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Feng Z, Min L, Liang L, Chen B, Chen H, Zhou Y, Deng W, Liu H, Hou J. Neutrophil Extracellular Traps Exacerbate Secondary Injury via Promoting Neuroinflammation and Blood-Spinal Cord Barrier Disruption in Spinal Cord Injury. Front Immunol 2021; 12:698249. [PMID: 34456910 PMCID: PMC8385494 DOI: 10.3389/fimmu.2021.698249] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 07/19/2021] [Indexed: 12/12/2022] Open
Abstract
As the first inflammatory cell recruited to the site of spinal cord injury (SCI), neutrophils were reported to be detrimental to SCI. However, the precise mechanisms as to how neutrophils exacerbate SCI remain largely obscure. In the present study, we demonstrated that infiltrated neutrophils produce neutrophil extracellular traps (NETs), which subsequently promote neuroinflammation and blood–spinal cord barrier disruption to aggravate spinal cord edema and neuronal apoptosis following SCI in rats. Both inhibition of NETs formation by peptidylarginine deiminase 4 (PAD4) inhibitor and disruption of NETs by DNase 1 alleviate secondary damage, thus restraining scar formation and promoting functional recovery after SCI. Furthermore, we found that NETs exacerbate SCI partly via elevating transient receptor potential vanilloid type 4 (TRPV4) level in the injured spinal cord. Therefore, our results indicate that NETs might be a promising therapeutic target for SCI.
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Affiliation(s)
- Zhou Feng
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Lingxia Min
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Liang Liang
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Beike Chen
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Hui Chen
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Yi Zhou
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Weiwei Deng
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Hongliang Liu
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Jingming Hou
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
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102
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Cross DJ, Huber BR, Silverman MA, Cline MM, Gill TB, Cross CG, Cook DG, Minoshima S. Intranasal Paclitaxel Alters Alzheimer's Disease Phenotypic Features in 3xTg-AD Mice. J Alzheimers Dis 2021; 83:379-394. [PMID: 34308901 DOI: 10.3233/jad-210109] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Microtubule stabilizing drugs, commonly used as anti-cancer therapeutics, have been proposed for treatment of Alzheimer's disease (AD); however, many do not cross the blood-brain barrier. OBJECTIVE This research investigated if paclitaxel (PTX) delivered via the intranasal (IN) route could alter the phenotypic progression of AD in 3xTg-AD mice. METHODS We administered intranasal PTX in 3XTg-AD mice (3xTg-AD n = 15, 10 weeks and n = 10, 44 weeks, PTX: 0.6 mg/kg or 0.9%saline (SAL)) at 2-week intervals. After treatment, 3XTg-AD mice underwent manganese-enhanced magnetic resonance imaging to measure in vivo axonal transport. In a separate 3XTg-AD cohort, PTX-treated mice were tested in a radial water tread maze at 52 weeks of age after four treatments, and at 72 weeks of age, anxiety was assessed by an elevated-plus maze after 14 total treatments. RESULTS PTX increased axonal transport rates in treated 3XTg-AD compared to controls (p≤0.003). Further investigation using an in vitro neuron model of Aβ-induced axonal transport disruption confirmed PTX prevented axonal transport deficits. Confocal microscopy after treatment found fewer phospho-tau containing neurons (5.25±3.8 versus 8.33±2.5, p < 0.04) in the CA1, altered microglia, and reduced reactive astrocytes. PTX improved performance of 3xTg-AD on the water tread maze compared to controls and not significantly different from WT (Day 5, 143.8±43 versus 91.5±77s and Day 12, 138.3±52 versus 107.7±75s for SAL versus PTX). Elevated plus maze revealed that PTX-treated 3xTg-AD mice spent more time exploring open arms (Open arm 129.1±80 versus 20.9±31s for PTX versus SAL, p≤0.05). CONCLUSION Taken collectively, these findings indicate that intranasal-administered microtubule-stabilizing drugs may offer a potential therapeutic option for treating AD.
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Affiliation(s)
- Donna J Cross
- Department of Radiology and Imaging Sciences>, University of Utah, Salt Lake City, UT, USA
| | - Bertrand R Huber
- Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA.,Department of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Michael A Silverman
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada.,Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Marcella M Cline
- The Geriatric Research, Education, and Clinical Center (GRECC), Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA.,Departments of Medicine, Pharmacology, Psychiatry & Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Trevor B Gill
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Chloe G Cross
- Department of Radiology and Imaging Sciences>, University of Utah, Salt Lake City, UT, USA
| | - David G Cook
- The Geriatric Research, Education, and Clinical Center (GRECC), Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA.,Departments of Medicine, Pharmacology, Psychiatry & Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Satoshi Minoshima
- Department of Radiology and Imaging Sciences>, University of Utah, Salt Lake City, UT, USA
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103
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Li Z, Yu S, Hu X, Li Y, You X, Tian D, Cheng L, Zheng M, Jing J. Fibrotic Scar After Spinal Cord Injury: Crosstalk With Other Cells, Cellular Origin, Function, and Mechanism. Front Cell Neurosci 2021; 15:720938. [PMID: 34539350 PMCID: PMC8441597 DOI: 10.3389/fncel.2021.720938] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 07/28/2021] [Indexed: 01/18/2023] Open
Abstract
The failure of axonal regeneration after spinal cord injury (SCI) results in permanent loss of sensorimotor function. The persistent presence of scar tissue, mainly fibrotic scar and astrocytic scar, is a critical cause of axonal regeneration failure and is widely accepted as a treatment target for SCI. Astrocytic scar has been widely investigated, while fibrotic scar has received less attention. Here, we review recent advances in fibrotic scar formation and its crosstalk with other main cellular components in the injured core after SCI, as well as its cellular origin, function, and mechanism. This study is expected to provide an important basis and novel insights into fibrotic scar as a treatment target for SCI.
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Affiliation(s)
| | | | | | | | | | | | - Li Cheng
- Department of Orthopaedics, The Second Hospital of Anhui Medical University, Hefei, China
| | - Meige Zheng
- Department of Orthopaedics, The Second Hospital of Anhui Medical University, Hefei, China
| | - Juehua Jing
- Department of Orthopaedics, The Second Hospital of Anhui Medical University, Hefei, China
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104
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Aldskogius H, Kozlova EN. Dorsal Root Injury-A Model for Exploring Pathophysiology and Therapeutic Strategies in Spinal Cord Injury. Cells 2021; 10:2185. [PMID: 34571835 PMCID: PMC8470715 DOI: 10.3390/cells10092185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 12/12/2022] Open
Abstract
Unraveling the cellular and molecular mechanisms of spinal cord injury is fundamental for our possibility to develop successful therapeutic approaches. These approaches need to address the issues of the emergence of a non-permissive environment for axonal growth in the spinal cord, in combination with a failure of injured neurons to mount an effective regeneration program. Experimental in vivo models are of critical importance for exploring the potential clinical relevance of mechanistic findings and therapeutic innovations. However, the highly complex organization of the spinal cord, comprising multiple types of neurons, which form local neural networks, as well as short and long-ranging ascending or descending pathways, complicates detailed dissection of mechanistic processes, as well as identification/verification of therapeutic targets. Inducing different types of dorsal root injury at specific proximo-distal locations provide opportunities to distinguish key components underlying spinal cord regeneration failure. Crushing or cutting the dorsal root allows detailed analysis of the regeneration program of the sensory neurons, as well as of the glial response at the dorsal root-spinal cord interface without direct trauma to the spinal cord. At the same time, a lesion at this interface creates a localized injury of the spinal cord itself, but with an initial neuronal injury affecting only the axons of dorsal root ganglion neurons, and still a glial cell response closely resembling the one seen after direct spinal cord injury. In this review, we provide examples of previous research on dorsal root injury models and how these models can help future exploration of mechanisms and potential therapies for spinal cord injury repair.
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Affiliation(s)
- Håkan Aldskogius
- Laboratory of Regenertive Neurobiology, Biomedical Center, Department of Neuroscience, Uppsala University, 75124 Uppsala, Sweden;
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105
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Yang Y, Chen X, Feng Z, Cai X, Zhu X, Cao M, Yang L, Chen Y, Wang Y, Feng H. MEC17-induced α-tubulin acetylation restores mitochondrial transport function and alleviates axonal injury after intracerebral hemorrhage in mice. J Neurochem 2021; 160:51-63. [PMID: 34407220 DOI: 10.1111/jnc.15493] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/25/2021] [Accepted: 08/09/2021] [Indexed: 02/01/2023]
Abstract
Injury to long axonal projections is a central pathological feature at the early phase of intracerebral hemorrhage (ICH). It has been reported to contribute to persistent functional disability following ICH. However, the molecular mechanisms that drive axonal degeneration remain unclear. Autologous blood was injected into the striatum to mimic the pathology of ICH. Observed significant swollen axons with characteristic retraction bulbs were found around the striatal hematoma at 24 h after ICH. Electronic microscopic examination revealed highly disorganized microtubule and swollen mitochondria in the retraction bulbs. MEC17 is a specific α-tubulin acetyltransferase, ablation of acetylated α-tubulin in MEC17-/- mice aggravated axonal injury, axonal transport mitochondria dysfunction, and motor dysfunction. In contrast, treatment with tubastatin A (TubA), which promotes microtubule acetylation, significantly alleviated axonal injury and protected the integrity of the corticospinal tract and fine motor function after ICH. Moreover, results showed that 41% mitochondria were preferentially bundled to the acetylated α-tubulin in identifiable axons and dendrites in primary neurons. This impaired axonal transport of mitochondria in primary neurons of MEC17-/- mice. Given that opening of mitochondrial permeability transition pore (mPTP) induces mitochondrial dysfunction and impairs ATP supply thereby promoting axonal injury, we enhanced the availability of acetylated α-tubulin using TubA and inhibited mPTP opening with cyclosporin A. The results indicated that this combined treatment synergistically protected corticospinal tract integrity and promoted fine motor control recovery. These findings reveal key intracellular mechanisms that drive axonal degeneration after ICH and highlight the need to target multiple factors and respective regulatory mechanisms as an effective approach to prevent axonal degeneration and motor dysfunction after ICH.
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Affiliation(s)
- Yang Yang
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China.,Department of Neurosurgery and State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University, Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Third Military Medical University (Army Medical University, Chongqing, China.,Wuxi Translational Medicine Center, Wuxi, Jiangsu, China
| | - Xuezhu Chen
- Department of Neurosurgery and State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University, Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Third Military Medical University (Army Medical University, Chongqing, China
| | - Zhizhong Feng
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China
| | - Xianfeng Cai
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China
| | - Xiaoming Zhu
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China
| | - Ming Cao
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China
| | - Likun Yang
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China.,Wuxi Translational Medicine Center, Wuxi, Jiangsu, China
| | - Yujie Chen
- Department of Neurosurgery and State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University, Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Third Military Medical University (Army Medical University, Chongqing, China
| | - Yuhai Wang
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China.,Wuxi Translational Medicine Center, Wuxi, Jiangsu, China
| | - Hua Feng
- Department of Neurosurgery and State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University, Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Third Military Medical University (Army Medical University, Chongqing, China
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106
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Unraveling Axon Guidance during Axotomy and Regeneration. Int J Mol Sci 2021; 22:ijms22158344. [PMID: 34361110 PMCID: PMC8347220 DOI: 10.3390/ijms22158344] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 02/06/2023] Open
Abstract
During neuronal development and regeneration axons extend a cytoskeletal-rich structure known as the growth cone, which detects and integrates signals to reach its final destination. The guidance cues “signals” bind their receptors, activating signaling cascades that result in the regulation of the growth cone cytoskeleton, defining growth cone advance, pausing, turning, or collapse. Even though much is known about guidance cues and their isolated mechanisms during nervous system development, there is still a gap in the understanding of the crosstalk between them, and about what happens after nervous system injuries. After neuronal injuries in mammals, only axons in the peripheral nervous system are able to regenerate, while the ones from the central nervous system fail to do so. Therefore, untangling the guidance cues mechanisms, as well as their behavior and characterization after axotomy and regeneration, are of special interest for understanding and treating neuronal injuries. In this review, we present findings on growth cone guidance and canonical guidance cues mechanisms, followed by a description and comparison of growth cone pathfinding mechanisms after axotomy, in regenerative and non-regenerative animal models.
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107
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Guan C, Luan L, Li J, Yang L. MiR-212-3p improves rat functional recovery and inhibits neurocyte apoptosis in spinal cord injury models via PTEN downregulation-mediated activation of AKT/mTOR pathway. Brain Res 2021; 1768:147576. [PMID: 34216580 DOI: 10.1016/j.brainres.2021.147576] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 06/24/2021] [Accepted: 06/28/2021] [Indexed: 12/30/2022]
Abstract
BACKGROUND Multiple cellular and molecular changes are involved in the etiology of spinal cord injury (SCI) and the recovery from SCI. Accumulating studies showed aberrant expression of microRNAs (miRNAs) after SCI. Here, we established in vivo and in vitro models to analyze the role of miR-212-3p in SCI. METHODS An in vivo model of SCI was established in Sprague-Dawley rats. SCI-induced histopathological changes of the spinal cord were observed by hematoxylin-eosin staining. Functional recovery of rats with SCI was evaluated using the Basso-Beattie-and-Bresnahan scale. PC12 cells were stimulated by lipopolysaccharide (LPS) to establish SCI model of neuronal apoptosis in vitro. Dual-luciferase reporter assay was performed to validate the potential target of miR-212-3p predicted by TargetScan 7.2. MTT assay and flow cytometry were carried out to measure the viability and apoptosis of PC12 cell, respectively. The expressions of miR-212-3p, PTEN, phosphorylated (p)-AKT, AKT, p-mTOR, mTOR, Cleaved caspase-3 and BCl-2 in spinal cord tissues and PC12 cells were analyzed by qRT-PCR or Western blot. RESULTS In the spinal cord of rats with SCI, the expressions of miR-212-3p, p-AKT, p-mTOR and BCl-2 were downregulated, whereas those of PTEN and Cleaved caspase-3 were upregulated. BBB scores were low, and there were histopathological changes, which were all reversed after the injection of agomiR-212-3p. MiR-212-3p directly targeted PTEN. Upregulated miR-212-3p in LPS-injured PC12 cells suppressed apoptosis, downregulated the expressions of PTEN and Cleaved caspase-3, promoted viability and upregulated the expressions of p-AKT, p-mTOR and BCl-2, which were all reversed by overexpressed PTEN. CONCLUSION MiR-212-3p improved functional recovery of SCI rats and inhibited LPS-induced neurocyte apoptosis by targeting PTEN to activate AKT/mTOR pathway.
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Affiliation(s)
- Congjin Guan
- Department of Neurosurgery, The First People's Hospital of Yunnan Province, Kunming University of Science and Technology Affiliated Hospital, China
| | - Liyi Luan
- Department of Orthopedic, The People's Hospital of Gaotang, China
| | - Ji Li
- School of Integrated Chinese and Western Medical, Southwest Medical University, China
| | - Lei Yang
- Department of Neurosurgery, Kunming Children's Hospital, China.
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108
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Clemente V, Hoshino A, Meints J, Shetty M, Starr T, Lee M, Bazzaro M. UNC-45A Is Highly Expressed in the Proliferative Cells of the Mouse Genital Tract and in the Microtubule-Rich Areas of the Mouse Nervous System. Cells 2021; 10:1604. [PMID: 34206743 PMCID: PMC8303485 DOI: 10.3390/cells10071604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 11/16/2022] Open
Abstract
UNC-45A (Protein unc-45 homolog A) is a cytoskeletal-associated protein with a dual and non-mutually exclusive role as a regulator of the actomyosin system and a Microtubule (MT)-destabilizing protein, which is overexpressed in human cancers including in ovarian cancer patients resistant to the MT-stabilizing drug paclitaxel. Mapping of UNC-45A in the mouse upper genital tract and central nervous system reveals its enrichment not only in highly proliferating and prone to remodeling cells, but also in microtubule-rich areas, of the ovaries and the nervous system, respectively. In both apparatuses, UNC-45A is also abundantly expressed in the ciliated epithelium. As regulators of actomyosin contractility and MT stability are essential for the physiopathology of the female reproductive tract and of neuronal development, our findings suggest that UNC-45A may have a role in ovarian cancer initiation and development as well as in neurodegeneration.
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Affiliation(s)
- Valentino Clemente
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Health, University of Minnesota, Minneapolis, MN 55455, USA; (V.C.); (A.H.); (M.S.); (T.S.)
| | - Asumi Hoshino
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Health, University of Minnesota, Minneapolis, MN 55455, USA; (V.C.); (A.H.); (M.S.); (T.S.)
| | - Joyce Meints
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; (J.M.); (M.L.)
| | - Mihir Shetty
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Health, University of Minnesota, Minneapolis, MN 55455, USA; (V.C.); (A.H.); (M.S.); (T.S.)
| | - Tim Starr
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Health, University of Minnesota, Minneapolis, MN 55455, USA; (V.C.); (A.H.); (M.S.); (T.S.)
| | - Michael Lee
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; (J.M.); (M.L.)
| | - Martina Bazzaro
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Health, University of Minnesota, Minneapolis, MN 55455, USA; (V.C.); (A.H.); (M.S.); (T.S.)
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109
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Roy A, Pathak Z, Kumar H. Strategies to neutralize RhoA/ROCK pathway after spinal cord injury. Exp Neurol 2021; 343:113794. [PMID: 34166685 DOI: 10.1016/j.expneurol.2021.113794] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/01/2021] [Accepted: 06/19/2021] [Indexed: 01/22/2023]
Abstract
Regeneration is bungled following CNS injuries, including spinal cord injury (SCI). Inherent decay of permissive conditions restricts the regrowth of the mature CNS after an injury. Hypertrophic scarring, insignificant intrinsic axon-growth activity, and axon-growth inhibitory molecules such as myelin inhibitors and scar inhibitors constitute a significant hindrance to spinal cord repair. Besides these molecules, a combined absence of various mechanisms responsible for axonal regeneration is the main reason behind the dereliction of the adult CNS to regenerate. The neutralization of specific inhibitors/proteins by stymieing antibodies or encouraging enzymatic degradation results in improved axon regeneration. Previous efforts to induce regeneration after SCI have stimulated axonal development in or near lesion sites, but not beyond them. Several pathways are responsible for the axonal growth obstruction after a CNS injury, including SCI. Herein, we summarize the axonal, glial, and intrinsic factor which impedes the regeneration. We have also discussed the methods to stabilize microtubules and through this to maintain the proper cytoskeletal dynamics of growth cone as disorganized microtubules lead to the failure of axonal regeneration. Moreover, we primarily focus on diverse inhibitors of axonal growth and molecular approaches to counteract them and their downstream intracellular signaling through the RhoA/ROCK pathway.
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Affiliation(s)
- Abhishek Roy
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat, India
| | - Zarna Pathak
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat, India
| | - Hemant Kumar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat, India.
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110
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Nahacka Z, Zobalova R, Dubisova M, Rohlena J, Neuzil J. Miro proteins connect mitochondrial function and intercellular transport. Crit Rev Biochem Mol Biol 2021; 56:401-425. [PMID: 34139898 DOI: 10.1080/10409238.2021.1925216] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mitochondria are organelles present in most eukaryotic cells, where they play major and multifaceted roles. The classical notion of the main mitochondrial function as the powerhouse of the cell per se has been complemented by recent discoveries pointing to mitochondria as organelles affecting a number of other auxiliary processes. They go beyond the classical energy provision via acting as a relay point of many catabolic and anabolic processes, to signaling pathways critically affecting cell growth by their implication in de novo pyrimidine synthesis. These additional roles further underscore the importance of mitochondrial homeostasis in various tissues, where its deregulation promotes a number of pathologies. While it has long been known that mitochondria can move within a cell to sites where they are needed, recent research has uncovered that mitochondria can also move between cells. While this intriguing field of research is only emerging, it is clear that mobilization of mitochondria requires a complex apparatus that critically involves mitochondrial proteins of the Miro family, whose role goes beyond the mitochondrial transfer, as will be covered in this review.
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Affiliation(s)
- Zuzana Nahacka
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Renata Zobalova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Maria Dubisova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic
| | - Jakub Rohlena
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Jiri Neuzil
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,School of Medical Science, Griffith University, Southport, Australia
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111
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Tsata V, Wehner D. Know How to Regrow-Axon Regeneration in the Zebrafish Spinal Cord. Cells 2021; 10:cells10061404. [PMID: 34204045 PMCID: PMC8228677 DOI: 10.3390/cells10061404] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/25/2021] [Accepted: 06/04/2021] [Indexed: 12/14/2022] Open
Abstract
The capacity for long-distance axon regeneration and functional recovery after spinal cord injury is poor in mammals but remarkable in some vertebrates, including fish and salamanders. The cellular and molecular basis of this interspecies difference is beginning to emerge. This includes the identification of target cells that react to the injury and the cues directing their pro-regenerative responses. Among existing models of successful spinal cord regeneration, the zebrafish is arguably the most understood at a mechanistic level to date. Here, we review the spinal cord injury paradigms used in zebrafish, and summarize the breadth of neuron-intrinsic and -extrinsic factors that have been identified to play pivotal roles in the ability of zebrafish to regenerate central nervous system axons and recover function.
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Affiliation(s)
- Vasiliki Tsata
- Experimental Surgery, Clinical and Translational Research Center, Biomedical Research Foundation Academy of Athens, 11527 Athens, Greece
- Correspondence: (V.T.); (D.W.)
| | - Daniel Wehner
- Max Planck Institute for the Science of Light, 91058 Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058 Erlangen, Germany
- Correspondence: (V.T.); (D.W.)
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112
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Srivastava E, Singh A, Kumar A. Spinal cord regeneration: A brief overview of the present scenario and a sneak peek into the future. Biotechnol J 2021; 16:e2100167. [PMID: 34080314 DOI: 10.1002/biot.202100167] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/17/2021] [Accepted: 05/28/2021] [Indexed: 01/01/2023]
Abstract
The central nervous system (CNS) portrays appreciable complexity in developing from a neural tube to controlling major functions of the body and orchestrated co-ordination in maintaining its homeostasis. Any insult or pathology to such an organized tissue leads to a plethora of events ranging from local hypoxia, ischemia, oxidative stress to reactive gliosis and scarring. Despite unravelling the pathophysiology of spinal cord injury (SCI) and linked cellular and molecular mechanism, the over exhaustive inflammatory response at the site of injury, limited intrinsic regeneration capability of CNS, and the dual role of glial scar halts the expected accomplishment. The review discusses major current treatment approaches for traumatic SCI, addressing their limitation and scope for further development in the field under three main categories- neuroprotection, neuro-regeneration, and neuroplasticity. We further propose that a multi-disciplinary combinatorial treatment approach exploring any two or all three heads simultaneously might alleviate the inhibitory milieu and ameliorate functional recovery.
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Affiliation(s)
- Ekta Srivastava
- Biomaterial and Tissue Engineering Group, Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India
| | - Anamika Singh
- Biomaterial and Tissue Engineering Group, Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India
| | - Ashok Kumar
- Biomaterial and Tissue Engineering Group, Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India.,Centre for Environmental Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India.,Centre for Nanosciences, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India.,The Mehta Family Centre for Engineering in Medicine, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India
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113
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Tran AP, Warren PM, Silver J. New insights into glial scar formation after spinal cord injury. Cell Tissue Res 2021; 387:319-336. [PMID: 34076775 PMCID: PMC8975767 DOI: 10.1007/s00441-021-03477-w] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/20/2021] [Indexed: 02/06/2023]
Abstract
Severe spinal cord injury causes permanent loss of function and sensation throughout the body. The trauma causes a multifaceted torrent of pathophysiological processes which ultimately act to form a complex structure, permanently remodeling the cellular architecture and extracellular matrix. This structure is traditionally termed the glial/fibrotic scar. Similar cellular formations occur following stroke, infection, and neurodegenerative diseases of the central nervous system (CNS) signifying their fundamental importance to preservation of function. It is increasingly recognized that the scar performs multiple roles affecting recovery following traumatic injury. Innovative research into the properties of this structure is imperative to the development of treatment strategies to recover motor function and sensation following CNS trauma. In this review, we summarize how the regeneration potential of the CNS alters across phyla and age through formation of scar-like structures. We describe how new insights from next-generation sequencing technologies have yielded a more complex portrait of the molecular mechanisms governing the astrocyte, microglial, and neuronal responses to injury and development, especially of the glial component of the scar. Finally, we discuss possible combinatorial therapeutic approaches centering on scar modulation to restore function after severe CNS injury.
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Affiliation(s)
- Amanda Phuong Tran
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Philippa Mary Warren
- Wolfson Centre for Age Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Guy's Campus, London Bridge, London, UK
| | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA.
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114
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Yin W, Xue W, Zhu H, Shen H, Xiao Z, Wu S, Zhao Y, Cao Y, Tan J, Li J, Liu W, Wang L, Meng L, Chen B, Zhao M, Jiang X, Li X, Ren C, Dai J. Scar tissue removal-activated endogenous neural stem cells aid Taxol-modified collagen scaffolds in repairing chronic long-distance transected spinal cord injury. Biomater Sci 2021; 9:4778-4792. [PMID: 34042920 DOI: 10.1039/d1bm00449b] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Scar tissue removal combined with biomaterial implantation is considered an effective measure to repair chronic transected spinal cord injury (SCI). However, whether more scar tissue removal surgeries could affect the treatment effects of biomaterial implantation still needs to be explored. In this study, we performed the first scar tissue removal surgery in the 3rd month and the second in the 6th month after completely removing 1 cm of spinal tissue in canines. We found that Taxol-modified linear ordered collagen scaffold (LOCS + Taxol) implantation could promote axonal regeneration, neurogenesis, and electrophysiological and functional recovery only in canines at the first scar tissue removal surgery, but not in canines at the second scar tissue removal surgery. Interestingly, we found that more endogenous neural stem cells (NSCs) around the injured site could be activated in canines with the first rather than the second scar tissue removal. Furthermore, we demonstrated that Taxol could promote the neuronal differentiation of NSCs in the myelin inhibition microenvironment through the p38 MAPK signaling pathway in vitro. Therefore, we speculated that endogenous NSC activation by the first scar tissue removal surgery and its further differentiation into neurons induced by Taxol may contribute to functional recovery in canines. Together, LOCS + Taxol implantation in combination with the first scar tissue removal provides a promising therapy for chronic long-distance transected SCI repair with the help of scar tissue removal activated endogenous NSCs.
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Affiliation(s)
- Wen Yin
- Department of Neurosurgery, Xiangya Hospital, Central South University (CSU), Changsha, Hunan 410008, China.
| | - Weiwei Xue
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hecheng Zhu
- Changsha Kexin Cancer Hospital, Changsha, Hunan 410205, China
| | - He Shen
- Key Laboratory for Nano-Bio Interface Research, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Zhifeng Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuyu Wu
- Department of Neurosurgery, Xiangya Hospital, Central South University (CSU), Changsha, Hunan 410008, China.
| | - Yannan Zhao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yudong Cao
- Department of Neurosurgery, Xiangya Hospital, Central South University (CSU), Changsha, Hunan 410008, China.
| | - Jun Tan
- Department of Neurosurgery, Xiangya Hospital, Central South University (CSU), Changsha, Hunan 410008, China.
| | - Juan Li
- Department of Neurosurgery, Xiangya Hospital, Central South University (CSU), Changsha, Hunan 410008, China.
| | - Weidong Liu
- Cancer Research Institute, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China.
| | - Lei Wang
- Cancer Research Institute, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China.
| | - Li Meng
- Department of Radiology, Xiangya Hospital, Central South University (CSU), Changsha, Hunan 410008, China
| | - Bing Chen
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ming Zhao
- Changsha Kexin Cancer Hospital, Changsha, Hunan 410205, China
| | - Xingjun Jiang
- Department of Neurosurgery, Xiangya Hospital, Central South University (CSU), Changsha, Hunan 410008, China.
| | - Xing Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China and Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Caiping Ren
- Cancer Research Institute, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China.
| | - Jianwu Dai
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
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115
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EFA6 in Axon Regeneration, as a Microtubule Regulator and as a Guanine Nucleotide Exchange Factor. Cells 2021; 10:cells10061325. [PMID: 34073530 PMCID: PMC8226579 DOI: 10.3390/cells10061325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 11/17/2022] Open
Abstract
Axon regeneration after injury is a conserved biological process that involves a large number of molecular pathways, including rapid calcium influx at injury sites, retrograde injury signaling, epigenetic transition, transcriptional reprogramming, polarized transport, and cytoskeleton reorganization. Despite the numerous efforts devoted to understanding the underlying cellular and molecular mechanisms of axon regeneration, the search continues for effective target molecules for improving axon regeneration. Although there have been significant historical efforts towards characterizing pro-regenerative factors involved in axon regeneration, the pursuit of intrinsic inhibitors is relatively recent. EFA6 (exchange factor for ARF6) has been demonstrated to inhibit axon regeneration in different organisms. EFA6 inhibition could be a promising therapeutic strategy to promote axon regeneration and functional recovery after axon injury. This review summarizes the inhibitory role on axon regeneration through regulating microtubule dynamics and through affecting ARF6 (ADP-ribosylation factor 6) GTPase-mediated integrin transport.
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116
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Knocking Out Non-muscle Myosin II in Retinal Ganglion Cells Promotes Long-Distance Optic Nerve Regeneration. Cell Rep 2021; 31:107537. [PMID: 32320663 PMCID: PMC7219759 DOI: 10.1016/j.celrep.2020.107537] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 03/03/2020] [Accepted: 03/30/2020] [Indexed: 12/13/2022] Open
Abstract
In addition to altered gene expression, pathological cytoskeletal dynamics in the axon are another key intrinsic barrier for axon regeneration in the central nervous system (CNS). Here, we show that knocking out myosin IIA and IIB (myosin IIA/B) in retinal ganglion cells alone, either before or after optic nerve crush, induces significant optic nerve regeneration. Combined Lin28a overexpression and myosin IIA/B knockout lead to an additive promoting effect and long-distance axon regeneration. Immunostaining, RNA sequencing, and western blot analyses reveal that myosin II deletion does not affect known axon regeneration signaling pathways or the expression of regeneration-associated genes. Instead, it abolishes the retraction bulb formation and significantly enhances the axon extension efficiency. The study provides clear evidence that directly targeting neuronal cytoskeleton is sufficient to induce significant CNS axon regeneration and that combining altered gene expression in the soma and modified cytoskeletal dynamics in the axon is a promising approach for long-distance CNS axon regeneration.
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117
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Anderson MA. Targeting Central Nervous System Regeneration with Cell Type Specificity. Neurosurg Clin N Am 2021; 32:397-405. [PMID: 34053727 DOI: 10.1016/j.nec.2021.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
There have been tremendous advances in identifying cellular and molecular mechanisms constraining axon growth and strategies have been developed to overcome regenerative failure. However, reproducible and meaningful functional recovery remains elusive. An emerging reason is that neurons possess subtype-specific activation requirements. Much of this evidence comes from studying retinal ganglion cells following optic nerve injury. This review summarizes key neuropathologic events following spinal cord injury, and draws on findings from the optic nerve to suggest how a similar framework may be used to dissect and manipulate the heterogeneous and subtype-specific responses of neurons useful to target for spinal cord injury.
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Affiliation(s)
- Mark A Anderson
- Brain Mind Institute, Faculty of Life Sciences, École Polytechnique Féderale de Lausanne (EPFL), Lausanne, Switzerland; Neural Repair Unit, NeuroRestore, Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.
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118
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Yao S, Wang L, Chen Q, Lu T, Pu X, Luo C. The effect of mild hypothermia plus rutin on the treatment of spinal cord injury and inflammatory factors by repressing TGF-β/smad pathway. Acta Cir Bras 2021; 36:e360307. [PMID: 33978063 PMCID: PMC8112105 DOI: 10.1590/acb360307] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/20/2021] [Indexed: 02/07/2023] Open
Abstract
Purpose To probe the mechanism of mild hypothermia combined with rutin in the
treatment of spinal cord injury (SCI). Methods Thirty rats were randomized into the following groups: control, sham, model,
mild hypothermia (MH), and mild hypothermia plus rutin (MH+Rutin). We used
modified Allen’s method to injure the spinal cord (T10) in rats, and then
treated it with MH or/and rutin immediately. BBB scores were performed on
all rats. We used HE staining for observing the injured spinal cord tissue;
ELISA for assaying TNF-α, IL-1β, IL-8, Myeloperoxidase (MPO), and
Malondialdehyde (MDA) contents; Dihydroethidium (DHE) for measuring the
reactive oxygen species (ROS) content; flow cytometry for detecting
apoptosis; and both RT-qPCR and Western blot for determining the expression
levels of TGF-β/Smad pathway related proteins (TGF-β, Smad2, and Smad3). Results In comparison with model group, the BBB score of MH increased to a certain
extent and MH+Rutin group increased more than MH group (p < 0.05). After
treatment with MH and MH+Rutin, the inflammatory infiltration diminished. MH
and MH+Rutin tellingly dwindled TNF-β, MDA and ROS contents (p < 0.01),
and minified spinal cord cell apoptosis. MH and MH+Rutin could patently
diminished TGF-β1, Smad2, and Smad3 expression (p < 0.01). Conclusions MH+Rutin can suppress the activation of TGF-β/Smad pathway, hence repressing
the cellular inflammatory response after SCI.
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119
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Xu L, Yao Y. Central Nervous System Fibroblast-Like Cells in Stroke and Other Neurological Disorders. Stroke 2021; 52:2456-2464. [PMID: 33940953 DOI: 10.1161/strokeaha.120.033431] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Fibroblasts are the most common cell type of connective tissues. In the central nervous system (CNS), fibroblast-like cells are mainly located in the meninges and perivascular Virchow-Robin space. The origins of these fibroblast-like cells and their functions in both CNS development and pathological conditions remain largely unknown. In this review, we first introduce the anatomic location and molecular markers of CNS fibroblast-like cells. Next, the functions of fibroblast-like cells in CNS development and neurological disorders, including stroke, CNS traumatic injuries, and other neurological diseases, are discussed. Third, current challenges and future directions in the field are summarized. We hope to provide a synthetic review that stimulates future research on CNS fibroblast-like cells.
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Affiliation(s)
- Lingling Xu
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens
| | - Yao Yao
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens
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120
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Liu D, Shen H, Shen Y, Long G, He X, Zhao Y, Yang Z, Dai J, Li X. Dual-Cues Laden Scaffold Facilitates Neurovascular Regeneration and Motor Functional Recovery After Complete Spinal Cord Injury. Adv Healthc Mater 2021; 10:e2100089. [PMID: 33739626 DOI: 10.1002/adhm.202100089] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/24/2021] [Indexed: 12/26/2022]
Abstract
Complete transection spinal cord injury (SCI) severely disrupts the integrity of both neural circuits and the microvasculature system. Hence, fabricating a functional bio-scaffold that could coordinate axonal regeneration and vascular reconstruction in the lesion area may emerge as a new paradigm for complete SCI repair. In this study, a photosensitive hydrogel scaffold loaded with collagen-binding stromal cell-derived factor-1a and Taxol liposomes is capable of inducing migration of endothelial cells and promoting neurite outgrowth of neurons in vitro. In addition, when implanted into a rat T8 complete transection SCI model, the above dual-cues laden scaffold exhibits a synergistic effect on facilitating axon and vessel regeneration in the lesion area within 10 days after injury. Moreover, long-term therapeutic effects are also observed after dual-cues laden scaffold implantation, including revascularization, descending and propriospinal axonal regeneration, fibrotic scar reduction, electrophysiological recovery, and motor function improvement. In summary, the dual-cues laden scaffold has good clinical application potential for patients with severe SCI.
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Affiliation(s)
- Dingyang Liu
- Department of Neurosurgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
- Key Laboratory of Organ Injury Aging and Regenerative Medicine of Hunan Province Changsha Hunan Province 410008 China
- Department of Spine Surgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
| | - He Shen
- Key Laboratory for Nano‐Bio Interface Research Division of Nanobiomedicine Suzhou Institute of Nano‐Tech and Nano‐Bionics Chinese Academy of Sciences Suzhou 215123 China
| | - Yeyu Shen
- Department of Neurosurgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
- Key Laboratory of Organ Injury Aging and Regenerative Medicine of Hunan Province Changsha Hunan Province 410008 China
- Department of Spine Surgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
| | - Ge Long
- Department of Anesthesia The Third Xiangya Hospital Central South University Changsha Hunan Province 410008 China
| | - Xinghui He
- Department of Neurosurgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
- Key Laboratory of Organ Injury Aging and Regenerative Medicine of Hunan Province Changsha Hunan Province 410008 China
- Department of Spine Surgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
| | - Yannan Zhao
- State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing 100101 China
| | - Zhiquan Yang
- Department of Neurosurgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
- Key Laboratory of Organ Injury Aging and Regenerative Medicine of Hunan Province Changsha Hunan Province 410008 China
- Department of Spine Surgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
| | - Jianwu Dai
- State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing 100101 China
| | - Xing Li
- Department of Neurosurgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
- Key Laboratory of Organ Injury Aging and Regenerative Medicine of Hunan Province Changsha Hunan Province 410008 China
- Department of Spine Surgery Xiangya Hospital Central South University Changsha Hunan Province 410008 China
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121
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Axon Growth of CNS Neurons in Three Dimensions Is Amoeboid and Independent of Adhesions. Cell Rep 2021; 32:107907. [PMID: 32698008 DOI: 10.1016/j.celrep.2020.107907] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/26/2020] [Accepted: 06/23/2020] [Indexed: 01/01/2023] Open
Abstract
During development of the central nervous system (CNS), neurons polarize and rapidly extend their axons to assemble neuronal circuits. The growth cone leads the axon to its target and drives axon growth. Here, we explored the mechanisms underlying axon growth in three dimensions. Live in situ imaging and super-resolution microscopy combined with pharmacological and molecular manipulations as well as biophysical force measurements revealed that growth cones extend CNS axons independent of pulling forces on their substrates and without the need for adhesions in three-dimensional (3D) environments. In 3D, microtubules grow unrestrained from the actomyosin cytoskeleton into the growth cone leading edge to enable rapid axon extension. Axons extend and polarize even in adhesion-inert matrices. Thus, CNS neurons use amoeboid mechanisms to drive axon growth. Together with our understanding that adult CNS axons regenerate by reactivating developmental processes, our findings illuminate how cytoskeletal manipulations enable axon regeneration in the adult CNS.
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122
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Advances in Regeneration of Retinal Ganglion Cells and Optic Nerves. Int J Mol Sci 2021; 22:ijms22094616. [PMID: 33924833 PMCID: PMC8125313 DOI: 10.3390/ijms22094616] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 02/07/2023] Open
Abstract
Glaucoma, the second leading cause of blindness worldwide, is an incurable neurodegenerative disorder due to the dysfunction of retinal ganglion cells (RGCs). RGCs function as the only output neurons conveying the detected light information from the retina to the brain, which is a bottleneck of vision formation. RGCs in mammals cannot regenerate if injured, and RGC subtypes differ dramatically in their ability to survive and regenerate after injury. Recently, novel RGC subtypes and markers have been uncovered in succession. Meanwhile, apart from great advances in RGC axon regeneration, some degree of experimental RGC regeneration has been achieved by the in vitro differentiation of embryonic stem cells and induced pluripotent stem cells or in vivo somatic cell reprogramming, which provides insights into the future therapy of myriad neurodegenerative disorders. Further approaches to the combination of different factors will be necessary to develop efficacious future therapeutic strategies to promote ultimate axon and RGC regeneration and functional vision recovery following injury.
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123
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Oprişoreanu AM, Smith HL, Krix S, Chaytow H, Carragher NO, Gillingwater TH, Becker CG, Becker T. Automated in vivo drug screen in zebrafish identifies synapse-stabilising drugs with relevance to spinal muscular atrophy. Dis Model Mech 2021; 14:259422. [PMID: 33973627 PMCID: PMC8106959 DOI: 10.1242/dmm.047761] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 03/10/2021] [Indexed: 12/14/2022] Open
Abstract
Synapses are particularly vulnerable in many neurodegenerative diseases and often the first to degenerate, for example in the motor neuron disease spinal muscular atrophy (SMA). Compounds that can counteract synaptic destabilisation are rare. Here, we describe an automated screening paradigm in zebrafish for small-molecule compounds that stabilize the neuromuscular synapse in vivo. We make use of a mutant for the axonal C-type lectin chondrolectin (chodl), one of the main genes dysregulated in SMA. In chodl-/- mutants, neuromuscular synapses that are formed at the first synaptic site by growing axons are not fully mature, causing axons to stall, thereby impeding further axon growth beyond that synaptic site. This makes axon length a convenient read-out for synapse stability. We screened 982 small-molecule compounds in chodl chodl-/- mutants and found four that strongly rescued motor axon length. Aberrant presynaptic neuromuscular synapse morphology was also corrected. The most-effective compound, the adenosine uptake inhibitor drug dipyridamole, also rescued axon growth defects in the UBA1-dependent zebrafish model of SMA. Hence, we describe an automated screening pipeline that can detect compounds with relevance to SMA. This versatile platform can be used for drug and genetic screens, with wider relevance to synapse formation and stabilisation.
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Affiliation(s)
- Ana-Maria Oprişoreanu
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
| | - Hannah L Smith
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
| | - Sophia Krix
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
| | - Helena Chaytow
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, EH16 4SB Edinburgh, UK
| | - Neil O Carragher
- Cancer Research UK Edinburgh Centre, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, EH4 2XR Edinburgh, UK
| | - Thomas H Gillingwater
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, EH16 4SB Edinburgh, UK
| | - Catherina G Becker
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, EH16 4SB Edinburgh, UK
| | - Thomas Becker
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
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124
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Combinatrial treatment of anti-High Mobility Group Box-1 monoclonal antibody and epothilone B improves functional recovery after spinal cord contusion injury. Neurosci Res 2021; 172:13-25. [PMID: 33864880 DOI: 10.1016/j.neures.2021.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 04/08/2021] [Accepted: 04/12/2021] [Indexed: 11/23/2022]
Abstract
Spinal cord injury (SCI) causes motor and sensory deficits and is currently considered an incurable disease. We have previously reported that administration of anti-High Mobility Group Box-1 monoclonal antibody (anti-HMGB1 mAb) preserved lesion area and improved locomotion recovery in mouse model of SCI. In order to further enhance the recovery, we here examined combinatorial treatment of anti-HMGB1 mAb and epothilone B (Epo B), which has been reported to promote axon regeneration. This combinatorial treatment significantly increased hindlimb movement compared with anti-HMGB1 mAb alone, although Epo B alone failed to increase functional recovery. These results are in agreement with that anti-HMGB1 mAb alone was able to decrease the lesion area spreading and increase the surviving neuron numbers around the lesion, whereas Epo B facilitated axon outgrowth only in combination with anti-HMGB1 mAb, suggesting that anti-HMGB1 mAb-dependent tissue preservation is necessary for Epo B to exhibit its therapeutic effect. Taken together, the combinatorial treatment can be considered as a novel and clinically applicable strategy for SCI.
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125
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de los Reyes Corrales T, Losada-Pérez M, Casas-Tintó S. JNK Pathway in CNS Pathologies. Int J Mol Sci 2021; 22:3883. [PMID: 33918666 PMCID: PMC8070500 DOI: 10.3390/ijms22083883] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/30/2021] [Accepted: 04/01/2021] [Indexed: 12/13/2022] Open
Abstract
The c-Jun N-terminal kinase (JNK) signalling pathway is a conserved response to a wide range of internal and external cellular stress signals. Beside the stress response, the JNK pathway is involved in a series of vital regulatory mechanisms during development and adulthood that are critical to maintain tissue homeostasis. These mechanisms include the regulation of apoptosis, growth, proliferation, differentiation, migration and invasion. The JNK pathway has a diverse functionality and cell-tissue specificity, and has emerged as a key player in regeneration, tumorigenesis and other pathologies. The JNK pathway is highly active in the central nervous system (CNS), and plays a central role when cells need to cope with pathophysiological insults during development and adulthood. Here, we review the implications of the JNK pathway in pathologies of the CNS. More specifically, we discuss some newly identified examples and mechanisms of JNK-driven tumor progression in glioblastoma, regeneration/repair after an injury, neurodegeneration and neuronal cell death. All these new discoveries support the central role of JNK in CNS pathologies and reinforce the idea of JNK as potential target to reduce their detrimental effects.
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126
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Park KY, Kim S, Kim MS. Effects of taxol on neuronal differentiation of postnatal neural stem cells cultured from mouse subventricular zone. Differentiation 2021; 119:1-9. [PMID: 33848959 DOI: 10.1016/j.diff.2021.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 03/20/2021] [Accepted: 03/29/2021] [Indexed: 10/21/2022]
Abstract
Taxol (paclitaxel), a chemotherapeutic agent for several cancers, can adversely affect the peripheral nervous system. Recently, its negative impact on cognitive function in cancer patients has become evident. In rodents, taxol impaired learning and memory, with other possible negative effects on the brain. In this study, we investigated the effects of taxol on cultured neural stem cells (NSCs) from the mouse neurogenic region, the subventricular zone (SVZ). Taxol significantly decreased both proliferation and neuronal differentiation of NSCs. Transient treatment with taxol for one day during a 4-day differentiation greatly decreased neurogenesis along with an abnormal cell cycle progression. Yet, taxol did not kill differentiated Tuj1+ neurons and those neurons had longer neurites than neurons under control conditions. For glial differentiation, taxol significantly reduced oligodendrogenesis as observed by immunostaining for Olig2 and O4. However, differentiation of astrocytes was not affected by taxol. In contrast, differentiated oligodendrocytes were extremely sensitive to taxol. Almost no Olig2-positive cells were observed after three days of treatment with taxol. Taxol has distinct effects on neurons and glial cells during their production through differentiation from NSCs as well as post-differentiation. Thus, we suggest that taxol might interfere with neurogenesis of NSCs possibly through a disturbance in the cell cycle and may eliminate differentiated oligodendrocytes.
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Affiliation(s)
- Ki-Youb Park
- Korea Science Academy of KAIST, 105-47 Baegyanggwanmun-ro, Busanjin-Gu, Busan, 614-100, South Korea.
| | - Seokyung Kim
- Korea Science Academy of KAIST, 105-47 Baegyanggwanmun-ro, Busanjin-Gu, Busan, 614-100, South Korea
| | - Man Su Kim
- College of Pharmacy, Inje University, Gimhae, 50834, South Korea
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127
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Li XH, Zhu X, Liu XY, Xu HH, Jiang W, Wang JJ, Chen F, Zhang S, Li RX, Chen XY, Tu Y. The corticospinal tract structure of collagen/silk fibroin scaffold implants using 3D printing promotes functional recovery after complete spinal cord transection in rats. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2021; 32:31. [PMID: 33751254 PMCID: PMC7985105 DOI: 10.1007/s10856-021-06500-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
No effective treatment has been established for nerve dysfunction caused by spinal cord injury (SCI). Orderly axonal growth at the site of spinal cord transection and creation of an appropriate biological microenvironment are important for functional recovery. To axially guiding axonal growth, designing a collagen/silk fibroin scaffold fabricated with 3D printing technology (3D-C/SF) emulated the corticospinal tract. The normal collagen/silk fibroin scaffold with freeze-drying technology (C/SF) or 3D-C/SF scaffold were implanted into rats with completely transected SCI to evaluate its effect on nerve repair during an 8-week observation period. Electrophysiological analysis and locomotor performance showed that the 3D-C/SF implants contributed to significant improvements in the neurogolical function of rats compared to C/SF group. By magnetic resonance imaging, 3D-C/SF implants promoted a striking degree of axonal regeneration and connection between the proximal and distal SCI sites. Compared with C/SF group, rats with 3D-C/SF scaffold exhibited fewer lesions and disordered structures in histological analysis and more GAP43-positive profiles at the lesion site. The above results indicated that the corticospinal tract structure of 3D printing collagen/silk fibroin scaffold improved axonal regeneration and promoted orderly connections within the neural network, which could provided a promising and innovative approach for tissue repair after SCI.
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Affiliation(s)
- Xiao-Hong Li
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, 300072, China
| | - Xiang Zhu
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of PAPF, Tianjin, 300162, China
- Henan provincial people's hospital of southeast branch, Zhu ma dian, 463500, China
| | - Xiao-Yin Liu
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of PAPF, Tianjin, 300162, China
- Tianjin Medical University, Tianjin, 300070, China
| | - Hai-Huan Xu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, 300072, China
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of PAPF, Tianjin, 300162, China
| | - Wei Jiang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, 300072, China
| | - Jing-Jing Wang
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of PAPF, Tianjin, 300162, China
| | - Feng Chen
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of PAPF, Tianjin, 300162, China
| | - Sai Zhang
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of PAPF, Tianjin, 300162, China
- Emergency Medical Center, Beijing Chaoyang Integrative medicine, Beijing, 100191, China
| | - Rui-Xin Li
- Central Laboratory, Tianjin Stomatological Hospital, Tianjin, 300041, China.
| | - Xu-Yi Chen
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of PAPF, Tianjin, 300162, China.
| | - Yue Tu
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of PAPF, Tianjin, 300162, China.
- Emergency Medical Center, Beijing Chaoyang Integrative medicine, Beijing, 100191, China.
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128
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Liu D, Shu M, Liu W, Shen Y, Long G, Zhao Y, Hou X, Xiao Z, Dai J, Li X. Binary scaffold facilitates in situ regeneration of axons and neurons for complete spinal cord injury repair. Biomater Sci 2021; 9:2955-2971. [PMID: 33634811 DOI: 10.1039/d0bm02212h] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The limited regrowth of transected axons and insufficient regeneration of lost neurons in adult mammals collectively hinder complete spinal cord injury (SCI) repair. Hence, designing an ideal bio-scaffold which could coordinate the regeneration of axons and neurons in situ might be able to effectively facilitate the reconstruction of neural circuits and the recovery of nerve function after complete SCI. In this study, a sponge-like collagen scaffold with good drug release characteristics and good nerve cell compatibility was prepared and used as a drug delivery platform. When doubly modified with Taxol liposomes and collagen-binding neurotrophic factor 3, the scaffold dually alleviated myelin-derived inhibition on neurite outgrowth of neurons and neuronal differentiation of neural stem cells in vitro. Meanwhile, the binary-drug modified scaffold was also able to simultaneously promote both axonal and neuronal regeneration when implanted into a complete transected SCI model. Additionally, the regenerated axons and neurons throughout the lesion site formed extensive synaptic connections. Finally, complete SCI rats that received binary scaffold implantation exhibited optimal neuroelectrophysiological recovery and hindlimb locomotor improvement. Taken together, implantation of the binary scaffold can establish neural bridging networks for functional recovery, representing a clinically promising strategy for complete SCI repair.
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Affiliation(s)
- Dingyang Liu
- Department of Neurosurgery, Xiangya Hospital of Central South University, Changsha, 410008, Hunan Province, China.
| | - Muya Shu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weiyuan Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yeyu Shen
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha 410008, Hunan Province, China and Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Ge Long
- Department of Anesthesia, the Third Xiangya Hospital of Central South University, Changsha, 410013, China
| | - Yannan Zhao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xianglin Hou
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhifeng Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianwu Dai
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xing Li
- Department of Neurosurgery, Xiangya Hospital of Central South University, Changsha, 410008, Hunan Province, China. and Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha 410008, Hunan Province, China and Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
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129
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Dorrier CE, Aran D, Haenelt EA, Sheehy RN, Hoi KK, Pintarić L, Chen Y, Lizama CO, Cautivo KM, Weiner GA, Popko B, Fancy SPJ, Arnold T, Daneman R. CNS fibroblasts form a fibrotic scar in response to immune cell infiltration. Nat Neurosci 2021; 24:234-244. [PMID: 33526922 PMCID: PMC7877789 DOI: 10.1038/s41593-020-00770-9] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 11/20/2020] [Indexed: 02/06/2023]
Abstract
Fibrosis is a common pathological response to inflammation in many peripheral tissues and can prevent tissue regeneration and repair. Here, we identified persistent fibrotic scarring in the CNS following immune cell infiltration in the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis. Using lineage tracing and single-cell sequencing in EAE, we determined that the majority of the fibrotic scar is derived from proliferative CNS fibroblasts, not pericytes or infiltrating bone marrow-derived cells. Ablating proliferating fibrotic cells using cell-specific expression of herpes thymidine kinase led to an increase in oligodendrocyte lineage cells within the inflammatory lesions and a reduction in motor disability. We further identified that interferon-gamma pathway genes are enriched in CNS fibrotic cells, and the fibrotic cell-specific deletion of Ifngr1 resulted in reduced fibrotic scarring in EAE. These data delineate a framework for understanding the CNS fibrotic response.
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Affiliation(s)
- Cayce E. Dorrier
- Departments of Pharmacology and Neurosciences, University
of California San Diego, La Jolla, California 92093 USA
| | - Dvir Aran
- Technion- Israel Institute of Technology, Haifa,
Israel
| | - Ezekiel A. Haenelt
- Departments of Pharmacology and Neurosciences, University
of California San Diego, La Jolla, California 92093 USA
| | - Ryan N. Sheehy
- Departments of Pharmacology and Neurosciences, University
of California San Diego, La Jolla, California 92093 USA
| | - Kimberly K. Hoi
- Department of Neurology, University of California San
Francisco, San Francisco, California 94158 USA
| | - Lucija Pintarić
- Departments of Pharmacology and Neurosciences, University
of California San Diego, La Jolla, California 92093 USA
| | - Yanan Chen
- Department of Neurology, Feinberg School of Medicine,
Northwestern University, Chicago, Illinois 60611 USA
| | - Carlos O. Lizama
- Cardiovascular Research Institute, University of
California San Francisco, San Francisco, California 94158 USA
| | - Kelly M. Cautivo
- Department of Laboratory Medicine, University of
California San Francisco, San Francisco, California 94143 USA
| | - Geoffrey A. Weiner
- Departments of Pharmacology and Neurosciences, University
of California San Diego, La Jolla, California 92093 USA
| | - Brian Popko
- Department of Neurology, Feinberg School of Medicine,
Northwestern University, Chicago, Illinois 60611 USA
| | - Stephen P. J. Fancy
- Department of Neurology, University of California San
Francisco, San Francisco, California 94158 USA
| | - Thomas Arnold
- Department of Pediatrics, University of California San
Francisco, California 94143 USA.,Co-Corresponding authors: Thomas
Arnold, MD, , Richard Daneman, PhD,
| | - Richard Daneman
- Departments of Pharmacology and Neurosciences, University
of California San Diego, La Jolla, California 92093 USA.,Co-Corresponding authors: Thomas
Arnold, MD, , Richard Daneman, PhD,
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130
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Role of Myc Proto-Oncogene as a Transcriptional Hub to Regulate the Expression of Regeneration-Associated Genes following Preconditioning Peripheral Nerve Injury. J Neurosci 2021; 41:446-460. [PMID: 33262248 DOI: 10.1523/jneurosci.1745-20.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 12/20/2022] Open
Abstract
Preconditioning peripheral nerve injury enhances the intrinsic growth capacity of DRGs sensory axons by inducing transcriptional upregulation of the regeneration-associated genes (RAGs). However, it is still unclear how preconditioning injury leads to the orchestrated induction of many RAGs. The present study identified Myc proto-oncogene as a transcriptional hub gene to regulate the expression of a distinct subset of RAGs in DRGs following the preconditioning injury. We demonstrated that c-MYC bound to the promoters of certain RAGs, such as Jun, Atf3, and Sprr1a, and that Myc upregulation following SNI preceded that of the RAGs bound by c-MYC. Marked DNA methylation of the Myc exon 3 sequences was implicated in the early transcriptional activation and accompanied by open histone marks. Myc deletion led to a decrease in the injury-induced expression of a distinct subset of RAGs, which were highly overlapped with the list of RAGs that were upregulated by Myc overexpression. Following dorsal hemisection spinal cord injury in female rats, Myc overexpression in DRGs significantly prevented the retraction of the sensory axons in a manner dependent on its downstream RAG, June Our results suggest that Myc plays a critical role in axon regeneration via its transcriptional activity to regulate the expression of a spectrum of downstream RAGs and subsequent effector molecules. Identification of more upstream hub transcription factors and the epigenetic mechanisms specific for individual hub transcription factors would advance our understanding of how the preconditioning injury induces orchestrated upregulation of RAGs.
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131
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Putting the axonal periodic scaffold in order. Curr Opin Neurobiol 2021; 69:33-40. [PMID: 33450534 DOI: 10.1016/j.conb.2020.12.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 01/01/2023]
Abstract
Neurons rely on a unique organization of their cytoskeleton to build, maintain and transform their extraordinarily intricate shapes. After decades of research on the neuronal cytoskeleton, it is exciting that novel assemblies are still discovered thanks to progress in cellular imaging methods. Indeed, super-resolution microscopy has revealed that axons are lined with a periodic scaffold of actin rings, spaced every 190nm by spectrins. Determining the architecture, composition, dynamics, and functions of this membrane-associated periodic scaffold is a current conceptual and technical challenge, as well as a very active area of research. This short review aims at summarizing the latest research on the axonal periodic scaffold, highlighting recent progress and open questions.
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132
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Nichols EL, Smith CJ. Functional Regeneration of the Sensory Root via Axonal Invasion. Cell Rep 2021; 30:9-17.e3. [PMID: 31914401 PMCID: PMC6996490 DOI: 10.1016/j.celrep.2019.12.008] [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] [Received: 06/13/2019] [Revised: 10/15/2019] [Accepted: 12/03/2019] [Indexed: 12/11/2022] Open
Abstract
Regeneration following spinal root avulsion is broadly unsuccessful
despite the regenerative capacity of other PNS-located nerves. By combining
focal laser lesioning to model root avulsion in zebrafish, time-lapse imaging,
and transgenesis, we identify that regenerating DRG neurons fail to recapitulate
developmental paradigms of actin-based invasion after injury. We demonstrate
that inducing actin reorganization into invasive components via pharmacological
and genetic approaches in the regenerating axon can rescue sensory axon spinal
cord entry. Cell-autonomous induction of invasion components using
constitutively active Src induces DRG axon regeneration, suggesting an intrinsic
mechanism can be activated to drive regeneration. Furthermore, analyses of
neuronal activity and animal behavior show restoration of sensory circuit
activity and behavior upon stimulating axons to re-enter the spinal cord via
invasion. Altogether, our data identify induction of invasive components as
sufficient for functional sensory root regeneration after injury. Dorsal root ganglion (DRG) sensory axons are unable to regenerate into
the spinal cord after injury. Nichols and Smith demonstrate in zebrafish that
injured DRG axons do not initiate actin-based invasion components during
re-entry into the spinal cord. Pharmacological and cell-autonomous genetic
manipulations that promote actin-mediated cell invasion to restore sensory
behavior.
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Affiliation(s)
- Evan L Nichols
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA; Center for Stem Cells and Regenerative Medicine, University of Notre Dame, Notre Dame, IN, USA
| | - Cody J Smith
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA; Center for Stem Cells and Regenerative Medicine, University of Notre Dame, Notre Dame, IN, USA.
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133
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Clark J, Zhu Z, Chuckowree J, Dickson T, Blizzard C. Efficacy of epothilones in central nervous system trauma treatment: what has age got to do with it? Neural Regen Res 2021; 16:618-620. [PMID: 33063710 PMCID: PMC8067923 DOI: 10.4103/1673-5374.295312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Central nervous system injury, specifically traumatic brain and spinal cord injury, can have significant long lasting effects. There are no comprehensive treatments to combat the injury and sequalae of events that occurring following a central nervous system trauma. Herein we discuss the potential for the epothilone family of microtubule stabilizing agents to improve outcomes following experimentally induced trauma. These drugs, which are able to cross the blood-brain barrier, may hold great promise for the treatment of central nervous system trauma and the current literature presents the extensive range of beneficial effects these drugs may have following trauma in animal models. Importantly, the effect of the epothilones can vary and our most recent contributions to this field indicate that the efficacy of epothilones following traumatic brain injury is dependent upon the age of the animals. Therefore, we present a case for a greater emphasis to be placed upon age when using an intervention aimed at neural regeneration and highlight the importance of tailoring the therapeutic regime in the clinic to the age of the patient to promote improved patient outcomes.
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Affiliation(s)
- Jayden Clark
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Zhendan Zhu
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Jyoti Chuckowree
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Tracey Dickson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Catherine Blizzard
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
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134
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Leite SC, Pinto-Costa R, Sousa MM. Actin dynamics in the growth cone: a key player in axon regeneration. Curr Opin Neurobiol 2020; 69:11-18. [PMID: 33359956 DOI: 10.1016/j.conb.2020.11.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 01/01/2023]
Abstract
Neuronal development, maintenance and function depends on the tight regulation of cytoskeleton organization and dynamics. Following injury, adult central nervous system neurons have a limited ability to regenerate and to recapitulate their robust developmental axon growth. This decreased regenerative capacity is set by their inability to establish regeneration-competent growth cones. Growth cones are actin-enriched structures that regulate axon extension rate and direction. During neuronal development, increasing actin dynamics in the growth cone through the regulation of the activity of specific actin-binding proteins leads to increased axon elongation. Here, we will focus on recent findings showing that enhanced axon regeneration in the adult nervous system can be achieved by promoting actin dynamics, or by decreasing actomyosin contraction in the growth cone. These discoveries underscore the importance of actin organization in the growth cone as a key factor to promote axon (re)growth that should be further explored in the future.
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Affiliation(s)
- Sérgio Carvalho Leite
- Institute of Psychiatry and Neurosciences of Paris, INSERM U1266, Université de Paris, 75014 Paris, France
| | - Rita Pinto-Costa
- Nerve Regeneration Group, i3S- Instituto de Investigação e Inovação em Saúde and IBMC- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Monica Mendes Sousa
- Nerve Regeneration Group, i3S- Instituto de Investigação e Inovação em Saúde and IBMC- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
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135
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Kugler C, Thielscher C, Tambe BA, Schwarz MK, Halle A, Bradke F, Petzold GC. Epothilones Improve Axonal Growth and Motor Outcomes after Stroke in the Adult Mammalian CNS. CELL REPORTS MEDICINE 2020; 1:100159. [PMID: 33377130 PMCID: PMC7762779 DOI: 10.1016/j.xcrm.2020.100159] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 10/16/2020] [Accepted: 11/20/2020] [Indexed: 11/25/2022]
Abstract
Stroke leads to the degeneration of short-range and long-range axonal connections emanating from peri-infarct tissue, but it also induces novel axonal projections. However, this regeneration is hampered by growth-inhibitory properties of peri-infarct tissue and fibrotic scarring. Here, we tested the effects of epothilone B and epothilone D, FDA-approved microtubule-stabilizing drugs that are powerful modulators of axonal growth and scar formation, on neuroplasticity and motor outcomes in a photothrombotic mouse model of cortical stroke. We find that both drugs, when administered systemically 1 and 15 days after stroke, augment novel peri-infarct projections connecting the peri-infarct motor cortex with neighboring areas. Both drugs also increase the magnitude of long-range motor projections into the brainstem and reduce peri-infarct fibrotic scarring. Finally, epothilone treatment induces an improvement in skilled forelimb motor function. Thus, pharmacological microtubule stabilization represents a promising target for therapeutic intervention with a wide time window to ameliorate structural and functional sequelae after stroke. 3D visualization of axonal sprouting and remapping after cortical stroke in mice Systemic treatment with microtubule-stabilizing epothilones augments axon sprouting Epothilone treatment reduces fibrotic scar formation Epothilone treatment improves motor function with a wide therapeutic time window
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Affiliation(s)
- Christof Kugler
- Neurovascular Diseases Laboratory, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Christian Thielscher
- Neurovascular Diseases Laboratory, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Bertrand A. Tambe
- Microglia and Neuroinflammation Laboratory, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Martin K. Schwarz
- Experimental Epileptology and Cognition Research, Bonn University, 53127 Bonn, Germany
| | - Annett Halle
- Microglia and Neuroinflammation Laboratory, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Frank Bradke
- Axon Growth and Regeneration Laboratory, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Gabor C. Petzold
- Neurovascular Diseases Laboratory, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
- Division of Vascular Neurology, Department of Neurology, University Hospital Bonn, 53127 Bonn, Germany
- Corresponding author
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136
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UTX/KDM6A deletion promotes the recovery of spinal cord injury by epigenetically triggering intrinsic neural regeneration. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 20:337-349. [PMID: 33553483 PMCID: PMC7820127 DOI: 10.1016/j.omtm.2020.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 12/02/2020] [Indexed: 12/20/2022]
Abstract
Interrupted axons that fail to regenerate mainly cause poor recovery after spinal cord injury (SCI). How neurons epigenetically respond to injury determines the intrinsic growth ability of axons. However, the mechanism underlying epigenetic regulation of axonal regeneration post-SCI remains largely unknown. In this study, we elucidated the role of the epigenetic regulatory network involving ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX)/microRNA-24 (miR-24)/NeuroD1 in axonal regeneration and functional recovery in mice following SCI. Our results showed that UTX was significantly increased post-SCI and repressed axonal regeneration in vitro. However, downregulation of UTX remarkably promoted axonal regeneration. Furthermore, miR-24 was increased post-SCI and positively regulated by UTX. miR-24 also inhibited axonal regeneration. Chromatin immunoprecipitation (ChIP) indicated that UTX binds to the miR-24 promoter and regulates miR-24 expression. Genome sequencing and bioinformatics analysis suggested that NeuroD1 is a potential downstream target of UTX/miR-24. A dual-luciferase reporter assay indicated that miR-24 binds to NeuroD1; moreover, it represses axonal regeneration by negatively regulating the expression of NeuroD1 via modulation of microtubule stability. UTX deletion in vivo prominently promoted axonal regeneration and improved functional recovery post-SCI, and silencing NeuroD1 restored UTX function. Our findings indicate that UTX could be a potential target in SCI.
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137
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Hunyara JL, Kolodkin AL. Repurposing developmental mechanisms in the adult nervous system. Curr Opin Genet Dev 2020; 65:14-21. [PMID: 32485480 PMCID: PMC10668600 DOI: 10.1016/j.gde.2020.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/15/2020] [Indexed: 12/26/2022]
Abstract
Molecules and cellular processes important for nervous system development can be repurposed in adulthood for the regulation of adult neurogenesis, synaptic plasticity, and neural regeneration following injury or degeneration. Efforts to recapitulate neural development in order to ameliorate injury or disease are promising, but these often fall short of functional restoration due in part to our incomplete understanding of how these damaged circuits initially developed. Despite these limitations, such strategies provide hope that harnessing developmental mechanisms can restore nervous system functions following damage or disease.
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Affiliation(s)
- John L Hunyara
- The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Alex L Kolodkin
- The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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138
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Wu D, Jin Y, Shapiro TM, Hinduja A, Baas PW, Tom VJ. Chronic neuronal activation increases dynamic microtubules to enhance functional axon regeneration after dorsal root crush injury. Nat Commun 2020; 11:6131. [PMID: 33257677 PMCID: PMC7705672 DOI: 10.1038/s41467-020-19914-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 11/05/2020] [Indexed: 12/26/2022] Open
Abstract
After a dorsal root crush injury, centrally-projecting sensory axons fail to regenerate across the dorsal root entry zone (DREZ) to extend into the spinal cord. We find that chemogenetic activation of adult dorsal root ganglion (DRG) neurons improves axon growth on an in vitro model of the inhibitory environment after injury. Moreover, repeated bouts of daily chemogenetic activation of adult DRG neurons for 12 weeks post-crush in vivo enhances axon regeneration across a chondroitinase-digested DREZ into spinal gray matter, where the regenerating axons form functional synapses and mediate behavioral recovery in a sensorimotor task. Neuronal activation-mediated axon extension is dependent upon changes in the status of tubulin post-translational modifications indicative of highly dynamic microtubules (as opposed to stable microtubules) within the distal axon, illuminating a novel mechanism underlying stimulation-mediated axon growth. We have identified an effective combinatory strategy to promote functionally-relevant axon regeneration of adult neurons into the CNS after injury.
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Affiliation(s)
- Di Wu
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Ying Jin
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Tatiana M Shapiro
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Abhishek Hinduja
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Peter W Baas
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Veronica J Tom
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA.
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139
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Wilkes OR, Moore AW. Distinct Microtubule Organizing Center Mechanisms Combine to Generate Neuron Polarity and Arbor Complexity. Front Cell Neurosci 2020; 14:594199. [PMID: 33328893 PMCID: PMC7711044 DOI: 10.3389/fncel.2020.594199] [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: 08/12/2020] [Accepted: 11/02/2020] [Indexed: 01/15/2023] Open
Abstract
Dendrite and axon arbor wiring patterns determine the connectivity and computational characteristics of a neuron. The identities of these dendrite and axon arbors are created by differential polarization of their microtubule arrays, and their complexity and pattern are generated by the extension and organization of these arrays. We describe how several molecularly distinct microtubule organizing center (MTOC) mechanisms function during neuron differentiation to generate and arrange dendrite and axon microtubules. The temporal and spatial organization of these MTOCs generates, patterns, and diversifies arbor wiring.
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Affiliation(s)
- Oliver R Wilkes
- Laboratory for Neurodiversity, RIKEN Center for Brain Science, Wako-shi, Japan.,Department of Cellular and Molecular Biology, Institute for Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Adrian W Moore
- Laboratory for Neurodiversity, RIKEN Center for Brain Science, Wako-shi, Japan
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140
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Manipulation of Axonal Outgrowth via Exogenous Low Forces. Int J Mol Sci 2020; 21:ijms21218009. [PMID: 33126477 PMCID: PMC7663625 DOI: 10.3390/ijms21218009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 12/24/2022] Open
Abstract
Neurons are mechanosensitive cells. The role of mechanical force in the process of neurite initiation, elongation and sprouting; nerve fasciculation; and neuron maturation continues to attract considerable interest among scientists. Force is an endogenous signal that stimulates all these processes in vivo. The axon is able to sense force, generate force and, ultimately, transduce the force in a signal for growth. This opens up fascinating scenarios. How are forces generated and sensed in vivo? Which molecular mechanisms are responsible for this mechanotransduction signal? Can we exploit exogenously applied forces to mimic and control this process? How can these extremely low forces be generated in vivo in a non-invasive manner? Can these methodologies for force generation be used in regenerative therapies? This review addresses these questions, providing a general overview of current knowledge on the applications of exogenous forces to manipulate axonal outgrowth, with a special focus on forces whose magnitude is similar to those generated in vivo. We also review the principal methodologies for applying these forces, providing new inspiration and insights into the potential of this approach for future regenerative therapies.
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141
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Yang L, Conley BM, Cerqueira SR, Pongkulapa T, Wang S, Lee JK, Lee KB. Effective Modulation of CNS Inhibitory Microenvironment using Bioinspired Hybrid-Nanoscaffold-Based Therapeutic Interventions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002578. [PMID: 32893402 PMCID: PMC7606660 DOI: 10.1002/adma.202002578] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/04/2020] [Indexed: 05/11/2023]
Abstract
Central nervous system (CNS) injuries are often debilitating, and most currently have no cure. This is due to the formation of a neuroinhibitory microenvironment at injury sites, which includes neuroinflammatory signaling and non-permissive extracellular matrix (ECM) components. To address this challenge, a viscous interfacial self-assembly approach, to generate a bioinspired hybrid 3D porous nanoscaffold platform for delivering anti-inflammatory molecules and establish a favorable 3D-ECM environment for the effective suppression of the neuroinhibitory microenvironment, is developed. By tailoring the structural and biochemical properties of the 3D porous nanoscaffold, enhanced axonal growth from the dual-targeting therapeutic strategy in a human induced pluripotent stem cell (hiPSC)-based in vitro model of neuroinflammation is demonstrated. Moreover, nanoscaffold-based approaches promote significant axonal growth and functional recovery in vivo in a spinal cord injury model through a unique mechanism of anti-inflammation-based fibrotic scar reduction. Given the critical role of neuroinflammation and ECM microenvironments in neuroinhibitory signaling, the developed nanobiomaterial-based therapeutic intervention may pave a new road for treating CNS injuries.
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Affiliation(s)
- Letao Yang
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, NJ, 08854, USA
| | - Brian M Conley
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, NJ, 08854, USA
| | - Susana R Cerqueira
- Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami School of Medicine, 1095 NW 14th Terrace, LPLC 4-19, Miami, FL, 33136, USA
| | - Thanapat Pongkulapa
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, NJ, 08854, USA
| | - Shenqiang Wang
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, NJ, 08854, USA
| | - Jae K Lee
- Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami School of Medicine, 1095 NW 14th Terrace, LPLC 4-19, Miami, FL, 33136, USA
| | - Ki-Bum Lee
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, NJ, 08854, USA
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142
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Photoswitchable paclitaxel-based microtubule stabilisers allow optical control over the microtubule cytoskeleton. Nat Commun 2020; 11:4640. [PMID: 32934232 PMCID: PMC7493900 DOI: 10.1038/s41467-020-18389-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
Small molecule inhibitors are prime reagents for studies in microtubule cytoskeleton research, being applicable across a range of biological models and not requiring genetic engineering. However, traditional chemical inhibitors cannot be experimentally applied with spatiotemporal precision suiting the length and time scales inherent to microtubule-dependent cellular processes. We have synthesised photoswitchable paclitaxel-based microtubule stabilisers, whose binding is induced by photoisomerisation to their metastable state. Photoisomerising these reagents in living cells allows optical control over microtubule network integrity and dynamics, cell division and survival, with biological response on the timescale of seconds and spatial precision to the level of individual cells within a population. In primary neurons, they enable regulation of microtubule dynamics resolved to subcellular regions within individual neurites. These azobenzene-based microtubule stabilisers thus enable non-invasive, spatiotemporally precise modulation of the microtubule cytoskeleton in living cells, and promise new possibilities for studying intracellular transport, cell motility, and neuronal physiology. Light-based modulation of the microtubule (MT) cytoskeleton is an attractive goal for spatiotemporally-resolved MT studies. Here the authors develop a first generation photoswitchable small molecule MT stabiliser based on paclitaxel, allowing optical control over cellular MT dynamics.
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143
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Xiao Z, Yao Y, Wang Z, Tian Q, Wang J, Gu L, Li B, Zheng Q, Wu Y. Local Delivery of Taxol From FGL-Functionalized Self-Assembling Peptide Nanofiber Scaffold Promotes Recovery After Spinal Cord Injury. Front Cell Dev Biol 2020; 8:820. [PMID: 32974351 PMCID: PMC7471253 DOI: 10.3389/fcell.2020.00820] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/03/2020] [Indexed: 12/23/2022] Open
Abstract
Taxol has been clinically approved as an antitumor drug, and it exerts its antitumor effect through the excessive stabilization of microtubules in cancer cells. Recently, moderate microtubule stabilization by Taxol has been shown to efficiently promote neurite regeneration and functional recovery after spinal cord injury (SCI). However, the potential for the clinical translation of Taxol in treating SCI is limited by its side effects and low ability to cross the blood-spinal cord barrier (BSCB). Self-assembled peptide hydrogels have shown potential as drug carriers for the local delivery of therapeutic agents. We therefore hypothesized that the localized delivery of Taxol by a self-assembled peptide scaffold would promote axonal regeneration by stabilizing microtubules during the treatment of SCI. In the present study, the mechanistic functions of the Taxol-releasing system were clarified in vitro and in vivo using immunofluorescence labeling, histology and neurobehavioral analyses. Based on the findings from the in vitro study, Taxol released from a biological functionalized SAP nanofiber scaffold (FGLmx/Taxol) remained active and promoted neurite extension. In this study, we used a weight-drop contusion model to induce SCI at T9. The local delivery of Taxol from FGLmx/Taxol significantly decreased glial scarring and increased the number of nerve fibers compared with the use of FGLmx and 5% glucose. Furthermore, animals administered FGLmx/Taxol exhibited neurite preservation, smaller cavity dimensions, and decreased inflammation and demyelination. Thus, the local delivery of Taxol from FGLmx/Taxol was effective at promoting recovery after SCI and has potential as a new therapeutic strategy for SCI.
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Affiliation(s)
- Zhiyong Xiao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yingtao Yao
- Wuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, Collaborative Innovation Center for Biomedical Engineering, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Zhiyu Wang
- Department of Pathology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Qing Tian
- Department of Orthopaedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jiedong Wang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Li Gu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bo Li
- Department of Orthopaedics, Beijing Jishuitan Hospital, Beijing, China
| | - Qixin Zheng
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yongchao Wu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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144
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Rigoni M, Negro S. Signals Orchestrating Peripheral Nerve Repair. Cells 2020; 9:E1768. [PMID: 32722089 PMCID: PMC7464993 DOI: 10.3390/cells9081768] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/19/2020] [Accepted: 07/20/2020] [Indexed: 12/22/2022] Open
Abstract
The peripheral nervous system has retained through evolution the capacity to repair and regenerate after assault from a variety of physical, chemical, or biological pathogens. Regeneration relies on the intrinsic abilities of peripheral neurons and on a permissive environment, and it is driven by an intense interplay among neurons, the glia, muscles, the basal lamina, and the immune system. Indeed, extrinsic signals from the milieu of the injury site superimpose on genetic and epigenetic mechanisms to modulate cell intrinsic programs. Here, we will review the main intrinsic and extrinsic mechanisms allowing severed peripheral axons to re-grow, and discuss some alarm mediators and pro-regenerative molecules and pathways involved in the process, highlighting the role of Schwann cells as central hubs coordinating multiple signals. A particular focus will be provided on regeneration at the neuromuscular junction, an ideal model system whose manipulation can contribute to the identification of crucial mediators of nerve re-growth. A brief overview on regeneration at sensory terminals is also included.
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Affiliation(s)
- Michela Rigoni
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy;
- Myology Center (Cir-Myo), University of Padua, 35129 Padua, Italy
| | - Samuele Negro
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy;
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145
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Lee J, Shin JE, Lee B, Kim H, Jeon Y, Ahn SH, Chi SW, Cho Y. The stem cell marker Prom1 promotes axon regeneration by down-regulating cholesterol synthesis via Smad signaling. Proc Natl Acad Sci U S A 2020; 117:15955-15966. [PMID: 32554499 PMCID: PMC7355016 DOI: 10.1073/pnas.1920829117] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Axon regeneration is regulated by a neuron-intrinsic transcriptional program that is suppressed during development but that can be reactivated following peripheral nerve injury. Here we identify Prom1, which encodes the stem cell marker prominin-1, as a regulator of the axon regeneration program. Prom1 expression is developmentally down-regulated, and the genetic deletion of Prom1 in mice inhibits axon regeneration in dorsal root ganglion (DRG) cultures and in the sciatic nerve, revealing the neuronal role of Prom1 in injury-induced regeneration. Elevating prominin-1 levels in cultured DRG neurons or in mice via adeno-associated virus-mediated gene delivery enhances axon regeneration in vitro and in vivo, allowing outgrowth on an inhibitory substrate. Prom1 overexpression induces the consistent down-regulation of cholesterol metabolism-associated genes and a reduction in cellular cholesterol levels in a Smad pathway-dependent manner, which promotes axonal regrowth. We find that prominin-1 interacts with the type I TGF-β receptor ALK4, and that they synergistically induce phosphorylation of Smad2. These results suggest that Prom1 and cholesterol metabolism pathways are possible therapeutic targets for the promotion of neural recovery after injury.
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Affiliation(s)
- Jinyoung Lee
- Department of Life Sciences, Korea University, 02841 Seoul, Republic of Korea
| | - Jung Eun Shin
- Department of Molecular Neuroscience, Dong-A University College of Medicine, 49201 Busan, Republic of Korea
| | - Bohm Lee
- Department of Life Sciences, Korea University, 02841 Seoul, Republic of Korea
| | - Hyemin Kim
- Department of Life Sciences, Korea University, 02841 Seoul, Republic of Korea
| | - Yewon Jeon
- Department of Life Sciences, Korea University, 02841 Seoul, Republic of Korea
| | - Seung Hyun Ahn
- Department of Life Sciences, Korea University, 02841 Seoul, Republic of Korea
| | - Sung Wook Chi
- Department of Life Sciences, Korea University, 02841 Seoul, Republic of Korea
| | - Yongcheol Cho
- Department of Life Sciences, Korea University, 02841 Seoul, Republic of Korea;
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146
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Rodemer W, Gallo G, Selzer ME. Mechanisms of Axon Elongation Following CNS Injury: What Is Happening at the Axon Tip? Front Cell Neurosci 2020; 14:177. [PMID: 32719586 PMCID: PMC7347967 DOI: 10.3389/fncel.2020.00177] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
After an injury to the central nervous system (CNS), functional recovery is limited by the inability of severed axons to regenerate and form functional connections with appropriate target neurons beyond the injury. Despite tremendous advances in our understanding of the mechanisms of axon growth, and of the inhibitory factors in the injured CNS that prevent it, disappointingly little progress has been made in restoring function to human patients with CNS injuries, such as spinal cord injury (SCI), through regenerative therapies. Clearly, the large number of overlapping neuron-intrinsic and -extrinsic growth-inhibitory factors attenuates the benefit of neutralizing any one target. More daunting is the distances human axons would have to regenerate to reach some threshold number of target neurons, e.g., those that occupy one complete spinal segment, compared to the distances required in most experimental models, such as mice and rats. However, the difficulties inherent in studying mechanisms of axon regeneration in the mature CNS in vivo have caused researchers to rely heavily on extrapolation from studies of axon regeneration in peripheral nerve, or of growth cone-mediated axon development in vitro and in vivo. Unfortunately, evidence from several animal models, including the transected lamprey spinal cord, has suggested important differences between regeneration of mature CNS axons and growth of axons in peripheral nerve, or during embryonic development. Specifically, long-distance regeneration of severed axons may not involve the actin-myosin molecular motors that guide embryonic growth cones in developing axons. Rather, non-growth cone-mediated axon elongation may be required to propel injured axons in the mature CNS. If so, it may be necessary to use other experimental models to promote regeneration that is sufficient to contact a critical number of target neurons distal to a CNS lesion. This review examines the cytoskeletal underpinnings of axon growth, focusing on the elongating axon tip, to gain insights into how CNS axons respond to injury, and how this might affect the development of regenerative therapies for SCI and other CNS injuries.
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Affiliation(s)
- William Rodemer
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Gianluca Gallo
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States.,Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States.,Department of Neurology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
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147
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Lu Y, Yang J, Wang X, Ma Z, Li S, Liu Z, Fan X. Research progress in use of traditional Chinese medicine for treatment of spinal cord injury. Biomed Pharmacother 2020; 127:110136. [PMID: 32335299 DOI: 10.1016/j.biopha.2020.110136] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/17/2020] [Accepted: 03/30/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Spinal cord injury (SCI) is a serious central nervous system disorder caused by trauma that has gradually become a major challenge in clinical medical research. As an important branch of worldwide medical research, traditional Chinese medicine (TCM) is rapidly moving towards a path of reform and innovation. Therefore, this paper systematically reviews research related to existing TCM treatments for SCI, with the aims of identifying deficits and shortcomings within the field, and proposing feasible alternative prospects. METHODS All data and conclusions in this paper were obtained from articles published by peers in relevant fields. PubMed, SciFinder, Google Scholar, Web of Science, and CNKI databases were searched for relevant articles. Results regarding TCM for SCI were identified and retrieved, then manually classified and selected for inclusion in this review. RESULTS The literature search identified a total of 652 articles regarding TCM for SCI. Twenty-eight treatments (16 active ingredients, nine herbs, and three compound prescriptions) were selected from these articles; the treatments have been used for the prevention and treatment of SCI. In general, these treatments involved antioxidative, anti-inflammatory, neuroprotective, and/or antiapoptotic effects of TCM compounds. CONCLUSIONS This paper showed that TCM treatments can serve as promising auxiliary therapies for functional recovery of patients with SCI. These findings will contribute to the development of diversified treatments for SCI.
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Affiliation(s)
- Yubao Lu
- The Second Clinical Medical College, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Jingjing Yang
- The Second Clinical Medical College, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Xuexi Wang
- School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu 730000, China.
| | - Zhanjun Ma
- The Second Clinical Medical College, Lanzhou University, Lanzhou, Gansu 730000, China.
| | - Sheng Li
- Lanzhou First People's Hospital, Lanzhou, Gansu 730000, China
| | - Zhaoyang Liu
- Department of Medical Imaging, Shanxi Medical University, Jinzhong, Shanxi 030600, China
| | - Xuegong Fan
- School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu 730000, China
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148
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Abstract
The brain is our most complex organ. During development, neurons extend axons, which may grow over long distances along well-defined pathways to connect to distant targets. Our current understanding of axon pathfinding is largely based on chemical signaling by attractive and repulsive guidance cues. These cues instruct motile growth cones, the leading tips of growing axons, where to turn and where to stop. However, it is not chemical signals that cause motion-motion is driven by forces. Yet our current understanding of the mechanical regulation of axon growth is very limited. In this review, I discuss the origin of the cellular forces controlling axon growth and pathfinding, and how mechanical signals encountered by growing axons may be integrated with chemical signals. This mechanochemical cross talk is an important but often overlooked aspect of cell motility that has major implications for many physiological and pathological processes involving neuronal growth.
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Affiliation(s)
- Kristian Franze
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom;
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149
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O'Hare Doig RL, Santhakumar S, Fehily B, Raja S, Solomon T, Bartlett CA, Fitzgerald M, Hodgetts SI. Acute Cellular and Functional Changes With a Combinatorial Treatment of Ion Channel Inhibitors Following Spinal Cord Injury. Front Mol Neurosci 2020; 13:85. [PMID: 32670018 PMCID: PMC7331598 DOI: 10.3389/fnmol.2020.00085] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 04/24/2020] [Indexed: 01/12/2023] Open
Abstract
Reducing the extent of secondary degeneration following spinal cord injury (SCI) is necessary to preserve function, but treatment options have thus far been limited. A combination of the ion channel inhibitors Lomerizine (Lom), YM872 and oxATP, to inhibit voltage-gated Ca2+ channels, Ca2+ permeable AMPA receptors, and purinergic P2X7 receptors respectively, effectively limits secondary consequences of injury in in vitro and in vivo models of CNS injury. Here, we investigated the efficacy of these inhibitors in a clinically relevant model of SCI. Fischer (F344) rats were subjected to a moderate (150 kD) contusive SCI at thoracic level T10 and assessed at 2 weeks or 10 weeks post-injury. Lom was delivered orally twice daily and YM872 and oxATP were delivered via osmotic mini-pump implanted at the time of SCI until 2 weeks following injury. Open field locomotion analysis revealed that treatment with the three inhibitors in combination improved the rate of functional recovery of the hind limb (compared to controls) as early as 1-day post-injury, with beneficial effects persisting to 14 days post-injury, while all three inhibitors were present. At 2 weeks following combinatorial treatment, the functional improvement was associated with significantly decreased cyst size, increased immunoreactivity of β-III tubulin+ve axons, myelin basic protein, and reduced lipid peroxidation by-products, and increased CC1+ve oligodendrocytes and NG2+ve/PDGFα+ve oligodendrocyte progenitor cell densities, compared to vehicle-treated SCI animals. The combination of Lom, oxATP, and YM872 shows preclinical promise for control of secondary degeneration following SCI, and further investigation of long-term sustained treatment is warranted.
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Affiliation(s)
- Ryan L O'Hare Doig
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia.,Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Neil Sachse Centre for Spinal Cord Research, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,Adelaide Spinal Research Group, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Sreya Santhakumar
- Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
| | - Brooke Fehily
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Sushmitha Raja
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Tanya Solomon
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Carole A Bartlett
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Curtin Health Innovation Research Institute, Curtin University, Nedlands, WA, Australia
| | - Stuart I Hodgetts
- Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
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150
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Nakamura F, Ohshima T, Goshima Y. Collapsin Response Mediator Proteins: Their Biological Functions and Pathophysiology in Neuronal Development and Regeneration. Front Cell Neurosci 2020; 14:188. [PMID: 32655376 PMCID: PMC7325199 DOI: 10.3389/fncel.2020.00188] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/29/2020] [Indexed: 12/19/2022] Open
Abstract
Collapsin response mediator proteins (CRMPs), which consist of five homologous cytosolic proteins, are one of the major phosphoproteins in the developing nervous system. The prominent feature of the CRMP family proteins is a new class of microtubule-associated proteins that play important roles in the whole process of developing the nervous system, such as axon guidance, synapse maturation, cell migration, and even in adult brain function. The CRMP C-terminal region is subjected to posttranslational modifications such as phosphorylation, which, in turn, regulates the interaction between the CRMPs and various kinds of proteins including receptors, ion channels, cytoskeletal proteins, and motor proteins. The gene-knockout of the CRMP family proteins produces different phenotypes, thereby showing distinct roles of all CRMP family proteins. Also, the phenotypic analysis of a non-phosphorylated form of CRMP2-knockin mouse model, and studies of pharmacological responses to CRMP-related drugs suggest that the phosphorylation/dephosphorylation process plays a pivotal role in pathophysiology in neuronal development, regeneration, and neurodegenerative disorders, thus showing CRMPs as promising target molecules for therapeutic intervention.
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Affiliation(s)
- Fumio Nakamura
- Department of Biochemistry, Tokyo Women's Medical University, Tokyo, Japan
| | - Toshio Ohshima
- Department of Life Science and Medical Bio-Science, Waseda University, Tokyo, Japan
| | - Yoshio Goshima
- Department of Molecular Pharmacology and Neurobiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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