1
|
Cunningham C, Viskontas M, Janowicz K, Sani Y, Håkansson M, Heidari A, Huang W, Bo X. The potential of gene therapies for spinal cord injury repair: a systematic review and meta-analysis of pre-clinical studies. Neural Regen Res 2023; 18:299-305. [PMID: 35900407 PMCID: PMC9396485 DOI: 10.4103/1673-5374.347941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Currently, there is no cure for traumatic spinal cord injury but one therapeutic approach showing promise is gene therapy. In this systematic review and meta-analysis, we aim to assess the efficacy of gene therapies in pre-clinical models of spinal cord injury and the risk of bias. In this meta-analysis, registered at PROSPERO (Registration ID: CRD42020185008), we identified relevant controlled in vivo studies published in English by searching the PubMed, Web of Science, and Embase databases. No restrictions of the year of publication were applied and the last literature search was conducted on August 3, 2020. We then conducted a random-effects meta-analysis using the restricted maximum likelihood estimator. A total of 71 studies met our inclusion criteria and were included in the systematic review. Our results showed that overall, gene therapies were associated with improvements in locomotor score (standardized mean difference [SMD]: 2.07, 95% confidence interval [CI]:1.68–2.47, Tau2 = 2.13, I2 = 83.6%) and axonal regrowth (SMD: 2.78, 95%CI: 1.92–3.65, Tau2 = 4.13, I2 = 85.5%). There was significant asymmetry in the funnel plots of both outcome measures indicating the presence of publication bias. We used a modified CAMARADES (Collaborative Approach to Meta-Analysis and Review of Animal Data in Experimental Studies) checklist to assess the risk of bias, finding that the median score was 4 (IQR:3–5). In particular, reports of allocation concealment and sample size calculations were lacking. In conclusion, gene therapies are showing promise as therapies for spinal cord injury repair, but there is no consensus on which gene or genes should be targeted.
Collapse
|
2
|
Xu J, He J, He H, Peng R, Xi J. Comparison of RNAi NgR and NEP1-40 in Acting on Axonal Regeneration After Spinal Cord Injury in Rat Models. Mol Neurobiol 2016; 54:8321-8331. [PMID: 27921243 DOI: 10.1007/s12035-016-0315-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 11/21/2016] [Indexed: 02/02/2023]
Abstract
This study was intended to compare the therapeutic efficacies of NEP1-40 and SiNgR199 on treating spinal cord injury (SCI). Nogo-A, growth associated protein 43 (GAP-43), microtubule associated protein 2 (MAP-2), and amyloid βA4 precursor protein (APP) expressions were determined using western blot and quantitative PCR. Neurite outgrowth detected the growth of neurites, and BDA anterograde tracing was used to label the regenerated axonal. Rats' behavior was assessed with Basso, Beattie, and Bresnahan locomotor rating scale (BBB). Somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) were recorded to evaluate the recovery of the sensory and motor systems. Successful establishment of SCI model was verified by immunocytochemical analysis. The increased expression of APP, as well as the decreased expression of GAP-43 and MAP-2, was observed in the SCI model group, but the trends were reversed after the treatments of NEP1-40, siNgR199, and NEP1-40 + siNgR199. Compared with the SCI group, the average neurite length and the BDA-positive fibers were increased in the NEP1-40, siNgR199, and NEP1-40 + siNgR199 groups. The rats in the siNgR199 group and the NEP1-40 + siNgR199 group both showed significantly higher BBB scores than SCI model group and NEP1-40 group. Suggested by electrophysiological evaluation, both the latency and the amplitude of SEPs as well as MEPs had recovered in the NEP1-40, siNgR199, and NEP1-40 + siNgR199 groups after SCI. Both NEP1-40 and siNgR had repairing effects on SCI, suggesting their role in facilitating axonal regeneration after SCI.
Collapse
Affiliation(s)
- Jing Xu
- Department of Otolaryngology-Head and Neck Surgery, Xiang-Ya Hospital, Otolaryngology Key Laboratory of Hunan Province, Central South University, Changsha, Hunan, 410008, China
| | - Jian He
- Department of Otolaryngology-Head and Neck Surgery, Xiang-Ya Hospital, Otolaryngology Key Laboratory of Hunan Province, Central South University, Changsha, Hunan, 410008, China
| | - Huang He
- Department of Neurosurgery, Xiang-Ya Hospital, Central South University, No. 87 Xiangya Road, Changsha, Hunan, 410008, China
| | - Renjun Peng
- Department of Neurosurgery, Xiang-Ya Hospital, Central South University, No. 87 Xiangya Road, Changsha, Hunan, 410008, China
| | - Jian Xi
- Department of Neurosurgery, Xiang-Ya Hospital, Central South University, No. 87 Xiangya Road, Changsha, Hunan, 410008, China.
| |
Collapse
|
3
|
Pohland M, Glumm R, Stoenica L, Höltje M, Kiwit J, Ahnert-Hilger G, Strauss U, Bräuer AU, Paul F, Glumm J. Studying Axonal Outgrowth and Regeneration of the Corticospinal Tract in Organotypic Slice Cultures. J Neurotrauma 2015; 32:1465-77. [DOI: 10.1089/neu.2014.3467] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Martin Pohland
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Robert Glumm
- NeuroCure Clinical Research Center and Clinical and Experimental Research Center for Multiple Sclerosis, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Luminita Stoenica
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Markus Höltje
- Institute for Integrative Neuroanatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jürgen Kiwit
- Department of Neurosurgery, HELIOS Klinikum Berlin Buch, Berlin, Germany
| | - Gudrun Ahnert-Hilger
- Institute for Integrative Neuroanatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ulf Strauss
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anja U. Bräuer
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Friedemann Paul
- NeuroCure Clinical Research Center and Clinical and Experimental Research Center for Multiple Sclerosis, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jana Glumm
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Department of Neurosurgery, HELIOS Klinikum Berlin Buch, Berlin, Germany
| |
Collapse
|
4
|
Abstract
Three theories of regeneration dominate neuroscience today, all purporting to explain why the adult central nervous system (CNS) cannot regenerate. One theory proposes that Nogo, a molecule expressed by myelin, prevents axonal growth. The second theory emphasizes the role of glial scars. The third theory proposes that chondroitin sulfate proteoglycans (CSPGs) prevent axon growth. Blockade of Nogo, CSPG, and their receptors indeed can stop axon growth in vitro and improve functional recovery in animal spinal cord injury (SCI) models. These therapies also increase sprouting of surviving axons and plasticity. However, many investigators have reported regenerating spinal tracts without eliminating Nogo, glial scar, or CSPG. For example, many motor and sensory axons grow spontaneously in contused spinal cords, crossing gliotic tissue and white matter surrounding the injury site. Sensory axons grow long distances in injured dorsal columns after peripheral nerve lesions. Cell transplants and treatments that increase cAMP and neurotrophins stimulate motor and sensory axons to cross glial scars and to grow long distances in white matter. Genetic studies deleting all members of the Nogo family and even the Nogo receptor do not always improve regeneration in mice. A recent study reported that suppressing the phosphatase and tensin homolog (PTEN) gene promotes prolific corticospinal tract regeneration. These findings cannot be explained by the current theories proposing that Nogo and glial scars prevent regeneration. Spinal axons clearly can and will grow through glial scars and Nogo-expressing tissue under some circumstances. The observation that deleting PTEN allows corticospinal tract regeneration indicates that the PTEN/AKT/mTOR pathway regulates axonal growth. Finally, many other factors stimulate spinal axonal growth, including conditioning lesions, cAMP, glycogen synthetase kinase inhibition, and neurotrophins. To explain these disparate regenerative phenomena, I propose that the spinal cord has evolved regenerative mechanisms that are normally suppressed by multiple extrinsic and intrinsic factors but can be activated by injury, mediated by the PTEN/AKT/mTOR, cAMP, and GSK3b pathways, to stimulate neural growth and proliferation.
Collapse
Affiliation(s)
- Wise Young
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, State University of New Jersey, Piscataway, NJ, USA
| |
Collapse
|
5
|
Abstract
Spinal cord injury is a complex pathology often resulting in functional impairment and paralysis. Gene therapy has emerged as a possible solution to the problems of limited neural tissue regeneration through the administration of factors promoting axonal growth, while also offering long-term local delivery of therapeutic molecules at the injury site. Of note, gene therapy is our response to the requirements of neural and glial cells following spinal cord injury, providing, in a time-dependent manner, growth substances for axonal regeneration and eliminating axonal growth inhibitors. Herein, we explore different gene therapy strategies, including targeting gene expression to modulate the presence of neurotrophic growth or survival factors and increase neural tissue plasticity. Special attention is given to describing advances in viral and non-viral gene delivery systems, as well as the available routes of gene delivery. Finally, we discuss the future of combinatorial gene therapies and give consideration to the implementation of gene therapy in humans.
Collapse
|
6
|
Hutson TH, Foster E, Moon LDF, Yáñez-Muñoz RJ. Lentiviral vector-mediated RNA silencing in the central nervous system. Hum Gene Ther Methods 2013; 25:14-32. [PMID: 24090197 DOI: 10.1089/hgtb.2013.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
RNA silencing is an established method for investigating gene function and has attracted particular interest because of the potential for generating RNA-based therapeutics. Using lentiviral vectors as an efficient delivery system that offers stable, long-term expression in postmitotic cells further enhances the applicability of an RNA-based gene therapy for the CNS. In this review we provide an overview of both lentiviral vectors and RNA silencing along with design considerations for generating lentiviral vectors capable of RNA silencing. We go on to describe the current preclinical data regarding lentiviral vector-mediated RNA silencing for CNS disorders and discuss the concerns of side effects associated with lentiviral vectors and small interfering RNAs and how these might be mitigated.
Collapse
Affiliation(s)
- Thomas H Hutson
- 1 Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London , Guy's Campus, London SE1 1UL, United Kingdom
| | | | | | | |
Collapse
|