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Fischer G, Bättig L, Stienen MN, Curt A, Fehlings MG, Hejrati N. Advancements in neuroregenerative and neuroprotective therapies for traumatic spinal cord injury. Front Neurosci 2024; 18:1372920. [PMID: 38812974 PMCID: PMC11133582 DOI: 10.3389/fnins.2024.1372920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/10/2024] [Indexed: 05/31/2024] Open
Abstract
Traumatic spinal cord injuries (SCIs) continue to be a major healthcare concern, with a rising prevalence worldwide. In response to this growing medical challenge, considerable scientific attention has been devoted to developing neuroprotective and neuroregenerative strategies aimed at improving the prognosis and quality of life for individuals with SCIs. This comprehensive review aims to provide an up-to-date and thorough overview of the latest neuroregenerative and neuroprotective therapies currently under investigation. These strategies encompass a multifaceted approach that include neuropharmacological interventions, cell-based therapies, and other promising strategies such as biomaterial scaffolds and neuro-modulation therapies. In addition, the review discusses the importance of acute clinical management, including the role of hemodynamic management as well as timing and technical aspects of surgery as key factors mitigating the secondary injury following SCI. In conclusion, this review underscores the ongoing scientific efforts to enhance patient outcomes and quality of life, focusing on upcoming strategies for the management of traumatic SCI. Each section provides a working knowledge of the fundamental preclinical and patient trials relevant to clinicians while underscoring the pathophysiologic rationale for the therapies.
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Affiliation(s)
- Gregor Fischer
- Department of Neurosurgery, Cantonal Hospital St.Gallen, Medical School of St.Gallen, St.Gallen, Switzerland
- Spine Center of Eastern Switzerland, Cantonal Hospital St.Gallen, Medical School of St.Gallen, St.Gallen, Switzerland
| | - Linda Bättig
- Department of Neurosurgery, Cantonal Hospital St.Gallen, Medical School of St.Gallen, St.Gallen, Switzerland
- Spine Center of Eastern Switzerland, Cantonal Hospital St.Gallen, Medical School of St.Gallen, St.Gallen, Switzerland
| | - Martin N. Stienen
- Department of Neurosurgery, Cantonal Hospital St.Gallen, Medical School of St.Gallen, St.Gallen, Switzerland
- Spine Center of Eastern Switzerland, Cantonal Hospital St.Gallen, Medical School of St.Gallen, St.Gallen, Switzerland
| | - Armin Curt
- Spinal Cord Injury Center, University Hospital Balgrist, Zurich, Switzerland
| | - Michael G. Fehlings
- Division of Neurosurgery and Spine Program, Department of Surgery, University of Toronto, Toronto, ON, Canada
- Division of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Nader Hejrati
- Department of Neurosurgery, Cantonal Hospital St.Gallen, Medical School of St.Gallen, St.Gallen, Switzerland
- Spine Center of Eastern Switzerland, Cantonal Hospital St.Gallen, Medical School of St.Gallen, St.Gallen, Switzerland
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Modi AD, Parekh A, Patel ZH. Methods for evaluating gait associated dynamic balance and coordination in rodents. Behav Brain Res 2024; 456:114695. [PMID: 37783346 DOI: 10.1016/j.bbr.2023.114695] [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: 07/12/2023] [Revised: 09/29/2023] [Accepted: 09/30/2023] [Indexed: 10/04/2023]
Abstract
Balance is the dynamic and unconscious control of the body's centre of mass to maintain postural equilibrium. Regulated by the vestibular system, head movement and acceleration are processed by the brain to adjust joints. Several conditions result in a loss of balance, including Alzheimer's Disease, Parkinson's Disease, Menière's Disease and cervical spondylosis, all of which are caused by damage to certain parts of the vestibular pathways. Studies about the impairment of the vestibular system are challenging to carry out in human trials due to smaller study sizes limiting applications of the results and a lacking understanding of the human balance control mechanism. In contrast, more controlled research can be performed in animal studies which have fewer confounding factors than human models and allow specific conditions that affect balance to be replicated. Balance control can be studied using rodent balance-related behavioural tests after spinal or brain lesions, such as the Basso, Beattie and Bresnahan (BBB) Locomotor Scale, Foot Fault Scoring System, Ledged Beam Test, Beam Walking Test, and Ladder Beam Test, which are discussed in this review article along with their advantages and disadvantages. These tests can be performed in preclinical rodent models of femoral nerve injury, stroke, spinal cord injury and neurodegenerative diseases.
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Affiliation(s)
- Akshat D Modi
- Department of Biological Sciences, University of Toronto, Scarborough, Ontario M1C 1A4, Canada; Department of Genetics and Development, Krembil Research Institute, Toronto, Ontario M5T 0S8, Canada.
| | - Anavi Parekh
- Department of Neuroscience, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Zeenal H Patel
- Department of Biological Sciences, University of Toronto, Scarborough, Ontario M1C 1A4, Canada; Department of Biochemistry, University of Toronto, Scarborough, Ontario M1C 1A4, Canada
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Mousavi SR, Farrokhi MR, Ghaffari MK, Karimi F, Keshavarz S, Dehghanian AR, Naseh M. The combination treatment of methylprednisolone and growth factor-rich serum ameliorates the structural and functional changes after spinal cord injury in rat. Spinal Cord 2024; 62:17-25. [PMID: 38001173 DOI: 10.1038/s41393-023-00942-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/21/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023]
Abstract
STUDY DESIGN Preclinical pharmacology. OBJECTIVES Our study aims to evaluate the combined effect of Methylprednisolone (MP) and growth factor-rich serum (GFRS) on structural and functional recovery in rats following spinal cord injury (SCI). SETTING Shiraz University of Medical Sciences, Shiraz, Iran METHODS: Male Sprague-Dawley rats were randomly assigned to five groups: sham group (laminectomy); SCI group (the spinal cord clip compression model); SCI-MP group (30 mg/kg MP was administrated intraperitoneally (IP) immediately after SCI); SCI-GFRS group (GFRS (200 µl, IP) was administrated for six consecutive days); and SCI-MP + GFRS group (the rats received MP (30 mg/kg, IP) immediately after SCI, and GFRS (200 µl, IP) for six consecutive days). Motor function was assessed weekly using the Basso, Beattie, and Bresnahan (BBB) scale. After 4 weeks, we conducted the rotarod test, then removed and prepared the spinal cords (including the epicenter of injury) for stereological and histological estimation, and biochemical assays. RESULTS The results showed that MP and GFRS combining treatment enhanced functional recovery, which was associated with a decrement in lesion volume, increased spared white and gray matter volume, reduced neuronal loss, as well as decreased necrosis and hemorrhage after SCI. Moreover, administration of MP and GFRS inhibited lipid peroxidation (malondialdehyde (MDA) content), and increased antioxidant enzymes including glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) after rat SCI. CONCLUSIONS We suggests that the combination treatment of MP and GFRS may ameliorate the structure and functional changes following SCI by reducing oxidative stress, and increasing the level of antioxidants enzymes.
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Affiliation(s)
- Seyed Reza Mousavi
- Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Neurosurgery, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Majid Reza Farrokhi
- Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Neurosurgery, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mahdi Khorsand Ghaffari
- Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fatemeh Karimi
- Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Anatomy Department, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Somaye Keshavarz
- Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Maryam Naseh
- Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
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Onder C, Onder C, Akesen S, Yumusak E, Akesen B. Riluzole is Effective on Spinal Decompression for Treating Acute Spinal Injury When Compared With Methylprednisolone and the Combination of Two Drugs: In Vivo Rat Model. Global Spine J 2023:21925682231159068. [PMID: 36812057 DOI: 10.1177/21925682231159068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
STUDY DESIGN Randomized controlled animal experiment. OBJECTIVES To determine and compare the efficacy of riluzole, MPS and the combination of two drugs in a rat model with acute spinal trauma, electrophysiologically and histopathologically. METHODS 59 rats were divided into 4 groups as control, riluzole (6 mg/kg, every 12 hours for 7 days), MPS (30 mg/kg, 2nd and 4th hours after injury) and riluzole + MPS. Spinal trauma was created and the subjects were followed for 7 days. Electrophysiological recordings were made via neuromonitoring. The subjects were sacrificed and histopathological examination was made. RESULTS For the amplitude values, mean alteration in the period from the spinal cord injury to the end of the 7th day is 15.89 ± 20.00%, 210.93 ± 199.44%, 24.75% ± 10.13% increase and 18.91 ± 30.01% decrease for the control, riluzole, riluzole + MPS and MPS groups, respectively. Although the riluzole treatment group produced the greatest increase in amplitude, it was observed that no treatment provided a significant improvement compared to the control group, in terms of latency and amplitude. It was observed that there was significantly less cavitation area in the riluzole treatment group compared to the control group (P = .020). (P < .05). CONCLUSIONS Electrophysiologically, no treatment was found to provide significant improvement. Histopathologically, it was observed that riluzole provided significant neural tissue protection.
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Affiliation(s)
- Cem Onder
- Faculty of Medicine, Department of Orthopaedics and Traumatology, Uludağ University, Bursa, Turkey
| | - Cigdem Onder
- Department of Physical Therapy and Rehabilitation, Sehitkamil Hospital, Gaziantep, Turkey
| | - Selcan Akesen
- Faculty of Medicine, Department of Anesthesiology and Reanimation, Uludağ University, Bursa, Turkey
| | - Ezgi Yumusak
- Faculty of Veterinary Medicine, Department of Pathology, Uludağ University, Bursa, Turkey
| | - Burak Akesen
- Faculty of Medicine, Department of Orthopaedics and Traumatology, Uludağ University, Bursa, Turkey
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Takami T, Shimokawa N, Parthiban J, Zileli M, Ali S. Pharmacologic and Regenerative Cell Therapy for Spinal Cord Injury: WFNS Spine Committee Recommendations. Neurospine 2020; 17:785-796. [PMID: 33401856 PMCID: PMC7788403 DOI: 10.14245/ns.2040408.204] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/15/2020] [Indexed: 12/17/2022] Open
Abstract
This is a review article examining the pharmacologic and regenerative cell therapy for spinal cord injury.
A literature search during last 10 years were conducted using key words. Case reports, experimental (nonhuman) studies, papers other than English language were excluded. Up-to-date information on the pharmacologic and regenerative cell therapy for spinal cord injury was reviewed and statements were produced to reach a consensus in 2 separate consensus meeting of WFNS Spine Committee. The statements were voted and reached a consensus using Delphi method.
Pharmacologic and regenerative cell therapy for spinal cord injury have long been an interest of many experimental and clinical researches. Clinical studies with methylpredinisolone have not shown clear cut benefit. Other drugs such as Rho inhibitor, minocycline, riluzole, granulocyte colony-stimulating factor have also been tried without significant benefits. Regenerative cell therapy using different types of stem cells, different inoculation techniques, and scaffolds have undergone many trials highlighting the efficacies of cells and their limitations.
This review article summarizes the current knowledge on pharmacologic and regenerative cell therapy for spinal cord injury. Unfortunately, there is a need for further experimental and human trials to recommend effective pharmacologic and regenerative cell therapy.
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Affiliation(s)
- Toshihiro Takami
- Department of Neurosurgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | | | - Jutty Parthiban
- Department of Neurosurgery, Kovai Medical Center and Hospital Coimbatore, Tamilnadu, India
| | - Mehmet Zileli
- Department of Neurosurgery, Ege University, Izmir, Turkey
| | - Sheena Ali
- Department of Neurosurgery, Kovai Medical Center and Hospital Coimbatore, Tamilnadu, India
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Neuroprotective effects of Riluzole and Curcumin in human astrocytes and spinal cord white matter hypoxia. Neurosci Lett 2020; 738:135351. [PMID: 32891672 DOI: 10.1016/j.neulet.2020.135351] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/26/2020] [Accepted: 08/31/2020] [Indexed: 12/12/2022]
Abstract
Damage to the spinal cord (SC) can result in irreversible impairments or complete loss of motor, sensory, and autonomic functions. Riluzole, a sodium channel-blocker and glutamate inhibitor, is in preclinical use for SC injury (SCI), and curcumin is an intracellular calcium inhibitor that attenuates glutamate-induced neurotoxicity. As riluzole and curcumin have different mechanisms to protect against SCI, we aimed to investigate the neuroprotective effects of a combination of riluzole and curcumin in human astrocytes and white matter injury (WMI) model of SCI. Our data show that a combination of riluzole (1 μM) and curcumin (1 μM) was effective in inhibiting hydrogen peroxide (H2O2)-induced oxidative dress in astrocytes derived from human SC, however, curcumin alone showed a significant inhibition. In addition, our results demonstrated that curcumin alone downregulates the hypoxia-induced expression of HIF-1, GFAP, and NF-H proteins in WMI, whereas riluzole alone and in combination with curcumin remained ineffective in changing the expression of these proteins. Contrarily, after inhibiting Ca2+ influx with EGTA, riluzole alone and in combination with curcumin significantly downregulated hypoxia-induced expression of GFAP and NF-H. After analysis of caspase 9 and cleaved caspase 9, we observed that curcumin and riluzole both inhibit apoptosis significantly, whereas their combination remains ineffective. Furthermore, we observed that neuroprotective effects of curcumin and riluzole are mediated through Nrf2/HO-1 signaling. In conclusion, our results demonstrate that curcumin and riluzole protect astrocytes from oxidative stress and white matter from hypoxia. However, their combination is not beneficial to reduce hypoxia-induced astrocytosis, axonal damage, and apoptosis. From our results, it is evident that curcumin is more effective in reducing WMI than riluzole.
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Bighinati A, Focarete ML, Gualandi C, Pannella M, Giuliani A, Beggiato S, Ferraro L, Lorenzini L, Giardino L, Calzà L. Improved Functional Recovery in Rat Spinal Cord Injury Induced by a Drug Combination Administered with an Implantable Polymeric Delivery System. J Neurotrauma 2020; 37:1708-1719. [PMID: 32212901 DOI: 10.1089/neu.2019.6949] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Spinal cord injury (SCI) is an incurable condition, in which a cascade of cellular and molecular events triggered by inflammation and excitotoxicity impairs endogenous regeneration, namely remyelination and axonal outgrowth. We designed a treatment solution based on an implantable biomaterial (electrospun poly (l-lactic acid) [PLLA]) loaded with ibuprofen and triiodothyronine (T3) to counteract inflammation, thus improving endogenous regeneration. In vivo efficacy was tested by implanting the drug-loaded PLLA in the rat model of T8 contusion SCI. We observed the expected recovery of locomotion beginning on day 7. In PLLA-implanted rats (i.e., controls), the recovery stabilized at 21 days post-lesion (DPL), after which no further improvement was observed. On the contrary, in PLLA + ibuprofen (Ibu) + T3 (PLLA-Ibu-T3) rats a further recovery and a significant treatment effect were observed, also confirmed by the gait analysis on 49 DPL. Glutamate release at 24 h and 8 DPL was reduced in PLLA-Ibu-T3- compared to PLLA-implanted rats, such as the estimated lesion volume at 60 DPL. The myelin- and 200-neurofilament-positive area fraction was higher in PLLA-Ibu-T3-implanted rats, where the percentage of astrocytes was significantly reduced. The implant of a PLLA electrospun scaffold loaded with Ibu and T3 significantly improves the endogenous regeneration, leading to an improvement of functional locomotion outcome in the SCI.
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Affiliation(s)
- Andrea Bighinati
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Maria Letizia Focarete
- Health Sciences and Technologies (HST) CIRI-SDV, Alma Mater Studiorum-University of Bologna, Bologna, Italy.,Department of Chemistry "Giacomo Ciamician" and National Consortium of Materials Science and Technology (INSTM, Bologna RU), Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Chiara Gualandi
- Department of Chemistry "Giacomo Ciamician" and National Consortium of Materials Science and Technology (INSTM, Bologna RU), Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | | | - Alessandro Giuliani
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Sarah Beggiato
- Department of Life Sciences and Biotechnology, Section of Medicinal and Health Products, University of Ferrara, Ferrara, Italy
| | - Luca Ferraro
- Department of Life Sciences and Biotechnology, Section of Medicinal and Health Products, University of Ferrara, Ferrara, Italy.,Iret Foundation, Ozzano Emilia, Emilia, Italy
| | - Luca Lorenzini
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Luciana Giardino
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy.,Health Sciences and Technologies (HST) CIRI-SDV, Alma Mater Studiorum-University of Bologna, Bologna, Italy.,Iret Foundation, Ozzano Emilia, Emilia, Italy
| | - Laura Calzà
- Health Sciences and Technologies (HST) CIRI-SDV, Alma Mater Studiorum-University of Bologna, Bologna, Italy.,Iret Foundation, Ozzano Emilia, Emilia, Italy.,Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Bologna, Italy
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8
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Srinivas S, Wali AR, Pham MH. Efficacy of riluzole in the treatment of spinal cord injury: a systematic review of the literature. Neurosurg Focus 2020; 46:E6. [PMID: 30835675 DOI: 10.3171/2019.1.focus18596] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/02/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVERiluzole is a glutamatergic modulator that has recently shown potential for neuroprotection after spinal cord injury (SCI). While the effects of riluzole are extensively documented in animal models of SCI, there remains heterogeneity in findings. Moreover, there is a paucity of data on the pharmacology of riluzole and its effects in humans. For the present study, the authors systematically reviewed the literature to provide a comprehensive understanding of the effects of riluzole in SCI.METHODSThe PubMed database was queried from 1996 to September 2018 to identify animal studies and clinical trials involving riluzole administration for SCI. Once articles were identified, they were processed for year of publication, study design, subject type, injury model, number of subjects in experimental and control groups, dose, timing/route of administration, and outcomes.RESULTSA total of 37 studies were included in this study. Three placebo-controlled clinical trials were included with a total of 73 patients with a mean age of 39.1 years (range 18-70 years). For the clinical trials included within this study, the American Spinal Injury Association Impairment Scale distributions for SCI were 42.6% grade A, 25% grade B, 26.6% grade C, and 6.2% grade D. Key findings from studies in humans included decreased nociception, improved motor function, and attenuated spastic reflexes. Twenty-six animal studies (24 in vivo, 1 in vitro, and 1 including both in vivo and in vitro) were included. A total of 520 animals/in vitro specimens were exposed to riluzole and 515 animals/in vitro specimens underwent other treatment for comparison. The average dose of riluzole for intraperitoneal, in vivo studies was 6.5 mg/kg (range 1-10 mg/kg). Key findings from animal studies included behavioral improvement, histopathological tissue sparing, and modified electrophysiology after SCI. Eight studies examined the pharmacology of riluzole in SCI. Key findings from pharmacological studies included riluzole dose-dependent effects on glutamate uptake and its modified bioavailability after SCI in both animal and clinical models.CONCLUSIONSSCI has many negative sequelae requiring neuroprotective intervention. While still relatively new in its applications for SCI, both animal and human studies demonstrate riluzole to be a promising pharmacological intervention to attenuate the devastating effects of this condition.
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Tetreault LA, Zhu MP, Wilson JR, Karadimas SK, Fehlings MG. The Impact of Riluzole on Neurobehavioral Outcomes in Preclinical Models of Traumatic and Nontraumatic Spinal Cord Injury: Results From a Systematic Review of the Literature. Global Spine J 2020; 10:216-229. [PMID: 32206521 PMCID: PMC7076594 DOI: 10.1177/2192568219835516] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
STUDY DESIGN Systematic review. OBJECTIVE To evaluate the impact of riluzole on neurobehavioral outcomes in preclinical models of nontraumatic and traumatic spinal cord injury (SCI). METHODS An extensive search of the literature was conducted in Medline, EMBASE, and Medline in Process. Studies were included if they evaluated the impact of riluzole on neurobehavioral outcomes in preclinical models of nontraumatic and traumatic SCI. Extensive data were extracted from relevant studies, including sample characteristics, injury model, outcomes assessed, timing of evaluation, and main results. The SYRCLE checklist was used to assess various sources of bias. RESULTS The search yielded a total of 3180 unique citations. A total of 16 studies were deemed relevant and were summarized in this review. Sample sizes ranged from 14 to 90, and injury models included traumatic SCI (n = 9), degenerative cervical myelopathy (n = 2), and spinal cord-ischemia (n = 5). The most commonly assessed outcome measures were BBB (Basso, Beattie, Besnahan) locomotor score and von Frey filament testing. In general, rats treated with riluzole exhibited significantly higher BBB locomotor scores than controls. Furthermore, riluzole significantly increased withdrawal thresholds to innocuous stimuli and tail flick latency following application of radiant heat stimuli. Finally, rats treated with riluzole achieved superior results on many components of gait assessment. CONCLUSION In preclinical models of traumatic and nontraumatic SCI, riluzole significantly improves locomotor scores, gait function, and neuropathic pain. This review provides the background information necessary to interpret the results of clinical trials on the impact of riluzole in traumatic and nontraumatic SCI.
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Affiliation(s)
- Lindsay A. Tetreault
- Toronto Western Hospital, Toronto, Ontario, Canada,University of Toronto, Toronto, Ontario, Canada,University College Cork, Cork, Ireland
| | - Mary P. Zhu
- University of Toronto, Toronto, Ontario, Canada,St Michael’s Hospital, Toronto, Ontario, Canada
| | - Jefferson R. Wilson
- University of Toronto, Toronto, Ontario, Canada,St Michael’s Hospital, Toronto, Ontario, Canada
| | - Spyridon K. Karadimas
- Toronto Western Hospital, Toronto, Ontario, Canada,University of Toronto, Toronto, Ontario, Canada
| | - Michael G. Fehlings
- Toronto Western Hospital, Toronto, Ontario, Canada,University of Toronto, Toronto, Ontario, Canada,Michael G. Fehlings, Division of Neurosurgery, Toronto Western Hospital, University of Toronto, 399 Bathurst Street, Toronto, Ontario M5T2S8, Canada.
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10
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Falcucci RM, Wertz R, Green JL, Meucci O, Salvino J, Fontana ACK. Novel Positive Allosteric Modulators of Glutamate Transport Have Neuroprotective Properties in an in Vitro Excitotoxic Model. ACS Chem Neurosci 2019; 10:3437-3453. [PMID: 31257852 DOI: 10.1021/acschemneuro.9b00061] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Dysfunction of excitatory amino acid transporters (EAATs) has been implicated in the pathogenesis of various neurological disorders, such as stroke, brain trauma, epilepsy, and several neurodegenerative disorders. EAAT2 is the main transporter subtype responsible for glutamate clearance in the brain, and plays a key role in regulating neurotransmission and preventing excitotoxicity. Therefore, compounds that increase the activity of EAAT2 have therapeutic potential for neuroprotection. In previous studies, we used virtual screening approaches to identify novel positive allosteric modulators (PAMs) of EAAT2. These compounds were shown to selectively increase the activity of EAAT2 and increase Vmax of transport, without changing substrate affinity. In this work, our major effort was to investigate whether increasing the activity of EAAT2 by allosteric modulation would translate to neuroprotection in in vitro primary culture models of excitotoxicity. To investigate potential neuroprotective effects of one EAAT2 PAM, GT949, we subjected cultures to acute and prolonged excitotoxic insults by exogenous application of glutamate, or oxidative stress by application of hydrogen peroxide. GT949 administration did not result in neuroprotection in the oxidative stress model, likely due to damage of the glutamate transporters. However, GT949 displayed neuroprotective properties after acute and prolonged glutamate-mediated excitotoxicity. We propose that this compound prevents excess glutamate signaling by increasing the rate of glutamate clearance by EAAT2, thereby preventing excitotoxic damage and cell death. This novel class of compounds is therefore an innovative approach for neuroprotection with potential for translation in in vivo animal models of excitotoxicity.
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Affiliation(s)
- Romulo Martelli Falcucci
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Ryan Wertz
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Jennifer Leigh Green
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Olimpia Meucci
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Joseph Salvino
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
| | - Andréia Cristina Karklin Fontana
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
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11
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Zhou LY, Tian ZR, Yao M, Chen XQ, Song YJ, Ye J, Yi NX, Cui XJ, Wang YJ. Riluzole promotes neurological function recovery and inhibits damage extension in rats following spinal cord injury: a meta-analysis and systematic review. J Neurochem 2019; 150:6-27. [PMID: 30786027 DOI: 10.1111/jnc.14686] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/03/2019] [Accepted: 02/15/2019] [Indexed: 12/24/2022]
Abstract
Spinal cord injury (SCI) is a devastating condition that has few treatment options. Riluzole, a sodium channel blocker used to treat amyotrophic lateral sclerosis, has been initially trialed in human SCI. We performed a systematic review to critically assess the efficacy of riluzole in locomotor recovery and damage extension in SCI rat models, and the potential for clinical translation. PubMed, Embase, Cochrane Library, and Chinese databases were searched from their inception date to March 2018. Two reviewers independently selected animal studies that evaluated neurological recovery and lesion area following riluzole treatment in SCI rat models, extracted data and assessed methodological quality. Pairwise meta-analysis, subgroup analysis, and network meta-analysis were performed to assess the effects of riluzole on SCI. Ten eligible studies were included. Two studies had high methodological quality. Overall, the Basso, Beattie, and Bresnahan scores were increased in riluzole-treated animals versus controls, and effect sizes showed a gradual increase from the 1st (five studies, n = 104, mean difference = 1.24, 95% CI = 0.11 to 2.37, p = 0.03) to 6th week after treatment (five studies, n = 120, mean difference = 2.34, 95% CI = 1.26 to 3.42, p < 0.0001). Riluzole was associated with improved outcomes in the inclined plane test and the tissue preservation area. Subgroup analyses suggested an association of locomotor recovery with riluzole dose. Network meta-analysis showed that 5 mg/kg riluzole exhibited greater protection than 2.5 and 8 mg/kg riluzole. Collectively, this review suggests that riluzole has a protective effect on SCI, with good safety and a clear mechanism of action and may be suitable for future clinical trials or applications. However, animal results should be interpreted with caution given the known limitations in animal experimental design and methodological quality.
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Affiliation(s)
- Long-Yun Zhou
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Rehabilitation Medicine College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zi-Rui Tian
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Min Yao
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xu-Qing Chen
- Affiliated Hospital of Nanjing University of Traditional Chinese Medicine, Nanjing, China
| | - Yong-Jia Song
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jie Ye
- Department of Orthopedics and Traumatology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Nan-Xing Yi
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xue-Jun Cui
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yong-Jun Wang
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Caglar YS, Demirel A, Dogan I, Huseynov R, Eroglu U, Ozgural O, Cansiz C, Bahadir B, Kilinc MC, Al-Beyati ES. Effect of Riluzole on Spinal Cord Regeneration with Hemisection Method Before Injury. World Neurosurg 2018. [DOI: 10.1016/j.wneu.2018.02.171] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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13
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Association of riluzole and dantrolene improves significant recovery after acute spinal cord injury in rats. Spine J 2018; 18:532-539. [PMID: 29155254 DOI: 10.1016/j.spinee.2017.10.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 10/15/2017] [Accepted: 10/26/2017] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Damage to the spinal cord can result in irreversible impairment or complete loss of motor, sensory, and autonomic functions. Riluzole and dantrolene have been shown to provide neuroprotection by reducing neuronal apoptosis after brain and spinal cord injury (SCI) in several animal models of neurologic disorders. As these drugs protect the injured spinal cord through different mechanisms, we investigated the cumulative effects of riluzole and dantrolene. PURPOSE This study aimed to investigate the neuroprotective efficacy of the combined administration of riluzole and dantrolene in experimental thoracic SCI. STUDY DESIGN Twenty-nine Wistar rats were laminectomized at T12 and divided in five groups. Rats in GI (n=6) underwent laminectomy alone and were treated with placebo. Rats in GII (n=6) underwent laminectomy followed by SCI and were treated with placebo. Rats in GIII (n=5) underwent laminectomy followed by SCI and were treated with riluzole and placebo 15 minutes and 1 hour after laminectomy, respectively. Rats in GIV (n=6) underwent laminectomy followed by SCI and were treated with placebo and dantrolene 15 minutes and 1 hour after laminectomy, respectively. Rats in GV (n=6) underwent laminectomy followed by SCI and were treated with riluzole and dantrolene 15 minutes and 1 hour after laminectomy, respectively. A compressive trauma was performed to induce SCI. METHODS Behavioral testing of hind limb function was performed using the Basso Beattie Bresnahan locomotor rating scale, which revealed significant recovery in the group treated with the association of riluzole and dantrolene compared with other groups. After euthanasia, the spinal cord was evaluated using light microscopy and immunochemistry with anti-NeuN and transferase dUTP nick-end-labeling (TUNEL) staining. RESULTS Animals treated with the association of riluzole and dantrolene showed a larger number of NeuN-positive neurons adjacent to the epicenter of injury (p≤.05). Furthermore, the TUNEL staining was similar between animals treated with riluzole and dantrolene and those that did not receive spinal cord trauma (p>.05). CONCLUSIONS These results showed that riluzole and dantrolene have a synergistic effect in neuroprotection after traumatic SCI by decreasing apoptotic cell death.
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Mechanism of Neuroprotection Against Experimental Spinal Cord Injury by Riluzole or Methylprednisolone. Neurochem Res 2017; 44:200-213. [PMID: 29290040 DOI: 10.1007/s11064-017-2459-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/12/2017] [Accepted: 12/26/2017] [Indexed: 12/29/2022]
Abstract
Any spinal cord injury carries the potential for persistent disability affecting motor, sensory and autonomic functions. To prevent this outcome, it is highly desirable to block a chain of deleterious reactions developing in the spinal areas immediately around the primary lesion. Thus, early timing of pharmacological neuroprotection should be one major strategy whose impact may be first studied with preclinical models. Using a simple in vitro model of the rat spinal cord it is possible to mimic pathological processes like excitotoxicity that damages neurons because of excessive glutamate receptor activation due to injury, or hypoxic/dysmetabolic insult that preferentially affects glia following vascular dysfunction. While ongoing research is exploring the various components of pathways leading to cell death, current treatment principally relies on the off-label use of riluzole (RLZ) or methylprednisolone sodium succinate (MPSS). The mechanism of action of these drugs is diverse as RLZ targets mainly neurons and MPSS targets glia. Even when applied after a transient excitotoxic stimulus, RLZ can provide effective prevention of secondary excitotoxic damage to premotoneurons, although not to motoneurons that remain very vulnerable. This observation indicates persistent inability to express locomotor activity despite pharmacological treatment conferring some histological protection. MPSS can protect glia from dysmetabolic insult, yet it remains poorly effective to prevent neuronal death. In summary, it appears that these pharmacological agents can produce delayed protection for certain cell types only, and that their combined administration does not provide additional benefit. The search should continue for better, mechanism-based neuroprotective agents.
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15
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Ozturk O, Tezcan AH, Adali Y, Yıldırım CH, Aksoy O, Yagmurdur H, Bilge A. Effect of ozone and methylprednisolone treatment following crush type sciatic nerve injury. Acta Cir Bras 2017; 31:730-735. [PMID: 27982260 DOI: 10.1590/s0102-865020160110000005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 10/17/2016] [Indexed: 12/19/2022] Open
Abstract
PURPOSE: To assess and compare the histopathological effects of ozone therapy and/or methylprednisolone (MPS) treatment on regeneration after crush type sciatic nerve injury. METHODS: Forty Sprague-Dawley male rats were randomly allocated into four groups. Four groups received the following regimens intraperitoneally every day for 14 days after formation of crush type injury on sciatic nerve: Group I: ozone (20mcg/ml); Group II: methylprednisolone (2mg/kg); Group III: ozone (20 mcg/ml) and methylprednisolone (2mg/kg); Group IV: isotonic saline (0.9%). The histomorphological evaluation was made after biopsies were obtained from the sites of injury. RESULTS: Significant differences were noted between groups in terms of degeneration (p=0.019), nerve sheath cell atrophy (p=0.012), intraneural inflammatory cellular infiltration (p=0.002), perineural granulation tissue formation (p=0.019), perineural vascular proliferation (p=0.004), perineural inflammatory cellular infiltration (p<0.001) and inflammation in peripheral tissue (p=0.006). Degeneration was remarkably low in Group III, while no change in nerve sheath cell was noted in Group II. CONCLUSION: The combined use of methylprednisolone and ozone treatment can have beneficial effects for regeneration after crush type nerve injury.
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Affiliation(s)
- Omur Ozturk
- Assistant Professor, Department of Anesthesiology and Reanimation, School of Medicine, Kafkas University, Kars, Turkey. Conception, design, scientific and intellectual contributions of the study, acquisition of data, statistical analysis, manuscript writing, final approval
| | - Aysu Hayriye Tezcan
- Assistant Professor, Department of Anesthesiology and Reanimation, School of Medicine, Kafkas University, Kars, Turkey. Conception, design, scientific and intellectual contributions of the study, acquisition of data, statistical analysis, manuscript writing, final approval
| | - Yasemen Adali
- Asstistant Professor, Department of Pathology, School of Medicine, Kafkas University, Kars, Turkey. Histopathological examinations
| | - Can Hakan Yıldırım
- Asstistant Professor, Department of Neurosurgery, School of Medicine, Kafkas University, Kars, Turkey. Analysis and interpretation of data
| | - Ozgur Aksoy
- Professor, Department of Surgery, School of Veterinary Medicine, Kafkas University, Kars, Turkey. Technical procedures
| | - Hatice Yagmurdur
- Professor, Department of Anesthesiology and Reanimation, School of Medicine, Kafkas University, Kars, Turkey. Critical revision, final approval
| | - Ali Bilge
- Assistant Professor, Department of Ortopedics and Traumatology, School of Medicine, Kafkas University, Kars, Turkey. Manuscript preparation, final approval
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16
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Drugs to Alter Extracellular Concentration of Glutamate: Modulators of Glutamate Uptake Systems. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/978-1-4939-7228-9_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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17
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Karklin Fontana AC, Fox DP, Zoubroulis A, Valente Mortensen O, Raghupathi R. Neuroprotective Effects of the Glutamate Transporter Activator (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline (MS-153) following Traumatic Brain Injury in the Adult Rat. J Neurotrauma 2016; 33:1073-83. [PMID: 26200170 PMCID: PMC4892232 DOI: 10.1089/neu.2015.4079] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Traumatic brain injury (TBI) in humans and in animals leads to an acute and sustained increase in tissue glutamate concentrations within the brain, triggering glutamate-mediated excitotoxicity. Excitatory amino acid transporters (EAATs) are responsible for maintaining extracellular central nervous system glutamate concentrations below neurotoxic levels. Our results demonstrate that as early as 5 min and up to 2 h following brain trauma in brain-injured rats, the activity (Vmax) of EAAT2 in the cortex and the hippocampus was significantly decreased, compared with sham-injured animals. The affinity for glutamate (KM) and the expression of glutamate transporter 1 (GLT-1) and glutamate aspartate transporter (GLAST) were not altered by the injury. Administration of (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline (MS-153), a GLT-1 activator, beginning immediately after injury and continuing for 24 h, significantly decreased neurodegeneration, loss of microtubule-associated protein 2 and NeuN (+) immunoreactivities, and attenuated calpain activation in both the cortex and the hippocampus at 24 h after the injury; the reduction in neurodegeneration remained evident up to 14 days post-injury. In synaptosomal uptake assays, MS-153 up-regulated GLT-1 activity in the naïve rat brain but did not reverse the reduced activity of GLT-1 in traumatically-injured brains. This study demonstrates that administration of MS-153 in the acute post-traumatic period provides acute and long-term neuroprotection for TBI and suggests that the neuroprotective effects of MS-153 are related to mechanisms other than GLT-1 activation, such as the inhibition of voltage-gated calcium channels.
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Affiliation(s)
| | - Douglas P. Fox
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Argie Zoubroulis
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Ole Valente Mortensen
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Ramesh Raghupathi
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
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Samaddar S. Effect of Docosahexaenoic Acid (DHA) on Spinal Cord Injury. ADVANCES IN NEUROBIOLOGY 2016; 12:27-39. [DOI: 10.1007/978-3-319-28383-8_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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19
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Fontana ACK. Current approaches to enhance glutamate transporter function and expression. J Neurochem 2015; 134:982-1007. [DOI: 10.1111/jnc.13200] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 05/19/2015] [Accepted: 05/20/2015] [Indexed: 12/12/2022]
Affiliation(s)
- Andréia C. K. Fontana
- Department of Pharmacology and Physiology; Drexel University College of Medicine; Philadelphia Pennsylvania USA
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20
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Albayrak S, Atci İB, Kalayci M, Yilmaz M, Kuloglu T, Aydin S, Kom M, Ayden O, Aydin S. Effect of carnosine, methylprednisolone and their combined application on irisin levels in the plasma and brain of rats with acute spinal cord injury. Neuropeptides 2015; 52:47-54. [PMID: 26142757 DOI: 10.1016/j.npep.2015.06.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 06/09/2015] [Accepted: 06/11/2015] [Indexed: 01/02/2023]
Abstract
Spinal cord injury (SCI) might occur to anybody at any time and any age. In its treatment, methylprednisolone (MP) is a first choice worldwide, but there is still no significant breakthrough in truly beneficial treatment due to SCI's complex pathophysiology. We investigated the effect of carnosine, methylprednisolone (MP) and its combination on irisin levels in the plasma, brain and medulla spinalis tissues in SCI using a rat model. The rats were divided into 6 groups: I (Control, saline); II (sham animals with laminectomy without cross-clamping); III (SCI); IV (SCI treated with 150mg/kg carnosine); V (SCI treated with 30mg/kg methylprednisolone); and VI (SCI treated with a combination of carnosine and MP). The animals were given traumatic SCI after laminectomy, using 70-g closing force aneurysm clips (Yasargil FE 721). Irisin concentration was measured by ELISA. The distribution of irisin in brain and spinal cord tissues was examined by immunochemistry. Irisin was mainly expressed in the astrocytes and microglia of brain tissues, and multipolar neurones of the anterior horn of spinal cord tissue in rats of all groups, indicating that irisin is physiologically indispensable. MP and carnosine and the combination of the two, significantly increased irisin in plasma and were accompanied by a significant rise in irisin immunoreactivity of brain and spinal cord tissues of the injured rats compared with control and sham. This finding raises the possibility that methylprednisolone and carnosine regulate the brain and spinal cord tissues in SCI by inducing irisin expression, and may therefore offer a better neurological prognosis.
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Affiliation(s)
- Serdal Albayrak
- Department of Neurosurgery, Elazig Education and Research Hospital, 23100, Elazig, Turkey
| | - İbrahim Burak Atci
- Department of Neurosurgery, Elazig Education and Research Hospital, 23100, Elazig, Turkey
| | - Mehmet Kalayci
- Laboratory of Medical Biochemistry, Elazig Education and Research Hospital, Elazig 23100, Turkey
| | - Musa Yilmaz
- Firat University, School of Medicine, Department of Medical Biochemistry (Firat Hormones Research Group), 23119 Elazig, Turkey
| | - Tuncay Kuloglu
- Firat University, School of Medicine, Department of Histology&Embryology, 23119, Elazig, Turkey
| | - Suna Aydin
- Cardiovascular Surgery- Anatomy, Elazig Education and Research Hospital, 23100, Elazig, Turkey
| | - Mustafa Kom
- Firat University, Veterinary of Medicine, Department of Surgery, Elazig 23119, Turkey
| | - Omer Ayden
- Department of Neurosurgery, Elazig Education and Research Hospital, 23100, Elazig, Turkey
| | - Suleyman Aydin
- Firat University, School of Medicine, Department of Medical Biochemistry (Firat Hormones Research Group), 23119 Elazig, Turkey.
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Riluzole as a neuroprotective drug for spinal cord injury: from bench to bedside. Molecules 2015; 20:7775-89. [PMID: 25939067 PMCID: PMC6272473 DOI: 10.3390/molecules20057775] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/16/2015] [Accepted: 04/24/2015] [Indexed: 12/20/2022] Open
Abstract
Spinal cord injury (SCI) is a devastating event resulting in permanent loss of neurological function. To date, effective therapies for SCI have not been established. With recent progress in neurobiology, however, there is hope that drug administration could improve outcomes after SCI. Riluzole is a benzothiazole anticonvulsant with neuroprotective effects. It has been approved by the U.S. Food and Drug Administration as a safe and well-tolerated treatment for patients with amyotrophic lateral sclerosis. The mechanism of action of riluzole involves the inhibition of pathologic glutamatergic transmission in synapses of neurons via sodium channel blockade. There is convincing evidence that riluzole diminishes neurological tissue destruction and promotes functional recovery in animal SCI models. Based on these results, a phase I/IIa clinical trial with riluzole was conducted for patients with SCI between 2010 and 2011. This trial demonstrated significant improvement in neurological outcomes and showed it to be a safe drug with no serious adverse effects. Currently, an international, multi-center clinical trial (Riluzole in Acute Spinal Cord Injury Study: RISCIS) in phase II/III is in progress with riluzole for patients with SCI (clinicaltrials.gov, registration number NCT01597518). This article reviews the pharmacology and neuroprotective mechanisms of riluzole, and focuses on existing preclinical evidence, and emerging clinical data in the treatment of SCI.
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23
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Viscomi MT, Molinari M. Remote neurodegeneration: multiple actors for one play. Mol Neurobiol 2014; 50:368-89. [PMID: 24442481 DOI: 10.1007/s12035-013-8629-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 12/24/2013] [Indexed: 12/19/2022]
Abstract
Remote neurodegeneration significantly influences the clinical outcome in many central nervous system (CNS) pathologies, such as stroke, multiple sclerosis, and traumatic brain and spinal cord injuries. Because these processes develop days or months after injury, they are accompanied by a therapeutic window of opportunity. The complexity and clinical significance of remote damage is prompting many groups to examine the factors of remote degeneration. This research is providing insights into key unanswered questions, opening new avenues for innovative neuroprotective therapies. In this review, we evaluate data from various remote degeneration models to describe the complexity of the systems that are involved and the importance of their interactions in reducing damage and promoting recovery after brain lesions. Specifically, we recapitulate the current data on remote neuronal degeneration, focusing on molecular and cellular events, as studied in stroke and brain and spinal cord injury models. Remote damage is a multifactorial phenomenon in which many components become active in specific time frames. Days, weeks, or months after injury onset, the interplay between key effectors differentially affects neuronal survival and functional outcomes. In particular, we discuss apoptosis, inflammation, oxidative damage, and autophagy-all of which mediate remote degeneration at specific times. We also review current findings on the pharmacological manipulation of remote degeneration mechanisms in reducing damage and sustaining outcomes. These novel treatments differ from those that have been proposed to limit primary lesion site damage, representing new perspectives on neuroprotection.
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Affiliation(s)
- Maria Teresa Viscomi
- Experimental Neurorehabilitation Laboratory, Santa Lucia Foundation I.R.C.C.S., Via del Fosso di Fiorano 65, 00143, Rome, Italy,
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24
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Chow DSL, Teng Y, Toups EG, Aarabi B, Harrop JS, Shaffrey CI, Johnson MM, Boakye M, Frankowski RF, Fehlings MG, Grossman RG. Pharmacology of riluzole in acute spinal cord injury. J Neurosurg Spine 2013; 17:129-40. [PMID: 22985379 DOI: 10.3171/2012.5.aospine12112] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The aim of this paper was to characterize individual and population pharmacokinetics of enterally administered riluzole in a Phase 1 clinical trial of riluzole as a neuroprotective agent in adults 18-70 years old with acute spinal cord injury (SCI). METHODS Thirty-five individuals with acute SCI, American Spinal Injury Association Impairment Scale Grades A-C, neurological levels from C-4 to T-12, who were enrolled in the Phase 1 clinical trial sponsored by the North American Clinical Trials Network for Treatment of Spinal Cord Injury, received 50 mg riluzole twice daily for 28 doses. The first dose was administered at a mean of 8.7 ± 2.2 hours postinjury. Trough plasma samples were collected within 1 hour predose, and peak plasma samples were collected 2 hours postdose on Days 3 and 14 of treatment. Riluzole concentrations were quantified by high-performance liquid chromatography assay. The data were analyzed for individual and population pharmacokinetics using basic structural and covariate models. The pharmacokinetic measures studied were the peak concentration (C(max)), trough concentration (C(min)), systemic exposure (AUC(0-12)), clearance (CL/F), and volume of distribution (V_F) normalized by the bioavailability (F). RESULTS The C(max) and AUC(0-12) achieved in SCI patients were lower than those in ALS patients on the same dose basis, due to a higher CL and larger V. The pharmacokinetics of riluzole (C(max), C(min), AUC(0-12), CL, and V) changed during the acute and subacute phases of SCI during the 14 days of therapy. It was consistently observed in patients at all clinical sites that C(max), C(min), and AUC(0-12) (128.9 ng/ml, 45.6 ng/ml, and 982.0 ng × hr/ml, respectively) were significantly higher on Day 3 than on Day 14 (76.5 ng/ml, 19.1 ng/ml, and 521.0 ng × hr/ml, respectively). These changes resulted from lower CL (49.5 vs 106.2 L/hour) and smaller V (557.1 vs 1297.9/L) on Day 3. No fluid imbalance or cytochrome P 1A2 induction due to concomitant medications was identified during the treatment course to account for such increases in V and CL, respectively. Possible mechanisms underlying these changes are discussed. CONCLUSIONS This is the first report of clinical pharmacokinetics of riluzole in patients with SCI. The C(max) and AUC(0-12) achieved in SCI patients were lower than those in ALS patients on the same dose basis, due to a higher clearance and larger volume of distribution in SCI patients. The finding in SCI patients of an increase in the clearance and distribution of riluzole between the 3rd and 14th days after SCI, with a lower plasma concentration of riluzole on the 14th day, stresses the importance of monitoring changes in drug metabolism after SCI in interpreting the safety and efficacy of therapeutic drugs that are used in clinical trials in SCI. Clinical trial registration no.: NCT00876889.
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Affiliation(s)
- Diana S L Chow
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, Texas 77030, USA.
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25
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Schaal SM, Garg MS, Ghosh M, Lovera L, Lopez M, Patel M, Louro J, Patel S, Tuesta L, Chan WM, Pearse DD. The therapeutic profile of rolipram, PDE target and mechanism of action as a neuroprotectant following spinal cord injury. PLoS One 2012; 7:e43634. [PMID: 23028463 PMCID: PMC3446989 DOI: 10.1371/journal.pone.0043634] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 07/24/2012] [Indexed: 01/08/2023] Open
Abstract
The extent of damage following spinal cord injury (SCI) can be reduced by various neuroprotective regimens that include maintaining levels of cyclic adenosine monophosphate (cyclic AMP), via administration of the phosphodiesterase 4 (PDE4) inhibitor Rolipram. The current study sought to determine the optimal neuroprotective dose, route and therapeutic window for Rolipram following contusive SCI in rat as well as its prominent PDE target and putative mechanism of protection. Rolipram or vehicle control (10% ethanol) was given subcutaneously (s.c.) daily for 2 wk post-injury (PI) after which the preservation of oligodendrocytes, neurons and central myelinated axons was stereologically assessed. Doses of 0.1 mg/kg to 1.0 mg/kg (given at 1 h PI) increased neuronal survival; 0.5 mg to 1.0 mg/kg protected oligodendrocytes and 1.0 mg/kg produced optimal preservation of central myelinated axons. Ethanol also demonstrated significant neuronal and oligo-protection; though the preservation provided was significantly less than Rolipram. Subsequent use of this optimal Rolipram dose, 1.0 mg/kg, via different routes (i.v., s.c. or oral, 1 h PI), demonstrated that i.v. administration produced the most significant and consistent cyto- and axo- protection, although all routes were effective. Examination of the therapeutic window for i.v. Rolipram (1.0 mg/kg), when initiated between 1 and 48 h after SCI, revealed maximal neuroprotection at 2 h post-SCI, although the protective efficacy of Rolipram could still be observed when administration was delayed for up to 48 h PI. Importantly, use of the optimal Rolipram regimen significantly improved locomotor function after SCI as measured by the BBB score. Lastly we show SCI-induced changes in PDE4A, B and D expression and phosphorylation as well as cytokine expression and immune cell infiltration. We demonstrate that Rolipram abrogates SCI-induced PDE4B1 and PDE4A5 production, PDE4A5 phosphorylation, MCP-1 expression and immune cell infiltration, while preventing post-injury reductions in IL-10. This work supports the use of Rolipram as an acute neuroprotectant following SCI and defines an optimal administration protocol and target for its therapeutic application.
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Affiliation(s)
- Sandra Marie Schaal
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- The Neuroscience Program, University of Miami, Miami, Florida, United States of America
| | - Maneesh Sen Garg
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Mousumi Ghosh
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Lilie Lovera
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Michael Lopez
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Monal Patel
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Jack Louro
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Samik Patel
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Luis Tuesta
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Wai-Man Chan
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Damien Daniel Pearse
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- The Neuroscience Program, University of Miami, Miami, Florida, United States of America
- The Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- The Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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Tator CH, Hashimoto R, Raich A, Norvell D, Fehlings MG, Harrop JS, Guest J, Aarabi B, Grossman RG. Translational potential of preclinical trials of neuroprotection through pharmacotherapy for spinal cord injury. J Neurosurg Spine 2012; 17:157-229. [DOI: 10.3171/2012.5.aospine12116] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
There is a need to enhance the pipeline of discovery and evaluation of neuroprotective pharmacological agents for patients with spinal cord injury (SCI). Although much effort and money has been expended on discovering effective agents for acute and subacute SCI, no agents that produce major benefit have been proven to date. The deficiencies of all aspects of the pipeline, including the basic science input and the clinical testing output, require examination to determine remedial strategies. Where has the neuroprotective/pharmacotherapy preclinical process failed and what needs to be done to achieve success? These are the questions raised in the present review, which has 2 objectives: 1) identification of articles that address issues related to the translational readiness of preclinical SCI pharmacological therapies; and 2) examination of the preclinical studies of 5 selected agents evaluated in animal models of SCI (including blunt force trauma, penetrating trauma, or ischemia). The 5 agents were riluzole, glyburide, magnesium sulfate, nimodipine, and minocycline, and these were selected because of their promise of translational readiness as determined by the North American Clinical Trials Network Consortium.
The authors found that there are major deficiencies in the effort that has been extended to coordinate and conduct preclinical neuroprotection/pharmacotherapy trials in the SCI field. Apart from a few notable exceptions such as the NIH effort to replicate promising strategies, this field has been poorly coordinated. Only a small number of articles have even attempted an overall evaluation of the neuroprotective/pharmacotherapy agents used in preclinical SCI trials. There is no consensus about how to select the agents for translation to humans on the basis of their preclinical performance and according to agreed-upon preclinical performance criteria.
In the absence of such a system and to select the next agent for translation, the Consortium has developed a Treatment Strategy Selection Committee, and this committee selected the most promising 5 agents for potential translation. The results show that the preclinical work on these 5 agents has left numerous gaps in knowledge about their preclinical performance and confirm the need for significant changes in preclinical neuroprotection/pharmacotherapy trials in SCI. A recommendation is made for the development and validation of a preclinical scoring system involving worldwide experts in preclinical and clinical SCI.
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Affiliation(s)
- Charles H. Tator
- 1Division of Neurosurgery and Spinal Program, Toronto Western Hospital and University of Toronto, Ontario, Canada
| | | | - Annie Raich
- 2Spectrum Research, Inc., Tacoma, Washington
| | | | - Michael G. Fehlings
- 1Division of Neurosurgery and Spinal Program, Toronto Western Hospital and University of Toronto, Ontario, Canada
| | - James S. Harrop
- 3Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - James Guest
- 4Department of Neurological Surgery and the Miami Project to Cure Paralysis, Miller School of Medicine, University of Miami, Florida
| | - Bizhan Aarabi
- 5Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland; and
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Mackinnon SE, Yee A, Ray WZ. Nerve transfers for the restoration of hand function after spinal cord injury. J Neurosurg 2012; 117:176-85. [DOI: 10.3171/2012.3.jns12328] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Spinal cord injury (SCI) remains a significant public health problem. Despite advances in understanding of the pathophysiological processes of acute and chronic SCI, corresponding advances in translational applications have lagged behind. Nerve transfers using an expendable nearby motor nerve to reinnervate a denervated nerve have resulted in more rapid and improved functional recovery than traditional nerve graft reconstructions following a peripheral nerve injury. The authors present a single case of restoration of some hand function following a complete cervical SCI utilizing nerve transfers.
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Affiliation(s)
| | - Andrew Yee
- 1Division of Plastic and Reconstructive Surgery, and
| | - Wilson Z. Ray
- 2Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri
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Targeting mTOR as a novel therapeutic strategy for traumatic CNS injuries. Drug Discov Today 2012; 17:861-8. [PMID: 22569182 DOI: 10.1016/j.drudis.2012.04.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 04/02/2012] [Accepted: 04/23/2012] [Indexed: 01/09/2023]
Abstract
The adult central nervous system (CNS) has a remarkable ability to repair itself. However, severe brain and spinal cord injuries (SCIs) cause lasting disability and there are only a few therapies that can prevent or restore function in such cases. In this review, we provide an overview of traumatic CNS injuries and discuss several emerging pharmacological options that have shown promise in preclinical and early clinical studies. We highlight therapies that modulate mammalian target of rapamycin (mTOR) signaling, a pathway that is well known for its roles in cell growth, metabolism and cancer. Interestingly, this pathway is also gaining newfound attention for its role in CNS repair and regeneration.
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Current and future therapeutic strategies for functional repair of spinal cord injury. Pharmacol Ther 2011; 132:57-71. [DOI: 10.1016/j.pharmthera.2011.05.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 05/09/2011] [Indexed: 12/26/2022]
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Kwon BK, Okon E, Hillyer J, Mann C, Baptiste D, Weaver LC, Fehlings MG, Tetzlaff W. A systematic review of non-invasive pharmacologic neuroprotective treatments for acute spinal cord injury. J Neurotrauma 2011; 28:1545-88. [PMID: 20146558 PMCID: PMC3143410 DOI: 10.1089/neu.2009.1149] [Citation(s) in RCA: 194] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
An increasing number of therapies for spinal cord injury (SCI) are emerging from the laboratory and seeking translation into human clinical trials. Many of these are administered as soon as possible after injury with the hope of attenuating secondary damage and maximizing the extent of spared neurologic tissue. In this article, we systematically review the available pre-clinical research on such neuroprotective therapies that are administered in a non-invasive manner for acute SCI. Specifically, we review treatments that have a relatively high potential for translation due to the fact that they are already used in human clinical applications, or are available in a form that could be administered to humans. These include: erythropoietin, NSAIDs, anti-CD11d antibodies, minocycline, progesterone, estrogen, magnesium, riluzole, polyethylene glycol, atorvastatin, inosine, and pioglitazone. The literature was systematically reviewed to examine studies in which an in-vivo animal model was utilized to assess the efficacy of the therapy in a traumatic SCI paradigm. Using these criteria, 122 studies were identified and reviewed in detail. Wide variations exist in the animal species, injury models, and experimental designs reported in the pre-clinical literature on the therapies reviewed. The review highlights the extent of investigation that has occurred in these specific therapies, and points out gaps in our knowledge that would be potentially valuable prior to human translation.
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Affiliation(s)
- Brian K Kwon
- University of British Columbia, Combined Neurosurgical and Orthopaedic Spine Program, Department of Orthopaedics, Vancouver, British Columbia, Canada.
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Rabchevsky AG, Patel SP, Springer JE. Pharmacological interventions for spinal cord injury: where do we stand? How might we step forward? Pharmacol Ther 2011; 132:15-29. [PMID: 21605594 DOI: 10.1016/j.pharmthera.2011.05.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 04/28/2011] [Indexed: 12/15/2022]
Abstract
Despite numerous studies reporting some measures of efficacy in the animal literature, there are currently no effective therapies for the treatment of traumatic spinal cord injuries (SCI) in humans. The purpose of this review is to delineate key pathophysiological processes that contribute to neurological deficits after SCI, as well as to describe examples of pharmacological approaches that are currently being tested in clinical trials, or nearing clinical translation, for the therapeutic management of SCI. In particular, we will describe the mechanistic rationale to promote neuroprotection and/or functional recovery based on theoretical, yet targeted pathological events. Finally, we will consider the clinical relevancy for emerging evidence that pharmacologically targeting mitochondrial dysfunction following injury may hold the greatest potential for increasing tissue sparing and, consequently, the extent of functional recovery following traumatic SCI.
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Affiliation(s)
- Alexander G Rabchevsky
- Spinal Cord & Brain injury Research Center, Lexington, University of Kentucky, KY 40536-0509, USA.
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Effect of inhibition of spinal cord glutamate transporters on inflammatory pain induced by formalin and complete Freund's adjuvant. Anesthesiology 2011; 114:412-23. [PMID: 21245732 DOI: 10.1097/aln.0b013e318205df50] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Spinal cord glutamate transporters clear synaptically released glutamate and maintain normal sensory transmission. However, their ultrastructural localization is unknown. Moreover, whether and how they participate in inflammatory pain has not been carefully studied. METHODS Immunogold labeling with electron microscopy was carried out to characterize synaptic and nonsynaptic localization of glutamate transporters in the superficial dorsal horn. Their expression and uptake activity after formalin- and complete Freund's adjuvant (CFA)-induced inflammation were evaluated by Western blot analysis and glutamate uptake assay. Effects of intrathecal glutamate transporter activator (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline and inhibitors (DL-threo-β-benzyloxyaspartate [TBOA], dihydrokainate, and DL-threo-β-hydroxyaspartate), or TBOA plus group III metabotropic glutamate receptor antagonist (RS)-α-methylserine-O-phosphate, on formalin- and CFA-induced inflammatory pain were examined. RESULTS In the superficial dorsal horn, excitatory amino acid carrier 1 is localized in presynaptic membrane, postsynaptic membrane, and axonal and dendritic membranes at nonsynaptic sites, whereas glutamate transporter-1 and glutamate/aspartate transporter are prominent in glial membranes. Although expression of these three spinal glutamate transporters was not altered 1 h after formalin injection or 6 h after CFA injection, glutamate uptake activity was decreased at these time points. Intrathecal (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline had no effect on formalin-induced pain behaviors. In contrast, intrathecal TBOA, dihydrokainate, and DL-threo-β-hydroxyaspartate reduced formalin-evoked pain behaviors in the second phase. Intrathecal TBOA also attenuated CFA-induced thermal hyperalgesia at 6 h after CFA injection. The antinociceptive effects of TBOA were blocked by coadministration of (RS)-α-methylserine-O-phosphate. CONCLUSION Our findings suggest that spinal glutamate transporter inhibition relieves inflammatory pain through activation of inhibitory presynaptic group III metabotropic glutamate receptors.
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Abstract
BACKGROUND Spinal cord injury (SCI) is a devastating event often resulting in permanent neurologic deficit. Research has revealed an understanding of mechanisms that occur after the primary injury and contribute to functional loss. By targeting these secondary mechanisms of injury, clinicians may be able to offer improved recovery after SCI. QUESTIONS/PURPOSES In this review, we highlight advances in the field of SCI by framing three questions: (1) What is the preclinical evidence for the neuroprotective agent riluzole that has allowed this agent to move into clinical trials? (2) What is the preclinical evidence for Rho antagonists that have allowed this group of compounds to move into clinical trials? (3) What is the evidence for early surgical decompression after SCI? METHODS We conducted a systematic review of MEDLINE and EMBASE-cited articles related to SCI to address these questions. RESULTS As a result of an improved understanding of the secondary mechanisms of SCI, specific clinical strategies have been established. We highlight three strategies that have made their way from bench to bedside: the sodium-glutamate antagonist riluzole, the Rho inhibitor Cethrin, and early surgical decompression. Each of these modalities is under clinical investigation. We highlight the fundamental science that led to this development. CONCLUSIONS As our understanding of the fundamental mechanisms of SCI improves, we must keep abreast of these discoveries to translate them into therapies that will hopefully benefit patients. We summarize this process of bench to bedside with regard to SCI.
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Abstract
STUDY DESIGN Literature review of basic scientific and clinical research in spinal cord injury (SCI). OBJECTIVE To provide physicians with an overview of the neurobiologic challenges of SCI, the current status of investigation for novel therapies that have been translated to human clinical trials, and the preclinical, scientific basis for each of these therapies. SUMMARY OF BACKGROUND DATA An abundance of recent scientific and clinical research activity has revealed numerous insights into the neurobiology of SCI, and has generated an abundance of potential therapies. An increasing number of such therapies are being translated into human SCI trials. Clinicians who attend to SCI patients are increasingly asked about potential treatments and clinical trials. METHODS Published data review of novel treatments that are either currently in human clinical trials for acute SCI or about to initiate clinical evaluation. RESULTS A number of treatments have bridged the "translational gap" and are currently either in the midst of human SCI trials, or are about to begin such clinical evaluation. These include minocycline, Cethrin, anti-Nogo antibodies, systemic hypothermia, Riluzole, magnesium chloride in polyethylene glycol, and human embryonic stem cell derived oligodendrocyte progenitors. A systematic review of the preclinical literature on these specific therapies reveals promising results in a variety of different SCI injury models. CONCLUSION The SCI community is encouraged by the progression of novel therapies from "bench to bedside" and the initiation of clinical trials for a number of different treatments. The task of clinical evaluation, however, is substantial, and many years will be required before the actual efficacy of the treatments currently in evaluation will be determined.
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Springer JE, Rao RR, Lim HR, Cho SI, Moon GJ, Lee HY, Park EJ, Noh JS, Gwag BJ. The functional and neuroprotective actions of Neu2000, a dual-acting pharmacological agent, in the treatment of acute spinal cord injury. J Neurotrauma 2010; 27:139-49. [PMID: 19772458 DOI: 10.1089/neu.2009.0952] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The goal of the present study was to examine the neuroprotective and functional significance of targeting both N-methyl-D-aspartate (NMDA) receptor-mediated excitotoxicity and oxidative stress using a dual-acting compound, Neu2000, in rat model of moderate spinal cord injury (SCI). An initial set of experiments was conducted in uninjured rats to study the pharmacokinetic profile of Neu2000 following intraperitoneal and intravenous administration. A second experiment measured free radical production in mitochondria isolated from sham or injured spinal cords of animals receiving vehicle or Neu2000 treatment. A third set of animals was divided into three treatment groups consisting of vehicle treatment, a single dose of Neu2000 (50 mg/kg) administered at 10 min following injury, or a repeated treatment paradigm consisting of a single bolus of Neu2000 at 10 min following injury (50 mg/kg) plus a maintenance dose (25 mg/kg) administered every 24 h for an additional 6 days. Animals were tested once a week for a period of 6 weeks for evidence of locomotor recovery in an open field and kinematic analysis of fine motor control using the DigiGait Image Analysis System. At the end of the testing period, spinal cord reconstruction was performed to obtain nonbiased stereological measures of tissue sparing. The results of this study demonstrate that Neu2000 treatment significantly reduced the production of mitochondrial free radicals and improved locomotor outcomes that were associated with a significant increase in the volume of spared spinal cord tissue.
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Affiliation(s)
- Joe E Springer
- Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, Kentucky 40536-0509, USA.
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Methylprednisolone fails to improve functional and histological outcome following spinal cord injury in rats. Exp Neurol 2009; 220:71-81. [DOI: 10.1016/j.expneurol.2009.07.030] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 07/27/2009] [Accepted: 07/28/2009] [Indexed: 11/22/2022]
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Kwon BK, Roy J, Lee JH, Okon E, Zhang H, Marx JC, Kindy MS. Magnesium Chloride in a Polyethylene Glycol Formulation as a Neuroprotective Therapy for Acute Spinal Cord Injury: Preclinical Refinement and Optimization. J Neurotrauma 2009; 26:1379-93. [DOI: 10.1089/neu.2009.0884] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Brian K. Kwon
- Combined Neurosurgical and Orthopaedic Spine Program (CNOSP), Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Josee Roy
- Medtronic Spine and Biologics, Memphis, Tennessee
| | - Jae H.T. Lee
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Elena Okon
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Hongbin Zhang
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Mark S. Kindy
- Medical University of South Carolina, Charleston, South Carolina
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Akhtar AZ, Pippin JJ, Sandusky CB. Animal studies in spinal cord injury: a systematic review of methylprednisolone. Altern Lab Anim 2009; 37:43-62. [PMID: 19292575 DOI: 10.1177/026119290903700108] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The objective of this study was to examine whether animal studies can reliably be used to determine the usefulness of methylprednisolone (MP) and other treatments for acute spinal cord injury (SCI) in humans. This was achieved by performing a systematic review of animal studies on the effects of MP administration on the functional outcome of acute SCI. Data were extracted from the published articles relating to: outcome; MP dosing regimen; species/strain; number of animals; methodological quality; type of injury induction; use of anaesthesia; functional scale used; and duration of follow-up. Subgroup analyses were performed, based on species or strain, injury method, MP dosing regimen, functional outcome measured, and methodological quality. Sixty-two studies were included, which involved a wide variety of animal species and strains. Overall, beneficial effects of MP administration were obtained in 34% of the studies, no effects in 58%, and mixed results in 8%. The results were inconsistent both among and within species, even when attempts were made to detect any patterns in the results through subgroup analyses. The results of this study demonstrate the barriers to the accurate prediction from animal studies of the effectiveness of MP in the treatment of acute SCI in humans. This underscores the need for the development and implementation of validated testing methods.
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Affiliation(s)
- Aysha Z Akhtar
- Physicians Committee for Responsible Medicine, Washington, DC, USA.
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Hawryluk GWJ, Rowland J, Kwon BK, Fehlings MG. Protection and repair of the injured spinal cord: a review of completed, ongoing, and planned clinical trials for acute spinal cord injury. Neurosurg Focus 2009; 25:E14. [PMID: 18980474 DOI: 10.3171/foc.2008.25.11.e14] [Citation(s) in RCA: 185] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Over the past 2 decades, advances in understanding the pathophysiology of spinal cord injury (SCI) have stimulated the recent emergence of several therapeutic strategies that are being examined in Phase I/II clinical trials. Ten randomized controlled trials examining methylprednisolone sodium succinate, tirilizad mesylate, monosialotetrahexosylganglioside, thyrotropin releasing hormone, gacyclidine, naloxone, and nimodipine have been completed. Although the primary outcomes in these trials were laregely negative, a secondary analysis of the North American Spinal Cord Injury Study II demonstrated that when administered within 8 hours of injury, methylprednisolone sodium succinate was associated with modest clinical benefits, which need to be weighed against potential complications. Thyrotropin releasing hormone (Phase II trial) and monosialotetrahexosylganglioside (Phase II and III trials) also showed some promise, but we are unaware of plans for future trials with these agents. These studies have, however, yielded many insights into the conduct of clinical trials for SCI. Several current or planned clinical trials are exploring interventions such as early surgical decompression (Surgical Treatment of Acute Spinal Cord Injury Study) and electrical field stimulation, neuroprotective strategies such as riluzole and minocycline, the inactivation of myelin inhibition by blocking Nogo and Rho, and the transplantation of various cellular substrates into the injured cord. Unfortunately, some experimental and poorly characterized SCI therapies are being offered outside a formal investigational structure, which will yield findings of limited scientific value and risk harm to patients with SCI who are understandably desperate for any intervention that might improve their function. Taken together, recent advances suggest that optimism for patients and clinicians alike is justified, as there is real hope that several safe and effective therapies for SCI may become available over the next decade.
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Affiliation(s)
- Gregory W J Hawryluk
- Division of Genetics and Development, Toronto Western Research Institute, Toronto, Ontario, Canada
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Kitzman PH. Effectiveness of riluzole in suppressing spasticity in the spinal cord injured rat. Neurosci Lett 2009; 455:150-3. [PMID: 19368865 DOI: 10.1016/j.neulet.2009.03.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 03/04/2009] [Accepted: 03/05/2009] [Indexed: 12/13/2022]
Abstract
UNLABELLED Spasticity poses a major detrimental impact on the quality of life in a significant number of people with spinal cord injury (SCI). Recent observations in our laboratory suggest that spinal transection at the sacral S(2) level induces a significant increase in glutamatergic input to sacrocaudal motoneurons during the time spasticity is present in the tail muscles. The present study examined the effectiveness of riluzole, an agent that has been shown to reduce glutamate release, in managing spasticity within the tail musculature. In this blinded, cross-over study animals with S(2) spinal transections were tested behaviorally for the progression of spasticity in the tail musculature using our established system. When the animals demonstrated a significant level of spastic behavior (e.g. increased response to quick stretch, noxious and non-noxious cutaneous stimuli), they received either saline or riluzole (8 or 10 mg/kg i.p.) and assessed behaviorally at 1, 3, 6, and 12 post-injection. RESULTS riluzole at 8 mg/kg significantly decreased the response of the tail muscle to noxious and non-noxious cutaneous stimuli for the first 3 h post-administration, while administration of riluzole at 10 mg/kg significantly decreased the responsiveness of the tail to all of the behavioral assessments. However, a significant percentage of the animals displayed motor impairments at this higher dosage. CONCLUSION suppression of glutamate release by the administration of riluzole can reduce several, but not all, aspects of spastic activity in the tail muscles at concentrations that do not elicit negative side-effects.
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Affiliation(s)
- Patrick H Kitzman
- Department of Rehabilitation Sciences, The University of Kentucky, Lexington, KY 40536-0200, USA.
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Chronic riluzole treatment increases glucose metabolism in rat prefrontal cortex and hippocampus. J Cereb Blood Flow Metab 2008; 28:1892-7. [PMID: 18628780 PMCID: PMC2739056 DOI: 10.1038/jcbfm.2008.78] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Riluzole is believed to modulate glutamatergic function by reducing glutamate release and facilitating astroglial uptake. We measured (13)C labeling in metabolites in prefrontal cortex and hippocampus during a 10 mins infusion of [1-(13)C]glucose in urethane anesthetized rats treated with riluzole (21 days, 4 mg/kg per day, i.p.) or saline. Total and (13)C concentrations of metabolites were determined in extracts using (1)H-[(13)C] NMR spectroscopy. In prefrontal cortex (P<0.05) and hippocampus (P<0.05) riluzole increased (13)C labeling over saline in glutamate-C4 (to 112% and 130%), GABA-C2 (to 142% and 171%), and glutamine-C4 (to 118% and 233%) without affecting total metabolite levels (P>0.2). Our findings indicate that contrary to expectation chronic riluzole enhanced glucose oxidative metabolism and glutamate/glutamine cycling.
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Tei R, Kaido T, Nakase H, Sakaki T. Protective effect of C1 esterase inhibitor on acute traumatic spinal cord injury in the rat. Neurol Res 2008; 30:761-7. [PMID: 18593519 DOI: 10.1179/174313208x284241] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE The complement system and activated neutrophils are thought to play a major role in initiating some of the inflammatory events that occur in spinal cord injury. The aim of the present study was to assess the effects of C1 esterase inhibitor (C1-INH) on traumatic spinal cord injury (SCI) in the rat. METHODS Thirty-eight male Wistar rats were used. Just after SCI by a pneumatic impact device, C1-INH (n=16, C1-INH group) or saline (n=16, saline group) was administered. Sham operated animals (n=6, sham group) received only laminectomy. Eighteen (six from each group) rats were killed and an assessment of leukocyte infiltration by myeloperoxidase (MPO) activity and immunoreactivity of MPO were performed 24 hours after SCI. Twenty (ten from each of C1-INH and saline groups) rats were examined using behavioral function on post-operative days. They were also examined after 7 days by histologic analysis using Luxol fast blue for axons and myelin. Lesion volume was calculated by considering a lesion as being composed of two cones with juxtaposed bases. During the experiment, sequential changes in regional spinal cord blood flow (rSCBF) were measured using the laser Doppler (LD) scanning technique. RESULTS The recovery of motor function was better in the C1-INH group than in the saline group. In the C1-INH group, immunoreactivity of MPO showed a tendency to be smaller than that of the saline group. Lesion volume was significantly smaller in the C1-INH group than in the control group (p<0.01) and MPO activity was also significantly smaller in the C1-INH group than in the control group (p<0.01). After SCI, the rSCBF value decreased gradually and significantly in both injured groups. Significant differences were observed from 30 to 120 minutes after SCI (p<0.05). DISCUSSION The results of this study provided the first evidence that C1-INH reduced accumulation of polymorphonuclear leukocytes (PMLs) and neuronal damage in acute stage after SCI. This protection was not related to an improvement in rSCBF.
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Affiliation(s)
- Rinsei Tei
- Department of Neurosurgery, Nara Medical University, Nara, Japan
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Abstract
BACKGROUND This review summarizes several promising pharmacological approaches for the therapeutic management of traumatic spinal cord injury (SCI), which are either in early-phase clinical trials or nearing clinical translation. OBJECTIVE This review provides the reader with an understanding of the key pathophysiological mechanisms that contribute to neurological deficits after SCI. Through discussion of the mechanism(s) of action of the selected therapeutic approaches potentially important targets to aid further drug discovery will be highlighted. METHODS Systematic literature review of the pre-clinical literature and clinical SCI trials related to neuroprotective, immunomodulatory and regenerative therapeutic approaches. RESULTS/CONCLUSION The next decade will witness an unprecedented number of clinical trials which will seek to translate key biomedical research discoveries. The promising drug-based therapeutic approaches include regenerative strategies to neutralize myelin-mediated neurite outgrowth inhibition, neuroprotective strategies to reduce apoptotic triggers, the targeting of cationic/glutamatergic toxicity, anti-inflammatory strategies and the use of approaches to stabilize disrupted cell membranes.
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Affiliation(s)
- Darryl C Baptiste
- Toronto Western Hospital, Division of Cellular & Molecular Biology, Toronto Western Research Institute and Krembil Neuroscience Centre, 12th Floor Room 407 McLaughlin Pavilion, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada
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Sullivan PG, Krishnamurthy S, Patel SP, Pandya JD, Rabchevsky AG. Temporal characterization of mitochondrial bioenergetics after spinal cord injury. J Neurotrauma 2007; 24:991-9. [PMID: 17600515 DOI: 10.1089/neu.2006.0242] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Mitochondrial dysfunction following spinal cord injury (SCI) may be critical for the development of secondary pathophysiology and neuronal cell death. Previous studies have demonstrated a loss of mitochondrial bioenergetics at 24 h following SCI. To begin to understand the evolution and study the contribution of mitochondrial dysfunction in pathophysiology of SCI, we investigated mitochondrial bioenergetics in the mid-thoracic region at 6, 12, and 24 h following contusion SCI. It is widely accepted that increased free radical generation plays a critical role in neuronal damage after SCI. Hence, to ascertain the role of free radicals in SCI-induced mitochondrial dysfunction, markers for oxidative damage, including nitrotyrosine (3-NT), lipid peroxidation byproduct (4-hydroxynonenal [HNE]), and protein oxidation (protein carbonyls) were quantified in the same samples of isolated mitochondria during the 24-h time course. The results demonstrate that a significant decline in mitochondrial function begins to occur 12 h post-injury and persists for a least 24 h following SCI. Furthermore, there was a progressive increase in mitochondrial oxidative damage that preceded the loss of mitochondrial bioenergetics, suggesting that free radical damage may be a major mitochondrial secondary injury process. Based on the present results, the temporal profile of mitochondrial dysfunction indicates that interventions targeting mitochondrial oxidative damage and dysfunction may serve as a beneficial pharmacological treatment for acute SCI.
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Affiliation(s)
- Patrick G Sullivan
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky 40536-0509, USA
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Trivedi A, Olivas AD, Noble-Haeusslein LJ. Inflammation and Spinal Cord Injury: Infiltrating Leukocytes as Determinants of Injury and Repair Processes. ACTA ACUST UNITED AC 2006; 6:283-292. [PMID: 18059979 DOI: 10.1016/j.cnr.2006.09.007] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The immune response that accompanies spinal cord injury contributes to both injury and reparative processes. It is this duality that is the focus of this review. Here we consider the complex cellular and molecular immune responses that lead to the infiltration of leukocytes and glial activation, promote oxidative stress and tissue damage, influence wound healing, and subsequently modulate locomotor recovery. Immunomodulatory strategies to improve outcomes are gaining momentum as ongoing research carefully dissects those pathways, which likely mediate cell injury from those, which favor recovery processes. Current therapeutic strategies address divergent approaches including early immunoblockade and vaccination with immune cells to prevent early tissue damage and support a wound-healing environment that favors plasticity. Despite these advances, there remain basic questions regarding how inflammatory cells interact in the injured spinal cord. Such questions likely arise as a result of our limited understanding of immune cell/neural interactions in a dynamic environment that culminates in progressive cell injury, demyelination, and regenerative failure.
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Affiliation(s)
- Alpa Trivedi
- Department of Neurosurgery, University of California San Francisco, CA 94143
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McEwen ML, Springer JE. Quantification of Locomotor Recovery following Spinal Cord Contusion in Adult Rats. J Neurotrauma 2006; 23:1632-53. [PMID: 17115910 DOI: 10.1089/neu.2006.23.1632] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Injury to the spinal cord not only disrupts the functioning of spinal circuits at the site of the impact, but also limits sensorimotor function caudal to the level of the lesion. Ratings of gross locomotor skill are generally used to quantify locomotor recovery following spinal cord injury (SCI). The purpose of this study was to assess behavioral recovery following SCI with three tasks: (1) BBB ratings, (2) walking on a horizontal ladder, and (3) footprint analyses. Behavioral testing was conducted for 6 postoperative weeks, and then the spinal cords were processed for the amount of white matter spared. As expected, BBB ratings dramatically decreased and then improved during recovery. The number of hindlimb foot-faults on the horizontal ladder increased after injury and remained elevated during the recovery period. Footprint analyses revealed that sham-control rats used several different gaits to cross the runway. In contrast, the locomotor function of rats with a SCI was impaired throughout the postoperative period. Some locomotor parameters of the injured rats improved slightly (velocity, stride length, stride duration, stance duration), some did not change (interlimb coordination, swing duration, forelimb base of support, hindpaw angle), and others declined (hindlimb base of support) during the recovery period. Together, these results show that gross locomotor skill improved after SCI, while recovery of fine locomotor function was more limited. Multiple tests should be included in future experiments in order to assess gross and fine changes in sensorimotor function following SCI.
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Affiliation(s)
- Melanie L McEwen
- University of Kentucky Medical Center, Department of Physical Medicine and Rehabilitation, Lexington, Kentucky 40536, USA.
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Abstract
Acute traumatic spinal cord injury (SCI) results in a devastating loss of neurological function below the level of injury and adversely affects multiple systems within the body. The pathobiology of SCI involves a primary mechanical insult to the spinal cord and activation of a delayed secondary cascade of events, which ultimately causes progressive degeneration of the spinal cord. Whereas cell death from the mechanical injury is predominated by necrosis, secondary injury events trigger a continuum of necrotic and apoptotic cell death mechanisms. These secondary events include vascular abnormalities, ischemia-reperfusion, glutamate excitotoxicity and disturbances in ionic homeostasis, oxidative cell injury, and a robust inflammatory response. No gold standard therapy for SCI has been established, although clinical trials with methylprednisolone (NASCIS II and III) and GM-1 ganglioside (Maryland and Sygen) have demonstrated modest, albeit potentially important therapeutic benefits. In light of the overwhelming impact of SCI on the individual, other therapeutic interventions are urgently needed. A number of promising pharmacological therapies are currently under investigation for neuroprotective abilities in animal models of SCI. These include the sodium (Na+) channel blocker riluzole, the tetracycline derivative minocycline, the fusogen copolymer polyethylene glycol (PEG), and the tissue-protective hormone erythropoietin (EPO). Moreover, clinical trials investigating the putative neuroprotective and neuroregenerative properties ascribed to the Rho pathway antagonist, Cethrin (BioAxone Therapeutic, Inc.), and implantation of activated autologous macrophages (ProCord; Proneuron Biotechnologies) in patients with thoracic and cervical SCI are now underway. We anticipate that these studies will harken an era of renewed interest in translational clinical trials. Ultimately, due to the multi-factorial pathophysiology of traumatic SCI, effective therapies will require combined approaches.
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Affiliation(s)
- Darryl C Baptiste
- Division of Cell and Molecular Biology, Toronto Western Research Institute and Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
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López-Vales R, García-Alías G, Forés J, Udina E, Gold BG, Navarro X, Verdú E. FK 506 reduces tissue damage and prevents functional deficit after spinal cord injury in the rat. J Neurosci Res 2005; 81:827-36. [PMID: 16041804 DOI: 10.1002/jnr.20605] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We examined the efficacy of FK 506 in reducing tissue damage after spinal cord injury in comparison to methylprednisolone (MP) treatment. Rats were subjected to a photochemical injury (T8) and were given a bolus of MP (30 mg/kg), FK 506 (2 mg/kg), or saline. An additional group received an initial bolus of FK 506 (2 mg/kg) followed by daily injections (0.2 mg/kg intraperitoneally). Functional recovery was evaluated using open-field walking, inclined plane tests, motor evoked potentials (MEPs), and the H-reflex response during 14 days postoperation (dpo). Tissue sparing and glial fibrillary acidic protein (GFAP), biotinylated tomato lectin LEC, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and interleukin 1 beta (IL-1 beta) immunoreactivity were quantified in the injured spinal cord. FK 506-treated animals demonstrated significantly better neurologic outcome, higher MEP amplitudes, and lower H-wave amplitude compared to that of saline-treated rats. In contrast, administration of MP did not result in significant differences with respect to the saline-treated group. Histologic examination revealed that tissue sparing was largest in FK 506-treated compared to saline and MP-treated animals. GFAP and COX-2 reactivity was decreased in animals treated with FK 506 compared to that in animals given MP or saline, whereas IL-1 beta expression was similarly reduced in both FK 506- and MP-treated groups. Microglia/macrophage response was reduced in FK 506 and MP-injected animals at 3 dpo, but only in MP-treated animals at 7 dpo with respect to saline-injected rats. Repeated administrations of FK 506 improved functional and histologic results to a greater degree than did a single bolus of FK 506. The results indicate that FK 506 administration protects the damaged spinal cord and should be considered as potential therapy for treating spinal cord injuries.
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Affiliation(s)
- Rubèn López-Vales
- Group of Neuroplasticity and Regeneration, Institute of Neuroscience and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Bellaterra, Spain
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Risterucci C, Coccurello R, Banasr M, Stutzmann JM, Amalric M, Nieoullon A. The metabotropic glutamate receptor subtype 5 antagonist MPEP and the Na+ channel blocker riluzole show different neuroprotective profiles in reversing behavioral deficits induced by excitotoxic prefrontal cortex lesions. Neuroscience 2005; 137:211-20. [PMID: 16242848 DOI: 10.1016/j.neuroscience.2005.08.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Revised: 07/02/2005] [Accepted: 08/23/2005] [Indexed: 10/25/2022]
Abstract
Overactivation of excitatory amino acid receptors has been involved in several neurodegenerative diseases. The present study aims at investigating the potential neuroprotective action of 2-methyl-6-(phenylethylnyl)-pyridine (MPEP), a selective non-competitive antagonist of metabotropic glutamate receptor subtype 5, and 2-amino-6-trifluoro methoxy-benzothiole (riluzole), a Na+ channel blocker exhibiting anti-glutamatergic properties, on the ibotenate-induced damage to the rat medial prefrontal cortex. The neuroprotective efficacy of these compounds was assessed on the recovery from behavioral deficits induced by prefrontal cortical excitotoxic lesions in a reaction time task. MPEP (3, 10 or 30 mg/kg) or riluzole (2, 4 or 8 mg/kg) was administered i.p. 30 min before and after medial prefrontal cortex lesions. As previously found, lesions to the medial prefrontal cortex significantly altered the motor preparatory processes involved in the reaction time task. These deficits were prevented by MPEP 3 mg/kg and riluzole 2 mg/kg while higher doses of either compound were ineffective. Furthermore, the neuron-specific nuclear protein immunostaining of the lesioned cortical area in animals treated with the efficient dose of either compound revealed that MPEP reduced the volume of the lesion whereas riluzole reversed the decrease of neuronal density within the lesioned area. Altogether, these results suggest a neuroprotective action of MPEP as well as riluzole at both behavioral and cellular levels on excitatory amino acid-induced toxicity.
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Affiliation(s)
- C Risterucci
- Laboratoire de Neurobiologie de la Cognition, CNRS UMR 6155, Université de Provence, Case C, 3 place Victor Hugo, 13331 Marseille cedex 3, France
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Fouad K, Schnell L, Bunge MB, Schwab ME, Liebscher T, Pearse DD. Combining Schwann cell bridges and olfactory-ensheathing glia grafts with chondroitinase promotes locomotor recovery after complete transection of the spinal cord. J Neurosci 2005; 25:1169-78. [PMID: 15689553 PMCID: PMC6725952 DOI: 10.1523/jneurosci.3562-04.2005] [Citation(s) in RCA: 352] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Numerous obstacles to successful regeneration of injured axons in the adult mammalian spinal cord exist. Consequently, a treatment strategy inducing axonal regeneration and significant functional recovery after spinal cord injury has to overcome these obstacles. The current study attempted to address multiple impediments to regeneration by using a combinatory strategy after complete spinal cord transection in adult rats: (1) to reduce inhibitory cues in the glial scar (chondroitinase ABC), (2) to provide a growth-supportive substrate for axonal regeneration [Schwann cells (SCs)], and (3) to enable regenerated axons to exit the bridge to re-enter the spinal cord (olfactory ensheathing glia). The combination of SC bridge, olfactory ensheathing glia, and chondroitinase ABC provided significant benefit compared with grafts only or the untreated group. Significant improvements were observed in the Basso, Beattie, and Bresnahan score and in forelimb/hindlimb coupling. This recovery was accompanied by increased numbers of both myelinated axons in the SC bridge and serotonergic fibers that grew through the bridge and into the caudal spinal cord. Although prominent descending tracts such as the corticospinal and reticulospinal tracts did not successfully regenerate through the bridge, it appeared that other populations of regenerated fibers were the driving force for the observed recovery; there was a significant correlation between numbers of myelinated fibers in the bridge and improved coupling of forelimb and hindlimb as well as open-field locomotion. Our study tests how proven experimental treatments interact in a well-established animal model, thus providing needed direction for the development of future combinatory treatment regimens.
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Affiliation(s)
- Karim Fouad
- University of Alberta, Faculty of Rehabilitation Medicine, Edmonton, Canada T6G 2G4.
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