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Aldrich JC, Scheinfeld AR, Lee SE, Dusenbery KJ, Mahach KM, Van de Veire BC, Fonken LK, Gaudet AD. Effects of dim light at night in C57BL/6 J mice on recovery after spinal cord injury. Exp Neurol 2024; 375:114725. [PMID: 38365132 PMCID: PMC10981559 DOI: 10.1016/j.expneurol.2024.114725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/09/2024] [Accepted: 02/12/2024] [Indexed: 02/18/2024]
Abstract
Spinal cord injury (SCI) can cause long-lasting locomotor deficits, pain, and mood disorders. Anatomical and functional outcomes are exacerbated by inflammation after SCI, which causes secondary damage. One promising target after SCI is manipulating the circadian system, which optimizes biology and behavior for time of day - including neuroimmune responses and mood-related behaviors. Circadian disruption after SCI is likely worsened by a disruptive hospital environment, which typically includes dim light-at-night (dLAN). Here, we hypothesized that mice subjected to SCI, then placed in dLAN, would exhibit worsened locomotor deficits, pain-like behavior, and anxiety-depressive-like symptoms compared to mice maintained in light days with dark nights (LD). C57BL/6 J mice received sham surgery or moderate T9 contusion SCI, then were placed permanently in LD or dLAN. dLAN after SCI did not worsen locomotor deficits; rather, SCI-dLAN mice showed slight improvement in open-field locomotion at the final timepoint. Although dLAN did not alter SCI-induced heat hyperalgesia, SCI-dLAN mice exhibited an increase in mechanical allodynia at 13 days post-SCI compared to SCI-LD mice. SCI-LD and SCI-dLAN mice had similar outcomes using sucrose preference (depressive-like) and open-field (anxiety-like) tests. At 21 dpo, SCI-dLAN mice had reduced preference for a novel juvenile compared to SCI-LD, implying that dLAN combined with SCI may worsen this mood-related behavior. Finally, lesion size was similar between SCI-LD and SCI-dLAN mice. Therefore, newly placing C57BL/6 J mice in dLAN after SCI had modest effects on locomotor, pain-like, and mood-related behaviors. Future studies should consider whether clinically-relevant circadian disruptors, alone or in combination, could be ameliorated to enhance outcomes after SCI.
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Affiliation(s)
- John C Aldrich
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Ashley R Scheinfeld
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Sydney E Lee
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Kalina J Dusenbery
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Kathryn M Mahach
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Brigid C Van de Veire
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Laura K Fonken
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin
| | - Andrew D Gaudet
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin.
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2
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Song Y, Xue T, Guo S, Yu Z, Yun C, Zhao J, Song Z, Liu Z. Inhibition of aquaporin-4 and its subcellular localization attenuates below-level central neuropathic pain by regulating astrocyte activation in a rat spinal cord injury model. Neurotherapeutics 2024; 21:e00306. [PMID: 38237380 DOI: 10.1016/j.neurot.2023.e00306] [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: 11/01/2023] [Accepted: 11/19/2023] [Indexed: 03/24/2024] Open
Abstract
The mechanisms of central neuropathic pain (CNP) caused by spinal cord injury have not been sufficiently studied. We have found that the upregulation of astrocytic aquaporin-4 (AQP4) aggravated peripheral neuropathic pain after spinal nerve ligation in rats. Using a T13 spinal cord hemisection model, we showed that spinal AQP4 was markedly upregulated after SCI and mainly expressed in astrocytes in the spinal dorsal horn (SDH). Inhibition of AQP4 with TGN020 suppressed astrocyte activation, attenuated the development and maintenance of below-level CNP and promoted motor function recovery in vivo. In primary astrocyte cultures, TGN020 also changed cell morphology, diminished cell proliferation and suppressed astrocyte activation. Moreover, T13 spinal cord hemisection induced cell-surface abundance of the AQP4 channel and perivascular localization in the SDH. Targeted inhibition of AQP4 subcellular localization with trifluoperazine effectively diminished astrocyte activation in vitro and further ablated astrocyte activation, attenuated the development and maintenance of below-level CNP, and accelerated functional recovery in vivo. Together, these results provide mechanistic insights into the roles of AQP4 in the development and maintenance of below-level CNP. Intervening with AQP4, including targeting AQP4 subcellular localization, might emerge as a promising agent to prevent chronic CNP after SCI.
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Affiliation(s)
- Yu Song
- Department of Spinal Surgery, The Third Affiliated Hospital of Soochow University, Changzhou 213003, China
| | - Tao Xue
- Department of Orthopedics, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213003, China
| | - Shiwu Guo
- Department of Orthopedics, Suzhou Kowloon Hospital, Shanghai Jiao Tong University School of Medicine, Suzhou, 215028, China
| | - Zhen Yu
- Department of Spinal Surgery, The Third Affiliated Hospital of Soochow University, Changzhou 213003, China
| | - Chengming Yun
- Department of Orthopedics, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213003, China
| | - Jie Zhao
- Department of Orthopedics, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213003, China
| | - Zhiwen Song
- Department of Spinal Surgery, The Third Affiliated Hospital of Soochow University, Changzhou 213003, China
| | - Zhiyuan Liu
- Department of Orthopedics, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213003, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou 221004, China; The Wujin Clinical College of Xuzhou Medical University, Changzhou 213003, China.
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3
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Aldrich JC, Scheinfeld AR, Lee SE, Dusenbery KJ, Mahach KM, Van de Veire BC, Fonken LK, Gaudet AD. Effects of dim light at night in C57BL/6J mice on recovery after spinal cord injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.15.557980. [PMID: 37745393 PMCID: PMC10516041 DOI: 10.1101/2023.09.15.557980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Spinal cord injury (SCI) can cause long-lasting locomotor deficits, pain, and mood disorders. Anatomical and functional outcomes are exacerbated by inflammation after SCI, which causes secondary damage. One promising target after SCI is manipulating the circadian system, which optimizes biology and behavior for time of day - including neuroimmune responses and mood-related behaviors. Circadian disruption after SCI is likely worsened by a disruptive hospital environment, which typically includes dim light-at-night (dLAN). Here, we hypothesized that mice subjected to SCI, then placed in dLAN, would exhibit worsened locomotor deficits, pain-like behavior, and anxiety-depressive-like symptoms compared to mice maintained in light days with dark nights (LD). C57BL/6J mice received sham surgery or moderate T9 contusion SCI, then were placed permanently in LD or dLAN. dLAN after SCI did not worsen locomotor deficits; rather, SCI-dLAN mice showed slight improvement in open-field locomotion at the final timepoint. Although dLAN did not alter SCI-induced heat hyperalgesia, SCI-dLAN mice exhibited an increase in mechanical allodynia at 13 days post-SCI compared to SCI-LD mice. SCI-LD and SCI-dLAN mice had similar outcomes using sucrose preference (depressive-like) and open-field (anxiety-like) tests. At 21 dpo, SCI-dLAN mice had reduced preference for a novel juvenile compared to SCI-LD, implying that dLAN combined with SCI may worsen this mood-related behavior. Finally, lesion size was similar between SCI-LD and SCI-dLAN mice. Therefore, newly placing C57BL/6J mice in dLAN after SCI had modest effects on locomotor, pain-like, and mood-related behaviors. Future studies should consider whether clinically-relevant circadian disruptors, alone or in combination, could be ameliorated to enhance outcomes after SCI.
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Affiliation(s)
- John C Aldrich
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Ashley R Scheinfeld
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Sydney E Lee
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Kalina J Dusenbery
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Kathryn M Mahach
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Brigid C Van de Veire
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Laura K Fonken
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin
| | - Andrew D Gaudet
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
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4
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Jabbari S, Abed DZ, Zakaria ZA, Mohammadi S. Effects of Chaerophyllum macropodum Boiss. leaves essential oil in inflammatory and neuropathic pain: uncovering the possible mechanism of action. Inflammopharmacology 2023; 31:3203-3216. [PMID: 37792093 DOI: 10.1007/s10787-023-01342-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 09/11/2023] [Indexed: 10/05/2023]
Abstract
BACKGROUND Chaerophyllum macropodum Boiss. (popularly known as "Jafari farangi kohestani") is a predominant medicinal plant traditionally utilized in the treatments of peritoneal inflammation and headache in Persian folk medicine. Here, we have revealed the anti-neuropathic and anti-nociceptive activities of C. macropodum leaves essential oil (CMEO) in addition to uncovering the possible mechanisms of action. METHODS Formalin-induced paw licking model was used to assess the anti-nociceptive activity of CMEO and its major constituent, terpinolene (TP). The anti-nociceptive activity of these compounds was determined by investigating the roles of various non-opioid and NO-cGMP-K+ channels. Additionally, the anti-neuropathic potential of CMEO and TP was determined using cervical spinal cord contusion/CCS technique. RESULTS The CMEO exerted significant anti-nociceptive activity with a remarkable activity seen in the second phase of formalin-induced paw licking model and this activity were remarkably reversed by pre-treatment of naloxone (an opioid antagonist). Pretreatment with several types of NO-cGMP-potassium channel pathway meaningfully reversed the anti-nociceptive potential of CMEO in phase II of formalin model. Moreover, pre-treatment with several antagonists of non-opioid receptors revealed that only the antagonist of TRPV-1, serotonin type 3, 5-HT2, α2 adrenergic, and CB1 receptors (capsaicin, ondansetron, ketanserin, yohimbine, and SR141716A, respectively) reversed CMEO anti-nociception. CMEO and TP also remarkably reversed hyperalgesia and mechanical allodynia in the CCS technique. CONCLUSION The CMEO exerts anti-nociceptive and anti-neuropathic activities via the modulation of NO-cGMP potassium channel pathway, opioid as well as several non-opioid receptor activity. TP might partly contribute to the observed activities of CMEO.
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Affiliation(s)
- Sajjad Jabbari
- Department of Biology, Faculty of Sciences, Islamic Azad University, Tehran North Branch, Tehran, Iran
| | - Donya Ziafatdoost Abed
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Zainul Amiruddin Zakaria
- Borneo Research On Algesia, Inflammation and Neurodegeneration (BRAIN) Group, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, 88400, Sabah, Malaysia
| | - Saeed Mohammadi
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
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5
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Lee SE, Greenough EK, Oancea P, Scheinfeld AR, Douglas AM, Gaudet AD. Sex Differences in Pain: Spinal Cord Injury in Female and Male Mice Elicits Behaviors Related to Neuropathic Pain. J Neurotrauma 2023; 40:833-844. [PMID: 36719772 DOI: 10.1089/neu.2022.0482] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Spinal cord injury (SCI) in humans frequently causes intractable chronic pain. Females are susceptible to worse pain than males, and females may show higher pain prevalence after SCI. Despite this difference in the clinical prevalence of SCI pain, few pre-clinical studies have systematically studied sex differences in SCI-elicited pain-related behaviors in rodents. Here, we leverage data from a large cohort of mice to test whether contusion SCI consistently causes pain symptoms in mice, and to establish whether female (vs. male) mice display heightened hypersensitivity after SCI. Mechanical and heat sensory thresholds were assessed using the von Frey and Hargreaves tests, respectively. In an initial experiment, female mice receiving moderate 60 kDyn SCI or moderate-to-severe 75 kDyn SCI at T9 both exhibited mechanical and heat pain symptoms compared with sham controls. A 75 kDyn SCI caused excess motor deficits that confounded defining pain sensitivity at acute times; therefore, the moderate SCI force was used for subsequent experiments. Next, adult female and male C57BL6/J mice received sham surgery or T9 moderate contusion SCI. Comparing female to male mice after SCI, we reveal that mice of both sexes displayed mechanical and heat hypersensitivity compared with sham controls, from acute-to-chronic post-injury times. Females had amplified SCI-elicited hypersensitivity compared with males. Our data suggest that thoracic contusion SCI elicits consistent and persistent pain-associated symptoms, which are more intense in female than in male mice. These results have important implications for uncovering sex-specific mechanisms and therapeutic targets to ameliorate neuropathic pain after SCI.
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Affiliation(s)
- Sydney E Lee
- Department of Psychology, College of Liberal Arts, and Dell Medical School, University of Texas at Austin, Austin, Texas, USA.,Department of Neurology, Dell Medical School, University of Texas at Austin, Austin, Texas, USA
| | - Emily K Greenough
- Department of Psychology, College of Liberal Arts, and Dell Medical School, University of Texas at Austin, Austin, Texas, USA.,Department of Neurology, Dell Medical School, University of Texas at Austin, Austin, Texas, USA
| | - Paul Oancea
- Department of Psychology, College of Liberal Arts, and Dell Medical School, University of Texas at Austin, Austin, Texas, USA.,Department of Neurology, Dell Medical School, University of Texas at Austin, Austin, Texas, USA
| | - Ashley R Scheinfeld
- Department of Psychology, College of Liberal Arts, and Dell Medical School, University of Texas at Austin, Austin, Texas, USA.,Department of Neurology, Dell Medical School, University of Texas at Austin, Austin, Texas, USA
| | - Apsaline M Douglas
- Department of Psychology, College of Liberal Arts, and Dell Medical School, University of Texas at Austin, Austin, Texas, USA.,Department of Neurology, Dell Medical School, University of Texas at Austin, Austin, Texas, USA
| | - Andrew D Gaudet
- Department of Psychology, College of Liberal Arts, and Dell Medical School, University of Texas at Austin, Austin, Texas, USA.,Department of Neurology, Dell Medical School, University of Texas at Austin, Austin, Texas, USA
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6
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Temmermand R, Barrett JE, Fontana ACK. Glutamatergic systems in neuropathic pain and emerging non-opioid therapies. Pharmacol Res 2022; 185:106492. [PMID: 36228868 PMCID: PMC10413816 DOI: 10.1016/j.phrs.2022.106492] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/05/2022] [Accepted: 10/06/2022] [Indexed: 01/14/2023]
Abstract
Neuropathic pain, a disease of the somatosensory nervous system, afflicts many individuals and adequate management with current pharmacotherapies remains elusive. The glutamatergic system of neurons, receptors and transporters are intimately involved in pain but, to date, there have been few drugs developed that therapeutically modulate this system. Glutamate transporters, or excitatory amino acid transporters (EAATs), remove excess glutamate around pain transmitting neurons to decrease nociception suggesting that the modulation of glutamate transporters may represent a novel approach to the treatment of pain. This review highlights and summarizes (1) the physiology of the glutamatergic system in neuropathic pain, (2) the preclinical evidence for dysregulation of glutamate transport in animal pain models, and (3) emerging novel therapies that modulate glutamate transporters. Successful drug discovery requires continuous focus on basic and translational methods to fully elucidate the etiologies of this disease to enable the development of targeted therapies. Increasing the efficacy of astrocytic EAATs may serve as a new way to successfully treat those suffering from this devastating disease.
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Affiliation(s)
- Rhea Temmermand
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - James E Barrett
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Andréia C K Fontana
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, USA.
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7
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Sanganahalli BG, Pavuluri S, Chitturi J, Herman P, Elkabes S, Heary R, Hyder F, Kannurpatti SS. Lateralized Supraspinal Functional Connectivity Correlate with Pain and Motor Dysfunction in Rat Hemicontusion Cervical Spinal Cord Injury. Neurotrauma Rep 2022; 3:421-432. [PMID: 36337081 PMCID: PMC9622206 DOI: 10.1089/neur.2022.0040] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Afferent nociceptive activity in the reorganizing spinal cord after SCI influences supraspinal regions to establish pain. Clinical evidence of poor motor functional recovery in SCI patients with pain, led us to hypothesize that sensory-motor integration transforms into sensory-motor interference to manifest pain. This was tested by investigating supraspinal changes in a rat model of hemicontusion cervical SCI. Animals displayed ipsilateral forelimb motor dysfunction and pain, which persisted at 6 weeks after SCI. Using resting state fMRI at 8 weeks after SCI, RSFC across 14 ROIs involved in nociception, indicated lateral differences with a relatively weaker right-right connectivity (deafferented-contralateral) compared to left-left (unaffected-ipsilateral). However, the sensory (S1) and motor (M1/M2) networks showed greater RSFC using right hemisphere ROI seeds when compared to left. Voxel seeds from the somatosensory forelimb (S1FL) and M1/M2 representations reproduced the SCI-induced sensory and motor RSFC enhancements observed using the ROI seeds. Larger local connectivity occurred in the right sensory and motor networks amidst a decreasing overall local connectivity. This maladaptive reorganization of the right (deafferented) hemisphere localized the sensory component of pain emerging from the ipsilateral forepaw. A significant expansion of the sensory and motor network s overlap occurred globally after SCI when compared to sham, supporting the hypothesis that sensory and motor interference manifests pain. Voxel-seed based analysis revealed greater sensory and motor network overlap in the left hemisphere when compared to the right. This left predominance of the overlap suggested relatively larger pain processing in the unaffected hemisphere, when compared to the deafferented side.
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Affiliation(s)
- Basavaraju G. Sanganahalli
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Swathi Pavuluri
- Department of Radiology, Rutgers Biomedical and Health Sciences–New Jersey Medical School, Newark, New Jersey, USA
| | - Jyothsna Chitturi
- Department of Radiology, Rutgers Biomedical and Health Sciences–New Jersey Medical School, Newark, New Jersey, USA
| | - Peter Herman
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Stella Elkabes
- Department of Neurosurgery, Rutgers Biomedical and Health Sciences–New Jersey Medical School, Newark, New Jersey, USA
| | - Robert Heary
- Hackensack Meridian School of Medicine, Mountainside Medical Center, Montclair, New Jersey, USA
| | - Fahmeed Hyder
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Sridhar S. Kannurpatti
- Department of Radiology, Rutgers Biomedical and Health Sciences–New Jersey Medical School, Newark, New Jersey, USA.,Address correspondence to: Sridhar S. Kannurpatti, PhD, Department of Radiology, RUTGERS–New Jersey Medical School, MSB, F-506, 185 South Orange Avenue, Newark, NJ 07103, USA.
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8
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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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9
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Sanganahalli BG, Chitturi J, Herman P, Elkabes S, Heary R, Hyder F, Kannurpatti S. Supraspinal sensorimotor and pain-related reorganization after a hemicontusion rat cervical spinal cord injury. J Neurotrauma 2021; 38:3393-3405. [PMID: 34714150 DOI: 10.1089/neu.2021.0190] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Since the presence of pain impedes motor recovery in individuals with spinal cord injury (SCI), it is necessary to understand their supraspinal substrates in translational animal models. Using functional magnetic resonance imaging (fMRI) in a rat model of hemicontusion cervical SCI, supraspinal changes were mapped and correlated with sensorimotor behavioral outcomes. Female adult rats underwent sham or SCI using a 2.5 mm impactor and 150 kDyne force. SCI permanently impaired motor activity in only the ipsilesional forelimb along with thermal hyperalgesia at 5 and 6 wks. Spinal MRI at 8 wks after SCI showed ipsilateral T1 and T2 lesions with no discernable lesions across shams. fMRI mapping during electrical forepaw stimulation indicated SCI-induced sensorimotor reorganization with an expansion of the contralesional forelimb representation. Resting state fMRI based functional connectivity density (FCD), a marker of regional neuronal hubs increased or decreased across brain regions involved in nociception. FCD increases after SCI were in the primary and secondary somatosensory cortices (S1 and S2), anterior cingulate cortex (ACC), insula and the prefrontal cortex (PFC) and decreases were across the hippocampus, thalamus, hypothalamus and amygdala in SCI. Resting state functional connectivity (RSFC) assessments from the FCD altered regions of interest indicated cortico-cortical RSFC increases and cortico-insular, cortico-thalamic and cortico-hypothalamic RSFC decreases after SCI. Hippocampus, amygdala and thalamus showed decreased RSFC with most cortical regions and between themselves except the hippocampus-amygdala network, which showed increased RSFC after SCI. While select nociceptive region's intrinsic activity associated strongly with evoked pain behaviors after SCI (eg., PFC, ACC, hippocampus, thalamus, hypothalamus, M1 and S1BF) other nociceptive regions had weaker associations (eg., amygdala, insula, auditory cortex, S1FL, S1HL, S2 and M2), but differed significantly in their intrinsic activities between sham and SCI. The weaker associated nociceptive regions may possibly encode both the evoked and affective components of pain.
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Affiliation(s)
- Basavaraju G Sanganahalli
- Yale University School of Medicine, 12228, Diagnostic Radiology, New Haven, Connecticut, United States;
| | - Jyothsna Chitturi
- Rutgers Biomedical and Health Sciences, 5751, Radiology, Newark, New Jersey, United States;
| | - Peter Herman
- Yale University School of Medicine, 12228, Magnetic Resonance Research Center, Department of Diagnostic Radiology and Biomedical Engineering, Section of Bioimaging Science, New Haven, Connecticut, United States;
| | - Stella Elkabes
- Rutgers Biomedical and Health Sciences, 5751, Neurosurgery, Newark, New Jersey, United States;
| | - Robert Heary
- Hackensack Meridian School of Medicine, 576909, Nutley, New Jersey, United States;
| | | | - Sridhar Kannurpatti
- Rutgers Biomedical and Health Sciences, 5751, Radiology, Newark, New Jersey, United States;
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10
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Ahmadimoghaddam D, Zarei M, Mohammadi S, Izadidastenaei Z, Salehi I. Bupleurum falcatum L. alleviates nociceptive and neuropathic pain: Potential mechanisms of action. JOURNAL OF ETHNOPHARMACOLOGY 2021; 273:113990. [PMID: 33689798 DOI: 10.1016/j.jep.2021.113990] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/26/2021] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE In Iranian folkloric medicine, Bupleurum falcatum L. (Chinese Thoroughwax) has been used as a selective analgesic remedy for several centuries. OBJECTIVE The current research was conducted to explore the anti-nociceptive and anti-allodynic action of Bupleurum falcatum L. roots essential oil (BFEO) in Swiss mice. MATERIALS AND METHODS Formalin-induced paw licking (FIPL) model was applied for exploring of BFEO antinociceptive effects (neurogenic or inflammatory pain). The involvements of L-arginine-NO-cGMP-KATP channel pathway and several receptors such as opioid, peroxisome proliferator-activated (PPA), cannabinoid, transient receptor potential vanilloid, and adrenergic receptors were assesses to detect the anti-nociceptive activity of BFEO. Cervical spinal cord contusion (CSC) paradigm was employed for induction of neuropathic pain. RESULTS BFEO (100 mg/kg), in the FIPL model, produced significant antinociception compared to the control mice (p < 0.01). Furthermore, L-arginine, methylene blue, glibenclamide, naloxonazine, GW9662, and SR141716A pre-treatments restored the BFEO anti-nociceptive effects (p < 0.05) in the FIPL (second phase) test (p < 0.05). Intraperitoneal administration of saikosaponin A (one of the main constituents of BFEO) partially alleviated (p < 0.05) pain in FIPL test. Likewise, in CSC mice, the von Frey assay exhibited that BFEO could alter mechanical allodynia. CONCLUSION Finally, it seems that, in male mice, BFEO has both anti-allodynic and anti-nociceptive effects. The present data also suggest activating the L-arginine-NO-cGMP-KATP channel pathway as well as interaction of opioid, PPA, and cannabinoid receptors in the BFEO anti-nociceptive activities. These results also propose that BFEO could effectively attenuate allodynia in CSC mice.
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Affiliation(s)
- Davoud Ahmadimoghaddam
- Department of Pharmacology and Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Zarei
- Department of Physiology, School of Medicine, Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Saeed Mohammadi
- Department of Physiology, School of Medicine, Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Zohreh Izadidastenaei
- Department of Physiology, School of Medicine, Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Iraj Salehi
- Department of Physiology, School of Medicine, Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
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11
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Tang J, Bair M, Descalzi G. Reactive Astrocytes: Critical Players in the Development of Chronic Pain. Front Psychiatry 2021; 12:682056. [PMID: 34122194 PMCID: PMC8192827 DOI: 10.3389/fpsyt.2021.682056] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/03/2021] [Indexed: 12/16/2022] Open
Abstract
Chronic pain is associated with long term plasticity of nociceptive pathways in the central nervous system. Astrocytes can profoundly affect synaptic function and increasing evidence has highlighted how altered astrocyte activity may contribute to the pathogenesis of chronic pain. In response to injury, astrocytes undergo a shift in form and function known as reactive astrogliosis, which affects their release of cytokines and gliotransmitters. These neuromodulatory substances have been implicated in driving the persistent changes in central nociceptive activity. Astrocytes also release lactate which neurons can use to produce energy during synaptic plasticity. Furthermore, recent research has provided insight into lactate's emerging role as a signaling molecule in the central nervous system, which may be involved in directly modulating neuronal and astrocytic activity. In this review, we present evidence for the involvement of astrocyte-derived tumor necrosis factor alpha in pain-associated plasticity, in addition to research suggesting the potential involvement of gliotransmitters D-serine and adenosine-5'-triphosphate. We also discuss work implicating astrocyte-neuron metabolic coupling, and the possible role of lactate, which has been sparsely studied in the context of chronic pain, in supporting pathological changes in central nociceptive activity.
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Affiliation(s)
| | | | - Giannina Descalzi
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
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12
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Brown EV, Falnikar A, Heinsinger N, Cheng L, Andrews CE, DeMarco M, Lepore AC. Cervical spinal cord injury-induced neuropathic pain in male mice is associated with a persistent pro-inflammatory macrophage/microglial response in the superficial dorsal horn. Exp Neurol 2021; 343:113757. [PMID: 33991526 DOI: 10.1016/j.expneurol.2021.113757] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/03/2021] [Accepted: 05/10/2021] [Indexed: 01/31/2023]
Abstract
A significant portion of individuals living with traumatic spinal cord injury (SCI) experiences some degree of debilitating neuropathic pain (NP). This pain remains largely intractable in a majority of cases, due in part to an incomplete understanding of its underlying mechanisms. Central sensitization, an increase in excitability of pain transmission neurons located in superficial dorsal horn (sDH), plays a key role in development and maintenance of SCI-induced NP. Resident microglia and peripheral monocyte-derived macrophages (referred to collectively as MMΦ) are involved in promoting SCI-induced DH neuron hyperexcitability. Importantly, these MMΦ consist of populations of cells that can exert pro-inflammatory or anti-inflammatory signaling within injured spinal cord. It is critical to spatiotemporally characterize this heterogeneity to understand MMΦ contribution to NP after SCI. Given that a majority of SCI cases are cervical in nature, we used a model of unilateral C5/C6 contusion that results in persistent at-level thermal hyperalgesia and mechanical allodynia, two forms of NP-related behavior, in the forepaw. The aim of this study was to characterize the sDH MMΦ response within intact cervical spinal cord segments caudal to the lesion (i.e. the location of primary afferent nociceptive input from the forepaw plantar surface). Cervical SCI promoted a persistent MMΦ response in sDH that coincided with the chronic NP phenotype. Using markers of pro- and anti-inflammatory MMΦ, we found that the MMΦ population within sDH exhibited significant heterogeneity that evolved over time post-injury, including a robust and persistent increase in pro-inflammatory MMΦ that was especially pronounced at later times. C5/C6 contusion SCI also induced below-level thermal hyperalgesia and mechanical allodynia in the hindpaw; however, we did not observe a pronounced MMΦ response in sDH of L4/L5 spinal cord, suggesting that different inflammatory cell mechanisms occurring in sDH may be involved in at-level versus below-level NP following SCI. In conclusion, our findings reveal significant MMΦ heterogeneity both within and across pain transmission locations after SCI. These data also show a prominent and persistent pro-inflammatory MMΦ response, suggesting a possible role in DH neuron hyperexcitability and NP.
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Affiliation(s)
- Eric V Brown
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Aditi Falnikar
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Nicolette Heinsinger
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Lan Cheng
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Carrie E Andrews
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Michael DeMarco
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Angelo C Lepore
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States.
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13
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Fakhri S, Abbaszadeh F, Jorjani M. On the therapeutic targets and pharmacological treatments for pain relief following spinal cord injury: A mechanistic review. Biomed Pharmacother 2021; 139:111563. [PMID: 33873146 DOI: 10.1016/j.biopha.2021.111563] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 12/11/2022] Open
Abstract
Spinal cord injury (SCI) is globally considered as one of the most debilitating disorders, which interferes with daily activities and life of the affected patients. Despite many developments in related recognizing and treating procedures, post-SCI neuropathic pain (NP) is still a clinical challenge for clinicians with no distinct treatments. Accordingly, a comprehensive search was conducted in PubMed, Medline, Scopus, Web of Science, and national database (SID and Irandoc). The relevant articles regarding signaling pathways, therapeutic targets and pharmacotherapy of post-SCI pain were also reviewed. Data were collected with no time limitation until November 2020. The present study provides the findings on molecular mechanisms and therapeutic targets, as well as developing the critical signaling pathways to introduce novel neuroprotective treatments of post-SCI pain. From the pathophysiological mechanistic point of view, post-SCI inflammation activates the innate immune system, in which the immune cells elicit secondary injuries. So, targeting the critical signaling pathways for pain management in the SCI population has significant importance in providing new treatments. Indeed, several receptors, ion channels, excitatory neurotransmitters, enzymes, and key signaling pathways could be used as therapeutic targets, with a pivotal role of n-methyl-D-aspartate, gamma-aminobutyric acid, and inflammatory mediators. The current review focuses on conventional therapies, as well as crucial signaling pathways and promising therapeutic targets for post-SCI pain to provide new insights into the clinical treatment of post-SCI pain. The need to develop innovative delivery systems to treat SCI is also considered.
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Affiliation(s)
- Sajad Fakhri
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Fatemeh Abbaszadeh
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Masoumeh Jorjani
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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14
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Zarei M, Ahmadimoghaddam D, Mohammadi S. Artemisia biennis Willd.: Anti-Nociceptive effects and possible mechanisms of action. JOURNAL OF ETHNOPHARMACOLOGY 2021; 268:113604. [PMID: 33232780 DOI: 10.1016/j.jep.2020.113604] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 11/10/2020] [Accepted: 11/18/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Artemisia biennis Willd. (Dermane in Persian) has been used as an antinociceptive remedy in Iranian folkloric medicine. OBJECTIVE The aim of the present study was to evaluate the anti-nociceptive effects of Artemisia biennis Willd. aerial part essential oil (ABAEO) on male Swiss mice. MATERIALS AND METHODS Nociceptive pain techniques including acetic acid-induced writhing (AAIW), formalin-induced paw licking (FPL), glutamate-induced paw licking (GPL), and tail-flick (TF) models were applied. We assessed opioid and L-arginine-NO-cGMP-KATP pathways to detect the possible anti-nociceptive properties of ABAEO. In addition, neuropathic pain was induced by the cervical spinal cord contusion model. RESULTS ABAEO (120 mg/kg) had a significant anti-nociceptive activities in comparison to the control animals (p < 0.05) in the AAIW, TF, GPL, and FPL assays. The selective opioid antagonist (naloxonazine) administration in the AAIW test alleviated the anti-nociceptive effect of ABAEO (p < 0.05). L-arginine, methylene blue, and glibenclamide treatment prevented the ABAEO anti-nociceptive effects (p < 0.05); however, sodium nitroprusside could profoundly potentiate the ABAEO-associated antinociception in the FPL (phase II) test (p < 0.05). In nociceptive pain models, Cr (one of the main constituents of ABAEO) showed significant anti-nociceptive effects (p < 0.05). Moreover, the von Frey results indicated that ABAEO could attenuate mechanical allodynia in mice. CONCLUSION Our observation revealed the anti-nociceptive effects of ABAEO in male mice. These effects could include, at least in part, modulating glutamatergic mechanisms via opioid systems. Our data output also indicates activating the L-arginine-NO-cGMP-KATP system in ABAEO anti-nociceptive activities.
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Affiliation(s)
- Mohammad Zarei
- Department of Physiology, School of Medicine, Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Davoud Ahmadimoghaddam
- Department of Pharmacology and Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Saeed Mohammadi
- Department of Physiology, School of Medicine, Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
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15
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Tu J, Vargas Castillo J, Das A, Diwan AD. Degenerative Cervical Myelopathy: Insights into Its Pathobiology and Molecular Mechanisms. J Clin Med 2021; 10:jcm10061214. [PMID: 33804008 PMCID: PMC8001572 DOI: 10.3390/jcm10061214] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/07/2021] [Accepted: 03/09/2021] [Indexed: 12/12/2022] Open
Abstract
Degenerative cervical myelopathy (DCM), earlier referred to as cervical spondylotic myelopathy (CSM), is the most common and serious neurological disorder in the elderly population caused by chronic progressive compression or irritation of the spinal cord in the neck. The clinical features of DCM include localised neck pain and functional impairment of motor function in the arms, fingers and hands. If left untreated, this can lead to significant and permanent nerve damage including paralysis and death. Despite recent advancements in understanding the DCM pathology, prognosis remains poor and little is known about the molecular mechanisms underlying its pathogenesis. Moreover, there is scant evidence for the best treatment suitable for DCM patients. Decompressive surgery remains the most effective long-term treatment for this pathology, although the decision of when to perform such a procedure remains challenging. Given the fact that the aged population in the world is continuously increasing, DCM is posing a formidable challenge that needs urgent attention. Here, in this comprehensive review, we discuss the current knowledge of DCM pathology, including epidemiology, diagnosis, natural history, pathophysiology, risk factors, molecular features and treatment options. In addition to describing different scoring and classification systems used by clinicians in diagnosing DCM, we also highlight how advanced imaging techniques are being used to study the disease process. Last but not the least, we discuss several molecular underpinnings of DCM aetiology, including the cells involved and the pathways and molecules that are hallmarks of this disease.
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Affiliation(s)
- Ji Tu
- Spine Labs, St. George and Sutherland Clinical School, University of New South Wales, Kogarah, NSW 2217, Australia; (J.T.); (A.D.D.)
| | | | - Abhirup Das
- Spine Labs, St. George and Sutherland Clinical School, University of New South Wales, Kogarah, NSW 2217, Australia; (J.T.); (A.D.D.)
- Spine Service, St. George Hospital, Kogarah, NSW 2217, Australia;
- Correspondence:
| | - Ashish D. Diwan
- Spine Labs, St. George and Sutherland Clinical School, University of New South Wales, Kogarah, NSW 2217, Australia; (J.T.); (A.D.D.)
- Spine Service, St. George Hospital, Kogarah, NSW 2217, Australia;
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16
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Blumenthal GH, Nandakumar B, Schnider AK, Detloff MR, Ricard J, Bethea JR, Moxon KA. Modelling at-level allodynia after mid-thoracic contusion in the rat. Eur J Pain 2021; 25:801-816. [PMID: 33296535 DOI: 10.1002/ejp.1711] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND The rat mid-thoracic contusion model has been used to study at-level tactile allodynia, a common type of pain that develops after spinal cord injury (SCI). An important advantage of this model is that not all animals develop hypersensitivity. Therefore, it can be used to examine mechanisms that are strictly related to the development of pain-like behaviour separately from mechanisms related to the injury itself. However, how to separate animals that develop hypersensitivity from those that do not is unclear. METHODS The aims of the current study were to identify where hypersensitivity and spasticity develop and use this information to identify metrics to separate animals that develop hypersensitivity from those that do not to study differences in their behaviour. To accomplish these aims, a grid was used to localize hypersensitivity on the dorsal trunk relative to thoracic dermatomes and supraspinal responses to tactile stimulation were tallied. These supraspinal responses were used to develop a hypersensitivity score to separate animals that develop hypersensitivity, or pain-like response to nonpainful stimuli. RESULTS Similar to humans, the development of hypersensitivity could occur with the development of spasticity or hyperreflexia. Moreover, the time course and prevalence of hypersensitivity phenotypes (at-, above-, or below level) produced by this model were similar to that observed in humans with SCI. CONCLUSION However, the amount of spared spinal matter in the cord did not explain the development of hypersensitivity, as previously reported. This approach can be used to study the mechanisms underlying the development of hypersensitivity separately from mechanisms related to injury alone.
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Affiliation(s)
- Gary H Blumenthal
- Department of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, USA.,Department of Biomedical Engineering, University of California-Davis, Davis, CA, USA
| | - Bharadwaj Nandakumar
- Department of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, USA.,Department of Biomedical Engineering, University of California-Davis, Davis, CA, USA
| | - Ashley K Schnider
- Department of Biomedical Engineering, University of California-Davis, Davis, CA, USA
| | - Megan R Detloff
- Department of Neurobiology and Anatomy, Spinal Cord Research Center, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Jerome Ricard
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - John R Bethea
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Karen A Moxon
- Department of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, USA.,Department of Biomedical Engineering, University of California-Davis, Davis, CA, USA.,Center for Neuroscience, Davis, CA, USA
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17
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Chitturi J, Sanganahalli BG, Herman P, Hyder F, Ni L, Elkabes S, Heary R, Kannurpatti SS. Association Between Magnetic Resonance Imaging-Based Spinal Morphometry and Sensorimotor Behavior in a Hemicontusion Model of Incomplete Cervical Spinal Cord Injury in Rats. Brain Connect 2020; 10:479-489. [PMID: 32981350 DOI: 10.1089/brain.2020.0812] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Aim: Structural connectivity in the reorganizing spinal cord after injury dictates functional connectivity and hence the neurological outcome. As magnetic resonance imaging (MRI)-based structural parameters are mostly accessible across spinal cord injury (SCI) patients, we studied MRI-based spinal morphological changes and their relationship to neurological outcome in the rat model of cervical SCI. Introduction: Functional connectivity assessments on patients with SCI rely heavily on MRI-based approaches to investigate the complete neural axis (both spinal cord and brain). Hence, underlying MRI-based structural and morphometric changes in the reorganizing spinal cord and their relationship to neurological outcomes is crucial for meaningful interpretation of functional connectivity changes across the neural axis. Methods: Young adult rats, aged 1.5 months, underwent a precise mechanical impact hemicontusion incomplete cervical SCI at the C4/C5 level, after which sensorimotor behavioral assessments were tracked during the reorganization period of 1-6 weeks, followed by MRI of the cervical spinal cord at 8 weeks after SCI. Results: A significant ipsilesional forelimb motor debilitation was observed from 1 to 6 weeks after injury. Heat sensitivity testing (Hargreaves) showed ipsilesional forelimb hypersensitivity at 5 and 6 weeks after SCI. MRI of the cervical spine showed ipsilateral T1- and T2-weighted lesions across all SCI rats compared with no significant lesions in sham rats. Morphometric assessments of the lesional and nonlesional changes showed the diverse nature of their interindividual variability in the SCI receiving rats. While the various T1 and T2 MRI lesional volumes associated weakly or moderately with neurological outcome, the nonlesional spinal morphometric changes associated much more strongly. The results have important implications for interpreting functional MRI-based functional connectivity after SCI by providing vital underlying structural changes and their relative neurological impact. Impact statement Functional connectivity assessments on patients with SCI relies heavily upon MRI based approaches. Hence, underlying MRI based structural and morphometric changes in the reorganizing spinal cord and its relationship to neurological outcomes is vital for meaningful interpretation of functional connectivity changes across the complete neural axis (both spinal cord and the brain).
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Affiliation(s)
- Jyothsna Chitturi
- Department of Radiology, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey, USA
| | - Basavaraju G Sanganahalli
- Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA.,Magnetic Resonance Research Center (MRRC), Yale University, New Haven, Connecticut, USA.,Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, Connecticut, USA
| | - Peter Herman
- Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA.,Magnetic Resonance Research Center (MRRC), Yale University, New Haven, Connecticut, USA.,Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, Connecticut, USA
| | - Fahmeed Hyder
- Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA.,Magnetic Resonance Research Center (MRRC), Yale University, New Haven, Connecticut, USA.,Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, Connecticut, USA.,Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Li Ni
- Department of Neurosurgery, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey, USA
| | - Stella Elkabes
- Department of Neurosurgery, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey, USA
| | - Robert Heary
- Hackensack University School of Medicine, Nutley, New Jersey, USA
| | - Sridhar S Kannurpatti
- Department of Radiology, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey, USA
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18
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Xie AX, Madayag A, Minton SK, McCarthy KD, Malykhina AP. Sensory satellite glial Gq-GPCR activation alleviates inflammatory pain via peripheral adenosine 1 receptor activation. Sci Rep 2020; 10:14181. [PMID: 32843670 PMCID: PMC7447794 DOI: 10.1038/s41598-020-71073-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Glial fibrillary acidic protein expressing (GFAP+) glia modulate nociceptive neuronal activity in both the peripheral nervous system (PNS) and the central nervous system (CNS). Resident GFAP+ glia in dorsal root ganglia (DRG) known as satellite glial cells (SGCs) potentiate neuronal activity by releasing pro-inflammatory cytokines and neuroactive compounds. In this study, we tested the hypothesis that SGC Gq-coupled receptor (Gq-GPCR) signaling modulates pain sensitivity in vivo using Gfap-hM3Dq mice. Complete Freund's adjuvant (CFA) was used to induce inflammatory pain, and mechanical sensitivity and thermal sensitivity were used to assess the neuromodulatory effect of glial Gq-GPCR activation in awake mice. Pharmacogenetic activation of Gq-GPCR signaling in sensory SGCs decreased heat-induced nociceptive responses and reversed inflammation-induced mechanical allodynia via peripheral adenosine A1 receptor activation. These data reveal a previously unexplored role of sensory SGCs in decreasing afferent excitability. The identified molecular mechanism underlying the analgesic role of SGCs offers new approaches for reversing peripheral nociceptive sensitization.
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MESH Headings
- Animals
- Benzilates/pharmacology
- Clozapine/analogs & derivatives
- Clozapine/pharmacology
- Freund's Adjuvant/toxicity
- GTP-Binding Protein alpha Subunits, Gq-G11/physiology
- Genes, Synthetic
- Hot Temperature
- Hyperalgesia/physiopathology
- Hyperalgesia/prevention & control
- Inflammation/chemically induced
- Inflammation/physiopathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Muscarinic Agonists/pharmacology
- Neuroglia/enzymology
- Neuroglia/physiology
- Nociception/physiology
- Nortropanes/pharmacology
- Promoter Regions, Genetic
- Purinergic P1 Receptor Agonists/pharmacology
- Purinergic P1 Receptor Antagonists/pharmacology
- Receptor, Adenosine A1/drug effects
- Receptor, Adenosine A1/physiology
- Receptor, Muscarinic M3/drug effects
- Receptor, Muscarinic M3/genetics
- Receptor, Muscarinic M3/physiology
- Receptors, G-Protein-Coupled
- Recombinant Fusion Proteins/drug effects
- Recombinant Fusion Proteins/metabolism
- Theophylline/analogs & derivatives
- Theophylline/pharmacology
- Touch
- Xanthines/pharmacology
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Affiliation(s)
- Alison Xiaoqiao Xie
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill (UNC-CH), Chapel Hill, USA.
- Division of Urology, Department of Surgery, University of Colorado Denver (UCD), Anschutz Medical Campus (AMC), 12700E 19th Ave., Room 6440D, Mail stop C317, Aurora, CO, 80045, USA.
- Department of Surgery, UCD-AMC, Aurora, CO, USA.
| | - Aric Madayag
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill (UNC-CH), Chapel Hill, USA
- NeuroCycle Therapeutics, Inc., 3829 N Cramer St., Shorewood, WI, 53211, USA
| | - Suzanne K Minton
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill (UNC-CH), Chapel Hill, USA
- Certara, 5511 Capital Center Drive, Ste. 204, Raleigh, NC, 27606, USA
| | - Ken D McCarthy
- Professor Emeritus in the Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 4010 Genetic Medicine Bldg, Campus Box 7365, Chapel Hill, NC, 27599-7365, USA
| | - Anna P Malykhina
- Division of Urology, Department of Surgery, University of Colorado Denver (UCD), Anschutz Medical Campus (AMC), 12700E 19th Ave., Room 6440D, Mail stop C317, Aurora, CO, 80045, USA
- Department of Physiology and Biophysics, University of Colorado School of Medicine, 12700 East 19th Ave., Rm 6001, Mail Stop C317, Aurora, CO, 80045, USA
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19
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Batista CM, Mariano ED, Onuchic F, Dale CS, dos Santos GB, Cristante AF, Otoch JP, Teixeira MJ, Morgalla M, Lepski G. Characterization of traumatic spinal cord injury model in relation to neuropathic pain in the rat. Somatosens Mot Res 2019; 36:14-23. [DOI: 10.1080/08990220.2018.1563537] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Chary Marquez Batista
- Department of Neurology, School of Medicine, Universidade de São Paulo, São Paulo, Brazil
| | - Eric Domingos Mariano
- Department of Neurology, School of Medicine, Universidade de São Paulo, São Paulo, Brazil
| | - Fernando Onuchic
- Department of Neurology, School of Medicine, Universidade de São Paulo, São Paulo, Brazil
| | | | - Gustavo Bispo dos Santos
- Department of Orthopedic and Traumatology, School of Medicine, Universidade de São Paulo, São Paulo, Brazil
| | - Alexandre Fogaça Cristante
- Department of Orthopedic and Traumatology, School of Medicine, Universidade de São Paulo, São Paulo, Brazil
| | - Jose Pinhata Otoch
- Department of Surgery, School of Medicine, Universidade de São Paulo, São Paulo, Brazil
| | | | - Matthias Morgalla
- Department of Neurosurgery, Eberhard-Karls University, Tuebingen, Germany
| | - Guilherme Lepski
- Department of Neurosurgery, Eberhard-Karls University, Tuebingen, Germany
- Department of Psychiatry, School of Medicine, University de São Paulo, São Paulo, Brazil
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20
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Batista CM, Mariano ED, Dale CS, Cristante AF, Britto LR, Otoch JP, Teixeira MJ, Morgalla M, Lepski G. Pain inhibition through transplantation of fetal neuronal progenitors into the injured spinal cord in rats. Neural Regen Res 2019; 14:2011-2019. [PMID: 31290460 PMCID: PMC6676883 DOI: 10.4103/1673-5374.259624] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Neuropathic pain after spinal cord injury (SCI) is a complex condition that responds poorly to usual treatments. Cell transplantation represents a promising therapy; nevertheless, the ideal cell type in terms of neurogenic potential and effectiveness against pain remains largely controversial. Here, we evaluated the ability of fetal neural stem cells (fNSC) to relieve chronic pain and, secondarily, their effects on motor recovery. Adult Wistar rats with traumatic SCI were treated, 10 days after injury, with intra-spinal injections of culture medium (sham) or fNSCs extracted from telencephalic vesicles (TV group) or the ventral medulla (VM group) of E/14 embryos. Sensory (von Frey filaments and hot plate) and motor (the Basso, Beattie, Bresnahan locomotor rating scale and inclined plane test) assessments were performed during 8 weeks. Thereafter, spinal cords were processed for immunofluorescence and transplanted cells were quantified by stereology. The results showed improvement of thermal hyperalgesia in the TV and VM groups at 4 and 5 weeks after transplantation, respectively. Moreover, mechanical allodynia improved in both the TV and VM groups at 8 weeks. No significant motor recovery was observed in the TV or VM groups compared with sham. Stereological analyses showed that ~70% of TV and VM cells differentiated into NeuN+ neurons, with a high proportion of enkephalinergic and GABAergic cells in the TV group and enkephalinergic and serotoninergic cells in the VM group. Our study suggests that neuronal precursors from TV and VM, once implanted into the injured spinal cord, maturate into different neuronal subtypes, mainly GABAergic, serotoninergic, and enkephalinergic, and all subtypes alleviate pain, despite no significant motor recovery. The study was approved by the Animal Ethics Committee of the Medical School of the University of São Paulo (protocol number 033/14) on March 4, 2016.
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Affiliation(s)
- Chary M Batista
- Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Eric D Mariano
- Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Camila S Dale
- Department of Anatomy, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Alexandre F Cristante
- Department of Orthopedic and Traumatology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Luiz R Britto
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Jose P Otoch
- Department of Surgery, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Manoel J Teixeira
- Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Matthias Morgalla
- Department of Neurosurgery, Eberhard-Karls University, Tuebingen, Germany
| | - Guilherme Lepski
- Department of Neurosurgery, Eberhard-Karls University, Tuebingen, Germany; Department of Psychiatry, School of Medicine, University of São Paulo, São Paulo, Brazil
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21
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Spinal Cord Injury in Rats Disrupts the Circadian System. eNeuro 2018; 5:eN-NWR-0328-18. [PMID: 30627655 PMCID: PMC6325559 DOI: 10.1523/eneuro.0328-18.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 11/01/2018] [Accepted: 11/11/2018] [Indexed: 01/05/2023] Open
Abstract
Spinal cord injury (SCI) perturbs many physiological systems. The circadian system helps maintain homeostasis throughout the body by synchronizing physiological and behavioral functions to predictable daily events. Whether disruption of these coordinated daily rhythms contributes to SCI-associated pathology remains understudied. Here, we hypothesized that SCI in rats would dysregulate several prominent circadian outputs including glucocorticoids, core temperature, activity, neuroinflammation, and circadian gene networks. Female and male Sprague Dawley rats were subjected to clinically relevant thoracic 9 moderate contusion SCI (or laminectomy sham surgery). Diurnal measures-including rhythms of plasma corticosterone (CORT), body temperature, and activity (using small implanted transmitters), and intraspinal circadian and inflammatory gene expression-were studied prior to and after surgery. SCI caused overall increases and disrupted rhythms of the major rodent glucocorticoid, CORT. Presurgery and sham rats displayed expected rhythms in body temperature and activity, whereas rats with SCI had blunted daily rhythms in body temperature and activity. In parallel, SCI disrupted intraspinal rhythms of circadian clock gene expression. Circadian clock genes can act as transcriptional regulators of inflammatory pathways. Indeed, SCI rats also showed dysregulated rhythms in inflammatory gene expression in both the epicenter and distal spinal cord. Our data show that moderate SCI in rats causes wide-ranging diurnal rhythm dysfunction, which is severe at acute time points and gradually recovers over time. Normalizing post-SCI diurnal rhythms could enhance the recovery of homeostasis and quality of life.
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22
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Kurita M, Matsuoka Y, Nakatsuka K, Ono D, Muto N, Kaku R, Morimatsu H. Norepinephrine-induced downregulation of GLT-1 mRNA in rat astrocytes. Biochem Biophys Res Commun 2018; 504:103-108. [PMID: 30170732 DOI: 10.1016/j.bbrc.2018.08.137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 08/22/2018] [Indexed: 01/30/2023]
Abstract
AIM OF THE RESEARCH Glutamate transporter-1 (GLT-1; also known as excitatory amino acid transporter 2) plays an important role in the maintenance of glutamate homeostasis in the synaptic cleft. Downregulation of GLT-1 in the spinal cord has been reported in chronic pain models, which suggests that GLT-1 is involved in the development of chronic pain. However, the mechanism by which GLT-1 is downregulated in the spinal cord is still unknown. We hypothesized that norepinephrine is involved in the regulation of GLT-1. The aim of this study was to investigate the effect of norepinephrine on GLT-1 expression in cultured astrocytes. METHODS This study involved both in vivo and in vitro experiments. We first validated changes in GLT-1 mRNA expression in the spinal cord of rats with spared nerve injury (SNI) using real-time RT-PCR. Next, cultured primary astrocytes from the rat spinal cord were stimulated with norepinephrine, and GLT-1 mRNA was subsequently quantitated. RNB cells, an astrocytic cell line, were also stimulated with norepinephrine and other α-adrenoceptor agonists. RESULTS SNI resulted in bilateral downregulation of GLT-1 in rat spinal cord. The in vitro study showed that norepinephrine and phenylephrine dose-dependently downregulated GLT-1 in primary astrocytes and RNB cells. Furthermore, the effect of norepinephrine was reversed by an α-adrenoceptor antagonist. CONCLUSION Norepinephrine downregulates GLT-1 mRNA expression in astrocytes via the α1-adrenoceptor. Our results provide new insight into the mechanisms involved in downregulation of GLT-1 in the chronic pain models.
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Affiliation(s)
- Masako Kurita
- Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan
| | - Yoshikazu Matsuoka
- Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan.
| | - Kosuke Nakatsuka
- Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan
| | - Daisuke Ono
- Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan
| | - Noriko Muto
- Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan
| | - Ryuji Kaku
- Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan
| | - Hiroshi Morimatsu
- Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan
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23
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Tashiro S, Nishimura S, Shinozaki M, Takano M, Konomi T, Tsuji O, Nagoshi N, Toyama Y, Liu M, Okano H, Nakamura M. The Amelioration of Pain-Related Behavior in Mice with Chronic Spinal Cord Injury Treated with Neural Stem/Progenitor Cell Transplantation Combined with Treadmill Training. J Neurotrauma 2018; 35:2561-2571. [PMID: 29790403 DOI: 10.1089/neu.2017.5537] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Progress in regenerative medicine is realizing the possibility of neural regeneration and functional recovery in spinal cord injury (SCI). Recently, rehabilitation has attracted much attention with respect to the synergistic promotion of functional recovery in combination with neural stem/progenitor cell (NS/PC) transplantation, even in the chronic refractory phase of SCI. Nevertheless, sensory disturbance is one of the most prominent sequelae, even though the effects of combination or single therapies have been investigated mostly in the context of motor recovery. To determine how combination therapy with treadmill training (TMT) and NS/PC transplantation affects the manifestation of thermal allodynia and tactile hyperalgesia in chronic phase SCI, four groups of SCI mice were used to assess pain-related behavior and histological changes: combined transplantation and TMT therapy, transplantation only, TMT only, and control groups. Thermal allodynia and coarse touch-pressure hyperalgesia exhibited significant recovery in the combined therapy group in comparison with controls, whereas there were no significant differences with fine touch-pressure hyperalgesia and motor function. Further investigation revealed fewer fibers remaining in the posterior funiculus, which contained the tracts associated with the two modalities showing less recovery; that is, touch-pressure hyperalgesia and motor function. A significant correlation was only observed between these two modalities. Although no remarkable histological recovery was found within the lesion epicenter, changes indicating amelioration of pain were observed in the lumbar enlargement of the combination therapy group. Our results suggest that amelioration of thermal allodynia and tactile hyperalgesia can be brought about by the additive effect of NS/PC transplantation and TMT. The degree of recovery seems dependent on the distribution of damage.
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Affiliation(s)
- Syoichi Tashiro
- 1 Department of Rehabilitation Medicine, Keio University School of Medicine , Tokyo, Japan
| | - Soraya Nishimura
- 2 Department of Orthopaedic Surgery, Keio University School of Medicine , Tokyo, Japan
| | - Munehisa Shinozaki
- 3 Department of Physiology, Keio University School of Medicine , Tokyo, Japan
| | - Morito Takano
- 2 Department of Orthopaedic Surgery, Keio University School of Medicine , Tokyo, Japan
| | - Tsunehiko Konomi
- 2 Department of Orthopaedic Surgery, Keio University School of Medicine , Tokyo, Japan .,4 Department of Orthopaedic Surgery, Murayama Medical Center , National Hospital Organization, Tokyo, Japan
| | - Osahiko Tsuji
- 2 Department of Orthopaedic Surgery, Keio University School of Medicine , Tokyo, Japan
| | - Narihito Nagoshi
- 2 Department of Orthopaedic Surgery, Keio University School of Medicine , Tokyo, Japan
| | - Yoshiaki Toyama
- 2 Department of Orthopaedic Surgery, Keio University School of Medicine , Tokyo, Japan
| | - Meigen Liu
- 1 Department of Rehabilitation Medicine, Keio University School of Medicine , Tokyo, Japan
| | - Hideyuki Okano
- 3 Department of Physiology, Keio University School of Medicine , Tokyo, Japan
| | - Masaya Nakamura
- 2 Department of Orthopaedic Surgery, Keio University School of Medicine , Tokyo, Japan
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24
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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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25
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Pallottie A, Ratnayake A, Ni L, Acioglu C, Li L, Mirabelli E, Heary RF, Elkabes S. A toll-like receptor 9 antagonist restores below-level glial glutamate transporter expression in the dorsal horn following spinal cord injury. Sci Rep 2018; 8:8723. [PMID: 29880832 PMCID: PMC5992189 DOI: 10.1038/s41598-018-26915-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 05/18/2018] [Indexed: 01/04/2023] Open
Abstract
Spinal cord (SC) trauma elicits pathological changes at the primary lesion and in regions distant from the injury epicenter. Therapeutic agents that target mechanisms at the injury site are likely to exert additional effects in these remote regions. We previously reported that a toll-like receptor 9 (TLR9) antagonist, oligodeoxynucleotide 2088 (ODN 2088), improves functional deficits and modulates the milieu at the epicenter in mice sustaining a mid-thoracic contusion. The present investigations use the same paradigm to assess ODN 2088-elicited alterations in the lumbar dorsal horn (LDH), a region remote from the injury site where SCI-induced molecular alterations have been well defined. We report that ODN 2088 counteracts the SCI-elicited decrease in glial glutamate aspartate transporter (GLAST) and glutamate transporter 1 (GLT1) levels, whereas the levels of the neuronal glutamate transporter excitatory amino acid carrier 1 (EAAC1) and astroglial GABA transporter 3 (GAT3) were unaffected. The restoration of GLAST and GLT1 was neither paralleled by a global effect on astrocyte and microglia activation nor by changes in the expression of cytokines and growth factors reported to regulate these transporters. We conclude that the effects of intrathecal ODN 2088 treatment extend to loci beyond the epicenter by selectively targeting glial glutamate transporters.
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Affiliation(s)
- Alexandra Pallottie
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Ayomi Ratnayake
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Li Ni
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Cigdem Acioglu
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Lun Li
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Ersilia Mirabelli
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Robert F Heary
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Stella Elkabes
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA. .,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.
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26
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Botulinum Toxin for Central Neuropathic Pain. Toxins (Basel) 2018; 10:toxins10060224. [PMID: 29857568 PMCID: PMC6024683 DOI: 10.3390/toxins10060224] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/26/2018] [Accepted: 05/28/2018] [Indexed: 11/17/2022] Open
Abstract
Botulinum toxin (BTX) is widely used to treat muscle spasticity by acting on motor neurons. Recently, studies of the effects of BTX on sensory nerves have been reported and several studies have been conducted to evaluate its effects on peripheral and central neuropathic pain. Central neuropathic pain includes spinal cord injury-related neuropathic pain, post-stroke shoulder pain, multiple sclerosis-related pain, and complex regional pain syndrome. This article reviews the mechanism of central neuropathic pain and assesses the effect of BTX on central neuropathic pain.
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27
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Zhao Z, Hiraoka Y, Ogawa H, Tanaka K. Region-specific deletions of the glutamate transporter GLT1 differentially affect nerve injury-induced neuropathic pain in mice. Glia 2018; 66:1988-1998. [DOI: 10.1002/glia.23452] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/20/2018] [Accepted: 04/13/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Zhuoyang Zhao
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima; Bunkyo-ku Tokyo 113-8510 Japan
| | - Yuichi Hiraoka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima; Bunkyo-ku Tokyo 113-8510 Japan
| | - Hiroshi Ogawa
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima; Bunkyo-ku Tokyo 113-8510 Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima; Bunkyo-ku Tokyo 113-8510 Japan
- Center for Brain Integration Research (CBIR), TMDU, 1-5-45 Yushima; Bunkyo-ku Tokyo 113-8510 Japan
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28
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Schneider LE, Henley KY, Turner OA, Pat B, Niedzielko TL, Floyd CL. Application of the Rat Grimace Scale as a Marker of Supraspinal Pain Sensation after Cervical Spinal Cord Injury. J Neurotrauma 2017; 34:2982-2993. [PMID: 27998207 DOI: 10.1089/neu.2016.4665] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Experimental models of neuropathic pain (NP) typically rely on withdrawal responses to assess the presence of pain. Reflexive withdrawal responses to a stimulus are used to evaluate evoked pain and, as such, do not include the assessment of spontaneous NP nor evaluation of the affective and emotional consequences of pain in animal models. Additionally, withdrawal responses can be mediated by spinal cord reflexes and may not accurately indicate supraspinal pain sensation. This is especially true in models of traumatic spinal cord injury (SCI), wherein spastic syndrome, a motor disorder characterized by exaggeration of the stretch reflex that is secondary to hyperexcitability of the spinal reflex, can cause paroxysmal withdrawals not associated with NP sensation. Consequently, the aim of this study was to utilize an assessment of supraspinal pain sensation, the Rat Grimace Scale (RGS), to measure both spontaneous and evoked NP after a contusion SCI at cervical level 5 in adult male rats. Spontaneous and evoked pain were assessed using the RGS to score facial action units before and after the application of a stimulus, respectively. Rodents exhibited significantly higher RGS scores at week 5 post-injury as compared to baseline and laminectomy controls before the application of the stimulus, suggesting the presence of spontaneous NP. Additionally, there was a significant increase in RGS scores after the application of the acetone. These data suggest that the RGS can be used to assess spontaneous NP and determine the presence of evoked supraspinal pain sensation after experimental cervical SCI.
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Affiliation(s)
- Lonnie E Schneider
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham , Birmingham, Alabama
| | - Kathryn Y Henley
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham , Birmingham, Alabama
| | - Omari A Turner
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham , Birmingham, Alabama
| | - Betty Pat
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham , Birmingham, Alabama
| | - Tracy L Niedzielko
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham , Birmingham, Alabama
| | - Candace L Floyd
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham , Birmingham, Alabama
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29
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Gaudet AD, Ayala MT, Schleicher WE, Smith EJ, Bateman EM, Maier SF, Watkins LR. Exploring acute-to-chronic neuropathic pain in rats after contusion spinal cord injury. Exp Neurol 2017; 295:46-54. [PMID: 28552717 DOI: 10.1016/j.expneurol.2017.05.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 04/25/2017] [Accepted: 05/25/2017] [Indexed: 01/25/2023]
Abstract
Spinal cord injury (SCI) causes chronic pain in 65% of individuals. Unfortunately, current pain management is inadequate for many SCI patients. Rodent models could help identify how SCI pain develops, explore new treatment strategies, and reveal whether acute post-SCI morphine worsens chronic pain. However, few studies explore or compare SCI-elicited neuropathic pain in rats. Here, we sought to determine how different clinically relevant contusion SCIs in male and female rats affect neuropathic pain, and whether acute morphine worsens later chronic SCI pain. First, female rats received sham surgery, or 150kDyn or 200kDyn midline T9 contusion SCI. These rats displayed modest mechanical allodynia and long-lasting thermal hyperalgesia. Next, a 150kDyn (1s dwell) midline contusion SCI was performed in male and female rats. Interestingly, males, but not females showed SCI-elicited mechanical allodynia; rats of both sexes had thermal hyperalgesia. In this model, acute morphine treatment had no significant effect on chronic neuropathic pain symptoms. Unilateral SCIs can also elicit neuropathic pain that could be exacerbated by morphine, so male rats received unilateral T13 contusion SCI (100kDyn). These rats exhibited significant, transient mechanical allodynia, but not thermal hyperalgesia. Acute morphine did not exacerbate chronic pain. Our data show that specific rat contusion SCI models cause neuropathic pain. Further, chronic neuropathic pain elicited by these contusion SCIs was not amplified by our course of early post-trauma morphine. Using clinically relevant rat models of SCI could help identify novel pain management strategies.
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Affiliation(s)
- Andrew D Gaudet
- Department of Psychology and Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA.
| | - Monica T Ayala
- Department of Psychology and Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA
| | - Wolfgang E Schleicher
- Department of Psychology and Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA
| | - Elana J Smith
- Department of Psychology and Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA
| | - Emily M Bateman
- Department of Psychology and Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA
| | - Steven F Maier
- Department of Psychology and Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA
| | - Linda R Watkins
- Department of Psychology and Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Muenzinger D244 | 345 UCB, Boulder, CO 80309, USA
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30
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Ceftriaxone-mediated upregulation of the glutamate transporter GLT-1 contrasts neurotoxicity evoked by kainate in rat organotypic spinal cord cultures. Neurotoxicology 2017; 60:34-41. [DOI: 10.1016/j.neuro.2017.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/01/2017] [Accepted: 02/27/2017] [Indexed: 12/13/2022]
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31
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Khariv V, Ni L, Ratnayake A, Sampath S, Lutz BM, Tao XX, Heary RF, Elkabes S. Impaired sensitivity to pain stimuli in plasma membrane calcium ATPase 2 (PMCA2) heterozygous mice: a possible modality- and sex-specific role for PMCA2 in nociception. FASEB J 2016; 31:224-237. [PMID: 27702770 DOI: 10.1096/fj.201600541r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/22/2016] [Indexed: 11/11/2022]
Abstract
Plasma membrane calcium ATPase 2 (PMCA2) is a calcium pump that plays important roles in neuronal function. Although it is expressed in pain-associated regions of the CNS, including in the dorsal horn (DH), its contribution to pain remains undefined. The present study assessed the role of PMCA2 in pain responsiveness and the link between PMCA2 and glutamate receptors, GABA receptors (GABARs), and glutamate transporters that have been implicated in pain processing in the DH of adult female and male PMCA2+/+ and PMCA2+/- mice. Behavioral assays evaluated mechanical and thermal pain responsiveness. Mechanical sensitivity was significantly increased by 52% and heat sensitivity was reduced by 29% in female, but not male, PMCA2+/- mice compared with PMCA2+/+ controls. There were female-specific changes in metabotropic glutamate receptor 1, NMDA receptor 2A, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit GluR1, GABABR1, and GABABR2 levels, whereas metabotropic glutamate receptor 5, NMDA receptor 2B, GluR2, and GABAARα2 levels were not altered. Glutamate aspartate transporter levels were higher and glial glutamate transporter 1 levels were lower in the DH of female, but not male, PMCA2+/- mice. These findings indicate a novel role for PMCA2 in modality- and sex-dependent pain responsiveness. Female-specific molecular changes potentially account for the altered pain responses.-Khariv, V., Ni, L., Ratnayake, A., Sampath, S., Lutz, B. M., Tao, X.-X., Heary, R. F., Elkabes, S. Impaired sensitivity to pain stimuli in plasma membrane calcium ATPase 2 (PMCA2) heterozygous mice: a possible modality- and sex-specific role for PMCA2 in nociception.
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Affiliation(s)
- Veronika Khariv
- Department of Neurological Surgery, The Reynolds Family Spine Laboratory, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA.,Graduate School of Biomedical Sciences, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Li Ni
- Department of Neurological Surgery, The Reynolds Family Spine Laboratory, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Ayomi Ratnayake
- Department of Neurological Surgery, The Reynolds Family Spine Laboratory, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Sujitha Sampath
- Department of Neurological Surgery, The Reynolds Family Spine Laboratory, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Brianna M Lutz
- Graduate School of Biomedical Sciences, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA.,Department of Anesthesiology, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA; and
| | - Xuan-Xiang Tao
- Department of Anesthesiology, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA; and
| | - Robert F Heary
- Department of Neurological Surgery, The Reynolds Family Spine Laboratory, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Stella Elkabes
- Department of Neurological Surgery, The Reynolds Family Spine Laboratory, New Jersey Medical School-Rutgers, The State University of New Jersey, Newark, New Jersey, USA;
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Kramer JLK, Minhas NK, Jutzeler CR, Erskine ELKS, Liu LJW, Ramer MS. Neuropathic pain following traumatic spinal cord injury: Models, measurement, and mechanisms. J Neurosci Res 2016; 95:1295-1306. [PMID: 27617844 DOI: 10.1002/jnr.23881] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/19/2016] [Accepted: 07/19/2016] [Indexed: 02/06/2023]
Abstract
Neuropathic pain following spinal cord injury (SCI) is notoriously difficult to treat and is a high priority for many in the SCI population. Resolving this issue requires animal models fidelic to the clinical situation in terms of injury mechanism and pain phenotype. This Review discusses the means by which neuropathic pain has been induced and measured in experimental SCI and compares these with human outcomes, showing that there is a substantial disconnection between experimental investigations and clinical findings in a number of features. Clinical injury level is predominantly cervical, whereas injury in the laboratory is modeled mainly at the thoracic cord. Neuropathic pain is primarily spontaneous or tonic in people with SCI (with a relatively smaller incidence of allodynia), but measures of evoked responses (to thermal and mechanical stimuli) are almost exclusively used in animals. There is even the question of whether pain per se has been under investigation in most experimental SCI studies rather than simply enhanced reflex activity with no affective component. This Review also summarizes some of the problems related to clinical assessment of neuropathic pain and how advanced imaging techniques may circumvent a lack of patient/clinician objectivity and discusses possible etiologies of neuropathic pain following SCI based on evidence from both clinical studies and animal models, with examples of cellular and molecular changes drawn from the entire neuraxis from primary afferent terminals to cortical sensory and affective centers. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- John L K Kramer
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Nikita K Minhas
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Catherine R Jutzeler
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Erin L K S Erskine
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Lisa J W Liu
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Matt S Ramer
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
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Shi LB, Tang PF, Zhang W, Zhao YP, Zhang LC, Zhang H. Naringenin inhibits spinal cord injury-induced activation of neutrophils through miR-223. Gene 2016; 592:128-133. [PMID: 27432064 DOI: 10.1016/j.gene.2016.07.037] [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: 03/13/2016] [Revised: 06/13/2016] [Accepted: 07/14/2016] [Indexed: 12/22/2022]
Abstract
Naringenin (NR), a flavonoid abundant in citrus fruits has been reported to possess anti-inflammatory properties. The present study aimed to investigate the protective of naringenin in rats after spinal cord injury (SCI) and the underlying mechanisms associated with neuroinflammation. Adult male Sprague-Dawley rats were subjected to laminectomy at T9-T11 and compression with a vascular clip. The spinal cords spanning the injury site about 0.8cm were collected for testing. There were five groups (n=7 in each group): (a) Control group; (b) sham group group; (c) SCI+saline; (d) SCI+NR (50mg/kg, p.o.) group and (e) SCI+NR (100mg/kg, p.o.) group. Different doses of NR (50mg/kg, p.o. and 100mg/kg, p.o.) or saline were administered once daily for 11 consecutive days, from 3days prior to surgery to 7days after surgery. The expression level of miR-223, NLRP3 and IL-1β were measured by RT- qPCR. The accumulation of neutrophils at the site of compression, as evaluated by measuring the tissue myeloperoxidase activity, significantly increased with time following the compression, peaking at 24h post compression. The expression of miR-223 was significant elevated in (b). However, spinal cord myeloperoxidase activity and the expression of miR-223 did not increase in sham-operated animals. NR significantly inhibited a SCI-induced activation of neutrophils through repressed miR-223 in group (d) and (e). There was a better effect in group (e) than group (d). miR-223 is thought to act as a fine-tuner of granulocyte production and the inflammatory response. Our findings suggested that repeated administration of naringenin (100mg/kg, p.o) may provide the protective effect of the spinal cord injury in rats, possibly through inhibiting neuroinflammation.
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Affiliation(s)
- Long-Bao Shi
- Department of Orthopedic Surgery, The General Hospital of the People's Liberation Army, Beijing 100853, China
| | - Pei-Fu Tang
- Department of Orthopedic Surgery, The General Hospital of the People's Liberation Army, Beijing 100853, China.
| | - Wei Zhang
- Department of Orthopedic Surgery, The General Hospital of the People's Liberation Army, Beijing 100853, China
| | - Yan-Peng Zhao
- Department of Orthopedic Surgery, The General Hospital of the People's Liberation Army, Beijing 100853, China
| | - Li-Cheng Zhang
- Department of Orthopedic Surgery, The General Hospital of the People's Liberation Army, Beijing 100853, China
| | - Hao Zhang
- Department of Orthopedic Surgery, The General Hospital of the People's Liberation Army, Beijing 100853, China
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Hunsberger HC, Wang D, Petrisko TJ, Alhowail A, Setti SE, Suppiramaniam V, Konat GW, Reed MN. Peripherally restricted viral challenge elevates extracellular glutamate and enhances synaptic transmission in the hippocampus. J Neurochem 2016; 138:307-16. [PMID: 27168075 PMCID: PMC4936939 DOI: 10.1111/jnc.13665] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 05/05/2016] [Accepted: 05/09/2016] [Indexed: 01/23/2023]
Abstract
Peripheral infections increase the propensity and severity of seizures in susceptible populations. We have previously shown that intraperitoneal injection of a viral mimic, polyinosinic-polycytidylic acid (PIC), elicits hypersusceptibility of mice to kainic acid (KA)-induced seizures. This study was undertaken to determine whether this seizure hypersusceptibility entails alterations in glutamate signaling. Female C57BL/6 mice were intraperitoneally injected with PIC, and after 24 h, glutamate homeostasis in the hippocampus was monitored using the enzyme-based microelectrode arrays. PIC challenge robustly increased the level of resting extracellular glutamate. While pre-synaptic potassium-evoked glutamate release was not affected, glutamate uptake was profoundly impaired and non-vesicular glutamate release was augmented, indicating functional alterations of astrocytes. Electrophysiological examination of hippocampal slices from PIC-challenged mice revealed a several fold increase in the basal synaptic transmission as compared to control slices. PIC challenge also increased the probability of pre-synaptic glutamate release as seen from a reduction of paired-pulse facilitation and synaptic plasticity as seen from an enhancement of long-term potentiation. Altogether, our results implicate a dysregulation of astrocytic glutamate metabolism and an alteration of excitatory synaptic transmission as the underlying mechanism for the development of hippocampal hyperexcitability, and consequently seizure hypersusceptibility following peripheral PIC challenge. Peripheral infections/inflammations enhance seizure susceptibility. Here, we explored the effect of peritoneal inflammation induced by a viral mimic on glutamate homeostasis and glutamatergic neurotransmission in the mouse hippocampus. We found that peritoneal inflammation elevated extracellular glutamate concentration and enhanced the probability of pre-synaptic glutamate release resulting in hyperexcitability of neuronal networks. These mechanisms are likely to underlie the enhanced seizure propensity.
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Affiliation(s)
- Holly C. Hunsberger
- Behavioral Neuroscience, Department of Psychology, West Virginia University, Morgantown, 26506 WV, USA
- Department of Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, 36849 AL, USA
| | - Desheng Wang
- Blanchette Rockefeller Neurosciences Institute, Morgantown, 26506 WV, USA
| | - Tiffany J. Petrisko
- Department of Neurobiology and Anatomy, School of Medicine, West Virginia University, Morgantown, 26506 WV, USA
| | - Ahmad Alhowail
- Department of Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, 36849 AL, USA
| | - Sharay E. Setti
- Department of Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, 36849 AL, USA
| | - Vishnu Suppiramaniam
- Department of Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, 36849 AL, USA
| | - Gregory W. Konat
- Department of Neurobiology and Anatomy, School of Medicine, West Virginia University, Morgantown, 26506 WV, USA
| | - Miranda N. Reed
- Department of Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, 36849 AL, USA
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Zhao J, Zhang Y, Zhao J, Wang C, Mao J, Li T, Wang X, Nie X, Jiang S, Wu Q. 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure influence the expression of glutamate transporter GLT-1 in C6 glioma cells via the Ca(2+) /protein kinase C pathway. J Appl Toxicol 2016; 36:1409-17. [PMID: 26988466 DOI: 10.1002/jat.3294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 12/16/2015] [Accepted: 12/29/2015] [Indexed: 12/20/2022]
Abstract
The widespread environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is considered one of the most toxic dioxin-like compounds. Although epidemiological studies have shown that TCDD exposure is linked to some neurological and neurophysiological disorders, the underlying mechanism of TCDD-mediated neurotoxicity has remained unclear. Astrocytes are the most abundant cells in the nervous systems, and are recognized as the important mediators of normal brain functions as well as neurological, neurodevelopmental and neurodegenerative brain diseases. In this study, we investigated the role of TCDD in regulating the expression of glutamate transporter GLT-1 in astrocytes. TCDD, at concentrations of 0.1-100 nm, had no significantly harmful effect on the viability of C6 glioma cells. However, the expression of GLT-1 in C6 glioma cells was downregulated in a dose- and time-dependent manner. TCDD also caused activation of protein kinase C (PKC), as TCDD induced translocation of the PKC from the cytoplasm or perinuclear to the membrane. The translocation of PKC was inhibited by one Ca(2+) blocker, nifedipine, suggesting that the effects are triggered by the initial elevated intracellular concentration of free Ca(2+) . Finally, we showed that inhibition of the PKC activity reverses the TCDD-triggered reduction of GLT-1. In summary, our results suggested that TCDD exposure could downregulate the expression of GLT-1 in C6 via Ca(2+) /PKC pathway. The downregulation of GLT-1 might participate in TCDD-mediated neurotoxicity. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jianya Zhao
- Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Yan Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Jianmei Zhao
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Cheng Wang
- Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Jiamin Mao
- Department of Labor and Environmental Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Ting Li
- Department of Labor and Environmental Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Xiaoke Wang
- Department of Labor and Environmental Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Xiaoke Nie
- Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Shengyang Jiang
- Department of Labor and Environmental Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Qiyun Wu
- Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China.
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36
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Yousuf MS, Kerr BJ. The Role of Regulatory Transporters in Neuropathic Pain. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 75:245-71. [PMID: 26920015 DOI: 10.1016/bs.apha.2015.12.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Neuropathic pain arises from an injury or disease of the somatosensory nervous system rather than stimulation of pain receptors. As a result, the fine balance between excitation and inhibition is perturbed leading to hyperalgesia and allodynia. Various neuropathic pain models provide considerable evidence that changes in the glutamatergic, GABAergic, and monoaminergic systems. Neurotransmitter reuptake transporter proteins have the potential to change the temporal and spatial profile of various neurotransmitters throughout the nervous system. This, in turn, can affect the downstream effects of these neurotransmitters and hence modulate pain. This chapter explores various reuptake transporter systems and implicates their role in pain processing. Understanding the transporter systems will enhance drug discovery targeting different facets of neuropathic pain.
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Affiliation(s)
- Muhammad Saad Yousuf
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Bradley J Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada; Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada; Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, Alberta, Canada.
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Falnikar A, Hala TJ, Poulsen DJ, Lepore AC. GLT1 overexpression reverses established neuropathic pain-related behavior and attenuates chronic dorsal horn neuron activation following cervical spinal cord injury. Glia 2015; 64:396-406. [PMID: 26496514 DOI: 10.1002/glia.22936] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 10/06/2015] [Indexed: 01/23/2023]
Abstract
Development of neuropathic pain occurs in a major portion of traumatic spinal cord injury (SCI) patients, resulting in debilitating and often long-term physical and psychological burdens. Following SCI, chronic dysregulation of extracellular glutamate homeostasis has been shown to play a key role in persistent central hyperexcitability of superficial dorsal horn neurons that mediate pain neurotransmission, leading to various forms of neuropathic pain. Astrocytes express the major CNS glutamate transporter, GLT1, which is responsible for the vast majority of functional glutamate uptake, particularly in the spinal cord. In our unilateral cervical contusion model of mouse SCI that is associated with ipsilateral forepaw heat hypersensitivity (a form of chronic at-level neuropathic pain-related behavior), we previously reported significant and long-lasting reductions in GLT1 expression and functional GLT1-mediated glutamate uptake in cervical spinal cord dorsal horn. To therapeutically address GLT1 dysfunction following cervical contusion SCI, we injected an adeno-associated virus type 8 (AAV8)-Gfa2 vector into the superficial dorsal horn to increase GLT1 expression selectively in astrocytes. Compared to both contusion-only animals and injured mice that received AAV8-eGFP control injection, AAV8-GLT1 delivery increased GLT1 protein expression in astrocytes of the injured cervical spinal cord dorsal horn, resulting in a significant and persistent reversal of already-established heat hypersensitivity. Furthermore, AAV8-GLT1 injection significantly reduced expression of the transcription factor and marker of persistently increased neuronal activation, ΔFosB, in superficial dorsal horn neurons. These results demonstrate that focal restoration of GLT1 expression in the superficial dorsal horn is a promising target for treating chronic neuropathic pain following SCI.
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Affiliation(s)
- Aditi Falnikar
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, Pennsylvania
| | - Tamara J Hala
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, Pennsylvania
| | - David J Poulsen
- Department of Neurosurgery, University at Buffalo, SUNY-School of Medicine and Biomedical Sciences, Buffalo, New York
| | - Angelo C Lepore
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, Pennsylvania
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Li K, Javed E, Scura D, Hala TJ, Seetharam S, Falnikar A, Richard JP, Chorath A, Maragakis NJ, Wright MC, Lepore AC. Human iPS cell-derived astrocyte transplants preserve respiratory function after spinal cord injury. Exp Neurol 2015. [PMID: 26216662 DOI: 10.1016/j.expneurol.2015.07.020] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Transplantation-based replacement of lost and/or dysfunctional astrocytes is a promising therapy for spinal cord injury (SCI) that has not been extensively explored, despite the integral roles played by astrocytes in the central nervous system (CNS). Induced pluripotent stem (iPS) cells are a clinically-relevant source of pluripotent cells that both avoid ethical issues of embryonic stem cells and allow for homogeneous derivation of mature cell types in large quantities, potentially in an autologous fashion. Despite their promise, the iPS cell field is in its infancy with respect to evaluating in vivo graft integration and therapeutic efficacy in SCI models. Astrocytes express the major glutamate transporter, GLT1, which is responsible for the vast majority of glutamate uptake in spinal cord. Following SCI, compromised GLT1 expression/function can increase susceptibility to excitotoxicity. We therefore evaluated intraspinal transplantation of human iPS cell-derived astrocytes (hIPSAs) following cervical contusion SCI as a novel strategy for reconstituting GLT1 expression and for protecting diaphragmatic respiratory neural circuitry. Transplant-derived cells showed robust long-term survival post-injection and efficiently differentiated into astrocytes in injured spinal cord of both immunesuppressed mice and rats. However, the majority of transplant-derived astrocytes did not express high levels of GLT1, particularly at early times post-injection. To enhance their ability to modulate extracellular glutamate levels, we engineered hIPSAs with lentivirus to constitutively express GLT1. Overexpression significantly increased GLT1 protein and functional GLT1-mediated glutamate uptake levels in hIPSAs both in vitro and in vivo post-transplantation. Compared to human fibroblast control and unmodified hIPSA transplantation, GLT1-overexpressing hIPSAs reduced (1) lesion size within the injured cervical spinal cord, (2) morphological denervation by respiratory phrenic motor neurons at the diaphragm neuromuscular junction, and (3) functional diaphragm denervation as measured by recording of spontaneous EMGs and evoked compound muscle action potentials. Our findings demonstrate that hiPSA transplantation is a therapeutically-powerful approach for SCI.
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Affiliation(s)
- Ke Li
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Elham Javed
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Daniel Scura
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Tamara J Hala
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Suneil Seetharam
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Aditi Falnikar
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Jean-Philippe Richard
- Department of Neurology, Johns Hopkins University School of Medicine, 855N. Wolfe St., Rangos 250, Baltimore, MD 21205, United States.
| | - Ashley Chorath
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Nicholas J Maragakis
- Department of Neurology, Johns Hopkins University School of Medicine, 855N. Wolfe St., Rangos 250, Baltimore, MD 21205, United States.
| | - Megan C Wright
- Department of Biology, Arcadia University, 450S. Easton Rd., 220 Boyer Hall, Glenside, PA 19038, United States.
| | - Angelo C Lepore
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
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Adenosine Monophosphate-activated Protein Kinase Regulates Interleukin-1β Expression and Glial Glutamate Transporter Function in Rodents with Neuropathic Pain. Anesthesiology 2015; 122:1401-13. [PMID: 25710409 DOI: 10.1097/aln.0000000000000619] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Neuroinflammation and dysfunctional glial glutamate transporters (GTs) in the spinal dorsal horn are implicated in the genesis of neuropathic pain. The authors determined whether adenosine monophosphate-activated protein kinase (AMPK) in the spinal dorsal horn regulates these processes in rodents with neuropathic pain. METHODS Hind paw withdrawal responses to radiant heat and mechanical stimuli were used to assess nociceptive behaviors. Spinal markers related to neuroinflammation and glial GTs were determined by Western blotting. AMPK activities were manipulated pharmacologically and genetically. Regulation of glial GTs was determined by measuring protein expression and activities of glial GTs. RESULTS AMPK activities were reduced in the spinal dorsal horn of rats (n = 5) with thermal hyperalgesia induced by nerve injury, which were accompanied with the activation of astrocytes, increased production of interleukin-1β and activities of glycogen synthase kinase 3β, and suppressed protein expression of glial glutamate transporter-1. Thermal hyperalgesia was reversed by spinal activation of AMPK in neuropathic rats (n = 10) and induced by inhibiting spinal AMPK in naive rats (n = 7 to 8). Spinal AMPKα knockdown (n = 6) and AMPKα1 conditional knockout (n = 6) induced thermal hyperalgesia and mechanical allodynia. These genetic alterations mimicked the changes of molecular markers induced by nerve injury. Pharmacological activation of AMPK enhanced glial GT activity in mice with neuropathic pain (n = 8) and attenuated glial glutamate transporter-1 internalization induced by interleukin-1β (n = 4). CONCLUSIONS These findings suggest that enhancing spinal AMPK activities could be an effective approach for the treatment of neuropathic pain.
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Nicaise C, Mitrecic D, Falnikar A, Lepore AC. Transplantation of stem cell-derived astrocytes for the treatment of amyotrophic lateral sclerosis and spinal cord injury. World J Stem Cells 2015; 7:380-398. [PMID: 25815122 PMCID: PMC4369494 DOI: 10.4252/wjsc.v7.i2.380] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/07/2014] [Accepted: 11/19/2014] [Indexed: 02/06/2023] Open
Abstract
Neglected for years, astrocytes are now recognized to fulfill and support many, if not all, homeostatic functions of the healthy central nervous system (CNS). During neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and spinal cord injury (SCI), astrocytes in the vicinity of degenerating areas undergo both morphological and functional changes that might compromise their intrinsic properties. Evidence from human and animal studies show that deficient astrocyte functions or loss-of-astrocytes largely contribute to increased susceptibility to cell death for neurons, oligodendrocytes and axons during ALS and SCI disease progression. Despite exciting advances in experimental CNS repair, most of current approaches that are translated into clinical trials focus on the replacement or support of spinal neurons through stem cell transplantation, while none focus on the specific replacement of astroglial populations. Knowing the important functions carried out by astrocytes in the CNS, astrocyte replacement-based therapies might be a promising approach to alleviate overall astrocyte dysfunction, deliver neurotrophic support to degenerating spinal tissue and stimulate endogenous CNS repair abilities. Enclosed in this review, we gathered experimental evidence that argue in favor of astrocyte transplantation during ALS and SCI. Based on their intrinsic properties and according to the cell type transplanted, astrocyte precursors or stem cell-derived astrocytes promote axonal growth, support mechanisms and cells involved in myelination, are able to modulate the host immune response, deliver neurotrophic factors and provide protective molecules against oxidative or excitotoxic insults, amongst many possible benefits. Embryonic or adult stem cells can even be genetically engineered in order to deliver missing gene products and therefore maximize the chance of neuroprotection and functional recovery. However, before broad clinical translation, further preclinical data on safety, reliability and therapeutic efficiency should be collected. Although several technical challenges need to be overcome, we discuss the major hurdles that have already been met or solved by targeting the astrocyte population in experimental ALS and SCI models and we discuss avenues for future directions based on latest molecular findings regarding astrocyte biology.
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Gegelashvili G, Bjerrum OJ. High-affinity glutamate transporters in chronic pain: an emerging therapeutic target. J Neurochem 2014; 131:712-30. [DOI: 10.1111/jnc.12957] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 09/18/2014] [Accepted: 09/25/2014] [Indexed: 01/13/2023]
Affiliation(s)
- Georgi Gegelashvili
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
- Institute of Chemical Biology; Ilia State University; Tbilisi Georgia
| | - Ole J. Bjerrum
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
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Watson JL, Hala TJ, Putatunda R, Sannie D, Lepore AC. Persistent at-level thermal hyperalgesia and tactile allodynia accompany chronic neuronal and astrocyte activation in superficial dorsal horn following mouse cervical contusion spinal cord injury. PLoS One 2014; 9:e109099. [PMID: 25268642 PMCID: PMC4182513 DOI: 10.1371/journal.pone.0109099] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 09/09/2014] [Indexed: 11/19/2022] Open
Abstract
In humans, sensory abnormalities, including neuropathic pain, often result from traumatic spinal cord injury (SCI). SCI can induce cellular changes in the CNS, termed central sensitization, that alter excitability of spinal cord neurons, including those in the dorsal horn involved in pain transmission. Persistently elevated levels of neuronal activity, glial activation, and glutamatergic transmission are thought to contribute to the hyperexcitability of these dorsal horn neurons, which can lead to maladaptive circuitry, aberrant pain processing and, ultimately, chronic neuropathic pain. Here we present a mouse model of SCI-induced neuropathic pain that exhibits a persistent pain phenotype accompanied by chronic neuronal hyperexcitability and glial activation in the spinal cord dorsal horn. We generated a unilateral cervical contusion injury at the C5 or C6 level of the adult mouse spinal cord. Following injury, an increase in the number of neurons expressing ΔFosB (a marker of chronic neuronal activation), persistent astrocyte activation and proliferation (as measured by GFAP and Ki67 expression), and a decrease in the expression of the astrocyte glutamate transporter GLT1 are observed in the ipsilateral superficial dorsal horn of cervical spinal cord. These changes have previously been associated with neuronal hyperexcitability and may contribute to altered pain transmission and chronic neuropathic pain. In our model, they are accompanied by robust at-level hyperaglesia in the ipsilateral forepaw and allodynia in both forepaws that are evident within two weeks following injury and persist for at least six weeks. Furthermore, the pain phenotype occurs in the absence of alterations in forelimb grip strength, suggesting that it represents sensory and not motor abnormalities. Given the importance of transgenic mouse technology, this clinically-relevant model provides a resource that can be used to study the molecular mechanisms contributing to neuropathic pain following SCI and to identify potential therapeutic targets for the treatment of chronic pathological pain.
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Affiliation(s)
- Jaime L. Watson
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Tamara J. Hala
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Rajarshi Putatunda
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Daniel Sannie
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Angelo C. Lepore
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
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