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Mokhtari T, Uludag K. Role of NLRP3 Inflammasome in Post-Spinal-Cord-Injury Anxiety and Depression: Molecular Mechanisms and Therapeutic Implications. ACS Chem Neurosci 2024; 15:56-70. [PMID: 38109051 DOI: 10.1021/acschemneuro.3c00596] [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: 12/19/2023] Open
Abstract
The majority of research on the long-term effects of spinal cord injury (SCI) has primarily focused on neuropathic pain (NP), psychological issues, and sensorimotor impairments. Among SCI patients, mood disorders, such as anxiety and depression, have been extensively studied. It has been found that chronic stress and NP have negative consequences and reduce the quality of life for individuals living with SCI. Our review examined both human and experimental evidence to explore the connection between mood changes following SCI and inflammatory pathways, with a specific focus on NLRP3 inflammasome signaling. We observed increased proinflammatory factors in the blood, as well as in the brain and spinal cord tissues of SCI models. The NLRP3 inflammasome plays a crucial role in various diseases by controlling the release of proinflammatory molecules like interleukin 1β (IL-1β) and IL-18. Dysregulation of the NLRP3 inflammasome in key brain regions associated with pain processing, such as the prefrontal cortex and hippocampus, contributes to the development of mood disorders following SCI. In this review, we summarized recent research on the expression and regulation of components related to NLRP3 inflammasome signaling in mood disorders following SCI. Finally, we discussed potential therapeutic approaches that target the NLRP3 inflammasome and regulate proinflammatory cytokines as a way to treat mood disorders following SCI.
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Affiliation(s)
- Tahmineh Mokhtari
- Hubei Key Laboratory of Embryonic Stem Cell Research, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan 442000, Hubei, People's Republic of China
- Department of Histology and Embryology, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan 442000, Hubei, People's Republic of China
| | - Kadir Uludag
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, People's Republic of China
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2
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Ramos D, Cruz CD. Involvement of microglia in chronic neuropathic pain associated with spinal cord injury - a systematic review. Rev Neurosci 2023; 34:933-950. [PMID: 37490300 DOI: 10.1515/revneuro-2023-0031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 06/10/2023] [Indexed: 07/26/2023]
Abstract
In recent decade microglia have been found to have a central role in the development of chronic neuropathic pain after injury to the peripheral nervous system. It is widely accepted that peripheral nerve injury triggers microglial activation in the spinal cord, which contributes to heightened pain sensation and eventually chronic pain states. The contribution of microglia to chronic pain arising after injury to the central nervous system, such as spinal cord injury (SCI), has been less studied, but there is evidence supporting microglial contribution to central neuropathic pain. In this systematic review, we focused on post-SCI microglial activation and how it is linked to emergence and maintenance of chronic neuropathic pain arising after SCI. We found that the number of studies using animal SCI models addressing microglial activity is still small, compared with the ones using peripheral nerve injury models. We have collected 20 studies for full inclusion in this review. Many mechanisms and cellular interactions are yet to be fully understood, although several studies report an increase of density and activity of microglia in the spinal cord, both in the vicinity of the injury and in the spared spinal tissue, as well as in the brain. Changes in microglial activity come with several molecular changes, including expression of receptors and activation of signalling pathways. As with peripheral neuropathic pain, microglia seem to be important players and might become a therapeutic target in the future.
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Affiliation(s)
- David Ramos
- Faculty of Medicine of Porto, University of Porto, Porto, Portugal
- Department of Biomedicine, Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of Porto, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Célia Duarte Cruz
- Department of Biomedicine, Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of Porto, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
- Translational Neurourology, IBMC and Instituto de Investigação e Inovação em Saúde-i3S, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
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3
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Niu Y, Liu J, Qin H, Liu Y, Huang N, Jiang J, Chen Y, Chen S, Bai T, Yang C, Cao Y, Liu S, Yuan H. Development of an innovative minimally invasive primate spinal cord injury model: A case report. IBRAIN 2023; 9:349-356. [PMID: 37786753 PMCID: PMC10527794 DOI: 10.1002/ibra.12117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 10/04/2023]
Abstract
Spinal cord injury (SCI) animal models have been widely created and utilized for repair therapy research, but more suitable experimental animals and accurate modeling methodologies are required to achieve the desired results. In this experiment, we constructed an innovative dorsal 1/4 spinal cord transection macaque model that had fewer severe problems, facilitating postoperative care and recovery. In essence, given that monkeys and humans share similar genetics and physiology, the efficacy of this strategy in a nonhuman primate SCI model basically serves as a good basis for its prospective therapeutic use in human SCI.
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Affiliation(s)
- Yong‐Min Niu
- Institute of NeuroscienceKunming Medical UniversityKunmingYunnanChina
| | - Jin‐Xiang Liu
- Institute of NeuroscienceKunming Medical UniversityKunmingYunnanChina
| | - Hao‐Yue Qin
- Department of AnesthesiologySouthwest Medical UniversityLuzhouSichuanChina
| | - Yi‐Fan Liu
- Yunnan Cancer HospitalThe Third Affiliated Hospital of Kunming Medical UniversityYunnanChina
| | - Ni‐Jiao Huang
- Department of Orthopaedic SurgeryAffiliated Hospital of Zunyi Medical UniversityZunyiGuizhouChina
| | - Ji‐Li Jiang
- Institute of NeuroscienceKunming Medical UniversityKunmingYunnanChina
| | - Yan‐Qiu Chen
- School of Preclinical MedicalZunyi Medical UniversityZunyiGuizhouChina
| | - Si‐Jing Chen
- Nursing SchoolZunyi Medical UniversityZunyiGuizhouChina
| | - Tao Bai
- School of Preclinical MedicalKunming Medical UniversityKunmingYunnanChina
| | - Chang‐Wei Yang
- Department of Nuclear MedicineAffiliated Hospital of Zunyi Medical UniversityZunyiGuizhouChina
| | - Yu Cao
- Department of Nuclear MedicineAffiliated Hospital of Zunyi Medical UniversityZunyiGuizhouChina
| | - Sheng Liu
- Pharmacology InstituteHeidelberg UniversityHeidelbergGermany
| | - Hao Yuan
- Department of Orthopaedic SurgeryAffiliated Hospital of Zunyi Medical UniversityZunyiGuizhouChina
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4
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Guan X, Gong X, Jiao ZY, Cao HY, Liu S, Lin C, Huang X, Lan H, Ma L, Xu B. Cyclin D1 mediates pain behaviour in a rat model of breast cancer-induced bone pain by a mechanism involving regulation of the proliferation of spinal microglia. Bone Joint Res 2022; 11:803-813. [PMID: 36374014 PMCID: PMC9680203 DOI: 10.1302/2046-3758.1111.bjr-2022-0018.r1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Aims The involvement of cyclin D1 in the proliferation of microglia, and the generation and maintenance of bone cancer pain (BCP), have not yet been clarified. We investigated the expression of microglia and cyclin D1, and the influences of cyclin D1 on pain threshold. Methods Female Sprague Dawley (SD) rats were used to establish a rat model of BCP, and the messenger RNA (mRNA) and protein expression of ionized calcium binding adaptor molecule 1 (IBA1) and cyclin D1 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot, respectively. The proliferation of spinal microglia was detected by immunohistochemistry. The pain behaviour test was assessed by quantification of spontaneous flinches, limb use, and guarding during forced ambulation, mechanical paw withdrawal threshold, and thermal paw withdrawal latency. Results IBA1 and cyclin D1 in the ipsilateral spinal horn increased in a time-dependent fashion. Spinal microglia proliferated in BCP rats. The microglia inhibitor minocycline attenuated the pain behaviour in BCP rats. The cyclin-dependent kinase inhibitor flavopiridol inhibited the proliferation of spinal microglia, and was associated with an improvement in pain behaviour in BCP rats. Conclusion Our results revealed that the inhibition of spinal microglial proliferation was associated with a decrease in pain behaviour in a rat model of BCP. Cyclin D1 acts as a key regulator of the proliferation of spinal microglia in a rat model of BCP. Disruption of cyclin D1, the restriction-point control of cell cycle, inhibited the proliferation of microglia and attenuated the pain behaviours in BCP rats. Cyclin D1 and the proliferation of spinal microglia may be potential targets for the clinical treatment of BCP. Cite this article: Bone Joint Res 2022;11(11):803–813.
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Affiliation(s)
- Xuehai Guan
- Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xiaofang Gong
- Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ziyin Y. Jiao
- Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Huiyu Y. Cao
- Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Susu Liu
- Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Chengxin Lin
- Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xiaofang Huang
- Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Hongmeng Lan
- Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Li Ma
- Department of Anesthesiology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Bing Xu
- Department of Rehabilitation, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi, China
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5
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Rivel M, Achiron A, Dolev M, Stern Y, Zeilig G, Defrin R. Unique features of central neuropathic pain in multiple sclerosis: Results of a cluster analysis. Eur J Pain 2022; 26:1107-1122. [PMID: 35263811 PMCID: PMC9313873 DOI: 10.1002/ejp.1934] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 02/23/2022] [Accepted: 03/06/2022] [Indexed: 11/25/2022]
Abstract
Background Central neuropathic pain (CNP) is an excruciating condition, prevalent in up to a third of patients with multiple sclerosis (MS). Identifying CNP among MS patients is particularly challenging considering the ample comorbid chronic pain conditions and sensory disturbances entailed by the disease. The aim was to identify sensory features unique to CNP beyond those of chronic pain and MS. Methods Participants were 112 MS patients: 44 with a diagnosis of CNP, 28 with a diagnosis of chronic musculoskeletal pain (MSP), and 40 pain free. Participants underwent testing of thermal and mechanical thresholds, thermal grill illusion (TGI), pain adaptation (PA), and offset analgesia (OA), and chronic pain was characterized. A two‐step cluster analysis was performed, and the association between the cluster membership and the clinical group membership (CNP, MSP, pain free) was evaluated. Results The CNP and MSP groups were similar in most of the chronic pain variables (e.g., severity, location and quality) and MS‐related variables (e.g., type, severity and medication intake). The three created clusters had unique sensory features: (1) ‘Hyposensitivity’ (increased thermal and touch thresholds) characterized the CNP group; (2) ‘Poor inhibition and hyperalgesia’ (worst PA and OA and decreased TGI threshold) characterized the MSP group; and (3) ‘Efficient inhibition’ (best PA and OA, smallest sensory loss) characterized the pain‐free group. Conclusions The unique sensory features of CNP and MSP provide insight into their pathophysiology, and evaluating them may increase the ability to provide individually based interventions. Efficient inhibition may protect MS patients from chronic pain. Significance Cluster analysis among patients with multiple sclerosis (MS) revealed that while central neuropathic pain is associated with thermal and mechanical hypoesthesia, musculoskeletal pain is involved with reduced pain inhibition and hyperalgesia; sensory profiles that provide insights into the mechanisms of these conditions and may promote an individually based pain management.
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Affiliation(s)
- Michal Rivel
- Department of Physical Therapy, School of Health Professions, Sackler Faculty of Medicine, Tel Aviv University.,Sagol School of Neuroscience, Tel Aviv University
| | - Anat Achiron
- Sagol School of Neuroscience, Tel Aviv University.,Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer.,Sackler Faculty of Medicine, Tel Aviv University
| | - Mark Dolev
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer
| | - Yael Stern
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer
| | - Gabi Zeilig
- Sackler Faculty of Medicine, Tel Aviv University.,Department of Neurological Rehabilitation, Sheba Medical Center, Tel Hashomer, Israel
| | - Ruth Defrin
- Department of Physical Therapy, School of Health Professions, Sackler Faculty of Medicine, Tel Aviv University.,Sagol School of Neuroscience, Tel Aviv University
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6
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Defrin R, Gruener H, Gaidukov E, Bondi M, Rachamim-Katz O, Ringler E, Blumen N, Zeilig G. From acute to long-term alterations in pain processing and modulation after spinal cord injury: mechanisms related to chronification of central neuropathic pain. Pain 2022; 163:e94-e105. [PMID: 33863855 DOI: 10.1097/j.pain.0000000000002315] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/10/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT A severe and debilitating consequence of a spinal cord injury (SCI) is central neuropathic pain (CNP). Our aim was to investigate the processes leading to CNP emergence and chronification by analyzing causal relationship over time between spinothalamic function, pain excitability, and pain inhibition after SCI. This longitudinal follow-up study included 53 patients with acute SCI and 20 healthy controls. Spinothalamic, pain excitability, and intrasegmental and extrasegmental pain inhibition indices were repeatedly evaluated at 1.5, 3, and 6 months post-SCI. Between- and within-group analyses were conducted among those patients who eventually developed CNP and those who did not. Healthy controls were evaluated twice for repeatability analysis. Patients who developed CNP, compared with those who did not, exhibited increased thermal thresholds (P < 0.05), reduced pain adaptation (P < 0.01), and conditioned pain modulation (P < 0.05), early post-injury, and the CNP group's manifestations remained worse throughout the follow-up. By contrast, allodynia frequency was initially similar across SCI groups, but gradually increased in the subacute phase onward only among the CNP group (P < 0.001), along with CNP emergence. Early worse spinothalamic and pain inhibition preceded CNP and predicted its occurrence, and early worse pain inhibition mediated the link between spinothalamic function and CNP. Crossover associations were observed between early and late pain inhibition and excitability. Inefficient intrasegmental and extrasegmental inhibition, possibly resulting from spinothalamic deafferentation, seems to ignite CNP chronification. Pain excitability probably contributes to CNP maintenance, possibly via further exhaustion of the inhibitory control. Preemptive treatment promoting antinociception early post-SCI may mitigate or prevent CNP.
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Affiliation(s)
- Ruth Defrin
- Department of Physical Therapy at Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Hila Gruener
- Department of Physical Therapy at Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Evgeni Gaidukov
- Department of Neurological Rehabilitation, Chaim Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Department of Rehabilitation Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moshe Bondi
- Department of Neurological Rehabilitation, Chaim Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Department of Rehabilitation Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Orna Rachamim-Katz
- Barzilai Day Care Rehabilitation Unit, Barzilai Medical Center, Ashkelon, Israel
| | - Erez Ringler
- Department of Neurological Rehabilitation, Chaim Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Department of Rehabilitation Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Nava Blumen
- Department of Neurological Rehabilitation, Chaim Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Department of Rehabilitation Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Gabi Zeilig
- Department of Neurological Rehabilitation, Chaim Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Department of Rehabilitation Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Zhang M, Liu Y, Hu G, Kang L, Ran Y, Su M, Yu S. Cognitive impairment in a classical rat model of chronic migraine may be due to alterations in hippocampal synaptic plasticity and N-methyl-D-aspartate receptor subunits. Mol Pain 2021; 16:1744806920959582. [PMID: 32869707 PMCID: PMC7517984 DOI: 10.1177/1744806920959582] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Although migraine is a major global public health problem, its impact on cognitive abilities remains controversial. Thus, the present study investigated the effects of repeated administration of inflammatory soup to the dura of rats, over three weeks, on spatial cognition, hippocampal synaptic plasticity, and the expression of N-methyl-D-aspartate receptor subunits. Additionally, low doses of amitriptyline (5 mg/kg) were applied to assess its therapeutic effects. The inflammatory soup group exhibited significant reductions in the cutaneous stimulation threshold, presence of mild cognitive impairment, and decreased long-term potentiation in right hippocampus. However, amitriptyline improved pain behaviors, enhanced cognitive function, and increased synaptic plasticity in the inflammatory soup rats. On the other hand, the administration of amitriptyline to normal rats negatively influenced synaptic plasticity and reduced the expression of N-methyl-D-aspartate receptor subunits. The present results indicate that inflammatory soup-induced dural nociception led to impairments in spatial cognition that could be attributed to reductions in hippocampal long-term potentiation and the decreased expression of N-methyl-D-aspartate receptor subunits.
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Affiliation(s)
- Mingjie Zhang
- Department of Neurology, the First Medical Centre, Chinese PLA General Hospital, PR China
| | - Yufei Liu
- Department of Neurology, Tianjin Third Central Hospital, PR China
| | - Guanqun Hu
- Department of Neurology, Tianjin Union Medicine Center, PR China
| | - Li Kang
- Department of Neurology, the First Medical Centre, Chinese PLA General Hospital, PR China
| | - Ye Ran
- Department of Neurology, the First Medical Centre, Chinese PLA General Hospital, PR China
| | - Min Su
- Department of Neurology, the First Medical Centre, Chinese PLA General Hospital, PR China
| | - Shengyuan Yu
- Department of Neurology, the First Medical Centre, Chinese PLA General Hospital, PR China
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8
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Animal Models of Cerebral Changes Secondary to Spinal Cord Injury. World Neurosurg 2020; 145:244-250. [PMID: 32980567 DOI: 10.1016/j.wneu.2020.09.103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 11/20/2022]
Abstract
Spinal cord injuries (SCIs) are difficult to treat. The first animal SCI model (featuring the dropping of a weight) was established by Allen in 1911, and other animal models have been developed since then. Most animal studies have focused only on the molecular features of SCIs, which remain disputed. Recently, it has become clear that SCI may trigger mental and cognitive disorders, however, and brain changes secondary to SCI are under investigation. No consensus on an optimal animal model for cerebral research has emerged. We discuss the appropriate SCI models for studying secondary brain changes.
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9
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Li Y, Ritzel RM, Khan N, Cao T, He J, Lei Z, Matyas JJ, Sabirzhanov B, Liu S, Li H, Stoica BA, Loane DJ, Faden AI, Wu J. Delayed microglial depletion after spinal cord injury reduces chronic inflammation and neurodegeneration in the brain and improves neurological recovery in male mice. Am J Cancer Res 2020; 10:11376-11403. [PMID: 33052221 PMCID: PMC7545988 DOI: 10.7150/thno.49199] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 09/02/2020] [Indexed: 12/15/2022] Open
Abstract
Neuropsychological deficits, including impairments in learning and memory, occur after spinal cord injury (SCI). In experimental SCI models, we and others have reported that such changes reflect sustained microglia activation in the brain that is associated with progressive neurodegeneration. In the present study, we examined the effect of pharmacological depletion of microglia on posttraumatic cognition, depressive-like behavior, and brain pathology after SCI in mice. Methods: Young adult male C57BL/6 mice were subjected to moderate/severe thoracic spinal cord contusion. Microglial depletion was induced with the colony-stimulating factor 1 receptor (CSF1R) antagonist PLX5622 administered starting either 3 weeks before injury or one day post-injury and continuing through 6 weeks after SCI. Neuroinflammation in the injured spinal cord and brain was assessed using flow cytometry and NanoString technology. Neurological function was evaluated using a battery of neurobehavioral tests including motor function, cognition, and depression. Lesion volume and neuronal counts were quantified by unbiased stereology. Results: Flow cytometry analysis demonstrated that PLX5622 pre-treatment significantly reduced the number of microglia, as well as infiltrating monocytes and neutrophils, and decreased reactive oxygen species production in these cells from injured spinal cord at 2-days post-injury. Post-injury PLX5622 treatment reduced both CD45int microglia and CD45hi myeloid counts at 7-days. Following six weeks of PLX5622 treatment, there were substantial changes in the spinal cord and brain transcriptomes, including those involved in neuroinflammation. These alterations were associated with improved neuronal survival in the brain and neurological recovery. Conclusion: These findings indicate that pharmacological microglia-deletion reduces neuroinflammation in the injured spinal cord and brain, improving recovery of cognition, depressive-like behavior, and motor function.
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Nakhjiri E, Vafaee MS, Hojjati SMM, Shahabi P, Shahpasand K. Tau Pathology Triggered by Spinal Cord Injury Can Play a Critical Role in the Neurotrauma Development. Mol Neurobiol 2020; 57:4845-4855. [PMID: 32808121 DOI: 10.1007/s12035-020-02061-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 08/07/2020] [Indexed: 02/08/2023]
Abstract
Traumatic spinal cord injury (SCI) can result in substantial neurological impairment along with significant emotional and psychological distress. It is clear that there is profound neurodegeneration upon SCI, gradually spread to other spinal cord regions and brain areas. Despite extensive considerations, it remains uncertain how pathogenicity diffuses in the cord. It has been reported that tau protein abnormal hyperphosphorylation plays a central role in neurodegeneration triggered by traumatic brain injury (TBI). Tau is a microtubule-associated protein, heavily implicated in neurodegenerative diseases. Importantly, tau pathology spreads in a traumatic brain in a timely manner. In particular, we have recently demonstrated that phosphorylated tau at Thr231 exists in two distinct cis and trans conformations, in which that cis P-tau is extremely neurotoxic, has a prion nature, and spreads to various brain areas and cerebrospinal fluid (CSF) upon trauma. On the other hand, tau pathology, in particular hyperphosphorylation at Thr231, has been observed upon SCI. Taken these together, we conclude that cis pT231-tau may accumulate and spread in the spinal cord as well as CSF and diffuse tau pathology in the central nervous system (CNS). Moreover, antibody against cis P-tau can target intracellular cis P-tau and protect pathology spreading. Thus, considering cis P-tau as a driver of tau pathology and neurodegeneration upon SCI would open new windows toward understanding the disease development and early biomarkers. Furthermore, it would help us develop effective therapies for SCI patients.
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Affiliation(s)
- Elnaz Nakhjiri
- Neurosciences Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Manuchehr S Vafaee
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
| | | | - Parviz Shahabi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Koorosh Shahpasand
- Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.
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11
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Li Y, Cao T, Ritzel RM, He J, Faden AI, Wu J. Dementia, Depression, and Associated Brain Inflammatory Mechanisms after Spinal Cord Injury. Cells 2020; 9:cells9061420. [PMID: 32521597 PMCID: PMC7349379 DOI: 10.3390/cells9061420] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/04/2020] [Accepted: 06/04/2020] [Indexed: 12/28/2022] Open
Abstract
Evaluation of the chronic effects of spinal cord injury (SCI) has long focused on sensorimotor deficits, neuropathic pain, bladder/bowel dysfunction, loss of sexual function, and emotional distress. Although not well appreciated clinically, SCI can cause cognitive impairment including deficits in learning and memory, executive function, attention, and processing speed; it also commonly leads to depression. Recent large-scale longitudinal population-based studies indicate that patients with isolated SCI (without concurrent brain injury) are at a high risk of dementia associated with substantial cognitive impairments. Yet, little basic research has addressed potential mechanisms for cognitive impairment and depression after injury. In addition to contributing to disability in their own right, these changes can adversely affect rehabilitation and recovery and reduce quality of life. Here, we review clinical and experimental work on the complex and varied responses in the brain following SCI. We also discuss potential mechanisms responsible for these less well-examined, important SCI consequences. In addition, we outline the existing and developing therapeutic options aimed at reducing SCI-induced brain neuroinflammation and post-injury cognitive and emotional impairments.
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Affiliation(s)
- Yun Li
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (Y.L.); (T.C.); (R.M.R.); (J.H.); (A.I.F.)
| | - Tuoxin Cao
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (Y.L.); (T.C.); (R.M.R.); (J.H.); (A.I.F.)
| | - Rodney M. Ritzel
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (Y.L.); (T.C.); (R.M.R.); (J.H.); (A.I.F.)
| | - Junyun He
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (Y.L.); (T.C.); (R.M.R.); (J.H.); (A.I.F.)
| | - Alan I. Faden
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (Y.L.); (T.C.); (R.M.R.); (J.H.); (A.I.F.)
- University of Maryland Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
| | - Junfang Wu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (Y.L.); (T.C.); (R.M.R.); (J.H.); (A.I.F.)
- University of Maryland Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
- Correspondence: ; Tel.: +1-410-706-5189
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12
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Cao T, Matyas JJ, Renn CL, Faden AI, Dorsey SG, Wu J. Function and Mechanisms of Truncated BDNF Receptor TrkB.T1 in Neuropathic Pain. Cells 2020; 9:cells9051194. [PMID: 32403409 PMCID: PMC7290366 DOI: 10.3390/cells9051194] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/08/2020] [Accepted: 05/08/2020] [Indexed: 12/11/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF), a major focus for regenerative therapeutics, has been lauded for its pro-survival characteristics and involvement in both development and recovery of function within the central nervous system (CNS). However, studies of tyrosine receptor kinase B (TrkB), a major receptor for BDNF, indicate that certain effects of the TrkB receptor in response to disease or injury may be maladaptive. More specifically, imbalance among TrkB receptor isoforms appears to contribute to aberrant signaling and hyperpathic pain. A truncated isoform of the receptor, TrkB.T1, lacks the intracellular kinase domain of the full length receptor and is up-regulated in multiple CNS injury models. Such up-regulation is associated with hyperpathic pain, and TrkB.T1 inhibition reduces neuropathic pain in various experimental paradigms. Deletion of TrkB.T1 also limits astrocyte changes in vitro, including proliferation, migration, and activation. Mechanistically, TrkB.T1 is believed to act through release of intracellular calcium in astrocytes, as well as through interactions with neurotrophins, leading to cell cycle activation. Together, these studies support a potential role for astrocytic TrkB.T1 in hyperpathic pain and suggest that targeted strategies directed at this receptor may have therapeutic potential.
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Affiliation(s)
- Tuoxin Cao
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (T.C.); (J.J.M.); (A.I.F.)
| | - Jessica J. Matyas
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (T.C.); (J.J.M.); (A.I.F.)
| | - Cynthia L. Renn
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD 21201, USA; (C.L.R.); (S.G.D.)
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
| | - Alan I. Faden
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (T.C.); (J.J.M.); (A.I.F.)
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
| | - Susan G. Dorsey
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD 21201, USA; (C.L.R.); (S.G.D.)
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
| | - Junfang Wu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (T.C.); (J.J.M.); (A.I.F.)
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
- Correspondence: ; Tel.: +1-410-706-5189
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13
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Regional Hyperexcitability and Chronic Neuropathic Pain Following Spinal Cord Injury. Cell Mol Neurobiol 2020; 40:861-878. [PMID: 31955281 DOI: 10.1007/s10571-020-00785-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 01/02/2020] [Indexed: 12/15/2022]
Abstract
Spinal cord injury (SCI) causes maladaptive changes to nociceptive synaptic circuits within the injured spinal cord. Changes also occur at remote regions including the brain stem, limbic system, cortex, and dorsal root ganglia. These maladaptive nociceptive synaptic circuits frequently cause neuronal hyperexcitability in the entire nervous system and enhance nociceptive transmission, resulting in chronic central neuropathic pain following SCI. The underlying mechanism of chronic neuropathic pain depends on the neuroanatomical structures and electrochemical communication between pre- and postsynaptic neuronal membranes, and propagation of synaptic transmission in the ascending pain pathways. In the nervous system, neurons are the only cell type that transmits nociceptive signals from peripheral receptors to supraspinal systems due to their neuroanatomical and electrophysiological properties. However, the entire range of nociceptive signaling is not mediated by any single neuron. Current literature describes regional studies of electrophysiological or neurochemical mechanisms for enhanced nociceptive transmission post-SCI, but few studies report the electrophysiological, neurochemical, and neuroanatomical changes across the entire nervous system following a regional SCI. We, along with others, have continuously described the enhanced nociceptive transmission in the spinal dorsal horn, brain stem, thalamus, and cortex in SCI-induced chronic central neuropathic pain condition, respectively. Thus, this review summarizes the current understanding of SCI-induced neuronal hyperexcitability and maladaptive nociceptive transmission in the entire nervous system that contributes to chronic central neuropathic pain.
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14
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Sabirzhanov B, Matyas J, Coll-Miro M, Yu LL, Faden AI, Stoica BA, Wu J. Inhibition of microRNA-711 limits angiopoietin-1 and Akt changes, tissue damage, and motor dysfunction after contusive spinal cord injury in mice. Cell Death Dis 2019; 10:839. [PMID: 31685802 PMCID: PMC6828685 DOI: 10.1038/s41419-019-2079-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 10/09/2019] [Accepted: 10/18/2019] [Indexed: 02/06/2023]
Abstract
Spinal cord injury (SCI) causes neuronal cell death and vascular damage, which contribute to neurological dysfunction. Given that many biochemical changes contribute to such secondary injury, treatment approaches have increasingly focused on combined therapies or use of multi-functional drugs. MicroRNAs (miRs) are small (20-23 nucleotide), non-protein-coding RNAs and can negatively regulate target gene expression at the post-transcriptional level. As individual miRs can potentially modulate expression of multiple relevant proteins after injury, they are attractive candidates as upstream regulators of the secondary SCI progression. In the present study we examined the role of miR-711 modulation after SCI. Levels of miR-711 were increased in injured spinal cord early after SCI, accompanied by rapid downregulation of its target angiopoietin-1 (Ang-1), an endothelial growth factor. Changes of miR-711 were also associated with downregulation of the pro-survival protein Akt (protein kinase B), another target of miR-711, with sequential activation of glycogen synthase kinase 3 and the pro-apoptotic BH3-only molecule PUMA. Central administration of a miR-711 hairpin inhibitor after SCI limited decreases of Ang-1/Akt expression and attenuated apoptotic pathways. Such treatment also reduced neuronal/axonal damage, protected microvasculature and improved motor dysfunction following SCI. In vitro, miR-711 levels were rapidly elevated by neuronal insults, but not by activated microglia and astrocytes. Together, our data suggest that post-traumatic miR-711 elevation contributes to neuronal cell death after SCI, in part by inhibiting Ang-1 and Akt pathways, and may serve as a novel therapeutic target.
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Affiliation(s)
- Boris Sabirzhanov
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Jessica Matyas
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Marina Coll-Miro
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Laina Lijia Yu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Alan I Faden
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA.,University of Maryland Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, 21201, USA
| | - Bogdan A Stoica
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Junfang Wu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA. .,University of Maryland Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, 21201, USA.
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15
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Uddin O, Studlack PE, Parihar S, Keledjian K, Cruz A, Farooq T, Shin N, Gerzanich V, Simard JM, Keller A. Chronic pain after blast-induced traumatic brain injury in awake rats. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2019; 6:100030. [PMID: 31223145 PMCID: PMC6565615 DOI: 10.1016/j.ynpai.2019.100030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 02/14/2019] [Accepted: 04/01/2019] [Indexed: 12/14/2022]
Abstract
Explosive blast-induced traumatic brain injury (blast-TBI) in military personnel is a leading cause of injury and persistent neurological abnormalities, including chronic pain. We previously demonstrated that chronic pain after spinal cord injury results from central sensitization in the posterior thalamus (PO). The presence of persistent headaches and back pain in veterans with blast-TBI suggests a similar involvement of thalamic sensitization. Here, we tested the hypothesis that pain after blast-TBI is associated with abnormal increases in activity of neurons in PO thalamus. We developed a novel model with two unique features: (1) blast-TBI was performed in awake, un-anesthetized rats, to simulate the human experience and to eliminate confounds of anesthesia and surgery inherent in other models; (2) only the cranium, rather than the entire body, was exposed to a collimated blast wave, with the blast wave striking the posterior cranium in the region of the occipital crest and foramen magnum. Three weeks after blast-TBI, rats developed persistent, ongoing spontaneous pain. Contrary to our hypothesis, we found no significant differences in the activity of PO neurons, or of neurons in the spinal trigeminal nucleus. There were also no significant changes in gliosis in either of these structures. This novel model will allow future studies on the pathophysiology of chronic pain after blast-TBI.
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Affiliation(s)
- Olivia Uddin
- Department of Anatomy and Neurobiology and Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD, USA
| | - Paige E. Studlack
- Department of Anatomy and Neurobiology and Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD, USA
| | - Saitu Parihar
- Department of Anatomy and Neurobiology and Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD, USA
| | - Kaspar Keledjian
- Department of Neurosurgery, University of Maryland School of Medicine, 10 S Pine St, MSTF 634B, Baltimore, MD, USA
| | - Alexis Cruz
- Department of Anatomy and Neurobiology and Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD, USA
| | - Tayyiaba Farooq
- Department of Anatomy and Neurobiology and Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD, USA
| | - Naomi Shin
- Department of Anatomy and Neurobiology and Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD, USA
| | - Volodymyr Gerzanich
- Department of Neurosurgery, University of Maryland School of Medicine, 10 S Pine St, MSTF 634B, Baltimore, MD, USA
| | - J. Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, 10 S Pine St, MSTF 634B, Baltimore, MD, USA
- Department of Pathology, University of Maryland School of Medicine, 10 S Pine St, MSTF, Room 634B, Baltimore, MD, USA
- Department of Physiology, University of Maryland School of Medicine, 10 S Pine St, MSTF, Room 634B, Baltimore, MD, USA
| | - Asaf Keller
- Department of Anatomy and Neurobiology and Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD, USA
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16
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Blaszczyk L, Maître M, Lesté-Lasserre T, Clark S, Cota D, Oliet SHR, Fénelon VS. Sequential alteration of microglia and astrocytes in the rat thalamus following spinal nerve ligation. J Neuroinflammation 2018; 15:349. [PMID: 30572902 PMCID: PMC6302506 DOI: 10.1186/s12974-018-1378-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 11/26/2018] [Indexed: 12/28/2022] Open
Abstract
Background Spinal reactive astrocytes and microglia are known to participate to the initiation and maintenance of neuropathic pain. However, whether reactive astrocytes and microglia in thalamic nuclei that process sensory-discriminative aspects of pain play a role in pain behavior remains poorly investigated. Therefore, the present study evaluated whether the presence of reactive glia (hypertrophy, increased number and upregulation of glial markers) in the ventral posterolateral thalamic nucleus (VPL) correlates with pain symptoms, 14 and 28 days after unilateral L5/L6 spinal nerve ligation (SNL) in rats. Methods Mechanical allodynia and hyperalgesia (von Frey filament stimulation) as well as ambulatory pain (dynamic weight bearing apparatus) were assessed. Levels of nine glial transcripts were determined by quantitative real-time PCR on laser microdissected thalamic nuclei, and levels of proteins were assessed by Western blot. We also studied by immunohistofluorescence the expression of glial markers that label processes (GFAP for astrocytes and iba-1 for microglia) and cell body (S100β for astrocytes and iba-1 for microglia) and quantified the immunostained surface and the number of astrocytes and microglia (conventional counts and optical dissector method of stereological counting). Results Differential, time-dependent responses were observed concerning microglia and astrocytes. Specifically, at day 14, iba-1 immunostained area and number of iba-1 immunopositive cells were decreased in the VPL of SNL as compared to naïve rats. By contrast, at day 28, GFAP-immunostained area was increased in the VPL of SNL as compared to naïve rats while number of GFAP/S100β immunopositive cells remained unchanged. Using quantitative real-time PCR of laser microdissected VPL, we found a sequential increase in mRNA expression of cathepsin S (day 14), fractalkine (day 28), and fractalkine receptor (day 14), three well-known markers of microglial reactivity. Using Western blot, we confirmed an increase in protein expression of fractalkine receptor at day 14. Conclusions Our results demonstrate a sequential alteration of microglia and astrocytes in the thalamus of animals with lesioned peripheral nerves. Furthermore, our data report unprecedented concomitant molecular signs of microglial activation and morphological signs of microglial decline in the thalamus of these animals.
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Affiliation(s)
- Lucie Blaszczyk
- Bordeaux University, Bordeaux, France.,Neurocentre Magendie, INSERM U1215, Bordeaux, France
| | - Marlène Maître
- Bordeaux University, Bordeaux, France.,Neurocentre Magendie, INSERM U1215, Bordeaux, France
| | - Thierry Lesté-Lasserre
- Bordeaux University, Bordeaux, France.,Neurocentre Magendie, INSERM U1215, Bordeaux, France
| | - Samantha Clark
- Bordeaux University, Bordeaux, France.,Neurocentre Magendie, INSERM U1215, Bordeaux, France
| | - Daniela Cota
- Bordeaux University, Bordeaux, France.,Neurocentre Magendie, INSERM U1215, Bordeaux, France
| | - Stéphane H R Oliet
- Bordeaux University, Bordeaux, France.,Neurocentre Magendie, INSERM U1215, Bordeaux, France
| | - Valérie S Fénelon
- Bordeaux University, Bordeaux, France. .,Neurocentre Magendie, INSERM U1215, Bordeaux, France.
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17
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Studlack PE, Keledjian K, Farooq T, Akintola T, Gerzanich V, Simard JM, Keller A. Blast-induced brain injury in rats leads to transient vestibulomotor deficits and persistent orofacial pain. Brain Inj 2018; 32:1866-1878. [PMID: 30346868 PMCID: PMC6381394 DOI: 10.1080/02699052.2018.1536282] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 09/18/2018] [Accepted: 10/03/2018] [Indexed: 12/12/2022]
Abstract
Blast-induced traumatic brain injury (blast-TBI) is associated with vestibulomotor dysfunction, persistent post-traumatic headaches and post-traumatic stress disorder, requiring extensive treatments and reducing quality-of-life. Treatment and prevention of these devastating outcomes require an understanding of their underlying pathophysiology through studies that take advantage of animal models. Here, we report that cranium-directed blast-TBI in rats results in signs of pain that last at least 8 weeks after injury. These occur without significantly elevated behavioural markers of anxiety-like conditions and are not associated with glial up-regulation in sensory thalamic nuclei. These injuries also produce transient vestibulomotor abnormalities that resolve within 3 weeks of injury. Thus, blast-TBI in rats recapitulates aspects of the human condition.
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Affiliation(s)
- Paige E. Studlack
- Program in Neuroscience and Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St., HSFII S251, Baltimore, MD 21201, USA
| | - Kaspar Keledjian
- Department of Neurosurgery, University of Maryland School of Medicine, 10 S. Pine St., MSTF 634B, Baltimore, MD 21201, USA
| | - Tayyiaba Farooq
- Program in Neuroscience and Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St., HSFII S251, Baltimore, MD 21201, USA
| | - Titilola Akintola
- Program in Neuroscience and Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St., HSFII S251, Baltimore, MD 21201, USA
| | - Volodymyr Gerzanich
- Department of Neurosurgery, University of Maryland School of Medicine, 10 S. Pine St., MSTF 634B, Baltimore, MD 21201, USA
| | - J. Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, 10 S. Pine St., MSTF 634B, Baltimore, MD 21201, USA
| | - Asaf Keller
- Program in Neuroscience and Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St., HSFII S251, Baltimore, MD 21201, USA
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18
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Shiao R, Lee-Kubli CA. Neuropathic Pain After Spinal Cord Injury: Challenges and Research Perspectives. Neurotherapeutics 2018; 15:635-653. [PMID: 29736857 PMCID: PMC6095789 DOI: 10.1007/s13311-018-0633-4] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neuropathic pain is a debilitating consequence of spinal cord injury (SCI) that remains difficult to treat because underlying mechanisms are not yet fully understood. In part, this is due to limitations of evaluating neuropathic pain in animal models in general, and SCI rodents in particular. Though pain in patients is primarily spontaneous, with relatively few patients experiencing evoked pains, animal models of SCI pain have primarily relied upon evoked withdrawals. Greater use of operant tasks for evaluation of the affective dimension of pain in rodents is needed, but these tests have their own limitations such that additional studies of the relationship between evoked withdrawals and operant outcomes are recommended. In preclinical SCI models, enhanced reflex withdrawal or pain responses can arise from pathological changes that occur at any point along the sensory neuraxis. Use of quantitative sensory testing for identification of optimal treatment approach may yield improved identification of treatment options and clinical trial design. Additionally, a better understanding of the differences between mechanisms contributing to at- versus below-level neuropathic pain and neuropathic pain versus spasticity may shed insights into novel treatment options. Finally, the role of patient characteristics such as age and sex in pathogenesis of neuropathic SCI pain remains to be addressed.
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Affiliation(s)
- Rani Shiao
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines, La Jolla, California, 92073, USA
| | - Corinne A Lee-Kubli
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines, La Jolla, California, 92073, USA.
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19
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Neuronal-Glial Interactions Maintain Chronic Neuropathic Pain after Spinal Cord Injury. Neural Plast 2017; 2017:2480689. [PMID: 28951789 PMCID: PMC5603132 DOI: 10.1155/2017/2480689] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 06/26/2017] [Accepted: 07/05/2017] [Indexed: 02/01/2023] Open
Abstract
The hyperactive state of sensory neurons in the spinal cord enhances pain transmission. Spinal glial cells have also been implicated in enhanced excitability of spinal dorsal horn neurons, resulting in pain amplification and distortions. Traumatic injuries of the neural system such as spinal cord injury (SCI) induce neuronal hyperactivity and glial activation, causing maladaptive synaptic plasticity in the spinal cord. Recent studies demonstrate that SCI causes persistent glial activation with concomitant neuronal hyperactivity, thus providing the substrate for central neuropathic pain. Hyperactive sensory neurons and activated glial cells increase intracellular and extracellular glutamate, neuropeptides, adenosine triphosphates, proinflammatory cytokines, and reactive oxygen species concentrations, all of which enhance pain transmission. In addition, hyperactive sensory neurons and glial cells overexpress receptors and ion channels that maintain this enhanced pain transmission. Therefore, post-SCI neuronal-glial interactions create maladaptive synaptic circuits and activate intracellular signaling events that permanently contribute to enhanced neuropathic pain. In this review, we describe how hyperactivity of sensory neurons contributes to the maintenance of chronic neuropathic pain via neuronal-glial interactions following SCI.
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20
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Steffensen N, Lehmbecker A, Gerhauser I, Wang Y, Carlson R, Tipold A, Baumgärtner W, Stein VM. Generation and characterization of highly purified canine Schwann cells from spinal nerve dorsal roots as potential new candidates for transplantation strategies. J Tissue Eng Regen Med 2017; 12:e422-e437. [DOI: 10.1002/term.2478] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 05/06/2017] [Accepted: 05/09/2017] [Indexed: 12/15/2022]
Affiliation(s)
- Nicole Steffensen
- Department of Small Animal Medicine and Surgery; University of Veterinary Medicine; Hannover Germany
| | - Annika Lehmbecker
- Department of Pathology; University of Veterinary Medicine; Hannover Germany
- Center for Systems Neuroscience; Hannover Germany
| | - Ingo Gerhauser
- Department of Pathology; University of Veterinary Medicine; Hannover Germany
| | - Yimin Wang
- Department of Pathology; University of Veterinary Medicine; Hannover Germany
- Center for Systems Neuroscience; Hannover Germany
| | - Regina Carlson
- Department of Small Animal Medicine and Surgery; University of Veterinary Medicine; Hannover Germany
| | - Andrea Tipold
- Department of Small Animal Medicine and Surgery; University of Veterinary Medicine; Hannover Germany
- Center for Systems Neuroscience; Hannover Germany
| | - Wolfgang Baumgärtner
- Department of Pathology; University of Veterinary Medicine; Hannover Germany
- Center for Systems Neuroscience; Hannover Germany
| | - Veronika M. Stein
- Department of Small Animal Medicine and Surgery; University of Veterinary Medicine; Hannover Germany
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21
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Guo JR, Wang H, Jin XJ, Jia DL, Zhou X, Tao Q. Effect and mechanism of inhibition of PI3K/Akt/mTOR signal pathway on chronic neuropathic pain and spinal microglia in a rat model of chronic constriction injury. Oncotarget 2017; 8:52923-52934. [PMID: 28881783 PMCID: PMC5581082 DOI: 10.18632/oncotarget.17629] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 01/03/2017] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE To explore the effects of inhibition of PI3K/Akt/mTOR signal pathway on chronic neuropathic pain (CNP) and spinal microglia in a rat model of chronic constriction injury (CCI). METHODS Male SD rats were assigned into control, sham, CCI, wortmannin, dimethyl sulfoxide (DMSO) and wortmannin-positive control groups. Paw withdrawal mechanical threshold (PWMT) and thermal withdrawal latency (TWL) were recorded. qRT-PCR and Western blotting were used to detect PI3K, Akt and mTOR expressions and their phosphorylation. OX-4 expression was detected by immunohistochemistry and glial fibrillary acidic protein (GFAP) and nerve growth factor (NGF) expressions by immunofluorescence. RESULTS PWMT and TWL decreased in the CCI group than in the sham group on the 7th and 14th day after operation. Compared with the control and sham groups, the CCI group showed increased PI3K, Akt and mTOR mRNA expressions and elevated PI3K, p-Akt, p-mTOR and P70S6K protein expressions. More OX-42-positive cells and higher integrated optical density (IOD) of GFAP and NGF were found in the CCI group than the sham group at the 14th day after operation. Compared with the DMSO group, the wortmannin group had higher PWMT and TWL, decreased PI3K, Akt and mTOR mRNA expressions and reduced PI3K, p-Akt, p-mTOR and P70S6K protein expressions. Less OX-42-positive cells and lower IOD of GFAP and NGF were found in the wortmannin group than the DMSO group 14th day after operation. CONCLUSION Inhibition of PI3K/Akt/mTOR signal pathway may alleviate CNP and reduce microglia and GFAP and NGF expressions in marrow in a rat model of CCI.
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Affiliation(s)
- Jian-Rong Guo
- Department of Anesthesiology, Gongli Hospital, Second Military Medical University, Shanghai 200135, P.R. China
| | - Huan Wang
- Department of Anesthesiology, Gongli Hospital, Second Military Medical University, Shanghai 200135, P.R. China
| | - Xiao-Ju Jin
- Department of Anesthesiology, Yijishan Hospital, Wannan Medical College, Wuhu 241001, P.R. China
| | - Dong-Lin Jia
- Pain Department, Peking University Third Hospital, Beijing, 100191, P.R. China
| | - Xun Zhou
- Department of Anesthesiology, Gongli Hospital, Second Military Medical University, Shanghai 200135, P.R. China
| | - Qiang Tao
- Department of Anesthesiology, Gongli Hospital, Second Military Medical University, Shanghai 200135, P.R. China
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22
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Li XM, Meng J, Li LT, Guo T, Yang LK, Shi QX, Li XB, Chen Y, Yang Q, Zhao JN. Effect of ZBD-2 on chronic pain, depressive-like behaviors, and recovery of motor function following spinal cord injury in mice. Behav Brain Res 2017; 322:92-99. [PMID: 28108322 PMCID: PMC5339413 DOI: 10.1016/j.bbr.2017.01.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/09/2017] [Accepted: 01/12/2017] [Indexed: 02/06/2023]
Abstract
ZBD-2 significantly attenuated the symptoms of chronic SCI-pain and pain-induced depressive-like behaviors. ZBD-2 inhibited the decreases in the expression of synaptic plasticity-related signaling proteins. ZBD-2 reversed chronic, SCI-induced gliocyte activation at the lesion site.
In addition to debilitating sensory and motor deficits, patients with spinal cord injury (SCI) may experience chronic hyperpathic pain (SCI-pain). Recent studies have revealed that translocator protein (TSPO) is involved in repairing neural cells as well as reducing anxiety and depression. However, the role of TSPO in SCI-pain and pain-induced depression remains unknown. The present study aimed to determine the effects of a new TSPO ligand, ZBD-2, on SCI-pain and consequent pain-induced depressive-like behaviors in mice. Treatment with ZBD-2 at either dose significantly attenuated the symptoms of chronic SCI-pain and pain-induced depressive-like behaviors. ZBD-2 reversed SCI-induced elevation of serum corticosterone levels, an index of hyper-activation of the hypothalamic–pituitary–adrenal (HPA) axis. Additionally, administration of ZBD-2 inhibited decreases in the expression of synaptic plasticity-related signaling proteins, including brain-derived neurotrophic factor (BDNF) and cyclic AMP-responsive element binding protein (CREB). Moreover, ZBD-2 administration reversed chronic, SCI-induced gliocyte activation at the lesion site. Therefore, ZBD-2 may improve chronic SCI-pain and pain-induced depressive-like behaviors via suppression of gliocyte activation and restoration of the synaptic plasticity-related signaling systems.
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Affiliation(s)
- Xiao-Ming Li
- Department of Orthopedics, Jinling Hospital, Clinical School of Nanjing, Second Military Medical University, Nanjing, 210002, China
| | - Jia Meng
- Department of Orthopedics, Jinling Hospital, Clinical School of Nanjing, Second Military Medical University, Nanjing, 210002, China
| | - Lin Tao Li
- Department of Orthopedics, Jinling Hospital, Clinical School of Nanjing, Second Military Medical University, Nanjing, 210002, China
| | - Ting Guo
- Department of Orthopedics, Jinling Hospital, Clinical School of Nanjing, Second Military Medical University, Nanjing, 210002, China
| | - Liu-Kun Yang
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, China
| | - Qi-Xin Shi
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, China
| | - Xu-Bo Li
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, China
| | - Yong Chen
- Department of Orthopedics, Jinling Hospital, Clinical School of Nanjing, Second Military Medical University, Nanjing, 210002, China.
| | - Qi Yang
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, China.
| | - Jian-Ning Zhao
- Department of Orthopedics, Jinling Hospital, Clinical School of Nanjing, Second Military Medical University, Nanjing, 210002, China.
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Jalan D, Saini N, Zaidi M, Pallottie A, Elkabes S, Heary RF. Effects of early surgical decompression on functional and histological outcomes after severe experimental thoracic spinal cord injury. J Neurosurg Spine 2017; 26:62-75. [DOI: 10.3171/2016.6.spine16343] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE
In acute traumatic brain injury, decompressive craniectomy is a common treatment that involves the removal of bone from the cranium to relieve intracranial pressure. The present study investigated whether neurological function following a severe spinal cord injury improves after utilizing either a durotomy to decompress the intradural space and/or a duraplasty to maintain proper flow of cerebrospinal fluid.
METHODS
Sixty-four adult female rats (n = 64) were randomly assigned to receive either a 3- or 5-level decompressive laminectomy (Groups A and B), laminectomy + durotomy (Groups C and D), or laminectomy + duraplasty with graft (Group E and F) at 24 hours following a severe thoracic contusion injury (200 kilodynes). Duraplasty involved the use of DuraSeal, a hydrogel dural sealant. Uninjured and injured control groups were included (Groups G, H). Hindlimb locomotor function was assessed by open field locomotor testing (BBB) and CatWalk gait analysis at 35 days postinjury. Bladder function was analyzed and bladder wall thickness was assessed histologically. At 35 days postinjury, mechanical and thermal allodynia were assessed by the Von Frey hair filament and hotplate paw withdrawal tests, respectively. Thereafter, the spinal cords were dissected, examined for gross anomalies at the injury site, and harvested for histological analyses to assess lesion volumes and white matter sparing. ANOVA was used for statistical analyses.
RESULTS
There was no significant improvement in motor function recovery in any treatment groups compared with injured controls. CatWalk gait analysis indicated a significant decrease in interlimb coordination in Groups B, C, and D (p < 0.05) and swing speed in Groups A, B, and D. Increased mechanical pain sensitivity was observed in Groups A, C, and F (p < 0.05). Rats in Group C also developed thermal pain hypersensitivity. Examination of spinal cords demonstrated increased lesion volumes in Groups C and F and increased white matter sparing in Group E (p < 0.05). The return of bladder automaticity was similar in all groups. Examination of the injury site during tissue harvest revealed that, in some instances, expansion of the hydrogel dural sealant caused compression of the spinal cord.
CONCLUSIONS
Surgical decompression provided no benefit in terms of neurological improvement in the setting of a severe thoracic spinal cord contusion injury in rats at 24 hours postinjury. Decompressive laminectomy and durotomy did not improve motor function recovery, and rats in both of these treatment modalities developed neuropathic pain. Performing a durotomy also led to increased lesion volumes. Placement of DuraSeal was shown to cause compression in some rats in the duraplasty treatment groups. Decompressive duraplasty of 3 levels does not affect functional outcomes after injury but did increase white matter sparing. Decompressive duraplasty of 5 levels led to neuropathic pain development and increased lesion volumes. Further comparison of dural repair techniques is necessary.
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Affiliation(s)
- Devesh Jalan
- 1Department of Neurological Surgery, Rutgers, The State University of New Jersey–New Jersey Medical School; and
| | - Neginder Saini
- 1Department of Neurological Surgery, Rutgers, The State University of New Jersey–New Jersey Medical School; and
| | - Mohammad Zaidi
- 1Department of Neurological Surgery, Rutgers, The State University of New Jersey–New Jersey Medical School; and
| | - Alexandra Pallottie
- 2Graduate School of Biomedical Sciences, Rutgers, The State University of New Jersey, Newark, New Jersey
| | - Stella Elkabes
- 1Department of Neurological Surgery, Rutgers, The State University of New Jersey–New Jersey Medical School; and
| | - Robert F. Heary
- 1Department of Neurological Surgery, Rutgers, The State University of New Jersey–New Jersey Medical School; and
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Does time heal all wounds? Experimental diffuse traumatic brain injury results in persisting histopathology in the thalamus. Behav Brain Res 2016; 340:137-146. [PMID: 28042008 DOI: 10.1016/j.bbr.2016.12.038] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/30/2016] [Accepted: 12/28/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND Thalamic dysfunction has been implicated in overall chronic neurological dysfunction after traumatic brain injury (TBI), however little is known about the underlying histopathology. In experimental diffuse TBI (dTBI), we hypothesize that persisting histopathological changes in the ventral posteromedial (VPM) nucleus of the thalamus is indicative of progressive circuit reorganization. Since circuit reorganization in the VPM impacts the whisker sensory system, the histopathology could explain the development of hypersensitivity to whisker stimulation by 28days post-injury; similar to light and sound hypersensitivity in human TBI survivors. METHODS Adult, male Sprague-Dawley rats underwent craniotomy and midline fluid percussion injury (FPI) (moderate severity; 1.8-2.0atm) or sham surgery. At 1d, 7d, and 28days post-FPI (d FPI) separate experiments confirmed the cytoarchitecture (Giemsa stain) and evaluated neuropathology (silver stain), activated astrocytes (GFAP), neuron morphology (Golgi stain) and microglial morphology (Iba-1) in the VPM. RESULTS Cytoarchitecture was unchanged throughout the time course, similar to previously published data; however, neuropathology and astrocyte activation were significantly increased at 7d and 28d and activated microglia were present at all time points. Neuron morphology was dynamic over the time course with decreased dendritic complexity (fewer branch points; decreased length of processes) at 7d FPI and return to sham values by 28d FPI. CONCLUSIONS These data indicate that dTBI results in persisting thalamic histopathology out to a chronic time point. While these changes can be indicative of either adaptive (recovery) or maladaptive (neurological dysfunction) circuit reorganization, they also provide a potential mechanism by which maladaptive circuit reorganization could contribute to the development of chronic neurological dysfunction. Understanding the processes that mediate circuit reorganization is critical to the development of future therapies for TBI patients.
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25
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Cell cycle inhibition limits development and maintenance of neuropathic pain following spinal cord injury. Pain 2016; 157:488-503. [PMID: 26797506 DOI: 10.1097/j.pain.0000000000000393] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Chronic pain after spinal cord injury (SCI) may present as hyperalgesia, allodynia, and/or spontaneous pain and is often resistant to conventional pain medications. Identifying more effective interventions to manage SCI pain requires improved understanding of the pathophysiological mechanisms involved. Cell cycle activation (CCA) has been implicated as a key pathophysiological event following SCI. We have shown that early central or systemic administration of a cell cycle inhibitor reduces CCA, prevents glial changes, and limits SCI-induced hyperesthesia. Here, we compared the effects of early vs late treatment with the pan-cyclin-dependent kinase inhibitor flavopiridol on allodynia as well as spontaneous pain. Adult C57BL/6 male mice subjected to moderate SCI were treated with intraperitoneal injections of flavopiridol (1 mg/kg), daily for 7 days beginning either 3 hours or 5 weeks after injury. Mechanical/thermal allodynia was evaluated, as well as spontaneous pain using the mouse grimace scale (MGS). We show that sensitivity to mechanical and thermal stimulation, and locomotor dysfunction were significantly reduced by early flavopiridol treatment compared with vehicle-treated controls. Spinal cord injury caused robust and extended increases of MGS up to 3 weeks after trauma. Early administration of flavopiridol significantly shortened duration of MGS changes. Late flavopiridol intervention significantly limited hyperesthesia at 7 days after treatment, associated with reduced glial changes, but without effect on locomotion. Thus, our data suggest that cell cycle modulation may provide an effective therapeutic strategy to reduce hyperesthesia after SCI, with a prolonged therapeutic window.
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26
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Wu J, Sabirzhanov B, Stoica BA, Lipinski MM, Zhao Z, Zhao S, Ward N, Yang D, Faden AI. Ablation of the transcription factors E2F1-2 limits neuroinflammation and associated neurological deficits after contusive spinal cord injury. Cell Cycle 2016; 14:3698-712. [PMID: 26505089 DOI: 10.1080/15384101.2015.1104436] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Traumatic spinal cord injury (SCI) induces cell cycle activation (CCA) that contributes to secondary injury and related functional impairments such as motor deficits and hyperpathia. E2F1 and E2F2 are members of the activator sub-family of E2F transcription factors that play an important role in proliferating cells and in cell cycle-related neuronal death, but no comprehensive study have been performed in SCI to determine the relative importance of these factors. Here we examined the temporal distribution and cell-type specificity of E2F1 and E2F2 expression following mouse SCI, as well as the effects of genetic deletion of E2F1-2 on neuronal cell death, neuroinflammation and associated neurological dysfunction. SCI significantly increased E2F1 and E2F2 expression in active caspase-3(+) neurons/oligodendrocytes as well as in activated microglia/astrocytes. Injury-induced up-regulation of cell cycle-related genes and protein was significantly reduced by intrathecal injection of high specificity E2F decoy oligodeoxynucleotides against the E2F-binding site or in E2F1-2 null mice. Combined E2F1+2 siRNA treatment show greater neuroprotection in vivo than E2F1 or E2F2 single siRNA treatment. Knockout of both E2F1 and E2F2 genes (E2Fdko) significantly reduced neuronal death, neuroinflammation, and tissue damage, as well as limiting motor dysfunction and hyperpathia after SCI. Both CCA reduction and functional improvement in E2Fdko mice were greater than those in E2F2ko model. These studies demonstrate that SCI-induced activation of E2F1-2 mediates CCA, contributing to gliopathy and neuronal/tissue loss associated with motor impairments and post-traumatic hyperesthesia. Thus, E2F1-2 provide a therapeutic target for decreasing secondary tissue damage and promoting recovery of function after SCI.
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Affiliation(s)
- Junfang Wu
- a Department of Anesthesiology and Center for Shock ; Trauma and Anesthesiology Research (STAR); University of Maryland School of Medicine ; Baltimore , MD USA.,b Department of Anatomy and Neurobiology ; University of Maryland School of Medicine ; Baltimore , MD USA
| | - Boris Sabirzhanov
- a Department of Anesthesiology and Center for Shock ; Trauma and Anesthesiology Research (STAR); University of Maryland School of Medicine ; Baltimore , MD USA
| | - Bogdan A Stoica
- a Department of Anesthesiology and Center for Shock ; Trauma and Anesthesiology Research (STAR); University of Maryland School of Medicine ; Baltimore , MD USA.,b Department of Anatomy and Neurobiology ; University of Maryland School of Medicine ; Baltimore , MD USA
| | - Marta M Lipinski
- a Department of Anesthesiology and Center for Shock ; Trauma and Anesthesiology Research (STAR); University of Maryland School of Medicine ; Baltimore , MD USA.,b Department of Anatomy and Neurobiology ; University of Maryland School of Medicine ; Baltimore , MD USA
| | - Zaorui Zhao
- a Department of Anesthesiology and Center for Shock ; Trauma and Anesthesiology Research (STAR); University of Maryland School of Medicine ; Baltimore , MD USA
| | - Shuxin Zhao
- a Department of Anesthesiology and Center for Shock ; Trauma and Anesthesiology Research (STAR); University of Maryland School of Medicine ; Baltimore , MD USA
| | - Nicole Ward
- a Department of Anesthesiology and Center for Shock ; Trauma and Anesthesiology Research (STAR); University of Maryland School of Medicine ; Baltimore , MD USA
| | - Dianer Yang
- a Department of Anesthesiology and Center for Shock ; Trauma and Anesthesiology Research (STAR); University of Maryland School of Medicine ; Baltimore , MD USA
| | - Alan I Faden
- a Department of Anesthesiology and Center for Shock ; Trauma and Anesthesiology Research (STAR); University of Maryland School of Medicine ; Baltimore , MD USA.,b Department of Anatomy and Neurobiology ; University of Maryland School of Medicine ; Baltimore , MD USA
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27
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Multiple organ dysfunction and systemic inflammation after spinal cord injury: a complex relationship. J Neuroinflammation 2016; 13:260. [PMID: 27716334 PMCID: PMC5053065 DOI: 10.1186/s12974-016-0736-y] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 09/28/2016] [Indexed: 12/24/2022] Open
Abstract
Spinal cord injury (SCI) is a devastating event that results in significant physical disabilities for affected individuals. Apart from local injury within the spinal cord, SCI patients develop a variety of complications characterized by multiple organ dysfunction or failure. These disorders, such as neurogenic pain, depression, lung injury, cardiovascular disease, liver damage, kidney dysfunction, urinary tract infection, and increased susceptibility to pathogen infection, are common in injured patients, hinder functional recovery, and can even be life threatening. Multiple lines of evidence point to pathological connections emanating from the injured spinal cord, post-injury systemic inflammation, and immune suppression as important multifactorial mechanisms underlying post-SCI complications. SCI triggers systemic inflammatory responses marked by increased circulation of immune cells and pro-inflammatory mediators, which result in the infiltration of inflammatory cells into secondary organs and persistence of an inflammatory microenvironment that contributes to organ dysfunction. SCI also induces immune deficiency through immune organ dysfunction, resulting in impaired responsiveness to pathogen infection. In this review, we summarize current evidence demonstrating the relevance of inflammatory conditions and immune suppression in several complications frequently seen following SCI. In addition, we highlight the potential pathways by which inflammatory and immune cues contribute to multiple organ failure and dysfunction and discuss current anti-inflammatory approaches used to alleviate post-SCI complications. A comprehensive review of this literature may provide new insights into therapeutic strategies against complications after SCI by targeting systemic inflammation.
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28
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Skovira JW, Kabadi SV, Wu J, Zhao Z, DuBose J, Rosenthal R, Fiskum G, Faden AI. Simulated Aeromedical Evacuation Exacerbates Experimental Brain Injury. J Neurotrauma 2016; 33:1292-302. [DOI: 10.1089/neu.2015.4189] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Jacob W. Skovira
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland
| | - Shruti V. Kabadi
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland
| | - Junfang Wu
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland
| | - Zaorui Zhao
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland
| | - Joseph DuBose
- Program in Trauma, Center for the Sustainment of Trauma and Readiness Skills (C-STARS), University of Maryland School of Medicine, Baltimore, Maryland
| | - Robert Rosenthal
- Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Gary Fiskum
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland
| | - Alan I. Faden
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland
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29
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Wu J, Zhao Z, Kumar A, Lipinski MM, Loane DJ, Stoica BA, Faden AI. Endoplasmic Reticulum Stress and Disrupted Neurogenesis in the Brain Are Associated with Cognitive Impairment and Depressive-Like Behavior after Spinal Cord Injury. J Neurotrauma 2016; 33:1919-1935. [PMID: 27050417 DOI: 10.1089/neu.2015.4348] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Clinical and experimental studies show that spinal cord injury (SCI) can cause cognitive impairment and depression that can significantly impact outcomes. Thus, identifying mechanisms responsible for these less well-examined, important SCI consequences may provide targets for more effective therapeutic intervention. To determine whether cognitive and depressive-like changes correlate with injury severity, we exposed mice to sham, mild, moderate, or severe SCI using the Infinite Horizon Spinal Cord Impactor and evaluated performance on a variety of neurobehavioral tests that are less dependent on locomotion. Cognitive impairment in Y-maze, novel objective recognition, and step-down fear conditioning tasks were increased in moderate- and severe-injury mice that also displayed depressive-like behavior as quantified in the sucrose preference, tail suspension, and forced swim tests. Bromo-deoxyuridine incorporation with immunohistochemistry revealed that SCI led to a long-term reduction in the number of newly-generated immature neurons in the hippocampal dentate gyrus, accompanied by evidence of greater neuronal endoplasmic reticulum (ER) stress. Stereological analysis demonstrated that moderate/severe SCI reduced neuronal survival and increased the number of activated microglia chronically in the cerebral cortex and hippocampus. The potent microglial activator cysteine-cysteine chemokine ligand 21 (CCL21) was elevated in the brain sites after SCI in association with increased microglial activation. These findings indicate that SCI causes chronic neuroinflammation that contributes to neuronal loss, impaired hippocampal neurogenesis and increased neuronal ER stress in important brain regions associated with cognitive decline and physiological depression. Accumulation of CCL21 in brain may subserve a pathophysiological role in cognitive changes and depression after SCI.
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Affiliation(s)
- Junfang Wu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine , Baltimore, Maryland
| | - Zaorui Zhao
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine , Baltimore, Maryland
| | - Alok Kumar
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine , Baltimore, Maryland
| | - Marta M Lipinski
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine , Baltimore, Maryland
| | - David J Loane
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine , Baltimore, Maryland
| | - Bogdan A Stoica
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine , Baltimore, Maryland
| | - Alan I Faden
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine , Baltimore, Maryland
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30
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Faden AI, Wu J, Stoica BA, Loane DJ. Progressive inflammation-mediated neurodegeneration after traumatic brain or spinal cord injury. Br J Pharmacol 2016; 173:681-91. [PMID: 25939377 PMCID: PMC4742301 DOI: 10.1111/bph.13179] [Citation(s) in RCA: 198] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/31/2015] [Accepted: 04/14/2015] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) has been linked to dementia and chronic neurodegeneration. Described initially in boxers and currently recognized across high contact sports, the association between repeated concussion (mild TBI) and progressive neuropsychiatric abnormalities has recently received widespread attention, and has been termed chronic traumatic encephalopathy. Less well appreciated are cognitive changes associated with neurodegeneration in the brain after isolated spinal cord injury. Also under-recognized is the role of sustained neuroinflammation after brain or spinal cord trauma, even though this relationship has been known since the 1950s and is supported by more recent preclinical and clinical studies. These pathological mechanisms, manifested by extensive microglial and astroglial activation and appropriately termed chronic traumatic brain inflammation or chronic traumatic inflammatory encephalopathy, may be among the most important causes of post-traumatic neurodegeneration in terms of prevalence. Importantly, emerging experimental work demonstrates that persistent neuroinflammation can cause progressive neurodegeneration that may be treatable even weeks after traumatic injury.
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Affiliation(s)
- Alan I Faden
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, USA
| | - Junfang Wu
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bogdan A Stoica
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, USA
| | - David J Loane
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, USA
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31
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Wu J, Stoica BA, Luo T, Sabirzhanov B, Zhao Z, Guanciale K, Nayar SK, Foss CA, Pomper MG, Faden AI. Isolated spinal cord contusion in rats induces chronic brain neuroinflammation, neurodegeneration, and cognitive impairment. Involvement of cell cycle activation. Cell Cycle 2015; 13:2446-58. [PMID: 25483194 DOI: 10.4161/cc.29420] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cognitive dysfunction has been reported in patients with spinal cord injury (SCI), but it has been questioned whether such changes may reflect concurrent head injury, and the issue has not been addressed mechanistically or in a well-controlled experimental model. Our recent rodent studies examining SCI-induced hyperesthesia revealed neuroinflammatory changes not only in supratentorial pain-regulatory sites, but also in other brain regions, suggesting that additional brain functions may be impacted following SCI. Here we examined effects of isolated thoracic SCI in rats on cognition, brain inflammation, and neurodegeneration. We show for the first time that SCI causes widespread microglial activation in the brain, with increased expression of markers for activated microglia/macrophages, including translocator protein and chemokine ligand 21 (C-C motif). Stereological analysis demonstrated significant neuronal loss in the cortex, thalamus, and hippocampus. SCI caused chronic impairment in spatial, retention, contextual, and fear-related emotional memory-evidenced by poor performance in the Morris water maze, novel objective recognition, and passive avoidance tests. Based on our prior work implicating cell cycle activation (CCA) in chronic neuroinflammation after SCI or traumatic brain injury, we evaluated whether CCA contributed to the observed changes. Increased expression of cell cycle-related genes and proteins was found in hippocampus and cortex after SCI. Posttraumatic brain inflammation, neuronal loss, and cognitive changes were attenuated by systemic post-injury administration of a selective cyclin-dependent kinase inhibitor. These studies demonstrate that chronic brain neurodegeneration occurs after isolated SCI, likely related to sustained microglial activation mediated by cell cycle activation.
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Affiliation(s)
- Junfang Wu
- a Department of Anesthesiology & Center for Shock, Trauma, and Anesthesiology Research (STAR); University of Maryland School of Medicine; Baltimore, MD USA
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32
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Disrupted autophagy after spinal cord injury is associated with ER stress and neuronal cell death. Cell Death Dis 2015; 6:e1582. [PMID: 25569099 PMCID: PMC4669738 DOI: 10.1038/cddis.2014.527] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/16/2014] [Accepted: 10/20/2014] [Indexed: 12/19/2022]
Abstract
Autophagy is a catabolic mechanism facilitating degradation of cytoplasmic proteins and organelles in a lysosome-dependent manner. Autophagy flux is necessary for normal neuronal homeostasis and its dysfunction contributes to neuronal cell death in several neurodegenerative diseases. Elevated autophagy has been reported after spinal cord injury (SCI); however, its mechanism, cell type specificity and relationship to cell death are unknown. Using a rat model of contusive SCI, we observed accumulation of LC3-II-positive autophagosomes starting at posttrauma day 1. This was accompanied by a pronounced accumulation of autophagy substrate protein p62, indicating that early elevation of autophagy markers reflected disrupted autophagosome degradation. Levels of lysosomal protease cathepsin D and numbers of cathepsin-D-positive lysosomes were also decreased at this time, suggesting that lysosomal damage may contribute to the observed defect in autophagy flux. Normalization of p62 levels started by day 7 after SCI, and was associated with increased cathepsin D levels. At day 1 after SCI, accumulation of autophagosomes was pronounced in ventral horn motor neurons and dorsal column oligodendrocytes and microglia. In motor neurons, disruption of autophagy strongly correlated with evidence of endoplasmic reticulum (ER) stress. As autophagy is thought to protect against ER stress, its disruption after SCI could contribute to ER-stress-induced neuronal apoptosis. Consistently, motor neurons showing disrupted autophagy co-expressed ER-stress-associated initiator caspase 12 and cleaved executioner caspase 3. Together, these findings indicate that SCI causes lysosomal dysfunction that contributes to autophagy disruption and associated ER-stress-induced neuronal apoptosis.
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33
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Spinal cord injury causes brain inflammation associated with cognitive and affective changes: role of cell cycle pathways. J Neurosci 2014; 34:10989-1006. [PMID: 25122899 DOI: 10.1523/jneurosci.5110-13.2014] [Citation(s) in RCA: 176] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Experimental spinal cord injury (SCI) causes chronic neuropathic pain associated with inflammatory changes in thalamic pain regulatory sites. Our recent studies examining chronic pain mechanisms after rodent SCI showed chronic inflammatory changes not only in thalamus, but also in other regions including hippocampus and cerebral cortex. Because changes appeared similar to those in our rodent TBI models that are associated with neurodegeneration and neurobehavioral dysfunction, we examined effects of mouse SCI on cognition, depressive-like behavior, and brain inflammation. SCI caused spatial and retention memory impairment and depressive-like behavior, as evidenced by poor performance in the Morris water maze, Y-maze, novel objective recognition, step-down passive avoidance, tail suspension, and sucrose preference tests. SCI caused chronic microglial activation in the hippocampus and cerebral cortex, where microglia with hypertrophic morphologies and M1 phenotype predominated. Stereological analyses showed significant neuronal loss in the hippocampus at 12 weeks but not 8 d after injury. Increased cell-cycle-related gene (cyclins A1, A2, D1, E2F1, and PCNA) and protein (cyclin D1 and CDK4) expression were found chronically in hippocampus and cerebral cortex. Systemic administration of the selective cyclin-dependent kinase inhibitor CR8 after SCI significantly reduced cell cycle gene and protein expression, microglial activation and neurodegeneration in the brain, cognitive decline, and depression. These studies indicate that SCI can initiate a chronic brain neurodegenerative response, likely related to delayed, sustained induction of M1-type microglia and related cell cycle activation, which result in cognitive deficits and physiological depression.
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Walters ET. Neuroinflammatory contributions to pain after SCI: roles for central glial mechanisms and nociceptor-mediated host defense. Exp Neurol 2014; 258:48-61. [PMID: 25017887 DOI: 10.1016/j.expneurol.2014.02.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/23/2014] [Accepted: 02/02/2014] [Indexed: 12/30/2022]
Abstract
Neuropathic pain after spinal cord injury (SCI) is common, often intractable, and can be severely debilitating. A number of mechanisms have been proposed for this pain, which are discussed briefly, along with methods for revealing SCI pain in animal models, such as the recently applied conditioned place preference test. During the last decade, studies of animal models have shown that both central neuroinflammation and behavioral hypersensitivity (indirect reflex measures of pain) persist chronically after SCI. Interventions that reduce neuroinflammation have been found to ameliorate pain-related behavior, such as treatment with agents that inhibit the activation states of microglia and/or astroglia (including IL-10, minocycline, etanercept, propentofylline, ibudilast, licofelone, SP600125, carbenoxolone). Reversal of pain-related behavior has also been shown with disruption by an inhibitor (CR8) and/or genetic deletion of cell cycle-related proteins, deletion of a truncated receptor (trkB.T1) for brain-derived neurotrophic factor (BDNF), or reduction by antisense knockdown or an inhibitor (AMG9810) of the activity of channels (TRPV1 or Nav1.8) important for electrical activity in primary nociceptors. Nociceptor activity is known to drive central neuroinflammation in peripheral injury models, and nociceptors appear to be an integral component of host defense. Thus, emerging results suggest that spinal and systemic effects of SCI can activate nociceptor-mediated host defense responses that interact via neuroinflammatory signaling with complex central consequences of SCI to drive chronic pain. This broader view of SCI-induced neuroinflammation suggests new targets, and additional complications, for efforts to develop effective treatments for neuropathic SCI pain.
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Affiliation(s)
- Edgar T Walters
- Department of Integrative Biology and Pharmacology, University of Texas Medical School at Houston, TX, USA.
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35
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Malmierca E, Chaves-Coira I, Rodrigo-Angulo M, Nuñez A. Corticofugal projections induce long-lasting effects on somatosensory responses in the trigeminal complex of the rat. Front Syst Neurosci 2014; 8:100. [PMID: 24904321 PMCID: PMC4033105 DOI: 10.3389/fnsys.2014.00100] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/08/2014] [Indexed: 11/17/2022] Open
Abstract
The sensory information flow at subcortical relay stations is controlled by the action of topographic connections from the neocortex. To determinate the functional properties of the somatosensory corticofugal projections to the principal (Pr5) and caudal spinal (Sp5C) trigeminal nuclei, we performed unitary recordings in anesthetized rats. To examine the effect of these cortical projections we used tactile stimulation of the whisker and electrical stimulation of somatosensory cortices. Corticofugal anatomical projections to Pr5 and Sp5C nuclei were detected by using retrograde fluorescent tracers. Neurons projecting exclusively to Pr5 were located in the cingulate cortex while neurons projecting to both Sp5C and Pr5 nuclei were located in the somatosensory and insular cortices (>75% of neurons). Physiological results indicated that primary somatosensory cortex produced a short-lasting facilitating or inhibiting effects (<5 min) of tactile responses in Pr5 nucleus through activation of NMDA glutamatergic or GABAA receptors since effects were blocked by iontophoretically application of APV and bicuculline, respectively. In contrast, stimulation of secondary somatosensory cortex did not affect most of the Pr5 neurons; however both cortices inhibited the nociceptive responses in the Sp5C nucleus through activation of glycinergic or GABAA receptors because effects were blocked by iontophoretically application of strychnine and bicuculline, respectively. These and anatomical results demonstrated that the somatosensory cortices projects to Pr5 nucleus to modulate tactile responses by excitatory and inhibitory actions, while projections to the Sp5C nucleus control nociceptive sensory transmission by only inhibitory effects. Thus, somatosensory cortices may modulate innocuous and noxious inputs simultaneously, contributing to the perception of specifically tactile or painful sensations.
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Affiliation(s)
- Eduardo Malmierca
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - Irene Chaves-Coira
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - Margarita Rodrigo-Angulo
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - Angel Nuñez
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
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