1
|
Kaszás D, Enyedi B. Addressing burning questions on axon regeneration. eLife 2024; 13:e101093. [PMID: 39172507 PMCID: PMC11341088 DOI: 10.7554/elife.101093] [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] [Indexed: 08/23/2024] Open
Abstract
Regeneration of sensory axons after a burn injury depends on early keratinocyte responses regulated by the wound microenvironment.
Collapse
Affiliation(s)
- Diána Kaszás
- Department of Physiology, Faculty of Medicine, Semmelweis UniversityBudapestHungary
| | - Balázs Enyedi
- Department of Physiology, Faculty of Medicine, Semmelweis UniversityBudapestHungary
| |
Collapse
|
2
|
Cao X, Zhang Y, Shi Y, Li Y, Gao L, Wang X, Sun L. Identification of critical mitochondrial hub gene for facial nerve regeneration. Biochem Cell Biol 2024; 102:179-193. [PMID: 38086039 DOI: 10.1139/bcb-2023-0224] [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] [Indexed: 01/23/2024] Open
Abstract
Mitochondria play a critical role in nerve regeneration, yet the impact of gene expression changes related to mitochondria in facial nerve regeneration remains unknown. To address this knowledge gap, we analyzed the expression profile of the facial motor nucleus (FMN) using data obtained from the Gene Expression Omnibus (GEO) database (GSE162977). By comparing different time points in the data, we identified differentially expressed genes (DEGs). Additionally, we collected mitochondria-related genes from the Gene Ontology (GO) database and intersected them with the DEGs, resulting in the identification of mitochondria-related DEGs (MIT-DEGs). To gain further insights, we performed functional enrichment and pathway analysis of the MIT-DEGs. To explore the interactions among these MIT-DEGs, we constructed a protein-protein interaction (PPI) network using the STRING database and identified hub genes using the Degree algorithm of Cytoscape software. To validate the relevance of these genes to nerve regeneration, we established a rat facial nerve injury (FNI) model and conducted a series of experiments. Through these experiments, we confirmed three MIT-DEGs (Myc, Lyn, and Cdk1) associated with facial nerve regeneration. Our findings provide valuable insights into the transcriptional changes of mitochondria-related genes in the FMN following FNI, which can contribute to the development of new treatment strategies for FNI.
Collapse
Affiliation(s)
- Xiaofang Cao
- Department of Dentistry, The Second Affiliated Hospital, Harbin Medical University, Harbin, China
- Heilongjiang Provincial Key Laboratory of Hard Tissue Development and Regeneration, Harbin Medical University, Harbin, China
| | - Yan Zhang
- Department of Dentistry, The Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Yu Shi
- Department of Dentistry, The Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Ying Li
- Heilongjiang Provincial Key Laboratory of Hard Tissue Development and Regeneration, Harbin Medical University, Harbin, China
- Heilongjiang Academy of Medical Sciences, Harbin, China
| | - Li Gao
- Department of Dentistry, The Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Xiumei Wang
- Department of Dentistry, The Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Liang Sun
- Department of Human Anatomy, School of Basic Medicine, Harbin Medical University, Harbin, China
| |
Collapse
|
3
|
Dejanovic B, Sheng M, Hanson JE. Targeting synapse function and loss for treatment of neurodegenerative diseases. Nat Rev Drug Discov 2024; 23:23-42. [PMID: 38012296 DOI: 10.1038/s41573-023-00823-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2023] [Indexed: 11/29/2023]
Abstract
Synapse dysfunction and loss are hallmarks of neurodegenerative diseases that correlate with cognitive decline. However, the mechanisms and therapeutic strategies to prevent or reverse synaptic damage remain elusive. In this Review, we discuss recent advances in understanding the molecular and cellular pathways that impair synapses in neurodegenerative diseases, including the effects of protein aggregation and neuroinflammation. We also highlight emerging therapeutic approaches that aim to restore synaptic function and integrity, such as enhancing synaptic plasticity, preventing synaptotoxicity, modulating neuronal network activity and targeting immune signalling. We discuss the preclinical and clinical evidence for each strategy, as well as the challenges and opportunities for developing effective synapse-targeting therapeutics for neurodegenerative diseases.
Collapse
Affiliation(s)
| | - Morgan Sheng
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jesse E Hanson
- Department of Neuroscience, Genentech, South San Francisco, CA, USA.
| |
Collapse
|
4
|
Lu Q, Zhang Y, Botchway BOA, Huang M, Liu X. Syntaphilin Inactivation Can Enhance Axonal Mitochondrial Transport to Improve Spinal Cord Injury. Mol Neurobiol 2023; 60:6556-6565. [PMID: 37458986 DOI: 10.1007/s12035-023-03494-6] [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: 02/25/2023] [Accepted: 07/08/2023] [Indexed: 09/28/2023]
Abstract
Mitochondria are important organelle of eukaryotic cells. They consists of a large number of different proteins that provide most of the ATP and supply power for the growth, function, and regeneration of neurons. Therefore, smitochondrial transport ensures that adequate ATP is supplied for metabolic activities. Spinal cord injury (SCI), a detrimental condition, has high morbidity and mortality rates. Currently, the available treatments only provide symptomatic relief for long-term disabilities. Studies have implicated mitochondrial transport as a critical factor in axonal regeneration. Hence, enhancing mitochondrial transports could be beneficial for ameliorating SCI. Syntaphilin (Snph) is a mitochondrial docking protein that acts as a "static anchor," and its inhibition enhances mitochondrial transports. Therefore, Snph as a key mediator of mitochondrial transports, may contribute to improving axonal regeneration following SCI. Herein, we examine Snph's biological effects and its relation to mitochondrial pathway. Then, we elaborate on mitochondrial transports after SCI, the possible role of Snph in SCI, and some possible therapeutic approaches by Snph.
Collapse
Affiliation(s)
- Qicheng Lu
- Department of Histology and Embryology, Medical College, Shaoxing University, Shaoxing, 312000, Zhejiang, China
| | - Yong Zhang
- Department of Histology and Embryology, Medical College, Shaoxing University, Shaoxing, 312000, Zhejiang, China
| | - Benson O A Botchway
- Institute of Neuroscience, Zhejiang University School of Medicine, Hangzhou, China
- Bupa Cromwell Hospital, London, UK
| | - Min Huang
- Department of Histology and Embryology, Medical College, Shaoxing University, Shaoxing, 312000, Zhejiang, China
| | - Xuehong Liu
- Department of Histology and Embryology, Medical College, Shaoxing University, Shaoxing, 312000, Zhejiang, China.
| |
Collapse
|
5
|
Guha L, Singh N, Kumar H. Different Ways to Die: Cell Death Pathways and Their Association With Spinal Cord Injury. Neurospine 2023; 20:430-448. [PMID: 37401061 PMCID: PMC10323345 DOI: 10.14245/ns.2244976.488] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 07/22/2023] Open
Abstract
Cell death is a systematic/nonsystematic process of cessation of normal morphology and functional properties of the cell to replace and recycle old cells with new also promoting inflammation in some cases. It is a complicated process comprising multiple pathways. Some are well-explored, and others have just begun to be. The research on appropriate control of cell death pathways after acute and chronic damage of neuronal cells is being widely researched today due to the lack of regeneration and recovering potential of a neuronal cell after sustaining damage and the inability to control the direction of neuronal growth. In the progression and onset of various neurological diseases, impairments in programmed cell death signaling processes, like necroptosis, apoptosis, ferroptosis, pyroptosis, and pathways directly or indirectly linked, like autophagy as in nonprogrammed necrosis, are observed. Spinal cord injury (SCI) involves the temporary or permanent disruption of motor activities due to the death of a neuronal and glial cell in the spinal cord accompanied by axonal degeneration. Recent years have seen a significant increase in research on the intricate biochemical interactions that occur after a SCI. Different cell death pathways may significantly impact the subsequent damage processes that lead to the eventual neurological deficiency after an injury to the spinal cord. A better knowledge of the molecular basis of the involved cell death pathways might help enhance neuronal and glial survival and neurological deficits, promoting a curative path for SCI.
Collapse
Affiliation(s)
- Lahanya Guha
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat, India
| | - Nidhi Singh
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER)- Ahmedabad, Gandhinagar, Gujarat, India
| | - Hemant Kumar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat, India
| |
Collapse
|
6
|
Autophagy protein ULK1 interacts with and regulates SARM1 during axonal injury. Proc Natl Acad Sci U S A 2022; 119:e2203824119. [PMID: 36375051 PMCID: PMC9704737 DOI: 10.1073/pnas.2203824119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Autophagy is a cellular catabolic pathway generally thought to be neuroprotective. However, autophagy and in particular its upstream regulator, the ULK1 kinase, can also promote axonal degeneration. We examined the role and the mechanisms of autophagy in axonal degeneration using a mouse model of contusive spinal cord injury (SCI). Consistent with activation of autophagy during axonal degeneration following SCI, autophagosome marker LC3, ULK1 kinase, and ULK1 target, phospho-ATG13, accumulated in the axonal bulbs and injured axons. SARM1, a TIR NADase with a pivotal role in axonal degeneration, colocalized with ULK1 within 1 h after SCI, suggesting possible interaction between autophagy and SARM1-mediated axonal degeneration. In our in vitro experiments, inhibition of autophagy, including Ulk1 knockdown and ULK1 inhibitor, attenuated neurite fragmentation and reduced accumulation of SARM1 puncta in neurites of primary cortical neurons subjected to glutamate excitotoxicity. Immunoprecipitation data demonstrated that ULK1 physically interacted with SARM1 in vitro and in vivo and that SAM domains of SARM1 were necessary for ULK1-SARM1 complex formation. Consistent with a role in regulation of axonal degeneration, in primary cortical neurons ULK1-SARM1 interaction increased upon neurite damage. Supporting a role for autophagy and ULK1 in regulation of SARM1 in axonal degeneration in vivo, axonal ULK1 activation and accumulation of SARM1 were both decreased after SCI in Becn1+/- autophagy hypomorph mice compared to wild-type (WT) controls. These findings suggest a regulatory crosstalk between autophagy and axonal degeneration pathways, which is mediated through ULK1-SARM1 interaction and contributes to the ability of SARM1 to accumulate in injured axons.
Collapse
|
7
|
Ostertag C, Klein D, Martini R. Presymptomatic macrophage targeting has a long-lasting therapeutic effect on treatment termination. Exp Neurol 2022; 357:114195. [PMID: 35931123 DOI: 10.1016/j.expneurol.2022.114195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 07/11/2022] [Accepted: 07/31/2022] [Indexed: 11/24/2022]
Abstract
Macrophage-mediated inflammation is a potent driver of disease progression in mouse models of Charcot-Marie-Tooth (CMT) 1 diseases. This leads to the possibility to consider these cells as therapeutic targets to dampen disease outcome in the so far non-treatable neuropathies. As a pharmacological proof-of-principle study, long-term targeting of nerve macrophages with the orally applied CSF-1 receptor specific kinase (c-FMS) inhibitor PLX5622 showed a substantial alleviation of the neuropathy in distinct CMT1 mouse models. However, regarding translational options, clinically relevant questions emerged regarding treatment onset, duration and termination. Corroborating previous data, we here show that in a model for CMT1B, peripheral neuropathy was substantially alleviated after early continuous PLX5622 treatment in CMT1B mice, leading to preserved motor function. However, late-onset treatment failed to mitigate histopathological and clinical features, despite a similar reduction in the number of macrophages. Surprisingly, in CMT1B mice, terminating early PLX5622 treatment at six months was still sufficient to preserve motor function at 12 months of age, suggesting a long-lasting, therapeutic effect of early macrophage depletion. This novel and unexpected finding may have important translational implications, since we here show that continuous macrophage targeting appears not to be necessary for disease alleviation, provided that the treatment starts within an early, critical time window.
Collapse
Affiliation(s)
- Charlotte Ostertag
- Department of Neurology, Developmental Neurobiology, University Hospital Würzburg, Würzburg, Germany
| | - Dennis Klein
- Department of Neurology, Developmental Neurobiology, University Hospital Würzburg, Würzburg, Germany.
| | - Rudolf Martini
- Department of Neurology, Developmental Neurobiology, University Hospital Würzburg, Würzburg, Germany.
| |
Collapse
|
8
|
Almasieh M, Faris H, Levin LA. Pivotal roles for membrane phospholipids in axonal degeneration. Int J Biochem Cell Biol 2022; 150:106264. [PMID: 35868612 DOI: 10.1016/j.biocel.2022.106264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/16/2022] [Accepted: 07/17/2022] [Indexed: 10/17/2022]
Abstract
Membrane phospholipids are critical components of several signaling pathways. Maintained in a variety of asymmetric distributions, their trafficking across the membrane can be induced by intra-, extra-, and intercellular events. A familiar example is the externalization of phosphatidylserine from the inner leaflet to the outer leaflet in apoptosis, inducing phagocytosis of the soma. Recently, it has been recognized that phospholipids in the axonal membrane may be a signal for axonal degeneration, regeneration, or other processes. This review focuses on key recent developments and areas for ongoing investigations. KEY FACTS: Phosphatidylserine externalization propagates along an axon after axonal injury and is delayed in the Wallerian degeneration slow (WldS) mutant. The ATP8A2 flippase mutant has spontaneous axonal degeneration. Microdomains of axonal degeneration in spheroid bodies have differential externalization of phosphatidylserine and phosphatidylethanolamine. Phospholipid trafficking could represent a mechanism for coordinated axonal degeneration and elimination, i.e. axoptosis, analogous to apoptosis of the cell body.
Collapse
Affiliation(s)
- Mohammadali Almasieh
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada
| | - Hannah Faris
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada
| | - Leonard A Levin
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, Canada.
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Holzer AK, Suciu I, Karreman C, Goj T, Leist M. Specific Attenuation of Purinergic Signaling during Bortezomib-Induced Peripheral Neuropathy In Vitro. Int J Mol Sci 2022; 23:ijms23073734. [PMID: 35409095 PMCID: PMC8998302 DOI: 10.3390/ijms23073734] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 12/18/2022] Open
Abstract
Human peripheral neuropathies are poorly understood, and the availability of experimental models limits further research. The PeriTox test uses immature dorsal root ganglia (DRG)-like neurons, derived from induced pluripotent stem cells (iPSC), to assess cell death and neurite damage. Here, we explored the suitability of matured peripheral neuron cultures for the detection of sub-cytotoxic endpoints, such as altered responses of pain-related P2X receptors. A two-step differentiation protocol, involving the transient expression of ectopic neurogenin-1 (NGN1) allowed for the generation of homogeneous cultures of sensory neurons. After >38 days of differentiation, they showed a robust response (Ca2+-signaling) to the P2X3 ligand α,β-methylene ATP. The clinical proteasome inhibitor bortezomib abolished the P2X3 signal at ≥5 nM, while 50−200 nM was required in the PeriTox test to identify neurite damage and cell death. A 24 h treatment with low nM concentrations of bortezomib led to moderate increases in resting cell intracellular Ca2+ concentration but signaling through transient receptor potential V1 (TRPV1) receptors or depolarization-triggered Ca2+ influx remained unaffected. We interpreted the specific attenuation of purinergic signaling as a functional cell stress response. A reorganization of tubulin to form dense structures around the cell somata confirmed a mild, non-cytotoxic stress triggered by low concentrations of bortezomib. The proteasome inhibitors carfilzomib, delanzomib, epoxomicin, and MG-132 showed similar stress responses. Thus, the model presented here may be used for the profiling of new proteasome inhibitors in regard to their side effect (neuropathy) potential, or for pharmacological studies on the attenuation of their neurotoxicity. P2X3 signaling proved useful as endpoint to assess potential neurotoxicants in peripheral neurons.
Collapse
Affiliation(s)
- Anna-Katharina Holzer
- In Vitro Toxicology and Biomedicine, Dept Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (A.-K.H.); (I.S.); (C.K.); (T.G.)
| | - Ilinca Suciu
- In Vitro Toxicology and Biomedicine, Dept Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (A.-K.H.); (I.S.); (C.K.); (T.G.)
- Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, 78457 Konstanz, Germany
| | - Christiaan Karreman
- In Vitro Toxicology and Biomedicine, Dept Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (A.-K.H.); (I.S.); (C.K.); (T.G.)
| | - Thomas Goj
- In Vitro Toxicology and Biomedicine, Dept Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (A.-K.H.); (I.S.); (C.K.); (T.G.)
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Dept Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (A.-K.H.); (I.S.); (C.K.); (T.G.)
- CAAT-Europe, University of Konstanz, 78457 Konstanz, Germany
- Correspondence: ; Tel.: +49-(0)-7531-88-5037
| |
Collapse
|
11
|
Quantification of Neurite Degeneration with Enhanced Accuracy and Efficiency in an In Vitro Model of Parkinson's Disease. eNeuro 2022; 9:ENEURO.0327-21.2022. [PMID: 35210286 PMCID: PMC8938979 DOI: 10.1523/eneuro.0327-21.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 01/21/2022] [Accepted: 01/30/2022] [Indexed: 11/21/2022] Open
Abstract
Neurite degeneration is associated with early stages of neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease (PD), and amyotrophic lateral sclerosis. One method that is commonly used to analyze neurite degeneration involves calculation of a Degeneration Index (DI) following utilization of the Analyze Particles tool of ImageJ to detect neurite fragments in micrographs of cultured cells. However, DI analyses are prone to several types of measurement error, can be time consuming to perform, and are limited in application. Here, we describe an improved method for performing DI analyses. Accuracy of measurements was enhanced through modification of selection criteria for detecting neurite fragments, removal of image artifacts and non-neurite materials from images, and optimization of image contrast. Such enhancements were implemented into an ImageJ macro that enables rapid and fully automated DI analysis of multiple images. The macro features operations for automated removal of cell bodies from micrographs, thus expanding the application of DI analyses to use in experiments involving dissociated cultures. We present experimental findings supporting that, compared with the conventional method, the enhanced analysis method yields measurements with increased accuracy and requires significantly less time to perform. Furthermore, we demonstrate the utility of the method to investigate neurite degeneration in a cell culture model of PD by conducting an experiment revealing the effects of c-Jun N-terminal kinase (JNK) on neurite degeneration induced by oxidative stress in human mesencephalic cells. This improved analysis method may be used to gain novel insight into factors underlying neurite degeneration and the progression of neurodegenerative disorders.
Collapse
|
12
|
Lee B, Oh Y, Cho E, DiAntonio A, Cavalli V, Shin JE, Choi HW, Cho Y. FK506-binding protein-like and FK506-binding protein 8 regulate dual leucine zipper kinase degradation and neuronal responses to axon injury. J Biol Chem 2022; 298:101647. [PMID: 35101451 PMCID: PMC8881485 DOI: 10.1016/j.jbc.2022.101647] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/21/2022] [Accepted: 01/23/2022] [Indexed: 12/17/2022] Open
Abstract
The dual leucine zipper kinase (DLK) is a key regulator of axon regeneration and degeneration in response to neuronal injury; however, regulatory mechanisms of the DLK function via its interacting proteins are largely unknown. To better understand the molecular mechanism of DLK function, we performed yeast two-hybrid screening analysis and identified FK506-binding protein-like (FKBPL, also known as WAF-1/CIP1 stabilizing protein 39) as a DLK-binding protein. FKBPL binds to the kinase domain of DLK and inhibits its kinase activity. In addition, FKBPL induces DLK protein degradation through ubiquitin-dependent pathways. We further assessed other members in the FKBP protein family and found that FK506-binding protein 8 (FKBP8) also induced DLK degradation. We identified the lysine 271 residue in the kinase domain as a major site of DLK ubiquitination and SUMO3 conjugation and was thus responsible for regulating FKBP8-mediated proteasomal degradation that was inhibited by the substitution of the lysine 271 to arginine. FKBP8-mediated degradation of DLK is mediated by autophagy pathway because knockdown of Atg5 inhibited DLK destabilization. We show that in vivo overexpression of FKBP8 delayed the progression of axon degeneration and suppressed neuronal death after axotomy in sciatic and optic nerves. Taken together, this study identified FKBPL and FKBP8 as novel DLK-interacting proteins that regulate DLK stability via the ubiquitin-proteasome and lysosomal protein degradation pathways.
Collapse
Affiliation(s)
- Bohm Lee
- Department of Life Sciences, Korea University, Seoul, Republic of Korea
| | - Yeonsoo Oh
- Department of Life Sciences, Korea University, Seoul, Republic of Korea
| | - Eunhye Cho
- Department of Life Sciences, Korea University, Seoul, Republic of Korea
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Valeria Cavalli
- Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri, USA; Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, Missouri, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jung Eun Shin
- Department of Molecular Neuroscience, Dong-A University College of Medicine, Busan, Republic of Korea; Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea
| | - Hae Woong Choi
- Department of Life Sciences, Korea University, Seoul, Republic of Korea.
| | - Yongcheol Cho
- Department of Life Sciences, Korea University, Seoul, Republic of Korea.
| |
Collapse
|
13
|
Progression of optic atrophy in traumatic optic neuropathy: retrograde neuronal degeneration in humans. Neurol Sci 2021; 43:1351-1358. [PMID: 34241727 DOI: 10.1007/s10072-021-05448-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 06/29/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVE We used optical coherence tomography (OCT) to document the time course of retrograde neuronal degeneration following indirect optic nerve injury. METHODS We retrospectively studied patients diagnosed with unilateral indirect traumatic optic neuropathy (TON). Patients with total or near-total optic atrophy were included. All patients underwent complete ophthalmological examinations, including OCT imaging, within 1 day and at 1, 2, 3, 4, 6, 8, 12, 24, and 48 weeks after trauma. RESULTS The mean thicknesses of the circumpapillary retinal nerve fiber layer (cpRNFL) and macular retinal ganglion cell-inner plexiform layer (mGCIPL) decreased significantly at 2 weeks after trauma (p = 0.027 and p = 0.043). Changes in mGCIPL thickness preceded changes in cpRNFL thickness. The rates of reduction in mGCIPL and cpRNFL thicknesses were greatest between 2 to 4 weeks and 4 to 6 weeks after trauma. The reduction in mGCIPL thickness then slowed, and stabilized at 12 weeks after trauma. The proportions of cpRNFL and mGCIPL losses at 2, 4, 6, 8, and 12 weeks compared to 24 weeks were 17.1, 33.7, 59.8, 77.9, and 87.9% and 30.0, 73.3, 76.1, 88.3, and 97.9%, respectively. CONCLUSIONS OCT revealed optic atrophy progression 2 weeks after trauma, which was most rapid from 2 to 6 weeks, and then gradually stabilized. Loss of retinal ganglion cell bodies and dendrites seemed to precede the axonal degeneration. Observations of morphological changes in retinal layers using OCT in TON patients improve our understanding of retrograde neuronal degeneration of the central nervous system.
Collapse
|
14
|
Hopkins EL, Gu W, Kobe B, Coleman MP. A Novel NAD Signaling Mechanism in Axon Degeneration and its Relationship to Innate Immunity. Front Mol Biosci 2021; 8:703532. [PMID: 34307460 PMCID: PMC8295901 DOI: 10.3389/fmolb.2021.703532] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/28/2021] [Indexed: 12/21/2022] Open
Abstract
Axon degeneration represents a pathological feature of many neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease where axons die before the neuronal soma, and axonopathies, such as Charcot-Marie-Tooth disease and hereditary spastic paraplegia. Over the last two decades, it has slowly emerged that a central signaling pathway forms the basis of this process in many circumstances. This is an axonal NAD-related signaling mechanism mainly regulated by the two key proteins with opposing roles: the NAD-synthesizing enzyme NMNAT2, and SARM1, a protein with NADase and related activities. The crosstalk between the axon survival factor NMNAT2 and pro-degenerative factor SARM1 has been extensively characterized and plays an essential role in maintaining the axon integrity. This pathway can be activated in necroptosis and in genetic, toxic or metabolic disorders, physical injury and neuroinflammation, all leading to axon pathology. SARM1 is also known to be involved in regulating innate immunity, potentially linking axon degeneration to the response to pathogens and intercellular signaling. Understanding this NAD-related signaling mechanism enhances our understanding of the process of axon degeneration and enables a path to the development of drugs for a wide range of neurodegenerative diseases.
Collapse
Affiliation(s)
- Eleanor L. Hopkins
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Weixi Gu
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Michael P. Coleman
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
15
|
Pinto MJ, Tomé D, Almeida RD. The Ubiquitinated Axon: Local Control of Axon Development and Function by Ubiquitin. J Neurosci 2021; 41:2796-2813. [PMID: 33789876 PMCID: PMC8018891 DOI: 10.1523/jneurosci.2251-20.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 01/15/2021] [Accepted: 01/22/2021] [Indexed: 02/01/2023] Open
Abstract
Ubiquitin tagging sets protein fate. With a wide range of possible patterns and reversibility, ubiquitination can assume many shapes to meet specific demands of a particular cell across time and space. In neurons, unique cells with functionally distinct axons and dendrites harboring dynamic synapses, the ubiquitin code is exploited at the height of its power. Indeed, wide expression of ubiquitination and proteasome machinery at synapses, a diverse brain ubiquitome, and the existence of ubiquitin-related neurodevelopmental diseases support a fundamental role of ubiquitin signaling in the developing and mature brain. While special attention has been given to dendritic ubiquitin-dependent control, how axonal biology is governed by this small but versatile molecule has been considerably less discussed. Herein, we set out to explore the ubiquitin-mediated spatiotemporal control of an axon's lifetime: from its differentiation and growth through presynaptic formation, function, and pruning.
Collapse
Affiliation(s)
- Maria J Pinto
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, 3004-504, Portugal
| | - Diogo Tomé
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, 3004-504, Portugal
- Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, 3810-193, Portugal
| | - Ramiro D Almeida
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, 3004-504, Portugal
- Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, 3810-193, Portugal
| |
Collapse
|
16
|
Involvement of Bcl-xL in Neuronal Function and Development. Int J Mol Sci 2021; 22:ijms22063202. [PMID: 33801158 PMCID: PMC8004157 DOI: 10.3390/ijms22063202] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 12/23/2022] Open
Abstract
The B-cell lymphoma (Bcl-2) family of proteins are mainly known for their role in the regulation of apoptosis by preventing pore formation at the mitochondrial outer membrane and subsequent caspase activation. However, Bcl-2 proteins also have non-canonical functions, independent of apoptosis. Indeed, the cell death machinery, including Bcl-2 homologs, was reported to be essential for the central nervous system (CNS), notably with respect to synaptic transmission and axon pruning. Here we focused on Bcl-xL, a close Bcl-2 homolog, which plays a major role in neuronal development, as bclx knock out mice prematurely die at embryonic day 13.5, showing massive apoptosis in the CNS. In addition, we present evidence that Bcl-xL fosters ATP generation by the mitochondria to fuel high energy needs by neurons, and its contribution to synaptic transmission. We discuss how Bcl-xL might control local and transient activation of caspases in neurons without causing cell death. Consistently, Bcl-xL may contribute to morphological changes, such as sprouting and retractation of axon branches, in the context of CNS plasticity. Regarding degenerative diseases and aging, a better understanding of the numerous roles of the cell death machinery in neurons may have future clinical implications.
Collapse
|
17
|
Patel A, Koul P, Harel A. Wallerian degeneration as a mimic of recurrence of myelitis. Pract Neurol 2021; 21:235-236. [PMID: 33737387 DOI: 10.1136/practneurol-2020-002911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2021] [Indexed: 11/04/2022]
Abstract
A middle-aged woman with idiopathic longitudinally extensive myelitis underwent repeat MR scan of cervical spine at 5-month follow-up, which showed new non-enhancing T2 hyperintensities, initially reported as myelitis recurrence. However, the hyperintensities involved both lateral corticospinal tracts caudal to the initial lesion and both dorsal columns rostral to the initial lesion and were therefore compatible with Wallerian degeneration. This radiological mimic should be considered in the differential of recurrence of myelitis.
Collapse
Affiliation(s)
- Arpan Patel
- Neurology, North Shore University Hospital, Manhasset, New York, USA
| | - Prateeka Koul
- Neurology, North Shore University Hospital, Manhasset, New York, USA
| | - Asaff Harel
- Neurology, North Shore University Hospital, Manhasset, New York, USA .,Neurology, Lenox Hill Hospital, New York, New York, USA
| |
Collapse
|
18
|
Wang B, Huang M, Shang D, Yan X, Zhao B, Zhang X. Mitochondrial Behavior in Axon Degeneration and Regeneration. Front Aging Neurosci 2021; 13:650038. [PMID: 33762926 PMCID: PMC7982458 DOI: 10.3389/fnagi.2021.650038] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/18/2021] [Indexed: 12/19/2022] Open
Abstract
Mitochondria are organelles responsible for bioenergetic metabolism, calcium homeostasis, and signal transmission essential for neurons due to their high energy consumption. Accumulating evidence has demonstrated that mitochondria play a key role in axon degeneration and regeneration under physiological and pathological conditions. Mitochondrial dysfunction occurs at an early stage of axon degeneration and involves oxidative stress, energy deficiency, imbalance of mitochondrial dynamics, defects in mitochondrial transport, and mitophagy dysregulation. The restoration of these defective mitochondria by enhancing mitochondrial transport, clearance of reactive oxidative species (ROS), and improving bioenergetic can greatly contribute to axon regeneration. In this paper, we focus on the biological behavior of axonal mitochondria in aging, injury (e.g., traumatic brain and spinal cord injury), and neurodegenerative diseases (Alzheimer's disease, AD; Parkinson's disease, PD; Amyotrophic lateral sclerosis, ALS) and consider the role of mitochondria in axon regeneration. We also compare the behavior of mitochondria in different diseases and outline novel therapeutic strategies for addressing abnormal mitochondrial biological behavior to promote axonal regeneration in neurological diseases and injuries.
Collapse
Affiliation(s)
- Biyao Wang
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Minghao Huang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Dehao Shang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xu Yan
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Baohong Zhao
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xinwen Zhang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| |
Collapse
|
19
|
Moss KR, Bopp TS, Johnson AE, Höke A. New evidence for secondary axonal degeneration in demyelinating neuropathies. Neurosci Lett 2021; 744:135595. [PMID: 33359733 PMCID: PMC7852893 DOI: 10.1016/j.neulet.2020.135595] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 10/31/2020] [Accepted: 12/19/2020] [Indexed: 12/28/2022]
Abstract
Development of peripheral nervous system (PNS) myelin involves a coordinated series of events between growing axons and the Schwann cell (SC) progenitors that will eventually ensheath them. Myelin sheaths have evolved out of necessity to maintain rapid impulse propagation while accounting for body space constraints. However, myelinating SCs perform additional critical functions that are required to preserve axonal integrity including mitigating energy consumption by establishing the nodal architecture, regulating axon caliber by organizing axonal cytoskeleton networks, providing trophic and potentially metabolic support, possibly supplying genetic translation materials and protecting axons from toxic insults. The intermediate steps between the loss of these functions and the initiation of axon degeneration are unknown but the importance of these processes provides insightful clues. Prevalent demyelinating diseases of the PNS include the inherited neuropathies Charcot-Marie-Tooth Disease, Type 1 (CMT1) and Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and the inflammatory diseases Acute Inflammatory Demyelinating Polyneuropathy (AIDP) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Secondary axon degeneration is a common feature of demyelinating neuropathies and this process is often correlated with clinical deficits and long-lasting disability in patients. There is abundant electrophysiological and histological evidence for secondary axon degeneration in patients and rodent models of PNS demyelinating diseases. Fully understanding the involvement of secondary axon degeneration in these diseases is essential for expanding our knowledge of disease pathogenesis and prognosis, which will be essential for developing novel therapeutic strategies.
Collapse
Affiliation(s)
- Kathryn R Moss
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Taylor S Bopp
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Anna E Johnson
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Ahmet Höke
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States.
| |
Collapse
|
20
|
p53 is required for nuclear but not mitochondrial DNA damage-induced degeneration. Cell Death Dis 2021; 12:104. [PMID: 33473103 PMCID: PMC7817838 DOI: 10.1038/s41419-020-03373-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 12/16/2020] [Accepted: 12/22/2020] [Indexed: 12/18/2022]
Abstract
While the consequences of nuclear DNA damage have been well studied, the exact consequences of acute and selective mitochondrial DNA (mtDNA) damage are less understood. DNA damaging chemotherapeutic drugs are known to activate p53-dependent apoptosis in response to sustained nuclear DNA damage. While it is recognized that whole-cell exposure to these drugs also damages mtDNA, the specific contribution of mtDNA damage to cellular degeneration is less clear. To examine this, we induced selective mtDNA damage in neuronal axons using microfluidic chambers that allow for the spatial and fluidic isolation of neuronal cell bodies (containing nucleus and mitochondria) from the axons (containing mitochondria). Exposure of the DNA damaging drug cisplatin selectively to only the axons induced mtDNA damage in axonal mitochondria, without nuclear damage. We found that this resulted in the selective degeneration of only the targeted axons that were exposed to DNA damage, where ROS was induced but mitochondria were not permeabilized. mtDNA damage-induced axon degeneration was not mediated by any of the three known axon degeneration pathways: apoptosis, axon pruning, and Wallerian degeneration, as Bax-deficiency, or Casp3-deficiency, or Sarm1-deficiency failed to protect the degenerating axons. Strikingly, p53, which is essential for degeneration after nuclear DNA damage, was also not required for degeneration induced with mtDNA damage. This was most evident when the p53-deficient neurons were globally exposed to cisplatin. While the cell bodies of p53-deficient neurons were protected from degeneration in this context, the axons farthest from the cell bodies still underwent degeneration. These results highlight how whole cell exposure to DNA damage activates two pathways of degeneration; a faster, p53-dependent apoptotic degeneration that is triggered in the cell bodies with nuclear DNA damage, and a slower, p53-independent degeneration that is induced with mtDNA damage.
Collapse
|
21
|
Abstract
Postamputation stump and phantom pain are highly prevalent but remain a difficult condition to treat. The underlying mechanisms are not fully clarified, but growing evidence suggests that changes in afferent nerves, including the formation of neuromas, play an important role. The main objective of this cross-sectional study was to investigate whether ultrasound-verified neuroma swellings are more frequent in amputees with postamputation pain than in amputees without pain (primary outcome). Sixty-seven amputees were included. Baseline characteristics including the frequency and intensity of spontaneous stump and phantom pain were obtained, and sensory characteristics and evoked responses were assessed. A high-frequency ultrasound examination of the amputated extremity was performed to obtain information on the presence, size, and elasticity of swollen neuromas and pressure pain thresholds. Swollen neuromas were present in 53 (79.1%) of the 67 amputees included in the study, in 47 (82.5%) of 57 amputees with pain and in 6 (60.0%) of 10 amputees without pain (P = 0.2). No difference was found in stump pain intensity (P = 0.42) during the last week or in phantom pain intensity in the last month (P = 0.74) between amputees with and without swollen neuromas. Our findings suggest that it is not the presence of swollen neuromas itself that drives postamputation pain. However, changes in the transected nerve endings may still be crucial for driving postamputation pain because a positive Tinel sign was significantly more frequent in amputees with pain, irrespectively of the degree of neuroma swelling.
Collapse
|
22
|
Gilloteaux J, Bouchat J, Brion JP, Nicaise C. The osmotic demyelination syndrome: the resilience of thalamic neurons is verified with transmission electron microscopy. Ultrastruct Pathol 2021; 44:450-480. [DOI: 10.1080/01913123.2020.1853865] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Jacques Gilloteaux
- Unit of Research in Molecular Physiology (Urphym- NARILIS), Department of Medicine, Université de Namur, Namur, Belgium
- Department of Anatomical Sciences, St George’s University School of Medicine, KB Taylor Global Scholar’s Program at UNN, School of Health and Life Sciences, Newcastle upon Tyne, UK
| | - Joanna Bouchat
- Unit of Research in Molecular Physiology (Urphym- NARILIS), Department of Medicine, Université de Namur, Namur, Belgium
| | - Jean-Pierre Brion
- Laboratory of Histology, Neuroanatomy and Neuropathology, Faculté de Médecine Université Libre de Bruxelles, Brussels, Belgium
| | - Charles Nicaise
- Unit of Research in Molecular Physiology (Urphym- NARILIS), Department of Medicine, Université de Namur, Namur, Belgium
| |
Collapse
|
23
|
Liu W, Vetreno RP, Crews FT. Hippocampal TNF-death receptors, caspase cell death cascades, and IL-8 in alcohol use disorder. Mol Psychiatry 2021; 26:2254-2262. [PMID: 32139808 PMCID: PMC7483234 DOI: 10.1038/s41380-020-0698-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 02/17/2020] [Accepted: 02/20/2020] [Indexed: 01/22/2023]
Abstract
The relationship between increased neuroimmune gene expression and hippocampal degeneration in alcohol use disorder (AUD) and other mental diseases is poorly understood. We report here that tumor necrosis factor receptor superfamily death receptor 3 (TNFRSF25, DR3) and Fas receptors (Fas) that initiate caspase cell death cascades are increased in AUD hippocampus and following a rat adolescent binge drinking model. Death receptors are known inducers of apoptosis and cell death that recruit death domain (DD) proteins FADD and TRADD and caspases to form death-inducing signaling complexes (DISC). In postmortem human AUD hippocampus, mRNA and IHC protein are increased for the entire death receptor cascade. In AUD hippocampus, ligand-death receptor pairs, i.e., TL1A-DR3 and FasL-Fas, were increased, as well as FADD and TRADD, and active caspase-8, -7, -9, and caspase-3. Further, pNFκB p65, a key neuroimmune transcription factor, and IL-8, a chemokine, were significantly increased. Interestingly, across AUD patients, increases in DR3 and Fas correlated with TRADD, and TRADD with active caspase+IR and IL-8+IR, consistent with coordinated activation of neuronal DISC mediated death cascades and neuroimmune gene induction in AUD. These findings support a role for DR3 and Fas neuroimmune signaling in AUD hippocampal neurodegeneration.
Collapse
Affiliation(s)
- Wen Liu
- grid.10698.360000000122483208Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7178 USA
| | - Ryan P. Vetreno
- grid.10698.360000000122483208Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7178 USA
| | - Fulton T. Crews
- grid.10698.360000000122483208Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7178 USA
| |
Collapse
|
24
|
Abstract
Bcl-xL is a pro-survival protein of the Bcl2 family found in the mitochondrial membrane. Bcl-xL supports growth, development, and maturation of neurons, and it also prevents neuronal death during neurotoxic stimulation. This article reviews the mechanisms and upstream signaling that regulate the activity and abundance of Bcl-xL. Our team and others have reported that oxidative stress is a key regulator of intracellular Bcl-xL balance in neurons. Oxidative stress regulates synthesis, degradation, and activity of Bcl-xL and therefore neuronal function. During apoptosis, pro-apoptotic Bcl2 proteins such as Bax and Bak translocate to and oligomerize in the mitochondrial membrane. Formation of oligomers causes release of cytochrome c and activation of caspases that lead to neuronal death. Bcl-xL binds directly to pro-apoptotic Bcl2 proteins to block apoptotic signaling. Although anti-apoptotic roles of Bcl-xL have been well documented, an increasing number of studies in recent decades show that protein binding partners of Bcl-xL are not limited to Bcl2 proteins. Bcl-xL forms a complex with F1Fo ATP synthase, DJ-1, DRP1, IP3R, and the ryanodine receptor. These proteins support physiological processes in neurons such as growth and development and prevent neuronal damage by regulating mitochondrial ATP production, synapse formation, synaptic vesicle recycling, neurotransmission, and calcium signaling. However, under conditions of oxidative stress, Bcl-xL undergoes proteolytic cleavage thus lowering the abundance of functional Bcl-xL in neurons. Additionally, oxidative stress alters formation of Bcl-xL-mediated multiprotein complexes by regulating post-translational phosphorylation. Finally, oxidative stress regulates transcription factors that target the Bcl-x gene and alter accessibility of microRNA to mRNA influencing mRNA levels of Bcl-xL. In this review, we discussed how Bcl-xL supports the normal physiology of neurons, and how oxidative stress contributes to pathology by manipulating the dynamics of Bcl-xL production, degradation, and activity.
Collapse
Affiliation(s)
- Han-A Park
- Department of Human Nutrition and Hospitality Management, College of Human Environmental Sciences, The University of Alabama, Tuscaloosa, AL, USA
| | - Katheryn Broman
- Department of Human Nutrition and Hospitality Management, College of Human Environmental Sciences, The University of Alabama, Tuscaloosa, AL, USA
| | - Elizabeth A Jonas
- Department of Internal Medicine, Section of Endocrinology, Yale University, New Haven, CT, USA
| |
Collapse
|
25
|
Cuddy SR, Schinlever AR, Dochnal S, Seegren PV, Suzich J, Kundu P, Downs TK, Farah M, Desai BN, Boutell C, Cliffe AR. Neuronal hyperexcitability is a DLK-dependent trigger of herpes simplex virus reactivation that can be induced by IL-1. eLife 2020; 9:e58037. [PMID: 33350386 PMCID: PMC7773336 DOI: 10.7554/elife.58037] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022] Open
Abstract
Herpes simplex virus-1 (HSV-1) establishes a latent infection in neurons and periodically reactivates to cause disease. The stimuli that trigger HSV-1 reactivation have not been fully elucidated. We demonstrate HSV-1 reactivation from latently infected mouse neurons induced by forskolin requires neuronal excitation. Stimuli that directly induce neurons to become hyperexcitable also induced HSV-1 reactivation. Forskolin-induced reactivation was dependent on the neuronal pathway of DLK/JNK activation and included an initial wave of viral gene expression that was independent of histone demethylase activity and linked to histone phosphorylation. IL-1β is released under conditions of stress, fever and UV exposure of the epidermis; all known triggers of clinical HSV reactivation. We found that IL-1β induced histone phosphorylation and increased the excitation in sympathetic neurons. Importantly, IL-1β triggered HSV-1 reactivation, which was dependent on DLK and neuronal excitability. Thus, HSV-1 co-opts an innate immune pathway resulting from IL-1 stimulation of neurons to induce reactivation.
Collapse
Affiliation(s)
- Sean R Cuddy
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
- Neuroscience Graduate Program, University of VirginiaCharlottesvilleUnited States
| | - Austin R Schinlever
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Sara Dochnal
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Philip V Seegren
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Jon Suzich
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Parijat Kundu
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Taylor K Downs
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Mina Farah
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Bimal N Desai
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Chris Boutell
- MRC-University of Glasgow Centre for Virus Research (CVR), Garscube CampusGlasgowUnited Kingdom
| | - Anna R Cliffe
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| |
Collapse
|
26
|
Eiró LG, Ferreira MKM, Bittencourt LO, Aragão WAB, Souza MPCD, Silva MCF, Dionizio A, Buzalaf MAR, Crespo-López ME, Lima RR. Chronic methylmercury exposure causes spinal cord impairment: Proteomic modulation and oxidative stress. Food Chem Toxicol 2020; 146:111772. [DOI: 10.1016/j.fct.2020.111772] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 12/19/2022]
|
27
|
Planning and Analysis of Axon Degeneration Screening Experiments. Methods Mol Biol 2020. [PMID: 32524473 DOI: 10.1007/978-1-0716-0585-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
A network of intersecting molecular pathways interacts to initiate and execute axon destruction. Maximum protection against axon degeneration likely requires more than manipulation of a single target. Here, we describe the process of designing a high-throughput arrayed screening assay for the identification of key factors responsible for axon destruction and/or protection. First, we go over some existing screens in the literature, then discuss the planning, tracking, analysis, and statistics around such a screening experiment. Prioritization of perturbations may allow laboratories to cost-effectively explore the process of screening. We also present the pairing of a combinatorial drug screen with a machine learning algorithm, predicting how to best modulate neurodegenerative and neuroprotective components.
Collapse
|
28
|
Axon degeneration: mechanistic insights lead to therapeutic opportunities for the prevention and treatment of peripheral neuropathy. Pain 2020; 160 Suppl 1:S17-S22. [PMID: 31008845 DOI: 10.1097/j.pain.0000000000001528] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Peripheral neuropathy is the most common neurodegenerative disease affecting hundreds of millions of patients worldwide and is an important cause of chronic pain. Typical peripheral neuropathies are characterized by dysesthesias including numbness, crawling skin, a sensation of "pins and needles," and burning and stabbing pain. In addition, peripheral neuropathy can affect the motor and autonomic systems leading to symptoms such as weakness, constipation, and dysregulation of blood pressure. Peripheral neuropathies can be either hereditary or acquired and are a common consequence of diabetes and treatment with chemotherapy agents. Many neuropathies are due to degeneration of long axons; however, the mechanisms driving axon loss were unknown, and so no therapies are available to preserve vulnerable axons and prevent the development of peripheral neuropathy. With the recent identification of SARM1 as an injury-activated NADase enzyme that triggers axon degeneration, there is now a coherent picture emerging for the mechanism of axonal self-destruction. Here, we will present evidence that inhibiting the SARM1 pathway can prevent the development of peripheral neuropathy, describe the emerging mechanistic understanding of the axon degeneration program, and discuss how these mechanistic insights may be translated to the clinic for the prevention and treatment of peripheral neuropathy and other neurodegenerative disorders.
Collapse
|
29
|
Singh P, Donlea JM. Bidirectional Regulation of Sleep and Synapse Pruning after Neural Injury. Curr Biol 2020; 30:1063-1076.e3. [PMID: 32142703 DOI: 10.1016/j.cub.2019.12.065] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/10/2019] [Accepted: 12/19/2019] [Indexed: 12/14/2022]
Abstract
Following acute neural injury, severed axons undergo programmed Wallerian degeneration over several following days. While sleep has been linked with synaptic reorganization under other conditions, the role of sleep in responses to neural injuries remains poorly understood. To study the relationship between sleep and neural injury responses, we examined Drosophila melanogaster following the removal of antennae or other sensory tissues. Daytime sleep is elevated after antennal or wing injury, but sleep returns to baseline levels within 24 h after injury. Similar increases in sleep are not observed when olfactory receptor neurons are silenced or when other sensory organs are severed, suggesting that increased sleep after injury is not attributed to sensory deprivation, nociception, or generalized inflammatory responses. Neuroprotective disruptions of the E3 ubiquitin ligase highwire and c-Jun N-terminal kinase basket in olfactory receptor neurons weaken the sleep-promoting effects of antennal injury, suggesting that post-injury sleep may be influenced by the clearance of damaged neurons. Finally, we show that pre-synaptic active zones are preferentially removed from severed axons within hours after injury and that depriving recently injured flies of sleep slows the removal of both active zones and damaged axons. These data support a bidirectional interaction between sleep and synapse pruning after antennal injury: locally increasing the need to clear neural debris is associated with increased sleep, which is required for efficient active zone removal after injury.
Collapse
Affiliation(s)
- Prabhjit Singh
- Department of Neurobiology, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, CA 90095-1763, USA
| | - Jeffrey M Donlea
- Department of Neurobiology, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, CA 90095-1763, USA.
| |
Collapse
|
30
|
Girouard MP, Simas T, Hua L, Morquette B, Khazaei MR, Unsain N, Johnstone AD, Rambaldi I, Sanz RL, Di Raddo ME, Gamage KK, Yong Y, Willis DE, Verge VMK, Barker PA, Deppmann C, Fournier AE. Collapsin Response Mediator Protein 4 (CRMP4) Facilitates Wallerian Degeneration and Axon Regeneration following Sciatic Nerve Injury. eNeuro 2020; 7:ENEURO.0479-19.2020. [PMID: 32001550 PMCID: PMC7053045 DOI: 10.1523/eneuro.0479-19.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 11/29/2022] Open
Abstract
In contrast to neurons in the CNS, damaged neurons from the peripheral nervous system (PNS) regenerate, but this process can be slow and imperfect. Successful regeneration is orchestrated by cytoskeletal reorganization at the tip of the proximal axon segment and cytoskeletal disassembly of the distal segment. Collapsin response mediator protein 4 (CRMP4) is a cytosolic phospho-protein that regulates the actin and microtubule cytoskeleton. During development, CRMP4 promotes growth cone formation and dendrite development. Paradoxically, in the adult CNS, CRMP4 impedes axon regeneration. Here, we investigated the involvement of CRMP4 in peripheral nerve injury in male and female Crmp4-/- mice following sciatic nerve injury. We find that sensory axon regeneration and Wallerian degeneration are impaired in Crmp4-/- mice following sciatic nerve injury. In vitro analysis of dissociated dorsal root ganglion (DRG) neurons from Crmp4-/- mice revealed that CRMP4 functions in the proximal axon segment to promote the regrowth of severed DRG neurons and in the distal axon segment where it facilitates Wallerian degeneration through calpain-dependent formation of harmful CRMP4 fragments. These findings reveal an interesting dual role for CRMP4 in proximal and distal axon segments of injured sensory neurons that coordinately facilitate PNS axon regeneration.
Collapse
Affiliation(s)
- Marie-Pier Girouard
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
| | - Tristan Simas
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
| | - Luyang Hua
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
| | - Barbara Morquette
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
| | - Mohamad R Khazaei
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
| | - Nicolas Unsain
- Instituto de Investigación Médica Mercedes y Martín Ferreyra (INIMEC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 5016 Córdoba, Argentina
| | - Aaron D Johnstone
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
| | - Isabel Rambaldi
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
| | - Ricardo L Sanz
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
| | | | - Kanchana K Gamage
- Department of Biology, University of Virginia, Charlottesville, Virginia 22903
| | - Yu Yong
- Department of Biology, University of Virginia, Charlottesville, Virginia 22903
| | - Dianna E Willis
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065
- Burke Institute, Weill Cornell Medicine, White Plains, New York 10605
| | - Valerie M K Verge
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan-CMSNRC, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Philip A Barker
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
- Department of Biology, University of British Columbia, Kelowna, British Columbia V1V 1V7, Canada
| | | | - Alyson E Fournier
- Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, Montréal, Québec H3A 2B4, Canada
| |
Collapse
|
31
|
Chiha W, Bartlett CA, Petratos S, Fitzgerald M, Harvey AR. Intravitreal application of AAV-BDNF or mutant AAV-CRMP2 protects retinal ganglion cells and stabilizes axons and myelin after partial optic nerve injury. Exp Neurol 2020; 326:113167. [PMID: 31904385 DOI: 10.1016/j.expneurol.2019.113167] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/20/2019] [Accepted: 12/31/2019] [Indexed: 12/29/2022]
Abstract
Secondary degeneration following an initial injury to the central nervous system (CNS) results in increased tissue loss and is associated with increasing functional impairment. Unilateral partial dorsal transection of the adult rat optic nerve (ON) has proved to be a useful experimental model in which to study factors that contribute to secondary degenerative events. Using this injury model, we here quantified the protective effects of intravitreally administered bi-cistronic adeno-associated viral (AAV2) vectors encoding either brain derived neurotrophic factor (BDNF) or a mutant, phospho-resistant, version of collapsin response mediator protein 2 (CRMP2T555A) on retinal ganglion cells (RGCs), their axons, and associated myelin. To test for potential synergistic interactions, some animals received combined injections of both vectors. Three months post-injury, all treatments maintained RGC numbers in central retina, but only AAV2-BDNF significantly protected ventrally located RGCs exclusively vulnerable to secondary degeneration. Behaviourally, treatments that involved AAV2-BDNF significantly restored the number of smooth-pursuit phases of optokinetic nystagmus. While all therapeutic regimens preserved axonal density and proportions of typical complexes, including heminodes and single nodes, BDNF treatments were generally more effective in maintaining the length of the node of Ranvier in myelin surrounding ventral ON axons after injury. Both AAV2-BDNF and AAV2-CRMP2T555A prevented injury-induced changes in G-ratio and overall myelin thickness, but only AAV2-BDNF administration protected against large-scale myelin decompaction in ventral ON. In summary, in a model of secondary CNS degeneration, both BDNF and CRMP2T555A vectors were neuroprotective, however different efficacies were observed for these overexpressed proteins in the retina and ON, suggesting disparate cellular and molecular targets driving responses for neural repair. The potential use of these vectors to treat other CNS injuries and pathologies is discussed.
Collapse
Affiliation(s)
- Wissam Chiha
- School of Biological Sciences, The University of Western Australia, WA 6009, Australia; Curtin Health Innovation Research Institute, Curtin University, Belmont, WA 6102, Australia
| | - Carole A Bartlett
- School of Biological Sciences, The University of Western Australia, WA 6009, Australia
| | - Steven Petratos
- Department of Neuroscience, Monash University, VIC 3004, Australia
| | - Melinda Fitzgerald
- Perron Institute for Neurological and Translational Science, Nedlands, WA 6009, Australia; Curtin Health Innovation Research Institute, Curtin University, Belmont, WA 6102, Australia
| | - Alan R Harvey
- School of Human Sciences, The University of Western Australia, WA 6009, Australia; Perron Institute for Neurological and Translational Science, Nedlands, WA 6009, Australia.
| |
Collapse
|
32
|
Li JN, Zhang Z, Wu GZ, Yao DB, Cui SS. Claudin-15 overexpression inhibits proliferation and promotes apoptosis of Schwann cells in vitro. Neural Regen Res 2020; 15:169-177. [PMID: 31535666 PMCID: PMC6862392 DOI: 10.4103/1673-5374.264463] [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] [Indexed: 01/09/2023] Open
Abstract
Our previous experiments have discovered that Claudin-15 was up-regulated in Schwann cells of the distal nerve stumps of rat models of sciatic nerve injury. However, how Claudin-15 affects Schwann cell function is still unknown. This study aimed to identify the effects of Claudin-15 on proliferation and apoptosis of Schwann cells cultured in vitro and explore the underlying mechanisms. Primary Schwann cells were obtained from rats. Claudin-15 in Schwann cells was knocked down using siRNA (siRNA-1 group) compared with the negative control siRNA transfection group (negative control group). Claudin-15 in Schwann cells was overexpressed using pGV230-Claudin-15 plasmid (pGV230-Claudin-15 group). The pGV230 transfection group (pGV230 group) acted as the control of the pGV230-Claudin-15 group. Cell proliferation was analyzed with EdU assay. Cell apoptosis was analyzed with flow cytometric analysis. Cell migration was analyzed with Transwell inserts. The mRNA and protein expressions were analyzed with quantitative polymerase chain reaction assay and western blot assay. The results showed that compared with the negative control group, cell proliferation rate was up-regulated; p-AKT/AKT ratio, apoptotic rate, p-c-Jun/c-Jun ratio, mRNA expression of protein kinase C alpha, Bcl-2 and Bax were down-regulated; and mRNA expression of neurotrophins basic fibroblast growth factor and neurotrophin-3 were increased in the siRNA-1 group. No significant difference was found in cell migration between the negative control and siRNA-1 groups. Compared with the pGV230 group, the cell proliferation rate was down-regulated; apoptotic rate, p-c-Jun/c-Jun ratio and c-Fos protein expression increased; mRNA expression of protein kinase C alpha and Bax decreased; and mRNA expressions of neurotrophins basic fibroblast growth factor and neurotrophin-3 were up-regulated in the pGV230-Claudin-15 group. The above results demonstrated that overexpression of Claudin-15 inhibited Schwann cell proliferation and promoted Schwann cell apoptosis in vitro. Silencing of Claudin-15 had the reverse effect and provided neuroprotective effect. This study was approved by the Experimental Animal Ethics Committee of Jilin University of China (approval No. 2016-nsfc001) on March 5, 2016.
Collapse
Affiliation(s)
- Jian-Nan Li
- China-Japan Union Hospital of Jilin University, Changchun, Jilin Province, China
| | - Zhan Zhang
- China-Japan Union Hospital of Jilin University, Changchun, Jilin Province, China
| | - Guang-Zhi Wu
- China-Japan Union Hospital of Jilin University, Changchun, Jilin Province, China
| | - Deng-Bing Yao
- School of Life Sciences, Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Shu-Sen Cui
- China-Japan Union Hospital of Jilin University, Changchun, Jilin Province, China
| |
Collapse
|
33
|
Abstract
The field of microfluidics allows for the precise spatial manipulation of small amounts of fluids. Within microstructures, laminar flow of fluids can be exploited to control the diffusion of small molecules, creating desired microenvironments for cells. Cellular neuroscience has benefited greatly from devices designed to fluidically isolate cell bodies and axons. Microfluidic devices specialized for neuron compartmentalization are made of polydimethylsiloxane (PDMS) which is gas permeable, is compatible with fluorescence microscopy, and has low cost. These devices are commonly used to study signals initiated exclusively on axons, somatodendritic compartments, or even single synapses. We have also found that microfluidic devices allow for rapid, reproducible interrogation of axon degeneration. Here, we describe the methodology for assessing axonal degeneration in microfluidic devices. We describe several use cases, including enucleation (removal of cell bodies) and trophic deprivation to investigate axon degeneration in pathological and developmental scenarios, respectively.
Collapse
Affiliation(s)
- Yu Yong
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Christopher Hughes
- Department of Physics and Astronomy, James Madison University, Harrisonburg, VA, USA
| | | |
Collapse
|
34
|
Richardson RJ, Fink JK, Glynn P, Hufnagel RB, Makhaeva GF, Wijeyesakere SJ. Neuropathy target esterase (NTE/PNPLA6) and organophosphorus compound-induced delayed neurotoxicity (OPIDN). ADVANCES IN NEUROTOXICOLOGY 2020; 4:1-78. [PMID: 32518884 PMCID: PMC7271139 DOI: 10.1016/bs.ant.2020.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Systemic inhibition of neuropathy target esterase (NTE) with certain organophosphorus (OP) compounds produces OP compound-induced delayed neurotoxicity (OPIDN), a distal degeneration of axons in the central nervous system (CNS) and peripheral nervous system (PNS), thereby providing a powerful model for studying a spectrum of neurodegenerative diseases. Axonopathies are important medical entities in their own right, but in addition, illnesses once considered primary neuronopathies are now thought to begin with axonal degeneration. These disorders include Alzheimer's disease, Parkinson's disease, and motor neuron diseases such as amyotrophic lateral sclerosis (ALS). Moreover, conditional knockout of NTE in the mouse CNS produces vacuolation and other degenerative changes in large neurons in the hippocampus, thalamus, and cerebellum, along with degeneration and swelling of axons in ascending and descending spinal cord tracts. In humans, NTE mutations cause a variety of neurodegenerative conditions resulting in a range of deficits including spastic paraplegia and blindness. Mutations in the Drosophila NTE orthologue SwissCheese (SWS) produce neurodegeneration characterized by vacuolization that can be partially rescued by expression of wild-type human NTE, suggesting a potential therapeutic approach for certain human neurological disorders. This chapter defines NTE and OPIDN, presents an overview of OP compounds, provides a rationale for NTE research, and traces the history of discovery of NTE and its relationship to OPIDN. It then briefly describes subsequent studies of NTE, including practical applications of the assay; aspects of its domain structure, subcellular localization, and tissue expression; abnormalities associated with NTE mutations, knockdown, and conventional or conditional knockout; and hypothetical models to help guide future research on elucidating the role of NTE in OPIDN.
Collapse
Affiliation(s)
- Rudy J. Richardson
- Molecular Simulations Laboratory, Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI, United States,Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States,Center for Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, United States,Michigan Institute for Computational Discovery and Engineering, University of Michigan, Ann Arbor, MI, United States,Corresponding author:
| | - John K. Fink
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States,Ann Arbor Veterans Affairs Medical Center, Ann Arbor, MI, United States
| | - Paul Glynn
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - Robert B. Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Galina F. Makhaeva
- Institute of Physiologically Active Compounds Russian Academy of Sciences, Chernogolovka, Russia
| | - Sanjeeva J. Wijeyesakere
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, United States
| |
Collapse
|
35
|
Schellino R, Boido M, Vercelli A. JNK Signaling Pathway Involvement in Spinal Cord Neuron Development and Death. Cells 2019; 8:E1576. [PMID: 31817379 PMCID: PMC6953032 DOI: 10.3390/cells8121576] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/02/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022] Open
Abstract
The c-Jun NH2-terminal protein kinase (JNK) is a Janus-faced kinase, which, in the nervous system, plays important roles in a broad range of physiological and pathological processes. Three genes, encoding for 10 JNK isoforms, have been identified: jnk1, jnk2, and jnk3. In the developing spinal cord, JNK proteins control neuronal polarity, axon growth/pathfinding, and programmed cell death; in adulthood they can drive degeneration and regeneration, after pathological insults. Indeed, recent studies have highlighted a role for JNK in motor neuron (MN) diseases, such as amyotrophic lateral sclerosis and spinal muscular atrophy. In this review we discuss how JNK-dependent signaling regulates apparently contradictory functions in the spinal cord, in both the developmental and adult stages. In addition, we examine the evidence that the specific targeting of JNK signaling pathway may represent a promising therapeutic strategy for the treatment of MN diseases.
Collapse
Affiliation(s)
- Roberta Schellino
- Department of Neuroscience Rita Levi Montalcini, University of Turin, 10126 Turin, Italy
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin, 10043 Orbassano (TO), Italy
| | - Marina Boido
- Department of Neuroscience Rita Levi Montalcini, University of Turin, 10126 Turin, Italy
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin, 10043 Orbassano (TO), Italy
- National Institute of Neuroscience (INN), 10125 Turin, Italy
| | - Alessandro Vercelli
- Department of Neuroscience Rita Levi Montalcini, University of Turin, 10126 Turin, Italy
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin, 10043 Orbassano (TO), Italy
- National Institute of Neuroscience (INN), 10125 Turin, Italy
| |
Collapse
|
36
|
Axonal degeneration in an in vitro model of ischemic white matter injury. Neurobiol Dis 2019; 134:104672. [PMID: 31707117 DOI: 10.1016/j.nbd.2019.104672] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 10/18/2019] [Accepted: 11/06/2019] [Indexed: 01/15/2023] Open
Abstract
Ischemic white matter injuries underlie cognitive decline in the elderly and vascular dementia. Ischemia in the subcortical white matter is caused by chronic reduction of blood flow due to narrowing of small arterioles. However, it remains unclear how chronic ischemia leads to white matter pathology. We aimed to develop an in vitro model of ischemic white matter injury using organotypic slice cultures. Cultured cerebellar slices preserved fully myelinated white matter tracts that were amenable to chronic hypoxic insult. Prolonged hypoxia caused progressive morphological evidence of axonal degeneration with focal constrictions and swellings. In contrast, myelin sheaths and oligodendrocytes exhibited remarkable resilience to hypoxia. The cytoskeletal degradation of axons was accompanied by mitochondrial shortening and lysosomal activation. Multiple pharmacological manipulations revealed that the AMPA glutamate receptor, calpain proteolysis, and lysosomal proteases were independently implicated in hypoxia-induced axonal degeneration in our model. Thus, our in vitro model would be a novel experimental system to explore molecular mechanisms of ischemic white matter injury. Furthermore, we verified that the in vitro assay could be successfully utilized to screen for molecules that can ameliorate hypoxia/ischemia-induced axonal degeneration.
Collapse
|
37
|
Hao Y, Waller TJ, Nye DM, Li J, Zhang Y, Hume RI, Rolls MM, Collins CA. Degeneration of Injured Axons and Dendrites Requires Restraint of a Protective JNK Signaling Pathway by the Transmembrane Protein Raw. J Neurosci 2019; 39:8457-8470. [PMID: 31492772 PMCID: PMC6807270 DOI: 10.1523/jneurosci.0016-19.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 08/08/2019] [Accepted: 08/22/2019] [Indexed: 12/15/2022] Open
Abstract
The degeneration of injured axons involves a self-destruction pathway whose components and mechanism are not fully understood. Here, we report a new regulator of axonal resilience. The transmembrane protein Raw is cell autonomously required for the degeneration of injured axons, dendrites, and synapses in Drosophila melanogaster In both male and female raw hypomorphic mutant or knock-down larvae, the degeneration of injured axons, dendrites, and synapses from motoneurons and sensory neurons is strongly inhibited. This protection is insensitive to reduction in the levels of the NAD+ synthesis enzyme Nmnat (nicotinamide mononucleotide adenylyl transferase), but requires the c-Jun N-terminal kinase (JNK) mitogen-activated protein (MAP) kinase and the transcription factors Fos and Jun (AP-1). Although these factors were previously known to function in axonal injury signaling and regeneration, Raw's function can be genetically separated from other axonal injury responses: Raw does not modulate JNK-dependent axonal injury signaling and regenerative responses, but instead restrains a protective pathway that inhibits the degeneration of axons, dendrites, and synapses. Although protection in raw mutants requires JNK, Fos, and Jun, JNK also promotes axonal degeneration. These findings suggest the existence of multiple independent pathways that share modulation by JNK, Fos, and Jun that influence how axons respond to stress and injury.SIGNIFICANCE STATEMENT Axonal degeneration is a major feature of neuropathies and nerve injuries and occurs via a cell autonomous self-destruction pathway whose mechanism is poorly understood. This study reports the identification of a new regulator of axonal degeneration: the transmembrane protein Raw. Raw regulates a cell autonomous nuclear signaling pathway whose yet unknown downstream effectors protect injured axons, dendrites, and synapses from degenerating. These findings imply that the susceptibility of axons to degeneration is strongly regulated in neurons. Future understanding of the cellular pathway regulated by Raw, which engages the c-Jun N-terminal kinase (JNK) mitogen-activated protein (MAP) kinase and Fos and Jun transcription factors, may suggest new strategies to increase the resiliency of axons in debilitating neuropathies.
Collapse
Affiliation(s)
- Yan Hao
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1085
| | - Thomas J Waller
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1085
| | - Derek M Nye
- Huck Institutes of the Life Sciences, and Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Jiaxing Li
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1085
| | - Yanxiao Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109-2218
| | - Richard I Hume
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1085
| | - Melissa M Rolls
- Huck Institutes of the Life Sciences, and Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Catherine A Collins
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1085,
| |
Collapse
|
38
|
Gabrych DR, Lau VZ, Niwa S, Silverman MA. Going Too Far Is the Same as Falling Short †: Kinesin-3 Family Members in Hereditary Spastic Paraplegia. Front Cell Neurosci 2019; 13:419. [PMID: 31616253 PMCID: PMC6775250 DOI: 10.3389/fncel.2019.00419] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/02/2019] [Indexed: 01/18/2023] Open
Abstract
Proper intracellular trafficking is essential for neuronal development and function, and when any aspect of this process is dysregulated, the resulting "transportopathy" causes neurological disorders. Hereditary spastic paraplegias (HSPs) are a family of such diseases attributed to over 80 spastic gait genes (SPG), specifically characterized by lower extremity spasticity and weakness. Multiple genes in the trafficking pathway such as those relating to microtubule structure and function and organelle biogenesis are representative disease loci. Microtubule motor proteins, or kinesins, are also causal in HSP, specifically mutations in Kinesin-I/KIF5A (SPG10) and two kinesin-3 family members; KIF1A (SPG30) and KIF1C (SPG58). KIF1A is a motor enriched in neurons, and involved in the anterograde transport of a variety of vesicles that contribute to pre- and post-synaptic assembly, autophagic processes, and neuron survival. KIF1C is ubiquitously expressed and, in addition to anterograde cargo transport, also functions in retrograde transport between the Golgi and the endoplasmic reticulum. Only a handful of KIF1C cargos have been identified; however, many have crucial roles such as neuronal differentiation, outgrowth, plasticity and survival. HSP-related kinesin-3 mutants are characterized mainly as loss-of-function resulting in deficits in motility, regulation, and cargo binding. Gain-of-function mutants are also seen, and are characterized by increased microtubule-on rates and hypermotility. Both sets of mutations ultimately result in misdelivery of critical cargos within the neuron. This likely leads to deleterious cell biological cascades that likely underlie or contribute to HSP clinical pathology and ultimately, symptomology. Due to the paucity of histopathological or cell biological data assessing perturbations in cargo localization, it has been difficult to positively link these mutations to the outcomes seen in HSPs. Ultimately, the goal of this review is to encourage future academic and clinical efforts to focus on "transportopathies" through a cargo-centric lens.
Collapse
Affiliation(s)
- Dominik R Gabrych
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Victor Z Lau
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Shinsuke Niwa
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan
| | - Michael A Silverman
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada.,Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, BC, Canada
| |
Collapse
|
39
|
Geisler S, Doan RA, Cheng GC, Cetinkaya-Fisgin A, Huang SX, Höke A, Milbrandt J, DiAntonio A. Vincristine and bortezomib use distinct upstream mechanisms to activate a common SARM1-dependent axon degeneration program. JCI Insight 2019; 4:129920. [PMID: 31484833 DOI: 10.1172/jci.insight.129920] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/01/2019] [Indexed: 12/21/2022] Open
Abstract
Chemotherapy-induced peripheral neuropathy is one of the most prevalent dose-limiting toxicities of anticancer therapy. Development of effective therapies to prevent chemotherapy-induced neuropathies could be enabled by a mechanistic understanding of axonal breakdown following exposure to neuropathy-causing agents. Here, we reveal the molecular mechanisms underlying axon degeneration induced by 2 widely used chemotherapeutic agents with distinct mechanisms of action: vincristine and bortezomib. We showed previously that genetic deletion of SARM1 blocks vincristine-induced neuropathy and demonstrate here that it also prevents axon destruction following administration of bortezomib in vitro and in vivo. Using cultured neurons, we found that vincristine and bortezomib converge on a core axon degeneration program consisting of nicotinamide mononucleotide NMNAT2, SARM1, and loss of NAD+ but engage different upstream mechanisms that closely resemble Wallerian degeneration after vincristine and apoptosis after bortezomib. We could inhibit the final common axon destruction pathway by preserving axonal NAD+ levels or expressing a candidate gene therapeutic that inhibits SARM1 in vitro. We suggest that these approaches may lead to therapies for vincristine- and bortezomib-induced neuropathies and possibly other forms of peripheral neuropathy.
Collapse
Affiliation(s)
- Stefanie Geisler
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.,Hope Center for Neurological Disorders, Washington University, St. Louis, Missouri, USA
| | - Ryan A Doan
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Galen C Cheng
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | | | - Shay X Huang
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Ahmet Höke
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jeffrey Milbrandt
- Hope Center for Neurological Disorders, Washington University, St. Louis, Missouri, USA.,Department of Genetics and
| | - Aaron DiAntonio
- Hope Center for Neurological Disorders, Washington University, St. Louis, Missouri, USA.,Department of Developmental Biology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| |
Collapse
|
40
|
Syc-Mazurek SB, Libby RT. Axon injury signaling and compartmentalized injury response in glaucoma. Prog Retin Eye Res 2019; 73:100769. [PMID: 31301400 DOI: 10.1016/j.preteyeres.2019.07.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 07/05/2019] [Accepted: 07/09/2019] [Indexed: 12/19/2022]
Abstract
Axonal degeneration is an active, highly controlled process that contributes to beneficial processes, such as developmental pruning, but also to neurodegeneration. In glaucoma, ocular hypertension leads to vision loss by killing the output neurons of the retina, the retinal ganglion cells (RGCs). Multiple processes have been proposed to contribute to and/or mediate axonal injury in glaucoma, including: neuroinflammation, loss of neurotrophic factors, dysregulation of the neurovascular unit, and disruption of the axonal cytoskeleton. While the inciting injury to RGCs in glaucoma is complex and potentially heterogeneous, axonal injury is ultimately thought to be the key insult that drives glaucomatous neurodegeneration. Glaucomatous neurodegeneration is a complex process, with multiple molecular signals contributing to RGC somal loss and axonal degeneration. Furthermore, the propagation of the axonal injury signal is complex, with injury triggering programs of degeneration in both the somal and axonal compartment. Further complicating this process is the involvement of multiple cell types that are known to participate in the process of axonal and neuronal degeneration after glaucomatous injury. Here, we review the axonal signaling that occurs after injury and the molecular signaling programs currently known to be important for somal and axonal degeneration after glaucoma-relevant axonal injuries.
Collapse
Affiliation(s)
- Stephanie B Syc-Mazurek
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, USA; Neuroscience Graduate Program, University of Rochester Medical Center, Rochester, NY, USA
| | - Richard T Libby
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, USA; Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, USA; The Center for Visual Sciences, University of Rochester, Rochester, NY, USA.
| |
Collapse
|
41
|
Chen YJ, Liu YC, Liu YW, Lee YB, Huang HC, Chen YY, Shih YH, Lee YC, Cheng CF, Meng TC. Nitrite Protects Neurons Against Hypoxic Damage Through S-nitrosylation of Caspase-6. Antioxid Redox Signal 2019; 31:109-126. [PMID: 30417658 DOI: 10.1089/ars.2018.7522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Aims: The coordination of neurons to execute brain functions requires plenty of oxygen. Thus, it is not surprising that the chronic hypoxia resulting from chronic obstructive pulmonary diseases (COPD) can cause neuronal damage. Injury in the cortex can give rise to anxiety and cognitive dysfunction. This study investigated what causes hypoxia-induced neuronal injury and what strategies might be used to protect neurons against such damage. Results: This study found that hypoxia in primary cortical neurons caused neurite retraction, a caspase-6-dependent process. The hypoxic stress activated caspase-6 within the neurite, leading to microtubule disassembly and neurite retraction. The effect of hypoxia on caspase-6 activation, microtubule disassembly, and neurite retraction was alleviated by nitrite treatment. The protective role of nitrite was further supported by the observation that the active-site Cys146 of caspase-6 was S-nitrosylated in hypoxic neuro-2a cells treated with nitrite. We further validated the beneficial effect of nitrite on neuronal function against hypoxic stress in vivo. Using the wild-type or Apo E-/- mice exposed to chronic hypoxia as a model, we demonstrated that supplementing drinking water with nitrite suppressed active caspase-6 in the cortex of the brain, concomitant with the prevention of hypoxia-induced anxiety in the animals. Innovation: These results are the first evidence of a new pathway for the activation of caspase-6 and the first to indicate that nitrite can protect neurons against chronic hypoxic insult. Conclusion: Our findings suggest that nitrite holds great potential for the treatment of diseases such as COPD associated with hypoxia-induced neuronal injury.
Collapse
Affiliation(s)
- Yen-Jung Chen
- 1 Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.,2 Institutes of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yun-Chung Liu
- 1 Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.,2 Institutes of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yu-Wen Liu
- 2 Institutes of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yu-Bin Lee
- 2 Institutes of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hsin-Chieh Huang
- 2 Institutes of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yi-Yun Chen
- 2 Institutes of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | | | - Ying-Chu Lee
- 2 Institutes of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Ching-Feng Cheng
- 4 Department of Medical Research, Tzu Chi University, Hualien, Taiwan.,5 Department of Pediatrics, Tzu Chi General Hospital, Hualien, Taiwan.,6 Institutes of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Tzu-Ching Meng
- 1 Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.,2 Institutes of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| |
Collapse
|
42
|
Courtney NL, Mole AJ, Thomson AK, Murray LM. Reduced P53 levels ameliorate neuromuscular junction loss without affecting motor neuron pathology in a mouse model of spinal muscular atrophy. Cell Death Dis 2019; 10:515. [PMID: 31273192 PMCID: PMC6609617 DOI: 10.1038/s41419-019-1727-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 04/23/2019] [Accepted: 05/28/2019] [Indexed: 11/09/2022]
Abstract
Spinal Muscular Atrophy (SMA) is a childhood motor neuron disease caused by mutations or deletions within the SMN1 gene. At endstages of disease there is profound loss of motor neurons, loss of axons within ventral roots and defects at the neuromuscular junctions (NMJ), as evidenced by pathological features such as pre-synaptic loss and swelling and post-synaptic shrinkage. Although these motor unit defects have been widely described, the time course and interdependancy of these aspects of motor unit degeneration are unclear. Recent reports have also revealed an early upregulation of transcripts associated with the P53 signalling pathway. The relationship between the upregulation of these transcripts and pathology within the motor unit is also unclear. In this study, we exploit the prolonged disease timecourse and defined pre-symptomatic period in the Smn2B/- mouse model to perform a temporal analysis of the different elements of motor unit pathology. We demonstrate that NMJ loss occurs prior to cell body loss, and coincides with the onset of symptoms. The onset of NMJ pathology also coincides with an increase in P53-related transcripts at the cell body. Finally, using a tamoxifen inducible P53 knockout, we demonstrate that post-natal reduction in P53 levels can reduce NMJ loss, but does not affect other aspects of NMJ pathology, motor neuron loss or the phenotype of the Smn2B/- mouse model. Together this work provides a detailed temporal description of pathology within motor units of an SMA mouse model, and demonstrates that NMJ loss is a P53-dependant process. This work supports the role for P53 as an effector of synaptic and axonal degeneration in a die-back neuropathy.
Collapse
Affiliation(s)
- Natalie L Courtney
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, Edinburgh, UK.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK
| | - Alannah J Mole
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, Edinburgh, UK.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK
| | - Alison K Thomson
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, Edinburgh, UK.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK
| | - Lyndsay M Murray
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, Edinburgh, UK. .,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, Scotland, EH8 9XD, UK.
| |
Collapse
|
43
|
Sporny M, Guez-Haddad J, Lebendiker M, Ulisse V, Volf A, Mim C, Isupov MN, Opatowsky Y. Structural Evidence for an Octameric Ring Arrangement of SARM1. J Mol Biol 2019; 431:3591-3605. [PMID: 31278906 DOI: 10.1016/j.jmb.2019.06.030] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/16/2019] [Accepted: 06/25/2019] [Indexed: 12/11/2022]
Abstract
SARM1 induces axonal degeneration in response to various insults and is therefore considered an attractive drug target for the treatment of neuro-degenerative diseases as well as for brain and spinal cord injuries. SARM1 activity depends on the integrity of the protein's SAM domains, as well as on the enzymatic conversion of NAD+ to ADPR (ADP Ribose) products by the SARM1's TIR domain. Therefore, inhibition of either SAM or TIR functions may constitute an effective therapeutic strategy. However, there is currently no SARM1-directed therapeutic approach available because of an insufficient structural and mechanistic understanding of this protein. In this study, we found that SARM1 assembles into an octameric ring. This arrangement was not described before in other SAM proteins, but is reminiscent of the apoptosome and inflammasome-well-known apoptotic ring-like oligomers. We show that both SARM1 and the isolated tandem SAM1-2 domains form octamers in solution, and electron microscopy analysis reveals an octameric ring of SARM1. We determined the crystal structure of SAM1-2 and found that it also forms a closed octameric ring in the crystal lattice. The SAM1-2 ring interactions are mediated by complementing "lock and key" hydrophobic grooves and inserts and electrostatic charges between the neighboring protomers. We have mutated several interacting SAM1-2 interfaces and measured how these mutations affect SARM1 apoptotic activity in cultured cells, and in this way identified critical oligomerization sites that facilitate cell death. These results highlight the importance of oligomerization for SARM1 function and reveal critical epitopes for future targeted drug development.
Collapse
Affiliation(s)
- Michael Sporny
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Julia Guez-Haddad
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Mario Lebendiker
- Wolfson Centre for Applied Structural Biology, The Hebrew University of Jerusalem, Israel
| | - Valeria Ulisse
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Allison Volf
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Carsten Mim
- Department of Biomedical Engineering and Health Solutions, Royal Technical Institute (KTH), Stockholm, Sweden; Department of Nutrition and Biosciences, Karolinska Institute, Huddinge, Sweden
| | | | - Yarden Opatowsky
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
| |
Collapse
|
44
|
Genetic inhibition of CRMP2 phosphorylation delays Wallerian degeneration after optic nerve injury. Biochem Biophys Res Commun 2019; 514:1037-1039. [DOI: 10.1016/j.bbrc.2019.05.060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 05/07/2019] [Indexed: 12/22/2022]
|
45
|
Zhu S, Chen R, Soba P, Jan YN. JNK signaling coordinates with ecdysone signaling to promote pruning of Drosophila sensory neuron dendrites. Development 2019; 146:dev.163592. [PMID: 30936183 DOI: 10.1242/dev.163592] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/25/2019] [Indexed: 12/15/2022]
Abstract
Developmental pruning of axons and dendrites is crucial for the formation of precise neuronal connections, but the mechanisms underlying developmental pruning are not fully understood. Here, we have investigated the function of JNK signaling in dendrite pruning using Drosophila class IV dendritic arborization (c4da) neurons as a model. We find that loss of JNK or its canonical downstream effectors Jun or Fos led to dendrite-pruning defects in c4da neurons. Interestingly, our data show that JNK activity in c4da neurons remains constant from larval to pupal stages but the expression of Fos is specifically activated by ecdysone receptor B1 (EcRB1) at early pupal stages, suggesting that ecdysone signaling provides temporal control of the regulation of dendrite pruning by JNK signaling. Thus, our work not only identifies a novel pathway involved in dendrite pruning and a new downstream target of EcRB1 in c4da neurons, but also reveals that JNK and Ecdysone signaling coordinate to promote dendrite pruning.
Collapse
Affiliation(s)
- Sijun Zhu
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA .,Department of Physiology, Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 20251, USA
| | - Rui Chen
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
| | - Peter Soba
- Department of Physiology, Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 20251, USA.,Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, University of Hamburg, Hamburg, Germany
| | - Yuh-Nung Jan
- Department of Physiology, Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 20251, USA
| |
Collapse
|
46
|
Axonal Degeneration Is Mediated by Necroptosis Activation. J Neurosci 2019; 39:3832-3844. [PMID: 30850513 DOI: 10.1523/jneurosci.0881-18.2019] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 02/01/2019] [Accepted: 02/14/2019] [Indexed: 01/22/2023] Open
Abstract
Axonal degeneration, which contributes to functional impairment in several disorders of the nervous system, is an important target for neuroprotection. Several individual factors and subcellular events have been implicated in axonal degeneration, but researchers have so far been unable to identify an integrative signaling pathway activating this self-destructive process. Through pharmacological and genetic approaches, we tested whether necroptosis, a regulated cell-death mechanism implicated in the pathogenesis of several neurodegenerative diseases, is involved in axonal degeneration. Pharmacological inhibition of the necroptotic kinase RIPK1 using necrostatin-1 strongly delayed axonal degeneration in the peripheral nervous system and CNS of wild-type mice of either sex and protected in vitro sensory axons from degeneration after mechanical and toxic insults. These effects were also observed after genetic knock-down of RIPK3, a second key regulator of necroptosis, and the downstream effector MLKL (Mixed Lineage Kinase Domain-Like). RIPK1 inhibition prevented mitochondrial fragmentation in vitro and in vivo, a typical feature of necrotic death, and inhibition of mitochondrial fission by Mdivi also resulted in reduced axonal loss in damaged nerves. Furthermore, electrophysiological analysis demonstrated that inhibition of necroptosis delays not only the morphological degeneration of axons, but also the loss of their electrophysiological function after nerve injury. Activation of the necroptotic pathway early during injury-induced axonal degeneration was made evident by increased phosphorylation of the downstream effector MLKL. Our results demonstrate that axonal degeneration proceeds by necroptosis, thus defining a novel mechanistic framework in the axonal degenerative cascade for therapeutic interventions in a wide variety of conditions that lead to neuronal loss and functional impairment.SIGNIFICANCE STATEMENT We show that axonal degeneration triggered by diverse stimuli is mediated by the activation of the necroptotic programmed cell-death program by a cell-autonomous mechanism. This work represents a critical advance for the field since it identifies a defined degenerative pathway involved in axonal degeneration in both the peripheral nervous system and the CNS, a process that has been proposed as an early event in several neurodegenerative conditions and a major contributor to neuronal death. The identification of necroptosis as a key mechanism for axonal degeneration is an important step toward the development of novel therapeutic strategies for nervous-system disorders, particularly those related to chemotherapy-induced peripheral neuropathies or CNS diseases in which axonal degeneration is a common factor.
Collapse
|
47
|
Araki T, Wakatsuki S. Regulation of neuronal/axonal degeneration by ZNRF1 ubiquitin ligase. Neurosci Res 2019; 139:21-25. [DOI: 10.1016/j.neures.2018.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 06/22/2018] [Accepted: 06/23/2018] [Indexed: 11/24/2022]
|
48
|
NMNAT Proteins that Limit Wallerian Degeneration Also Regulate Critical Period Plasticity in the Visual Cortex. eNeuro 2019; 6:eN-NWR-0277-18. [PMID: 30671537 PMCID: PMC6338469 DOI: 10.1523/eneuro.0277-18.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 12/03/2018] [Accepted: 12/04/2018] [Indexed: 01/21/2023] Open
Abstract
Many brain regions go through critical periods of development during which plasticity is enhanced. These critical periods are associated with extensive growth and retraction of thalamocortical and intracortical axons. Here, we investigated whether a signaling pathway that is central in Wallerian axon degeneration also regulates critical period plasticity in the primary visual cortex (V1). Wallerian degeneration is characterized by rapid disintegration of axons once they are separated from the cell body. This degenerative process is initiated by reduced presence of cytoplasmic nicotinamide mononucleotide adenylyltransferases (NMNATs) and is strongly delayed in mice overexpressing cytoplasmic NMNAT proteins, such as WldS mutant mice producing a UBE4b-NMNAT1 fusion protein or NMNAT3 transgenic mice. Here, we provide evidence that in WldS mice and NMNAT3 transgenic mice, ocular dominance (OD) plasticity in the developing visual cortex is reduced. This deficit is only observed during the second half of the critical period. Additionally, we detect an early increase of visual acuity in the V1 of WldS mice. We do not find evidence for Wallerian degeneration occurring during OD plasticity. Our findings suggest that NMNATs do not only regulate Wallerian degeneration during pathological conditions but also control cellular events that mediate critical period plasticity during the physiological development of the cortex.
Collapse
|
49
|
Arrazola MS, Court FA. Compartmentalized necroptosis activation in excitotoxicity-induced axonal degeneration: a novel mechanism implicated in neurodegenerative disease pathology. Neural Regen Res 2019; 14:1385-1386. [PMID: 30964063 PMCID: PMC6524512 DOI: 10.4103/1673-5374.253520] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- Macarena S Arrazola
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor de Chile, Santiago, Chile; FONDAP Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - Felipe A Court
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor de Chile, Santiago, Chile; FONDAP Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Buck Institute for Research on Ageing, Novato, San Francisco, CA, USA
| |
Collapse
|
50
|
Belanger K, Schlatter G, Hébraud A, Marin F, Testelin S, Dakpé S, Devauchelle B, Egles C. A multi-layered nerve guidance conduit design adapted to facilitate surgical implantation. Health Sci Rep 2018; 1:e86. [PMID: 30623049 PMCID: PMC6295612 DOI: 10.1002/hsr2.86] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 07/16/2018] [Accepted: 07/18/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND AIMS The gold standard procedure after a severe nerve injury is the nerve autograft, yet this technique has drawbacks. In recent years, progress has been made in the development of artificial nerve guides to replace the autograft, but no device has been able to demonstrate superiority. The present study introduces an adaptable foundation design for peripheral nerve regeneration. METHODS Silk fibroin was electrospun, creating a tri-layered material with aligned fiber surfaces and a randomly deposited fiber interior. This material was rolled into a micro-channeled conduit, which was then enveloped by a jacket layer of the same tri-layered material. RESULTS The proposed implant design succeeds in incorporating various desirable aspects of synthetic nerve guides, while facilitating the surgical implantation process for medical application. The aligned fiber surfaces of the conduit support axon guidance, while the tri-layered architecture improves its structural integrity compared with a fully aligned fiber material. Moreover, the jacket layer creates a small niche on each end which facilitates surgical implantation. An in vivo study in rats showed that nerve regeneration using this device was comparable to results after direct suture. CONCLUSION This proof-of-principle study, therefore, advances the development of tissue engineered nerve grafts by creating an optimized guidance conduit design capable of successful nerve regeneration.
Collapse
Affiliation(s)
- Kayla Belanger
- UMR 7338, Biomécanique et Bioingénierie, Centre de recherches de RoyallieuSorbonne Universités, Université de Technologie de Compiègne, CNRSCompiègne cedexFrance
| | - Guy Schlatter
- ICPEES Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé, UMR 7515, CNRSUniversité de StrasbourgStrasbourg cedexFrance
| | - Anne Hébraud
- ICPEES Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé, UMR 7515, CNRSUniversité de StrasbourgStrasbourg cedexFrance
| | - Frédéric Marin
- UMR 7338, Biomécanique et Bioingénierie, Centre de recherches de RoyallieuSorbonne Universités, Université de Technologie de Compiègne, CNRSCompiègne cedexFrance
| | - Sylvie Testelin
- Facing Faces Institute, Amiens University Hospital CenterAmiens Cedex 1France
| | - Stéphanie Dakpé
- Facing Faces Institute, Amiens University Hospital CenterAmiens Cedex 1France
| | - Bernard Devauchelle
- Facing Faces Institute, Amiens University Hospital CenterAmiens Cedex 1France
| | - Christophe Egles
- UMR 7338, Biomécanique et Bioingénierie, Centre de recherches de RoyallieuSorbonne Universités, Université de Technologie de Compiègne, CNRSCompiègne cedexFrance
- Tufts University, School of Dental MedicineBostonMAUSA
| |
Collapse
|