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Yang R, Du J, Li L, Xu X, Liang S. Central role of purinergic receptors with inflammation in neuropathic pain-related macrophage-SGC-neuron triad. Neuropharmacology 2023; 228:109445. [PMID: 36740014 DOI: 10.1016/j.neuropharm.2023.109445] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 01/16/2023] [Accepted: 01/25/2023] [Indexed: 02/05/2023]
Abstract
Adenosine triphosphate (ATP) acts on P2 purinergic receptors as an extracellular signaling molecule. P2 purinergic receptors include P2X ionotropic receptors and P2Y metabotropic receptors. Satellite glial cells (SGCs) and macrophages express P2X and P2Y receptors. Inflammatory cytokines and pro-nociceptive mediators are released by activated macrophages and SGCs, which can act on neurons to promote excitability and firing. In the primary sensory ganglia, in response to signals of injury, SGCs and macrophages accumulate around primary sensory neurons, forming a macrophage-SGC-neuron triad. In addition to affecting the pathological alterations of inflammation-related neuropathic pain, inflammatory cytokines and pro-nociceptive mediators are released by the action of ATP on P2X and P2Y receptors in macrophages and SGCs. Macrophages and SGCs work together to enhance and prolong neuropathic pain. The macrophage-SGC-neuron triad communicates with each other through ATP and other inflammatory mediators and maintains and promotes the initiation and development of inflammation related-neuropathic pain. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
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Affiliation(s)
- Runan Yang
- Neuropharmacology Laboratory of Physiology Department, Basic Medical School of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Junpei Du
- Neuropharmacology Laboratory of Physiology Department, Basic Medical School of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Lin Li
- Neuropharmacology Laboratory of Physiology Department, Basic Medical School of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Xiumei Xu
- Neuropharmacology Laboratory of Physiology Department, Basic Medical School of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Shangdong Liang
- Neuropharmacology Laboratory of Physiology Department, Basic Medical School of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, People's Republic of China.
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Spinal cord astrocyte P2X7Rs mediate the inhibitory effect of electroacupuncture on visceral hypersensitivity of rat with irritable bowel syndrome. Purinergic Signal 2023; 19:43-53. [PMID: 35389158 PMCID: PMC9984627 DOI: 10.1007/s11302-021-09830-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 11/17/2021] [Indexed: 10/18/2022] Open
Abstract
This study explored the role of P2X7 receptors in spinal cord astrocytes in the electroacupuncture-induced inhibition of visceral hypersensitivity (VH) in rats with irritable bowel syndrome (IBS). Visceral hypersensitivity of IBS was intracolonically induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). Visceromotor responses to colorectal distension (CRD-20,40,60,80 mmHg) and abdominal withdrawal reflex scoring (AWRs) were recorded after electroacupuncture at bilateral Zusanli (ST36) and Sanyinjiao (SP6) acupoints to evaluate the analgesic effect of electroacupuncture on visceral pain in rats with IBS. Fluorocitric acid (FCA), an astrocyte activity inhibitor, was injected intrathecally before electroacupuncture intervention and AWRs were recorded. Western blot and real-time qPCR were used to detect the expression of NMDA and P2X7 receptor to observe the regulation effect of electroacupuncture on NMDA receptor in the spinal cord of rats with visceral hypersensitivity. Intrathecal injection of P2X7 agonist or antagonist was administered before electroacupuncture treatment. To observe the effect of P2X7 receptor in spinal astrocytes on the inhibition of visceral hyperalgesia by electroacupuncture, the changes of AWR score, NMDA receptor in the spinal cord, and GFAP expression in astrocytes were detected. Inflammation of the colon had basically subsided at day 21 post-TNBS; persistent visceral hypersensitivity could be suppressed by electroacupuncture. This analgesic effect could be inhibited by FCA. The analgesic effect, downregulation of NMDA receptor NR1 subunit, and P2X7 protein of electroacupuncture were all reversed by FCA. P2X7 receptor antagonist A740003 can cooperate with EA to carry out analgesic effect in rats with visceral pain and downregulate the expression of NR1, NR2B, and GFAP in spinal dorsal horn. However, the P2X7 receptor agonist BzATP could partially reverse the analgesic effect of EA, inhibiting the downregulatory effect of EA on the expression of NR1, NR2B, and GFAP. These results indicate that EA may downregulate the expression of the NMDA receptor by inhibiting the P2X7 receptor in the spinal cord, thereby inhibiting spinal cord sensitization in IBS rats with visceral pain, in which astrocytes are an important medium.
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Ita ME, Singh S, Troche HR, Welch RL, Winkelstein BA. Intra-articular MMP-1 in the spinal facet joint induces sustained pain and neuronal dysregulation in the DRG and spinal cord, and alters ligament kinematics under tensile loading. Front Bioeng Biotechnol 2022; 10:926675. [PMID: 35992346 PMCID: PMC9382200 DOI: 10.3389/fbioe.2022.926675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/27/2022] [Indexed: 12/03/2022] Open
Abstract
Chronic joint pain is a major healthcare challenge with a staggering socioeconomic burden. Pain from synovial joints is mediated by the innervated collagenous capsular ligament that surrounds the joint and encodes nociceptive signals. The interstitial collagenase MMP-1 is elevated in painful joint pathologies and has many roles in collagen regulation and signal transduction. Yet, the role of MMP-1 in mediating nociception in painful joints remains poorly understood. The goal of this study was to determine whether exogenous intra-articular MMP-1 induces pain in the spinal facet joint and to investigate effects of MMP-1 on mediating the capsular ligament’s collagen network, biomechanical response, and neuronal regulation. Intra-articular MMP-1 was administered into the cervical C6/C7 facet joints of rats. Mechanical hyperalgesia quantified behavioral sensitivity before, and for 28 days after, injection. On day 28, joint tissue structure was assessed using histology. Multiscale ligament kinematics were defined under tensile loading along with microstructural changes in the collagen network. The amount of degraded collagen in ligaments was quantified and substance P expression assayed in neural tissue since it is a regulatory of nociceptive signaling. Intra-articular MMP-1 induces behavioral sensitivity that is sustained for 28 days (p < 0.01), absent any significant effects on the structure of joint tissues. Yet, there are changes in the ligament’s biomechanical and microstructural behavior under load. Ligaments from joints injected with MMP-1 exhibit greater displacement at yield (p = 0.04) and a step-like increase in the number of anomalous reorganization events of the collagen fibers during loading (p ≤ 0.02). Collagen hybridizing peptide, a metric of damaged collagen, is positively correlated with the spread of collagen fibers in the unloaded state after MMP-1 (p = 0.01) and that correlation is maintained throughout the sub-failure regime (p ≤ 0.03). MMP-1 injection increases substance P expression in dorsal root ganglia (p < 0.01) and spinal cord (p < 0.01) neurons. These findings suggest that MMP-1 is a likely mediator of neuronal signaling in joint pain and that MMP-1 presence in the joint space may predispose the capsular ligament to altered responses to loading. MMP-1-mediated pathways may be relevant targets for treating degenerative joint pain in cases with subtle or no evidence of structural degeneration.
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Affiliation(s)
- Meagan E. Ita
- Spine Pain Research Laboratory, Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Sagar Singh
- Spine Pain Research Laboratory, Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Harrison R. Troche
- Spine Pain Research Laboratory, Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Rachel L. Welch
- Spine Pain Research Laboratory, Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Beth A. Winkelstein
- Spine Pain Research Laboratory, Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, United States
- *Correspondence: Beth A. Winkelstein,
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Corydalis decumbens Can Exert Analgesic Effects in a Mouse Neuropathic Pain Model by Modulating MAPK Signaling. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2022; 2022:7722951. [PMID: 35669365 PMCID: PMC9166945 DOI: 10.1155/2022/7722951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 04/02/2022] [Accepted: 04/21/2022] [Indexed: 11/17/2022]
Abstract
Objectives This study is aimed at investigating the analgesic effect of the administration of Corydalis decumbens (CD) in a mouse model of postherpetic neuralgia (PHN) and at elucidating its mechanism of analgesic action. Methods Adult Kunming (KM) mice were randomly divided into control, CD, and vehicle-treated groups. Neuropathic pain was induced with a single intraperitoneal injection of resiniferatoxin (RTX). Thermal hyperalgesia was assessed with a hot/cold plate test, and mechanical allodynia was evaluated using von Frey filaments. The activation states of astrocytes, microglia, and the mitogen-activated protein kinase (MAPK) pathway in the spinal cord were determined by immunofluorescence staining and Western blot analysis of Iba-1, GFAP, phospho-p38, and phospho-Jun N-terminal kinase (JNK). Results RTX diminished thermal sensitivity and gradually increased sensitivity to tactile stimulation. The expression of Iba-1, GFAP, phospho-p38 MAPK, and phospho-JNK was upregulated in the RTX-induced postherpetic neuralgia mouse model. Systemic treatment with CD significantly ameliorated thermal sensitivity and mechanical hyperalgesia and was accompanied by a reduction in the expression of Iba-1 and GFAP and reduced phosphorylation of p38 and JNK. Conclusions This study suggests that CD is effective at ameliorating mechanical hyperalgesia in PHN mice and that its mechanism of action may involve modulation of MAPK phosphorylation and glial cell activation. Thus, CD may be a promising alternative therapy for PHN.
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Yu TW, Lane HY, Lin CH. Novel Therapeutic Approaches for Alzheimer's Disease: An Updated Review. Int J Mol Sci 2021; 22:ijms22158208. [PMID: 34360973 PMCID: PMC8348485 DOI: 10.3390/ijms22158208] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/25/2021] [Accepted: 07/27/2021] [Indexed: 12/16/2022] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disease and accounts for most cases of dementia. The prevalence of AD has increased in the current rapidly aging society and contributes to a heavy burden on families and society. Despite the profound impact of AD, current treatments are unable to achieve satisfactory therapeutic effects or stop the progression of the disease. Finding novel treatments for AD has become urgent. In this paper, we reviewed novel therapeutic approaches in five categories: anti-amyloid therapy, anti-tau therapy, anti-neuroinflammatory therapy, neuroprotective agents including N-methyl-D-aspartate (NMDA) receptor modulators, and brain stimulation. The trend of therapeutic development is shifting from a single pathological target to a more complex mechanism, such as the neuroinflammatory and neurodegenerative processes. While drug repositioning may accelerate pharmacological development, non-pharmacological interventions, especially repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), also have the potential for clinical application. In the future, it is possible for physicians to choose appropriate interventions individually on the basis of precision medicine.
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Affiliation(s)
- Tien-Wei Yu
- Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan;
| | - Hsien-Yuan Lane
- Department of Psychiatry and Brain Disease Research Center, China Medical University Hospital, Taichung 40402, Taiwan
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402, Taiwan
- Department of Psychology, College of Medical and Health Sciences, Asia University, Taichung 41354, Taiwan
- Correspondence: (H.-Y.L.); (C.-H.L.); Tel.: +886-921-067-260 (H.-Y.L.); +886-7-7317123 (ext. 8753) (C.-H.L.); Fax: +886-4-2236-1042 (H.-Y.L.); +886-7-7326817 (C.-H.L.)
| | - Chieh-Hsin Lin
- Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan;
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402, Taiwan
- School of Medicine, Chang Gung University, Taoyuan 333, Taiwan
- Correspondence: (H.-Y.L.); (C.-H.L.); Tel.: +886-921-067-260 (H.-Y.L.); +886-7-7317123 (ext. 8753) (C.-H.L.); Fax: +886-4-2236-1042 (H.-Y.L.); +886-7-7326817 (C.-H.L.)
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Fu J, Mu G, Qiu L, Zhao J, Ou C. c-Abl-p38 α signaling pathway mediates dopamine neuron loss in trigeminal neuralgia. Mol Pain 2021; 16:1744806920930855. [PMID: 32498644 PMCID: PMC7278317 DOI: 10.1177/1744806920930855] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Trigeminal neuralgia is a common neuropathic pain in the head and face. The pathogenesis of trigeminal neuralgia is complex, and so far, the pathogenesis of trigeminal neuralgia involving peripheral and central nervous inflammation theory has not been explained clearly. The loss of dopamine neurons in striatum may play an important role in the development of trigeminal nerve, but the reason is not clear. C-Abl is a nonreceptor tyrosine kinase, which can be activated abnormally in the environment of neuroinflammation and cause neuron death. We found that in the rat model of infraorbital nerve ligation trigeminal neuralgia, the pain threshold decreased, the expression of c-Abl increased significantly, the downstream activation product p38 was also activated abnormally and the loss of dopamine neurons in striatum increased. When treated with imatinib mesylate (STI571), a specific c-Abl family kinase inhibitor, the p38 expression was decreased and the loss of dopaminergic neurons was reduced. The mechanical pain threshold of rats was also improved. In conclusion, c-abl-p38 signaling pathway may play an important role in the pathogenesis of trigeminal neuralgia, and it is one of the potential targets for the treatment of trigeminal neuralgia.
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Affiliation(s)
- Jia Fu
- Department of Pain, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Guo Mu
- Department of Pain, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Ling Qiu
- Department of Pain, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jiaomei Zhao
- Department of Pain, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Cehua Ou
- Department of Pain, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Laboratory of Anesthesiology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
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Ding S, Yu Q, Wang J, Zhu L, Li T, Guo X, Zhang X. Activation of ATF3/AP-1 signaling pathway is required for P2X3-induced endometriosis pain. Hum Reprod 2021; 35:1130-1144. [PMID: 32303740 DOI: 10.1093/humrep/deaa061] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 02/26/2020] [Indexed: 12/22/2022] Open
Abstract
STUDY QUESTION Does P2X ligand-gated ion channel 3 (P2X3) play a role in endometriosis pain? SUMMARY ANSWER Upregulation of P2X3 in dorsal root ganglia (DRG) tissues via the activating transcription factor 3 (ATF3)/activator protein (AP)-1 pathway contributed to endometriosis-associated hyperalgesia, which could be attenuated by the chitosan oligosaccharide stearic acid (CSOSA)/liposomes (LPs)/SP600125 delivery system. WHAT IS KNOWN ALREADY Infiltrating nerve fibers and elevated nociceptors in endometriotic lesions are associated with endometriosis pain. P2X3 has been demonstrated to play an important role in neuropathic pain. STUDY DESIGN, SIZE, DURATION A rat model of endometriosis was used to investigate the signaling pathways involved in P2X3-induced pain. PARTICIPANTS/MATERIALS, SETTING, METHODS Degrees of hyperalgesia, endogenous adenosine 5'-triphosphate (ATP) contents and P2X3 expression levels in endometriotic lesions and DRG tissues were detected in a rat model of endometriosis. The expression levels of ATF3 and P2X3 were measured using qRT-PCR, western blot analysis and immunofluorescence analysis after adenosine 5'-diphosphate (ADP) exposure in DRG cells. Plasmids encoding ATF3 and its siRNA were used to investigate the role of ATF3 on ADP-induced P2X3 upregulation. The activity of ATF binding to the P2X3 promoter was evaluated by using chromatin immunoprecipitation (CHIP) and luciferase assays. SP600125, an inhibitor of c-JUN N-terminal kinase, was wrapped in CSOSA/LPs delivery system and its inhibitory effects on ADP-induced upregulation of P2X3 in DRG cells and endometriosis-induced hyperalgesia in rats were tested. MAIN RESULTS AND THE ROLE OF CHANCE The concentrations of endogenous ATP and expression levels of P2X3 were significantly increased in both endometriotic lesions and DRG tissues in endometriosis rat models and were found to be positively correlated with the severity of hyperalgesia. In DRG cells, P2X3 expression levels were elevated by ADP stimulation, but dramatically inhibited by blocking ATF3 with its siRNA and SP600125. CHIP and luciferase assay showed that ADP increased the binding of ATF3 to the P2X3 promoter, resulting in an increase in P2X3 expression levels. In the CSOSA/LPs/SP600125 delivery system, the drug could be effectively concentrated in endometriotic lesions, and it could alleviate endometriosis-induced hyperalgesia, reduce the size of endometriotic lesions and attenuate upregulated P2X3 expression levels in endometriosis rat models. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION Changes in the sensitivity and function of P2X3 caused by endometriosis need to be further investigated. WIDER IMPLICATIONS OF THE FINDINGS This study indicates that ATP and the P2X3 receptor are involved in endometriosis pain, thus providing a novel therapeutic approach for the treatment of endometriosis pain by targeting the P2X3 receptor. STUDY FUNDING/COMPETING INTEREST(S) This work was funded by National Key R&D Program of China (Grant No. 2017YFC1001202) and National Natural Science Foundation of China (Grant Nos. 81974225, 81671429 and 81471433). There are no competing interests.
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Affiliation(s)
- Shaojie Ding
- Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, Zhejiang, P.R. China
| | - Qin Yu
- Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, Zhejiang, P.R. China
| | - Jianzhang Wang
- Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, Zhejiang, P.R. China
| | - Libo Zhu
- Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, Zhejiang, P.R. China
| | - Tiantian Li
- Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, Zhejiang, P.R. China
| | - Xinyue Guo
- Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, Zhejiang, P.R. China
| | - Xinmei Zhang
- Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, Zhejiang, P.R. China
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Hu X, Liu Y, Wu J, Liu Y, Liu W, Chen J, Yang F. Inhibition of P2X7R in the amygdala ameliorates symptoms of neuropathic pain after spared nerve injury in rats. Brain Behav Immun 2020; 88:507-514. [PMID: 32311494 DOI: 10.1016/j.bbi.2020.04.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 03/23/2020] [Accepted: 04/11/2020] [Indexed: 12/26/2022] Open
Abstract
The amygdala circuitry and P2X7 receptor (P2X7R) have both been shown to play important roles in the modulation of neuropathic pain (NP). However, little is known about the functional role of P2X7R in the amygdala for the regulation of NP. This study aims to evaluate the alleviative effect of intra-amygdala microinfusion of a pharmacological antagonist of P2X7R (A-438079) on NP and explore its possible mechanism of action. Male Sprague-Dawley rats were used to construct the animal model of NP through spared nerve injury (SNI). The SNI rats randomly received chronic bilateral microinjection of A-438079 (100 pmol/side) or saline into the amygdalae via cannulas. Mechanical paw withdrawal threshold (MWT) and thermal withdrawal duration (TWD) were measured by von Frey monofilaments. Besides, tail suspension test (TST), forced swimming test (FST), open field test (OFT) and sucrose preference test (SPT) were performed to assess depression- and anxiety-like behaviors. Immunofluorescence assay was employed to determine the levels of glial fibrillary acidic protein (GFAP), ionized calcium binding adaptor molecule 1 (IBA-1) and connexin 43 (Cx43) in the spinal cord. In addition, the change of growth associated protein 43 (GAP43) level in the spinal cord was assessed by Western blot. Our data showed that chronic treatment with A-438079 increased MWT and decreased TWD on days 11-21 post-SNI while decreased depression-like and anxiety-like behaviors. A-438079 administration significantly attenuated the elevated immunoreactivities of IBA-1 and GFAP in microglia and astrocytes after SNI. Furthermore, the decreased expression of GAP-43 in the spinal cord due to SNI was significantly attenuated by A-438079. However, when A-438079 and a pharmacological agonist (BzATP) of P2X7R were given simultaneously, all the effects caused by A-438079 alone were reversed. In brief, our study revealed the protective role of inhibiting P2X7R in the amygdala against symptoms associated with NP, possibly attributing to its inhibitory effects on spinal microglia and astrocytes.
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Affiliation(s)
- Xiaoling Hu
- Department of Anesthesiology, The First Affiliated Hospital of University of South China, Hunan Province 421001, China
| | - Yiming Liu
- Department of Anesthesiology, Affiliated Nanhua Hospital, University of South China, Hunan Province 421001, China
| | - Junting Wu
- Department of Anesthesiology, The First Affiliated Hospital of University of South China, Hunan Province 421001, China
| | - Yu Liu
- Department of Anesthesiology, The First Affiliated Hospital of University of South China, Hunan Province 421001, China
| | - Wenjie Liu
- Department of Anesthesiology, The First Affiliated Hospital of University of South China, Hunan Province 421001, China
| | - Ji Chen
- Department of Endocrinology, The First Affiliated Hospital of University of South China, Hunan Province 421001, China
| | - Fengrui Yang
- Department of Anesthesiology, The First Affiliated Hospital of University of South China, Hunan Province 421001, China; Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Zhou YQ, Liu DQ, Chen SP, Sun J, Wang XM, Tian YK, Wu W, Ye DW. Minocycline as a promising therapeutic strategy for chronic pain. Pharmacol Res 2018; 134:305-310. [PMID: 30042091 DOI: 10.1016/j.phrs.2018.07.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/03/2018] [Accepted: 07/03/2018] [Indexed: 01/25/2023]
Abstract
Chronic pain remains to be a clinical challenge due to insufficient therapeutic strategies. Minocycline is a member of the tetracycline class of antibiotics, which has been used in clinic for decades. It is frequently reported that minocycline may has many non-antibiotic properties, among which is its anti-nociceptive effect. The results from our lab and others suggest that minocycline exerts strong analgesic effect in animal models of chronic pain including visceral pain, chemotherapy-induced periphery neuropathy, periphery injury induced neuropathic pain, diabetic neuropathic pain, spinal cord injury, inflammatory pain and bone cancer pain. In this review, we summarize the mechanisms underlying the analgesic effect of minocycline in preclinical studies. Due to a good safety record when used chronically, minocycline may become a promising therapeutic strategy for chronic pain in clinic.
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Affiliation(s)
- Ya-Qun Zhou
- Anesthesiology Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dai-Qiang Liu
- Anesthesiology Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shu-Ping Chen
- Anesthesiology Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jia Sun
- Anesthesiology Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Mei Wang
- Anesthesiology Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu-Ke Tian
- Anesthesiology Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Wu
- Department of Orthopaedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Da-Wei Ye
- Cancer Center, Tongji Hospital, Tongji Medical college, Huazhong University of Science and Technology, Wuhan, China.
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Chen Y, Huang LYM. A simple and fast method to image calcium activity of neurons from intact dorsal root ganglia using fluorescent chemical Ca 2+ indicators. Mol Pain 2017; 13:1744806917748051. [PMID: 29212403 PMCID: PMC5731619 DOI: 10.1177/1744806917748051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Chemical calcium indicators have been commonly used to monitor calcium (Ca2+) activity in cell bodies, i.e., somata, of isolated dorsal root ganglion neurons. Recent studies have shown that dorsal root ganglion somata play an essential role in soma–glia interactions and actively participate in the transmission of nociceptive signals. It is therefore desirable to develop methods to study Ca2+ activity in neurons and glia in intact dorsal root ganglia. In our previous studies, we found that incubation of intact dorsal root ganglia with acetoxymethyl dye resulted in efficient Ca2+ dye loading into glial cells but limited dye loading into neurons. Here, we introduce a useful method to load Ca2+ dyes in intact dorsal root ganglion neurons through electroporation. We found that electroporation greatly facilitated loading of Fluo-4 acetoxymethyl, Oregon green bapta-1-488 acetoxymethyl, and Fluo-4 pentapotassium salt into dorsal root ganglion neurons. In contrast, electroporation did not further facilitate dye loading into glia. Using electroporation followed by incubation of acetoxymethyl form Ca2+ dye, we can load acetoxymethyl Ca2+ dye well in both neurons and glia. With this approach, we found that inflammation induced by complete Freund’s adjuvant significantly increased the incidence of neuron–glia interactions in dorsal root ganglia. We also confirmed the actions of capsaicin and morphine on Ca2+ responses in dorsal root ganglion neurons. Thus, by promoting the loading of Ca2+ dye in neurons and glia through electroporation and incubation, Ca2+ activities in neurons and neuron–glia interactions can be well studied in intact dorsal root ganglia.
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Affiliation(s)
- Yong Chen
- 1 Department of Neuroscience, Cell Biology and Anatomy, 12338 University of Texas Medical Branch, Galveston , TX, USA
| | - Li-Yen M Huang
- 1 Department of Neuroscience, Cell Biology and Anatomy, 12338 University of Texas Medical Branch, Galveston , TX, USA
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Wu J, Cheng Y, Zhang R, Liu D, Luo YM, Chen KL, Ren S, Zhang J. P2Y1R is involved in visceral hypersensitivity in rats with experimental irritable bowel syndrome. World J Gastroenterol 2017; 23:6339-6349. [PMID: 28974901 PMCID: PMC5603501 DOI: 10.3748/wjg.v23.i34.6339] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/15/2017] [Accepted: 06/19/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To evaluate the role of P2Y1R in visceral hypersensitivity in rats with experimental irritable bowel syndrome.
METHODS A rat model of irritable bowel syndrome was generated by intra-colonic administration of acetic acid (AA) and assessed by histology and myeloperoxidase (MPO) activity assay. Then P2Y1R expression in the colonic tissue was detected by Western blot. In order to explore the regulatory role of P2Y1R in visceral hypersensitivity, an agonist (MRS2365) and an antagonist (MRS2179) of P2Y1R were intra-colonically administered and effects were tested through a colorectal distension test. The abdominal withdrawal reflex and abdominal electromyography were tested during the course.
RESULTS Model assessment tests showed an obvious inflammatory reaction that appeared on the 2nd d after the AA injection, and the inflammatory reaction gradually recovered and almost disappeared on the 7th d. The model finished on day 8 and showed a clear feature of IBS that had no organic lesion. The average expression of P2Y1R was significantly higher in the AA group than in the naïve group (0.319 ± 0.02 vs 0.094 ± 0.016, P < 0.001). MRS2365 could effectively raise the colonic hypersensitivity status at intervention doses of 10 (AUC value from 0.30 ± 0.089 to 1.973 ± 0.127 mv·s, P < 0.01) and 100 μmol/L (AUC value from 0.290 ± 0.079 to 1.983 ± 0.195 mv·s, P < 0.01); MRS2179 could effectively reduce the hypersensitivity status at intervention dose of 100 μmol/L (from a mean baseline AUC value of 1.587 ± 0.099 mv·s to 0.140 ± 0.089 mv·s, P < 0.0001). Differences between the MRS2179 group (1.88 ± 1.45) and either the MRS2365 group (3.96 ± 0.19) or the combined treatment (MRS2179 and MRS2365) group (3.28 ± 0.11) were significant (P < 0.01).
CONCLUSION P2Y1R plays a regulatory role in visceral hypersensitivity in rats with experimental IBS. Specific antagonists of P2Y1R may have potential therapeutic value in treating abdominal pain in IBS.
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Affiliation(s)
- Jie Wu
- Department of Gastroenterology, The Second Affiliated Hospital of School of Medicine, Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
| | - Yan Cheng
- Department of Gastroenterology, The Second Affiliated Hospital of School of Medicine, Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
| | - Rong Zhang
- Department of Gastroenterology, Shaanxi Provincial People’s Hospital, Xi’an 710068, Shaanxi Province, China
| | - Dong Liu
- Department of Gastroenterology, The Second Affiliated Hospital of School of Medicine, Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
| | - Yu-Mei Luo
- Department of Gastroenterology, The First Affiliated Hospital of School of Medicine, Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China
| | - Kun-Lun Chen
- Fourth Cadre Ward, The Second Affiliated Hospital of School of Medicine, Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
| | - Song Ren
- Fourth Cadre Ward, The Second Affiliated Hospital of School of Medicine, Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
| | - Jun Zhang
- Department of Gastroenterology, The Second Affiliated Hospital of School of Medicine, Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
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12
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Cao S, Deng W, Li Y, Qin B, Zhang L, Yu S, Xie P, Xiao Z, Yu T. Chronic constriction injury of sciatic nerve changes circular RNA expression in rat spinal dorsal horn. J Pain Res 2017; 10:1687-1696. [PMID: 28761373 PMCID: PMC5522680 DOI: 10.2147/jpr.s139592] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Mechanisms of neuropathic pain are still largely unknown. Molecular changes in spinal dorsal horn may contribute to the initiation and development of neuropathic pain. Circular RNAs (circRNAs) have been identified as microRNA sponges and involved in various biological processes, but whether their expression profile changes in neuropathic pain condition is not reported. METHODS To test whether neuropathic pain influences circRNA expression, we developed a sciatic chronic constriction injury (CCI) model in rats. The CCI ipsilateral spinal dorsal horns of lumbar enlargement segments (L3-L5) were collected, and the total RNA was extracted and subjected to Arraystar Rat circRNA Microarray. Quantitative real-time polymerase chain reaction (qPCR) was used to confirm the circRNA expression profile. To estimate functions of differential circRNAs, bioinformatics analyses including gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes Pathway analyses were performed for the top 100 circRNAs and circRNA-microRNA networks were constructed for the top 10 circRNAs. RESULTS circRNA microarrays showed that 469 circRNAs were differentially expressed between CCI and sham-operated rats (fold change ≥2). In all, 363 of them were significantly upregulated, and the other 106 were downregulated in the CCI group. Three of them (circRNA_013779, circRNA_008008, and circRNA_003724) overexpressed >10 times after CCI insult. Expression levels of eight circRNAs were verified using qPCR. GO analysis revealed that thousands of predicted target genes were involved in the biological processes, cellular component, and molecular function; in addition, dozens of these genes were enriched in the Hippo signaling pathway, MAPK signaling pathway, and so on. Competing endogenous RNAs analysis showed that circRNA_008008 and circRNA_013779 are the two largest nodes in the circRNA-microRNA interaction network of the top 10 circRNAs. CONCLUSION CCI resulted in a comprehensive expression profile of circRNAs in the spinal dorsal horn in rats. CircRNAs in the dorsal horn could be helpful to reveal molecular mechanisms of neuropathic pain.
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Affiliation(s)
- Song Cao
- Department of Pain Medicine, Affiliated Hospital of Zunyi Medical University
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University
| | - Wenwen Deng
- Department of Cardiology, Affiliated Hospital of Zunyi Medical University
| | - Ying Li
- Department of Pain Medicine, Affiliated Hospital of Zunyi Medical University
| | - Bangyong Qin
- Department of Pain Medicine, Affiliated Hospital of Zunyi Medical University
| | - Lin Zhang
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University
| | - Shouyang Yu
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University
| | - Peng Xie
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University
| | - Zhi Xiao
- Research Center for Medicine and Biology, Zunyi Medical University, Zunyi, Guizhou, China
| | - Tian Yu
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University
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13
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Nascimento DSM, Potes CS, Soares ML, Ferreira AC, Malcangio M, Castro-Lopes JM, Neto FLM. Drug-Induced HSP90 Inhibition Alleviates Pain in Monoarthritic Rats and Alters the Expression of New Putative Pain Players at the DRG. Mol Neurobiol 2017; 55:3959-3975. [PMID: 28550532 DOI: 10.1007/s12035-017-0628-x] [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: 01/30/2017] [Accepted: 05/19/2017] [Indexed: 01/17/2023]
Abstract
Purinergic receptors (P2XRs) have been widely associated with pain states mostly due to their involvement in neuron-glia communication. Interestingly, we have previously shown that satellite glial cells (SGC), surrounding dorsal root ganglia (DRG) neurons, become activated and proliferate during monoarthritis (MA) in the rat. Here, we demonstrate that P2X7R expression increases in ipsilateral DRG after 1 week of disease, while P2X3R immunoreactivity decreases. We have also reported a significant induction of the activating transcriptional factor 3 (ATF3) in MA. In this study, we show that ATF3 knocked down in DRG cell cultures does not affect the expression of P2X7R, P2X3R, or glial fibrillary acidic protein (GFAP). We suggest that P2X7R negatively regulates P2X3R, which, however, is unlikely mediated by ATF3. Interestingly, we found that ATF3 knockdown in vitro induced significant decreases in the heat shock protein 90 (HSP90) expression. Thus, we evaluated in vivo the involvement of HSP90 in MA and demonstrated that the HSP90 messenger RNA levels increase in ipsilateral DRG of inflamed animals. We also show that HSP90 is mostly found in a cleaved form in this condition. Moreover, administration of a HSP90 inhibitor, 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), attenuated MA-induced mechanical allodynia in the first hours. The drug also reversed the HSP90 upregulation and cleavage. 17-DMAG seemed to attenuate glial activation and neuronal sensitization (as inferred by downregulation of GFAP and P2X3R in ipsilateral DRG) which might correlate with the observed pain alleviation. Our data indicate a role of HSP90 in MA pathophysiology, but further investigation is necessary to clarify the underlying mechanisms.
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Affiliation(s)
- Diana Sofia Marques Nascimento
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Catarina Soares Potes
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Miguel Luz Soares
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Laboratório de Apoio à Investigação em Medicina Molecular (LAIMM), Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - António Carlos Ferreira
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Laboratório de Apoio à Investigação em Medicina Molecular (LAIMM), Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Marzia Malcangio
- Wolfson Centre for Age Related Diseases, King's College London, London, UK
| | - José Manuel Castro-Lopes
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Fani Lourença Moreira Neto
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal. .,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal. .,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
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14
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Guth CM, Luo W, Jolayemi O, Chadalavada KS, Komalavilas P, Cheung-Flynn J, Brophy CM. Adenosine triphosphate as a molecular mediator of the vascular response to injury. J Surg Res 2017; 216:80-86. [PMID: 28807217 DOI: 10.1016/j.jss.2017.03.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/03/2017] [Accepted: 03/23/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND Human saphenous veins used for arterial bypass undergo stretch injury at the time of harvest and preimplant preparation. Vascular injury promotes intimal hyperplasia, the leading cause of graft failure, but the molecular events leading to this response are largely unknown. This study investigated adenosine triphosphate (ATP) as a potential molecular mediator in the vascular response to stretch injury, and the downstream effects of the purinergic receptor, P2X7R, and p38 MAPK activation. MATERIALS AND METHODS A subfailure stretch rat aorta model was used to determine the effect of stretch injury on release of ATP and vasomotor responses. Stretch-injured tissues were treated with apyrase, the P2X7R antagonist, A438079, or the p38 MAPK inhibitor, SB203580, and subsequent contractile forces were measured using a muscle bath. An exogenous ATP (eATP) injury model was developed and the experiment repeated. Change in p38 MAPK phosphorylation after stretch and eATP tissue injury was determined using Western blotting. Noninjured tissue was incubated in the p38 MAPK activator, anisomycin, and subsequent contractile function and p38 MAPK phosphorylation were analyzed. RESULTS Stretch injury was associated with release of ATP. Contractile function was decreased in tissue subjected to subfailure stretch, eATP, and anisomycin. Contractile function was restored by apyrase, P2X7R antagonism, and p38-MAPK inhibition. Stretch, eATP, and anisomycin-injured tissue demonstrated increased phosphorylation of p38 MAPK. CONCLUSIONS Taken together, these data suggest that the vascular response to stretch injury is associated with release of ATP and activation of the P2X7R/P38 MAPK pathway, resulting in contractile dysfunction. Modulation of this pathway in vein grafts after harvest and before implantation may reduce the vascular response to injury.
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Affiliation(s)
- Christy M Guth
- Department of Surgery, Vanderbilt University, Nashville, Tennessee.
| | - Weifung Luo
- Department of Surgery, Vanderbilt University, Nashville, Tennessee
| | - Olukemi Jolayemi
- Department of Surgery, Vanderbilt University, Nashville, Tennessee
| | | | | | | | - Colleen M Brophy
- Department of Surgery, Vanderbilt University, Nashville, Tennessee; VA Tennessee Valley Healthcare System, Nashville, Tennessee
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15
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Gao YH, Li CW, Wang JY, Tan LH, Duanmu CL, Jing XH, Chang XR, Liu JL. Effect of electroacupuncture on the cervicospinal P2X7 receptor/fractalkine/CX3CR1 signaling pathway in a rat neck-incision pain model. Purinergic Signal 2016; 13:215-225. [PMID: 28028627 DOI: 10.1007/s11302-016-9552-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/13/2016] [Indexed: 01/16/2023] Open
Abstract
Increasing evidence supports that acupuncture intervention is an effective approach for intraoperative and postoperative pain. Neuron-microglia crosstalk, mediated by the purinergic P2X7 receptor (R)/fractalkine/CX3CR1 cascade in the spinal cord dorsal horn, plays a pivotal role in pain processing. However, its involvement in the analgesic effect of electroacupuncture (EA) remains unclear. In this study, a rat neck-incision pain model was established by making a longitudinal incision along the midline of the neck and subsequent repeated mechanical stimulation. EA stimulation was applied to bilateral LI18, LI4-PC6, or ST36-GB34. The thermal pain threshold, cervicospinal ATP concentration, expression levels of purinergic P2XR and P2YR subunits mRNAs, and fractalkine, CX3CR1 and p38 MAPK proteins, were detected separately. The neck incision induced strong thermal hyperalgesia and upregulation of spinal ATP within 48 h. No significant change was found in thermal hyperalgesia after a single session of EA intervention. However, a single session of EA dramatically enhanced the neck incision-induced upregulation of ATP and upregulated the expression of P2X7R, which was reversed by two sessions of EA. Two sessions of EA at bilateral LI18 or LI4-PC6 attenuated hyperalgesia significantly, accompanied with downregulation of P2X7R/fractalkine/ CX3CR1 signaling after three sessions of EA. EA stimulation of LI18 or LI4-PC6 alleviates thermal hyperalgesia in neck-incision pain rats, which may be associated with its effects in regulating the neck incision-induced increase of ATP and P2X7R and subsequently suppressing fractalkine/CX3CR1 signaling in the cervical spinal cord.
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Affiliation(s)
- Y H Gao
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - C W Li
- College of Acupuncture and Moxibustion and Tui-na, Hunan University of Chinese Medicine, Changsha, Hunan Province, 410208, China.,First Affiliated Hospital of Hunan Traditional Chinese Medical College, Zhuzhou, Hunan Province, 412012, China
| | - J Y Wang
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - L H Tan
- Department of Biochemistry and Moleculobiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - C L Duanmu
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - X H Jing
- Meridian Research Center, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - X R Chang
- College of Acupuncture and Moxibustion and Tui-na, Hunan University of Chinese Medicine, Changsha, Hunan Province, 410208, China
| | - J L Liu
- Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
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