51
|
Morioka N, Nakamura Y, Zhang FF, Hisaoka-Nakashima K, Nakata Y. Role of Connexins in Chronic Pain and Their Potential as Therapeutic Targets for Next-Generation Analgesics. Biol Pharm Bull 2019; 42:857-866. [PMID: 31155584 DOI: 10.1248/bpb.b19-00195] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic pain, including inflammatory, neuropathic pain, is a serious clinical issue. There are increasing numbers of patients with chronic pain due to the growing number of elderly and it is estimated that about 25% of the global population will develop chronic pain. Chronic pain patients are refractory to medications used to treat acute pain such as opioids and non-steroidal anti-inflammatory drugs. Furthermore, the complexity and diversity of chronic pain mechanisms hinder the development of new analgesics. Thus, a better understanding of the mechanism of chronic pain is needed, which would facilitate the development of novel analgesics based on novel mechanisms. With this goal, connexins (Cxs) could be targeted for the development of new analgesics. Connexins are proteins with 20 subtypes, and function as channels, gap junctions between cells, and hemichannels that sample the extracellular space and release molecules such as neurotransmitters. Furthermore, Cxs could have functions independent of channel activity. Recent studies have shown that Cxs could be crucial in the induction and maintenance of chronic pain, and modulation of the activity or the expression of Cxs ameliorates nociceptive hypersensitivity in multiple chronic pain models. This review will cite novel findings on the role of of Cxs in the nociceptive transduction pathway under the chronic pain state and antinociceptive effects of various molecules modulating activity or expression of Cxs. Also, the potential of Cx modulation as a therapeutic strategy for intractable chronic pain will be discussed.
Collapse
Affiliation(s)
- Norimitsu Morioka
- Department of Pharmacology, Hiroshima University Graduate School of Biomedical & Health Sciences
| | - Yoki Nakamura
- Department of Pharmacology, Hiroshima University Graduate School of Biomedical & Health Sciences
| | - Fang Fang Zhang
- Department of Pharmacology, Hiroshima University Graduate School of Biomedical & Health Sciences.,Institute of Pharmacology, Taishan Medical University
| | - Kazue Hisaoka-Nakashima
- Department of Pharmacology, Hiroshima University Graduate School of Biomedical & Health Sciences
| | - Yoshihiro Nakata
- Department of Pharmacology, Hiroshima University Graduate School of Biomedical & Health Sciences
| |
Collapse
|
52
|
Brocardo L, Acosta LE, Piantanida AP, Rela L. Beneficial and Detrimental Remodeling of Glial Connexin and Pannexin Functions in Rodent Models of Nervous System Diseases. Front Cell Neurosci 2019; 13:491. [PMID: 31780897 PMCID: PMC6851021 DOI: 10.3389/fncel.2019.00491] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 10/17/2019] [Indexed: 01/30/2023] Open
Abstract
A variety of glial cell functions are supported by connexin and pannexin proteins. These functions include the modulation of synaptic gain, the control of excitability through regulation of the ion and neurotransmitter composition of the extracellular milieu and the promotion of neuronal survival. Connexins and pannexins support these functions through diverse molecular mechanisms, including channel and non-channel functions. The former comprise the formation of gap junction-mediated networks supported by connexin intercellular channels and the formation of pore-like membrane structures or hemichannels formed by both connexins and pannexins. Non-channel functions involve adhesion properties and the participation in signaling intracellular cascades. Pathological conditions of the nervous system such as ischemia, neurodegeneration, pathogen infection, trauma and tumors are characterized by distinctive remodeling of connexin expression and function. However, whether these changes can be interpreted as part of the pathogenesis, or as beneficial compensatory effects, remains under debate. Here we review the available evidence addressing this matter with a special emphasis in mouse models with selective manipulation of glial connexin and pannexin proteins in vivo. We postulate that the beneficial vs. detrimental effects of glial connexin remodeling in pathological conditions depend on the impact of remodeling on the different connexin and pannexin channel and non-channel functions, on the characteristics of the inflammatory environment and on the type of interaction among glial cells types.
Collapse
Affiliation(s)
- Lucila Brocardo
- Grupo de Neurociencia de Sistemas, Facultad de Medicina, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Luis Ernesto Acosta
- Grupo de Neurociencia de Sistemas, Facultad de Medicina, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ana Paula Piantanida
- Grupo de Neurociencia de Sistemas, Facultad de Medicina, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Lorena Rela
- Grupo de Neurociencia de Sistemas, Facultad de Medicina, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| |
Collapse
|
53
|
Deng GC, Lu M, Zhao YY, Yuan Y, Chen G. Activated spinal astrocytes contribute to the later phase of carrageenan-induced prostatitis pain. J Neuroinflammation 2019; 16:189. [PMID: 31653262 PMCID: PMC6814979 DOI: 10.1186/s12974-019-1584-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 09/10/2019] [Indexed: 12/30/2022] Open
Abstract
Background Prostatodynia is the main symptom of chronic prostatitis and the main reason that patients go to the hospital for treatment. Although a variety of factors, including inflammatory immune response, nervous system sensitization, and psychological factors, have been shown to play important roles in the induction and development of chronic pain in prostatitis, the underlying cause of chronic prostatodynia maintenance in prostatitis patients remains unclear. Methods A mouse model of chronic prostatitis induced by carrageenan injection was used. The von Frey test was used to measure pain behavior. The microglial and astrocyte activations were immunohistochemically demonstrated with antibodies against Iba1 and GFAP. The expression of cytokine or signaling pathway was detected by enzyme-linked immunosorbent assay (ELISA) and Western blotting. Results In this study, we provide several lines of evidence to demonstrate that activated spinal astrocytes contribute to the later phase (5 weeks after carrageenan injection) of carrageenan-induced prostatitis pain. First, activation of spinal astrocytes but not microglia was found in the spinal cord dorsal horn at 5 weeks. Second, intrathecal injection of the astroglial toxin L-2-Aminoadipate acid (L-AA) but not microglial inhibitor minocycline reduced mechanical allodynia at 5 weeks. Third, chronic prostatitis induced a profound and persistent upregulation of connexin-43 hemichannels in spinal astrocytes, and spinal injection of the connexin-43 inhibitor carbenoxolone (CBX) effectively reduced pain symptoms. Fourth, increased expression and release of chemokine C-X-C motif ligand 1 (CXCL1) in the spinal dorsal horn and intrathecal injection of a CXCL1 neutralizing antibody or the CXCR2 (a major receptor of CXCL1) antagonist SB225002 significantly reduced mechanical allodynia at 5 weeks. Conclusions In this study, we found that a novel mechanism of activated spinal astrocytes plays a crucial role in maintaining chronic prostatitis-induced persistent pain via connexin-43-regulated CXCL1 production and secretion.
Collapse
Affiliation(s)
- Guo-Chuang Deng
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Ming Lu
- Department of Urology, The Second Affiliated Hospital of Nantong University (The First People's Hospital of Nantong), Nantong, China
| | - Ya-Yu Zhao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Ying Yuan
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Gang Chen
- Department of Tissue and Embryology, Medical School of Nantong University, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China. .,Department of Anesthesiology, Affiliated Hospital of Nantong University, Nantong, China.
| |
Collapse
|
54
|
Abstract
Astrocytes are critical for maintaining the homeostasis of the CNS. Increasing evidence suggests that a number of neurological and neuropsychiatric disorders, including chronic pain, may result from astrocyte 'gliopathy'. Indeed, in recent years there has been substantial progress in our understanding of how astrocytes can regulate nociceptive synaptic transmission via neuronal-glial and glial-glial cell interactions, as well as the involvement of spinal and supraspinal astrocytes in the modulation of pain signalling and the maintenance of neuropathic pain. A role of astrocytes in the pathogenesis of chronic itch is also emerging. These developments suggest that targeting the specific pathways that are responsible for astrogliopathy may represent a novel approach to develop therapies for chronic pain and chronic itch.
Collapse
|
55
|
Sarrouilhe D, Mesnil M, Dejean C. Targeting Gap Junctions: New Insights into the Treatment of Major Depressive Disorder. Curr Med Chem 2019; 26:3775-3791. [DOI: 10.2174/0929867325666180327103530] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 12/22/2017] [Accepted: 03/21/2018] [Indexed: 01/05/2023]
Abstract
Background:Major depressive disorder (MDD) is a multifactorial chronic and debilitating mood disease with high lifetime prevalence and associated with excess mortality. Treatments for this disease are not effective in all patients showing the need to find new therapeutic targets.Objective:This review aims to update our knowledge on the involvement of astroglial gap junctions and hemichannels in MDD and to show how they have become potential targets for the treatment of this pathology.Methods:The method applied in this review includes a systematic compilation of the relevant literature.Results and Conclusion:The use of rodent models of depression, gene analysis of hippocampal tissues of MDD patients and post-mortem studies on the brains from MDD patients suggest that astrocytic gap junction dysfunction may be a part of MDD etiologies. Chronic antidepressant treatments of rats, rat cultured cortical astrocytes and human astrocytoma cell lines support the hypothesis that the up-regulation of gap junctional coupling between astrocytes could be an underlying mechanism for the therapeutic effect of antidepressants. However, two recent functional studies suggest that connexin43 hemichannel activity is a part of several antidepressants’ mode of action and that astrocyte gap junctional intercellular communication and hemichannels exert different effects on antidepressant drug response. Even if they emerge as new therapeutic targets for new and more active treatments, further studies are needed to decipher the sophisticated and respective role of astrocytic gap junctions and hemichannels in MDD.
Collapse
Affiliation(s)
- Denis Sarrouilhe
- Laboratoire de Physiologie Humaine, Faculte de Medecine et Pharmacie, Universite de Poitiers, 6 rue de la Miletrie, Bat D1, TSA 51115, 86073 Poitiers, Cedex 9, France
| | - Marc Mesnil
- STIM, ERL 7003, CNRS-Universite de Poitiers, Pole Biologie Sante, Bat B36, TSA 51106, 1 rue Georges Bonnet, 86073 Poitiers, Cedex 9, France
| | - Catherine Dejean
- Service Pharmacie, Pavillon Janet, Centre Hospitalier Henri Laborit, 370 avenue Jacques Coeur, 86021 Poitiers Cedex, France
| |
Collapse
|
56
|
Li T, Chen X, Zhang C, Zhang Y, Yao W. An update on reactive astrocytes in chronic pain. J Neuroinflammation 2019; 16:140. [PMID: 31288837 PMCID: PMC6615111 DOI: 10.1186/s12974-019-1524-2] [Citation(s) in RCA: 184] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/18/2019] [Indexed: 12/17/2022] Open
Abstract
Chronic pain is a critical clinical problem with an increasing prevalence. However, there are limited effective prevention measures and treatments for chronic pain. Astrocytes are the most abundant glial cells in the central nervous system and play important roles in both physiological and pathological conditions. Over the past few decades, a growing body of evidence indicates that astrocytes are involved in the regulation of chronic pain. Recently, reactive astrocytes were further classified into A1 astrocytes and A2 astrocytes according to their functions. After nerve injury, A1 astrocytes can secrete neurotoxins that induce rapid death of neurons and oligodendrocytes, whereas A2 astrocytes promote neuronal survival and tissue repair. These findings can well explain the dual effects of reactive astrocytes in central nervous injury and diseases. In this review, we will summarise the (1) changes in the morphology and function of astrocytes after noxious stimulation and nerve injury, (2) molecular regulators and signalling mechanisms involved in the activation of astrocytes and chronic pain, (3) the role of spinal and cortical astrocyte activation in chronic pain, and (4) the roles of different subtypes of reactive astrocytes (A1 and A2 phenotypes) in nerve injury that is associated with chronic pain. This review provides updated information on the role of astrocytes in the regulation of chronic pain. In particular, we discuss recent findings about A1 and A2 subtypes of reactive astrocytes and make several suggestions for potential therapeutic targets for chronic pain.
Collapse
Affiliation(s)
- Ting Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xuhui Chen
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Chuanhan Zhang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yue Zhang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wenlong Yao
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| |
Collapse
|
57
|
Wang A, Xu C. The role of connexin43 in neuropathic pain induced by spinal cord injury. Acta Biochim Biophys Sin (Shanghai) 2019; 51:555-561. [PMID: 31056639 DOI: 10.1093/abbs/gmz038] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Indexed: 12/12/2022] Open
Abstract
Neuropathic pain is caused by the damage or dysfunction of the nervous system. In many neuropathic pain models, there is an increase in the number of gap junction (GJ) channels, especially the upregulation of the expression of connexin43 (Cx43), leading to the secretion of various types of cytokines and involvement in the formation of neuropathic pain. GJs are widely distributed in mammalian organs and tissues, and Cx43 is the most abundant connexin (Cx) in mammals. Astrocytes are the most abundant glial cell type in the central nervous system (CNS), which mainly express Cx43. More importantly, GJs play an important role in regulating cell metabolism, signaling, and function. Many existing literatures showed that Cx43 plays an important role in the nervous system, especially in the CNS under normal and pathological conditions. However, many internal mechanisms have not yet been thoroughly explored. In this review, we summarized the current understanding of the role and association of Cx and pannexin channels in neuropathic pain, especially after spinal cord injury, as well as some of our own insights and thoughts which suggest that Cx43 may become an emerging therapeutic target for future neuropathic pain, bringing new hope to patients.
Collapse
Affiliation(s)
- Anhui Wang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, China
| | - Changshui Xu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, China
| |
Collapse
|
58
|
Wang M, Qin C, Luo X, Wang J, Wang X, Xie M, Hu J, Cao J, Hu T, Goldman SA, Nedergaard M, Wang W. Astrocytic connexin 43 potentiates myelin injury in ischemic white matter disease. Am J Cancer Res 2019; 9:4474-4493. [PMID: 31285774 PMCID: PMC6599652 DOI: 10.7150/thno.31942] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 04/19/2019] [Indexed: 01/05/2023] Open
Abstract
Rational: Myelin loss is a characteristic feature of both ischemic white matter disease and its associated vascular dementia, and is a hallmark of chronic cerebral hypoperfusion due to carotid artery stenosis. Yet the cellular mechanisms involved in ischemic dysmyelination are not well-understood, and no effective treatment has emerged to prevent or slow hypoperfusion-related demyelination. In a study employing the bilateral common carotid artery stenosis (BCAS) mouse model, we found reduced cerebral blood flow velocity and arteriolar pulsatility, and confirmed that prolonged BCAS provoked myelin disruption. These pathological features were associated with marked cognitive decline, in the absence of evident damage to axons. Methods: To assess the role of astroglial communication in BCAS-associated demyelination, we investigated the effect of deleting or inhibiting connexin 43 (Cx43), a constituent of astroglial gap junctions and hemichannels. Results: Genetic deletion and pharmacological inhibition of gap junctions both protected myelin integrity and rescued cognitive decline in the BCAS-treated mice. Gap junction inhibition also suppressed the transient increase in extracellular glutamate observed in the callosal white matter of wild-type mice exposed to BCAS. Conclusion: These findings suggest that astrocytic Cx43 may be a viable target for attenuating the demyelination and cognitive decline associated with chronic cerebral hypoperfusion.
Collapse
|
59
|
Nelson NA, Wang X, Cook D, Carey EM, Nimmerjahn A. Imaging spinal cord activity in behaving animals. Exp Neurol 2019; 320:112974. [PMID: 31175843 DOI: 10.1016/j.expneurol.2019.112974] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/02/2019] [Accepted: 06/04/2019] [Indexed: 01/06/2023]
Abstract
The spinal cord is the primary neurological link between the brain and peripheral organs. How important it is in everyday life is apparent in patients with spinal cord injury or motoneuron disease, who have dramatically reduced musculoskeletal control or capacity to sense their environment. Despite its crucial role in sensory and motor processing little is known about the cellular and molecular signaling events that underlie spinal cord function under naturalistic conditions. While genetic, electrophysiological, pharmacological, and circuit tracing studies have revealed important roles for different molecularly defined neurons, these approaches insufficiently describe the moment-to-moment neuronal and non-neuronal activity patterns that underlie sensory-guided motor behaviors in health and disease. The recent development of imaging methods for real-time interrogation of cellular activity in the spinal cord of behaving mice has removed longstanding technical obstacles to spinal cord research and allowed new insight into how different cell types encode sensory information from mechanoreceptors and nociceptors in the skin. Here, we review the current state-of-the-art in interrogating cellular and microcircuit function in the spinal cord of behaving mammals and discuss current opportunities and technological challenges.
Collapse
Affiliation(s)
- Nicholas A Nelson
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Biologial Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92037, USA
| | - Xiang Wang
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Daniela Cook
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Erin M Carey
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Axel Nimmerjahn
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
| |
Collapse
|
60
|
Jin YZ, Zhang P, Hao T, Wang LM, Guo MD, Gan YH. Connexin 43 contributes to temporomandibular joint inflammation induced-hypernociception via sodium channel 1.7 in trigeminal ganglion. Neurosci Lett 2019; 707:134301. [PMID: 31152853 DOI: 10.1016/j.neulet.2019.134301] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/27/2019] [Accepted: 05/28/2019] [Indexed: 01/05/2023]
Abstract
We previously demonstrated that sodium channel 1.7 (Nav1.7) in trigeminal ganglion (TG) was a critical factor in temporomandibular joint (TMJ) inflammation-induced hypernociception, but the mechanism underlying inflammation-induced upregulation of Nav1.7 remained unclear. Glial-neuron interaction plays a critical role in pain process and connexin 43 (Cx43), a gap junction protein expressed in satellite glial cells (SGCs) has been shown to play an important role in several pain models. In the present study, we investigate the role of Cx43 in TMJ inflammation-induced hypernociception and its possible impact on neuronal Nav1.7. We induced TMJ inflammation in rats by injecting complete Freund's adjuvant (CFA) into TMJ and observed a decrease in head withdraw threshold after 24 h. Electron microscopy showed morphological alterations of SGCs in TMJ-inflamed rats. The expression of Cx43, glial fibrillary acidic protein (GFAP), and Nav1.7 increased greatly compared with controls. In addition, pretreatment with Cx43 blockers in TMJ-inflamed rats could alleviate mechanical hypernociception, inhibit SGCs activation and IL-1βrelease, and thus block the upregulation of Nav1.7. These findings indicate that the propagation of SGCs activation via Cx43 plays a critical role in Nav1.7-involved mechanical hypernociception induced by TMJ inflammation.
Collapse
Affiliation(s)
- Yi-Zhou Jin
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, PR China; Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Peng Zhang
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, PR China; Department of Oral and Maxillofacial Surgery, Qingdao Municipal Hospital, Shandong, PR China
| | - Ting Hao
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, PR China; Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Lu-Ming Wang
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, PR China; Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Mu-Di Guo
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, PR China; Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Ye-Hua Gan
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, PR China; Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, PR China.
| |
Collapse
|
61
|
Du L, Hu X, Yang W, Yasheng H, Liu S, Zhang W, Zhou Y, Cui W, Zhu J, Qiao Z, Maoying Q, Chu Y, Zhou H, Wang Y, Mi W. Spinal IL-33/ST2 signaling mediates chronic itch in mice through the astrocytic JAK2-STAT3 cascade. Glia 2019; 67:1680-1693. [PMID: 31087583 DOI: 10.1002/glia.23639] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 03/29/2019] [Accepted: 04/23/2019] [Indexed: 12/22/2022]
Abstract
Interleukin-33 (IL-33) and its receptor ST2 contribute to spinal glial activation and chronic pain. A recent study showed that peripheral IL-33 plays a pivotal role in the pathogenesis of chronic itch induced by poison ivy. However, how IL-33/ST2 signaling in the spinal cord potentially mediates chronic itch remains elusive. Here, we determined that St2-/- substantially reduced scratching behaviors in 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD) as well as acetone and diethylether followed by water-induced dry skin in mice. Intrathecal administration of the neutralizing anti-ST2 or anti-IL-33 antibody remarkably decreased the scratching response in DNFB-induced ACD mice. Expression of spinal IL-33 and ST2 significantly increased in ACD mice, as evidenced by increased mRNA and protein levels. Immunofluorescence and in situ hybridization demonstrated that increased expression of spinal IL-33 was predominant in oligodendrocytes and astrocytes, whereas ST2 was mainly expressed in astrocytes. Further studies showed that in ACD mice, the activation of astrocytes and increased phosphorylation of signal transducer and activator of transcription 3 (STAT3) were markedly attenuated by St2-/- . Intrathecal injection of Janus Kinase 2 Inhibitor AG490 significantly alleviated scratching behaviors in ACD mice. rIL-33 pretreatment exacerbated gastrin-releasing peptide (GRP)-evoked scratching behaviors. This increased gastrin-releasing peptide receptor (GRPR) expression was abolished by St2-/- . Tnf-α upregulation was suppressed by St2-/- . Our results indicate that the spinal IL-33/ST2 signaling pathway contributes to chronic itch via astrocytic JAK2-STAT3 cascade activation, promoting TNF-α release to regulate the GRP/GRPR signaling-related itch response. Thus, these findings provide a potential therapeutic option for treating chronic pruritus.
Collapse
Affiliation(s)
- Lixia Du
- 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, Fudan University, Shanghai, People's Republic of China
| | - Xueming Hu
- 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, Fudan University, Shanghai, People's Republic of China
| | - Wei Yang
- 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, Fudan University, Shanghai, People's Republic of China
| | - Hanikezi Yasheng
- 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, Fudan University, Shanghai, People's Republic of China
| | - Shenbin Liu
- 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, Fudan University, Shanghai, People's Republic of China
| | - Wenwen 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, Fudan University, Shanghai, People's Republic of China
| | - Yang Zhou
- 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, Fudan University, Shanghai, People's Republic of China
| | - Wenqiang 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, Fudan University, Shanghai, People's Republic of China
| | - Jianyu Zhu
- 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, Fudan University, Shanghai, People's Republic of China
| | - Zheng Qiao
- 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, Fudan University, Shanghai, People's Republic of China
| | - Qiliang Maoying
- 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, Fudan University, Shanghai, People's Republic of China
| | - Yuxia 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, Fudan University, Shanghai, People's Republic of China
| | - Hong Zhou
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Yanqing 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, Fudan University, Shanghai, People's Republic of China
| | - Wenli 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, Fudan University, Shanghai, People's Republic of China
| |
Collapse
|
62
|
Vicario N, Pasquinucci L, Spitale FM, Chiechio S, Turnaturi R, Caraci F, Tibullo D, Avola R, Gulino R, Parenti R, Parenti C. Simultaneous Activation of Mu and Delta Opioid Receptors Reduces Allodynia and Astrocytic Connexin 43 in an Animal Model of Neuropathic Pain. Mol Neurobiol 2019; 56:7338-7354. [PMID: 31030416 DOI: 10.1007/s12035-019-1607-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 04/12/2019] [Indexed: 12/27/2022]
Abstract
Neuropathic pain is a chronic condition triggered by lesions to the somatosensory nervous system in which pain stimuli occur spontaneously or as pathologically amplified responses. In this scenario, the exchange of signaling molecules throughout cell-to-cell and cell-to-extracellular environment communications plays a key role in the transition from acute to chronic pain. As such, connexin 43 (Cx43), the core glial gap junction and hemichannel-forming protein, is considered a triggering factor for disease chronicization in the central nervous system (CNS). Drugs targeting μ opioid receptors (MOR) are currently used for moderate to severe pain conditions, but their use in chronic pain is limited by the tolerability profile. δ opioid receptors (DOR) have become attractive targets for the treatment of persistent pain and have been associated with the inhibition of pain-sustaining factors. Moreover, it has been shown that simultaneous targeting of MOR and DOR leads to an improved pharmacological fingerprint. Herein, we aimed to study the effects of the benzomorphan ligand LP2, a multitarget MOR/DOR agonist, in an experimental model of neuropathic pain induced by the unilateral sciatic nerve chronic constriction injury (CCI) on male Sprague-Dawley rats. Results showed that LP2 significantly ameliorated mechanical allodynia from the early phase of treatment up to 21 days post-ligatures. We additionally showed that LP2 prevented CCI-induced Cx43 alterations and pro-apoptotic signaling in the CNS. These findings increase the knowledge of neuropathic pain development and the role of spinal astrocytic Cx43, suggesting new approaches for the treatment of neuropathic pain.
Collapse
Affiliation(s)
- Nunzio Vicario
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, 95123, Catania, Italy
| | - Lorella Pasquinucci
- Department of Drug Sciences, Section of Medicinal Chemistry, University of Catania, 95125, Catania, Italy
| | - Federica M Spitale
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, 95123, Catania, Italy
| | - Santina Chiechio
- Department of Drug Sciences, Section of Pharmacology and Toxicology, University of Catania, 95125, Catania, Italy.,Oasi Research Institute-IRCCS, 94018, Troina, Italy
| | - Rita Turnaturi
- Department of Drug Sciences, Section of Medicinal Chemistry, University of Catania, 95125, Catania, Italy
| | - Filippo Caraci
- Department of Drug Sciences, Section of Pharmacology and Toxicology, University of Catania, 95125, Catania, Italy.,Oasi Research Institute-IRCCS, 94018, Troina, Italy
| | - Daniele Tibullo
- Department of Biomedical and Biotechnological Sciences, Section of Biochemistry, University of Catania, 95123, Catania, Italy
| | - Roberto Avola
- Department of Biomedical and Biotechnological Sciences, Section of Biochemistry, University of Catania, 95123, Catania, Italy
| | - Rosario Gulino
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, 95123, Catania, Italy
| | - Rosalba Parenti
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, 95123, Catania, Italy.
| | - Carmela Parenti
- Department of Drug Sciences, Section of Pharmacology and Toxicology, University of Catania, 95125, Catania, Italy
| |
Collapse
|
63
|
Xing L, Yang T, Cui S, Chen G. Connexin Hemichannels in Astrocytes: Role in CNS Disorders. Front Mol Neurosci 2019; 12:23. [PMID: 30787868 PMCID: PMC6372977 DOI: 10.3389/fnmol.2019.00023] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 01/21/2019] [Indexed: 12/19/2022] Open
Abstract
In the central nervous system (CNS), astrocytes form networks interconnected by gap junctions made from connexins of the subtypes Cx30 and Cx43. When unopposed by an adjoining hemichannel, astrocytic connexins can act as hemichannels to control the release of small molecules such as ATP and glutamate into the extracellular space. Accruing evidence indicates that astrocytic connexins are crucial for the coordination and maintenance of physiologic CNS activity. Here we provide an update on the role of astrocytic connexins in neurodegenerative disorders, glioma, and ischemia. In addition, we address the regulation of Cx43 in chronic pain.
Collapse
Affiliation(s)
- LingYan Xing
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Tuo Yang
- Department of Hand Surgery, China-Japan Union Hospital of Jilin University, Changchun, China
| | - ShuSen Cui
- Department of Hand Surgery, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Gang Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Department of Anesthesiology, Affiliated Hospital of Nantong University, Nantong, China
| |
Collapse
|
64
|
Morales-Soto W, Gulbransen BD. Enteric Glia: A New Player in Abdominal Pain. Cell Mol Gastroenterol Hepatol 2018; 7:433-445. [PMID: 30739868 PMCID: PMC6369218 DOI: 10.1016/j.jcmgh.2018.11.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/16/2018] [Accepted: 11/19/2018] [Indexed: 12/14/2022]
Abstract
Chronic abdominal pain is the most common gastrointestinal issue and contributes to the pathophysiology of functional bowel disorders and inflammatory bowel disease. Current theories suggest that neuronal plasticity and broad alterations along the brain-gut axis contribute to the development of chronic abdominal pain, but the specific mechanisms involved in chronic abdominal pain remain incompletely understood. Accumulating evidence implicates glial cells in the development and maintenance of chronic pain. Astrocytes and microglia in the central nervous system and satellite glia in dorsal root ganglia contribute to chronic pain states through reactive gliosis, the modification of glial networks, and the synthesis and release of neuromodulators. In addition, new data suggest that enteric glia, a unique type of peripheral glia found within the enteric nervous system, have the potential to modify visceral perception through interactions with neurons and immune cells. Understanding these emerging roles of enteric glia is important to fully understand the mechanisms that drive chronic pain and to identify novel therapeutic targets. In this review, we discuss enteric glial cell signaling mechanisms that have the potential to influence chronic abdominal pain.
Collapse
Affiliation(s)
| | - Brian D. Gulbransen
- Correspondence Address correspondence to: Brian D. Gulbransen, PhD, Neuroscience Program and Department of Physiology, Michigan State University, 567 Wilson Road, East Lansing, Michigan 48824. fax: (517) 355-5125.
| |
Collapse
|
65
|
Fang M, Yamasaki R, Li G, Masaki K, Yamaguchi H, Fujita A, Isobe N, Kira JI. Connexin 30 Deficiency Attenuates Chronic but Not Acute Phases of Experimental Autoimmune Encephalomyelitis Through Induction of Neuroprotective Microglia. Front Immunol 2018; 9:2588. [PMID: 30464764 PMCID: PMC6234958 DOI: 10.3389/fimmu.2018.02588] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 10/19/2018] [Indexed: 01/25/2023] Open
Abstract
Glial connexins (Cxs) form gap junction channels through which a pan-glial network plays key roles in maintaining homeostasis of the central nervous system (CNS). In multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), expression of astrocytic Cx43 is lost in acute lesions but upregulated in chronic plaques, while astrocytic Cx30 is very low in normal white matter and changes in its expression have not been convincingly shown. In Cx30 or Cx43 single knockout (KO) mice and even in Cx30/Cx43 double KO mice, acute EAE is unaltered. However, the effects of Cx30/Cx43 deficiency on chronic EAE remains to be elucidated. We aimed to clarify the roles of Cx30 in chronic neuroinflammation by studying EAE induced by myelin oligodendrocyte glycoprotein peptide 35–55 in Cx30 KO mice. We found that Cx30 deficiency improved the clinical symptoms and demyelination of chronic but not acute EAE without influencing CD3+ T cell infiltration. Furthermore, increased ramified microglia in the naïve state and induced earlier and stronger microglial activation in the acute and chronic phases of EAE was observed. These activated microglia had an anti-inflammatory phenotype, as shown by the upregulation of arginase-1 and brain-derived neurotrophic factor and the downregulation of nitric oxide synthase 2. In the naïve state, Cx30 deficiency induced modest enlargement of astrocytic processes in the spinal cord gray matter and a partial reduction of Cx43 expression in the spinal cord white matter. These astrocytes in Cx30 KO mice showed earlier and stronger activation during the acute phase of EAE, with upregulated A2 astrocyte markers and a significant decrease in Cx43 in the chronic phases. Spinal cord neurons and axons were more preserved in Cx30 KO mice than in littermates in the chronic phase of EAE. These findings suggest that Cx30 deficiency increased ramified microglia in the CNS in the naïve state and improved chronic EAE through redirecting microglia toward an anti-inflammatory phenotype, suggesting a hitherto unknown critical role of astrocytic Cx30 in regulating microglial number and functional state.
Collapse
Affiliation(s)
- Mei Fang
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Ryo Yamasaki
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Guangrui Li
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Katsuhisa Masaki
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hiroo Yamaguchi
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Atsushi Fujita
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Noriko Isobe
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.,Department of Neurological Therapeutics, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Jun-Ichi Kira
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| |
Collapse
|
66
|
Abstract
Due to strong electrical coupling, syncytial isopotentiality emerges as a physiological mechanism that coordinates astrocytes into a highly efficient system in brain homeostasis. Although this electrophysiological phenomenon has now been observed in astrocyte networks established by different astrocyte subtypes, the spinal cord remains a brain region that is still unexplored. In ALDH1L1-eGFP transgenic mice, astrocytes can be visualized by confocal microscopy and the spinal cord astrocytes in grey matter are organized in a distinctive pattern. Namely, each astrocyte resides with more directly coupled neighbors at shorter interastrocytic distances compared to protoplasmic astrocytes in the hippocampal CA1 region. In whole-cell patch clamp recording, the spinal cord grey matter astrocytes exhibit passive K+ conductance and a highly hyperpolarized membrane potential of −80 mV. To answer whether syncytial isopotentiality is a shared feature of astrocyte networks in the spinal cord, the K+ content in a physiological recording solution was substituted by equimolar Na+ for whole-cell recording in spinal cord slices. In uncoupled single astrocytes, this substitution of endogenous K+ with Na+ is known to depolarize astrocytes to around 0 mV as predicted by Goldman–Hodgkin–Katz (GHK) equation. In contrast, the existence of syncytial isopotentiality is indicated by a disobedience of the GHK predication as the recorded astrocyte’s membrane potential remains at a quasi-physiological level that is comparable to its neighbors due to strong electrical coupling. We showed that the strength of syncytial isopotentiality in spinal cord grey matter is significantly stronger than that of astrocyte network in the hippocampal CA1 region. Thus, this study corroborates the notion that syncytial isopotentiality most likely represents a system-wide electrical feature of astrocytic networks throughout the brain.
Collapse
|
67
|
Luo X, Fitzsimmons B, Mohan A, Zhang L, Terrando N, Kordasiewicz H, Ji RR. Intrathecal administration of antisense oligonucleotide against p38α but not p38β MAP kinase isoform reduces neuropathic and postoperative pain and TLR4-induced pain in male mice. Brain Behav Immun 2018; 72:34-44. [PMID: 29128611 PMCID: PMC5940592 DOI: 10.1016/j.bbi.2017.11.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 10/27/2017] [Accepted: 11/08/2017] [Indexed: 02/06/2023] Open
Abstract
p38 mitogen-activated protein kinase (MAPK) consists of two major isoforms: p38α and p38β; however, it remains unclear which isoform is more important for chronic pain development. Recently, we developed potent, long-lasting, and p38 MAPK subtype-specific antisense oligonucleotides (ASOs). We examined the therapeutic effects of isoform-specific ASOs in several chronic pain models following single intrathecal injection (300 μg/10 μl) in CD1 mice. In the chronic constriction injury (CCI) model, p38α MAPK ASO, given on post-operative day 5, reduced CCI-induced mechanical allodynia in male but not female mice. In contrast, mechanical allodynia after CCI in both sexes was not affected by p38β MAPK ASO. Intrathecal injection of p38α or p38β ASO resulted in a partial reduction (≈ 50%) of spinal p38α or p38β mRNA level, respectively, in both sexes at two weeks. In contrast, intrathecal injection of the ASOs did not affect p38α and p38β MAPK mRNA levels in dorsal root ganglia. Intrathecal p38α ASO also reduced postoperative pain (mechanical and cold allodynia) in male mice after tibia fracture. However, intrathecal p38α ASO had no effect on mechanical allodynia in male mice after paclitaxel treatment. Intrathecal p38α MAPK ASO pre-treatment also prevented TLR4-mediated mechanical allodynia and downregulated levels of p38α MAPK and phosphorylated p38 MAPK following intrathecal treatment of lipopolysaccharide. In summary, our findings suggest that p38α MAPK is the major p38 MAPK isoform in the spinal cord and regulates chronic pain in a sex and model-dependent manner. Intrathecal p38α MAPK ASO may offer a new treatment for some chronic pain conditions.
Collapse
Affiliation(s)
- Xin Luo
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, United States.
| | | | - Apoorva Mohan
- Neuroscience Drug Discovery, Ionis Pharmaceuticals, Carlsbad, CA 92010
| | - Linlin Zhang
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
| | - Niccolo Terrando
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
| | | | - Ru-Rong Ji
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, United States; Department of Anesthesiology and Neurobiology, Duke University Medical Center, NC 27710, United States.
| |
Collapse
|
68
|
Ji RR, Nackley A, Huh Y, Terrando N, Maixner W. Neuroinflammation and Central Sensitization in Chronic and Widespread Pain. Anesthesiology 2018; 129:343-366. [PMID: 29462012 PMCID: PMC6051899 DOI: 10.1097/aln.0000000000002130] [Citation(s) in RCA: 706] [Impact Index Per Article: 117.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chronic pain is maintained in part by central sensitization, a phenomenon of synaptic plasticity, and increased neuronal responsiveness in central pain pathways after painful insults. Accumulating evidence suggests that central sensitization is also driven by neuroinflammation in the peripheral and central nervous system. A characteristic feature of neuroinflammation is the activation of glial cells, such as microglia and astrocytes, in the spinal cord and brain, leading to the release of proinflammatory cytokines and chemokines. Recent studies suggest that central cytokines and chemokines are powerful neuromodulators and play a sufficient role in inducing hyperalgesia and allodynia after central nervous system administration. Sustained increase of cytokines and chemokines in the central nervous system also promotes chronic widespread pain that affects multiple body sites. Thus, neuroinflammation drives widespread chronic pain via central sensitization. We also discuss sex-dependent glial/immune signaling in chronic pain and new therapeutic approaches that control neuroinflammation for the resolution of chronic pain.
Collapse
Affiliation(s)
- Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710
| | - Andrea Nackley
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
| | - Yul Huh
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
| | - Niccolò Terrando
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
| | - William Maixner
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
| |
Collapse
|
69
|
Shiao R, Lee-Kubli CA. Neuropathic Pain After Spinal Cord Injury: Challenges and Research Perspectives. Neurotherapeutics 2018; 15:635-653. [PMID: 29736857 PMCID: PMC6095789 DOI: 10.1007/s13311-018-0633-4] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neuropathic pain is a debilitating consequence of spinal cord injury (SCI) that remains difficult to treat because underlying mechanisms are not yet fully understood. In part, this is due to limitations of evaluating neuropathic pain in animal models in general, and SCI rodents in particular. Though pain in patients is primarily spontaneous, with relatively few patients experiencing evoked pains, animal models of SCI pain have primarily relied upon evoked withdrawals. Greater use of operant tasks for evaluation of the affective dimension of pain in rodents is needed, but these tests have their own limitations such that additional studies of the relationship between evoked withdrawals and operant outcomes are recommended. In preclinical SCI models, enhanced reflex withdrawal or pain responses can arise from pathological changes that occur at any point along the sensory neuraxis. Use of quantitative sensory testing for identification of optimal treatment approach may yield improved identification of treatment options and clinical trial design. Additionally, a better understanding of the differences between mechanisms contributing to at- versus below-level neuropathic pain and neuropathic pain versus spasticity may shed insights into novel treatment options. Finally, the role of patient characteristics such as age and sex in pathogenesis of neuropathic SCI pain remains to be addressed.
Collapse
Affiliation(s)
- Rani Shiao
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines, La Jolla, California, 92073, USA
| | - Corinne A Lee-Kubli
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines, La Jolla, California, 92073, USA.
| |
Collapse
|
70
|
Function of Connexins in the Interaction between Glial and Vascular Cells in the Central Nervous System and Related Neurological Diseases. Neural Plast 2018; 2018:6323901. [PMID: 29983707 PMCID: PMC6015683 DOI: 10.1155/2018/6323901] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/06/2018] [Accepted: 05/14/2018] [Indexed: 02/05/2023] Open
Abstract
Neuronal signaling together with synapse activity in the central nervous system requires a precisely regulated microenvironment. Recently, the blood-brain barrier is considered as a “neuro-glia-vascular unit,” a structural and functional compound composed of capillary endothelial cells, glial cells, pericytes, and neurons, which plays a pivotal role in maintaining the balance of the microenvironment in and out of the brain. Tight junctions and adherens junctions, which function as barriers of the blood-brain barrier, are two well-known kinds in the endothelial cell junctions. In this review, we focus on the less-concerned contribution of gap junction proteins, connexins in blood-brain barrier integrity under physio-/pathology conditions. In the neuro-glia-vascular unit, connexins are expressed in the capillary endothelial cells and prominent in astrocyte endfeet around and associated with maturation and function of the blood-brain barrier through a unique signaling pathway and an interaction with tight junction proteins. Connexin hemichannels and connexin gap junction channels contribute to the physiological or pathological progress of the blood-brain barrier; in addition, the interaction with other cell-cell-adhesive proteins is also associated with the maintenance of the blood-brain barrier. Lastly, we explore the connexins and connexin channels involved in the blood-brain barrier in neurological diseases and any programme for drug discovery or delivery to target or avoid the blood-brain barrier.
Collapse
|
71
|
Faw TD, Lerch JK, Thaxton TT, Deibert RJ, Fisher LC, Basso DM. Unique Sensory and Motor Behavior in Thy1-GFP-M Mice before and after Spinal Cord Injury. J Neurotrauma 2018; 35:2167-2182. [PMID: 29385890 DOI: 10.1089/neu.2017.5395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Sensorimotor recovery after spinal cord injury (SCI) is of utmost importance to injured individuals and will rely on improved understanding of SCI pathology and recovery. Novel transgenic mouse lines facilitate discovery, but must be understood to be effective. The purpose of this study was to characterize the sensory and motor behavior of a common transgenic mouse line (Thy1-GFP-M) before and after SCI. Thy1-GFP-M positive (TG+) mice and their transgene negative littermates (TG-) were acquired from two sources (in-house colony, n = 32, Jackson Laboratories, n = 4). C57BL/6J wild-type (WT) mice (Jackson Laboratories, n = 10) were strain controls. Moderate-severe T9 contusion (SCI) or transection (TX) occurred in TG+ (SCI, n = 25, TX, n = 5), TG- (SCI, n = 5), and WT (SCI, n = 10) mice. To determine responsiveness to rehabilitation, a cohort of TG+ mice with SCI (n = 4) had flat treadmill (TM) training 42-49 days post-injury (dpi). To characterize recovery, we performed Basso Mouse Scale, Grid Walk, von Frey Hair, and Plantar Heat Testing before and out to day 42 post-SCI. Open field locomotion was significantly better in the Thy1 SCI groups (TG+ and TG-) compared with WT by 7 dpi (p < 0.01) and was maintained through 42 dpi (p < 0.01). These unexpected locomotor gains were not apparent during grid walking, indicating severe impairment of precise motor control. Thy1 derived mice were hypersensitive to mechanical stimuli at baseline (p < 0.05). After SCI, mechanical hyposensitivity emerged in Thy1 derived groups (p < 0.001), while thermal hyperalgesia occurred in all groups (p < 0.001). Importantly, consistent findings across TG+ and TG- groups suggest that the effects are mediated by the genetic background rather than transgene manipulation itself. Surprisingly, TM training restored mechanical and thermal sensation to baseline levels in TG+ mice with SCI. This behavioral profile and responsiveness to chronic training will be important to consider when choosing models to study the mechanisms underlying sensorimotor recovery after SCI.
Collapse
Affiliation(s)
- Timothy D Faw
- 1 Neuroscience Graduate Program, The Ohio State University , Columbus, Ohio.,2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| | - Jessica K Lerch
- 3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio.,4 Department of Neuroscience, The Ohio State University , Columbus, Ohio
| | - Tyler T Thaxton
- 2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| | - Rochelle J Deibert
- 2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| | - Lesley C Fisher
- 2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| | - D Michele Basso
- 2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| |
Collapse
|
72
|
Yang H, Yan H, Li X, Liu J, Cao S, Huang B, Huang D, Wu L. Inhibition of Connexin 43 and Phosphorylated NR2B in Spinal Astrocytes Attenuates Bone Cancer Pain in Mice. Front Cell Neurosci 2018; 12:129. [PMID: 29867362 PMCID: PMC5951934 DOI: 10.3389/fncel.2018.00129] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 04/23/2018] [Indexed: 12/14/2022] Open
Abstract
Bone cancer pain (BCP) is common in patients with advanced cancers when the tumors are metastasized to bone. The limited understanding of the complex pathogenesis of BCP leads to the poor effectiveness of clinical treatment. Previous studies have shown that astrocyte-specific connexin (Cx) 43, a forming protein of gap junction (GJ) and hemichannel, and N-methyl-D-aspartate receptors (NMDARs), especially the phosphorylated NMDAR 2B subunit (NR2B) phosphorylated NR2B (p-NR2B) subunit are involved in BCP. However, the relationship between Cx43 and p-NR2B in BCP remains unclear. In the present study, we investigated the expressions of Cx43, glial fibrillary acidic protein (GFAP, a marker of astrocytes), and p-NR2B in the spinal dorsal horn (SDH) in a mouse model of BCP established by intra-femural inoculation of Lewis lung carcinoma (LLC) cells via intrathecal (ith) injection of the GJ/hemichannel blocker carbenoxolone (CARB) and the NMDAR antagonist MK801, respectively. We found that the characters of BCP were mimicked by intra-femural inoculation of LLC cells in mice, and the expressions of Cx43, GFAP and p-NR2B in BCP mice were remarkably increased in a time-dependent manner from day 7 to day 21 after cell inoculation with a gradual aggravate in spontaneous pain and mechanical allodynia. Furthermore, Cx43 was predominantly expressed in the spinal astrocytes. Both CARB and MK801 inhibited the expressions of Cx43, GFAP and p-NR2B with attenuated pain hypersensitivity in BCP mice. In addition, Cx43 was co-localized with p-NR2B in the SDH, which further evidenced the presence of functional NR2B in the spinal astrocytes in BCP mice. Our findings demonstrate that inhibition of Cx43 and p-NR2B in spinal astrocytes could attenuate BCP in mice and Cx43 and p-NR2B in the astrocytes of the SDH may play an important role via their combination action in the development and maintenance of BCP in mice. These results may provide a potential therapeutic target in the prevention and/or treatment of BCP.
Collapse
Affiliation(s)
- Hui Yang
- Department of Anesthesiology, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Physiology, School of Basic Medical Science, Central South University, Changsha, China.,Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South University, Changsha, China
| | - Hui Yan
- Department of Neurosurgery, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xin Li
- Department of Anesthesiology, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South University, Changsha, China
| | - Jing Liu
- Department of Anesthesiology, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South University, Changsha, China
| | - Shousong Cao
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Baisheng Huang
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, China
| | - Dong Huang
- Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South University, Changsha, China
| | - Lixiang Wu
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, China
| |
Collapse
|
73
|
Li H, Kong W, Chambers CR, Yu D, Ganea D, Tuma RF, Ward SJ. The non-psychoactive phytocannabinoid cannabidiol (CBD) attenuates pro-inflammatory mediators, T cell infiltration, and thermal sensitivity following spinal cord injury in mice. Cell Immunol 2018; 329:1-9. [PMID: 29784129 DOI: 10.1016/j.cellimm.2018.02.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/27/2018] [Accepted: 02/28/2018] [Indexed: 01/27/2023]
Abstract
We evaluated the effects of the non-psychoactive cannabinoid cannabidiol (CBD) on the inflammatory response and recovery of function following spinal cord injury (SCI). Female C57Bl/6 mice were exposed to spinal cord contusion injury (T9-10) and received vehicle or CBD (1.5 mg/kg IP) injections for 10 weeks following injury. The effect of SCI and CBD treatment on inflammation was assessed via microarray, qRT-PCR and flow cytometry. Locomotor and bladder function and changes in thermal and mechanical hind paw sensitivity were also evaluated. There was a significant decrease in pro-inflammatory cytokines and chemokines associated with T-cell differentiation and invasion in the SCI-CBD group as well as a decrease in T cell invasion into the injured cord. A higher percentage of SCI mice in the vehicle-treated group (SCI-VEH) went on to develop moderate to severe (0-65.9% baseline thermal threshold) thermal sensitivity as compared with CBD-treated (SCI-CBD) mice. CBD did not affect recovery of locomotor or bladder function following SCI. Taken together, CBD treatment attenuated the development of thermal sensitivity following spinal cord injury and this effect may be related to protection against pathological T-cell invasion.
Collapse
Affiliation(s)
- Hongbo Li
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, United States.
| | - Weimin Kong
- Microbiology and Immunology Department, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, United States.
| | - Christina R Chambers
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, United States
| | - Daohai Yu
- Department of Clinical Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, United States.
| | - Doina Ganea
- Microbiology and Immunology Department, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, United States.
| | - Ronald F Tuma
- Center for Substance Abuse Research, Department of Physiology, Lewis Katz School of Medicine, Temple University, Philadelphia PA 19140, United States.
| | - Sara Jane Ward
- Center for Substance Abuse Research, Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, United States.
| |
Collapse
|
74
|
Watase T, Shimizu K, Ohara K, Komiya H, Kanno K, Hatori K, Noma N, Honda K, Tsuboi Y, Katagiri A, Shinoda M, Ogiso B, Iwata K. Role of medullary astroglial glutamine synthesis in tooth pulp hypersensitivity associated with frequent masseter muscle contraction. Mol Pain 2018; 14:1744806918763270. [PMID: 29448913 PMCID: PMC5858619 DOI: 10.1177/1744806918763270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background The mechanisms underlying tooth pulp hypersensitivity associated with masseter muscle hyperalgesia remain largely underinvestigated. In the present study, we aimed to determine whether masseter muscle contraction induced by daily electrical stimulation influences the mechanical head-withdrawal threshold and genioglossus electromyography activity caused by the application of capsaicin to the upper first molar tooth pulp. We further investigated whether astroglial glutamine synthesis is involved in first molar tooth pulp hypersensitivity associated with masseter muscle contraction. Methods The first molar tooth pulp was treated with capsaicin or vehicle in masseter muscle contraction or sham rats, following which the astroglial glutamine synthetase inhibitor methionine sulfoximine or Phosphate buffered saline (PBS) was applied. Astroglial activation was assessed via immunohistochemistry. Results The mechanical head-withdrawal threshold of the ipsilateral masseter muscle was significantly decreased in masseter muscle contraction rats than in sham rats. Genioglossus electromyography activity was significantly higher in masseter muscle contraction rats than sham rats. Glial fibrillary acidic protein-immunoreactive cell density was significantly higher in masseter muscle contraction rats than in sham rats. Administration of methionine sulfoximine induced no significant changes in the density of glial fibrillary acidic protein-immunoreactive cells relative to PBS treatment. However, mechanical head-withdrawal threshold was significantly higher in masseter muscle contraction rats than PBS-treated rats after methionine sulfoximine administration. Genioglossus electromyography activity following first molar tooth pulp capsaicin treatment was significantly lower in methionine sulfoximine-treated rats than in PBS-treated rats. In the ipsilateral region, the total number of phosphorylated extracellular signal-regulated protein kinase immunoreactive cells in the medullary dorsal horn was significantly smaller upon first molar tooth pulp capsaicin application in methionine sulfoximine-treated rats than in PBS-treated rats. Conclusions Our results suggest that masseter muscle contraction induces astroglial activation, and that this activation spreads from caudal to the obex in the medullary dorsal horn, resulting in enhanced neuronal excitability associated with astroglial glutamine synthesis in medullary dorsal horn neurons receiving inputs from the tooth pulp. These findings provide significant insight into the mechanisms underlying tooth pulp hypersensitivity associated with masseter muscle contraction.
Collapse
Affiliation(s)
- Tetsuro Watase
- Department of Anatomy, Nihon University School of Dentistry, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Japan
| | - Kohei Shimizu
- Department of Endodontics, Nihon University School of Dentistry, Japan
- Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Japan
- Kohei Shimizu, Department of Endodontics, Nihon University School of Dentistry, 1-8-13 Kandasurugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
| | - Kinuyo Ohara
- Department of Endodontics, Nihon University School of Dentistry, Japan
| | - Hiroki Komiya
- Department of Endodontics, Nihon University School of Dentistry, Japan
| | - Kohei Kanno
- Department of Endodontics, Nihon University School of Dentistry, Japan
| | - Keisuke Hatori
- Department of Endodontics, Nihon University School of Dentistry, Japan
- Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Japan
| | - Noboru Noma
- Department of Oral Diagnostic Sciences, Nihon University School of Dentistry, Japan
- Division of Clinical Research, Dental Research Center, Nihon University School of Dentistry, Japan
| | - Kuniya Honda
- Department of Physiology, Nihon University School of Dentistry, Japan
| | - Yoshiyuki Tsuboi
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Japan
- Department of Physiology, Nihon University School of Dentistry, Japan
| | - Ayano Katagiri
- Department of Oral Physiology, Osaka University Graduate School of Dentistry
| | - Masamichi Shinoda
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Japan
- Department of Physiology, Nihon University School of Dentistry, Japan
| | - Bunnai Ogiso
- Department of Endodontics, Nihon University School of Dentistry, Japan
- Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Japan
| | - Koichi Iwata
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Japan
- Department of Physiology, Nihon University School of Dentistry, Japan
| |
Collapse
|
75
|
Retamal MA, Riquelme MA, Stehberg J, Alcayaga J. Connexin43 Hemichannels in Satellite Glial Cells, Can They Influence Sensory Neuron Activity? Front Mol Neurosci 2017; 10:374. [PMID: 29200997 PMCID: PMC5696352 DOI: 10.3389/fnmol.2017.00374] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 10/27/2017] [Indexed: 12/30/2022] Open
Abstract
In this review article, we summarize the current insight on the role of Connexin- and Pannexin-based channels as modulators of sensory neurons. The somas of sensory neurons are located in sensory ganglia (i.e., trigeminal and nodose ganglia). It is well known that within sensory ganglia, sensory neurons do not form neither electrical nor chemical synapses. One of the reasons for this is that each soma is surrounded by glial cells, known as satellite glial cells (SGCs). Recent evidence shows that connexin43 (Cx43) hemichannels and probably pannexons located at SGCs have an important role in paracrine communication between glial cells and sensory neurons. This communication may be exerted via the release of bioactive molecules from SGCs and their subsequent action on receptors located at the soma of sensory neurons. The glio-neuronal communication seems to be relevant for the establishment of chronic pain, hyperalgesia and pathologies associated with tissue inflammation. Based on the current literature, it is possible to propose that Cx43 hemichannels expressed in SGCs could be a novel pharmacological target for treating chronic pain, which need to be directly evaluated in future studies.
Collapse
Affiliation(s)
- Mauricio A Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clinica Alemana Universidad del Desarrollo, Santiago, Chile.,Department of Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Manuel A Riquelme
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, United States
| | - Jimmy Stehberg
- Laboratorio de Neurobiología, Centro de Investigaciones Biomedicas, Universidad Andres Bello, Santiago, Chile
| | - Julio Alcayaga
- Department of Biology, Cell Physiology Center, University of Chile, Santiago, Chile
| |
Collapse
|
76
|
Rosen S, Ham B, Mogil JS. Sex differences in neuroimmunity and pain. J Neurosci Res 2017; 95:500-508. [PMID: 27870397 DOI: 10.1002/jnr.23831] [Citation(s) in RCA: 210] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/14/2016] [Accepted: 06/20/2016] [Indexed: 12/12/2022]
Abstract
Differences in the prevalence of chronic pain in women vs. men are well known, and decades of laboratory experimentation have demonstrated that women are more sensitive to pain than are men. Attention has thus shifted to investigating mechanisms underlying such differences. Recent evidence suggests that neuroimmune modulation of pain may represent an important cause of sex differences. The current Review examines the evidence for gonadal hormone modulation of the immune system, immune system modulation of pain, and interactions that might help to explain sex differences in pain. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Sarah Rosen
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Boram Ham
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Jeffrey S Mogil
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
77
|
Wang L, Peng Y, Peng J, Shao M, Ma L, Zhu Z, Zhong G, Xia Z, Huang H. Tramadol attenuates the sensitivity of glioblastoma to temozolomide through the suppression of Cx43‑mediated gap junction intercellular communication. Int J Oncol 2017; 52:295-304. [PMID: 29115581 DOI: 10.3892/ijo.2017.4188] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/05/2017] [Indexed: 11/06/2022] Open
Abstract
Analgesics and antineoplastic drugs are often used concurrently for cancer patients. Our previous study reported that gap junctions composed of connexin32 (Cx32) was implicated in the effect of analgesics on cisplatin cytotoxicity. However, the effect of analgesic on the most widely expressed connexin (Cx), connexin43 (Cx43), and whether such effect mediates the influence on chemotherapeutic efficiency remain unknown. By manipulation of Cx43 expression or gap junction function, we found that there were gap junction-dependent and independent effect of Cx43 on temozolomide (TMZ) sensitivity in U87 glioblastoma cells. Studies on survival and apoptosis showed widely used analgesic tramadol significantly reduced TMZ-induced cytotoxicity in control and negative control cells but not shCx43-transfected cells. Proliferation assay demonstrated tramadol suppressed TMZ-induced cytotoxicity only on high density (with gap junction formation) but not on low density (without gap junction formation). Tramadol inhibited dye-coupling through gap junctions between U87 cells. Tramadol treatment for 72 h did not alter Cx43 expression, but decreased Cx43 phosphorylation accompanied with reduced p-ERK and p-JNK. Our results indicated that long-term treatment with tramadol reduced TMZ cytotoxicity in U87 cells by suppressing Cx43-composed gap junctions, suggesting identification and usage of antinociceptive drugs which do not downregulate connexin activity should have beneficial therapeutic consequences.
Collapse
Affiliation(s)
- Lingzhi Wang
- Department of Anaesthesia, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510260, P.R. China
| | - Yuexia Peng
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Jianxin Peng
- Department of Hepatobiliary Surgery, Guangdong Province Traditional Chinese Medicine Hospital, Guangzhou, Guangdong 510120, P.R. China
| | - Min Shao
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Li Ma
- Department of Cardiovascular Internal Medicine, Tianyou Hospital, Wuhan University of Science and Technology, Wuhan, Hubei 430064, P.R. China
| | - Zhuoli Zhu
- Department of Anaesthesia, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510260, P.R. China
| | - Guocheng Zhong
- Department of Anaesthesia, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510260, P.R. China
| | - Zhengyuan Xia
- Department of Anaesthesia, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510260, P.R. China
| | - Huansen Huang
- Department of Anaesthesia, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510260, P.R. China
| |
Collapse
|
78
|
Microglia and astrocyte activation in the spinal cord of lame horses. Vet Anaesth Analg 2017; 45:92-102. [PMID: 29223561 DOI: 10.1016/j.vaa.2017.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 10/06/2017] [Accepted: 10/10/2017] [Indexed: 12/30/2022]
Abstract
OBJECTIVE To determine the microglial and astrocyte response to painful lameness in horses. STUDY DESIGN Ionized calcium binding adaptor molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP) expression, cell density and morphology were determined through immunofluorescence within the dorsal horn of equine spinal cord. ANIMALS A total of five adult horses with acute or chronic unilateral lameness, previously scheduled for euthanasia. METHODS Musculoskeletal lameness was evaluated in five horses through visual evaluation according to clinical guidelines. Spinal cord samples were obtained immediately after euthanasia, and distal limb lesions were confirmed through dissection and radiography. Iba-1 immunostaining was used for detection and characterization of dorsal horn microglia. GFAP was used for immunostaining of dorsal horn astrocytes. Iba-1 and GFAP labeled cells were quantified in the dorsal horn, and intensity of fluorescence was compared between the ipsi- and contralateral dorsal horn to the affected limb, and between dorsal horn segments of all horses. RESULTS Iba-1 expression was higher in the ipsilateral dorsal horn of the affected limb in contrast to the contralateral side dorsal horn. GFAP markers did not demonstrate increased astrocytic activity on the dorsal horn ipsilateral side to the distal limb lesion of affected horses. Horses with acute lameness predominantly had a spherical shape microglial phenotype, while cells from chronic lameness cases had variable morphology. Astrocytes evidenced small somas and large processes in both acute and chronic lameness, with higher GFAP localization in the main branches. As in the case of rodents, the localization of microglia and astrocytes in horses was mainly situated within laminae I, II and III. CONCLUSIONS AND CLINICAL RELEVANCE Iba-1 and GFAP are functional and morphological markers of spinal microglial cells and astrocytes in horses with lameness.
Collapse
|
79
|
Meneses CS, Müller HY, Herzberg DE, Uberti B, Bustamante HA, Werner MP. Immunofluorescence characterization of spinal cord dorsal horn microglia and astrocytes in horses. PeerJ 2017; 5:e3965. [PMID: 29085760 PMCID: PMC5661433 DOI: 10.7717/peerj.3965] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/06/2017] [Indexed: 12/12/2022] Open
Abstract
The role of glial cells in pain modulation has recently gathered attention. The objective of this study was to determine healthy spinal microglia and astrocyte morphology and disposition in equine spinal cord dorsal horns using Iba-1 and GFAP/Cx-43 immunofluorescence labeling, respectively. Five adult horses without visible wounds or gait alterations were selected. Spinal cord segments were obtained post-mortem for immunohistochemical and immunocolocalization assays. Immunodetection of spinal cord dorsal horn astrocytes was done using a polyclonal goat antibody raised against Glial Fibrillary Acidic Protein (GFAP) and a polyclonal rabbit antibody against Connexin 43 (Cx-43). For immunodetection of spinal cord dorsal horn microglia, a polyclonal rabbit antibody against a synthetic peptide corresponding to the C-terminus of ionized calcium-binding adaptor molecule 1 (Iba-1) was used. Epifluorescence and confocal images were obtained for the morphological and organizational analysis. Evaluation of shape, area, cell diameter, cell process length and thickness was performed on dorsal horn microglia and astrocyte. Morphologically, an amoeboid spherical shape with a mean cell area of 92.4 + 34 µm2 (in lamina I, II and III) was found in horse microglial cells, located primarily in laminae I, II and III. Astrocyte primary stem branches (and cellular bodies to a much lesser extent) are mainly detected using GFAP. Thus, double GFAP/Cx-43 immunolabeling was needed in order to accurately characterize the morphology, dimension and cell density of astrocytes in horses. Horse and rodent astrocytes seem to have similar dimensions and localization. Horse astrocyte cells have an average diameter of 56 + 14 µm, with a main process length of 28 + 8 µm, and thickness of 1.4 + 0.3 µm, mainly situated in laminae I, II and III. Additionally, a close association between end-point astrocyte processes and microglial cell bodies was found. These results are the first characterization of cell morphology and organizational aspects of horse spinal glia. Iba-1 and GFAP/Cx-43 can successfully immune-label microglia and astrocytes respectively in horse spinal cords, and thus reveal cell morphology and corresponding distribution within the dorsal horn laminae of healthy horses. The conventional hyper-ramified shape that is normally visible in resting microglial cells was not found in horses. Instead, horse microglial cells had an amoeboid spherical shape. Horse protoplasmic astroglia is significantly smaller and structurally less complex than human astrocytes, with fewer main GFAP processes. Instead, horse astrocytes tend to be similar to those found in rodent’s model, with small somas and large cell processes. Microglia and astrocytes were found in the more superficial regions of the dorsal horn, similarly to that previously observed in humans and rodents. Further studies are needed to demonstrate the molecular mechanisms involved in the neuron-glia interaction in horses.
Collapse
Affiliation(s)
| | - Heine Yacob Müller
- Veterinary Sciences Graduate School, Universidad Austral de Chile, Valdivia, Chile
| | | | - Benjamín Uberti
- Veterinary Clinical Sciences Department, Universidad Austral de Chile, Valdivia, Chile
| | | | | |
Collapse
|
80
|
Attenuation of mechanical pain hypersensitivity by treatment with Peptide5, a connexin-43 mimetic peptide, involves inhibition of NLRP3 inflammasome in nerve-injured mice. Exp Neurol 2017; 300:1-12. [PMID: 29055716 DOI: 10.1016/j.expneurol.2017.10.016] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 09/22/2017] [Accepted: 10/17/2017] [Indexed: 02/07/2023]
Abstract
Connexin43 (Cx43) hemichannels in spinal cord astrocytes are implicated in the maintenance of neuropathic pain following peripheral nerve injury. Peptide5 is a Cx43 mimetic peptide that blocks hemichannels. In this study, we investigated the effects of spinal delivery of Peptide5 on mechanical pain hypersensitivity in two mouse models of neuropathic pain, peripheral nerve injury and chemotherapy-induced peripheral neuropathy (CIPN). We demonstrated that 10days following a chronic constriction injury (CCI) of the sciatic nerve, Cx43 expression, co-localised predominantly with astrocytes, was increased in the ipsilateral L3-L5 lumbar spinal cord. An intrathecal injection of Peptide5 into nerve-injured mice, on day 10 when pain was well-established, caused significant improvement in mechanical pain hypersensitivity 8h after injection. Peptide5 treatment resulted in significantly reduced Cx43, and microglial and astrocyte activity in the dorsal horn of the spinal cord, as compared to control saline-treated CCI mice. Further in vitro investigations on primary astrocyte cultures showed that 1h pre-treatment with Peptide5 significantly reduced adenosine triphosphate (ATP) release in response to extracellular calcium depletion. Since ATP is a known activator of the NOD-like receptor protein 3 (NLRP3) inflammasome complex, a key mediator of neuroinflammation, we examined the effects of Peptide5 treatment on NLRP3 inflammasome expression. We found that NLRP3, its adaptor apoptosis-associated spec-like protein (ASC) and caspase-1 protein were increased in the ipsilateral spinal cord of CCI mice and reduced to naïve levels following Peptide5 treatment. In the models of oxaliplatin- and paclitaxel-induced peripheral neuropathy, treatment with Peptide5 had no effect on mechanical pain hypersensitivity. Interestingly, in these CIPN models, although spinal Cx43 expression was significantly increased at day 13 following chemotherapy, NLRP3 expression was not altered. These results suggest that the analgesic effect of Peptide5 is specifically achieved by reducing NLRP3 expression. Together, our findings demonstrate that blocking Cx43 hemichannels with Peptide5 after nerve injury attenuates mechanical pain hypersensitivity by specifically targeting the NLRP3 inflammasome in the spinal cord.
Collapse
|
81
|
Leybaert L, Lampe PD, Dhein S, Kwak BR, Ferdinandy P, Beyer EC, Laird DW, Naus CC, Green CR, Schulz R. Connexins in Cardiovascular and Neurovascular Health and Disease: Pharmacological Implications. Pharmacol Rev 2017; 69:396-478. [PMID: 28931622 PMCID: PMC5612248 DOI: 10.1124/pr.115.012062] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Connexins are ubiquitous channel forming proteins that assemble as plasma membrane hemichannels and as intercellular gap junction channels that directly connect cells. In the heart, gap junction channels electrically connect myocytes and specialized conductive tissues to coordinate the atrial and ventricular contraction/relaxation cycles and pump function. In blood vessels, these channels facilitate long-distance endothelial cell communication, synchronize smooth muscle cell contraction, and support endothelial-smooth muscle cell communication. In the central nervous system they form cellular syncytia and coordinate neural function. Gap junction channels are normally open and hemichannels are normally closed, but pathologic conditions may restrict gap junction communication and promote hemichannel opening, thereby disturbing a delicate cellular communication balance. Until recently, most connexin-targeting agents exhibited little specificity and several off-target effects. Recent work with peptide-based approaches has demonstrated improved specificity and opened avenues for a more rational approach toward independently modulating the function of gap junctions and hemichannels. We here review the role of connexins and their channels in cardiovascular and neurovascular health and disease, focusing on crucial regulatory aspects and identification of potential targets to modify their function. We conclude that peptide-based investigations have raised several new opportunities for interfering with connexins and their channels that may soon allow preservation of gap junction communication, inhibition of hemichannel opening, and mitigation of inflammatory signaling.
Collapse
Affiliation(s)
- Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Paul D Lampe
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Stefan Dhein
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Brenda R Kwak
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Peter Ferdinandy
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Eric C Beyer
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Dale W Laird
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Christian C Naus
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Colin R Green
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Rainer Schulz
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| |
Collapse
|
82
|
Wang H, Sun X. Carbon Monoxide-Releasing Molecule-2 Inhibits Connexin 43-Hemichannel Activity in Spinal Cord Astrocytes to Attenuate Neuropathic Pain. J Mol Neurosci 2017; 63:58-69. [DOI: 10.1007/s12031-017-0957-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 07/26/2017] [Indexed: 12/30/2022]
|
83
|
Chen F, Chen F, Shang Z, Shui Y, Wu G, Liu C, Lin Z, Lin Y, Yu L, Kang D, Tao W, Li Y. White matter microstructure degenerates in patients with postherpetic neuralgia. Neurosci Lett 2017; 656:152-157. [DOI: 10.1016/j.neulet.2017.07.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 07/05/2017] [Accepted: 07/14/2017] [Indexed: 11/30/2022]
|
84
|
Charvériat M, Naus CC, Leybaert L, Sáez JC, Giaume C. Connexin-Dependent Neuroglial Networking as a New Therapeutic Target. Front Cell Neurosci 2017; 11:174. [PMID: 28694772 PMCID: PMC5483454 DOI: 10.3389/fncel.2017.00174] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 06/08/2017] [Indexed: 12/12/2022] Open
Abstract
Astrocytes and neurons dynamically interact during physiological processes, and it is now widely accepted that they are both organized in plastic and tightly regulated networks. Astrocytes are connected through connexin-based gap junction channels, with brain region specificities, and those networks modulate neuronal activities, such as those involved in sleep-wake cycle, cognitive, or sensory functions. Additionally, astrocyte domains have been involved in neurogenesis and neuronal differentiation during development; they participate in the “tripartite synapse” with both pre-synaptic and post-synaptic neurons by tuning down or up neuronal activities through the control of neuronal synaptic strength. Connexin-based hemichannels are also involved in those regulations of neuronal activities, however, this feature will not be considered in the present review. Furthermore, neuronal processes, transmitting electrical signals to chemical synapses, stringently control astroglial connexin expression, and channel functions. Long-range energy trafficking toward neurons through connexin-coupled astrocytes and plasticity of those networks are hence largely dependent on neuronal activity. Such reciprocal interactions between neurons and astrocyte networks involve neurotransmitters, cytokines, endogenous lipids, and peptides released by neurons but also other brain cell types, including microglial and endothelial cells. Over the past 10 years, knowledge about neuroglial interactions has widened and now includes effects of CNS-targeting drugs such as antidepressants, antipsychotics, psychostimulants, or sedatives drugs as potential modulators of connexin function and thus astrocyte networking activity. In physiological situations, neuroglial networking is consequently resulting from a two-way interaction between astrocyte gap junction-mediated networks and those made by neurons. As both cell types are modulated by CNS drugs we postulate that neuroglial networking may emerge as new therapeutic targets in neurological and psychiatric disorders.
Collapse
Affiliation(s)
| | - Christian C Naus
- Department of Cellular and Physiological Science, Life Science Institute, University of British ColumbiaVancouver, BC, Canada
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent UniversityGhent, Belgium
| | - Juan C Sáez
- Departamento de Fisiología, Pontificia Universidad Católica de ChileSantiago, Chile.,Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto MilenioValparaíso, Chile
| | - Christian Giaume
- Center of Interdisciplinary Research in Biology, Collège de FranceParis, France
| |
Collapse
|
85
|
Abstract
Rapid advances in Ca2+ imaging techniques enable us to simultaneously monitor the activities of hundreds of astrocytes in the intact brain, thus providing a powerful tool for understanding the functions of both host and engrafted astrocytes in sensory processing in vivo. These techniques include both improved Ca2+ indicators and advanced optical recording methods. Astrocytes in multiple cortical and sub-cortical areas are able to respond to the corresponding sensory modalities. These sensory stimuli produce astrocytic Ca2+ responses through different cellular mechanisms. In addition, it has been suggested that astrocytic gene deficiencies in various sensory systems cause impairments in sensory circuits and cognition. Therefore, glial transplantation would be a potentially interesting approach for the cell-based therapy for glia-related disorders. There are multiple cell sources for glial transplantation, including neural stem cells, glial progenitors, and pluripotent stem cells. Both in vitro and in vivo studies have shown that engrafted astrocytes derived from these cell sources are capable of responding to sensory stimulation by elevating the intracellular Ca2+ concentration. These results indicate that engrafted astrocytes not only morphologically but also functionally integrate into the host neural network. Until now, many animal studies have proven that glial transplantation would be a good choice for treating multiple glial disorders. Together, these studies on the sensory responses of host and engrafted astrocytes have provided us a novel perspective in both neuron-glia circuit functions and future treatment strategies for glial disorders.
Collapse
Affiliation(s)
- Kuan Zhang
- Brain Research Center and State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University, Chongqing, China
| | - Xiaowei Chen
- Brain Research Center and State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University, Chongqing, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| |
Collapse
|
86
|
Chen G, Luo X, Qadri MY, Berta T, Ji RR. Sex-Dependent Glial Signaling in Pathological Pain: Distinct Roles of Spinal Microglia and Astrocytes. Neurosci Bull 2017; 34:98-108. [PMID: 28585113 DOI: 10.1007/s12264-017-0145-y] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 03/16/2017] [Indexed: 12/18/2022] Open
Abstract
Increasing evidence suggests that spinal microglia regulate pathological pain in males. In this study, we investigated the effects of several microglial and astroglial modulators on inflammatory and neuropathic pain following intrathecal injection in male and female mice. These modulators were the microglial inhibitors minocycline and ZVEID (a caspase-6 inhibitor) and the astroglial inhibitors L-α-aminoadipate (L-AA, an astroglial toxin) and carbenoxolone (a connexin 43 inhibitor), as well as U0126 (an ERK kinase inhibitor) and D-JNKI-1 (a c-Jun N-terminal kinase inhibitor). We found that spinal administration of minocycline or ZVEID, or Caspase6 deletion, reduced formalin-induced inflammatory and nerve injury-induced neuropathic pain primarily in male mice. In contrast, intrathecal L-AA reduced neuropathic pain but not inflammatory pain in both sexes. Intrathecal U0126 and D-JNKI-1 reduced neuropathic pain in both sexes. Nerve injury caused spinal upregulation of the astroglial markers GFAP and Connexin 43 in both sexes. Collectively, our data confirmed male-dominant microglial signaling but also revealed sex-independent astroglial signaling in the spinal cord in inflammatory and neuropathic pain.
Collapse
Affiliation(s)
- Gang Chen
- Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA. .,Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
| | - Xin Luo
- Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - M Yawar Qadri
- Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Temugin Berta
- Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA.,Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, OH, 45267, USA
| | - Ru-Rong Ji
- Department of Anesthesiology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA
| |
Collapse
|
87
|
Nielsen BS, Hansen DB, Ransom BR, Nielsen MS, MacAulay N. Connexin Hemichannels in Astrocytes: An Assessment of Controversies Regarding Their Functional Characteristics. Neurochem Res 2017; 42:2537-2550. [DOI: 10.1007/s11064-017-2243-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/17/2017] [Accepted: 03/17/2017] [Indexed: 12/19/2022]
|
88
|
Truncated TrkB.T1-Mediated Astrocyte Dysfunction Contributes to Impaired Motor Function and Neuropathic Pain after Spinal Cord Injury. J Neurosci 2017; 37:3956-3971. [PMID: 28270575 DOI: 10.1523/jneurosci.3353-16.2017] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 02/03/2017] [Accepted: 02/08/2017] [Indexed: 12/30/2022] Open
Abstract
Following spinal cord injury (SCI), astrocytes demonstrate long-lasting reactive changes, which are associated with the persistence of neuropathic pain and motor dysfunction. We previously demonstrated that upregulation of trkB.T1, a truncated isoform of the brain-derived neurotrophic factor receptor (BDNF), contributes to gliosis after SCI, but little is known about the effects of trkB.T1 on the function of astrocytes. As trkB.T1 is the sole isoform of trkB receptors expressed on astrocytes, we examined the function of trkB.T1-driven astrocytes in vitro and in vivo Immunohistochemistry showed that trkB.T1+ cells were significantly upregulated 7 d after injury, with sustained elevation in white matter through 8 weeks. The latter increase was predominantly found in astrocytes. TrkB.T1 was also highly expressed by neurons and microglia/macrophages at 7 d after injury and declined by 8 weeks. RNA sequencing of cultured astrocytes derived from trkB.T1+/+ (WT) and trkB.T1-/- (KO) mice revealed downregulation of migration and proliferation pathways in KO astrocytes. KO astrocytes also exhibited slower migration/proliferation in vitro in response to FBS or BDNF compared with WT astrocytes. Reduced proliferation of astrocytes was also confirmed after SCI in astrocyte-specific trkB.T1 KO mice; using mechanical allodynia and pain-related measurements on the CatWalk, these animals also showed reduced hyperpathic responses, along with improved motor coordination. Together, our data indicate that trkB.T1 in astrocytes contributes to neuropathic pain and neurological dysfunction following SCI, suggesting that trkB.T1 may provide a novel therapeutic target for SCI.SIGNIFICANCE STATEMENT Neuropathic pain after spinal cord injury (SCI) may in part be caused by upregulation of the brain-derived neurotrophic factor (BDNF) receptor trkB.T1, a truncated isoform of BDNF. TrkB.T1 is the only isoform of tropomyosin-related receptor kinase type B (trkB) receptors expressed on astrocytes. Here, we showed that trkB.T1 is significantly increased in the injured mouse spinal cord, where it is predominantly found in astrocytes. RNA sequencing of cultured astrocytes demonstrated downregulation of migration and proliferation pathways in trkB.T1 KO astrocytes. This was validated in vivo, where deletion of trkB.T1 in astrocytes reduced cell proliferation and migration. After SCI, astrocyte-specific trkB.T1 KO mice showed reduced hyperpathic responses and improved motor coordination. Therefore, the trkB.T1 receptor plays a significant pathophysiological role after SCI, and may provide a novel therapeutic target for SCI.
Collapse
|
89
|
Yang Z, Lv Q, Wang Z, Dong X, Yang R, Zhao W. Identification of crucial genes associated with rat traumatic spinal cord injury. Mol Med Rep 2017; 15:1997-2006. [PMID: 28260098 PMCID: PMC5364992 DOI: 10.3892/mmr.2017.6267] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 12/09/2016] [Indexed: 11/05/2022] Open
Abstract
The aim of the present study was to investigate the key genes associated with traumatic spinal cord injuries (TSCI). The dataset GSE52763 was downloaded from the Gene Expression Omnibus, for which lumbar spinal cord samples were obtained from rats at 1 and 3 weeks following contusive spinal cord injury and 1 week subsequent to a sham laminectomy, and used to identify differentially expressed genes (DEGs). Functional enrichment analysis, co‑expression analysis and transcription factor (TF) identification were performed for DEGs common to the 1 and 3 week injury samples. In total, 234 upregulated and 51 downregulated DEGs were common to the 1 and 3 week injury samples. The upregulated DEGs were significantly enriched in Gene Ontology terms concerning immunity (e.g. Itgal and Ccl2) and certain pathways, including natural killer cell mediated cytotoxicity [e.g. Ras‑related C3 botulinum toxin substrate 2 (Rac2) and TYRO protein tyrosine kinase binding protein (Tyrobp)]. The downregulated DEGs were highly enriched in female gonad development [e.g. progesterone receptor (Pgr)], and the steroid biosynthesis pathway. A total of 139 genes had co‑expression associations and the majority of them were upregulated genes. The upregulated co‑expressed genes were predominantly enriched in biological regulation, including TGFB induced factor homeobox 1 (Tgif1) and Rac2. The downregulated co‑expressed genes were enriched in anatomical structure development (e.g. Dnm3). A total of 92 co‑expressed genes composed the protein‑protein interaction network. Additionally, 9 TFs (e.g. Pgr and Tgif1) were identified from the DEGs. It was hypothesized that the genes including Tgif1, Rac2, Tyrobp, and Pgr may be closely associated with TSCI.
Collapse
Affiliation(s)
- Zibin Yang
- Department of Spinal Surgery, The People's Hospital of Dali Prefecture, Dali, Yunnan 671000, P.R. China
| | - Qiao Lv
- Department of Spinal Surgery, The People's Hospital of Dali Prefecture, Dali, Yunnan 671000, P.R. China
| | - Zhengxiang Wang
- Department of Spinal Surgery, The People's Hospital of Dali Prefecture, Dali, Yunnan 671000, P.R. China
| | - Xiliang Dong
- Department of Spinal Surgery, The People's Hospital of Dali Prefecture, Dali, Yunnan 671000, P.R. China
| | - Rongxin Yang
- Department of Spinal Surgery, The People's Hospital of Dali Prefecture, Dali, Yunnan 671000, P.R. China
| | - Wei Zhao
- Department of Spinal Surgery, The People's Hospital of Dali Prefecture, Dali, Yunnan 671000, P.R. China
| |
Collapse
|
90
|
Pereira A. Astroglial hydro-ionic waves guided by the extracellular matrix: An exploratory model. J Integr Neurosci 2017; 16:57-72. [DOI: 10.3233/jin-160003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Alfredo Pereira
- Institute of Biosciences, São Paulo State University, Brazil. E-mail:
| |
Collapse
|
91
|
Unconventional Role of Caspase-6 in Spinal Microglia Activation and Chronic Pain. Mediators Inflamm 2017; 2017:9383184. [PMID: 28270702 PMCID: PMC5320069 DOI: 10.1155/2017/9383184] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 11/06/2016] [Indexed: 12/30/2022] Open
Abstract
Chronic pain affects ~20% of the worldwide population. The clinical management of chronic pain is mostly palliative and results in limited success. Current treatments mostly target the symptoms or neuronal signaling of chronic pain. It has been increasingly recognized that glial cells, such as microglia, and inflammatory signaling play a major role in the pathogenesis of chronic pain. Caspases (CASPs) are a family of protease enzymes involved in apoptosis and inflammation. They are pivotal components in a variety of neurological diseases. However, little is known about the role of CASPs in microglial modulation as to chronic pain. In particular, our recent studies have shown that CASP6 regulates chronic pain via microglial inflammatory signaling. Inhibition of microglia and CASP signaling might provide a new strategy for the prevention and treatment of chronic pain.
Collapse
|
92
|
Reversal of TRESK Downregulation Alleviates Neuropathic Pain by Inhibiting Activation of Gliocytes in the Spinal Cord. Neurochem Res 2017; 42:1288-1298. [PMID: 28160200 DOI: 10.1007/s11064-016-2170-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 11/03/2016] [Accepted: 12/28/2016] [Indexed: 10/20/2022]
Abstract
Despite the consensus that activation of TWIK-related spinal cord K+ (TRESK) might contribute to the pathogenesis of chronic pain, the specific mechanisms underlying the transfer and development of pain signals still remain obscure. In the present study, we validated that TRESK was expressed in neurons instead of glial cells. Furthermore, in the SNI model of neuropathic pain (NP), downregulation of TRESK in spinal cord neurons resulted in upregulation of connexin 36 (Cx36) and connexin 43 (Cx43), both being subtypes of gap junctions in the spinal cord, with gliocytes in the spinal cord activated ultimately. Compared with SNI rats, intrathecal injection of TRESK gene recombinant adenovirus significantly downregulated the expression levels of Cx36 and Cx43 and suppressed the activation of gliocytes in the spinal cord, with hyperalgesia significantly reduced. In conclusion, TRESK contributes to the pathogenesis of NP by upregulation of synaptic transmission and activation of gliocytes.
Collapse
|
93
|
Walters ET. How is chronic pain related to sympathetic dysfunction and autonomic dysreflexia following spinal cord injury? Auton Neurosci 2017; 209:79-89. [PMID: 28161248 DOI: 10.1016/j.autneu.2017.01.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/24/2017] [Accepted: 01/25/2017] [Indexed: 12/29/2022]
Abstract
Autonomic dysreflexia (AD) and neuropathic pain occur after severe injury to higher levels of the spinal cord. Mechanisms underlying these problems have rarely been integrated in proposed models of spinal cord injury (SCI). Several parallels suggest significant overlap of these mechanisms, although the relationships between sympathetic function (dysregulated in AD) and nociceptive function (dysregulated in neuropathic pain) are complex. One general mechanism likely to be shared is central sensitization - enhanced responsiveness and synaptic reorganization of spinal circuits that mediate sympathetic reflexes or that process and relay pain-related information to the brain. Another is enhanced sensory input to spinal circuits caused by extensive alterations in primary sensory neurons. Both AD and SCI-induced neuropathic pain are associated with spinal sprouting of peptidergic nociceptors that might increase synaptic input to the circuits involved in AD and SCI pain. In addition, numerous nociceptors become hyperexcitable, hypersensitive to chemicals associated with injury and inflammation, and spontaneously active, greatly amplifying sensory input to sensitized spinal circuits. As discussed with the aid of a preliminary functional model, these effects are likely to have mutually reinforcing relationships with each other, and with consequences of SCI-induced interruption of descending excitatory and inhibitory influences on spinal circuits, with SCI-induced inflammation in the spinal cord and in DRGs, and with activity in sympathetic fibers within DRGs that promotes local inflammation and spontaneous activity in sensory neurons. This model suggests that interventions selectively targeting hyperactivity in C-nociceptors might be useful for treating chronic pain and AD after high SCI.
Collapse
Affiliation(s)
- Edgar T Walters
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA.
| |
Collapse
|
94
|
Lees JG, Makker PGS, Tonkin RS, Abdulla M, Park SB, Goldstein D, Moalem-Taylor G. Immune-mediated processes implicated in chemotherapy-induced peripheral neuropathy. Eur J Cancer 2017; 73:22-29. [PMID: 28104535 DOI: 10.1016/j.ejca.2016.12.006] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 12/13/2016] [Indexed: 12/29/2022]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) and associated neuropathic pain are challenging complications of cancer treatment. Many of the major classes of chemotherapeutics can cause neurotoxicity and significantly modulate the immune system. There is ongoing investigation regarding whether reciprocal crosstalk between the nervous and immune systems occurs and, indeed, contributes to neuropathic pain during treatment with chemotherapeutics. An emerging concept is that neuroinflammation is one of the major mechanisms underlying CIPN. Here, we discuss recent findings, which provide insight into this complex process of neuroimmune interactions. Findings show limited infiltration of leukocytes into the nervous system of CIPN animals and varying degrees of peripheral and central glial activation depending on the chemotherapeutic drug, dose, schedule, and timing. Most evidence suggests an increase in pro-inflammatory cytokine expression and changes in immune signalling pathways. There is, however, limited evidence available from human studies and it remains unclear whether neuroinflammatory responses are the cause of neuropathy or a bystander effect of the chemotherapy treatment.
Collapse
Affiliation(s)
- Justin G Lees
- School of Medical Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Preet G S Makker
- School of Medical Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Ryan S Tonkin
- School of Medical Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Munawwar Abdulla
- School of Medical Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Susanna B Park
- Brain and Mind Centre, University of Sydney, NSW, 2050, Australia; Prince of Wales Clinical School, University of New South Wales, Sydney, NSW, 2052, Australia
| | - David Goldstein
- Prince of Wales Clinical School, University of New South Wales, Sydney, NSW, 2052, Australia; Department of Medical Oncology, Prince of Wales Hospital, Sydney, 2031, Australia
| | - Gila Moalem-Taylor
- School of Medical Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
| |
Collapse
|
95
|
Jeanson T, Duchêne A, Richard D, Bourgoin S, Picoli C, Ezan P, Mouthon F, Giaume C, Hamon M, Charvériat M. Potentiation of Amitriptyline Anti-Hyperalgesic-Like Action By Astroglial Connexin 43 Inhibition in Neuropathic Rats. Sci Rep 2016; 6:38766. [PMID: 27941941 PMCID: PMC5150232 DOI: 10.1038/srep38766] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/10/2016] [Indexed: 02/06/2023] Open
Abstract
Antidepressants, prescribed as first line treatment of neuropathic pain, have a limited efficacy and poorly tolerated side effects. Because recent studies pointed out the implication of astroglial connexins (Cx) in both neuropathic pain and antidepressive treatment, we investigated whether their blockade by mefloquine could modulate the action of the tricyclic antidepressant amitriptyline. Using primary cultures, we found that both mefloquine and amitriptyline inhibited Cx43-containing gap junctions, and that the drug combination acted synergically. We then investigated whether mefloquine could enhance amitriptyline efficacy in a preclinical model of neuropathic pain. Sprague-Dawley rats that underwent chronic unilateral constriction injury (CCI) to the sciatic nerve (SN) were treated with either amitriptyline, mefloquine or the combination of both drugs. Whereas acute treatments were ineffective, chronic administration of amitriptyline reduced CCI-SN-induced hyperalgesia-like behavior, and this effect was markedly enhanced by co-administration of mefloquine, which was inactive on its own. No pharmacokinetic interactions between both drugs were observed and CCI-SN-induced neuroinflammatory and glial activation markers remained unaffected by these treatments in dorsal root ganglia and spinal cord. Mechanisms downstream of CCI-SN-induced neuroinflammation and glial activation might therefore be targeted. Connexin inhibition in astroglia could represent a promising approach towards improving neuropathic pain therapy by antidepressants.
Collapse
Affiliation(s)
- Tiffany Jeanson
- Theranexus, Lyon, France.,CIRB, Collège de France, Paris, France
| | | | - Damien Richard
- CHU Clermont-Ferrand, Service de Pharmacologie Médicale, Clermont-Ferrand, France
| | | | | | | | | | | | | | | |
Collapse
|
96
|
Choi SR, Roh DH, Yoon SY, Kwon SG, Choi HS, Han HJ, Beitz AJ, Lee JH. Astrocyte sigma-1 receptors modulate connexin 43 expression leading to the induction of below-level mechanical allodynia in spinal cord injured mice. Neuropharmacology 2016; 111:34-46. [PMID: 27567941 DOI: 10.1016/j.neuropharm.2016.08.027] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/21/2016] [Accepted: 08/23/2016] [Indexed: 01/13/2023]
Abstract
We have previously shown using a spinal cord injury (SCI) model that gap junctions contribute to the early spread of astrocyte activation in the lumbar spinal cord and that this astrocyte communication plays critical role in the induction of central neuropathic pain. Sigma-1 receptors (Sig-1Rs) have been implicated in spinal astrocyte activation and the development of peripheral neuropathic pain, yet their contribution to central neuropathic pain remains unknown. Thus, we investigated whether SCI upregulates spinal Sig-1Rs, which in turn increase the expression of the astrocytic gap junction protein, connexin 43 (Cx43) leading to the induction of central neuropathic pain. A thoracic spinal cord hemisection significantly increased both astrocyte activation and Cx43 expression in lumbar dorsal horn. Sig-1Rs were also increased in lumbar dorsal horn astrocytes, but not neurons or microglia. Intrathecal injection of an astrocyte metabolic inhibitor (fluorocitrate); a gap junction/hemichannel blocker (carbenoxolone); or a Cx43 mimetic peptide (43Gap26) significantly reduced SCI-induced bilateral below-level mechanical allodynia. Blockade of Sig-1Rs with BD1047 during the induction phase of pain significantly suppressed the SCI-induced development of mechanical allodynia, astrocyte activation, increased expression of Cx43 in both total and membrane levels, and increased association of Cx43 with Sig-1R. However, SCI did not change the expression of oligodendrocyte (Cx32) or neuronal (Cx36) gap junction proteins. These findings demonstrate that SCI activates astrocyte Sig-1Rs leading to increases in the expression of the gap junction protein, Cx43 and astrocyte activation in the lumbar dorsal horn, and ultimately contribute to the induction of bilateral below-level mechanical allodynia.
Collapse
Affiliation(s)
- Sheu-Ran Choi
- Department of Veterinary Physiology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Dae-Hyun Roh
- Department of Maxillofacial Tissue Regeneration and Research Center for Tooth and Periodontal Tissue Regeneration, School of Dentistry, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Seo-Yeon Yoon
- Pain Cognitive Function Research Center, Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Soon-Gu Kwon
- Department of Veterinary Physiology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Hoon-Seong Choi
- Department of Veterinary Physiology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Ho-Jae Han
- Department of Veterinary Physiology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Alvin J Beitz
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, MN 55108, USA
| | - Jang-Hern Lee
- Department of Veterinary Physiology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.
| |
Collapse
|
97
|
Lee GH, Jang B, Choi HS, Kim HJ, Park JH, Jeon YC, Carp RI, Kim YS, Choi EK. Upregulation of Connexin 43 Expression Via C-Jun N-Terminal Kinase Signaling in Prion Disease. J Alzheimers Dis 2016; 49:1005-19. [PMID: 26599051 DOI: 10.3233/jad-150283] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Prion infection leads to neuronal cell death, glial cell activation, and the accumulation of misfolded prion proteins. However, the altered cellular environments in animals with prion diseases are poorly understood. In the central nervous system, cells connect the cytoplasm of adjacent cells via connexin (Cx)-assembled gap junction channels to allow the direct exchange of small molecules, including ions, neurotransmitters, and signaling molecules, which regulate the activities of the connected cells. Here, we investigate the role of Cx43 in the pathogenesis of prion diseases. Upregulated Cx43 expression, which was dependent on c-Jun N-Terminal Kinase (JNK)/c-Jun signaling cascades, was found in prion-affected brain tissues and hippocampal neuronal cells. Scrapie infection-induced Cx43 formed aggregated plaques within the cytoplasmic compartments at the cell-cell interfaces. The ethidium bromide (EtBr) uptake assay and scrape-loading dye transfer assay demonstrated that increased Cx43 has functional consequences for the activity of Cx43 hemichannels. Interestingly, blockade of PrPSc accumulation reduced Cx43 expression through the inhibition of JNK signaling, indicating that PrPSc accumulation may be directly involved in JNK activation-mediated Cx43 upregulation. Overall, our findings describe a scrapie infection-mediated novel regulatory signaling pathway of Cx43 expression and may suggest a role for Cx43 in the pathogenesis of prion diseases.
Collapse
Affiliation(s)
- Geon-Hwi Lee
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea.,Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Gangwon-do, Republic of Korea
| | - Byungki Jang
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea
| | - Hong-Seok Choi
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea.,Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Gangwon-do, Republic of Korea
| | - Hee-Jun Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea
| | - Jeong-Ho Park
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea.,Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Gangwon-do, Republic of Korea
| | - Yong-Chul Jeon
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea
| | - Richard I Carp
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Yong-Sun Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea.,Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Gangwon-do, Republic of Korea
| | - Eun-Kyoung Choi
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea.,Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Gangwon-do, Republic of Korea
| |
Collapse
|
98
|
Kramer JLK, Minhas NK, Jutzeler CR, Erskine ELKS, Liu LJW, Ramer MS. Neuropathic pain following traumatic spinal cord injury: Models, measurement, and mechanisms. J Neurosci Res 2016; 95:1295-1306. [PMID: 27617844 DOI: 10.1002/jnr.23881] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/19/2016] [Accepted: 07/19/2016] [Indexed: 02/06/2023]
Abstract
Neuropathic pain following spinal cord injury (SCI) is notoriously difficult to treat and is a high priority for many in the SCI population. Resolving this issue requires animal models fidelic to the clinical situation in terms of injury mechanism and pain phenotype. This Review discusses the means by which neuropathic pain has been induced and measured in experimental SCI and compares these with human outcomes, showing that there is a substantial disconnection between experimental investigations and clinical findings in a number of features. Clinical injury level is predominantly cervical, whereas injury in the laboratory is modeled mainly at the thoracic cord. Neuropathic pain is primarily spontaneous or tonic in people with SCI (with a relatively smaller incidence of allodynia), but measures of evoked responses (to thermal and mechanical stimuli) are almost exclusively used in animals. There is even the question of whether pain per se has been under investigation in most experimental SCI studies rather than simply enhanced reflex activity with no affective component. This Review also summarizes some of the problems related to clinical assessment of neuropathic pain and how advanced imaging techniques may circumvent a lack of patient/clinician objectivity and discusses possible etiologies of neuropathic pain following SCI based on evidence from both clinical studies and animal models, with examples of cellular and molecular changes drawn from the entire neuraxis from primary afferent terminals to cortical sensory and affective centers. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- John L K Kramer
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Nikita K Minhas
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Catherine R Jutzeler
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Erin L K S Erskine
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Lisa J W Liu
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Matt S Ramer
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
99
|
The pathophysiological role of astrocytic endothelin-1. Prog Neurobiol 2016; 144:88-102. [DOI: 10.1016/j.pneurobio.2016.04.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/23/2016] [Accepted: 04/25/2016] [Indexed: 12/13/2022]
|
100
|
|