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Georgelou K, Saridaki EA, Karali K, Papagiannaki A, Charalampopoulos I, Gravanis A, Tzeranis DS. Microneurotrophin BNN27 Reduces Astrogliosis and Increases Density of Neurons and Implanted Neural Stem Cell-Derived Cells after Spinal Cord Injury. Biomedicines 2023; 11:biomedicines11041170. [PMID: 37189788 DOI: 10.3390/biomedicines11041170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/02/2023] [Accepted: 04/12/2023] [Indexed: 05/17/2023] Open
Abstract
Microneurotrophins, small-molecule mimetics of endogenous neurotrophins, have demonstrated significant therapeutic effects on various animal models of neurological diseases. Nevertheless, their effects on central nervous system injuries remain unknown. Herein, we evaluate the effects of microneurotrophin BNN27, an NGF analog, in the mouse dorsal column crush spinal cord injury (SCI) model. BNN27 was delivered systemically either by itself or combined with neural stem cell (NSC)-seeded collagen-based scaffold grafts, demonstrated recently to improve locomotion performance in the same SCI model. Data validate the ability of NSC-seeded grafts to enhance locomotion recovery, neuronal cell integration with surrounding tissues, axonal elongation and angiogenesis. Our findings also show that systemic administration of BNN27 significantly reduced astrogliosis and increased neuron density in mice SCI lesion sites at 12 weeks post injury. Furthermore, when BNN27 administration was combined with NSC-seeded PCS grafts, BNN27 increased the density of survived implanted NSC-derived cells, possibly addressing a major challenge of NSC-based SCI treatments. In conclusion, this study provides evidence that small-molecule mimetics of endogenous neurotrophins can contribute to effective combinatorial treatments for SCI, by simultaneously regulating key events of SCI and supporting grafted cell therapies in the lesion site.
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Affiliation(s)
- Konstantina Georgelou
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
| | | | - Kanelina Karali
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
| | - Argyri Papagiannaki
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Ioannis Charalampopoulos
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
| | - Achille Gravanis
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
| | - Dimitrios S Tzeranis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
- Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 2109, Cyprus
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2
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Yousefifard M, Sarveazad A, Babahajian A, Rafiei Alavi SN, Neishaboori AM, Vaccaro AR, Hosseini M, Rahimi-Movaghar V. Growth Factor Gene-Modified Cells in Spinal Cord Injury Recovery; a Systematic Review. World Neurosurg 2022; 162:150-162.e1. [PMID: 35276395 DOI: 10.1016/j.wneu.2022.03.012] [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: 12/12/2021] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Numerous pre-clinical studies have been performed in recent years on the effects of growth factor gene-modified cells' administration in spinal cord injury (SCI). However, findings of these studies are contradictory. OBJECTIVE The present study aims to conduct a systematic review and meta-analysis on animal studies evaluating the effects of growth factor gene-modified cells' administration on locomotion recovery following SCI. METHODS A search of the Medline, Embase, Scopus and Web of Science databases was conducted, including all animal studies until the end of 2020. Two researchers screened search results, summarized relevant studies and assessed risk of bias, independently. RESULTS Thirty-three studies were included in the final analysis. Transplantation of growth factor gene-modified cells in the injured spinal cord resulted in a significant improvement in animals' locomotion compared with non-treated animals [standardized mean difference (SMD)=1.86; 95% CI: 1.39-2.33; p<0.0001)] and non-genetically modified cells treated animals (SMD=1.30; 0.80-1.79; p<0.0001). Transplantation efficacy of these cells failed to achieve significance in moderate lesions (p=0.091), when using modified neural stem/progenitor cells (p=0.164), when using synthetic neurotrophins (p=0.086) and when the number of transplanted cells was less than 1.0 × 105 cells per animal (p = 0.119). CONCLUSION The result showed that transplantation of growth factor gene-modified cells significantly improved locomotion in SCI animal models. However, there is a major concern regarding the safety of genetically modified cells' transplantation, in terms of overexpressing growth factors. Further studies are needed before any effort to perform a translational and clinical study.
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Affiliation(s)
- Mahmoud Yousefifard
- Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Arash Sarveazad
- Colorectal Research Center, Iran University of Medical Sciences, Tehran, Iran; Nursing Care Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Asrin Babahajian
- Liver and digestive research center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | | | | | - Alex R Vaccaro
- Department of Orthopedics and Neurosurgery, Rothman Institute, Thomas Jefferson University, Philadelphia, USA
| | - Mostafa Hosseini
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
| | - Vafa Rahimi-Movaghar
- Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran; Brain and Spinal Injuries Research Center (BASIR), Neuroscience Institute, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran.
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3
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Gómez RM, Sánchez MY, Portela-Lomba M, Ghotme K, Barreto GE, Sierra J, Moreno-Flores MT. Cell therapy for spinal cord injury with olfactory ensheathing glia cells (OECs). Glia 2018; 66:1267-1301. [PMID: 29330870 DOI: 10.1002/glia.23282] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 11/20/2017] [Accepted: 11/28/2017] [Indexed: 01/18/2023]
Abstract
The prospects of achieving regeneration in the central nervous system (CNS) have changed, as most recent findings indicate that several species, including humans, can produce neurons in adulthood. Studies targeting this property may be considered as potential therapeutic strategies to respond to injury or the effects of demyelinating diseases in the CNS. While CNS trauma may interrupt the axonal tracts that connect neurons with their targets, some neurons remain alive, as seen in optic nerve and spinal cord (SC) injuries (SCIs). The devastating consequences of SCIs are due to the immediate and significant disruption of the ascending and descending spinal pathways, which result in varying degrees of motor and sensory impairment. Recent therapeutic studies for SCI have focused on cell transplantation in animal models, using cells capable of inducing axon regeneration like Schwann cells (SchCs), astrocytes, genetically modified fibroblasts and olfactory ensheathing glia cells (OECs). Nevertheless, and despite the improvements in such cell-based therapeutic strategies, there is still little information regarding the mechanisms underlying the success of transplantation and regarding any secondary effects. Therefore, further studies are needed to clarify these issues. In this review, we highlight the properties of OECs that make them suitable to achieve neuroplasticity/neuroregeneration in SCI. OECs can interact with the glial scar, stimulate angiogenesis, axon outgrowth and remyelination, improving functional outcomes following lesion. Furthermore, we present evidence of the utility of cell therapy with OECs to treat SCI, both from animal models and clinical studies performed on SCI patients, providing promising results for future treatments.
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Affiliation(s)
- Rosa M Gómez
- Fundación de Neuroregeneración en Colombia, Grupo de investigación NeuroRec, Bogota D.C, Colombia
| | - Magdy Y Sánchez
- Fundación de Neuroregeneración en Colombia, Grupo de investigación NeuroRec, Bogota D.C, Colombia.,Maestría en Neurociencias, Universidad Nacional de Colombia, Bogota D.C, Colombia
| | - Maria Portela-Lomba
- Facultad de CC Experimentales, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Madrid, Spain
| | - Kemel Ghotme
- Facultad de Medicina, Universidad de la Sabana, Chía, Colombia
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogota D.C, Colombia.,Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Javier Sierra
- Facultad de CC Experimentales, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Madrid, Spain
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4
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Tuszynski MH, Weidner N, McCormack M, Miller I, Powell H, Conner J. Grafts of Genetically Modified Schwann Cells to the Spinal Cord: Survival, Axon Growth, and Myelination. Cell Transplant 2017; 7:187-96. [PMID: 9588600 DOI: 10.1177/096368979800700213] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Schwann cells naturally support axonal regeneration after injury in the peripheral nervous system, and have also shown a significant, albeit limited, ability to support axonal growth and remyelination after grafting to the central nervous system (CNS). It is possible that Schwann cell-induced axonal growth in the CNS could be substantially increased by genetic manipulation to secrete augmented amounts of neurotrophic factors. To test this hypothesis, cultured primary adult rat Schwann cells were genetically modified using retroviral vectors to produce and secrete high levels of human nerve growth factor (NGF). These cells were then grafted to the midthoracic spinal cords of adult rats. Findings were compared to animals that received grafts of nontransduced Schwann cells. Spinal cord lesions were not placed prior to grafting because the primary aim of this study was to examine features of grafted Schwann cell survival, growth, and effects on host axons. In vitro prior to grafting, Schwann cells secreted 1.5 + 0.1 ng human NGF/ml/106 cells/day. Schwann cell transplants readily survived for 2 wk to 1 yr after in vivo placement. Some NGF-transduced grafts slowly increased in size over time compared to nontransduced grafts; the latter remained stable in size. NGF-transduced transplants were densely penetrated by primary sensory nociceptive axons originating from the dorsolateral fasciculus of the spinal cord, whereas control grafts showed significantly fewer penetrating sensory axons. Over time, Schwann cell grafts also became penetrated by TH- and DBH-labeled axons of putative coerulospinal origin, unlike control cell grafts. Ultrastructurally, axons in both graft types were extensively myelinated by Schwann cells. Grafted animals showed no changes in gross locomotor function. In vivo expression of the human NGF transgene was demonstrated for periods of at least 6 m. These findings demonstrate that primary adult Schwann cells 1) can be transduced to secrete augmented levels of neurotrophic factors, 2) survive grafting to the CNS for prolonged time periods, 3) elicit robust growth of host neurotrophin-responsive axons, 4) myelinate CNS axons, and 5) express the transgene for prolonged time periods in vivo. Some grafts slowly enlarge over time, a feature that may be attributable to the propensity of Schwann cells to immortalize after multiple passages. Transduced Schwann cells merit further study as tools for promoting CNS regeneration.
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Affiliation(s)
- M H Tuszynski
- Department of Neurosciences, University of California-San Diego, La Jolla 92093-0608, USA
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5
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Tuszynski MH. Review : Gene Therapy: Applications to the Neurosciences and to Neurological Disease. Neuroscientist 2016. [DOI: 10.1177/107385849800400612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Gene expression is involved in some way in every human disease. As our knowledge of gene structure and function has blossomed in the last 2 decades, so too has our potential genetically-based repertoire for combating disease. Gene therapy refers to the manipulation of gene expression, either by augmenting the expression of therapeutic genes or by diminishing the expression of deleterious genes. In some neurological diseases, such as trauma, ischemia, and neurodegenerative disorders, gene therapy might be used to express genes for such substances as growth factors or neurotransmitters to prevent neuronal degeneration or to compensate for lost function, respectively. In other cases, gene therapy could be used to block the expression of genes that cause disease such as β-amyloid precursor protein or the Huntingtin gene. In inherited diseases of the nervous system such as muscular dystrophy, normal gene copies could be placed into the nervous system to compensate for lost function resulting from abnormal gene expression. The tools for achieving well-targeted, sustained, and safe gene delivery in the nervous system are now becoming available, and this technology is likely to substantially alter the nature of neurological therapy in the future. NEUROSCIENTIST 4:398-407, 1998
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Affiliation(s)
- Mark H. Tuszynski
- Department of Neurosciences University of California-San
Diego La Jolla, California Veterans Affairs Medical Center San Diego, California
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6
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Li C, Chen X, Qiao S, Liu X, Liu C, Zhu D, Su J, Wang Z. Effects of Wharton's jelly cells of the human umbilical cord on acute spinal cord injury in rats, and expression of interleukin-1β and nerve growth factor in spinal cord tissues. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2015; 44:1254-8. [PMID: 25801039 DOI: 10.3109/21691401.2015.1019671] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To study the effects of Wharton's jelly cells (WJCs) on acute spinal cord injury (SCI), 81 rats were divided into a sham surgery group, a model group, and a WJC transplantation group (n = 27). Motor functions of the model and WJC transplantation groups were partially recovered, and the recovery was better in the latter group. The WJC transplantation group had integral spinal cord tissues. Compared with the model group, the WJC transplantation group expressed significantly less interleukin-1β (IL-1β) and more nerve growth factor (NGF) (P < 0.05). WJC transplantation changed the microenvironment of the SCI site, inhibited IL-1β expression, increased NGF expression, promoted the recovery of neurological function, and relieved secondary SCI.
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Affiliation(s)
- Cheng Li
- a Department of Orthopedic Surgery , Changhai Hospital, The Second Military Medical University , Shanghai , P. R. China
| | - Xiao Chen
- a Department of Orthopedic Surgery , Changhai Hospital, The Second Military Medical University , Shanghai , P. R. China
| | - Suchi Qiao
- a Department of Orthopedic Surgery , Changhai Hospital, The Second Military Medical University , Shanghai , P. R. China
| | - Xinwei Liu
- b Laboratory of Severe and War-Related Trauma Center, General Hospital of Shenyang Military Area Command of Chinese PLA , Shenyang , P. R. China
| | - Chang Liu
- a Department of Orthopedic Surgery , Changhai Hospital, The Second Military Medical University , Shanghai , P. R. China
| | - Degang Zhu
- a Department of Orthopedic Surgery , Changhai Hospital, The Second Military Medical University , Shanghai , P. R. China
| | - Jiacan Su
- a Department of Orthopedic Surgery , Changhai Hospital, The Second Military Medical University , Shanghai , P. R. China
| | - Zhiwei Wang
- a Department of Orthopedic Surgery , Changhai Hospital, The Second Military Medical University , Shanghai , P. R. China
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7
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Shakhbazau A, Shcharbin D, Seviaryn I, Goncharova N, Kosmacheva S, Potapnev M, Bryszewska M, Kumar R, Biernaskie J, Midha R. Dendrimer-Driven Neurotrophin Expression Differs in Temporal Patterns between Rodent and Human Stem Cells. Mol Pharm 2012; 9:1521-8. [DOI: 10.1021/mp300041k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Antos Shakhbazau
- Department
of Clinical Neurosciences,
Faculty of Medicine, University of Calgary, Calgary, Canada
- Hotchkiss
Brain Institute, University of Calgary,
Calgary, Canada
| | - Dzmitry Shcharbin
- Institute
of Biophysics and Cell
Engineering, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Ihar Seviaryn
- Republic Centre for Hematology and Transfusiology, Minsk, Belarus
| | | | | | - Mihail Potapnev
- Republic Centre for Hematology and Transfusiology, Minsk, Belarus
| | - Maria Bryszewska
- Department of General Biophysics, University of Lodz, Lodz, Poland
| | - Ranjan Kumar
- Department
of Clinical Neurosciences,
Faculty of Medicine, University of Calgary, Calgary, Canada
- Hotchkiss
Brain Institute, University of Calgary,
Calgary, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada
| | - Jeffrey Biernaskie
- Hotchkiss
Brain Institute, University of Calgary,
Calgary, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada
| | - Rajiv Midha
- Department
of Clinical Neurosciences,
Faculty of Medicine, University of Calgary, Calgary, Canada
- Hotchkiss
Brain Institute, University of Calgary,
Calgary, Canada
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8
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Filous AR, Miller JH, Coulson-Thomas YM, Horn KP, Alilain WJ, Silver J. Immature astrocytes promote CNS axonal regeneration when combined with chondroitinase ABC. Dev Neurobiol 2011; 70:826-41. [PMID: 20629049 DOI: 10.1002/dneu.20820] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Regeneration of injured adult CNS axons is inhibited by formation of a glial scar. Immature astrocytes are able to support robust neurite outgrowth and reduce scarring, therefore, we tested whether these cells would have this effect if transplanted into brain injuries. Utilizing an in vitro spot gradient model that recreates the strongly inhibitory proteoglycan environment of the glial scar we found that, alone, immature, but not mature, astrocytes had a limited ability to form bridges across the most inhibitory outer rim. In turn, the astrocyte bridges could promote adult sensory axon re-growth across the gradient. The use of selective enzyme inhibitors revealed that MMP-2 enables immature astrocytes to cross the proteoglycan rim. The bridge-building process and axon regeneration across the immature glial bridges were greatly enhanced by chondroitinase ABC pretreatment of the spots. We used microlesions in the cingulum of the adult rat brains to test the ability of matrix modification and immature astrocytes to form a bridge for axon regeneration in vivo. Injured axons were visualized via p75 immunolabeling and the extent to which these axons regenerated was quantified. Immature astrocytes coinjected with chondroitinase ABC-induced axonal regeneration beyond the distal edge of the lesion. However, when used alone, neither treatment was capable of promoting axonal regeneration. Our findings indicate that when faced with a minimal lesion, neurons of the basal forebrain can regenerate in the presence of a proper bridge across the lesion and when levels of chondroitin sulfate proteoglycans (CSPGs) in the glial scar are reduced.
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Affiliation(s)
- Angela R Filous
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA.
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Kusano K, Enomoto M, Hirai T, Tsoulfas P, Sotome S, Shinomiya K, Okawa A. Transplanted neural progenitor cells expressing mutant NT3 promote myelination and partial hindlimb recovery in the chronic phase after spinal cord injury. Biochem Biophys Res Commun 2010; 393:812-7. [DOI: 10.1016/j.bbrc.2010.02.088] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2010] [Accepted: 02/14/2010] [Indexed: 12/26/2022]
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10
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Heavner SB, Rubin AD, Fung K, Old M, Hogikyan ND, Feldman EL. Dysfunction of the recurrent laryngeal nerve and the potential of gene therapy. Ann Otol Rhinol Laryngol 2007; 116:441-8. [PMID: 17672247 DOI: 10.1177/000348940711600609] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Injury to the recurrent laryngeal nerve causes vocal fold paresis or paralysis resulting in poor voice quality, and possibly swallowing dysfunction and/or airway compromise. Injury can occur as part of a neurodegenerative disease process or can be due to direct nerve trauma or tumor invasion. Management depends upon symptoms, the cause and severity of injury, and the prognosis for recovery of nerve function. Surgical treatment techniques can improve symptoms, but do not restore physiologic motion. Gene therapy may be a useful adjunct to enhance nerve regeneration in the setting of neurodegenerative disease or trauma. Remote injection of viral vectors into the recurrent laryngeal nerve is the least invasive way to deliver neurotrophic factors to the nerve's cell bodies within the nucleus ambiguus, and in turn to promote nerve regeneration and enhance both nuclear and nerve survival. The purpose of this review is to discuss the potential role for gene therapy in treatment of the unsolved problem of vocal fold paralysis.
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Affiliation(s)
- S Brett Heavner
- Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor 48109-2200, USA
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11
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Fitch MT, Silver J. CNS injury, glial scars, and inflammation: Inhibitory extracellular matrices and regeneration failure. Exp Neurol 2007; 209:294-301. [PMID: 17617407 PMCID: PMC2268907 DOI: 10.1016/j.expneurol.2007.05.014] [Citation(s) in RCA: 733] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 05/22/2007] [Indexed: 11/20/2022]
Abstract
Spinal cord and brain injuries lead to complex cellular and molecular interactions within the central nervous system in an attempt to repair the initial tissue damage. Many studies have illustrated the importance of the glial cell response to injury, and the influences of inflammation and wound healing processes on the overall morbidity and permanent disability that result. The abortive attempts of neuronal regeneration after spinal cord injury are influenced by inflammatory cell activation, reactive astrogliosis and the production of both growth promoting and inhibitory extracellular molecules. Despite the historical perspective that the glial scar was a mechanical barrier to regeneration, inhibitory molecules in the forming scar and methods to overcome them have suggested molecular modification strategies to allow neuronal growth and functional regeneration. Unlike myelin associated inhibitory molecules, which remain at largely static levels before and after central nervous system trauma, inhibitory extracellular matrix molecules are dramatically upregulated during the inflammatory stages after injury providing a window of opportunity for the delivery of candidate therapeutic interventions. While high dose methylprednisolone steroid therapy alone has not proved to be the solution to this difficult clinical problem, other strategies for modulating inflammation and changing the make up of inhibitory molecules in the extracellular matrix are providing robust evidence that rehabilitation after spinal cord and brain injury has the potential to significantly change the outcome for what was once thought to be permanent disability.
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Affiliation(s)
- Michael T Fitch
- Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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12
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Hendriks WT, Ruitenberg MJ, Blits B, Boer GJ, Verhaagen J. Viral vector-mediated gene transfer of neurotrophins to promote regeneration of the injured spinal cord. PROGRESS IN BRAIN RESEARCH 2004; 146:451-76. [PMID: 14699980 DOI: 10.1016/s0079-6123(03)46029-9] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Injuries to the adult mammalian spinal cord often lead to severe damage to both ascending (sensory) pathways and descending (motor) nerve pathways without the perspective of complete functional recovery. Future spinal cord repair strategies should comprise a multi-factorial approach addressing several issues, including optimalization of survival and function of spared central nervous system neurons in partial lesions and the modulation of trophic and inhibitory influences to promote and guide axonal regrowth. Neurotrophins have emerged as promising molecules to augment neuroprotection and neuronal regeneration. Although intracerebroventricular, intrathecal and local protein delivery of neurotrophins to the injured spinal cord has resulted in enhanced survival and regeneration of injured neurons, there are a number of drawbacks to these methods. Viral vector-mediated transfer of neurotrophin genes to the injured spinal cord is emerging as a novel and effective strategy to express neurotrophins in the injured nervous system. Ex vivo transfer of neurotrophic factor genes is explored as a way to bridge lesions cavities for axonal regeneration. Several viral vector systems, based on herpes simplex virus, adenovirus, adeno-associated virus, lentivirus, and moloney leukaemia virus, have been employed. The genetic modification of fibroblasts, Schwann cells, olfactory ensheathing glia cells, and stem cells, prior to implantation to the injured spinal cord has resulted in improved cellular nerve guides. So far, neurotrophic factor gene transfer to the injured spinal cord has led to results comparable to those obtained with direct protein delivery, but has a number of advantages. The steady advances that have been made in combining new viral vector systems with a range of promising cellular platforms for ex vivo gene transfer (e.g., primary embryonic neurons, Schwann cells, olfactory ensheating glia cells and neural stem cells) holds promising perspectives for the development of new neurotrophic factor-based therapies to repair the injured nervous system.
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Affiliation(s)
- William T Hendriks
- Graduate School for Neurosciences Amsterdam, Department of Neuroregeneration, Netherlands Institute for Brain Research, Meibergdreef 33, 1105 AZ, Amsterdam, The Netherlands
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Loy DN, Talbott JF, Onifer SM, Mills MD, Burke DA, Dennison JB, Fajardo LC, Magnuson DSK, Whittemore SR. Both dorsal and ventral spinal cord pathways contribute to overground locomotion in the adult rat. Exp Neurol 2002; 177:575-80. [PMID: 12429203 DOI: 10.1006/exnr.2002.7959] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Identification of long tracts responsible for spontaneous locomotion is critical for spinal cord injury (SCI) repair strategies. We recently demonstrated that extensive demyelination of adult rat thoracic ventral columns, ventromedial, and ventrolateral white matter produces persistent, significant open-field hindlimb locomotor deficits. Locomotor movements resulting from stimulation of the pontomedullary locomotor region are inhibited by dorsolateral funiculus (DLF) lesions suggesting that important pathways for locomotion may also exist in the dorsal white matter. However, dorsal hemisections that interrupt dorsal columns/dorsal corticospinal tract (DC/CST) and DLF pathways do not produce persistent, severe locomotor deficits in the adult rat. We studied the contributions of myelinated tracts in the DLF and DC/CST to overground locomotion following complete conduction blockade of axons in the ventrolateral funiculus (VLF), a region important for locomotor movements and for transcranial magnetic motor-evoked potentials (tcMMEP). Animals received ethidium bromide plus photon irradiation to produce discrete demyelinating lesions sufficient to stop axonal conduction in the VLF, combined VLF + DLF, or combined VLF + DC/CST. Open-field BBB scores and tcMMEPs were studied at 1, 2, 3, and 4 weeks postlesion. VLF lesions resulted in mean BBB scores of 17 at 4 weeks. VLF + DC/CST and VLF + DLF lesions resulted in mean BBB scores of 15.9 and 11.1, respectively. TcMMEPs were absent in all lesion types confirming VLF conduction blockade throughout the study. Our data indicate that significant contributions to locomotion from myelinated pathways within the rat DLF can be revealed when combined with simultaneous compromise of the VLF.
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Affiliation(s)
- David N Loy
- MD/PhD Program, University of Louisville School of Medicine, Louisville, Kentucky 40292, USA
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14
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Lacroix S, Tuszynski MH. Neurotrophic factors and gene therapy in spinal cord injury. Neurorehabil Neural Repair 2001; 14:265-75. [PMID: 11402877 DOI: 10.1177/154596830001400403] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Although it was once thought that the central nervous system (CNS) of mammals was incapable of substantial recovery from injury, it is now clear that the adult CNS remains responsive to various substances that can promote cell survival and stimulate axonal growth. Among these substances are growth factors, including the neurotrophins and cytokines, and growth-supportive cells such as Schwann cells, olfactory ensheathing glia, and stem cells. We review the effects of these substances on promoting axonal growth after spinal cord injury, placing particular emphasis on the genetic delivery of nervous system growth factors to specific sites of injury as a means of promoting axonal growth and, in limited instances, functional recovery.
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Affiliation(s)
- S Lacroix
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0626, USA
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Rubin AD, Hogikyan ND, Sullivan K, Boulis N, Feldman EL. Remote delivery of rAAV-GFP to the rat brainstem through the recurrent laryngeal nerve. Laryngoscope 2001; 111:2041-5. [PMID: 11801993 DOI: 10.1097/00005537-200111000-00032] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
OBJECTIVE To demonstrate that a recombinant adeno-associated viral vector (rAAV) carrying the gene for green fluorescent protein (GFP) could be delivered to the rat brainstem by remote injection into the recurrent laryngeal nerve. STUDY DESIGN/METHODS rAAV-GFP is a serotype 2 adeno-associated vector containing the cDNA of GFP and woodchuck hepatitis virus posttranscriptional regulatory element (WPRE) under the control of the CAG promoter (obtained from Matthew During, PhD, Thomas Jefferson Medical College). Five microliters or 10 microL of 1.4 x 109 particles/microL of rAAV-GFP were injected into the right recurrent laryngeal nerve of adult Sprague-Dawley rats. Rats were killed and perfused at 3 (n = 3) and 11 weeks (n = 3). Brainstems were removed and cryosectioned. Fluorescent in-situ hybridization (FISH) was performed on cryosections from animals killed at 3 weeks using a cDNA probe for woodchuck polyribosomal enzyme within the rAAV vector. In a third group (n = 2), Fluoro-Gold (Fluorochrome, Inc., Denver, CO) was injected into the right thyroarytenoid muscle for comparison of neuronal uptake distribution. These rats were killed and perfused at 3 weeks. RESULTS The presence of GFP was noted in neurons throughout the medulla of all rat brainstems after unilateral rAAV-GFP injection at both 3 and 11 weeks. In contrast to the Fluoro-Gold, GFP was noted bilaterally and outside of the nucleus ambiguus. FISH confirmed the presence of virus within neurons expressing GFP at 3 weeks. CONCLUSIONS Remote delivery of rAAV-GFP to the rat brainstem is possible through injection into the recurrent laryngeal nerve. This has important therapeutic implications for the future treatment of recurrent laryngeal nerve injury and neurodegenerative diseases.
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Affiliation(s)
- A D Rubin
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109, USA.
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Abstract
Although medical advancements have significantly increased the survival of spinal cord injury patients, restoration of function has not yet been achieved. Neural transplantation has been studied over the past decade in animal models as a repair strategy for spinal cord injury. Although spinal cord neural transplantation has yet to reach the point of clinical application and much work remains to be done, reconstructive strategies offer the greatest hope for the treatment of spinal cord injury in the future. This article presents the scientific basis of neural transplantation as a repair strategy and reviews the current status of neural transplantation in spinal cord injury.
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Affiliation(s)
- S D Christie
- Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada
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Abstract
Spinal cord injury is often characterized by immediate and irreversible loss of sensory and motor functions below the level of injury. Cellular transplantation in various experimental models of spinal cord injury has been used as a strategy for reducing deficits and improving functional recovery. The general strategy has been aimed at promoting regeneration of intrinsic injured axons with the development of alternative pathways that facilitate a partial functional connection. Other objectives of cellular transplantation studies have included replacement of lost cellular elements, alleviation of chronic pain, and modulation of the inflammatory response after injury. This review focuses on the cell types that have been used in spinal cord transplantation studies in the context of evolving biological perspectives, technological advances, and new therapeutic strategies and serves as a point of reference for future studies.
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Affiliation(s)
- K Barami
- Department of Neurosurgery, Wayne State University, Detroit Medical Center, Michigan, USA.
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Blesch A, Uy HS, Diergardt N, Tuszynski MH. Neurite outgrowth can be modulated in vitro using a tetracycline-repressible gene therapy vector expressing human nerve growth factor. J Neurosci Res 2000; 59:402-9. [PMID: 10679776 DOI: 10.1002/(sici)1097-4547(20000201)59:3<402::aid-jnr14>3.0.co;2-q] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The delivery of neurotrophic factors to the adult nervous system has potential applications for the treatment of neurodegenerative diseases and trauma. In vivo and ex vivo gene therapy offer a means of delivering growth factors and other therapeutic substances to the central nervous system (CNS) in an intraparenchymal, accurately targeted, and regionally restricted manner. Ideally, gene therapy delivery systems should also be regulatable, allowing exogenous control of amount of gene product delivery. In the present experiment, a tetracycline-regulatable gene expression system was generated to determine whether controllable release of nerve growth factor (NGF) and green fluorescent protein (GFP) from primary rat fibroblasts could modulate biological responses (neurite outgrowth) in vitro. Using a tetracycline-repressible construct, it was found that NGF mRNA, NGF protein, and NGF-induced neurite outgrowth could be tightly regulated within a 24 hour period, and in a dose-dependent fashion, by exposure to the tetracycline analog doxycycline. Similarly, levels of green fluorescence could be regulated in GFP-transfected cells. These findings in a neurobiological system lay the framework for future studies using regulated neurotrophin delivery in in vivo models of neurodegenerative diseases and CNS injury.
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Affiliation(s)
- A Blesch
- Department of Neurosciences-0626, University of California, San Diego, La Jolla, California 92093-0626, USA
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Weidner N, Blesch A, Grill RJ, Tuszynski MH. Nerve growth factor-hypersecreting Schwann cell grafts augment and guide spinal cord axonal growth and remyelinate central nervous system axons in a phenotypically appropriate manner that correlates with expression of L1. J Comp Neurol 1999; 413:495-506. [PMID: 10495438 DOI: 10.1002/(sici)1096-9861(19991101)413:4<495::aid-cne1>3.0.co;2-z] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Schwann cells contribute to efficient axonal regeneration after peripheral nerve injury and, when grafted to the central nervous system (CNS), also support a modest degree of central axonal regeneration. This study examined (1) whether Schwann cells grafted to the CNS exhibit normal patterns of differentiation and association with spinal axons and what signals putatively modulate these interactions, and (2) whether Schwann cells overexpressing neurotrophic factors enhance axonal regeneration. Thus, primary Schwann cells were transduced to hypersecrete human nerve growth factor (NGF) and were grafted to spinal cord injury sites in adult rats. Comparisons were made to nontransfected Schwann cells. From 3 days to 6 months later, grafted Schwann cells exhibited a phenotypic and temporal course of differentiation that matched patterns normally observed after peripheral nerve injury. Schwann cells spontaneously aligned into regular spatial arrays within the cord, appropriately remyelinated coerulospinal axons that regenerated into grafts, and appropriately ensheathed but did not myelinate sensory axons extending into grafts. Coordinate expression of the cell adhesion molecule L1 on Schwann cells and axons correlated with establishment of appropriate patterns of axon-Schwann cell ensheathment. Transduction of Schwann cells to overexpress NGF robustly increased axonal growth but did not otherwise alter the nature of interactions with growing axons. These findings suggest that signals expressed on Schwann cells that modulate peripheral axonal regeneration and myelination are also recognized in the CNS and that the modification of Schwann cells to overexpress growth factors significantly augments their capacity to support extensive axonal growth in models of CNS injury.
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Affiliation(s)
- N Weidner
- Department of Neurosciences, University of California-San Diego, La Jolla, California 92093-0626, USA
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20
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Affiliation(s)
- P R Sanberg
- Division of Neurological Surgery, University of South Florida College of Medicine, Tampa 33612, USA
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21
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Boulis NM, Bhatia V, Brindle TI, Holman HT, Krauss DJ, Blaivas M, Hoff JT. Adenoviral nerve growth factor and beta-galactosidase transfer to spinal cord: a behavioral and histological analysis. J Neurosurg 1999; 90:99-108. [PMID: 10413133 DOI: 10.3171/spi.1999.90.1.0099] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The present study characterizes the time course and loci of gene expression induced by the administration of adenoviral vectors into spinal cord. Although a marked inflammatory response to these vectors occurred, no effect on spinal cord function was seen in the 1st postoperative week. The expression of transgenic genes delivered by viral vectors is being exploited throughout the nervous system. The present study utilized adenoviral vectors containing the Rous sarcoma virus (RSV) promoter and a nuclear localization signal to achieve transgenic expression in mammalian spinal cord. METHODS Initial experiments utilizing the vector Ad.RSVlacZ (10(12) particles/ml) injected into the region of the central canal resulted in viral gene expression stretching over approximately 1.2 cm of spinal cord. Gene expression was first detected 3 days following viral administration and lasted until postinjection Day 14 with peak expression at Day 7. A variety of cell types in both white and gray matter expressed lacZ. Transgenic expression of the neurotrophin nerve growth factor (NGF) was achieved using injections of Ad.RSVNGF. On histological examination mononuclear inflammatory infiltrate and gliosis were revealed surrounding the injection sites of spinal cords receiving adenovirus but not vehicle. To assess spinal cord function during viral gene expression, animals previously trained in an operant runway task were tested at 7 days postinjection (the peak of viral gene expression) and demonstrated no changes in spinal cord function. CONCLUSIONS Results of this study using adenoviral neurotrophic gene transfer indicate that it provided an effective tool for the delivery of potentially therapeutic proteins to the injured or diseased spinal cord.
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Affiliation(s)
- N M Boulis
- Division of Neurosurgery, University of Michigan, Ann Arbor 48109, USA
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22
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Abstract
Important advances have been made in our understanding of conditions that influence the intrinsic capacity of mature CNS neurons to initiate and maintain a regrowth response. The combination of exogenous neurotrophic support with strategies to alter the terrain at the injury site itself suggests that there are important interactions between them that lead to increased axonal regeneration. The ability of chronically injured neurons to initiate a regeneration response is unexpected. Our view of the role that inhibitors play in restricting axonal growth has also expanded. The findings indicate that the windows of opportunity for enhancing growth after spinal cord injury may be more numerous than previously thought.
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Affiliation(s)
- B S Bregman
- Department of Cell Biology, Division of Neurobiology, Georgetown University School of Medicine, 3900 Reservoir Road NW, Washington, DC 20007, USA.
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