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Evidence of p75 Neurotrophin Receptor Involvement in the Central Nervous System Pathogenesis of Classical Scrapie in Sheep and a Transgenic Mouse Model. Int J Mol Sci 2021; 22:ijms22052714. [PMID: 33800240 PMCID: PMC7962525 DOI: 10.3390/ijms22052714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/27/2021] [Accepted: 02/28/2021] [Indexed: 11/17/2022] Open
Abstract
Neurotrophins constitute a group of growth factor that exerts important functions in the nervous system of vertebrates. They act through two classes of transmembrane receptors: tyrosine-kinase receptors and the p75 neurotrophin receptor (p75NTR). The activation of p75NTR can favor cell survival or apoptosis depending on diverse factors. Several studies evidenced a link between p75NTR and the pathogenesis of prion diseases. In this study, we investigated the distribution of several neurotrophins and their receptors, including p75NTR, in the brain of naturally scrapie-affected sheep and experimentally infected ovinized transgenic mice and its correlation with other markers of prion disease. No evident changes in infected mice or sheep were observed regarding neurotrophins and their receptors except for the immunohistochemistry against p75NTR. Infected mice showed higher abundance of p75NTR immunostained cells than their non-infected counterparts. The astrocytic labeling correlated with other neuropathological alterations of prion disease. Confocal microscopy demonstrated the co-localization of p75NTR and the astrocytic marker GFAP, suggesting an involvement of astrocytes in p75NTR-mediated neurodegeneration. In contrast, p75NTR staining in sheep lacked astrocytic labeling. However, digital image analyses revealed increased labeling intensities in preclinical sheep compared with non-infected and terminal sheep in several brain nuclei. This suggests that this receptor is overexpressed in early stages of prion-related neurodegeneration in sheep. Our results confirm a role of p75NTR in the pathogenesis of classical ovine scrapie in both the natural host and in an experimental transgenic mouse model.
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Schott BH, Kronenberg G, Schmidt U, Düsedau HP, Ehrentraut S, Geisel O, von Bohlen Und Halbach O, Gass P, Dunay IR, Hellweg R. Robustly High Hippocampal BDNF levels under Acute Stress in Mice Lacking the Full-length p75 Neurotrophin Receptor. PHARMACOPSYCHIATRY 2021; 54:205-213. [PMID: 33592642 DOI: 10.1055/a-1363-1680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Brain-derived neurotrophic factor (BDNF) exerts its effects on neural plasticity via 2 distinct receptor types, the tyrosine kinase TrkB and the p75 neurotrophin receptor (p75NTR). The latter can promote inflammation and cell death while TrkB is critically involved in plasticity and memory, particularly in the hippocampus. Acute and chronic stress have been associated with suppression of hippocampal BDNF expression and impaired hippocampal plasticity. We hypothesized that p75NTR might be involved in the hippocampal stress response, in particular in stress-induced BDNF suppression, which might be accompanied by increased neuroinflammation. METHOD We assessed hippocampal BDNF protein concentrations in wild-type mice compared that in mice lacking the long form of the p75NTR (p75NTRExIII-/-) with or without prior exposure to a 1-hour restraint stress challenge. Hippocampal BDNF concentrations were measured using an optimized ELISA. Furthermore, whole-brain mRNA expression of pro-inflammatory interleukin-6 (Il6) was assessed with RT-PCR. RESULTS Deletion of full-length p75NTR was associated with higher hippocampal BDNF protein concentration in the stress condition, suggesting persistently high hippocampal BDNF levels in p75NTR-deficient mice, even under stress. Stress elicited increased whole-brain Il6 mRNA expression irrespective of genotype; however, p75NTRExIII-/- mice showed elevated baseline Il6 expression and thus a lower relative increase. CONCLUSIONS Our results provide evidence for a role of p75NTR signaling in the regulation of hippocampal BDNF levels, particularly under stress. Furthermore, p75NTR signaling modulates baseline but not stress-related Il6 gene expression in mice. Our findings implicate p75NTR signaling as a potential pathomechanism in BDNF-dependent modulation of risk for neuropsychiatric disorders.
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Affiliation(s)
- Björn H Schott
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Göttingen, Germany.,Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Berlin, Germany.,Leibniz Institute for Neurobiology, Department of Behavioral Neurology, Magdeburg, Germany.,German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Golo Kronenberg
- Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Berlin, Germany.,University of Leicester and Leicestershire Partnership NHS Trust, Leicester, United Kingdom
| | - Ulrike Schmidt
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Göttingen, Germany.,Department of Psychiatry and Psychotherapy, University Medical Center Bonn, Bonn, Germany
| | - Henning P Düsedau
- Institute of Inflammation and Neurodegeneration, Otto von Guericke University, Magdeburg, Germany
| | - Stefanie Ehrentraut
- Institute of Inflammation and Neurodegeneration, Otto von Guericke University, Magdeburg, Germany
| | - Olga Geisel
- Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Berlin, Germany
| | | | - Peter Gass
- Central Institute for Mental Health, Department of Psychiatry and Psychotherapy, Heidelberg University, Mannheim Faculty, Germany
| | - Ildiko Rita Dunay
- Institute of Inflammation and Neurodegeneration, Otto von Guericke University, Magdeburg, Germany
| | - Rainer Hellweg
- Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Berlin, Germany
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Becker K, Cana A, Baumgärtner W, Spitzbarth I. p75 Neurotrophin Receptor: A Double-Edged Sword in Pathology and Regeneration of the Central Nervous System. Vet Pathol 2018; 55:786-801. [PMID: 29940812 DOI: 10.1177/0300985818781930] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The low-affinity nerve growth factor receptor p75NTR is a major neurotrophin receptor involved in manifold and pleiotropic functions in the developing and adult central nervous system (CNS). Although known for decades, its entire functions are far from being fully elucidated. Depending on the complex interactions with other receptors and on the cellular context, p75NTR is capable of performing contradictory tasks such as mediating cell death as well as cell survival. In parallel, as a prototype marker for certain differentiation stages of Schwann cells and related CNS aldynoglial cells, p75NTR has recently gained increasing notice as a marker for cells with proposed regenerative potential in CNS diseases, such as demyelinating disease and traumatic CNS injury. Besides its pivotal role as a marker for transplantation candidate cells, recent studies in canine neuroinflammatory CNS conditions also highlight a spontaneous endogenous occurrence of p75NTR-positive glia, which potentially play a role in Schwann cell-mediated CNS remyelination. The aim of the present communication is to review the pleiotropic functions of p75NTR in the CNS with a special emphasis on its role as an immunohistochemical marker in neuropathology. Following a brief illustration of the expression of p75NTR in neurogenesis and in developed neuronal populations, the implications of p75NTR expression in astrocytes, oligodendrocytes, and microglia are addressed. A special focus is put on the role of p75NTR as a cell marker for specific differentiation stages of Schwann cells and a regeneration-promoting CNS population, collectively referred to as aldynoglia.
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Affiliation(s)
- Kathrin Becker
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Armend Cana
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,2 Center for Systems Neuroscience, Hannover, Germany
| | - Wolfgang Baumgärtner
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,2 Center for Systems Neuroscience, Hannover, Germany
| | - Ingo Spitzbarth
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,2 Center for Systems Neuroscience, Hannover, Germany
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Su X, Fang D, Liu Y, Ramamoorthi M, Zeitouni A, Chen W, Tran SD. Three-dimensional organotypic culture of human salivary glands: the slice culture model. Oral Dis 2016; 22:639-48. [PMID: 27214128 DOI: 10.1111/odi.12508] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/05/2016] [Accepted: 05/16/2016] [Indexed: 12/21/2022]
Abstract
OBJECTIVE A challenge in studying human salivary glands is to maintain the cells ex vivo in their three-dimensional (3D) morphology with an intact native extracellular matrix (ECM) environment. This paper established a human salivary 3D organotypic slice culture model that could maintain its physiological functions as well as allowing a direct visualization of the cells. METHODS Human salivary biopsies from six patients were embedded in agarose and submerged in cold buffer for thin (50 μm) sectioning using a vibratome. 'Salivary slices' were mechanically supported by a porous membrane insert that allowed an air-liquid interface and cultured in serum-free culture media. Cell viability, proliferation, apoptosis, physiological functions, and gene expression were assessed during 14 days of culture. RESULTS Human salivary slices maintained cell survival (70-40%) and proliferation (6-17%) for 14 days ex vivo. The protein secretory (amylase) function decreased, but fluid (intracellular calcium mobilization) function was maintained. Acinar, ductal, and myoepithelial cell populations survived and maintained their 3D organization within the slice culture model. CONCLUSION The human salivary slice culture model kept cells alive ex vivo for 14 days as well as maintaining their 3D morphology and physiological functions.
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Affiliation(s)
- X Su
- Craniofacial Tissue Engineering and Stem Cells Laboratory, Faculty of Dentistry, McGill University, Montreal, QC, Canada.,College of Stomatology, Guangxi Medical University, Nanning, Guangxi, China
| | - D Fang
- Craniofacial Tissue Engineering and Stem Cells Laboratory, Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - Y Liu
- Craniofacial Tissue Engineering and Stem Cells Laboratory, Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - M Ramamoorthi
- Craniofacial Tissue Engineering and Stem Cells Laboratory, Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - A Zeitouni
- Department of Otolaryngology, McGill University Health Center, McGill University, Montreal, QC, Canada
| | - W Chen
- College of Stomatology, Guangxi Medical University, Nanning, Guangxi, China.
| | - S D Tran
- Craniofacial Tissue Engineering and Stem Cells Laboratory, Faculty of Dentistry, McGill University, Montreal, QC, Canada.
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Spitzbarth I, Lempp C, Kegler K, Ulrich R, Kalkuhl A, Deschl U, Baumgärtner W, Seehusen F. Immunohistochemical and transcriptome analyses indicate complex breakdown of axonal transport mechanisms in canine distemper leukoencephalitis. Brain Behav 2016; 6:e00472. [PMID: 27247850 PMCID: PMC4864272 DOI: 10.1002/brb3.472] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 02/24/2016] [Accepted: 03/11/2016] [Indexed: 12/03/2022] Open
Abstract
INTRODUCTION CDV-DL (Canine distemper virus-induced demyelinating leukoencephalitis) represents a spontaneously occurring animal model for demyelinating disorders. Axonopathy represents a key pathomechanism in this disease; however, its underlying pathogenesis has not been addressed in detail so far. This study aimed at the characterization of axonal cytoskeletal, transport, and potential regenerative changes with a parallel focus upon Schwann cell remyelination. METHODS Immunohistochemistry of canine cerebellar tissue as well as a comparative analysis of genes from an independent microarray study were performed. RESULTS Increased axonal immunoreactivity for nonphosphorylated neurofilament was followed by loss of cytoskeletal and motor proteins. Interestingly, a subset of genes encoding for neurofilament subunits and motor proteins was up-regulated in the chronic stage compared to dogs with subacute CDV-DL. However, immunohistochemically, hints for axonal regeneration were restricted to up-regulated axonal positivity of hypoxia-inducible factor 1 alpha, while growth-associated protein 43, erythropoietin and its receptor were not or even down-regulated. Periaxin-positive structures, indicative of Schwann cell remyelination, were only detected within few advanced lesions. CONCLUSIONS The present findings demonstrate a complex sequence of axonal cytoskeletal breakdown mechanisms. Moreover, though sparse, this is the first report of Schwann cell remyelination in CDV-DL. Facilitation of these very limited endogenous regenerative responses represents an important topic for future research.
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Affiliation(s)
- Ingo Spitzbarth
- Department of Pathology University of Veterinary Medicine Hannover Foundation Bünteweg 17 30559 Hannover Germany; Center for Systems Neuroscience Bünteweg 2 30559 Hannover Germany
| | - Charlotte Lempp
- Department of Pathology University of Veterinary Medicine Hannover Foundation Bünteweg 17 30559 Hannover Germany
| | - Kristel Kegler
- Department of Pathology University of Veterinary Medicine Hannover Foundation Bünteweg 17 30559 Hannover Germany; Center for Systems Neuroscience Bünteweg 2 30559 Hannover Germany
| | - Reiner Ulrich
- Department of Pathology University of Veterinary Medicine Hannover Foundation Bünteweg 17 30559 Hannover Germany; Center for Systems Neuroscience Bünteweg 2 30559 Hannover Germany
| | - Arno Kalkuhl
- Department of Non-Clinical Drug Safety Boehringer Ingelheim Pharma GmbH & Co KG Biberach (Riß) Germany
| | - Ulrich Deschl
- Department of Non-Clinical Drug Safety Boehringer Ingelheim Pharma GmbH & Co KG Biberach (Riß) Germany
| | - Wolfgang Baumgärtner
- Department of Pathology University of Veterinary Medicine Hannover Foundation Bünteweg 17 30559 Hannover Germany; Center for Systems Neuroscience Bünteweg 2 30559 Hannover Germany
| | - Frauke Seehusen
- Department of Pathology University of Veterinary Medicine Hannover Foundation Bünteweg 17 30559 Hannover Germany
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Kegler K, Spitzbarth I, Imbschweiler I, Wewetzer K, Baumgärtner W, Seehusen F. Contribution of Schwann Cells to Remyelination in a Naturally Occurring Canine Model of CNS Neuroinflammation. PLoS One 2015. [PMID: 26196511 PMCID: PMC4510361 DOI: 10.1371/journal.pone.0133916] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Gliogenesis under pathophysiological conditions is of particular clinical relevance since it may provide evidence for regeneration promoting cells recruitable for therapeutic purposes. There is evidence that neurotrophin receptor p75 (p75NTR)-expressing cells emerge in the lesioned CNS. However, the phenotype and identity of these cells, and signals triggering their in situ generation under normal conditions and certain pathological situations has remained enigmatic. In the present study, we used a spontaneous, idiopathic and inflammatory CNS condition in dogs with prominent lympho-histiocytic infiltration as a model to study the phenotype of Schwann cells and their relation to Schwann cell remyelination within the CNS. Furthermore, the phenotype of p75NTR-expressing cells within the injured CNS was compared to their counter-part in control sciatic nerve and after peripheral nerve injury. In addition, organotypic slice cultures were used to further elucidate the origin of p75NTR-positive cells. In cerebral and cerebellar white and grey matter lesions as well as in the brain stem, p75NTR-positive cells co-expressed the transcription factor Sox2, but not GAP-43, GFAP, Egr2/Krox20, periaxin and PDGFR-α. Interestingly, and contrary to the findings in control sciatic nerves, p75NTR-expressing cells only co-localized with Sox2 in degenerative neuropathy, thus suggesting that such cells might represent dedifferentiated Schwann cells both in the injured CNS and PNS. Moreover, effective Schwann cell remyelination represented by periaxin- and P0-positive mature myelinating Schwann cells, was strikingly associated with the presence of p75NTR/Sox2-expressing Schwann cells. Intriguingly, the emergence of dedifferentiated Schwann cells was not affected by astrocytes, and a macrophage-dominated inflammatory response provided an adequate environment for Schwann cells plasticity within the injured CNS. Furthermore, axonal damage was reduced in brain stem areas with p75NTR/Sox2-positive cells. This study provides novel insights into the involvement of Schwann cells in CNS remyelination under natural occurring CNS inflammation. Targeting p75NTR/Sox2-expressing Schwann cells to enhance their differentiation into competent remyelinating cells appears to be a promising therapeutic approach for inflammatory/demyelinating CNS diseases.
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Affiliation(s)
- Kristel Kegler
- Department of Pathology, University of Veterinary Medicine, Hannover, Germany
- Center of Systems Neuroscience, Hannover, Germany
| | - Ingo Spitzbarth
- Department of Pathology, University of Veterinary Medicine, Hannover, Germany
- Center of Systems Neuroscience, Hannover, Germany
| | - Ilka Imbschweiler
- Department of Pathology, University of Veterinary Medicine, Hannover, Germany
| | - Konstantin Wewetzer
- Center of Systems Neuroscience, Hannover, Germany
- Department of Functional and Applied Anatomy, Center of Anatomy, Hannover Medical School, Hannover, Germany
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine, Hannover, Germany
- Center of Systems Neuroscience, Hannover, Germany
- * E-mail:
| | - Frauke Seehusen
- Department of Pathology, University of Veterinary Medicine, Hannover, Germany
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