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Witkin JM, Radin DP, Rana S, Fuller DD, Fusco AF, Demers JC, Pradeep Thakre P, Smith JL, Lippa A, Cerne R. AMPA receptors play an important role in the biological consequences of spinal cord injury: Implications for AMPA receptor modulators for therapeutic benefit. Biochem Pharmacol 2024; 228:116302. [PMID: 38763261 DOI: 10.1016/j.bcp.2024.116302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/07/2024] [Accepted: 05/16/2024] [Indexed: 05/21/2024]
Abstract
Spinal cord injury (SCI) afflicts millions of individuals globally. There are few therapies available to patients. Ascending and descending excitatory glutamatergic neural circuits in the central nervous system are disrupted by SCI, making α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) a potential therapeutic drug target. Emerging research in preclinical models highlights the involvement of AMPARs in vital processes following SCI including breathing, pain, inflammation, bladder control, and motor function. However, there are no clinical trial data reported in this patient population to date. No work on the role of AMPA receptors in sexual dysfunction after SCI has been disclosed. Compounds with selective antagonist and potentiating effects on AMPA receptors have benefit in animal models of SCI, with antagonists generally showing protective effects early after injury and potentiators (ampakines) producing improved breathing and bladder function. The role of AMPARs in pathophysiology and recovery after SCI depends upon the time post injury, and the timing of AMPAR augmentation or antagonism. The roles of inflammation, synaptic plasticity, sensitization, neurotrophic factors, and neuroprotection are considered in this context. The data summarized and discussed in this paper document proof of principle and strongly encourage additional studies on AMPARs as novel gateways to therapeutic benefit for patients suffering from SCI. The availability of both AMPAR antagonists such as perampanel and AMPAR allosteric modulators (i.e., ampakines) such as CX1739, that have been safely administered to humans, provides an expedited means of clinical inquiry for possible therapeutic advances.
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Affiliation(s)
- Jeffrey M Witkin
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent Hospital, Indianapolis, IN, USA; Departments of Neuroscience and Trauma Research, Ascension St. Vincent Hospital, Indianapolis, IN, USA; RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA.
| | | | - Sabhya Rana
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA
| | - David D Fuller
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA
| | - Anna F Fusco
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA
| | - Julie C Demers
- Indiana University/Purdue University, Indianapolis, IN, USA
| | - Prajwal Pradeep Thakre
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA
| | - Jodi L Smith
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent Hospital, Indianapolis, IN, USA
| | - Arnold Lippa
- RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA
| | - Rok Cerne
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent Hospital, Indianapolis, IN, USA; RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA; Faculty of Medicine, University of Ljubljana, Zaloška Cesta 4, Ljubljana, Slovenia
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2
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Shamsnia HS, Peyrovinasab A, Amirlou D, Sirouskabiri S, Rostamian F, Basiri N, Shalmani LM, Hashemi M, Hushmandi K, Abdolghaffari AH. BDNF-TrkB Signaling Pathway in Spinal Cord Injury: Insights and Implications. Mol Neurobiol 2024:10.1007/s12035-024-04381-4. [PMID: 39046702 DOI: 10.1007/s12035-024-04381-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 07/18/2024] [Indexed: 07/25/2024]
Abstract
Spinal cord injury (SCI) is a neurodegenerative disorder that has critical impact on patient's life expectance and life span, and this disorder also leads to negative socioeconomic features. SCI is defined as a firm collision to the spinal cord which leads to the fracture and the dislocation of vertebrae. The current available treatment is surgery. However, it cannot fully treat SCI, and many consequences remain after the surgery. Accordingly, finding new therapeutics is critical. BDNF-TrkB signaling is a vital signaling in neuronal differentiation, survival, overgrowth, synaptic plasticity, etc. Hence, many studies evaluate its impact on various neurodegenerative disorders. There are several studies evaluating this signaling in SCI, and they show promising outcomes. It was shown that various exercises, chemical interventions, etc. had significant positive impact on SCI by affecting BDNF-TrkB signaling pathway. This study aims to accumulate and evaluate these data and inspect whether this signaling is effective or not.
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Affiliation(s)
- Hedieh Sadat Shamsnia
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Amirreza Peyrovinasab
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Dorsa Amirlou
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Shirin Sirouskabiri
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Fatemeh Rostamian
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Nasim Basiri
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Leila Mohaghegh Shalmani
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran.
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
| | - Mehrdad Hashemi
- Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
- Farhikhtegan Medical Convergence Sciences Research Center, Farhikhtegan Hospital Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
| | | | - Amir Hossein Abdolghaffari
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran.
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
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3
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Chen SY, Yang RL, Wu XC, Zhao DZ, Fu SP, Lin FQ, Li LY, Yu LM, Zhang Q, Zhang T. Mesenchymal Stem Cell Transplantation: Neuroprotection and Nerve Regeneration After Spinal Cord Injury. J Inflamm Res 2023; 16:4763-4776. [PMID: 37881652 PMCID: PMC10595983 DOI: 10.2147/jir.s428425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 10/03/2023] [Indexed: 10/27/2023] Open
Abstract
Spinal Cord Injury (SCI), with its morbidity characteristics of high disability rate and high mortality rate, is a disease that is highly destructive to both the physiology and psychology of the patient, and for which there is still a lack of effective treatment. Following spinal cord injury, a cascade of secondary injury reactions known as ischemia, peripheral inflammatory cell infiltration, oxidative stress, etc. create a microenvironment that is unfavorable to neural recovery and ultimately results in apoptosis and necrosis of neurons and glial cells. Mesenchymal stem cell (MSC) transplantation has emerged as a more promising therapeutic options in recent years. MSC can promote spinal cord injury repair through a variety of mechanisms, including immunomodulation, neuroprotection, and nerve regeneration, giving patients with spinal cord injury hope. In this paper, it is discussed the neuroprotection and nerve regeneration components of MSCs' therapeutic method for treating spinal cord injuries.
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Affiliation(s)
- Si-Yu Chen
- Key Laboratory of Cell Engineering of Guizhou Province, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
| | - Rui-Lin Yang
- Key Laboratory of Cell Engineering of Guizhou Province, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
| | - Xiang-Chong Wu
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
| | - De-Zhi Zhao
- Key Laboratory of Cell Engineering of Guizhou Province, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
| | - Sheng-Ping Fu
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
| | - Feng-Qin Lin
- Key Laboratory of Cell Engineering of Guizhou Province, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
| | - Lin-Yan Li
- Key Laboratory of Cell Engineering of Guizhou Province, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
| | - Li-Mei Yu
- Key Laboratory of Cell Engineering of Guizhou Province, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
| | - Qian Zhang
- Department of Human Anatomy, Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
| | - Tao Zhang
- Key Laboratory of Cell Engineering of Guizhou Province, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, People’s Republic of China
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4
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Farid H, Gelford WB, Goss LL, Garrett TL, Elbasiouny SM. Fast Blue and Cholera Toxin-B Survival Guide for Alpha-Motoneurons Labeling: Less Is Better in Young B6SJL Mice, but More Is Better in Aged C57Bl/J Mice. Bioengineering (Basel) 2023; 10:141. [PMID: 36829635 PMCID: PMC9952226 DOI: 10.3390/bioengineering10020141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/03/2023] [Accepted: 01/17/2023] [Indexed: 01/22/2023] Open
Abstract
Fast Blue (FB) and Cholera Toxin-B (CTB) are two retrograde tracers extensively used to label alpha-motoneurons (α-MNs). The overall goals of the present study were to (1) assess the effectiveness of different FB and CTB protocols in labeling α-MNs, (2) compare the labeling quality of these tracers at standard concentrations reported in the literature (FB 2% and CTB 0.1%) versus lower concentrations to overcome tracer leakage, and (3) determine an optimal protocol for labeling α-MNs in young B6SJL and aged C57Bl/J mice (when axonal transport is disrupted by aging). Hindlimb muscles of young B6SJL and aged C57Bl/J mice were intramuscularly injected with different FB or CTB concentrations and then euthanized at either 3 or 5 days after injection. Measurements were performed to assess labeling quality via seven different parameters. Our results show that tracer protocols of lower concentration and shorter labeling durations were generally better in labeling young α-MNs, whereas tracer protocols of higher tracer concentration and longer labeling durations were generally better in labeling aged α-MNs. A 0.2%, 3-day FB protocol provided optimal labeling of young α-MNs without tracer leakage, whereas a 2%, 5-day FB protocol or 0.1% CTB protocol provided optimal labeling of aged α-MNs. These results inform future studies on the selection of optimal FB and CTB protocols for α-MNs labeling in normal, aging, and neurodegenerative disease conditions.
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Affiliation(s)
- Hasan Farid
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, College of Science and Mathematics, Wright State University, Dayton, OH 45435, USA
| | - Weston B. Gelford
- Department of Biomedical, Industrial, and Human Factors Engineering, College of Engineering and Computer Science, Wright State University, Dayton, OH 45435, USA
| | - Lori L. Goss
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, College of Science and Mathematics, Wright State University, Dayton, OH 45435, USA
| | - Teresa L. Garrett
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, College of Science and Mathematics, Wright State University, Dayton, OH 45435, USA
| | - Sherif M. Elbasiouny
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, College of Science and Mathematics, Wright State University, Dayton, OH 45435, USA
- Department of Biomedical, Industrial, and Human Factors Engineering, College of Engineering and Computer Science, Wright State University, Dayton, OH 45435, USA
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5
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Stepanova OV, Fursa GA, Andretsova SS, Shishkina VS, Voronova AD, Chadin AV, Karsuntseva EK, Reshetov IV, Chekhonin VP. Prospects for the use of olfactory mucosa cells in bioprinting for the treatment of spinal cord injuries. World J Clin Cases 2023; 11:322-331. [PMID: 36686356 PMCID: PMC9850961 DOI: 10.12998/wjcc.v11.i2.322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/28/2022] [Accepted: 01/05/2023] [Indexed: 01/12/2023] Open
Abstract
The review focuses on the most important areas of cell therapy for spinal cord injuries. Olfactory mucosa cells are promising for transplantation. Obtaining these cells is safe for patients. The use of olfactory mucosa cells is effective in restoring motor function due to the remyelination and regeneration of axons after spinal cord injuries. These cells express neurotrophic factors that play an important role in the functional recovery of nerve tissue after spinal cord injuries. In addition, it is possible to increase the content of neurotrophic factors, at the site of injury, exogenously by the direct injection of neurotrophic factors or their delivery using gene therapy. The advantages of olfactory mucosa cells, in combination with neurotrophic factors, open up wide possibilities for their application in three-dimensional and four-dimensional bioprinting technology treating spinal cord injuries.
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Affiliation(s)
- Olga Vladislavovna Stepanova
- Department of Basic and Applied Neurobiology, V.P. Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow 119034, Russia
- Department of Neurohumoral and Immunological Research, National Medical Research Center of Cardiology, Moscow 121552, Russia
| | - Grigorii Andreevich Fursa
- Department of Basic and Applied Neurobiology, V.P. Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow 119034, Russia
| | - Svetlana Sergeevna Andretsova
- Department of Basic and Applied Neurobiology, V.P. Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow 119034, Russia
- Department of Biology, Moscow State University, Moscow 119991, Russia
| | - Valentina Sergeevna Shishkina
- Department of Basic and Applied Neurobiology, V.P. Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow 119034, Russia
| | - Anastasia Denisovna Voronova
- Department of Basic and Applied Neurobiology, V.P. Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow 119034, Russia
| | - Andrey Viktorovich Chadin
- Department of Basic and Applied Neurobiology, V.P. Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow 119034, Russia
| | | | | | - Vladimir Pavlovich Chekhonin
- Department of Basic and Applied Neurobiology, V.P. Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow 119034, Russia
- Department of Medical Nanobiotechnologу, N.I. Pirogov Russian National Research Medical University, Moscow 117997, Russia
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6
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Anderson MA, Squair JW, Gautier M, Hutson TH, Kathe C, Barraud Q, Bloch J, Courtine G. Natural and targeted circuit reorganization after spinal cord injury. Nat Neurosci 2022; 25:1584-1596. [PMID: 36396975 DOI: 10.1038/s41593-022-01196-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/05/2022] [Indexed: 11/18/2022]
Abstract
A spinal cord injury disrupts communication between the brain and the circuits in the spinal cord that regulate neurological functions. The consequences are permanent paralysis, loss of sensation and debilitating dysautonomia. However, the majority of circuits located above and below the injury remain anatomically intact, and these circuits can reorganize naturally to improve function. In addition, various neuromodulation therapies have tapped into these processes to further augment recovery. Emerging research is illuminating the requirements to reconstitute damaged circuits. Here, we summarize these natural and targeted reorganizations of circuits after a spinal cord injury. We also advocate for new concepts of reorganizing circuits informed by multi-omic single-cell atlases of recovery from injury. These atlases will uncover the molecular logic that governs the selection of 'recovery-organizing' neuronal subpopulations, and are poised to herald a new era in spinal cord medicine.
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Affiliation(s)
- Mark A Anderson
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland.,Wyss Center for Bio and Neuroengineering, Geneva, Switzerland
| | - Jordan W Squair
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Matthieu Gautier
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Thomas H Hutson
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland.,Wyss Center for Bio and Neuroengineering, Geneva, Switzerland
| | - Claudia Kathe
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Quentin Barraud
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Jocelyne Bloch
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Grégoire Courtine
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland. .,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland. .,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland.
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7
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Wang Z, Romanski A, Mehra V, Wang Y, Brannigan M, Campbell BC, Petsko GA, Tsoulfas P, Blackmore MG. Brain-wide analysis of the supraspinal connectome reveals anatomical correlates to functional recovery after spinal injury. eLife 2022; 11:76254. [PMID: 35838234 PMCID: PMC9345604 DOI: 10.7554/elife.76254] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 07/12/2022] [Indexed: 11/15/2022] Open
Abstract
The supraspinal connectome is essential for normal behavior and homeostasis and consists of numerous sensory, motor, and autonomic projections from brain to spinal cord. Study of supraspinal control and its restoration after damage has focused mostly on a handful of major populations that carry motor commands, with only limited consideration of dozens more that provide autonomic or crucial motor modulation. Here, we assemble an experimental workflow to rapidly profile the entire supraspinal mesoconnectome in adult mice and disseminate the output in a web-based resource. Optimized viral labeling, 3D imaging, and registration to a mouse digital neuroanatomical atlas assigned tens of thousands of supraspinal neurons to 69 identified regions. We demonstrate the ability of this approach to clarify essential points of topographic mapping between spinal levels, measure population-specific sensitivity to spinal injury, and test the relationships between region-specific neuronal sparing and variability in functional recovery. This work will spur progress by broadening understanding of essential but understudied supraspinal populations.
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Affiliation(s)
- Zimei Wang
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Adam Romanski
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Vatsal Mehra
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Yunfang Wang
- Department of Neurological Surgery, University of Miami, Miami, United States
| | - Matthew Brannigan
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Benjamin C Campbell
- Helen and Robert Appel Alzheimer's Disease Research Institute, Cornell University, New York, United States
| | - Gregory A Petsko
- Helen and Robert Appel Alzheimer's Disease Research Institute, Cornell University, New York, United States
| | - Pantelis Tsoulfas
- Department of Neurological Surgery, University of Miami, Miami, United States
| | - Murray G Blackmore
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
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8
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Zhao C, Rao JS, Duan H, Hao P, Shang J, Fan Y, Zhao W, Gao Y, Yang Z, Sun YE, Li X. Chronic spinal cord injury repair by NT3-chitosan only occurs after clearance of the lesion scar. Signal Transduct Target Ther 2022; 7:184. [PMID: 35710784 PMCID: PMC9203793 DOI: 10.1038/s41392-022-01010-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 03/22/2022] [Accepted: 04/06/2022] [Indexed: 11/24/2022] Open
Abstract
Spinal cord injury (SCI) is a severe damage usually leading to limb dysesthesia, motor dysfunction, and other physiological disability. We have previously shown that NT3-chitosan could trigger an acute SCI repairment in rats and non-human primates. Due to the negative effect of inhibitory molecules in glial scar on axonal regeneration, however, the role of NT3-chitosan in the treatment of chronic SCI remains unclear. Compared with the fresh wound of acute SCI, how to handle the lesion core and glial scars is a major issue related to chronic-SCI repair. Here we report, in a chronic complete SCI rat model, establishment of magnetic resonance-diffusion tensor imaging (MR-DTI) methods to monitor spatial and temporal changes of the lesion area, which matched well with anatomical analyses. Clearance of the lesion core via suction of cystic tissues and trimming of solid scar tissues before introducing NT3-chitosan using either a rigid tubular scaffold or a soft gel form led to robust neural regeneration, which interconnected the severed ascending and descending axons and accompanied with electrophysiological and motor functional recovery. In contrast, cystic tissue extraction without scar trimming followed by NT3-chitosan injection, resulted in little, if any regeneration. Taken together, after lesion core clearance, NT3-chitosan can be used to enable chronic-SCI repair and MR-DTI-based mapping of lesion area and monitoring of ongoing regeneration can potentially be implemented in clinical studies for subacute/chronic-SCI repair.
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Affiliation(s)
- Can Zhao
- Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China.,Institute of Rehabilitation Engineering, China Rehabilitation Science Institute, Beijing, 100068, China
| | - Jia-Sheng Rao
- Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Hongmei Duan
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Peng Hao
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Junkui Shang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Yubo Fan
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Chinese Education Ministry, School of Biological Science and Medical Engineering, Beihang University, Beijing, 10083, China.,School of Engineering Medicine, Beihang University, Beijing, 10083, China
| | - Wen Zhao
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Yudan Gao
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Zhaoyang Yang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.
| | - Yi Eve Sun
- Shanghai Institute of Stem Cell Research and Clinical Translation, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China. .,Department of Psychiatry and Biobehavioral Sciences, UCLA Medical School, Los Angeles, CA, 90095, USA.
| | - Xiaoguang Li
- Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China. .,Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.
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9
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Restoration of ER proteostasis attenuates remote apoptotic cell death after spinal cord injury by reducing autophagosome overload. Cell Death Dis 2022; 13:381. [PMID: 35444186 PMCID: PMC9021197 DOI: 10.1038/s41419-022-04830-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 03/30/2022] [Accepted: 04/04/2022] [Indexed: 02/07/2023]
Abstract
The pathogenic mechanisms that underlie the progression of remote degeneration after spinal cord injury (SCI) are not fully understood. In this study, we examined the relationship between endoplasmic reticulum (ER) stress and macroautophagy, hereafter autophagy, and its contribution to the secondary damage and outcomes that are associated with remote degeneration after SCI. Using a rat model of spinal cord hemisection at the cervical level, we measured ER stress and autophagy markers in the axotomized neurons of the red nucleus (RN). In SCI animals, mRNA and protein levels of markers of ER stress, such as GRP78, CHOP, and GADD34, increased 1 day after the injury, peaking on Day 5. Notably, in SCI animals, the increase of ER stress markers correlated with a blockade in autophagic flux, as evidenced by the increase in microtubule-associated protein 2 light chain 3 (LC3-II) and p62/SQSTM1 (p62) and the decline in LAMP1 and LAMP2 levels. After injury, treatment with guanabenz protected neurons from UPR failure and increased lysosomes biogenesis, unblocking autophagic flux. These effects correlated with greater activation of TFEB and improved neuronal survival and functional recovery—effects that persisted after suspension of the treatment. Collectively, our results demonstrate that in remote secondary damage, impairments in autophagic flux are intertwined with ER stress, an association that contributes to the apoptotic cell death and functional damage that are observed after SCI.
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10
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Murtaza M, Mohanty L, Ekberg JAK, St John JA. Designing Olfactory Ensheathing Cell Transplantation Therapies: Influence of Cell Microenvironment. Cell Transplant 2022; 31:9636897221125685. [PMID: 36124646 PMCID: PMC9490465 DOI: 10.1177/09636897221125685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Olfactory ensheathing cell (OEC) transplantation is emerging as a promising treatment option for injuries of the nervous system. OECs can be obtained relatively easily from nasal biopsies, and exhibit several properties such as secretion of trophic factors, and phagocytosis of debris that facilitate neural regeneration and repair. But a major limitation of OEC-based cell therapies is the poor survival of transplanted cells which subsequently limit their therapeutic efficacy. There is an unmet need for approaches that enable the in vitro production of OECs in a state that will optimize their survival and integration after transplantation into the hostile injury site. Here, we present an overview of the strategies to modulate OECs focusing on oxygen levels, stimulating migratory, phagocytic, and secretory properties, and on bioengineering a suitable environment in vitro.
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Affiliation(s)
- Mariyam Murtaza
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD, Australia
| | - Lipsa Mohanty
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD, Australia
| | - Jenny A K Ekberg
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD, Australia
| | - James A St John
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD, Australia
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11
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Cheng L, Sami A, Ghosh B, Goudsward HJ, Smith GM, Wright MC, Li S, Lepore AC. Respiratory axon regeneration in the chronically injured spinal cord. Neurobiol Dis 2021; 155:105389. [PMID: 33975016 DOI: 10.1016/j.nbd.2021.105389] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/19/2021] [Accepted: 05/05/2021] [Indexed: 02/01/2023] Open
Abstract
Promoting the combination of robust regeneration of damaged axons and synaptic reconnection of these growing axon populations with appropriate neuronal targets represents a major therapeutic goal following spinal cord injury (SCI). A key impediment to achieving this important aim includes an intrinsic inability of neurons to extend axons in adult CNS, particularly in the context of the chronically-injured spinal cord. We tested whether an inhibitory peptide directed against phosphatase and tensin homolog (PTEN: a central inhibitor of neuron-intrinsic axon growth potential) could restore inspiratory diaphragm function by reconnecting critical respiratory neural circuitry in a rat model of chronic cervical level 2 (C2) hemisection SCI. We found that systemic delivery of PTEN antagonist peptide 4 (PAP4) starting at 8 weeks after C2 hemisection promoted substantial, long-distance regeneration of injured bulbospinal rostral Ventral Respiratory Group (rVRG) axons into and through the lesion and back toward phrenic motor neurons (PhMNs) located in intact caudal C3-C5 spinal cord. Despite this robust rVRG axon regeneration, PAP4 stimulated only minimal recovery of diaphragm function. Furthermore, re-lesion through the hemisection site completely removed PAP4-induced functional improvement, demonstrating that axon regeneration through the lesion was responsible for this partial functional recovery. Interestingly, there was minimal formation of putative excitatory monosynaptic connections between regrowing rVRG axons and PhMN targets, suggesting that (1) limited rVRG-PhMN synaptic reconnectivity was responsible at least in part for the lack of a significant functional effect, (2) chronically-injured spinal cord presents an obstacle to achieving synaptogenesis between regenerating axons and post-synaptic targets, and (3) addressing this challenge is a potentially-powerful strategy to enhance therapeutic efficacy in the chronic SCI setting. In conclusion, our study demonstrates a non-invasive and transient pharmacological approach in chronic SCI to repair the critically-important neural circuitry controlling diaphragmatic respiratory function, but also sheds light on obstacles to circuit plasticity presented by the chronically-injured spinal cord.
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Affiliation(s)
- Lan Cheng
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Armin Sami
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Biswarup Ghosh
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Hannah J Goudsward
- Department of Biology, Arcadia University, 450 S. Easton Rd., 220 Boyer Hall, Glenside, PA 19038, USA
| | - George M Smith
- Department of Neuroscience, Shriners Hospitals for Pediatric Research Center, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140-5104, USA
| | - Megan C Wright
- Department of Biology, Arcadia University, 450 S. Easton Rd., 220 Boyer Hall, Glenside, PA 19038, USA
| | - Shuxin Li
- Department of Neuroscience, Shriners Hospitals for Pediatric Research Center, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140-5104, USA
| | - Angelo C Lepore
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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12
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Muheremu A, Shu L, Liang J, Aili A, Jiang K. Sustained delivery of neurotrophic factors to treat spinal cord injury. Transl Neurosci 2021; 12:494-511. [PMID: 34900347 PMCID: PMC8633588 DOI: 10.1515/tnsci-2020-0200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 12/16/2022] Open
Abstract
Acute spinal cord injury (SCI) is a devastating condition that results in tremendous physical and psychological harm and a series of socioeconomic problems. Although neurons in the spinal cord need neurotrophic factors for their survival and development to reestablish their connections with their original targets, endogenous neurotrophic factors are scarce and the sustainable delivery of exogeneous neurotrophic factors is challenging. The widely studied neurotrophic factors such as brain-derived neurotrophic factor, neurotrophin-3, nerve growth factor, ciliary neurotrophic factor, basic fibroblast growth factor, and glial cell-derived neurotrophic factor have a relatively short cycle that is not sufficient enough for functionally significant neural regeneration after SCI. In the past decades, scholars have tried a variety of cellular and viral vehicles as well as tissue engineering scaffolds to safely and sustainably deliver those necessary neurotrophic factors to the injury site, and achieved satisfactory neural repair and functional recovery on many occasions. Here, we review the neurotrophic factors that have been used in trials to treat SCI, and vehicles that were commonly used for their sustained delivery.
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Affiliation(s)
- Aikeremujiang Muheremu
- Department of Spine Surgery, Sixth Affiliated Hospital of Xinjiang Medical University, 39 Wuxing Nan Rd, Tianshan District, Urumqi, Xinjiang, 86830001, People’s Republic of China
| | - Li Shu
- Department of Orthopedics, Sixth Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, 86830001, People’s Republic of China
| | - Jing Liang
- Department of Laboratory Medicine, Sixth Affiliated Hospital of Xinjiang Medical University, 39, Wuxing Nan Rd, Tianshan District, Urumqi, Xinjiang, 86830001, People’s Republic of China
| | - Abudunaibi Aili
- Department of Spine Surgery, Sixth Affiliated Hospital of Xinjiang Medical University, 39 Wuxing Nan Rd, Tianshan District, Urumqi, Xinjiang, 86830001, People’s Republic of China
| | - Kan Jiang
- Department of Orthopedics, Sixth Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, 86830001, People’s Republic of China
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13
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Patsakos EM, Bayley MT, Kua A, Cheng C, Eng J, Ho C, Noonan VK, Querée M, Craven BC. Development of the Canadian Spinal Cord Injury Best Practice (Can-SCIP) Guideline: Methods and overview. J Spinal Cord Med 2021; 44:S52-S68. [PMID: 34779719 PMCID: PMC8604491 DOI: 10.1080/10790268.2021.1953312] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
INTRODUCTION Spinal cord injury (SCI) is a life-altering injury that leads to a complex constellation of changes in an individual's sensory, motor, and autonomic function which is largely determined by the level and severity of cord impairment. Available SCI-specific clinical practice guidelines (CPG) address specific impairments, health conditions or a segment of the care continuum, however, fail to address all the important clinical questions arising throughout an individual's care journey. To address this gap, an interprofessional panel of experts in SCI convened to develop the Canadian Spinal Cord Injury Best Practice (Can-SCIP) Guideline. This article provides an overview of the methods underpinning the Can-SCIP Guideline process. METHODS The Can-SCIP Guideline was developed using the Guidelines Adaptation Cycle. A comprehensive search for existing SCI-specific CPGs was conducted. The quality of eligible CPGs was evaluated using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument. An expert panel (n = 52) convened, and groups of relevant experts met to review and recommend adoption or refinement of existing recommendations or develop new recommendations based on evidence from systematic reviews conducted by the Spinal Cord Injury Research Evidence (SCIRE) team. The expert panel voted to approve selected recommendations using an online survey tool. RESULTS The Can-SCIP Guideline includes 585 total recommendations from 41 guidelines, 96 recommendations that pertain to the Components of the Ideal SCI Care System section, and 489 recommendations that pertain to the Management of Secondary Health Conditions section. Most recommendations (n = 281, 48%) were adopted from existing guidelines without revision, 215 (36.8%) recommendations were revised for application in a Canadian context, and 89 recommendations (15.2%) were created de novo. CONCLUSION The Can-SCIP Guideline is the first living comprehensive guideline for adults with SCI in Canada across the care continuum.
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Affiliation(s)
- Eleni M. Patsakos
- KITE Research Institute, Toronto Rehabilitation Institute – University Health Network, Toronto, Ontario, Canada
| | - Mark T. Bayley
- KITE Research Institute, Toronto Rehabilitation Institute – University Health Network, Toronto, Ontario, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ailene Kua
- KITE Research Institute, Toronto Rehabilitation Institute – University Health Network, Toronto, Ontario, Canada
| | - Christiana Cheng
- Praxis Spinal Cord Institute, International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Janice Eng
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Physiotherapy, GF Strong Rehabilitation Centre, Vancouver, British Columbia, Canada
| | - Chester Ho
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Vanessa K. Noonan
- Praxis Spinal Cord Institute, International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthew Querée
- GF Strong Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - B. Catharine Craven
- KITE Research Institute, Toronto Rehabilitation Institute – University Health Network, Toronto, Ontario, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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14
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Sahu MK, Kaushik K, Das A, Jha H. In vitro and in silico antioxidant and antiproliferative activity of rhizospheric fungus Talaromyces purpureogenus isolate-ABRF2. BIORESOUR BIOPROCESS 2020. [DOI: 10.1186/s40643-020-00303-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractThe present study evaluated the potential biological activities of rhizospheric fungi isolated from the Achanakmar Biosphere Reserve, India. Fungus, Talaromyces purpureogenus isolate-ABRF2 from the soil of the Achanakmar biosphere was characterized by using morphological, biochemical and molecular techniques. Fungus was screened for the production of secondary metabolites using a specific medium. The metabolites were extracted using a suitable solvent and each fraction was subsequently evaluated for their antioxidant, antimicrobial, antiproliferative and anti-aging properties. The ethanolic extract depicted the highest antioxidant activity with 83%, 79%, 80% and 74% as assessed by ferric reducing power, 2,2-diphenyl 1-picrylhydrazyl, 2,2′-azino-bis3-ethylbenzthiazoline-6-sulfonic and phosphomolybdenum assays, respectively. Similarly, ethanolic extracts depicted marked antimicrobial activity as compared with standard antibiotics and antifungal agents as well as demonstrated significant antiproliferative property against a panel of mammalian cancer cell lines. Furthermore, different fractions of the purified ethanolic extract obtained using adsorption column chromatography were evaluated for antiproliferative property and identification of an active metabolite in the purified fraction using gas chromatography–mass spectroscopy and nuclear magnetic resonance techniques yielded 3-methyl-4-oxo-pentanoic acid. Thus, the present study suggests that the active metabolite 3-methyl-4-oxo-pentanoic acid extracted from Talaromyces purpureogenus isolate-ABRF2 has a potential antiproliferative, anti-aging, and antimicrobial therapeutic properties that will be further evaluated using in vivo studies in future.
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15
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Magnetization Transfer Ratio and Morphometrics of the Spinal Cord Associates with Surgical Recovery in Patients with Degenerative Cervical Myelopathy. World Neurosurg 2020; 144:e939-e947. [PMID: 33010502 DOI: 10.1016/j.wneu.2020.09.148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 11/21/2022]
Abstract
OBJECTIVES We assessed the prognostic value of the preoperative magnetization transfer ratio (MTR) and morphometrics of the spinal cord in patients with degenerative cervical myelopathy (DCM) in a longitudinal cohort study. METHODS Thirteen subjects with DCM underwent 3T magnetization transfer imaging. The MTR was calculated for the spinal cord regions and specific white matter tracts. Morphometric measures were extracted. Clinical (modified Japanese Orthopaedics Association [mJOA] and Nurick scale scores) and health-related quality of life scores were assessed before and after cervical decompression surgery. The association between the magnetic resonance imaging (MRI) metrics and postoperative recovery was assessed (Spearman's correlation). Receiver operating characteristics were used to assess the accuracy of MRI metrics in identifying ≥50% recovery in function. RESULTS Preoperative anterior cord MTRs were associated with recovery in mJOA scores (ρ = 0.608; P = 0.036; area under the curve [AUC], 0.66). Preoperative lateral cord MTR correlated with the neck disability index (ρ = 0.699; P = 0.011) and pain interference scale (ρ = 0.732; P = 0.007). Preoperative rubrospinal tract MTR was associated with mJOA score recovery (ρ = 0.573; P = 0.041; AUC, 0.86). Preoperative corticospinal tract and reticulospinal MTRs were related to recovery in pain interference scores (ρ = 0.591; P = 0.033; and ρ = 0.583; P = 0.035, respectively). Eccentricity of the cord was associated with Nurick scores (ρ = 0.606; P = 0.028) and mJOA scores (ρ = 0.651; P = 0.025; AUC, 0.92). CONCLUSIONS Preoperative MTR and eccentricity measurements of the spinal cord have prognostic value in assessing the response to surgery and recovery in patients with DCM. Advanced MRI and atlas-based postprocessing techniques can inform interventions and advance the healthcare received by patients with DCM.
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16
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Giorgetti E, Panesar M, Zhang Y, Joller S, Ronco M, Obrecht M, Lambert C, Accart N, Beckmann N, Doelemeyer A, Perrot L, Fruh I, Mueller M, Pierrel E, Summermatter S, Bidinosti M, Shimshek DR, Brachat S, Nash M. Modulation of Microglia by Voluntary Exercise or CSF1R Inhibition Prevents Age-Related Loss of Functional Motor Units. Cell Rep 2020; 29:1539-1554.e7. [PMID: 31693894 DOI: 10.1016/j.celrep.2019.10.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 07/27/2019] [Accepted: 10/01/2019] [Indexed: 01/05/2023] Open
Abstract
Age-related loss of skeletal muscle innervation by motor neurons leads to impaired neuromuscular function and is a well-established clinical phenomenon. However, the underlying pathogenesis remains unclear. Studying mice, we find that the number of motor units (MUs) can be maintained by counteracting neurotoxic microglia in the aged spinal cord. We observe that marked innervation changes, detected by motor unit number estimation (MUNE), occur prior to loss of muscle function in aged mice. This coincides with gene expression changes indicative of neuronal remodeling and microglial activation in aged spinal cord. Voluntary exercise prevents loss of MUs and reverses microglia activation. Depleting microglia by CSF1R inhibition also prevents the age-related decline in MUNE and neuromuscular junction disruption, implying a causal link. Our results suggest that age-related changes in spinal cord microglia contribute to neuromuscular decline in aged mice and demonstrate that removal of aged neurotoxic microglia can prevent or reverse MU loss.
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Affiliation(s)
- Elisa Giorgetti
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland.
| | - Moh Panesar
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Yunyu Zhang
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Stefanie Joller
- Neuroscience, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Marie Ronco
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Michael Obrecht
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Christian Lambert
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Nathalie Accart
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Nicolau Beckmann
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Arno Doelemeyer
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Ludovic Perrot
- Global Sci Operations, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Isabelle Fruh
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Matthias Mueller
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Eliane Pierrel
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Serge Summermatter
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Michael Bidinosti
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Derya R Shimshek
- Neuroscience, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Sophie Brachat
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Mark Nash
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland.
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Rodemer W, Selzer ME. Role of axon resealing in retrograde neuronal death and regeneration after spinal cord injury. Neural Regen Res 2019; 14:399-404. [PMID: 30539805 PMCID: PMC6334596 DOI: 10.4103/1673-5374.245330] [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] [Indexed: 01/13/2023] Open
Abstract
Spinal cord injury leads to persistent behavioral deficits because mammalian central nervous system axons fail to regenerate. A neuron's response to axon injury results from a complex interplay of neuron-intrinsic and environmental factors. The contribution of axotomy to the death of neurons in spinal cord injury is controversial because very remote axotomy is unlikely to result in neuronal death, whereas death of neurons near an injury may reflect environmental factors such as ischemia and inflammation. In lampreys, axotomy due to spinal cord injury results in delayed apoptosis of spinal-projecting neurons in the brain, beyond the extent of these environmental factors. This retrograde apoptosis correlates with delayed resealing of the axon, and can be reversed by inducing rapid membrane resealing with polyethylene glycol. Studies in mammals also suggest that polyethylene glycol may be neuroprotective, although the mechanism(s) remain unclear. This review examines the early, mechanical, responses to axon injury in both mammals and lampreys, and the potential of polyethylene glycol to reduce injury-induced pathology. Identifying the mechanisms underlying a neuron's response to axotomy will potentially reveal new therapeutic targets to enhance regeneration and functional recovery in humans with spinal cord injury.
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Affiliation(s)
- William Rodemer
- Shriners Hospital Pediatric Research Center (Center for Neural Repair and Rehabilitation), Philadelphia, PA, USA
| | - Michael E Selzer
- Shriners Hospital Pediatric Research Center (Center for Neural Repair and Rehabilitation); Department of Neurology, the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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18
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Rapid and robust restoration of breathing long after spinal cord injury. Nat Commun 2018; 9:4843. [PMID: 30482901 PMCID: PMC6258702 DOI: 10.1038/s41467-018-06937-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/03/2018] [Indexed: 12/31/2022] Open
Abstract
There exists an abundance of barriers that hinder functional recovery following spinal cord injury, especially at chronic stages. Here, we examine the rescue of breathing up to 1.5 years following cervical hemisection in the rat. In spite of complete hemidiaphragm paralysis, a single injection of chondroitinase ABC in the phrenic motor pool restored robust and persistent diaphragm function while improving neuromuscular junction anatomy. This treatment strategy was more effective when applied chronically than when assessed acutely after injury. The addition of intermittent hypoxia conditioning further strengthened the ventilatory response. However, in a sub-population of animals, this combination treatment caused excess serotonergic (5HT) axon sprouting leading to aberrant tonic activity in the diaphragm that could be mitigated via 5HT2 receptor blockade. Through unmasking of the continuing neuroplasticity that develops after injury, our treatment strategy ensured rapid and robust patterned respiratory recovery after a near lifetime of paralysis. Respiratory failure is one of the leading causes of death following spinal cord injury and it is unclear if normal respiratory motor activity can be recovered after chronic injury-induced paralysis. Here, authors show that treatment with chondroitinase ABC induces robust rescue of breathing up to 1.5 years following complete hemidiaphragm paralysis.
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19
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Petrova V, Eva R. The Virtuous Cycle of Axon Growth: Axonal Transport of Growth-Promoting Machinery as an Intrinsic Determinant of Axon Regeneration. Dev Neurobiol 2018; 78:898-925. [PMID: 29989351 DOI: 10.1002/dneu.22608] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/25/2018] [Accepted: 05/26/2018] [Indexed: 02/02/2023]
Abstract
Injury to the brain and spinal cord has devastating consequences because adult central nervous system (CNS) axons fail to regenerate. Injury to the peripheral nervous system (PNS) has a better prognosis, because adult PNS neurons support robust axon regeneration over long distances. CNS axons have some regenerative capacity during development, but this is lost with maturity. Two reasons for the failure of CNS regeneration are extrinsic inhibitory molecules, and a weak intrinsic capacity for growth. Extrinsic inhibitory molecules have been well characterized, but less is known about the neuron-intrinsic mechanisms which prevent axon re-growth. Key signaling pathways and genetic/epigenetic factors have been identified which can enhance regenerative capacity, but the precise cellular mechanisms mediating their actions have not been characterized. Recent studies suggest that an important prerequisite for regeneration is an efficient supply of growth-promoting machinery to the axon; however, this appears to be lacking from non-regenerative axons in the adult CNS. In the first part of this review, we summarize the evidence linking axon transport to axon regeneration. We discuss the developmental decline in axon regeneration capacity in the CNS, and comment on how this is paralleled by a similar decline in the selective axonal transport of regeneration-associated receptors such as integrins and growth factor receptors. In the second part, we discuss the mechanisms regulating selective polarized transport within neurons, how these relate to the intrinsic control of axon regeneration, and whether they can be targeted to enhance regenerative capacity. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 00: 000-000, 2018.
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Affiliation(s)
- Veselina Petrova
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 OPY, United Kingdom
| | - Richard Eva
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 OPY, United Kingdom
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20
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Seif M, Ziegler G, Freund P. Progressive Ventricles Enlargement and Cerebrospinal Fluid Volume Increases as a Marker of Neurodegeneration in Patients with Spinal Cord Injury: A Longitudinal Magnetic Resonance Imaging Study. J Neurotrauma 2018; 35:2941-2946. [PMID: 29993326 PMCID: PMC6306675 DOI: 10.1089/neu.2017.5522] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Next to gray and white matter atrophy, cerebrospinal fluid (CSF) volume and ventricular dilation may be surrogate biomarkers for brain atrophy in spinal cord injury (SCI). We therefore aimed to track brain atrophy by means of CSF volume changes and ventricular enlargements over two years after SCI. Fifteen patients with SCI and 18 healthy controls underwent a series of T1-weighted scans during five time points over two years. Changes of CSF/intracranial volume (CSF/ICV) ratio, CSF volume, and ventricular enlargement rate over time were determined. Sample sizes with 80% power and 5% significance were calculated to detect a range of treatment effects for a two-armed trial. There was a significant cross-sectional increased CSF/ICV ratio in patients compared with controls at each time point (p < 0.02). The rate of CSF/ICV changes, however, was not significantly different between groups over time. CSF volume increased linearly over bilateral sensorimotor cortices (left: p = 0.002, right: p = 0.042) and in the supracerebellar space (p < 0.001) within two years. An acceleration of the enlargement within the third (p = 0.017) and the fourth (p = 0.006) ventricles was observed in patients over time. Sample size estimation for six-month trials with CSF volume requires 25 patients per treatment arm to detect a hypothetical treatment effect in terms of slowing of atrophy rate of 30%. This study shows that SCI-induced changes in CSF/ICV ratio and ventricular expansion rate provide additional information on the neurodegenerative processes after injury. The sensitivity to scoring treatment effects speaks to its potential to serve as a sensitive biomarker in addition to local atrophy measures.
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Affiliation(s)
- Maryam Seif
- 1 Spinal Cord Injury Center, University of Zurich, Zurich, Switzerland.,2 Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Gabriel Ziegler
- 3 Dementia Research, Otto-von-Guericke-University, Magdeburg, Germany.,4 German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Patrick Freund
- 1 Spinal Cord Injury Center, University of Zurich, Zurich, Switzerland.,2 Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,5 Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, UCL, London, United Kingdom
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21
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Moon LDF. Chromatolysis: Do injured axons regenerate poorly when ribonucleases attack rough endoplasmic reticulum, ribosomes and RNA? Dev Neurobiol 2018; 78:1011-1024. [PMID: 30027624 PMCID: PMC6334169 DOI: 10.1002/dneu.22625] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/31/2018] [Accepted: 06/04/2018] [Indexed: 02/06/2023]
Abstract
After axonal injury, chromatolysis (fragmentation of Nissl substance) can occur in the soma. Electron microscopy shows that chromatolysis involves fission of the rough endoplasmic reticulum. In CNS neurons (which do not regenerate axons back to their original targets) or in motor neurons or dorsal root ganglion neurons denied axon regeneration (e.g., by transection and ligation), chromatolysis is often accompanied by degranulation (loss of ribosomes from rough endoplasmic reticulum), disaggregation of polyribosomes and degradation of monoribosomes into dust‐like particles. Ribosomes and rough endoplasmic reticulum may also be degraded in autophagic vacuoles by ribophagy and reticulophagy, respectively. In other words, chromatolysis is disruption of parts of the protein synthesis infrastructure. Whereas some neurons may show transient or no chromatolysis, severely injured neurons can remain chromatolytic and never again synthesize normal levels of protein; some may atrophy or die. Ribonuclease(s) might cause the following features of chromatolysis: fragmentation and degranulation of rough endoplasmic reticulum, disaggregation of polyribosomes and degradation of monoribosomes. For example, ribonucleases in the EndoU/PP11 family can modify rough endoplasmic reticulum; many ribonucleases can degrade mRNA causing polyribosomes to unchain and disperse, and they can disassemble monoribosomes; Ribonuclease 5 can control rRNA synthesis and degrade tRNA; Ribonuclease T2 can degrade ribosomes, endoplasmic reticulum and RNA within autophagic vacuoles; and Ribonuclease IRE1α acts as a stress sensor within the endoplasmic reticulum. Regeneration might be improved after axonal injury by protecting the protein synthesis machinery from catabolism; targeting ribonucleases using inhibitors can enhance neurite outgrowth and could be a profitable strategy in vivo. © 2018 Wiley Periodicals, Inc. Develop Neurobiol, 2018
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Affiliation(s)
- Lawrence David Falcon Moon
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, 16-20 Newcomen Street, London, SE1 1UL, United Kingdom
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22
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Minakov AN, Chernov AS, Asutin DS, Konovalov NA, Telegin GB. Experimental Models of Spinal Cord Injury in Laboratory Rats. Acta Naturae 2018; 10:4-10. [PMID: 30397521 PMCID: PMC6209407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Indexed: 11/15/2022] Open
Abstract
Pathologies associated with spinal cord injury are some of the leading diseases in the world. The search for new therapeutic agents and 3D biodegradable materials for the recovery of spinal cord functions is a topical issue. In this review, we have summarized the literature data on the most common experimental models of spinal cord injury in laboratory rats and analyzed the experience of using 3D biodegradable materials (scaffolds) in experimental studies of spinal trauma. The advantages and disadvantages of the described models are systematically analyzed in this review.
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Affiliation(s)
- A. N. Minakov
- Branch of Shemyakin and Ovchinnikov institute of bioorganic chemistry Russian academy of sciences, Prospekt Nauki, 6, Moscow region, Pushchino, 142290, Russia
| | - A. S. Chernov
- Branch of Shemyakin and Ovchinnikov institute of bioorganic chemistry Russian academy of sciences, Prospekt Nauki, 6, Moscow region, Pushchino, 142290, Russia
| | - D. S. Asutin
- Federal State Autonomous Institution «N .N. Burdenko National Scientific and Practical Center for Neurosurgery» of the Ministry of Healthcare of the Russian Federation, 4th Tverskaya-Yamskaya Str., 16, Moscow, 125047, Russia
| | - N. A. Konovalov
- Federal State Autonomous Institution «N .N. Burdenko National Scientific and Practical Center for Neurosurgery» of the Ministry of Healthcare of the Russian Federation, 4th Tverskaya-Yamskaya Str., 16, Moscow, 125047, Russia
| | - G. B. Telegin
- Branch of Shemyakin and Ovchinnikov institute of bioorganic chemistry Russian academy of sciences, Prospekt Nauki, 6, Moscow region, Pushchino, 142290, Russia
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23
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Riemann L, Younsi A, Scherer M, Zheng G, Skutella T, Unterberg AW, Zweckberger K. Transplantation of Neural Precursor Cells Attenuates Chronic Immune Environment in Cervical Spinal Cord Injury. Front Neurol 2018; 9:428. [PMID: 29951030 PMCID: PMC6008566 DOI: 10.3389/fneur.2018.00428] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 05/22/2018] [Indexed: 11/13/2022] Open
Abstract
Inflammation after traumatic spinal cord injury (SCI) is non-resolving and thus still present in chronic injury stages. It plays a key role in the pathophysiology of SCI and has been associated with further neurodegeneration and development of neuropathic pain. Neural precursor cells (NPCs) have been shown to reduce the acute and sub-acute inflammatory response after SCI. In the present study, we examined effects of NPC transplantation on the immune environment in chronic stages of SCI. SCI was induced in rats by clip-compression of the cervical spinal cord at the level C6-C7. NPCs were transplanted 10 days post-injury. The functional outcome was assessed weekly for 8 weeks using the Basso, Beattie, and Bresnahan scale, the CatWalk system, and the grid walk test. Afterwards, the rats were sacrificed, and spinal cord sections were examined for M1/M2 macrophages, T lymphocytes, astrogliosis, and apoptosis using immunofluorescence staining. Rats treated with NPCs had compared to the control group significantly fewer pro-inflammatory M1 macrophages and reduced immunodensity for inducible nitric oxide synthase (iNOS), their marker enzyme. Anti-inflammatory M2 macrophages were rarely present 8 weeks after the SCI. In this model, the sub-acute transplantation of NPCs did not support survival and proliferation of M2 macrophages. Post-traumatic apoptosis, however, was significantly reduced in the NPC group, which might be explained by the altered microenvironment following NPC transplantation. Corresponding to these findings, reactive astrogliosis was significantly reduced in NPC-transplanted animals. Furthermore, we could observe a trend toward smaller cavity sizes and functional improvement following NPC transplantation. Our data suggest that transplantation of NPCs following SCI might attenuate inflammation even in chronic injury stages. This might prevent further neurodegeneration and could also set a stage for improved neuroregeneration after SCI.
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Affiliation(s)
- Lennart Riemann
- Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander Younsi
- Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Moritz Scherer
- Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Guoli Zheng
- Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Thomas Skutella
- Department of Neuroanatomy, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Andreas W Unterberg
- Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Klaus Zweckberger
- Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
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24
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Zhang G, Hu J, Rodemer W, Li S, Selzer ME. RhoA activation in axotomy-induced neuronal death. Exp Neurol 2018; 306:76-91. [PMID: 29715475 DOI: 10.1016/j.expneurol.2018.04.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 04/18/2018] [Accepted: 04/27/2018] [Indexed: 01/11/2023]
Abstract
After spinal cord injury (SCI) in mammals, severed axons fail to regenerate, due to both extrinsic inhibitory factors, e.g., the chondroitin sulfate proteoglycans (CSPGs) and myelin-associated growth inhibitors (MAIs), and a developmental loss of intrinsic growth capacity. The latter is suggested by findings in lamprey that the 18 pairs of individually identified reticulospinal neurons vary greatly in their ability to regenerate their axons through the same spinal cord environment. Moreover, those neurons that are poor regenerators undergo very delayed apoptosis, and express common molecular markers after SCI. Thus the signaling pathways for retrograde cell death might converge with those inhibiting axon regeneration. Many extrinsic growth-inhibitory molecules activate RhoA, whereas inhibiting RhoA enhances axon growth. Whether RhoA also is involved in retrograde neuronal death after axotomy is less clear. Therefore, we cloned lamprey RhoA and correlated its mRNA expression and activation state with apoptosis signaling in identified reticulospinal neurons. RhoA mRNA was expressed widely in normal lamprey brain, and only slightly more in poorly-regenerating neurons than in good regenerators. However, within a day after spinal cord transection, RhoA mRNA was found in severed axon tips. Beginning at 5 days post-SCI RhoA mRNA was upregulated selectively in pre-apoptotic neuronal perikarya, as indicated by labelling with fluorescently labeled inhibitors of caspase activation (FLICA). After 2 weeks post-transection, RhoA expression decreased in the perikarya, and was translocated anterogradely into the axons. More striking than changes in RhoA mRNA levels, RhoA was continuously active selectively in FLICA-positive neurons through 9 weeks post-SCI. At that time, almost no neurons whose axons had regenerated were FLICA-positive. These findings are consistent with a role for RhoA activation in triggering retrograde neuronal death after SCI, and suggest that RhoA may be a point of convergence for inhibition of both axon regeneration and neuronal survival after axotomy.
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Affiliation(s)
- Guixin Zhang
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), USA
| | - Jianli Hu
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), USA
| | - William Rodemer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), USA; Dept. Anatomy and Cell Biology, The Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Philadelphia, PA 19140, USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), USA; Dept. of Neurology, USA.
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25
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Huang Y, Jiang Y, Wu Q, Wu X, An X, Chubykin AA, Cheng JX, Xu XM, Yang C. Nanoladders Facilitate Directional Axonal Outgrowth and Regeneration. ACS Biomater Sci Eng 2018; 4:1037-1045. [DOI: 10.1021/acsbiomaterials.7b00981] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Yimin Huang
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Ying Jiang
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, Massachusetts 02215, United States
| | - Qiuyu Wu
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, Indiana 47907, United States
| | - Xiangbing Wu
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, Indiana 46202, United States
| | - Xingda An
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Alexander A. Chubykin
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, Indiana 47907, United States
| | - Ji-Xin Cheng
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
- Department of Electrical and Computer Engineering, Boston University, 8 St Mary’s Street, Boston, Massachusetts 02215, United States
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, Massachusetts 02215, United States
| | - Xiao-Ming Xu
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, Indiana 46202, United States
| | - Chen Yang
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
- Department of Electrical and Computer Engineering, Boston University, 8 St Mary’s Street, Boston, Massachusetts 02215, United States
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26
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Warren PM, Tran AP, Silver J. Perspectives on "the biology of spinal cord regeneration success and failure". Neural Regen Res 2018; 13:1358-1359. [PMID: 30106043 PMCID: PMC6108194 DOI: 10.4103/1673-5374.235226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
| | - Amanda Phuong Tran
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, USA
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27
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Hilton BJ, Bradke F. Can injured adult CNS axons regenerate by recapitulating development? Development 2017; 144:3417-3429. [PMID: 28974639 DOI: 10.1242/dev.148312] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In the adult mammalian central nervous system (CNS), neurons typically fail to regenerate their axons after injury. During development, by contrast, neurons extend axons effectively. A variety of intracellular mechanisms mediate this difference, including changes in gene expression, the ability to form a growth cone, differences in mitochondrial function/axonal transport and the efficacy of synaptic transmission. In turn, these intracellular processes are linked to extracellular differences between the developing and adult CNS. During development, the extracellular environment directs axon growth and circuit formation. In adulthood, by contrast, extracellular factors, such as myelin and the extracellular matrix, restrict axon growth. Here, we discuss whether the reactivation of developmental processes can elicit axon regeneration in the injured CNS.
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Affiliation(s)
- Brett J Hilton
- Laboratory for Axon Growth and Regeneration, German Centre for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Frank Bradke
- Laboratory for Axon Growth and Regeneration, German Centre for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
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28
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Ahuja CS, Nori S, Tetreault L, Wilson J, Kwon B, Harrop J, Choi D, Fehlings MG. Traumatic Spinal Cord Injury-Repair and Regeneration. Neurosurgery 2017; 80:S9-S22. [PMID: 28350947 DOI: 10.1093/neuros/nyw080] [Citation(s) in RCA: 510] [Impact Index Per Article: 72.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 01/12/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Traumatic spinal cord injuries (SCI) have devastating consequences for the physical, financial, and psychosocial well-being of patients and their caregivers. Expediently delivering interventions during the early postinjury period can have a tremendous impact on long-term functional recovery. PATHOPHYSIOLOGY This is largely due to the unique pathophysiology of SCI where the initial traumatic insult (primary injury) is followed by a progressive secondary injury cascade characterized by ischemia, proapoptotic signaling, and peripheral inflammatory cell infiltration. Over the subsequent hours, release of proinflammatory cytokines and cytotoxic debris (DNA, ATP, reactive oxygen species) cyclically adds to the harsh postinjury microenvironment. As the lesions mature into the chronic phase, regeneration is severely impeded by the development of an astroglial-fibrous scar surrounding coalesced cystic cavities. Addressing these challenges forms the basis of current and upcoming treatments for SCI. MANAGEMENT This paper discusses the evidence-based management of a patient with SCI while emphasizing the importance of early definitive care. Key neuroprotective therapies are summarized including surgical decompression, methylprednisolone, and blood pressure augmentation. We then review exciting neuroprotective interventions on the cusp of translation such as Riluzole, Minocycline, magnesium, therapeutic hypothermia, and CSF drainage. We also explore the most promising neuroregenerative strategies in trial today including Cethrin™, anti-NOGO antibody, cell-based approaches, and bioengineered biomaterials. Each section provides a working knowledge of the key preclinical and patient trials relevant to clinicians while highlighting the pathophysiologic rationale for the therapies. CONCLUSION We conclude with our perspectives on the future of treatment and research in this rapidly evolving field.
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Affiliation(s)
- Christopher S Ahuja
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada.,Department of Surgery, University of Toronto, Toronto, Canada.,Department of Genetics and Development, University of Toronto, Toronto, Canada
| | - Satoshi Nori
- Department of Genetics and Development, University of Toronto, Toronto, Canada
| | | | - Jefferson Wilson
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada.,Department of Surgery, University of Toronto, Toronto, Canada.,Spine Program, University of Toronto, Toronto, Canada
| | - Brian Kwon
- Vancouver Spine Institute, Vancouver General Hospital, Vancouver, Canada.,Department of Surgery, University of British Columbia, Vancouver, Canada
| | - James Harrop
- Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
| | - David Choi
- National Hospital for Neurology and Neurosurgery, University College London, London, England
| | - Michael G Fehlings
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada.,Department of Surgery, University of Toronto, Toronto, Canada.,Spine Program, University of Toronto, Toronto, Canada.,Department of Genetics and Development, University of Toronto, Toronto, Canada
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29
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Nori S, Ahuja CS, Fehlings MG. Translational Advances in the Management of Acute Spinal Cord Injury: What is New? What is Hot? Neurosurgery 2017; 64:119-128. [DOI: 10.1093/neuros/nyx217] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 04/04/2017] [Indexed: 01/10/2023] Open
Affiliation(s)
- Satoshi Nori
- Department of Genetics and Develop-ment, University of Toronto, Toronto, Canada
| | - Christopher S. Ahuja
- Department of Genetics and Develop-ment, University of Toronto, Toronto, Canada
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
- Department of Surgery, University of Toronto, Toronto, Canada
| | - Michael G. Fehlings
- Department of Genetics and Develop-ment, University of Toronto, Toronto, Canada
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
- Department of Surgery, University of Toronto, Toronto, Canada
- Spine Program, University of Toronto, Toronto, Canada
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30
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Maclean FL, Wang Y, Walker R, Horne MK, Williams RJ, Nisbet DR. Reducing Astrocytic Scarring after Traumatic Brain Injury with a Multifaceted Anti-Inflammatory Hydrogel System. ACS Biomater Sci Eng 2017; 3:2542-2549. [DOI: 10.1021/acsbiomaterials.7b00524] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Francesca L. Maclean
- Laboratory
of Advanced Biomaterials, Research School of Engineering, The Australian National University, Canberra, Australia
| | - Yi Wang
- Laboratory
of Advanced Biomaterials, Research School of Engineering, The Australian National University, Canberra, Australia
| | - Rohan Walker
- School
of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, Australia
- Centre
for Brain and Mental Health Research, Hunter Medical Research Institute, New
Lambton Heights, Australia
| | - Malcolm K. Horne
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Australia
- Department
of Medicine, University of Melbourne, St. Vincent’s Hospital, Fitzroy, Australia
| | - Richard J. Williams
- School of
Engineering, RMIT University, Melbourne, Australia
- BioFab3D, St. Vincent’s Hospital, Fitzroy, Australia
| | - David R. Nisbet
- Laboratory
of Advanced Biomaterials, Research School of Engineering, The Australian National University, Canberra, Australia
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31
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Wang N, Xiao Z, Zhao Y, Wang B, Li X, Li J, Dai J. Collagen scaffold combined with human umbilical cord‐derived mesenchymal stem cells promote functional recovery after scar resection in rats with chronic spinal cord injury. J Tissue Eng Regen Med 2017; 12:e1154-e1163. [DOI: 10.1002/term.2450] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 01/17/2017] [Accepted: 05/04/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Nuo Wang
- Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental Biology, Chinese Academy of Sciences Beijing China
| | - Zhifeng Xiao
- Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental Biology, Chinese Academy of Sciences Beijing China
| | - Yannan Zhao
- Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental Biology, Chinese Academy of Sciences Beijing China
| | - Bin Wang
- Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental Biology, Chinese Academy of Sciences Beijing China
| | - Xing Li
- Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental Biology, Chinese Academy of Sciences Beijing China
| | - Jing Li
- Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental Biology, Chinese Academy of Sciences Beijing China
| | - Jianwu Dai
- Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental Biology, Chinese Academy of Sciences Beijing China
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32
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Yungher BJ, Ribeiro M, Park KK. Regenerative Responses and Axon Pathfinding of Retinal Ganglion Cells in Chronically Injured Mice. Invest Ophthalmol Vis Sci 2017; 58:1743-1750. [PMID: 28324115 PMCID: PMC5361588 DOI: 10.1167/iovs.16-19873] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose Enhanced regeneration of retinal ganglion cell (RGC) axons can be achieved by modification of numerous neuronal-intrinsic factors. However, axon growth initiation and the pathfinding behavior of these axons after traumatic injury remain poorly understood outside of acute injury paradigms, despite the clinical relevance of more chronic settings. We therefore examined RGC axon regeneration following therapeutic delivery that is postponed until 2 months after optic nerve crush injury. Methods Optic nerve regeneration was induced by virally mediated (adeno-associated virus) ciliary neurotrophic factor (AAV-CNTF) administered either immediately or 56 days after optic nerve crush in wild-type or Bax knockout (KO) mice. Retinal ganglion nerve axon regeneration was assessed 21 and 56 days after viral injection. Immunohistochemical analysis of RGC injury signals and extrinsic factors in the optic nerve were also examined at 5 and 56 days post crush. Results In addition to sustained expression of injury response proteins in surviving RGCs, we observe axon regrowth in wild-type and apoptosis-deficient Bax KO mice following AAV-CNTF treatment. Fewer instances of aberrant axon growth are seen, at least in the area near the lesion site, in animals given treatment 56 days after crush injury compared to the animals given treatment immediately after injury. We also find evidence of long distance growth into a visual target in Bax KO mice despite postponed initiation of this regenerative program. Conclusions These studies provide evidence against an intrinsic critical period for RGC axon regeneration or degradation of injury signals. Regeneration results from Bax KO mice imply highly sustained regenerative capacity in RGCs, highlighting the importance of long-lasting neuroprotective strategies as well as of RGC axon guidance research in chronically injured animals.
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Affiliation(s)
- Benjamin J Yungher
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Márcio Ribeiro
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Kevin K Park
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States
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33
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Hilton BJ, Moulson AJ, Tetzlaff W. Neuroprotection and secondary damage following spinal cord injury: concepts and methods. Neurosci Lett 2017; 652:3-10. [DOI: 10.1016/j.neulet.2016.12.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/28/2016] [Accepted: 12/02/2016] [Indexed: 01/29/2023]
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34
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Relationship between brainstem neurodegeneration and clinical impairment in traumatic spinal cord injury. NEUROIMAGE-CLINICAL 2017. [PMID: 28649492 PMCID: PMC5470571 DOI: 10.1016/j.nicl.2017.05.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Background Brainstem networks are pivotal in sensory and motor function and in recovery following experimental spinal cord injury (SCI). Objective To quantify neurodegeneration and its relation to clinical impairment in major brainstem pathways and nuclei in traumatic SCI. Methods Quantitative MRI data of 30 chronic traumatic SCI patients (15 with tetraplegia and 15 with paraplegia) and 23 controls were acquired. Patients underwent a full neurological examination. We calculated quantitative myelin-sensitive (magnetisation transfer saturation (MT) and longitudinal relaxation rate (R1)) and iron-sensitive (effective transverse relaxation rate (R2*)) maps. We constructed brainstem tissue templates using a multivariate Gaussian mixture model and assessed volume loss, myelin reductions, and iron accumulation across the brainstem pathways (e.g. corticospinal tracts (CSTs) and medial lemniscus), and nuclei (e.g. red nucleus and periaqueductal grey (PAG)). The relationship between structural changes and clinical impairment were assessed using regression analysis. Results Volume loss was detected in the CSTs and in the medial lemniscus. Myelin-sensitive MT and R1 were reduced in the PAG, the CSTs, the dorsal medulla and pons. No iron-sensitive changes in R2* were detected. Lower pinprick score related to more myelin reductions in the PAG, whereas lower functional independence was related to more myelin reductions in the vestibular and pontine nuclei. Conclusion Neurodegeneration, indicated by volume loss and myelin reductions, is evident in major brainstem pathways and nuclei following traumatic SCI; the magnitude of these changes relating to clinical impairment. Thus, quantitative MRI protocols offer new targets, which may be used as neuroimaging biomarkers in treatment trials. Quantitative MRI revealed in-vivo brainstem neurodegeneration in SCI patients. Atrophy was evident in major sensorimotor brainstem pathways. The magnitude of myelin reduction in brainstem nuclei related to clinical disability
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35
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Hodgetts SI, Harvey AR. Neurotrophic Factors Used to Treat Spinal Cord Injury. VITAMINS AND HORMONES 2016; 104:405-457. [PMID: 28215303 DOI: 10.1016/bs.vh.2016.11.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The application of neurotrophic factors as a therapy to improve morphological and behavioral outcomes after experimental spinal cord injury (SCI) has been the focus of many studies. These studies vary markedly in the type of neurotrophic factor that is delivered, the mode of administration, and the location, timing, and duration of the treatment. Generally, the majority of studies have had significant success if neurotrophic factors are applied in or close to the lesion site during the acute or the subacute phase after SCI. Comparatively fewer studies have administered neurotrophic factors in order to directly target the somata of injured neurons. The mode of delivery varies between acute injection of recombinant proteins, subacute or chronic delivery using a variety of strategies including osmotic minipumps, cell-mediated delivery, delivery using polymer release vehicles or supporting bridges of some sort, or the use of gene therapy to modify neurons, glial cells, or precursor/stem cells. In this brief review, we summarize the state of play of many of the therapies using these factors, most of which have been undertaken in rodent models of SCI.
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Affiliation(s)
- S I Hodgetts
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, WA, Australia; Western Australian Neuroscience Research Institute, Perth, WA, Australia.
| | - A R Harvey
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, WA, Australia; Western Australian Neuroscience Research Institute, Perth, WA, Australia
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36
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Batty NJ, Fenrich KK, Fouad K. The role of cAMP and its downstream targets in neurite growth in the adult nervous system. Neurosci Lett 2016; 652:56-63. [PMID: 27989572 DOI: 10.1016/j.neulet.2016.12.033] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 12/13/2016] [Accepted: 12/14/2016] [Indexed: 01/23/2023]
Abstract
Injured neurons in the adult mammalian central nervous system (CNS) have a very limited capacity for axonal regeneration and neurite outgrowth. This inability to grow new axons or to regrow injured axons is due to the presence of molecules that inhibit axonal growth, and age related changes in the neuron's innate growth capabilities. Available levels of cAMP are thought to have an important role in linking both of these factors. Elevated levels of cAMP in the developing nervous system are important for the guidance and stability of growth cones. As the nervous system matures, cAMP levels decline and the growth promoting effects of cAMP diminish. It has frequently been demonstrated that increasing neuronal cAMP can enhance neurite growth and regeneration. Some methods used to increase cAMP include administration of cAMP agonists, conditioning lesions, or electrical stimulation. Furthermore, it has been proposed that multiple stages of cAMP induced growth exist, one directly caused by its downstream effector Protein Kinase A (PKA) and one caused by the eventual upregulation of gene transcription. Although the role cAMP in promoting axon growth is well accepted, the downstream pathways that mediate cAMP-mediated axonal growth are less clear. This is partly because various key studies that explored the link between PKA and axonal outgrowth relied on the PKA inhibitors KT5720 and H89. More recent studies have shown that both of these drugs are less specific than initially thought and can inhibit a number of other signalling molecules including the Exchange Protein Activated by cAMP (EPAC). Consequently, it has recently been shown that a number of intracellular signalling pathways previously attributed to PKA can now be attributed solely to activation of EPAC specific pathways, or the simultaneous co-activation of PKA and EPAC specific pathways. These new studies open the door to new potential treatments for repairing the injured spinal cord.
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Affiliation(s)
- Nicholas J Batty
- Neuroscience and Mental Health Institute, 3-88 Corbett Hall, University of Alberta, Edmonton, AB T6E 2G4, Canada
| | - Keith K Fenrich
- Neuroscience and Mental Health Institute, 3-88 Corbett Hall, University of Alberta, Edmonton, AB T6E 2G4, Canada; Department of Physical Therapy, 3-88 Corbett Hall, University of Alberta, Edmonton, AB T6E 2G4, Canada
| | - Karim Fouad
- Neuroscience and Mental Health Institute, 3-88 Corbett Hall, University of Alberta, Edmonton, AB T6E 2G4, Canada; Department of Physical Therapy, 3-88 Corbett Hall, University of Alberta, Edmonton, AB T6E 2G4, Canada.
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Hu J, Zhang G, Rodemer W, Jin LQ, Shifman M, Selzer ME. The role of RhoA in retrograde neuronal death and axon regeneration after spinal cord injury. Neurobiol Dis 2016; 98:25-35. [PMID: 27888137 DOI: 10.1016/j.nbd.2016.11.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 10/24/2016] [Accepted: 11/20/2016] [Indexed: 01/13/2023] Open
Abstract
Paralysis following spinal cord injury (SCI) is due to interruption of axons and their failure to regenerate. It has been suggested that the small GTPase RhoA may be an intracellular signaling convergence point for several types of growth-inhibiting extracellular molecules. Even if this is true in vitro, it is not clear from studies in mammalian SCI, whether the effects of RhoA manipulations on axon growth in vivo are due to a RhoA-mediated inhibition of true regeneration or only of collateral sprouting from spared axons, since work on SCI generally is performed with partial injury models. RhoA also has been implicated in local neuronal apoptosis after SCI, but whether this reflects an effect on axotomy-induced cell death or an effect on other pathological mechanisms is not known. In order to resolve these ambiguities, we studied the effects of RhoA knockdown in the sea lamprey central nervous system (CNS), where after complete spinal cord transection (TX), robust but incomplete regeneration of large axons belonging to individually identified reticulospinal (RS) neurons occurs, and where some RS neurons show unambiguous delayed retrograde apoptosis after axotomy. RhoA protein was detected in neurons and axons of the lamprey brain and spinal cord, and its expression was increased post-TX. Knockdown of RhoA in vivo by retrogradely-delivered morpholino antisense oligonucleotides (MOs) to the RS neurons significantly reduced retrograde apoptosis signaling in identified RS neurons post-SCI, as indicated by Fluorochrome Labeled Inhibitor of Caspases (FLICA) in brain wholemounts. In individual RS neurons, the reduction of caspase activation by RhoA knockdown began at 2weeks post-TX and was still seen at 8weeks. RhoA knockdown slowed axon retraction and possibly increased early axon regeneration in the proximal stump. The number of axons regenerating beyond the lesion more than 5mm at 10weeks post-TX also was increased. Thus RhoA knockdown both enhanced true axon regeneration and inhibited retrograde apoptosis signaling after SCI.
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Affiliation(s)
- Jianli Hu
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Philadelphia, PA 19140, USA
| | - Guixin Zhang
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Philadelphia, PA 19140, USA
| | - William Rodemer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Philadelphia, PA 19140, USA
| | - Li-Qing Jin
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Philadelphia, PA 19140, USA
| | - Michael Shifman
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Philadelphia, PA 19140, USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Philadelphia, PA 19140, USA; Dept. of Neurology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Philadelphia, PA 19140, USA.
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Nothias JM, Mitsui T, Shumsky JS, Fischer I, Antonacci MD, Murray M. Combined Effects of Neurotrophin Secreting Transplants, Exercise, and Serotonergic Drug Challenge Improve Function in Spinal Rats. Neurorehabil Neural Repair 2016; 19:296-312. [PMID: 16263962 DOI: 10.1177/1545968305281209] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objectives. To determine the effects of neurotrophin-secreting transplants combined with exercise and serotonergic drug challenges on recovery of hindlimb function in rats with midthoracic spinal cord transection injuries. Methods. Spinalized animals received transplants of fibroblasts genetically modified to express brain-derived neurotrophic factor and neurotrophin-3 and daily cycling exercise. Hindlimb movement in an open-field test (BBB) was scored weekly. Serotonin agonists were used monthly to further stimulate motor function. Axonal growth was quantified in the transplant and at L5 using immunocytochemical markers. Weights of hindlimb muscles were used to assess muscle atrophy. Results. Neurotrophin-secreting transplants stimulated axonal growth, and cycling prevented muscle atrophy, but individual treatments did not improve motor scores. Combined treatments resulted in improvements in motor function. Serotonergic agonists further improved function in all groups, and transplant groups with exercise achieved weight-supporting levels following drug treatment. Conclusion. Combined treatments, but not individual treatments, improved hindlimb function.
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Affiliation(s)
- J-M Nothias
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
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Abstract
Several studies have shown that minocycline, a semisynthetic, second-generation tetracycline derivative, is neuroprotective in animal models of central nervous system trauma and several neurodegenerative diseases. Common to all these reports are the beneficial effects of minocycline in reducing neural inflammation and preventing cell death. Here, the authors review the proposed mechanisms of action of minocycline and suggest that minocycline may inhibit several aspects of the inflammatory response and prevent cell death through the inhibition of the p38 mitogen-activated protein kinase pathway, an important regulator of immune cell function and cell death.
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Affiliation(s)
- David P Stirling
- ICORD (International Collaboration On Repair Discoveries), University of British Columbia, Vancouver, BC, Canada
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Moorjani S. Miniaturized Technologies for Enhancement of Motor Plasticity. Front Bioeng Biotechnol 2016; 4:30. [PMID: 27148525 PMCID: PMC4834582 DOI: 10.3389/fbioe.2016.00030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 03/21/2016] [Indexed: 11/13/2022] Open
Abstract
The idea that the damaged brain can functionally reorganize itself – so when one part fails, there lies the possibility for another to substitute – is an exciting discovery of the twentieth century. We now know that motor circuits once presumed to be hardwired are not, and motor-skill learning, exercise, and even mental rehearsal of motor tasks can turn genes on or off to shape brain architecture, function, and, consequently, behavior. This is a very significant alteration from our previously static view of the brain and has profound implications for the rescue of function after a motor injury. Presentation of the right cues, applied in relevant spatiotemporal geometries, is required to awaken the dormant plastic forces essential for repair. The focus of this review is to highlight some of the recent progress in neural interfaces designed to harness motor plasticity, and the role of miniaturization in development of strategies that engage diverse elements of the neuronal machinery to synergistically facilitate recovery of function after motor damage.
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Affiliation(s)
- Samira Moorjani
- Department of Physiology and Biophysics, and the Washington National Primate Research Center, University of Washington , Seattle, WA , USA
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41
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He Z, Jin Y. Intrinsic Control of Axon Regeneration. Neuron 2016; 90:437-51. [DOI: 10.1016/j.neuron.2016.04.022] [Citation(s) in RCA: 337] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/10/2016] [Accepted: 04/13/2016] [Indexed: 01/12/2023]
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Li H, Ham TR, Neill N, Farrag M, Mohrman AE, Koenig AM, Leipzig ND. A Hydrogel Bridge Incorporating Immobilized Growth Factors and Neural Stem/Progenitor Cells to Treat Spinal Cord Injury. Adv Healthc Mater 2016; 5:802-12. [PMID: 26913590 DOI: 10.1002/adhm.201500810] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/20/2015] [Indexed: 01/06/2023]
Abstract
Spinal cord injury (SCI) causes permanent, often complete disruption of central nervous system (CNS) function below the damaged region, leaving patients without the ability to regenerate lost tissue. To engineer new CNS tissue, a unique spinal cord bridge is created to deliver stem cells and guide their organization and development with site-specifically immobilized growth factors. In this study, this bridge is tested, consisting of adult neural stem/progenitor cells contained within a methacrylamide chitosan (MAC) hydrogel and protected by a chitosan conduit. Interferon-γ (IFN-γ) and platelet-derived growth factor-AA (PDGF-AA) are recombinantly produced and tagged with an N-terminal biotin. They are immobilized to streptavidin-functionalized MAC to induce either neuronal or oligodendrocytic lineages, respectively. These bridges are tested in a rat hemisection model of SCI between T8 and T9. After eight weeks treatments including chitosan conduits result in a significant reduction in lesion area and macrophage infiltration around the lesion site (p < 0.0001). Importantly, neither immobilized IFN-γ nor PDGF-AA increased macrophage infiltration. Retrograde tracing demonstrates improved neuronal regeneration through the use of immobilized growth factors. Immunohistochemistry staining demonstrates that immobilized growth factors are effective in differentiating encapsulated cells into their anticipated lineages within the hydrogel, while qualitatively reducing glial fibrillary acid protein expression.
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Affiliation(s)
- Hang Li
- Department of Chemical and Biomolecular Engineering; The University of Akron; Whitby Hall 211 Akron OH 44325 USA
| | - Trevor R. Ham
- Department of Biomedical Engineering; The University of Akron; Auburn Science and Engineering Center; 275 West Tower Akron OH 44325 USA
| | - Nicholas Neill
- Department of Chemical and Biomolecular Engineering; The University of Akron; Whitby Hall 211 Akron OH 44325 USA
| | - Mahmoud Farrag
- Department of Biology; The University of Akron; Auburn Science and Engineering Center D401; Akron OH 44325 USA
| | - Ashley E. Mohrman
- Department of Chemical and Biomolecular Engineering; The University of Akron; Whitby Hall 211 Akron OH 44325 USA
| | - Andrew M. Koenig
- Department of Chemical and Biomolecular Engineering; The University of Akron; Whitby Hall 211 Akron OH 44325 USA
| | - Nic D. Leipzig
- Department of Chemical and Biomolecular Engineering; The University of Akron; Whitby Hall 211 Akron OH 44325 USA
- Department of Biomedical Engineering; The University of Akron; Auburn Science and Engineering Center; 275 West Tower Akron OH 44325 USA
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Hou J, Xiang Z, Yan R, Zhao M, Wu Y, Zhong J, Guo L, Li H, Wang J, Wu J, Sun T, Liu H. Motor recovery at 6 months after admission is related to structural and functional reorganization of the spine and brain in patients with spinal cord injury. Hum Brain Mapp 2016; 37:2195-209. [PMID: 26936834 DOI: 10.1002/hbm.23163] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 01/25/2016] [Accepted: 02/19/2016] [Indexed: 12/19/2022] Open
Abstract
This study aimed to explore structural and functional reorganization of the brain in the early stages of spinal cord injury (SCI) and identify brain areas that contribute to motor recovery. We studied 25 patients with SCI, including 10 with good motor recovery and 15 with poor motor recovery, along with 25 matched healthy controls. The mean period post-SCI was 9.2 ± 3.5 weeks in good recoverers and 8.8 ± 2.6 weeks in poor recoverers. All participants underwent structural and functional MRI on a 3-T magnetic resonance system. We evaluated differences in cross-sectional spinal cord area at the C2/C3 level, brain cortical thickness, white matter microstructure, and functional connectivity during the resting state among the three groups. We also evaluated associations between structural and functional reorganization and the rate of motor recovery. After SCI, compared with good recoverers, poor recoverers had a significantly decreased cross-sectional spinal cord area, cortical thickness in the right supplementary motor area and premotor cortex, and fractional anisotropy (FA) in the right primary motor cortex and posterior limb of the internal capsule. Meanwhile, poor recoverers showed decreased functional connectivity between the primary motor cortex and higher order motor areas (supplementary motor area and premotor cortex), while good recoverers showed increased functional connectivity among these regions. The structural and functional reorganization of the spine and brain was associated with motor recovery rate in all SCI patients. In conclusion, structural and functional reorganization of the spine and brain directly affected the motor recovery of SCI. Less structural atrophy and enhanced functional connectivity are associated with good motor recovery in patients with SCI. Multimodal imaging has the potential to predict motor recovery in the early stage of SCI. Hum Brain Mapp 37:2195-2209, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Jingming Hou
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Zimin Xiang
- Department of Orthopedics, Chinese PLA Beijing Army General Hospital, Beijing, China.,Department of Orthopedics, Fuzhou General Hospital, Nanjing Military Command, Fuzhou, China
| | - Rubing Yan
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Ming Zhao
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Yongtao Wu
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jianfeng Zhong
- Department of Orthopedics, Chinese PLA Beijing Army General Hospital, Beijing, China
| | - Lei Guo
- Department of Orthopedics, Chinese PLA Beijing Army General Hospital, Beijing, China
| | - Haitao Li
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jian Wang
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jixiang Wu
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Tiansheng Sun
- Department of Orthopedics, Chinese PLA Beijing Army General Hospital, Beijing, China
| | - Hongliang Liu
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University, Chongqing, China
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Butenschön J, Zimmermann T, Schmarowski N, Nitsch R, Fackelmeier B, Friedemann K, Radyushkin K, Baumgart J, Lutz B, Leschik J. PSA-NCAM positive neural progenitors stably expressing BDNF promote functional recovery in a mouse model of spinal cord injury. Stem Cell Res Ther 2016; 7:11. [PMID: 26762640 PMCID: PMC4712602 DOI: 10.1186/s13287-015-0268-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/07/2015] [Accepted: 12/18/2015] [Indexed: 12/13/2022] Open
Abstract
Background Neural stem cells for the treatment of spinal cord injury (SCI) are of particular interest for future therapeutic use. However, until now, stem cell therapies are often limited due to the inhibitory environment following the injury. Therefore, in this study, we aimed at testing a combinatorial approach with BDNF (brain-derived neurotrophic factor) overexpressing early neural progenitors derived from mouse embryonic stem cells. BDNF is a neurotrophin, which both facilitates neural differentiation of stem cells and favors regeneration of damaged axons. Methods Mouse embryonic stem cells, modified to stably express BDNF-GFP, were differentiated into PSA-NCAM positive progenitors, which were enriched, and SSEA1 depleted by a sequential procedure of magnetic-activated and fluorescence-activated cell sorting. Purified cells were injected into the lesion core seven days after contusion injury of the spinal cord in mice, and the Basso mouse scale (BMS) test to evaluate motor function was performed for 5 weeks after transplantation. To analyze axonal regeneration the anterograde tracer biotinylated dextran amine was injected into the sensorimotor cortex two weeks prior to tissue analysis. Cellular differentiation was analyzed by immunohistochemistry of spinal cord sections. Results Motor function was significantly improved in animals obtaining transplanted BDNF-GFP-overexpressing cells as compared to GFP-expressing cells and vehicle controls. Stem cell differentiation in vivo revealed an increase of neuronal and oligodendrocytic lineage differentiation by BDNF as evaluated by immunohistochemistry of the neuronal marker MAP2 (microtubule associated protein 2) and the oligodendrocytic markers ASPA (aspartoacylase) and Olig2 (oligodendrocyte transcription factor 2). Furthermore, axonal tracing showed a significant increase of biotin dextran amine positive corticospinal tract fibers in BDNF-GFP-cell transplanted animals caudally to the lesion site. Conclusions The combinatorial therapy approach by transplanting BDNF-overexpressing neural progenitors improved motor function in a mouse contusion model of SCI. Histologically, we observed enhanced neuronal and oligodendrocytic differentiation of progenitors as well as enhanced axonal regeneration. Electronic supplementary material The online version of this article (doi:10.1186/s13287-015-0268-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jennifer Butenschön
- Institute of Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
| | - Tina Zimmermann
- Institute of Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
| | - Nikolai Schmarowski
- Institute of Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Robert Nitsch
- Institute of Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Barbara Fackelmeier
- Institute of Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
| | - Kevin Friedemann
- Institute of Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany. .,Institute of Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg University, Langenbeckstrasse 1, 55131, Mainz, Germany. .,Mouse Behavior Outcome Unit, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University, Hanns-Dieter-Hüsch-Weg 19, 55128, Mainz, Germany.
| | - Konstantin Radyushkin
- Mouse Behavior Outcome Unit, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University, Hanns-Dieter-Hüsch-Weg 19, 55128, Mainz, Germany.
| | - Jan Baumgart
- Institute of Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg University, Langenbeckstrasse 1, 55131, Mainz, Germany. .,Translational Animal Research Center (TARC), University Medical Center, Johannes Gutenberg University, Hanns-Dieter-Hüsch-Weg 19, 55128, Mainz, Germany.
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
| | - Julia Leschik
- Institute of Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
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Goganau I, Blesch A. Gene Therapy for Spinal Cord Injury. Transl Neurosci 2016. [DOI: 10.1007/978-1-4899-7654-3_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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46
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Intrinsic Neuronal Mechanisms in Axon Regeneration After Spinal Cord Injury. Transl Neurosci 2016. [DOI: 10.1007/978-1-4899-7654-3_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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47
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Gordon T, Tetzlaff W. Regeneration-associated genes decline in chronically injured rat sciatic motoneurons. Eur J Neurosci 2015; 42:2783-91. [DOI: 10.1111/ejn.13070] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 09/09/2015] [Accepted: 09/10/2015] [Indexed: 02/02/2023]
Affiliation(s)
- Tessa Gordon
- Neuroscience and Mental Health Institute; Faculty of Medicine and Dentistry; University of Alberta; Edmonton AB T6G 2S2 Canada
- Department of Surgery; Division of Plastic Reconstructive Surgery; 5549A The Hospital for Sick Children; 555 University Avenue Toronto ON M5G 1X8 Canada
| | - Wolfram Tetzlaff
- ICORD (International Collaboration on Repair Discoveries); Blusson Spinal Cord Centre; 818 W. 10th Avenue Vancouver BC V5Z 1M9 Canada
- Departments of Zoology and Surgery; University of British Columbia; Vancouver BC Canada
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48
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Siebert JR, Eade AM, Osterhout DJ. Biomaterial Approaches to Enhancing Neurorestoration after Spinal Cord Injury: Strategies for Overcoming Inherent Biological Obstacles. BIOMED RESEARCH INTERNATIONAL 2015; 2015:752572. [PMID: 26491685 PMCID: PMC4600545 DOI: 10.1155/2015/752572] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/22/2015] [Indexed: 01/14/2023]
Abstract
While advances in technology and medicine have improved both longevity and quality of life in patients living with a spinal cord injury, restoration of full motor function is not often achieved. This is due to the failure of repair and regeneration of neuronal connections in the spinal cord after injury. In this review, the complicated nature of spinal cord injury is described, noting the numerous cellular and molecular events that occur in the central nervous system following a traumatic lesion. In short, postinjury tissue changes create a complex and dynamic environment that is highly inhibitory to the process of neural regeneration. Strategies for repair are outlined with a particular focus on the important role of biomaterials in designing a therapeutic treatment that can overcome this inhibitory environment. The importance of considering the inherent biological response of the central nervous system to both injury and subsequent therapeutic interventions is highlighted as a key consideration for all attempts at improving functional recovery.
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Affiliation(s)
- Justin R. Siebert
- Lake Erie College of Osteopathic Medicine at Seton Hill, Greensburg, PA 15601, USA
| | - Amber M. Eade
- Lake Erie College of Osteopathic Medicine at Seton Hill, Greensburg, PA 15601, USA
| | - Donna J. Osterhout
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
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49
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Abstract
UNLABELLED Chronic spinal cord injury (SCI) is a formidable hurdle that prevents a large number of injured axons from crossing the lesion, particularly the corticospinal tract (CST). This study shows that Pten deletion in the adult mouse cortex enhances compensatory sprouting of uninjured CST axons. Furthermore, forced upregulation of mammalian target of rapamycin (mTOR) initiated either 1 month or 1 year after injury promoted regeneration of CST axons. Our results indicate that both developmental and injury-induced mTOR downregulation in corticospinal motor neurons can be reversed in adults. Modulating neuronal mTOR activity is a potential strategy for axon regeneration after chronic SCI. SIGNIFICANCE STATEMENT As one of the long descending tracts controlling voluntary movement, the corticospinal tract (CST) plays an important role for functional recovery after spinal cord injury. The regeneration of CST has been a major challenge in the field, especially after chronic injuries. Here we developed a strategy to modulate Pten/mammalian target of rapamycin signaling in adult corticospinal motor neurons in the postinjury paradigm. It not only promoted the sprouting of uninjured CST axons, but also enabled the regeneration of injured axons past the lesion in a mouse model of spinal cord injury, even when treatment was delayed up to 1 year after the original injury. The results considerably extend the window of opportunity for regenerating CST axons severed in spinal cord injuries.
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50
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Zhu Y, Liu F, Zou X, Torbey M. Comparison of unbiased estimation of neuronal number in the rat hippocampus with different staining methods. J Neurosci Methods 2015; 254:73-9. [PMID: 26238727 DOI: 10.1016/j.jneumeth.2015.07.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 07/20/2015] [Accepted: 07/23/2015] [Indexed: 01/28/2023]
Abstract
BACKGROUND NeuN and Nissl staining (toluidine blue, cresyl violet staining) are routinely used methods in unbiased stereological estimation of the total number of hippocampal neurons. NEW METHOD In the present study, we stained serial frozen coronal sections from 5 normal adult male Sprague-Dawley rat brains with different methods, measured the deformation of hippocampal area in brain sections and estimated the total number of hippocampal neurons using the optical fractionator. RESULTS The deformation in x, y-axis was not obviously different with different staining protocols, but shrinkage in z-axis was significant after staining (p < 0.001). NeuN staining produced significant higher estimate number than cresyl violet staining by 24% (p = 0.002), however, NeuN and Cresyl Violet staining showed a high degree of correlation in quantification of total neuronal numbers and both methods are suitable for unbiased stereological estimation. COMPARISON WITH EXISTING METHOD (S) NeuN is more reliable but if time is limited or the number of animals used in experiments is high, cresyl violet staining may be a feasible method. CONCLUSIONS Compared with previous estimates of the neurons number in rat hippocampus, our present data is reliable and the stereological analysis based on our system is a cost-effective unbiased method for estimation of neuron number.
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Affiliation(s)
- Yongjin Zhu
- Department of Neurology, Wexner Medical Center, The Ohio State University, Columbus, OH, United States
| | - Fuxin Liu
- Department of Neurology, Wexner Medical Center, The Ohio State University, Columbus, OH, United States
| | - Xunchang Zou
- Department of Neurology, Wexner Medical Center, The Ohio State University, Columbus, OH, United States
| | - Michel Torbey
- Department of Neurology, Wexner Medical Center, The Ohio State University, Columbus, OH, United States; Neurosurgery, Wexner Medical Center, The Ohio State University, Columbus, OH, United States.
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