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Liu Q, Han J, Zhang X. Peripheral and central pathogenesis of postherpetic neuralgia. Skin Res Technol 2024; 30:e13867. [PMID: 39101621 PMCID: PMC11299165 DOI: 10.1111/srt.13867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Accepted: 06/22/2024] [Indexed: 08/06/2024]
Abstract
BACKGROUND Postherpetic neuralgia (PHN) is a classic chronic condition with multiple signs of peripheral and central neuropathy. Unfortunately, the pathogenesis of PHN is not well defined, limiting clinical treatment and disease management. OBJECTIVE To describe the peripheral and central pathological axes of PHN, including peripheral nerve injury, inflammation induction, central nervous system sensitization, and brain functional and structural network activity. METHODS A bibliographic survey was carried out, selecting relevant articles that evaluated the characterization of the pathogenesis of PHN, including peripheral and central pathological axes. RESULTS Currently, due to the complexity of the pathophysiological mechanisms of PHN and the incomplete understanding of the exact mechanism of neuralgia. CONCLUSION It is essential to conduct in-depth research to clarify the origins of PHN pathogenesis and explore effective and comprehensive therapies for PHN.
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Affiliation(s)
- Qiuping Liu
- First Teaching Hospital of Tianjin University of Traditional Chinese MedicineTianjinChina
- National Clinical Research Center for Chinese Medicine Acupuncture and MoxibustionTianjinChina
- Department of Rheumatology and ImmunologyFirst Affiliated Hospital of Army Medical UniversityChongqingChina
| | - Jingxian Han
- First Teaching Hospital of Tianjin University of Traditional Chinese MedicineTianjinChina
- National Clinical Research Center for Chinese Medicine Acupuncture and MoxibustionTianjinChina
| | - Xuezhu Zhang
- First Teaching Hospital of Tianjin University of Traditional Chinese MedicineTianjinChina
- National Clinical Research Center for Chinese Medicine Acupuncture and MoxibustionTianjinChina
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2
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Su Y, Verkhratsky A, Yi C. Targeting connexins: possible game changer in managing neuropathic pain? Trends Mol Med 2024; 30:642-659. [PMID: 38594094 DOI: 10.1016/j.molmed.2024.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/08/2024] [Accepted: 03/18/2024] [Indexed: 04/11/2024]
Abstract
Neuropathic pain is a chronic debilitating condition caused by nerve injury or a variety of diseases. At the core of neuropathic pain lies the aberrant neuronal excitability in the peripheral and/or central nervous system (PNS and CNS). Enhanced connexin expression and abnormal activation of connexin-assembled gap junctional channels are prominent in neuropathic pain along with reactive gliosis, contributing to neuronal hypersensitivity and hyperexcitability. In this review, we delve into the current understanding of how connexin expression and function contribute to the pathogenesis and pathophysiology of neuropathic pain and argue for connexins as potential therapeutic targets for neuropathic pain management.
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Affiliation(s)
- Yixun Su
- Research Centre, Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK; Achucarro Center for Neuroscience, IKERBASQUE, Bilbao, Spain; Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania; Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
| | - Chenju Yi
- Research Centre, Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China; Guangdong Provincial Key Laboratory of Brain Function and Disease, Guangzhou, China; Shenzhen Key Laboratory of Chinese Medicine Active substance screening and Translational Research, Shenzhen, China.
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3
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He L, Ma S, Ding Z, Huang Z, Zhang Y, Xi C, Zou K, Deng Q, Huang WJM, Guo Q, Huang C. Inhibition of NFAT5-Dependent Astrocyte Swelling Alleviates Neuropathic Pain. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2302916. [PMID: 38195869 PMCID: PMC10953562 DOI: 10.1002/advs.202302916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 12/03/2023] [Indexed: 01/11/2024]
Abstract
Astrocyte swelling is implicated in various neurological disorders. However, whether astrocyte swelling contributes to neuropathic pain remains elusive. This study elucidates the pivotal role of the nuclear factor of activated T-cells 5 (NFAT5) emerges as a master regulator of astrocyte swelling in the spinal dorsal horn (SDH) during neuropathic pain. Despite the ubiquitous expression of NFAT5 protein in SDH cell types, it selectively induces swelling specifically in astrocytes, not in microglia. Mechanistically, NFAT5 directly controls the expression of the water channel aquaporin-4 (AQP4), a key regulator exclusive to astrocytes. Additionally, aurora kinase B (AURKB) orchestrates NFAT5 phosphorylation, enhancing its protein stability and nuclear translocation, thereby regulating AQP4 expression. The findings establish NFAT5 as a crucial regulator for neuropathic pain through the modulation of astrocyte swelling. The AURKB-NFAT5-AQP4 pathway in astrocytes emerges as a potential therapeutic target to combat neuropathic pain.
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Affiliation(s)
- Liqiong He
- Department of AnesthesiologyXiangya HospitalCentral South UniversityChangsha410008China
| | - Shengyun Ma
- Department of Cellular and Molecular MedicineUniversity of California San DiegoSan DiegoCA92093USA
| | - Zijin Ding
- Department of AnesthesiologyXiangya HospitalCentral South UniversityChangsha410008China
| | - Zhifeng Huang
- Department of AnesthesiologyXiangya HospitalCentral South UniversityChangsha410008China
| | - Yu Zhang
- Department of AnesthesiologyXiangya HospitalCentral South UniversityChangsha410008China
| | - Caiyun Xi
- Department of AnesthesiologyXiangya HospitalCentral South UniversityChangsha410008China
| | - Kailu Zou
- Department of AnesthesiologyXiangya HospitalCentral South UniversityChangsha410008China
| | - Qingwei Deng
- Department of AnesthesiologyXiangya HospitalCentral South UniversityChangsha410008China
| | - Wendy Jia Men Huang
- Department of Cellular and Molecular MedicineUniversity of California San DiegoSan DiegoCA92093USA
| | - Qulian Guo
- Department of AnesthesiologyXiangya HospitalCentral South UniversityChangsha410008China
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangsha410008China
| | - Changsheng Huang
- Department of AnesthesiologyXiangya HospitalCentral South UniversityChangsha410008China
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangsha410008China
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4
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Khir NAM, Noh ASM, Long I, Zakaria R, Ismail CAN. Recent progress on anti-nociceptive effects of carbon monoxide releasing molecule-2 (CORM-2). Mol Cell Biochem 2024; 479:539-552. [PMID: 37106243 DOI: 10.1007/s11010-023-04749-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023]
Abstract
The role of carbon monoxide (CO) has evolved albeit controversial disputes on its toxicity. This biological gasotransmitter participates in the endogenous regulation of neurotransmitters and neuropeptides released in the nervous system. Exogenous CO gas inhalation at a lower concentration has been the subject of investigations, which have revealed its biological homeostatic mechanisms and protective effects against many pathological conditions. This therapeutic procedure of CO is, however, limited due to its immediate release, which favours haemoglobin at a high affinity with the subsequent generation of toxic carboxyhaemoglobin in tissues. In order to address this problem, carbon monoxide releasing molecule-2 (CORM-2) or also known as tricarbonyldichlororuthenium II dimer is developed to liberate a controlled amount of CO in the biological systems. In this review, we examine several potential mechanisms exerted by this therapeutic compound to produce the anti-nociceptive effect that has been demonstrated in previous studies. This review could shed light on the role of CORM-2 to reduce pain, especially in cases of chronic and neuropathic pain.
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Affiliation(s)
- Nurul Ajilah Mohamed Khir
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia
- International Medical School, Management and Science University, 40100, Shah Alam, Selangor, Malaysia
| | - Ain' Sabreena Mohd Noh
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia
| | - Idris Long
- Biomedicine Programme, School of Health Sciences, Universiti Sains Malaysia Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia
| | - Rahimah Zakaria
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia
| | - Che Aishah Nazariah Ismail
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia.
- Brain and Behaviour Cluster, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia.
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5
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Zhang D, Hua Z, Li Z. The role of glutamate and glutamine metabolism and related transporters in nerve cells. CNS Neurosci Ther 2024; 30:e14617. [PMID: 38358002 PMCID: PMC10867874 DOI: 10.1111/cns.14617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/15/2023] [Accepted: 01/10/2024] [Indexed: 02/16/2024] Open
Abstract
BACKGROUND Glutamate and glutamine are the most abundant amino acids in the blood and play a crucial role in cell survival in the nervous system. Various transporters found in cell and mitochondrial membranes, such as the solute carriers (SLCs) superfamily, are responsible for maintaining the balance of glutamate and glutamine in the synaptic cleft and within cells. This balance affects the metabolism of glutamate and glutamine as non-essential amino acids. AIMS This review aims to provide an overview of the transporters and enzymes associated with glutamate and glutamine in neuronal cells. DISCUSSION We delve into the function of glutamate and glutamine in the nervous system by discussing the transporters involved in the glutamate-glutamine cycle and the key enzymes responsible for their mutual conversion. Additionally, we highlight the role of glutamate and glutamine as carbon and nitrogen donors, as well as their significance as precursors for the synthesis of reduced glutathione (GSH). CONCLUSION Glutamate and glutamine play a crucial role in the brain due to their special effects. It is essential to focus on understanding glutamate and glutamine metabolism to comprehend the physiological behavior of nerve cells and to treat nervous system disorders and cancer.
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Affiliation(s)
- Dongyang Zhang
- Department of PediatricsShengjing Hospital of China Medical UniversityShenyangLiaoningChina
- Medical Research Center, Liaoning Key Laboratory of Research and Application of Animal Models for Environment and Metabolic DiseasesShengjing Hospital of China Medical UniversityShenyangLiaoningChina
| | - Zhongyan Hua
- Department of PediatricsShengjing Hospital of China Medical UniversityShenyangLiaoningChina
- Medical Research Center, Liaoning Key Laboratory of Research and Application of Animal Models for Environment and Metabolic DiseasesShengjing Hospital of China Medical UniversityShenyangLiaoningChina
| | - Zhijie Li
- Department of PediatricsShengjing Hospital of China Medical UniversityShenyangLiaoningChina
- Medical Research Center, Liaoning Key Laboratory of Research and Application of Animal Models for Environment and Metabolic DiseasesShengjing Hospital of China Medical UniversityShenyangLiaoningChina
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6
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McAllister BB, Stokes-Heck S, Harding EK, van den Hoogen NJ, Trang T. Targeting Pannexin-1 Channels: Addressing the 'Gap' in Chronic Pain. CNS Drugs 2024; 38:77-91. [PMID: 38353876 DOI: 10.1007/s40263-024-01061-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/07/2024] [Indexed: 02/22/2024]
Abstract
Chronic pain complicates many diseases and is notoriously difficult to treat. In search of new therapeutic targets, pannexin-1 (Panx1) channels have sparked intense interest as a key mechanism involved in a variety of chronic pain conditions. Panx1 channels are transmembrane proteins that release ions and small molecules, such as adenosine triphosphate (ATP). They are expressed along important nodes of the pain pathway, modulating activity of diverse cell types implicated in the development and progression of chronic pain caused by injury or pathology. This review highlights advances that have unlocked the core structure and machinery controlling Panx1 function with a focus on understanding and treating chronic pain.
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Affiliation(s)
- Brendan B McAllister
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Sierra Stokes-Heck
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Erika K Harding
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Nynke J van den Hoogen
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Tuan Trang
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.
- Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada.
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7
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Rivera-Villaseñor A, Higinio-Rodríguez F, López-Hidalgo M. Astrocytes in Pain Perception: A Systems Neuroscience Approach. ADVANCES IN NEUROBIOLOGY 2024; 39:193-212. [PMID: 39190076 DOI: 10.1007/978-3-031-64839-7_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
Astrocytes play an active role in the function of the brain integrating neuronal activity and regulating back neuronal dynamic. They have recently emerged as active contributors of brain's emergent properties such as perceptions. Here, we analyzed the role of astrocytes in pain perception from the lens of systems neuroscience, and we do this by analyzing how astrocytes encode nociceptive information within brain processing areas and how they are key regulators of the internal state that determines pain perception. Specifically, we discuss the dynamic interactions between astrocytes and neuromodulators, such as noradrenaline, highlighting their role in shaping the level of activation of the neuronal ensemble, thereby influencing the experience of pain. Also, we will discuss the possible implications of an "Astro-NeuroMatrix" in the integration of pain across sensory, affective, and cognitive dimensions of pain perception.
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Affiliation(s)
- Angélica Rivera-Villaseñor
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico
| | - Frida Higinio-Rodríguez
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico
| | - Mónica López-Hidalgo
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico.
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8
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Li Y, Acosta FM, Jiang JX. Gap Junctions or Hemichannel-Dependent and Independent Roles of Connexins in Fibrosis, Epithelial-Mesenchymal Transitions, and Wound Healing. Biomolecules 2023; 13:1796. [PMID: 38136665 PMCID: PMC10742173 DOI: 10.3390/biom13121796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/09/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Fibrosis initially appears as a normal response to damage, where activated fibroblasts produce large amounts of the extracellular matrix (ECM) during the wound healing process to assist in the repair of injured tissue. However, the excessive accumulation of the ECM, unresolved by remodeling mechanisms, leads to organ dysfunction. Connexins, a family of transmembrane channel proteins, are widely recognized for their major roles in fibrosis, the epithelial-mesenchymal transition (EMT), and wound healing. Efforts have been made in recent years to identify novel mediators and targets for this regulation. Connexins form gap junctions and hemichannels, mediating communications between neighboring cells and inside and outside of cells, respectively. Recent evidence suggests that connexins, beyond forming channels, possess channel-independent functions in fibrosis, the EMT, and wound healing. One crucial channel-independent function is their role as the primary functional component for cell adhesion. Other channel-independent functions of connexins involve their roles in mitochondria and exosomes. This review summarizes the latest advances in the channel-dependent and independent roles of connexins in fibrosis, the EMT, and wound healing, with a particular focus on eye diseases, emphasizing their potential as novel, promising therapeutic targets.
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Affiliation(s)
- Yuting Li
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
- Department of Pathology, Basic Medical School, Ningxia Medical University, Yinchuan 750004, China
| | - Francisca M. Acosta
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
| | - Jean X. Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
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9
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Morales-Soto W, Gonzales J, Jackson WF, Gulbransen BD. Enteric glia promote visceral hypersensitivity during inflammation through intercellular signaling with gut nociceptors. Sci Signal 2023; 16:eadg1668. [PMID: 37988454 PMCID: PMC10733972 DOI: 10.1126/scisignal.adg1668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 10/17/2023] [Indexed: 11/23/2023]
Abstract
Inflammation in the intestines causes abdominal pain that is challenging to manage. The terminals of sensory neurons innervating the gut are surrounded by glia. Here, using a mouse model of acute colitis, we found that enteric glia contribute to visceral pain by secreting factors that sensitized sensory nerves innervating the gut in response to inflammation. Acute colitis induced a transient increase in the production of proinflammatory cytokines in the intestines of male and female mice. Of these, IL-1β was produced in part by glia and augmented the opening of the intercellular communication hemichannel connexin-43 in glia, which made normally innocuous stimuli painful in female mice. Chemogenetic glial activation paired with calcium imaging in nerve terminals demonstrated that glia sensitized gut-innervating nociceptors only under inflammatory conditions. This inflammatory, glial-driven visceral hypersensitivity involved an increased abundance of the enzyme COX-2 in glia, resulting in greater production and release of prostaglandin E2 that activated EP4 receptors on sensory nerve terminals. Blocking EP4 receptors reduced nociceptor sensitivity in response to glial stimulation in tissue samples from colitis-model mice, and impairing glial connexin-43 reduced visceral hypersensitivity induced by IL-1β in female mice. The findings suggest that therapies targeting enteric glial-neuron signaling might alleviate visceral pain caused by inflammatory disorders.
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Affiliation(s)
- Wilmarie Morales-Soto
- Department of Physiology, Neuroscience Program, Michigan State University, East Lansing, MI, 48824 USA
| | - Jacques Gonzales
- Department of Physiology, Neuroscience Program, Michigan State University, East Lansing, MI, 48824 USA
| | - William F. Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, 48824 USA
| | - Brian D. Gulbransen
- Department of Physiology, Neuroscience Program, Michigan State University, East Lansing, MI, 48824 USA
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Fu B, Jiang J, Huang Y. The analgesic effects of dezocine in rats with chronic constriction injuries. Exp Anim 2023; 72:496-504. [PMID: 37331802 PMCID: PMC10658089 DOI: 10.1538/expanim.23-0036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/01/2023] [Indexed: 06/20/2023] Open
Abstract
Neuropathic pain (NP) is caused by diseases or dysfunction of nervous system and has a considerable negative impact on patients' quality of life. Opioid analgesics can be used for NP treatment. However, the effect of dezocine on NC remains unknown. In this study, we aimed to investigate the analgesic and intestinal effects of various doses of dezocine in rats with chronic constriction injuries (CCI). 100 rats were equally divided into 5 groups: the low (D1 group), medium (D2 group), and high (D3 group) doses of dezocine, and sham operation and model groups. The effects of dezocine on pain, analgesic effect, pain response, and tension and contraction frequencies of intestinal smooth muscles were assessed. With an increase in the dezocine dosage, the cumulative pain scores of rats decreased and analgesic effect significantly increased; mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) improved in varying degrees. The expression of the NP-related proteins glial fibrillary acidic protein (GFAP) and connexin 43 (Cx43) was also improved by dezocine treatment. The results of western blot and ELISA showed that IL-6, and monocyte chemotactic protein-1 (MCP-1) levels also decreased significantly with an increase in the dezocine dose, indicated that dezocine alleviated the inflammatory microenvironment. The dezocine exhibited no significant effect on the tension or contraction frequencies of intestinal smooth muscles of rats. In conclusion, the analgesic effect of dezocine on rats with CCI is dose-dependent and has little effect on the tension or contraction frequencies of intestinal smooth muscles. Our research proved the analgesic effect of dezocine in rats with CCI, and provided further insights into new therapies for NP treatment.
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Affiliation(s)
- Baojun Fu
- Department of Anesthesiology, Sixth affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, No. 21 Yinquan South Road, Qingcheng District, Qingyuan, Guangdong Province 511518, P.R. China
| | - Jingjing Jiang
- Department of Anesthesiology, Sixth affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, No. 21 Yinquan South Road, Qingcheng District, Qingyuan, Guangdong Province 511518, P.R. China
| | - Yuqiong Huang
- Department of Anesthesiology, Sixth affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, No. 21 Yinquan South Road, Qingcheng District, Qingyuan, Guangdong Province 511518, P.R. China
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Alhadlaq MW, Masocha W. Microglia and p38 MAPK Inhibitors Suppress Development of Mechanical Allodynia in Both Sexes in a Mouse Model of Antiretroviral-Induced Neuropathic Pain. Int J Mol Sci 2023; 24:12805. [PMID: 37628987 PMCID: PMC10454318 DOI: 10.3390/ijms241612805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Microglia activation in the spinal cord play a major role in the pathogenesis of neuropathic pain. The p38 mitogen-activated protein kinase (MAPK) regulates microglia activation. Previously, 2',3'-dideoxycytidine (ddC), a nucleoside reverse transcriptase inhibitor (NRTI), was found to induce mechanical allodynia and microglia activation in the spinal cords of male and female mice. In this study, we investigated the role of spinal microglia and p38 MAPK signaling in the development of mechanical allodynia using immunofluorescence staining and treatment with microglia and p38 MAPK inhibitors in both sexes. Male and female mice (BALB/c strain) treated intraperitoneally once daily with ddC 25 mg/kg for five consecutive days developed mechanical allodynia, assessed using the dynamic plantar aesthesiometer. Treatment with ddC increased microglia markers CD11b and ionized calcium-binding adapter molecule 1 (Iba1) staining intensity in male mice, while only CD11b was increased in female mice. Both sexes had increased phosphorylated p38 MAPK staining intensity. The administration of minocycline, an inhibitor of microglia activation, and adezmapimod, a selective p38 MAPK inhibitor, suppressed mechanical allodynia in both sexes at day 7 after ddC treatment. Therefore, microglia activation and p38 MAPK signaling are important for the development of antiretroviral drug-induced mechanical allodynia.
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Affiliation(s)
- Maryam W. Alhadlaq
- Molecular Biology Program, College of Graduate Studies, Kuwait University, Safat, Kuwait City 13110, Kuwait;
- Department of Pharmacology and Therapeutics, College of Pharmacy, Kuwait University, Safat, Kuwait City 13110, Kuwait
| | - Willias Masocha
- Department of Pharmacology and Therapeutics, College of Pharmacy, Kuwait University, Safat, Kuwait City 13110, Kuwait
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12
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Nabhan AB. Pathophysiology, Clinical Implications and Management of Orofacial Neuropathic Pain- with special attention to Trigeminal neuralgia: A Narrative Review. BIOMEDICAL AND PHARMACOLOGY JOURNAL 2023; 16:835-846. [DOI: 10.13005/bpj/2666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Background: It is a widely held belief that if the trigeminal nerve is damaged, the victim would experience agonising and unrelenting external pain. A lesion to the trigeminal nerve may have a wide-reaching effect, such as on one side of the face in particular, or it might have a more localised effect, such as on some or all of your gums. The risk of damage increases the likelihood that it will be difficult to speak and swallow. This nerve provides sensation to a part of your face that may be constantly aching or tingling for some people. However, the trigeminal nerve injury-related persistent orofacial pain might be brought on by a wide variety of unknown triggers. Aim: In this study investigate the clinical manifestations of chronic orofacial pain brought on by a damage to the trigeminal nerve, as well as the diagnostic and therapeutic approaches available to treat this condition. Methodology Through the use of search phrases such as "Trigeminal nerve injury," "Trigeminal ganglion," "Trigeminal spinal subnucleus caudalis," "Craniofacial pain," "Oral prognosis," and "treatment," the computerised databases for the last twenty years have been investigated. There are now two hundred objects in total that have been accumulated. There have been around fifty of them that are pertinent to the discussion that is going on in this work. Majority of the patients fair enough with the pharmacology treatment/drugs like the carbamazepine & oxcarbazepine which forms the first line treatment options followed by lamotrigine & baclofen encompassing the second line of drugs along with adjuvant drug support of topiramate, levetiracetam, gabapentin, pregabalin. As the field of science has explored &advanced for the latest treatment options include microvascular decompression, gamma knife radiosurgery, percutaneous rhizotomies variable based on the evidences & guidelines 54 Conclusion: New diagnostic criteria and treatment alternatives have become available for people who suffer from trigeminal neuropathy and orofacial neuropathic pain as a result of recent developments in fundamental animal research that have led to their development. Despite the results, more research needs to investigate a greater variety of distinct non-neuronal cell feature approaches.
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Affiliation(s)
- Abdullah Bin Nabhan
- Oral Medicine and Orofacial Pain, College of Dentistry, Prince Sattam Bin Abdulaziz University, Al Kharj, Riyadh, Saudi Arabia
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13
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Prokhorenko MA, Smyth JT. Astrocyte store-operated calcium entry is required for centrally mediated neuropathic pain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.08.544231. [PMID: 37333230 PMCID: PMC10274864 DOI: 10.1101/2023.06.08.544231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Central sensitization is a critical step in chronic neuropathic pain formation following acute nerve injury. Central sensitization is defined by nociceptive and somatosensory circuitry changes in the spinal cord leading to dysfunction of antinociceptive gamma-aminobutyric acid (GABA)ergic cells (Li et al., 2019), amplification of ascending nociceptive signals, and hypersensitivity (Woolf, 2011). Astrocytes are key mediators of the neurocircuitry changes that underlie central sensitization and neuropathic pain, and astrocytes respond to and regulate neuronal function through complex Ca2+ signaling mechanisms. Clear definition of the astrocyte Ca2+ signaling mechanisms involved in central sensitization may lead to new therapeutic targets for treatment of chronic neuropathic pain, as well as enhance our understanding of the complex central nervous system (CNS) adaptions that occur following nerve injury. Ca2+ release from astrocyte endoplasmic reticulum (ER) Ca2+ stores via the inositol 1,4,5-trisphosphate receptor (IP3R) is required for centrally mediated neuropathic pain (Kim et al, 2016); however recent evidence suggests the involvement of additional astrocyte Ca2+ signaling mechanisms. We therefore investigated the role of astrocyte store-operated Ca2+ entry (SOCE), which mediates Ca2+ influx in response to ER Ca2+ store depletion. Using an adult Drosophila melanogaster model of central sensitization based on thermal allodynia in response to leg amputation nerve injury (Khuong et al., 2019), we show that astrocytes exhibit SOCE-dependent Ca2+ signaling events three to four days following nerve injury. Astrocyte-specific suppression of Stim and Orai, the key mediators of SOCE Ca2+ influx, completely inhibited the development of thermal allodynia seven days following injury, and also inhibited the loss of ventral nerve cord (VNC) GABAergic neurons that is required for central sensitization in flies. We lastly show that constitutive SOCE in astrocytes results in thermal allodynia even in the absence of nerve injury. Our results collectively demonstrate that astrocyte SOCE is necessary and sufficient for central sensitization and development of hypersensitivity in Drosophila, adding key new understanding to the astrocyte Ca2+ signaling mechanisms involved in chronic pain.
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Affiliation(s)
- Mariya A. Prokhorenko
- Neuroscience Graduate Program and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD
| | - Jeremy T. Smyth
- Neuroscience Graduate Program and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD
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Breitinger U, Breitinger HG. Excitatory and inhibitory neuronal signaling in inflammatory and diabetic neuropathic pain. Mol Med 2023; 29:53. [PMID: 37069517 PMCID: PMC10111846 DOI: 10.1186/s10020-023-00647-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 03/27/2023] [Indexed: 04/19/2023] Open
Abstract
Pain, although unpleasant, is an essential warning mechanism against injury and damage of the organism. An intricate network of specialised sensors and transmission systems contributes to reception, transmission and central sensitization of pain. Here, we briefly introduce some of the main aspects of pain signal transmission, including nociceptors and nociceptive signals, mechanisms of inflammatory and neuropathic pain, and the situation of diabetes-associated neuropathic pain. The role of glia-astrocytes, microglia, satellite glia cells-and their specific channels, transporters and signaling pathways is described. A focus is on the contribution of inhibitory synaptic signaling to nociception and a possible role of glycine receptors in glucose-mediated analgesia and treatment-induced diabetic neuropathy. Inhibitory receptors such as GABAA- and glycine receptors are important contributors to nociceptive signaling; their contribution to altered pain sensation in diabetes may be of clinical relevance, and they could be promising therapeutic targets towards the development of novel analgesics.
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Affiliation(s)
- Ulrike Breitinger
- Department of Biochemistry, German University in Cairo, New Cairo, 11835, Egypt
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15
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Fabbri R, Spennato D, Conte G, Konstantoulaki A, Lazzarini C, Saracino E, Nicchia GP, Frigeri A, Zamboni R, Spray DC, Benfenati V. The emerging science of Glioception: Contribution of glia in sensing, transduction, circuit integration of interoception. Pharmacol Ther 2023; 245:108403. [PMID: 37024060 DOI: 10.1016/j.pharmthera.2023.108403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/08/2023]
Abstract
Interoception is the process by which the nervous system regulates internal functions to achieve homeostasis. The role of neurons in interoception has received considerable recent attention, but glial cells also contribute. Glial cells can sense and transduce signals including osmotic, chemical, and mechanical status of extracellular milieu. Their ability to dynamically communicate "listening" and "talking" to neurons is necessary to monitor and regulate homeostasis and information integration in the nervous system. This review introduces the concept of "Glioception" and focuses on the process by which glial cells sense, interpret and integrate information about the inner state of the organism. Glial cells are ideally positioned to act as sensors and integrators of diverse interoceptive signals and can trigger regulatory responses via modulation of the activity of neuronal networks, both in physiological and pathological conditions. We believe that understanding and manipulating glioceptive processes and underlying molecular mechanisms provide a key path to develop new therapies for the prevention and alleviation of devastating interoceptive dysfunctions, among which pain is emphasized here with more focused details.
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Affiliation(s)
- Roberta Fabbri
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy; Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, viale del Risorgimento 2, 40136 Bologna, Italy.
| | - Diletta Spennato
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy; Department of Bioscience, Biotechnologies and Biopharmaceutics, Centre of Excellence in Comparative Genomics, University of Bari "Aldo Moro", Bari, BA, Italy
| | - Giorgia Conte
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy
| | - Aikaterini Konstantoulaki
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy; Department of Chemistry "Giacomo Ciamician", University of Bologna, Via Selmi, 2, 40126 Bologna, BO, Italy
| | - Chiara Lazzarini
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy
| | - Emanuela Saracino
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy
| | - Grazia Paola Nicchia
- School of Medicine, Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, BA, Italy; Department of Bioscience, Biotechnologies and Biopharmaceutics, Centre of Excellence in Comparative Genomics, University of Bari "Aldo Moro", Bari, BA, Italy
| | - Antonio Frigeri
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Bioscience, Biotechnologies and Biopharmaceutics, Centre of Excellence in Comparative Genomics, University of Bari "Aldo Moro", Bari, BA, Italy
| | - Roberto Zamboni
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Valentina Benfenati
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy.
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Yang Q, Jiang M, Xu S, Yang L, Yang P, Song Y, Zhu H, Wang Y, Sun Y, Yan C, Yuan Z, Liu X, Bai Z. Mirror image pain mediated by D2 receptor regulation of astrocytic Cx43 phosphorylation and channel opening. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166657. [PMID: 36716897 DOI: 10.1016/j.bbadis.2023.166657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/21/2022] [Accepted: 01/20/2023] [Indexed: 01/29/2023]
Abstract
Mirror image pain (MIP), a clinical syndrome of contralateral pain hypersensitivity caused by unilateral injury, has been identified in various neuropathological conditions. Gap junctional protein Connexin 43 (Cx43), its phosphorylation levels and dopamine D2 receptor (DRD2) play key integrating roles in pain processing. We presume D2DR activity may affect Cx43 hemichannel opening via Cx43 phosphorylation levels to regulate MIP. This study shows that spinal astrocytic Cx43 directly interacts with DRD2 to mediate MIP. DRD2 and Cx43 expression levels were asymmetrically elevated in bilateral spinal during MIP, and DRD2 modulated the opening of primary astrocytic Cx43 hemichannels. Furthermore, Cx43 phosphorylation at Ser373 was increased during MIP, but decreased in DRD2 knockout (KO) mice. Finally, activation of spinal protein kinase A (PKA) altered the expression of Cx43 and its phosphorylation bilaterally, thus reversing the analgesic effect in DRD2 KO mice. Together, these data reveal that spinal Cx43 phosphorylation and channel opening are regulated by DRD2 via PKA activation, and that spinal Cx43 and DRD2 are key molecular sensors mediating mirror image pain.
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Affiliation(s)
- Qinghu Yang
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China; Yanan Engineering & Technological Research Centre for Resource Peptide Drugs, Yanan 716000, China; Yanan Key Laboratory for Neural Immuno-Tumor and Stem Cell, Yanan 716000, China
| | - Ming Jiang
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China; Yanan Engineering & Technological Research Centre for Resource Peptide Drugs, Yanan 716000, China; Yanan Key Laboratory for Neural Immuno-Tumor and Stem Cell, Yanan 716000, China
| | - Sen Xu
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China
| | - Liang Yang
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China; Yanan Engineering & Technological Research Centre for Resource Peptide Drugs, Yanan 716000, China; Yanan Key Laboratory for Neural Immuno-Tumor and Stem Cell, Yanan 716000, China
| | - Pan Yang
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China
| | - Yutian Song
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China
| | - Hongni Zhu
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China
| | - Yu Wang
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China
| | - Yahan Sun
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China
| | - Chengxiang Yan
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China
| | - Zhaoyue Yuan
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China
| | - Xia Liu
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China; Yanan Engineering & Technological Research Centre for Resource Peptide Drugs, Yanan 716000, China; Yanan Key Laboratory for Neural Immuno-Tumor and Stem Cell, Yanan 716000, China.
| | - Zhantao Bai
- School of Life Science & Research Center for Natural Peptide Drugs, Shaanxi Engineering & Technological Research Centre for Conservation & Utilization of Regional Biological Resources, Yanan University, Yanan 716000, China; Yanan Engineering & Technological Research Centre for Resource Peptide Drugs, Yanan 716000, China; Yanan Key Laboratory for Neural Immuno-Tumor and Stem Cell, Yanan 716000, China.
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17
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McGinnis A, Ji RR. The Similar and Distinct Roles of Satellite Glial Cells and Spinal Astrocytes in Neuropathic Pain. Cells 2023; 12:965. [PMID: 36980304 PMCID: PMC10047571 DOI: 10.3390/cells12060965] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/19/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Preclinical studies have identified glial cells as pivotal players in the genesis and maintenance of neuropathic pain after nerve injury associated with diabetes, chemotherapy, major surgeries, and virus infections. Satellite glial cells (SGCs) in the dorsal root and trigeminal ganglia of the peripheral nervous system (PNS) and astrocytes in the central nervous system (CNS) express similar molecular markers and are protective under physiological conditions. They also serve similar functions in the genesis and maintenance of neuropathic pain, downregulating some of their homeostatic functions and driving pro-inflammatory neuro-glial interactions in the PNS and CNS, i.e., "gliopathy". However, the role of SGCs in neuropathic pain is not simply as "peripheral astrocytes". We delineate how these peripheral and central glia participate in neuropathic pain by producing different mediators, engaging different parts of neurons, and becoming active at different stages following nerve injury. Finally, we highlight the recent findings that SGCs are enriched with proteins related to fatty acid metabolism and signaling such as Apo-E, FABP7, and LPAR1. Targeting SGCs and astrocytes may lead to novel therapeutics for the treatment of neuropathic pain.
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Affiliation(s)
- Aidan McGinnis
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
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18
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Jiang H, Zhang Y, Wang ZZ, Chen NH. Connexin 43: An Interface Connecting Neuroinflammation to Depression. Molecules 2023; 28:molecules28041820. [PMID: 36838809 PMCID: PMC9961786 DOI: 10.3390/molecules28041820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023] Open
Abstract
Major depressive disorder (MDD) is a leading chronic mental illness worldwide, characterized by anhedonia, pessimism and even suicidal thoughts. Connexin 43 (Cx43), mainly distributed in astrocytes of the brain, is by far the most widely and ubiquitously expressed connexin in almost all vital organs. Cx43 forms gap junction channels in the brain, which mediate energy exchange and effectively maintain physiological homeostasis. Increasing evidence suggests the crucial role of Cx43 in the pathogenesis of MDD. Neuroinflammation is one of the most common pathological features of the central nervous system dysfunctions. Inflammatory factors are abnormally elevated in patients with depression and are closely related to nearly all links of depression. After activating the inflammatory pathway in the brain, the release and uptake of glutamate and adenosine triphosphate, through Cx43 in the synaptic cleft, would be affected. In this review, we have summarized the association between Cx43 and neuroinflammation, the cornerstones linking inflammation and depression, and Cx43 abnormalities in depression. We also discuss the significant association of Cx43 in inflammation and depression, which will help to explore new antidepressant drug targets.
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Affiliation(s)
- Hong Jiang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical, Science and Peking Union Medical College, Beijing 100050, China
| | - Yi Zhang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Zhen-Zhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical, Science and Peking Union Medical College, Beijing 100050, China
- Correspondence: (Z.-Z.W.); (N.-H.C.); Tel.: +86-10-6316-5182 (Z.-Z.W.); +86-10-63165177 (N.-H.C.)
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical, Science and Peking Union Medical College, Beijing 100050, China
- Correspondence: (Z.-Z.W.); (N.-H.C.); Tel.: +86-10-6316-5182 (Z.-Z.W.); +86-10-63165177 (N.-H.C.)
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19
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Chin JS, Milbreta U, Becker DL, Chew SY. Targeting connexin 43 expression via scaffold mediated delivery of antisense oligodeoxynucleotide preserves neurons, enhances axonal extension, reduces astrocyte and microglial activation after spinal cord injury. J Tissue Eng 2023; 14:20417314221145789. [PMID: 36798907 PMCID: PMC9926388 DOI: 10.1177/20417314221145789] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 12/01/2022] [Indexed: 02/12/2023] Open
Abstract
Injury to the central nervous system (CNS) provokes an inflammatory reaction and secondary damage that result in further tissue damage and destruction of neurons away from the injury site. Upon injury, expression of connexin 43 (Cx43), a gap junction protein, upregulates and is responsible for the spread and amplification of cell death signals through these gap junctions. In this study, we hypothesise that the downregulation of Cx43 by scaffold-mediated controlled delivery of antisense oligodeoxynucleotide (asODN), would minimise secondary injuries and cell death, and thereby support tissue regeneration after nerve injuries. Specifically, using spinal cord injury (SCI) as a proof-of-principle, we utilised a fibre-hydrogel scaffold for sustained delivery of Cx43asODN, while providing synergistic topographical cues to guide axonal ingrowth. Correspondingly, scaffolds loaded with Cx43asODN, in the presence of NT-3, suppressed Cx43 up-regulation after complete transection SCI in rats. These scaffolds facilitated the sustained release of Cx43asODN for up to 25 days. Importantly, asODN treatment preserved neurons around the injury site, promoted axonal extension, decreased glial scarring, and reduced microglial activation after SCI. Our results suggest that implantation of such scaffold-mediated asODN delivery platform could serve as an effective alternative SCI therapeutic approach.
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Affiliation(s)
- Jiah Shin Chin
- Nanyang Institute of Health Technologies, Interdisciplinary Graduate School, Nanyang Technological University, Singapore,School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore
| | - Ulla Milbreta
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore
| | - David L Becker
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore,Skin Research Institute Singapore, Clinical Sciences Building, Singapore
| | - Sing Yian Chew
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore,School of Materials Science and Engineering, Nanyang Technological University, Singapore,Sing Yian Chew, School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, 639798, Singapore.
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20
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Xing J, Wang Η, Chen L, Wang H, Huang H, Huang J, Xu C. Blocking Cx43 alleviates neuropathic pain in rats with chronic constriction injury via the P2X4 and P38/ERK-P65 pathways. Int Immunopharmacol 2023; 114:109506. [PMID: 36442284 DOI: 10.1016/j.intimp.2022.109506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
Neuropathic pain is a growing concern in the medical community, and studies on new analgesic targets for neuropathic pain have become a new hot spot. Whether Connexin43 (Cx43) has a key role in neuropathic pain mediated by the purinergic 2X4 (P2X4) receptor in rats with chronic constriction injury (CCI) was explored in this study. Our experimental results show that blockade of Cx43 could attenuate neuropathic pain in rats suffering from CCI via the P2X4, p38, ERK, and NF-kB signalling pathways. These results suggest that Cx43 may be a promising therapeutic target for the development of novel pharmacological agents in the management of neuropathic pain.
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Affiliation(s)
- Juping Xing
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, Jiangxi, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang 330006, Jiangxi, PR China
| | - Ηongji Wang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, Jiangxi, PR China
| | - Lisha Chen
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, Jiangxi, PR China
| | - Hanxi Wang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, Jiangxi, PR China
| | - Huan Huang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, Jiangxi, PR China
| | - Jiabao Huang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, Jiangxi, PR China
| | - Changshui Xu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, Jiangxi, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang 330006, Jiangxi, PR China; The Clinical Medical School, Jiangxi Medical College, Shangrao 334000, Jiangxi, PR China; The First Affiliated Hospital, Jiangxi Medical College, Shangrao 334000, Jiangxi, PR China.
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21
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Xu J, Li P, Lu F, Chen Y, Guo Q, Yang Y. Domino reaction of neurovascular unit in neuropathic pain after spinal cord injury. Exp Neurol 2023; 359:114273. [PMID: 36375510 DOI: 10.1016/j.expneurol.2022.114273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/25/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022]
Abstract
The mechanism of neuropathic pain after spinal cord injury is complex, and the communication between neurons, glia, and blood vessels in neurovascular units significantly affects the occurrence and development of neuropathic pain. After spinal cord injury, a domino chain reaction occurs in the neuron-glia-vessel, which affects the permeability of the blood-spinal cord barrier and jointly promotes the development of neuroinflammation. This article discusses the signal transduction between neuro-glial-endothelial networks from a multidimensional point of view and reviews its role in neuropathic pain after spinal cord injury.
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Affiliation(s)
- Jingmei Xu
- Department of Anesthesiology, Xiangya Hospital, Central South University, 87th Xiangya Road, Kaifu District, Changsha, Hunan, China
| | - Ping Li
- National Clinical Research Center for Geriatric Disorders,Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China; Department of Obstetrics, Xiangya Hospital, Central South University, 87th Xiangya Road, Kaifu District, Changsha, Hunan, China
| | - Feng Lu
- Department of Anesthesiology, First Affiliated Hospital of Gannan medical university, Ganzhou 341000, China
| | - Yulu Chen
- Department of Anesthesiology, Xiangya Hospital, Central South University, 87th Xiangya Road, Kaifu District, Changsha, Hunan, China
| | - Qulian Guo
- Department of Anesthesiology, Xiangya Hospital, Central South University, 87th Xiangya Road, Kaifu District, Changsha, Hunan, China; National Clinical Research Center for Geriatric Disorders,Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China
| | - Yong Yang
- Department of Anesthesiology, Xiangya Hospital, Central South University, 87th Xiangya Road, Kaifu District, Changsha, Hunan, China; National Clinical Research Center for Geriatric Disorders,Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China.
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22
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Astrocytic connexin 43 deletion ameliorates SNI-induced neuropathic pain by reducing microglia activation. Biochem Biophys Res Commun 2023; 638:192-199. [PMID: 36462493 DOI: 10.1016/j.bbrc.2022.11.071] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 10/12/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
Neuropathic pain (NP) is a chronic disease caused by damage to the peripheral or central nervous system. Connexin 43 (Cx43), the primary connexin expressed by astrocytes, has been reported to be significantly increased in NP. However, the roles and mechanisms of Cx43 in the development and maintenance of NP remain largely unknown, while microglia activation has been commonly regarded as a key factor of NP. In the present study, we found that Cx43 deletion significantly ameliorated spared nerve injury (SNI)-induced NP and suppressed SNI induced c-Fos expression in the spinal cord. Notably, Cx43 deletion led to much less SNI-induced microglia activation in the spinal cord. These results suggest that astrocyte Cx43 may play a significant role in regulating microglial activation and NP.
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23
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Connexin 30 Deficiency Ameliorates Disease Progression at the Early Phase in a Mouse Model of Amyotrophic Lateral Sclerosis by Suppressing Glial Inflammation. Int J Mol Sci 2022; 23:ijms232416046. [PMID: 36555685 PMCID: PMC9782489 DOI: 10.3390/ijms232416046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Connexin 30 (Cx30), which forms gap junctions between astrocytes, regulates cell adhesion and migration, and modulates glutamate transport. Cx30 is upregulated on activated astroglia in central nervous system inflammatory lesions, including spinal cord lesions in mutant superoxide dismutase 1 (mSOD1) transgenic amyotrophic lateral sclerosis (ALS) model mice. Here, we investigated the role of Cx30 in mSOD1 mice. Cx30 was highly expressed in the pre-onset stage in mSOD1 mice. mSOD1 mice with knockout (KO) of the Cx30 gene (Cx30KO-mSOD1 mice) showed delayed disease onset and tended to have an extended survival period (log-rank, p = 0.09). At the progressive and end stages of the disease, anterior horn cells were significantly preserved in Cx30KO-mSOD1 mice. In lesions of these mice, glial fibrillary acidic protein/C3-positive inflammatory astroglia were decreased. Additionally, the activation of astrocytes in Cx30KO-mSOD1 mice was reduced compared with mSOD1 mice by gene expression microarray. Furthermore, expression of connexin 43 at the pre-onset stage was downregulated in Cx30KO-mSOD1 mice. These findings suggest that reduced expression of astroglial Cx30 at the early disease stage in ALS model mice protects neurons by attenuating astroglial inflammation.
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Herman-de-Sousa C, Costa MA, Silva RP, Ferreirinha F, Ribeiro S, Correia-de-Sá P. A2A receptor-induced overexpression of pannexin-1 channels indirectly mediates adenosine fibrogenic actions by favouring ATP release from human subcutaneous fibroblasts. Life Sci 2022; 310:121080. [DOI: 10.1016/j.lfs.2022.121080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 10/09/2022] [Accepted: 10/11/2022] [Indexed: 11/09/2022]
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Baracaldo-Santamaría D, Corrales-Hernández MG, Ortiz-Vergara MC, Cormane-Alfaro V, Luque-Bernal RM, Calderon-Ospina CA, Cediel-Becerra JF. Connexins and Pannexins: Important Players in Neurodevelopment, Neurological Diseases, and Potential Therapeutics. Biomedicines 2022; 10:2237. [PMID: 36140338 PMCID: PMC9496069 DOI: 10.3390/biomedicines10092237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
Cell-to-cell communication is essential for proper embryonic development and its dysfunction may lead to disease. Recent research has drawn attention to a new group of molecules called connexins (Cxs) and pannexins (Panxs). Cxs have been described for more than forty years as pivotal regulators of embryogenesis; however, the exact mechanism by which they provide this regulation has not been clearly elucidated. Consequently, Cxs and Panxs have been linked to congenital neurodegenerative diseases such as Charcot-Marie-Tooth disease and, more recently, chronic hemichannel opening has been associated with adult neurodegenerative diseases (e.g., Alzheimer's disease). Cell-to-cell communication via gap junctions formed by hexameric assemblies of Cxs, known as connexons, is believed to be a crucial component in developmental regulation. As for Panxs, despite being topologically similar to Cxs, they predominantly seem to form channels connecting the cytoplasm to the extracellular space and, despite recent research into Panx1 (Pannexin 1) expression in different regions of the brain during the embryonic phase, it has been studied to a lesser degree. When it comes to the nervous system, Cxs and Panxs play an important role in early stages of neuronal development with a wide span of action ranging from cellular migration during early stages to neuronal differentiation and system circuitry formation. In this review, we describe the most recent available evidence regarding the molecular and structural aspects of Cx and Panx channels, their role in neurodevelopment, congenital and adult neurological diseases, and finally propose how pharmacological modulation of these channels could modify the pathogenesis of some diseases.
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Affiliation(s)
- Daniela Baracaldo-Santamaría
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - María Gabriela Corrales-Hernández
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Maria Camila Ortiz-Vergara
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Valeria Cormane-Alfaro
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Ricardo-Miguel Luque-Bernal
- Anatomy and Embriology Units, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Carlos-Alberto Calderon-Ospina
- Pharmacology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
- GENIUROS Research Group, Center for Research in Genetics and Genomics (CIGGUR), School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
| | - Juan-Fernando Cediel-Becerra
- Histology and Embryology Unit, Department of Biomedical Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111221, Colombia
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Nakajima N, Ohnishi Y, Yamamoto M, Setoyama D, Imai H, Takenaka T, Matsumoto M, Hosomi K, Saitoh Y, Furue H, Kishima H. Excess intracellular ATP causes neuropathic pain following spinal cord injury. Cell Mol Life Sci 2022; 79:483. [PMID: 35972649 PMCID: PMC11072579 DOI: 10.1007/s00018-022-04510-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/16/2022] [Accepted: 08/01/2022] [Indexed: 11/03/2022]
Abstract
Intractable neuropathic pain following spinal cord injury (NP-SCI) reduces a patient's quality of life. Excessive release of ATP into the extracellular space evokes neuroinflammation via purinergic receptor. Neuroinflammation plays an important role in the initiation and maintenance of NP. However, little is known about whether or not extracellular ATP cause NP-SCI. We found in the present study that excess of intracellular ATP at the lesion site evokes at-level NP-SCI. No significant differences in the body weight, locomotor function, or motor behaviors were found in groups that were negative and positive for at-level allodynia. The intracellular ATP level at the lesion site was significantly higher in the allodynia-positive mice than in the allodynia-negative mice. A metabolome analysis revealed that there were no significant differences in the ATP production or degradation between allodynia-negative and allodynia-positive mice. Dorsal horn neurons in allodynia mice were found to be inactivated in the resting state, suggesting that decreased ATP consumption due to neural inactivity leads to a build-up of intracellular ATP. In contrast to the findings in the resting state, mechanical stimulation increased the neural activity of dorsal horn and extracellular ATP release at lesion site. The forced production of intracellular ATP at the lesion site in non-allodynia mice induced allodynia. The inhibition of P2X4 receptors in allodynia mice reduced allodynia. These results suggest that an excess buildup of intracellular ATP in the resting state causes at-level NP-SCI as a result of the extracellular release of ATP with mechanical stimulation.
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Affiliation(s)
- Nobuhiko Nakajima
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yuichiro Ohnishi
- Department of Research Promotion and Management, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita, Osaka, 564-8565, Japan.
- Department of Neurosurgery, Osaka Gyoumeikan Hospital, Osaka, Japan.
| | - Masamichi Yamamoto
- Department of Research Promotion and Management, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita, Osaka, 564-8565, Japan.
| | - Daiki Setoyama
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hirohiko Imai
- Department of Systems Science, Graduate School of Informatics, Kyoto University, Kyoto, Japan
| | - Tomofumi Takenaka
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Mari Matsumoto
- Department of Research Promotion and Management, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita, Osaka, 564-8565, Japan
| | - Koichi Hosomi
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan
- Department of Neuromodulation and Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yoichi Saitoh
- Department of Neuromodulation and Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Hidemasa Furue
- Department of Neurophysiology, Hyogo College of Medicine, Hyogo, Japan
| | - Haruhiko Kishima
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan
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Lu Y, Li B, Xu A, Liang X, Xu T, Jin H, Xie Y, Wang R, Liu X, Gao X, Han Y, Zeng J. NF-κB and AP-1 are required for the lipopolysaccharide-induced expression of MCP-1, CXCL1, and Cx43 in cultured rat dorsal spinal cord astrocytes. Front Mol Neurosci 2022; 15:859558. [PMID: 35966011 PMCID: PMC9368326 DOI: 10.3389/fnmol.2022.859558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 06/28/2022] [Indexed: 11/13/2022] Open
Abstract
TLR4 and Cx43 signaling in dorsal spinal cord has been shown to be involved in the development of neuropathic pain. However, it is not clear whether TLR4 signaling is associated with the expression of MCP-1, CXCL1, and Cx43 in LPS (lipopolysaccharide)-treated rat dorsal spinal cord astrocytes under in vitro condition. In the present study, we found that TLR4 antagonist TAK-242 significantly inhibited LPS-induced MCP-1, CXCL1, and Cx43 expression, suggesting the role of TLR4 in response to LPS in cultured dorsal spinal cord astrocytes. Application of TAK-242 significantly blocked LPS-induced NF-κB and AP-1 activity and the expression of MCP-1, CXCL1 and Cx43. Furthermore, NF-κB inhibitor PDTC and AP-1 inhibitor SR11302 significantly blocked LPS-induced MCP-1, CXCL1, and Cx43 expression. DNA-binding activity of NF-κB, its effect on MCP-1 expression was suppressed by PDTC and SR11302. On the other hand, DNA-binding activity of AP-1, its effect on CXCL1 or Cx43 expression was also suppressed by PDTC and SR11302. In addition, PDTC was found to inhibit the nuclear translocation of AP-1 and the expression of c-Jun induced by LPS, which suggested that NF-κBp65 is essential for the AP-1 activity. Similarly, SR11302 significantly blocked LPS-induced the nuclear translocation of NF-κBp65 and the expression of NF-κBp65 induced by LPS. Pretreatment with CBX, Gap26, or Gap19 (Cx43 blockers) significantly inhibited abnormal astrocytic hemichannel opening and chemokines (MCP-1 and CXCL1) release in LPS-stimulated astrocytes. In summary, cell culture experiments revealed that LPS stimulation could evoke TLR4 signaling with the subsequent activation of NF-κB and AP-1, resulting in the expression of MCP-1, CXCL1, and Cx43. TLR4 activation increased Cx43 hemichannel, but not gap-junction activities and induced the release of the MCP-1 and CXCL1 from astrocytes via Cx43 hemichannel. These findings may help us to understand the role of astrocytic signaling in inflammatory response within dorsal spinal cord tissue.
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CXCR4/CX43 Regulate Diabetic Neuropathic Pain via Intercellular Interactions between Activated Neurons and Dysfunctional Astrocytes during Late Phase of Diabetes in Rats and the Effects of Antioxidant N-Acetyl-L-Cysteine. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:8547563. [PMID: 35799894 PMCID: PMC9256426 DOI: 10.1155/2022/8547563] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 06/15/2022] [Indexed: 12/12/2022]
Abstract
Growing evidence suggests that the interactions between astrocytes and neurons exert important functions in the central sensitization of the spinal cord dorsal horn in rodents with diabetes and neuropathic pain (DNP). However, it still remains unclear how signal transmission occurs in the spinal cord dorsal horn between astrocytes and neurons, especially in subjects with DNP. Chemokine CXC receptor 4 (CXCR4) plays critical roles in DNP, and connexin 43 (CX43), which is also primarily expressed by astrocytes, contributes to the development of neuropathy. We thus postulated that astrocytic and neuronal CXCR4 induces and produces inflammatory factors under persistent peripheral noxious stimulation in DNP, while intercellular CX43 can transmit inflammatory stimulation signals. The results showed that streptozotocin-induced type 1 diabetic rats developed heat hyperalgesia and mechanical allodynia. Diabetes led to persistent neuropathic pain. Diabetic rats developed peripheral sensitization at the early phase (2 weeks) and central sensitization at the late phase (5 weeks) after diabetes induction. Both CXCR4 and CX43, which are localized and coexpressed in neurons and astrocytes, were enhanced significantly in the dorsal horn of spinal cord in rats undergoing DNP during late phase of diabetes, and the CXCR4 antagonist AMD3100 reduced the expression of CX43. The nociceptive behavior was reversed, respectively, by AMD3100 at the early phase and by the antioxidant N-acetyl-L-cysteine (NAC) at the late phase. Furthermore, rats with DNP demonstrated downregulation of glial fibrillary acidic protein (GFAP) as well as upregulation of c-fos in the spinal cord dorsal horn at the late phase compared to the controls, and upregulation of GFAP and downregulation of c-fos were observed upon treatment with NAC. Given that GFAP and c-fos are, respectively, makers of astrocyte and neuronal activation, our findings suggest that CXCR4 as an inflammatory stimulation protein and CX43 as an intercellular signal transmission protein both may induce neurons excitability and astrocytes dysfunction in developing DNP.
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Mulkey DK, Olsen ML, Ou M, Cleary CM, Du G. Putative Roles of Astrocytes in General Anesthesia. Curr Neuropharmacol 2022; 20:5-15. [PMID: 33588730 PMCID: PMC9199541 DOI: 10.2174/1570159x19666210215120755] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/29/2021] [Accepted: 02/06/2021] [Indexed: 02/08/2023] Open
Abstract
General anesthetics are a mainstay of modern medicine, and although much progress has been made towards identifying molecular targets of anesthetics and neural networks contributing to endpoints of general anesthesia, our understanding of how anesthetics work remains unclear. Reducing this knowledge gap is of fundamental importance to prevent unwanted and life-threatening side-effects associated with general anesthesia. General anesthetics are chemically diverse, yet they all have similar behavioral endpoints, and so for decades, research has sought to identify a single underlying mechanism to explain how anesthetics work. However, this effort has given way to the 'multiple target hypothesis' as it has become clear that anesthetics target many cellular proteins, including GABAA receptors, glutamate receptors, voltage-independent K+ channels, and voltagedependent K+, Ca2+ and Na+ channels, to name a few. Yet, despite evidence that astrocytes are capable of modulating multiple aspects of neural function and express many anesthetic target proteins, they have been largely ignored as potential targets of anesthesia. The purpose of this brief review is to highlight the effects of anesthetic on astrocyte processes and identify potential roles of astrocytes in behavioral endpoints of anesthesia (hypnosis, amnesia, analgesia, and immobilization).
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Affiliation(s)
- Daniel K. Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, StorrsCT, USA;,Address correspondence to this author at the Department of Physiology and Neurobiology, University of Connecticut, Storrs CT, USA; E-mail:
| | | | | | - Colin M. Cleary
- Department of Physiology and Neurobiology, University of Connecticut, StorrsCT, USA
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Muñoz MF, Griffith TN, Contreras JE. Mechanisms of ATP release in pain: role of pannexin and connexin channels. Purinergic Signal 2021; 17:549-561. [PMID: 34792743 PMCID: PMC8677853 DOI: 10.1007/s11302-021-09822-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 10/18/2021] [Indexed: 12/21/2022] Open
Abstract
Pain is a physiological response to bodily damage and serves as a warning of potential threat. Pain can also transform from an acute response to noxious stimuli to a chronic condition with notable emotional and psychological components that requires treatment. Indeed, the management of chronic pain is currently an important unmet societal need. Several reports have implicated the release of the neurotransmitter adenosine triphosphate (ATP) and subsequent activation of purinergic receptors in distinct pain etiologies. Purinergic receptors are broadly expressed in peripheral neurons and the spinal cord; thus, purinergic signaling in sensory neurons or in spinal circuits may be critical for pain processing. Nevertheless, an outstanding question remains: what are the mechanisms of ATP release that initiate nociceptive signaling? Connexin and pannexin channels are established conduits of ATP release and have been suggested to play important roles in a variety of pathologies, including several models of pain. As such, these large-pore channels represent a new and exciting putative pharmacological target for pain treatment. Herein, we will review the current evidence for a role of connexin and pannexin channels in ATP release during nociceptive signaling, such as neuropathic and inflammatory pain. Collectively, these studies provide compelling evidence for an important role of connexins and pannexins in pain processing.
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Affiliation(s)
- Manuel F. Muñoz
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, USA
| | - Theanne N. Griffith
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, USA
| | - Jorge E. Contreras
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, USA
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Spinal cord injury in mice impacts central and peripheral pathology in a severity-dependent manner. Pain 2021; 163:1172-1185. [PMID: 34490852 DOI: 10.1097/j.pain.0000000000002471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 08/25/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT Chronic pain is a common medical complication experienced by those living with spinal cord injury (SCI) and leads to worsened quality of life. The pathophysiology of SCI pain is poorly understood, hampering the development of safe and efficacious therapeutics. We therefore sought to develop a clinically relevant model of SCI with a strong pain phenotype and characterize the central and peripheral pathology after injury. A contusion (50 kdyn) injury, with and without sustained compression (60 seconds) of the spinal cord, was carried out on female C57BL/6J mice. Mice with compression of the spinal cord exhibited significantly greater heat and mechanical hypersensitivity starting at 7 days post-injury, concomitant with reduced locomotor function, compared to those without compression. Immunohistochemical analysis of spinal cord tissue revealed significantly less myelin sparing and increased macrophage activation in mice with compression compared to those without. As measured by flow cytometry, immune cell infiltration and activation were significantly greater in the spinal cord (phagocytic myeloid cells and microglia) and dorsal root ganglia (Ly6C+ monocytes) following compression injury. We also decided to investigate the gastrointestinal microbiome, as it has been shown to be altered in SCI patients and has recently been shown to play a role in immune system maturation and pain. We found increased dysbiosis of the gastrointestinal microbiome in an injury severity-dependent manner. The use of this contusion-compression model of SCI may help advance the preclinical assessment of acute and chronic SCI pain and lead to a better understanding of mechanisms contributing to this pain.
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Shinoda M, Imamura Y, Hayashi Y, Noma N, Okada-Ogawa A, Hitomi S, Iwata K. Orofacial Neuropathic Pain-Basic Research and Their Clinical Relevancies. Front Mol Neurosci 2021; 14:691396. [PMID: 34295221 PMCID: PMC8291146 DOI: 10.3389/fnmol.2021.691396] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/21/2021] [Indexed: 01/01/2023] Open
Abstract
Trigeminal nerve injury is known to cause severe persistent pain in the orofacial region. This pain is difficult to diagnose and treat. Recently, many animal studies have reported that rewiring of the peripheral and central nervous systems, non-neuronal cell activation, and up- and down-regulation of various molecules in non-neuronal cells are involved in the development of this pain following trigeminal nerve injury. However, there are many unknown mechanisms underlying the persistent orofacial pain associated with trigeminal nerve injury. In this review, we address recent animal data regarding the involvement of various molecules in the communication of neuronal and non-neuronal cells and examine the possible involvement of ascending pathways in processing pathological orofacial pain. We also address the clinical observations of persistent orofacial pain associated with trigeminal nerve injury and clinical approaches to their diagnosis and treatment.
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Affiliation(s)
- Masamichi Shinoda
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
| | - Yoshiki Imamura
- Department of Oral Diagnostic Sciences, Nihon University School of Dentistry, Tokyo, Japan
| | - Yoshinori Hayashi
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
| | - Noboru Noma
- Department of Oral Diagnostic Sciences, Nihon University School of Dentistry, Tokyo, Japan
| | - Akiko Okada-Ogawa
- Department of Oral Diagnostic Sciences, Nihon University School of Dentistry, Tokyo, Japan
| | - Suzuro Hitomi
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
| | - Koichi Iwata
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
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Carbenoxolone has the potential to ameliorate acute incision pain in rats. Mol Med Rep 2021; 24:520. [PMID: 34013377 PMCID: PMC8160483 DOI: 10.3892/mmr.2021.12159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 01/07/2021] [Indexed: 12/23/2022] Open
Abstract
Carbenoxolone (CBX) is primarily used to relieve various types of neuropathic and inflammatory pain. However, little is known concerning the role of CBX in acute pain and its functional mechanisms therein and this was investigated in the present study. Rats underwent toe incision and behavioral tests were performed to assess mechanical hypersensitivity. The expression levels of pannexin 1 (Px1) and connexin 43 (Cx43) were detected using western blot analysis 2, 4, 6 or 24 h after toe incision, and the expression of TNF-α, IL-1β and P substance (SP) was determined by ELISA; Px1 and Cx43 expression was also examined by immunofluorescence staining. At 2, 6 and 12 h post-toe incision, the postoperative pain threshold was significantly reduced, which was subsequently recovered at 2 and 6 h post-surgery following pretreatment with CBX or pannexin 1 mimetic inhibitory peptide. CBX reduced Px1 levels at 4 and 24 h post-incision. However, Cx43 levels were reduced by CBX as little as 2 h post-surgery. Furthermore, CBX not only distinctly decreased the levels of Px1 and Cx43, but also reduced the co-localization of Px1 or Cx43 with glial fibrillary acidic protein, 2 h after incision. It was also observed that the protein levels of inflammatory makers (IL-1β, SP and TNF-α) showed a tendency to decline at 2, 4, 6 and 24 h after incision. Collectively, the expression of Px1 and Cx43 in astrocytes may be involved in pain behaviors diminished by CBX, and CBX potentially reduces acute pain by decreasing Px1 and Cx43 levels. Px1 and Cx43 from spinal astrocytes may serve important roles in the early stages and maintenance of acute pain, while preoperative injection of CBX has the potential to relieve hyperalgesia.
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Brown EV, Falnikar A, Heinsinger N, Cheng L, Andrews CE, DeMarco M, Lepore AC. Cervical spinal cord injury-induced neuropathic pain in male mice is associated with a persistent pro-inflammatory macrophage/microglial response in the superficial dorsal horn. Exp Neurol 2021; 343:113757. [PMID: 33991526 DOI: 10.1016/j.expneurol.2021.113757] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/03/2021] [Accepted: 05/10/2021] [Indexed: 01/31/2023]
Abstract
A significant portion of individuals living with traumatic spinal cord injury (SCI) experiences some degree of debilitating neuropathic pain (NP). This pain remains largely intractable in a majority of cases, due in part to an incomplete understanding of its underlying mechanisms. Central sensitization, an increase in excitability of pain transmission neurons located in superficial dorsal horn (sDH), plays a key role in development and maintenance of SCI-induced NP. Resident microglia and peripheral monocyte-derived macrophages (referred to collectively as MMΦ) are involved in promoting SCI-induced DH neuron hyperexcitability. Importantly, these MMΦ consist of populations of cells that can exert pro-inflammatory or anti-inflammatory signaling within injured spinal cord. It is critical to spatiotemporally characterize this heterogeneity to understand MMΦ contribution to NP after SCI. Given that a majority of SCI cases are cervical in nature, we used a model of unilateral C5/C6 contusion that results in persistent at-level thermal hyperalgesia and mechanical allodynia, two forms of NP-related behavior, in the forepaw. The aim of this study was to characterize the sDH MMΦ response within intact cervical spinal cord segments caudal to the lesion (i.e. the location of primary afferent nociceptive input from the forepaw plantar surface). Cervical SCI promoted a persistent MMΦ response in sDH that coincided with the chronic NP phenotype. Using markers of pro- and anti-inflammatory MMΦ, we found that the MMΦ population within sDH exhibited significant heterogeneity that evolved over time post-injury, including a robust and persistent increase in pro-inflammatory MMΦ that was especially pronounced at later times. C5/C6 contusion SCI also induced below-level thermal hyperalgesia and mechanical allodynia in the hindpaw; however, we did not observe a pronounced MMΦ response in sDH of L4/L5 spinal cord, suggesting that different inflammatory cell mechanisms occurring in sDH may be involved in at-level versus below-level NP following SCI. In conclusion, our findings reveal significant MMΦ heterogeneity both within and across pain transmission locations after SCI. These data also show a prominent and persistent pro-inflammatory MMΦ response, suggesting a possible role in DH neuron hyperexcitability and NP.
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Affiliation(s)
- Eric V Brown
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Aditi Falnikar
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Nicolette Heinsinger
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Lan Cheng
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Carrie E Andrews
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Michael DeMarco
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States
| | - Angelo C Lepore
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, 233 South 10th Street, BLSB 245, Philadelphia, PA 19107, United States.
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Zheng XS, Zheng H, Xu D, Liu PP, Li B, Cao ZM, Liu Y, Liu Y. Effect of zymosan on the expression and function of the gap-junction protein connexin 43 in human corneal fibroblasts. Int J Ophthalmol 2021; 14:341-348. [PMID: 33747807 DOI: 10.18240/ijo.2021.03.02] [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: 05/18/2020] [Accepted: 11/17/2020] [Indexed: 12/27/2022] Open
Abstract
AIM To study the effect of zymosan, a ligand found on the surface of fungi, on gap junctional intercellular communication (GJIC) in cultured human corneal fibroblasts (HCFs). METHODS Zymosan was added to the medium of cultured HCFs with or without the administration of mitogen-activated protein kinase (MAPK) inhibitors or the inhibitor kappa B kinase 2 (IKK2) inhibitor IV. The protein and mRNA levels of connexin 43 (Cx43) in HCFs were measured by Western blot, immunofluorescence, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses. The GJIC activity was tested using a dye-coupling assay. RESULTS The reduction of Cx43 protein and mRNA levels as well as a significant decrease in GJIC activity were observed in cultured HCFs when zymosan was added into the culture medium. Compared with controls (no zymosan), the protein level of Cx43 was reduced by 45% and 54% in the presence of zymosan at 200 and 600 µg/mL, respectively (P<0.05); and it was reduced by 45%, 48%, and 75% in the presence of zymosan (600 µg/mL) for 24, 36, and 48h, respectively (P<0.05). The mRNA expression of Cx43 was reduced by 98% in the presence of zymosan (P<0.05). The effects of zymosan on Cx43 expression and GJIC activity were attenuated by the administration of PD98059 [an extracellular signal-regulated kinase (ERK) signaling inhibitor] (P<0.05), c-Jun NH2-terminal kinase (JNK) inhibitor II (P<0.05), and IKK2 inhibitor IV (P<0.05). CONCLUSION Zymosan inhibits the activity of GJIC in cultured HCFs. This effect is likely regulated via the nuclear factor-κB (NF-κB), MAPK/ERK, and JNK signaling pathways. The inhibitory effects of zymosan on Cx43 expression and GJIC activity in HCFs may induce damage of corneal stroma during corneal fungal infection.
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Affiliation(s)
- Xiao-Shuo Zheng
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Hui Zheng
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Dan Xu
- Institute of Environmental Systems Biology, Environmental Science and Engineering College, Dalian Maritime University, Dalian 116027, Liaoning Province, China
| | - Ping-Ping Liu
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Bing Li
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Zi-Mu Cao
- Institute of Environmental Systems Biology, Environmental Science and Engineering College, Dalian Maritime University, Dalian 116027, Liaoning Province, China
| | - Yang Liu
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Ye Liu
- Department of Pathology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
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Kronschläger MT, Siegert ASM, Resch FJ, Rajendran PS, Khakh BS, Sandkühler J. Lamina-specific properties of spinal astrocytes. Glia 2021; 69:1749-1766. [PMID: 33694249 PMCID: PMC8252791 DOI: 10.1002/glia.23990] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/19/2022]
Abstract
Astrocytes are indispensable for proper neuronal functioning. Given the diverse needs of neuronal circuits and the variety of tasks astrocytes perform, the perceived homogeneous nature of astrocytes has been questioned. In the spinal dorsal horn, complex neuronal circuitries regulate the integration of sensory information of different modalities. The dorsal horn is organized in a distinct laminar manner based on termination patterns of high‐ and low‐threshold afferent fibers and neuronal properties. Neurons in laminae I (L1) and II (L2) integrate potentially painful, nociceptive information, whereas neurons in lamina III (L3) and deeper laminae integrate innocuous, tactile information from the periphery. Sensory information is also integrated by an uncharacterized network of astrocytes. How these lamina‐specific characteristics of neuronal circuits of the dorsal horn are of functional importance for properties of astrocytes is currently unknown. We addressed if astrocytes in L1, L2, and L3 of the upper dorsal horn of mice are differentially equipped for the needs of neuronal circuits that process sensory information of different modalities. We found that astrocytes in L1 and L2 were characterized by a higher density, higher expression of GFAP, Cx43, and GLAST and a faster coupling speed than astrocytes located in L3. L1 astrocytes were more responsive to Kir4.1 blockade and had higher levels of AQP4 compared to L3 astrocytes. In contrast, basic membrane properties, network formation, and somatic intracellular calcium signaling were similar in L1–L3 astrocytes. Our data indicate that the properties of spinal astrocytes are fine‐tuned for the integration of nociceptive versus tactile information.
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Affiliation(s)
- Mira T Kronschläger
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria.,Department of Physiology, David Geffen Schoof of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Anna S M Siegert
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Felix J Resch
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Pradeep S Rajendran
- UCLA Cardiac Arrhythmia Center, Neurocardiology Research Program of Excellence, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen Schoof of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Jürgen Sandkühler
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
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Midavaine É, Côté J, Marchand S, Sarret P. Glial and neuroimmune cell choreography in sexually dimorphic pain signaling. Neurosci Biobehav Rev 2021; 125:168-192. [PMID: 33582232 DOI: 10.1016/j.neubiorev.2021.01.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/03/2020] [Accepted: 01/25/2021] [Indexed: 12/17/2022]
Abstract
Chronic pain is a major global health issue that affects all populations regardless of sex, age, ethnicity/race, or country of origin, leading to persistent physical and emotional distress and to the loss of patients' autonomy and quality of life. Despite tremendous efforts in the elucidation of the mechanisms contributing to the pathogenesis of chronic pain, the identification of new potential pain targets, and the development of novel analgesics, the pharmacological treatment options available for pain management remain limited, and most novel pain medications have failed to achieve advanced clinical development, leaving many patients with unbearable and undermanaged pain. Sex-specific susceptibility to chronic pain conditions as well as sex differences in pain sensitivity, pain tolerance and analgesic efficacy are increasingly recognized in the literature and have thus prompted scientists to seek mechanistic explanations. Hence, recent findings have highlighted that the signaling mechanisms underlying pain hypersensitivity are sexually dimorphic, which sheds light on the importance of conducting preclinical and clinical pain research on both sexes and of developing sex-specific pain medications. This review thus focuses on the clinical and preclinical evidence supporting the existence of sex differences in pain neurobiology. Attention is drawn to the sexually dimorphic role of glial and immune cells, which are both recognized as key players in neuroglial maladaptive plasticity at the origin of the transition from acute pain to chronic pathological pain. Growing evidence notably attributes to microglial cells a pivotal role in the sexually dimorphic pain phenotype and in the sexually dimorphic analgesic efficacy of opioids. This review also summarizes the recent advances in understanding the pathobiology underpinning the development of pain hypersensitivity in both males and females in different types of pain conditions, with particular emphasis on the mechanistic signaling pathways driving sexually dimorphic pain responses.
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Affiliation(s)
- Élora Midavaine
- Department of Pharmacology-Physiology, Institut de pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du Centre hospitalier universitaire de Sherbrooke, CIUSSS de l'Estrie - CHUS, Sherbrooke, Québec, Canada.
| | - Jérôme Côté
- Department of Pharmacology-Physiology, Institut de pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du Centre hospitalier universitaire de Sherbrooke, CIUSSS de l'Estrie - CHUS, Sherbrooke, Québec, Canada
| | - Serge Marchand
- Department of Pharmacology-Physiology, Institut de pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du Centre hospitalier universitaire de Sherbrooke, CIUSSS de l'Estrie - CHUS, Sherbrooke, Québec, Canada
| | - Philippe Sarret
- Department of Pharmacology-Physiology, Institut de pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du Centre hospitalier universitaire de Sherbrooke, CIUSSS de l'Estrie - CHUS, Sherbrooke, Québec, Canada.
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Bannerman CA, Douchant K, Sheth PM, Ghasemlou N. The gut-brain axis and beyond: Microbiome control of spinal cord injury pain in humans and rodents. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2021; 9:100059. [PMID: 33426367 PMCID: PMC7779861 DOI: 10.1016/j.ynpai.2020.100059] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/26/2020] [Accepted: 12/10/2020] [Indexed: 12/17/2022]
Abstract
Spinal cord injury (SCI) is a devastating injury to the central nervous system in which 60 to 80% of patients experience chronic pain. Unfortunately, this pain is notoriously difficult to treat, with few effective options currently available. Patients are also commonly faced with various compounding injuries and medical challenges, often requiring frequent hospitalization and antibiotic treatment. Change in the gut microbiome from the "normal" state to one of imbalance, referred to as gut dysbiosis, has been found in both patients and rodent models following SCI. Similarities exist in the bacterial changes observed after SCI and other diseases with chronic pain as an outcome. These changes cause a shift in the regulation of inflammation, causing immune cell activation and secretion of inflammatory mediators that likely contribute to the generation/maintenance of SCI pain. Therefore, correcting gut dysbiosis may be used as a tool towards providing patients with effective pain management and improved quality of life.
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Affiliation(s)
- Courtney A. Bannerman
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
| | - Katya Douchant
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
- Gastrointestinal Disease Research Unit, Kingston Health Sciences Center, Kingston, Ontario, Canada
| | - Prameet M. Sheth
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
- Department of Pathology and Molecular Medicine, Queen’s University, Kingston, Ontario, Canada
- Division of Microbiology, Kingston Health Sciences Centre, Kingston, Ontario, Canada
- Gastrointestinal Disease Research Unit, Kingston Health Sciences Center, Kingston, Ontario, Canada
| | - Nader Ghasemlou
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
- Department of Anesthesiology and Perioperative Medicine, Kingston Health Sciences Centre, Kingston, Ontario, Canada
- Centre for Neuroscience Studies, Queen’s University, Kingston, Ontario, Canada
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Li Q, Ma TL, Qiu YQ, Cui WQ, Chen T, Zhang WW, Wang J, Mao-Ying QL, Mi WL, Wang YQ, Chu YX. Connexin 36 Mediates Orofacial Pain Hypersensitivity Through GluK2 and TRPA1. Neurosci Bull 2020; 36:1484-1499. [PMID: 33067780 PMCID: PMC7719140 DOI: 10.1007/s12264-020-00594-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 09/06/2020] [Indexed: 12/15/2022] Open
Abstract
Trigeminal neuralgia is a debilitating condition, and the pain easily spreads to other parts of the face. Here, we established a mouse model of partial transection of the infraorbital nerve (pT-ION) and found that the Connexin 36 (Cx36) inhibitor mefloquine caused greater alleviation of pT-ION-induced cold allodynia compared to the reduction of mechanical allodynia. Mefloquine reversed the pT-ION-induced upregulation of Cx36, glutamate receptor ionotropic kainate 2 (GluK2), transient receptor potential ankyrin 1 (TRPA1), and phosphorylated extracellular signal regulated kinase (p-ERK) in the trigeminal ganglion. Cold allodynia but not mechanical allodynia induced by pT-ION or by virus-mediated overexpression of Cx36 in the trigeminal ganglion was reversed by the GluK2 antagonist NS102, and knocking down Cx36 expression in Nav1.8-expressing nociceptors by injecting virus into the orofacial skin area of Nav1.8-Cre mice attenuated cold allodynia but not mechanical allodynia. In conclusion, we show that Cx36 contributes greatly to the development of orofacial pain hypersensitivity through GluK2, TRPA1, and p-ERK signaling.
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Affiliation(s)
- Qian Li
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China
| | - Tian-Le Ma
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China
| | - You-Qi Qiu
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China
| | - Wen-Qiang Cui
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China
- Department of Pain Management, Shandong Provincial Qianfoshan Hospital, The First Hospital Affiliated with Shandong First Medical University, Jinan, 250000, China
| | - Teng Chen
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China
| | - Wen-Wen Zhang
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China
| | - Jing Wang
- Department of Nephropathy, The Third Affiliated Hospital of Shenzhen University, Luohu Hospital Group, Shenzhen, 518001, China
| | - Qi-Liang Mao-Ying
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China
| | - Wen-Li Mi
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China
| | - Yan-Qing Wang
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China
| | - Yu-Xia Chu
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.
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Kuebart A, Wollborn V, Huhn R, Hermanns H, Werdehausen R, Brandenburger T. Intraneural Application of microRNA-1 Mimetic Nucleotides Does Not Resolve Neuropathic Pain After Chronic Constriction Injury in Rats. J Pain Res 2020; 13:2907-2914. [PMID: 33223847 PMCID: PMC7671483 DOI: 10.2147/jpr.s266937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/14/2020] [Indexed: 11/23/2022] Open
Abstract
Background Alterations of the expression of microRNAs (miRNAs) in chronic pain models seem to play a crucial role in the development of neuropathic pain, with microRNA-1 (miR-1) being of particular interest. Recently, we were able to show that decreased miR-1 levels were associated with increased expression of brain-derived neurotrophic factor (BDNF) and Connexin 43 (Cx43). We hypothesized that miR-1 mimetic nucleotides could alleviate neuropathic pain caused by chronic constriction injury in rats. Methods MiR-1 mimetic nucleotides were evaluated for effectiveness, functionality, and intracellular stability by transfecting human glioblastoma cells (U-87 MG). In vivo transfection with miR-1 mimics and corresponding scrambled miRNAs serving as control was performed by repetitive injection (days 0, 3, and 7) into the sciatic nerve following chronic constriction injury (CCI) in rats. Quantitative PCR was used to measure miR-1 content. Cx43 expression was determined by Western blot analysis. Effects on neuropathic pain were assessed by detecting paw withdrawal thresholds using an automated filament application. Results Transfection of miR-1 mimics was confirmed in U-87 MG cells, with miR-1 content being increased significantly after 48 h and after 96 h (p<0.05). Effective downregulation of Cx43 expression was observed 48 and 96 h after transfection (−44 ± 0.07% and −40 ± 0.11%; p<0.05). In vivo, repetitive transfection with miR-1 mimetic nucleotides led to a 17.9-fold (± 14.2) increase of miR-1 in the sciatic nerve. However, the protein expression of Cx43 in sciatic nerves as well as paw withdrawal thresholds for mechanical stimulation was not significantly increased 10 days after chronic constriction injury. Conclusion While transfection with miR-1 mimics effective reduces Cx43 expression in vitro and restores miR-1 after CCI, we did neither observe altered levels of Cx43 protein level in nerves nor a beneficial effect on mechanical allodynia in vivo, most likely caused by insufficient Cx43 suppression.
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Affiliation(s)
- Anne Kuebart
- Department of Anesthesiology, University Hospital Düsseldorf, Medical Faculty, Düsseldorf 40225, Germany
| | - Verena Wollborn
- Department of Anesthesiology, University Hospital Düsseldorf, Medical Faculty, Düsseldorf 40225, Germany
| | - Ragnar Huhn
- Department of Anesthesiology, University Hospital Düsseldorf, Medical Faculty, Düsseldorf 40225, Germany
| | - Henning Hermanns
- Department of Anesthesiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Robert Werdehausen
- Department of Anesthesiology and Intensive Care, University of Leipzig, Medical Faculty, Leipzig 04103, Germany
| | - Timo Brandenburger
- Department of Anesthesiology, University Hospital Düsseldorf, Medical Faculty, Düsseldorf 40225, Germany
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Abou-Mrad Z, Alomari SO, Bsat S, Moussalem CK, Alok K, El Houshiemy MN, Alomari AO, Minassian GB, Omeis IA. Role of connexins in spinal cord injury: An update. Clin Neurol Neurosurg 2020; 197:106102. [DOI: 10.1016/j.clineuro.2020.106102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/16/2020] [Accepted: 07/18/2020] [Indexed: 01/25/2023]
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Are glia targets for neuropathic orofacial pain therapy? J Am Dent Assoc 2020; 152:774-779. [PMID: 32921390 DOI: 10.1016/j.adaj.2020.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 05/14/2020] [Indexed: 01/06/2023]
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Connexin Hemichannel Mimetic Peptide Attenuates Cortical Interneuron Loss and Perineuronal Net Disruption Following Cerebral Ischemia in Near-Term Fetal Sheep. Int J Mol Sci 2020; 21:ijms21186475. [PMID: 32899855 PMCID: PMC7554896 DOI: 10.3390/ijms21186475] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 12/19/2022] Open
Abstract
Perinatal hypoxia-ischemia is associated with disruption of cortical gamma-aminobutyric acid (GABA)ergic interneurons and their surrounding perineuronal nets, which may contribute to persisting neurological deficits. Blockade of connexin43 hemichannels using a mimetic peptide can alleviate seizures and injury after hypoxia-ischemia. In this study, we tested the hypothesis that connexin43 hemichannel blockade improves the integrity of cortical interneurons and perineuronal nets. Term-equivalent fetal sheep received 30 min of bilateral carotid artery occlusion, recovery for 90 min, followed by a 25-h intracerebroventricular infusion of vehicle or a mimetic peptide that blocks connexin hemichannels or by a sham ischemia + vehicle infusion. Brain tissues were stained for interneuronal markers or perineuronal nets. Cerebral ischemia was associated with loss of cortical interneurons and perineuronal nets. The mimetic peptide infusion reduced loss of glutamic acid decarboxylase-, calretinin-, and parvalbumin-expressing interneurons and perineuronal nets. The interneuron and perineuronal net densities were negatively correlated with total seizure burden after ischemia. These data suggest that the opening of connexin43 hemichannels after perinatal hypoxia-ischemia causes loss of cortical interneurons and perineuronal nets and that this exacerbates seizures. Connexin43 hemichannel blockade may be an effective strategy to attenuate seizures and may improve long-term neurological outcomes after perinatal hypoxia-ischemia.
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Fundamental sex differences in morphine withdrawal-induced neuronal plasticity. Pain 2020; 161:2022-2034. [PMID: 32345917 DOI: 10.1097/j.pain.0000000000001901] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 04/21/2020] [Indexed: 12/25/2022]
Abstract
ABSTRACT Withdrawal from systemic opioids can induce long-term potentiation (LTP) at spinal C-fibre synapses ("opioid-withdrawal-LTP"). This is considered to be a cellular mechanism underlying opioid withdrawal-induced hyperalgesia, which is a major symptom of the opioid withdrawal syndrome. Opioids can activate glial cells leading to the release of proinflammatory mediators. These may influence synaptic plasticity and could thus contribute to opioid-withdrawal-LTP. Here, we report a sexual dimorphism in the mechanisms of morphine-withdrawal-LTP in adult rats. We recorded C-fibre-evoked field potentials in the spinal cord dorsal horn from deeply anaesthetised male and female rats. In both sexes, we induced a robust LTP through withdrawal from systemic morphine infusion (8 mg·kg-1 bolus, followed by a 1-hour infusion at a rate of 14 mg·kg-1·h-1). This paradigm also induced mechanical hypersensitivity of similar magnitude in both sexes. In male rats, systemic but not spinal application of (-)naloxone blocked the induction of morphine-withdrawal-LTP, suggesting the involvement of descending pronociceptive pathways. Furthermore, we showed that in male rats, the induction of morphine-withdrawal-LTP required the activation of spinal astrocytes and the release of the proinflammatory cytokines tumour necrosis factor and interleukin-1. In striking contrast, in female rats, the induction of morphine-withdrawal-LTP was independent of spinal glial cells. Instead, blocking µ-opioid receptors in the spinal cord was sufficient to prevent a facilitation of synaptic strength. Our study revealed fundamental sex differences in the mechanisms underlying morphine-withdrawal-LTP at C-fibre synapses: supraspinal and gliogenic mechanisms in males and a spinal, glial cell-independent mechanism in females.
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Liu J, Li X, Ke A. High-mobility group box-1 induces mechanical pain hypersensitivity through astrocytic connexin 43 via the toll-like receptor-4/JNK signaling pathway. Synapse 2020; 75:e22184. [PMID: 32761652 DOI: 10.1002/syn.22184] [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: 05/29/2020] [Revised: 07/26/2020] [Accepted: 07/27/2020] [Indexed: 12/28/2022]
Abstract
The present study aimed to investigate the effects of high-mobility group box-1 (HMGB-1) on mechanical pain hypersensitivity and the underlying mechanism. Mouse primary astrocytes were isolated and treated as specified. A CCK-8 assay was used to determine cytotoxicity and a gap junctional communication assay was performed. Ethidium bromide (EtBr) uptake was used to evaluate the hemichannel activity of primary astrocytes. A mouse model of neuropathic pain was developed and paw withdrawal threshold was used to evaluate hind paw sensitivity. RT-qPCR and Western blot were used to determine mRNA and protein expression of genes, respectively. ELISA was used to measure the release of inflammatory cytokines. Treatment with HMGB-1 increased the expression of both toll-like receptor-4 (TLR-4) and connexin 43 (Cx43) in mouse primary astrocytes. HMGB-1 also promoted gap junctional intercellular communication and hemichannel function. Our results also demonstrated that HMGB-1-regulated Cx43 through the JNK signaling pathway, and Cx43 was involved in HMGB-1-mediated inflammation in astrocytes. In vivo analysis supported the idea that HMGB-1-induced mechanical hypersensitivity was associated with Cx43. We therefore conclude that HMGB-1-induced mechanical pain hypersensitivity occurs through modulating astrocytic Cx43 via the TLR-4/JNK signaling pathway.
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Affiliation(s)
- Jiang Liu
- Department of Anesthesiology, Tangshan Gongren Hospital, Tangshan, China
| | - Xiuhua Li
- Department of Anesthesiology, Tangshan Gongren Hospital, Tangshan, China
| | - Ana Ke
- Department of Anesthesiology, Tangshan Gongren Hospital, Tangshan, China
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Donnelly CR, Andriessen AS, Chen G, Wang K, Jiang C, Maixner W, Ji RR. Central Nervous System Targets: Glial Cell Mechanisms in Chronic Pain. Neurotherapeutics 2020; 17:846-860. [PMID: 32820378 PMCID: PMC7609632 DOI: 10.1007/s13311-020-00905-7] [Citation(s) in RCA: 133] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Interactions between central glial cells and neurons in the pain circuitry are critical contributors to the pathogenesis of chronic pain. In the central nervous system (CNS), two major glial cell types predominate: astrocytes and microglia. Injuries or pathological conditions which evoke pain are concurrently associated with the presence of a reactive microglia or astrocyte state, which is characterized by a variety of changes in the morphological, molecular, and functional properties of these cells. In this review, we highlight the changes that reactive microglia and astrocytes undergo following painful injuries and insults and discuss the critical and interactive role these two cell types play in the initiation and maintenance of chronic pain. Additionally, we focus on several crucial mechanisms by which microglia and astrocytes contribute to chronic pain and provide commentary on the therapeutic promise of targeting these pathways. In particular, we discuss how the inflammasome in activated microglia drives maturation and release of key pro-inflammatory cytokines, which drive pain through neuronal- and glial regulations. Moreover, we highlight several potentially-druggable hemichannels and proteases produced by reactive microglia and astrocytes in pain states and discuss how these pathways regulate distinct phases during pain pathogenesis. We also review two emerging areas in chronic pain research: 1) sexually dimorphic glial cell signaling and 2) the role of oligodendrocytes. Finally, we highlight important considerations for potential pain therapeutics targeting glial cell mediators as well as questions that remain in our conceptual understanding of glial cell activation in pain states.
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Affiliation(s)
- Christopher R Donnelly
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA.
| | - Amanda S Andriessen
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Gang Chen
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Kaiyuan Wang
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Changyu Jiang
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - William Maixner
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA.
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA.
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Qualitative sex differences in pain processing: emerging evidence of a biased literature. Nat Rev Neurosci 2020; 21:353-365. [PMID: 32440016 DOI: 10.1038/s41583-020-0310-6] [Citation(s) in RCA: 341] [Impact Index Per Article: 85.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2020] [Indexed: 02/07/2023]
Abstract
Although most patients with chronic pain are women, the preclinical literature regarding pain processing and the pathophysiology of chronic pain has historically been derived overwhelmingly from the study of male rodents. This Review describes how the recent adoption by a number of funding agencies of policies mandating the incorporation of sex as a biological variable into preclinical research has correlated with an increase in the number of studies investigating sex differences in pain and analgesia. Trends in the field are analysed, with a focus on newly published findings of qualitative sex differences: that is, those findings that are suggestive of differential processing mechanisms in each sex. It is becoming increasingly clear that robust differences exist in the genetic, molecular, cellular and systems-level mechanisms of acute and chronic pain processing in male and female rodents and humans.
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Shinoda M, Hayashi Y, Kubo A, Iwata K. Pathophysiological mechanisms of persistent orofacial pain. J Oral Sci 2020; 62:131-135. [PMID: 32132329 DOI: 10.2334/josnusd.19-0373] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Nociceptive stimuli to the orofacial region are typically received by the peripheral terminal of trigeminal ganglion (TG) neurons, and noxious orofacial information is subsequently conveyed to the trigeminal spinal subnucleus caudalis and the upper cervical spinal cord (C1-C2). This information is further transmitted to the cortical somatosensory regions and limbic system via the thalamus, which then leads to the perception of pain. It is a well-established fact that the presence of abnormal pain in the orofacial region is etiologically associated with neuroplastic changes that may occur at any point in the pain transmission pathway from the peripheral to the central nervous system (CNS). Recently, several studies have reported that functional plastic changes in a large number of cells, including TG neurons, glial cells (satellite cells, microglia, and astrocytes), and immune cells (macrophages and neutrophils), contribute to the sensitization and disinhibition of neurons in the peripheral and CNS, which results in orofacial pain hypersensitivity.
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Affiliation(s)
| | | | - Asako Kubo
- Department of Physiology, Nihon University School of Dentistry
| | - Koichi Iwata
- Department of Physiology, Nihon University School of Dentistry
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Zheng H, Liu Y, Xu D, Liu P, Yang X, Li B, Cao Z, Liu Y, Zheng X. Inhibition of Gap Junction-Mediated Intercellular Communication by Poly(I:C) in Cultured Human Corneal Fibroblasts. Curr Eye Res 2020; 45:1043-1050. [PMID: 32078434 DOI: 10.1080/02713683.2020.1716986] [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] [Indexed: 12/29/2022]
Abstract
PURPOSE/AIM Corneal stromal fibroblasts are connected to each other via gap junctions, which contribute to maintenance of corneal homeostasis. Viral infection of the corneal stroma can result in inflammation and scarring. The effects of polyinosinic-polycytidylic acid [poly(I:C)], an analog of viral double-stranded RNA, on gap junctional intercellular communication (GJIC) in cultured human corneal fibroblasts (HCFs) were examined. MATERIALS AND METHODS Cultured HCFs were exposed to poly(I:C) in the absence or presence of inhibitors of mitogen-activated protein kinase (MAPK) signaling or the antioxidant N-acetyl-L-cysteine (NAC). Expression of the gap junction protein connexin 43 (Cx43) was examined by immunoblot and immunofluorescence analyses. The level of Cx43 mRNA or microRNA-21 or -130a was determined by quantitative reverse transcription-polymerase chain reaction analysis. GJIC was measured with a dye coupling assay. The amount of malondialdehyde and the activity of superoxide dismutase (SOD) were measured with assay kits. RESULTS Exposure of HCFs to poly(I:C) resulted in down-regulation of Cx43 expression and GJIC activity as well as in up-regulation of microRNA-21 expression. Poly(I:C) increased the amount of malondialdehyde and reduced the activity of SOD in the cells, and these effects were prevented by NAC. The inhibitory effects of poly(I:C) on both Cx43 expression and GJIC activity were attenuated by NAC and by c-Jun NH2-terminal kinase (JNK) inhibitor II. CONCLUSIONS Poly(I:C) inhibited Cx43 expression and GJIC in cultured HCFs, possibly as a result of the associated up-regulation of microRNA-21. Poly(I:C) also increased oxidative stress in these cells, and such stress together with signaling by the MAPK JNK was implicated in the effects of poly(I:C) on Cx43 expression and GJIC activity. Down-regulation of GJIC activity among corneal fibroblasts by double-stranded RNA may thus contribute to the disruption of stromal homeostasis during viral infection of the cornea.
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Affiliation(s)
- Hui Zheng
- Department of Ophthalmology, Fifth Affiliated Hospital, Sun Yat-sen University , Zhuhai, PR China
| | - Ye Liu
- Department of Pathology, Fifth Affiliated Hospital, Sun Yat-sen University , Zhuhai, PR China
| | - Dan Xu
- Institute of Environmental Systems Biology, Environmental Science and Engineering College, Dalian Maritime University , Dalian, PR China
| | - Pingping Liu
- Department of Ophthalmology, Fifth Affiliated Hospital, Sun Yat-sen University , Zhuhai, PR China
| | - Xiuxia Yang
- Department of Ophthalmology, Fifth Affiliated Hospital, Sun Yat-sen University , Zhuhai, PR China
| | - Bing Li
- Department of Ophthalmology, Fifth Affiliated Hospital, Sun Yat-sen University , Zhuhai, PR China
| | - Zimu Cao
- Institute of Environmental Systems Biology, Environmental Science and Engineering College, Dalian Maritime University , Dalian, PR China
| | - Yang Liu
- Department of Ophthalmology, Fifth Affiliated Hospital, Sun Yat-sen University , Zhuhai, PR China
| | - Xiaoshuo Zheng
- Department of Ophthalmology, Fifth Affiliated Hospital, Sun Yat-sen University , Zhuhai, PR China
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Li WB, Liu S, Zhang MZ, Liu H, Dong XH, Hao Y, Liu YF, Wang YB. Hyperbaric oxygen therapy relieved pruritus and pain of keloid patients. Am J Transl Res 2020; 12:574-582. [PMID: 32194905 PMCID: PMC7061847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Objective: Keloid patients usually have local pruritus and pain. In our clinical work, we have found keloid patients after receiving hyperbaric oxygen (HBO) therapy reflect less pruritus and pain. The hypothesis was that patients with keloid and a history of HBO therapy would have less pruritus and pain than patients without HBO therapy, and the pruritus or pain-related factors were detected in keloid with/without HBO therapy and normal skin. Methods: Three groups of samples were established: keloid samples from patients with HBO therapy for two weeks before and after surgery (H group); keloid samples from patients without HBO therapy (G group); normal skin samples from patients without obvious scar (N group). Hematoxylin and eosin (H&E) staining was used to observe morphological changes. Pruritus/pain related factors: Tryptophan Hydroxylase1 (TPH1), connexin-43 (Cx43) and transient receptor potential vanilloid type 1 (TRPV1) were detected by immunofluorescence and western blot technology. The expression of these factors' mRNA was also measured by the real-time quantitative polymerase chain reaction (RT-qPCR). Results: Among three groups, G group presented significantly highest expression levels of TPH1, Cx43 and TRPV1, conversely, N group presented significantly lowest expression levels of TPH1, Cx43 and TRPV1. Conclusion: TPH1, Cx43 and TRPV1 were overexpressed in the samples of keloid patients, indicating that the pruritus and pain of keloid might be related to these factors. Furthermore, TPH1, Cx43 and TRPV1 were expressed highest in keloid patients without HBO therapy, indicating that HBO therapy might relief pruritus of keloid patients by regulating these factors.
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Affiliation(s)
- Wen-Bo Li
- Department of Radiology, Peking Union Medical College HospitalBeijing 100730, China
| | - Shu Liu
- Department of General Surgery, Civil Aviation General HospitalBeijing 100028, China
| | - Ming-Zi Zhang
- Department of Plastic Surgery, Peking Union Medical College HospitalBeijing 100730, China
| | - Hao Liu
- Department of Plastic Surgery, Peking Union Medical College HospitalBeijing 100730, China
| | - Xin-Hang Dong
- Department of Plastic Surgery, Peking Union Medical College HospitalBeijing 100730, China
| | - Yan Hao
- Department of Plastic Surgery, Peking Union Medical College HospitalBeijing 100730, China
| | - Yi-Fang Liu
- Beijing Vocational College of AgricultureBeijing 102442, China
| | - You-Bin Wang
- Department of Radiology, Peking Union Medical College HospitalBeijing 100730, China
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