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Ji X, Walczak P, van Beusekom HM, Casas AI, Clarkson A, Farr T, Jolkkonen J, Liang Y, Modo MM, Rosado-de-Castro PH, Ruscher K, Wang YJ, Wu H, Zille M, Li S, Boltze J. Join us on an amazing journey towards next-generation treatments for CNS disorders: Launch of Neuroprotection, a new high-quality journal in translational neuroscience. Neuroprotection 2023; 1:5-8. [PMID: 37701815 PMCID: PMC10494522 DOI: 10.1002/nep3.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 07/29/2022] [Indexed: 09/14/2023]
Affiliation(s)
- Xuming Ji
- Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Piotr Walczak
- Center for Advanced Imaging Research, Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, MD, USA
| | - Heleen M.M. van Beusekom
- Department of Cardiology, Erasmus MC Rotterdam, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Ana I. Casas
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), Department of Neurology, University Clinics Essen, Essen, Germany
| | - Andrew Clarkson
- Department of Anatomy, Brain Health Research Center and Brain Research New Zealand, Dunedin, New Zealand
| | - Tracy Farr
- Medical School, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Jukka Jolkkonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Yajie Liang
- Center for Advanced Imaging Research, Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, MD, USA
| | - Michel M. Modo
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Paulo H. Rosado-de-Castro
- Department of Anatomy, Institute of Biomedical Sciences, and Department of Radiology, School of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Karsten Ruscher
- Laboratory for Experimental Brain Research, University of Lund, Lund, Sweden
| | - Yan-Jiang Wang
- Department of Neurology and Center for Clinical Neuroscience, Daping Hospital, Chongqing, China
| | - Haitao Wu
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Marietta Zille
- Department of Pharmaceutical Sciences, Division of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Shen Li
- Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- Department of Neurology and Psychiatry, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Johannes Boltze
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
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Ayanwuyi L, Tokarska N, McLean NA, Johnston JM, Verge VMK. Brief electrical nerve stimulation enhances intrinsic repair capacity of the focally demyelinated central nervous system. Neural Regen Res 2021; 17:1042-1050. [PMID: 34558531 PMCID: PMC8552867 DOI: 10.4103/1673-5374.324848] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Our lab has shown that brief electrical nerve stimulation (ES) has a dramatic impact on remyelination of lysophosphatidyl choline (LPC)-induced focally demyelinated rat peripheral nerves, while also inducing an axon-protective phenotype and shifting macrophages from a predominantly pro-inflammatory toward a pro-repair phenotype. Whether this same potential exists in the central nervous system is not known. Thus, for proof of principle studies, the peripheral nerve demyelination and ES model was adapted to the central nervous system, whereby a unilateral focal LPC-induced demyelination of the dorsal column at the lumbar enlargement where the sciatic nerve afferents enter was created, so that subsequent ipsilateral sciatic nerve ES results in increased neural activity in the demyelinated axons. Data reveal a robust focal demyelination at 7 days post-LPC injection. Delivery of 1-hour ES at 7 days post-LPC polarizes macrophages/microglia toward a pro-repair phenotype when examined at 14 days post-LPC; results in smaller LPC-associated regions of inflammation compared to non-stimulated controls; results in significantly more cells of the oligodendroglial lineage in the demyelinated region; elevates myelin basic protein levels; and shifts the paranodal protein Caspr along demyelinated axons to a more restricted distribution, consistent with reformation of the paranodes of the nodes of Ranvier. ES also significantly enhanced levels of phosphorylated neurofilaments detected in the zones of demyelination, which has been shown to confer axon protection. Collectively these findings support that strategies that increase neural activity, such as brief electrical stimulation, can be beneficial for promoting intrinsic repair following focal demyelinating insults in demyelinating diseases such as multiple sclerosis. All animal procedures performed were approved by the University of Saskatchewan's Animal Research Ethics Board (protocol# 20090087; last approval date: November 5, 2020).
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Affiliation(s)
- Lydia Ayanwuyi
- Department of Anatomy, Physiology and Pharmacology; Cameco MS Neuroscience Research Center, University of Saskatchewan, Saskatoon, SK, Canada
| | - Nataliya Tokarska
- Department of Anatomy, Physiology and Pharmacology; Cameco MS Neuroscience Research Center, University of Saskatchewan, Saskatoon, SK, Canada
| | - Nikki A McLean
- Department of Anatomy, Physiology and Pharmacology; Cameco MS Neuroscience Research Center, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jayne M Johnston
- Department of Anatomy, Physiology and Pharmacology; Cameco MS Neuroscience Research Center, University of Saskatchewan, Saskatoon, SK, Canada
| | - Valerie M K Verge
- Department of Anatomy, Physiology and Pharmacology; Cameco MS Neuroscience Research Center, University of Saskatchewan, Saskatoon, SK, Canada
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Abstract
Injuries to the central or peripheral nervous system frequently cause long-term disabilities because damaged neurons are unable to efficiently self-repair. This inherent deficiency necessitates the need for new treatment options aimed at restoring lost function to patients. Compared to humans, a number of species possess far greater regenerative capabilities, and can therefore provide important insights into how our own nervous systems can be repaired. In particular, several invertebrate species have been shown to rapidly initiate regeneration post-injury, allowing separated axon segments to re-join. This process, known as axonal fusion, represents a highly efficient repair mechanism as a regrowing axon needs to only bridge the site of damage and fuse with its separated counterpart in order to re-establish its original structure. Our recent findings in the nematode Caenorhabditis elegans have expanded the promise of axonal fusion by demonstrating that it can restore complete function to damaged neurons. Moreover, we revealed the importance of injury-induced changes in the composition of the axonal membrane for mediating axonal fusion, and discovered that the level of axonal fusion can be enhanced by promoting a neuron's intrinsic growth potential. A complete understanding of the molecular mechanisms controlling axonal fusion may permit similar approaches to be applied in a clinical setting.
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Affiliation(s)
- Jean-Sébastien Teoh
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Michelle Yu-Ying Wong
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Tarika Vijayaraghavan
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Brent Neumann
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
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Abay ZC, Wong MY, Teoh JS, Vijayaraghavan T, Hilliard MA, Neumann B. Phosphatidylserine save-me signals drive functional recovery of severed axons in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2017; 114:E10196-205. [PMID: 29109263 DOI: 10.1073/pnas.1703807114] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Nervous system injury can cause lifelong disability, because repair rarely leads to reconnection with the target tissue. In the nematode Caenorhabditis elegans and in several other species, regeneration can proceed through a mechanism of axonal fusion, whereby regrowing axons reconnect and fuse with their own separated fragments, rapidly and efficiently restoring the original axonal tract. We have found that the process of axonal fusion restores full function to damaged neurons. In addition, we show that injury-induced changes to the axonal membrane that result in exposure of lipid “save-me” signals mediate the level of axonal fusion. Thus, our results establish axonal fusion as a complete regenerative mechanism that can be modulated by changing the level of save-me signals exposed after injury. Functional regeneration after axonal injury requires transected axons to regrow and reestablish connection with their original target tissue. The spontaneous regenerative mechanism known as axonal fusion provides a highly efficient means of achieving targeted reconnection, as a regrowing axon is able to recognize and fuse with its own detached axon segment, thereby rapidly reestablishing the original axonal tract. Here, we use behavioral assays and fluorescent reporters to show that axonal fusion enables full recovery of function after axotomy of Caenorhabditis elegans mechanosensory neurons. Furthermore, we reveal that the phospholipid phosphatidylserine, which becomes exposed on the damaged axon to function as a “save-me” signal, defines the level of axonal fusion. We also show that successful axonal fusion correlates with the regrowth potential and branching of the proximal fragment and with the retraction length and degeneration of the separated segment. Finally, we identify discrete axonal domains that vary in their propensity to regrow through fusion and show that the level of axonal fusion can be genetically modulated. Taken together, our results reveal that axonal fusion restores full function to injured neurons, is dependent on exposure of phospholipid signals, and is achieved through the balance between regenerative potential and level of degeneration.
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