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Schmidt S, Holzer M, Arendt T, Sonntag M, Morawski M. Tau Protein Modulates Perineuronal Extracellular Matrix Expression in the TauP301L-acan Mouse Model. Biomolecules 2022; 12:biom12040505. [PMID: 35454094 PMCID: PMC9027016 DOI: 10.3390/biom12040505] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/21/2022] [Accepted: 03/24/2022] [Indexed: 02/04/2023] Open
Abstract
Tau mutations promote the formation of tau oligomers and filaments, which are neuropathological signs of several tau-associated dementias. Types of neurons in the CNS are spared of tau pathology and are surrounded by a specialized form of extracellular matrix; called perineuronal nets (PNs). Aggrecan, the major PN proteoglycans, is suggested to mediate PNs neuroprotective function by forming an external shield preventing the internalization of misfolded tau. We recently demonstrated a correlation between aggrecan amount and the expression and phosphorylation of tau in a TauP310L-acan mouse model, generated by crossbreeding heterozygous aggrecan mice with a significant reduction of aggrecan and homozygous TauP301L mice. Neurodegenerative processes have been associated with changes of PN structure and protein signature. In this study, we hypothesized that the structure and protein expression of PNs in this TauP310L-acan mouse is regulated by tau. Immunohistochemical and biochemical analyses demonstrate that protein levels of PN components differ between TauP301LHET-acanWT and TauP301LHET-acanHET mice, accompanied by changes in the expression of protein phosphatase 2 A. In addition, tau can modulate PN components such as brevican. Co-immunoprecipitation experiments revealed a physical connection between PN components and tau. These data demonstrate a complex, mutual interrelation of tau and the proteoglycans of the PN.
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Reinert A, Reinert T, Arendt T, Morawski M. High Iron and Iron Household Protein Contents in Perineuronal Net-Ensheathed Neurons Ensure Energy Metabolism with Safe Iron Handling. Int J Mol Sci 2022; 23:ijms23031634. [PMID: 35163558 PMCID: PMC8836250 DOI: 10.3390/ijms23031634] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/24/2022] [Accepted: 01/28/2022] [Indexed: 11/16/2022] Open
Abstract
A subpopulation of neurons is less vulnerable against iron-induced oxidative stress and neurodegeneration. A key feature of these neurons is a special extracellular matrix composition that forms a perineuronal net (PN). The PN has a high affinity to iron, which suggests an adapted iron sequestration and metabolism of the ensheathed neurons. Highly active, fast-firing neurons-which are often ensheathed by a PN-have a particular high metabolic demand, and therefore may have a higher need in iron. We hypothesize that PN-ensheathed neurons have a higher intracellular iron concentration and increased levels of iron proteins. Thus, analyses of cellular and regional iron and the iron proteins transferrin (Tf), Tf receptor 1 (TfR), ferritin H/L (FtH/FtL), metal transport protein 1 (MTP1 aka ferroportin), and divalent metal transporter 1 (DMT1) were performed on Wistar rats in the parietal cortex (PC), subiculum (SUB), red nucleus (RN), and substantia nigra (SNpr/SNpc). Neurons with a PN (PN+) have higher iron concentrations than neurons without a PN: PC 0.69 mM vs. 0.51 mM, SUB 0.84 mM vs. 0.69 mM, SN 0.71 mM vs. 0.63 mM (SNpr)/0.45 mM (SNpc). Intracellular Tf, TfR and MTP1 contents of PN+ neurons were consistently increased. The iron concentration of the PN itself is not increased. We also determined the percentage of PN+ neurons: PC 4%, SUB 5%, SNpr 45%, RN 86%. We conclude that PN+ neurons constitute a subpopulation of resilient pacemaker neurons characterized by a bustling iron metabolism and outstanding iron handling capabilities. These properties could contribute to the low vulnerability of PN+ neurons against iron-induced oxidative stress and degeneration.
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Affiliation(s)
- Anja Reinert
- Institute of Anatomy, Histology and Embryology, Leipzig University, An den Tierkliniken 43, 04103 Leipzig, Germany
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstraße 19, 04103 Leipzig, Germany; (T.R.); (T.A.); (M.M.)
- Correspondence:
| | - Tilo Reinert
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstraße 19, 04103 Leipzig, Germany; (T.R.); (T.A.); (M.M.)
- Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1A, 04103 Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstraße 19, 04103 Leipzig, Germany; (T.R.); (T.A.); (M.M.)
| | - Markus Morawski
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstraße 19, 04103 Leipzig, Germany; (T.R.); (T.A.); (M.M.)
- Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1A, 04103 Leipzig, Germany
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3
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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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Rusch H, Brammerloh M, Stieler J, Sonntag M, Mohammadi S, Weiskopf N, Arendt T, Kirilina E, Morawski M. Finding the best clearing approach - Towards 3D wide-scale multimodal imaging of aged human brain tissue. Neuroimage 2021; 247:118832. [PMID: 34929383 DOI: 10.1016/j.neuroimage.2021.118832] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 12/13/2021] [Accepted: 12/16/2021] [Indexed: 11/16/2022] Open
Abstract
The accessibility of new wide-scale multimodal imaging techniques led to numerous clearing techniques emerging over the last decade. However, clearing mesoscopic-sized blocks of aged human brain tissue remains an extremely challenging task. Homogenizing refractive indices and reducing light absorption and scattering are the foundation of tissue clearing. Due to its dense and highly myelinated nature, especially in white matter, the human brain poses particular challenges to clearing techniques. Here, we present a comparative study of seven tissue clearing approaches and their impact on aged human brain tissue blocks (> 5 mm). The goal was to identify the most practical and efficient method in regards to macroscopic transparency, brief clearing time, compatibility with immunohistochemical processing and wide-scale multimodal microscopic imaging. We successfully cleared 26 × 26 × 5 mm3-sized human brain samples with two hydrophilic and two hydrophobic clearing techniques. Optical properties as well as light and antibody penetration depths highly vary between these methods. In addition to finding the best clearing approach, we compared three microscopic imaging setups (the Zeiss Laser Scanning Microscope (LSM) 880 , the Miltenyi Biotec Ultramicroscope ll (UM ll) and the 3i Marianas LightSheet microscope) regarding optimal imaging of large-scale tissue samples. We demonstrate that combining the CLARITY technique (Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging compatible Tissue hYdrogel) with the Zeiss LSM 880 and combining the iDISCO technique (immunolabeling-enabled three-dimensional imaging of solvent-cleared organs) with the Miltenyi Biotec UM ll are the most practical and efficient approaches to sufficiently clear aged human brain tissue and generate 3D microscopic images. Our results point out challenges that arise from seven clearing and three imaging techniques applied to non-standardized tissue samples such as aged human brain tissue.
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Affiliation(s)
- Henriette Rusch
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Liebigstraße 19, Leipzig 04103, Germany
| | - Malte Brammerloh
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Science, Stephanstraße 1a, Leipzig 04103, Germany; Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, University of Leipzig, Linnéstraße 5, Leipzig 04103, Germany; International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Stephanstraße 1a, Leipzig 04103, Germany
| | - Jens Stieler
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Liebigstraße 19, Leipzig 04103, Germany
| | - Mandy Sonntag
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Liebigstraße 19, Leipzig 04103, Germany
| | - Siawoosh Mohammadi
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Science, Stephanstraße 1a, Leipzig 04103, Germany; Institute of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistraße 52, Hamburg 20246, Germany
| | - Nikolaus Weiskopf
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Science, Stephanstraße 1a, Leipzig 04103, Germany; Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, University of Leipzig, Linnéstraße 5, Leipzig 04103, Germany
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Liebigstraße 19, Leipzig 04103, Germany
| | - Evgeniya Kirilina
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Science, Stephanstraße 1a, Leipzig 04103, Germany; Center for Cognitive Neuroscience Berlin, Free University Berlin, Habelschwerdter Allee 45, Berlin 14195, Germany
| | - Markus Morawski
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Liebigstraße 19, Leipzig 04103, Germany; Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Science, Stephanstraße 1a, Leipzig 04103, Germany.
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5
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Brammerloh M, Morawski M, Friedrich I, Reinert T, Lange C, Pelicon P, Vavpetič P, Jankuhn S, Jäger C, Alkemade A, Balesar R, Pine K, Gavriilidis F, Trampel R, Reimer E, Arendt T, Weiskopf N, Kirilina E. Measuring the iron content of dopaminergic neurons in substantia nigra with MRI relaxometry. Neuroimage 2021; 239:118255. [PMID: 34119638 PMCID: PMC8363938 DOI: 10.1016/j.neuroimage.2021.118255] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [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: 03/25/2021] [Revised: 06/02/2021] [Accepted: 06/07/2021] [Indexed: 12/19/2022] Open
Abstract
Dopaminergic neurons dominate effective transverse relaxation in nigrosome 1. Ion beam microscopy reveals highest iron concentrations in dopaminergic neurons. Developed biophysical model links MRI parameters to cellular iron content. Ferritin- and neuromelanin-bound iron impact MRI parameters differently. Quantitative MRI provides a potential biomarker of iron in dopaminergic neurons.
In Parkinson’s disease, the depletion of iron-rich dopaminergic neurons in nigrosome 1 of the substantia nigra precedes motor symptoms by two decades. Methods capable of monitoring this neuronal depletion, at an early disease stage, are needed for early diagnosis and treatment monitoring. Magnetic resonance imaging (MRI) is particularly suitable for this task due to its sensitivity to tissue microstructure and in particular, to iron. However, the exact mechanisms of MRI contrast in the substantia nigra are not well understood, hindering the development of powerful biomarkers. In the present report, we illuminate the contrast mechanisms in gradient and spin echo MR images in human nigrosome 1 by combining quantitative 3D iron histology and biophysical modeling with quantitative MRI on post mortem human brain tissue. We show that the dominant contribution to the effective transverse relaxation rate (R2*) in nigrosome 1 originates from iron accumulated in the neuromelanin of dopaminergic neurons. This contribution is appropriately described by a static dephasing approximation of the MRI signal. We demonstrate that the R2* contribution from dopaminergic neurons reflects the product of cell density and cellular iron concentration. These results demonstrate that the in vivo monitoring of neuronal density and iron in nigrosome 1 may be feasible with MRI and provide directions for the development of biomarkers for an early detection of dopaminergic neuron depletion in Parkinson’s disease.
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Affiliation(s)
- Malte Brammerloh
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany; International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity; Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Linnéstr. 5, Leipzig 04103, Germany.
| | - Markus Morawski
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany; Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstr. 19, Leipzig, 04103, Germany
| | - Isabel Friedrich
- Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstr. 19, Leipzig, 04103, Germany
| | - Tilo Reinert
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany; Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Linnéstr. 5, Leipzig 04103, Germany
| | - Charlotte Lange
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany; Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Linnéstr. 5, Leipzig 04103, Germany
| | - Primož Pelicon
- Jožef Stefan Institute, Jamova 39, Ljubljana SI-1000, Slovenia
| | - Primož Vavpetič
- Jožef Stefan Institute, Jamova 39, Ljubljana SI-1000, Slovenia
| | - Steffen Jankuhn
- Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Linnéstr. 5, Leipzig 04103, Germany
| | - Carsten Jäger
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany; Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstr. 19, Leipzig, 04103, Germany
| | - Anneke Alkemade
- Integrative Model-based Cognitive Neuroscience Research Unit, University of Amsterdam, Amsterdam, Nieuwe Achtergracht 129B, 1001 NK Amsterdam, The Netherlands
| | - Rawien Balesar
- Integrative Model-based Cognitive Neuroscience Research Unit, University of Amsterdam, Amsterdam, Nieuwe Achtergracht 129B, 1001 NK Amsterdam, The Netherlands; The Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, Netherlands
| | - Kerrin Pine
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany
| | - Filippos Gavriilidis
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany
| | - Robert Trampel
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany
| | - Enrico Reimer
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstr. 19, Leipzig, 04103, Germany
| | - Nikolaus Weiskopf
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany; Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Linnéstr. 5, Leipzig 04103, Germany
| | - Evgeniya Kirilina
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig 04103, Germany; Center for Cognitive Neuroscience Berlin, Free University Berlin, Habelschwerdter Allee 45, Berlin, 14195, Germany
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6
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Curry-Hyde A, Gray LG, Chen BJ, Ueberham U, Arendt T, Janitz M. Cell type-specific circular RNA expression in human glial cells. Genomics 2020; 112:5265-5274. [DOI: 10.1016/j.ygeno.2020.09.042] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/02/2020] [Accepted: 09/19/2020] [Indexed: 12/11/2022]
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7
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Kirilina E, Helbling S, Morawski M, Pine K, Reimann K, Jankuhn S, Dinse J, Deistung A, Reichenbach JR, Trampel R, Geyer S, Müller L, Jakubowski N, Arendt T, Bazin PL, Weiskopf N. Superficial white matter imaging: Contrast mechanisms and whole-brain in vivo mapping. Sci Adv 2020; 6:6/41/eaaz9281. [PMID: 33028535 PMCID: PMC7541072 DOI: 10.1126/sciadv.aaz9281] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 08/26/2020] [Indexed: 05/11/2023]
Abstract
Superficial white matter (SWM) contains the most cortico-cortical white matter connections in the human brain encompassing the short U-shaped association fibers. Despite its importance for brain connectivity, very little is known about SWM in humans, mainly due to the lack of noninvasive imaging methods. Here, we lay the groundwork for systematic in vivo SWM mapping using ultrahigh resolution 7 T magnetic resonance imaging. Using biophysical modeling informed by quantitative ion beam microscopy on postmortem brain tissue, we demonstrate that MR contrast in SWM is driven by iron and can be linked to the microscopic iron distribution. Higher SWM iron concentrations were observed in U-fiber-rich frontal, temporal, and parietal areas, potentially reflecting high fiber density or late myelination in these areas. Our SWM mapping approach provides the foundation for systematic studies of interindividual differences, plasticity, and pathologies of this crucial structure for cortico-cortical connectivity in humans.
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Affiliation(s)
- Evgeniya Kirilina
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany.
- Center for Cognitive Neuroscience Berlin, Free University Berlin, Habelschwerdter Allee 45, 14195 Berlin, Germany
| | - Saskia Helbling
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Markus Morawski
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstr. 19, 04103 Leipzig, Germany
| | - Kerrin Pine
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Katja Reimann
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstr. 19, 04103 Leipzig, Germany
| | - Steffen Jankuhn
- Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Linnéstraße 5, 04103 Leipzig, Germany
| | - Juliane Dinse
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Andreas Deistung
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Philosophenweg 3, 07743 Jena, Germany
- Department of Radiology University Hospital Halle (Saale), Ernst-Grube-Str. 40, 06120 Halle, Germany
| | - Jürgen R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Philosophenweg 3, 07743 Jena, Germany
| | - Robert Trampel
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Stefan Geyer
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Larissa Müller
- Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany
| | - Norbert Jakubowski
- Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany
- Spetec GmbH, Berghamer Str. 2, 85435 Erding, Germany
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstr. 19, 04103 Leipzig, Germany
| | - Pierre-Louis Bazin
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
- Integrative Model-Based Cognitive Neuroscience Research Unit, University of Amsterdam, 1001 NK Amsterdam, The Netherlands
| | - Nikolaus Weiskopf
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
- Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Linnéstraße 5, 04103 Leipzig, Germany
- Wellcome Centre for Human Neuroimaging, Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK
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Curry-Hyde A, Ueberham U, Chen BJ, Zipfel I, Mills JD, Bochmann J, Jendrek R, Takenaka K, Kirazov L, Kirazov E, Jünger J, Brückner MK, Arendt T, Janitz M. Analysis of the Circular Transcriptome in the Synaptosomes of Aged Mice. Neuroscience 2020; 449:202-213. [PMID: 32926955 DOI: 10.1016/j.neuroscience.2020.09.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 06/02/2020] [Revised: 08/28/2020] [Accepted: 09/02/2020] [Indexed: 12/21/2022]
Abstract
Recently, circular RNAs (circRNAs) have been revealed to be an important non-coding element of the transcriptome. The brain contains the most abundant and widespread expression of circRNA. There are also indications that the circular transcriptome undergoes dynamic changes as a result of brain ageing. Diminished cognitive function with increased age reflects the dysregulation of synaptic function and ineffective neurotransmission through alterations of the synaptic proteome. Here, we present changes in the circular transcriptome in ageing synapses using a mouse model. Specifically, we observed an accumulation of uniquely expressed circular transcripts in the synaptosomes of aged mice compared to young mice. Individual circRNA expression patterns were characterized by an increased abundance in the synaptosomes of young or aged mice, whereas the opposite expression was observed for the parental gene linear transcripts. These changes in expression were validated by RT-qPCR. We provide the first comprehensive survey of the circular transcriptome in mammalian synapses, thereby paving the way for future studies. Additionally, we present 16 genes that express solely circRNAs, without linear RNAs co-expression, exclusively in young and aged synaptosomes, suggesting a synaptic gene network that functions along canonical splicing activity.
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Affiliation(s)
- Ashton Curry-Hyde
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Uwe Ueberham
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Bei Jun Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Ivonne Zipfel
- Institute of Clinical Immunology, University of Leipzig, Leipzig, Germany
| | - James D Mills
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Jana Bochmann
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Renate Jendrek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Konii Takenaka
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Ludmil Kirazov
- Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Evgeni Kirazov
- Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Jennifer Jünger
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Martina K Brückner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Michael Janitz
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia; Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany.
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9
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Schmidt S, Stapf C, Schmutzler S, Lachmann I, Arendt T, Holzer M, Sonntag M, Morawski M. Aggrecan modulates the expression and phosphorylation of tau in a novel bigenic TauP301L - Acan mouse model. Eur J Neurosci 2020; 53:3889-3904. [PMID: 32737917 DOI: 10.1111/ejn.14923] [Citation(s) in RCA: 4] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/11/2020] [Accepted: 07/21/2020] [Indexed: 01/17/2023]
Abstract
Selected types of neurons in the central nervous system are associated with a specialized form of extracellular matrix. These so-called perineuronal nets (PNs) are supramolecular structures surrounding neuronal somata, proximal dendrites and axon initial segments. PNs are involved in the regulation of plasticity and synaptic physiology. In addition, PNs were proposed to carry neuroprotective functions as PN-ensheathed neurons are mostly spared of tau pathology in brains of Alzheimer patients. Recently, the neuroprotective action of PNs was confirmed experimentally, demonstrating (i) that mainly aggrecan mediates the neuroprotective function of PNs and (ii) that aggrecan seems to generate an external shielding preventing the internalization of pathological forms of tau. In the present study, we aimed at extending these findings and hypothesized that aggrecan further provides an intracellular protection by preventing mutation-triggered formation of pathological forms of tau. We used crossbreds of TauP301L mice and heterozygous aggrecan mice which are characterized by spontaneous deletion of the aggrecan allele. We analysed the extent of tau pathology in dependence of aggrecan protein amount by applying immunohistochemistry, Western blotting and ELISA. The results clearly indicate that aggrecan has no significant impact on tau aggregation in the brainstem of our mouse model. Still, reduced aggrecan levels were accompanied by increased levels of tau protein and reduced number of Tau-1-positive neurons, which indicate an increase in phosphorylation of tau. In conclusion, these data demonstrate a correlation between aggrecan and P301L mutation-triggered tau expression and phosphorylation in our bigenic mouse model.
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Affiliation(s)
- Sophie Schmidt
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Caroline Stapf
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Sandra Schmutzler
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | | | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Max Holzer
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Mandy Sonntag
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Markus Morawski
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
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10
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Schmidt S, Arendt T, Morawski M, Sonntag M. Neurocan Contributes to Perineuronal Net Development. Neuroscience 2020; 442:69-86. [PMID: 32634529 DOI: 10.1016/j.neuroscience.2020.06.040] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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: 04/13/2020] [Revised: 06/11/2020] [Accepted: 06/26/2020] [Indexed: 11/27/2022]
Abstract
Perineuronal nets (PNs) are matrix molecule assemblies surrounding neuronal somata, dendrites and axon initial segments in a lattice-like appearance. PN molecules are involved in many structural and physiological processes during development and in adulthood, suggesting a crucial role in normal brain function. Neurocan, as one of the main PN proteoglycans, is suggested to control important developmental processes of neuronal tissue. This statement relies on thorough and excellent experimental work mainly conducted in reduced systems, such as cell cultures. However, previous data collected in neurocan-deficient mice do not seem to support neurocan's role in development since brain development in general and the formation of PNs especially in the hippocampus were reported to be undisturbed in neurocan-deficient mice. Here, we aim to re-address the role of neurocan in developmental processes by investigating the influence of neurocan on PN formation in the medial nucleus of the trapezoid body, a PN-enriched nucleus in the auditory brainstem, using neurocan-deficient mice. Immunohistochemical and biochemical analyses demonstrate that neurocan controls the regulation of PN development by influencing mRNA and protein quantity of various PN molecules. Resulting alterations in PN fine structure are critical for PN function as estimated by reduced amount of GAD65/67 and prolongation of synaptic transmission delay of calyx of Held synapses. Thus, neurocan contributes to proper PN formation and synapse physiology in the MNTB.
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Affiliation(s)
- Sophie Schmidt
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Liebigstraße 19, 04103 Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Liebigstraße 19, 04103 Leipzig, Germany
| | - Markus Morawski
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Liebigstraße 19, 04103 Leipzig, Germany
| | - Mandy Sonntag
- Paul Flechsig Institute of Brain Research, Medical Faculty, University of Leipzig, Liebigstraße 19, 04103 Leipzig, Germany.
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11
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Ueberham U, Arendt T. Genomic Indexing by Somatic Gene Recombination of mRNA/ncRNA - Does It Play a Role in Genomic Mosaicism, Memory Formation, and Alzheimer's Disease? Front Genet 2020; 11:370. [PMID: 32411177 PMCID: PMC7200996 DOI: 10.3389/fgene.2020.00370] [Citation(s) in RCA: 4] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/25/2020] [Indexed: 12/26/2022] Open
Abstract
Recent evidence indicates that genomic individuality of neurons, characterized by DNA-content variation, is a common if not universal phenomenon in the human brain that occurs naturally but can also show aberrancies that have been linked to the pathomechanism of Alzheimer’s disease and related neurodegenerative disorders. Etiologically, this genomic mosaic has been suggested to arise from defects of cell cycle regulation that may occur either during brain development or in the mature brain after terminal differentiation of neurons. Here, we aim to draw attention towards another mechanism that can give rise to genomic individuality of neurons, with far-reaching consequences. This mechanism has its origin in the transcriptome rather than in replication defects of the genome, i.e., somatic gene recombination of RNA. We continue to develop the concept that somatic gene recombination of RNA provides a physiological process that, through integration of intronless mRNA/ncRNA into the genome, allows a particular functional state at the level of the individual neuron to be indexed. By insertion of defined RNAs in a somatic recombination process, the presence of specific mRNA transcripts within a definite temporal context can be “frozen” and can serve as an index that can be recalled at any later point in time. This allows information related to a specific neuronal state of differentiation and/or activity relevant to a memory trace to be fixed. We suggest that this process is used throughout the lifetime of each neuron and might have both advantageous and deleterious consequences.
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Affiliation(s)
- Uwe Ueberham
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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12
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Curry-Hyde A, Ueberham U, Arendt T, Janitz M. Neural circular transcriptomes across mammalian species. Genomics 2020; 112:1162-1166. [DOI: 10.1016/j.ygeno.2019.06.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/24/2019] [Accepted: 06/27/2019] [Indexed: 01/16/2023]
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Bullmann T, Feneberg E, Kretzschmann TP, Ogunlade V, Holzer M, Arendt T. Hibernation Impairs Odor Discrimination - Implications for Alzheimer's Disease. Front Neuroanat 2019; 13:69. [PMID: 31379517 PMCID: PMC6646461 DOI: 10.3389/fnana.2019.00069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 02/26/2019] [Accepted: 06/21/2019] [Indexed: 11/13/2022] Open
Abstract
Reversible formation of PHF-like phosphorylated tau, an early feature of Alzheimer's disease (AD) was previously shown to occur in torpor during hibernation in the Golden hamster (Syrian hamster, Mesocricetus auratus). Here, we tackled the question to what extent hibernating Golden hamsters can serve as a model for the early stage of AD. During early AD, anosmia, the loss of olfactory function, is a common and typical feature. We, thus, investigated tau phosphorylation, synaptic plasticity and behavioral physiology of the olfactory system during hibernation. Tau was phosphorylated on several AD-relevant epitopes, and distribution of PHF-like phosphorylated tau in the olfactory bulb was quite similar to what is seen in AD. Tau phosphorylation was not associated with a destabilization of microtubules and did not lead to fibril formation. Previously, we observed a transient spine reduction in pyramidal cells in the hippocampus, which is correlated with the distribution of phosphorylated tau. Here we show that granule cells in the olfactory bulb are devoid of phosphorylated tau and maintain their spines number during torpor. No reduction of synaptic proteins was observed. However, hibernation did impair the recall performance in a two-odor discrimination task. We conclude that hibernation is associated with a specific olfactory memory deficit, which might not be attributed to the formation of PHF-like phosphorylated tau within the olfactory bulb. We discuss a possible involvement of modulatory input provided by cholinergic neurons in the basal forebrain, which are affected by hibernation.
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Affiliation(s)
- Torsten Bullmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Emily Feneberg
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Tanja Petra Kretzschmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Vera Ogunlade
- Department of Neuropathology, University of Leipzig, Leipzig, Germany
| | - Max Holzer
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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14
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Abstract
Hibernation is a natural phenomenon in many species which helps them to survive under extreme ambient conditions, such as cold temperatures and reduced availability of food in the winter months. It is characterized by a dramatic and regulated drop of body temperature, which in some cases can be near 0°C. Additionally, neural control of hibernation is maintained over all phases of a hibernation bout, including entrance into, during and arousal from torpor, despite a marked decrease in overall neural activity in torpor. In the present review, we provide an overview on what we know about neuronal activity in the hibernating brain focusing on cold-induced adaptations. We discuss pioneer and more recent in vitro and in vivo electrophysiological data and molecular analyses of activity markers which strikingly contributed to our understanding of the brain's sensitivity to dramatic changes in temperature across the hibernation cycle. Neuronal activity is markedly reduced with decreasing body temperature, and many neurons may fire infrequently in torpor at low brain temperatures. Still, there is convincing evidence that specific regions maintain their ability to generate action potentials in deep torpor, at least in response to adequate stimuli. Those regions include the peripheral system and primary central regions. However, further experiments on neuronal activity are needed to more precisely determine temperature effects on neuronal activity in specific cell types and specific brain nuclei.
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Affiliation(s)
- Mandy Sonntag
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
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15
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Reinert A, Morawski M, Seeger J, Arendt T, Reinert T. Iron concentrations in neurons and glial cells with estimates on ferritin concentrations. BMC Neurosci 2019; 20:25. [PMID: 31142282 PMCID: PMC6542065 DOI: 10.1186/s12868-019-0507-7] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [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: 03/01/2019] [Accepted: 05/21/2019] [Indexed: 01/21/2023] Open
Abstract
Background Brain iron is an essential as well as a toxic redox active element. Physiological levels are not uniform among the different cell types. Besides the availability of quantitative methods, the knowledge about the brain iron lags behind. Thereby, disclosing the mechanisms of brain iron homeostasis helps to understand pathological iron-accumulations in diseased and aged brains. With our study we want to contribute closing the gap by providing quantitative data on the concentration and distribution of iron in neurons and glial cells in situ. Using a nuclear microprobe and scanning proton induced X-ray emission spectrometry we performed quantitative elemental imaging on rat brain sections to analyze the iron concentrations of neurons and glial cells. Results Neurons were analyzed in the neocortex, subiculum, substantia nigra and deep cerebellar nuclei revealing an iron level between \documentclass[12pt]{minimal}
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\begin{document}$$(0.68\pm 2)\,\upmu \hbox {M}$$\end{document}(0.68±2)μM. The iron concentration of neocortical oligodendrocytes is fivefold higher, of microglia threefold higher and of astrocytes twofold higher compared to neurons. We also analyzed the distribution of subcellular iron concentrations in the cytoplasm, nucleus and nucleolus of neurons. The cytoplasm contains on average 73% of the total iron, the nucleolus—although a hot spot for iron—due to its small volume only 6% of total iron. Additionally, the iron level in subcellular fractions were measured revealing that the microsome fraction, which usually contains holo-ferritin, has the highest iron content. We also present an estimate of the cellular ferritin concentration calculating \documentclass[12pt]{minimal}
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\begin{document}$$133\pm 25$$\end{document}133±25 ferritin molecules per \documentclass[12pt]{minimal}
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\begin{document}$$\upmu \hbox {m}$$\end{document}μm in rat neurons. Conclusion Glial cells are the most iron-rich cells in the brain. Imbalances in iron homeostasis that lead to neurodegeneration may not only be originate from neurons but also from glial cells. It is feasible to estimate the ferritin concentration based on measured iron concentrations and a reasonable assumptions on iron load in the brain.
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Affiliation(s)
- Anja Reinert
- Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 43, 04103, Leipzig, Germany.
| | - Markus Morawski
- Paul Flechsig Institute, Liebigstr. 58, 04103, Leipzig, Germany
| | - Johannes Seeger
- Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 43, 04103, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute, Liebigstr. 58, 04103, Leipzig, Germany
| | - Tilo Reinert
- Max Planck Institute, Stephanstr. 1A, 04103, Leipzig, Germany.,Felix Bloch Institute, Linnéstr. 5, 04103, Leipzig, Germany
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16
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Morawski M, Kirilina E, Scherf N, Jäger C, Reimann K, Trampel R, Gavriilidis F, Geyer S, Biedermann B, Arendt T, Weiskopf N. Developing 3D microscopy with CLARITY on human brain tissue: Towards a tool for informing and validating MRI-based histology. Neuroimage 2018; 182:417-428. [PMID: 29196268 PMCID: PMC6189522 DOI: 10.1016/j.neuroimage.2017.11.060] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 11/22/2017] [Accepted: 11/26/2017] [Indexed: 01/21/2023] Open
Abstract
Recent breakthroughs in magnetic resonance imaging (MRI) enabled quantitative relaxometry and diffusion-weighted imaging with sub-millimeter resolution. Combined with biophysical models of MR contrast the emerging methods promise in vivo mapping of cyto- and myelo-architectonics, i.e., in vivo histology using MRI (hMRI) in humans. The hMRI methods require histological reference data for model building and validation. This is currently provided by MRI on post mortem human brain tissue in combination with classical histology on sections. However, this well established approach is limited to qualitative 2D information, while a systematic validation of hMRI requires quantitative 3D information on macroscopic voxels. We present a promising histological method based on optical 3D imaging combined with a tissue clearing method, Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging compatible Tissue hYdrogel (CLARITY), adapted for hMRI validation. Adapting CLARITY to the needs of hMRI is challenging due to poor antibody penetration into large sample volumes and high opacity of aged post mortem human brain tissue. In a pilot experiment we achieved transparency of up to 8 mm-thick and immunohistochemical staining of up to 5 mm-thick post mortem brain tissue by a combination of active and passive clearing, prolonged clearing and staining times. We combined 3D optical imaging of the cleared samples with tailored image processing methods. We demonstrated the feasibility for quantification of neuron density, fiber orientation distribution and cell type classification within a volume with size similar to a typical MRI voxel. The presented combination of MRI, 3D optical microscopy and image processing is a promising tool for validation of MRI-based microstructure estimates.
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Affiliation(s)
- Markus Morawski
- Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstr. 19, 04103, Leipzig, Germany.
| | - Evgeniya Kirilina
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany; Center for Cognitive Neuroscience Berlin, Free University Berlin, Habelschwerdter Allee 45, 14195, Berlin, Germany.
| | - Nico Scherf
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany
| | - Carsten Jäger
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany
| | - Katja Reimann
- Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstr. 19, 04103, Leipzig, Germany
| | - Robert Trampel
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany
| | - Filippos Gavriilidis
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany
| | - Stefan Geyer
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany
| | - Bernd Biedermann
- Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstr. 19, 04103, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstr. 19, 04103, Leipzig, Germany
| | - Nikolaus Weiskopf
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany
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Sonntag M, Blosa M, Schmidt S, Reimann K, Blum K, Eckrich T, Seeger G, Hecker D, Schick B, Arendt T, Engel J, Morawski M. Synaptic coupling of inner ear sensory cells is controlled by brevican-based extracellular matrix baskets resembling perineuronal nets. BMC Biol 2018; 16:99. [PMID: 30253762 PMCID: PMC6156866 DOI: 10.1186/s12915-018-0566-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/15/2018] [Indexed: 02/08/2023] Open
Abstract
Background Perineuronal nets (PNNs) are specialized aggregations of extracellular matrix (ECM) molecules surrounding specific neurons in the central nervous system (CNS). PNNs are supposed to control synaptic transmission and are frequently associated with neurons firing at high rates, including principal neurons of auditory brainstem nuclei. The origin of high-frequency activity of auditory brainstem neurons is the indefatigable sound-driven transmitter release of inner hair cells (IHCs) in the cochlea. Results Here, we show that synaptic poles of IHCs are ensheathed by basket-like ECM complexes formed by the same molecules that constitute PNNs of neurons in the CNS, including brevican, aggreccan, neurocan, hyaluronan, and proteoglycan link proteins 1 and 4 and tenascin-R. Genetic deletion of brevican, one of the main components, resulted in a massive degradation of ECM baskets at IHCs, a significant impairment in spatial coupling of pre- and postsynaptic elements and mild impairment of hearing. Conclusions These ECM baskets potentially contribute to control of synaptic transmission at IHCs and might be functionally related to PNNs of neurons in the CNS. Electronic supplementary material The online version of this article (10.1186/s12915-018-0566-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mandy Sonntag
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Maren Blosa
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Sophie Schmidt
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Katja Reimann
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Kerstin Blum
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Tobias Eckrich
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Gudrun Seeger
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Dietmar Hecker
- Department of Otorhinolaryngology, School of Medicine, Saarland University, Homburg, Germany
| | - Bernhard Schick
- Department of Otorhinolaryngology, School of Medicine, Saarland University, Homburg, Germany
| | - Thomas Arendt
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Jutta Engel
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Markus Morawski
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany.
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18
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Weinrich L, Sonntag M, Arendt T, Morawski M. Neuroanatomical characterization of perineuronal net components in the human cochlear nucleus and superior olivary complex. Hear Res 2018; 367:32-47. [PMID: 30025262 DOI: 10.1016/j.heares.2018.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/21/2018] [Accepted: 07/06/2018] [Indexed: 10/28/2022]
Abstract
The human auditory brainstem, especially the cochlear nucleus (CN) and the superior olivary complex (SOC) are characterized by a high density of neurons associated with perineuronal nets (PNs). PNs build a specific form of extracellular matrix surrounding the neuronal somata, proximal dendrites and axon initial segments. They restrict synaptic plasticity and control high-frequency synaptic activity, a prominent characteristic of neurons of the auditory brainstem. The distribution of PNs within the auditory brainstem has been investigated in a number of mammalian species. However, much less is known regarding PNs in the human auditory brainstem. The present study aimed at the immunohistochemical identification of PNs in the cochlear nucleus (CN) and superior olivary complex (SOC) in the human brainstem. We focused on the complex nature and molecular variability of PNs in the CN and SOC by using specific antibodies against the main PN components (aggrecan, brevican, neurocan and hyaluronan and proteoglycan link protein 1). Virtually all subnuclei within the ventral CN and SOC were found to be associated with PNs. Direct comparison between gerbil and human yielded similar fine structure of PNs and confirmed the typical tight interdigitation of PNs with synaptic terminals in both species. Noticeably, an elaborate combination of immunohistochemical labelings clearly supports the still debated existence of the medial nucleus of trapezoid body (MNTB) in the human brain. In conclusion, the present study demonstrates that PNs form a prominent extracellular structure on CN and SOC neurons in the human brain, potentially stabilizing synaptic contacts, which is in agreement with many other mammalian species.
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Affiliation(s)
- Luise Weinrich
- Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Mandy Sonntag
- Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Markus Morawski
- Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany.
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19
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Oberstadt M, Stieler J, Simpong DL, Römuß U, Urban N, Schaefer M, Arendt T, Holzer M. TDP-43 self-interaction is modulated by redox-active compounds Auranofin, Chelerythrine and Riluzole. Sci Rep 2018; 8:2248. [PMID: 29396541 PMCID: PMC5797228 DOI: 10.1038/s41598-018-20565-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 01/19/2018] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) represents a fatal neurodegenerative disease, which is characterized by a rapid loss of lower and upper motor neurons. As a major neuropathological hallmark, protein aggregates containing the Transactivating Response Region (TAR) DNA Binding Protein (TDP-43) are detectable in about 95% of sporadic ALS patients. TDP-43 interacts with itself physiologically to form liquid droplets, which may progress to pathological aggregates. In this study, we established the NanoBit luciferase complementation assay to measure TDP-43 self-interaction and found the fusion of the split luciferase subunits to the N-terminus of the protein as the strongest interacting partners. A screen of pharmacologically active compounds from the LOPAC®1280 library identified auranofin, chelerythrine and riluzole as dose-dependent inhibitors of TDP-43 self-interaction. Further analysis of drug action of the gold-containing thioredoxin reductase inhibitor auranofin revealed a redistribution from insoluble TDP-43 protein pool to PBS-soluble protein pool in N2a cells. In addition, auranofin treatment diminished reduced glutathione as a sign for oxidative modulation.
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Affiliation(s)
- Moritz Oberstadt
- Department of Neurology, University of Leipzig, Liebigstraße 20, 04103, Leipzig, Germany.
| | - Jens Stieler
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstraße 19, 04103, Leipzig, Germany
| | - David Larbi Simpong
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstraße 19, 04103, Leipzig, Germany
| | - Ute Römuß
- Department of Neurology, University of Leipzig, Liebigstraße 20, 04103, Leipzig, Germany
| | - Nicole Urban
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Härtelstraße 16-18, 04107, Leipzig, Germany
| | - Michael Schaefer
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Härtelstraße 16-18, 04107, Leipzig, Germany
| | - Thomas Arendt
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstraße 19, 04103, Leipzig, Germany
| | - Max Holzer
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstraße 19, 04103, Leipzig, Germany
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Kaluski S, Portillo M, Besnard A, Stein D, Einav M, Zhong L, Ueberham U, Arendt T, Mostoslavsky R, Sahay A, Toiber D. Neuroprotective Functions for the Histone Deacetylase SIRT6. Cell Rep 2017; 18:3052-3062. [PMID: 28355558 DOI: 10.1016/j.celrep.2017.03.008] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [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: 10/15/2016] [Revised: 01/09/2017] [Accepted: 03/01/2017] [Indexed: 02/06/2023] Open
Abstract
The histone deacetylase SIRT6 promotes DNA repair, but its activity declines with age with a concomitant accumulation of DNA damage. Furthermore, SIRT6 knockout mice exhibit an accelerated aging phenotype and die prematurely. Here, we report that brain-specific SIRT6-deficient mice survive but present behavioral defects with major learning impairments by 4 months of age. Moreover, the brains of these mice show increased signs of DNA damage, cell death, and hyperphosphorylated Tau-a critical mark in several neurodegenerative diseases. Mechanistically, SIRT6 regulates Tau protein stability and phosphorylation through increased activation of the kinase GSK3α/β. Finally, SIRT6 mRNA and protein levels are reduced in patients with Alzheimer's disease. Taken together, our results suggest that SIRT6 is critical to maintain genomic stability in the brain and that its loss leads to toxic Tau stability and phosphorylation. Therefore, SIRT6 and its downstream signaling could be targeted in Alzheimer's disease and age-related neurodegeneration.
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Affiliation(s)
- Shai Kaluski
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Miguel Portillo
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Antoine Besnard
- The Massachusetts General Hospital Cancer Center and The MGH Center for Regenerative Medicine, Harvard Medical School, Boston, MA 02114, USA; The Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Daniel Stein
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Monica Einav
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Lei Zhong
- The Massachusetts General Hospital Cancer Center and The MGH Center for Regenerative Medicine, Harvard Medical School, Boston, MA 02114, USA; The Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Uwe Ueberham
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstrasse 19, 04103 Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstrasse 19, 04103 Leipzig, Germany
| | - Raul Mostoslavsky
- The Massachusetts General Hospital Cancer Center and The MGH Center for Regenerative Medicine, Harvard Medical School, Boston, MA 02114, USA; The Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Amar Sahay
- The Massachusetts General Hospital Cancer Center and The MGH Center for Regenerative Medicine, Harvard Medical School, Boston, MA 02114, USA; The Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Debra Toiber
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
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21
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Affiliation(s)
- Thomas Arendt
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Uwe Ueberham
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Michael Janitz
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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22
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Abstract
Multiple system atrophy (MSA) is a complex, multifactorial, debilitating neurodegenerative disease that is often misdiagnosed and misunderstood. MSA has two subclasses, MSA-P and MSA-C, defined by the dominance of parkinsonism or cerebellar dysfunction in the earlier stages of disease, coupled with dysautonomia. This distinction between subclasses becomes largely redundant as the disease progresses. Aggregation of α-synuclein is a clinical marker used to confirm MSA diagnoses, which can only be performed postmortem. Transcriptome profiling provides in-depth information about the diseased state and can contribute to further understanding of MSA, enabling easier and more rapid diagnosis as well as contributing to improving the quality of life of people with MSA. Currently, there is no method of diagnosing MSA with certainty, and there is no cure for this disease. This review provides an update on current advances in investigations of molecular pathology of MSA with particular focus on perturbation of individual gene expression and MSA transcriptome.
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Affiliation(s)
- Ashton Curry-Hyde
- 1 School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Bei Jun Chen
- 1 School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Uwe Ueberham
- 2 Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- 2 Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Michael Janitz
- 1 School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.,2 Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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23
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Huang S, Yang B, Chen BJ, Bliim N, Ueberham U, Arendt T, Janitz M. The emerging role of circular RNAs in transcriptome regulation. Genomics 2017; 109:401-407. [PMID: 28655641 DOI: 10.1016/j.ygeno.2017.06.005] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 06/19/2017] [Accepted: 06/22/2017] [Indexed: 01/01/2023]
Abstract
Circular RNAs (circRNAs) are a recently discovered form of RNA that has been found to regulate mammalian transcription. CircRNAs are covalently closed, single-stranded transcripts produced from precursor mRNA. While initially circRNAs were considered to be splicing artefacts, next-generation RNA sequencing of non-polyadenylated transcriptomes has recently shown that the expression of circRNAs is widespread and over 20% of expressed genes in examined cells and tissues can produce these transcripts. Until now thousands of circRNAs have been discovered in organisms ranging from Drosophila melanogaster to Homo sapiens. Functional studies indicate that these transcripts regulate expression of protein-coding linear transcripts and thus comprise an important component of gene expression regulation. Here we provide a comprehensive overview on the biology of circRNAs, including the expression patterns and function. Moreover, we discuss current methodologies for the discovery and validation of circular transcripts. Finally, perspectives on the utilization of circRNA as molecular markers of complex diseases are presented.
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Affiliation(s)
- S Huang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - B Yang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - B J Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - N Bliim
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - U Ueberham
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - T Arendt
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - M Janitz
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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24
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Muche A, Arendt T, Schliebs R. Oxidative stress affects processing of amyloid precursor protein in vascular endothelial cells. PLoS One 2017; 12:e0178127. [PMID: 28617802 PMCID: PMC5472258 DOI: 10.1371/journal.pone.0178127] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 05/09/2017] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Oxidative stress is thought to be a key player in the pathogenesis of neurodegenerative dementia, including Alzheimer's disease (AD). It has been assumed that oxidative stress contributes to the ß-amyloid deposition in cerebral blood vessels. METHODS In order to prove this hypothesis, we examined the effect of oxidative stress on the processing of amyloid precursor protein (APP) in primary endothelial cells (EC) derived from cerebral cortical tissue of transgenic Tg2576 mice. Following exposure of EC by 1 μM hydrogen peroxide for up to 48 hours, formation and secretion of APP cleavage products sAPPα and sAPPß into the culture medium as well as the expression of endothelial APP were assessed. RESULTS Oxidative stress resulted in enhanced secretion of sAPPß into the culture medium as compared to controls (absence of hydrogen peroxide), which was accompanied by an increased APP expression, induction of VEGF synthesis, nitric oxide and oxygen free radicals productions, and differential changes of endothelial phospo-p42/44 MAPK expression. CONCLUSION The data suggest that oxidative stress may represent a major risk factor in causing Aß deposition in the brain vascular system by initiating the amyloidogenic route of endothelial APP processing. The enhanced β-secretase activity following oxidative stress exposure, possibly promoted by phosphorylation of p42/44 MAPK.
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Affiliation(s)
- Abebe Muche
- Department of Human Anatomy, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
- * E-mail:
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Reinhard Schliebs
- Paul Flechsig Institute for Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
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Arendt T, Stieler J, Ueberham U. Is sporadic Alzheimer's disease a developmental disorder? J Neurochem 2017; 143:396-408. [PMID: 28397252 DOI: 10.1111/jnc.14036] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 03/29/2017] [Accepted: 04/06/2017] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder of higher age that specifically occurs in human. Its clinical phase, characterized by a decline in physiological, psychological, and social functioning, is preceded by a long clinically silent phase of at least several decades that might perhaps even start very early in life. Overall, key functional abilities in AD patients decline in reverse order of the development of these abilities during normal childhood and adolescence. Early symptoms of AD, thus, typically affect mental functions that have been acquired only during very recent hominid evolution and as such are specific to human. Neurofibrillar degeneration, a typical neuropathological lesion of the disease and one of the most robust pathological correlates of cognitive impairment, is rarely seen in non-primate mammals and even non-human primates hardly develop a pathology comparable to those seen in AD patients. Neurofibrillar degeneration is not randomly distributed throughout the AD brain. It preferentially affects brain areas that become increasingly predominant during the evolutionary process of encephalization. During progression of the disease, it affects cortical areas in a stereotypic sequence that inversely recapitulates ontogenetic brain development. The specific distribution of cortical pathology in AD, moreover, appears to be determined by the modular organization of the cerebral cortex which basically is a structural reflection of its ontogeny. Here, we summarize recent evidence that phylogenetic and ontogenetic dimensions of brain structure and function provide the key to our understanding of AD. More recent molecular biological studies of the potential pathogenetic role of a genomic mosaic in the brains of patients with AD might even provide arguments for a developmental origin of AD. This article is part of a series "Beyond Amyloid".
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Affiliation(s)
- Thomas Arendt
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Leipzig, Germany
| | - Jens Stieler
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Leipzig, Germany
| | - Uwe Ueberham
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Leipzig, Germany
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Abstract
Amyotrophic lateral sclerosis (ALS) represents a rapidly progressing neurodegenerative disease and is characterized by a degeneration of motor neurons. Motor neurons are particularly susceptible to selective and early degeneration because of their extended axon length and their dependency on the cytoskeleton for its stability, signaling, and axonal transport. The motor neuron cytoskeleton comprises actin filaments, neurofilaments like peripherin, and microtubules. The Transactivating Response Region (TAR) DNA Binding Protein (TDP-43) forms characteristic cytoplasmic aggregates in motor neurons of ALS patients, and at least in part, the pathogenesis of ALS seems to be driven by toxic pTDP-43 aggregates in cytoplasm, which lead to a diminished axon formation and reduced axon length. Diminished axon formation and reduced axon length suggest an interaction of TDP-43 with the cytoskeleton of motor neurons. TDP-43 interacts with several cytoskeletal components, e.g., the microtubule-associated protein 1B (MAP1B) or the neurofilament light chain (NFL) through direct binding to its RNA. From a clinical perspective, cytoskeletal biomarkers like phosphorylated neurofilament heavy chain (pNFH) and NFL are already clinically used in ALS patients to predict survival, disease progression, and duration. Thus, in this review, we focus on the interaction of TDP-43 with the different cytoskeleton components such as actin filaments, neurofilaments, and microtubules as well as their associated proteins as one aspect in the complex pathogenesis of ALS.
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Affiliation(s)
- Moritz Oberstadt
- Department of Neurology, University of Leipzig, Liebigstraße 20, 04103, Leipzig, Germany.
| | - Joseph Claßen
- Department of Neurology, University of Leipzig, Liebigstraße 20, 04103, Leipzig, Germany
| | - Thomas Arendt
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstraße 19, 04103, Leipzig, Germany
| | - Max Holzer
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstraße 19, 04103, Leipzig, Germany
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27
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Chen BJ, Ueberham U, Mills JD, Kirazov L, Kirazov E, Knobloch M, Bochmann J, Jendrek R, Takenaka K, Bliim N, Arendt T, Janitz M. RNA sequencing reveals pronounced changes in the noncoding transcriptome of aging synaptosomes. Neurobiol Aging 2017; 56:67-77. [PMID: 28499146 DOI: 10.1016/j.neurobiolaging.2017.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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: 01/15/2017] [Revised: 03/31/2017] [Accepted: 04/08/2017] [Indexed: 12/12/2022]
Abstract
Normal aging is associated with impairments in cognitive functions. These alterations are caused by diminutive changes in the biology of synapses, and ineffective neurotransmission, rather than loss of neurons. Hitherto, only a few studies, exploring molecular mechanisms of healthy brain aging in higher vertebrates, utilized synaptosomal fractions to survey local changes in aging-related transcriptome dynamics. Here we present, for the first time, a comparative analysis of the synaptosomes transcriptome in the aging mouse brain using RNA sequencing. Our results show changes in the expression of genes contributing to biological pathways related to neurite guidance, synaptosomal physiology, and RNA splicing. More intriguingly, we also discovered alterations in the expression of thousands of novel, unannotated lincRNAs during aging. Further, detailed characterization of the cleavage and polyadenylation factor I subunit 1 (Clp1) mRNA and protein expression indicates its increased expression in neuronal processes of hippocampal stratum radiatum in aging mice. Together, our study uncovers a new layer of transcriptional regulation which is targeted by aging within the local environment of interconnecting neuronal cells.
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Affiliation(s)
- Bei Jun Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Uwe Ueberham
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, School of Medicine, Leipzig, Germany
| | - James D Mills
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Ludmil Kirazov
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, School of Medicine, Leipzig, Germany; Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Evgeni Kirazov
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, School of Medicine, Leipzig, Germany; Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Mara Knobloch
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, School of Medicine, Leipzig, Germany
| | - Jana Bochmann
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, School of Medicine, Leipzig, Germany
| | - Renate Jendrek
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, School of Medicine, Leipzig, Germany
| | - Konii Takenaka
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Nicola Bliim
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Thomas Arendt
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, School of Medicine, Leipzig, Germany
| | - Michael Janitz
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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Doehner W, Praße L, Wolpers J, Brückner MK, Ueberham U, Arendt T. Transgenerational transmission of an anticholinergic endophenotype with memory dysfunction. Neurobiol Aging 2016; 51:19-30. [PMID: 28033505 DOI: 10.1016/j.neurobiolaging.2016.11.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [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: 07/04/2016] [Revised: 11/21/2016] [Accepted: 11/26/2016] [Indexed: 10/20/2022]
Abstract
Impaired cholinergic neurotransmission associated with cognitive dysfunction occurs in various mental disorders of different etiologies including Alzheimer's disease and postalcoholic dementia and others. To address the question whether there exists a common endophenotype with a defined genetic and/or epigenetic signature causing mental dysfunction in these disorders, we investigated 2 generations of offspring born to alcohol-treated mothers. Here, we show that memory impairment and reduced synthesis of acetylcholine occurs in both F1 (exposed to ethanol in utero) and F2 generation (never been exposed to ethanol). Effects in the F2 generation are most likely consequences of transgenerationally transmitted epigenetic modifications in stem cells induced by alcohol. This clearly documents the role of ancestral history of drug abuse on the brain development of subsequent generations. The results further suggest an epigenetic trait for an anticholinergic endophenotype associated with cognitive dysfunction which might be relevant to our understanding of mental impairment in neurodegenerative disorders such as Alzheimer's disease and related disorders.
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Affiliation(s)
- Wolfram Doehner
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Leipzig, Germany
| | - Lieselotte Praße
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Leipzig, Germany
| | - James Wolpers
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Leipzig, Germany
| | - Martina K Brückner
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Leipzig, Germany
| | - Uwe Ueberham
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Leipzig, Germany.
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Arendt T, Morawski M, Gärtner U, Fröhlich N, Schulze F, Wohmann N, Jäger C, Eisenlöffel C, Gertz HJ, Mueller W, Brauer K. Inhomogeneous distribution of Alzheimer pathology along the isocortical relief. Are cortical convolutions an Achilles heel of evolution? Brain Pathol 2016; 27:603-611. [PMID: 27564538 DOI: 10.1111/bpa.12442] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [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: 07/05/2016] [Accepted: 08/19/2016] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease (AD) is neuropathologically characterized by neuritic plaques and neurofibrillary tangles. Progression of both plaques and tangles throughout the brain follows a hierarchical distribution which is defined by intrinsic cytoarchitectonic features and extrinsic connectivity patterns. What has less well been studied is how cortical convolutions influence the distribution of AD pathology. Here, the distribution of both plaques and tangles within subsulcal gyral components (fundi) to components forming their top regions at the subarachnoidal brain surface (crowns) by stereological methods in seven different cortical areas was systematically compared. Further, principle differences in cytoarchitectonic organization of cortical crowns and fundi that might provide the background for regionally selective vulnerability were attempted to identify. It was shown that both plaques and tangles were more prominent in sulcal fundi than gyri crowns. The differential distribution of pathology along convolutions corresponds to subgyral differences in the vascular network, GFAP-positive astrocytes and intracortical and subcortical connectivity. While the precise mechanisms accounting for these differences remain open, the presence of systematic inhomogeneities in the distribution of AD pathology along cortical convolutions indicates that the phylogenetic shaping of the cortex is associated with features that render the human brain vulnerable to AD pathology.
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Affiliation(s)
- Thomas Arendt
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, Universität Leipzig, Liebigstrasse 19, Leipzig, 04103, Germany
| | - Markus Morawski
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, Universität Leipzig, Liebigstrasse 19, Leipzig, 04103, Germany
| | - Ulrich Gärtner
- Institute for Anatomy and Cell Biology, Justus-Liebig-University Giessen, Aulweg 123, Giessen, 35385, Germany
| | - Nadine Fröhlich
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, Universität Leipzig, Liebigstrasse 19, Leipzig, 04103, Germany
| | - Falko Schulze
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, Universität Leipzig, Liebigstrasse 19, Leipzig, 04103, Germany
| | - Nils Wohmann
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, Universität Leipzig, Liebigstrasse 19, Leipzig, 04103, Germany
| | - Carsten Jäger
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, Universität Leipzig, Liebigstrasse 19, Leipzig, 04103, Germany
| | - Christian Eisenlöffel
- Department of Neuropathology, Universität Leipzig, Liebigstrasse 24, Leipzig, 04103, Germany
| | - Hermann-Josef Gertz
- Department of Psychiatry, Universität Leipzig, Semmelweisstrasse 10, Leipzig, 4103, Germany
| | - Wolf Mueller
- Department of Neuropathology, Universität Leipzig, Liebigstrasse 24, Leipzig, 04103, Germany
| | - Kurt Brauer
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, Universität Leipzig, Liebigstrasse 19, Leipzig, 04103, Germany
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Zwirner J, Möbius D, Bechmann I, Arendt T, Hoffmann KT, Jäger C, Lobsien D, Möbius R, Planitzer U, Winkler D, Morawski M, Hammer N. Subthalamic nucleus volumes are highly consistent but decrease age-dependently-a combined magnetic resonance imaging and stereology approach in humans. Hum Brain Mapp 2016; 38:909-922. [PMID: 27726278 DOI: 10.1002/hbm.23427] [Citation(s) in RCA: 24] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 09/08/2016] [Accepted: 09/26/2016] [Indexed: 01/03/2023] Open
Abstract
The subthalamic nucleus (STN) is a main target structure of deep brain stimulation (DBS) in idiopathic Parkinson's disease. Nevertheless, there is an ongoing discussion regarding human STN volumes and neuron count, which could potentially have an impact on STN-DBS. Moreover, a suspected functional subdivision forms the basis of the tripartite hypothesis, which has not yet been morphologically substantiated. In this study, it was aimed to investigate the human STN by means of combined magnetic resonance imaging (MRI) and stereology. STN volumes were obtained from 14 individuals (ranging from 65 to 96 years, 25 hemispheres) in 3 T MRI and in luxol-stained histology slices. Neuron number and cell densities were investigated stereologically over the entire STN and in pre-defined subregions in anti-human neuronal protein HuC/D-stained slices. STN volumes measured with MRI were smaller than in stereology but appeared to be highly consistent, measuring on average 99 ± 6 mm3 (MRI) and 132 ± 20 mm3 (stereology). The neuron count was 431,088 ± 72,172. Both STN volumes and cell count decreased age-dependently. Neuron density was different for the dorsal, medial and ventral subregion with significantly higher values ventrally than dorsally. Small variations in STN volumes in both MRI and stereology contradict previous findings of large variations in STN size. Age-dependent decreases in STN volumes and neuron numbers might influence the efficacy of STN-DBS in a geriatric population. Though the study is limited in sample size, site-dependent differences for the STN subregions form a morphological basis for the tripartite theory. Hum Brain Mapp 38:909-922, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Johann Zwirner
- Faculty of Medicine, Institute of Anatomy University of Leipzig, Leipzig, Germany
| | - Dustin Möbius
- Faculty of Medicine, Institute of Anatomy University of Leipzig, Leipzig, Germany
| | - Ingo Bechmann
- Faculty of Medicine, Institute of Anatomy University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul-Flechsig-Institute for Brain Research University of Leipzig, Leipzig, Germany
| | - Karl-Titus Hoffmann
- Department of Neuroradiology, University Clinic of Leipzig, Faculty of Medicine, Leipzig, Germany
| | - Carsten Jäger
- Paul-Flechsig-Institute for Brain Research University of Leipzig, Leipzig, Germany
| | - Donald Lobsien
- Department of Neuroradiology, University Clinic of Leipzig, Faculty of Medicine, Leipzig, Germany
| | - Robert Möbius
- Faculty of Medicine, Institute of Anatomy University of Leipzig, Leipzig, Germany
| | - Uwe Planitzer
- Department of Neurosurgery, University Clinic of Leipzig, Faculty of Medicine, Leipzig, Germany
| | - Dirk Winkler
- Department of Neurosurgery, University Clinic of Leipzig, Faculty of Medicine, Leipzig, Germany
| | - Markus Morawski
- Paul-Flechsig-Institute for Brain Research University of Leipzig, Leipzig, Germany
| | - Niels Hammer
- Faculty of Medicine, Institute of Anatomy University of Leipzig, Leipzig, Germany.,Department of Anatomy, University of Otago, Dunedin, New Zealand
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Weigel S, Meissner J, Zharkovsky A, Arendt T, Rossner S, Morawski M. Effect of brevican deficiency on neuroplasticity mediating molecules. SpringerPlus 2015. [PMCID: PMC4798379 DOI: 10.1186/2193-1801-4-s1-p55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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33
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Morawski M, Reinert T, Meyer-Klaucke W, Wagner FE, Tröger W, Reinert A, Jäger C, Brückner G, Arendt T. Ion exchanger in the brain: Quantitative analysis of perineuronally fixed anionic binding sites suggests diffusion barriers with ion sorting properties. Sci Rep 2015; 5:16471. [PMID: 26621052 PMCID: PMC4664884 DOI: 10.1038/srep16471] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [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: 11/14/2014] [Accepted: 10/12/2015] [Indexed: 12/01/2022] Open
Abstract
Perineuronal nets (PNs) are a specialized form of brain extracellular matrix, consisting of negatively charged glycosaminoglycans, glycoproteins and proteoglycans in the direct microenvironment of neurons. Still, locally immobilized charges in the tissue have not been accessible so far to direct observations and quantifications. Here, we present a new approach to visualize and quantify fixed charge-densities on brain slices using a focused proton-beam microprobe in combination with ionic metallic probes. For the first time, we can provide quantitative data on the distribution and net amount of pericellularly fixed charge-densities, which, determined at 0.4–0.5 M, is much higher than previously assumed. PNs, thus, represent an immobilized ion exchanger with ion sorting properties high enough to partition mobile ions in accord with Donnan-equilibrium. We propose that fixed charge-densities in the brain are involved in regulating ion mobility, the volume fraction of extracellular space and the viscosity of matrix components.
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Affiliation(s)
- Markus Morawski
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstrasse 19, D04103 Leipzig, Germany
| | - Tilo Reinert
- Physics Department, University of North Texas, 1155 Union Circle #311427, Denton, Texas 76203, USA
| | | | - Friedrich E Wagner
- Physik-Department E15, Technische Universität München, James-Franck-Straße, D85748 Garching, Germany
| | - Wolfgang Tröger
- Max-Planck-Innovation GmbH, Amalienstrasse 33, D80799 Munich, Germany
| | - Anja Reinert
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstrasse 19, D04103 Leipzig, Germany
| | - Carsten Jäger
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstrasse 19, D04103 Leipzig, Germany
| | - Gert Brückner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstrasse 19, D04103 Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Liebigstrasse 19, D04103 Leipzig, Germany
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Suttkus A, Holzer M, Morawski M, Arendt T. The neuronal extracellular matrix restricts distribution and internalization of aggregated Tau-protein. Neuroscience 2015; 313:225-35. [PMID: 26621125 DOI: 10.1016/j.neuroscience.2015.11.040] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [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: 08/06/2015] [Revised: 11/13/2015] [Accepted: 11/17/2015] [Indexed: 12/30/2022]
Abstract
Alzheimer's disease (AD) is a chronic degenerative disorder characterized by fibrillary aggregates of Aß and Tau-protein. Formation and progression of these pathological hallmarks throughout the brain follow a specific spatio-temporal pattern which provides the basis for neuropathological staging. Previously, we could demonstrate that cortical and subcortical neurons are less frequently affected by neurofibrillary degeneration if they are enwrapped by a specialized form of the hyaluronan-based extracellular matrix (ECM), the so called 'perineuronal net' (PN). PNs are composed of large aggregating chondroitin sulfate proteoglycans connected to a hyaluronan backbone, stabilized by link proteins and cross-linked via tenascin-R. Recently, PN-associated neurons were shown to be better protected against iron-induced neurodegeneration compared to neurons without PN, indicating a neuroprotective function. Here, we investigated the role of PNs in distribution and internalization of exogenous Tau-protein by using organotypic slice cultures of wildtype mice as well as mice lacking the ECM-components aggrecan, HAPLN1 or tenascin-R. We could demonstrate that PNs restrict both distribution and internalization of Tau. Accordingly, PN-ensheathed neurons were less frequently affected by Tau-internalization, than neurons without PN. Finally, the PNs as well as their three investigated components were shown to modulate the processes of distribution as well as internalization of Tau.
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Affiliation(s)
- A Suttkus
- University of Leipzig, Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, Liebigstraße 19, 04103 Leipzig, Germany.
| | - M Holzer
- University of Leipzig, Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, Liebigstraße 19, 04103 Leipzig, Germany
| | - M Morawski
- University of Leipzig, Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, Liebigstraße 19, 04103 Leipzig, Germany
| | - T Arendt
- University of Leipzig, Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, Liebigstraße 19, 04103 Leipzig, Germany
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Ueberham U, Rohn S, Ueberham E, Wodischeck S, Hilbrich I, Holzer M, Brückner MK, Gruschka H, Arendt T. Pin1 promotes degradation of Smad proteins and their interaction with phosphorylated tau in Alzheimer's disease. Neuropathol Appl Neurobiol 2015; 40:815-32. [PMID: 24964035 DOI: 10.1111/nan.12163] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 06/13/2014] [Indexed: 11/29/2022]
Abstract
AIMS Neurodegeneration in Alzheimer's disease (AD) is characterized by pathological protein aggregates and inadequate activation of cell cycle regulating proteins. Recently, Smad proteins were identified to control the expression of AD relevant proteins such as APP, CDK4 and CDK inhibitors, both critical regulators of cell cycle activation. This might indicate a central role for Smads in AD pathology where they show a substantial deficiency and disturbed subcellular distribution in neurones. Still, the mechanisms driving relocation and decrease of neuronal Smad in AD are not well understood. However, Pin1, a peptidyl-prolyl-cis/trans-isomerase, which allows isomerization of tau protein, was recently identified also controlling the fate of Smads. Here we analyse a possible role of Pin1 for Smad disturbances in AD. METHODS Multiple immunofluorescence labelling and confocal laser-scanning microscopy were performed to examine the localization of Smad and Pin1 in human control and AD hippocampi. Ectopic Pin1 expression in neuronal cell cultures combined with Western blot analysis and immunoprecipitation allowed studying Smad level and subcellular distribution. Luciferase reporter assays, electromobility shift, RNAi-technique and qRT-PCR revealed a potential transcriptional impact of Smad on Pin1 promoter. RESULTS We report on a colocalization of phosphorylated Smad in AD with Pin1. Pin1 does not only affect Smad phosphorylation and stability but also regulates subcellular localization of Smad2 and supports its binding to phosphorylated tau protein. Smads, in turn, exert a negative feed-back regulation on Pin1. CONCLUSION Our data suggest both Smad proteins and Pin1 to be elements of a vicious circle with potential pathogenetic significance in AD.
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Affiliation(s)
- Uwe Ueberham
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, Paul Flechsig Institute of Brain Research, Leipzig, Germany
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Bullmann T, Seeger G, Stieler J, Hanics J, Reimann K, Kretzschmann TP, Hilbrich I, Holzer M, Alpár A, Arendt T. Tau phosphorylation-associated spine regression does not impair hippocampal-dependent memory in hibernating golden hamsters. Hippocampus 2015; 26:301-18. [DOI: 10.1002/hipo.22522] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 08/12/2015] [Accepted: 08/31/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Torsten Bullmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
- Frey Initiative Research Unit, RIKEN Quantitative Biology Center; Japan
| | - Gudrun Seeger
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Jens Stieler
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - János Hanics
- MTA-SE NAP B Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences; Budapest Hungary
- Department of Anatomy; Semmelweis University; Budapest Hungary
| | - Katja Reimann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Tanja Petra Kretzschmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Isabel Hilbrich
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Max Holzer
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Alán Alpár
- MTA-SE NAP B Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences; Budapest Hungary
- Department of Anatomy; Semmelweis University; Budapest Hungary
| | - Thomas Arendt
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
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Arendt T, Brückner MK, Lösche A. Regional mosaic genomic heterogeneity in the elderly and in Alzheimer's disease as a correlate of neuronal vulnerability. Acta Neuropathol 2015; 130:501-10. [PMID: 26298468 DOI: 10.1007/s00401-015-1465-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 07/31/2015] [Accepted: 07/31/2015] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by fibrillary aggregates of Aβ peptide and tau protein. The distribution of these pathological hallmarks throughout the brain is not random; it follows a predictive pattern that is used for pathological staging. However, most etiopathogenetic concepts, irrespective of whether they focus on Aβ or tau pathology, leave a key question unanswered: what is the explanation for the different vulnerabilities of brain regions in AD? The pattern of regional progression of neurofibrillary degeneration in AD to some extent inversely recapitulates ontogenetic and phylogenetic brain development. Accordingly, degeneration preferentially affects brain areas that have recently been acquired or restructured during anthropoid evolution, which means that the involvement of a neurodevelopmental mechanism is highly likely. Since evolutionary expansion of the neocortex is based on a substantial extension of the mitotic activity of progenitor cells, we propose a conceptual link between neurogenesis in anthropoid primates and a higher risk of accumulating mitotic errors that give rise to genomic aberrations commonly referred to as DNA content variation (DCV). If increased rates of DCV make neurons more vulnerable to AD-related pathology, one might expect there to be a higher rate of DCV in areas that are affected very early during the course of AD, as compared to areas which are hardly affected or are affected only during the most advanced stages. Therefore, in the present study, we comparatively analyzed the DCV in five different cortical areas that are affected during the early stage (entorhinal cortex), the intermediate stage (temporal, frontal, and parietal association cortex), and the late stage (primary sensory occipital cortex) of AD in both normal elderly subjects and AD patients. On average, we observed about 10 % neuronal mosaic DCV in the normal elderly and a two- to threefold increase in DCV in AD patients. We were able to demonstrate, moreover, that the neuronal DCV in the cerebral cortex of the normal elderly as well as the increased neuronal DCV in AD patients are not randomly distributed but instead show systematic regional differences which correspond to differences in vulnerability. These findings provide additional evidence that mosaic genomic heterogeneity may play a key role in AD pathology.
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Affiliation(s)
- Thomas Arendt
- Department of Molecular and Cellular Mechanism of Neurodegeneration, Paul Flechsig Institute for Brain Research, Universität Leipzig, Liebigstrasse 19, 04103, Leipzig, Germany.
| | - Martina K Brückner
- Department of Molecular and Cellular Mechanism of Neurodegeneration, Paul Flechsig Institute for Brain Research, Universität Leipzig, Liebigstrasse 19, 04103, Leipzig, Germany
| | - Andreas Lösche
- Core Unit Fluorescence Technologies of the Medical Faculty, Universität Leipzig, Liebigstrasse 19, 04103, Leipzig, Germany
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Blosa M, Sonntag M, Jäger C, Weigel S, Seeger J, Frischknecht R, Seidenbecher CI, Matthews RT, Arendt T, Rübsamen R, Morawski M. The extracellular matrix molecule brevican is an integral component of the machinery mediating fast synaptic transmission at the calyx of Held. J Physiol 2015. [PMID: 26223835 DOI: 10.1113/jp270849] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The proteoglycan brevican is a major component of the extracellular matrix of perineuronal nets and is highly enriched in the perisynaptic space suggesting a role for synaptic transmission. We have introduced the calyx of Held in the auditory brainstem as a model system to study the impact of brevican on dynamics and reliability of synaptic transmission. In vivo extracellular single-unit recordings at the calyx of Held in brevican-deficient mice yielded a significant increase in the action potential (AP) transmission delay and a prolongation of pre- and postsynaptic APs. The changes in dynamics of signal transmission were accompanied by the reduction of presynaptic vGlut1 and ultrastructural changes in the perisynaptic space. These data show that brevican is an important mediator of fast synaptic transmission at the calyx of Held. ABSTRACT The extracellular matrix is an integral part of the neural tissue. Its most conspicuous manifestation in the brain are the perineuronal nets (PNs) which surround somata and proximal dendrites of distinct neuron types. The chondroitin sulfate proteoglycan brevican is a major component of PNs. In contrast to other PN-comprising proteoglycans (e.g. aggrecan and neurocan), brevican is mainly expressed in the perisynaptic space closely associated with both the pre- and postsynaptic membrane. This specific localization prompted the hypothesis that brevican might play a role in synaptic transmission. In the present study we specifically investigated the role of brevican in synaptic transmission at a central synapse, the calyx of Held in the medial nucleus of the trapezoid body, by the use of in vivo electrophysiology, immunohistochemistry, biochemistry and electron microscopy. In vivo extracellular single-unit recordings were acquired in brevican-deficient mice and the dynamics and reliability of synaptic transmission were compared to wild-type littermates. In knockout mice, the speed of pre-to-postsynaptic action potential (AP) transmission was reduced and the duration of the respective pre- and postsynaptic APs increased. The reliability of signal transmission, however, was not affected by the lack of brevican. The changes in dynamics of signal transmission were accompanied by the reduction of (i) presynaptic vGlut1 and (ii) the size of subsynaptic cavities. The present results suggest an essential role of brevican for the functionality of high-speed synaptic transmission at the calyx of Held.
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Affiliation(s)
- Maren Blosa
- Paul Flechsig Institute for Brain Research, Faculty of Medicine, University of Leipzig, 04103, Leipzig, Germany
| | - Mandy Sonntag
- Paul Flechsig Institute for Brain Research, Faculty of Medicine, University of Leipzig, 04103, Leipzig, Germany.,Institute of Biology, Faculty of Biology, Pharmacy and Psychology, University of Leipzig, 04103, Leipzig, Germany
| | - Carsten Jäger
- Paul Flechsig Institute for Brain Research, Faculty of Medicine, University of Leipzig, 04103, Leipzig, Germany
| | - Solveig Weigel
- Paul Flechsig Institute for Brain Research, Faculty of Medicine, University of Leipzig, 04103, Leipzig, Germany
| | - Johannes Seeger
- Institute of Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, University of Leipzig, 04103, Leipzig, Germany
| | | | | | - Russell T Matthews
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, NY, 13210, USA
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, Faculty of Medicine, University of Leipzig, 04103, Leipzig, Germany
| | - Rudolf Rübsamen
- Institute of Biology, Faculty of Biology, Pharmacy and Psychology, University of Leipzig, 04103, Leipzig, Germany
| | - Markus Morawski
- Paul Flechsig Institute for Brain Research, Faculty of Medicine, University of Leipzig, 04103, Leipzig, Germany
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Bajic V, Spremo-Potparevic B, Zivkovic L, Isenovic ER, Arendt T. Cohesion and the aneuploid phenotype in Alzheimer's disease: A tale of genome instability. Neurosci Biobehav Rev 2015; 55:365-74. [PMID: 26003528 DOI: 10.1016/j.neubiorev.2015.05.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 03/26/2015] [Accepted: 05/12/2015] [Indexed: 12/20/2022]
Abstract
Neurons are postmitotic cells that are in permanent cell cycle arrest. However, components of the cell cycle machinery that are expressed in Alzheimer's disease (AD) neurons are showing features of a cycling cell and those attributed to a postmitotic cell as well. Furthermore, the unique physiological operations taking place in neurons, ascribed to "core cell cycle regulators" are also key regulators in cell division. Functions of these cell cycle regulators include neuronal migration, axonal elongation, axon pruning, dendrite morphogenesis and synaptic maturation and plasticity. In this review, we focus on cohesion and cohesion related proteins in reference to their neuronal functions and how impaired centromere/cohesion dynamics may connect cell cycle dysfunction to aneuploidy in AD.
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Affiliation(s)
- Vladan Bajic
- Institute for Nuclear Research "Vinca", Laboratory for Radiobiology and Molecular Genetics, University of Belgrade, P.O. 522, 11001 Belgrade, Serbia.
| | - Biljana Spremo-Potparevic
- Faculty of Pharmacy, Institute of Physiology, Department of Biology and Human Genetics, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia.
| | - Lada Zivkovic
- Faculty of Pharmacy, Institute of Physiology, Department of Biology and Human Genetics, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia.
| | - Esma R Isenovic
- Institute for Nuclear Research "Vinca", Laboratory for Radiobiology and Molecular Genetics, University of Belgrade, P.O. 522, 11001 Belgrade, Serbia.
| | - Thomas Arendt
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, School of Medicine, Leipzig, Germany.
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40
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Bullmann T, Arendt T, Frey U, Hanashima C. A transportable, inexpensive electroporator for in utero electroporation. Dev Growth Differ 2015; 57:369-377. [PMID: 25988525 DOI: 10.1111/dgd.12216] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [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: 03/09/2015] [Revised: 03/31/2015] [Accepted: 04/08/2015] [Indexed: 01/14/2023]
Abstract
Electroporation is a useful technique to study gene function during development but its broad application is hampered due to the expensive equipment needed. We describe the construction of a transportable, simple and inexpensive electroporator delivering square pulses with varying length and amplitude. The device was successfully used for in utero electroporation in mouse with a performance comparable to that of commercial products.
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Affiliation(s)
- Torsten Bullmann
- Frey Initiative Research Unit, RIKEN Quantitative Biology Center, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan.,Laboratory for Neocortical Development, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan.,Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstraβe 19, 04103, Leipzig, Germany
| | - Thomas Arendt
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstraβe 19, 04103, Leipzig, Germany
| | - Urs Frey
- Frey Initiative Research Unit, RIKEN Quantitative Biology Center, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Carina Hanashima
- Laboratory for Neocortical Development, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
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Herrmann L, Wiegmann C, Arsalan-Werner A, Hilbrich I, Jäger C, Flach K, Suttkus A, Lachmann I, Arendt T, Holzer M. Hook proteins: association with Alzheimer pathology and regulatory role of hook3 in amyloid beta generation. PLoS One 2015; 10:e0119423. [PMID: 25799409 PMCID: PMC4370497 DOI: 10.1371/journal.pone.0119423] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 01/13/2015] [Indexed: 11/20/2022] Open
Abstract
Defects in intracellular transport are implicated in the pathogenesis of Alzheimer’s disease (AD). Hook proteins are a family of cytoplasmic linker proteins that participate in endosomal transport. In this study we show that Hook1 and Hook3 are expressed in neurons while Hook2 is predominantly expressed in astrocytes. Furthermore, Hook proteins are associated with pathological hallmarks in AD; Hook1 and Hook3 are localized to tau aggregates and Hook2 to glial components within amyloid plaques. Additionally, the expression of Hook3 is reduced in AD. Modelling of Hook3 deficiency in cultured cells leads to slowing of endosomal transport and increases β-amyloid production. We propose that Hook3 plays a role in pathogenic events exacerbating AD.
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Affiliation(s)
- Lydia Herrmann
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanism of Neurodegeneration, University of Leipzig, Leipzig, Germany
| | - Caspar Wiegmann
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanism of Neurodegeneration, University of Leipzig, Leipzig, Germany
| | - Annika Arsalan-Werner
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanism of Neurodegeneration, University of Leipzig, Leipzig, Germany
| | - Isabel Hilbrich
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanism of Neurodegeneration, University of Leipzig, Leipzig, Germany
| | - Carsten Jäger
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanism of Neurodegeneration, University of Leipzig, Leipzig, Germany
| | - Katharina Flach
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanism of Neurodegeneration, University of Leipzig, Leipzig, Germany
| | - Anne Suttkus
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanism of Neurodegeneration, University of Leipzig, Leipzig, Germany
| | | | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanism of Neurodegeneration, University of Leipzig, Leipzig, Germany
| | - Max Holzer
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanism of Neurodegeneration, University of Leipzig, Leipzig, Germany
- * E-mail:
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Muche A, Bigl M, Arendt T, Schliebs R. Expression of vascular endothelial growth factor (VEGF) mRNA, VEGF receptor 2 (Flk-1) mRNA, and of VEGF co-receptor neuropilin (Nrp)-1 mRNA in brain tissue of aging Tg2576 mice by in situ hybridization. Int J Dev Neurosci 2015; 43:25-34. [PMID: 25797338 DOI: 10.1016/j.ijdevneu.2015.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 12/11/2014] [Revised: 03/05/2015] [Accepted: 03/05/2015] [Indexed: 01/23/2023] Open
Abstract
Vascular endothelial growth factor (VEGF) has been characterized as a heparin binding angiogenic growth factor displaying high specificity for endothelial cells. It is profoundly accumulated and co-localized with amyloid beta (Aβ) plaques in the brain of Alzheimer's disease patients. In order to examine the effect of Aβ plaques on the expression level of VEGF mRNA and its receptors, brain tissue of both transgenic Tg2576 and wild type mice at ages ranging from 13 to 22 months was subjected to in situ hybridization followed by densitometric assessment using computer-assisted image analysis. Strong expression of VEGF mRNA, fetal liver kinase (Flk)-1 mRNA, and neuropilin (Nrp)-1 mRNA in the piriform, entorhinal, somatosensory, frontal cortex and hippocampal formation of both transgenic and non-transgenic mice brain was detected. Developmentally, only expression of VEGF mRNA was increased with age in the entorhinal, and somatosensory cortex of wild type mice. In 20-month-old transgenic Tg2576 mice, up-regulation of VEGF mRNA, Flk-1 mRNA, and Nrp-1 mRNA transcripts was observed in the entorhinal cortex compared to age-matched wild type mice. Our data suggest up-regulation of VEGF mRNA, Flk-1 mRNA and Nrp-1 mRNA, at least in the entorhinal cortex at ages when Aβ deposition in Tg2576 is typically increasing.
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Affiliation(s)
- Abebe Muche
- Department of Human Anatomy, College of Medicine and Health Sciences, University of Gondar, Ethiopia; Paul Flechsig Institute for Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany.
| | - Marina Bigl
- Institute of Biochemistry, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Reinhard Schliebs
- Paul Flechsig Institute for Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
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Arendt T, Brückner MK, Morawski M, Jäger C, Gertz HJ. Early neurone loss in Alzheimer's disease: cortical or subcortical? Acta Neuropathol Commun 2015; 3:10. [PMID: 25853173 PMCID: PMC4359478 DOI: 10.1186/s40478-015-0187-1] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 01/16/2015] [Indexed: 11/17/2022] Open
Abstract
Alzheimer’s disease (AD) is a degenerative disorder where the distribution of pathology throughout the brain is not random but follows a predictive pattern used for pathological staging. While the involvement of defined functional systems is fairly well established for more advanced stages, the initial sites of degeneration are still ill defined. The prevailing concept suggests an origin within the transentorhinal and entorhinal cortex (EC) from where pathology spreads to other areas. Still, this concept has been challenged recently suggesting a potential origin of degeneration in nonthalamic subcortical nuclei giving rise to cortical innervation such as locus coeruleus (LC) and nucleus basalis of Meynert (NbM). To contribute to the identification of the early site of degeneration, here, we address the question whether cortical or subcortical degeneration occurs more early and develops more quickly during progression of AD. To this end, we stereologically assessed neurone counts in the NbM, LC and EC layer-II in the same AD patients ranging from preclinical stages to severe dementia. In all three areas, neurone loss becomes detectable already at preclinical stages and is clearly manifest at prodromal AD/MCI. At more advanced AD, cell loss is most pronounced in the NbM > LC > layer-II EC. During early AD, however, the extent of cell loss is fairly balanced between all three areas without clear indications for a preference of one area. We can thus not rule out that there is more than one way of spreading from its site of origin or that degeneration even occurs independently at several sites in parallel.
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Ueberham E, Glöckner P, Göhler C, Straub BK, Teupser D, Schönig K, Braeuning A, Höhn AK, Jerchow B, Birchmeier W, Gaunitz F, Arendt T, Sansom O, Gebhardt R, Ueberham U. Global increase of p16INK4a in APC-deficient mouse liver drives clonal growth of p16INK4a-negative tumors. Mol Cancer Res 2015; 13:239-49. [PMID: 25270420 DOI: 10.1158/1541-7786.mcr-14-0278-t] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UNLABELLED Reduction of β-catenin (CTNNB1) destroying complex components, for example, adenomatous polyposis coli (APC), induces β-catenin signaling and subsequently triggers activation of genes involved in proliferation and tumorigenesis. Though diminished expression of APC has organ-specific and threshold-dependent influence on the development of liver tumors in mice, the molecular basis is poorly understood. Therefore, a detailed investigation was conducted to determine the underlying mechanism in the development of liver tumors under reduced APC levels. Mouse liver at different developmental stages was analyzed in terms of β-catenin target genes including Cyp2e1, Glul, and Ihh using real-time RT-PCR, reporter gene assays, and immunohistologic methods with consideration of liver zonation. Data from human livers with mutations in APC derived from patients with familial adenomatous polyposis (FAP) were also included. Hepatocyte senescence was investigated by determining p16(INK4a) expression level, presence of senescence-associated β-galactosidase activity, and assessing ploidy. A β-catenin activation of hepatocytes does not always result in β-catenin positive but unexpectedly also in mixed and β-catenin-negative tumors. In summary, a senescence-inducing program was found in hepatocytes with increased β-catenin levels and a positive selection of hepatocytes lacking p16(INK4a), by epigenetic silencing, drives the development of liver tumors in mice with reduced APC expression (Apc(580S) mice). The lack of p16(INK4a) was also detected in liver tumors of mice with triggers other than APC reduction. IMPLICATIONS Epigenetic silencing of p16(Ink4a) in selected liver cells bypassing senescence is a general principle for development of liver tumors with β-catenin involvement in mice independent of the initial stimulus.
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Affiliation(s)
- Elke Ueberham
- Faculty of Medicine, Institute of Biochemistry, University of Leipzig, Leipzig, Germany. Department of Cell Engineering/GLP, Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany
| | - Pia Glöckner
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, Paul Flechsig Institute of Brain Research, Leipzig, Germany
| | - Claudia Göhler
- Faculty of Medicine, Institute of Biochemistry, University of Leipzig, Leipzig, Germany
| | - Beate K Straub
- Institute of Pathology, University Clinic, University Heidelberg, Heidelberg, Germany
| | - Daniel Teupser
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany. Institute of Laboratory Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Kai Schönig
- Central Institute of Mental Health, Department of Molecular Biology, University of Heidelberg, Mannheim, Germany
| | - Albert Braeuning
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Tübingen, Germany
| | | | - Boris Jerchow
- Max-Delbrueck-Center for Molecular Medicine, Berlin-Buch, Germany
| | | | - Frank Gaunitz
- Department of Neurosurgery, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, Paul Flechsig Institute of Brain Research, Leipzig, Germany
| | - Owen Sansom
- The Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | - Rolf Gebhardt
- Faculty of Medicine, Institute of Biochemistry, University of Leipzig, Leipzig, Germany
| | - Uwe Ueberham
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, Paul Flechsig Institute of Brain Research, Leipzig, Germany.
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Granold M, Moosmann B, Staib-Lasarzik I, Arendt T, Del Rey A, Engelhard K, Behl C, Hajieva P. High membrane protein oxidation in the human cerebral cortex. Redox Biol 2014; 4:200-7. [PMID: 25600696 PMCID: PMC4803790 DOI: 10.1016/j.redox.2014.12.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/19/2014] [Accepted: 12/22/2014] [Indexed: 11/19/2022] Open
Abstract
Oxidative stress is thought to be one of the main mediators of neuronal damage in human neurodegenerative disease. Still, the dissection of causal relationships has turned out to be remarkably difficult. Here, we have analyzed global protein oxidation in terms of carbonylation of membrane proteins and cytoplasmic proteins in three different mammalian species: aged human cortex and cerebellum from patients with or without Alzheimer's disease, mouse cortex and cerebellum from young and old animals, and adult rat hippocampus and cortex subjected or not subjected to cerebral ischemia. Most tissues showed relatively similar levels of protein oxidation. However, human cortex was affected by severe membrane protein oxidation, while exhibiting lower than average cytoplasmic protein oxidation. In contrast, ex vivo autooxidation of murine cortical tissue primarily induced aqueous protein oxidation, while in vivo biological aging or cerebral ischemia had no major effect on brain protein oxidation. The unusually high levels of membrane protein oxidation in the human cortex were also not predicted by lipid peroxidation, as the levels of isoprostane immunoreactivity in human samples were considerably lower than in rodent tissues. Our results indicate that the aged human cortex is under steady pressure from specific and potentially detrimental membrane protein oxidation. The pronounced difference between humans, mice and rats regarding the primary site of cortical oxidation might have contributed to the unresolved difficulties in translating into therapies the wealth of data describing successful antioxidant neuroprotection in rodents. Membrane proteins from the human cerebral cortex show specific and severe oxidation. This contrasts to human cerebellum and to mouse cortex and cerebellum of any age. It also contrasts to adult rat cortex and hippocampus with or without ischemia. Lipid peroxidation is not a predictor of membrane protein oxidation. Membrane protein oxidation might be related to impending neurodegeneration.
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Affiliation(s)
- Matthias Granold
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Bernd Moosmann
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
| | - Irina Staib-Lasarzik
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Adriana Del Rey
- Institute of Physiology and Pathophysiology, Philipps University, Marburg, Germany
| | - Kristin Engelhard
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Christian Behl
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Parvana Hajieva
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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Arendt T, Stieler J, Holzer M. Brain hypometabolism triggers PHF-like phosphorylation of tau, a major hallmark of Alzheimer's disease pathology. J Neural Transm (Vienna) 2014; 122:531-9. [PMID: 25480630 DOI: 10.1007/s00702-014-1342-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/21/2014] [Indexed: 11/26/2022]
Abstract
Sporadic Alzheimer's disease (AD) is a chronic progressive neurodegenerative disorder of unknown cause characterized by fibrillar accumulation of the Aß-peptide and aggregates of the microtubule-associated protein tau in a hyperphosphorylated form. Already at preclinical stages, AD is characterized by hypometabolic states which are a good predictor of cognitive decline. Here, we summarize recent evidence derived from the study of hibernating animals that brain hypometabolism can trigger PHF-like hyperphosphorylation of tau. We put forward the concept that particular types of neurons respond to a hypometabolic state with an elevated phosphorylation of tau protein which represents a physiological mechanism involved in regulating synaptic gain. If, in contrast to hibernation, the hypometabolic state is not terminated after a definite time but rather persists and progresses, the elevated phosphorylation of tau protein endures and the protective reaction associated with it might turn into a pathological cascade leading to neurodegeneration.
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Affiliation(s)
- Thomas Arendt
- Paul Flechsig Institute of Brain Research, University of Leipzig, Jahnallee 59, 04109, Leipzig, Germany,
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Morawski M, Schilling S, Kreuzberger M, Waniek A, Jäger C, Koch B, Cynis H, Kehlen A, Arendt T, Hartlage-Rübsamen M, Demuth HU, Roßner S. Glutaminyl cyclase in human cortex: correlation with (pGlu)-amyloid-β load and cognitive decline in Alzheimer's disease. J Alzheimers Dis 2014; 39:385-400. [PMID: 24164736 DOI: 10.3233/jad-131535] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Brains of Alzheimer's disease (AD) patients are characterized in part by the formation of high molecular weight aggregates of amyloid-β (Aβ) peptides, which interfere with neuronal function and provoke neuronal cell death. The pyroglutamate (pGlu) modification of Aβ was demonstrated to be catalyzed by the enzyme glutaminyl cyclase (QC) and to enhance pathogenicity and neurotoxicity. Here, we addressed the role of QC in AD pathogenesis in human cortex. Two sets of human postmortem brain tissue from a total of 13 non-demented controls and 11 AD cases were analyzed by immunohistochemistry and unbiased stereology, quantitative RT-PCR, and enzymatic activity assays for the expression level of QC in temporal and entorhinal cortex. Additionally, cortical Aβ and pGlu-Aβ concentrations were quantified by ELISA. Data on QC expression and Aβ peptide concentrations were correlated with each other and with the Mini-Mental State Examination (MMSE) of individual cases. In control cases, QC expression was higher in the more vulnerable entorhinal cortex than in temporal cortex. In AD brains, QC mRNA expression and the immunoreactivity of QC were increased in both cortical regions and frequently associated with pGlu-Aβ deposits. The analyses of individual cases revealed significant correlations between QC mRNA levels and the concentration of insoluble pGlu-Aβ aggregates, but not of unmodified Aβ peptides. Elevated pGlu-Aβ load showed a better correlation with the decline in MMSE than elevated concentration of unmodified Aβ. Our observations provide evidence for an involvement of QC in AD pathogenesis and cognitive decline by QC-catalyzed pGlu-Aβ formation.
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Affiliation(s)
- Markus Morawski
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | | | - Moritz Kreuzberger
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Alexander Waniek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Carsten Jäger
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | | | - Holger Cynis
- Probiodrug AG, Halle/S., Germany Center for Neurologic Disease, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | | | | | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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Flach K, Ramminger E, Hilbrich I, Arsalan-Werner A, Albrecht F, Herrmann L, Goedert M, Arendt T, Holzer M. Axotrophin/MARCH7 acts as an E3 ubiquitin ligase and ubiquitinates tau protein in vitro impairing microtubule binding. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1527-38. [PMID: 24905733 PMCID: PMC4311138 DOI: 10.1016/j.bbadis.2014.05.029] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [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: 11/14/2013] [Revised: 05/05/2014] [Accepted: 05/28/2014] [Indexed: 12/11/2022]
Abstract
Tau is the major microtubule-associated protein in neurons involved in microtubule stabilization in the axonal compartment. Changes in tau gene expression, alternative splicing and posttranslational modification regulate tau function and in tauopathies can result in tau mislocalization and dysfunction, causing tau aggregation and cell death. To uncover proteins involved in the development of tauopathies, a yeast two-hybrid system was used to screen for tau-interacting proteins. We show that axotrophin/MARCH7, a RING-variant domain containing protein with similarity to E3 ubiquitin ligases interacts with tau. We defined the tau binding domain to amino acids 552–682 of axotrophin comprising the RING-variant domain. Co-immunoprecipitation and co-localization confirmed the specificity of the interaction. Intracellular localization of axotrophin is determined by an N-terminal nuclear targeting signal and a C-terminal nuclear export signal. In AD brain nuclear localization is lost and axotrophin is rather associated with neurofibrillary tangles. We find here that tau becomes mono-ubiquitinated by recombinant tau-interacting RING-variant domain, which diminishes its microtubule-binding. In vitro ubiquitination of four-repeat tau results in incorporation of up to four ubiquitin molecules compared to two molecules in three-repeat tau. In summary, we present a novel tau modification occurring preferentially on 4-repeat tau protein which modifies microtubule-binding and may impact on the pathogenesis of tauopathies. We search for tau-interacting proteins using a cytotrap yeast two-hybrid assay. MARCH7 was identified as a tau-binding protein and confirmed by several methods. Recombinant MARCH7 Ring-variant domain uses Ubc5 for E3 self-ubiquitinating activity. MARCH7 Ring-variant domain mono-ubiquitinates tau protein at multiple sites including the microtubule-binding domain. Mono-ubiquitination of tau protein diminishes its microtubule-binding.
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Affiliation(s)
- Katharina Flach
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, 04109 Leipzig, Germany
| | - Ellen Ramminger
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, 04109 Leipzig, Germany
| | - Isabel Hilbrich
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, 04109 Leipzig, Germany
| | - Annika Arsalan-Werner
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, 04109 Leipzig, Germany
| | - Franziska Albrecht
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, 04109 Leipzig, Germany
| | - Lydia Herrmann
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, 04109 Leipzig, Germany
| | - Michel Goedert
- MRC, Laboratory of Molecular Biology, Neurobiology Division, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, 04109 Leipzig, Germany
| | - Max Holzer
- Paul Flechsig Institute of Brain Research, Department of Molecular and Cellular Mechanisms of Neurodegeneration, University of Leipzig, 04109 Leipzig, Germany.
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Wolf J, Jäger C, Morawski M, Lachmann I, Schönknecht P, Mothes T, Arendt T. Tissue transglutaminase in Alzheimer's disease - facts and fiction: a reply to "Tissue transglutaminase is a biochemical marker for Alzheimer's disease". Neurobiol Aging 2013; 35:e5-9. [PMID: 24300236 DOI: 10.1016/j.neurobiolaging.2013.09.042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 09/27/2013] [Indexed: 01/06/2023]
Affiliation(s)
- Johannes Wolf
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, Medical Faculty of the University Leipzig, Leipzig, Germany
| | - Carsten Jäger
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Markus Morawski
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | | | - Peter Schönknecht
- Department of Psychiatry and Psychotherapy, University Hospital Leipzig, Leipzig, Germany
| | - Thomas Mothes
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, Medical Faculty of the University Leipzig, Leipzig, Germany.
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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50
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