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Schulte S, Decker D, Nowduri B, Gries M, Christmann A, Meyszner A, Rabe H, Saumer M, Schäfer KH. Improving morphological and functional properties of enteric neuronal networks in vitro using a novel upside-down culture approach. Am J Physiol Gastrointest Liver Physiol 2024; 326:G567-G582. [PMID: 38193168 DOI: 10.1152/ajpgi.00170.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 12/05/2023] [Accepted: 12/21/2023] [Indexed: 01/10/2024]
Abstract
The enteric nervous system (ENS) comprises millions of neurons and glia embedded in the wall of the gastrointestinal tract. It not only controls important functions of the gut but also interacts with the immune system, gut microbiota, and the gut-brain axis, thereby playing a key role in the health and disease of the whole organism. Any disturbance of this intricate system is mirrored in an alteration of electrical functionality, making electrophysiological methods important tools for investigating ENS-related disorders. Microelectrode arrays (MEAs) provide an appropriate noninvasive approach to recording signals from multiple neurons or whole networks simultaneously. However, studying isolated cells of the ENS can be challenging, considering the limited time that these cells can be kept vital in vitro. Therefore, we developed an alternative approach cultivating cells on glass samples with spacers (fabricated by photolithography methods). The spacers allow the cells to grow upside down in a spatially confined environment while enabling acute consecutive recordings of multiple ENS cultures on the same MEA. Upside-down culture also shows beneficial effects on the growth and behavior of enteric neural cultures. The number of dead cells was significantly decreased, and neural networks showed a higher resemblance to the myenteric plexus ex vivo while producing more stable signals than cultures grown in the conventional way. Overall, our results indicate that the upside-down approach not only allows to investigate the impact of neurological diseases in vitro but could also offer insights into the growth and development of the ENS under conditions much closer to the in vivo environment.NEW & NOTEWORTHY In this study, we devised a novel approach for culturing and electrophysiological recording of the enteric nervous system using custom-made glass substrates with spacers. This allows to turn cultures of isolated myenteric plexus upside down, enhancing the use of the microelectrode array technique by allowing recording of multiple cultures consecutively using only one chip. In addition, upside-down culture led to significant improvements in the culture conditions, resulting in a more in vivo-like growth.
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Affiliation(s)
- Steven Schulte
- Department of Informatics and Microsystems Technology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Dominique Decker
- Department of Informatics and Microsystems Technology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Bharat Nowduri
- Department of Informatics and Microsystems Technology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Manuela Gries
- Department of Informatics and Microsystems Technology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Anne Christmann
- Department of Informatics and Microsystems Technology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Antoine Meyszner
- Department of Informatics and Microsystems Technology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Holger Rabe
- Department of Informatics and Microsystems Technology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Monika Saumer
- Department of Informatics and Microsystems Technology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
| | - Karl-Herbert Schäfer
- Department of Informatics and Microsystems Technology, University of Applied Sciences Kaiserslautern, Zweibrücken, Germany
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2
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Yeo H, Ahn SS, Ou S, Yun SJ, Lim Y, Koh D, Lee YH, Shin SY. The EGR1-Artemin Axis in Keratinocytes Enhances the Innervation of Epidermal Sensory Neurons during Skin Inflammation Induced by House Dust Mite Extract from Dermatophagoidesfarinae. J Invest Dermatol 2024:S0022-202X(24)00090-3. [PMID: 38302010 DOI: 10.1016/j.jid.2024.01.017] [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: 06/27/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 02/03/2024]
Abstract
Epidermal hyperinnervation is a critical feature of pruritus during skin inflammation. However, the mechanisms underlying epidermal hyperinnervation are unclear. This study investigates the role of the transcription factor EGR1 in epidermal innervation by utilizing wild-type (Egr1+/+) and Egr1-null (Egr1‒/‒) mice topically applied Dermatophagoides farinae extract from dust mite. Our findings revealed that Egr1‒/‒ mice exhibited reduced scratching behaviors and decreased density of epidermal innervation compared with Egr1+/+ mice. Furthermore, we identified artemin, a neurotrophic factor, as an EGR1 target responsible for Dermatophagoides farinae extract-induced hyperinnervation. It has been demonstrated that Dermatophagoides farinae extract stimulates toll-like receptors in keratinocytes. To elucidate the cellular mechanism, we stimulated keratinocytes with Pam3CSK4, a toll-like receptor 1/2 ligand. Pam3CSK4 triggered a toll-like receptor 1/2-mediated signaling cascade involving IRAK4, IκB kinase, MAPKs, ELK1, EGR1, and artemin, leading to increased neurite outgrowth and neuronal migration. In addition, increased expression of EGR1 and artemin was observed in the skin tissues of patients with atopic dermatitis. These findings highlight the significance of the EGR1-artemin axis in keratinocytes, promoting the process of epidermal innervation and suggesting it as a potential therapeutic target for alleviating itch and pain associated with house dust mite-induced skin inflammation.
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Affiliation(s)
- Hyunjin Yeo
- Department of Biological Sciences, Sang-huh College of Life Science, Konkuk University, Seoul, Republic of Korea
| | - Sung Shin Ahn
- Department of Biological Sciences, Sang-huh College of Life Science, Konkuk University, Seoul, Republic of Korea
| | - Sukjin Ou
- Department of Biological Sciences, Sang-huh College of Life Science, Konkuk University, Seoul, Republic of Korea
| | - Sook Jung Yun
- Department of Dermatology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Yoongho Lim
- Division of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Dongsoo Koh
- Department of Applied Chemistry, Dongduk Women's University, Seoul, Republic of Korea
| | - Young Han Lee
- Department of Biological Sciences, Sang-huh College of Life Science, Konkuk University, Seoul, Republic of Korea; Cancer and Metabolism Institute, Konkuk University, Seoul, Republic of Korea
| | - Soon Young Shin
- Department of Biological Sciences, Sang-huh College of Life Science, Konkuk University, Seoul, Republic of Korea; Cancer and Metabolism Institute, Konkuk University, Seoul, Republic of Korea.
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3
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Villard C. Spatial confinement: A spur for axonal growth. Semin Cell Dev Biol 2023; 140:54-62. [PMID: 35927121 DOI: 10.1016/j.semcdb.2022.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 07/16/2022] [Accepted: 07/16/2022] [Indexed: 01/28/2023]
Abstract
The concept of spatial confinement is the basis of cell positioning and guidance in in vitro studies. In vivo, it reflects many situations faced during embryonic development. In vitro, spatial confinement of neurons is achieved using different technological approaches: adhesive patterning, topographical structuring, microfluidics and the use of hydrogels. The notion of chemical or physical frontiers is particularly central to the behaviors of growth cones and neuronal processes under confinement. They encompass phenomena of cell spreading, boundary crossing, and path finding on surfaces with different adhesive properties. However, the most universal phenomenon related to confinement, regardless of how it is implemented, is the acceleration of neuronal growth. Overall, a bi-directional causal link emerges between the shape of the growth cone and neuronal elongation dynamics, both in vivo and in vitro. The sensing of adhesion discontinuities by filopodia and the subsequent spatial redistribution and size adaptation of these actin-rich filaments seem critical for the growth rate in conditions in which adhesive contacts and actin-associated clutching forces dominate. On the other hand, the involvement of microtubules, specifically demonstrated in 3D hydrogel environments and leading to ameboid-like locomotion, could be relevant in a wider range of growth situations. This review brings together a literature collected in distinct scientific fields such as development, mechanobiology and bioengineering that highlight the consequences of confinement and raise new questions at different cellular scales. Its ambition is to stimulate new research that could lead to a better understanding of what gives neurons their ability to establish and regulate their exceptional size.
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Affiliation(s)
- Catherine Villard
- Laboratoire Interdisciplinaire des Energies de Demain (LIED), Université Paris Cité, UMR 8236 CNRS, F-75013 Paris, France.
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4
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Rizk E, Madrid A, Koueik J, Sun D, Stewart K, Chen D, Luo S, Hong F, Papale LA, Hariharan N, Alisch RS, Iskandar BJ. Purified regenerating retinal neurons reveal regulatory role of DNA methylation-mediated Na+/K+-ATPase in murine axon regeneration. Commun Biol 2023; 6:120. [PMID: 36717618 PMCID: PMC9886953 DOI: 10.1038/s42003-023-04463-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 01/11/2023] [Indexed: 01/31/2023] Open
Abstract
While embryonic mammalian central nervous system (CNS) axons readily grow and differentiate, only a minority of fully differentiated mature CNS neurons are able to regenerate injured axons, leading to stunted functional recovery after injury and disease. To delineate DNA methylation changes specifically associated with axon regeneration, we used a Fluorescent-Activated Cell Sorting (FACS)-based methodology in a rat optic nerve transection model to segregate the injured retinal ganglion cells (RGCs) into regenerating and non-regenerating cell populations. Whole-genome DNA methylation profiling of these purified neurons revealed genes and pathways linked to mammalian RGC regeneration. Moreover, whole-methylome sequencing of purified uninjured adult and embryonic RGCs identified embryonic molecular profiles reactivated after injury in mature neurons, and others that correlate specifically with embryonic or adult axon growth, but not both. The results highlight the contribution to both embryonic growth and adult axon regeneration of subunits encoding the Na+/K+-ATPase. In turn, both biochemical and genetic inhibition of the Na+/K+-ATPase pump significantly reduced RGC axon regeneration. These data provide critical molecular insights into mammalian CNS axon regeneration, pinpoint the Na+/K+-ATPase as a key regulator of regeneration of injured mature CNS axons, and suggest that successful regeneration requires, in part, reactivation of embryonic signals.
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Affiliation(s)
- Elias Rizk
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA ,grid.240473.60000 0004 0543 9901Department of Neurological Surgery, Penn State Milton S. Hershey Medical Center, Hershey, PA 17033 USA
| | - Andy Madrid
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
| | - Joyce Koueik
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
| | - Dandan Sun
- grid.21925.3d0000 0004 1936 9000Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA
| | - Krista Stewart
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
| | - David Chen
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
| | - Susan Luo
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
| | - Felissa Hong
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
| | - Ligia A. Papale
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
| | - Nithya Hariharan
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
| | - Reid S. Alisch
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
| | - Bermans J. Iskandar
- grid.14003.360000 0001 2167 3675Department of Neurological Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792 USA
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5
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Sessler CD, Zhou Y, Wang W, Hartley ND, Fu Z, Graykowski D, Sheng M, Wang X, Liu J. Optogenetic polymerization and assembly of electrically functional polymers for modulation of single-neuron excitability. SCIENCE ADVANCES 2022; 8:eade1136. [PMID: 36475786 PMCID: PMC9728971 DOI: 10.1126/sciadv.ade1136] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/28/2022] [Indexed: 06/17/2023]
Abstract
Ionic conductivity and membrane capacitance are two foundational parameters that govern neuron excitability. Conventional optogenetics has emerged as a powerful tool to temporarily manipulate membrane ionic conductivity in intact biological systems. However, no analogous method exists for precisely manipulating cell membrane capacitance to enable long-lasting modulation of neuronal excitability. Genetically targetable chemical assembly of conductive and insulating polymers can modulate cell membrane capacitance, but further development of this technique has been hindered by poor spatiotemporal control of the polymer deposition and cytotoxicity from the widely diffused peroxide. We address these issues by harnessing genetically targetable photosensitizer proteins to assemble electrically functional polymers in neurons with precise spatiotemporal control. Using whole-cell patch-clamp recordings, we demonstrate that this optogenetic polymerization can achieve stepwise modulation of both neuron membrane capacitance and intrinsic excitability. Furthermore, cytotoxicity can be limited by controlling light exposure, demonstrating a promising new method for precisely modulating cell excitability.
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Affiliation(s)
- Chanan D. Sessler
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Yiming Zhou
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Wenbo Wang
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Nolan D. Hartley
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Zhanyan Fu
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - David Graykowski
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Morgan Sheng
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Xiao Wang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jia Liu
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
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6
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Intrinsic heterogeneity in axon regeneration. Biochem Soc Trans 2022; 50:1753-1762. [DOI: 10.1042/bst20220624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/01/2022] [Accepted: 11/07/2022] [Indexed: 11/18/2022]
Abstract
The nervous system is composed of a variety of neurons and glial cells with different morphology and functions. In the mammalian peripheral nervous system (PNS) or the lower vertebrate central nervous system (CNS), most neurons can regenerate extensively after axotomy, while the neurons in the mammalian CNS possess only limited regenerative ability. This heterogeneity is common within and across species. The studies about the transcriptomes after nerve injury in different animal models have revealed a series of molecular and cellular events that occurred in neurons after axotomy. However, responses of various types of neurons located in different positions of individuals were different remarkably. Thus, researchers aim to find the key factors that are conducive to regeneration, so as to provide the molecular basis for solving the regeneration difficulties after CNS injury. Here we review the heterogeneity of axonal regeneration among different cell subtypes in different animal models or the same organ, emphasizing the importance of comparative studies within and across species.
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7
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Zai W, Xu N, Wu W, Wang Y, Wang R. Effect of task-oriented training on gross motor function, balance and activities of daily living in children with cerebral palsy: A systematic review and meta-analysis. Medicine (Baltimore) 2022; 101:e31565. [PMID: 36343029 PMCID: PMC9646623 DOI: 10.1097/md.0000000000031565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND To systematically evaluate task-oriented training (TOT) on the improvement of gross motor function, balance and activities of daily living in children with cerebral palsy (CP). METHODS A number of randomized controlled trials (RCTs) of TOT in children with CP were searched from Pubmed, Cochrane Library, Web of Science, EmBase, China National Knowledge Infrastructure, Chinese Biology Medicine, Chinese Scientific Journals Database and Wanfang data from the establishment of database to March 2022. The methodological quality of the included studies was evaluated, and meta-analysis was performed by RevMan5.4 software. RESULTS A total of 16 studies were included in the systematic review (n = 893). Meta-analysis showed that the gross motor function measure (GMFM) (MD = 11.05, 95%CI [8.26, 13.83], P < .00001), dimension D (MD = 3.05, 95%CI [1.58, 4.53], P < .0001) of the GMFM, dimension E (MD = 7.36, 95%CI [5.88, 8.84], P < .00001) of the GMFM, the Berg Balance Scale (BBS) (MD = 6.23, 95%CI [3.31, 9.15], P < .0001), the pediatric evaluation of disability inventory (PEDI) mobile function (MD = 6.44, 95%CI [3.85, 9.02], P < .00001) score improved significantly in the TOT group compared with the control group. CONCLUSIONS Current evidence shows that TOT could effectively improve gross motor function, balance and activities of daily living in children with CP. Due to the limitations of the number and quality of the included studies, the above conclusions need to be verified by more high-quality studies.
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Affiliation(s)
- Weiyi Zai
- School of Rehabilitation Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Ning Xu
- School of Rehabilitation Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
- * Correspondence: Ning Xu, School of Rehabilitation Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250355, China (e-mail: ) and Wei Wu, Qilu Hospital of Shandong University, Jinan, Shandong 250012, China (e-mail: )
| | - Wei Wu
- Qilu Hospital of Shandong University, Jinan, Shandong, China
- * Correspondence: Ning Xu, School of Rehabilitation Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250355, China (e-mail: ) and Wei Wu, Qilu Hospital of Shandong University, Jinan, Shandong 250012, China (e-mail: )
| | - Yueying Wang
- School of Rehabilitation Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Runfang Wang
- School of Rehabilitation Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
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8
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Patkar S, Uwanogho D, Modo M, Tate RJ, Plevin R, Carswell HVO. Targeting 17β-estradiol biosynthesis in neural stem cells improves stroke outcome. Front Cell Neurosci 2022; 16:917181. [PMID: 35936502 PMCID: PMC9355602 DOI: 10.3389/fncel.2022.917181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 06/27/2022] [Indexed: 11/18/2022] Open
Abstract
Dax-1 (dosage-sensitive sex reversal adrenal hypoplasia congenital region on X-chromosome gene 1) blocks 17β-estradiol biosynthesis and its knockdown would be expected to increase 17β-estradiol production. We hypothesized that knockdown of Dax-1 in a conditionally immortalized neural stem cell (NSC) line, MHP36, is a useful approach to increase 17β-estradiol production. Short hairpin (sh) RNA targeted to Dax-1 in NSCs, namely MHP36-Dax1KD cells, resulted in the degradation of Dax-1 RNA and attenuation of Dax-1 protein expression. In vitro, MHP36-Dax1KD cells exhibited overexpression of aromatase and increased 17β-estradiol secretion compared to MHP36 cells. As 17β-estradiol has been shown to promote the efficacy of cell therapy, we interrogated the application of 17β-estradiol-enriched NSCs in a relevant in vivo disease model. We hypothesized that MHP36-Dax1KD cells will enhance functional recovery after transplantation in a stroke model. C57BL/6 male adult mice underwent ischemia/reperfusion by left middle cerebral artery occlusion for 45 min using an intraluminal thread. Two days later male mice randomly received vehicle, MHP36 cells, MHP36-Dax1KD cells, and MHP36 cells suspended in 17β-estradiol (100 nm) or 17β-estradiol alone (100 nm) with serial behavioral testing over 28 days followed by post-mortem histology and blinded analysis. Recovery of sensorimotor function was accelerated and enhanced, and lesion volume was reduced by MHP36-Dax1KD transplants. Regarding mechanisms, immunofluorescence indicated increased synaptic plasticity and neuronal differentiation after MHP36-Dax1KD transplants. In conclusion, knockdown of Dax-1 is a useful target to increase 17β-estradiol biosynthesis in NSCs and improves functional recovery after stroke in vivo, possibly mediated through neuroprotection and improved synaptic plasticity. Therefore, targeting 17β-estradiol biosynthesis in stem cells may be a promising therapeutic strategy for enhancing the efficacy of stem cell-based therapies for stroke.
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Affiliation(s)
- Shalmali Patkar
- Strathclyde Institute of Pharmacy and Biological Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Dafe Uwanogho
- Department of Neuroscience, James Black Centre, King’s College London, London, United Kingdom
| | - Michel Modo
- Department of Neuroscience, James Black Centre, King’s College London, London, United Kingdom
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Rothwelle J. Tate
- Strathclyde Institute of Pharmacy and Biological Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Robin Plevin
- Strathclyde Institute of Pharmacy and Biological Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Hilary V. O. Carswell
- Strathclyde Institute of Pharmacy and Biological Sciences, University of Strathclyde, Glasgow, United Kingdom
- *Correspondence: Hilary V. O. Carswell
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9
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Mrówczyńska E, Mazur AJ. Integrin-Linked Kinase (ILK) Plays an Important Role in the Laminin-Dependent Development of Dorsal Root Ganglia during Chicken Embryogenesis. Cells 2021; 10:cells10071666. [PMID: 34359835 PMCID: PMC8304069 DOI: 10.3390/cells10071666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/24/2021] [Accepted: 06/29/2021] [Indexed: 12/25/2022] Open
Abstract
Integrin-linked kinase (ILK) is mainly localized in focal adhesions where it interacts and modulates the downstream signaling of integrins affecting cell migration, adhesion, and survival. The interaction of dorsal root ganglia (DRG) cells, being part of the peripheral nervous system (PNS), with the extracellular matrix (ECM) via integrins is crucial for proper PNS development. A few studies have focused on ILK’s role in PNS development, but none of these have focused on chicken. Therefore, we decided to investigate ILK’s role in the development of Gallus gallus domesticus’s DRG. First, using RT-PCR, Western blotting, and in situ hybridization, we show that ILK is expressed in DRG. Next, by immunocytochemistry, we show ILK’s localization both intracellularly and on the cell membrane of DRG neurons and Schwann cell precursors (SCPs). Finally, we describe ILK’s involvement in multiple aspects of DRG development by performing functional experiments in vitro. IgG-mediated interruption of ILK’s action improved DRG neurite outgrowth, modulated their directionality, stimulated SCPs migration, and impacted growth cone morphology in the presence of laminin-1 or laminin-1 mimicking peptide IKVAV. Taken together, our results show that ILK is important for chicken PNS development, probably via its exposure to the ECM.
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Affiliation(s)
- Ewa Mrówczyńska
- Correspondence: (E.M.); (A.J.M.); Tel.: +48-71-375-7972 (E.M.); +48-71-375-6206 (A.J.M.)
| | - Antonina Joanna Mazur
- Correspondence: (E.M.); (A.J.M.); Tel.: +48-71-375-7972 (E.M.); +48-71-375-6206 (A.J.M.)
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10
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Brown SR, Washabaugh EP, Dutt-Mazumder A, Wojtys EM, Palmieri-Smith RM, Krishnan C. Functional Resistance Training to Improve Knee Strength and Function After Acute Anterior Cruciate Ligament Reconstruction: A Case Study. Sports Health 2020; 13:136-144. [PMID: 33337984 DOI: 10.1177/1941738120955184] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Thigh muscle weakness after anterior cruciate ligament reconstruction (ACLR) can persist after returning to activity. While resistance training can improve muscle function, "nonfunctional" training methods are not optimal for inducing transfer of benefits to activities such as walking. Here, we tested the feasibility of a novel functional resistance training (FRT) approach to restore strength and function in an individual with ACLR. HYPOTHESIS FRT would improve knee strength and function after ACLR. STUDY DESIGN Case report. LEVEL OF EVIDENCE Level 5. METHODS A 15-year-old male patient volunteered for an 8-week intervention where he performed 30 minutes of treadmill walking, 3 times per week, while wearing a custom-designed knee brace that provided resistance to the thigh muscles of his ACLR leg. Thigh strength, gait mechanics, and corticospinal and spinal excitability were assessed before and immediately after the 8-week intervention. Voluntary muscle activation was evaluated immediately after the intervention. RESULTS Knee extensor and flexor strength increased in the ACLR leg from pre- to posttraining (130 to 225 N·m [+74%] and 44 to 88 N·m [+99%], respectively) and increases in between-limb extensor and flexor strength symmetry (45% to 92% [+74%] and 47% to 72% [+65%], respectively) were also noted. After the intervention, voluntary muscle activation in the ACLR leg was 72%, compared with the non-ACLR leg at 75%. Knee angle and moment during late stance phase decreased (ie, improved) in the ACLR leg and appeared more similar to the non-ACLR leg after FRT training (18° to 14° [-23.4] and 0.07 to -0.02 N·m·kg-1·m-1 [-122.8%], respectively). Corticospinal and spinal excitability in the ACLR leg decreased (3511 to 2511 [-28.5%] and 0.42 to 0.24 [-43.7%], respectively) from pre- to posttraining. CONCLUSION A full 8 weeks of FRT that targeted both quadriceps and hamstring muscles lead to improvements in strength and gait, suggesting that FRT may constitute a promising and practical alternative to traditional methods of resistance training. CLINICAL RELEVANCE FRT may serve as a viable approach to improve knee strength and function after ACL reconstruction.
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Affiliation(s)
- Scott R Brown
- Neuromuscular and Rehabilitation Robotics Laboratory (NeuRRo Lab), Department of Physical Medicine and Rehabilitation, Michigan Medicine, University of Michigan, Ann Arbor, Michigan
| | - Edward P Washabaugh
- Neuromuscular and Rehabilitation Robotics Laboratory (NeuRRo Lab), Department of Physical Medicine and Rehabilitation, Michigan Medicine, University of Michigan, Ann Arbor, Michigan.,Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
| | - Aviroop Dutt-Mazumder
- Neuromuscular and Rehabilitation Robotics Laboratory (NeuRRo Lab), Department of Physical Medicine and Rehabilitation, Michigan Medicine, University of Michigan, Ann Arbor, Michigan
| | - Edward M Wojtys
- Department of Orthopaedic Surgery, Michigan Medicine, University of Michigan, Ann Arbor, Michigan
| | - Riann M Palmieri-Smith
- Neuromuscular and Rehabilitation Robotics Laboratory (NeuRRo Lab), Department of Physical Medicine and Rehabilitation, Michigan Medicine, University of Michigan, Ann Arbor, Michigan.,Department of Orthopaedic Surgery, Michigan Medicine, University of Michigan, Ann Arbor, Michigan.,School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Chandramouli Krishnan
- Neuromuscular and Rehabilitation Robotics Laboratory (NeuRRo Lab), Department of Physical Medicine and Rehabilitation, Michigan Medicine, University of Michigan, Ann Arbor, Michigan.,Biomedical Engineering, University of Michigan, Ann Arbor, Michigan.,School of Kinesiology, University of Michigan, Ann Arbor, Michigan.,Michigan Robotics Institute, University of Michigan, Ann Arbor, Michigan
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11
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Ko SH, Apple EC, Liu Z, Chen L. Age-dependent autophagy induction after injury promotes axon regeneration by limiting NOTCH. Autophagy 2020; 16:2052-2068. [PMID: 31920157 DOI: 10.1080/15548627.2020.1713645] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Macroautophagy/autophagy is essential for maintaining cellular homeostasis through the degradation of organelles and proteins. It also has a prominent role in modulating aging. However, the role of autophagy in the neuronal response to axon injury and axon regeneration, particularly in the context of aging, remains largely unknown. Our candidate genetic screen for axon regeneration regulators has identified genes in the autophagy pathway. Using a reporter that monitors autophagosomes and autolysosomes, we were able to monitor the dynamics of autophagy during axon regeneration. In response to axon injury, there was a significant increase in the number of autophagic vesicles. Injury-triggered autophagy activation and axon regeneration capacity undergo an age-dependent decline, and autophagy-activating agents partially rescued these declines. We found that DLK-1 was both required and sufficient for injury-induced autophagy activation. Autophagic vesicles co-localized with the NOTCH4 ortholog, LIN-12 receptor, a previously identified inhibitor of axon regeneration. Epistasis analyses indicate that LIN-12 might be a target of autophagy in axon regeneration. Together, our data suggest that DLK-mediated injury signaling can activate autophagy, which might limit the level of LIN-12 and NOTCH proteins to promote axon regeneration. Our findings reveal that autophagy activation can promote axon regeneration in neurons that lack maximal regrowth capacity, providing a promising therapeutic strategy for axon injury. Abbreviations: 3-MA: 3-methyladenine; ALs: autolysosomes; APs: autophagosomes; ARF-6: ADP-Ribosylation Factor related 6; ATG-9: AuTophaGy (yeast Atg homolog) 9; ATG9A: autophagy related 9A; BA1: bafilomycin A1; BEC-1: BEClin (human autophagy) homolog; BECN1: beclin 1; C. elegans: Caenorhabditis elegans; CEBP-1: C/EBP (CCAAT/enhancer-binding protein) homolog; CNS: central nervous system; DLK-1: Dual-Leucine zipper Kinase; DMSO: dimethyl sulfoxide; DRG: dorsal root ganglion; FOS: Fos proto-oncogene, AP-1 transcription factor subunit; GABA: gamma-aminobutyric acid; GFP: green fluorescent protein; HDA-3: Histone DeAcetylase; IP3: inositol trisphosphate; ITR-1: Inositol Triphosphate Receptor; KLF-2: Kruppel-Like Factor (zinc finger protein) 2; LGG-1: LC3, GABARAP and GATE-16 family; MAK-2: MAP kinase Activated protein Kinase; MAP kinase: mitogen-activated protein kinase; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MKK-4: mitogen activated protein kinase kinase 4; MTOR: mechanistic target of rapamycin kinase; NGM: nematode growth medium; NICD: Notch intracellular domain; NOTCH: notch receptor; PLM: posterior lateral microtubule; PMK-3: P38 Map kinase family; PNS: peripheral nervous system; SCG10: superior cervical ganglion protein 10; SCI: spinal cord injury; UNC-51: UNCoordinated 51; ULK1: unc-51 like autophagy activating kinase 1; wnd: wallenda.
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Affiliation(s)
- Su-Hyuk Ko
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
| | - Ellen C Apple
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
| | - Zhijie Liu
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
| | - Lizhen Chen
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
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12
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Rodemer W, Hu J, Selzer ME, Shifman MI. Heterogeneity in the regenerative abilities of central nervous system axons within species: why do some neurons regenerate better than others? Neural Regen Res 2020; 15:996-1005. [PMID: 31823869 PMCID: PMC7034288 DOI: 10.4103/1673-5374.270298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Some neurons, especially in mammalian peripheral nervous system or in lower vertebrate or in vertebrate central nervous system (CNS) regenerate after axotomy, while most mammalian CNS neurons fail to regenerate. There is an emerging consensus that neurons have different intrinsic regenerative capabilities, which theoretically could be manipulated therapeutically to improve regeneration. Population-based comparisons between “good regenerating” and “bad regenerating” neurons in the CNS and peripheral nervous system of most vertebrates yield results that are inconclusive or difficult to interpret. At least in part, this reflects the great diversity of cells in the mammalian CNS. Using mammalian nervous system imposes several methodical limitations. First, the small sizes and large numbers of neurons in the CNS make it very difficult to distinguish regenerating neurons from non-regenerating ones. Second, the lack of identifiable neurons makes it impossible to correlate biochemical changes in a neuron with axonal damage of the same neuron, and therefore, to dissect the molecular mechanisms of regeneration on the level of single neurons. This review will survey the reported responses to axon injury and the determinants of axon regeneration, emphasizing non-mammalian model organisms, which are often under-utilized, but in which the data are especially easy to interpret.
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Affiliation(s)
- William Rodemer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Jianli Hu
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation); Department of Neurology, the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Michael I Shifman
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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13
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The C. elegans BRCA2-ALP/Enigma Complex Regulates Axon Regeneration via a Rho GTPase-ROCK-MLC Phosphorylation Pathway. Cell Rep 2019; 24:1880-1889. [PMID: 30110643 DOI: 10.1016/j.celrep.2018.07.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 05/28/2018] [Accepted: 07/16/2018] [Indexed: 12/11/2022] Open
Abstract
The ability of specific neurons to regenerate their axons after injury is governed by cell-intrinsic regeneration pathways. However, the mechanisms regulating axon regeneration are not well understood. Here, we identify the brc-2 gene encoding a homolog of the mammalian BRCA2 tumor suppressor as a regulator of axon regeneration in Caenorhabditis elegans motor neurons. We show that the RHO-1/Rho GTPase-LET-502/ROCK (Rho-associated coiled-coil kinase)-regulatory non-muscle myosin light-chain (MLC-4/MLC) phosphorylation signaling pathway regulates axon regeneration. BRC-2 functions between RHO-1 and LET-502, suggesting that BRC-2 is required for the activation of LET-502 by RHO-1-GTP. We also find that one component that interacts with BRC-2, the ALP (α-actinin-associated LIM protein)/Enigma protein ALP-1, is required for regeneration and acts between LET-502 and MLC-4 phosphorylation. Furthermore, we demonstrate that ALP-1 associates with LET-502 and MLC-4. Thus, ALP-1 serves as a platform to activate MLC-4 phosphorylation mediated by the RHO-1-LET-502 signaling pathway.
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14
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Fu H, Han G, Li H, Liang X, Hu D, Zhang L, Tang P. Identification of Key Genes and Pathways Involved in the Heterogeneity of Intrinsic Growth Ability Between Neurons After Spinal Cord Injury in Adult Zebrafish. Neurochem Res 2019; 44:2057-2067. [PMID: 31325155 DOI: 10.1007/s11064-019-02841-1] [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: 12/07/2018] [Revised: 05/05/2019] [Accepted: 07/03/2019] [Indexed: 02/07/2023]
Abstract
In the adult central nervous system (CNS), axon regeneration is a major hurdle for functional recovery after trauma. The intrinsic growth potential of an injured axon varies widely between neurons. The underlying molecular mechanisms of such heterogeneity are largely unclear. In the present study, the adult zebrafish dataset GSE56842 were downloaded. Differentially expressed genes (DEGs) were sorted and deeply analyzed by bioinformatics methods. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs were performed with the DAVID. A DEGs-associated protein-protein interaction network was constructed from the STRING database and visualized with Cytoscape software. In total, 621 DEGs were identified. GO analysis showed that the biological processes of DEGs focused mainly on the Notch signaling pathway, cell differentiation and positive regulation of neuron differentiation. The molecular functions mainly included calcium-transporting ATPase activity and calcium ion binding and structural constituents of the cytoskeleton. The cellular components included the plasma membrane, spectrin, and cytoplasmic and membrane-bound vesicles. KEGG pathway analysis showed that these DEGs were mainly involved in the metabolic pathway and Notch signaling pathway, and subnetworks revealed that genes within modules were involved in the metabolic pathway, Wnt signaling pathway, and calcium signaling pathway. This study identified DEG candidate genes and pathways involved in the heterogeneity of the intrinsic growth ability between neurons after spinal cord injury in adult zebrafish, which could facilitate our understanding of the molecular mechanisms underlying axon regeneration, and these candidate genes and pathways could be therapeutic targets for the treatment of CNS injury.
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Affiliation(s)
- Haitao Fu
- School of Medicine, Nankai University, Tianjin, 300110, China.,Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, 100853, China
| | - Gonghai Han
- Kunming Medical University, Kunming, 650500, China
| | - Haojiang Li
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, 030000, China
| | - Xuezhen Liang
- The First Clinical Medical School, Shandong University of Traditional Chinese Medicine, Shandong, 250355, China
| | - Die Hu
- Qingdao Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao, 266071, China
| | - Licheng Zhang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, 100853, China.
| | - Peifu Tang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, 100853, China.
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15
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C. elegans Tensin Promotes Axon Regeneration by Linking the Met-like SVH-2 and Integrin Signaling Pathways. J Neurosci 2019; 39:5662-5672. [PMID: 31109965 DOI: 10.1523/jneurosci.2059-18.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 01/04/2023] Open
Abstract
Axon regeneration is a conserved mechanism induced by axon injury that initiates a neuronal response leading to regrowth of the axon. In Caenorhabditis elegans, the initiation of axon regeneration is regulated by the JNK MAP kinase (MAPK) pathway. We have previously identified a number of genes affecting the JNK pathway using an RNAi-based screen. Analysis of these genes, called the svh genes, has shed new light on the regulation of axon regeneration, revealing the involvement of a signaling cascade consisting of a growth factor SVH-1 and its receptor, the tyrosine kinase SVH-2. Here, we characterize the svh-6/tns-1 gene, which is a homolog of mammalian tensin, and show that it is a positive regulator of axon regeneration in motor neurons. We demonstrate that TNS-1 interacts with tyrosine-autophosphorylated SVH-2 and the integrin β subunit PAT-3 via its SH2 and PTB domains, respectively, to promote axon regeneration. These results suggest that TNS-1 acts as an adaptor to link the SVH-2 and integrin signaling pathways.SIGNIFICANCE STATEMENT The Caenorhabditis elegans JNK MAPK pathway regulates the initiation of axon regeneration. Previously, we showed that a signaling cascade consisting of the HGF-like growth factor SVH-1 and its Met-like receptor tyrosine kinase SVH-2 promotes axon regeneration through activation of the JNK pathway. In this study, we show that the C. elegans tensin, TNS-1, is required for efficient regeneration after axon injury. Phosphorylation of SVH-2 on tyrosine mediates its interaction with the SH2 domain of TNS-1 to positively regulate axon regeneration. Furthermore, TNS-1 interacts via its PTB domain with the integrin β subunit PAT-3. These results suggest that TNS-1 plays a critical role in the regulation of axon regeneration by linking the SVH-2 and integrin signaling pathways.
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16
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Farrukh F, Davies E, Berry M, Logan A, Ahmed Z. BMP4/Smad1 Signalling Promotes Spinal Dorsal Column Axon Regeneration and Functional Recovery After Injury. Mol Neurobiol 2019; 56:6807-6819. [PMID: 30924076 PMCID: PMC6728286 DOI: 10.1007/s12035-019-1555-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/13/2019] [Indexed: 01/08/2023]
Abstract
Signalling through the BMP4/Smad1 pathway promotes corticospinal tract axon regeneration and functional recovery in mice. However, unlike humans and rats, mice do not cavitate. Here, we investigated if activation of the BMP4/Smad1 pathway promotes axon regeneration and functional recovery in a rat model that cavitates. We show that dorsal root ganglion neurons (DRGN) in injury models, including the non-regenerating dorsal column (DC) and the regenerating sciatic nerve (SN) crush and preconditioning (p) SN + DC (pSN + DC) paradigms, regulate the BMP4/Smad1 signalling pathway. For example, mRNA expression of positive regulators of the BMP4/Smad1 pathway was highly up-regulated whilst negative regulators were significantly down-regulated in DRGN in the regenerating SN and pSN + DC models compared to non-regenerating DC models, matched by concomitant changes in protein expression detected in DRGN by immunohistochemistry. BMP4 peptide promoted significant DRGN survival and disinhibited neurite outgrowth in vitro, whilst AAV-BMP4 delivery in vivo stimulated DC axon regeneration and functional recovery in a model that cavitates. Our results show that activation of the BMP4/Smad1 pathway is a potential therapeutic target in the search for axon regenerative signalling pathways in the CNS.
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Affiliation(s)
- Fatima Farrukh
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Elise Davies
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Martin Berry
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Ann Logan
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Zubair Ahmed
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
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17
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Yun T, Ko HR, Ahn J, Jin EJ, Jo JM, Kwon IS, Cho SW, Chang YS, Park WS, Ahn JY. B23/Nucleophosmin promotes reconstitution of synaptic path in hippocampus after injury. Biochem Biophys Res Commun 2019; 508:1082-1087. [PMID: 30553452 DOI: 10.1016/j.bbrc.2018.12.036] [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: 11/14/2018] [Revised: 12/03/2018] [Accepted: 12/05/2018] [Indexed: 10/27/2022]
Abstract
B23, also known as nucleophosmin (NPM), is multifunctional protein directly implicated in cell proliferation, cell cycle progression, and cell survival. In the current study, in addition to confirming its anti-apoptotic function in neuronal survival, we demonstrated that the spatial-temporal expression profile of B23 during development of hippocampal neurons is high in the embryonic stage, down-regulated after birth, and preferentially localized at the tips of growing neuritis and branching points. Overexpression of B23 promotes axon growth with abundant branching points in growing hippocampal neurons, but depletion of B23 impairs axon growth, leading to neuronal death. Following injury to the trisynaptic path in hippocampal slice, overexpression of B23 remarkably increased the number and length of regenerative fibers in the mossy fiber path. Our study suggests that B23 expression in developing neurons is essential for neuritogenesis and axon growth and that up-regulation of B23 may be a strategy for enhancing the reconstitution of synaptic paths after injury to hippocampal synapses.
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Affiliation(s)
- Taegwan Yun
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea; Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea
| | - Hyo Rim Ko
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea; Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea
| | - Jaeyoung Ahn
- Department of Medicine, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea
| | - Eun-Ju Jin
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea; Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea
| | - Jung Min Jo
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea
| | - Il-Sun Kwon
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea
| | - Sung-Woo Cho
- Department of Biochemistry and Molecular Biology, University of Ulsan, College of Medicine, Seoul, 05505, South Korea
| | - Yun Sil Chang
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, and Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, South Korea; Stem Cell & Regenerative Medicine Institute, Samsung Medical Center, Seoul, 06351, South Korea
| | - Won Soon Park
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, and Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, South Korea; Stem Cell & Regenerative Medicine Institute, Samsung Medical Center, Seoul, 06351, South Korea.
| | - Jee-Yin Ahn
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea; Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea; Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, 06351, South Korea.
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18
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Nardo G, Trolese MC, Verderio M, Mariani A, de Paola M, Riva N, Dina G, Panini N, Erba E, Quattrini A, Bendotti C. Counteracting roles of MHCI and CD8 + T cells in the peripheral and central nervous system of ALS SOD1 G93A mice. Mol Neurodegener 2018; 13:42. [PMID: 30092791 PMCID: PMC6085701 DOI: 10.1186/s13024-018-0271-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/02/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The major histocompatibility complex I (MHCI) is a key molecule for the interaction of mononucleated cells with CD8+T lymphocytes. We previously showed that MHCI is upregulated in the spinal cord microglia and motor axons of transgenic SOD1G93A mice. METHODS To assess the role of MHCI in the disease, we examined transgenic SOD1G93A mice crossbred with β2 microglobulin-deficient mice, which express little if any MHCI on the cell surface and are defective for CD8+ T cells. RESULTS The lack of MHCI and CD8+ T cells in the sciatic nerve affects the motor axon stability, anticipating the muscle atrophy and the disease onset. In contrast, MHCI depletion in resident microglia and the lack of CD8+ T cell infiltration in the spinal cord protect the cervical motor neurons delaying the paralysis of forelimbs and prolonging the survival of SOD1G93A mice. CONCLUSIONS We provided straightforward evidence for a dual role of MHCI in the peripheral nervous system (PNS) compared to the CNS, pointing out regional and temporal differences in the clinical responses of ALS mice. These findings offer a possible explanation for the failure of systemic immunomodulatory treatments and suggest new potential strategies to prevent the progression of ALS.
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Affiliation(s)
- Giovanni Nardo
- Laboratory of Molecular Neurobiology, Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy.
| | - Maria Chiara Trolese
- Laboratory of Molecular Neurobiology, Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy
| | - Mattia Verderio
- Laboratory of Molecular Neurobiology, Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy
| | - Alessandro Mariani
- Laboratory of Analytical Biochemistry, Department of Environmental Health Sciences, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy
| | - Massimiliano de Paola
- Laboratory of Analytical Biochemistry, Department of Environmental Health Sciences, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy
| | - Nilo Riva
- Neuropathology Unit, Department of Neurology, INSPE- San Raffaele Scientific Institute, Dibit II, Via Olgettina 48, 20132, Milan, Italy
| | - Giorgia Dina
- Neuropathology Unit, Department of Neurology, INSPE- San Raffaele Scientific Institute, Dibit II, Via Olgettina 48, 20132, Milan, Italy
| | - Nicolò Panini
- Laboratory of Cancer Pharmacology Department of Oncology, Flow Cytometry Unit, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, via La Masa 19, 20156, Milan, Italy
| | - Eugenio Erba
- Laboratory of Cancer Pharmacology Department of Oncology, Flow Cytometry Unit, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, via La Masa 19, 20156, Milan, Italy
| | - Angelo Quattrini
- Neuropathology Unit, Department of Neurology, INSPE- San Raffaele Scientific Institute, Dibit II, Via Olgettina 48, 20132, Milan, Italy
| | - Caterina Bendotti
- Laboratory of Molecular Neurobiology, Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy
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19
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Breau MA, Schneider-Maunoury S. [Stretch-induced axon growth: a universal, yet poorly explored process]. Biol Aujourdhui 2018; 211:215-222. [PMID: 29412131 DOI: 10.1051/jbio/2017028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Indexed: 12/21/2022]
Abstract
The growth of axons is a key step in neuronal circuit assembly. The axon starts elongating with the migration of its growth cone in response to molecular signals present in the surrounding embryonic tissues. Following the formation of a synapse between the axon and the target cell, the distance which separates the cell body from the synapse continues to increase to accommodate the growth of the organism. This second phase of elongation, which is universal and crucial since it contributes to an important proportion of the final axon size, has been historically referred to as "stretch-induced axon growth". It is indeed likely to result from a mechanical tension generated by the growth of the body, but the underlying mechanisms remain poorly characterized. This article reviews the experimental studies of this process, mainly analysed on cultured neurons so far. The recent development of in vivo imaging techniques and tools to probe and perturb mechanical forces within embryos will shed new light on this universal mode of axonal growth. This knowledge may inspire the design of novel tissue engineering strategies dedicated to brain and spinal cord repair.
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Affiliation(s)
- Marie Anne Breau
- Institut de Biologie Paris-Seine (IBPS), Laboratoire de Biologie du Développement, CNRS UMR7622, INSERM U1156, 75005 Paris, France - Sorbonne Universités, UPMC Université Paris 06, 75005 Paris, France
| | - Sylvie Schneider-Maunoury
- Institut de Biologie Paris-Seine (IBPS), Laboratoire de Biologie du Développement, CNRS UMR7622, INSERM U1156, 75005 Paris, France - Sorbonne Universités, UPMC Université Paris 06, 75005 Paris, France
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20
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Janjic JM, Gorantla VS. Peripheral Nerve Nanoimaging: Monitoring Treatment and Regeneration. AAPS JOURNAL 2017; 19:1304-1316. [PMID: 28779380 DOI: 10.1208/s12248-017-0129-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 07/23/2017] [Indexed: 12/18/2022]
Abstract
Accidental and iatrogenic trauma are major causes of peripheral nerve injury. Healing after nerve injury is complex and often incomplete, which can lead to acute or chronic pain and functional impairment. Current assessment methods for nerve regeneration lack sensitivity and objectivity. There is a need for reliable and reproducible, noninvasive strategies with adequate spatial and temporal resolution for longitudinal evaluation of degeneration or regeneration after injury/treatment. Methods for noninvasive monitoring of the efficacy and effectiveness of neurotherapeutics in nerve regeneration or of neuropathic pain are needed to ensure adequacy and responsiveness to management, especially given the large variability in the patient populations, etiologies, and complexity of nerve injuries. Surrogate biomarkers are needed with positive predictive correlation for the dynamics and kinetics of neuroregeneration. They can provide direct real-time insight into the efficacy and mechanisms of individualized therapeutic intervention. Here, we review the state-of-the-art tools, technologies, and therapies in peripheral nerve injury and regeneration as well as provide perspectives for the future. We present compelling evidence that advancements in nanomedicine and innovation in nanotechnology such as nanotheranostics hold groundbreaking potential as paradigm shifts in noninvasive peripheral nerve imaging and drug delivery. Nanotechnology, which revolutionized molecular imaging in cancer and inflammatory disease, can be used to delineate dynamic molecular imaging signatures of neuroinflammation and neuroregeneration while simultaneously monitoring cellular or tissue response to drug therapy. We believe that current clinical successes of nanotechnology can and should be adopted and adapted to the science of peripheral nerve injury and regeneration.
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Affiliation(s)
- Jelena M Janjic
- Graduate School of Pharmaceutical Sciences, School of Pharmacy, Duquesne University, 600 Forbes Avenue, 415 Mellon Hall, Pittsburgh, Pennsylvania, 15282, USA. .,Chronic Pain Research Consortium, Duquesne University, 600 Forbes Avenue, Pittsburgh, Pennsylvania, 15282, USA. .,McGowan Institute for Regenerative Medicine, University of Pittsburgh, 1602 E. Carson Street, Pittsburgh, Pennsylvania, 15203, USA.
| | - Vijay S Gorantla
- Departments of Surgery, Ophthalmology and Bioengineering, Wake Forest Baptist Medical Center, Wake Forest Institute for Regenerative Medicine, 391 Technology Way, Winston-Salem, North Carolina, 27101, USA
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21
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Weng YL, An R, Cassin J, Joseph J, Mi R, Wang C, Zhong C, Jin SG, Pfeifer GP, Bellacosa A, Dong X, Hoke A, He Z, Song H, Ming GL. An Intrinsic Epigenetic Barrier for Functional Axon Regeneration. Neuron 2017; 94:337-346.e6. [PMID: 28426967 PMCID: PMC6007997 DOI: 10.1016/j.neuron.2017.03.034] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Revised: 02/05/2017] [Accepted: 03/23/2017] [Indexed: 12/15/2022]
Abstract
Mature neurons in the adult peripheral nervous system can effectively switch from a dormant state with little axonal growth to robust axon regeneration upon injury. The mechanisms by which injury unlocks mature neurons' intrinsic axonal growth competence are not well understood. Here, we show that peripheral sciatic nerve lesion in adult mice leads to elevated levels of Tet3 and 5-hydroxylmethylcytosine in dorsal root ganglion (DRG) neurons. Functionally, Tet3 is required for robust axon regeneration of DRG neurons and behavioral recovery. Mechanistically, peripheral nerve injury induces DNA demethylation and upregulation of multiple regeneration-associated genes in a Tet3- and thymine DNA glycosylase-dependent fashion in DRG neurons. In addition, Pten deletion-induced axon regeneration of retinal ganglion neurons in the adult CNS is attenuated upon Tet1 knockdown. Together, our study suggests an epigenetic barrier that can be removed by active DNA demethylation to permit axon regeneration in the adult mammalian nervous system.
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Affiliation(s)
- Yi-Lan Weng
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ran An
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200040, China
| | - Jessica Cassin
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Pre-doctoral Human Genetics Training Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jessica Joseph
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ruifa Mi
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Chen Wang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Chun Zhong
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Seung-Gi Jin
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Gerd P. Pfeifer
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Alfonso Bellacosa
- Cancer Epigenetics and Cancer Biology Programs, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ahmet Hoke
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Zhigang He
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Hongjun Song
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Pre-doctoral Human Genetics Training Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Guo-li Ming
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Zhang X, Hu M, Zhang L, An J, Yan W, Zhang Z, Liu J, Lu H, Chen X, Liu Y. MTEP impedes the neuronal polarization and the activity of the Akt-NF-κB pathway in rat hippocampal neurons. J Neurosci Res 2016; 95:1730-1744. [DOI: 10.1002/jnr.24002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 11/23/2016] [Accepted: 11/28/2016] [Indexed: 01/08/2023]
Affiliation(s)
- Xiaohua Zhang
- Institute of Neurobiology; Xi'an Jiaotong University Health Science Center; Xi'an Shaanxi People's Republic of China
| | - Ming Hu
- Department of Human Anatomy and Histoembryology, School of Basic Medical Science; Xi'an Jiaotong University; Xi'an Shaanxi People's Republic of China
| | - Lin Zhang
- Department of Neurology; Xi'an Center Hospital; Xi'an Shaanxi People's Republic of China
| | - Jing An
- Institute of Neurobiology; Xi'an Jiaotong University Health Science Center; Xi'an Shaanxi People's Republic of China
| | - Wenhui Yan
- Department of Pharmacology, School of Basic Medical Science; Xi'an Jiaotong University Health Science Center; Xi'an Shaanxi People's Republic of China
| | - Zhichao Zhang
- Institute of Neurobiology; Xi'an Jiaotong University Health Science Center; Xi'an Shaanxi People's Republic of China
| | - Jianxin Liu
- Institute of Neurobiology; Xi'an Jiaotong University Health Science Center; Xi'an Shaanxi People's Republic of China
| | - Haixia Lu
- Institute of Neurobiology; Xi'an Jiaotong University Health Science Center; Xi'an Shaanxi People's Republic of China
| | - Xinlin Chen
- Institute of Neurobiology; Xi'an Jiaotong University Health Science Center; Xi'an Shaanxi People's Republic of China
| | - Yong Liu
- Institute of Neurobiology; Xi'an Jiaotong University Health Science Center; Xi'an Shaanxi People's Republic of China
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23
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Nardo G, Trolese MC, de Vito G, Cecchi R, Riva N, Dina G, Heath PR, Quattrini A, Shaw PJ, Piazza V, Bendotti C. Immune response in peripheral axons delays disease progression in SOD1 G93A mice. J Neuroinflammation 2016; 13:261. [PMID: 27717377 PMCID: PMC5055725 DOI: 10.1186/s12974-016-0732-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/23/2016] [Indexed: 11/16/2022] Open
Abstract
Background Increasing evidence suggests that the immune system has a beneficial role in the progression of amyotrophic lateral sclerosis (ALS) although the mechanism remains unclear. Recently, we demonstrated that motor neurons (MNs) of C57SOD1G93A mice with slow disease progression activate molecules classically involved in the cross-talk with the immune system. This happens a lot less in 129SvSOD1G93A mice which, while expressing the same amount of transgene, had faster disease progression and earlier axonal damage. The present study investigated whether and how the immune response is involved in the preservation of motor axons in the mouse model of familial ALS with a more benign disease course. Methods First, the extent of axonal damage, Schwann cell proliferation, and neuromuscular junction (NMJ) denervation were compared between the two ALS mouse models at the disease onset. Then, we compared the expression levels of different immune molecules, the morphology of myelin sheaths, and the presence of blood-derived immune cell infiltrates in the sciatic nerve of the two SOD1G93A mouse strains using immunohistochemical, immunoblot, quantitative reverse transcription PCR, and rotating-polarization Coherent Anti-Stokes Raman Scattering techniques. Results Muscle denervation, axonal dysregulation, and myelin disruption together with reduced Schwann cell proliferation are prominent in 129SvSOD1G93A compared to C57SOD1G93A mice at the disease onset, and this correlates with a faster disease progression in the first strain. On the contrary, a striking increase of immune molecules such as CCL2, MHCI, and C3 was seen in sciatic nerves of slow progressor C57SOD1G93A mice and this was accompanied by heavy infiltration of CD8+ T lymphocytes and macrophages. These phenomena were not detectable in the peripheral nervous system of fast-progressing mice. Conclusions These data show for the first time that damaged MNs in SOD1-related ALS actively recruit immune cells in the peripheral nervous system to delay muscle denervation and prolong the lifespan. On the contrary, the lack of this response has a negative impact on the disease course. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0732-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Giovanni Nardo
- Laboratory of Molecular Neurobiology, Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy.
| | - Maria Chiara Trolese
- Laboratory of Molecular Neurobiology, Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy
| | - Giuseppe de Vito
- NEST, Scuola Normale Superiore, Piazza San Silvestro 12, I-56127, Pisa, Italy.,Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, I-56127, Pisa, Italy
| | - Roberta Cecchi
- NEST, Scuola Normale Superiore, Piazza San Silvestro 12, I-56127, Pisa, Italy
| | - Nilo Riva
- Neuropathology Unit, Department of Neurology, INSPE, San Raffaele Scientific Institute, Dibit II, Via Olgettina 48, 20132, Milan, Italy
| | - Giorgia Dina
- Neuropathology Unit, Department of Neurology, INSPE, San Raffaele Scientific Institute, Dibit II, Via Olgettina 48, 20132, Milan, Italy
| | - Paul R Heath
- Department of Neuroscience, Academic Neurology Unit, Faculty of Medicine, Dentistry and Health, Sheffield Institute for Translational Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
| | - Angelo Quattrini
- Neuropathology Unit, Department of Neurology, INSPE, San Raffaele Scientific Institute, Dibit II, Via Olgettina 48, 20132, Milan, Italy
| | - Pamela J Shaw
- Department of Neuroscience, Academic Neurology Unit, Faculty of Medicine, Dentistry and Health, Sheffield Institute for Translational Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
| | - Vincenzo Piazza
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, I-56127, Pisa, Italy
| | - Caterina Bendotti
- Laboratory of Molecular Neurobiology, Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy.
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Abstract
The spatial organization of neurites, the thin processes (i.e., dendrites and axons) that stem from a neuron's soma, conveys structural information required for proper brain function. The alignment, direction and overall geometry of neurites in the brain are subject to continuous remodeling in response to healthy and noxious stimuli. In the developing brain, during neurogenesis or in neuroregeneration, these structural changes are indicators of the ability of neurons to establish axon-to-dendrite connections that can ultimately develop into functional synapses. Enabling a proper quantification of this structural remodeling would facilitate the identification of new phenotypic criteria to classify developmental stages and further our understanding of brain function. However, adequate algorithms to accurately and reliably quantify neurite orientation and alignment are still lacking. To fill this gap, we introduce a novel algorithm that relies on multiscale directional filters designed to measure local neurites orientation over multiple scales. This innovative approach allows us to discriminate the physical orientation of neurites from finer scale phenomena associated with local irregularities and noise. Building on this multiscale framework, we also introduce a notion of alignment score that we apply to quantify the degree of spatial organization of neurites in tissue and cultured neurons. Numerical codes were implemented in Python and released open source and freely available to the scientific community.
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25
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Nardo G, Trolese MC, Bendotti C. Major Histocompatibility Complex I Expression by Motor Neurons and Its Implication in Amyotrophic Lateral Sclerosis. Front Neurol 2016; 7:89. [PMID: 27379008 PMCID: PMC4904147 DOI: 10.3389/fneur.2016.00089] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/30/2016] [Indexed: 12/13/2022] Open
Abstract
Neuronal expression of major histocompatibility complex I (MHCI)-related molecules in adults and during CNS diseases is involved in the synaptic plasticity and axonal regeneration with mechanisms either dependent or independent of their immune functions. Motor neurons are highly responsive in triggering the expression of MHCI molecules during normal aging or following insults and diseases, and this has implications in the synaptic controls, axonal regeneration, and neuromuscular junction stability of these neurons. We recently reported that MHCI and immunoproteasome are strongly activated in spinal motor neurons and their peripheral motor axon in a mouse model of familial amyotrophic lateral sclerosis (ALS) during the course of the disease. This response was prominent in ALS mice with slower disease progression in which the axonal structure and function was better preserved than in fast-progressing mice. This review summarizes and discusses our observations in the light of knowledge about the possible role of MHCI in motor neurons providing additional insight into the pathophysiology of ALS.
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Affiliation(s)
- Giovanni Nardo
- Laboratory of Molecular Neurobiology, Department of Neuroscience, Mario Negri Institute for Pharmacological Research IRCCS , Milan , Italy
| | - Maria Chiara Trolese
- Laboratory of Molecular Neurobiology, Department of Neuroscience, Mario Negri Institute for Pharmacological Research IRCCS , Milan , Italy
| | - Caterina Bendotti
- Laboratory of Molecular Neurobiology, Department of Neuroscience, Mario Negri Institute for Pharmacological Research IRCCS , Milan , Italy
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26
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Grummisch JA, Jadavji NM, Smith PD. tPA promotes cortical neuron survival via mTOR-dependent mechanisms. Mol Cell Neurosci 2016; 74:25-33. [PMID: 26995507 DOI: 10.1016/j.mcn.2016.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 03/08/2016] [Accepted: 03/14/2016] [Indexed: 10/22/2022] Open
Abstract
Tissue plasminogen activator (tPA) is a thrombolytic agent commonly used in the treatment of ischemic stroke. While the thrombolytic effects of tPA have been well established, the impact of this blood-brain barrier (BBB) crossing drug on neurons is not known. Given the widespread use of tPA in the clinical setting and the strict therapeutic window established for effective use of the drug, we examined the molecular mechanisms mediating the impact of tPA on postnatal cortical neurons isolated from the mouse brain. Dissociated postnatal primary cortical neurons were treated with tPA and the effects on neuron survival were evaluated. Pharmacological inhibitors of several signaling pathways previously implicated in neuroprotection (mTOR, JAK/STAT, MAPK and PKA-dependent mechanisms) were used to pinpoint the mechanistic effectors of tPA on neuron survival in vitro. We report here that tPA treatment results in a time-dependent neuroprotective effect on postnatal cortical neurons that relies predominantly on Janus kinase (JAK) and mammalian target of rapamycin (mTOR) signaling mechanisms. Taken together, these data suggest that tPA promotes neuroprotection in a temporally-regulated manner and that both JAK and mTOR signaling effectors are critical mediators of this neuroprotective effect. The results suggest the possibility of targeting these defined mechanisms to potentially expand the therapeutic window for tPA.
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Affiliation(s)
- Julia A Grummisch
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada.
| | - Nafisa M Jadavji
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada.
| | - Patrice D Smith
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada.
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27
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Alagapan S, Franca E, Pan L, Leondopulos S, Wheeler BC, DeMarse TB. Structure, Function, and Propagation of Information across Living Two, Four, and Eight Node Degree Topologies. Front Bioeng Biotechnol 2016; 4:15. [PMID: 26973833 PMCID: PMC4770194 DOI: 10.3389/fbioe.2016.00015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 02/04/2016] [Indexed: 11/13/2022] Open
Abstract
In this study, we created four network topologies composed of living cortical neurons and compared resultant structural-functional dynamics including the nature and quality of information transmission. Each living network was composed of living cortical neurons and were created using microstamping of adhesion promoting molecules and each was "designed" with different levels of convergence embedded within each structure. Networks were cultured over a grid of electrodes that permitted detailed measurements of neural activity at each node in the network. Of the topologies we tested, the "Random" networks in which neurons connect based on their own intrinsic properties transmitted information embedded within their spike trains with higher fidelity relative to any other topology we tested. Within our patterned topologies in which we explicitly manipulated structure, the effect of convergence on fidelity was dependent on both topology and time-scale (rate vs. temporal coding). A more detailed examination using tools from network analysis revealed that these changes in fidelity were also associated with a number of other structural properties including a node's degree, degree-degree correlations, path length, and clustering coefficients. Whereas information transmission was apparent among nodes with few connections, the greatest transmission fidelity was achieved among the few nodes possessing the highest number of connections (high degree nodes or putative hubs). These results provide a unique view into the relationship between structure and its affect on transmission fidelity, at least within these small neural populations with defined network topology. They also highlight the potential role of tools such as microstamp printing and microelectrode array recordings to construct and record from arbitrary network topologies to provide a new direction in which to advance the study of structure-function relationships.
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Affiliation(s)
- Sankaraleengam Alagapan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida , Gainesville, FL , USA
| | - Eric Franca
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida , Gainesville, FL , USA
| | - Liangbin Pan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida , Gainesville, FL , USA
| | - Stathis Leondopulos
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida , Gainesville, FL , USA
| | - Bruce C Wheeler
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA; Department of Biomedical Engineering, University of California San Diego, San Diego, CA, USA
| | - Thomas B DeMarse
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA; Department of Pediatric Neurology, University of Florida, Gainesville, FL, USA
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28
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Sachdeva R, Theisen CC, Ninan V, Twiss JL, Houlé JD. Exercise dependent increase in axon regeneration into peripheral nerve grafts by propriospinal but not sensory neurons after spinal cord injury is associated with modulation of regeneration-associated genes. Exp Neurol 2015; 276:72-82. [PMID: 26366525 DOI: 10.1016/j.expneurol.2015.09.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 07/28/2015] [Accepted: 09/08/2015] [Indexed: 01/04/2023]
Abstract
Insufficient regeneration of central nervous system (CNS) axons contributes to persisting neurological dysfunction after spinal cord injury (SCI). Peripheral nerve grafts (PNGs) support regeneration by thousands of injured intraspinal axons and help them bypass some of the extracellular barriers that form after SCI. However this number represents but a small portion of the total number of axons that are injured. Here we tested if rhythmic sensory stimulation during cycling exercise would boost the intrinsic regenerative state of neurons to enhance axon regeneration into PNGs after a lower thoracic (T12) spinal transection of adult rats. Using True Blue retrograde tracing, we show that 4 weeks of cycling improves regeneration into a PNG from lumbar interneurons but not by primary sensory neurons. The majority of neurons that regenerate their axon are within 5 mm of the lesion and their number increased 70% with exercise. Importantly propriospinal neurons in more distant regions (5-20 mm from the lesion) that routinely exhibit very limited regeneration responded to exercise by increasing the number of regenerating neurons by 900%. There was no exercise-associated increase in regeneration from sensory neurons. Analyses using fluorescent in situ hybridization showed that this increase in regenerative response is associated with changes in levels of mRNAs encoding the regeneration associated genes (RAGs) GAP43, β-actin and Neuritin. While propriospinal neurons showed increased mRNA levels in response to SCI alone and then to grafting and exercise, sensory neurons did not respond to SCI, but there was a response to the presence of a PNG. Thus, exercise is a non-invasive approach to modulate gene expression in injured neurons leading to an increase in regeneration. This sets the stage for future studies to test whether exercise will promote axon outgrowth beyond the PNG and reconnection with spinal cord neurons, thereby demonstrating a potential clinical application of this combined therapeutic intervention.
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Affiliation(s)
- Rahul Sachdeva
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Catherine C Theisen
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Vinu Ninan
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - John D Houlé
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA.
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NKCC1 Activation Is Required for Myelinated Sensory Neurons Regeneration through JNK-Dependent Pathway. J Neurosci 2015; 35:7414-27. [PMID: 25972170 DOI: 10.1523/jneurosci.4079-14.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
After peripheral nerve injury, axons are able to regenerate, although specific sensory reinnervation and functional recovery are usually worse for large myelinated than for small sensory axons. The mechanisms that mediate the regeneration of different sensory neuron subpopulations are poorly known. The Na(+)-K(+)-Cl(-) cotransporter 1 (NKCC1) is particularly relevant in setting the intracellular chloride concentration. After axotomy, increased NKCC1 phosphorylation has been reported to be important for neurite outgrowth of sensory neurons; however, the mechanisms underlying its effects are still unknown. In the present study we used in vitro and in vivo models to assess the differential effects of blocking NKCC1 activity on the regeneration of different types of dorsal root ganglia (DRGs) neurons after sciatic nerve injury in the rat. We observed that blocking NKCC1 activity by bumetanide administration induces a selective effect on neurite outgrowth and regeneration of myelinated fibers without affecting unmyelinated DRG neurons. To further study the mechanism underlying NKCC1 effects, we also assessed the changes in mitogen-activated protein kinase (MAPK) signaling under NKCC1 modulation. The inhibition of NKCC1 activity in vitro and in vivo modified pJNK1/2/3 expression in DRG neurons. Together, our study identifies a mechanism selectively contributing to myelinated axon regeneration, and point out the role of Cl(-) modulation in DRG neuron regeneration and in the activation of MAPKs, particularly those belonging to the JNK family.
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30
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Belin S, Nawabi H, Wang C, Tang S, Latremoliere A, Warren P, Schorle H, Uncu C, Woolf CJ, He Z, Steen JA. Injury-induced decline of intrinsic regenerative ability revealed by quantitative proteomics. Neuron 2015; 86:1000-1014. [PMID: 25937169 DOI: 10.1016/j.neuron.2015.03.060] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 11/21/2014] [Accepted: 03/20/2015] [Indexed: 12/28/2022]
Abstract
Neurons differ in their responses to injury, but the underlying mechanisms remain poorly understood. Using quantitative proteomics, we characterized the injury-triggered response from purified intact and axotomized retinal ganglion cells (RGCs). Subsequent informatics analyses revealed a network of injury-response signaling hubs. In addition to confirming known players, such as mTOR, this also identified new candidates, such as c-myc, NFκB, and Huntingtin. Similar to mTOR, c-myc has been implicated as a key regulator of anabolic metabolism and is downregulated by axotomy. Forced expression of c-myc in RGCs, either before or after injury, promotes dramatic RGC survival and axon regeneration after optic nerve injury. Finally, in contrast to RGCs, neither c-myc nor mTOR was downregulated in injured peripheral sensory neurons. Our studies suggest that c-myc and other injury-responsive pathways are critical to the intrinsic regenerative mechanisms and might represent a novel target for developing neural repair strategies in adults.
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Affiliation(s)
- Stephane Belin
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Homaira Nawabi
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Chen Wang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Shaojun Tang
- Department of Pathology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Alban Latremoliere
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Peter Warren
- Department of Urology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Hubert Schorle
- Department of Developmental Pathology, University of Bonn Medical School, Sigmund Freud Strasse 25, 53127 Bonn, Germany
| | - Ceren Uncu
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Zhigang He
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| | - Judith A Steen
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
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31
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Dawson AJ, Miotke JA, Meyer RL. Intraocular BDNF promotes ectopic branching, alters motility and stimulates abnormal collaterals in regenerating optic fibers. Brain Res 2015; 1613:13-26. [PMID: 25847715 DOI: 10.1016/j.brainres.2015.03.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 01/02/2023]
Abstract
A great deal of effort has been invested in using trophic factors and other bioactive molecules to promote cell survival and axonal regeneration in the adult central nervous system. Far less attention has been paid to investigating potential effects that trophic factors may have that might interfere with recovery. In the visual system, BDNF has been previously reported to prevent regeneration. To test if BDNF is inherently incompatible with regeneration, BDNF was given intraocularly during optic nerve regeneration in the adult goldfish. In vivo imaging and anatomical analysis of selectively labeled axons were used as a sensitive assay for effects on regeneration within the tectum. BDNF had no detectable inhibitory effect on the ability of axons to regenerate. Normal numbers of axons regenerated into the tectum, exhibited dynamic growth and retractions similar to controls, and were able to navigate to their correct target zone in the tectum. However, BDNF was found to have additional effects that adversely affected the quality of regeneration. It promoted premature branching at ectopic locations, diminished the growth rate of axons through the tectum, and resulted in the formation of ectopic collaterals. Thus, although BDNF has robust effects on axonal behavior, it is, nevertheless, compatible with axonal regeneration, axon navigation and the formation of terminal arbors.
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Affiliation(s)
- Amy J Dawson
- Department of Developmental and Cell Biology, University of California at Irvine, Irvine, CA 92697, USA; Division of Arts and Sciences, New River Community College, Dublin, VA 24084, USA.
| | - Jill A Miotke
- Department of Developmental and Cell Biology, University of California at Irvine, Irvine, CA 92697, USA.
| | - Ronald L Meyer
- Department of Developmental and Cell Biology, University of California at Irvine, Irvine, CA 92697, USA.
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Zhou H, Li X, Wu Q, Li F, Fu Z, Liu C, Liang Z, Chu T, Wang T, Lu L, Ning G, Kong X, Feng S. shRNA against PTEN promotes neurite outgrowth of cortical neurons and functional recovery in spinal cord contusion rats. Regen Med 2014; 10:411-29. [PMID: 25495396 DOI: 10.2217/rme.14.88] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
AIM To explore neurite growth/regeneration and spinal cord injury repair after PTEN silencing via lentivirus-mediated RNAi. MATERIALS & METHODS Cortical neurons were seeded on or adjacent to chondroitin sulfate proteoglycans. The length, number and crossing behavior of neurites were calculated. Lentivirus was locally injected into spinal cord contusion rats. The functional recovery and immunohistochemical staining were analyzed. RESULTS Neurites with PTEN silencing exhibited significant enhancements in elongation, initiation and crossing ability when they encountered chondroitin sulfate proteoglycans in vitro. In vivo PTEN silencing improved functional recovery significantly, and promoted axon and synapse formation, but not scar formation. CONCLUSIONS PTEN silencing may be promising for spinal cord injury repair.
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Affiliation(s)
- Hengxing Zhou
- 1Department of Orthopaedics, Tianjin Medical University General Hospital, No. 154 Anshan Road, Heping District, Tianjin 300052, PR China
| | | | - Qiang Wu
- 3Department of Orthopaedics, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, No. 314 Anshanxi Road, Nankai District, Tianjin 300193, PR China
| | - Fuyuan Li
- 1Department of Orthopaedics, Tianjin Medical University General Hospital, No. 154 Anshan Road, Heping District, Tianjin 300052, PR China
| | | | - Chang Liu
- 4School of Medicine, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, PR China
| | - Zhipin Liang
- 4School of Medicine, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, PR China
| | - Tianci Chu
- 1Department of Orthopaedics, Tianjin Medical University General Hospital, No. 154 Anshan Road, Heping District, Tianjin 300052, PR China
| | - Tianyi Wang
- 1Department of Orthopaedics, Tianjin Medical University General Hospital, No. 154 Anshan Road, Heping District, Tianjin 300052, PR China
| | - Lu Lu
- 1Department of Orthopaedics, Tianjin Medical University General Hospital, No. 154 Anshan Road, Heping District, Tianjin 300052, PR China
| | - Guangzhi Ning
- 1Department of Orthopaedics, Tianjin Medical University General Hospital, No. 154 Anshan Road, Heping District, Tianjin 300052, PR China
| | - Xiaohong Kong
- 4School of Medicine, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, PR China
| | - Shiqing Feng
- 1Department of Orthopaedics, Tianjin Medical University General Hospital, No. 154 Anshan Road, Heping District, Tianjin 300052, PR China
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Liu D, Wei N, Man HY, Lu Y, Zhu LQ, Wang JZ. The MT2 receptor stimulates axonogenesis and enhances synaptic transmission by activating Akt signaling. Cell Death Differ 2014; 22:583-96. [PMID: 25501601 DOI: 10.1038/cdd.2014.195] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Revised: 10/26/2014] [Accepted: 10/30/2014] [Indexed: 12/15/2022] Open
Abstract
The MT2 receptor is a principal type of G protein-coupled receptor that mainly mediates the effects of melatonin. Deficits of melatonin/MT2 signaling have been found in many neurological disorders, including Alzheimer's disease, the most common cause of dementia in the elderly, suggesting that preservation of the MT2 receptor may be beneficial to these neurological disorders. However, direct evidence linking the MT2 receptor to cognition-related synaptic plasticity remains to be established. Here, we report that the MT2 receptor, but not the MT1 receptor, is essential for axonogenesis both in vitro and in vivo. We find that axon formation is retarded in MT2 receptor knockout mice, MT2-shRNA electroporated brain slices or primary neurons treated with an MT2 receptor selective antagonist. Activation of the MT2 receptor promotes axonogenesis that is associated with an enhancement in excitatory synaptic transmission in central neurons. The signaling components downstream of the MT2 receptor consist of the Akt/GSK-3β/CRMP-2 cascade. The MT2 receptor C-terminal motif binds to Akt directly. Either inhibition of the MT2 receptor or disruption of MT2 receptor-Akt binding reduces axonogenesis and synaptic transmission. Our data suggest that the MT2 receptor activates Akt/GSK-3β/CRMP-2 signaling and is necessary and sufficient to mediate functional axonogenesis and synaptic formation in central neurons.
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Affiliation(s)
- D Liu
- 1] Department of Pathophyiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [2] Sino-Canada Collaborative Platform on Molecular Biology of Neurological Disease, Key Laboratory of Neurological Diseases, Ministry of Education, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [3] The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan 430030, China
| | - N Wei
- 1] Department of Pathophyiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [2] Sino-Canada Collaborative Platform on Molecular Biology of Neurological Disease, Key Laboratory of Neurological Diseases, Ministry of Education, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [3] The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan 430030, China
| | - H-Y Man
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Y Lu
- 1] Sino-Canada Collaborative Platform on Molecular Biology of Neurological Disease, Key Laboratory of Neurological Diseases, Ministry of Education, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [2] The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan 430030, China
| | - L-Q Zhu
- 1] Department of Pathophyiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [2] Sino-Canada Collaborative Platform on Molecular Biology of Neurological Disease, Key Laboratory of Neurological Diseases, Ministry of Education, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [3] The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan 430030, China
| | - J-Z Wang
- 1] Department of Pathophyiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [2] Sino-Canada Collaborative Platform on Molecular Biology of Neurological Disease, Key Laboratory of Neurological Diseases, Ministry of Education, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [3] The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan 430030, China
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Fagoe ND, van Heest J, Verhaagen J. Spinal cord injury and the neuron-intrinsic regeneration-associated gene program. Neuromolecular Med 2014; 16:799-813. [PMID: 25269879 DOI: 10.1007/s12017-014-8329-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/20/2014] [Indexed: 12/14/2022]
Abstract
Spinal cord injury (SCI) affects millions of people worldwide and causes a significant physical, emotional, social and economic burden. The main clinical hallmark of SCI is the permanent loss of motor, sensory and autonomic function below the level of injury. In general, neurons of the central nervous system (CNS) are incapable of regeneration, whereas injury to the peripheral nervous system is followed by axonal regeneration and usually results in some degree of functional recovery. The weak neuron-intrinsic regeneration-associated gene (RAG) response upon injury is an important reason for the failure of neurons in the CNS to regenerate an axon. This response consists of the expression of many RAGs, including regeneration-associated transcription factors (TFs). Regeneration-associated TFs are potential key regulators of the RAG program. The function of some regeneration-associated TFs has been studied in transgenic and knock-out mice and by adeno-associated viral vector-mediated overexpression in injured neurons. Here, we review these studies and propose that AAV-mediated gene delivery of combinations of regeneration-associated TFs is a potential strategy to activate the RAG program in injured CNS neurons and achieve long-distance axon regeneration.
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Affiliation(s)
- Nitish D Fagoe
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Academy of Arts and Sciences, Meibergdreef 47, 1105 BA, Amsterdam, The Netherlands,
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35
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Streijger F, Lee JHT, Duncan GJ, Ng MTL, Assinck P, Bhatnagar T, Plunet WT, Tetzlaff W, Kwon BK. Combinatorial treatment of acute spinal cord injury with ghrelin, ibuprofen, C16, and ketogenic diet does not result in improved histologic or functional outcome. J Neurosci Res 2014; 92:870-83. [PMID: 24658967 DOI: 10.1002/jnr.23372] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 11/28/2013] [Accepted: 01/20/2014] [Indexed: 11/09/2022]
Abstract
Because of the complex, multifaceted nature of spinal cord injury (SCI), it is widely believed that a combination of approaches will be superior to individual treatments. Therefore, we employed a rat model of cervical SCI to evaluate the combination of four noninvasive treatments that individually have been reported to be effective for acute SCI during clinically relevant therapeutic time windows. These treatments included ghrelin, ibuprofen, C16, and ketogenic diet (KD). These were selected not only because of their previously reported efficacy in SCI models but also for their potentially different mechanisms of action. The administration of ghrelin, ibuprofen, C16, and KD several hours to days postinjury was based on previous observations by others that each treatment had profound effects on the pathophysiology and functional outcome following SCI. Here we showed that, with the exception of a modest improvement in performance on the Montoya staircase test at 8-10 weeks postinjury, the combinatorial treatment with ghrelin, ibuprofen, C16, and KD did not result in any significant improvements in the rearing test, grooming test, or horizontal ladder. Histologic analysis of the spinal cords did not reveal any significant differences in tissue sparing between treatment and control groups. Although single approaches of ghrelin, ibuprofen, C16, and KD have been reported to be beneficial after SCI, our results show that the combination of the four interventions did not confer significant functional or histological improvements in a cervical model of SCI. Possible interactions among the treatments may have negated their beneficial effects, emphasizing the challenges that have to be addressed when considering combinatorial drug therapies for SCI.
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Affiliation(s)
- F Streijger
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada; Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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36
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Muramatsu R, Yamashita T. Concept and molecular basis of axonal regeneration after central nervous system injury. Neurosci Res 2014; 78:45-9. [DOI: 10.1016/j.neures.2013.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 05/14/2013] [Accepted: 07/05/2013] [Indexed: 11/25/2022]
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Abstract
The extensive lengths of neuronal processes necessitate efficient mechanisms for communication with the cell body. Neuronal regeneration after nerve injury requires new transcription; thus, long-distance retrograde signalling from axonal lesion sites to the soma and nucleus is required. In recent years, considerable progress has been made in elucidating the mechanistic basis of this system. This has included the discovery of a priming role for early calcium waves; confirmation of central roles for mitogen-activated protein kinase signalling effectors, the importin family of nucleocytoplasmic transport factors and molecular motors such as dynein; and demonstration of the importance of local translation as a key regulatory mechanism. These recent findings provide a coherent mechanistic framework for axon-soma communication in the injured nerve and shed light on the integration of cytoplasmic and nuclear transport in all eukaryotic cells.
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Affiliation(s)
- Ida Rishal
- Department of Biological Chemistry, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Mike Fainzilber
- Department of Biological Chemistry, Weizmann Institute of Science, 76100 Rehovot, Israel
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38
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de Winter F, Hoyng S, Tannemaat M, Eggers R, Mason M, Malessy M, Verhaagen J. Gene therapy approaches to enhance regeneration of the injured peripheral nerve. Eur J Pharmacol 2013; 719:145-152. [DOI: 10.1016/j.ejphar.2013.04.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 03/28/2013] [Accepted: 04/03/2013] [Indexed: 01/26/2023]
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39
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Ji SJ, Jaffrey SR. Axonal transcription factors: novel regulators of growth cone-to-nucleus signaling. Dev Neurobiol 2013; 74:245-58. [PMID: 23897628 DOI: 10.1002/dneu.22112] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 07/11/2013] [Accepted: 07/15/2013] [Indexed: 02/03/2023]
Abstract
Developing axons contain transcripts that are locally translated to influence the axonal proteome. Recent studies have shown that axonal transcripts include mRNAs encoding transcription factors. These mRNAs are translated to produce transcription factors that can be retrogradely trafficked back to the nucleus, where they regulate gene expression programs. These findings point to a novel mechanism of growth cone-to-nucleus signaling that occurs when growth cones encounter extracellular signaling molecules that stimulate local translation of these transcription factors, thereby influencing gene transcription. Here we summarize recent findings on local translation of transcription factors in axons and their roles in different neuronal processes such as neuronal specification, survival, and axon regeneration. Comprehensive axonal transcriptome studies have revealed transcripts that encode many more transcription factors and cofactors, suggesting a potentially broad role for this type of signaling. We review the progress on the approaches and tools that have been developed to study local translation and retrograde trafficking of transcription factors. We also highlight the challenges in the field and discuss the potential routes to resolving them.
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Affiliation(s)
- Sheng-Jian Ji
- Department of Pharmacology, Weill Medical College, Cornell University, New York, New York, 10065
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40
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Buffo A, Rossi F. Origin, lineage and function of cerebellar glia. Prog Neurobiol 2013; 109:42-63. [PMID: 23981535 DOI: 10.1016/j.pneurobio.2013.08.001] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/06/2013] [Accepted: 08/07/2013] [Indexed: 11/16/2022]
Abstract
The glial cells of the cerebellum, and particularly astrocytes and oligodendrocytes, are characterized by a remarkable phenotypic variety, in which highly peculiar morphological features are associated with specific functional features, unique among the glial cells of the entire CNS. Here, we provide a critical report about the present knowledge of the development of cerebellar glia, including lineage relationships between cerebellar neurons, astrocytes and oligodendrocytes, the origins and the genesis of the repertoire of glial types, and the processes underlying their acquisition of mature morphological and functional traits. In parallel, we describe and discuss some fundamental roles played by specific categories of glial cells during cerebellar development. In particular, we propose that Bergmann glia exerts a crucial scaffolding activity that, together with the organizing function of Purkinje cells, is necessary to achieve the normal pattern of foliation and layering of the cerebellar cortex. Moreover, we discuss some of the functional tasks of cerebellar astrocytes and oligodendrocytes that are distinctive of cerebellar glia throughout the CNS. Notably, we report about the regulation of synaptic signalling in the molecular and granular layer mediated by Bergmann glia and parenchymal astrocytes, and the functional interaction between oligodendrocyte precursor cells and neurons. On the whole, this review provides an extensive overview of the available literature and some novel insights about the origin and differentiation of the variety of cerebellar glial cells and their function in the developing and mature cerebellum.
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Affiliation(s)
- Annalisa Buffo
- Rita Levi-Montalcini Department of Neuroscience, University of Turin, Corso Raffaello, 30, 10125 Turin, Italy; Neuroscience Institute Cavalieri Ottolenghi, Neuroscience Institute of Turin, University of Turin, Regione Gonzole 10, 10043 Orbassano, Turin, Italy.
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41
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Abstract
Synaptic activity initiates biochemical processes that have various outcomes, including the formation of memories, increases in neuronal survival and the development of chronic pain and addiction. Virtually all activity-induced, long-lasting adaptations of brain functions require a dialogue between synapses and the nucleus that results in changes in gene expression. Calcium signals that are induced by synaptic activity and propagate into the nucleus are a major route for synapse-to-nucleus communication. Recent findings indicate that diverse forms of neuroadaptation require calcium transients in the nucleus to switch on the necessary genomic programme. Deficits in nuclear calcium signalling as a result of a reduction in synaptic activity or increased extrasynaptic NMDA receptor signalling may underlie the aetiologies of various diseases, including neurodegeneration and cognitive dysfunction.
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Affiliation(s)
- Hilmar Bading
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, INF 364, 69120 Heidelberg, Germany. Hilmar.Bading@ uni-hd.de
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42
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Noninvasive strategies to promote functional recovery after stroke. Neural Plast 2013; 2013:854597. [PMID: 23864962 PMCID: PMC3707231 DOI: 10.1155/2013/854597] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 06/02/2013] [Indexed: 01/17/2023] Open
Abstract
Stroke is a common and disabling global health-care problem, which is the third most common cause of death and one of the main causes of acquired adult disability in many countries. Rehabilitation interventions are a major component of patient care. In the last few years, brain stimulation, mirror therapy, action observation, or mental practice with motor imagery has emerged as interesting options as add-on interventions to standard physical therapies. The neural bases for poststroke recovery rely on the concept of plasticity, namely, the ability of central nervous system cells to modify their structure and function in response to external stimuli. In this review, we will discuss recent noninvasive strategies employed to enhance functional recovery in stroke patients and we will provide an overview of neural plastic events associated with rehabilitation in preclinical models of stroke.
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43
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Hu Y, Zhong W, Wan JMF, Yu ACH. Ultrasound can modulate neuronal development: impact on neurite growth and cell body morphology. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:915-25. [PMID: 23415289 DOI: 10.1016/j.ultrasmedbio.2012.12.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 12/06/2012] [Accepted: 12/08/2012] [Indexed: 05/21/2023]
Abstract
Neuronal development is known to be a dynamic process that can be modulated by presenting guidance cues to neuronal cells. We show that ultrasound, when applied at pulsed settings and with intensities slightly greater than clinical diagnosis levels, can potentially act as a repulsive cue for modulating neuronal growth dynamics. Using differentiated Neuro-2a cells as the model, we have examined in vitro how neuronal development can change during and after exposure to 1-MHz ultrasound for different acoustic settings. Neurite retraction and cell body shrinkage were found in neuronal cells over a 10-min exposure period with 1.168 W/cm(2) spatial-peak, time-averaged intensity (based on 0.84 MPa peak acoustic pressure, 100-cycle pulse duration, and 500-Hz pulse repetition frequency). These effects were found to result in instances of neuronal cell body displacement. The extent of the effects was dependent on acoustic intensity, with peak acoustic pressure being a more important contributing factor compared with pulse duration. The morphological changes were found to be non-destructive, in that post-exposure neurite outgrowth and neuritogenesis were respectively observed in neurite-bearing and neurite-less neuronal cells. Our results also showed that mechanotransduction might be involved in mediating ultrasound-neuron interactions, as the morphological changes were suppressed if stretch-activated ion channels were blocked or if calcium messenger ions were chelated. Overall, these findings suggest that ultrasound can potentially influence how neuronal cells develop through modifying their cytomechanical characteristics.
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Affiliation(s)
- Yaxin Hu
- Medical Engineering Program, The University of Hong Kong, Pokfulam, Hong Kong SAR
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44
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Kelly CE, Thymiakou E, Dixon JE, Tanaka S, Godwin J, Episkopou V. Rnf165/Ark2C enhances BMP-Smad signaling to mediate motor axon extension. PLoS Biol 2013; 11:e1001538. [PMID: 23610558 PMCID: PMC3627648 DOI: 10.1371/journal.pbio.1001538] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 03/07/2013] [Indexed: 12/21/2022] Open
Abstract
Little is known about extrinsic signals required for the advancement of motor neuron (MN) axons, which extend over long distances in the periphery to form precise connections with target muscles. Here we present that Rnf165 (Arkadia-like; Arkadia2; Ark2C) is expressed specifically in the nervous system and that its loss in mice causes motor innervation defects that originate during development and lead to wasting and death before weaning. The defects range from severe reduction of motor axon extension as observed in the dorsal forelimb to shortening of presynaptic branches of the phrenic nerve, as observed in the diaphragm. Molecular functional analysis showed that in the context of the spinal cord Ark2C enhances transcriptional responses of the Smad1/5/8 effectors, which are activated (phosphorylated) downstream of Bone Morphogenetic Protein (BMP) signals. Consistent with Ark2C-modulated BMP signaling influencing motor axons, motor pools in the spinal cord were found to harbor phosphorylated Smad1/5/8 (pSmad) and treatment of primary MN with BMP inhibitor diminished axon length. In addition, genetic reduction of BMP-Smad signaling in Ark2C (+/-) mice caused the emergence of Ark2C (-/-) -like dorsal forelimb innervation deficits confirming that enhancement of BMP-Smad responses by Ark2C mediates efficient innervation. Together the above data reveal an involvement of BMP-Smad signaling in motor axon advancement.
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Affiliation(s)
- Claire E. Kelly
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Efstathia Thymiakou
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - James E. Dixon
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Shinya Tanaka
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Jonathan Godwin
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Vasso Episkopou
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
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45
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Albus CA, Rishal I, Fainzilber M. Cell length sensing for neuronal growth control. Trends Cell Biol 2013; 23:305-10. [PMID: 23511112 DOI: 10.1016/j.tcb.2013.02.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 02/03/2013] [Accepted: 02/11/2013] [Indexed: 11/27/2022]
Abstract
Neurons exhibit great size differences, and must coordinate biosynthesis rates in cell bodies with the growth needs of different lengths of axons. Classically, axon growth has been viewed mainly as a consequence of extrinsic influences. However, recent publications have proposed at least two different intrinsic axon growth-control mechanisms. We suggest that these mechanisms form part of a continuum of axon growth-control mechanisms, wherein initial growth rates are pre-programmed by transcription factor levels, and subsequent elongating growth is dependent on feedback from intrinsic length-sensing enabled by bidirectional motor-dependent oscillating signals. This model might explain intrinsic limits on elongating neuronal growth and provides a mechanistic framework for determining the connections between genome expression and cellular growth rates in neurons.
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Affiliation(s)
- Christin A Albus
- Department of Biological Chemistry, Weizmann Institute of Science, 76100 Rehovot, Israel
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46
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Rishal I, Kam N, Perry RBT, Shinder V, Fisher EMC, Schiavo G, Fainzilber M. A motor-driven mechanism for cell-length sensing. Cell Rep 2013; 1:608-16. [PMID: 22773964 PMCID: PMC3389498 DOI: 10.1016/j.celrep.2012.05.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Size homeostasis is fundamental in cell biology, but it is not clear how large cells such as neurons can assess their own size or length. We examined a role for molecular motors in intracellular length sensing. Computational simulations suggest that spatial information can be encoded by the frequency of an oscillating retrograde signal arising from a composite negative feedback loop between bidirectional motor-dependent signals. The model predicts that decreasing either or both anterograde or retrograde signals should increase cell length, and this prediction was confirmed upon application of siRNAs for specific kinesin and/or dynein heavy chains in adult sensory neurons. Heterozygous dynein heavy chain 1 mutant sensory neurons also exhibited increased lengths both in vitro and during embryonic development. Moreover, similar length increases were observed in mouse embryonic fibroblasts upon partial downregulation of dynein heavy chain 1. Thus, molecular motors critically influence cell-length sensing and growth control.
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Affiliation(s)
- Ida Rishal
- Department of Biological Chemistry, Weizmann Institute of Science, 76100 Rehovot, Israel
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47
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Salerno KM, Jing X, Diges CM, Davis BM, Albers KM. TRAF family member-associated NF-kappa B activator (TANK) expression increases in injured sensory neurons and is transcriptionally regulated by Sox11. Neuroscience 2013; 231:28-37. [PMID: 23201825 PMCID: PMC3558548 DOI: 10.1016/j.neuroscience.2012.11.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 11/08/2012] [Accepted: 11/12/2012] [Indexed: 12/17/2022]
Abstract
Peripheral nerve injury evokes rapid and complex changes in gene transcription and cellular signaling pathways. Understanding how these changes are functionally related is essential for developing new approaches that accelerate and improve nerve regeneration. Toward this goal we found that nerve injury induces a rapid and significant up-regulation of the transcription factor Sox11 in dorsal root ganglia (DRG) neurons. Gain and loss of function studies have shown this increase is essential for normal axon regeneration. To determine how Sox11 impacts neuronal gene expression, DRG neurons were treated with Sox11 siRNA to identify potential transcriptional targets. One gene significantly reduced by Sox11 knockdown was TRAF (tumor necrosis factor (TNF) receptor-associated factor)-associated NF-κB activator (TANK). Here we show that TANK is expressed in DRG neurons, that TANK expression is increased in response to peripheral nerve injury and that Sox11 overexpression in vitro increases TANK expression. Injury and in vitro overexpression were also found to preferentially increase TANK transcript variant 3 and a larger TANK protein isoform. To determine if Sox11 regulates TANK transcription bioinformatic analysis was used to identify potential Sox-binding motifs within 5kbp of the TANK 5' untranslated region (UTR) across several mammalian genomes. Two sites in the mouse TANK gene were examined. Luciferase expression assays coupled with site-directed mutagenesis showed each site contributes to enhanced TANK promoter activity. In addition, chromatin immunoprecipitation assays showed direct Sox11 binding in regions containing the two identified Sox motifs in the mouse TANK 5'-UTR. These studies are the first to show that TANK is expressed in DRG neurons, that TANK is increased by peripheral nerve injury and that the regulation of TANK expression is, at least in part, controlled by the injury-associated transcription factor Sox11.
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Affiliation(s)
- K M Salerno
- Pittsburgh Center for Pain Research, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, United States
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48
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Dupraz S, Grassi D, Karnas D, Nieto Guil AF, Hicks D, Quiroga S. The insulin-like growth factor 1 receptor is essential for axonal regeneration in adult central nervous system neurons. PLoS One 2013; 8:e54462. [PMID: 23349896 PMCID: PMC3548777 DOI: 10.1371/journal.pone.0054462] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 12/11/2012] [Indexed: 11/18/2022] Open
Abstract
Axonal regeneration is an essential condition to re-establish functional neuronal connections in the injured adult central nervous system (CNS), but efficient regrowth of severed axons has proven to be very difficult to achieve. Although significant progress has been made in identifying the intrinsic and extrinsic mechanisms involved, many aspects remain unresolved. Axonal development in embryonic CNS (hippocampus) requires the obligate activation of the insulin-like growth factor 1 receptor (IGF-1R). Based on known similarities between axonal growth in fetal compared to mature CNS, we decided to examine the expression of the IGF-1R, using an antibody to the βgc subunit or a polyclonal anti-peptide antibody directed to the IGF-R (C20), in an in vitro model of adult CNS axonal regeneration, namely retinal ganglion cells (RGC) derived from adult rat retinas. Expression of both βgc and the β subunit recognized by C20 antibody were low in freshly isolated adult RGC, but increased significantly after 4 days in vitro. As in embryonic axons, βgc was localised to distal regions and leading growth cones in RGC. IGF-1R-βgc co-localised with activated p85 involved in the phosphatidylinositol-3 kinase (PI3K) signaling pathway, upon stimulation with IGF-1. Blocking experiments using either an antibody which neutralises IGF-1R activation, shRNA designed against the IGF-1R sequence, or the PI3K pathway inhibitor LY294002, all significantly reduced axon regeneration from adult RGC in vitro (∼40% RGC possessed axons in controls vs 2-8% in the different blocking studies). Finally, co-transfection of RGC with shRNA to silence IGF-1R together with a vector containing a constitutively active form of downstream PI3K (p110), fully restored axonal outgrowth in vitro. Hence these data demonstrate that axonal regeneration in adult CNS neurons requires re-expression and activation of IGF-1R, and targeting this system may offer new therapeutic approaches to enhancing axonal regeneration following trauma.
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Affiliation(s)
- Sebastián Dupraz
- Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba y Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
| | - Diego Grassi
- Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba y Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
| | - Diana Karnas
- Rhythms, Life and Death in the Retina, Centre National de la Recherche Scientifique (CNRS) UPR-3212 Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Alvaro F. Nieto Guil
- Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba y Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
| | - David Hicks
- Rhythms, Life and Death in the Retina, Centre National de la Recherche Scientifique (CNRS) UPR-3212 Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Santiago Quiroga
- Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba y Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
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49
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Dahlin LB. The Role of Timing in Nerve Reconstruction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 109:151-64. [DOI: 10.1016/b978-0-12-420045-6.00007-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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50
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Franco CF, Soares R, Pires E, Santos R, Coelho AV. Radial nerve cord protein phosphorylation dynamics during starfish arm tip wound healing events. Electrophoresis 2012; 33:3764-78. [DOI: 10.1002/elps.201200274] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/05/2012] [Accepted: 07/14/2012] [Indexed: 01/14/2023]
Affiliation(s)
- Catarina F. Franco
- Instituto de Tecnologia Química e Biológica; Universidade Nova de Lisboa; Oeiras; Portugal
| | - Renata Soares
- Instituto de Tecnologia Química e Biológica; Universidade Nova de Lisboa; Oeiras; Portugal
| | - Elisabete Pires
- Instituto de Tecnologia Química e Biológica; Universidade Nova de Lisboa; Oeiras; Portugal
| | | | - Ana V. Coelho
- Instituto de Tecnologia Química e Biológica; Universidade Nova de Lisboa; Oeiras; Portugal
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