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Qu W, Wu X, Wu W, Wang Y, Sun Y, Deng L, Walker M, Chen C, Dai H, Han Q, Ding Y, Xia Y, Smith G, Li R, Liu NK, Xu XM. Chondroitinase ABC combined with Schwann cell transplantation enhances restoration of neural connection and functional recovery following acute and chronic spinal cord injury. Neural Regen Res 2025; 20:1467-1482. [PMID: 39075913 DOI: 10.4103/nrr.nrr-d-23-01338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 05/16/2024] [Indexed: 07/31/2024] Open
Abstract
JOURNAL/nrgr/04.03/01300535-202505000-00029/figure1/v/2024-07-28T173839Z/r/image-tiff Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties. A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury. A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity, and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar, thus limiting axonal reentry into the host spinal cord. Here we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord injury. We report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders, Schwann cells migrated for considerable distances in both rostral and caudal directions. Such Schwann cell migration led to enhanced axonal regrowth, including the serotonergic and dopaminergic axons originating from supraspinal regions, and promoted recovery of locomotor and urinary bladder functions. Importantly, the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury, even when treatment was delayed for 3 months to mimic chronic spinal cord injury. These findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.
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Affiliation(s)
- Wenrui Qu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Hand Surgery, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Xiangbing Wu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Wei Wu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ying Wang
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Yan Sun
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Lingxiao Deng
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Melissa Walker
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chen Chen
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Heqiao Dai
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Qi Han
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ying Ding
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Yongzhi Xia
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - George Smith
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - Rui Li
- Department of Hand Surgery, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Nai-Kui Liu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Xiao-Ming Xu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
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2
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Pradhyumnan H, Perez GG, Patel SH, Blaya MO, Bramlett HM, Raval AP. A Perspective on Hormonal Contraception Usage in Central Nervous System Injury. J Neurotrauma 2024; 41:541-551. [PMID: 37975282 DOI: 10.1089/neu.2023.0219] [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] [Indexed: 11/19/2023] Open
Abstract
Naturally occurring life stages in women are associated with changes in the milieu of endogenous ovarian hormones. Women of childbearing age may be exposed to exogenous ovarian hormone(s) because of their use of varying combinations of estrogen and progesterone hormones-containing oral contraceptives (OC; also known as "the pill"). If women have central nervous system (CNS) injury such as spinal cord injury (SCI) and traumatic brain injury (TBI) during their childbearing age, they are likely to retain their reproductive capabilities and may use OC. Many deleterious side effects of long-term OC use have been reported, such as aberrant blood clotting and endothelial dysfunction that consequently increase the risk of myocardial infarction, venous thromboembolism, and ischemic brain injury. Although controversial, studies have suggested that OC use is associated with neuropsychiatric ramifications, including uncontrollable mood swings and poorer cognitive performance. Our understanding about how the combination of endogenous hormones and OC-conferred exogenous hormones affect outcomes after CNS injuries remains limited. Therefore, understanding the impact of OC use on CNS injury outcomes needs further investigation to reveal underlying mechanisms, promote reporting in clinical or epidemiological studies, and raise awareness of possible compounded consequences. The goal of the current review is to discuss the impacts of CNS injury on endogenous ovarian hormones and vice-versa, as well as the putative consequences of exogenous ovarian hormones (OC) on the CNS to identify potential gaps in our knowledge to consider for future laboratory, epidemiological, and clinical studies.
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Affiliation(s)
- Hari Pradhyumnan
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratory (CVDRL), Department of Neurology, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Gina G Perez
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratory (CVDRL), Department of Neurology, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Shahil H Patel
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratory (CVDRL), Department of Neurology, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Meghan O Blaya
- Department of Neurological Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, USA
- The Miami Project to Cure Paralysis, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Helen M Bramlett
- Department of Neurological Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, USA
- The Miami Project to Cure Paralysis, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, USA
- Bruce W. Carter Department of Veterans Affairs Medical Center, Miami, Florida, USA
| | - Ami P Raval
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratory (CVDRL), Department of Neurology, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, USA
- Bruce W. Carter Department of Veterans Affairs Medical Center, Miami, Florida, USA
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3
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Liu NK, Deng LX, Wang M, Lu QB, Wang C, Wu X, Wu W, Wang Y, Qu W, Han Q, Xia Y, Ravenscraft B, Li JL, You SW, Wipf P, Han X, Xu XM. Restoring mitochondrial cardiolipin homeostasis reduces cell death and promotes recovery after spinal cord injury. Cell Death Dis 2022; 13:1058. [PMID: 36539405 PMCID: PMC9768173 DOI: 10.1038/s41419-022-05369-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 09/06/2022] [Accepted: 10/24/2022] [Indexed: 12/24/2022]
Abstract
Alterations in phospholipids have long been associated with spinal cord injury (SCI). However, their specific roles and signaling cascades in mediating cell death and tissue repair remain unclear. Here we investigated whether alterations of cardiolipin (CL), a family of mitochondrion-specific phospholipids, play a crucial role in mitochondrial dysfunction and neuronal death following SCI. Lipidomic analysis was used to determine the profile of CL alteration in the adult rat spinal cord following a moderate contusive SCI at the 10th thoracic (T10) level. Cellular, molecular, and genetic assessments were performed to determine whether CL alterations mediate mitochondrial dysfunction and neuronal death after SCI, and, if so, whether reversing CL alteration leads to neuroprotection after SCI. Using lipidomic analysis, we uncovered CL alterations at an early stage of SCI. Over 50 distinct CL species were identified, of which 50% showed significantly decreased abundance after SCI. The decreased CL species contained mainly polyunsaturated fatty acids that are highly susceptible to peroxidation. In parallel, 4-HNE, a lipid peroxidation marker, significantly increased after SCI. We found that mitochondrial oxidative stress not only induced CL oxidation, but also resulted in CL loss by activating cPLA2 to hydrolyze CL. CL alterations induced mitochondrial dysfunction and neuronal death. Remarkably, pharmacologic inhibition of CL alterations with XJB-5-131, a novel mitochondria-targeted electron and reactive oxygen species scavenger, reduced cell death, tissue damage and ameliorated motor deficits after SCI in adult rats. These findings suggest that CL alteration could be a novel mechanism that mediates injury-induced neuronal death, and a potential therapeutic target for ameliorating secondary SCI.
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Affiliation(s)
- Nai-Kui Liu
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Ling-Xiao Deng
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Miao Wang
- Frontage Laboratories, Exton, PA 19341 USA
| | - Qing-Bo Lu
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Chunyan Wang
- grid.4367.60000 0001 2355 7002Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - Xiangbing Wu
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Wei Wu
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Ying Wang
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Wenrui Qu
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Qi Han
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Yongzhi Xia
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Baylen Ravenscraft
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Jin-Lian Li
- grid.233520.50000 0004 1761 4404Department of Anatomy and K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi’an, 710032 P. R. China
| | - Si-Wei You
- grid.233520.50000 0004 1761 4404Institute of Neuroscience, The Fourth Military Medical University, Xi’an, P. R. China
| | - Peter Wipf
- grid.21925.3d0000 0004 1936 9000Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 USA
| | - Xianlin Han
- grid.267309.90000 0001 0629 5880Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229 USA
| | - Xiao-Ming Xu
- grid.257413.60000 0001 2287 3919Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202 USA
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4
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Goins J, Henkel N, Coulibaly AP, Isaacson LG. Activated Microglia in the Rat Spinal Cord Following Peripheral Axon Injury Promote Glial and Neuronal Plasticity Which is Necessary for Long-Term Neuronal Survival. Cell Mol Neurobiol 2021; 41:309-326. [PMID: 32335774 DOI: 10.1007/s10571-020-00853-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 04/16/2020] [Indexed: 12/11/2022]
Abstract
Following the transection of peripheral sympathetic preganglionic axons comprising the cervical sympathetic trunk (CST), we observe robust glial and neuronal plasticity at 1 week post-injury in the rat spinal cord intermediolateral cell column (IML), which houses the injured parent neuronal cell bodies. This plasticity contributes to neuroprotection, as no neuronal loss in the IML is present at 16 weeks post-injury. Here, we administered the antibiotic minocycline or vehicle (VEH) daily for 1 week after CST transection to investigate the role of activated microglia in IML glial and neuronal plasticity and subsequent neuronal survival. At 1 week post-injury, minocycline treatment did not alter microglia number in the IML, but led to a dampened microglia activation state. In addition, the increases in oligodendrocyte (OL) lineage cells and activated astrocytes following injury in VEH rats were attenuated in the minocycline-treated rats. Further, the normal downregulation of choline acetyltransferase (ChAT) in the injured neurons was blunted. At 16 weeks post-injury, fewer ChAT+ neurons were present in the minocycline-treated rats, suggesting that activated microglia together with the glial and neuronal plasticity at 1 week post-injury contribute to the long-term survival of the injured neurons. These results provide evidence for beneficial crosstalk between activated microglia and neurons as well as other glial cells in the cord following peripheral axon injury, which ultimately leads to neuroprotection. The influences of microglia activation in promoting neuronal survival should be considered when developing therapies to administer minocycline for the treatment of neurological pathologies.
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Affiliation(s)
- Jessie Goins
- Center for Neuroscience and Behavior, Miami University, Oxford, OH, 45056, USA
- Department of Biology, Miami University, Oxford, OH, 45056, USA
| | - Nicholas Henkel
- Center for Neuroscience and Behavior, Miami University, Oxford, OH, 45056, USA
- Department of Biology, Miami University, Oxford, OH, 45056, USA
| | - Aminata P Coulibaly
- Center for Neuroscience and Behavior, Miami University, Oxford, OH, 45056, USA
- Department of Biology, Miami University, Oxford, OH, 45056, USA
| | - Lori G Isaacson
- Center for Neuroscience and Behavior, Miami University, Oxford, OH, 45056, USA.
- Department of Biology, Miami University, Oxford, OH, 45056, USA.
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5
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Yu CG, Bondada V, Ghoshal S, Singh R, Pistilli CK, Dayaram K, Iqbal H, Sands M, Davis KL, Bondada S, Geddes JW. Repositioning Flubendazole for Spinal Cord Injury. J Neurotrauma 2019; 36:2618-2630. [PMID: 30747048 DOI: 10.1089/neu.2018.6160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We previously reported the serendipitous observation that fenbendazole, a benzimidazole anthelmintic, improved functional and pathological outcomes following thoracic spinal cord contusion injury in mice when administered pre-injury. Fenbendazole is widely used in veterinary medicine. However, it is not approved for human use and it was uncertain if only post-injury administration would offer similar benefits. In the present study we evaluated post-injury administration of a closely related, human anthelmintic drug, flubendazole, using a rat spinal cord contusion injury model. Flubendazole, administered i.p. 5 or 10 mg/kg day, beginning 3 h post-injury and daily thereafter for 2 or 4 weeks, resulted in improved locomotor function after contusion spinal cord injury (SCI) compared with vehicle-treated controls. Histological analysis of spinal cord sections showed that such treatment with flubendazole also reduced lesion volume and improved total tissue sparing, white matter sparing, and gray matter sparing. Flubendazole inhibited the activation of glial fibrillary acidic protein (GFAP); suppressed cyclin B1 expression and Bruton tyrosine kinase activation, markers of B cell activation/proliferation and inflammation; and reduced B cell autoimmune response. Together, these results suggest the use of the benzimidazole anthelmintic flubendazole as a potential therapeutic for SCI.
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Affiliation(s)
- Chen Guang Yu
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Vimala Bondada
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Sarbani Ghoshal
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Ranjana Singh
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Christina K Pistilli
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Kavi Dayaram
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Hina Iqbal
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Madison Sands
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Kate L Davis
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Subarrao Bondada
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky
| | - James W Geddes
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, Kentucky
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Chakrabarti M, Das A, Samantaray S, Smith JA, Banik NL, Haque A, Ray SK. Molecular mechanisms of estrogen for neuroprotection in spinal cord injury and traumatic brain injury. Rev Neurosci 2016; 27:271-81. [DOI: 10.1515/revneuro-2015-0032] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 08/27/2015] [Indexed: 01/18/2023]
Abstract
AbstractEstrogen (EST) is a steroid hormone that exhibits several important physiological roles in the human body. During the last few decades, EST has been well recognized as an important neuroprotective agent in a variety of neurological disorders in the central nervous system (CNS), such as spinal cord injury (SCI), traumatic brain injury (TBI), Alzheimer’s disease, and multiple sclerosis. The exact molecular mechanisms of EST-mediated neuroprotection in the CNS remain unclear due to heterogeneity of cell populations that express EST receptors (ERs) in the CNS as well as in the innate and adaptive immune system. Recent investigations suggest that EST protects the CNS from injury by suppressing pro-inflammatory pathways, oxidative stress, and cell death, while promoting neurogenesis, angiogenesis, and neurotrophic support. In this review, we have described the currently known molecular mechanisms of EST-mediated neuroprotection and neuroregeneration in SCI and TBI. At the same time, we have emphasized on the recent in vitro and in vivo findings from our and other laboratories, implying potential clinical benefits of EST in the treatment of SCI and TBI.
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Affiliation(s)
- Mrinmay Chakrabarti
- 1Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, 6439 Garners Ferry Road, Columbia, SC 29209, USA
| | - Arabinda Das
- 2Department of Neurosurgery and Neurology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Supriti Samantaray
- 2Department of Neurosurgery and Neurology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Joshua A. Smith
- 2Department of Neurosurgery and Neurology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Naren L. Banik
- 2Department of Neurosurgery and Neurology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Azizul Haque
- 3Department of Microbiology and Immunology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Swapan K. Ray
- 1Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, 6439 Garners Ferry Road, Columbia, SC 29209, USA
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Ewan EE, Hagg T. Intrathecal Acetyl-L-Carnitine Protects Tissue and Improves Function after a Mild Contusive Spinal Cord Injury in Rats. J Neurotrauma 2015; 33:269-77. [PMID: 26415041 DOI: 10.1089/neu.2015.4030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Primary and secondary ischemia after spinal cord injury (SCI) contributes to tissue and axon degeneration, which may result from decreased energy substrate availability for cellular and axonal mitochondrial adenosine triphosphate (ATP) production. Therefore, providing spinal tissue with an alternative energy substrate during ischemia may be neuroprotective after SCI. To assess this, rats received a mild contusive SCI (120 kdyn, Infinite Horizons impactor) at thoracic level 9 (T9), which causes loss of ∼ 80% of the ascending sensory dorsal column axonal projections to the gracile nucleus. Immediately afterwards, the energy substrate acetyl-L-carnitine (ALC; 1 mg/day) or phosphate-buffered saline (PBS) was infused intrathecally (sub-arachnoid) for 6 days via an L5/6 catheter attached to a subcutaneous Alzet pump. ALC treatment improved overground locomotor function (Basso-Beattie-Breshnahan [BBB] score 18 vs. 13) at 6 days, total spared epicenter (71% vs. 57%) and penumbra white matter (90% vs. 85%), ventral penumbra microvessels (108% vs. 79%), and penumbra motor neurons (42% vs. 15%) at 15 days post-SCI, compared with PBS treatment. However, the ascending sensory projections (anterogradely traced with cholera toxin B from the sciatic nerves) and dorsal column white matter and perfused blood vessels were not protected. Furthermore, grid walking, a task we have shown to be dependent on dorsal column function, was not improved. Thus, mitochondrial substrate replacement may only be efficacious in areas of lesser or temporary ischemia, such as the ventral spinal cord and injury penumbra in this study. The current data also support our previous evidence that microvessel loss is central to secondary tissue degeneration.
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Affiliation(s)
- Eric E Ewan
- Kentucky Spinal Cord Injury Research Center and Department of Neurological Surgery, University of Louisville , Louisville, Kentucky
| | - Theo Hagg
- Kentucky Spinal Cord Injury Research Center and Department of Neurological Surgery, University of Louisville , Louisville, Kentucky
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8
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Liu NK, Deng LX, Zhang YP, Lu QB, Wang XF, Hu JG, Oakes E, Bonventre JV, Shields CB, Xu XM. Cytosolic phospholipase A2 protein as a novel therapeutic target for spinal cord injury. Ann Neurol 2014; 75:644-58. [PMID: 24623140 PMCID: PMC4320750 DOI: 10.1002/ana.24134] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 02/28/2014] [Accepted: 03/10/2014] [Indexed: 12/17/2022]
Abstract
Objective The objective of this study was to investigate whether cytosolic phospholipase A2 (cPLA2), an important isoform of PLA2 that mediates the release of arachidonic acid, plays a role in the pathogenesis of spinal cord injury (SCI). Methods A combination of molecular, histological, immunohistochemical, and behavioral assessments were used to test whether blocking cPLA2 activation pharmacologically or genetically reduced cell death, protected spinal cord tissue, and improved behavioral recovery after a contusive SCI performed at the 10th thoracic level in adult mice. Results SCI significantly increased cPLA2 expression and activation. Activated cPLA2 was localized mainly in neurons and oligodendrocytes. Notably, the SCI-induced cPLA2 activation was mediated by the extracellular signal-regulated kinase signaling pathway. In vitro, activation of cPLA2 by ceramide-1-phosphate or A23187 induced spinal neuronal death, which was substantially reversed by arachidonyl trifluoromethyl ketone, a cPLA2 inhibitor. Remarkably, blocking cPLA2 pharmacologically at 30 minutes postinjury or genetically deleting cPLA2 in mice ameliorated motor deficits, and reduced cell loss and tissue damage after SCI. Interpretation cPLA2 may play a key role in the pathogenesis of SCI, at least in the C57BL/6 mouse, and as such could be an attractive therapeutic target for ameliorating secondary tissue damage and promoting recovery of function after SCI.
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Affiliation(s)
- Nai-Kui Liu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, and Goodman Campbell Brain and Spine, Indiana University School of Medicine, Indianapolis, IN
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9
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Mosquera L, Colón JM, Santiago JM, Torrado AI, Meléndez M, Segarra AC, Rodríguez-Orengo JF, Miranda JD. Tamoxifen and estradiol improved locomotor function and increased spared tissue in rats after spinal cord injury: their antioxidant effect and role of estrogen receptor alpha. Brain Res 2014; 1561:11-22. [PMID: 24637260 DOI: 10.1016/j.brainres.2014.03.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/20/2014] [Accepted: 03/05/2014] [Indexed: 12/17/2022]
Abstract
17β-Estradiol is a multi-active steroid that imparts neuroprotection via diverse mechanisms of action. However, its role as a neuroprotective agent after spinal cord injury (SCI), or the involvement of the estrogen receptor-alpha (ER-α) in locomotor recovery, is still a subject of much debate. In this study, we evaluated the effects of estradiol and of Tamoxifen (an estrogen receptor mixed agonist/antagonist) on locomotor recovery following SCI. To control estradiol cyclical variability, ovariectomized female rats received empty or estradiol filled implants, prior to a moderate contusion to the spinal cord. Estradiol improved locomotor function at 7, 14, 21, and 28 days post injury (DPI), when compared to control groups (measured with the BBB open field test). This effect was ER-α mediated, because functional recovery was blocked with an ER-α antagonist. We also observed that ER-α was up-regulated after SCI. Long-term treatment (28 DPI) with estradiol and Tamoxifen reduced the extent of the lesion cavity, an effect also mediated by ER-α. The antioxidant effects of estradiol were seen acutely at 2 DPI but not at 28 DPI, and this acute effect was not receptor mediated. Rats treated with Tamoxifen recovered some locomotor activity at 21 and 28 DPI, which could be related to the antioxidant protection seen at these time points. These results show that estradiol improves functional outcome, and these protective effects are mediated by the ER-α dependent and independent-mechanisms. Tamoxifen׳s effects during late stages of SCI support the use of this drug as a long-term alternative treatment for this condition.
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Affiliation(s)
- Laurivette Mosquera
- Department of Physiology, University of Puerto Rico-School of Medicine, San Juan, PR 00936, USA
| | - Jennifer M Colón
- Department of Physiology, University of Puerto Rico-School of Medicine, San Juan, PR 00936, USA
| | - José M Santiago
- University of Puerto Rico Carolina Campus, Department of Natural Sciences, Carolina, PR 00984, USA
| | - Aranza I Torrado
- Department of Physiology, University of Puerto Rico-School of Medicine, San Juan, PR 00936, USA
| | | | - Annabell C Segarra
- Department of Physiology, University of Puerto Rico-School of Medicine, San Juan, PR 00936, USA
| | - José F Rodríguez-Orengo
- Department of Biochemistry, University of Puerto Rico-School of Medicine, San Juan, PR 00936, USA
| | - Jorge D Miranda
- Department of Physiology, University of Puerto Rico-School of Medicine, San Juan, PR 00936, USA.
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Muradov JM, Ewan EE, Hagg T. Dorsal column sensory axons degenerate due to impaired microvascular perfusion after spinal cord injury in rats. Exp Neurol 2013; 249:59-73. [PMID: 23978615 DOI: 10.1016/j.expneurol.2013.08.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/05/2013] [Accepted: 08/17/2013] [Indexed: 11/27/2022]
Abstract
The mechanisms contributing to axon loss after spinal cord injury (SCI) are largely unknown but may involve microvascular loss as we have previously suggested. Here, we used a mild contusive injury (120 kdyn IH impactor) at T9 in rats focusing on ascending primary sensory dorsal column axons, anterogradely traced from the sciatic nerves. The injury caused a rapid and progressive loss of dorsal column microvasculature and oligodendrocytes at the injury site and penumbra and an ~70% loss of the sensory axons by 24 h. To model the microvascular loss, focal ischemia of the T9 dorsal columns was achieved via phototoxic activation of intravenously injected rose bengal. This caused an ~53% loss of sensory axons and an ~80% loss of dorsal column oligodendrocytes by 24 h. Axon loss correlated with the extent and axial length of microvessel and oligodendrocyte loss along the dorsal column. To determine if oligodendrocyte loss contributes to axon loss, the glial toxin ethidium bromide (EB; 0.3 μg/μl) was microinjected into the T9 dorsal columns, and resulted in an ~88% loss of dorsal column oligodendrocytes and an ~56% loss of sensory axons after 72 h. EB also caused an ~75% loss of microvessels. Lower concentrations of EB resulted in less axon, oligodendrocyte and microvessel loss, which were highly correlated (R(2) = 0.81). These data suggest that focal spinal cord ischemia causes both oligodendrocyte and axon degeneration, which are perhaps linked. Importantly, they highlight the need of limiting the penumbral spread of ischemia and oligodendrocyte loss after SCI in order to protect axons.
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Affiliation(s)
- Johongir M Muradov
- Kentucky Spinal Cord Injury Research Center, University of Louisville, KY 40292, USA; Department of Neurological Surgery, University of Louisville, KY 40292, USA
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Rapid activation of nuclear factor κB by 17β-estradiol and selective estrogen receptor modulators: pathways mediating cellular protection. Shock 2012; 38:128-36. [PMID: 22683727 DOI: 10.1097/shk.0b013e31825da754] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
17β-Estradiol (E2) treatment activates a set of protective response that has been found to protect cells from injury and more importantly to significantly abate the injuries associated with trauma-hemorrhage in vivo. Rapid NF-κB activation has been found to be an important signaling step in E2-mediated protection in cell culture, in vivo ischemia, and trauma-hemorrhage. In the current study, we investigated the signaling cascades linking E2 signaling with NF-κB activation and the protective response and compared them with the effects of two selective estrogen receptor modulators (SERMs), raloxifene and tamoxifen. Two candidate pathways, mitogen-activated protein kinases and phosphatidylinositol-3-kinase (PI3K) were studied. Selective inhibitors were used to identify each pathway's contribution to NF-κB activation. Treatment of human coronary artery endothelial cells with E2 activated PI3K/Akt, p38, and JNK, all of which activated ERK1/2 followed by NF-κB activation. The combined activation of Akt, p38, and JNK was essential to activate NF-κB. The two SERMs activated PI3K and p38, which then phosphorylated ERK1/2 and activated NF-κB independent of the JNK pathway. Nuclear factor κB activation by these compounds protected cells from hypoxia/reoxygenation injury. However, E2, unlike either SERM, led to modest increases in apoptosis through the JNK pathway. Selective estrogen receptor modulator treatment led to increased expression of the protective proteins, Mn superoxide dismutase, and endothelial nitric oxide synthase, which was not seen with E2. These results provide new insight into the pathways activating NF-κB by E2 and SERMs and demonstrate that SERMs may have greater protective benefits than E2 in adult endothelial cells and potentially in vivo, as well.
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Tehranipou M, Ghadamyari T. The Effects of Root Aquatic Extract of Salvia staminea on Neuronal Density of Alpha Motoneurons in Spinal Cord Anterior Horn after Sciatic Nerve Compression in Rats. ACTA ACUST UNITED AC 2009. [DOI: 10.3923/jbs.2010.48.52] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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13
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Tehranipou M, Javaheri R. Neuroprotetive Effect of Curcuma longa Alcoholic Extract on Peripheral
Nerves Degeneration after Sciatic Nerve Compression in Rats. ACTA ACUST UNITED AC 2009. [DOI: 10.3923/jbs.2009.889.893] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Another barrier to regeneration in the CNS: activated macrophages induce extensive retraction of dystrophic axons through direct physical interactions. J Neurosci 2008; 28:9330-41. [PMID: 18799667 DOI: 10.1523/jneurosci.2488-08.2008] [Citation(s) in RCA: 259] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Injured axons of the adult CNS undergo lengthy retraction from the initial site of axotomy after spinal cord injury. Macrophage infiltration correlates spatiotemporally with this deleterious phenomenon, but the direct involvement of these inflammatory cells has not been demonstrated. In the present study, we examined the role of macrophages in axonal retraction within the dorsal columns after spinal cord injury in vivo and found that retraction occurred between days 2 and 28 after lesion and that the ends of injured axons were associated with ED-1+ cells. Clodronate liposome-mediated depletion of infiltrating macrophages resulted in a significant reduction in axonal retraction; however, we saw no evidence of regeneration. We used time-lapse imaging of adult dorsal root ganglion neurons in an in vitro model of the glial scar to examine macrophage-axon interactions and observed that adhesive contacts and considerable physical interplay between macrophages and dystrophic axons led to extensive axonal retraction. The induction of retraction was dependent on both the growth state of the axon and the activation state of the macrophage. Only dystrophic adult axons were susceptible to macrophage "attack." Unlike intrinsically active cell line macrophages, both primary macrophages and microglia required activation to induce axonal retraction. Contact with astrocytes had no deleterious effect on adult dystrophic axons, suggesting that the induction of extensive retraction was specific to phagocytic cells. Our data are the first to indicate a direct role of activated macrophages in axonal retraction by physical cell-cell interactions with injured axons.
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Small-molecule protein tyrosine phosphatase inhibition as a neuroprotective treatment after spinal cord injury in adult rats. J Neurosci 2008; 28:7293-303. [PMID: 18632933 DOI: 10.1523/jneurosci.1826-08.2008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Spinal cord injury causes progressive secondary tissue degeneration, leaving many injured people with neurological disabilities. There are no satisfactory neuroprotective treatments. Protein tyrosine phosphatases inactivate neurotrophic factor receptors and downstream intracellular signaling molecules. Thus, we tested whether the peroxovanadium compound potassium bisperoxo(1,10-phenanthroline)oxovanadate (V) [bpV(phen)], a stable, potent and selective protein tyrosine phosphatase inhibitor, would be neuroprotective after a thoracic spinal cord contusion in adult rats. Intrathecal bpV(phen) infusions through a lumbar puncture rescued dorsal column sensory axons innervating the nucleus gracilis and white matter at the injury epicenter. At the most effective dose, essentially all of these axons and most of the white matter at the epicenter were spared (vs approximately 60% with control infusions). bpV(phen) treatments started 4 h after contusion were fully effective. This treatment greatly improved and normalized sensorimotor function in a grid-walking test and provided complete axonal protection over 6 weeks. The treatment rescued sensory-evoked potentials that disappeared after dorsal column transection. bpV(phen) affected early degenerative mechanisms, because the main effects were seen at 7 d and lasted beyond the treatment period. The neuroprotection appeared to be mediated by rescue of blood vessels. bpV(phen) reduced apoptosis of cultured endothelial cells. These results show that a small molecule, used in a clinically relevant manner, reduces loss of long-projecting axons, myelin, blood vessels, and function in a model relevant to the most common type of spinal cord injury in humans. They reveal a novel mechanism of spinal cord degeneration involving protein tyrosine phosphatases that can be targeted with therapeutic drugs.
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Levene HB, Mohamed FB, Faro SH, Seshadri AB, Loftus CM, Tuma RF, Jallo JI. Small mammal MRI imaging in spinal cord injury: A novel practical technique for using a 1.5T MRI. J Neurosci Methods 2008; 172:245-9. [DOI: 10.1016/j.jneumeth.2008.05.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 04/24/2008] [Accepted: 05/03/2008] [Indexed: 11/24/2022]
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Reimplantation of avulsed lumbosacral ventral roots in the rat ameliorates injury-induced degeneration of primary afferent axon collaterals in the spinal dorsal columns. Neuroscience 2007; 152:338-45. [PMID: 18291596 DOI: 10.1016/j.neuroscience.2007.11.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Revised: 11/09/2007] [Accepted: 11/18/2007] [Indexed: 01/13/2023]
Abstract
Injuries to the cauda equina/conus medullaris portion of the spinal cord can result in motor, sensory, and autonomic dysfunction, and neuropathic pain. In rats, unilateral avulsion of the motor efferents from the lumbosacral spinal cord results in at-level allodynia, along with a corresponding glial and inflammatory response in the dorsal horn of the spinal cord segments immediately rostral to the lesion. Here, we investigated the fate of intramedullary primary sensory projections following a motor efferent lesion. The lumbosacral (L6 and S1) ventral roots were unilaterally avulsed from the rat spinal cord (VRA; n=9). A second experimental group had the avulsed roots acutely reimplanted into the lateral funiculus (Imp; n=5), as this neural repair strategy is neuroprotective, and promotes the functional reinnervation of peripheral targets. A laminectomy-only group served as controls (Lam; n=7). At 8 weeks post-lesion, immunohistochemical examination showed a 42% reduction (P<0.001) in the number of RT97-positive axons in the ascending tracts of the dorsal funiculus of the L4-5 spinal segment in VRA rats. Evidence for degenerating myelin was also present. Reimplantation of the avulsed roots ameliorated axon and myelin degeneration. Axons in the descending dorsal corticospinal tract were unaffected in all groups, suggesting a specificity of this lesion for spinal primary sensory afferents. These results show for the first time that a lesion restricted to motor roots can induce the degeneration of intramedullary sensory afferents. Importantly, reimplantation of the lesioned motor roots ameliorated sensory axon degeneration. These data further support the therapeutic potential for reimplantation of avulsed ventral roots following trauma to the cauda equina/conus medullaris.
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Onifer SM, Nunn CD, Decker JA, Payne BN, Wagoner MR, Puckett AH, Massey JM, Armstrong J, Kaddumi EG, Fentress KG, Wells MJ, West RM, Calloway CC, Schnell JT, Whitaker CM, Burke DA, Hubscher CH. Loss and spontaneous recovery of forelimb evoked potentials in both the adult rat cuneate nucleus and somatosensory cortex following contusive cervical spinal cord injury. Exp Neurol 2007; 207:238-47. [PMID: 17678895 PMCID: PMC2141689 DOI: 10.1016/j.expneurol.2007.06.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 06/15/2007] [Accepted: 06/19/2007] [Indexed: 11/26/2022]
Abstract
Varying degrees of neurologic function spontaneously recovers in humans and animals during the days and months after spinal cord injury (SCI). For example, abolished upper limb somatosensory potentials (SSEPs) and cutaneous sensations can recover in persons post-contusive cervical SCI. To maximize recovery and the development/evaluation of repair strategies, a better understanding of the anatomical locations and physiological processes underlying spontaneous recovery after SCI is needed. As an initial step, the present study examined whether recovery of upper limb SSEPs after contusive cervical SCI was due to the integrity of some spared dorsal column primary afferents that terminate within the cuneate nucleus and not one of several alternate routes. C5-6 contusions were performed on male adult rats. Electrophysiological techniques were used in the same rat to determine forelimb evoked neuronal responses in both cortex (SSEPs) and the cuneate nucleus (terminal extracellular recordings). SSEPs were not evoked 2 days post-SCI but were found at 7 days and beyond, with an observed change in latencies between 7 and 14 days (suggestive of spared axon remyelination). Forelimb evoked activity in the cuneate nucleus at 15 but not 3 days post-injury occurred despite dorsal column damage throughout the cervical injury (as seen histologically). Neuroanatomical tracing (using 1% unconjugated cholera toxin B subunit) confirmed that upper limb primary afferent terminals remained within the cuneate nuclei. Taken together, these results indicate that neural transmission between dorsal column primary afferents and cuneate nuclei neurons is likely involved in the recovery of upper limb SSEPs after contusive cervical SCI.
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Affiliation(s)
- Stephen M Onifer
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY 40292, USA.
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Swartz KR, Fee DB, Joy KM, Roberts KN, Sun S, Scheff NN, Wilson ME, Scheff SW. Gender differences in spinal cord injury are not estrogen-dependent. J Neurotrauma 2007; 24:473-80. [PMID: 17402853 DOI: 10.1089/neu.2006.0167] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent attention has been given to gender differences in neurotrauma, and the anecdotal suggestion is that females have better outcomes than males, suggesting that circulating levels of estrogen (E(2)) may be neuroprotective. In order to address this issue, both young adult male and ovariectomized female rats were subjected to a T10 spinal cord injury (SCI), and E2 levels were maintained at chronic, constant circulating levels. Animals were clinically evaluated for locomotor changes using the Basso-Beattie-Bresnahan (BBB) scoring system. Morphologic differences were evaluated with unbiased stereology. Data analysis failed to reveal any significant benefit for the E2 therapy in either males or females. We did find a non-estrogen-dependent difference between male and female rats in length of injury, and percent of spared tissue, with female outcomes more favorable. These results suggest that E(2) does not provide a viable therapy following SCI.
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Affiliation(s)
- Karin R Swartz
- Division of Neurosurgery, Department of Surgery, University of Kentucky Medical Center, Lexington, Kentucky 40536, USA.
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Baker KA, Hagg T. Developmental and injury-induced expression of alpha1beta1 and alpha6beta1 integrins in the rat spinal cord. Brain Res 2006; 1130:54-66. [PMID: 17161391 PMCID: PMC1794000 DOI: 10.1016/j.brainres.2006.10.072] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 10/20/2006] [Accepted: 10/26/2006] [Indexed: 12/27/2022]
Abstract
Loss and damage to blood vessels are thought to contribute to secondary tissue loss after spinal cord injury. Integrins might be therapeutic targets to protect the vasculature and/or promote angiogenesis, as their activation can promote tubule formation and survival of endothelial cells in vitro. Here, we show that immunostaining with an antibody against the alpha1beta1 integrin heterodimer is present only in blood vessels from postnatal day 1 (P1) through adulthood in Sprague-Dawley rats. After a spinal cord contusion at T9 in adults, the area of alpha1beta1 integrin positive blood vessels increases within 11 mm from the injury site at 3 days post-injury and remains prominent within the injured core only at 7 days. Staining for the alpha6beta1 integrin heterodimer increases in blood vessels between P10 and adulthood and is present in preganglionic neurons of the intermediolateral cell column (IML) at all ages. The alpha6beta1 integrin is also expressed by motor neurons postnatally, and oligodendrocyte precursors (OPCs), as previously reported. After the contusion, the area of alpha6beta1-stained blood vessels is increased at 3 days and most prominently, 1 mm from the injury site, followed by a significant reduction at 7 days, when alpha6beta1 integrin staining is most prominent around the injured core. Staining is also present in a subset of microglia and/or macrophages. These results raise the possibility that alpha1beta1 and alpha6beta1 integrins in blood vessels might be targeted to reduce blood vessel loss and promote angiogenesis, which may promote tissue sparing after spinal cord injury.
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Affiliation(s)
- K Adam Baker
- Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, MDR Building, Room 616, University of Louisville, Louisville, KY, USA
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Chaovipoch P, Jelks KAB, Gerhold LM, West EJ, Chongthammakun S, Floyd CL. 17beta-estradiol is protective in spinal cord injury in post- and pre-menopausal rats. J Neurotrauma 2006; 23:830-52. [PMID: 16774470 DOI: 10.1089/neu.2006.23.830] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The neuroprotective effects of 17 beta -estradiol have been shown in models of central nervous system injury, including ischemia, brain injury, and more recently, spinal cord injury (SCI). Recent epidemiological trends suggest that SCIs in elderly women are increasing; however, the effects of menopause on estrogen-mediated neuroprotection are poorly understood. The objective of this study was to evaluate the effects of 17beta-estradiol and reproductive aging on motor function, neuronal death, and white matter sparing after SCI of post- and pre-menopausal rats. Two-month-old or 1- year-old female rats were ovariectomized and implanted with a silastic capsule containing 180 microg/mL of 17beta-estradiol or vehicle. Complete crush SCI at T8-9 was performed 1 week later. Additional animals of each age group were left ovary-intact but were spinal cord injured. The Basso, Beattie, Bresnahan (BBB) locomotor test was performed. Spinal cords were collected on post-SCI days 1, 7, and 21, and processed for histological markers. Administration of 17beta-estradiol to ovariectomized rats improved recovery of hind-limb locomotion, increased white matter sparing, and decreased apoptosis in both the post- and pre-menopausal rats. Also, ovary-intact 1-year-old rats did worse than ovary-intact 2-month-old rats, suggesting that endogenous estrogen confers neuroprotection in young rats, which is lost in older animals. Taken together, these data suggest that estrogen is neuroprotective in SCI and that the loss of endogenous estrogen-mediated neuroprotective seen in older rats can be attenuated with exogenous administration of 17beta-estradiol.
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Affiliation(s)
- Pimonporn Chaovipoch
- Department of Neurological Surgery, University of California, Davis, California 95616, USA.
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