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Abdelaziz MA, Chen WH, Chang YW, Mindaye SA, Chen CC. Exploring the role of spinal astrocytes in the onset of hyperalgesic priming signals in acid-induced chronic muscle pain. PNAS NEXUS 2024; 3:pgae362. [PMID: 39228816 PMCID: PMC11370897 DOI: 10.1093/pnasnexus/pgae362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Accepted: 08/13/2024] [Indexed: 09/05/2024]
Abstract
Hyperalgesic priming, a form of pain plasticity initiated by initial injury, leads to heightened sensitivity to subsequent noxious stimuli, contributing to chronic pain development in animals. While astrocytes play active roles in modulating synaptic transmission in various pain models, their specific involvement in hyperalgesic priming remains elusive. Here, we show that spinal astrocytes are essential for hyperalgesic priming formation in a mouse model of acid-induced muscle pain. We observed spinal astrocyte activation 4 h after initial acid injection, and inhibition of this activation prevented chronic pain development upon subsequent acid injection. Chemogenetic activation of spinal astrocytes mimicked the first acid-induced hyperalgesic priming. We also demonstrated that spinal phosphorylated extracellular regulated kinase (pERK)-positive neurons were mainly vesicular glutamate transporter-2 positive (Vglut2+) neurons after the first acid injection, and inhibition of spinal pERK prevented astrocyte activation. Furthermore, pharmacological inhibition of astrocytic glutamate transporters glutamate transporter-1 and glutamate-aspartate transporter abolished the hyperalgesic priming. Collectively, our results suggest that pERK activation in Vglut2+ neurons activate astrocytes through astrocytic glutamate transporters. This process eventually establishes hyperalgesic priming through spinal D-serine. We conclude that spinal astrocytes play a crucial role in the transition from acute to chronic pain.
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Affiliation(s)
- Mohamed Abbas Abdelaziz
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Cheng Kung University and Academia Sinica, Taipei 11529, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
- Zoology Department, Faculty of Science, Al-Azhar University Assiut Branch, Assiut 71524, Egypt
| | - Wei-Hsin Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Yu-Wang Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Selomon Assefa Mindaye
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Cheng Kung University and Academia Sinica, Taipei 11529, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Chien-Chang Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
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2
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Costa A, Micheli L, Sordi V, Ciampi C, Lucci J, Passani MB, Provensi G. Preventing social defeat stress-induced behavioural and neurochemical alterations by repeated treatment with a mix of Centella asiatica, Echinacea purpurea and Zingiber officinale standardized extracts. Front Pharmacol 2024; 15:1439811. [PMID: 39253374 PMCID: PMC11381240 DOI: 10.3389/fphar.2024.1439811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 08/12/2024] [Indexed: 09/11/2024] Open
Abstract
Background: Prolonged exposure to stress is a risk factor for the onset of several disorders. Modern life is burdened by a pervasive prevalence of stress, which represents a major societal challenge requiring new therapeutic strategies. In this context, botanical drug-based therapies can have a paramount importance. Methods: Here we studied the preventive effects of a repeated treatment (p.o. daily, 3 weeks) with a combination of Centella asiatica (200 mg/kg), Echinacea purpurea (20 mg/kg) and Zingiber officinale (150 mg/kg) standardized extracts, on the chronic social defeat stress (CSDS) deleterious outcomes. After 10 days of CSDS exposure, male mice' performances were evaluated in paradigms relevant for social (social interaction test), emotional (tail suspension test), cognitive (novel object recognition) domains as well as for pain perception (cold plate and von Frey tests) and motor skills (rotarod). Mice were then sacrificed, the spinal cords, hippocampi and frontal cortices dissected and processed for RT-PCR analysis. Results: Extracts mix treatment prevented stress-induced social aversion, memory impairment, mechanical and thermal allodynia and reduced behavioural despair independently of stress exposure. The treatment stimulated hippocampal and cortical BDNF and TrkB mRNA levels and counteracted stress-induced alterations in pro- (TNF-α, IL-1β and IL-6) and anti-inflammatory (IL4, IL10) cytokines expression in the same areas. It also modulated expression of pain related genes (GFAP and Slc1a3) in the spinal cord. Conclusion: The treatment with the extracts mix obtained from C. asiatica, E. purpurea and Z. officinale may represent a promising strategy to promote resilience and prevent the deleterious effects induced by extended exposure to psychosocial stress.
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Affiliation(s)
- Alessia Costa
- Section of Pharmacology and Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Laura Micheli
- Section of Pharmacology and Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Virginia Sordi
- Section of Pharmacology and Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
- Pharmacology Unit, School of Pharmacy, University of Camerino, Camerino, Italy
| | - Clara Ciampi
- Section of Pharmacology and Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Jacopo Lucci
- Bios-Therapy, Physiological Systems for Health S.p.A., Sansepolcro, Italy
- Aboca S.p.A. Società Agricola, Innovation and Medical Science Division, Sansepolcro, Italy
| | | | - Gustavo Provensi
- Section of Pharmacology and Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
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Salavatian S, Robbins EM, Kuwabara Y, Castagnola E, Cui XT, Mahajan A. Real-time in vivo thoracic spinal glutamate sensing during myocardial ischemia. Am J Physiol Heart Circ Physiol 2023; 325:H1304-H1317. [PMID: 37737733 PMCID: PMC10908408 DOI: 10.1152/ajpheart.00299.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 09/18/2023] [Accepted: 09/18/2023] [Indexed: 09/23/2023]
Abstract
In the spinal cord, glutamate serves as the primary excitatory neurotransmitter. Monitoring spinal glutamate concentrations offers valuable insights into spinal neural processing. Consequently, spinal glutamate concentration has the potential to emerge as a useful biomarker for conditions characterized by increased spinal neural network activity, especially when uptake systems become dysfunctional. In this study, we developed a multichannel custom-made flexible glutamate-sensing probe for the large-animal model that is capable of measuring extracellular glutamate concentrations in real time and in vivo. We assessed the probe's sensitivity and specificity through in vitro and ex vivo experiments. Remarkably, this developed probe demonstrates nearly instantaneous glutamate detection and allows continuous monitoring of glutamate concentrations. Furthermore, we evaluated the mechanical and sensing performance of the probe in vivo, within the pig spinal cord. Moreover, we applied the glutamate-sensing method using the flexible probe in the context of myocardial ischemia-reperfusion (I/R) injury. During I/R injury, cardiac sensory neurons in the dorsal root ganglion transmit excitatory signals to the spinal cord, resulting in sympathetic activation that potentially leads to fatal arrhythmias. We have successfully shown that our developed glutamate-sensing method can detect this spinal network excitation during myocardial ischemia. This study illustrates a novel technique for measuring spinal glutamate at different spinal cord levels as a surrogate for the spinal neural network activity during cardiac interventions that engage the cardio-spinal neural pathway.NEW & NOTEWORTHY In this study, we have developed a new flexible sensing probe to perform an in vivo measurement of spinal glutamate signaling in a large animal model. Our initial investigations involved precise testing of this probe in both in vitro and ex vivo environments. We accurately assessed the sensitivity and specificity of our glutamate-sensing probe and demonstrated its performance. We also evaluated the performance of our developed flexible probe during the insertion and compared it with the stiff probe during animal movement. Subsequently, we used this innovative technique to monitor the spinal glutamate signaling during myocardial ischemia and reperfusion that can cause fatal ventricular arrhythmias. We showed that glutamate concentration increases during the myocardial ischemia, persists during the reperfusion, and is associated with sympathoexcitation and increases in myocardial substrate excitability.
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Affiliation(s)
- Siamak Salavatian
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Elaine Marie Robbins
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Yuki Kuwabara
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Elisa Castagnola
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- Center for Neural Basis of Cognition, Pittsburgh, Pennsylvania, United States
- McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania, United States
| | - Aman Mahajan
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
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Smith PA. Neuropathic pain; what we know and what we should do about it. FRONTIERS IN PAIN RESEARCH 2023; 4:1220034. [PMID: 37810432 PMCID: PMC10559888 DOI: 10.3389/fpain.2023.1220034] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023] Open
Abstract
Neuropathic pain can result from injury to, or disease of the nervous system. It is notoriously difficult to treat. Peripheral nerve injury promotes Schwann cell activation and invasion of immunocompetent cells into the site of injury, spinal cord and higher sensory structures such as thalamus and cingulate and sensory cortices. Various cytokines, chemokines, growth factors, monoamines and neuropeptides effect two-way signalling between neurons, glia and immune cells. This promotes sustained hyperexcitability and spontaneous activity in primary afferents that is crucial for onset and persistence of pain as well as misprocessing of sensory information in the spinal cord and supraspinal structures. Much of the current understanding of pain aetiology and identification of drug targets derives from studies of the consequences of peripheral nerve injury in rodent models. Although a vast amount of information has been forthcoming, the translation of this information into the clinical arena has been minimal. Few, if any, major therapeutic approaches have appeared since the mid 1990's. This may reflect failure to recognise differences in pain processing in males vs. females, differences in cellular responses to different types of injury and differences in pain processing in humans vs. animals. Basic science and clinical approaches which seek to bridge this knowledge gap include better assessment of pain in animal models, use of pain models which better emulate human disease, and stratification of human pain phenotypes according to quantitative assessment of signs and symptoms of disease. This can lead to more personalized and effective treatments for individual patients. Significance statement: There is an urgent need to find new treatments for neuropathic pain. Although classical animal models have revealed essential features of pain aetiology such as peripheral and central sensitization and some of the molecular and cellular mechanisms involved, they do not adequately model the multiplicity of disease states or injuries that may bring forth neuropathic pain in the clinic. This review seeks to integrate information from the multiplicity of disciplines that seek to understand neuropathic pain; including immunology, cell biology, electrophysiology and biophysics, anatomy, cell biology, neurology, molecular biology, pharmacology and behavioral science. Beyond this, it underlines ongoing refinements in basic science and clinical practice that will engender improved approaches to pain management.
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Affiliation(s)
- Peter A. Smith
- Neuroscience and Mental Health Institute and Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
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5
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Li F, Li D, Liu J, Tang S, Yan J, Li H, Wan Z, Wang L, Yan X. Activation of Protease-Activated Receptor-1 Causes Chronic Pain in Lupus-Prone Mice Via Suppressing Spinal Glial Glutamate Transporter Function and Enhancing Glutamatergic Synaptic Activity. THE JOURNAL OF PAIN 2023; 24:1163-1180. [PMID: 36641029 DOI: 10.1016/j.jpain.2023.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 12/25/2022] [Accepted: 01/03/2023] [Indexed: 01/13/2023]
Abstract
Systemic lupus erythematosus (SLE) is an unpredictable autoimmune disease where the body's immune system mistakenly attacks healthy tissues in many parts of the body. Chronic pain is one of the most frequently reported symptoms among SLE patients. We previously reported that MRL lupus prone (MRL/lpr) mice develop hypersensitivity to mechanical and heat stimulation. In the present study, we found that the spinal protease-activated receptor-1(PAR1) plays an important role in the genesis of chronic pain in MRL/lpr mice. Female MRL/lpr mice with chronic pain had activation of astrocytes, over-expression of thrombin and PAR1, enhanced glutamatergic synaptic activity, as well as suppressed activity of adenosine monophosphate-activated protein kinase (AMPK) and glial glutamate transport function in the spinal cord. Intrathecal injection of either the PAR1 antagonist, or AMPK activator attenuated heat hyperalgesia and mechanical allodynia in MRL/lpr mice. Furthermore, we also identified that the enhanced glutamatergic synaptic activity and suppressed activity of glial glutamate transporters in the spinal dorsal horn of MRL/lpr mice are caused by activation of the PAR1 and suppression of AMPK signaling pathways. These findings suggest that targeting the PAR1 and AMPK signaling pathways in the spinal cord may be a useful approach for treating chronic pain caused by SLE. PERSPECTIVE: Our study provides evidence suggesting activation of PAR1 and suppression of AMPK in the spinal cord induces thermal hyperalgesia and mechanical allodynia in a lupus mouse model. Targeting signaling pathways regulating the PAR1 and AMPK could potentially provide a novel approach to the management of chronic pain caused by SLE.
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Affiliation(s)
- Fen Li
- Department of Neurology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China
| | - Dongsheng Li
- Department of Cardiology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China
| | - Jianguang Liu
- Department of Neurology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China
| | - Shifan Tang
- Department of Cardiology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China
| | - Jie Yan
- Department of Forensic Science, School of Basic Medical Science, Central South University, Changsha, Hunan, China
| | - Hongwei Li
- Department of Internal Medicine, School of Medicine, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Zhengyun Wan
- Department of Internal Medicine, School of Medicine, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Lian Wang
- Department of Internal Medicine, School of Medicine, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Xisheng Yan
- Department of Cardiology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China.
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6
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Boikov SI, Sibarov DA, Stepanenko YD, Karelina TV, Antonov SM. Calcium-Dependent Interplay of Lithium and Tricyclic Antidepressants, Amitriptyline and Desipramine, on N-methyl-D-aspartate Receptors. Int J Mol Sci 2022; 23:ijms232416177. [PMID: 36555818 PMCID: PMC9787943 DOI: 10.3390/ijms232416177] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/13/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
The facilitated activity of N-methyl-D-aspartate receptors (NMDARs) in the central and peripheral nervous systems promotes neuropathic pain. Amitriptyline (ATL) and desipramine (DES) are tricyclic antidepressants (TCAs) whose anti-NMDAR properties contribute to their analgetic effects. At therapeutic concentrations <1 µM, these medicines inhibit NMDARs by enhancing their calcium-dependent desensitization (CDD). Li+, which suppresses the sodium−calcium exchanger (NCX) and enhances NMDAR CDD, also exhibits analgesia. Here, the effects of different [Li+]s on TCA inhibition of currents through native NMDARs in rat cortical neurons recorded by the patch-clamp technique were investigated. We demonstrated that the therapeutic [Li+]s of 0.5−1 mM cause an increase in ATL and DES IC50s of ~10 folds and ~4 folds, respectively, for the Ca2+-dependent NMDAR inhibition. The Ca2+-resistant component of NMDAR inhibition by TCAs, the open-channel block, was not affected by Li+. In agreement, clomipramine providing exclusively the NMDAR open-channel block is not sensitive to Li+. This Ca2+-dependent interplay between Li+, ATL, and DES could be determined by their competition for the same molecular target. Thus, submillimolar [Li+]s may weaken ATL and DES effects during combined therapy. The data suggest that Li+, ATL, and DES can enhance NMDAR CDD through NCX inhibition. This ability implies a drug−drug or ion−drug interaction when these medicines are used together therapeutically.
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7
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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: 8] [Impact Index Per Article: 4.0] [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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8
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Su PYP, Zhang L, He L, Zhao N, Guan Z. The Role of Neuro-Immune Interactions in Chronic Pain: Implications for Clinical Practice. J Pain Res 2022; 15:2223-2248. [PMID: 35957964 PMCID: PMC9359791 DOI: 10.2147/jpr.s246883] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/19/2022] [Indexed: 11/23/2022] Open
Abstract
Chronic pain remains a public health problem and contributes to the ongoing opioid epidemic. Current pain management therapies still leave many patients with poorly controlled pain, thus new or improved treatments are desperately needed. One major challenge in pain research is the translation of preclinical findings into effective clinical practice. The local neuroimmune interface plays an important role in the initiation and maintenance of chronic pain and is therefore a promising target for novel therapeutic development. Neurons interface with immune and immunocompetent cells in many distinct microenvironments along the nociceptive circuitry. The local neuroimmune interface can modulate the activity and property of the neurons to affect peripheral and central sensitization. In this review, we highlight a specific subset of many neuroimmune interfaces. In the central nervous system, we examine the interface between neurons and microglia, astrocytes, and T lymphocytes. In the periphery, we profile the interface between neurons in the dorsal root ganglion with T lymphocytes, satellite glial cells, and macrophages. To bridge the gap between preclinical research and clinical practice, we review the preclinical studies of each neuroimmune interface, discuss current clinical treatments in pain medicine that may exert its action at the neuroimmune interface, and highlight opportunities for future clinical research efforts.
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Affiliation(s)
- Po-Yi Paul Su
- Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, CA, USA
| | - Lingyi Zhang
- Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, CA, USA
- Department of Anesthesiology, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Liangliang He
- Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, CA, USA
- Department of Pain Management, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Na Zhao
- Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, CA, USA
| | - Zhonghui Guan
- Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, CA, USA
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9
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Guo S, Song Z, He J, Yin G, Zhu J, Liu H, Yang L, Ji X, Xu X, Liu Z, Liu J. Akt/Aquaporin-4 Signaling Aggravates Neuropathic Pain by Activating Astrocytes after Spinal Nerve Ligation in Rats. Neuroscience 2021; 482:116-131. [PMID: 34942314 DOI: 10.1016/j.neuroscience.2021.12.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 12/20/2022]
Abstract
Aquaporins (AQPs) play critical physiological roles in water balance in the central nervous system (CNS). Aquaporin-4 (AQP4), the principal aquaporin expressed in the CNS, has been implicated in the processing of sensory and pain transmission. Akt signaling is also involved in pain mediation, such as neuroinflammatory pain and bone cancer pain. Previously, we found that expression of AQP4 and p-Akt was altered in the rat spinal cord after spinal nerve ligation (SNL). Here, we further investigated the effects of the AQP4 and Akt pathways in the spinal dorsal horn (SDH) on the pathogenesis of neuropathic pain (NP). Spinal AQP4 was significantly upregulated after SNL and was primarily expressed in astrocytes in the SDH. Inhibition of AQP4 with TGN-020 attenuated the development and maintenance of NP by inhibiting glial activation and anti-neuroinflammatory mechanisms. Moreover, inhibition of AQP4 suppressed astrocyte activation both in the SDH and in primary cultures. Similar to AQP4, we found that p-Akt was also significantly elevated after SNL. Inhibition of Akt with MK2206 suppressed AQP4 upregulation and astrocyte activation both in vivo and in vitro. Furthermore, Akt blockade with MK2206 alleviated NP in the early and late phases after SNL. These results elucidate the mechanisms involved in the roles of Akt/AQP4 signaling in the development and maintenance of NP. AQP4 is likely to be a novel therapeutic target for NP management.
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Affiliation(s)
- Shiwu Guo
- Department of Spinal Surgery, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China
| | - Zhiwen Song
- Department of Spinal Surgery, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China
| | - Junsheng He
- Department of Spinal Surgery, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China
| | - Gang Yin
- Department of Orthopedics, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213003, China
| | - Jianguo Zhu
- Department of Orthopedics, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213003, China
| | - Haifeng Liu
- Department of Orthopedics, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213003, China
| | - Lei Yang
- Department of Orthopedics, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213003, China
| | - Xubiao Ji
- Department of Orthopedics, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213003, China
| | - Xu Xu
- 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.
| | - Jinbo Liu
- Department of Spinal Surgery, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China.
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10
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Kartha S, Ghimire P, Winkelstein BA. Inhibiting spinal secretory phospholipase A 2 after painful nerve root injury attenuates established pain and spinal neuronal hyperexcitability by altering spinal glutamatergic signaling. Mol Pain 2021; 17:17448069211066221. [PMID: 34919471 PMCID: PMC8721705 DOI: 10.1177/17448069211066221] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Neuropathic injury is accompanied by chronic inflammation contributing to the onset and maintenance of pain after an initial insult. In addition to their roles in promoting immune cell activation, inflammatory mediators like secretory phospholipase A2 (sPLA2) modulate nociceptive and excitatory neuronal signaling during the initiation of pain through hydrolytic activity. Despite having a known role in glial activation and cytokine release, it is unknown if sPLA2 contributes to the maintenance of painful neuropathy and spinal hyperexcitability later after neural injury. Using a well-established model of painful nerve root compression, this study investigated if inhibiting spinal sPLA2 7 days after painful injury modulates the behavioral sensitivity and/or spinal dorsal horn excitability that is typically evident. The effects of sPLA2 inhibition on altered spinal glutamatergic signaling was also probed by measuring spinal intracellular glutamate levels and spinal glutamate transporter (GLAST and GLT1) and receptor (mGluR5, GluR1, and NR1) expression. Spinal sPLA2 inhibition at day 7 abolishes behavioral sensitivity, reduces both evoked and spontaneous neuronal firing in the spinal cord, and restores the distribution of neuronal phenotypes to those of control conditions. Inhibiting spinal sPLA2 also increases intracellular glutamate concentrations and restores spinal expression of GLAST, GLT1, mGluR5, and GluR1 to uninjured expression with no effect on NR1. These findings establish a role for spinal sPLA2 in maintaining pain and central sensitization after neural injury and suggest this may be via exacerbating glutamate excitotoxicity in the spinal cord.
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Affiliation(s)
- Sonia Kartha
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Prabesh Ghimire
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Beth A Winkelstein
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.,Department of Neurosurgery, University of Pennsylvania, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
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11
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Viatchenko-Karpinski V, Kong L, Weng HR. Activation of microglial GPR109A alleviates thermal hyperalgesia in female lupus mice by suppressing IL-18 and glutamatergic synaptic activity. Glia 2021; 70:634-649. [PMID: 34919284 DOI: 10.1002/glia.24130] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 11/10/2022]
Abstract
Many patients with systemic lupus erythematosus (SLE) live with chronic pain despite advances in medical management in reducing mortality related to SLE. Few animal studies have addressed mechanisms and treatment for chronic pain caused by SLE. In this study, we provide the first evidence for the analgesic effects of a GPR109A specific agonist (MK1903) and its action mechanisms in thermal hyperalgesia in female MRL/lpr mice, an SLE mouse model. Specifically, we show that MRL/lpr mice had a higher sensitivity to thermal stimuli at age 11-16 weeks, which was accompanied with significantly microglial and astrocytic activation, increases in p38 MAPK and glutamatergic synaptic activities in the spinal dorsal horn. We demonstrate that thermal hyperalgesia in MRL/lpr mice was significantly attenuated by intrathecal injection of MK1903. GPR109A was expressed in spinal microglia but not astrocytes or neurons. Its expression was significantly increased in MRL/lpr mice with thermal hyperalgesia. Activation of GPR109A receptors in microglia attenuated glutamatergic synaptic activity via suppressing production of interleukin-18 (IL-18). We provide evidence that activation of GPR109A attenuated thermal hyperalgesia in the SLE animal model via suppressing p38 MAPK activity and production of IL-18. Our study suggests that targeting the microglial GPR109A is a potent approach for reversing spinal neuroinflammation, abnormal excitatory synaptic activity, and management of thermal hyperalgesia caused by SLE.
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Affiliation(s)
| | - Lingwei Kong
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia, USA
| | - Han-Rong Weng
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia, USA.,Department of Basic Sciences, California Northstate University College of Medicine, Elk Grove, Georgia, USA
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12
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Boakye PA, Tang SJ, Smith PA. Mediators of Neuropathic Pain; Focus on Spinal Microglia, CSF-1, BDNF, CCL21, TNF-α, Wnt Ligands, and Interleukin 1β. FRONTIERS IN PAIN RESEARCH 2021; 2:698157. [PMID: 35295524 PMCID: PMC8915739 DOI: 10.3389/fpain.2021.698157] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/14/2021] [Indexed: 01/04/2023] Open
Abstract
Intractable neuropathic pain is a frequent consequence of nerve injury or disease. When peripheral nerves are injured, damaged axons undergo Wallerian degeneration. Schwann cells, mast cells, fibroblasts, keratinocytes and epithelial cells are activated leading to the generation of an "inflammatory soup" containing cytokines, chemokines and growth factors. These primary mediators sensitize sensory nerve endings, attract macrophages, neutrophils and lymphocytes, alter gene expression, promote post-translational modification of proteins, and alter ion channel function in primary afferent neurons. This leads to increased excitability and spontaneous activity and the generation of secondary mediators including colony stimulating factor 1 (CSF-1), chemokine C-C motif ligand 21 (CCL-21), Wnt3a, and Wnt5a. Release of these mediators from primary afferent neurons alters the properties of spinal microglial cells causing them to release tertiary mediators, in many situations via ATP-dependent mechanisms. Tertiary mediators such as BDNF, tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and other Wnt ligands facilitate the generation and transmission of nociceptive information by increasing excitatory glutamatergic transmission and attenuating inhibitory GABA and glycinergic transmission in the spinal dorsal horn. This review focusses on activation of microglia by secondary mediators, release of tertiary mediators from microglia and a description of their actions in the spinal dorsal horn. Attention is drawn to the substantial differences in the precise roles of various mediators in males compared to females. At least 25 different mediators have been identified but the similarity of their actions at sensory nerve endings, in the dorsal root ganglia and in the spinal cord means there is considerable redundancy in the available mechanisms. Despite this, behavioral studies show that interruption of the actions of any single mediator can relieve signs of pain in experimental animals. We draw attention this paradox. It is difficult to explain how inactivation of one mediator can relieve pain when so many parallel pathways are available.
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Affiliation(s)
- Paul A. Boakye
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Shao-Jun Tang
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Peter A. Smith
- Neuroscience and Mental Health Institute and Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
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13
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Liang Y, Ma Y, Wang J, Nie L, Hou X, Wu W, Zhang X, Tian Y. Leptin Contributes to Neuropathic Pain via Extrasynaptic NMDAR-nNOS Activation. Mol Neurobiol 2021; 58:1185-1195. [PMID: 33099751 PMCID: PMC7878206 DOI: 10.1007/s12035-020-02180-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/14/2020] [Indexed: 11/28/2022]
Abstract
Leptin is an adipocytokine that is primarily secreted by white adipose tissue, and it contributes to the pathogenesis of neuropathic pain in collaboration with N-methyl-D-aspartate receptors (NMDARs). Functional NMDARs are a heteromeric complex that primarily comprise two NR1 subunits and two NR2 subunits. NR2A is preferentially located at synaptic sites, and NR2B is enriched at extrasynaptic sites. The roles of synaptic and extrasynaptic NMDARs in the contribution of leptin to neuropathic pain are not clear. The present study examined whether the important role of leptin in neuropathic pain was related to synaptic or extrasynaptic NMDARs. We used a rat model of spared nerve injury (SNI) and demonstrated that the intrathecal administration of the NR2A-selective antagonist NVP-AAM077 and the NR2B-selective antagonist Ro25-6981 prevented and reversed mechanical allodynia following SNI. Administration of exogenous leptin mimicked SNI-induced behavioral allodynia, which was also prevented by NVP-AAM077 and Ro25-6981. Mechanistic studies showed that leptin enhanced NR2B- but not NR2A-mediated currents in spinal lamina II neurons of naïve rats. Leptin also upregulated the expression of NR2B, which was blocked by the NR2B-selective antagonist Ro25-6981, in cultured dorsal root ganglion (DRG) neurons. Leptin enhanced neuronal nitric oxide synthase (nNOS) expression, which was also blocked by Ro25-6981, in cultured DRG cells. However, leptin did not change NR2A expression, and the NR2A-selective antagonist NVP-AAM077 had no effect on leptin-enhanced nNOS expression. Our data suggest an important cellular link between the spinal effects of leptin and the extrasynaptic NMDAR-nNOS-mediated cellular mechanism of neuropathic pain.
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Affiliation(s)
- Yanling Liang
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, No. 1838 Guangzhou Avenue, Guangzhou, 510515, China
| | - Yuxin Ma
- Department of Anatomy, School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Jieqin Wang
- Department of Pancreatobiliary Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510515, China
| | - Lei Nie
- Department of Anesthesiology, The Third Xiangya Hospital of Central South University, Changsha, 410000, China
| | - Xusheng Hou
- Department of Functional Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Wenyu Wu
- Target and Interventional Therapy Department of Oncology, First People's Hospital of Foshan, Foshan, 528000, China
| | - Xingmei Zhang
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, No. 1838 Guangzhou Avenue, Guangzhou, 510515, China.
| | - Yinghong Tian
- Experiment Teaching & Administration Center, School of Basic Medical Sciences, Southern Medical University, No. 1838 Guangzhou Avenue, Guangzhou, 510515, China.
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14
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The role of glutamate transporter-1 in firing activity of locus coeruleus neurons and nociception in rats. Exp Brain Res 2021; 239:1287-1294. [PMID: 33619583 DOI: 10.1007/s00221-021-06065-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 02/13/2021] [Indexed: 10/22/2022]
Abstract
Locus coeruleus (LC) is considered to be the main source of norepinephrine in the central nervous system (CNS) and plays important role in relieving pain in the body. Changes in the activity of synaptic excitatory amino acid transporters (EAATs) would be an applicable way to regulate synaptic transmission in the LC. In the present study, we examined the role of astrocytic glutamate transporter-1 (GLT1) in the firing activity of LC neurons and the sensation of pain in rats. Male Wistar rats were divided into three control (CNT), ceftriaxone (CFT) and dihydrokainic acid (DHK) groups. Animals were given intraperitoneal injections for nine consecutive days after which the electrophysiological and behavioral experiments were performed to determine the single-unit activity of LC neurons and pain sensation. Results of this study revealed that CFT as a well-known up-regulator of GLT1 expression decreases the latency of pain sensation in rats but inhibition of GLT1 activity by DHK showed no significant effects. Furthermore, the results obtained by single-unit recording from LC showed a significant decrease in evoked response in CFT group compared to the CNT group. Therefore, this study suggests that GLT1 might be considered as a potential therapeutic target for pain modulation in the future.
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15
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Abstract
Astrocytes are critical for maintaining the homeostasis of the CNS. Increasing evidence suggests that a number of neurological and neuropsychiatric disorders, including chronic pain, may result from astrocyte 'gliopathy'. Indeed, in recent years there has been substantial progress in our understanding of how astrocytes can regulate nociceptive synaptic transmission via neuronal-glial and glial-glial cell interactions, as well as the involvement of spinal and supraspinal astrocytes in the modulation of pain signalling and the maintenance of neuropathic pain. A role of astrocytes in the pathogenesis of chronic itch is also emerging. These developments suggest that targeting the specific pathways that are responsible for astrogliopathy may represent a novel approach to develop therapies for chronic pain and chronic itch.
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16
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Alterations in evoked and spontaneous activity of dorsal horn wide dynamic range neurons in pathological pain: a systematic review and analysis. Pain 2019; 160:2199-2209. [DOI: 10.1097/j.pain.0000000000001632] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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17
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Boakye PA, Rancic V, Whitlock KH, Simmons D, Longo FM, Ballanyi K, Smith PA. Receptor dependence of BDNF actions in superficial dorsal horn: relation to central sensitization and actions of macrophage colony stimulating factor 1. J Neurophysiol 2019; 121:2308-2322. [PMID: 30995156 DOI: 10.1152/jn.00839.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Peripheral nerve injury elicits an enduring increase in the excitability of the spinal dorsal horn. This change, which contributes to the development of neuropathic pain, is a consequence of release and prolonged exposure of dorsal horn neurons to various neurotrophins and cytokines. We have shown in rats that nerve injury increases excitatory synaptic drive to excitatory neurons but decreases drive to inhibitory neurons. Both effects, which contribute to an increase in dorsal horn excitability, appear to be mediated by microglia-derived BDNF. We have used multiphoton Ca2+ imaging and whole cell recording of spontaneous excitatory postsynaptic currents in defined-medium organotypic cultures of GAD67-GFP+ mice spinal cord to determine the receptor dependence of these opposing actions of BDNF. In mice, as in rats, BDNF enhances excitatory transmission onto excitatory neurons. This is mediated via presynaptic TrkB and p75 neurotrophin receptors and exclusively by postsynaptic TrkB. By contrast with findings from rats, in mice BDNF does not decrease excitation of inhibitory neurons. The cytokine macrophage colony-stimulating factor 1 (CSF-1) has also been implicated in the onset of neuropathic pain. Nerve injury provokes its de novo synthesis in primary afferents, its release in spinal cord, and activation of microglia. We now show that CSF-1 increases excitatory drive to excitatory neurons via a BDNF-dependent mechanism and decreases excitatory drive to inhibitory neurons via BDNF-independent processes. Our findings complete missing steps in the cascade of events whereby peripheral nerve injury instigates increased dorsal horn excitability in the context of central sensitization and the onset of neuropathic pain. NEW & NOTEWORTHY Nerve injury provokes synthesis of macrophage colony-stimulating factor 1 (CSF-1) in primary afferents and its release in the dorsal horn. We show that CSF-1 increases excitatory drive to excitatory dorsal horn neurons via BDNF activation of postsynaptic TrkB and presynaptic TrkB and p75 neurotrophin receptors. CSF-1 decreases excitatory drive to inhibitory neurons via a BDNF-independent processes. This completes missing steps in understanding how peripheral injury instigates central sensitization and the onset of neuropathic pain.
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Affiliation(s)
- Paul A Boakye
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada
| | - Vladimir Rancic
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada.,Department of Physiology, University of Alberta , Edmonton , Canada
| | - Kerri H Whitlock
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada
| | - Danielle Simmons
- Department of Neurology and Neurological Sciences, Stanford University , Stanford, California
| | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University , Stanford, California
| | - Klaus Ballanyi
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada.,Department of Physiology, University of Alberta , Edmonton , Canada
| | - Peter A Smith
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada.,Department of Pharmacology, University of Alberta , Edmonton , Canada
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18
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Liu ZY, Song ZW, Guo SW, He JS, Wang SY, Zhu JG, Yang HL, Liu JB. CXCL12/CXCR4 signaling contributes to neuropathic pain via central sensitization mechanisms in a rat spinal nerve ligation model. CNS Neurosci Ther 2019; 25:922-936. [PMID: 30955244 PMCID: PMC6698967 DOI: 10.1111/cns.13128] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/11/2019] [Accepted: 03/13/2019] [Indexed: 12/20/2022] Open
Abstract
Background Previous studies have demonstrated that the CXCL12/CXCR4 signaling axis is involved in the regulation of neuropathic pain (NP). Here, we performed experiments to test whether the CXCL12/CXCR4 signaling pathway contributes to the pathogenesis of neuropathic pain after spinal nerve ligation (SNL) via central sensitization mechanisms. Methods Neuropathic pain was induced and assessed in a SNL rat model. The expression and distribution of CXCL12 or CXCR4 were examined by immunofluorescence staining and western blot. The effects of CXCL12 rat peptide, CXCL12 neutralizing antibody, CXCR4 antagonist, and astrocyte metabolic inhibitor on pain hypersensitivity were explored by behavioral tests in naive or SNL rats. We measured the expression level of c‐Fos and CGRP to evaluate the sensitization of neurons by RT‐PCR. The activation of astrocyte and microglia was analyzed by measuring the level of GFAP and iba‐1. The mRNA levels of the pro‐inflammatory cytokines such as TNF‐α, IL‐1β, and IL‐6 and Connexin 30, Connexin 43, EAAT 1, EAAT 2 were also detected by RT‐PCR. Results First, we found that the expression of CXCL12 and CXCR4 was upregulated after SNL. CXCL12 was mainly expressed in the neurons while CXCR4 was expressed both in astrocytes and neurons in the spinal dorsal horn after SNL. Moreover, intrathecal administration of rat peptide, CXCL12, induced hypersensitivity in naive rats, which was partly reversed by fluorocitrate. In addition, the CXCL12 rat peptide increased mRNA levels of c‐Fos, GFAP, and iba‐1. A single intrathecal injection of CXCL12 neutralizing antibody transiently reversed neuropathic pain in the SNL rat model. Consecutive use of CXCL12 neutralizing antibody led to significant delay in the induction of neuropathic pain, and reduced the expression of GFAP and iba‐1 in the spinal dorsal horn. Finally, repeated intrathecal administration of the CXCR4 antagonist, AMD3100, significantly suppressed the initiation and duration of neuropathic pain. The mRNA levels of c‐Fos, CGRP, GFAP, iba‐1, and pro‐inflammatory cytokines, also including Connexin 30 and Connexin 43 were decreased after injection of AMD3100, while EAAT 1 and EAAT 2 mRNAs were increased. Conclusion We demonstrate that the CXCL12/CXCR4 signaling pathway contributes to the development and maintenance of neuropathic pain via central sensitization mechanisms. Importantly, intervening with CXCL12/CXCR4 presents an effective therapeutic approach to treat the neuropathic pain.
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Affiliation(s)
- Zhi-Yuan Liu
- Department of Spinal Surgery, The Third Affiliated Hospital of Soochow University, Changzhou, China.,Department of Orthopedics, The Affiliated Wujin Hospital of Jiangsu University, Changzhou, China
| | - Zhi-Wen Song
- Department of Spinal Surgery, The Third Affiliated Hospital of Soochow University, Changzhou, China
| | - Shi-Wu Guo
- Department of Spinal Surgery, The Third Affiliated Hospital of Soochow University, Changzhou, China
| | - Jun-Sheng He
- Department of Spinal Surgery, The Third Affiliated Hospital of Soochow University, Changzhou, China
| | - Shen-Yu Wang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jian-Guo Zhu
- Department of Orthopedics, The Affiliated Wujin Hospital of Jiangsu University, Changzhou, China
| | - Hui-Lin Yang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jin-Bo Liu
- Department of Spinal Surgery, The Third Affiliated Hospital of Soochow University, Changzhou, China
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19
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Yan X, Li F, Maixner DW, Yadav R, Gao M, Ali MW, Hooks SB, Weng HR. Interleukin-1beta released by microglia initiates the enhanced glutamatergic activity in the spinal dorsal horn during paclitaxel-associated acute pain syndrome. Glia 2019; 67:482-497. [PMID: 30578561 DOI: 10.1002/glia.23557] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 10/08/2018] [Accepted: 10/08/2018] [Indexed: 01/30/2023]
Abstract
Patients receiving paclitaxel for cancer treatment often develop an acute pain syndrome (paclitaxel-associated acute pain syndrome, P-APS), which occurs immediately after paclitaxel treatment. Mechanisms underlying P-APS remain largely unknown. We recently reported that rodents receiving paclitaxel develop acute pain and activation of spinal microglial toll like receptor 4 (TLR4) by paclitaxel penetrating into the spinal cord is a critical event in the genesis of P-APS. Our current study dissected cellular and molecular mechanisms underlying the P-APS. We demonstrated that bath-perfusion of paclitaxel, at a concentration similar to that found in the cerebral spinal fluid in animals receiving i.v. paclitaxel (2 mg/kg), resulted in increased calcium activity in microglia instantly, and in astrocytes with 6 min delay. TLR4 activation in microglia by paclitaxel caused microglia to rapidly release interleukin-1β (IL-1β) but not tumor necrosis factor α, IL-6, or interferon-γ. IL-1β release from microglia depended on capthepsin B. IL-1β acted on astrocytes, leading to elevated calcium activity and suppressed glutamate uptake. IL-1β also acted on neurons to increase presynaptic glutamate release and postsynaptic AMPA receptor activity in the spinal dorsal horn. Knockout of IL-1 receptors prevented the development of acute pain induced by paclitaxel in mice. Our study indicates that IL-1β is a crucial molecule used by microglia to alter functions in astrocytes and neurons upon activation of TLR4 in the genesis of P-APS, and targeting the signaling pathways regulating the production and function of IL-1β from microglia is a potential avenue for the development of analgesics for the treatment of P-APS.
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Affiliation(s)
- Xisheng Yan
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia
- Department of Cardiovascular Medicine, Wuhan Third Hospital, Wuhan, China
| | - Fen Li
- Department of Neurology, Wuhan Third Hospital, Wuhan, China
| | - Dylan W Maixner
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia
| | - Ruchi Yadav
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia
| | - Mei Gao
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia
| | - Mourad Wagdy Ali
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia
| | - Shelley B Hooks
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia
| | - Han-Rong Weng
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia
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20
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Guo W, Imai S, Zou S, Yang J, Watanabe M, Wang J, Dubner R, Wei F, Ren K. Altered glial glutamate transporter expression in descending circuitry and the emergence of pain chronicity. Mol Pain 2019; 15:1744806918825044. [PMID: 30799685 PMCID: PMC6348548 DOI: 10.1177/1744806918825044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The glutamate type 1 transporter (GLT1) plays a major role in glutamate homeostasis in the brain. Although alterations of GLT1 activity have been linked to persistent pain, the significance of these changes is poorly understood. Focusing on the rostral ventromedial medulla, a key site in pain modulation, we examined the expression and function of GLT1 and related transcription factor kappa B-motif binding phosphoprotein (KBBP) in rats after adjuvant-induced hind paw inflammation. RESULTS After inflammation, GLT1 and KBBP showed an early upregulation and gradual transition to downregulation that lasted throughout the eight-week observation period. Nitration of GLT1 was reduced at 30 min and increased at eight weeks after inflammation, suggesting an initial increase and later decrease in transporter activity. Mechanical hyperalgesia and paw edema exhibited an initial developing phase with peak hyperalgesia at 4 to 24 h, a subsequent attenuating phase, followed by a late persistent phase that lasted for months. The downregulation of GLT1 occurred at a time when hyperalgesia transitioned into the persistent phase. In the rostral ventromedial medulla, pharmacological block with dihydrokainic acid and RNAi of GLT1 and KBBP increased nociception and overexpression of GLT1 reversed persistent hyperalgesia. Further, the initial upregulation of GLT1 and KBBP was blocked by local anesthetic block, and pretreatment with dihydrokainic acid facilitated the development of hyperalgesia. CONCLUSIONS These results suggest that the initial increased GLT1 activity depends on injury input and serves to dampen the development of hyperalgesia. However, later downregulation of GLT1 fosters the net descending facilitation as injury persists, leading to the emergence of persistent pain.
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Affiliation(s)
- Wei Guo
- 1 Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
- 2 Program in Neuroscience, University of Maryland, Baltimore, MD, USA
| | - Satoshi Imai
- 1 Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
- 2 Program in Neuroscience, University of Maryland, Baltimore, MD, USA
| | - Shiping Zou
- 1 Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
- 2 Program in Neuroscience, University of Maryland, Baltimore, MD, USA
| | - Jiale Yang
- 1 Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
- 2 Program in Neuroscience, University of Maryland, Baltimore, MD, USA
| | - Mineo Watanabe
- 1 Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
- 2 Program in Neuroscience, University of Maryland, Baltimore, MD, USA
- 3 Department of Oral Biology, Division of Molecular Medical Science, Hiroshima, Japan
| | - Jing Wang
- 1 Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
- 2 Program in Neuroscience, University of Maryland, Baltimore, MD, USA
- 4 Key Laboratory of Bone and Joint Diseases of Gansu province, Institute of Orthopedics, the Second Hospital of Lanzhou University, Lanzhou, China
| | - Ronald Dubner
- 1 Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
- 2 Program in Neuroscience, University of Maryland, Baltimore, MD, USA
| | - Feng Wei
- 1 Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
- 2 Program in Neuroscience, University of Maryland, Baltimore, MD, USA
| | - Ke Ren
- 1 Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
- 2 Program in Neuroscience, University of Maryland, Baltimore, MD, USA
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21
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Zhang FX, Ge SN, Dong YL, Shi J, Feng YP, Li Y, Li YQ, Li JL. Vesicular glutamate transporter isoforms: The essential players in the somatosensory systems. Prog Neurobiol 2018; 171:72-89. [PMID: 30273635 DOI: 10.1016/j.pneurobio.2018.09.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 08/28/2018] [Accepted: 09/23/2018] [Indexed: 02/08/2023]
Abstract
In nervous system, glutamate transmission is crucial for centripetal conveyance and cortical perception of sensory signals of different modalities, which necessitates vesicular glutamate transporters 1-3 (VGLUT 1-3), the three homologous membrane-bound protein isoforms, to load glutamate into the presysnaptic vesicles. These VGLUTs, especially VGLUT1 and VGLUT2, selectively label and define functionally distinct neuronal subpopulations at each relay level of the neural hierarchies comprising spinal and trigeminal sensory systems. In this review, by scrutinizing each structure of the organism's fundamental hierarchies including dorsal root/trigeminal ganglia, spinal dorsal horn/trigeminal sensory nuclear complex, somatosensory thalamic nuclei and primary somatosensory cortex, we summarize and characterize in detail within each relay the neuronal clusters expressing distinct VGLUT protein/transcript isoforms, with respect to their regional distribution features (complementary distribution in some structures), axonal terminations/peripheral innervations and physiological functions. Equally important, the distribution pattern and characteristics of VGLUT1/VGLUT2 axon terminals within these structures are also epitomized. Finally, the correlation of a particular VGLUT isoform and its physiological role, disclosed thus far largely via studying the peripheral receptors, is generalized by referring to reports on global and conditioned VGLUT-knockout mice. Also, researches on VGLUTs relating to future direction are tentatively proposed, such as unveiling the elusive differences between distinct VGLUTs in mechanism and/or pharmacokinetics at ionic/molecular level, and developing VGLUT-based pain killers.
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Affiliation(s)
- Fu-Xing Zhang
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Shun-Nan Ge
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China; Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, PR China
| | - Yu-Lin Dong
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Juan Shi
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Yu-Peng Feng
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Yang Li
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, PR China
| | - Yun-Qing Li
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China; Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, PR China.
| | - Jin-Lian Li
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China.
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22
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Eljaja L, Bjerrum OJ, Honoré PH, Abrahamsen B. Effects of the excitatory amino acid transporter subtype 2 (EAAT-2) inducer ceftriaxone on different pain modalities in rat. Scand J Pain 2018; 2:132-136. [PMID: 29913736 DOI: 10.1016/j.sjpain.2011.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 03/12/2011] [Indexed: 12/17/2022]
Abstract
Glutamate is the major excitatory amino acid in the mammalian CNS and is involved in transmission of pain together with processes for cognition, memory and learning. In order to terminate glutamatergic neurotransmission and avoid excitotoxic damage, a balanced glutamate homeostasis is of critical importance. The level of glutamate in the synaptic cleft is regulated through the action of five subtypes of excitatory amino acid transporters (EAAT1-5). Ceftriaxone, a β-lactam, induces EAAT-2 and has proven effect for the treatment of neuropathic pain. This pilot study investigated the effects of ceftriaxone upon acute and inflammatory pain and additionally, the analgesic effect of ceftriaxone after introduction of neuropathic pain. Methods Rats were tested before, during and after treatment of ceftriaxone for changes in response to both mechanical and thermal stimuli, using calibrated von Frey filaments and Hargreaves instrument, respectively. Inflammatory responses were investigated by assessing the response to intra-plantar injections of formalin; lastly, neuropathic pain was introduced using the spinal nerve ligation (SNL) model after which changes in both mechanical and thermal responses were again investigated. Results A significant increase in mechanical withdrawal threshold was observed following acute pain inducement in ceftriaxone treated rats. A marked increase in thermal withdrawal latency was also observed. In response to intra plantar administered formalin, ceftriaxone delayed the intensity of nocifensive behaviours. Applying the SNL model of neuropathic pain on naive rats created significant mechanical allodynia, but only a negligibly different response to thermal stimulation. After treatment with ceftriaxone the treated rats developed a hypoalgesic response to thermal stimulation, whilst the response to mechanical pain was insignificant. Conclusion In conclusion, ceftriaxone clearly interfered in the transmission of noxious signalling and proved in this study to have an effect upon acute thermal and mechanical pain thresholds as well as pathologic pain conditions. The present results are a piece in the large puzzle where administration route, dosage and pain models must be thoroughly investigated before a study can be planned for a proof of concept in different clinical pain states. Implications The current study demonstrates that ceftriaxone has a mitigating effect upon many pain modalities including acute and inflammatory, and that these modalities should be included in future studies characterising the anti-nociceptive effect of beta-lactams such as ceftriaxone. The fact that β-lactams also has antibiotic properties implies that similar chemical structures could be identified with the positive effect upon expression levels of EAAT2, but lacking the antibiotic side effect.
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Affiliation(s)
- Laila Eljaja
- Department of Pharmacology and Pharmacotherapy, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Ole J Bjerrum
- Department of Pharmacology and Pharmacotherapy, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Per Hartvig Honoré
- Department of Pharmacology and Pharmacotherapy, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Bjarke Abrahamsen
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
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23
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Stockstill K, Doyle TM, Yan X, Chen Z, Janes K, Little JW, Braden K, Lauro F, Giancotti LA, Harada CM, Yadav R, Xiao WH, Lionberger JM, Neumann WL, Bennett GJ, Weng HR, Spiegel S, Salvemini D. Dysregulation of sphingolipid metabolism contributes to bortezomib-induced neuropathic pain. J Exp Med 2018; 215:1301-1313. [PMID: 29703731 PMCID: PMC5940258 DOI: 10.1084/jem.20170584] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 07/31/2017] [Accepted: 03/21/2018] [Indexed: 11/04/2022] Open
Abstract
The development of chemotherapy-induced painful peripheral neuropathy is a major dose-limiting side effect of many chemotherapeutics, including bortezomib, but the mechanisms remain poorly understood. We now report that bortezomib causes the dysregulation of de novo sphingolipid metabolism in the spinal cord dorsal horn to increase the levels of sphingosine-1-phosphate (S1P) receptor 1 (S1PR1) ligands, S1P and dihydro-S1P. Accordingly, genetic and pharmacological disruption of S1PR1 with multiple S1PR1 antagonists, including FTY720, blocked and reversed neuropathic pain. Mice with astrocyte-specific alterations of S1pr1 did not develop neuropathic pain and lost their ability to respond to S1PR1 inhibition, strongly implicating astrocytes as a primary cellular substrate for S1PR1 activity. At the molecular level, S1PR1 engaged astrocyte-driven neuroinflammation and altered glutamatergic homeostasis, processes blocked by S1PR1 antagonism. Our findings establish S1PR1 as a target for therapeutic intervention and provide insight into cellular and molecular pathways. As FTY720 also shows promising anticancer potential and is FDA approved, rapid clinical translation of our findings is anticipated.
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Affiliation(s)
- Katherine Stockstill
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO
| | - Timothy M Doyle
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO
| | - Xisheng Yan
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA
| | - Zhoumou Chen
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO
| | - Kali Janes
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO
| | - Joshua W Little
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO
- Department of Surgery, Center for Anatomical Science and Education, Saint Louis University School of Medicine, St. Louis, MO
| | - Kathryn Braden
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO
| | - Filomena Lauro
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO
| | | | - Caron Mitsue Harada
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO
| | - Ruchi Yadav
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA
| | - Wen Hua Xiao
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA
| | - Jack M Lionberger
- Department of Internal Medicine, Division of Hematology, Oncology, and Cellular Therapeutics, Saint Louis University School of Medicine, St. Louis, MO
| | - William L Neumann
- Department of Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville, Edwardsville, IL
| | - Gary J Bennett
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA
| | - Han-Rong Weng
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA
| | - Sarah Spiegel
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, School of Medicine, Richmond, VA
| | - Daniela Salvemini
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO
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24
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Dodds KN, Beckett EAH, Evans SF, Hutchinson MR. Spinal Glial Adaptations Occur in a Minimally Invasive Mouse Model of Endometriosis: Potential Implications for Lesion Etiology and Persistent Pelvic Pain. Reprod Sci 2018; 26:357-369. [PMID: 29730970 DOI: 10.1177/1933719118773405] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Glial adaptations within the central nervous system are well known to modulate central sensitization and pain. Recently, it has been suggested that activity of glial-related proinflammatory cytokines may potentiate peripheral inflammation, via central neurogenic processes. However, a role for altered glial function has not yet been investigated in the context of endometriosis, a chronic inflammatory condition in women associated with peripheral lesions, often manifesting with persistent pelvic pain. Using a minimally invasive mouse model of endometriosis, we investigated associations between peripheral endometriosis-like lesions and adaptations in central glial reactivity. Spinal cords (T13-S1) from female C57BL/6 mice with endometriosis-like lesions (ENDO) were imaged via fluorescent immunohistochemistry for the expression of glial fibrillary acidic protein (GFAP; astrocytes) and CD11b (microglia) in the dorsal horn (n = 5). Heightened variability ( P = .02) as well as an overall increase ( P = .04) in the mean area of GFAP immunoreactivity was found in ENDO versus saline-injected control animals. Interestingly, spinal levels showing the greatest alterations in GFAP immunoreactivity appeared to correlate with the spatial location of lesions within the abdominopelvic cavity. A subtle but significant increase in the mean area of CD11b immunostaining was also observed in ENDO mice compared to controls ( P = .02). This is the first study to describe adaptations in nonneuronal, immune-like cells of the central nervous system attributed to the presence of endometriosis-like lesions.
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Affiliation(s)
- Kelsi N Dodds
- 1 Discipline of Physiology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Elizabeth A H Beckett
- 1 Discipline of Physiology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Susan F Evans
- 2 Discipline of Pharmacology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Mark R Hutchinson
- 1 Discipline of Physiology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia.,3 Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, University of Adelaide, Adelaide, South Australia, Australia
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25
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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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26
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27
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Kristensen PJ, Gegelashvili G, Munro G, Heegaard AM, Bjerrum OJ. The β-lactam clavulanic acid mediates glutamate transport-sensitive pain relief in a rat model of neuropathic pain. Eur J Pain 2017; 22:282-294. [PMID: 28984398 DOI: 10.1002/ejp.1117] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2017] [Indexed: 12/30/2022]
Abstract
BACKGROUND Following nerve injury, down-regulation of astroglial glutamate transporters (GluTs) with subsequent extracellular glutamate accumulation is a key factor contributing to hyperexcitability within the spinal dorsal horn. Some β-lactam antibiotics can up-regulate GluTs, one of which, ceftriaxone, displays analgesic effects in rodent chronic pain models. METHODS Here, the antinociceptive actions of another β-lactam clavulanic acid, which possesses negligible antibiotic activity, were compared with ceftriaxone in rats with chronic constriction injury (CCI)-induced neuropathic pain. In addition, the protein expression of glutamate transporter-1 (GLT1), its splice variant GLT1b and glutamate-aspartate transporter (GLAST) was measured in the spinal cord of CCI rats. Finally, protein expression of the same GluTs was evaluated in cultured astrocytes obtained from rodents and humans. RESULTS Repeated injection of ceftriaxone or clavulanic acid over 10 days alleviated CCI-induced mechanical hypersensitivity, whilst clavulanic acid was additionally able to affect the thermal hypersensitivity. In addition, clavulanic acid up-regulated expression of GLT1b within the spinal cord of CCI rats, whereas ceftriaxone failed to modulate expression of any GluTs in this model. However, both clavulanic acid and ceftriaxone up-regulated GLT1 expression in rat cortical and human spinal astrocyte cultures. Furthermore, clavulanic acid increased expression of GLT1b and GLAST in rat astrocytes in a dose-dependent manner. CONCLUSIONS Thus, clavulanic acid up-regulates GluTs in cultured rodent- and human astroglia and alleviates CCI-induced hypersensitivity, most likely through up-regulation of GLT1b in spinal dorsal horn. SIGNIFICANCE Chronic dosing of clavulanic acid alleviates neuropathic pain in rats and up-regulates glutamate transporters both in vitro and in vivo. Crucially, a similar up-regulation of glutamate transporters in human spinal astrocytes by clavulanic acid supports the development of novel β-lactam-based analgesics, devoid of antibacterial activity, for the clinical treatment of chronic pain.
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Affiliation(s)
- P J Kristensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.,Department of In Vivo Neurodegeneration, H. Lundbeck A/S, Valby, Denmark
| | - G Gegelashvili
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.,Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
| | - G Munro
- Department of In Vivo Neurodegeneration, H. Lundbeck A/S, Valby, Denmark
| | - A M Heegaard
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - O J Bjerrum
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
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28
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Chelini A, Brogi S, Paolino M, Di Capua A, Cappelli A, Giorgi G, Farzad M, Di Cesare Mannelli L, Micheli L, Ghelardini C, Anzini M. Synthesis and Biological Evaluation of Novel Neuroprotective Pyridazine Derivatives as Excitatory Amino Acid Transporter 2 (EAAT2) Activators. J Med Chem 2017; 60:5216-5221. [DOI: 10.1021/acs.jmedchem.7b00383] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Alessia Chelini
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro
2, 53100 Siena, Italy
| | - Simone Brogi
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro
2, 53100 Siena, Italy
| | - Marco Paolino
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro
2, 53100 Siena, Italy
| | - Angela Di Capua
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro
2, 53100 Siena, Italy
- Griffith
Institute for Drug Discovery, Griffith University, Nathan 4111, Queensland, Australia
| | - Andrea Cappelli
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro
2, 53100 Siena, Italy
| | - Gianluca Giorgi
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro
2, 53100 Siena, Italy
| | - Mersedeh Farzad
- Oncological
Clinical Trials and Medical Oncology Unit, Alta Valdelsa Hospital, 53036 Campostaggia, Siena, Italy
| | - Lorenzo Di Cesare Mannelli
- Dipartimento
di Neuroscienze, Area del Farmaco e Salute del Bambino (NEUROFARBA), Viale Pieraccini, 6, 50139 Firenze, Italy
| | - Laura Micheli
- Dipartimento
di Neuroscienze, Area del Farmaco e Salute del Bambino (NEUROFARBA), Viale Pieraccini, 6, 50139 Firenze, Italy
| | - Carla Ghelardini
- Dipartimento
di Neuroscienze, Area del Farmaco e Salute del Bambino (NEUROFARBA), Viale Pieraccini, 6, 50139 Firenze, Italy
| | - Maurizio Anzini
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro
2, 53100 Siena, Italy
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29
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Sung CS, Wen ZH, Feng CW, Chen CH, Huang SY, Chen NF, Chen WF, Wong CS. Potentiation of spinal glutamatergic response in the neuron-glia interactions underlies the intrathecal IL-1β-induced thermal hyperalgesia in rats. CNS Neurosci Ther 2017; 23:580-589. [PMID: 28544775 DOI: 10.1111/cns.12705] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/15/2017] [Accepted: 04/18/2017] [Indexed: 01/09/2023] Open
Abstract
AIMS We previously demonstrated that intrathecal IL-1β upregulated phosphorylation of p38 mitogen-activated protein kinase (P-p38 MAPK) and inducible nitric oxide synthase (iNOS) in microglia and astrocytes in spinal cord, increased nitric oxide (NO) release into cerebrospinal fluid, and induced thermal hyperalgesia in rats. This study investigated the role of spinal glutamatergic response in intrathecal IL-1β-induced nociception in rats. METHODS The pretreatment effects of MK-801 (5 μg), minocycline (20 μg), and SB203580 (5 μg) on intrathecal IL-1β (100 ng) in rats were measured by behavior, Western blotting, CSF analysis, and immunofluorescence studies. RESULTS IL-1β increased phosphorylation of NR-1 (p-NR1) subunit of N-methyl-D-aspartate receptors in neurons and microglia, reduced glutamate transporters (GTs; glutamate/aspartate transporter by 60.9%, glutamate transporter-1 by 55.0%, excitatory amino acid carrier-1 by 39.8%; P<.05 for all), and increased glutamate (29%-133% increase from 1.5 to 12 hours; P<.05) and NO (44%-101% increase from 4 to 12 hours; P<.05) levels in cerebrospinal fluid. MK-801 significantly inhibited all the IL-1β-induced responses; however, minocycline and SB203580 blocked the IL-1β-downregulated GTs and elevated glutamate but not the upregulated p-NR1. CONCLUSION The enhanced glutamatergic response and neuron-glia interaction potentiate the intrathecal IL-1β-activated P-p38/iNOS/NO signaling and thermal hyperalgesia.
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Affiliation(s)
- Chun-Sung Sung
- Department of Anesthesiology, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Zhi-Hong Wen
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan.,Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Chien-Wei Feng
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan.,Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan.,Doctoral Degree Program in Marine Biotechnology, Academia Sinica, Taipei, Taiwan
| | - Chun-Hong Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan.,Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan.,Doctoral Degree Program in Marine Biotechnology, Academia Sinica, Taipei, Taiwan
| | - Shi-Ying Huang
- Center for Neuroscience, National Sun Yat-Sen University, Kaohsiung, Taiwan.,College of Oceanology and Food Science, Quanzhou Normal University, Quanzhou, China
| | - Nan-Fu Chen
- Division of Neurosurgery, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Wu-Fu Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan.,Division of Neurosurgery, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chih-Shung Wong
- Department of Anesthesiology, Cathay General Hospital, Taipei, Taiwan
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30
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Amyloid-beta peptide decreases expression and function of glutamate transporters in nervous system cells. Int J Biochem Cell Biol 2017; 85:75-84. [DOI: 10.1016/j.biocel.2017.01.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/26/2016] [Accepted: 01/29/2017] [Indexed: 12/26/2022]
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31
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Yadav R, Weng HR. EZH2 regulates spinal neuroinflammation in rats with neuropathic pain. Neuroscience 2017; 349:106-117. [PMID: 28257897 DOI: 10.1016/j.neuroscience.2017.02.041] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 02/08/2017] [Accepted: 02/17/2017] [Indexed: 01/10/2023]
Abstract
Alteration in gene expression along the pain signaling pathway is a key mechanism contributing to the genesis of neuropathic pain. Accumulating studies have shown that epigenetic regulation plays a crucial role in nociceptive process in the spinal dorsal horn. In this present study, we investigated the role of enhancer of zeste homolog-2 (EZH2), a subunit of the polycomb repressive complex 2, in the spinal dorsal horn in the genesis of neuropathic pain in rats induced by partial sciatic nerve ligation. EZH2 is a histone methyltransferase, which catalyzes the methylation of histone H3 on K27 (H3K27), resulting in gene silencing. We found that levels of EZH2 and tri-methylated H3K27 (H3K27TM) in the spinal dorsal horn were increased in rats with neuropathic pain on day 3 and day 10 post nerve injuries. EZH2 was predominantly expressed in neurons in the spinal dorsal horn under normal conditions. The number of neurons with EZH2 expression was increased after nerve injury. More strikingly, nerve injury drastically increased the number of microglia with EZH2 expression by more than sevenfold. Intrathecal injection of the EZH2 inhibitor attenuated the development and maintenance of mechanical and thermal hyperalgesia in rats with nerve injury. Such analgesic effects were concurrently associated with the reduced levels of EZH2, H3K27TM, Iba1, GFAP, TNF-α, IL-1β, and MCP-1 in the spinal dorsal horn in rats with nerve injury. Our results highly suggest that targeting the EZH2 signaling pathway could be an effective approach for the management of neuropathic pain.
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Affiliation(s)
- Ruchi Yadav
- Department of Pharmaceutical and Biomedical Sciences, the University of Georgia, USA
| | - Han-Rong Weng
- Department of Pharmaceutical and Biomedical Sciences, the University of Georgia, USA.
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32
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Yang H, Meijer HGE, Buitenweg JR, van Gils SA. Estimation and Identifiability of Model Parameters in Human Nociceptive Processing Using Yes-No Detection Responses to Electrocutaneous Stimulation. Front Psychol 2016; 7:1884. [PMID: 27994563 PMCID: PMC5136566 DOI: 10.3389/fpsyg.2016.01884] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 11/15/2016] [Indexed: 12/29/2022] Open
Abstract
Healthy or pathological states of nociceptive subsystems determine different stimulus-response relations measured from quantitative sensory testing. In turn, stimulus-response measurements may be used to assess these states. In a recently developed computational model, six model parameters characterize activation of nerve endings and spinal neurons. However, both model nonlinearity and limited information in yes-no detection responses to electrocutaneous stimuli challenge to estimate model parameters. Here, we address the question whether and how one can overcome these difficulties for reliable parameter estimation. First, we fit the computational model to experimental stimulus-response pairs by maximizing the likelihood. To evaluate the balance between model fit and complexity, i.e., the number of model parameters, we evaluate the Bayesian Information Criterion. We find that the computational model is better than a conventional logistic model regarding the balance. Second, our theoretical analysis suggests to vary the pulse width among applied stimuli as a necessary condition to prevent structural non-identifiability. In addition, the numerically implemented profile likelihood approach reveals structural and practical non-identifiability. Our model-based approach with integration of psychophysical measurements can be useful for a reliable assessment of states of the nociceptive system.
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Affiliation(s)
- Huan Yang
- Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente Enschede, Netherlands
| | - Hil G E Meijer
- Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente Enschede, Netherlands
| | - Jan R Buitenweg
- Biomedical Signals and Systems, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente Enschede, Netherlands
| | - Stephan A van Gils
- Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente Enschede, Netherlands
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33
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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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34
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Dodds KN, Beckett EAH, Evans SF, Grace PM, Watkins LR, Hutchinson MR. Glial contributions to visceral pain: implications for disease etiology and the female predominance of persistent pain. Transl Psychiatry 2016; 6:e888. [PMID: 27622932 PMCID: PMC5048206 DOI: 10.1038/tp.2016.168] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/14/2016] [Accepted: 07/22/2016] [Indexed: 12/27/2022] Open
Abstract
In the central nervous system, bidirectional signaling between glial cells and neurons ('neuroimmune communication') facilitates the development of persistent pain. Spinal glia can contribute to heightened pain states by a prolonged release of neurokine signals that sensitize adjacent centrally projecting neurons. Although many persistent pain conditions are disproportionately common in females, whether specific neuroimmune mechanisms lead to this increased susceptibility remains unclear. This review summarizes the major known contributions of glia and neuroimmune interactions in pain, which has been determined principally in male rodents and in the context of somatic pain conditions. It is then postulated that studying neuroimmune interactions involved in pain attributed to visceral diseases common to females may offer a more suitable avenue for investigating unique mechanisms involved in female pain. Further, we discuss the potential for primed spinal glia and subsequent neurogenic inflammation as a contributing factor in the development of peripheral inflammation, therefore, representing a predisposing factor for females in developing a high percentage of such persistent pain conditions.
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Affiliation(s)
- K N Dodds
- Discipline of Physiology, School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - E A H Beckett
- Discipline of Physiology, School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - S F Evans
- Discipline of Pharmacology, School of Medicine, University of Adelaide, Adelaide, SA, Australia
- Pelvic Pain SA, Norwood, SA, Australia
| | - P M Grace
- Discipline of Pharmacology, School of Medicine, University of Adelaide, Adelaide, SA, Australia
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - L R Watkins
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - M R Hutchinson
- Discipline of Physiology, School of Medicine, University of Adelaide, Adelaide, SA, Australia
- ARC Centre of Excellence for Nanoscale BioPhotonics, University of Adelaide, Adelaide, SA, Australia
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Bettio LEB, Gil-Mohapel J, Rodrigues ALS. Guanosine and its role in neuropathologies. Purinergic Signal 2016; 12:411-26. [PMID: 27002712 PMCID: PMC5023624 DOI: 10.1007/s11302-016-9509-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/08/2016] [Indexed: 02/08/2023] Open
Abstract
Guanosine is a purine nucleoside thought to have neuroprotective properties. It is released in the brain under physiological conditions and even more during pathological events, reducing neuroinflammation, oxidative stress, and excitotoxicity, as well as exerting trophic effects in neuronal and glial cells. In agreement, guanosine was shown to be protective in several in vitro and/or in vivo experimental models of central nervous system (CNS) diseases including ischemic stroke, Alzheimer's disease, Parkinson's disease, spinal cord injury, nociception, and depression. The mechanisms underlying the neurobiological properties of guanosine seem to involve the activation of several intracellular signaling pathways and a close interaction with the adenosinergic system, with a consequent stimulation of neuroprotective and regenerative processes in the CNS. Within this context, the present review will provide an overview of the current literature on the effects of guanosine in the CNS. The elucidation of the complex signaling events underlying the biochemical and cellular effects of this nucleoside may further establish guanosine as a potential therapeutic target for the treatment of several neuropathologies.
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Affiliation(s)
- Luis E B Bettio
- Department of Biochemistry, Center of Biological Sciences, Federal University of Santa Catarina, 88040-900, Florianópolis, SC, Brazil
- Division of Medical Sciences and UBC Island Medical Program, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - Joana Gil-Mohapel
- Division of Medical Sciences and UBC Island Medical Program, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - Ana Lúcia S Rodrigues
- Department of Biochemistry, Center of Biological Sciences, Federal University of Santa Catarina, 88040-900, Florianópolis, SC, Brazil.
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Yang H, Meijer HGE, Doll RJ, Buitenweg JR, van Gils SA. Dependence of Nociceptive Detection Thresholds on Physiological Parameters and Capsaicin-Induced Neuroplasticity: A Computational Study. Front Comput Neurosci 2016; 10:49. [PMID: 27252644 PMCID: PMC4879143 DOI: 10.3389/fncom.2016.00049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 05/06/2016] [Indexed: 01/10/2023] Open
Abstract
Physiological properties of peripheral and central nociceptive subsystems can be altered over time due to medical interventions. The effective change for the whole nociceptive system can be reflected in changes of psychophysical characteristics, e.g., detection thresholds. However, it is challenging to separate contributions of distinct altered mechanisms with measurements of thresholds only. Here, we aim to understand how these alterations affect Aδ-fiber-mediated nociceptive detection of electrocutaneous stimuli. First, with a neurophysiology-based model, we study the effects of single-model parameters on detection thresholds. Second, we derive an expression of model parameters determining the functional relationship between detection thresholds and the interpulse interval for double-pulse stimuli. Third, in a case study with topical capsaicin treatment, we translate neuroplasticity into plausible changes of model parameters. Model simulations qualitatively agree with changes in experimental detection thresholds. The simulations with individual forms of neuroplasticity confirm that nerve degeneration is the dominant mechanism for capsaicin-induced increases in detection thresholds. In addition, our study suggests that capsaicin-induced central plasticity may last at least 1 month.
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Affiliation(s)
- Huan Yang
- Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of TwenteEnschede, Netherlands
| | - Hil G. E. Meijer
- Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of TwenteEnschede, Netherlands
| | - Robert J. Doll
- Biomedical Signals and Systems, MIRA Institute for Technical Medicine and Biomedical Technology, University of TwenteEnschede, Netherlands
| | - Jan R. Buitenweg
- Biomedical Signals and Systems, MIRA Institute for Technical Medicine and Biomedical Technology, University of TwenteEnschede, Netherlands
| | - Stephan A. van Gils
- Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of TwenteEnschede, Netherlands
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Zeng J, Cui LY, Feng Y, Ding MX. Electroacupuncture relieves neuropathic pain via upregulation of glutamate transporters in the spinal cord of rats. Neurosci Lett 2016; 620:38-42. [DOI: 10.1016/j.neulet.2016.03.041] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/16/2016] [Accepted: 03/23/2016] [Indexed: 10/22/2022]
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Giardini ME, Zippo AG, Valente M, Krstajic N, Biella GEM. Electrophysiological and Anatomical Correlates of Spinal Cord Optical Coherence Tomography. PLoS One 2016; 11:e0152539. [PMID: 27050096 PMCID: PMC4822845 DOI: 10.1371/journal.pone.0152539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 03/15/2016] [Indexed: 11/19/2022] Open
Abstract
Despite the continuous improvement in medical imaging technology, visualizing the spinal cord poses severe problems due to structural or incidental causes, such as small access space and motion artifacts. In addition, positional guidance on the spinal cord is not commonly available during surgery, with the exception of neuronavigation techniques based on static pre-surgical data and of radiation-based methods, such as fluoroscopy. A fast, bedside, intraoperative real-time imaging, particularly necessary during the positioning of endoscopic probes or tools, is an unsolved issue. The objective of our work, performed on experimental rats, is to demonstrate potential intraoperative spinal cord imaging and probe guidance by optical coherence tomography (OCT). Concurrently, we aimed to demonstrate that the electromagnetic OCT irradiation exerted no particular effect at the neuronal and synaptic levels. OCT is a user-friendly, low-cost and endoscopy-compatible photonics-based imaging technique. In particular, by using a Fourier-domain OCT imager, operating at 850 nm wavelength and scanning transversally with respect to the spinal cord, we have been able to: 1) accurately image tissue structures in an animal model (muscle, spine bone, cerebro-spinal fluid, dura mater and spinal cord), and 2) identify the position of a recording microelectrode approaching and inserting into the cord tissue 3) check that the infrared radiation has no actual effect on the electrophysiological activity of spinal neurons. The technique, potentially extendable to full three-dimensional image reconstruction, shows prospective further application not only in endoscopic intraoperative analyses and for probe insertion guidance, but also in emergency and adverse situations (e.g. after trauma) for damage recognition, diagnosis and fast image-guided intervention.
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Affiliation(s)
- Mario E. Giardini
- Department of Biomedical Engineering, University of Strathclyde, Wolfson Centre, 106 Rottenrow, Glasgow G4 0NW, United Kingdom
| | - Antonio G. Zippo
- Institute of Molecular Bioimaging and Physiology, National Research Council (CNR), Via Fratelli Cervi 93, 20090 Segrate (Milan), Italy
| | - Maurizio Valente
- Institute of Molecular Bioimaging and Physiology, National Research Council (CNR), Via Fratelli Cervi 93, 20090 Segrate (Milan), Italy
| | - Nikola Krstajic
- CMOS Sensors Group, Integrated Micro & Nano Systems, School of Engineering, University of Edinburgh, The King's Buildings, Edinburgh EH9 3JL, United Kingdom
| | - Gabriele E. M. Biella
- Institute of Molecular Bioimaging and Physiology, National Research Council (CNR), Via Fratelli Cervi 93, 20090 Segrate (Milan), Italy
- * E-mail:
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Maixner DW, Yan X, Hooks SB, Weng HR. AMPKα1 knockout enhances nociceptive behaviors and spinal glutamatergic synaptic activities via production of reactive oxygen species in the spinal dorsal horn. Neuroscience 2016; 326:158-169. [PMID: 27058143 DOI: 10.1016/j.neuroscience.2016.03.061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 03/25/2016] [Accepted: 03/28/2016] [Indexed: 12/15/2022]
Abstract
Emerging studies have shown that pharmacological activation of adenosine monophosphate-activated protein kinase (AMPK) produces potent analgesic effects in different animal pain models. Currently, the spinal molecular and synaptic mechanism by which AMPK regulates the pain signaling system remains unclear. To address this issue, we utilized the Cre-LoxP system to conditionally knockout the AMPKα1 gene in the nervous system of mice. We demonstrated that AMPKα1 is imperative for maintaining normal nociception, and mice deficient for AMPKα1 exhibit mechanical allodynia. This is concomitantly associated with increased glutamatergic synaptic activities in neurons located in the superficial spinal dorsal horn, which results from the increased glutamate release from presynaptic terminals and function of ligand-gated glutamate receptors at the postsynaptic neurons. Additionally, AMPKα1 knockout mice have increased activities of extracellular signal-regulated kinases (ERK) and p38 mitogen-activated protein kinases (p38), as well as elevated levels of interleukin-1β (IL-1β), reactive oxygen species (ROS), and heme oxygenase 1 (HO-1) in the spinal dorsal horn. Systemic administration of a non-specific ROS scavenger (phenyl-N-tert-butylnitrone, PBN) or a HO-1 activator (Cobalt protoporphyrin IX, CoPP) attenuated allodynia in AMPKα1 knockout mice. Bath-perfusion of the ROS scavenger or HO-1 activator effectively attenuated the increased ROS levels and glutamatergic synaptic activities in the spinal dorsal horn. Our findings suggest that ROS are the key down-stream signaling molecules mediating the behavioral hypersensitivity in AMPKα1 knockout mice. Thus, targeting AMPKα1 may represent an effective approach for the treatment of pathological pain conditions associated with neuroinflammation at the spinal dorsal horn.
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Affiliation(s)
- Dylan W Maixner
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia 30602, USA
| | - Xisheng Yan
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia 30602, USA.,Department of Cardiovascular Medicine, The Third Hospital of Wuhan, Wuhan 430074, Hubei Province, China.,Department of Endocrinology and Metabolism, Shanghai Tenth People's hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Shelley B Hooks
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia 30602, USA
| | - Han-Rong Weng
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, Athens, Georgia 30602, USA
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Cui L, Ding Y, Zeng J, Feng Y, Li M, Ding M. Spinal Glutamate Transporters Are Involved in the Development of Electroacupuncture Tolerance. Int J Mol Sci 2016; 17:357. [PMID: 26978348 PMCID: PMC4813218 DOI: 10.3390/ijms17030357] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 02/28/2016] [Accepted: 03/04/2016] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Electroacupuncture (EA) tolerance is a gradual decline in EA antinociception because of its repeated or prolonged use. This study aims to explore the role of spinal glutamate transporters (GTs) in EA tolerance (EAT). METHODS Rats were treated with EA once per day for eight consecutive days, and their L4-5 spinal cords were collected at days 0, 2, 4, 6 and 8. The levels of three spinal GTs and their mRNAs were detected with Western blot and pPCR, respectively. Then, riluzole, a positive GT regulator, was administered intrathecally in order to observe its effect on EA analgesia after repeated EA. RESULTS The expression levels of the spinal GTs increased at days 2 and 4, and gradually decreased as the times of EA increased. At day 8, no difference was observed in the spinal GTs between the sham treatment and the EA treatment. Intrathecal administration of riluzole dose-dependently attenuated the decreased EA analgesia. CONCLUSION These results indicated the participation of the spinal GTs in EAT.
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Affiliation(s)
- Luying Cui
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Yi Ding
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Jie Zeng
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Yan Feng
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Meng Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Mingxing Ding
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
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Liu B, Liu X, Tang SJ. Interactions of Opioids and HIV Infection in the Pathogenesis of Chronic Pain. Front Microbiol 2016; 7:103. [PMID: 26903982 PMCID: PMC4748029 DOI: 10.3389/fmicb.2016.00103] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 01/19/2016] [Indexed: 12/30/2022] Open
Abstract
Over 50% of HIV-1/AIDS patients suffer chronic pain. Currently, opioids are the cornerstone medications for treating severe pain in these patients. Ironically, emerging clinical data indicates that repeated use of opiate pain medicines might in fact heighten the chronic pain states in HIV patients. Both laboratory-based and clinical studies strongly suggest that opioids exacerbate the detrimental effects of HIV-1 infection on the nervous system, both on neurons and glia. The combination of opioids and HIV-1infection may promote the damage of neurons, including those in the pain sensory and transmission pathway, by activating both caspase-dependent and caspase-independent pro-apoptotic pathways. In addition, the opiate-HIV-1 interaction may also cause widespread disturbance of glial function and elicit glial-derived pro-inflammatory responses that dysregulate neuronal function. The deregulation of neuron-glia cross-talk that occurs with the combination of HIV-1 and opioids appears to play an important role in the development of the pathological pain state. In this article, we wish to provide an overview of the potential molecular and cellular mechanisms by which opioids may interact with HIV-1 to cause neurological problems, especially in the context of HIV-associated pathological pain. Elucidating the underlying mechanisms will help researchers and clinicians to understand how chronic use of opioids for analgesia enhances HIV-associated pain. It will also assist in optimizing therapeutic approaches to prevent or minimize this significant side effect of opiate analgesics in pain management for HIV patients.
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Affiliation(s)
- Bolong Liu
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, GalvestonTX, USA; Department of Urology, Third Affiliated Hospital of Sun Yat-Sen UniversityGuangzhou, China
| | - Xin Liu
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston TX, USA
| | - Shao-Jun Tang
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston TX, USA
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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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Yang H, Meijer HGE, Doll RJ, Buitenweg JR, van Gils SA. Computational modeling of Adelta-fiber-mediated nociceptive detection of electrocutaneous stimulation. BIOLOGICAL CYBERNETICS 2015; 109:479-91. [PMID: 26228799 PMCID: PMC4572082 DOI: 10.1007/s00422-015-0656-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 07/10/2015] [Indexed: 06/01/2023]
Abstract
Sensitization is an example of malfunctioning of the nociceptive pathway in either the peripheral or central nervous system. Using quantitative sensory testing, one can only infer sensitization, but not determine the defective subsystem. The states of the subsystems may be characterized using computational modeling together with experimental data. Here, we develop a neurophysiologically plausible model replicating experimental observations from a psychophysical human subject study. We study the effects of single temporal stimulus parameters on detection thresholds corresponding to a 0.5 detection probability. To model peripheral activation and central processing, we adapt a stochastic drift-diffusion model and a probabilistic hazard model to our experimental setting without reaction times. We retain six lumped parameters in both models characterizing peripheral and central mechanisms. Both models have similar psychophysical functions, but the hazard model is computationally more efficient. The model-based effects of temporal stimulus parameters on detection thresholds are consistent with those from human subject data.
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Affiliation(s)
- Huan Yang
- Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
| | - Hil G E Meijer
- Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Robert J Doll
- Biomedical Signals and Systems, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Jan R Buitenweg
- Biomedical Signals and Systems, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Stephan A van Gils
- Applied Analysis, MIRA Institute for Technical Medicine and Biomedical Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
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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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Paclitaxel induces acute pain via directly activating toll like receptor 4. Mol Pain 2015; 11:10. [PMID: 25868824 PMCID: PMC4363343 DOI: 10.1186/s12990-015-0005-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/10/2015] [Indexed: 01/01/2023] Open
Abstract
Paclitaxel, a powerful anti-neoplastic drug, often causes pathological pain, which significantly reduces the quality of life in patients. Paclitaxel-induced pain includes pain that occurs immediately after paclitaxel treatment (paclitaxel-associated acute pain syndrome, P-APS) and pain that persists for weeks to years after cessation of paclitaxel treatment (paclitaxel induced chronic neuropathic pain). Mechanisms underlying P-APS remain unknown. In this study, we found that paclitaxel causes acute pain in rodents in a dose-dependent manner. The paclitaxel-induced acute pain occurs within 2 hrs after a single intravenous injection of paclitaxel. This is accompanied by low levels of paclitaxel penetrating into the cerebral spinal fluid and spinal dorsal horn. We demonstrated that an intrathecal injection of paclitaxel induces mechanical allodynia in a dose-dependent manner. Paclitaxel causes activation of toll like receptor 4 (TLR4) in the spinal dorsal horn and dorsal root ganglions. Through activating TLR4, paclitaxel increases glutamatergic synaptic activities and reduces glial glutamate transporter activities in the dorsal horn. Activations of TLR4 are necessary in the genesis of paclitaxel-induced acute pain. The cellular and molecular signaling pathways revealed in this study could provide rationales for the development of analgesics and management strategies for P-APS in patients.
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Yang KY, Mun JH, Park KD, Kim MJ, Ju JS, Kim ST, Bae YC, Ahn DK. Blockade of spinal glutamate recycling produces paradoxical antinociception in rats with orofacial inflammatory pain. Prog Neuropsychopharmacol Biol Psychiatry 2015; 57:100-9. [PMID: 25445477 DOI: 10.1016/j.pnpbp.2014.10.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 10/06/2014] [Accepted: 10/20/2014] [Indexed: 01/06/2023]
Abstract
In our current study, we investigated the role of spinal glutamate recycling in the development of orofacial inflammatory pain. DL-threo-β-benzyloxyaspartate (TBOA) or methionine sulfoximine (MSO) was administered intracisternally to block spinal glutamate transporter and glutamine synthetase activity in astroglia. Intracisternal administration of high dose TBOA (10 μg) produced thermal hyperalgesia in naïve rats but significantly attenuated the thermal hyperalgesia in rats that had been pretreated with interleukin (IL)-1β or Complete Freund's Adjuvant (CFA). In contrast, intracisternal injection of MSO produced anti-hyperalgesic effects against thermal stimuli in CFA-treated rats only. To confirm the paradoxical antinociceptive effects of TBOA and MSO, we examined changes in c-Fos expression in the medullary dorsal horn produced by thermal stimulation in naïve, IL-1β-, or CFA-treated rats, after intracisternal injections of TBOA and MSO. Intracisternal administration of TBOA significantly increased c-Fos immunoreactivity in naïve rats. In contrast, intracisternal administration of TBOA significantly decreased the up-regulation of c-Fos immunoreactivity in the medullary dorsal horn of IL-1β- and CFA-treated rats. However, intracisternal injection of MSO blocked the up-regulation of c-Fos immunoreactivity in CFA-treated rats only. We also investigated the effects of botulinum toxin type A (BoNT-A) on TBOA-induced paradoxical antinociception in CFA-treated rats, as BoNT-A inhibits the release of neurotransmitters, including glutamate. BoNT-A treatment reversed behavioral responses produced by intracisternal administration of TBOA in CFA-treated rats. These results suggest that the paradoxical responses produced by blocking glutamate transporters under inflammatory pain conditions are mediated by the modulation of glutamate release from presynaptic terminals. Moreover, blockade of glutamate reuptake could represent a new therapeutic target for the treatment of chronic inflammatory pain conditions.
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Affiliation(s)
- Kui Y Yang
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, South Korea.
| | - Jun H Mun
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, South Korea.
| | - Ki D Park
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, South Korea.
| | - Min J Kim
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, South Korea.
| | - Jin S Ju
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, South Korea.
| | - Seong T Kim
- Department of Orofacial Pain and Oral Medicine, School of Dentistry, Yonsei University, Seoul, South Korea.
| | - Yong C Bae
- Oral Anatomy, School of Dentistry, Kyungpook National University, Daegu, South Korea.
| | - Dong K Ahn
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, South Korea.
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Stephens RL. Glutamate transporter activators as anti-nociceptive agents. Eurasian J Med 2015; 43:182-5. [PMID: 25610189 DOI: 10.5152/eajm.2011.39] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 11/23/2011] [Indexed: 12/21/2022] Open
Abstract
The effective management of chronic pain remains enigmatic. There is a paucity of effective mechanistically-based approaches employed. Chronic visceral pain is a particularly difficult subcategory to manage. Glutamate is the most predominant excitatory neurotransmitter and mediates many aspects of sensory function including acute and chronic pain. There is a growing literature describing the efficacy of physiologically dominant glutamate transporter GLT-1 up-regulation in attenuating chronic visceral and somatic nociception. Since glutamate is the major excitatory neurotransmitter released in the first central synapse of the pain-transmitting afferent neurons, augmentation of GLT-1 activity, which reduces extracellular levels of glutamate, may be an important target for pain management strategies. This review summarizes studies in our laboratory and others which highlight findings that GLT-1 up-regulation by transgenic, pharmacologic and viral transfection approaches attenuate a host of nociceptive responses emanating from visceral or somatic sources in animal models. The study also outlines the future work that will be required to ascertain the translational potential of this approach.
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Affiliation(s)
- Robert L Stephens
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio, USA
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48
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Yan X, Jiang E, Weng HR. Activation of toll like receptor 4 attenuates GABA synthesis and postsynaptic GABA receptor activities in the spinal dorsal horn via releasing interleukin-1 beta. J Neuroinflammation 2015; 12:222. [PMID: 25571780 PMCID: PMC4302431 DOI: 10.1186/s12974-014-0222-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/13/2014] [Indexed: 12/26/2022] Open
Abstract
Toll like receptor 4 (TLR4) is an innate immune pattern recognition receptor, expressed predominantly on microglia in the CNS. Activation of spinal TLR4 plays a critical role in the genesis of pathological pain induced by nerve injury, bone cancer, and tissue inflammation. Currently, it remains unknown how synaptic activities in the spinal dorsal horn are regulated by TLR4 receptors. Through recording GABAergic currents in neurons and glial glutamate transporter currents in astrocytes in rodent spinal slices, we determined whether and how TLR4 modulates GABAergic synaptic activities in the superficial spinal dorsal horn. We found that activation of TLR4 by lipopolysaccharide (LPS) reduces GABAergic synaptic activities through both presynaptic and postsynaptic mechanisms. Specifically, LPS causes the release of IL-1β from microglia. IL-1β in turn suppresses GABA receptor activities at the postsynaptic site through activating protein kinase C (PKC) in neurons. GABA synthesis at the presynaptic site is reduced upon activation of TLR4. Glial glutamate transporter activities are suppressed by IL-1β and PKC activation induced by LPS. The suppression of glial glutamate transporter activities leads to a deficiency of glutamine supply, which results in an attenuation of the glutamate-glutamine cycle-dependent GABA synthesis. These findings shed light on understanding synaptic plasticity induced by activation of TLR4 under neuroinflammation and identify GABA receptors, glial glutamate transporters, IL-1β and PKC as therapeutic targets to abrogate abnormal neuronal activities following activation of TLR4 in pathological pain conditions.
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Affiliation(s)
- Xisheng Yan
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, 240 West Green Street, Athens, GA, 30602, USA. .,Department of Pain Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA. .,Department of Cardiovascular Medicine, the Third Hospital of Wuhan, Wuhan, Hubei Province, China.
| | - Enshe Jiang
- Department of Pain Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA. .,Institute of Public Hygiene, Henan University Nursing School, Kaifeng, China.
| | - Han-Rong Weng
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, 240 West Green Street, Athens, GA, 30602, USA. .,Department of Pain Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
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49
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Old EA, Clark AK, Malcangio M. The role of glia in the spinal cord in neuropathic and inflammatory pain. Handb Exp Pharmacol 2015; 227:145-170. [PMID: 25846618 DOI: 10.1007/978-3-662-46450-2_8] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Chronic pain, both inflammatory and neuropathic, is a debilitating condition in which the pain experience persists after the painful stimulus has resolved. The efficacy of current treatment strategies using opioids, NSAIDS and anticonvulsants is limited by the extensive side effects observed in patients, underlining the necessity for novel therapeutic targets. Preclinical models of chronic pain have recently provided evidence for a critical role played by glial cells in the mechanisms underlying the chronicity of pain, both at the site of damage in the periphery and in the dorsal horn of the spinal cord. Here microglia and astrocytes respond to the increased input from the periphery and change morphology, increase in number and release pro-nociceptive mediators such as ATP, cytokines and chemokines. These gliotransmitters can sensitise neurons by activation of their cognate receptors thereby contributing to central sensitization which is fundamental for the generation of allodynia, hyperalgesia and spontaneous pain.
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Affiliation(s)
- Elizabeth Amy Old
- Wolfson Centre for Age Related Diseases, King's College London, London, UK
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50
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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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