1
|
Parishar P, Rajagopalan M, Iyengar S. Changes in the dopaminergic circuitry and adult neurogenesis linked to reinforcement learning in corvids. Front Neurosci 2024; 18:1359874. [PMID: 38808028 PMCID: PMC11130420 DOI: 10.3389/fnins.2024.1359874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 04/29/2024] [Indexed: 05/30/2024] Open
Abstract
The caudolateral nidopallium (NCL, an analog of the prefrontal cortex) is known to be involved in learning, memory, and discrimination in corvids (a songbird), whereas the involvement of other brain regions in these phenomena is not well explored. We used house crows (Corvus splendens) to explore the neural correlates of learning and decision-making by initially training them on a shape discrimination task followed by immunohistochemistry to study the immediate early gene expression (Arc), a dopaminoceptive neuronal marker (DARPP-32, Dopamine- and cAMP-regulated phosphoprotein, Mr 32 kDa) to understand the involvement of the reward pathway and an immature neuronal marker (DCX, doublecortin) to detect learning-induced changes in adult neurogenesis. We performed neuronal counts and neuronal tracing, followed by morphometric analyses. Our present results have demonstrated that besides NCL, other parts of the caudal nidopallium (NC), avian basal ganglia, and intriguingly, vocal control regions in house crows are involved in visual discrimination. We have also found that training on the visual discrimination task can be correlated with neurite pruning in mature dopaminoceptive neurons and immature DCX-positive neurons in the NC of house crows. Furthermore, there is an increase in the incorporation of new neurons throughout NC and the medial striatum which can also be linked to learning. For the first time, our results demonstrate that a combination of structural changes in mature and immature neurons and adult neurogenesis are linked to learning in corvids.
Collapse
|
2
|
Restoring After Central Nervous System Injuries: Neural Mechanisms and Translational Applications of Motor Recovery. Neurosci Bull 2022; 38:1569-1587. [DOI: 10.1007/s12264-022-00959-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/29/2022] [Indexed: 11/06/2022] Open
Abstract
AbstractCentral nervous system (CNS) injuries, including stroke, traumatic brain injury, and spinal cord injury, are leading causes of long-term disability. It is estimated that more than half of the survivors of severe unilateral injury are unable to use the denervated limb. Previous studies have focused on neuroprotective interventions in the affected hemisphere to limit brain lesions and neurorepair measures to promote recovery. However, the ability to increase plasticity in the injured brain is restricted and difficult to improve. Therefore, over several decades, researchers have been prompted to enhance the compensation by the unaffected hemisphere. Animal experiments have revealed that regrowth of ipsilateral descending fibers from the unaffected hemisphere to denervated motor neurons plays a significant role in the restoration of motor function. In addition, several clinical treatments have been designed to restore ipsilateral motor control, including brain stimulation, nerve transfer surgery, and brain–computer interface systems. Here, we comprehensively review the neural mechanisms as well as translational applications of ipsilateral motor control upon rehabilitation after CNS injuries.
Collapse
|
3
|
Hemati-Gourabi M, Cao T, Romprey MK, Chen M. Capacity of astrocytes to promote axon growth in the injured mammalian central nervous system. Front Neurosci 2022; 16:955598. [PMID: 36203815 PMCID: PMC9530187 DOI: 10.3389/fnins.2022.955598] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/15/2022] [Indexed: 01/02/2023] Open
Abstract
Understanding the regulation of axon growth after injury to the adult central nervous system (CNS) is crucial to improve neural repair. Following acute focal CNS injury, astrocytes are one cellular component of the scar tissue at the primary lesion that is traditionally associated with inhibition of axon regeneration. Advances in genetic models and experimental approaches have broadened knowledge of the capacity of astrocytes to facilitate injury-induced axon growth. This review summarizes findings that support a positive role of astrocytes in axon regeneration and axon sprouting in the mature mammalian CNS, along with potential underlying mechanisms. It is important to recognize that astrocytic functions, including modulation of axon growth, are context-dependent. Evidence suggests that the local injury environment, neuron-intrinsic regenerative potential, and astrocytes’ reactive states determine the astrocytic capacity to support axon growth. An integrated understanding of these factors will optimize therapeutic potential of astrocyte-targeted strategies for neural repair.
Collapse
Affiliation(s)
| | - Tuoxin Cao
- Spinal Cord and Brain Injury Research Center, Lexington, KY, United States
| | - Megan K. Romprey
- Spinal Cord and Brain Injury Research Center, Lexington, KY, United States
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States
| | - Meifan Chen
- Spinal Cord and Brain Injury Research Center, Lexington, KY, United States
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States
- *Correspondence: Meifan Chen,
| |
Collapse
|
4
|
Chen M, Ingle L, Plautz EJ, Kong X, Tang R, Ghosh N, Romprey MK, Fenske WK, Goldberg MP. LZK-dependent stimulation of astrocyte reactivity promotes corticospinal axon sprouting. Front Cell Neurosci 2022; 16:969261. [PMID: 36187291 PMCID: PMC9520579 DOI: 10.3389/fncel.2022.969261] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 08/10/2022] [Indexed: 11/13/2022] Open
Abstract
Injury to the adult mammalian central nervous system induces compensatory plasticity of spared axons—referred to as collateral axon sprouting—that can facilitate neural recovery. The contribution of reactive astrocytes to axon sprouting remains elusive. Here, we sought to investigate the role of axon degeneration-reactive astrocytes in the regulation of collateral axon sprouting that occurs in the mouse spinal cord after unilateral photothrombotic stroke of the primary motor cortex. We identified astrocytic leucine zipper-bearing kinase (LZK) as a positive regulator of astrocyte reactivity to corticospinal axon degeneration. Remarkably, genetic stimulation of astrocyte reactivity, via LZK overexpression in adult astrocytes, enhanced corticospinal axon sprouting. LZK promoted the production of astrocyte-derived ciliary neurotrophic factor (CNTF) that likely enhanced axon growth in mice with astrocytic LZK overexpression after injury. Our finding that LZK-dependent stimulation of astrocyte reactivity promotes corticospinal axon sprouting highlights the potential of engineering astrocytes to support injury-induced axon plasticity for neural repair.
Collapse
Affiliation(s)
- Meifan Chen
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY, United States
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, United States
- *Correspondence: Meifan Chen,
| | - Laura Ingle
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Erik J. Plautz
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Xiangmei Kong
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Rui Tang
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Neil Ghosh
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Megan K. Romprey
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY, United States
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - William K. Fenske
- Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Mark P. Goldberg
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Neurology, University of Texas Health Science Center San Antonio, San Antonio, TX, United States
- Mark P. Goldberg,
| |
Collapse
|
5
|
Vamour N, Dequirez PL, Seguier D, Vermersch P, De Wachter S, Biardeau X. Early interventions to prevent lower urinary tract dysfunction after spinal cord injury: a systematic review. Spinal Cord 2022; 60:382-394. [PMID: 35379959 DOI: 10.1038/s41393-022-00784-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 02/25/2022] [Accepted: 02/25/2022] [Indexed: 12/09/2022]
Abstract
STUDY DESIGN Systematic review. OBJECTIVES To synthetise the available scientific literature reporting early interventions to prevent neurogenic lower urinary tract dysfunction (NLUTD) after acute supra-sacral spinal cord injury (SCI). METHODS The present systematic review is reported according to the PRISMA guidelines and identified articles published through April 2021 in the PubMed, Embase, ScienceDirect and Scopus databases with terms for early interventions to prevent NLUTD after SCI. Abstract and full-text screenings were performed by three reviewers independently, while two reviewers performed data extraction independently. An article was considered relevant if it assessed: an in-vivo model of supra-sacral SCI, including a group undergoing an early intervention compared with at least one control group, and reporting clinical, urodynamic, biological and/or histological data. RESULTS Of the 30 studies included in the final synthesis, 9 focused on neurotransmission, 2 on the inflammatory response, 10 on neurotrophicity, 9 on electrical nerve modulation and 1 on multi-system neuroprosthetic training. Overall, 29/30 studies reported significant improvement in urodynamic parameters, for both the storage and the voiding phase. These findings were often associated with substantial modifications at the bladder and spinal cord level, including up/downregulation of neurotransmitters and receptors expression, neural proliferation or axonal sprouting and a reduction of inflammatory response and apoptosis. CONCLUSIONS The present review supports the concept of early interventions to prevent NLUTD after supra-sacral SCI, allowing for the emergence of a potential preventive approach in the coming decades.
Collapse
Affiliation(s)
| | | | | | - Patrick Vermersch
- Univ. Lille, Inserm UMR-S1172 LilNCog, Lille Neuroscience and Cognition, CHU Lille, FHU Precise, F-59000, Lille, France
| | - Stefan De Wachter
- Department of Urology, Antwerp University Hospital, Edegem, Belgium.,Antwerp Surgical Training, Anatomy and Research Centre (ASTARC), Faculty of Medicine and Health Sciences, Wlrijk, Belgium
| | - Xavier Biardeau
- Univ. Lille, Inserm UMR-S1172 LilNCog, Lille Neuroscience and Cognition, CHU Lille, F-59000, Lille, France
| |
Collapse
|
6
|
Exosomal microRNAs have great potential in the neurorestorative therapy for traumatic brain injury. Exp Neurol 2022; 352:114026. [DOI: 10.1016/j.expneurol.2022.114026] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/09/2022] [Accepted: 02/22/2022] [Indexed: 11/19/2022]
|
7
|
Central Nervous System Tissue Regeneration after Intracerebral Hemorrhage: The Next Frontier. Cells 2021; 10:cells10102513. [PMID: 34685493 PMCID: PMC8534252 DOI: 10.3390/cells10102513] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/13/2021] [Accepted: 09/17/2021] [Indexed: 12/11/2022] Open
Abstract
Despite marked advances in surgical techniques and understanding of secondary brain injury mechanisms, the prognosis of intracerebral hemorrhage (ICH) remains devastating. Harnessing and promoting the regenerative potential of the central nervous system may improve the outcomes of patients with hemorrhagic stroke, but approaches are still in their infancy. In this review, we discuss the regenerative phenomena occurring in animal models and human ICH, provide results related to cellular and molecular mechanisms of the repair process including by microglia, and review potential methods to promote tissue regeneration in ICH. We aim to stimulate research involving tissue restoration after ICH.
Collapse
|
8
|
Venkatesh I, Mehra V, Wang Z, Simpson MT, Eastwood E, Chakraborty A, Beine Z, Gross D, Cabahug M, Olson G, Blackmore MG. Co-occupancy identifies transcription factor co-operation for axon growth. Nat Commun 2021; 12:2555. [PMID: 33953205 PMCID: PMC8099911 DOI: 10.1038/s41467-021-22828-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 03/29/2021] [Indexed: 12/13/2022] Open
Abstract
Transcription factors (TFs) act as powerful levers to regulate neural physiology and can be targeted to improve cellular responses to injury or disease. Because TFs often depend on cooperative activity, a major challenge is to identify and deploy optimal sets. Here we developed a bioinformatics pipeline, centered on TF co-occupancy of regulatory DNA, and used it to predict factors that potentiate the effects of pro-regenerative Klf6 in vitro. High content screens of neurite outgrowth identified cooperative activity by 12 candidates, and systematic testing in a mouse model of corticospinal tract (CST) damage substantiated three novel instances of pairwise cooperation. Combined Klf6 and Nr5a2 drove the strongest growth, and transcriptional profiling of CST neurons identified Klf6/Nr5a2-responsive gene networks involved in macromolecule biosynthesis and DNA repair. These data identify TF combinations that promote enhanced CST growth, clarify the transcriptional correlates, and provide a bioinformatics approach to detect TF cooperation.
Collapse
Affiliation(s)
- Ishwariya Venkatesh
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA.
| | - Vatsal Mehra
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Zimei Wang
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Matthew T Simpson
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Erik Eastwood
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | | | - Zac Beine
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Derek Gross
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Michael Cabahug
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Greta Olson
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Murray G Blackmore
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA.
| |
Collapse
|
9
|
Yang LQ, Chen M, Ren DL, Hu B. Dual Oxidase Mutant Retards Mauthner-Cell Axon Regeneration at an Early Stage via Modulating Mitochondrial Dynamics in Zebrafish. Neurosci Bull 2020; 36:1500-1512. [PMID: 33123984 DOI: 10.1007/s12264-020-00600-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 07/25/2020] [Indexed: 12/17/2022] Open
Abstract
Dual oxidase (duox)-derived reactive oxygen species (ROS) have been correlated with neuronal polarity, cerebellar development, and neuroplasticity. However, there have not been many comprehensive studies of the effect of individual duox isoforms on central-axon regeneration in vivo. Here, we explored this question in zebrafish, an excellent model organism for central-axon regeneration studies. In our research, mutation of the duox gene with CRISPR/Cas9 significantly retarded the single-axon regeneration of the zebrafish Mauthner cell in vivo. Using deep transcriptome sequencing, we found that the expression levels of related functional enzymes in mitochondria were down-regulated in duox mutant fish. In vivo imaging showed that duox mutants had significantly disrupted mitochondrial transport and redox state in single Mauthner-cell axon. Our research data provide insights into how duox is involved in central-axon regeneration by changing mitochondrial transport.
Collapse
Affiliation(s)
- Lei-Qing Yang
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Biomedical Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Min Chen
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Biomedical Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Da-Long Ren
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Biomedical Sciences, University of Science and Technology of China, Hefei, 230026, China.
- Anhui Province Key Laboratory of Local Livestock and Poultry Genetic Resource Conservation and Bio-breeding, College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, China.
| | - Bing Hu
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Biomedical Sciences, University of Science and Technology of China, Hefei, 230026, China.
| |
Collapse
|
10
|
Jara JS, Agger S, Hollis ER. Functional Electrical Stimulation and the Modulation of the Axon Regeneration Program. Front Cell Dev Biol 2020; 8:736. [PMID: 33015031 PMCID: PMC7462022 DOI: 10.3389/fcell.2020.00736] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 07/15/2020] [Indexed: 01/07/2023] Open
Abstract
Neural injury in mammals often leads to persistent functional deficits as spontaneous repair in the peripheral nervous system (PNS) is often incomplete, while endogenous repair mechanisms in the central nervous system (CNS) are negligible. Peripheral axotomy elicits growth-associated gene programs in sensory and motor neurons that can support reinnervation of peripheral targets given sufficient levels of debris clearance and proximity to nerve targets. In contrast, while damaged CNS circuitry can undergo a limited amount of sprouting and reorganization, this innate plasticity does not re-establish the original connectivity. The utility of novel CNS circuitry will depend on effective connectivity and appropriate training to strengthen these circuits. One method of enhancing novel circuit connectivity is through the use of electrical stimulation, which supports axon growth in both central and peripheral neurons. This review will focus on the effects of CNS and PNS electrical stimulation in activating axon growth-associated gene programs and supporting the recovery of motor and sensory circuits. Electrical stimulation-mediated neuroplasticity represents a therapeutically viable approach to support neural repair and recovery. Development of appropriate clinical strategies employing electrical stimulation will depend upon determining the underlying mechanisms of activity-dependent axon regeneration and the heterogeneity of neuronal subtype responses to stimulation.
Collapse
Affiliation(s)
| | - Sydney Agger
- Burke Neurological Institute, White Plains, NY, United States
| | - Edmund R Hollis
- Burke Neurological Institute, White Plains, NY, United States.,Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, United States
| |
Collapse
|
11
|
Li J, Zhang Q, Li S, Niu L, Ma J, Wen L, Zhang L, Li C. α7nAchR mediates transcutaneous auricular vagus nerve stimulation-induced neuroprotection in a rat model of ischemic stroke by enhancing axonal plasticity. Neurosci Lett 2020; 730:135031. [DOI: 10.1016/j.neulet.2020.135031] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 12/20/2022]
|
12
|
Tanaka T, Ito T, Sumizono M, Ono M, Kato N, Honma S, Ueno M. Combinational Approach of Genetic SHP-1 Suppression and Voluntary Exercise Promotes Corticospinal Tract Sprouting and Motor Recovery Following Brain Injury. Neurorehabil Neural Repair 2020; 34:558-570. [PMID: 32441214 DOI: 10.1177/1545968320921827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background. Brain injury often causes severe motor dysfunction, leading to difficulties with living a self-reliant social life. Injured neural circuits must be reconstructed to restore functions, but the adult brain is limited in its ability to restore neuronal connections. The combination of molecular targeting, which enhances neural plasticity, and rehabilitative motor exercise is an important therapeutic approach to promote neuronal rewiring in the spared circuits and motor recovery. Objective. We tested whether genetic reduction of Src homology 2-containing phosphatase-1 (SHP-1), an inhibitor of brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB) signaling, has synergistic effects with rehabilitative training to promote reorganization of motor circuits and functional recovery in a mouse model of brain injury. Methods. Rewiring of the corticospinal circuit was examined using neuronal tracers following unilateral cortical injury in control mice and in Shp-1 mutant mice subjected to voluntary exercise. Recovery of motor functions was assessed using motor behavior tests. Results. We found that rehabilitative exercise decreased SHP-1 and increased BDNF and TrkB expression in the contralesional motor cortex after the injury. Genetic reduction of SHP-1 and voluntary exercise significantly increased sprouting of corticospinal tract axons and enhanced motor recovery in the impaired forelimb. Conclusions. Our data demonstrate that combining voluntary exercise and SHP-1 suppression promotes motor recovery and neural circuit reorganization after brain injury.
Collapse
Affiliation(s)
- Takashi Tanaka
- Kanazawa Medical University, Kahoku, Ishikawa, Japan.,Kindai University, Osaka-Sayama, Osaka, Japan
| | - Tetsufumi Ito
- Kanazawa Medical University, Kahoku, Ishikawa, Japan
| | - Megumi Sumizono
- Kyushu University of Nursing and Social Welfare, Tamana, Kumamoto, Japan
| | - Munenori Ono
- Kanazawa Medical University, Kahoku, Ishikawa, Japan
| | - Nobuo Kato
- Kanazawa Medical University, Kahoku, Ishikawa, Japan
| | - Satoru Honma
- Kanazawa Medical University, Kahoku, Ishikawa, Japan
| | | |
Collapse
|
13
|
Knock down of lncRNA H19 promotes axon sprouting and functional recovery after cerebral ischemic stroke. Brain Res 2020; 1732:146681. [PMID: 31991123 DOI: 10.1016/j.brainres.2020.146681] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/14/2020] [Accepted: 01/22/2020] [Indexed: 12/14/2022]
Abstract
Ischemic stroke is a leading cause of irreversible brain damages and disabilities. In the past decade, much attention has been focused on exploring effective strategies to promote circuit reorganization and functional recovery post injury. Here, we showed that the expression level of a long non-coding RNA (lncRNA H19) is bilaterally increased in the sensorimotor cortex after a cerebral ischemia induced by middle cerebral artery occlusion (MCAO). Knock down of contralaterally elevated H19 robustly enhanced the midline-crossing sprouting of the intact corticospinal axons in the spinal cord. Furthermore, H19 knockdown mice showed significant improvement on the performance of the food pellet retrieval assay, a skilled, cortical dependent motor task. Mechanistically, lncRNA H19 inhibition increased IGF1R expression and activated IGF1 mediated mTOR pathway. Our research thereby provided novel insights into identifying therapeutic targets for ischemic stroke.
Collapse
|
14
|
Gao J, Xia B, Li S, Huang L, Ma T, Shi X, Luo K, Yang Y, Zhao L, Zhang H, Luo B, Huang J. Magnetic Field Promotes Migration of Schwann Cells with Chondroitinase ABC (ChABC)-Loaded Superparamagnetic Nanoparticles Across Astrocyte Boundary in vitro. Int J Nanomedicine 2020; 15:315-332. [PMID: 32021182 PMCID: PMC6980842 DOI: 10.2147/ijn.s227328] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 12/17/2019] [Indexed: 12/12/2022] Open
Abstract
PURPOSE The clinical outcome of spinal cord injury is usually poor due to the lack of axonal regeneration and glia scar formation. As one of the most classical supporting cells in neural regeneration, Schwann cells (SCs) provide bioactive substrates for axonal migration and release molecules that regulate axonal growth. However, the effect of SC transplantation is limited by their poor migration capacity in the astrocyte-rich central nervous system. METHODS In this study, we first magnetofected SCs with chondroitinase ABC-polyethylenimine functionalized superparamagnetic iron oxide nanoparticles (ChABC/PEI-SPIONs) to induce overexpression of ChABC for the removal of chondroitin sulfate proteoglycans. These are inhibitory factors and forming a dense scar that acts as a barrier to the regenerating axons. In vitro, we observed the migration of SCs in the region of astrocytes after the application of a stable external magnetic field. RESULTS We found that magnetofection with ChABC/PEI-SPIONs significantly up-regulated the expression of ChABC in SCs. Under the driven effect of the directional magnetic field (MF), the migration of magnetofected SCs was enhanced in the direction of the magnetic force. The number of SCs with ChABC/PEI-SPIONs migrated and the distance of migration into the astrocyte region was significantly increased. The number of SCs with ChABC/PEI-SPIONs that migrated into the astrocyte region was 11.6- and 4.6-fold higher than those observed for the intact control and non-MF groups, respectively. Furthermore, it was found that SCs with ChABC/PEI-SPIONs were in close contact with astrocytes and no longer formed boundaries in the presence of MF. CONCLUSION The mobility of the SCs with ChABC/PEI-SPIONs was enhanced along the axis of MF, holding the potential to promote nerve regeneration by providing a bioactive microenvironment and relieving glial obstruction to axonal regeneration in the treatment of spinal cord injury.
Collapse
Affiliation(s)
- Jianbo Gao
- Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Bing Xia
- Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Shengyou Li
- Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Liangliang Huang
- Department of Orthopaedics, The General Hospital of Central Theater Command of People’s Liberation Army, Wuhan, People’s Republic of China
| | - Teng Ma
- Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Xiaowei Shi
- Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Kai Luo
- Department of Orthopaedics, The 985th Hospital of the PLA Joint Logistics Support Force, Taiyuan, People’s Republic of China
| | - Yujie Yang
- Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Laihe Zhao
- Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Hao Zhang
- Department of Spinal Surgery, People’s Hospital of Longhua District, Shenzhen, People’s Republic of China
| | - Beier Luo
- Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, People’s Republic of China
| | - Jinghui Huang
- Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of China
| |
Collapse
|
15
|
Cirillo C, Brihmat N, Castel-Lacanal E, Le Friec A, Barbieux-Guillot M, Raposo N, Pariente J, Viguier A, Simonetta-Moreau M, Albucher JF, Olivot JM, Desmoulin F, Marque P, Chollet F, Loubinoux I. Post-stroke remodeling processes in animal models and humans. J Cereb Blood Flow Metab 2020; 40:3-22. [PMID: 31645178 PMCID: PMC6928555 DOI: 10.1177/0271678x19882788] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 08/28/2019] [Accepted: 09/05/2019] [Indexed: 01/05/2023]
Abstract
After cerebral ischemia, events like neural plasticity and tissue reorganization intervene in lesioned and non-lesioned areas of the brain. These processes are tightly related to functional improvement and successful rehabilitation in patients. Plastic remodeling in the brain is associated with limited spontaneous functional recovery in patients. Improvement depends on the initial deficit, size, nature and localization of the infarction, together with the sex and age of the patient, all of them affecting the favorable outcome of reorganization and repair of damaged areas. A better understanding of cerebral plasticity is pivotal to design effective therapeutic strategies. Experimental models and clinical studies have fueled the current understanding of the cellular and molecular processes responsible for plastic remodeling. In this review, we describe the known mechanisms, in patients and animal models, underlying cerebral reorganization and contributing to functional recovery after ischemic stroke. We also discuss the manipulations and therapies that can stimulate neural plasticity. We finally explore a new topic in the field of ischemic stroke pathophysiology, namely the brain-gut axis.
Collapse
Affiliation(s)
- Carla Cirillo
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Nabila Brihmat
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Evelyne Castel-Lacanal
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Alice Le Friec
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | | | - Nicolas Raposo
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Jérémie Pariente
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Alain Viguier
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Marion Simonetta-Moreau
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Jean-François Albucher
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Jean-Marc Olivot
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Franck Desmoulin
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Philippe Marque
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - François Chollet
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| | - Isabelle Loubinoux
- Toulouse NeuroImaging Center (ToNIC), INSERM, University Paul Sabatier, UPS, Toulouse, France
| |
Collapse
|
16
|
Chen X, Jiang Y, Wang J, Liu Y, Xiao M, Song C, Bai Y, Yinuo Han N, Han F. Synapse impairment associated with enhanced apoptosis in post-traumatic stress disorder. Synapse 2019; 74:e22134. [PMID: 31562782 DOI: 10.1002/syn.22134] [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: 08/22/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 12/31/2022]
Abstract
Synapse impairment is associated with post-traumatic stress disorder (PTSD), which is characterized by enhanced apoptosis in the hippocampus, amygdala, and other brain regions. However, there are no detailed studies on the relationship between apoptosis and synaptic connectivity in PTSD. In this review, we discuss results from various studies describing the synaptic changes observed in the PTSD brain. A decreased number of dendrites/spines or increased number of immature spines in the hippocampus, medial prefrontal cortex, and other brain regions has been reported. Studies on axon guidance, myelination, and the cytoskeleton suggest that PTSD may involve axon overgrowth and overbranching. Apoptosis affects synapse formation; low levels of caspase maintain the balance between growth cone attraction and repulsion and inhibit axon elongation. PTSD enhances neuronal apoptosis through caspase activation, which disrupts the balance between growth cone attraction and repulsion and alters growth cone trajectory, leading to axon mistargeting. Meanwhile, caspase activation induces dendritic pruning and dendrite degeneration. These events contribute to the formation of fewer and aberrant synapses, which is associated with enhanced apoptosis in PTSD.
Collapse
Affiliation(s)
- Xinzhao Chen
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, China
| | - Yifan Jiang
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, China
| | - Jiayu Wang
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, China
| | - Yishu Liu
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, China
| | - Menglei Xiao
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, China
| | - Congshan Song
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, China
| | - Yu Bai
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, China
| | - Nancy Yinuo Han
- Faculty of Science, University of British Columbia, Vancouver, British Columbia, Canada
| | - Fang Han
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, China
| |
Collapse
|
17
|
Belgrad J, Dutta DJ, Bromley-Coolidge S, Kelly KA, Michalovicz LT, Sullivan KA, O'Callaghan JP, Fields RD. Oligodendrocyte involvement in Gulf War Illness. Glia 2019; 67:2107-2124. [PMID: 31339622 PMCID: PMC6899710 DOI: 10.1002/glia.23668] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 06/05/2019] [Accepted: 06/14/2019] [Indexed: 11/25/2022]
Abstract
Low level sarin nerve gas and other anti‐cholinesterase agents have been implicated in Gulf War illness (GWI), a chronic multi‐symptom disorder characterized by cognitive, pain and fatigue symptoms that continues to afflict roughly 32% of veterans from the 1990–1991 Gulf War. How disrupting cholinergic synaptic transmission could produce chronic illness is unclear, but recent research indicates that acetylcholine also mediates communication between axons and oligodendrocytes. Here we investigated the hypothesis that oligodendrocyte development is disrupted by Gulf War agents, by experiments using the sarin‐surrogate acetylcholinesterase inhibitor, diisopropyl fluorophosphate (DFP). The effects of corticosterone, which is used in some GWI animal models, were also investigated. The data show that DFP decreased both the number of mature and dividing oligodendrocytes in the rat prefrontal cortex (PFC), but differences were found between PFC and corpus callosum. The differences seen between the PFC and corpus callosum likely reflect the higher percentage of proliferating oligodendroglia in the adult PFC. In cell culture, DFP also decreased oligodendrocyte survival through a non‐cholinergic mechanism. Corticosterone promoted maturation of oligodendrocytes, and when used in combination with DFP it had protective effects by increasing the pool of mature oligodendrocytes and decreasing proliferation. Cell culture studies indicate direct effects of both DFP and corticosterone on OPCs, and by comparison with in vivo results, we conclude that in addition to direct effects, systemic effects and interruption of neuron–glia interactions contribute to the detrimental effects of GW agents on oligodendrocytes. Our results demonstrate that oligodendrocytes are an important component of the pathophysiology of GWI.
Collapse
Affiliation(s)
- Jillian Belgrad
- Section on Nervous System Development and Plasticity, The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland
| | - Dipankar J Dutta
- Section on Nervous System Development and Plasticity, The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland.,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland
| | - Samantha Bromley-Coolidge
- Section on Nervous System Development and Plasticity, The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland
| | - Kimberly A Kelly
- Centers for Disease Control and Prevention, Morgantown, West Virginia
| | | | - Kimberly A Sullivan
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts
| | | | - Richard Douglas Fields
- Section on Nervous System Development and Plasticity, The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland
| |
Collapse
|
18
|
Bray ER, Yungher BJ, Levay K, Ribeiro M, Dvoryanchikov G, Ayupe AC, Thakor K, Marks V, Randolph M, Danzi MC, Schmidt TM, Chaudhari N, Lemmon VP, Hattar S, Park KK. Thrombospondin-1 Mediates Axon Regeneration in Retinal Ganglion Cells. Neuron 2019; 103:642-657.e7. [PMID: 31255486 DOI: 10.1016/j.neuron.2019.05.044] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 02/11/2019] [Accepted: 05/28/2019] [Indexed: 12/20/2022]
Abstract
Neuronal subtypes show diverse injury responses, but the molecular underpinnings remain elusive. Using transgenic mice that allow reliable visualization of axonal fate, we demonstrate that intrinsically photosensitive retinal ganglion cells (ipRGCs) are both resilient to cell death and highly regenerative. Using RNA sequencing (RNA-seq), we show genes that are differentially expressed in ipRGCs and that associate with their survival and axon regeneration. Strikingly, thrombospondin-1 (Thbs1) ranked as the most differentially expressed gene, along with the well-documented injury-response genes Atf3 and Jun. THBS1 knockdown in RGCs eliminated axon regeneration. Conversely, RGC overexpression of THBS1 enhanced regeneration in both ipRGCs and non-ipRGCs, an effect that was dependent on syndecan-1, a known THBS1-binding protein. All structural domains of the THBS1 were not equally effective; the trimerization and C-terminal domains promoted regeneration, while the THBS type-1 repeats were dispensable. Our results identify cell-type-specific induction of Thbs1 as a novel gene conferring high regenerative capacity.
Collapse
Affiliation(s)
- Eric R Bray
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Benjamin J Yungher
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Konstantin Levay
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Marcio Ribeiro
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Gennady Dvoryanchikov
- Department of Physiology & Biophysics, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Ana C Ayupe
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Kinjal Thakor
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Victoria Marks
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Michael Randolph
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Matt C Danzi
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Tiffany M Schmidt
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Nirupa Chaudhari
- Department of Physiology & Biophysics, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Vance P Lemmon
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Samer Hattar
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Kevin K Park
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| |
Collapse
|
19
|
Chen M, Huang RC, Yang LQ, Ren DL, Hu B. In vivo
imaging of evoked calcium responses indicates the intrinsic axonal regenerative capacity of zebrafish. FASEB J 2019; 33:7721-7733. [DOI: 10.1096/fj.201802649r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Min Chen
- Hefei National Laboratory for Physical Sciences at the MicroscaleSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
| | - Rong-Chen Huang
- Hefei National Laboratory for Physical Sciences at the MicroscaleSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
| | - Lei-Qing Yang
- Hefei National Laboratory for Physical Sciences at the MicroscaleSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
| | - Da-Long Ren
- Hefei National Laboratory for Physical Sciences at the MicroscaleSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
- Chinese Academy of Sciences Key Laboratory of Brain Function and DiseaseUniversity of Science and Technology of ChinaHefeiChina
| | - Bing Hu
- Hefei National Laboratory for Physical Sciences at the MicroscaleSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
- Chinese Academy of Sciences Key Laboratory of Brain Function and DiseaseUniversity of Science and Technology of ChinaHefeiChina
| |
Collapse
|
20
|
Talebian S, Gharesouran J, Ghafouri-Fard S, Esfahani BS, Arsang-Jang S, Omrani MD, Taheri M, Rezazadeh M. Assessment of expression of RELN signaling pathway in multiple sclerosis patients. Immunobiology 2019; 224:402-407. [PMID: 30777599 DOI: 10.1016/j.imbio.2019.02.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/02/2019] [Accepted: 02/08/2019] [Indexed: 12/22/2022]
Abstract
Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system. Nearly 85% of MS patients are recognized with relapsing-remitting MS (RRMS), a typical clinical course of disease which is distinguished by several episodes of relapses, separated by remissions of neurological impairment. Failure of repair mechanisms is a main factor in progression of neurological dysfunction in MS. Several lines of evidence suggest that Reelin (RELN) signaling pathway can contribute in the regulation of repair mechanisms in MS patients. In the present study, we assessed expression levels of RELN and Disabled-1 (DAB1), two key genes in RELN signaling pathway, in peripheral blood of 50 RRMS patients and 50 matched healthy subjects. RELN was significantly down-regulated in total MS patients, and total female patients compared with the matched controls. However, no statistically significant difference was found in DAB1 mRNA expression between MS patients and controls. Furthermore, considerable correlations were detected between expression levels of RELN and DAB1 in the patients group. There were no significant correlations between expression levels of genes and EDSS, disease duration or age at onset. Our study provides evidences for the role of RELN signaling pathway in the pathogenesis of MS. Further studies are required to clarify the exact clinical significance of this pathway in MS patients.
Collapse
Affiliation(s)
- Shahrzad Talebian
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jalal Gharesouran
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Soudeh Ghafouri-Fard
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Behnaz Salek Esfahani
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Shahram Arsang-Jang
- Clinical Research Development Center (CRDU), Qom University of Medical Sciences, Qom, Iran
| | - Mir Davood Omrani
- Urogenital Stem Cell Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Taheri
- Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Maryam Rezazadeh
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| |
Collapse
|
21
|
Neuropilin-1-mediated pruning of corticospinal tract fibers is required for motor recovery after spinal cord injury. Cell Death Dis 2019; 10:67. [PMID: 30683854 PMCID: PMC6347615 DOI: 10.1038/s41419-019-1338-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/25/2018] [Accepted: 01/07/2019] [Indexed: 11/30/2022]
Abstract
Following incomplete spinal cord injury (SCI), reorganization of the corticospinal tract (CST) contributes to spontaneous motor recovery. Axotomized CST fibers form collaterals and make synapses with interneurons, followed by pruning of excess fibers. Although axonal pruning is involved in refinement of neural circuits, its molecular mechanisms and functional roles remain poorly understood. To address these questions, we performed dorsal hemisections of mouse thoracic spinal cord. We observed that Neuropilin-1 (Nrp1) mRNA was upregulated in layer 5 pyramidal neurons in the motor cortex 14 days after SCI, when the pruning occurred. Nrp1 knockdown using adeno-associated virus (AAV) vector encoding Nrp1 shRNA in the hindlimb motor area impaired the pruning of collaterals after SCI. Nrp1 knockout by injecting AAV vector encoding Cre recombinase into Nrp1 floxed mice also suppressed axonal pruning. Propriospinal neurons, interneurons that connect CST and motoneurons, expressed Semaphorin 3A (Sema3A), the ligand of Nrp1. Furthermore, the genetic deletion of Nrp1 specifically in the hindlimb motor area suppressed the recovery of skilled movement at 21 and 28 days after SCI. The present findings demonstrate that the pruning of collaterals mediated by Nrp1 is required for motor recovery after SCI, and suggest that refinement of the neuronal network facilitates motor recovery.
Collapse
|
22
|
Neumann B, Linton C, Giordano-Santini R, Hilliard MA. Axonal fusion: An alternative and efficient mechanism of nerve repair. Prog Neurobiol 2018; 173:88-101. [PMID: 30500382 DOI: 10.1016/j.pneurobio.2018.11.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/22/2018] [Accepted: 11/26/2018] [Indexed: 02/07/2023]
Abstract
Injuries to the nervous system can cause lifelong morbidity due to the disconnect that occurs between nerve cells and their cellular targets. Re-establishing these lost connections is the ultimate goal of endogenous regenerative mechanisms, as well as those induced by exogenous manipulations in a laboratory or clinical setting. Reconnection between severed neuronal fibers occurs spontaneously in some invertebrate species and can be induced in mammalian systems. This process, known as axonal fusion, represents a highly efficient means of repair after injury. Recent progress has greatly enhanced our understanding of the molecular control of axonal fusion, demonstrating that the machinery required for the engulfment of apoptotic cells is repurposed to mediate the reconnection between severed axon fragments, which are subsequently merged by fusogen proteins. Here, we review our current understanding of naturally occurring axonal fusion events, as well as those being ectopically produced with the aim of achieving better clinical outcomes.
Collapse
Affiliation(s)
- Brent Neumann
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne VIC 3800, Australia.
| | - Casey Linton
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rosina Giordano-Santini
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Massimo A Hilliard
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
| |
Collapse
|
23
|
The Role of Apoptotic Signaling in Axon Guidance. J Dev Biol 2018; 6:jdb6040024. [PMID: 30340315 PMCID: PMC6316149 DOI: 10.3390/jdb6040024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/16/2018] [Accepted: 10/16/2018] [Indexed: 12/28/2022] Open
Abstract
Navigating growth cones are exposed to multiple signals simultaneously and have to integrate competing cues into a coherent navigational response. Integration of guidance cues is traditionally thought to occur at the level of cytoskeletal dynamics. Drosophila studies indicate that cells exhibit a low level of continuous caspase protease activation, and that axon guidance cues can activate or suppress caspase activity. We base a model for axon guidance on these observations. By analogy with other systems in which caspase signaling has non-apoptotic functions, we propose that caspase signaling can either reinforce repulsion or negate attraction in response to external guidance cues by cleaving cytoskeletal proteins. Over the course of an entire trajectory, incorrectly navigating axons may pass the threshold for apoptosis and be eliminated, whereas axons making correct decisions will survive. These observations would also explain why neurotrophic factors can act as axon guidance cues and why axon guidance systems such as Slit/Robo signaling may act as tumor suppressors in cancer.
Collapse
|
24
|
Abstract
A recent study indicates that reducing fibrotic scarring by genetically abrogating the proliferation of type A pericytes promotes axon regeneration and functional recovery after spinal cord injury. Questions remain regarding the identity of the cells being manipulated and the balance between the beneficial and detrimental effects of fibrotic scarring.
Collapse
|
25
|
Sekiya T, Holley MC. 'Surface Transplantation' for Nerve Injury and Repair: The Quest for Minimally Invasive Cell Delivery. Trends Neurosci 2018; 41:429-441. [PMID: 29625774 DOI: 10.1016/j.tins.2018.03.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 02/22/2018] [Accepted: 03/07/2018] [Indexed: 12/15/2022]
Abstract
Cell transplantation is an ambitious, but arguably realistic, therapy for repair of the nervous system. Cell delivery is a major challenge for clinical translation, especially given the apparently inhibitory astrogliotic environment in degenerated tissue. However, astrogliotic tissue also contains endogenous structural and biochemical cues that can be harnessed for functional repair. Minimizing damage to these cues during cell delivery could enhance cell integration. This theory is supported by studies with an auditory astrocyte scar model, in which cells delivered onto the surface of the damaged nerve were more successfully integrated in the host than those injected into the tissue. We consider the application of this less invasive approach for nerve injury and its potential application to some neurodegenerative disorders.
Collapse
Affiliation(s)
- Tetsuji Sekiya
- Department of Otolaryngology, Head and Neck Surgery, Kyoto University Graduate School of Medicine, Sakyou-ku, Kyoto, 606-8507, Japan; Hikone Chuo Hospital, Department of Neurological Surgery, Hikone Chuo Hospital, 421 Nishiima-cho, Hikone, 522-0054, Japan.
| | - Matthew C Holley
- Department of Biomedical Science, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom
| |
Collapse
|
26
|
In Vivo Imaging of CNS Injury and Disease. J Neurosci 2017; 37:10808-10816. [PMID: 29118209 DOI: 10.1523/jneurosci.1826-17.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 10/02/2017] [Accepted: 10/03/2017] [Indexed: 02/06/2023] Open
Abstract
In vivo optical imaging has emerged as a powerful tool with which to study cellular responses to injury and disease in the mammalian CNS. Important new insights have emerged regarding axonal degeneration and regeneration, glial responses and neuroinflammation, changes in the neurovascular unit, and, more recently, neural transplantations. Accompanying a 2017 SfN Mini-Symposium, here, we discuss selected recent advances in understanding the neuronal, glial, and other cellular responses to CNS injury and disease with in vivo imaging of the rodent brain or spinal cord. We anticipate that in vivo optical imaging will continue to be at the forefront of breakthrough discoveries of fundamental mechanisms and therapies for CNS injury and disease.
Collapse
|
27
|
Luarte A, Cornejo VH, Bertin F, Gallardo J, Couve A. The axonal endoplasmic reticulum: One organelle-many functions in development, maintenance, and plasticity. Dev Neurobiol 2017; 78:181-208. [PMID: 29134778 DOI: 10.1002/dneu.22560] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 11/02/2017] [Accepted: 11/07/2017] [Indexed: 12/11/2022]
Abstract
The endoplasmic reticulum (ER) is highly conserved in eukaryotes and neurons. Indeed, the localization of the organelle in axons has been known for nearly half a century. However, the relevance of the axonal ER is only beginning to emerge. In this review, we discuss the structure of the ER in axons, examining the role of ER-shaping proteins and highlighting reticulons. We analyze the multiple functions of the ER and their potential contribution to axonal physiology. First, we examine the emerging roles of the axonal ER in lipid synthesis, protein translation, processing, quality control, and secretory trafficking of transmembrane proteins. We also review the impact of the ER on calcium dynamics, focusing on intracellular mechanisms and functions. We describe the interactions between the ER and endosomes, mitochondria, and synaptic vesicles. Finally, we analyze available proteomic data of axonal preparations to reveal the dynamic functionality of the ER in axons during development. We suggest that the dynamic proteome and a validated axonal interactome, together with state-of-the-art methodologies, may provide interesting research avenues in axon physiology that may extend to pathology and regeneration. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 181-208, 2018.
Collapse
Affiliation(s)
- Alejandro Luarte
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Víctor Hugo Cornejo
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Francisca Bertin
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Javiera Gallardo
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Andrés Couve
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| |
Collapse
|
28
|
Phosphatidylserine save-me signals drive functional recovery of severed axons in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2017; 114:E10196-E10205. [PMID: 29109263 PMCID: PMC5703272 DOI: 10.1073/pnas.1703807114] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Nervous system injury can cause lifelong disability, because repair rarely leads to reconnection with the target tissue. In the nematode Caenorhabditis elegans and in several other species, regeneration can proceed through a mechanism of axonal fusion, whereby regrowing axons reconnect and fuse with their own separated fragments, rapidly and efficiently restoring the original axonal tract. We have found that the process of axonal fusion restores full function to damaged neurons. In addition, we show that injury-induced changes to the axonal membrane that result in exposure of lipid “save-me” signals mediate the level of axonal fusion. Thus, our results establish axonal fusion as a complete regenerative mechanism that can be modulated by changing the level of save-me signals exposed after injury. Functional regeneration after axonal injury requires transected axons to regrow and reestablish connection with their original target tissue. The spontaneous regenerative mechanism known as axonal fusion provides a highly efficient means of achieving targeted reconnection, as a regrowing axon is able to recognize and fuse with its own detached axon segment, thereby rapidly reestablishing the original axonal tract. Here, we use behavioral assays and fluorescent reporters to show that axonal fusion enables full recovery of function after axotomy of Caenorhabditis elegans mechanosensory neurons. Furthermore, we reveal that the phospholipid phosphatidylserine, which becomes exposed on the damaged axon to function as a “save-me” signal, defines the level of axonal fusion. We also show that successful axonal fusion correlates with the regrowth potential and branching of the proximal fragment and with the retraction length and degeneration of the separated segment. Finally, we identify discrete axonal domains that vary in their propensity to regrow through fusion and show that the level of axonal fusion can be genetically modulated. Taken together, our results reveal that axonal fusion restores full function to injured neurons, is dependent on exposure of phospholipid signals, and is achieved through the balance between regenerative potential and level of degeneration.
Collapse
|
29
|
Loubinoux I, Brihmat N, Castel-Lacanal E, Marque P. Cerebral imaging of post-stroke plasticity and tissue repair. Rev Neurol (Paris) 2017; 173:577-583. [DOI: 10.1016/j.neurol.2017.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 09/11/2017] [Accepted: 09/12/2017] [Indexed: 01/17/2023]
|
30
|
Abstract
In this issue of Neuron, Tedeschi et al. (2016) describe the voltage-gated calcium channel subunit alpha2delta2 as a developmental switch from axon elongation to synapse formation and transmission that doubles as a suppressor of axon regeneration, providing a molecular clue for the synaptic stabilization hypothesis of CNS regeneration failure.
Collapse
Affiliation(s)
- Jessica M Meves
- Neurosciences Graduate Program and Department of Neurosciences, University of California San Diego, School of Medicine, 9500 Gilman Drive, MC 0691, La Jolla, CA 92093, USA
| | - Binhai Zheng
- Neurosciences Graduate Program and Department of Neurosciences, University of California San Diego, School of Medicine, 9500 Gilman Drive, MC 0691, La Jolla, CA 92093, USA.
| |
Collapse
|
31
|
Liu Y, Wang X, Li W, Zhang Q, Li Y, Zhang Z, Zhu J, Chen B, Williams PR, Zhang Y, Yu B, Gu X, He Z. A Sensitized IGF1 Treatment Restores Corticospinal Axon-Dependent Functions. Neuron 2017; 95:817-833.e4. [PMID: 28817801 DOI: 10.1016/j.neuron.2017.07.037] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/23/2017] [Accepted: 07/28/2017] [Indexed: 01/07/2023]
Abstract
A major hurdle for functional recovery after both spinal cord injury and cortical stroke is the limited regrowth of the axons in the corticospinal tract (CST) that originate in the motor cortex and innervate the spinal cord. Despite recent advances in engaging the intrinsic mechanisms that control CST regrowth, it remains to be tested whether such methods can promote functional recovery in translatable settings. Here we show that post-lesional AAV-assisted co-expression of two soluble proteins, namely insulin-like growth factor 1 (IGF1) and osteopontin (OPN), in cortical neurons leads to robust CST regrowth and the recovery of CST-dependent behavioral performance after both T10 lateral spinal hemisection and a unilateral cortical stroke. In these mice, a compound able to increase axon conduction, 4-aminopyridine-3-methanol, promotes further improvement in CST-dependent behavioral tasks. Thus, our results demonstrate a potentially translatable strategy for restoring cortical dependent function after injury in the adult.
Collapse
Affiliation(s)
- Yuanyuan Liu
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Xuhua Wang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Wenlei Li
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing 210004, China
| | - Qian Zhang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an 710032, China
| | - Yi Li
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Zicong Zhang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Junjie Zhu
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Bo Chen
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Philip R Williams
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Yiming Zhang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Bin Yu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Xiaosong Gu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Zhigang He
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| |
Collapse
|
32
|
Xia Y, Chen D, Xia H, Liao Z, Tang W, Yan Y. Serotonergic projections to lumbar levels and its plasticity following spinal cord injury. Neurosci Lett 2017; 649:70-77. [PMID: 28396282 DOI: 10.1016/j.neulet.2017.04.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 03/26/2017] [Accepted: 04/06/2017] [Indexed: 01/25/2023]
Abstract
The descending serotonergic pathway, which originates in various populations of brainstem neurons, plays an important role in generating the rhythmic motor pattern associated with locomotor movement. Although the development of its innervation has been studied in rodent spinal cord, it has not been clearly identified how the projection of serotonergic pathway is related to its function. Here, we evaluated the pattern of serotonergic innervation on the lumbar spinal cord from embryonic day 14.5 (E14.5) to adulthood. Before birth, we found that 5-hydroxytryptamine (5-HT) fibers invade the lumbar cord as early as E14.5, penetrate into the gray matter from lateral funiculus by E16.5, and then mainly occupied the ventral horn by E18.5 before localizing in the dorsal horn. After birth, we found that 5-HT invasion of both dorsal horn and ventral horn were present by the 7th postnatal day (P7). Additionally, the 5-HT innervation of these two areas evolved progressively from a diffuse network to a more restricted pattern, particularly at the ventral horn within the motoneuron area from P21 to adulthood. This 5-HT innervation pattern in the lumbar cord provides anatomical evidence that serotonergic fibers establish direct connections with lumbar motoneurons, which offers us a solid foundation that enhancing the plasticity of serotonergic pathway following SCI may facilitate locomotor functional recovery. Therefore, we employed treadmill training to activate serotonergic plasticity after SCI. We found that mice which underwent treadmill training exhibited a better locomotor functional recovery. Meanwhile, the density of 5-HT fibers in the ventral horn was significantly increased and the synaptic formation of 5-HT fibers with lumbar motoneurons was also significantly rescued in the training group mice after SCI. These findings demonstrate that the descending serotonergic projection is a robust and flexible parallel pathway for modulating spinal locomotor function.
Collapse
Affiliation(s)
- Yongzhi Xia
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Dan Chen
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Haijian Xia
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Zhengbu Liao
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Wenyuan Tang
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Yi Yan
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
| |
Collapse
|
33
|
Xu Y, Chen M, Hu B, Huang R, Hu B. In vivo Imaging of Mitochondrial Transport in Single-Axon Regeneration of Zebrafish Mauthner Cells. Front Cell Neurosci 2017; 11:4. [PMID: 28174522 PMCID: PMC5258718 DOI: 10.3389/fncel.2017.00004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 01/09/2017] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial transport is essential for neuronal function, but the evidence of connections between mitochondrial transport and axon regeneration in the central nervous system (CNS) of living vertebrates remains limited. Here, we developed a novel model to explore mitochondrial transport in a single Mauthner axon (M axon) of zebrafish with non-invasive in vivo imaging. To confirm the feasibility of using this model, we treated labeled zebrafish with nocodazole and demonstrated that it could disrupt mitochondrial transport. We also used two-photon laser axotomy to precisely axotomize M axons and simultaneously recorded their regeneration and the process of mitochondrial transport in living zebrafish larvae. The findings showed that the injured axons with stronger regenerative capability maintain greater mitochondrial motility. Furthermore, to stimulate axon regeneration, treatment with dibutyryl cyclic adenosine monophosphate (db-cAMP) could also augment mitochondrial motility. Taken together, our results provide new evidence that mitochondrial motility is positively correlated with axon regeneration in the living vertebrate CNS. This promising model will be useful for further studies on the interaction between axon regeneration and mitochondrial dynamics, using various genetic and pharmacological techniques.
Collapse
Affiliation(s)
- Yang Xu
- Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China Hefei, China
| | - Min Chen
- Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China Hefei, China
| | - Bingbing Hu
- Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China Hefei, China
| | - Rongchen Huang
- Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China Hefei, China
| | - Bing Hu
- Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China Hefei, China
| |
Collapse
|
34
|
Affiliation(s)
- Anne Jacobi
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Munich, Germany
| | - Florence M Bareyre
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Munich, Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| |
Collapse
|
35
|
A surviving intact branch stabilizes remaining axon architecture after injury as revealed by in vivo imaging in the mouse spinal cord. Neuron 2015; 86:947-954. [PMID: 25937174 DOI: 10.1016/j.neuron.2015.03.061] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 02/17/2015] [Accepted: 03/24/2015] [Indexed: 01/21/2023]
Abstract
The complex morphology of axons presents a challenge in understanding axonal responses to injury and disease. By in vivo two-photon imaging of spinal dorsal column sensory axons, we systematically examined the effect of injury location relative to the main bifurcation point on axon degeneration and regeneration following highly localized laser injuries. Retrograde but not anterograde degeneration was strongly blocked at the bifurcation point at both the acute and subacute phases. Eliminating either the ascending or descending branch led to a poor regenerative response, while eliminating both led to a strong regenerative response. Thus, a surviving intact branch suppresses both retrograde degeneration and regeneration of the injured branch, thereby preserving the remaining axon architecture. Regenerating axons exhibited a dynamic pattern with alternating phases of regeneration and pruning over a chronic period. In vivo imaging continues to reveal new insights on axonal responses to injury in the mammalian spinal cord.
Collapse
|