showed that the three spine types were relatively stable, although their stability significantly decreased after treatment with Aβ oligomers. Unexpectedly, we observed that the density of total dendritic spines increased in organotypic hippocampal slices treated with Aβ compared to control cultures. Specifically, the fraction of stubby spines significantly increased, while mushroom and thin spines remained unaltered. Pharmacological tools revealed that acute Aβ oligomers induced spine changes through mechanisms involving CaMKII and integrin β1 activities. Additionally, analysis of dendritic complexity based on a 3D reconstruction of the whole neuron morphology showed an increase in the apical dendrite length and branching points in CA1 organotypic hippocampal slices treated with Aβ. In contrast to spines, the morphological changes were affected by integrin β1 but not by CaMKII inhibition. Altogether, these data indicate that the Aβ oligomers exhibit early dual effects by acutely enhancing dendritic complexity and spine density.
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Affiliation(s)
- Carolina Ortiz-Sanz
- Department of Neuroscience, University of Basque Country (UPV/EHU) and CIBERNED, Leioa, Spain.,Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Adhara Gaminde-Blasco
- Department of Neuroscience, University of Basque Country (UPV/EHU) and CIBERNED, Leioa, Spain.,Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Jorge Valero
- Achucarro Basque Center for Neuroscience, Leioa, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany.,Center for Cellular Nanoanalytics, University of Osnabrück, Osnabrück, Germany.,Institute of Cognitive Science, University of Osnabrück, Osnabrück, Germany
| | - José L Zugaza
- Achucarro Basque Center for Neuroscience, Leioa, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain.,Department of Genetics, Physical Anthropology and Animal Physiology, UPV/EHU, Leioa, Spain
| | - Carlos Matute
- Department of Neuroscience, University of Basque Country (UPV/EHU) and CIBERNED, Leioa, Spain.,Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Elena Alberdi
- Department of Neuroscience, University of Basque Country (UPV/EHU) and CIBERNED, Leioa, Spain.,Achucarro Basque Center for Neuroscience, Leioa, Spain
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22
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Bog M, Xu S, Himmelbach A, Brandt R, Wagner F, Appenroth KJ, Sree KS. Genotyping-by-Sequencing for Species Delimitation in Lemna Section Uninerves Hegelm. (Lemnaceae). The Duckweed Genomes 2020. [DOI: 10.1007/978-3-030-11045-1_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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23
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Kazdal D, Allgäuer M, Budczies J, Kriegsmann M, Leichsenring J, Volckmar A, Kirchner M, Neumann O, Brandt R, Rempel E, Tala S, Harms A, Plögler C, Von Winterfeld M, Penzel R, Schirmacher P, Endris V, Stenzinger A. P1.04-13 Delineating Spatial Heterogeneity of Tumor Mutational Burden (TMB) Counts in Pulmonary Adenocarcinoma. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.08.916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Trushina NI, Bakota L, Mulkidjanian AY, Brandt R. The Evolution of Tau Phosphorylation and Interactions. Front Aging Neurosci 2019; 11:256. [PMID: 31619983 PMCID: PMC6759874 DOI: 10.3389/fnagi.2019.00256] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [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: 06/28/2019] [Accepted: 08/28/2019] [Indexed: 12/18/2022] Open
Abstract
Tau is a neuronal microtubule-associated protein (MAP) that is involved in the regulation of axonal microtubule assembly. However, as a protein with intrinsically disordered regions (IDRs), tau also interacts with many other partners in addition to microtubules. Phosphorylation at selected sites modulates tau's various intracellular interactions and regulates the properties of IDRs. In Alzheimer's disease (AD) and other tauopathies, tau exhibits pathologically increased phosphorylation (hyperphosphorylation) at selected sites and aggregates into neurofibrillary tangles (NFTs). By bioinformatics means, we tested the hypothesis that the sequence of tau has changed during the vertebrate evolution in a way that novel interactions developed and also the phosphorylation pattern was affected, which made tau prone to the development of tauopathies. We report that distinct regions of tau show functional specialization in their molecular interactions. We found that tau's amino-terminal region, which is involved in biological processes related to "membrane organization" and "regulation of apoptosis," exhibited a strong evolutionary increase in protein disorder providing the basis for the development of novel interactions. We observed that the predicted phosphorylation sites have changed during evolution in a region-specific manner, and in some cases the overall number of phosphorylation sites increased owing to the formation of clusters of phosphorylatable residues. In contrast, disease-specific hyperphosphorylated sites remained highly conserved. The data indicate that novel, non-microtubule related tau interactions developed during evolution and suggest that the biological processes, which are mediated by these interactions, are of pathological relevance. Furthermore, the data indicate that predicted phosphorylation sites in some regions of tau, including a cluster of phosphorylatable residues in the alternatively spliced exon 2, have changed during evolution. In view of the "antagonistic pleiotropy hypothesis" it may be worth to take disease-associated phosphosites with low evolutionary conservation as relevant biomarkers into consideration.
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Affiliation(s)
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Armen Y Mulkidjanian
- Department of Physics, University of Osnabrück, Osnabrück, Germany.,School of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia.,A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany.,Center for Cellular Nanoanalytics, University of Osnabrück, Osnabrück, Germany.,Institute of Cognitive Science, University of Osnabrück, Osnabrück, Germany
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25
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Schob C, Morellini F, Ohana O, Bakota L, Hrynchak MV, Brandt R, Brockmann MD, Cichon N, Hartung H, Hanganu-Opatz IL, Kraus V, Scharf S, Herrmans-Borgmeyer I, Schweizer M, Kuhl D, Wöhr M, Vörckel KJ, Calzada-Wack J, Fuchs H, Gailus-Durner V, Hrabě de Angelis M, Garner CC, Kreienkamp HJ, Kindler S. Cognitive impairment and autistic-like behaviour in SAPAP4-deficient mice. Transl Psychiatry 2019; 9:7. [PMID: 30664629 PMCID: PMC6341115 DOI: 10.1038/s41398-018-0327-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 09/20/2018] [Accepted: 11/08/2018] [Indexed: 12/02/2022] Open
Abstract
In humans, genetic variants of DLGAP1-4 have been linked with neuropsychiatric conditions, including autism spectrum disorder (ASD). While these findings implicate the encoded postsynaptic proteins, SAPAP1-4, in the etiology of neuropsychiatric conditions, underlying neurobiological mechanisms are unknown. To assess the contribution of SAPAP4 to these disorders, we characterized SAPAP4-deficient mice. Our study reveals that the loss of SAPAP4 triggers profound behavioural abnormalities, including cognitive deficits combined with impaired vocal communication and social interaction, phenotypes reminiscent of ASD in humans. These behavioural alterations of SAPAP4-deficient mice are associated with dramatic changes in synapse morphology, function and plasticity, indicating that SAPAP4 is critical for the development of functional neuronal networks and that mutations in the corresponding human gene, DLGAP4, may cause deficits in social and cognitive functioning relevant to ASD-like neurodevelopmental disorders.
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Affiliation(s)
- Claudia Schob
- Institute for Human Genetics, University Medical Centre Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Fabio Morellini
- Behavioral Biology, Centre for Molecular Neurobiology Hamburg (ZMNH), University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Ora Ohana
- Institute for Molecular and Cellular Cognition, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, 49076, Osnabrück, Germany
| | - Mariya V Hrynchak
- Department of Neurobiology, University of Osnabrück, 49076, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, 49076, Osnabrück, Germany
| | - Marco D Brockmann
- Developmental Neurophysiology, Department of Neuroanatomy, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Nicole Cichon
- Developmental Neurophysiology, Department of Neuroanatomy, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Henrike Hartung
- Developmental Neurophysiology, Department of Neuroanatomy, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Ileana L Hanganu-Opatz
- Developmental Neurophysiology, Department of Neuroanatomy, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Vanessa Kraus
- Behavioral Biology, Centre for Molecular Neurobiology Hamburg (ZMNH), University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Sarah Scharf
- Behavioral Biology, Centre for Molecular Neurobiology Hamburg (ZMNH), University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Irm Herrmans-Borgmeyer
- Transgenic Mouse Facility, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michaela Schweizer
- Morphology and Electron Microscopy, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dietmar Kuhl
- Institute for Molecular and Cellular Cognition, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus Wöhr
- Behavioral Neuroscience, Experimental and Biological Psychology, Faculty of Psychology, Philipps-University of Marburg, 35032, Marburg, Germany
| | - Karl J Vörckel
- Behavioral Neuroscience, Experimental and Biological Psychology, Faculty of Psychology, Philipps-University of Marburg, 35032, Marburg, Germany
| | - Julia Calzada-Wack
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Centre Munich, German Research Centre for Environmental Health, 85764, Neuherberg, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Centre Munich, German Research Centre for Environmental Health, 85764, Neuherberg, Germany
| | - Valérie Gailus-Durner
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Centre Munich, German Research Centre for Environmental Health, 85764, Neuherberg, Germany
| | - Martin Hrabě de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Centre Munich, German Research Centre for Environmental Health, 85764, Neuherberg, Germany
- Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, 85354, Freising, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Craig C Garner
- German Centre for Neurodegenerative Diseases (DZNE), c/o Charité University Medical Centre, 10117, Berlin, Germany
| | - Hans-Jürgen Kreienkamp
- Institute for Human Genetics, University Medical Centre Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Stefan Kindler
- Institute for Human Genetics, University Medical Centre Hamburg-Eppendorf, 20246, Hamburg, Germany.
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26
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Gauthier-Kemper A, Suárez Alonso M, Sündermann F, Niewidok B, Fernandez MP, Bakota L, Heinisch JJ, Brandt R. Annexins A2 and A6 interact with the extreme N terminus of tau and thereby contribute to tau's axonal localization. J Biol Chem 2018; 293:8065-8076. [PMID: 29636414 DOI: 10.1074/jbc.ra117.000490] [Citation(s) in RCA: 51] [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: 10/17/2017] [Revised: 04/08/2018] [Indexed: 12/18/2022] Open
Abstract
During neuronal development, the microtubule-associated protein tau becomes enriched in the axon, where it remains concentrated in the healthy brain. In tauopathies such as Alzheimer's disease, tau redistributes from the axon to the somatodendritic compartment. However, the cellular mechanism that regulates tau's localization remains unclear. We report here that tau interacts with the Ca2+-regulated plasma membrane-binding protein annexin A2 (AnxA2) via tau's extreme N terminus encoded by the first exon (E1). Bioinformatics analysis identified two conserved eight-amino-acids-long motifs within E1 in mammals. Using a heterologous yeast system, we found that disease-related mutations and pseudophosphorylation of Tyr-18, located within E1 but outside of the two conserved regions, do not influence tau's interaction with AnxA2. We further observed that tau interacts with the core domain of AnxA2 in a Ca2+-induced open conformation and interacts also with AnxA6. Moreover, lack of E1 moderately increased tau's association rate to microtubules, consistent with the supposition that the presence of the tau-annexin interaction reduces the availability of tau to interact with microtubules. Of note, intracellular competition through overexpression of E1-containing constructs reduced tau's axonal enrichment in primary neurons. Our results suggest that the E1-mediated tau-annexin interaction contributes to the enrichment of tau in the axon and is involved in its redistribution in pathological conditions.
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Affiliation(s)
| | - María Suárez Alonso
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Frederik Sündermann
- Department of Neurobiology, University of Osnabrück, D-49076 Osnabrück, Germany
| | - Benedikt Niewidok
- Department of Neurobiology, University of Osnabrück, D-49076 Osnabrück, Germany
| | - Maria-Pilar Fernandez
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, D-49076 Osnabrück, Germany
| | | | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, D-49076 Osnabrück, Germany.
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27
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Bongard D, Degefa TH, Schön P, Giese M, Brandt R, Walder L. Evaluation and Elucidation of DNA-Containing Viologen Dendrimer Complex Formation. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800204] [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: 11/12/2022]
Affiliation(s)
- Dirk Bongard
- Institute of Chemistry of New Materials; University of Osnabrück; Barbarastr. 7 49069 Osnabrück Germany
| | - Tesfaye Hailu Degefa
- Institute of Chemistry of New Materials; University of Osnabrück; Barbarastr. 7 49069 Osnabrück Germany
| | - Peter Schön
- Materials Science and Technology of Polymers; MESA+ Institute for Nanotechnology; University of Twente; P. O. Box 217 7500 AE Enschede The Netherlands
| | - Maria Giese
- Department of Neurobiology; University of Osnabrück; Barbarastr. 11 49076 Osnabrück Germany
| | - Roland Brandt
- Department of Neurobiology; University of Osnabrück; Barbarastr. 11 49076 Osnabrück Germany
| | - Lorenz Walder
- Institute of Chemistry of New Materials; University of Osnabrück; Barbarastr. 7 49069 Osnabrück Germany
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28
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Niewidok B, Igaev M, Pereira da Graca A, Strassner A, Lenzen C, Richter CP, Piehler J, Kurre R, Brandt R. Single-molecule imaging reveals dynamic biphasic partition of RNA-binding proteins in stress granules. J Cell Biol 2018; 217:1303-1318. [PMID: 29463567 PMCID: PMC5881506 DOI: 10.1083/jcb.201709007] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 12/25/2017] [Accepted: 01/23/2018] [Indexed: 11/22/2022] Open
Abstract
Niewidok et al. analyze the distribution and dynamics of RNA-binding proteins (RBPs) with single-molecule resolution in living neuronal cells, providing direct support for liquid droplet behavior of stress granules in living cells and revealing transient binding of RBPs in nanocores. Stress granules (SGs) are cytosolic, nonmembranous RNA–protein complexes. In vitro experiments suggested that they are formed by liquid–liquid phase separation; however, their properties in mammalian cells remain unclear. We analyzed the distribution and dynamics of two paradigmatic RNA-binding proteins (RBPs), Ras GTPase-activating protein SH3-domain–binding protein (G3BP1) and insulin-like growth factor II mRNA-binding protein 1 (IMP1), with single-molecule resolution in living neuronal cells. Both RBPs exhibited different exchange kinetics between SGs. Within SGs, single-molecule localization microscopy revealed distributed hotspots of immobilized G3BP1 and IMP1 that reflect the presence of relatively immobile nanometer-sized nanocores. We demonstrate alternating binding in nanocores and anomalous diffusion in the liquid phase with similar characteristics for both RBPs. Reduction of low-complexity regions in G3BP1 resulted in less detectable mobile molecules in the liquid phase without change in binding in nanocores. The data provide direct support for liquid droplet behavior of SGs in living cells and reveal transient binding of RBPs in nanocores. Our study uncovers a surprising disconnect between SG partitioning and internal diffusion and interactions of RBPs.
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Affiliation(s)
- Benedikt Niewidok
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Maxim Igaev
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | | | - Andre Strassner
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Christine Lenzen
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | | | - Jacob Piehler
- Department of Biophysics, University of Osnabrück, Osnabrück, Germany
| | - Rainer Kurre
- Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
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29
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Citadini JM, Brandt R, Williams CR, Gomes FR. Evolution of morphology and locomotor performance in anurans: relationships with microhabitat diversification. J Evol Biol 2018; 31:371-381. [PMID: 29297953 DOI: 10.1111/jeb.13228] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [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: 08/19/2017] [Revised: 11/18/2017] [Accepted: 12/17/2017] [Indexed: 11/30/2022]
Abstract
The relationships between morphology, performance, behavior and ecology provide evidence for multiple and complex phenotypic adaptations. The anuran body plan, for example, is evolutionarily conserved and shows clear specializations to jumping performance back at least to the early Jurassic. However, there are instances of more recent adaptation to habit diversity in the post-cranial skeleton, including relative limb length. The present study tested adaptive models of morphological evolution in anurans associated with the diversity of microhabitat use (semi-aquatic arboreal, fossorial, torrent, and terrestrial) in species of anuran amphibians from Brazil and Australia. We use phylogenetic comparative methods to determine which evolutionary models, including Brownian motion (BM) and Ornstein-Uhlenbeck (OU) are consistent with morphological variation observed across anuran species. Furthermore, this study investigated the relationship of maximum distance jumped as a function of components of morphological variables and microhabitat use. We found there are multiple optima of limb lengths associated to different microhabitats with a trend of increasing hindlimbs in torrent, arboreal, semi-aquatic whereas fossorial and terrestrial species evolve toward optima with shorter hindlimbs. Moreover, arboreal, semi-aquatic and torrent anurans have higher jumping performance and longer hindlimbs, when compared to terrestrial and fossorial species. We corroborate the hypothesis that evolutionary modifications of overall limb morphology have been important in the diversification of locomotor performance along the anuran phylogeny. Such evolutionary changes converged in different phylogenetic groups adapted to similar microhabitat use in two different zoogeographical regions.
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Affiliation(s)
- J M Citadini
- Department of Physiology, Bioscience Institute, University of São Paulo, São Paulo, SP, Brazil
| | - R Brandt
- Department of Biology, FFCLRP/USP, Ribeirão Preto, SP, Brazil
| | - C R Williams
- Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
| | - F R Gomes
- Department of Physiology, Bioscience Institute, University of São Paulo, São Paulo, SP, Brazil
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30
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Monteiro Abreu N, Jeserich G, Brandt R, Bakota L. The importance of electrode positions – Electrophysiological recordings from acute hippocampus slices of 3-months and 1-year-old male mice in the CA1 region. Front Cell Neurosci 2018. [DOI: 10.3389/conf.fncel.2018.38.00099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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31
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Affiliation(s)
- U. Besserer
- Forschungszentrum Karlsruhe GmbH, Tritiumlabor, Postfach3640 D-76021 Karlsruhe, Germany
| | - R.-D. Penzhorn
- Forschungszentrum Karlsruhe GmbH, Tritiumlabor, Postfach3640 D-76021 Karlsruhe, Germany
| | - R. Brandt
- Philipps-Universitat Marburg Hans Meerwein-Straβe D-35032 Marburg, Germany
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32
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Brandt R. Targeting microtubules in axonal re- and degeneration (Commentary on Li et al. ()). Eur J Neurosci 2017; 46:1647-1649. [PMID: 28570010 DOI: 10.1111/ejn.13615] [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: 12/01/2022]
Affiliation(s)
- Roland Brandt
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
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33
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Brandt R, Bakota L. Microtubule dynamics and the neurodegenerative triad of Alzheimer's disease: The hidden connection. J Neurochem 2017; 143:409-417. [PMID: 28267200 DOI: 10.1111/jnc.14011] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 01/03/2017] [Accepted: 02/17/2017] [Indexed: 02/03/2023]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder and is, on a histopathological level, characterized by the presence of extracellular amyloid plaques composed of the protein fragment Aβ, and intracellular neurofibrillary tangles, which contain the microtubule-associated protein tau in a hyperphosphorylated state. In AD defects in microtubule (MT) assembly and organization have also been reported; however, it is unclear whether MT abnormalities have a causal and early role in the disease process or represent a common end point downstream of the neurodegenerative cascade. Recent evidence indicates that microtubule-stabilizing drugs prevent axonopathy in animal models of tauopathies and reverse Aβ-induced loss of synaptic connectivity in an ex vivo model of amyloidosis. This could suggest that MT dysfunction connects some of the degenerative events and provides a useful target to simultaneously prevent several neurodegenerative processes in AD. Here, we describe how changes in the structure and dynamics of MTs are involved in the different aspects of the neurodegenerative triad of AD. We discuss evidence that MTs are affected both by tau-dependent and tau-independent mechanisms but appear to be regulated in a distinct way in different neuronal compartments. We argue that modulation of MT dynamics could be of potential benefit but needs to be precisely controlled in a cell and compartment-specific manner to avoid harmful side effects. This article is part of the series "Beyond Amyloid".
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Affiliation(s)
- Roland Brandt
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
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Bakota L, Ussif A, Jeserich G, Brandt R. Systemic and network functions of the microtubule-associated protein tau: Implications for tau-based therapies. Mol Cell Neurosci 2017; 84:132-141. [PMID: 28318914 DOI: 10.1016/j.mcn.2017.03.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [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: 11/30/2016] [Revised: 02/23/2017] [Accepted: 03/05/2017] [Indexed: 01/04/2023] Open
Abstract
Tau is a microtubule-associated neuronal protein, whose primary role was long thought to regulate axonal microtubule assembly. Tau is subject to many posttranslational modifications and can aggregate into neurofibrillary tangles, which are considered to be a hallmark of several neurodegenerative diseases collectively called "tauopathies". The most common tauopathy is Alzheimer's disease, where tau pathology correlates with sites of neurodegeneration. Tau belongs to the class of intrinsically disordered proteins, which are known to interact with many partners and are considered to be involved in various signaling, regulation and recognition processes. Thus more recent evidence indicates that tau functionally interacts with many proteins and different cellular structures, which may have an important physiological role and may be involved in neurodegenerative processes. Furthermore, tau can be released from neurons and exert functional effects on other cells. This review article weighs the evidence that tau has subtle but important systemic effects on neuronal network function by maintaining physiological neuronal transmission and synaptic plasticity, which are possibly independent from tau's microtubule modulating activities. Implications for tau-based therapeutic approaches are discussed.
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Affiliation(s)
- Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Abdala Ussif
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Gunnar Jeserich
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany.
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Penazzi L, Lorengel J, Sündermann F, Golovyashkina N, Marre S, Mathis CM, Lewejohann L, Brandt R, Bakota L. DMSO modulates CNS function in a preclinical Alzheimer's disease model. Neuropharmacology 2017; 113:434-444. [DOI: 10.1016/j.neuropharm.2016.10.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 10/15/2016] [Accepted: 10/18/2016] [Indexed: 11/25/2022]
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Abstract
Alzheimer’s disease (AD) is characterised by a progressive loss of cognitive functions. Histopathologically, AD is defined by the presence of extracellular amyloid plaques containing Aβ and intracellular neurofibrillary tangles composed of hyperphosphorylated tau proteins. According to the now well-accepted amyloid cascade hypothesis is the Aβ pathology the primary driving force of AD pathogenesis, which then induces changes in tau protein leading to a neurodegenerative cascade during the progression of disease. Since many earlier drug trials aiming at preventing Aβ pathology failed to demonstrate efficacy, tau and microtubules have come into focus as prominent downstream targets. The article aims to develop the current concept of the involvement of tau in the neurodegenerative triad of synaptic loss, cell death and dendritic simplification. The function of tau as a microtubule-associated protein and versatile interaction partner will then be introduced and the rationale and progress of current tau-directed therapy will be discussed in the biological context.
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Affiliation(s)
- Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany.
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Niewidok B, Igaev M, Sündermann F, Janning D, Bakota L, Brandt R. Presence of a carboxy-terminal pseudorepeat and disease-like pseudohyperphosphorylation critically influence tau's interaction with microtubules in axon-like processes. Mol Biol Cell 2016; 27:3537-3549. [PMID: 27582388 PMCID: PMC5221586 DOI: 10.1091/mbc.e16-06-0402] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 08/24/2016] [Indexed: 12/31/2022] Open
Abstract
A refined FDAP approach is used to analyze tau’s behavior in axon-like processes. A conserved C-terminal pseudorepeat and disease-like pseudohyperphosphorylation critically influence tau’s microtubule interaction. The results contribute to an understanding of pathological processes that lead to tau’s redistribution during disease. A current challenge of cell biology is to investigate molecular interactions in subcellular compartments of living cells to overcome the artificial character of in vitro studies. To dissect the interaction of the neuronal microtubule (MT)-associated protein tau with MTs in axon-like processes, we used a refined fluorescence decay after photoactivation approach and single-molecule tracking. We found that isoform variation had only a minor influence on the tau–MT interaction, whereas the presence of a C-terminal pseudorepeat region (PRR) greatly increased MT binding by a greater-than-sixfold reduction of the dissociation rate. Bioinformatic analysis revealed that the PRR contained a highly conserved motif of 18 amino acids. Disease-associated tau mutations in the PRR (K369I, G389R) did not influence apparent MT binding but increased its dynamicity. Simulation of disease-like tau hyperphosphorylation dramatically diminished the tau–MT interaction by a greater-than-fivefold decrease of the association rate with no major change in the dissociation rate. Apparent binding of tau to MTs was similar in axons and dendrites but more sensitive to increased phosphorylation in axons. Our data indicate that under the conditions of high MT density that prevail in the axon, tau’s MT binding and localization are crucially affected by the presence of the PRR and tau hyperphosphorylation.
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Affiliation(s)
- Benedikt Niewidok
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Maxim Igaev
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Frederik Sündermann
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Dennis Janning
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
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Abstract
The cytoskeleton is the major intracellular structure that determines the morphology of neurons and maintains their structural integrity. It is therefore not surprising that a disturbance of cytoskeletal structure and functionunderlies many neurodegenerative diseases. This special issue brings together current information on the three majorneuronal cytoskeletal filament systems, microtubules, microfilaments and neurofilaments, and aims to provide a comprehensive overview of the role of the key components of these three systems under both physiological and pathological conditions. It therefore also addresses the role of microtubule-associated proteins (with a focus on tau) and motor proteins (with a focus on kinesin).
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Affiliation(s)
- Roland Brandt
- Neurobiologie der Universität Osnabrück, Barbarastrasse 11, D-49076 Osnabrück, Germany.
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia Campus, Brisbane, QLD 4072, Australia.
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Bongard D, Degefa TH, Schön P, Giese M, Brandt R, Walder L. Evaluation and Elucidation of DNA-Containing Viologen Dendrimer Complex Formation. European J Org Chem 2016. [DOI: 10.1002/ejoc.201501485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Heinisch JJ, Brandt R. Signaling pathways and posttranslational modifications of tau in Alzheimer's disease: the humanization of yeast cells. Microb Cell 2016; 3:135-146. [PMID: 28357346 DOI: 10.15698/mic2016.04.489] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In the past decade, yeast have been frequently employed to study the molecular mechanisms of human neurodegenerative diseases, generally by means of heterologous expression of genes encoding the relevant hallmark proteins. However, it has become evident that substantial posttranslational modifications of many of these proteins are required for the development and progression of potentially disease relevant changes. This is exemplified by the neuronal tau proteins, which are critically involved in a class of neuro-degenerative diseases collectively called tauopathies and which includes Alz-heimer's disease (AD) as its most common representative. In the course of the disease, tau changes its phosphorylation state and becomes hyperphosphory-lated, gets truncated by proteolytic cleavage, is subject to O-glycosylation, sumoylation, ubiquitinylation, acetylation and some other modifications. This poses the important question, which of these posttranslational modifications are naturally occurring in the yeast model or can be reconstituted by heterol-ogous gene expression. Here, we present an overview on common modifica-tions as they occur in tau during AD, summarize their potential relevance with respect to disease mechanisms and refer to the native yeast enzyme orthologs capable to perform these modifications. We will also discuss potential approaches to humanize yeast in order to create modification patterns resembling the situation in mammalian cells, which could enhance the value of Saccharomyces cerevisiae and Kluyveromyces lactis as disease models.
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Affiliation(s)
- Jürgen J Heinisch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, D-49076 Osnabrück, Germany
| | - Roland Brandt
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Neurobiologie, Barbarastr. 11, D-49076 Osnabrück, Germany
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Heinisch JJ, Brandt R. Signaling pathways and posttranslational modifications of tau in Alzheimer's disease: the humanization of yeast cells. Microb Cell 2016. [PMID: 28357346 DOI: 10.15698/mic2016.04] [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] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In the past decade, yeast have been frequently employed to study the molecular mechanisms of human neurodegenerative diseases, generally by means of heterologous expression of genes encoding the relevant hallmark proteins. However, it has become evident that substantial posttranslational modifications of many of these proteins are required for the development and progression of potentially disease relevant changes. This is exemplified by the neuronal tau proteins, which are critically involved in a class of neuro-degenerative diseases collectively called tauopathies and which includes Alz-heimer's disease (AD) as its most common representative. In the course of the disease, tau changes its phosphorylation state and becomes hyperphosphory-lated, gets truncated by proteolytic cleavage, is subject to O-glycosylation, sumoylation, ubiquitinylation, acetylation and some other modifications. This poses the important question, which of these posttranslational modifications are naturally occurring in the yeast model or can be reconstituted by heterol-ogous gene expression. Here, we present an overview on common modifica-tions as they occur in tau during AD, summarize their potential relevance with respect to disease mechanisms and refer to the native yeast enzyme orthologs capable to perform these modifications. We will also discuss potential approaches to humanize yeast in order to create modification patterns resembling the situation in mammalian cells, which could enhance the value of Saccharomyces cerevisiae and Kluyveromyces lactis as disease models.
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Affiliation(s)
- Jürgen J Heinisch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, D-49076 Osnabrück, Germany
| | - Roland Brandt
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Neurobiologie, Barbarastr. 11, D-49076 Osnabrück, Germany
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Penazzi L, Tackenberg C, Ghori A, Golovyashkina N, Niewidok B, Selle K, Ballatore C, Smith AB, Bakota L, Brandt R. Aβ-mediated spine changes in the hippocampus are microtubule-dependent and can be reversed by a subnanomolar concentration of the microtubule-stabilizing agent epothilone D. Neuropharmacology 2016; 105:84-95. [PMID: 26772969 DOI: 10.1016/j.neuropharm.2016.01.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 10/10/2015] [Accepted: 01/03/2016] [Indexed: 10/25/2022]
Abstract
Dendritic spines represent the major postsynaptic input of excitatory synapses. Loss of spines and changes in their morphology correlate with cognitive impairment in Alzheimer's disease (AD) and are thought to occur early during pathology. Therapeutic intervention at a preclinical stage of AD to modify spine changes might thus be warranted. To follow the development and to potentially interfere with spine changes over time, we established a long term ex vivo model from organotypic cultures of the hippocampus from APP transgenic and control mice. The cultures exhibit spine loss in principal hippocampal neurons, which closely resembles the changes occurring in vivo, and spine morphology progressively changes from mushroom-shaped to stubby. We demonstrate that spine changes are completely reversed within few days after blocking amyloid-β (Aβ) production with the gamma-secretase inhibitor DAPT. We show that the microtubule disrupting drug nocodazole leads to spine loss similar to Aβ expressing cultures and suppresses DAPT-mediated spine recovery in slices from APP transgenic mice. Finally, we report that epothilone D (EpoD) at a subnanomolar concentration, which slightly stabilizes microtubules in model neurons, completely reverses Aβ-induced spine loss and increases thin spine density. Taken together the data indicate that Aβ causes spine changes by microtubule destabilization and that spine recovery requires microtubule polymerization. Moreover, our results suggest that a low, subtoxic concentration of EpoD is sufficient to reduce spine loss during the preclinical stage of AD.
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Affiliation(s)
- Lorène Penazzi
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Christian Tackenberg
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Adnan Ghori
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Nataliya Golovyashkina
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Benedikt Niewidok
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Karolin Selle
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Carlo Ballatore
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, United States; Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076 Osnabrück, Germany.
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Brandt R. Meet Our Editorial Board Member. Curr Neuropharmacol 2015. [DOI: 10.2174/1570159x1306151126144206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Abstract
Neurons are the basic information-processing units of the nervous system. In fulfilling their task, they establish a structural polarity with an axon that can be over a meter long and dendrites with a complex arbor, which can harbor ten-thousands of spines. Microtubules and their associated proteins play important roles during the development of neuronal morphology, the plasticity of neurons, and neurodegenerative processes. They are dynamic structures, which can quickly adapt to changes in the environment and establish a structural scaffold with high local variations in composition and stability. This review presents a comprehensive overview about the role of microtubules and their dynamic behavior during the formation and maturation of processes and spines in the healthy brain, during aging and under neurodegenerative conditions. The review ends with a discussion of microtubule-targeted therapies as a perspective for the supportive treatment of neurodegenerative disorders.
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Affiliation(s)
- Lorène Penazzi
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
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Golovyashkina N, Penazzi L, Ballatore C, Smith AB, Bakota L, Brandt R. Region-specific dendritic simplification induced by Aβ, mediated by tau via dysregulation of microtubule dynamics: a mechanistic distinct event from other neurodegenerative processes. Mol Neurodegener 2015; 10:60. [PMID: 26541821 PMCID: PMC4634596 DOI: 10.1186/s13024-015-0049-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 09/28/2015] [Indexed: 12/30/2022] Open
Abstract
Background Dendritic simplification, a key feature of the neurodegenerative triad of Alzheimer’s disease (AD) in addition to spine changes and neuron loss, occurs in a region-specific manner. However, it is unknown how changes in dendritic complexity are mediated and how they relate to spine changes and neuron loss. Results To investigate the mechanisms of dendritic simplification in an authentic CNS environment we employed an ex vivo model, based on targeted expression of enhanced green fluorescent protein (EGFP)-tagged constructs in organotypic hippocampal slices of mice. Algorithm-based 3D reconstruction of whole neuron morphology in different hippocampal regions was performed on slices from APPSDL-transgenic and control animals. We demonstrate that induction of dendritic simplification requires the combined action of amyloid beta (Aβ) and human tau. Simplification is restricted to principal neurons of the CA1 region, recapitulating the region specificity in AD patients, and occurs at sites of Schaffer collateral input. We report that γ-secretase inhibition and treatment with the NMDA-receptor antagonist, CPP, counteract dendritic simplification. The microtubule-stabilizing drug epothilone D (EpoD) induces simplification in control cultures per se. Similar morphological changes were induced by a phosphoblocking tau construct, which also increases microtubule stability. In fact, low nanomolar concentrations of naturally secreted Aβ decreased phosphorylation at S262 in a cellular model, a site which is known to directly modulate tau-microtubule interactions. Conclusions The data provide evidence that dendritic simplification is mechanistically distinct from other neurodegenerative events and involves microtubule stabilization by dendritic tau, which becomes dephosphorylated at certain sites. They imply that treatments leading to an overall decrease of tau phosphorylation might have a negative impact on neuronal connectivity.
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Affiliation(s)
- Nataliya Golovyashkina
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany.
| | - Lorène Penazzi
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany.
| | - Carlo Ballatore
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, 19014, USA. .,Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, 19014, USA.
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany.
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany.
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Affiliation(s)
- R. Brandt
- Department of Biology; FFCLRP; University of São Paulo; Ribeirão Preto Sao Paulo Brazil
| | - F. Galvani
- Department of Biology; FFCLRP; University of São Paulo; Ribeirão Preto Sao Paulo Brazil
| | - T. Kohlsdorf
- Department of Biology; FFCLRP; University of São Paulo; Ribeirão Preto Sao Paulo Brazil
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Raasch K, Malecki E, Siemann M, Martinez MM, Heinisch JJ, Müller J, Bakota L, Kaltschmidt C, Kaltschmidt B, Rosemeyer H, Brandt R. Identification of Nucleoside Analogs as Inducers of Neuronal Differentiation in a Human Reporter Cell Line and Adult Stem Cells. Chem Biol Drug Des 2015; 86:129-43. [PMID: 25444247 DOI: 10.1111/cbdd.12488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 08/04/2014] [Revised: 11/10/2014] [Accepted: 11/20/2014] [Indexed: 01/13/2023]
Abstract
Nucleoside analogs (NSAs) were among the first chemotherapeutic agents and could also be useful for the manipulation of cell fate. To investigate the potential of NSAs for the induction of neuronal differentiation, we developed a novel phenotypic assay based on a human neuron-committed teratocarcinoma cell line (NT2) as a model for neuronal progenitors and constructed a NT2-based reporter cell line that expressed eGFP under the control of a neuron-specific promoter. We tested 38 structurally related NSAs and determined their activity to induce neuronal differentiation by immunocytochemistry of neuronal marker proteins, live cell imaging, fluorometric detection and immunoblot analysis. We identified twelve NSAs, which induced neuronal differentiation to different extents. NSAs with highest activity carried a halogen substituent at their pyrimidine nucleobase and an unmodified or 2'-O-methyl substituted 2-deoxy-β-D-ribofuranosyl residue as glyconic moiety. Cladribine, a purine nucleoside with similar structural features and in use to treat leukemia and multiple sclerosis, induced also differentiation of adult human neural crest-derived stem cells. Our results suggest that NSAs could be useful for the manipulation of neuronal cell fate in cell replacement therapy or treatment of neurodegenerative disorders. The data on the structure and function relationship will help to design compounds with increased activity and low toxicity.
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Affiliation(s)
- Katharina Raasch
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
| | - Edith Malecki
- Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, 49076, Osnabrück, Germany
| | - Maria Siemann
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
| | - Malayko M Martinez
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
| | - Jürgen J Heinisch
- Department of Genetics, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
| | - Janine Müller
- Department of Molecular Neurobiology, University of Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
| | - Christian Kaltschmidt
- Department of Molecular Neurobiology, University of Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Barbara Kaltschmidt
- Department of Molecular Neurobiology, University of Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Helmut Rosemeyer
- Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, 49076, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Barbarastrasse 11, 49076, Osnabrück, Germany
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Bongard D, Bohr W, Swierczek M, Degefa TH, Walder L, Brandt R. Alkylene-bridged viologen dendrimers: versatile cell delivery tools with biosensing properties. Org Biomol Chem 2014; 12:9583-91. [PMID: 25335762 DOI: 10.1039/c4ob00560k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of two types of viologen dendrimers with peripheral carboxyl groups is described. Their interaction with plasmid DNA and CT-DNA and the influence of time evolution and electrolyte on dendriplex formation have been electrochemically investigated. A negative potential shift appearing in the cyclic voltammograms of the dendrimers indicates dendriplex formation on the time scale of 15 to 19 minutes, i.e. similar to those determined empirically for other dendrimer types. The presence or absence of the negative potential shift can be used to check the stability towards sodium chloride and different cell growth media directing to sucrose for cell incubation experiments. The electrolyte content of commercially available cell growth media inhibits the dendriplex formation in solution prior to plasmid addition. Furthermore, a low salt stability of 20 mM sodium chloride for viologen dendriplexes has been confirmed, also recommending the use of lysosomotropic sucrose. The two types of viologen dendrimers have been combined with two plasmids differing in the number of base pairs. Four immortal cell lines have been tested to check the suitability of viologen dendriplexes as gene delivery systems. Probably due to the absence of terminal amino groups and endosomolytic substances only a small transfection efficiency of dendriplexes was achieved at low pH, generally excluding in vivo applications. With the larger pHSV-eGFP plasmid (5743 bp) no transfected cells were observed indicating a preference for shorter plasmids.
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Affiliation(s)
- Dirk Bongard
- Institute of Chemistry of New Materials, University of Osnabrück, Barbarastr. 7, D-49076 Osnabrück, Germany.
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Brandt R, Paululat A. Microcompartments in the Drosophila heart and the mammalian brain: general features and common principles. Biol Chem 2014; 394:217-30. [PMID: 23314534 DOI: 10.1515/hsz-2012-0261] [Citation(s) in RCA: 11] [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] [Received: 07/26/2012] [Accepted: 11/26/2012] [Indexed: 11/15/2022]
Abstract
Microcompartments are sub-organellar functional units and may have an important role in cellular physiology. They can act as highly dynamic or even transiently forming organizing compartments within cells. In this review, we would like to extend the concept of microcompartments as subcellular structures in individual cells in a way that it includes specializations that occur between different cells and between cells and components of the extracellular matrix. To develop the general features and properties of these structures, we will present two quite different examples - the development and maturation of the Drosophila heart and the dynamics of synaptic contacts in the mammalian brain. We argue that the molecular architecture, the function and the maintenance of these specializations follows common principles independent of the organ or the organism under investigation. They fulfill the criteria for being proper microcompartments, including their function as local units for the segregation of responses, their ability to serve as organizing platforms in a temporally and spatially highly restricted manner, and their regulation through instructions from neighboring cells or extracellular matrix components in a locally restricted and autonomous manner.
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Affiliation(s)
- Roland Brandt
- Department of Neurobiology , University of Osnabruck, D-49076 Osnabruck, Germany
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Bisanzo M, Brandt R, Kisoke T, Kyomugisha F, Arthur A, Thomas S. 13 Ketamine Use in a Resource-Limited Setting: Continued Safety in a Maturing African Non-Physician Clinician System. Ann Emerg Med 2014. [DOI: 10.1016/j.annemergmed.2014.07.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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