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Cheng F, Yan F, Yang A, Liu J, Ma J. Activation of G protein-coupled receptor 39 alleviates neuropathic pain and chronic inflammation. J Biochem Mol Toxicol 2024; 38:e23545. [PMID: 37842769 DOI: 10.1002/jbt.23545] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/20/2023] [Accepted: 09/26/2023] [Indexed: 10/17/2023]
Abstract
Neuropathic pain (NP) is mainly caused by lesions or diseases of the somatosensory nervous system and triggers severe physical burdens to patients. It is claimed that activated microglia-mediated neuroinflammation participates in the development of NP, which is regulated by p38 mitogen-activated protein kinase (MAPK)/nuclear factor-κappa B (NF-κB) p65 signaling. G protein-coupled receptor 39 (GPR39) is a trans-membrane protein involved in the activation of cellular transduction pathways, and TC-G 1008, a GPR39 agonist, is believed to have inhibitory effects on neuroinflammation. Our study will explore the possible alleviatory function of TC-G 1008 on NP in a rat model. GPR39 was found markedly downregulated in the spinal dorsal horn of chronic constriction injury (CCI)-stimulated rats. Rats were treated with CCI, followed by intranasal administration with 7.5 and 15 mg/kg TC-G 1008 at 1, 25, 49, and 73 h postmodeling, respectively. Drastically lowered values of paw withdrawal threshold and paw withdrawal latency, upregulated ionized calcium-binding adapter molecule 1, increased release of inflammatory cytokines, elevated spinal malondialdehyde levels, and reduced spinal glutathione peroxidase levels were observed in CCI-stimulated rats, all of which were markedly alleviated and rescued by TC-G 1008. Furthermore, the levels of p-p38/p38 and p-NF-κB p65 were found signally repressed in the spinal dorsal horn of CCI-stimulated rats, which was notably reversed by TC-G 1008. Collectively, TC-G 1008 markedly alleviated NP and neuroinflammation in CCI-treated rats. Our findings provide an attractive future direction for the treatment of NP.
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Affiliation(s)
- Fang Cheng
- Department of Anesthesiology and Pain Clinic, The Affiliated Lianyungang Oriental Hospital of Kangda College of Nanjing Medical University, Lianyungang, China
- Department of Oncology, The Affiliated Lianyungang Oriental Hospital of Xuzhou Medical University, Lianyungang, China
| | - Fengfeng Yan
- Department of Anesthesiology and Pain Clinic, The Affiliated Lianyungang Oriental Hospital of Kangda College of Nanjing Medical University, Lianyungang, China
- Department of Oncology, The Affiliated Lianyungang Oriental Hospital of Xuzhou Medical University, Lianyungang, China
| | - Aixing Yang
- Department of Anesthesiology and Pain Clinic, The Affiliated Lianyungang Oriental Hospital of Kangda College of Nanjing Medical University, Lianyungang, China
- Department of Oncology, The Affiliated Lianyungang Oriental Hospital of Xuzhou Medical University, Lianyungang, China
| | - Jing Liu
- Department of Anesthesiology and Pain Clinic, The Affiliated Lianyungang Oriental Hospital of Kangda College of Nanjing Medical University, Lianyungang, China
- Department of Oncology, The Affiliated Lianyungang Oriental Hospital of Xuzhou Medical University, Lianyungang, China
| | - Jianxin Ma
- Department of Oncology, The Affiliated Lianyungang Oriental Hospital of Xuzhou Medical University, Lianyungang, China
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Borghi SM, Fattori V, Ruiz-Miyazawa KW, Miranda-Sapla MM, Casagrande R, Pinge-Filho P, Pavanelli WR, Verri WA. Leishmania (L). amazonensis induces hyperalgesia in balb/c mice: Contribution of endogenous spinal cord TNFα and NFκB activation. Chem Biol Interact 2017; 268:1-12. [DOI: 10.1016/j.cbi.2017.02.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/27/2017] [Accepted: 02/14/2017] [Indexed: 02/07/2023]
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Khan M, Shunmugavel A, Dhammu TS, Matsuda F, Singh AK, Singh I. Oral administration of cytosolic PLA2 inhibitor arachidonyl trifluoromethyl ketone ameliorates cauda equina compression injury in rats. J Neuroinflammation 2015; 12:94. [PMID: 25971887 PMCID: PMC4436116 DOI: 10.1186/s12974-015-0311-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/28/2015] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Phospholipase A2 (PLA2)-derived proinflammatory lipid mediators such as prostaglandin E2 (PGE2), leukotrienes B4 (LTB4), lysophosphatidylcholine (LPC), and free fatty acids (FFA) are implicated in spinal cord injury (SCI) pathologies. Reducing the levels of these injurious bioactive lipid mediators is reported to ameliorate SCI. However, the specific role of the group IVA isoform of PLA2 cytosolic PLA2 (cPLA2) in lumbar spinal canal stenosis (LSS) due to cauda equina compression (CEC) injury is not clear. In this study, we investigated the role of cPLA2 in a rat model of CEC using a non-toxic cPLA2-preferential inhibitor, arachidonyl trifluoromethyl ketone (ATK). METHODS LSS was induced in adult female rats by CEC procedure using silicone blocks within the epidural spaces of L4 to L6 vertebrae. cPLA2 inhibitor ATK (7.5 mg/kg) was administered by oral gavage at 2 h following the CEC. cPLA2-derived injurious lipid mediators and the expression/activity of cPLA2, 5-lipoxygenase (5-LOX), and cyclooxygenase-2 (COX-2) were assessed. ATK-treated (CEC + ATK) were compared with vehicle-treated (CEC + VEH) animals in terms of myelin levels, pain threshold, and motor function. RESULTS ATK treatment of CEC animals reduced the phosphorylation of cPLA2 (pcPLA2) determined by Western blot, improved locomotor function evaluated by rotarod task, and reduced pain threshold evaluated by mechanical hyperalgesia method. Levels of FFA and LPC, along with PGE2 and LTB4, were reduced in CEC + ATK compared with CEC + VEH group. However, ATK treatment reduced neither the activity/expression of 5-LOX nor the expression of COX-2 in CEC + VEH animals. Increased cPLA2 activity in the spinal cord from CEC + VEH animals correlated well with decreased spinal cord as well as cauda equina fiber myelin levels, which were restored after ATK treatment. CONCLUSION The data indicate that cPLA2 activity plays a significant role in tissue injury and pain after LSS. Reducing the levels of proinflammatory and tissue damaging eicosanoids and the deleterious lipid mediator LPC shows therapeutic potential. ATK inhibits cPLA2 activity, thereby decreasing the levels of injurious lipid mediators, reducing pain, improving functional deficits, and conferring protection against LSS injury. Thus, it shows potential for preclinical evaluation in LSS.
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Affiliation(s)
- Mushfiquddin Khan
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, 29425, USA.
| | | | - Tajinder S Dhammu
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, 29425, USA.
| | - Fumiyo Matsuda
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, 29425, USA. .,School of Health Science, Kagoshima University, Kagoshima, Japan.
| | - Avtar K Singh
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA. .,Ralph H. Johnson VA Medical Center, Charleston, SC, USA.
| | - Inderjit Singh
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, 29425, USA.
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Souza GR, Cunha TM, Silva RL, Lotufo CM, Verri WA, Funez MI, Villarreal CF, Talbot J, Sousa LP, Parada CA, Cunha FQ, Ferreira SH. Involvement of nuclear factor kappa B in the maintenance of persistent inflammatory hypernociception. Pharmacol Biochem Behav 2015; 134:49-56. [PMID: 25902407 DOI: 10.1016/j.pbb.2015.04.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 04/07/2015] [Accepted: 04/15/2015] [Indexed: 01/09/2023]
Abstract
The pathophysiology of chronic inflammatory pain remains poorly understood. In this context, we developed an experimental model in which successive daily injection of prostaglandin E2 (PGE2) for 14days into rat hind paws produces a persistent state of hypernociception (i.e. decrease in mechanical nociceptive threshold). This state persists for more than 30days after discontinuing PGE2 injection. In the present study, we investigated the participation of nuclear factor kappa B (NF-κB), in the maintenance of this process. Mechanical hypernociception was evaluated using the electronic von Frey test. Activation of NF-κB signaling was measured through the determination of NF-κB p65 subunit translocation to the nucleus of dorsal root ganglion neurons (DRG) by immunofluorescence and western blotting. Herein, we detected an increase in NF-κB p65 subunit translocation to the nucleus of DRG neurons along with persistent inflammatory hypernociception compared with controls. Intrathecal treatment with either dexamethasone or PDTC (NF-κB activation inhibitor) after ending of the induction phase of the persistent inflammatory hypernociception, curtailed the hypernociception period as well as reducing NF-κB p65 subunit translocation. Treatment with antisense oligonucleotides against the NF-κB p65 subunit for 5 consecutive days also reduced persistent inflammatory hypernociception. Inhibition of PKA and PKCε reduced persistent inflammatory hypernociception, which was associated with inhibition of NF-κB p65 subunit translocation. Together these results suggest that peripheral activation of NF-κB by PKA and PKC in primary sensory neurons plays an important role in maintaining persistent inflammatory pain.
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Affiliation(s)
- Guilherme R Souza
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Thiago M Cunha
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Rangel L Silva
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Celina M Lotufo
- Instituto de Ciências Biomédicas, Federal University of Uberlandia, Umuarama, MG 38405-320 Uberlândia, Brazil
| | - Waldiceu A Verri
- Departamento de Ciencias Patologicas, Universidade Estadual de Londrina, Londrina, Parana, Brazil
| | - Mani I Funez
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Christiane F Villarreal
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Jhimmy Talbot
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Lirlândia P Sousa
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Carlos A Parada
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Fernando Q Cunha
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil.
| | - Sergio H Ferreira
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil.
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Spinal NF-κB and chemokine ligand 5 expression during spinal glial cell activation in a neuropathic pain model. PLoS One 2015; 10:e0115120. [PMID: 25635831 PMCID: PMC4312098 DOI: 10.1371/journal.pone.0115120] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 11/18/2014] [Indexed: 12/30/2022] Open
Abstract
Background The NF-κB pathway and chemokine (C-C motif) ligand 5 (CCL5) are involved in pain modulation; however, the precise mechanisms of their interactions in chronic neuropathic pain have yet to be established. Methods The present study examined the roles of spinal NF-κB and CCL5 in a neuropathic pain model after chronic constriction injury (CCI) surgery. CCI-induced pain facilitation was evaluated using the Plantar and von Frey tests. The changes in NF-κB and CCL5 expression were analyzed by immunohistochemistry and Western blot analyses. Results Spinal NF-κB and CCL5 expression increased after CCI surgery. Repeated intrathecal infusions of pyrrolidine dithiocarbamate (PDTC, a NF-κB inhibitor) decreased CCL5 expression, inhibited the activation of microglia and astrocytes, and attenuated CCI-induced allodynia and hyperalgesia. Intrathecal injection of a CCL5-neutralizing antibody attenuated CCI-induced pain facilitation and also suppressed spinal glial cell activation after CCI surgery. However, the CCL5-neutralizing antibody did not affect NF-κB expression. Furthermore, selective glial inhibitors, minocycline and fluorocitrate, attenuated the hyperalgesia induced by intrathecal CCL5. Conclusions The inhibition of spinal CCL5 expression may provide a new method to prevent and treat nerve injury-induced neuropathic pain.
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Luo JG, Zhao XL, Xu WC, Zhao XJ, Wang JN, Lin XW, Sun T, Fu ZJ. Activation of spinal NF-κB/p65 contributes to peripheral inflammation and hyperalgesia in rat adjuvant-induced arthritis. Arthritis Rheumatol 2014; 66:896-906. [PMID: 24757142 DOI: 10.1002/art.38328] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 12/17/2013] [Indexed: 12/27/2022]
Abstract
OBJECTIVE It is known that noxious stimuli from inflamed tissue may increase the excitability of spinal dorsal horn neurons (a process known as central sensitization), which can signal back and contribute to peripheral inflammation. However, the underlying mechanisms have yet to be fully defined. A number of recent studies have indicated that spinal NF-κB/p65 is involved in central sensitization, as well as pain-related behavior. Thus, the aim of this study was to determine whether NF-κB/p65 can facilitate a peripheral inflammatory response in rat adjuvant-induced arthritis (AIA). METHODS Lentiviral vectors encoding short hairpin RNAs that target NF-κB/p65 (LV-shNF-κB/p65) were constructed for gene silencing. The spines of rats with AIA were injected with LV-shNF-κB/p65 on day 3 or day 10 after treatment with Freund's complete adjuvant (CFA). During an observation period of 20 days, pain-related behavior, paw swelling, and joint histopathologic changes were evaluated. Moreover, the expression levels of spinal tumor necrosis factor α (TNFα), interleukin-1β (IL-1β), and cyclooxygenase 2 (COX-2) were assessed on day 14 after CFA treatment. RESULTS The presence of peripheral inflammation in rats with AIA induced an increase in NF-κB/p65 expression in the spinal cord, mainly in the dorsal horn neurons and astrocytes. Delivery of LV-shNF-κB/p65 to the spinal cord knocked down the expression of NF-κB/p65 and significantly attenuated hyperalgesia, paw edema, and joint destruction. In addition, spinal delivery of LV-shNF-κB/p65 reduced the overexpression of spinal TNFα, IL-1β, and COX-2. CONCLUSION These findings indicate that spinal NF-κB/p65 plays an important role in the initiation and development of both peripheral inflammation and hyperalgesia. Thus, inhibition of spinal NF-κB/p65 expression may provide a potential treatment to manage painful inflammatory disorders.
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Affiliation(s)
- Jian-Gang Luo
- Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
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Xu J, Zhu MD, Zhang X, Tian H, Zhang JH, Wu XB, Gao YJ. NFκB-mediated CXCL1 production in spinal cord astrocytes contributes to the maintenance of bone cancer pain in mice. J Neuroinflammation 2014; 11:38. [PMID: 24580964 PMCID: PMC3941254 DOI: 10.1186/1742-2094-11-38] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 02/21/2014] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Bone cancer pain (BCP) is one of the most disabling factors in patients suffering from primary bone cancer or bone metastases. Recent studies show several chemokines (for example, CCL2, CXCL10) in the spinal cord are involved in the pathogenesis of BCP. Here we investigated whether and how spinal CXCL1 contributes to BCP. METHODS Mouse prostate tumor cell line, RM-1 cells were intramedullary injected into the femur to induce BCP. The mRNA expression of CXCL1 and CXCR2 was detected by quantitative real-time PCR. The protein expression and distribution of CXCL1, NFκB, and CXCR2 was examined by immunofluorescence staining and western blot. The effect of CXCL1 neutralizing antibody, NFκB antagonist, and CXCR2 antagonist on pain hypersensitivity was checked by behavioral testing. RESULTS Intramedullary injection of RM-1 cells into the femur induced cortical bone damage and persistent (>21 days) mechanical allodynia and heat hyperalgesia. Tumor cell inoculation also produced CXCL1 upregulation in activated astrocytes in the spinal cord for more than 21 days. Inhibition of CXCL1 by intrathecal administration of CXCL1 neutralizing antibody at 7 days after inoculation attenuated mechanical allodynia and heat hyperalgesia. In cultured astrocytes, TNF-α induced robust CXCL1 expression, which was dose-dependently decreased by NFκB inhibitor. Furthermore, inoculation induced persistent NFκB phosphorylation in spinal astrocytes. Intrathecal injection of NFκB inhibitor attenuated BCP and reduced CXCL1 increase in the spinal cord. Finally, CXCR2, the primary receptor of CXCL1, was upregulated in dorsal horn neurons after inoculation. Inhibition of CXCR2 by its selective antagonist SB225002 attenuated BCP. CONCLUSION NFκB mediates CXCL1 upregulation in spinal astrocytes in the BCP model. In addition, CXCL1 may be released from astrocytes and act on CXCR2 on neurons in the spinal cord and be involved in the maintenance of BCP. Inhibition of the CXCL1 signaling may provide a new therapy for BCP management.
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Affiliation(s)
| | | | | | | | | | | | - Yong-Jing Gao
- Pain Research Laboratory, Institute of Nautical Medicine, Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong 226001, China.
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Li L, Xie R, Hu S, Wang Y, Yu T, Xiao Y, Jiang X, Gu J, Hu CY, Xu GY. Upregulation of cystathionine beta-synthetase expression by nuclear factor-kappa B activation contributes to visceral hypersensitivity in adult rats with neonatal maternal deprivation. Mol Pain 2012; 8:89. [PMID: 23249427 PMCID: PMC3545973 DOI: 10.1186/1744-8069-8-89] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 12/12/2012] [Indexed: 12/11/2022] Open
Abstract
Background Irritable bowel syndrome (IBS) is characterized by chronic visceral hyperalgesia (CVH) that manifested with persistent or recurrent abdominal pain and altered bowel movement. However, the pathogenesis of the CVH remains unknown. The aim of this study was to investigate roles of endogenous hydrogen sulfide (H2S) producing enzyme cystathionine beta-synthetase (CBS) and p65 nuclear factor-kappa B subunits in CVH. Results CVH was induced by neonatal maternal deprivation (NMD) in male rats on postnatal days 2–15 and behavioral experiments were conducted at the age of 7–15 weeks. NMD significantly increased expression of CBS in colon-innervating DRGs from the 7th to 12th week. This change in CBS express is well correlated with the time course of enhanced visceromoter responses to colorectal distention (CRD), an indicator of visceral pain. Administration of AOAA, an inhibitor of CBS, produced a dose-dependent antinociceptive effect on NMD rats while it had no effect on age-matched healthy control rats. AOAA also reversed the enhanced neuronal excitability seen in colon-innervating DRGs. Application of NaHS, a donor of H2S, increased excitability of colon-innervating DRG neurons acutely dissociated from healthy control rats. Intrathecal injection of NaHS produced an acute visceral hyperalgesia. In addition, the content of p65 in nucleus was remarkably higher in NMD rats than that in age-matched controls. Intrathecal administration of PDTC, an inhibitor of p65, markedly reduced expression of CBS and attenuated nociceptive responses to CRD. Conclusion The present results suggested that upregulation of CBS expression, which is mediated by activation of p65, contributes to NMD-induced CVH. This pathway might be a potential target for relieving CVH in patients with IBS.
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Affiliation(s)
- Lin Li
- Department of Gastroenterology, the Second Affiliated Hospital, Soochow University, Suzhou 215123, PR China
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Kuang X, Huang Y, Gu HF, Zu XY, Zou WY, Song ZB, Guo QL. Effects of intrathecal epigallocatechin gallate, an inhibitor of Toll-like receptor 4, on chronic neuropathic pain in rats. Eur J Pharmacol 2011; 676:51-6. [PMID: 22173123 DOI: 10.1016/j.ejphar.2011.11.037] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 11/21/2011] [Accepted: 11/27/2011] [Indexed: 12/22/2022]
Abstract
Numerous studies revealed that spinal inflammation and immune response play an important role in neuropathic pain. In this study, we investigated the effects of intrathecal injection of a Toll-like receptor (TLR4) inhibitor epigallocatechin gallate (EGCG) on neuropathic pain induced by chronic constriction injury of the sciatic nerve (CCI). A total of 120 rats were randomly assigned into 4 groups: sham-operated group, CCI group, CCI plus normal saline group and CCI plus EGCG group. CCI and sham surgeries were performed and both thermal hyperalgesia and mechanical allodynia were tested. Lumbar spinal cord was sampled and the mRNA and protein expressions of TLR4 and High Mobility Group 1 protein (HMGB1) were detected, the contents of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-10 (IL-10) were measured by ELISA, and immunohistochemistry for nuclear factor kappa B (NF-κB) was also carried out. When compared with the sham group, both mechanical and heat pain thresholds were significantly decreased, and the mRNA and protein expressions of TLR4 and HMGB1, the contents of TNF-α, IL-1β and IL-10 in the spinal cords and NF-κB expression in the spinal dorsal horn were markedly increased in CCI rats (P<0.05). After intrathecal injection of EGCG (1mg/kg) once daily from 1day before to 3days after CCI surgery, the expressions of TLR4, NF-κB, HMGB1, TNF-α and IL-1β were markedly decreased while the content of IL-10 in the spinal cord increased significantly accompanied by dramatical improvement of pain behaviors in CCI rats (P<0.05). These results show that the TLR4 signaling pathway plays an important role in the occurrence and development of neuropathic pain, and the therapy targeting TLR4 might be a novel strategy in the treatment of neuropathic pain.
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Affiliation(s)
- Xin Kuang
- Department of Anesthesiology, Xiangya Hospital of Central South University, Changsha, Hunan Province 410008, People's Republic of China
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A chronic pain: inflammation-dependent chemoreceptor adaptation in rat carotid body. Respir Physiol Neurobiol 2011; 178:362-9. [PMID: 21397054 DOI: 10.1016/j.resp.2011.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 03/02/2011] [Accepted: 03/03/2011] [Indexed: 11/20/2022]
Abstract
Experiments in recent years have revealed labile electrophysiological and neurochemical phenotypes in primary afferent neurons exposed to specific stimulus conditions associated with the development of chronic pain. These studies collectively demonstrate that the mechanisms responsible for functional plasticity are primarily mediated by novel neuroimmune interactions involving circulating and resident immune cells and their secretory products, which together induce hyperexcitability in the primary sensory neurons. In another peripheral sensory modality, namely the arterial chemoreceptors, sustained stimulation in the form of chronic hypoxia (CH) elicits increased chemoafferent excitability from the mammalian carotid body. Previous studies which focused on functional changes in oxygen-sensitive type I cells in this organ have only partially elucidated the molecular and cellular mechanisms which initiate and control this adaptive response. Recent studies in our laboratory indicate a unique role for the immune system in regulating the chemo-adaptive response of the carotid body to physiologically relevant levels of hypoxia.
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Chou CW, Wong GT, Lim G, Wang S, Irwin MG, Mao J. Spatiotemporal pattern of concurrent spinal and supraspinal NF-κB expression after peripheral nerve injury. THE JOURNAL OF PAIN 2011; 12:13-21. [PMID: 20537956 PMCID: PMC2978259 DOI: 10.1016/j.jpain.2010.03.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 03/02/2010] [Accepted: 03/24/2010] [Indexed: 01/09/2023]
Abstract
UNLABELLED The expression of NF-κB in the spinal cord is associated with neuropathic pain. However, little is known about its expression beyond the spinal cord. Here we examined a spatial and temporal pattern of the NF-κB expression in both spinal and supraspinal regions. After chronic constriction injury (CCI) of the sciatic nerve, NF-κB (p65) expression was significantly increased in the ipsilateral spinal cord. In contrast, the NF-κB expression in the contralateral primary somatosensory cortex was decreased with no significant differences seen in the thalamus. In the contralateral anterior cingulate cortex, the NF-κB expression was increased significantly on day 14 as compared with the sham group. In the contralateral amygdala, the NF-κB expression showed a time-dependent downregulation after CCI, which became significant on day 14. MK-801 reduced nociceptive behaviors and reversed the direction of NF-κB expression. These results indicate that the CCI-induced expression of p65 NF-κB is both time-dependent and region-specific, in areas that process both sensory-discriminative and motivational-affective dimensions of pain. PERSPECTIVE This article presents a spatiotemporal mapping of the NF-κB expression in spinal and supraspinal regions after peripheral nerve injury. These findings point to an involvement of NF-κB beyond the spinal cord in both the sensory discriminative and emotional affective aspects of neuropathic pain processing.
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Affiliation(s)
- Chiu-Wen Chou
- MGH Center for Translational Pain Research, Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
- Department of Anaesthesiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Gordon T.C. Wong
- Department of Anaesthesiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Grewo Lim
- MGH Center for Translational Pain Research, Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Shuxing Wang
- MGH Center for Translational Pain Research, Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Michael G. Irwin
- Department of Anaesthesiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Jianren Mao
- MGH Center for Translational Pain Research, Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
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Intrathecal infusion of pyrrolidine dithiocarbamate for the prevention and reversal of neuropathic pain in rats using a sciatic chronic constriction injury model. Reg Anesth Pain Med 2010; 35:231-7. [PMID: 20921832 DOI: 10.1097/aap.0b013e3181df245b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND OBJECTIVES Recent studies have suggested that nuclear factor κB (NF-κB) may play a role in mediating nerve injury-induced neuropathic pain. Here, we examined the effects of intrathecal pyrrolidine dithiocarbamate (PDTC), a NF-κB inhibitor, on the development of neuropathic pain, spinal microglial activation, and CX3CR1 expression induced by sciatic chronic constriction injury (CCI) model in rats. METHODS Under chloral hydrate anesthesia, male Sprague-Dawley rats (300-350 g) fitted with intrathecal catheters underwent either sciatic CCI or sham surgery. Intrathecal saline or PDTC (100 or 1000 pmol/d) was infused 1 day before or 3 days after CCI (n = 8). The rat hind-paw withdrawal threshold to mechanical stimuli and withdrawal latency to radiant heat were determined before surgery and from days 1 to 7 after CCI. Spinal microglial activation was evaluated with OX-42 immunoreactivity, and spinal CX3CR1 expression was assessed by Western blotting. RESULTS Chronic constriction injury induced mechanical allodynia and thermal hyperalgesia and microglial activation as demonstrated by OX-42 expression. Whereas it had no apparent effect on spinal cord histology, intrathecal administration of PDTC prevented the development of the mechanical and thermal hyperalgesia and inhibited nerve injury-induced microglial activation and spinal CX3CR1 expression. CONCLUSIONS In this study, we have shown the protective effect of intrathecal PDTC on the development of nociceptive behaviors induced by CCI in rats. The activation of NF-κB pathway may contribute to spinal microglial activation and CX3CR1 up-regulation.
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