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Wu W, He Y, Chen Y, Fu Y, He S, Liu K, Qu JY. In vivo imaging in mouse spinal cord reveals that microglia prevent degeneration of injured axons. Nat Commun 2024; 15:8837. [PMID: 39397028 PMCID: PMC11471772 DOI: 10.1038/s41467-024-53218-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 10/02/2024] [Indexed: 10/15/2024] Open
Abstract
Microglia, the primary immune cells in the central nervous system, play a critical role in regulating neuronal function and fate through their interaction with neurons. Despite extensive research, the specific functions and mechanisms of microglia-neuron interactions remain incompletely understood. In this study, we demonstrate that microglia establish direct contact with myelinated axons at Nodes of Ranvier in the spinal cord of mice. The contact associated with neuronal activity occurs in a random scanning pattern. In response to axonal injury, microglia rapidly transform their contact into a robust wrapping form, preventing acute axonal degeneration from extending beyond the nodes. This wrapping behavior is dependent on the function of microglial P2Y12 receptors, which may be activated by ATP released through axonal volume-activated anion channels at the nodes. Additionally, voltage-gated sodium channels (NaV) and two-pore-domain potassium (K2P) channels contribute to the interaction between nodes and glial cells following injury, and inhibition of NaV delays axonal degeneration. Through in vivo imaging, our findings reveal a neuroprotective role of microglia during the acute phase of single spinal cord axon injury, achieved through neuron-glia interaction.
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Grants
- ITCPD/17-9 Innovation and Technology Commission (ITF)
- ITCPD/17-9 Innovation and Technology Commission (ITF)
- 32101211, 32192400 National Natural Science Foundation of China (National Science Foundation of China)
- 82171384 National Natural Science Foundation of China (National Science Foundation of China)
- the Hong Kong Research Grants Council through grants (16102122, 16102123, 16102421, 16102518, 16102920, T13-607/12R, T13-605/18W, T13-602/21N, C6002-17GF, C6001-19E);the Area of Excellence Scheme of the University Grants Committee (AoE/M-604/16, AOE/M-09/12) and the Hong Kong University of Science & Technology (HKUST) through grant 30 for 30 Research Initiative Scheme.
- Guangdong Basic and Applied Basic Research Foundation 2024A1515012414 Shenzhen Medical Research Fund (B2301004)
- Guangzhou Key Projects of Brain Science and Brain-Like Intelligence Technology (20200730009), Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions (2019SHIBS0001);the Area of Excellence Scheme of the University Grants Committee (AoE/M-604/16); Hong Kong Research Grants Council through grants (T13-602/21N, C6034-21G)
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Affiliation(s)
- Wanjie Wu
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong, P. R. China
| | - Yingzhu He
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong, P. R. China
| | - Yujun Chen
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, P. R. China
| | - Yiming Fu
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong, P. R. China
| | - Sicong He
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Kai Liu
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, P. R. China.
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Hong Kong, P. R. China.
- StateKey Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, P. R. China.
- Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen, Guangdong, China.
- HKUST Shenzhen Research Institute, Guangdong, China.
- Shenzhen-Hong Kong Institute of Brain Science, Guangdong, China.
| | - Jianan Y Qu
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong, P. R. China.
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Hong Kong, P. R. China.
- Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Hong Kong, P. R. China.
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2
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El Masri J, Fadlallah H, Al Sabsabi R, Afyouni A, Al-Sayegh M, Abou-Kheir W. Adipose-Derived Stem Cell Therapy in Spinal Cord Injury. Cells 2024; 13:1505. [PMID: 39273075 PMCID: PMC11394073 DOI: 10.3390/cells13171505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Revised: 09/04/2024] [Accepted: 09/05/2024] [Indexed: 09/15/2024] Open
Abstract
Spinal cord injury (SCI) is a serious condition accompanied by severe adverse events that affect several aspects of the patient's life, such as motor, sensory, and functional impairment. Despite its severe consequences, definitive treatment for these injuries is still missing. Therefore, researchers have focused on developing treatment strategies aimed at ensuring full recovery post-SCI. Accordingly, attention has been drawn toward cellular therapy using mesenchymal stem cells. Considering their wide availability, decreased immunogenicity, wide expansion capacity, and impressive effectiveness in many therapeutic approaches, adipose-derived stem cell (ADSC) injections in SCI cases have been investigated and showed promising results. In this review, SCI pathophysiology and ADSC transplantation benefits are discussed independently, together with SCI animal models and adipose stem cell preparation and application techniques. The mechanisms of healing in an SCI post-ADSC injection, the outcomes of this therapeutic approach, and current clinical trials are also deliberated, in addition to the challenges and future perspectives, aiming to encourage further research in this field.
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Affiliation(s)
- Jad El Masri
- Department of Anatomy, Cell Biology, and Physiological Sciences, American University of Beirut, Beirut 1107-2020, Lebanon
- Faculty of Medical Sciences, Lebanese University, Beirut 1533, Lebanon
| | - Hiba Fadlallah
- Department of Anatomy, Cell Biology, and Physiological Sciences, American University of Beirut, Beirut 1107-2020, Lebanon
| | - Rahaf Al Sabsabi
- Faculty of Medical Sciences, Lebanese University, Beirut 1533, Lebanon
| | - Ahmad Afyouni
- Faculty of Medical Sciences, Lebanese University, Beirut 1533, Lebanon
| | - Mohamed Al-Sayegh
- Biology Division, New York University Abu Dhabi, Abu Dhabi 2460, United Arab Emirates
| | - Wassim Abou-Kheir
- Department of Anatomy, Cell Biology, and Physiological Sciences, American University of Beirut, Beirut 1107-2020, Lebanon
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3
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Askari S, Misgeld T. Brain imaging turned inside out. Nat Biotechnol 2024; 42:1028-1029. [PMID: 37957343 DOI: 10.1038/s41587-023-02036-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Affiliation(s)
- Shahrzad Askari
- Institute of Neuronal Cell Biology, Technical University of Munich (TUM), Munich, Germany
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich (TUM), Munich, Germany.
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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4
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Yavuz B, Mutlu EC, Ahmed Z, Ben-Nissan B, Stamboulis A. Applications of Stem Cell-Derived Extracellular Vesicles in Nerve Regeneration. Int J Mol Sci 2024; 25:5863. [PMID: 38892052 PMCID: PMC11172915 DOI: 10.3390/ijms25115863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/15/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
Extracellular vesicles (EVs), including exosomes, microvesicles, and other lipid vesicles derived from cells, play a pivotal role in intercellular communication by transferring information between cells. EVs secreted by progenitor and stem cells have been associated with the therapeutic effects observed in cell-based therapies, and they also contribute to tissue regeneration following injury, such as in orthopaedic surgery cases. This review explores the involvement of EVs in nerve regeneration, their potential as drug carriers, and their significance in stem cell research and cell-free therapies. It underscores the importance of bioengineers comprehending and manipulating EV activity to optimize the efficacy of tissue engineering and regenerative therapies.
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Affiliation(s)
- Burcak Yavuz
- Vocational School of Health Services, Altinbas University, 34147 Istanbul, Turkey;
| | - Esra Cansever Mutlu
- Biomaterials Research Group, School of Metallurgy and Materials, College of Engineering and Physical Science, University of Birmingham, Birmingham B15 2TT, UK;
| | - Zubair Ahmed
- Neuroscience & Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Edgbaston B15 2TT, UK
| | - Besim Ben-Nissan
- Translational Biomaterials and Medicine Group, School of Life Sciences, University of Technology Sydney, P.O. Box 123, Broadway, NSW 2007, Australia;
| | - Artemis Stamboulis
- Biomaterials Research Group, School of Metallurgy and Materials, College of Engineering and Physical Science, University of Birmingham, Birmingham B15 2TT, UK;
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5
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Jenkner S, Clark JM, Gronthos S, O’Hare Doig RL. Molars to Medicine: A Focused Review on the Pre-Clinical Investigation and Treatment of Secondary Degeneration following Spinal Cord Injury Using Dental Stem Cells. Cells 2024; 13:817. [PMID: 38786039 PMCID: PMC11119219 DOI: 10.3390/cells13100817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/01/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Spinal cord injury (SCI) can result in the permanent loss of mobility, sensation, and autonomic function. Secondary degeneration after SCI both initiates and propagates a hostile microenvironment that is resistant to natural repair mechanisms. Consequently, exogenous stem cells have been investigated as a potential therapy for repairing and recovering damaged cells after SCI and other CNS disorders. This focused review highlights the contributions of mesenchymal (MSCs) and dental stem cells (DSCs) in attenuating various secondary injury sequelae through paracrine and cell-to-cell communication mechanisms following SCI and other types of neurotrauma. These mechanistic events include vascular dysfunction, oxidative stress, excitotoxicity, apoptosis and cell loss, neuroinflammation, and structural deficits. The review of studies that directly compare MSC and DSC capabilities also reveals the superior capabilities of DSC in reducing the effects of secondary injury and promoting a favorable microenvironment conducive to repair and regeneration. This review concludes with a discussion of the current limitations and proposes improvements in the future assessment of stem cell therapy through the reporting of the effects of DSC viability and DSC efficacy in attenuating secondary damage after SCI.
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Affiliation(s)
- Sandra Jenkner
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, North Terrace, Adelaide 5000, Australia; (S.J.); (S.G.)
- Neil Sachse Centre for Spinal Cord Research, Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, Australia;
| | - Jillian Mary Clark
- Neil Sachse Centre for Spinal Cord Research, Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, Australia;
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, North Terrace, Adelaide 5000, Australia
| | - Stan Gronthos
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, North Terrace, Adelaide 5000, Australia; (S.J.); (S.G.)
- Mesenchymal Stem Cell Laboratory, Precision Medicine Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, Australia
| | - Ryan Louis O’Hare Doig
- Neil Sachse Centre for Spinal Cord Research, Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, Australia;
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, North Terrace, Adelaide 5000, Australia
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6
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Mauker P, Beckmann D, Kitowski A, Heise C, Wientjens C, Davidson AJ, Wanderoy S, Fabre G, Harbauer AB, Wood W, Wilhelm C, Thorn-Seshold J, Misgeld T, Kerschensteiner M, Thorn-Seshold O. Fluorogenic Chemical Probes for Wash-free Imaging of Cell Membrane Damage in Ferroptosis, Necrosis, and Axon Injury. J Am Chem Soc 2024. [PMID: 38592946 DOI: 10.1021/jacs.3c07662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Selectively labeling cells with damaged membranes is needed not only for identifying dead cells in culture, but also for imaging membrane barrier dysfunction in pathologies in vivo. Most membrane permeability stains are permanently colored or fluorescent dyes that need washing to remove their non-uptaken extracellular background and reach good image contrast. Others are DNA-binding environment-dependent fluorophores, which lack design modularity, have potential toxicity, and can only detect permeabilization of cell volumes containing a nucleus (i.e., cannot delineate damaged volumes in vivo nor image non-nucleated cell types or compartments). Here, we develop modular fluorogenic probes that reveal the whole cytosolic volume of damaged cells, with near-zero background fluorescence so that no washing is needed. We identify a specific disulfonated fluorogenic probe type that only enters cells with damaged membranes, then is enzymatically activated and marks them. The esterase probe MDG1 is a reliable tool to reveal live cells that have been permeabilized by biological, biochemical, or physical membrane damage, and it can be used in multicolor microscopy. We confirm the modularity of this approach by also adapting it for improved hydrolytic stability, as the redox probe MDG2. We conclude by showing the unique performance of MDG probes in revealing axonal membrane damage (which DNA fluorogens cannot achieve) and in discriminating damage on a cell-by-cell basis in embryos in vivo. The MDG design thus provides powerful modular tools for wash-free in vivo imaging of membrane damage, and indicates how designs may be adapted for selective delivery of drug cargoes to these damaged cells: offering an outlook from selective diagnosis toward therapy of membrane-compromised cells in disease.
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Affiliation(s)
- Philipp Mauker
- Department of Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstr. 7, 81377 Munich, Germany
| | - Daniela Beckmann
- Institute of Clinical Neuroimmunology, LMU University Hospital, Ludwig-Maximilians University of Munich, Marchioninistr. 15, 81377 Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians University of Munich, Grosshaderner Strasse 9, 82152 Martinsried, Germany
| | - Annabel Kitowski
- Department of Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstr. 7, 81377 Munich, Germany
| | - Constanze Heise
- Department of Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstr. 7, 81377 Munich, Germany
| | - Chantal Wientjens
- Immunopathology Unit, Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Andrew J Davidson
- Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh BioQuarter, 5 Little France Drive, Edinburgh EH16 4UU, U.K
| | - Simone Wanderoy
- University Hospital, Technical University of Munich, Ismaninger Straße 22, 81675 Munich, Germany
- Max Planck Institute for Biological Intelligence, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Gabin Fabre
- Pharmacology & Transplantation, UMR 1248 INSERM, University of Limoges, 87000 Limoges, France
| | - Angelika B Harbauer
- Max Planck Institute for Biological Intelligence, Am Klopferspitz 18, 82152 Martinsried, Germany
- Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Strasse 17, 81377 Munich, Germany
- Institute of Neuronal Cell Biology, Technical University of Munich, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Will Wood
- Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh BioQuarter, 5 Little France Drive, Edinburgh EH16 4UU, U.K
| | - Christoph Wilhelm
- Immunopathology Unit, Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Julia Thorn-Seshold
- Department of Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstr. 7, 81377 Munich, Germany
| | - Thomas Misgeld
- Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Strasse 17, 81377 Munich, Germany
- Institute of Neuronal Cell Biology, Technical University of Munich, Biedersteiner Straße 29, 80802 Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen-Strasse 17, 81377 Munich, Germany
| | - Martin Kerschensteiner
- Institute of Clinical Neuroimmunology, LMU University Hospital, Ludwig-Maximilians University of Munich, Marchioninistr. 15, 81377 Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians University of Munich, Grosshaderner Strasse 9, 82152 Martinsried, Germany
- Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Strasse 17, 81377 Munich, Germany
| | - Oliver Thorn-Seshold
- Department of Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstr. 7, 81377 Munich, Germany
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7
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Cheng YT, Lett KM, Xu C, Schaffer CB. Three-photon excited fluorescence microscopy enables imaging of blood flow, neural structure and inflammatory response deep into mouse spinal cord in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.04.588110. [PMID: 38617307 PMCID: PMC11014502 DOI: 10.1101/2024.04.04.588110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Nonlinear optical microscopy enables non-invasive imaging in scattering samples with cellular resolution. The spinal cord connects the brain with the periphery and governs fundamental behaviors such as locomotion and somatosensation. Because of dense myelination on the dorsal surface, imaging to the spinal grey matter is challenging, even with two-photon microscopy. Here we show that three-photon excited fluorescence (3PEF) microscopy enables multicolor imaging at depths of up to ~550 μm into the mouse spinal cord, in vivo. We quantified blood flow across vessel types along the spinal vascular network. We then followed the response of neurites and microglia after occlusion of a surface venule, where we observed depth-dependent structural changes in neurites and interactions of perivascular microglia with vessel branches upstream from the clot. This work establishes that 3PEF imaging enables studies of functional dynamics and cell type interactions in the top 550 μm of the murine spinal cord, in vivo.
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Affiliation(s)
- Yu-Ting Cheng
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
| | - Kawasi M. Lett
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Chris Xu
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA
| | - Chris B. Schaffer
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
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8
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Liu J, Qi L, Bao S, Yan F, Chen J, Yu S, Dong C. The acute spinal cord injury microenvironment and its impact on the homing of mesenchymal stem cells. Exp Neurol 2024; 373:114682. [PMID: 38199509 DOI: 10.1016/j.expneurol.2024.114682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/08/2023] [Accepted: 01/02/2024] [Indexed: 01/12/2024]
Abstract
Spinal cord injury (SCI) is a highly debilitating condition that inflicts devastating harm on the lives of affected individuals, underscoring the urgent need for effective treatments. By activating inflammatory cells and releasing inflammatory factors, the secondary injury response creates an inflammatory microenvironment that ultimately determines whether neurons will undergo necrosis or regeneration. In recent years, mesenchymal stem cells (MSCs) have garnered increasing attention for their therapeutic potential in SCI. MSCs not only possess multipotent differentiation capabilities but also have homing abilities, making them valuable as carriers and mediators of therapeutic agents. The inflammatory microenvironment induced by SCI recruits MSCs to the site of injury through the release of various cytokines, chemokines, adhesion molecules, and enzymes. However, this mechanism has not been previously reported. Thus, a comprehensive exploration of the molecular mechanisms and cellular behaviors underlying the interplay between the inflammatory microenvironment and MSC homing is crucial. Such insights have the potential to provide a better understanding of how to harness the therapeutic potential of MSCs in treating inflammatory diseases and facilitating injury repair. This review aims to delve into the formation of the inflammatory microenvironment and how it influences the homing of MSCs.
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Affiliation(s)
- Jinyi Liu
- Department of Anatomy, Medical College of Nantong University, Nantong, China
| | - Longju Qi
- Affiliated Nantong Hospital 3 of Nantong University, Nantong, China
| | - Shengzhe Bao
- Department of Anatomy, Medical College of Nantong University, Nantong, China
| | - Fangsu Yan
- Department of Anatomy, Medical College of Nantong University, Nantong, China
| | - Jiaxi Chen
- Department of Anatomy, Medical College of Nantong University, Nantong, China
| | - Shumin Yu
- Department of Anatomy, Medical College of Nantong University, Nantong, China
| | - Chuanming Dong
- Department of Anatomy, Medical College of Nantong University, Nantong, China; Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China.
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Dogan EO, Bouley J, Zhong J, Harkins AL, Keeler AM, Bosco DA, Brown RH, Henninger N. Genetic ablation of Sarm1 attenuates expression and mislocalization of phosphorylated TDP-43 after mouse repetitive traumatic brain injury. Acta Neuropathol Commun 2023; 11:206. [PMID: 38124145 PMCID: PMC10731794 DOI: 10.1186/s40478-023-01709-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
Traumatic brain injury (TBI), particularly when moderate-to-severe and repetitive, is a strong environmental risk factor for several progressive neurodegenerative disorders. Mislocalization and deposition of transactive response DNA binding protein 43 (TDP-43) has been reported in both TBI and TBI-associated neurodegenerative diseases. It has been hypothesized that axonal pathology, an early event after TBI, may promote TDP-43 dysregulation and serve as a trigger for neurodegenerative processes. We sought to determine whether blocking the prodegenerative Sarm1 (sterile alpha and TIR motif containing 1) axon death pathway attenuates TDP-43 pathology after TBI. We subjected 111 male Sarm1 wild type, hemizygous, and knockout mice to moderate-to-severe repetitive TBI (rTBI) using a previously established injury paradigm. We conducted serial neurological assessments followed by histological analyses (NeuN, MBP, Iba-1, GFAP, pTDP-43, and AT8) at 1 month after rTBI. Genetic ablation of the Sarm1 gene attenuated the expression and mislocalization of phosphorylated TDP-43 (pTDP-43) and accumulation of pTau. In addition, Sarm1 knockout mice had significantly improved cortical neuronal and axonal integrity, functional deficits, and improved overall survival after rTBI. In contrast, removal of one Sarm1 allele delayed, but did not prevent, neurological deficits and neuroaxonal loss. Nevertheless, Sarm1 haploinsufficient mice showed significantly less microgliosis, pTDP-43 pathology, and pTau accumulation when compared to wild type mice. These data indicate that the Sarm1-mediated prodegenerative pathway contributes to pathogenesis in rTBI including the pathological accumulation of pTDP-43. This suggests that anti-Sarm1 therapeutics are a viable approach for preserving neurological function after moderate-to-severe rTBI.
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Affiliation(s)
- Elif O Dogan
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
| | - James Bouley
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
| | - Jianjun Zhong
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Ashley L Harkins
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
- Graduate Program in Neuroscience, Morningside Graduate School of Biomedical Sciences, University of Massachusetts Chan Medical School, Worcester, MA, 01655, USA
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| | - Allison M Keeler
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Pediatrics, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- NeuroNexus Institute, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| | - Daryl A Bosco
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
| | - Robert H Brown
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
| | - Nils Henninger
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA.
- Department of Psychiatry, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA.
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10
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Ames S, Adams K, Geisen ME, Stirling DP. Ca 2+-induced myelin pathology precedes axonal spheroid formation and is mediated in part by store-operated Ca 2+ entry after spinal cord injury. Neural Regen Res 2023; 18:2720-2726. [PMID: 37449636 DOI: 10.4103/1673-5374.373656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
The formation of axonal spheroid is a common feature following spinal cord injury. To further understand the source of Ca2+ that mediates axonal spheroid formation, we used our previously characterized ex vivo mouse spinal cord model that allows precise perturbation of extracellular Ca2+. We performed two-photon excitation imaging of spinal cords isolated from Thy1YFP+ transgenic mice and applied the lipophilic dye, Nile red, to record dynamic changes in dorsal column axons and their myelin sheaths respectively. We selectively released Ca2+ from internal stores using the Ca2+ ionophore ionomycin in the presence or absence of external Ca2+. We reported that ionomycin dose-dependently induces pathological changes in myelin and pronounced axonal spheroid formation in the presence of normal 2 mM Ca2+ artificial cerebrospinal fluid. In contrast, removal of external Ca2+ significantly decreased ionomycin-induced myelin and axonal spheroid formation at 2 hours but not at 1 hour after treatment. Using mice that express a neuron-specific Ca2+ indicator in spinal cord axons, we confirmed that ionomycin induced significant increases in intra-axonal Ca2+, but not in the absence of external Ca2+. Periaxonal swelling and the resultant disruption in the axo-myelinic interface often precedes and is negatively correlated with axonal spheroid formation. Pretreatment with YM58483 (500 nM), a well-established blocker of store-operated Ca2+ entry, significantly decreased myelin injury and axonal spheroid formation. Collectively, these data reveal that ionomycin-induced depletion of internal Ca2+ stores and subsequent external Ca2+ entry through store-operated Ca2+ entry contributes to pathological changes in myelin and axonal spheroid formation, providing new targets to protect central myelinated fibers.
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Affiliation(s)
- Spencer Ames
- Kentucky Spinal Cord Injury Research Center; Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Kia Adams
- Kentucky Spinal Cord Injury Research Center; Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Mariah E Geisen
- Kentucky Spinal Cord Injury Research Center; Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY, USA
| | - David P Stirling
- Kentucky Spinal Cord Injury Research Center; Department of Neurological Surgery; Anatomical Sciences and Neurobiology; Microbiology and Immunology, University of Louisville, School of Medicine, Louisville, KY, USA
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McCracken S, Fitzpatrick MJ, Hall AL, Wang Z, Kerschensteiner D, Morgan JL, Williams PR. Diversity in homeostatic calcium set points predicts retinal ganglion cell survival following optic nerve injury in vivo. Cell Rep 2023; 42:113165. [PMID: 37751356 PMCID: PMC10947246 DOI: 10.1016/j.celrep.2023.113165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 06/29/2023] [Accepted: 09/07/2023] [Indexed: 09/28/2023] Open
Abstract
Retinal ganglion cell (RGC) degeneration drives vision loss in blinding conditions. RGC death is often triggered by axon degeneration in the optic nerve. Here, we study the contributions of dynamic and homeostatic Ca2+ levels to RGC death from axon injury. We find that axonal Ca2+ elevations from optic nerve injury do not propagate over distance or reach RGC somas, and acute and chronic Ca2+ dynamics do not affect RGC survival. Instead, we discover that baseline Ca2+ levels vary widely between RGCs and predict their survival after axon injury, and that lowering these levels reduces RGC survival. Further, we find that well-surviving RGC types have higher baseline Ca2+ levels than poorly surviving types. Finally, we observe considerable variation in the baseline Ca2+ levels of different RGCs of the same type, which are predictive of within-type differences in survival.
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Affiliation(s)
- Sean McCracken
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Graduate Program in Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael J Fitzpatrick
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Graduate Program in Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Medical Scientist Training Program, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Allison L Hall
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Postbaccalaureate Program in Developmental Biology & Regenerative Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zelun Wang
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Graduate Program in Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Medical Scientist Training Program, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Daniel Kerschensteiner
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Josh L Morgan
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Philip R Williams
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA.
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12
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Ahmed RU, Medina‐Aguinaga D, Adams S, Knibbe CA, Morgan M, Gibson D, Kim J, Sharma M, Chopra M, Davison S, Sherwood LC, Negahdar M, Bert R, Ugiliweneza B, Hubscher C, Budde MD, Xu J, Boakye M. Predictive values of spinal cord diffusion magnetic resonance imaging to characterize outcomes after contusion injury. Ann Clin Transl Neurol 2023; 10:1647-1661. [PMID: 37501362 PMCID: PMC10502634 DOI: 10.1002/acn3.51855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/21/2023] [Accepted: 07/09/2023] [Indexed: 07/29/2023] Open
Abstract
OBJECTIVES To explore filtered diffusion-weighted imaging (fDWI), in comparison with conventional magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI), as a predictor for long-term locomotor and urodynamic (UD) outcomes in Yucatan minipig model of spinal cord injury (SCI). Additionally, electrical conductivity of neural tissue using D-waves above and below the injury was measured to assess correlations between fDWI and D-waves data. METHODS Eleven minipigs with contusion SCI at T8-T10 level underwent MRI at 3T 4 h. post-SCI. Parameters extracted from region of interest analysis included Daxial from fDWI at injury site, fractional anisotropy and radial diffusivity from DTI above the injury site along with measures of edema length and cord width at injury site from T2 -weighted images. Locomotor recovery was assessed pre- and weekly post-SCI through porcine thoracic injury behavior scale (PTIBS) and UD were performed pre- and at 12 weeks of SCI. D-waves latency and amplitude differences were recorded before and immediately after SCI. RESULTS Two groups of pigs were found based on the PTIBS at week 12 (p < 0.0001) post-SCI and were labeled "poor" and "good" recovery. D-waves amplitude decreased below injury and increased above injury. UD outcomes pre/post SCI changed significantly. Conventional MRI metrics from T2 -weighted images were significantly correlated with diffusion MRI metrics. Daxial at injury epicenter was diminished by over 50% shortly after SCI, and it differentiated between good and poor locomotor recovery and UD outcomes. INTERPRETATION Similar to small animal studies, fDWI from acute imaging after SCI is a promising predictor for functional outcomes in large animals.
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Affiliation(s)
- Rakib Uddin Ahmed
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research CenterUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Daniel Medina‐Aguinaga
- Department of Anatomical Sciences and NeurobiologyUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Shawns Adams
- Department of NeurosurgeryDuke UniversityRaleighNorth CarolinaUSA
| | - Chase A. Knibbe
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research CenterUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Monique Morgan
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research CenterUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Destiny Gibson
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research CenterUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Joo‐won Kim
- Department of RadiologyBaylor College of MedicineHoustonTexasUSA
- Department of PsychiatryBaylor College of MedicineHoustonTexasUSA
| | - Mayur Sharma
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research CenterUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Manpreet Chopra
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research CenterUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Steven Davison
- Comparative Medicine Research UnitUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Leslie C. Sherwood
- Comparative Medicine Research UnitUniversity of LouisvilleLouisvilleKentuckyUSA
| | - M.J. Negahdar
- Department of RadiologyUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Robert Bert
- Department of RadiologyUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Beatrice Ugiliweneza
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research CenterUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Charles Hubscher
- Department of Anatomical Sciences and NeurobiologyUniversity of LouisvilleLouisvilleKentuckyUSA
| | - Matthew D. Budde
- Department of NeurosurgeryMedical College of WisconsinMilwaukeeWisconsinUSA
- Clement J. Zablocki Veterans Affairs Medical CenterMilwaukeeWisconsinUSA
| | - Junqian Xu
- Department of RadiologyBaylor College of MedicineHoustonTexasUSA
- Department of PsychiatryBaylor College of MedicineHoustonTexasUSA
| | - Maxwell Boakye
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research CenterUniversity of LouisvilleLouisvilleKentuckyUSA
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13
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Meyer BP, Lee SY, Kurpad SN, Budde MD. Differential Trajectory of Diffusion and Perfusion Magnetic Resonance Imaging of Rat Spinal Cord Injury. J Neurotrauma 2023; 40:918-930. [PMID: 36226406 PMCID: PMC10150724 DOI: 10.1089/neu.2022.0283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Traumatic spinal cord injury causes rapid neuronal and vascular injury, and predictive biomarkers are needed to facilitate acute patient management. This study examined the progression of magnetic resonance imaging (MRI) biomarkers after spinal cord injury and their ability to predict long-term neurological outcomes in a rodent model, with an emphasis on diffusion-weighted imaging (DWI) markers of axonal injury and perfusion-weighted imaging of spinal cord blood flow (SCBF). Adult Sprague-Dawley rats received a cervical contusion injury of varying severity (injured = 30, sham = 9). MRI at 4 h, 48-h, and 12-weeks post-injury included T1, T2, perfusion, and DWI. Locomotor outcome was assessed up to 12 weeks post-injury. At 4 h, the deficit in SCBF was larger than the DWI lesion, and although SCBF partially recovered by 48 h, the DWI lesion expanded. At 4 h, the volume of the SCBF deficit (R2 = 0.56, padj < 0.01) was significantly correlated with 12-week locomotor outcome, whereas DWI (R2 = 0.30, padj < 0.01) was less predictive of outcome. At 48 h, SCBF (R2 = 0.41, padj < 0.01) became less associated with outcome, and DWI (R2 = 0.38, padj < 0.01) lesion volume became more closely related to outcome. Spinal cord perfusion has unique spatiotemporal dynamics compared with diffusion measures of axonal damage and highlights the importance of acute perfusion abnormalities. Perfusion and diffusion offer complementary and clinically relevant insight into physiological and structural abnormalities following spinal cord injury beyond those afforded by T1 or T2 contrasts.
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Affiliation(s)
- Briana P. Meyer
- Neuroscience Doctoral Program, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Seung-Yi Lee
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Shekar N. Kurpad
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Matthew D. Budde
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Clement J. Zablocki Veterans' Affairs Medical Center, Milwaukee, Wisconsin, USA
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14
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Cunningham ME, McGonigal R, Barrie JA, Campbell CI, Yao D, Willison HJ. Axolemmal nanoruptures arising from paranodal membrane injury induce secondary axon degeneration in murine Guillain-Barré syndrome. J Peripher Nerv Syst 2023; 28:17-31. [PMID: 36710500 PMCID: PMC10947354 DOI: 10.1111/jns.12532] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023]
Abstract
The major determinant of poor outcome in Guillain-Barré syndrome (GBS) is axonal degeneration. Pathways leading to primary axonal injury in the motor axonal variant are well established, whereas mechanisms of secondary axonal injury in acute inflammatory demyelinating polyneuropathy (AIDP) are unknown. We recently developed an autoantibody-and complement-mediated model of murine AIDP, in which prominent injury to glial membranes at the node of Ranvier results in severe disruption to paranodal components. Acutely, axonal integrity was maintained, but over time secondary axonal degeneration occurred. Herein, we describe the differential mechanisms underlying acute glial membrane injury and secondary axonal injury in this model. Ex vivo nerve-muscle explants were injured for either acute or extended periods with an autoantibody-and complement-mediated injury to glial paranodal membranes. This model was used to test several possible mechanisms of axon degeneration including calpain activation, and to monitor live axonal calcium signalling. Glial calpains induced acute disruption of paranodal membrane proteins in the absence of discernible axonal injury. Over time, we observed progressive axonal degeneration which was markedly attenuated by axon-specific calpain inhibition. Injury was unaffected by all other tested methods of protection. Trans-axolemmal diffusion of fluorescent proteins and live calcium imaging studies indirectly demonstrated the presence of nanoruptures in the axon membrane. This study outlines one mechanism by which secondary axonal degeneration arises in the AIDP variant of GBS where acute paranodal loop injury is prominent. The data also support the development of calpain inhibitors to attenuate both primary and secondary axonal degeneration in GBS.
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Affiliation(s)
| | - Rhona McGonigal
- School of Infection & ImmunityUniversity of GlasgowGlasgowUK
| | | | | | - Denggao Yao
- School of Infection & ImmunityUniversity of GlasgowGlasgowUK
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15
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McGonigal R, Cunningham ME, Smyth D, Chou M, Barrie JA, Wilkie A, Campbell C, Saatman KE, Lunn M, Willison HJ. The endogenous calpain inhibitor calpastatin attenuates axon degeneration in murine Guillain-Barré syndrome. J Peripher Nerv Syst 2023; 28:4-16. [PMID: 36335586 PMCID: PMC10947122 DOI: 10.1111/jns.12520] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/24/2022] [Accepted: 10/30/2022] [Indexed: 11/08/2022]
Abstract
Axon degeneration accounts for the poor clinical outcome in Guillain-Barré syndrome (GBS), yet no treatments target this key pathogenic stage. Animal models demonstrate anti-ganglioside antibodies (AGAb) induce axolemmal complement pore formation through which calcium flux activates the intra-axonal calcium-dependent proteases, calpains. We previously showed protection of axonal components using soluble calpain inhibitors in ex vivo GBS mouse models, and herein, we assess the potential of axonally-restricted calpain inhibition as a neuroprotective therapy operating in vivo. Using transgenic mice that over-express the endogenous human calpain inhibitor calpastatin (hCAST) neuronally, we assessed distal motor nerve integrity in our established GBS models. We induced immune-mediated injury with monoclonal AGAb plus a source of human complement. The calpain substrates neurofilament and AnkyrinG, nerve structural proteins, were assessed by immunolabelling and in the case of neurofilament, by single-molecule arrays (Simoa). As the distal intramuscular portion of the phrenic nerve is prominently targeted in our in vivo model, respiratory function was assessed by whole-body plethysmography as the functional output in the acute and extended models. hCAST expression protects distal nerve structural integrity both ex and in vivo, as shown by attenuation of neurofilament breakdown by immunolabelling and Simoa. In an extended in vivo model, while mice still initially undergo respiratory distress owing to acute conduction failure, the recovery phase was accelerated by hCAST expression. Axonal calpain inhibition can protect the axonal integrity of the nerve in an in vivo GBS paradigm and hasten recovery. These studies reinforce the strong justification for developing further animal and human clinical studies using exogenous calpain inhibitors.
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Affiliation(s)
- Rhona McGonigal
- School of Infection & ImmunityUniversity of GlasgowGlasgowUnited Kingdom
| | | | - Duncan Smyth
- National Hospital for Neurology and Neurosurgery, Centre for Neuromuscular DiseasesUniversity College LondonLondonUnited Kingdom
| | - Michael Chou
- National Hospital for Neurology and Neurosurgery, Centre for Neuromuscular DiseasesUniversity College LondonLondonUnited Kingdom
| | - Jennifer A. Barrie
- School of Infection & ImmunityUniversity of GlasgowGlasgowUnited Kingdom
| | - Andrew Wilkie
- School of Infection & ImmunityUniversity of GlasgowGlasgowUnited Kingdom
| | - Clare Campbell
- School of Infection & ImmunityUniversity of GlasgowGlasgowUnited Kingdom
| | - Kathryn E. Saatman
- Department of Physiology, Spinal Cord and Brain Injury Research CenterUniversity of KentuckyLexingtonKYUSA
| | - Michael Lunn
- National Hospital for Neurology and Neurosurgery, Centre for Neuromuscular DiseasesUniversity College LondonLondonUnited Kingdom
| | - Hugh J. Willison
- School of Infection & ImmunityUniversity of GlasgowGlasgowUnited Kingdom
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16
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Herwerth M, Wyss M. Axon degeneration: new actor in an old play. Neural Regen Res 2023; 18:547-548. [DOI: 10.4103/1673-5374.350200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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17
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The role of PI3K/Akt signalling pathway in spinal cord injury. Biomed Pharmacother 2022; 156:113881. [DOI: 10.1016/j.biopha.2022.113881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 10/13/2022] [Accepted: 10/13/2022] [Indexed: 11/18/2022] Open
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18
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Patel AA, Sakurai A, Himmel NJ, Cox DN. Modality specific roles for metabotropic GABAergic signaling and calcium induced calcium release mechanisms in regulating cold nociception. Front Mol Neurosci 2022; 15:942548. [PMID: 36157080 PMCID: PMC9502035 DOI: 10.3389/fnmol.2022.942548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
Calcium (Ca2+) plays a pivotal role in modulating neuronal-mediated responses to modality-specific sensory stimuli. Recent studies in Drosophila reveal class III (CIII) multidendritic (md) sensory neurons function as multimodal sensors regulating distinct behavioral responses to innocuous mechanical and nociceptive thermal stimuli. Functional analyses revealed CIII-mediated multimodal behavioral output is dependent upon activation levels with stimulus-evoked Ca2+ displaying relatively low vs. high intracellular levels in response to gentle touch vs. noxious cold, respectively. However, the mechanistic bases underlying modality-specific differential Ca2+ responses in CIII neurons remain incompletely understood. We hypothesized that noxious cold-evoked high intracellular Ca2+ responses in CIII neurons may rely upon Ca2+ induced Ca2+ release (CICR) mechanisms involving transient receptor potential (TRP) channels and/or metabotropic G protein coupled receptor (GPCR) activation to promote cold nociceptive behaviors. Mutant and/or CIII-specific knockdown of GPCR and CICR signaling molecules [GABA B -R2, Gαq, phospholipase C, ryanodine receptor (RyR) and Inositol trisphosphate receptor (IP3R)] led to impaired cold-evoked nociceptive behavior. GPCR mediated signaling, through GABA B -R2 and IP3R, is not required in CIII neurons for innocuous touch evoked behaviors. However, CICR via RyR is required for innocuous touch-evoked behaviors. Disruptions in GABA B -R2, IP3R, and RyR in CIII neurons leads to significantly lower levels of cold-evoked Ca2+ responses indicating GPCR and CICR signaling mechanisms function in regulating Ca2+ release. CIII neurons exhibit bipartite cold-evoked firing patterns, where CIII neurons burst during rapid temperature change and tonically fire during steady state cold temperatures. GABA B -R2 knockdown in CIII neurons resulted in disorganized firing patterns during cold exposure. We further demonstrate that application of GABA or the GABA B specific agonist baclofen potentiates cold-evoked CIII neuron activity. Upon ryanodine application, CIII neurons exhibit increased bursting activity and with CIII-specific RyR knockdown, there is an increase in cold-evoked tonic firing and decrease in bursting. Lastly, our previous studies implicated the TRPP channel Pkd2 in cold nociception, and here, we show that Pkd2 and IP3R genetically interact to specifically regulate cold-evoked behavior, but not innocuous mechanosensation. Collectively, these analyses support novel, modality-specific roles for metabotropic GABAergic signaling and CICR mechanisms in regulating intracellular Ca2+ levels and cold-evoked behavioral output from multimodal CIII neurons.
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Affiliation(s)
| | | | | | - Daniel N. Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
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19
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Kalluri SR, Srivastava R, Kenet S, Tanti GK, Dornmair K, Bennett JL, Misgeld T, Hemmer B, Wyss MT, Herwerth M. P2R Inhibitors Prevent Antibody-Mediated Complement Activation in an Animal Model of Neuromyelitis Optica : P2R Inhibitors Prevent Autoantibody Injury. Neurotherapeutics 2022; 19:1603-1616. [PMID: 35821382 PMCID: PMC9606199 DOI: 10.1007/s13311-022-01269-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2022] [Indexed: 11/28/2022] Open
Abstract
Purinergic 2 receptors (P2Rs) contribute to disease-related immune cell signaling and are upregulated in various pathological settings, including neuroinflammation. P2R inhibitors have been used to treat inflammatory diseases and can protect against complement-mediated cell injury. However, the mechanisms behind these anti-inflammatory properties of P2R inhibitors are not well understood, and their potential in CNS autoimmunity is underexplored. Here, we tested the effects of P2R inhibitors on glial toxicity in a mouse model of neuromyelitis optica spectrum disorder (NMOSD). NMOSD is a destructive CNS autoimmune disorder, in which autoantibodies against astrocytic surface antigen Aquaporin 4 (AQP4) mediate complement-dependent loss of astrocytes. Using two-photon microscopy in vivo, we found that various classes of P2R inhibitors prevented AQP4-IgG/complement-dependent astrocyte death. In vitro, these drugs inhibited the binding of AQP4-IgG or MOG-IgG to their antigen in a dose-dependent manner. Size-exclusion chromatography and circular dichroism spectroscopy revealed a partial unfolding of antibodies in the presence of various P2R inhibitors, suggesting a shared interference with IgG antibodies leading to their conformational change. Our study demonstrates that P2R inhibitors can disrupt complement activation by direct interaction with IgG. This mechanism is likely to influence the role of P2R inhibitors in autoimmune disease models and their therapeutic impact in human disease.
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Affiliation(s)
- Sudhakar Reddy Kalluri
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
| | - Rajneesh Srivastava
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
| | - Selin Kenet
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität, Munich, Germany
| | - Goutam K Tanti
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
| | - Klaus Dornmair
- Institute of Clinical Neuroimmunology, University Hospital and Biomedical Center, LMU Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Jeffrey L Bennett
- Departments of Neurology and Ophthalmology, Programs in Neuroscience and Immunology, University of Colorado School of Medicine, Colorado, USA
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Bernhard Hemmer
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Matthias T Wyss
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University Zurich and ETH Zurich, Zurich, Switzerland
| | - Marina Herwerth
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany.
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany.
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, University Zurich and ETH Zurich, Zurich, Switzerland.
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20
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Cunningham ME, McGonigal R, Barrie JA, Yao D, Willison HJ. Real time imaging of intra-axonal calcium flux in an explant mouse model of axonal Guillain-Barré syndrome. Exp Neurol 2022; 355:114127. [PMID: 35640716 PMCID: PMC7614209 DOI: 10.1016/j.expneurol.2022.114127] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/12/2022] [Accepted: 05/26/2022] [Indexed: 11/19/2022]
Abstract
The acute motor axonal variant of Guillain-Barré syndrome is associated with the attack of motor axons by anti-ganglioside antibodies which activate complement on the axonal plasma membrane. Animal models have indirectly implicated complement pore-mediated calcium influx as a trigger of axonal damage, through the activation of the protease calpain. However, this calcium influx has never been imaged directly. Herein we describe a method to detect changes in intra-axonal calcium in an ex vivo mouse model of axonal Guillain-Barré syndrome and describe the influence of calcium on axonal injury and the effects of calpain inhibition on axonal outcome. Using ex vivo nerve-muscle explants from Thy1-TNXXL mice which axonally express a genetically encoded calcium indicator, we studied the effect of the binding and activation of complement by an anti-GD1b ganglioside antibody which targets the motor axon. Using live multiphoton imaging, we found that a wave of calcium influx extends retrogradely from the motor nerve terminal as far back as the large bundles within the muscle explant. Despite terminal complement pores being detectable only at the motor nerve terminal and, to a lesser degree, the most distal node of Ranvier, disruption of axonal proteins occurred at more proximal sites implicating the intra-axonal calcium wave. Morphological analysis indicated two different types of calcium-induced changes: acutely, distal axons showed swelling and breakdown at sites where complement pores were present. Distally, in areas of raised calcium which lacked detectable complement pores, axons developed a spindly, vacuolated appearance suggestive of early signs of degeneration. All morphological changes were prevented with treatment with a calpain inhibitor. This is the first investigation of axonal calcium dynamics in a mouse model of Guillain-Barré syndrome and demonstrates the proximal reach of calcium influx following an injury which is confined to the most distal parts of the motor axon. We also demonstrate that calpain inhibition remains a promising candidate for both acute and sub-acute consequences of calcium-induced calpain activation.
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Affiliation(s)
- Madeleine E Cunningham
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Rhona McGonigal
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Jennifer A Barrie
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Denggao Yao
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Hugh J Willison
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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21
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Xiao S, Zhong N, Yang Q, Li A, Tong W, Zhang Y, Yao G, Wang S, Liu J, Liu Z. Aucubin promoted neuron functional recovery by suppressing inflammation and neuronal apoptosis in a spinal cord injury model. Int Immunopharmacol 2022; 111:109163. [PMID: 35994851 DOI: 10.1016/j.intimp.2022.109163] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/27/2022] [Accepted: 08/11/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Spinal cord injury (SCI) can cause severe motor impairment. Post-SCI treatment has focused primarily on secondary injury, with neuroinflammation and neuronal apoptosis as the primary therapeutic targets. Aucubin (Au), a Chinese herbal medicine, exerts anti-inflammatory and neuroprotective effects. The therapeutic effects of Aucubin in SCI have not been reported. METHODS In this study, we carried out an in vivo SCI model and a series of in vitro experiments to explore the therapeutic effect of Aucubin. Western Blotting and immunofluorescence were used to study the effect of Aucubin on microglial polarization and neuronal apoptosis and its underlying mechanism. RESULTS We found that Aucubin can promote axonal regeneration by reducing neuroinflammation and neuronal apoptosis, which is beneficial to motor recovery after spinal cord injury in rats. Our further in vitro experiments showed that Aucubin can activate the toll-like receptor 4 (TLR4)/myeloid differentiation protein-88 (MyD88)/IκBα/nuclear factor kappa B (NF-κB) signaling pathway to reduce neuroinflammation and reverse mitochondrial dysfunction to reduce neuronal apoptosis. CONCLUSIONS In summary, these results suggest that Aucubin may ameliorate secondary injury after SCI by reducing neuroinflammation and neuronal apoptosis. Therefore, Au may be a promising post-SCI therapeutic drug.
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Affiliation(s)
- Shining Xiao
- Medical Innovation Center, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China; Institute of Spine and Spinal Cord, Nanchang University, Nanchang 330006, China; The First Clinical Medical College of Nanchang University, Nanchang 330006, China
| | - Nanshan Zhong
- Medical Innovation Center, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China; Institute of Spine and Spinal Cord, Nanchang University, Nanchang 330006, China; The First Clinical Medical College of Nanchang University, Nanchang 330006, China
| | - Quanming Yang
- Department of Orthopedics, Ningbo First Hospital, Ningbo 315000, China
| | - Anan Li
- Medical Innovation Center, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China; Institute of Spine and Spinal Cord, Nanchang University, Nanchang 330006, China; The First Clinical Medical College of Nanchang University, Nanchang 330006, China
| | - Weilai Tong
- Medical Innovation Center, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China; Institute of Spine and Spinal Cord, Nanchang University, Nanchang 330006, China; The First Clinical Medical College of Nanchang University, Nanchang 330006, China
| | - Yu Zhang
- Medical Innovation Center, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China; Institute of Spine and Spinal Cord, Nanchang University, Nanchang 330006, China; The First Clinical Medical College of Nanchang University, Nanchang 330006, China
| | - Geliang Yao
- Medical Innovation Center, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China; Institute of Spine and Spinal Cord, Nanchang University, Nanchang 330006, China; The First Clinical Medical College of Nanchang University, Nanchang 330006, China
| | - Shijiang Wang
- Medical Innovation Center, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China; Institute of Spine and Spinal Cord, Nanchang University, Nanchang 330006, China; The First Clinical Medical College of Nanchang University, Nanchang 330006, China
| | - Jiaming Liu
- Medical Innovation Center, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China; Institute of Spine and Spinal Cord, Nanchang University, Nanchang 330006, China.
| | - Zhili Liu
- Medical Innovation Center, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China; Institute of Spine and Spinal Cord, Nanchang University, Nanchang 330006, China.
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22
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Noristani HN. Intrinsic regulation of axon regeneration after spinal cord injury: Recent advances and remaining challenges. Exp Neurol 2022; 357:114198. [DOI: 10.1016/j.expneurol.2022.114198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/20/2022] [Accepted: 08/02/2022] [Indexed: 11/16/2022]
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23
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McGonigal R, Campbell CI, Barrie JA, Yao D, Cunningham ME, Crawford CL, Rinaldi S, Rowan EG, Willison HJ. Schwann cell nodal membrane disruption triggers bystander axonal degeneration in a Guillain-Barré syndrome mouse model. J Clin Invest 2022; 132:158524. [PMID: 35671105 PMCID: PMC9282931 DOI: 10.1172/jci158524] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 06/02/2022] [Indexed: 11/25/2022] Open
Abstract
In Guillain-Barré syndrome (GBS), both axonal and demyelinating variants can be mediated by complement-fixing anti-GM1 ganglioside autoantibodies that target peripheral nerve axonal and Schwann cell (SC) membranes, respectively. Critically, the extent of axonal degeneration in both variants dictates long-term outcome. The differing pathomechanisms underlying direct axonal injury and the secondary bystander axonal degeneration following SC injury are unresolved. To investigate this, we generated glycosyltransferase-disrupted transgenic mice that express GM1 ganglioside either exclusively in neurons [GalNAcT-/--Tg(neuronal)] or glia [GalNAcT-/--Tg(glial)], thereby allowing anti-GM1 antibodies to solely target GM1 in either axonal or SC membranes, respectively. Myelinated-axon integrity in distal motor nerves was studied in transgenic mice exposed to anti-GM1 antibody and complement in ex vivo and in vivo injury paradigms. Axonal targeting induced catastrophic acute axonal disruption, as expected. When mice with GM1 in SC membranes were targeted, acute disruption of perisynaptic glia and SC membranes at nodes of Ranvier (NoRs) occurred. Following glial injury, axonal disruption at NoRs also developed subacutely, progressing to secondary axonal degeneration. These models differentiate the distinctly different axonopathic pathways under axonal and glial membrane targeting conditions, and provide insights into primary and secondary axonal injury, currently a major unsolved area in GBS research.
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Affiliation(s)
- Rhona McGonigal
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Clare I. Campbell
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Jennifer A. Barrie
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Denggao Yao
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Madeleine E. Cunningham
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Colin L. Crawford
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Simon Rinaldi
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | | | - Hugh J. Willison
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
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24
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Herwerth M, Kenet S, Schifferer M, Winkler A, Weber M, Snaidero N, Wang M, Lohrberg M, Bennett JL, Stadelmann C, Hemmer B, Misgeld T. A new form of axonal pathology in a spinal model of neuromyelitis optica. Brain 2022; 145:1726-1742. [PMID: 35202467 PMCID: PMC9166560 DOI: 10.1093/brain/awac079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 01/31/2022] [Accepted: 02/12/2022] [Indexed: 11/14/2022] Open
Abstract
Neuromyelitis optica is a chronic neuroinflammatory disease, which primarily targets astrocytes and often results in severe axon injury of unknown mechanism. Neuromyelitis optica patients harbour autoantibodies against the astrocytic water channel protein, aquaporin-4 (AQP4-IgG), which induce complement-mediated astrocyte lysis and subsequent axon damage. Using spinal in vivo imaging in a mouse model of such astrocytopathic lesions, we explored the mechanism underlying neuromyelitis optica-related axon injury. Many axons showed a swift and morphologically distinct 'pearls-on-string' transformation also readily detectable in human neuromyelitis optica lesions, which especially affected small calibre axons independently of myelination. Functional imaging revealed that calcium homeostasis was initially preserved in this 'acute axonal beading' state, ruling out disruption of the axonal membrane, which sets this form of axon injury apart from previously described forms of traumatic and inflammatory axon damage. Morphological, pharmacological and genetic analyses showed that AQP4-IgG-induced axon injury involved osmotic stress and ionic overload, but does not appear to use canonical pathways of Wallerian-like degeneration. Subcellular analysis demonstrated remodelling of the axonal cytoskeleton in beaded axons, especially local loss of microtubules. Treatment with the microtubule stabilizer epothilone, a putative therapy approach for traumatic and degenerative axonopathies, prevented axonal beading, while destabilizing microtubules sensitized axons for beading. Our results reveal a distinct form of immune-mediated axon pathology in neuromyelitis optica that mechanistically differs from known cascades of post-traumatic and inflammatory axon loss, and suggest a new strategy for neuroprotection in neuromyelitis optica and related diseases.
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Affiliation(s)
- Marina Herwerth
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Selin Kenet
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians University, Munich, Germany
| | - Martina Schifferer
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Anne Winkler
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Melanie Weber
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Nicolas Snaidero
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Mengzhe Wang
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Melanie Lohrberg
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Jeffrey L. Bennett
- Departments of Neurology and Ophthalmology, Programs in Neuroscience and Immunology, University of Colorado School of Medicine, Aurora, USA
| | - Christine Stadelmann
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Bernhard Hemmer
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
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25
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Radomski KL, Zi X, Lischka FW, Noble MD, Galdzicki Z, Armstrong RC. Acute axon damage and demyelination are mitigated by 4-aminopyridine (4-AP) therapy after experimental traumatic brain injury. Acta Neuropathol Commun 2022; 10:67. [PMID: 35501931 PMCID: PMC9059462 DOI: 10.1186/s40478-022-01366-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/11/2022] [Indexed: 11/10/2022] Open
Abstract
Damage to long axons in white matter tracts is a major pathology in closed head traumatic brain injury (TBI). Acute TBI treatments are needed that protect against axon damage and promote recovery of axon function to prevent long term symptoms and neurodegeneration. Our prior characterization of axon damage and demyelination after TBI led us to examine repurposing of 4-aminopyridine (4-AP), an FDA-approved inhibitor of voltage-gated potassium (Kv) channels. 4-AP is currently indicated to provide symptomatic relief for patients with chronic stage multiple sclerosis, which involves axon damage and demyelination. We tested clinically relevant dosage of 4-AP as an acute treatment for experimental TBI and found multiple benefits in corpus callosum axons. This randomized, controlled pre-clinical study focused on the first week after TBI, when axons are particularly vulnerable. 4-AP treatment initiated one day post-injury dramatically reduced axon damage detected by intra-axonal fluorescence accumulations in Thy1-YFP mice of both sexes. Detailed electron microscopy in C57BL/6 mice showed that 4-AP reduced pathological features of mitochondrial swelling, cytoskeletal disruption, and demyelination at 7 days post-injury. Furthermore, 4-AP improved the molecular organization of axon nodal regions by restoring disrupted paranode domains and reducing Kv1.2 channel dispersion. 4-AP treatment did not resolve deficits in action potential conduction across the corpus callosum, based on ex vivo electrophysiological recordings at 7 days post-TBI. Thus, this first study of 4-AP effects on axon damage in the acute period demonstrates a significant decrease in multiple pathological hallmarks of axon damage after experimental TBI.
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Affiliation(s)
- Kryslaine L. Radomski
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
| | - Xiaomei Zi
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
| | - Fritz W. Lischka
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Biomedical Instrumentation Center, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
| | - Mark D. Noble
- Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester, 601 Elmwood Ave, Box 633, Rochester, NY 14642 USA
| | - Zygmunt Galdzicki
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
| | - Regina C. Armstrong
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814 USA
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26
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Orem BC, Rajaee A, Stirling DP. Inhibiting Calcium Release from Ryanodine Receptors Protects Axons after Spinal Cord Injury. J Neurotrauma 2022; 39:311-319. [PMID: 34913747 PMCID: PMC8817717 DOI: 10.1089/neu.2021.0350] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Ryanodine receptors (RyRs) mediate calcium release from calcium stores and have been implicated in axonal degeneration. Here, we use an intravital imaging approach to determine axonal fate after spinal cord injury (SCI) in real-time and assess the efficacy of ryanodine receptor inhibition as a potential therapeutic approach to prevent intra-axonal calcium-mediated axonal degeneration. Adult 6-8 week old Thy1YFP transgenic mice that express YFP in axons, as well as triple transgenic Avil-Cre:Ai9:Ai95 mice that express the genetically-encoded calcium indicator GCaMP6f in tdTomato positive axons, were used to visualize axons and calcium changes in axons, respectively. Mice received a mild SCI at the T12 level of the spinal cord. Ryanodine, a RyR antagonist, was given at a concentration of 50 μM intrathecally within 15 min of SCI or delayed 3 h after injury and compared with vehicle-treated mice. RyR inhibition within 15 min of SCI significantly reduced axonal spheroid formation from 1 h to 24 h after SCI and increased axonal survival compared with vehicle controls. Delayed ryanodine treatment increased axonal survival and reduced intra-axonal calcium levels at 24 h after SCI but had no effect on axonal spheroid formation. Together, our results support a role for RyR in secondary axonal degeneration.
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Affiliation(s)
- Ben C. Orem
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, Louisville, Kentucky, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, Kentucky, USA
| | - Arezoo Rajaee
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, Kentucky, USA
| | - David P. Stirling
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, Kentucky, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, Kentucky, USA
- Department of Microbiology and Immunology, University of Louisville, School of Medicine, Louisville, Kentucky, USA
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27
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Ji H, Sapar ML, Sarkar A, Wang B, Han C. Phagocytosis and self-destruction break down dendrites of Drosophila sensory neurons at distinct steps of Wallerian degeneration. Proc Natl Acad Sci U S A 2022; 119:e2111818119. [PMID: 35058357 PMCID: PMC8795528 DOI: 10.1073/pnas.2111818119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 12/01/2021] [Indexed: 12/12/2022] Open
Abstract
After injury, severed dendrites and axons expose the "eat-me" signal phosphatidylserine (PS) on their surface while they break down. The degeneration of injured axons is controlled by a conserved Wallerian degeneration (WD) pathway, which is thought to activate neurite self-destruction through Sarm-mediated nicotinamide adenine dinucleotide (NAD+) depletion. While neurite PS exposure is known to be affected by genetic manipulations of NAD+, how the WD pathway coordinates both neurite PS exposure and self-destruction and whether PS-induced phagocytosis contributes to neurite breakdown in vivo remain unknown. Here, we show that in Drosophila sensory dendrites, PS exposure and self-destruction are two sequential steps of WD resulting from Sarm activation. Surprisingly, phagocytosis is the main driver of dendrite degeneration induced by both genetic NAD+ disruptions and injury. However, unlike neuronal Nmnat loss, which triggers PS exposure only and results in phagocytosis-dependent dendrite degeneration, injury activates both PS exposure and self-destruction as two redundant means of dendrite degeneration. Furthermore, the axon-death factor Axed is only partially required for self-destruction of injured dendrites, acting in parallel with PS-induced phagocytosis. Lastly, injured dendrites exhibit a unique rhythmic calcium-flashing that correlates with WD. Therefore, both NAD+-related general mechanisms and dendrite-specific programs govern PS exposure and self-destruction in injury-induced dendrite degeneration in vivo.
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Affiliation(s)
- Hui Ji
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Maria L Sapar
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Ankita Sarkar
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Bei Wang
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Chun Han
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853;
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
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28
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Liao HY, Wang ZQ, Ran R, Zhou KS, Ma CW, Zhang HH. Biological Functions and Therapeutic Potential of Autophagy in Spinal Cord Injury. Front Cell Dev Biol 2022; 9:761273. [PMID: 34988074 PMCID: PMC8721099 DOI: 10.3389/fcell.2021.761273] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/24/2021] [Indexed: 12/12/2022] Open
Abstract
Autophagy is an evolutionarily conserved lysosomal degradation pathway that maintains metabolism and homeostasis by eliminating protein aggregates and damaged organelles. Many studies have reported that autophagy plays an important role in spinal cord injury (SCI). However, the spatiotemporal patterns of autophagy activation after traumatic SCI are contradictory. Most studies show that the activation of autophagy and inhibition of apoptosis have neuroprotective effects on traumatic SCI. However, reports demonstrate that autophagy is strongly associated with distal neuronal death and the impaired functional recovery following traumatic SCI. This article introduces SCI pathophysiology, the physiology and mechanism of autophagy, and our current review on its role in traumatic SCI. We also discuss the interaction between autophagy and apoptosis and the therapeutic effect of activating or inhibiting autophagy in promoting functional recovery. Thus, we aim to provide a theoretical basis for the biological therapy of SCI.
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Affiliation(s)
- Hai-Yang Liao
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Zhi-Qiang Wang
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Rui Ran
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Kai-Sheng Zhou
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Chun-Wei Ma
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Hai-Hong Zhang
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
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29
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Varadarajan SG, Hunyara JL, Hamilton NR, Kolodkin AL, Huberman AD. Central nervous system regeneration. Cell 2022; 185:77-94. [PMID: 34995518 PMCID: PMC10896592 DOI: 10.1016/j.cell.2021.10.029] [Citation(s) in RCA: 84] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 02/06/2023]
Abstract
Neurons of the mammalian central nervous system fail to regenerate. Substantial progress has been made toward identifying the cellular and molecular mechanisms that underlie regenerative failure and how altering those pathways can promote cell survival and/or axon regeneration. Here, we summarize those findings while comparing the regenerative process in the central versus the peripheral nervous system. We also highlight studies that advance our understanding of the mechanisms underlying neural degeneration in response to injury, as many of these mechanisms represent primary targets for restoring functional neural circuits.
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Affiliation(s)
| | - John L Hunyara
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Natalie R Hamilton
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alex L Kolodkin
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Andrew D Huberman
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; Department of Ophthalmology, Stanford University, Stanford, CA 94305, USA.
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30
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Keilhoff G, Pinkernelle J, Fansa H. The Ryanodine receptor stabilizer S107 fails to support motor neuronal neuritogenesis in vitro. Tissue Cell 2021; 73:101625. [PMID: 34419737 DOI: 10.1016/j.tice.2021.101625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/02/2021] [Accepted: 08/15/2021] [Indexed: 11/30/2022]
Abstract
Calcium homeostasis is essential for neuronal cell survival/differentiation. Imbalance of the Ca2+ homeostasis due to excessive Ca2+ overload is essential for spinal cord injury (SCI). The overload resulted from Ca2+ flux across the plasma membrane and from internal Ca2+ store release (mitochondria, endoplasmic reticulum, ER). Inositol trisphosphate receptors (IP3R) and ryanodine receptors (RyR) are involved in releasing Ca2+ from ER contributing to axonal degeneration following SCI. In turn, block of both receptors is axoprotective. The calstabin RyR subunit, stabilizing the channel in a state of reduced activity, prevents pathological Ca2+ release too. We investigated whether S107, a RyR-stabilizing compound (Rycal), is beneficial for survival and neuritogenesis of spinal cord motor neurons in vitro. We used a spinal cord slice model and the motor neuron-like NSC-34 cell line. Effects of S107 were tested by propidium iodide/fluorescein diacetate vital staining, mitotic index determination via BrdU-incorporation, and neurite sprouting parameters. Results showed that S107 (i) had no effect on gliosis resulting from slices preparation; (ii) had no effect on motor neuronal survival and proliferation; and (iii) impaired neurite sprouting, no matter whether it was a differentiation (NSC-34 cells) or regeneration (spinal cord slices) process. The results underline the need for a flexible Ca2+homeostasis provided by the ER for re-initiation of neuritogenesis.
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Affiliation(s)
- Gerburg Keilhoff
- Institute of Biochemistry and Cell Biology, Medical Faculty, University of Magdeburg, 39120, Magdeburg, Germany.
| | - Josephine Pinkernelle
- Institute of Biochemistry and Cell Biology, Medical Faculty, University of Magdeburg, 39120, Magdeburg, Germany
| | - Hisham Fansa
- Department of Plastic, Reconstructive, and Aesthetic Surgery, Hand Surgery, Klinikum Bielefeld, OWL-University, 33604, Bielefeld, Germany; Department of Plastic Surgery, and Breast Centre, Spital Zollikerberg, 8125, Zollikerberg, Switzerland
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31
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Murphy SA, Furger R, Kurpad SN, Arpinar VE, Nencka A, Koch K, Budde MD. Filtered Diffusion-Weighted MRI of the Human Cervical Spinal Cord: Feasibility and Application to Traumatic Spinal Cord Injury. AJNR Am J Neuroradiol 2021; 42:2101-2106. [PMID: 34620590 DOI: 10.3174/ajnr.a7295] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 07/07/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE In traumatic spinal cord injury, DTI is sensitive to injury but is unable to differentiate multiple pathologies. Axonal damage is a central feature of the underlying cord injury, but prominent edema confounds its detection. The purpose of this study was to examine a filtered DWI technique in patients with acute spinal cord injury. MATERIALS AND METHODS The MR imaging protocol was first evaluated in a cohort of healthy subjects at 3T (n = 3). Subsequently, patients with acute cervical spinal cord injury (n = 8) underwent filtered DWI concurrent with their acute clinical MR imaging examination <24 hours postinjury at 1.5T. DTI was obtained with 25 directions at a b-value of 800 s/mm2. Filtered DWI used spinal cord-optimized diffusion-weighting along 26 directions with a "filter" b-value of 2000 s/mm2 and a "probe" maximum b-value of 1000 s/mm2. Parallel diffusivity metrics obtained from DTI and filtered DWI were compared. RESULTS The high-strength diffusion-weighting perpendicular to the cord suppressed signals from tissues outside of the spinal cord, including muscle and CSF. The parallel ADC acquired from filtered DWI at the level of injury relative to the most cranial region showed a greater decrease (38.71%) compared with the decrease in axial diffusivity acquired by DTI (17.68%). CONCLUSIONS The results demonstrated that filtered DWI is feasible in the acute setting of spinal cord injury and reveals spinal cord diffusion characteristics not evident with conventional DTI.
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Affiliation(s)
- S A Murphy
- From the Department of Neurosurgery (S.A.M., R.F., S.N.K., M.D.B.)
| | - R Furger
- From the Department of Neurosurgery (S.A.M., R.F., S.N.K., M.D.B.)
- Center for Neurotrauma Research (R.F., S.N.K., M.D.B.)
| | - S N Kurpad
- From the Department of Neurosurgery (S.A.M., R.F., S.N.K., M.D.B.)
- Center for Neurotrauma Research (R.F., S.N.K., M.D.B.)
| | - V E Arpinar
- Center for Imaging Research (V.E.A., A.N., K.K.), Medical College of Wisconsin, Milwaukee, Wisconsin
| | - A Nencka
- Center for Imaging Research (V.E.A., A.N., K.K.), Medical College of Wisconsin, Milwaukee, Wisconsin
| | - K Koch
- Center for Imaging Research (V.E.A., A.N., K.K.), Medical College of Wisconsin, Milwaukee, Wisconsin
| | - M D Budde
- From the Department of Neurosurgery (S.A.M., R.F., S.N.K., M.D.B.)
- Center for Neurotrauma Research (R.F., S.N.K., M.D.B.)
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32
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Fague L, Liu YA, Marsh-Armstrong N. The basic science of optic nerve regeneration. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1276. [PMID: 34532413 PMCID: PMC8421956 DOI: 10.21037/atm-20-5351] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 01/15/2021] [Indexed: 12/25/2022]
Abstract
Diverse insults to the optic nerve result in partial to total vision loss as the axons of retinal ganglion cells are destroyed. In glaucoma, axons are injured at the optic nerve head; in other optic neuropathies, axons can be damaged along the entire visual pathway. In all cases, as mammals cannot regenerate injured central nervous system cells, once the axons are lost, vision loss is irreversible. However, much has been learned about how retinal ganglion cells respond to axon injuries, and many of these crucial discoveries offer hope for future regenerative therapies. Here we review the current understanding regarding the temporal progression of axonal degeneration. We summarize known survival and regenerative mechanisms in mammals, including specific signaling pathways, key transcription factors, and reprogramming genes. We cover mechanisms intrinsic to retinal ganglion cells as well as their interactions with myeloid and glial cell populations in the retina and optic nerve that affect survival and regeneration. Finally, we highlight some non-mammalian species that are able to regenerate their retinal ganglion cell axons after injury, as understanding these successful regenerative responses may be essential to the rational design of future clinical interventions to regrow the optic nerve. In the end, a combination of many different molecular and cellular interventions will likely be the only way to achieve functional recovery of vision and restore quality of life to millions of patients around the world.
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Affiliation(s)
- Lindsay Fague
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Yin Allison Liu
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Nicholas Marsh-Armstrong
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
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Bradshaw DV, Knutsen AK, Korotcov A, Sullivan GM, Radomski KL, Dardzinski BJ, Zi X, McDaniel DP, Armstrong RC. Genetic inactivation of SARM1 axon degeneration pathway improves outcome trajectory after experimental traumatic brain injury based on pathological, radiological, and functional measures. Acta Neuropathol Commun 2021; 9:89. [PMID: 34001261 PMCID: PMC8130449 DOI: 10.1186/s40478-021-01193-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/06/2021] [Indexed: 02/07/2023] Open
Abstract
Traumatic brain injury (TBI) causes chronic symptoms and increased risk of neurodegeneration. Axons in white matter tracts, such as the corpus callosum (CC), are critical components of neural circuits and particularly vulnerable to TBI. Treatments are needed to protect axons from traumatic injury and mitigate post-traumatic neurodegeneration. SARM1 protein is a central driver of axon degeneration through a conserved molecular pathway. Sarm1−/− mice with knockout (KO) of the Sarm1 gene enable genetic proof-of-concept testing of the SARM1 pathway as a therapeutic target. We evaluated Sarm1 deletion effects after TBI using a concussive model that causes traumatic axonal injury and progresses to CC atrophy at 10 weeks, indicating post-traumatic neurodegeneration. Sarm1 wild-type (WT) mice developed significant CC atrophy that was reduced in Sarm1 KO mice. Ultrastructural classification of pathology of individual axons, using electron microscopy, demonstrated that Sarm1 KO preserved more intact axons and reduced damaged or demyelinated axons. Longitudinal MRI studies in live mice identified significantly reduced CC volume after TBI in Sarm1 WT mice that was attenuated in Sarm1 KO mice. MR diffusion tensor imaging detected reduced fractional anisotropy in both genotypes while axial diffusivity remained higher in Sarm1 KO mice. Immunohistochemistry revealed significant attenuation of CC atrophy, myelin loss, and neuroinflammation in Sarm1 KO mice after TBI. Functionally, Sarm1 KO mice exhibited beneficial effects in motor learning and sleep behavior. Based on these findings, Sarm1 inactivation can protect axons and white matter tracts to improve translational outcomes associated with CC atrophy and post-traumatic neurodegeneration.
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Spatial calcium kinetics after a traumatic brain injury. Biomech Model Mechanobiol 2021; 20:1413-1430. [PMID: 33772677 DOI: 10.1007/s10237-021-01453-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 03/09/2021] [Indexed: 10/21/2022]
Abstract
Accurate modelling of intracellular calcium ion ([Formula: see text]) concentration evolution is valuable as it is known to rapidly increase during a Traumatic Brain Injury. In the work presented here, our older non-spatial model dealing with the effect of mechanical stress upon the [Formula: see text] transportation in a neuron is spatialized by considering the brain tissue as a solid continuum with the [Formula: see text] activity occurring at every material point. Starting with one-dimensional representation, the brain tissue geometry is progressively made realistic and under the action of pressure or kinematic impulses, the effect of dimensionality and material behaviour on the correlation between the stress and concomitant [Formula: see text] concentration is investigated. The spatial calcium kinetics model faithfully captures the experimental observations concerning the [Formula: see text] concentration, load rate, magnitude and duration and most importantly shows that the critical location for primary injury may not be the most important location as far as secondary injury is concerned.
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Zrzavy T, Schwaiger C, Wimmer I, Berger T, Bauer J, Butovsky O, Schwab JM, Lassmann H, Höftberger R. Acute and non-resolving inflammation associate with oxidative injury after human spinal cord injury. Brain 2021; 144:144-161. [PMID: 33578421 PMCID: PMC7880675 DOI: 10.1093/brain/awaa360] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/08/2020] [Accepted: 08/11/2020] [Indexed: 12/25/2022] Open
Abstract
Traumatic spinal cord injury is a devastating insult followed by progressive cord atrophy and neurodegeneration. Dysregulated or non-resolving inflammatory processes can disturb neuronal homeostasis and drive neurodegeneration. Here, we provide an in-depth characterization of innate and adaptive inflammatory responses as well as oxidative tissue injury in human traumatic spinal cord injury lesions compared to non-traumatic control cords. In the lesion core, microglia were rapidly lost while intermediate (co-expressing pro- as well as anti-inflammatory molecules) blood-borne macrophages dominated. In contrast, in the surrounding rim, TMEM119+ microglia numbers were maintained through local proliferation and demonstrated a predominantly pro-inflammatory phenotype. Lymphocyte numbers were low and mainly consisted of CD8+ T cells. Only in a subpopulation of patients, CD138+/IgG+ plasma cells were detected, which could serve as candidate cellular sources for a developing humoral immunity. Oxidative neuronal cell body and axonal injury was visualized by intracellular accumulation of amyloid precursor protein (APP) and oxidized phospholipids (e06) and occurred early within the lesion core and declined over time. In contrast, within the surrounding rim, pronounced APP+/e06+ axon-dendritic injury of neurons was detected, which remained significantly elevated up to months/years, thus providing mechanistic evidence for ongoing neuronal damage long after initial trauma. Dynamic and sustained neurotoxicity after human spinal cord injury might be a substantial contributor to (i) an impaired response to rehabilitation; (ii) overall failure of recovery; or (iii) late loss of recovered function (neuro-worsening/degeneration).
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Affiliation(s)
- Tobias Zrzavy
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Carmen Schwaiger
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Isabella Wimmer
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Thomas Berger
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Jan Bauer
- Center for Brain Research, Medical University of Vienna, Austria
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Womeńs Hospital, Harvard Medical School, Boston, MA, USA
- Evergrande Center for Immunologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jan M Schwab
- The Belford Center for Spinal Cord Injury, The Ohio State University, Columbus, OH 43210, USA
- Department of Neurology, The Ohio State University, Columbus, OH 43210, USA
- Department of Physical Medicine & Rehabilitation, The Ohio State University, Columbus, OH 43210, USA
- Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA
| | - Hans Lassmann
- Center for Brain Research, Medical University of Vienna, Austria
| | - Romana Höftberger
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
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A bioactive injectable self-healing anti-inflammatory hydrogel with ultralong extracellular vesicles release synergistically enhances motor functional recovery of spinal cord injury. Bioact Mater 2021; 6:2523-2534. [PMID: 33615043 PMCID: PMC7873581 DOI: 10.1016/j.bioactmat.2021.01.029] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 01/17/2021] [Accepted: 01/24/2021] [Indexed: 12/19/2022] Open
Abstract
The repair and motor functional recovery after spinal cord injury (SCI) remains a worldwide challenge. The inflammatory microenvironment is one of main obstacles on inhibiting the recovery of SCI. Using mesenchymal stem cells (MSCs) derived extracellular vesicles to replace MSCs transplantation and mimic cell paracrine secretions provides a potential strategy for microenvironment regulation. However, the effective preservation and controlled release of extracellular vesicles in the injured spinal cord tissue are still not satisfied. Herein, we fabricated an injectable adhesive anti-inflammatory F127-polycitrate-polyethyleneimine hydrogel (FE) with sustainable and long term extracellular vesicle release (FE@EVs) for improving motor functional recovery after SCI. The orthotopic injection of FE@EVs hydrogel could encapsulate extracellular vesicles on the injured spinal cord, thereby synergistically induce efficient integrated regulation through suppressing fibrotic scar formation, reducing inflammatory reaction, promoting remyelination and axonal regeneration. This study showed that combining extracellular vesicles into bioactive multifunctional hydrogel should have great potential in achieving satisfactory locomotor recovery of central nervous system diseases. The novel FE hydrogel was designed for encapsulating the extracellular vesicles (FE@EVs). FE hydrogel exert the capabilities of temperature-responsive, injectable, adhesive and biocompatible. FE hydrogel with sustainable and long-term extracellular vesicle release for improving motor functional recovery after SCI. FE@EVs plays a vital role in pathological process of spinal cord injury in rats.
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Hughes RO, Bosanac T, Mao X, Engber TM, DiAntonio A, Milbrandt J, Devraj R, Krauss R. Small Molecule SARM1 Inhibitors Recapitulate the SARM1 -/- Phenotype and Allow Recovery of a Metastable Pool of Axons Fated to Degenerate. Cell Rep 2021; 34:108588. [PMID: 33406435 PMCID: PMC8179325 DOI: 10.1016/j.celrep.2020.108588] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 11/09/2020] [Accepted: 12/10/2020] [Indexed: 02/06/2023] Open
Abstract
Axonal degeneration is responsible for disease progression and accumulation of disability in many neurodegenerative conditions. The axonal degenerative process can generate a metastable pool of damaged axons that remain structurally and functionally viable but fated to degenerate in the absence of external intervention. SARM1, an NADase that depletes axonal energy stores upon activation, is the central driver of an evolutionarily conserved program of axonal degeneration. We identify a potent and selective small molecule isoquinoline inhibitor of SARM1 NADase that recapitulates the SARM1-/- phenotype and protects axons from degeneration induced by axotomy or mitochondrial dysfunction. SARM1 inhibition post-mitochondrial injury with rotenone allows recovery and rescues axons that already entered the metastable state. We conclude that SARM1 inhibition with small molecules has the potential to treat axonopathies of the central and peripheral nervous systems by preventing axonal degeneration and by allowing functional recovery of a metastable pool of damaged, but viable, axons.
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Affiliation(s)
- Robert O Hughes
- Disarm Therapeutics, a wholly owned subsidiary of Eli Lilly & Co, Cambridge, MA 02142, USA
| | - Todd Bosanac
- Disarm Therapeutics, a wholly owned subsidiary of Eli Lilly & Co, Cambridge, MA 02142, USA
| | - Xianrong Mao
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Thomas M Engber
- Disarm Therapeutics, a wholly owned subsidiary of Eli Lilly & Co, Cambridge, MA 02142, USA
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jeffrey Milbrandt
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Rajesh Devraj
- Disarm Therapeutics, a wholly owned subsidiary of Eli Lilly & Co, Cambridge, MA 02142, USA
| | - Raul Krauss
- Disarm Therapeutics, a wholly owned subsidiary of Eli Lilly & Co, Cambridge, MA 02142, USA.
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Canty AJ, Jackson JS, Huang L, Trabalza A, Bass C, Little G, Tortora M, Khan S, De Paola V. In vivo imaging of injured cortical axons reveals a rapid onset form of Wallerian degeneration. BMC Biol 2020; 18:170. [PMID: 33208154 PMCID: PMC7677840 DOI: 10.1186/s12915-020-00869-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 09/16/2020] [Indexed: 12/22/2022] Open
Abstract
Background Despite the widespread occurrence of axon and synaptic loss in the injured and diseased nervous system, the cellular and molecular mechanisms of these key degenerative processes remain incompletely understood. Wallerian degeneration (WD) is a tightly regulated form of axon loss after injury, which has been intensively studied in large myelinated fibre tracts of the spinal cord, optic nerve and peripheral nervous system (PNS). Fewer studies, however, have focused on WD in the complex neuronal circuits of the mammalian brain, and these were mainly based on conventional endpoint histological methods. Post-mortem analysis, however, cannot capture the exact sequence of events nor can it evaluate the influence of elaborated arborisation and synaptic architecture on the degeneration process, due to the non-synchronous and variable nature of WD across individual axons. Results To gain a comprehensive picture of the spatiotemporal dynamics and synaptic mechanisms of WD in the nervous system, we identify the factors that regulate WD within the mouse cerebral cortex. We combined single-axon-resolution multiphoton imaging with laser microsurgery through a cranial window and a fluorescent membrane reporter. Longitudinal imaging of > 150 individually injured excitatory cortical axons revealed a threshold length below which injured axons consistently underwent a rapid-onset form of WD (roWD). roWD started on average 20 times earlier and was executed 3 times slower than WD described in other regions of the nervous system. Cortical axon WD and roWD were dependent on synaptic density, but independent of axon complexity. Finally, pharmacological and genetic manipulations showed that a nicotinamide adenine dinucleotide (NAD+)-dependent pathway could delay cortical roWD independent of transcription in the damaged neurons, demonstrating further conservation of the molecular mechanisms controlling WD in different areas of the mammalian nervous system. Conclusions Our data illustrate how in vivo time-lapse imaging can provide new insights into the spatiotemporal dynamics and synaptic mechanisms of axon loss and assess therapeutic interventions in the injured mammalian brain.
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Affiliation(s)
- Alison Jane Canty
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Australia.
| | - Johanna Sara Jackson
- Dementia Research Institute at Imperial College, Department of Brain Sciences, Imperial College London, London, W12 0NN, UK
| | - Lieven Huang
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Antonio Trabalza
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Cher Bass
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Graham Little
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Maria Tortora
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Shabana Khan
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Vincenzo De Paola
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK. .,Medical Research Council London Institute of Medical Sciences, London, W12 0NN, UK.
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Spinal Cord Injury: Pathophysiology, Multimolecular Interactions, and Underlying Recovery Mechanisms. Int J Mol Sci 2020; 21:ijms21207533. [PMID: 33066029 PMCID: PMC7589539 DOI: 10.3390/ijms21207533] [Citation(s) in RCA: 503] [Impact Index Per Article: 125.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/17/2020] [Accepted: 09/24/2020] [Indexed: 12/30/2022] Open
Abstract
Spinal cord injury (SCI) is a destructive neurological and pathological state that causes major motor, sensory and autonomic dysfunctions. Its pathophysiology comprises acute and chronic phases and incorporates a cascade of destructive events such as ischemia, oxidative stress, inflammatory events, apoptotic pathways and locomotor dysfunctions. Many therapeutic strategies have been proposed to overcome neurodegenerative events and reduce secondary neuronal damage. Efforts have also been devoted in developing neuroprotective and neuro-regenerative therapies that promote neuronal recovery and outcome. Although varying degrees of success have been achieved, curative accomplishment is still elusive probably due to the complex healing and protective mechanisms involved. Thus, current understanding in this area must be assessed to formulate appropriate treatment modalities to improve SCI recovery. This review aims to promote the understanding of SCI pathophysiology, interrelated or interlinked multimolecular interactions and various methods of neuronal recovery i.e., neuroprotective, immunomodulatory and neuro-regenerative pathways and relevant approaches.
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Orem BC, Rajaee A, Stirling DP. IP 3R-mediated intra-axonal Ca 2+ release contributes to secondary axonal degeneration following contusive spinal cord injury. Neurobiol Dis 2020; 146:105123. [PMID: 33011333 DOI: 10.1016/j.nbd.2020.105123] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/15/2020] [Accepted: 09/28/2020] [Indexed: 01/11/2023] Open
Abstract
Secondary axonal loss contributes to the persistent functional disability following trauma. Consequently, preserving axons following spinal cord injury (SCI) is a major therapeutic goal to improve neurological outcome; however, the complex molecular mechanisms that mediate secondary axonal degeneration remain unclear. We previously showed that IP3R-mediated Ca2+ release contributes to axonal dieback and axonal loss following an ex vivo laser-induced SCI. Nevertheless, targeting IP3R in a clinically relevant in vivo model of SCI and determining its contribution to secondary axonal degeneration has yet to be explored. Here we used intravital two-photon excitation microscopy to assess the role of IP3R in secondary axonal degeneration in real-time after a contusive-SCI in vivo. To visualize Ca2+ changes specifically in spinal axons over time, adult 6-8 week-old triple transgenic Avil-Cre:Ai9:Ai95 (sensory neuron-specific expression of tdTomato and the genetic calcium indicator GCaMP6f) mice were subjected to a mild (30 kdyn) T12 contusive-SCI and received delayed treatment with the IP3R blocker 2-APB (100 μM, intrathecal delivery at 3, and 24 h following injury) or vehicle control. To determine the IP3R subtype involved, we knocked-down IP3R3 using capped phosphodiester oligonucleotides. Delayed treatment with 2-APB significantly reduced axonal spheroids, increased axonal survival, and reduced intra-axonal Ca2+ accumulation within dorsal column axons at 24 h following SCI in vivo. Additionally, knockdown of IP3R3 yielded increased axon survival 24 h post-SCI. These results suggest that IP3R-mediated Ca2+ release contributes to secondary axonal degeneration in vivo following SCI.
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Affiliation(s)
- Ben C Orem
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, KY 40202, USA
| | - Arezoo Rajaee
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Departments of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY 40202, USA
| | - David P Stirling
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Departments of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Microbiology and Immunology, University of Louisville, School of Medicine, Louisville, KY 40202, USA.
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Birkner K, Wasser B, Ruck T, Thalman C, Luchtman D, Pape K, Schmaul S, Bitar L, Krämer-Albers EM, Stroh A, Meuth SG, Zipp F, Bittner S. β1-Integrin- and KV1.3 channel-dependent signaling stimulates glutamate release from Th17 cells. J Clin Invest 2020; 130:715-732. [PMID: 31661467 DOI: 10.1172/jci126381] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 10/22/2019] [Indexed: 12/22/2022] Open
Abstract
Although the impact of Th17 cells on autoimmunity is undisputable, their pathogenic effector mechanism is still enigmatic. We discovered soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) complex proteins in Th17 cells that enable a vesicular glutamate release pathway that induces local intracytoplasmic calcium release and subsequent damage in neurons. This pathway is glutamine dependent and triggered by binding of β1-integrin to vascular cell adhesion molecule 1 (VCAM-1) on neurons in the inflammatory context. Glutamate secretion could be blocked by inhibiting either glutaminase or KV1.3 channels, which are known to be linked to integrin expression and highly expressed on stimulated T cells. Although KV1.3 is not expressed in CNS tissue, intrathecal administration of a KV1.3 channel blocker or a glutaminase inhibitor ameliorated disability in experimental neuroinflammation. In humans, T cells from patients with multiple sclerosis secreted higher levels of glutamate, and cerebrospinal fluid glutamine levels were increased. Altogether, our findings demonstrate that β1-integrin- and KV1.3 channel-dependent signaling stimulates glutamate release from Th17 cells upon direct cell-cell contact between Th17 cells and neurons.
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Affiliation(s)
- Katharina Birkner
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Beatrice Wasser
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Tobias Ruck
- Department of Neurology, University of Muenster, Muenster, Germany
| | - Carine Thalman
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Dirk Luchtman
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Katrin Pape
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Samantha Schmaul
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Lynn Bitar
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Albrecht Stroh
- Institute for Pathophysiology, FTN, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sven G Meuth
- Department of Neurology, University of Muenster, Muenster, Germany
| | - Frauke Zipp
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan Bittner
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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Vaquié A, Sauvain A, Duman M, Nocera G, Egger B, Meyenhofer F, Falquet L, Bartesaghi L, Chrast R, Lamy CM, Bang S, Lee SR, Jeon NL, Ruff S, Jacob C. Injured Axons Instruct Schwann Cells to Build Constricting Actin Spheres to Accelerate Axonal Disintegration. Cell Rep 2020; 27:3152-3166.e7. [PMID: 31189102 DOI: 10.1016/j.celrep.2019.05.060] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/11/2019] [Accepted: 05/17/2019] [Indexed: 01/26/2023] Open
Abstract
After a peripheral nerve lesion, distal ends of injured axons disintegrate into small fragments that are subsequently cleared by Schwann cells and later by macrophages. Axonal debris clearing is an early step of the repair process that facilitates regeneration. We show here that Schwann cells promote distal cut axon disintegration for timely clearing. By combining cell-based and in vivo models of nerve lesion with mouse genetics, we show that this mechanism is induced by distal cut axons, which signal to Schwann cells through PlGF mediating the activation and upregulation of VEGFR1 in Schwann cells. In turn, VEGFR1 activates Pak1, leading to the formation of constricting actomyosin spheres along unfragmented distal cut axons to mediate their disintegration. Interestingly, oligodendrocytes can acquire a similar behavior as Schwann cells by enforced expression of VEGFR1. These results thus identify controllable molecular cues of a neuron-glia crosstalk essential for timely clearing of damaged axons.
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Affiliation(s)
- Adrien Vaquié
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Alizée Sauvain
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Mert Duman
- Department of Biology, University of Fribourg, Fribourg, Switzerland; Department of Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Gianluigi Nocera
- Department of Biology, University of Fribourg, Fribourg, Switzerland; Department of Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Boris Egger
- Department of Biology, University of Fribourg, Fribourg, Switzerland; Bioimage Light Microscopy Facility, University of Fribourg, Fribourg, Switzerland
| | - Felix Meyenhofer
- Department of Biology, University of Fribourg, Fribourg, Switzerland; Department of Medicine, University of Fribourg, Fribourg, Switzerland; Bioimage Light Microscopy Facility, University of Fribourg, Fribourg, Switzerland
| | - Laurent Falquet
- Department of Biology, University of Fribourg, Fribourg, Switzerland; Department of Medicine, University of Fribourg, Fribourg, Switzerland; Bioinformatics Core Facility, University of Fribourg and Swiss Institute of Bioinformatics, Fribourg, Switzerland
| | - Luca Bartesaghi
- Departments of Neuroscience and Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Roman Chrast
- Departments of Neuroscience and Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | | | - Seokyoung Bang
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, South Korea
| | - Seung-Ryeol Lee
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, South Korea
| | - Noo Li Jeon
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, South Korea
| | - Sophie Ruff
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Claire Jacob
- Department of Biology, University of Fribourg, Fribourg, Switzerland; Department of Biology, Johannes Gutenberg University Mainz, Mainz, Germany.
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Salvadores N, Court FA. The necroptosis pathway and its role in age-related neurodegenerative diseases: will it open up new therapeutic avenues in the next decade? Expert Opin Ther Targets 2020; 24:679-693. [PMID: 32310729 DOI: 10.1080/14728222.2020.1758668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Necroptosis is a programmed form of necrotic cell death. Growing evidence demonstrates that necroptosis contributes to cell demise in different pathological conditions including age-dependent neurodegenerative diseases (NDs). These findings open new avenues for understanding the mechanisms of neuronal loss in NDs, which might eventually translate into novel therapeutic interventions. AREAS COVERED We reviewed key aspects of necroptosis, in health and disease, focusing on evidence demonstrating its involvement in the pathogenesis of age-related NDs. We then highlight the activation of this pathway in the mechanism of axonal degeneration. We searched on PubMed the literature regarding necroptosis published between 2008 and 2020 and reviewed all publications were necroptosis was studied in the context of age-related NDs. EXPERT OPINION Axonal loss and neuronal death are the ultimate consequences of NDs that translate into disease phenotypes. Targeting degenerative mechanisms of the neuron appears as a strategy that might cover a wide range of diseases. Thus, the participation of necroptosis as a common mediator of neuronal demise emerges as a promising target for therapeutic intervention. Considering evidence demonstrating that necroptosis mediates axonal degeneration, we propose and discuss the potential of targeting necroptosis-mediated axonal destruction as a strategy to tackle NDs before neuronal loss occurs.
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Affiliation(s)
- Natalia Salvadores
- Faculty of Sciences, Center for Integrative Biology, Universidad Mayor , Santiago, Chile.,Fondap Geroscience Center for Brain Health and Metabolism , Santiago, Chile
| | - Felipe A Court
- Faculty of Sciences, Center for Integrative Biology, Universidad Mayor , Santiago, Chile.,Fondap Geroscience Center for Brain Health and Metabolism , Santiago, Chile
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Rajaee A, Geisen ME, Sellers AK, Stirling DP. Repeat intravital imaging of the murine spinal cord reveals degenerative and reparative responses of spinal axons in real-time following a contusive SCI. Exp Neurol 2020; 327:113258. [PMID: 32105708 DOI: 10.1016/j.expneurol.2020.113258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 02/06/2020] [Accepted: 02/22/2020] [Indexed: 12/18/2022]
Abstract
Spinal cord injury (SCI) induces a secondary degenerative response that causes the loss of spared axons and worsens neurological outcome. The complex molecular mechanisms that mediate secondary axonal degeneration remain poorly understood. To further our understanding of secondary axonal degeneration following SCI, we assessed the spatiotemporal dynamics of axonal spheroid and terminal bulb formation following a contusive SCI in real-time in vivo. Adult 6-8 week old Thy1YFP transgenic mice underwent a T12 laminectomy for acute imaging sessions or were implanted with a custom spinal cord imaging chamber for chronic imaging of the spinal cord. Two-photon excitation time-lapse microscopy was performed prior to a mild contusion SCI (30 kilodyne, IH Impactor) and at 1-4 h and 1-14 days post-SCI. We quantified the number of axonal spheroids, their size and distribution, the number of endbulbs, and axonal survival from 1 h to 14 days post-SCI. Our data reveal that the majority of axons underwent swelling and axonal spheroid formation acutely after SCI resulting in the loss of ~70% of axons by 1 day after injury. In agreement, the number of axonal spheroids rapidly increased at 1 h after SCI and remained significantly elevated up to 14 days after SCI. Furthermore, the distribution of axonal spheroids spread mediolaterally over time indicative of delayed secondary degenerative processes. In contrast, axonal endbulbs were relatively sparse and their numbers peaked at 1 day after injury. Intriguingly, axonal survival significantly increased at 7 and 14 days compared to 3 days after SCI revealing a potential endogenous axonal repair process that mirrors the known spontaneous functional recovery after SCI. In support, ~43% of tracked axonal spheroids resolved over the course of observation revealing their dynamic nature. Furthermore, axonal spheroids and endbulbs accumulated mitochondria and excessive tubulin polyglutamylation suggestive of disrupted axonal transport as a shared mechanism. Collectively, this study provides important insight into both degenerative and recoverable responses of axons following contusive SCI in real-time. Understanding how axons spontaneously recover after SCI will be an important avenue for future SCI research and may help guide future clinical trials.
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Affiliation(s)
- Arezoo Rajaee
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY 40202, USA
| | - Mariah E Geisen
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY 40202, USA
| | - Alexandra K Sellers
- Department of Bioengineering, University of Louisville, School of Medicine, Louisville, KY 40202, USA
| | - David P Stirling
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Department of Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, KY 40202, USA; Department of Microbiology and Immunology, University of Louisville, School of Medicine, Louisville, KY 40202, USA.
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Davies AJ, Rinaldi S, Costigan M, Oh SB. Cytotoxic Immunity in Peripheral Nerve Injury and Pain. Front Neurosci 2020; 14:142. [PMID: 32153361 PMCID: PMC7047751 DOI: 10.3389/fnins.2020.00142] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 02/04/2020] [Indexed: 12/13/2022] Open
Abstract
Cytotoxicity and consequent cell death pathways are a critical component of the immune response to infection, disease or injury. While numerous examples of inflammation causing neuronal sensitization and pain have been described, there is a growing appreciation of the role of cytotoxic immunity in response to painful nerve injury. In this review we highlight the functions of cytotoxic immune effector cells, focusing in particular on natural killer (NK) cells, and describe the consequent action of these cells in the injured nerve as well as other chronic pain conditions and peripheral neuropathies. We describe how targeted delivery of cytotoxic factors via the immune synapse operates alongside Wallerian degeneration to allow local axon degeneration in the absence of cell death and is well-placed to support the restoration of homeostasis within the nerve. We also summarize the evidence for the expression of endogenous ligands and receptors on injured nerve targets and infiltrating immune cells that facilitate direct neuro-immune interactions, as well as modulation of the surrounding immune milieu. A number of chronic pain and peripheral neuropathies appear comorbid with a loss of function of cellular cytotoxicity suggesting such mechanisms may actually help to resolve neuropathic pain. Thus while the immune response to peripheral nerve injury is a major driver of maladaptive pain, it is simultaneously capable of directing resolution of injury in part through the pathways of cellular cytotoxicity. Our growing knowledge in tuning immune function away from inflammation toward recovery from nerve injury therefore holds promise for interventions aimed at preventing the transition from acute to chronic pain.
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Affiliation(s)
- Alexander J. Davies
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Simon Rinaldi
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Michael Costigan
- Department of Anesthesia, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
- Department of Neurobiology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Seog Bae Oh
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
- Dental Research Institute and Department of Neurobiology & Physiology, School of Dentistry, Seoul National University, Seoul, South Korea
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46
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Yu X, Jiaerken Y, Wang S, Hong H, Jackson A, Yuan L, Lou M, Jiang Q, Zhang M, Huang P. Changes in the Corticospinal Tract Beyond the Ischemic Lesion Following Acute Hemispheric Stroke: A Diffusion Kurtosis Imaging Study. J Magn Reson Imaging 2020; 52:512-519. [PMID: 31981400 DOI: 10.1002/jmri.27066] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 11/07/2022] Open
Affiliation(s)
- Xinfeng Yu
- Department of RadiologyThe 2 Affiliated Hospital, Zhejiang University School of Medicine Hangzhou China
| | - Yeerfan Jiaerken
- Department of RadiologyThe 2 Affiliated Hospital, Zhejiang University School of Medicine Hangzhou China
| | - Shuyue Wang
- Department of RadiologyThe 2 Affiliated Hospital, Zhejiang University School of Medicine Hangzhou China
| | - Hui Hong
- Department of RadiologyThe 2 Affiliated Hospital, Zhejiang University School of Medicine Hangzhou China
| | - Alan Jackson
- Wolfson Molecular Imaging CentreUniversity of Manchester Manchester UK
| | - Lixia Yuan
- Institutes of Psychological SciencesCollege of Education, Hangzhou Normal University Hangzhou China
| | - Min Lou
- Department of NeurologyThe 2 Affiliated Hospital, Zhejiang University School of Medicine Hangzhou China
| | - Quan Jiang
- Department of NeurologyHenry Ford Health System Detroit Michigan USA
| | - Minming Zhang
- Department of RadiologyThe 2 Affiliated Hospital, Zhejiang University School of Medicine Hangzhou China
| | - Peiyu Huang
- Department of RadiologyThe 2 Affiliated Hospital, Zhejiang University School of Medicine Hangzhou China
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Abstract
Neuronal activity can be modulated by mechanical stimuli. To study this phenomenon quantitatively, we mechanically stimulated rat cortical neurons by shear stress and local indentation. Neurons show 2 distinct responses, classified as transient and sustained. Transient responses display fast kinetics, similar to spontaneous neuronal activity, whereas sustained responses last several minutes before returning to baseline. Local soma stimulations with micrometer-sized beads evoke transient responses at low forces of ∼220 nN and pressures of ∼5.6 kPa and sustained responses at higher forces of ∼360 nN and pressures of ∼9.2 kPa. Among the neuronal compartments, axons are highly susceptible to mechanical stimulation and predominantly show sustained responses, whereas the less susceptible dendrites predominantly respond transiently. Chemical perturbation experiments suggest that mechanically evoked responses require the influx of extracellular calcium through ion channels. We propose that subtraumatic forces/pressures applied to neurons evoke neuronal responses via nonspecific gating of ion channels.
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Orem BC, Partain SB, Stirling DP. Inhibiting store-operated calcium entry attenuates white matter secondary degeneration following SCI. Neurobiol Dis 2019; 136:104718. [PMID: 31846736 DOI: 10.1016/j.nbd.2019.104718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 11/22/2019] [Accepted: 12/13/2019] [Indexed: 01/11/2023] Open
Abstract
Axonal degeneration plays a key role in the pathogenesis of numerous neurological disorders including spinal cord injury. After the irreversible destruction of the white matter elements during the primary (mechanical) injury, spared axons and their supporting glial cells begin to breakdown causing an expansion of the lesion site. Here we mechanistically link external sources of calcium entry through axoplasmic reticulum calcium store depletion that contributes to secondary axonal degeneration through a process called store-operated calcium entry. There is increasing evidence suggesting that store-operated calcium entry impairment is responsible for numerous disorders. Nevertheless, its role following spinal cord injury remains poorly understood. We hypothesize that store-operated calcium entry mediates secondary white matter degeneration after spinal cord injury. We used our previously published model of laser-induced spinal cord injury to focally transect mid cervical dorsal column axons from live 6-8-week-old heterozygous CNPaseGFP/+: Thy1YFP+ double transgenic murine spinal cord preparations (five treated, eight controls) and documented the dynamic changes in axons over time using two-photon excitation microscopy. We report that 1 hour delayed treatment with YM-58483, a potent inhibitor of store-operated calcium entry, significantly decreased intra-axonal calcium accumulation, axonal dieback both proximal and distal to the lesion site, reduced secondary axonal "bystander" damage acutely after injury, and promoted greater oligodendrocyte survival compared to controls. We also targeted store-operated calcium entry following a clinically relevant contusion spinal cord injury model in vivo. Adult, 6-8-week-old Advillin-Cre: Ai9 mice were subjected to a mild 30 kdyn contusion and imaged to observe secondary axonal degeneration in live animals. We found that delayed treatment with YM-58483 increased axonal survival and reduced axonal spheroid formation compared to controls (n = 5 mice per group). These findings suggest that blocking store-operated calcium entry acutely is neuroprotective and introduces a novel target to prevent pathological calcium entry following spinal cord injury using a clinically relevant model.
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Affiliation(s)
- Ben C Orem
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY 40202, USA; Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40202, USA
| | - Steven B Partain
- Department of Bioengineering, University of Louisville, Louisville, KY 40202, USA
| | - David P Stirling
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY 40202, USA; Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, Louisville, KY 40202, USA; Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202, USA.
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Barros Ribeiro da Silva V, Porcionatto M, Toledo Ribas V. The Rise of Molecules Able To Regenerate the Central Nervous System. J Med Chem 2019; 63:490-511. [PMID: 31518122 DOI: 10.1021/acs.jmedchem.9b00863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Injury to the adult central nervous system (CNS) usually leads to permanent deficits of cognitive, sensory, and/or motor functions. The failure of axonal regeneration in the damaged CNS limits functional recovery. The lack of information concerning the biological mechanism of axonal regeneration and its complexity has delayed the process of drug discovery for many years compared to other drug classes. Starting in the early 2000s, the ability of many molecules to stimulate axonal regrowth was evaluated through automated screening techniques; many hits and some new mechanisms involved in axonal regeneration were identified. In this Perspective, we discuss the rise of the CNS regenerative drugs, the main biological techniques used to test these drug candidates, some of the most important screens performed so far, and the main challenges following the identification of a drug that is able to induce axonal regeneration in vivo.
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Affiliation(s)
| | - Marimélia Porcionatto
- Universidade Federal de São Paulo , Escola Paulista de Medicina, Laboratório de Neurobiologia Molecular, Departmento de Bioquímica , Rua Pedro de Toledo, 669 - third floor, 04039-032 São Paulo , São Paolo , Brazil
| | - Vinicius Toledo Ribas
- Universidade Federal de Minas Gerais , Instituto de Ciências Biológicas, Departamento de Morfologia, Laboratório de Neurobiologia Av. Antônio Carlos, 6627, room O3-245 , - Campus Pampulha, 31270-901 , Belo Horizonte , Minas Gerais , Brazil
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Wang C, Gong Z, Huang X, Wang J, Xia K, Ying L, Shu J, Yu C, Zhou X, Li F, Liang C, Chen Q. An injectable heparin-Laponite hydrogel bridge FGF4 for spinal cord injury by stabilizing microtubule and improving mitochondrial function. Am J Cancer Res 2019; 9:7016-7032. [PMID: 31660084 PMCID: PMC6815951 DOI: 10.7150/thno.37601] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 07/25/2019] [Indexed: 12/13/2022] Open
Abstract
Rationale: Spinal cord injury (SCI) remains a critical clinical challenge. The controlled release of FGF4, a novel neuroprotective factor, from a versatile Laponite hydrogel to the injured site was a promising strategy to promote axon regeneration and motor functional recovery after SCI. Methods: Characterization of Laponite, Laponite/Heparin (Lap/Hep) and Laponite/Heparin loaded with FGF4 (Lap/Hep@FGF4) hydrogels were measured by rheometer. Multiple comprehensive evaluations were used to detect motor functional recovery and the axonal rehabilitation after Lap/Hep@FGF4 treatment in vivo (SCI rat model). Moreover, microtubule dynamic and energy transportation, which regulated axonal regeneration was evaluated by Lap/Hep@FGF4 gel in vitro (primary neuron). Results: FGF4 released from Lap/Hep gel locally achieves strong protection and regeneration after SCI. The Lap/Hep@FGF4 group revealed remarkable motor functional recovery and axonal regrowth after SCI through suppressing inflammatory reaction, increasing remyelination and reducing glial/fibrotic scars. Furthermore, the underlying mechanism of axonal rehabilitation were demonstrated via enhancing microtubule stability and regulating mitochondrial localization after Lap/Hep@FGF4 treatment. Conclusion: This promising sustained release system provides a synergistic effective approach to enhance recovery after SCI underlying a novel mechanism of axonal rehabilitation, and shows a translational prospect for the clinical treatment of SCI.
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