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Masala N, Mittag M, Giovannetti EA, O'Neil DA, Distler F, Rupprecht P, Helmchen F, Yuste R, Fuhrmann M, Beck H, Wenzel M, Kelly T. Aberrant hippocampal Ca 2+ micro-waves following synapsin-dependent adeno-associated viral expression of Ca 2+ indicators. bioRxiv 2024:2023.11.08.566169. [PMID: 37986838 PMCID: PMC10659308 DOI: 10.1101/2023.11.08.566169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Genetically encoded calcium indicators (GECIs) such as GCaMP are invaluable tools in neuroscience to monitor neuronal activity using optical imaging. The viral transduction of GECIs is commonly used to target expression to specific brain regions, can be conveniently used with any mouse strain of interest without the need for prior crossing with a GECI mouse line and avoids potential hazards due to the chronic expression of GECIs during development. A key requirement for monitoring neuronal activity with an indicator is that the indicator itself minimally affects activity. Here, using common adeno-associated viral (AAV) transduction procedures, we describe spatially confined aberrant Ca2+ micro-waves slowly travelling through the hippocampus following expression of GCaMP6, GCaMP7 or R-CaMP1.07 driven by the synapsin promoter with AAV-dependent gene transfer, in a titre-dependent fashion. Ca2+ micro-waves developed in hippocampal CA1 and CA3, but not dentate gyrus (DG) nor neocortex, were typically first observed at 4 weeks after viral transduction, and persisted up to at least 8 weeks. The phenomenon was robust, observed across laboratories with various experimenters and setups. Our results indicate that aberrant hippocampal Ca2+ micro-waves depend on the promoter and viral titre of the GECI, density of expression as well as the targeted brain region. We used an alternative viral transduction method of GCaMP which avoids this artifact. The results show that commonly used Ca2+-indicator AAV transduction procedures can produce artefactual Ca2+ responses. Our aim is to raise awareness in the field of these artefactual transduction-induced Ca2+ micro-waves and we provide a potential solution.
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Affiliation(s)
- Nicola Masala
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Darik A O'Neil
- NeuroTechnology Center, Columbia University, New York, NY, USA
| | - Fabian Distler
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
| | - Peter Rupprecht
- Brain Research Institute, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Fritjof Helmchen
- Brain Research Institute, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Rafael Yuste
- NeuroTechnology Center, Columbia University, New York, NY, USA
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Heinz Beck
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Michael Wenzel
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Tony Kelly
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
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2
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Hauer C, Schmalfuss L, Unfer G, Schletterer M, Fuhrmann M, Holzapfel P. Evaluation of the potential stranding risk for aquatic organisms according to long-term morphological changes and grain size in alpine rivers impacted by hydropeaking. Sci Total Environ 2023; 883:163667. [PMID: 37100145 DOI: 10.1016/j.scitotenv.2023.163667] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/12/2023]
Abstract
Hydropeaking is one of the major hydropower-related disturbances of natural processes in river systems. The artificial flow fluctuations that are caused by the on-demand production of electricity are known for their severe impacts on aquatic ecosystems. These particularly affect those species and life stages that are not able to adjust their habitat selection to rapid up- and downramping rates. To date, the stranding risk has both experimentally and numerically mainly been investigated with variable hydropeaking graphs over stable river bathymetries. There is a lack of knowledge on how single, discrete peaking events vary concerning their impact on the stranding risk when the river morphology changes in the long-term perspective. The present study precisely addresses this knowledge gap by investigating morphological changes on the reach scale over a period of 20 years and the related variability of the lateral ramping velocity as a proxy for stranding risk. Two alpine gravel bed rivers impacted by hydropeaking over decades were tested by applying a one-dimensional and two-dimensional unsteady modelling approach. Both the Bregenzerach River and the Inn River exhibit alternating gravel bars on the reach scale. The results of the morphological development, however, showed different developments in the period 1995-2015. The Bregenzerach River displayed continuous aggradation (uplift of river bed) over the various selected submonitoring periods. In contrast, the Inn River showed continuous incision (erosion of river bed). The stranding risk exhibited high variability on a single cross-sectional basis. However, on the reach scale, no significant changes in stranding risk were calculated for either river reach. In addition, the impacts of river incision on the substrate composition were investigated. Here, in line with preceding studies, the results show that the coarsening of substrate increases the stranding risk and that especially the d90 (90 % finer of the grain size distribution) must be considered. The present study reveals that the quantified stranding risk of aquatic organisms is a function of the general morphological (bar) characteristics of the impacted river and both the morphological and grain size development have an impact on the potential stranding risk of aquatic organisms and should be considered in the revision of licences in the management of multi-stressed river systems.
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Affiliation(s)
- C Hauer
- CD-Laboratory for Sediment Research and Management, Institute of Hydraulics and River Sciences, Department of Water, Atmosphere and Environment, University of Natural Resources and Life Sciences Vienna, Muthgasse 107, 1190 Wien, Austria.
| | - L Schmalfuss
- CD-Laboratory for Sediment Research and Management, Institute of Hydraulics and River Sciences, Department of Water, Atmosphere and Environment, University of Natural Resources and Life Sciences Vienna, Muthgasse 107, 1190 Wien, Austria
| | - G Unfer
- Christian Doppler Laboratory for Meta EcosystemDynamics in Riverine Landscapes, DepartmentWater‑Atmosphere‑Environment, Institute of Hydrobiology and Aquatic Ecosystem Management, University of Natural Resources and Life Sciences, GregorMendel Str. 33, 1180 Vienna, Austria
| | - M Schletterer
- Christian Doppler Laboratory for Meta EcosystemDynamics in Riverine Landscapes, DepartmentWater‑Atmosphere‑Environment, Institute of Hydrobiology and Aquatic Ecosystem Management, University of Natural Resources and Life Sciences, GregorMendel Str. 33, 1180 Vienna, Austria; Department of Hydropower Engineering, TIWAG-Tiroler Wasserkraft AG, Innsbruck, Austria
| | - M Fuhrmann
- CD-Laboratory for Sediment Research and Management, Institute of Hydraulics and River Sciences, Department of Water, Atmosphere and Environment, University of Natural Resources and Life Sciences Vienna, Muthgasse 107, 1190 Wien, Austria
| | - P Holzapfel
- CD-Laboratory for Sediment Research and Management, Institute of Hydraulics and River Sciences, Department of Water, Atmosphere and Environment, University of Natural Resources and Life Sciences Vienna, Muthgasse 107, 1190 Wien, Austria
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3
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Reinhardt L, Musacchio F, Bichmann M, Behrendt A, Ercan-Herbst E, Stein J, Becher I, Haberkant P, Mader J, Schöndorf DC, Schmitt M, Korffmann J, Reinhardt P, Pohl C, Savitski M, Klein C, Gasparini L, Fuhrmann M, Ehrnhoefer DE. Dual truncation of tau by caspase-2 accelerates its CHIP-mediated degradation. Neurobiol Dis 2023; 182:106126. [PMID: 37086756 DOI: 10.1016/j.nbd.2023.106126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/30/2023] [Accepted: 04/12/2023] [Indexed: 04/24/2023] Open
Abstract
Intraneuronal aggregates of the microtubule binding protein Tau are a hallmark of different neurodegenerative diseases including Alzheimer's disease (AD). In these aggregates, Tau is modified by posttranslational modifications such as phosphorylation as well as by proteolytic cleavage. Here we identify a novel Tau cleavage site at aspartate 65 (D65) that is specific for caspase-2. In addition, we show that the previously described cleavage site at D421 is also efficiently processed by caspase-2, and both sites are cleaved in human brain samples. Caspase-2-generated Tau fragments show increased aggregation potential in vitro, but do not accumulate in vivo after AAV-mediated overexpression in mouse hippocampus. Interestingly, we observe that steady-state protein levels of caspase-2 generated Tau fragments are low in our in vivo model despite strong RNA expression, suggesting efficient clearance. Consistent with this hypothesis, we find that caspase-2 cleavage significantly improves the recognition of Tau by the ubiquitin E3 ligase CHIP, leading to increased ubiquitination and faster degradation of Tau fragments. Taken together our data thus suggest that CHIP-induced ubiquitination is of particular importance for the clearance of caspase-2 generated Tau fragments in vitro and in vivo.
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Affiliation(s)
- Lydia Reinhardt
- BioMed X Institute, Im Neuenheimer Feld 515, 69120 Heidelberg, Germany; AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - Fabrizio Musacchio
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
| | - Maria Bichmann
- BioMed X Institute, Im Neuenheimer Feld 515, 69120 Heidelberg, Germany
| | - Annika Behrendt
- BioMed X Institute, Im Neuenheimer Feld 515, 69120 Heidelberg, Germany
| | - Ebru Ercan-Herbst
- BioMed X Institute, Im Neuenheimer Feld 515, 69120 Heidelberg, Germany
| | - Juliane Stein
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - Isabelle Becher
- European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Per Haberkant
- European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Julia Mader
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - David C Schöndorf
- BioMed X Institute, Im Neuenheimer Feld 515, 69120 Heidelberg, Germany; AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - Melanie Schmitt
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - Jürgen Korffmann
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - Peter Reinhardt
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - Christian Pohl
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - Mikhail Savitski
- European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Corinna Klein
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - Laura Gasparini
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
| | - Dagmar E Ehrnhoefer
- BioMed X Institute, Im Neuenheimer Feld 515, 69120 Heidelberg, Germany; AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery, Knollstrasse, 67061 Ludwigshafen am Rhein, Germany.
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4
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Nebeling FC, Poll S, Justus LC, Steffen J, Keppler K, Mittag M, Fuhrmann M. Microglial motility is modulated by neuronal activity and correlates with dendritic spine plasticity in the hippocampus of awake mice. eLife 2023; 12:83176. [PMID: 36749020 PMCID: PMC9946443 DOI: 10.7554/elife.83176] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 02/03/2023] [Indexed: 02/08/2023] Open
Abstract
Microglia, the resident immune cells of the brain, play a complex role in health and disease. They actively survey the brain parenchyma by physically interacting with other cells and structurally shaping the brain. Yet, the mechanisms underlying microglial motility and significance for synapse stability, especially in the hippocampus during adulthood, remain widely unresolved. Here, we investigated the effect of neuronal activity on microglial motility and the implications for the formation and survival of dendritic spines on hippocampal CA1 neurons in vivo. We used repetitive two-photon in vivo imaging in the hippocampus of awake and anesthetized mice to simultaneously study the motility of microglia and their interaction with dendritic spines. We found that CA3 to CA1 input is sufficient to modulate microglial process motility. Simultaneously, more dendritic spines emerged in mice after awake compared to anesthetized imaging. Interestingly, the rate of microglial contacts with individual dendritic spines and dendrites was associated with the stability, removal, and emergence of dendritic spines. These results suggest that microglia might sense neuronal activity via neurotransmitter release and actively participate in synaptic rewiring of the hippocampal neural network during adulthood. Further, this study has profound relevance for hippocampal learning and memory processes.
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Affiliation(s)
| | - Stefanie Poll
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Lena Christine Justus
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Julia Steffen
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Kevin Keppler
- Light Microscopy Facility, German Center for Neurodegenerative DiseasesBonnGermany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
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5
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Kaczmarczyk L, Bansal V, Rajput A, Rahman RU, Krzyżak W, Degen J, Poll S, Fuhrmann M, Bonn S, Jackson WS. Correction: Tagger-A Swiss army knife for multiomics to dissect cell type-specific mechanisms of gene expression in mice. PLoS Biol 2022; 20:e3001882. [PMID: 36318742 PMCID: PMC9625337 DOI: 10.1371/journal.pbio.3001882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
[This corrects the article DOI: 10.1371/journal.pbio.3000374.].
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6
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Poll S, Fuhrmann M. O-LM interneurons: Gatekeepers of pyramidal neuron activity in the hippocampus. Neuron 2022; 110:1606-1608. [PMID: 35588712 DOI: 10.1016/j.neuron.2022.04.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A balanced and fine-tuned ratio of neuronal excitation and inhibition is a prerequisite for information processing. In this issue of Neuron, He et al. (2022) reveal a causal link between reduced input to local somatostatin-expressing, MeCP2-negative O-LM interneurons in CA1 and long-term memory impairment in a mouse model of Rett syndrome.
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Affiliation(s)
- Stefanie Poll
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Venusberg-Campus 1/99, 53127 Bonn, Germany; Cellular Neuropathology and Cognition Group, Institute of Experimental Epileptology and Cognition Research, University of Bonn, Venusberg-Campus 1/76, 53127 Bonn, Germany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Venusberg-Campus 1/99, 53127 Bonn, Germany.
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7
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Fuhrmann M, Georgiades E, Cattell G, Brosnahan C, Lane HS, Hick PM. Aquatic pathogens and biofouling: pilot study of ostreid herpesvirus 1 translocation by bivalves. Biofouling 2021; 37:949-963. [PMID: 34628999 DOI: 10.1080/08927014.2021.1985474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 09/16/2021] [Accepted: 09/21/2021] [Indexed: 06/13/2023]
Abstract
Ostreid herpesvirus 1 (OsHV-1) has caused mass mortalities in Pacific oysters (Crassostrea gigas) in Europe, Australia, and New Zealand. While aquaculture-associated movements of infected Pacific oysters are a well-known cause of OsHV-1 spread once established in a region, translocation via biofouling of aquaculture equipment or vessels needs further investigation to explain the more distant spread of OsHV-1. Laboratory experiments were designed to test for transmission of OsHV-1 between infected and naïve Pacific oysters via a simulated biofouling translocation scenario. Three common biofouling species [Sydney rock oysters (Saccostrea glomerata), Mediterranean mussels (Mytilus galloprovincialis) and Pacific oysters] were tested as intermediaries using a cohabitation challenge with Pacific oysters infected by injection. Transmission occurred, albeit for one of eight replicates when Pacific oysters were the intermediary species. This demonstrated a possible pathway for pathogen spread via biofouling containing Pacific oysters while highlighting the complexity of OsHV-1 transmission. Such complexities require further investigation to inform future risk assessments and management of fouled aquaculture equipment and vessels.
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Affiliation(s)
- M Fuhrmann
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camden, New South Wales, Australia
| | - E Georgiades
- Ministry for Primary Industries, Wellington, New Zealand
| | - G Cattell
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camden, New South Wales, Australia
| | - C Brosnahan
- Ministry for Primary Industries, Wellington, New Zealand
| | - H S Lane
- Ministry for Primary Industries, Wellington, New Zealand
| | - P M Hick
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camden, New South Wales, Australia
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8
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Whittington RJ, Hick P, Fuhrmann M, Liu O, Paul-Pont I. Removal of oyster pathogens from seawater. Environ Int 2021; 150:106258. [PMID: 33243468 DOI: 10.1016/j.envint.2020.106258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 06/11/2023]
Affiliation(s)
- R J Whittington
- School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia.
| | - P Hick
- School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia
| | - M Fuhrmann
- School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia
| | - O Liu
- School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia; Aquatic Pest and Health Policy, Animal Health Policy Branch, Biosecurity Animal Division, Australian Government Department of Agriculture, Water and the Environment, Canberra, ACT 2601, Australia(1)
| | - I Paul-Pont
- School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia; Laboratoire des Sciences de l'Environnement Marin (LEMAR), CNRS/UBO/IRD/IFREMER Institut Universitaire Europeen de la Mer, 29280 Plouzane, France(1)
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9
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Sosulina L, Mittag M, Geis HR, Hoffmann K, Klyubin I, Qi Y, Steffen J, Friedrichs D, Henneberg N, Fuhrmann F, Justus D, Keppler K, Cuello AC, Rowan MJ, Fuhrmann M, Remy S. Hippocampal hyperactivity in a rat model of Alzheimer's disease. J Neurochem 2021; 157:2128-2144. [PMID: 33583024 DOI: 10.1111/jnc.15323] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 01/19/2021] [Accepted: 01/31/2021] [Indexed: 12/21/2022]
Abstract
Neuronal network dysfunction is a hallmark of Alzheimer's disease (AD). However, the underlying pathomechanisms remain unknown. We analyzed the hippocampal micronetwork in transgenic McGill-R-Thy1-APP rats (APPtg) at the beginning of extracellular amyloid beta (Aβ) deposition. We established two-photon Ca2+ -imaging in vivo in the hippocampus of rats and found hyperactivity of CA1 neurons. Patch-clamp recordings in brain slices in vitro revealed increased neuronal input resistance and prolonged action potential width in CA1 pyramidal neurons. We did neither observe changes in synaptic inhibition, nor in excitation. Our data support the view that increased intrinsic excitability of CA1 neurons may precede inhibitory dysfunction at an early stage of Aβ-deposition and disease progression.
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Affiliation(s)
- Liudmila Sosulina
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Cellular Neuroscience, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Hans-Rüdiger Geis
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Kerstin Hoffmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Igor Klyubin
- Department of Pharmacology and Therapeutics, Trinity College, Dublin, Ireland
| | - Yingjie Qi
- Department of Pharmacology and Therapeutics, Trinity College, Dublin, Ireland
| | - Julia Steffen
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Detlef Friedrichs
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Niklas Henneberg
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Falko Fuhrmann
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Daniel Justus
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Kevin Keppler
- Light Microscopy Facility, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, Trinity College, Dublin, Ireland
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Stefan Remy
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Cellular Neuroscience, Leibniz Institute for Neurobiology, Magdeburg, Germany
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10
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Bertan F, Wischhof L, Sosulina L, Mittag M, Dalügge D, Fornarelli A, Gardoni F, Marcello E, Di Luca M, Fuhrmann M, Remy S, Bano D, Nicotera P. Loss of Ryanodine Receptor 2 impairs neuronal activity-dependent remodeling of dendritic spines and triggers compensatory neuronal hyperexcitability. Cell Death Differ 2020; 27:3354-3373. [PMID: 32641776 PMCID: PMC7853040 DOI: 10.1038/s41418-020-0584-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/15/2020] [Accepted: 06/17/2020] [Indexed: 12/17/2022] Open
Abstract
Dendritic spines are postsynaptic domains that shape structural and functional properties of neurons. Upon neuronal activity, Ca2+ transients trigger signaling cascades that determine the plastic remodeling of dendritic spines, which modulate learning and memory. Here, we study in mice the role of the intracellular Ca2+ channel Ryanodine Receptor 2 (RyR2) in synaptic plasticity and memory formation. We demonstrate that loss of RyR2 in pyramidal neurons of the hippocampus impairs maintenance and activity-evoked structural plasticity of dendritic spines during memory acquisition. Furthermore, post-developmental deletion of RyR2 causes loss of excitatory synapses, dendritic sparsification, overcompensatory excitability, network hyperactivity and disruption of spatially tuned place cells. Altogether, our data underpin RyR2 as a link between spine remodeling, circuitry dysfunction and memory acquisition, which closely resemble pathological mechanisms observed in neurodegenerative disorders.
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Affiliation(s)
- Fabio Bertan
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Lena Wischhof
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Manuel Mittag
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Dennis Dalügge
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Fabrizio Gardoni
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Monica Di Luca
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Martin Fuhrmann
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Stefan Remy
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Cellular Neuroscience, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Daniele Bano
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
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11
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Poll S, Mittag M, Musacchio F, Justus LC, Giovannetti EA, Steffen J, Wagner J, Zohren L, Schoch S, Schmidt B, Jackson WS, Ehninger D, Fuhrmann M. Memory trace interference impairs recall in a mouse model of Alzheimer’s disease. Nat Neurosci 2020; 23:952-958. [DOI: 10.1038/s41593-020-0652-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 05/04/2020] [Indexed: 12/20/2022]
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12
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Kaczmarczyk L, Bansal V, Rajput A, Rahman RU, Krzyżak W, Degen J, Poll S, Fuhrmann M, Bonn S, Jackson WS. Tagger-A Swiss army knife for multiomics to dissect cell type-specific mechanisms of gene expression in mice. PLoS Biol 2019; 17:e3000374. [PMID: 31393866 PMCID: PMC6701817 DOI: 10.1371/journal.pbio.3000374] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 05/13/2019] [Revised: 08/20/2019] [Accepted: 07/17/2019] [Indexed: 12/22/2022] Open
Abstract
A deep understanding of how regulation of the multiple levels of gene expression in mammalian tissues give rise to complex phenotypes has been impeded by cellular diversity. A handful of techniques were developed to tag-select nucleic acids of interest in specific cell types, thereby enabling their capture. We expanded this strategy by developing the Tagger knock-in mouse line bearing a quad-cistronic transgene combining enrichment tools for nuclei, nascent RNA, translating mRNA, and mature microRNA (miRNA). We demonstrate that Tagger can capture the desired nucleic acids, enabling multiple omics approaches to be applied to specific cell types in vivo using a single transgenic mouse line. This Methods and Resources paper describes Tagger, a knock-in mouse line bearing a quad-cistronic transgene that enables the capture of translating mRNAs, mature miRNAs, pulse-labeled total RNA, and the nucleus, all from specific cells of complex tissues.
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Affiliation(s)
- Lech Kaczmarczyk
- Wallenberg Center for Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Vikas Bansal
- Institute for Medical Systems Biology, Center for Molecular Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ashish Rajput
- Institute for Medical Systems Biology, Center for Molecular Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Raza-ur Rahman
- Institute for Medical Systems Biology, Center for Molecular Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Wiesław Krzyżak
- Life & Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Joachim Degen
- Life & Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Stefanie Poll
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | | | - Stefan Bonn
- Institute for Medical Systems Biology, Center for Molecular Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- German Center for Neurodegenerative Diseases, Tübingen, Germany
- * E-mail: (SB); (WSJ)
| | - Walker Scot Jackson
- Wallenberg Center for Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- German Center for Neurodegenerative Diseases, Bonn, Germany
- * E-mail: (SB); (WSJ)
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13
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Martinez Hernandez A, Urbanke H, Gillman AL, Lee J, Ryazanov S, Agbemenyah HY, Benito E, Jain G, Kaurani L, Grigorian G, Leonov A, Rezaei-Ghaleh N, Wilken P, Arce FT, Wagner J, Fuhrmann M, Caruana M, Camilleri A, Vassallo N, Zweckstetter M, Benz R, Giese A, Schneider A, Korte M, Lal R, Griesinger C, Eichele G, Fischer A. The diphenylpyrazole compound anle138b blocks Aβ channels and rescues disease phenotypes in a mouse model for amyloid pathology. EMBO Mol Med 2019; 10:32-47. [PMID: 29208638 PMCID: PMC5760857 DOI: 10.15252/emmm.201707825] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [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] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease is a devastating neurodegenerative disease eventually leading to dementia. An effective treatment does not yet exist. Here we show that oral application of the compound anle138b restores hippocampal synaptic and transcriptional plasticity as well as spatial memory in a mouse model for Alzheimer's disease, when given orally before or after the onset of pathology. At the mechanistic level, we provide evidence that anle138b blocks the activity of conducting Aβ pores without changing the membrane embedded Aβ-oligomer structure. In conclusion, our data suggest that anle138b is a novel and promising compound to treat AD-related pathology that should be investigated further.
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Affiliation(s)
- Ana Martinez Hernandez
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany.,Department for Genes and Behavior, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Hendrik Urbanke
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Alan L Gillman
- Department of Bioengineering, Materials Science and Engineering, Department of Mechanical and Aerospace Engineering and Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA, USA
| | - Joon Lee
- Department of Bioengineering, Materials Science and Engineering, Department of Mechanical and Aerospace Engineering and Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA, USA
| | - Sergey Ryazanov
- Department of NMR Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Hope Y Agbemenyah
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Eva Benito
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Gaurav Jain
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Lalit Kaurani
- DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Gayane Grigorian
- Department of Cellular Neurobiology, Technical University Braunschweig, Braunschweig, Germany
| | - Andrei Leonov
- Department of NMR Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Nasrollah Rezaei-Ghaleh
- Department of NMR Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Translational Structural Biology of Dementia, German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Petra Wilken
- DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany.,Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany.,Group for Translational Research in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Fernando Teran Arce
- Department of Bioengineering, Materials Science and Engineering, Department of Mechanical and Aerospace Engineering and Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jens Wagner
- Group for Neuroimmunology and Imaging, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Martin Fuhrmann
- Group for Neuroimmunology and Imaging, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Mario Caruana
- Department of Physiology and Biochemistry, Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta
| | - Angelique Camilleri
- Department of Physiology and Biochemistry, Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta
| | - Neville Vassallo
- Department of Physiology and Biochemistry, Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta
| | - Markus Zweckstetter
- Department of NMR Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany.,Department of Translational Structural Biology of Dementia, German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany.,Department of Neurology, University Medical Center Göttingen, University of Göttingen, Göttingen, Germany
| | - Roland Benz
- Life Sciences and Chemistry, Jacobs University of Bremen, Bremen, Germany
| | - Armin Giese
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Anja Schneider
- DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany.,Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany.,Group for Translational Research in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Martin Korte
- Department of Cellular Neurobiology, Technical University Braunschweig, Braunschweig, Germany .,Helmholtz Center for Infections Research, Braunschweig, Germany
| | - Ratnesh Lal
- Department of Bioengineering, Materials Science and Engineering, Department of Mechanical and Aerospace Engineering and Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA, USA
| | - Christian Griesinger
- Department of NMR Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany .,DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Gregor Eichele
- Department for Genes and Behavior, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Andre Fischer
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany .,Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
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14
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Lechner K, Niessner H, Bettelheim P, Deutsch E, Fasching I, Fuhrmann M, Hinterberger W, Korninger C, Neumann E, Liszka K, Knapp W, Mayr WR, Stingl G, Zeitlhuber U. T-Cell Alterations in Hemophiliacs Treated with Commercial Clotting Factor Concentrates. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1665253] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryVarious immunological parameters were determined in 46 patients with severe hemophilia A and in 9 patients with severe hemophilia B. All patients were treated over many years with commercial factor VIII or IX concentrates. Patients with severe classic hemophilia had a significantly reduced relative and absolute number of T-helper cells and a significantly increased relative and absolute number of T-suppressor cells. About half of these patients had an inverse T-helper/suppressor cell ratio. Patients with moderate hemophilia A and severe hemophilia B did not show these abnormalities. Hemophiliacs with an inverse ratio had a significantly higher concentration of serum total protein, IgG and IgM. No relationship between the amount of factor VIII concentrate administered, the HLA-type of the patient, the presence or absence of CMV-antibodies, hepatitis markers, thrombocytopenia and abnormal liver function tests to the T-cell abnormalities could be established. Lymphadenopathy was frequently associated with an inverse ratio. Indirect evidence suggests that the alterations of the immune system began in 1979/80.
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Affiliation(s)
- K Lechner
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - H Niessner
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - P Bettelheim
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - E Deutsch
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - I Fasching
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - M Fuhrmann
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - W Hinterberger
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - C Korninger
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - E Neumann
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - K Liszka
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - W Knapp
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - W R Mayr
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - G Stingl
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
| | - U Zeitlhuber
- The Division of Hematology and Blood Coagulation, First Department of Medicine; Institute of Immunology; Institute of Blood Group Serology; Department of Dermatology and Department of Pediatrics, University of Vienna, Austria
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15
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Pfeiffer T, Poll S, Bancelin S, Angibaud J, Inavalli VK, Keppler K, Mittag M, Fuhrmann M, Nägerl UV. Chronic 2P-STED imaging reveals high turnover of dendritic spines in the hippocampus in vivo. eLife 2018; 7:34700. [PMID: 29932052 PMCID: PMC6014725 DOI: 10.7554/elife.34700] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [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: 12/28/2017] [Accepted: 06/05/2018] [Indexed: 11/13/2022] Open
Abstract
Rewiring neural circuits by the formation and elimination of synapses is thought to be a key cellular mechanism of learning and memory in the mammalian brain. Dendritic spines are the postsynaptic structural component of excitatory synapses, and their experience-dependent plasticity has been extensively studied in mouse superficial cortex using two-photon microscopy in vivo. By contrast, very little is known about spine plasticity in the hippocampus, which is the archetypical memory center of the brain, mostly because it is difficult to visualize dendritic spines in this deeply embedded structure with sufficient spatial resolution. We developed chronic 2P-STED microscopy in mouse hippocampus, using a ‘hippocampal window’ based on resection of cortical tissue and a long working distance objective for optical access. We observed a two-fold higher spine density than previous studies and measured a spine turnover of ~40% within 4 days, which depended on spine size. We thus provide direct evidence for a high level of structural rewiring of synaptic circuits and new insights into the structure-dynamics relationship of hippocampal spines. Having established chronic super-resolution microscopy in the hippocampus in vivo, our study enables longitudinal and correlative analyses of nanoscale neuroanatomical structures with genetic, molecular and behavioral experiments.
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Affiliation(s)
- Thomas Pfeiffer
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Stefanie Poll
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Stephane Bancelin
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Julie Angibaud
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Vvg Krishna Inavalli
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Kevin Keppler
- Light Microscope Facility, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - U Valentin Nägerl
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
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16
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Reichenbach N, Delekate A, Breithausen B, Keppler K, Poll S, Schulte T, Peter J, Plescher M, Hansen JN, Blank N, Keller A, Fuhrmann M, Henneberger C, Halle A, Petzold GC. P2Y1 receptor blockade normalizes network dysfunction and cognition in an Alzheimer's disease model. J Exp Med 2018; 215:1649-1663. [PMID: 29724785 PMCID: PMC5987918 DOI: 10.1084/jem.20171487] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 02/12/2018] [Accepted: 04/12/2018] [Indexed: 11/04/2022] Open
Abstract
Astrocytic hyperactivity is an important contributor to neuronal-glial network dysfunction in Alzheimer's disease (AD). We have previously shown that astrocyte hyperactivity is mediated by signaling through the P2Y1 purinoreceptor (P2Y1R) pathway. Using the APPPS1 mouse model of AD, we here find that chronic intracerebroventricular infusion of P2Y1R inhibitors normalizes astroglial and neuronal network dysfunction, as measured by in vivo two-photon microscopy, augments structural synaptic integrity, and preserves hippocampal long-term potentiation. These effects occur independently from β-amyloid metabolism or plaque burden but are associated with a higher morphological complexity of periplaque reactive astrocytes, as well as reduced dystrophic neurite burden and greater plaque compaction. Importantly, APPPS1 mice chronically treated with P2Y1R antagonists, as well as APPPS1 mice carrying an astrocyte-specific genetic deletion (Ip3r2-/-) of signaling pathways downstream of P2Y1R activation, are protected from the decline of spatial learning and memory. In summary, our study establishes the restoration of network homoeostasis by P2Y1R inhibition as a novel treatment target in AD.
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Affiliation(s)
| | | | - Björn Breithausen
- Institute of Cellular Neurosciences, University Hospital Bonn, Bonn, Germany
| | - Kevin Keppler
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Stefanie Poll
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | | | - Jan Peter
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | | | - Jan N Hansen
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Nelli Blank
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Armin Keller
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | | | - Christian Henneberger
- German Center for Neurodegenerative Diseases, Bonn, Germany.,Institute of Cellular Neurosciences, University Hospital Bonn, Bonn, Germany.,Institute of Neurology, University College London, London, England, UK
| | - Annett Halle
- German Center for Neurodegenerative Diseases, Bonn, Germany.,Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Gabor C Petzold
- German Center for Neurodegenerative Diseases, Bonn, Germany .,Department of Neurology, University Hospital Bonn, Bonn, Germany
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17
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Varol D, Mildner A, Blank T, Shemer A, Barashi N, Yona S, David E, Boura-Halfon S, Segal-Hayoun Y, Chappell-Maor L, Keren-Shaul H, Leshkowitz D, Hornstein E, Fuhrmann M, Amit I, Maggio N, Prinz M, Jung S. Dicer Deficiency Differentially Impacts Microglia of the Developing and Adult Brain. Immunity 2017. [DOI: 10.1016/j.immuni.2017.05.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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18
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Scifo E, Calza G, Fuhrmann M, Soliymani R, Baumann M, Lalowski M. Recent advances in applying mass spectrometry and systems biology to determine brain dynamics. Expert Rev Proteomics 2017; 14:545-559. [PMID: 28539064 DOI: 10.1080/14789450.2017.1335200] [Citation(s) in RCA: 7] [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] [Indexed: 02/01/2023]
Abstract
INTRODUCTION Neurological disorders encompass various pathologies which disrupt normal brain physiology and function. Poor understanding of their underlying molecular mechanisms and their societal burden argues for the necessity of novel prevention strategies, early diagnostic techniques and alternative treatment options to reduce the scale of their expected increase. Areas covered: This review scrutinizes mass spectrometry based approaches used to investigate brain dynamics in various conditions, including neurodegenerative and neuropsychiatric disorders. Different proteomics workflows for isolation/enrichment of specific cell populations or brain regions, sample processing; mass spectrometry technologies, for differential proteome quantitation, analysis of post-translational modifications and imaging approaches in the brain are critically deliberated. Future directions, including analysis of cellular sub-compartments, targeted MS platforms (selected/parallel reaction monitoring) and use of mass cytometry are also discussed. Expert commentary: Here, we summarize and evaluate current mass spectrometry based approaches for determining brain dynamics in health and diseases states, with a focus on neurological disorders. Furthermore, we provide insight on current trends and new MS technologies with potential to improve this analysis.
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Affiliation(s)
- Enzo Scifo
- a Department of Psychiatry, and of Pharmacology and Toxicology , University of Toronto, Campbell Family Mental Health Research Institute of CAMH , Toronto , Canada
| | - Giulio Calza
- b Medicum, Meilahti Clinical Proteomics Core Facility, Biochemistry/Developmental Biology, Faculty of Medicine , FI-00014 University of Helsinki , Helsinki , Finland
| | - Martin Fuhrmann
- c Neuroimmunology and Imaging Group , German Center for Neurodegenerative Diseases (DZNE) , Bonn , Germany
| | - Rabah Soliymani
- b Medicum, Meilahti Clinical Proteomics Core Facility, Biochemistry/Developmental Biology, Faculty of Medicine , FI-00014 University of Helsinki , Helsinki , Finland
| | - Marc Baumann
- b Medicum, Meilahti Clinical Proteomics Core Facility, Biochemistry/Developmental Biology, Faculty of Medicine , FI-00014 University of Helsinki , Helsinki , Finland
| | - Maciej Lalowski
- b Medicum, Meilahti Clinical Proteomics Core Facility, Biochemistry/Developmental Biology, Faculty of Medicine , FI-00014 University of Helsinki , Helsinki , Finland
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19
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Schmid LC, Mittag M, Poll S, Steffen J, Wagner J, Geis HR, Schwarz I, Schmidt B, Schwarz MK, Remy S, Fuhrmann M. Dysfunction of Somatostatin-Positive Interneurons Associated with Memory Deficits in an Alzheimer's Disease Model. Neuron 2016; 92:114-125. [PMID: 27641495 DOI: 10.1016/j.neuron.2016.08.034] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 04/11/2016] [Accepted: 08/19/2016] [Indexed: 02/09/2023]
Abstract
Alzheimer's disease (AD) is characterized by cognitive decline and neuronal network dysfunction, but the underlying mechanisms remain unknown. In the hippocampus, microcircuit activity during learning and memory processes is tightly controlled by O-LM interneurons. Here, we investigated the effect of beta-amyloidosis on O-LM interneuron structural and functional connectivity, combining two-photon in vivo imaging of synaptic morphology, awake Ca2+ imaging, and retrograde mono-transsynaptic rabies tracing. We find severely impaired synaptic rewiring that occurs on the O-LM interneuron input and output level in a mouse model of AD. Synaptic rewiring that occurs upon fear learning on O-LM interneuron input level is affected in mice with AD-like pathology. This process requires the release of acetylcholine from septo-hippocampal projections. We identify decreased cholinergic action on O-LM interneurons in APP/PS1 mice as a key pathomechanism that contributes to memory impairment in a mouse model, with potential relevance for human AD.
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Affiliation(s)
- Lena C Schmid
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Stefanie Poll
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Julia Steffen
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Jens Wagner
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Hans-Rüdiger Geis
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Inna Schwarz
- Functional Neuroconnectomics Group, Department of Epileptology, Medical School, University of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - Boris Schmidt
- Clemens-Schöpf-Institute, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Martin K Schwarz
- Functional Neuroconnectomics Group, Department of Epileptology, Medical School, University of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - Stefan Remy
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
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20
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Wagner J, Krauss S, Shi S, Ryazanov S, Steffen J, Miklitz C, Leonov A, Kleinknecht A, Göricke B, Weishaupt JH, Weckbecker D, Reiner AM, Zinth W, Levin J, Ehninger D, Remy S, Kretzschmar HA, Griesinger C, Giese A, Fuhrmann M. Reducing tau aggregates with anle138b delays disease progression in a mouse model of tauopathies. Acta Neuropathol 2015; 130:619-31. [PMID: 26439832 PMCID: PMC4612332 DOI: 10.1007/s00401-015-1483-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/24/2015] [Accepted: 09/24/2015] [Indexed: 12/29/2022]
Abstract
Pathological tau aggregation leads to filamentous tau inclusions and characterizes neurodegenerative tauopathies such as Alzheimer’s disease and frontotemporal dementia and parkinsonism linked to chromosome 17. Tau aggregation coincides with clinical symptoms and is thought to mediate neurodegeneration. Transgenic mice overexpressing mutant human P301S tau exhibit many neuropathological features of human tauopathies including behavioral deficits and increased mortality. Here, we show that the di-phenyl-pyrazole anle138b binds to aggregated tau and inhibits tau aggregation in vitro and in vivo. Furthermore, anle138b treatment effectively ameliorates disease symptoms, increases survival time and improves cognition of tau transgenic PS19 mice. In addition, we found decreased synapse and neuron loss accompanied by a decreased gliosis in the hippocampus. Our results suggest that reducing tau aggregates with anle138b may represent an effective and promising approach for the treatment of human tauopathies.
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21
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Fuhrmann F, Justus D, Sosulina L, Kaneko H, Beutel T, Friedrichs D, Schoch S, Schwarz MK, Fuhrmann M, Remy S. Locomotion, Theta Oscillations, and the Speed-Correlated Firing of Hippocampal Neurons Are Controlled by a Medial Septal Glutamatergic Circuit. Neuron 2015; 86:1253-64. [PMID: 25982367 DOI: 10.1016/j.neuron.2015.05.001] [Citation(s) in RCA: 220] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/27/2015] [Accepted: 04/29/2015] [Indexed: 12/19/2022]
Abstract
Before the onset of locomotion, the hippocampus undergoes a transition into an activity-state specialized for the processing of spatially related input. This brain-state transition is associated with increased firing rates of CA1 pyramidal neurons and the occurrence of theta oscillations, which both correlate with locomotion velocity. However, the neural circuit by which locomotor activity is linked to hippocampal oscillations and neuronal firing rates is unresolved. Here we reveal a septo-hippocampal circuit mediated by glutamatergic (VGluT2(+)) neurons that is activated before locomotion onset and that controls the initiation and velocity of locomotion as well as the entrainment of theta oscillations. Moreover, via septo-hippocampal projections onto alveus/oriens interneurons, this circuit regulates feedforward inhibition of Schaffer collateral and perforant path input to CA1 pyramidal neurons in a locomotion-dependent manner. With higher locomotion speed, the increased activity of medial septal VGluT2 neurons is translated into increased axo-somatic depolarization and higher firing rates of CA1 pyramidal neurons. VIDEO ABSTRACT.
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Affiliation(s)
- Falko Fuhrmann
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Daniel Justus
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Liudmila Sosulina
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Hiroshi Kaneko
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Tatjana Beutel
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Detlef Friedrichs
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Susanne Schoch
- Department of Epileptology, University of Bonn Medical Center, Sigmund-Freud Strasse 25, 53127 Bonn, Germany; Section of Translational Epilepsy Research, Department of Neuropathology, University of Bonn Medical Center, Sigmund-Freud Strasse 25, 53127 Bonn, Germany
| | - Martin Karl Schwarz
- Functional Neuroconnectomics Group, Department of Epileptology, Life & Brain Center, University of Bonn, Medical School, Sigmund-Freud Strasse 25, D-53105 Bonn, Germany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Stefan Remy
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany; Department of Epileptology, University of Bonn Medical Center, Sigmund-Freud Strasse 25, 53127 Bonn, Germany.
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Qi Y, Klyubin I, Harney SC, Hu N, Cullen WK, Grant MK, Steffen J, Wilson EN, Do Carmo S, Remy S, Fuhrmann M, Ashe KH, Cuello AC, Rowan MJ. Longitudinal testing of hippocampal plasticity reveals the onset and maintenance of endogenous human Aß-induced synaptic dysfunction in individual freely behaving pre-plaque transgenic rats: rapid reversal by anti-Aß agents. Acta Neuropathol Commun 2014; 2:175. [PMID: 25540024 PMCID: PMC4293804 DOI: 10.1186/s40478-014-0175-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 12/04/2014] [Indexed: 11/26/2022] Open
Abstract
Long before synaptic loss occurs in Alzheimer’s disease significant harbingers of disease may be detected at the functional level. Here we examined if synaptic long-term potentiation is selectively disrupted prior to extracellular deposition of Aß in a very complete model of Alzheimer’s disease amyloidosis, the McGill-R-Thy1-APP transgenic rat. Longitudinal studies in freely behaving animals revealed an age-dependent, relatively rapid-onset and persistent inhibition of long-term potentiation without a change in baseline synaptic transmission in the CA1 area of the hippocampus. Thus the ability of a standard 200 Hz conditioning protocol to induce significant NMDA receptor-dependent short- and long-term potentiation was lost at about 3.5 months of age and this deficit persisted for at least another 2–3 months, when plaques start to appear. Consistent with in vitro evidence for a causal role of a selective reduction in NMDA receptor-mediated synaptic currents, the deficit in synaptic plasticity in vivo was associated with a reduction in the synaptic burst response to the conditioning stimulation and was overcome using stronger 400 Hz stimulation. Moreover, intracerebroventricular treatment for 3 days with an N-terminally directed monoclonal anti- human Aß antibody, McSA1, transiently reversed the impairment of synaptic plasticity. Similar brief treatment with the BACE1 inhibitor LY2886721 or the γ-secretase inhibitor MRK-560 was found to have a comparable short-lived ameliorative effect when tracked in individual rats. These findings provide strong evidence that endogenously generated human Aß selectively disrupts the induction of long-term potentiation in a manner that enables potential therapeutic options to be assessed longitudinally at the pre-plaque stage of Alzheimer’s disease amyloidosis.
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Fuhrmann M, Kleiber S, Steffen J, Schmid LC, Wagner J, Schmidt B, Ehninger D. O3‐05‐06: FORMATION OF A HIPPOCAMPAL MEMORY ENGRAM AND ITS IMPAIRMENT IN A MOUSE MODEL OF AD. Alzheimers Dement 2014. [DOI: 10.1016/j.jalz.2014.04.298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
| | | | | | | | | | - Boris Schmidt
- Clemens Schoepf Institut, Technische Universitaet DarmstadtDarmstadtGermany
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24
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Schiwon M, Weisheit C, Franken L, Gutweiler S, Dixit A, Meyer-Schwesinger C, Pohl JM, Maurice NJ, Thiebes S, Lorenz K, Quast T, Fuhrmann M, Baumgarten G, Lohse MJ, Opdenakker G, Bernhagen J, Bucala R, Panzer U, Kolanus W, Gröne HJ, Garbi N, Kastenmüller W, Knolle PA, Kurts C, Engel DR. Crosstalk between sentinel and helper macrophages permits neutrophil migration into infected uroepithelium. Cell 2014; 156:456-68. [PMID: 24485454 DOI: 10.1016/j.cell.2014.01.006] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 10/21/2013] [Accepted: 01/06/2014] [Indexed: 12/16/2022]
Abstract
The phagocytes of the innate immune system, macrophages and neutrophils, contribute to antibacterial defense, but their functional specialization and cooperation is unclear. Here, we report that three distinct phagocyte subsets play highly coordinated roles in bacterial urinary tract infection. Ly6C(-) macrophages acted as tissue-resident sentinels that attracted circulating neutrophils and Ly6C(+) macrophages. Such Ly6C(+) macrophages played a previously undescribed helper role: once recruited to the site of infection, they produced the cytokine TNF, which caused Ly6C(-) macrophages to secrete CXCL2. This chemokine activated matrix metalloproteinase-9 in neutrophils, allowing their entry into the uroepithelium to combat the bacteria. In summary, the sentinel macrophages elicit the powerful antibacterial functions of neutrophils only after confirmation by the helper macrophages, reminiscent of the licensing role of helper T cells in antiviral adaptive immunity. These findings identify helper macrophages and TNF as critical regulators in innate immunity against bacterial infections in epithelia.
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Affiliation(s)
- Marzena Schiwon
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Christina Weisheit
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany; Clinic for Anesthesiology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Lars Franken
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Sebastian Gutweiler
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Akanksha Dixit
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | | | - Judith-Mira Pohl
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Nicholas J Maurice
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Stephanie Thiebes
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Kristina Lorenz
- Institute of Pharmacology and Toxicology, University of Würzburg, 97078 Würzburg, Germany
| | - Thomas Quast
- Life and Medical Sciences Institute, Friedrich-Wilhelms-Universität, 53115 Bonn, Germany
| | - Martin Fuhrmann
- German Center for Neurodegenerative Diseases (DZNE), 53125 Bonn, Germany
| | - Georg Baumgarten
- Clinic for Anesthesiology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Martin J Lohse
- Institute of Pharmacology and Toxicology, University of Würzburg, 97078 Würzburg, Germany
| | - Ghislain Opdenakker
- Laboratory of Immunobiology, Rega Institute for Medical Research, University of Leuven, 3000 KU Leuven, Belgium
| | - Jürgen Bernhagen
- Institute of Biochemistry and Molecular Cell Biology, RWTH Aachen University, 52062 Aachen, Germany
| | - Rick Bucala
- Yale University School of Medicine, New Haven, CT 06510, USA
| | - Ulf Panzer
- Medizinische Klinik III, University Clinic Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Waldemar Kolanus
- Life and Medical Sciences Institute, Friedrich-Wilhelms-Universität, 53115 Bonn, Germany
| | - Hermann-Josef Gröne
- Cellular and Molecular Pathology, German Cancer Research Center Heidelberg, 69120 Heidelberg, Germany
| | - Natalio Garbi
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Wolfgang Kastenmüller
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Percy A Knolle
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany
| | - Christian Kurts
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany.
| | - Daniel R Engel
- Institute of Experimental Immunology, University Clinic of Bonn, 53127 Bonn, Germany.
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Jung CKE, Fuhrmann M, Honarnejad K, Van Leuven F, Herms J. Role of presenilin1 in structural plasticity of cortical dendritic spines in vivo. J Neurochem 2011; 119:1064-73. [DOI: 10.1111/j.1471-4159.2011.07503.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Fuhrmann M, Ochs S, Keppler K, Langer A, Hoelter S, Herms J. P3‐150: Role of chemokine receptor CX3CR1 in Alzheimer's transgenic mice. Alzheimers Dement 2011. [DOI: 10.1016/j.jalz.2011.05.1590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - Simon Ochs
- Ludwig‐Maximilians‐University MunichMunichGermany
| | | | - Albert Langer
- German Research Center for Environmental HealthMunichGermany
| | - Sabine Hoelter
- German Research Center for Environmental HealthMunichGermany
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27
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Warnken M, Reitzenstein U, Sommer A, Fuhrmann M, Mayer P, Enzmann H, Juergens UR, Racké K. Characterization of proliferative effects of insulin, insulin analogues and insulin-like growth factor-1 (IGF-1) in human lung fibroblasts. Naunyn Schmiedebergs Arch Pharmacol 2010; 382:511-24. [PMID: 20924562 DOI: 10.1007/s00210-010-0561-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 09/02/2010] [Indexed: 11/25/2022]
Abstract
Insulin has been approved for inhaled application, but safety concerns remain, because of un-physiologically high insulin concentrations in the lung. Since insulin may act as growth factor, possible proliferative effects of insulin, insulin analogues and insulin-like growth factor-1 (IGF-1) on human lung fibroblasts were studied. As measure of proliferation [(3)H]-thymidine incorporation was studied in HEL-299, MRC-5, IMR-90 and primary human lung fibroblasts. In all cells, mRNA encoding IGF-1 receptors and two variants of insulin receptors was detected. Insulin and IGF-1 stimulated [(3)H]-thymidine incorporation in all cells. Comparison of the concentration-dependent effects in HEL-299 cells showed that IGF-1 and insulin glargine were more potent (EC(50), 3 and 6 nM) and more effective (maximum increase, by 135-150%) than insulin and insulin detemir (EC(50), 22 and 110 nM; maximum increase: by 80%). Proliferative effects of IGF-1 and insulin were inhibited to the same extent by an antibody (1H7) directed against the IGF-1 receptor α-subunit. Insulin-induced stimulation of [(3)H]-thymidine incorporation was reduced by 83% after siRNA-mediated down-regulation of IGF-1 receptor by about 75%, but not affected by a similar down-regulation of the insulin receptor. Insulin and IGF-1 caused rapid up-regulation of the early genes FOS, EGR-1 and EGR-2 as well as of the gene coding for IGF-1. In conclusion, in human lung fibroblasts insulin exerts marked proliferative effects and the pharmacological profile of this response as well as specific receptor knock-down experiments suggest mediation via IGF-1 receptors. The risk of unwanted structural lung alterations by long-term inhalative application of insulin should be considered.
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Affiliation(s)
- M Warnken
- Institute of Pharmacology and Toxicology, University of Bonn, Reuterstraβe 2b, 53113, Bonn, Germany
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Herms J, Burgold S, Bittner T, Fuhrmann M, Kieser D, Schmidt B. O4‐08‐07: Amyloid‐β Plaques Pop Up or Rather Grow? Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.08.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Jochen Herms
- Ludwig Maximilian University of MunichMunich Germany
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29
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Kienast Y, von Baumgarten L, Fuhrmann M, Klinkert WEF, Goldbrunner R, Herms J, Winkler F. Real-time imaging reveals the single steps of brain metastasis formation. Nat Med 2009; 16:116-22. [PMID: 20023634 DOI: 10.1038/nm.2072] [Citation(s) in RCA: 754] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 08/13/2009] [Indexed: 12/22/2022]
Abstract
Brain metastasis frequently occurs in individuals with cancer and is often fatal. We used multiphoton laser scanning microscopy to image the single steps of metastasis formation in real time. Thus, it was possible to track the fate of individual metastasizing cancer cells in vivo in relation to blood vessels deep in the mouse brain over minutes to months. The essential steps in this model were arrest at vascular branch points, early extravasation, persistent close contacts to microvessels and perivascular growth by vessel cooption (melanoma) or early angiogenesis (lung cancer). Inefficient steps differed between the tumor types. Long-term dormancy was only observed for single perivascular cancer cells, some of which moved continuously. Vascular endothelial growth factor-A (VEGF-A) inhibition induced long-term dormancy of lung cancer micrometastases by preventing angiogenic growth to macrometastases. The ability to image the establishment of brain metastases in vivo provides new insights into their evolution and response to therapies.
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Affiliation(s)
- Yvonne Kienast
- Department of Neurology, Ludwig-Maximilians University, Munich, Germany
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30
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Winkler F, Kienast Y, Fuhrmann M, Von Baumgarten L, Burgold S, Mitteregger G, Kretzschmar H, Herms J. Imaging glioma cell invasion in vivo reveals mechanisms of dissemination and peritumoral angiogenesis. Glia 2009; 57:1306-15. [PMID: 19191326 DOI: 10.1002/glia.20850] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Infiltration of cancer cells into normal tissue is a hallmark of malignant gliomas and compromises treatment options. A lack of appropriate models limits the study of this invasion in vivo, which makes it difficult to fully understand its anatomy and the role of dynamic interactions with structures of the normal brain. We developed a novel methodology by utilizing multiphoton laser scanning microscopy (MPLSM) to image the movement of glioma cells deep within the normal brain of live mice in real time. This allowed us to track the invasion of individual RFP-expressing GL261 cells in relation to perfused vasculature or GFP-labeled endothelial cells repetitively over days, up to a depth of 0.5 mm. Glioma cells moved faster and more efficiently when the abluminal site of a blood vessel was utilized for invasion. Cells that invaded perivascularly were frequently found next to (a) multiple capillary structures where microvessels run parallel to each other, (b) capillary loops or glomeruloid-like bodies, and (c) dilated capillaries. Dynamic MPLSM for more than 48 h revealed that single invasive glioma cells induced intussusceptive microvascular growth and capillary loop formation, specifically at the microvascular site with which they had contact. As the main tumor grew by cooption of existing brain vessels, these peritumoral vascular changes may create a beneficial environment for glioma growth. In conclusion, our study revealed new mechanisms of peritumoral angiogenesis and invasion in gliomas, providing an explanation for their interdependence.
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Affiliation(s)
- Frank Winkler
- Department of Neurology, Ludwig-Maximilians University, Munich, Germany.
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Bittner T, Fuhrmann M, Burgold S, Kretzschmar H, LaFerla FM, Herms J. P4‐024: Long‐term in vivo imaging identifies multiple events that trigger dendritic spine loss in 3xTg‐AD mice. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.04.894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | | | | | | | | | - Jochen Herms
- Ludwig Maximilians Universität MünchenMünchenGermany
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32
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Burgold S, Fuhrmann M, Schmidt B, Kretzschmar H, Herms J. P4‐027: Kinetics of dendritic structural plasticity in the living brain of an Alzheimer's disease mouse model acquired with two photon microscopy. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.04.897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
| | | | - Boris Schmidt
- Clemens Schöpf‐Institute of Chemistry and BiochemistryDarmstadtGermany
| | | | - Jochen Herms
- Center for Neuropathology and Prion DiseaseMunichGermany
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Fuhrmann M, Bittner T, Jung C, Burgold S, Mitteregger G, Kretzschmar H, LaFerla FM, Herms J. O1‐03‐03: Microglia mediated and fractalkine receptor dependent neuron loss in a mouse model of Alzheimer's disease. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.05.207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | - Tobias Bittner
- Center of Neuropathology and Prion ResearchMunichGermany
| | - Christian Jung
- Center of Neuropathology and Prion ResearchMunichGermany
| | | | | | | | | | - Jochen Herms
- Center of Neuropathology and Prion ResearchMunichGermany
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Joly D, Schmit V, Helmstetter C, Ehrmann J, Fuhrmann M, Gobelet V, Roubiou M, Reibel S, Karst Provot A, Wagner JP. La consultation de soutien par un manipulateur dans le cadre du dispositif d’annonce ; expérience dans un centre libéral. Cancer Radiother 2008. [DOI: 10.1016/j.canrad.2008.08.092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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35
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Winkler F, Kienast Y, Fuhrmann M, von Baumgarten L, Herms J. Invasive glioma cells remodel their guiding blood vessel: in vivo microscopy reveals strategies for effective tumour dissemination. Akt Neurol 2008. [DOI: 10.1055/s-0028-1086516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Strieth S, Nussbaum CF, Eichhorn ME, Fuhrmann M, Teifel M, Michaelis U, Berghaus A, Dellian M. Tumor-selective vessel occlusions by platelets after vascular targeting chemotherapy using paclitaxel encapsulated in cationic liposomes. Int J Cancer 2007; 122:452-60. [DOI: 10.1002/ijc.23088] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Ferris RL, Trask DK, Strieth S, Nussbaum C, Eichhorn ME, Fuhrmann M, Teifel M, Michaelis U, Berghaus A, Dellian M. 08:30: Targeted Tumor-Selective Thromboses by Liposomal Paclitaxel. Otolaryngol Head Neck Surg 2007. [DOI: 10.1016/j.otohns.2007.06.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Spine loss represents a common hallmark of neurodegenerative diseases. However, little is known about the underlying mechanisms, especially the relationship between spine elimination and neuritic destruction. We imaged cortical dendrites throughout a neurodegenerative disease using scrapie in mice as a model. Two-photon in vivo imaging over 2 months revealed a linear decrease of spine density. Interestingly, only persistent spines (lifetime > or = 8 d) disappeared, whereas the density of transient spines (lifetime < or = 4 d) was unaffected. Before spine loss, dendritic varicosities emerged preferentially at sites where spines protrude from the dendrite. These results implicate that the location where the spine protrudes from the dendrite may be particularly vulnerable and that dendritic varicosities may actually cause spine loss.
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Affiliation(s)
- Martin Fuhrmann
- Center of Neuropathology and Prion Research, Ludwig Maximilians University, 81377 Munich, Germany
| | - Gerda Mitteregger
- Center of Neuropathology and Prion Research, Ludwig Maximilians University, 81377 Munich, Germany
| | - Hans Kretzschmar
- Center of Neuropathology and Prion Research, Ludwig Maximilians University, 81377 Munich, Germany
| | - Jochen Herms
- Center of Neuropathology and Prion Research, Ludwig Maximilians University, 81377 Munich, Germany
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Holzer W, Penzkofer A, Fuhrmann M, Hegemann P. Spectroscopic Characterization of Flavin Mononucleotide Bound to the LOV1 Domain of Phot1 from Chlamydomonas reinhardtii¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2002)0750479scofmb2.0.co2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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40
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Burgio G, Fuhrmann M, Kerler W, Müller-Preussker M. Vortex free energy and deconfinement in center-blind discretizations of Yang-Mills theories. Int J Clin Exp Med 2006. [DOI: 10.1103/physrevd.74.071502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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41
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Fuhrmann M, Bittner T, Mitteregger G, Haider N, Moosmang S, Kretzschmar H, Herms J. Loss of the cellular prion protein affects the Ca2+ homeostasis in hippocampal CA1 neurons. J Neurochem 2006; 98:1876-85. [PMID: 16945105 DOI: 10.1111/j.1471-4159.2006.04011.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previous neurophysiological studies on prion protein deficient (Prnp(-/-)) mice have revealed a significant reduction of slow afterhyperpolarization currents (sI(AHP)) in hippocampal CA1 pyramidal cells. Here we aim to determine whether loss of PrP(C.) directly affects the potassium channels underlying sI(AHP) or if sI(AHP) is indirectly disturbed by altered intracellular Ca(2+) fluxes. Patch-clamp measurements and confocal Ca(2+) imaging in acute hippocampal slice preparations of Prnp(-/-) mice compared to littermate control mice revealed a reduced Ca(2+) rise in CA1 neurons lacking PrP(C) following a depolarization protocol known to induce sI(AHP). Moreover, we observed a reduced Ca(2+) influx via l-type voltage gated calcium channels (VGCCs). No differences were observed in the protein expression of the pore forming alpha1 subunit of VGCCs Prnp(-/-) mice. Surprisingly, the beta2 subunit, critically involved in the transport of the alpha1 subunit to the plasma membrane, was found to be up-regulated in knock out hippocampal tissue. On mRNA level however, no differences could be detected for the alpha1C, D and beta2-4 subunits. In conclusion our data support the notion that lack of PrP(C.) does not directly affect the potassium channels underlying sI(AHP), but modulates these channels due to its effect on the intracellular free Ca(2+) concentration via a reduced Ca(2+) influx through l-type VGCCs.
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Affiliation(s)
- Martin Fuhrmann
- Center of Neuropathology and Prion Research, Ludwig Maximilians University, 81377 Munich, Germany
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Herms J, Anliker B, Heber S, Ring S, Fuhrmann M, Kretzschmar H, Sisodia S, Müller U. Cortical dysplasia resembling human type 2 lissencephaly in mice lacking all three APP family members. EMBO J 2004; 23:4106-15. [PMID: 15385965 PMCID: PMC524337 DOI: 10.1038/sj.emboj.7600390] [Citation(s) in RCA: 247] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2004] [Accepted: 08/09/2004] [Indexed: 11/09/2022] Open
Abstract
The Alzheimer's disease beta-amyloid precursor protein (APP) is a member of a larger gene family that includes the amyloid precursor-like proteins, termed APLP1 and APLP2. We previously documented that APLP2-/-APLP1-/- and APLP2-/-APP-/- mice die postnatally, while APLP1-/-APP-/- mice and single mutants were viable. We now report that mice lacking all three APP/APLP family members survive through embryonic development, and die shortly after birth. In contrast to double-mutant animals with perinatal lethality, 81% of triple mutants showed cranial abnormalities. In 68% of triple mutants, we observed cortical dysplasias characterized by focal ectopic neuroblasts that had migrated through the basal lamina and pial membrane, a phenotype that resembles human type II lissencephaly. Moreover, at E18.5 triple mutants showed a partial loss of cortical Cajal Retzius (CR) cells, suggesting that APP/APLPs play a crucial role in the survival of CR cells and neuronal adhesion. Collectively, our data reveal an essential role for APP family members in normal brain development and early postnatal survival.
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Affiliation(s)
- Jochen Herms
- Zentrum für Neuropathologie und Prionforschung, Universität München, München, Germany
| | - Brigitte Anliker
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, Frankfurt, Germany
| | - Sabine Heber
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, Frankfurt, Germany
| | - Sabine Ring
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, Frankfurt, Germany
| | - Martin Fuhrmann
- Zentrum für Neuropathologie und Prionforschung, Universität München, München, Germany
| | - Hans Kretzschmar
- Zentrum für Neuropathologie und Prionforschung, Universität München, München, Germany
| | - Sangram Sisodia
- Department of Neurobiology, Pharmacology and Physiology, University of Chicago, Chicago, IL, USA
| | - Ulrike Müller
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, Frankfurt, Germany
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, Deutschordenstr. 46, 60528 Frankfurt, Germany. Tel.: +49 69 96769 317; Fax: +49 69 96769 441; E-mail:
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Müller U, Anliker B, Heber S, Fuhrmann M, Kretzschmar H, Sisodia S, Herms J. O4-04-07 Cortical dysplasia resembling human type 2 lissencephaly in mice lacking all three APP-family members. Neurobiol Aging 2004. [DOI: 10.1016/s0197-4580(04)80278-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Suttorp N, Ehreiser P, Hippenstiel S, Fuhrmann M, Krüll M, Tenor H, Schudt C. Hyperpermeability of pulmonary endothelial monolayer: protective role of phosphodiesterase isoenzymes 3 and 4. Lung 2004; 174:181-94. [PMID: 8830194 DOI: 10.1007/bf00173310] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The regulation of endothelial permeability is poorly understood. An increase in endothelial permeability in the pulmonary microvasculature, however, is critical in noncardiogenic pulmonary edema and other diffuse inflammatory reactions. In the present study thrombin and Escherichia coli hemolysin (HlyA), a membrane-perturbing bacterial exotoxin, were used to alter hydraulic permeability of porcine pulmonary artery and human endothelial cell monolayers. We also investigated the pharmacological approach of adenylyl cyclase activation/phosphodiesterase (PDE) inhibition to block endothelial hyperpermeability. Thrombin (1-5 units/ml) and HlyA (0.5-3 hemolytic units/ml) dose and time dependently (> 15 min) increased endothelial permeability. Forskolin, cholera toxin, and prostaglandin E1, which all stimulate adenylyl cyclase activity, abrogated this effect. One mM dibutyryl cAMP, a cell membrane-permeable cAMP analogue, was similarly active. Endothelial hyperpermeability was also reduced dose dependently by inhibitors of different PDE isoenzymes (motapizone, rolipram, and zardaverine, which block PDE3 and/or PDE4). The effectiveness of PDE inhibitors was increased in the presence of adenylyl cyclase activators. Analysis of cyclic nucleotide hydrolyzing PDE activity in lysates of human umbilical vein endothelial cells showed high activities of PDE isoenzymes 2, 3, and 4. Consistent with the functional data PDE3 and PDE4 were the major cAMP hydrolysis enzymes in intact endothelial cells. We conclude that the hyperpermeability of pulmonary endothelial monolayers, evoked by thrombin or HlyA, can be blocked by the simultaneous activation of adenylyl cyclase and inhibition of PDEs, especially of PDE3 and PDE4. The demonstration of PDE isoenzymes 2-4 in human endothelial cells will help optimize this therapeutic approach.
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Affiliation(s)
- N Suttorp
- Department of Internal Medicine, Justus Liebig-University of Giessen, Germany
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Holzer W, Penzkofer A, Fuhrmann M, Hegemann P. Spectroscopic characterization of flavin mononucleotide bound to the LOV1 domain of Phot1 from Chlamydomonas reinhardtii. Photochem Photobiol 2002; 75:479-87. [PMID: 12017473 DOI: 10.1562/0031-8655(2002)075<0479:scofmb>2.0.co;2] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The absorption and emission behavior of flavin mononucleotide (FMN) in the light-, oxygen- and voltage-sensitive (LOV) domain LOV1 of the photoreceptor Phot1 from the green alga Chlamydomonas reinhardtii was studied. The results from the wild-type (LOV1-WT) were compared with those from a mutant in which cysteine 57 was replaced by serine (LOV1-C57S), and with free FMN in aqueous solution. A fluorescence quantum yield of phi(F) = 0.30 and a fluorescence lifetime of tau(F) = 4.6 ns were determined for FMN in the mutant LOV1-C57S, whereas these quantities are reduced to about phi(F) = 0.17 and tau(F) = 2.9 ns for LOV1-WT, indicating an enhanced intersystem crossing in LOV1-WT because of the adjacent sulfur of C57. A single-exponential fluorescence decay was observed in picosecond laser time-resolved fluorescence measurements for both LOV1-WT and LOV1-C57S as expected for excited singlet state relaxation by intersystem crossing and internal conversion. An excitation intensity dependent fluorescence signal saturation was observed in steady-state fluorescence measurements for LOV1-WT, which is thought to be because of the formation of a long-lived intermediate flavin-C(4a)-cysteinyl adduct in the triplet state (few microseconds triplet lifetime, adduct lifetime around 150 s). No photobleaching was observed for LOV1-C57S, because no thiol group is present in the vicinity of FMN for an adduct formation.
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Affiliation(s)
- W Holzer
- Institut II-Experimentelle und Angewandte Physik, Universität Regensburg, Germany
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Abstract
Elemental mercury, contaminated with radionuclides, presents a waste disposal problem throughout the Department of Energy complex. In this paper we describe a new process to immobilize elemental mercury wastes, including those contaminated with radionuclides, in a form that is non-dispersible, will meet EPA leaching criteria, and has low mercury vapor pressure. In this stabilization and solidification process, elemental mercury is combined with an excess of powdered sulfur polymer cement (SPC) and sulfide additives in a mixing vessel and heated to approximately 40 degrees C for several hours, until all of the mercury is converted into mercuric sulfide (HgS). Additional SPC is then added and the temperature of the mixture raised to 135 degrees C, resulting in a molten liquid which is poured into a mold where it cools and solidifies. The final treated waste was characterized by powder X-ray diffraction and found to be a mixture of the hexagonal and orthorhombic forms of mercuric sulfide. The Toxicity Characteristic Leaching Procedure was used to assess mercury releases, which for the optimized process averaged 25.8 microg/l, with some samples being well below the new EPA Universal Treatment Standard of 25 microg/l. Longer term leach tests were also conducted, indicating that the leaching process was dominated by diffusion. Values for the effective diffusion coefficient averaged 7.6x10(-18) cm2/s. Concentrations of mercury vapor from treated waste in equilibrium static headspace tests averaged 0.6 mg/m3.
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Affiliation(s)
- M Fuhrmann
- Environmental Research & Technology Division, Environmental Sciences Department, Brookhaven National Laboratory, Upton, NY 11973-5000, USA.
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Fuhrmann M, Stahlberg A, Govorunova E, Rank S, Hegemann P. The abundant retinal protein of the Chlamydomonas eye is not the photoreceptor for phototaxis and photophobic responses. J Cell Sci 2001; 114:3857-63. [PMID: 11719552 DOI: 10.1242/jcs.114.21.3857] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The chlamyopsin gene (cop) encodes the most abundant eyespot protein in the unicellular green alga Chlamydomonas reinhardtii. This opsin-related protein (COP) binds retinal and was thought to be the photoreceptor controlling photomovement responses via a set of photoreceptor currents. Unfortunately, opsin-deficient mutants are not available and targeted disruption of non-selectable nuclear genes is not yet possible in any green alga. Here we show that intron-containing gene fragments directly linked to their intron-less antisense counterpart provide efficient post-transcriptional gene silencing (PTGS) in C. reinhardtii, thus allowing an efficient reduction of a specific gene product in a green alga. In opsin-deprived transformants, flash-induced photoreceptor currents (PC) are left unchanged. Moreover, photophobic responses as studied by motion analysis and phototaxis tested in a light-scattering assay were indistinguishable from the responses of untransformed wild-type cells. We conclude that phototaxis and photophobic responses in C. reinhardtii are triggered by an as yet unidentified rhodopsin species.
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Affiliation(s)
- M Fuhrmann
- Institut für Biochemie I, Universität Regensburg, 93040 Regensburg, Germany.
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Abstract
Endothelial differentiation gene (EDG) receptors are a new family of eight G protein-coupled receptors for the lysophospholipids lysophosphatitic acid and sphingosine-1-phosphate. In the present experiments, the expression of EDG receptors in rat and human alveolar macrophages was studied by reverse transcription-polymerase chain reaction (RT-PCR). In alveolar macrophages of both species, mRNA for multiple EDG receptors could be detected, but the pattern of expression was different in both species. In human alveolar macrophages, mRNA for EDG1, EDG2, EDG4, EDG7 receptors and, to a lesser extent, for the EDG7 receptor was detected, whereas in rat macrophages, mRNA for EDG2, EDG5 receptors and, to a lesser extent, for the EDG6 receptor was found. In functional experiments, it was observed that lysophosphatitic acid and sphingosine-1-phosphate can stimulate O(2)(-) generation in rat and human alveolar macrophages suggesting that lysophosphatitic acid and sphingosine-1-phosphate possibly acting via EDG receptors may play a role in controlling the activation of macrophages.
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Affiliation(s)
- C Hornuss
- Institute of Pharmacology and Toxicology, University of Bonn, Reuterstrasse 2b, D-53113 Bonn, Germany
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Sizova I, Fuhrmann M, Hegemann P. A Streptomyces rimosus aphVIII gene coding for a new type phosphotransferase provides stable antibiotic resistance to Chlamydomonas reinhardtii. Gene 2001; 277:221-9. [PMID: 11602359 DOI: 10.1016/s0378-1119(01)00616-3] [Citation(s) in RCA: 230] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Although Chlamydomonas reinhardtii serves as the most popular algal model system, no efficient enzymatic selection marker for the nuclear transformation of wild-type cells is available. We sequenced an aminoglycoside 3'-phosphotransferase gene (aph) from Streptomyces rimosus. Though the derived protein sequence is homologous to members of APH type V, it constitutes a new type, named APHVIII. Since the aphVIII gene has a codon bias similar to that of the nuclear genome of green algae, the aphVIII coding sequence was fused to the 5'- and 3'-untranslated regions of the C. reinhardtii rbcS2 gene. C. reinhardtii transformants were capable of inactivating the antibiotics paromomycin, kanamycin, and neomycin, to which wild-type cells are sensitive. After addition of the 5'-region of hsp70A as a second promoter and insertion of the rbcS2 intron I, the transformation rate increased to two transformants per 1 x 10(5) cells, which is close to the efficiency of transforming auxotrophic strains with the homologous marker arg7. Transformation with the promoter-less aphVIII led to random gene fusion at high frequency. In an aphVIII-based reporter gene assay we have found a so far unknown promoter activity of the 3'-untranslated region of rbcS2, that may promote antisense RNA synthesis from the rbcS2 gene in vivo. We conclude that the aphVIII gene is a useful marker for nuclear transformation and promoter tagging of C. reinhardtii wild-type and probably other green algae.
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Affiliation(s)
- I Sizova
- Biological Institute, St. Petersburg State University, Oranienbaumskoye sch., 2, St. Petersburg, 198904 Russia.
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Fuhrmann M. [The policy of population increase and the improvement of men: population discourse in the political and economic theory of the German Enlightenment]. Aufklarung (Hambg) 2001; 13:243-282. [PMID: 20017275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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