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Blocking SphK/S1P/S1PR1 axis signaling pathway alleviates remifentanil-induced hyperalgesia in rats. Neurosci Lett 2023; 801:137131. [PMID: 36801239 DOI: 10.1016/j.neulet.2023.137131] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/28/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023]
Abstract
Recent research shows a correlation between altered sphingolipid metabolism and nociceptive processing. Activation of the sphingosine-1-phosphate receptor 1 subtype (S1PR1) by its ligand, sphingosine-1-phosphate (S1P), causes neuropathic pain. However, its role in remifentanil-induced hyperalgesia (RIH) has not been investigated. The purpose of this research was to establish if the SphK/S1P/S1PR1 axis mediated remifentanil-induced hyperalgesia and identify its potential targets. This study examined the protein expression of ceramide, sphingosine kinases (SphK), S1P, and S1PR1 in the spinal cord of rats treated with remifentanil (1.0 μg/kg/min for 60 min). Prior to receiving remifentanil, rats were injected with SK-1 (a SphK inhibitor); LT1002 (a S1P monoclonal antibody); CYM-5442, FTY720, and TASP0277308(the S1PR1 antagonists); CYM-5478 (a S1PR2 agonist); CAY10444 (a S1PR3 antagonist); Ac-YVAD-CMK (a caspase-1 antagonist); MCC950 (the NOD-like receptor protein 3 (NLRP3) inflammasome antagonist); and N-tert-Butyl-α-phenylnitrone (PBN, a reactive oxygen species (ROS) scavenger). Mechanical and thermal hyperalgesia were evaluated at baseline (24 h prior to remifentanil infusion) and 2, 6, 12, and 24 h following remifentanil administration. The expression of the NLRP3-related protein (NLRP3, caspase-1), pro-inflammatory cytokines (interleukin-1β(IL-1β), IL-18), and ROS was found in the spinal dorsal horns. In the meantime, immunofluorescence was used to ascertain if S1PR1 co-localizes with astrocytes. Remifentanil infusion induced considerable hyperalgesia in addition to increased ceramide, SphK, S1P, and S1PR1, NLRP3-related protein (NLRP3, Caspase-1, IL-1β, IL-18) and ROS expression, and S1PR1 localized astrocytes. By blocking the SphK/S1P/S1PR1 axis, remifentanil-induced hyperalgesia was reduced, as was the expression of NLRP3, caspase-1, pro-inflammatory cytokines (IL-1β, IL-18) and ROS in the spinal cord. In addition, we observed that suppressing NLRP3 or ROS signal attenuated the mechanical and thermal hyperalgesia induced by remifentanil. Our findings indicate that the SphK/SIP/S1PR1 axis regulates the expression of NLRP3, Caspase-1, IL-1β, IL-18 and ROS in the spinal dorsal horn to mediate remifentanil-induced hyperalgesia. These findings may contribute to pain and SphK/S1P/S1PR1 axis research positively, and inform the future study of this commonly used analgesic.
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Yuan Y, Zhao Y, Shen M, Wang C, Dong B, Xie K, Yu Y, Yu Y. Spinal NLRP3 inflammasome activation mediates IL-1β release and contributes to remifentanil-induced postoperative hyperalgesia by regulating NMDA receptor NR1 subunit phosphorylation and GLT-1 expression in rats. Mol Pain 2022; 18:17448069221093016. [PMID: 35322721 PMCID: PMC9703502 DOI: 10.1177/17448069221093016] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Trafficking and activation of N-methyl-D-aspartate (NMDA) receptors play an important role in initiating and maintaining postoperative remifentanil-induced hyperalgesia (RIH). Activation of the NOD-like receptor protein 3 (NLRP3) inflammasome has been linked to the development of inflammatory and neuropathic pain. We hypothesized that activation of NLRP3 inflammasome mediates IL-1β release and contributes to RIH in rats by increasing NMDA receptor NR1 (NR1) subunit phosphorylation and decreasing glutamate transporter-1 (GLT-1) expression. METHODS Acute exposure to remifentanil (1.2 μg/kg/min for 60 min) was used to establish RIH in rats. Thermal and mechanical hyperalgesia were tested at baseline (24 h before remifentanil infusion) and 2, 6, 24, and 48 h after remifentanil infusion. The levels of IL-1β, GLT-1, phosphorylated NR1 (phospho-NR1), and NLRP3 inflammasome activation indicators [NLRP3, Toll-like receptor 4 (TLR4), P2X purinoceptor 7 (P2X7R), and caspase-1] were measured after the last behavioral test. A selective IL-1β inhibitor (IL-1β inhibitor antagonist; IL-1ra) or three different selective NLRP3 inflammasome activation inhibitors [(+)-naloxone (a TLR4 inhibitor), A438079 (a P2X7R inhibitor), or ac-YVADcmk (a caspase-1 inhibitor)] were intrathecally administered immediately before remifentanil infusion into rats. RESULTS Remifentanil induced significant postoperative hyperalgesia, increased IL-1β and phospho-NR1 levels and activated the NLRP3 inflammasome by increasing TLR4, P2X7R, NLRP3, and caspase-1 expression, but it decreased GLT-1 expression in the L4-L6 spinal cord segments of rats, which was markedly improved by intrathecal administration of IL-1ra, (+)-naloxone, A438079, or ac-YVADcmk. CONCLUSION NLRP3 inflammasome activation mediates IL-1β release and contributes to RIH in rats by inducing NMDA receptor NR1 subunit phosphorylation and decreasing GLT-1 expression. Inhibiting the activation of the NLRP3 inflammasome may be an effective treatment for RIH.
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Affiliation(s)
- Yuan Yuan
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Yue Zhao
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Mengxi Shen
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Chenxu Wang
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Beibei Dong
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Keliang Xie
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Yang Yu
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China,Yang Yu, Department of Anesthesia, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin 300052, P.R. China.
| | - Yonghao Yu
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China,Yonghao Yu, Department of Anesthesia, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin 300052, P.R. China.
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An K, Cui Y, Zhong X, Li K, Zhang J, Liu H, Wen Z. Immortalized Bone Mesenchymal Stromal Cells With Inducible Galanin Expression Produce Controllable Pain Relief in Neuropathic Rats. Cell Transplant 2022; 31:9636897221103861. [PMID: 35726855 PMCID: PMC9218486 DOI: 10.1177/09636897221103861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Management of chronic pain is one of the most difficult problems in modern practice. Grafted human telomerase reverse transcriptase–immortalized bone marrow mesenchymal stromal cells (hTERT-BMSCs) with inducible galanin (GAL) expression have been considered to be a potentially safe and controllable approach for the alleviation of chronic pain. Therefore, in this study, we aimed to assess the feasibility of hTERT-BMSCs/Tet-on/GAL cells secreting GAL under the transcriptional control of doxycycline (Dox) for controllable pain relief. After transplanted into the subarachnoid space of neuropathic rats induced by spared nerve injury of sciatic nerve, their analgesic actions were investigated by behavioral tests. The results showed that the pain-related behaviors, mechanical allodynia, and thermal hyperalgesia were significantly alleviated during 1 to 7 weeks after grafts of hTERT-BMSCs/Tet-on/GAL cells without motor incoordination. Importantly, these effects could be reversed by GAL receptor antagonist M35 and regulated by Dox induction as compared with control. Moreover, the GAL level in cerebrospinal fluid and spinal GAL receptor 1 (GalR1) expression were correlated with Dox administration, but not GAL receptor 2 (GalR2). Meanwhile, spinal protein kinase Mζ (PKMζ) expression was also inhibited significantly. Taken together, these data suggest that inducible release of GAL from transplanted cells was able to produce controllable pain relief in neuropathic rats via inhibiting the PKMζ activation and activating its GalR1 rather than GalR2. This provides a promising step toward a novel stem cell–based strategy for pain therapy.
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Affiliation(s)
- Ke An
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Yingpeng Cui
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Xiaolong Zhong
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.,Department of Anesthesiology, Guangzhou First people's Hospital, Guangzhou, China
| | - Kunhe Li
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Jinjun Zhang
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Huiping Liu
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.,Department of Anesthesiology, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Zhishuang Wen
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
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Arman A, Deng F, Goldys EM, Liu G, Hutchinson MR. In vivo intrathecal IL-1β quantification in rats: Monitoring the molecular signals of neuropathic pain. Brain Behav Immun 2020; 88:442-450. [PMID: 32272226 DOI: 10.1016/j.bbi.2020.04.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 04/03/2020] [Accepted: 04/04/2020] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND Neuropathic pain, or pain after nerve injury, is a disorder with a significant reliance on the signalling of cytokines such as IL-1β. However, quantifying the cytokine release repeatedly over time in vivo is technically challenging. AIM To evaluate if changes in IL-1β are correlated with the presentation of mechanical allodynia over time, by repeatedly quantifying intrathecal IL-1β concentrations following chronic constriction injury of the sciatic nerve in rats. Also, to establish any possible correlation between biochemical spinal marker expression and the in vivo quantification of IL-1β. Finally, to assess the expression of the mature IL-1β in lumbar spinal cord samples. METHOD The Chronic Constriction Injury model (CCI) was used to initiate nerve injury in male Sprague Dawley rats and the generation of behavioural mechanical allodynia was quantified. Using an indwelling intrathecal catheter, a stainless steel (SS) wire biosensing device was repeatedly introduced to quantify intrathecal IL-1β concentrations at three timepoints of 0, 7, and 14 days post CCI. Fixed spinal cord samples (L4-L5), collected on day 14, were imaged for the expression of glial fibrillary acidic protein (GFAP, astrocytes) and ionized calcium binding adaptor molecule 1 (IBA1, microglia). Snap frozen spinal cord tissues (L4-L5) were also processed for western blot analysis. RESULTS Using the novel SS based biosensing device we established that CCI caused a significant increase in intrathecal IL-1β concentrations from day 0 to day 7 (p = 0.001) and to day 14 (p < 0.0001), while the sham group did not show any significant increase. We also further showed that the degree of mechanical allodynia correlated positively with the increase in the intrathecal concentration of IL-1β in the active CCI animals (p = 0.0007). While there was a significant increase in the ipsilateral GFAP expression in injured animals compared to sham animals (p = 0.03), we did not find any significant correlation between in vivo IL-1β concentration on days 7 and 14 and the area of dorsal horn GFAP or IBA1 positive structures on day 14. The result of western blot analysis of whole lumbar spinal cord revealed that there was no significant change (p = 0.7579) in IL-1β expression on day 14 in the CCI group compared to the sham group. CONCLUSION For the first time we have established that the SS based immunosensing platform technology can repeatedly sample the intrathecal space for bioactive peptides, such as IL-1β. Using this novel approach, we have been able to establish the correlation of the intrathecal concentration of IL-1β with the extent of mechanical allodynia, providing a molecular biomarker of the degree of the exaggerated pain state.
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Affiliation(s)
- Azim Arman
- ARC Centre of Excellence for Nanoscale Biophotonics, The University of Adelaide, SA 5005, Australia; Institute for Photonics and Advanced Sensing (IPAS) and Adelaide Medical School, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Fei Deng
- Graduate School of Biomedical Engineering, ARC Centre of Excellence in Nanoscale Biophotonics, Faculty of Engineering, University of New South Wales, Sydney, NSW 2052, Australia; Australian Centre for NanoMedicine, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ewa M Goldys
- Graduate School of Biomedical Engineering, ARC Centre of Excellence in Nanoscale Biophotonics, Faculty of Engineering, University of New South Wales, Sydney, NSW 2052, Australia; Australian Centre for NanoMedicine, University of New South Wales, Sydney, NSW 2052, Australia
| | - Guozhen Liu
- Graduate School of Biomedical Engineering, ARC Centre of Excellence in Nanoscale Biophotonics, Faculty of Engineering, University of New South Wales, Sydney, NSW 2052, Australia; Australian Centre for NanoMedicine, University of New South Wales, Sydney, NSW 2052, Australia.
| | - Mark R Hutchinson
- ARC Centre of Excellence for Nanoscale Biophotonics, The University of Adelaide, SA 5005, Australia; Institute for Photonics and Advanced Sensing (IPAS) and Adelaide Medical School, The University of Adelaide, Adelaide, SA 5005, Australia.
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Yin Q, Wang JF, Xu XH, Xie H. Effect of lycopene on pain facilitation and the SIRT1/mTOR pathway in the dorsal horn of burn injury rats. Eur J Pharmacol 2020; 889:173365. [PMID: 32712090 DOI: 10.1016/j.ejphar.2020.173365] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/18/2020] [Accepted: 07/09/2020] [Indexed: 12/12/2022]
Abstract
To explore the effect of intrathecal injection of lycopene on pain facilitation, glial activation, and the SIRT1/mTOR pathway in the dorsal horn of rats with burn injury pain (BIP). Here we found that the mechanical pain threshold increased in the lycopene group compared with that of the control group, (P < 0.05). Compared with expression in the sham group, mTOR, pS6, p4EBP, GFAP, and Iba-1 decreased and SIRT1 increased in the lycopene group (P < 0.01). Glial activation in the spinal dorsal horn of BIP rats was alleviated by lycopene (P < 0.01). The SIRT1 and mTOR were mainly distributed in neurons in the spinal dorsal horn in the BIP model. Intrathecal injection of 3-MA (a mTOR agonist) or EX-527 (an inhibitor of Sirt1) partially antagonized lycopene-induced analgesia. Intrathecal injection of rapamycin (an mTOR inhibitor) or SRT1720 (an agonist of Sirt1) induced analgesia in BIP rats. 3-MA abrogated the SRT1720-induced analgesic effects. The present data indicated that the SIRT1/mTOR pathway changed in the spinal dorsal horn of BIP rats; Lycopene alleviated the pain sensitization of BIP rats by regulating the SIRT1/mTOR pathway and glial activation in the spinal dorsal horn.
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Affiliation(s)
- Qin Yin
- The Second Affliated Hospital of Soochow University, No. 1055, Sanxiang Road, Suzhou 215004, China; The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, PR China
| | | | - Xiao-Hua Xu
- The People's Hospital of Kizilsu Kirghiz Autonomous Prefecture, Xinjiang 845350, PR China
| | - Hong Xie
- The Second Affliated Hospital of Soochow University, No. 1055, Sanxiang Road, Suzhou 215004, China.
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Liu P, Song C, Wang C, Li Y, Su L, Li J, Zhao Q, Wang Z, Shen M, Wang G, Yu Y, Zhang L. Spinal SNAP-25 regulates membrane trafficking of GluA1-containing AMPA receptors in spinal injury-induced neuropathic pain in rats. Neurosci Lett 2020; 715:134616. [PMID: 31705923 DOI: 10.1016/j.neulet.2019.134616] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/21/2019] [Accepted: 11/04/2019] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Synaptosomal associated proteins of 25 kDa (SNAP-25), as a member of stable soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex, is critical for membrane fusion and required for the release of neurotransmitters. The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor is implicated in pathologic pain. This study aimed to investigate whether and how SNAP-25 regulated AMPA receptors in neuropathic pain. METHODS Male Sprague-Dawley rats underwent L4 spinal nerve ligation (SNL) or the sham procedure. After assessing mechanical allodynia and thermal sensitivity, the ipsilateral portion of the L4-5 spinal cord was harvested. The expression level of SNAP-25 was analyzed by Western blot analysis and real-time quantitative polymerase chain reaction. SNAP-25 phosphorylation and AMPA receptor membrane trafficking levels were evaluated with Western blot analysis. An association between SNAP-25 and AMPA membrane trafficking was confirmed by SNAP-25 expression or phosphorylation inhibition. RESULTS The SNL procedure induced and maintained mechanical allodynia and thermal hyperalgesia. SNL increased the expression and phosphorylation of SNAP-25 and the membrane trafficking of AMPA receptors in the spinal cord. SNAP-25 expression or phosphorylation inhibition alleviated neuropathic pain and downregulated membrane trafficking of AMPA receptors after SNL. GluA1-containing AMPA receptor inhibition relieved mechanical allodynia and thermal hyperalgesia after SNL. CONCLUSIONS The upregulation of SNAP-25-dependent membrane trafficking of AMPA receptors via SNAP-25 phosphorylation at Ser187 contributed to SNL-induced neuropathic pain. Thus, the inhibition of SNAP-25 expression or phosphorylation might serve as a treatment for neuropathic pain. However, the mechanism of GluA1-containing AMPA receptor membrane trafficking mediated by SNAP-25 phosphorylation in neuropathic pain deserves further exploration.
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Affiliation(s)
- Peng Liu
- Department of General Surgery, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Chengcheng Song
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Chunyan Wang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Yize Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Lin Su
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Jing Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Qi Zhao
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Zhen Wang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Mengxi Shen
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Guolin Wang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Yonghao Yu
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Linlin Zhang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China.
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Deng F, Arman A, Goldys EM, Hutchinson MR, Liu G. A Method for in Vivo Quantification Of Cytokine IL-1β In The Rat Intrathecal Space. ACS APPLIED BIO MATERIALS 2019; 3:539-546. [DOI: 10.1021/acsabm.9b00958] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Fei Deng
- ARC Centre of Excellence in Nanoscale Biophotonics, University of New South Wales, Sydney, New South Wales 2052, Australia
- Australian Centre for NanoMedicine, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Azim Arman
- ARC Centre of Excellence for Nanoscale Biophotonics, The University of Adelaide, Adelaide, South Australia 5005, Australia
- Institute for Photonics and Advanced Sensing (IPAS) and Adelaide Medical School, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Ewa M. Goldys
- ARC Centre of Excellence in Nanoscale Biophotonics, University of New South Wales, Sydney, New South Wales 2052, Australia
- Australian Centre for NanoMedicine, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Mark R. Hutchinson
- ARC Centre of Excellence for Nanoscale Biophotonics, The University of Adelaide, Adelaide, South Australia 5005, Australia
- Institute for Photonics and Advanced Sensing (IPAS) and Adelaide Medical School, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Guozhen Liu
- ARC Centre of Excellence in Nanoscale Biophotonics, University of New South Wales, Sydney, New South Wales 2052, Australia
- Australian Centre for NanoMedicine, University of New South Wales, Sydney, New South Wales 2052, Australia
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Peng Y, Zhang X, Zhang T, Grace PM, Li H, Wang Y, Li H, Chen H, Watkins LR, Hutchinson MR, Yin H, Wang X. Lovastatin inhibits Toll-like receptor 4 signaling in microglia by targeting its co-receptor myeloid differentiation protein 2 and attenuates neuropathic pain. Brain Behav Immun 2019; 82:432-444. [PMID: 31542403 DOI: 10.1016/j.bbi.2019.09.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/13/2019] [Accepted: 09/14/2019] [Indexed: 12/23/2022] Open
Abstract
There is growing interest in drug repositioning to find new therapeutic indications for drugs already approved for use in people. Lovastatin is an FDA approved drug that has been used clinically for over a decade as a lipid-lowering medication. While lovastatin is classically considered to act as a hydroxymethylglutaryl (HMG)-CoA reductase inhibitor, the present series of studies reveal a novel lovastatin effect, that being as a Toll-like receptor 4 (TLR4) antagonist. Lovastatin selectively inhibits lipopolysaccharide (LPS)-induced TLR4-NF-κB activation without affecting signaling by other homologous TLRs. In vitro biophysical binding and cellular thermal shift assay (CETSA) show that lovastatin is recognized by TLR4's coreceptor myeloid differentiation protein 2 (MD-2). This finding is supported by molecular dynamics simulations that lovastatin targets the LPS binding pocket of MD-2 and lovastatin binding stabilizes the MD-2 conformation. In vitro studies of BV-2 microglial cells revealed that lovastatin inhibits multiple effects of LPS, including activation of NFkB; mRNA expression of tumor necrosis factor-a, interleukin-6 and cyclo-oxygenase 2; production of nitric oxide and reactive oxygen species; as well as phagocytic activity. Furthermore, intrathecal delivery of lovastatin over lumbosacral spinal cord of rats attenuated both neuropathic pain from sciatic nerve injury and expression of the microglial activation marker CD11 in lumbar spinal cord dorsal horn. Given the well-established role of microglia and proinflammatory signaling in neuropathic pain, these data are supportive that lovastatin, as a TLR4 antagonist, may be productively repurposed for treating chronic pain.
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Affiliation(s)
- Yinghua Peng
- State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin 130112, China; Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Yantai University, Yantai 264005, China
| | - Xiaozheng Zhang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Tianshu Zhang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Peter M Grace
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado at Boulder, Boulder, CO 80309, USA
| | - Hongyuan Li
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Yibo Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Hang Li
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Hongqian Chen
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Linda R Watkins
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado at Boulder, Boulder, CO 80309, USA
| | - Mark R Hutchinson
- Discipline of Physiology, Adelaide Medical School, University of Adelaide, South Australia, Australia; ARC Centre of Excellence for Nanoscale Biophotonics, University of Adelaide, South Australia 5000, Australia
| | - Hang Yin
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center for Life Sciences, Tsinghua University, Beijing 100082, China
| | - Xiaohui Wang
- Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Yantai University, Yantai 264005, China; Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China; Department of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China.
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9
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Meng X, Jin X, Wei X, Wang L, Yang J, Ji F. Low‑affinity neurotrophin receptor p75 of brain‑derived neurotrophic factor contributes to cancer‑induced bone pain by upregulating mTOR signaling. Exp Ther Med 2019; 18:4379-4387. [PMID: 31777542 PMCID: PMC6862244 DOI: 10.3892/etm.2019.8097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/04/2019] [Indexed: 11/06/2022] Open
Abstract
Crucial to the development and maintenance of pain sensations is neurotrophin receptor p75 (p75NTR), the low affinity receptor of brain-derived neurotrophic factor (BDNF). This receptor is widespread among dorsal root ganglion (DRG) neurons and the spinal cord. Few reports have demonstrated the specific role of p75NTR in the development of cancer-induced bone pain (CIBP). Therefore the present study examined whether p75NTR contributed to CIBP by upregulating mammalian target of rapamycin (mTOR) signaling. A CIBP rat model was induced and reverse transcription-quantitative polymerase chain reaction was employed to determine p75NTR and mTOR mRNA expression. Immunofluorescence analysis was performed to determine the coexpression of p75NTR and mTOR in DRG neurons, as well as the spinal cord. Von Frey filaments were used to measure the 50% likelihood of paw withdrawal thresholds (PWTs). Spontaneous pain was assessed by ambulatory score. The results demonstrated that compared with the control group, mTOR activation in primary cultured DRG neurons was significantly increased. In addition, mTOR and p75NTR expression was significantly enhanced in the BDNF-treated primary DRG in the BDNF group. In vivo experiments determined that mTOR and p75NTR levels were increased in the CIBP rats compared with the sham group. PWT, in response to mechanical stimulation, was significantly lower compared with that in sham rats and the ambulatory score was significantly higher than that in sham rats. Finally, intrathecal injection of a p75NTR-targeting small interfering RNA significantly decreased mTOR and p75NTR expression levels in DRG neurons and the spinal cord of CIBP rats, as well as partially reversing the decline in PWTs and the increase in ambulatory score. In conclusion, the present study determined that the activation of BDNF/p75NTR/mTOR signaling may participate in nociceptive transmission in CIBP, suggesting a novel mechanism and potential therapeutic target for CIBP treatment and management.
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Affiliation(s)
- Xiao‑Wen Meng
- Department of Anesthesiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
| | - Xiao‑Hong Jin
- Department of Anesthesiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
| | - Xiang Wei
- Department of Anesthesiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
| | - Li‑Na Wang
- Department of Anesthesiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
| | - Jian‑Ping Yang
- Department of Anesthesiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
| | - Fu‑Hai Ji
- Department of Anesthesiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
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Wang X, Liu Y, Wu X, Zhang Y, Pan R, Yu W, Wu F. Engineered endomorphin-2 gene: A novel therapy for improving morphine reinstatement in CPP model of rats by using deficient adenovirus as the vector. Biochem Biophys Res Commun 2019; 513:141-146. [DOI: 10.1016/j.bbrc.2019.03.183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 03/27/2019] [Indexed: 12/12/2022]
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11
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Song C, Liu P, Zhao Q, Guo S, Wang G. TRPV1 channel contributes to remifentanil-induced postoperative hyperalgesia via regulation of NMDA receptor trafficking in dorsal root ganglion. J Pain Res 2019; 12:667-677. [PMID: 30863139 PMCID: PMC6388729 DOI: 10.2147/jpr.s186591] [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] [Indexed: 12/19/2022] Open
Abstract
Background Remifentanil is widely used in general anesthesia due to its reliability and rapid onset. However, remifentanil-induced postoperative hyperalgesia might be a challenge nowadays. Accumulating evidence suggests that the transient receptor potential vanilloid 1 (TRPV1) was involved in the development of neuropathic pain and hyperalgesia. However, the contribution of TRPV1 in modulating remifentanil-induced postoperative hyperalgesia is still unknown. The aim of this study is the contribution of TRPV1 to the surface expression of N-methyl-d-aspartate (NMDA) receptors in remifentanil-induced postoperative hyperalgesia. Methods The hot plate test and the Von Frey test were performed to evaluate thermal and mechanical hyperalgesia. Capsazepine (CPZ) was administrated intrathecally to confirm our results. TRPV1, NMDA receptors, CaMKII (calcium/calmodulin-dependent kinase II), and protein kinase C (PKC) in the dorsal root ganglion (DRG) were detected by Western blotting. Immunofluorescence assay was applied to analyze the distribution of TRPV1 and the relationship between TRPV1 and NMDA receptor subunit 1 (NR1). Results Remifentanil-induced both thermal and mechanical postoperative hyperalgesia. Here, we found the membrane trafficking of NR1, possibly due to the activation of TRPV1 in DRG neurons after remifentanil infusion. Furthermore, intrathecal injection of CPZ was able to relieve remifentanil-induced postoperative hyperalgesia according to a behavioral test and CPZ confirmed that TRPV1 is involved in NR1 trafficking. In addition, CaMKII/PKC but not protein kinase A (PKA) contributed to remifentanil-induced postoperative hyperalgesia. Conclusion Our study demonstrates that TRPV1 receptors are involved in remifentanil-induced postoperative hyperalgesia. TRPV1 contributes to the persistence of remifentanil-induced postoperative hyperalgesia through the trafficking of NMDA receptors via the activation of CaMKII-PKC signaling pathways in DRG neurons.
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Affiliation(s)
- Chengcheng Song
- Tianjin Research Institute of Anesthesiology, Tianjin, China, .,Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China, .,Tianjin Medical University, Tianjin, China,
| | - Peng Liu
- Tianjin Medical University, Tianjin, China, .,Department of General Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Qi Zhao
- Tianjin Research Institute of Anesthesiology, Tianjin, China, .,Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China, .,Tianjin Medical University, Tianjin, China,
| | - Suqian Guo
- Tianjin Research Institute of Anesthesiology, Tianjin, China, .,Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China, .,Tianjin Medical University, Tianjin, China,
| | - Guolin Wang
- Tianjin Research Institute of Anesthesiology, Tianjin, China, .,Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China, .,Tianjin Medical University, Tianjin, China,
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12
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Liu Y, Zhang Y, Pan R, Chen M, Wang X, Kong E, Yu W, Sun Y, Wu F. Lentiviral‑mediated inducible silencing of TLR4 attenuates neuropathic pain in a rat model of chronic constriction injury. Mol Med Rep 2018; 18:5545-5551. [PMID: 30365084 PMCID: PMC6236283 DOI: 10.3892/mmr.2018.9560] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 08/10/2018] [Indexed: 12/12/2022] Open
Abstract
An increasing body of evidence has indicated that spinal microglial Toll-like receptor 4 (TLR4) may serve a significant role in the development and maintenance of neuropathic pain (NP). In the present study, experiments were conducted to evaluate the contribution of a tetracycline inducible lentiviral-mediated delivery system for the expression of TLR4 small interfering (si)RNA to NP in rats with chronic constriction injury (CCI). Behavioral tests, including paw withdrawal latency and paw withdrawal threshold, and biochemical analysis of the spinal cord, including western blotting, reverse transcription-quantitative polymerase chain reaction and ELISA, were conducted following CCI to the sciatic nerve. Intrathecal administration of LvOn-si-TLR4 with doxycycline (Dox) attenuated allodynia and hyperalgesia. Biochemical analysis revealed that the mRNA and proteins levels of TLR4 were unregulated following CCI to the sciatic nerve, which was then blocked by intrathecal administration of LvOn-siTLR4 with Dox. The LvOn-siTLR4 was also demonstrated to have no effect on TLR4 or the pain response without Dox, which indicated that the expression of siRNA was Dox-inducible in the lentivirus delivery system. In conclusion, TLR4 may serve a significant role in neuropathy and the results of the present study provide an inducible lentivirus-mediated siRNA against TLR4 that may serve as a potential novel strategy to be applied in gene therapy for NP in the future.
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Affiliation(s)
- Yantao Liu
- Department of Anesthesiology and Intensive Care, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Yan Zhang
- Department of Anesthesiology, Zhejiang Zhoushan Hospital, Zhoushan, Zhejiang 316021, P.R. China
| | - Ruirui Pan
- Department of Anesthesiology and Intensive Care, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Mo Chen
- Department of Anesthesiology and Intensive Care, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Xiaoqiang Wang
- Department of Anesthesiology and Intensive Care, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Erliang Kong
- Department of Anesthesiology and Intensive Care, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Weifeng Yu
- Department of Anesthesiology and Intensive Care, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Yuming Sun
- Department of Anesthesiology and Intensive Care, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Feixiang Wu
- Department of Anesthesiology and Intensive Care, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
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MicroRNA-124 and microRNA-146a both attenuate persistent neuropathic pain induced by morphine in male rats. Brain Res 2018; 1692:9-11. [PMID: 29723521 DOI: 10.1016/j.brainres.2018.04.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 04/16/2018] [Accepted: 04/30/2018] [Indexed: 11/22/2022]
Abstract
We have recently reported that a short course of morphine, starting 10 days after sciatic chronic constriction injury (CCI), prolonged the duration of mechanical allodynia for months after morphine ceased. Maintenance of this morphine-induced persistent sensitization was dependent on microglial reactivity and Toll-like receptor 4 signaling. Given that microRNAs (miRNAs) such as miR-124 and miR-146a possess the ability to modulate such signaling, we directly compared their function in this model. We found that both miRNAs reversed established allodynia in our model of morphine-induced persistent sensitization. The efficacy of miR-124 and miR-146a were comparable, and in both cases allodynia returned within hours to days of miRNA dosing conclusion. Our findings demonstrate that miRNAs targeting Toll-like receptor signaling are effective in reversing neuropathic pain, which underscores the clinical potential of these non-coding RNAs.
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14
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Wen C, Xu M, Mo C, Cheng Z, Guo Q, Zhu X. JMJD6 exerts function in neuropathic pain by regulating NF‑κB following peripheral nerve injury in rats. Int J Mol Med 2018; 42:633-642. [PMID: 29620141 DOI: 10.3892/ijmm.2018.3613] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/30/2018] [Indexed: 11/06/2022] Open
Abstract
Treatment of neuropathic pain (NPP) continues to be a major challenge, and the underlying mechanisms remain to be elucidated. Previous studies have demonstrated that histone methylation is important in synaptic plasticity of the nervous system and may affect nuclear factor‑κB (NF‑κB) signaling through epigenetic mechanisms. The present study aimed to investigate the role of Jumonji C domain 6 (JMJD6), a histone demethylase, in a chronic constriction injury (CCI) model of NPP. On the third day post‑CCI surgery, a JMJD6 overexpressing lentiviral vector (LV‑JMJD6) was intrathecally injected in the rats. Mechanical withdrawal threshold and thermal withdrawal latency were assessed prior surgery and on days 3, 7, 10 and 14 post‑CCI. The results showed that intrathecal injection with the LV‑JMJD6 attenuated CCI‑induced pain facilitation. The expression of JMJD6 was lower following CCI surgery, and its expression was significantly increased following intrathecal injection with LV‑JMJD6, compared with levels in normal saline (NS)‑ and negative control lentiviral vector (NC)‑treated rats. The expression of spinal NF‑κB phosphorylated (p‑)p65 subunit and its downstream pain‑associated effectors, including interleukin 1β (IL‑1β), tumor necrosis factor‑α (TNF‑α) and vascular endothelial growth factor (VEGF), were increased following CCI surgery. Intrathecal injection with LV‑JMJD6 suppressed activation of the p‑p65 subunit in CCI rats. In addition, expression levels of its downstream effectors IL‑1β, TNF‑α and VEGF were attenuated by intrathecal treatment with LV‑JMJD6, compared with those in the NS‑ and NC‑treated CCI rats. Furthermore, the JMJD6‑ and p65‑immunoreactive cells overlapped in the spinal dorsal horn, however, co‑immunoprecipitation showed that JMJD6 and the NF‑κB p65 subunit did not directly interact, indicating other functional connections may exist between these factors following CCI surgery. Collectively, these findings indicated an important mechanism underlying the pathogenesis of NPP. JMJD6 may exert its therapeutic function in NPP by regulating NF‑κB following CCI.
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Affiliation(s)
- Cen Wen
- Department of Anesthesiology, Xiangya Hospital of Central South University, Changsha, Hunan 410008, P.R. China
| | - Mengyuan Xu
- Department of Anesthesiology, Xiangya Hospital of Central South University, Changsha, Hunan 410008, P.R. China
| | - Cheng Mo
- Department of Anesthesiology, Xiangya Hospital of Central South University, Changsha, Hunan 410008, P.R. China
| | - Zhigang Cheng
- Department of Anesthesiology, Xiangya Hospital of Central South University, Changsha, Hunan 410008, P.R. China
| | - Qulian Guo
- Department of Anesthesiology, Xiangya Hospital of Central South University, Changsha, Hunan 410008, P.R. China
| | - Xiaoyan Zhu
- Department of Anesthesiology, Xiangya Hospital of Central South University, Changsha, Hunan 410008, P.R. China
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15
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Grace PM, Wang X, Strand KA, Baratta MV, Zhang Y, Galer EL, Yin H, Maier SF, Watkins LR. DREADDed microglia in pain: Implications for spinal inflammatory signaling in male rats. Exp Neurol 2018. [PMID: 29530713 DOI: 10.1016/j.expneurol.2018.03.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The absence of selective pharmacological tools is a major barrier to the in vivo study of microglia. To address this issue, we developed a Gq- and Gi-coupled Designer Receptor Exclusively Activated by a Designer Drug (DREADD) to enable selective stimulation or inhibition of microglia, respectively. DREADDs under a CD68 (microglia/macrophage) promoter were intrathecally transfected via an AAV9 vector. Naïve male rats intrathecally transfected with Gq (stimulatory) DREADDs exhibited significant allodynia following intrathecal administration of the DREADD-selective ligand clozapine-N-oxide (CNO), which was abolished by intrathecal interleukin-1 receptor antagonist. Chronic constriction injury-induced allodynia was attenuated by intrathecal CNO in male rats intrathecally transfected with Gi (inhibitory) DREADDs. To explore mechanisms, BV2 cells were stably transfected with Gq or Gi DREADDs in vitro. CNO treatment induced pro-inflammatory mediator production per se from cells expressing Gq-DREADDs, and inhibited lipopolysaccharide- and CCL2-induced inflammatory signaling from cells expressing Gi-DREADDs. These studies are the first to manipulate microglia function using DREADDs, which allow the role of glia in pain to be conclusively demonstrated, unconfounded by neuronal off-target effects that exist for all other drugs that also inhibit glia. Hence, these studies are the first to conclusively demonstrate that in vivo stimulation of resident spinal microglia in intact spinal cord is a) sufficient for allodynia, and b) necessary for allodynia induced by peripheral nerve injury. DREADDs are a unique tool to selectively explore the physiological and pathological role of microglia in vivo.
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Affiliation(s)
- Peter M Grace
- Department of Psychology and Neuroscience, The Center for Neuroscience, University of Colorado, Boulder, CO, USA; Discipline of Pharmacology, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.
| | - Xiaohui Wang
- Department of Psychology and Neuroscience, The Center for Neuroscience, University of Colorado, Boulder, CO, USA; Department of Chemistry and Biochemistry, BioFrontiers Institute, The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Keith A Strand
- Department of Psychology and Neuroscience, The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Michael V Baratta
- Department of Psychology and Neuroscience, The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Yingning Zhang
- Department of Psychology and Neuroscience, The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Erika L Galer
- Department of Psychology and Neuroscience, The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Hang Yin
- Department of Chemistry and Biochemistry, BioFrontiers Institute, The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Steven F Maier
- Department of Psychology and Neuroscience, The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Linda R Watkins
- Department of Psychology and Neuroscience, The Center for Neuroscience, University of Colorado, Boulder, CO, USA
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16
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Sun J, Li N, Duan G, Liu Y, Guo S, Wang C, Zhu C, Zhang X. Increased Na v1.7 expression in the dorsal root ganglion contributes to pain hypersensitivity after plantar incision in rats. Mol Pain 2018; 14:1744806918782323. [PMID: 29790813 PMCID: PMC6050993 DOI: 10.1177/1744806918782323] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 05/06/2018] [Accepted: 05/07/2018] [Indexed: 11/15/2022] Open
Abstract
Postoperative pain remains a complex problem that is difficult to manage in the clinical context, seriously affecting rehabilitation and the quality of life of patients after surgery. Nociceptors, of which the cell bodies are located in the dorsal root ganglion, are crucial for initiating and conducting the pain signal. The peripheral voltage-gated sodium channels, including Nav1.7, which is mainly expressed in the dorsal root ganglion, are key to understanding the mechanism underlying postoperative pain. Nav1.7, in particular, of which mutations in the encoding gene ( SCN9A) can determine whether pain occurs, has aroused most attention. Previous studies have shown that Nav1.7 in dorsal root ganglion is critical for the development of inflammatory pain and some neuropathic pain. However, the expression of Nav1.7 in the dorsal root ganglion after surgery and its role in postoperative pain hypersensitivity remain unclear. Therefore, in this study, in order to gain a better understanding of the role of dorsal root ganglion Nav1.7 in pain hypersensitivity following operation, we dynamically examined the pain-related behavior and expression of Nav1.7 in L4-L6 dorsal root ganglion before and after plantar incision in rats (an acute postoperative pain model). After plantar incision, the mechanical and thermal pain threshold decreased significantly, the cumulative pain score was increased significantly, meanwhile quantitative polymerase chain reaction and Western blotting results showed that expression of Nav1.7 in L4-L6 dorsal root ganglion was enhanced significantly. After pretreatment using SCN9A-RNAi-LV delivered via an intrathecal tube, immunohistochemistry showed that increased expression of Nav1.7 in L4-L6 dorsal root ganglion after plantar incision was inhibited, as also confirmed by quantitative polymerase chain reaction and Western blotting. Moreover, pain hypersensitivity was alleviated. These results suggested that Nav1.7 of L4-L6 dorsal root ganglion plays an important role in the development of pain hypersensitivity after plantar incision.
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Affiliation(s)
- Jiaoli Sun
- Department of Anesthesiology, Tongji Hospital, Tongji Medical
College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s
Republic of China
| | - Ningbo Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical
College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s
Republic of China
| | - Guangyou Duan
- Department of Anesthesiology, Tongji Hospital, Tongji Medical
College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s
Republic of China
| | - Yi Liu
- Department of Anesthesiology, Tongji Hospital, Tongji Medical
College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s
Republic of China
| | - Shanna Guo
- Department of Anesthesiology, Tongji Hospital, Tongji Medical
College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s
Republic of China
| | - Cong Wang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical
College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s
Republic of China
| | - Changmao Zhu
- Department of Anesthesiology, Tongji Hospital, Tongji Medical
College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s
Republic of China
| | - Xianwei Zhang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical
College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s
Republic of China
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Bang WS, Kim KT, Seo YJ, Cho DC, Sung JK, Kim CH. Curcumin Increase the Expression of Neural Stem/Progenitor Cells and Improves Functional Recovery after Spinal Cord Injury. J Korean Neurosurg Soc 2017; 61:10-18. [PMID: 29354231 PMCID: PMC5769840 DOI: 10.3340/jkns.2017.0203.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/12/2017] [Accepted: 05/31/2017] [Indexed: 12/03/2022] Open
Abstract
Objective To investigates the effect of curcumin on proliferation of spinal cord neural stem/progenitor cells (SC-NSPCs) and functional outcome in a rat spinal cord injury (SCI) model. Methods Sixty adult male Sprague-Dawley rats were randomly and blindly allocated into three groups (sham control group; curcumin treated group after SCI; vehicle treated group after SCI). Functional recovery was evaluated by the Basso, Beattie, and Bresnahan (BBB) scale during 6 weeks after SCI. The expression of SC-NSPC proliferation and astrogliosis were analyzed by nestin/Bromodeoxyuridine (BrdU) and Glial fibrillary acidic protein (GFAP) staining. The injured spinal cord was then examined histologically, including quantification of cavitation. Results The BBB score of the SCI-curcumin group was better than that of SCI-vehicle group up to 14 days (p<0.05). The co-immunoreactivity of nestin/BrdU in the SCI-curcumin group was much higher than that of the SCI-vehicle group 1 week after surgery (p<0.05). The GFAP immunoreactivity of the SCI-curcumin group was remarkably lower than that of the SCI-vehicle group 4 weeks after surgery (p<0.05). The lesion cavity was significantly reduced in the curcumin group as compared to the control group (p<0.05). Conclusion These results indicate that curcumin could increase the expression of SC-NSPCs, and reduce the activity of reactive astrogliosis and lesion cavity. Consequently curcumin could improve the functional recovery after SCI via SC-NSPC properties.
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Affiliation(s)
- Woo-Seok Bang
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Kyoung-Tae Kim
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Ye Jin Seo
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Dae-Chul Cho
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Joo-Kyung Sung
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Chi Heon Kim
- Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea
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Li J, Zhao PP, Hao T, Wang D, Wang Y, Zhu YZ, Wu YQ, Zhou CH. Urotensin II inhibitor eases neuropathic pain by suppressing the JNK/NF-κB pathway. J Endocrinol 2017; 232:165-174. [PMID: 27895138 DOI: 10.1530/joe-16-0255] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 11/07/2016] [Indexed: 12/12/2022]
Abstract
Urotensin II (U-II), a cyclic peptide originally isolated from the caudal neurosecretory system of fishes, can produce proinflammatory effects through its specific G protein-coupled receptor, GPR14. Neuropathic pain, a devastating disease, is related to excessive inflammation in the spinal dorsal horn. However, the relationship between U-II and neuropathic pain has not been reported. This study was designed to investigate the effect of U-II antagonist on neuropathic pain and to understand the associated mechanisms. We reported that U-II and its receptor GPR14 were persistently upregulated and activated in the dorsal horn of L4-6 spinal cord segments after chronic constriction injury (CCI) in rats. Intrathecal injection of SB657510, a specific antagonist against U-II, reversed CCI-induced thermal hyperalgesia and mechanical allodynia. Furthermore, we found that SB657510 reduced the expression of phosphorylated c-Jun N-terminal kinase (p-JNK) and nuclear factor-κB (NF-κB) p65 as well as subsequent secretion of interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α). It was also showed that both the JNK inhibitor SP600125 and the NF-κB inhibitor PDTC significantly attenuated thermal hyperalgesia and mechanical allodynia in CCI rats. Our present research showed that U-II receptor antagonist alleviated neuropathic pain possibly through the suppression of the JNK/NF-κB pathway in CCI rats, which will contribute to the better understanding of function of U-II and pathogenesis of neuropathic pain.
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Affiliation(s)
- Jing Li
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical University, Xuzhou, China
| | - Pan-Pan Zhao
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical University, Xuzhou, China
| | - Ting Hao
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical University, Xuzhou, China
| | - Dan Wang
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical University, Xuzhou, China
| | - Yu Wang
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical University, Xuzhou, China
| | - Yang-Zi Zhu
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical University, Xuzhou, China
| | - Yu-Qing Wu
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical University, Xuzhou, China
- Department of Anesthetic PharmacologyXuzhou Medical University, Xuzhou, China
| | - Cheng-Hua Zhou
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical University, Xuzhou, China
- Jiangsu Key Laboratory of New Drug Research and Clinical PharmacyXuzhou Medical University, Xuzhou, China
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Mohrman AE, Farrag M, Huang H, Ossowski S, Haft S, Shriver LP, Leipzig ND. Spinal Cord Transcriptomic and Metabolomic Analysis after Excitotoxic Injection Injury Model of Syringomyelia. J Neurotrauma 2017; 34:720-733. [DOI: 10.1089/neu.2015.4341] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ashley E. Mohrman
- Department of Chemical and Biomolecular Engineering, University of Akron, Akron, Ohio
| | - Mahmoud Farrag
- Department of Integrated Biosciences Program, University of Akron, Akron, Ohio
| | - He Huang
- Department of Chemistry, University of Akron, Akron, Ohio
| | - Stephan Ossowski
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Stephanie Haft
- Langley Porter Psychiatric Institute, University of California San Francisco, San Francisco, California
| | | | - Nic D. Leipzig
- Department of Chemical and Biomolecular Engineering, University of Akron, Akron, Ohio
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Grace PM, Loram LC, Christianson JP, Strand KA, Flyer-Adams JG, Penzkover KR, Forsayeth JR, van Dam AM, Mahoney MJ, Maier SF, Chavez RA, Watkins LR. Behavioral assessment of neuropathic pain, fatigue, and anxiety in experimental autoimmune encephalomyelitis (EAE) and attenuation by interleukin-10 gene therapy. Brain Behav Immun 2017; 59:49-54. [PMID: 27189037 PMCID: PMC5108696 DOI: 10.1016/j.bbi.2016.05.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 04/30/2016] [Accepted: 05/14/2016] [Indexed: 02/04/2023] Open
Abstract
Relapsing-remitting multiple sclerosis is commonly associated with motor impairments, neuropathic pain, fatigue, mood disorders, and decreased life expectancy. However, preclinical pharmacological studies predominantly rely on clinical scoring of motor deficit as the sole behavioral endpoint. Thus, the translational potential of these studies is limited. Here, we have assessed the therapeutic potential of a novel anti-inflammatory interleukin-10 (IL-10) non-viral gene therapy formulation (XT-101-R) in a rat relapsing remitting experimental autoimmune encephalomyelitis (EAE) model. EAE induced motor deficits and neuropathic pain as reflected by induction of low-threshold mechanical allodynia, suppressed voluntary wheel running, decreased social exploration, and was associated with markedly enhanced mortality. We also noted that voluntary wheel running was depressed prior to the onset of motor deficit, and may therefore serve as a predictor of clinical symptoms onset. XT-101-R was intrathecally dosed only once at the onset of motor deficits, and attenuated each of the EAE-induced symptoms and improved survival, relative to vehicle control. This is the first pharmacological assessment of such a broad range of EAE symptoms, and provides support for IL-10 gene therapy as a clinical strategy for the treatment of multiple sclerosis.
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Affiliation(s)
- Peter M. Grace
- Department of Psychology and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Lisa C. Loram
- Department of Psychology and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - John P. Christianson
- Department of Psychology and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Keith A. Strand
- Department of Psychology and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Johanna G. Flyer-Adams
- Department of Psychology and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Kathryn R. Penzkover
- Department of Chemical & Biological Engineering Pharmacology, University of Colorado, Boulder, CO, USA
| | | | - Anne-Marie van Dam
- Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam, Netherlands
| | - Melissa J. Mahoney
- Department of Chemical & Biological Engineering Pharmacology, University of Colorado, Boulder, CO, USA
| | - Steven F. Maier
- Department of Psychology and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | | | - Linda R. Watkins
- Department of Psychology and The Center for Neuroscience, University of Colorado, Boulder, CO, USA,Xalud Therapeutics, San Francisco, CA, USA
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Han Y, Kim KT. Neural Growth Factor Stimulates Proliferation of Spinal Cord Derived-Neural Precursor/Stem Cells. J Korean Neurosurg Soc 2016; 59:437-41. [PMID: 27651860 PMCID: PMC5028602 DOI: 10.3340/jkns.2016.59.5.437] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 05/10/2016] [Accepted: 06/08/2016] [Indexed: 01/08/2023] Open
Abstract
Objective Recently, regenerative therapies have been used in clinical trials (heart, cartilage, skeletal). We don't make use of these treatments to spinal cord injury (SCI) patients yet, but regenerative therapies are rising interest in recent study about SCI. Neural precursor/stem cell (NPSC) proliferation is a significant event in functional recovery of the central nervous system (CNS). However, brain NPSCs and spinal cord NPSCs (SC-NPSCs) have many differences including gene expression and proliferation. The purpose of this study was to investigate the influence of neural growth factor (NGF) on the proliferation of SC-NPSCs. Methods NPSCs (2×104) were suspended in 100 µL of neurobasal medium containing NGF-7S (Sigma-Aldrich) and cultured in a 96-well plate for 12 days. NPSC proliferation was analyzed five times for either concentration of NGF (0.02 and 2 ng/mL). Sixteen rats after SCI were randomly allocated into two groups. In group 1 (SCI-vehicle group, n=8), animals received 1.0 mL of the saline vehicle solution. In group 2 (SCI-NGF group, n=8), the animals received single doses of NGF (Sigma-Aldrich). A dose of 0.02 ng/mL of NGF or normal saline as a vehicle control was intra-thecally injected daily at 24 hour intervals for 7 days. For Immunohistochemistry analysis, rats were sacrificed after one week and the spinal cords were obtained. Results The elevation of cell proliferation with 0.02 ng/mL NGF was significant (p<0.05) but was not significant for 2 ng/mL NGF. The optical density was increased in the NGF 0.02 ng/mL group compared to the control group and NGF 2 ng/mL groups. The density of nestin in the SCI-NGF group was significantly increased over the SCI-vehicle group (p<0.05). High power microscopy revealed that the density of nestin in the SCI-NGF group was significantly increased over the SCI-vehicle group. Conclusion SC-NPSC proliferation is an important pathway in the functional recovery of SCI. NGF enhances SC-NPSC proliferation in vitro and in vivo. NGF may be a useful option for treatment of SCI patients pending further studies to verify the clinical applicability.
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Affiliation(s)
- Youngmin Han
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Kyoung-Tae Kim
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
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Hou Y, Wang L, Gao J, Jin X, Ji F, Yang J. A modified procedure for lumbar intrathecal catheterization in rats. Neurol Res 2016; 38:725-32. [DOI: 10.1080/01616412.2016.1196870] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Morphine paradoxically prolongs neuropathic pain in rats by amplifying spinal NLRP3 inflammasome activation. Proc Natl Acad Sci U S A 2016; 113:E3441-50. [PMID: 27247388 DOI: 10.1073/pnas.1602070113] [Citation(s) in RCA: 258] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Opioid use for pain management has dramatically increased, with little assessment of potential pathophysiological consequences for the primary pain condition. Here, a short course of morphine, starting 10 d after injury in male rats, paradoxically and remarkably doubled the duration of chronic constriction injury (CCI)-allodynia, months after morphine ceased. No such effect of opioids on neuropathic pain has previously been reported. Using pharmacologic and genetic approaches, we discovered that the initiation and maintenance of this multimonth prolongation of neuropathic pain was mediated by a previously unidentified mechanism for spinal cord and pain-namely, morphine-induced spinal NOD-like receptor protein 3 (NLRP3) inflammasomes and associated release of interleukin-1β (IL-1β). As spinal dorsal horn microglia expressed this signaling platform, these cells were selectively inhibited in vivo after transfection with a novel Designer Receptor Exclusively Activated by Designer Drugs (DREADD). Multiday treatment with the DREADD-specific ligand clozapine-N-oxide prevented and enduringly reversed morphine-induced persistent sensitization for weeks to months after cessation of clozapine-N-oxide. These data demonstrate both the critical importance of microglia and that maintenance of chronic pain created by early exposure to opioids can be disrupted, resetting pain to normal. These data also provide strong support for the recent "two-hit hypothesis" of microglial priming, leading to exaggerated reactivity after the second challenge, documented here in the context of nerve injury followed by morphine. This study predicts that prolonged pain is an unrealized and clinically concerning consequence of the abundant use of opioids in chronic pain.
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Wu FX, He Y, Di HT, Sun YM, Pan RR, Yu WF, Liu R. An Engineered Endomorphin-2 Gene for Morphine Withdrawal Syndrome. PLoS One 2016; 11:e0149877. [PMID: 27003293 PMCID: PMC4803333 DOI: 10.1371/journal.pone.0149877] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 02/06/2016] [Indexed: 11/19/2022] Open
Abstract
An optimal therapeutics to manage opioid withdrawal syndrome is desired for opioid addiction treatment. Down-regulation of endogenous endomorphin-2 (EM2) level in the central nervous system after continuous morphine exposure was observed, which suggested that increase of EM2 could be an alternative novel method for opioid dependence. As a short peptide, the short half-life of EM2 limits its clinical usage through conventional administration. In the present study, we engineered an EM2 gene using a signal peptide of mouse growth factor for an out-secretory expression of EM2 and an adenovirus as a vector, which ultimately sustained the release of EM-2. After administration of the adenovirus in central nervous system, a sustained increase of EM2 level in the cerebral spinal fluid (CSF) was observed along with a reduction of morphine withdrawal syndrome. These findings suggest that the engineered EM2 gene delivered to the central nervous system could be a novel therapeutics for withdrawal syndrome in opioid dependent subjects.
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Affiliation(s)
- Fei-xiang Wu
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, 200438, China
- Department of Anesthesiology and Critical Care, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
| | - Yan He
- Department of Anesthesiology, Dongfang Hospital, Fujian, 354200, China
| | - Hui-ting Di
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Yu-ming Sun
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Rui-rui Pan
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Wei-feng Yu
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, 200438, China
- * E-mail: (WFW); (RYL)
| | - Renyu Liu
- Department of Anesthesiology and Critical Care, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
- * E-mail: (WFW); (RYL)
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Zhao S, Liu FF, Wu YM, Jiang YQ, Guo YX, Wang XL. Upregulation of spinal NMDA receptors mediates hydrogen sulfide-induced hyperalgesia. J Neurol Sci 2016; 363:176-81. [PMID: 27000247 DOI: 10.1016/j.jns.2016.02.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 02/04/2016] [Accepted: 02/23/2016] [Indexed: 01/23/2023]
Abstract
Hydrogen sulfide (H2S) is an endogenous neurotransmitter that importantly regulates various physiological and pathological events including pain signal transduction. In this study, we investigated the role of spinal NMDA receptors in the nociception induced by intraplantar injection of NaHS, an H2S donor. Intraplantar injection of NaHS into hindpaw significantly decreased the paw withdrawal threshold (PWT) in contralateral hindpaw. However, intraplantar formalin injection did not produce PWT in contralateral hindpaw. Intrathecal injection of methemoglobin, a H2S scavenger, abolished hyperalgesia induced by NaHS. In addition, NaHS-induced hyperalgesia was partly, but significantly, attenuated by intrathecal injection of hydroxylamine, a cystathionine-β-synthase (CBS) inhibitor. RT-PCR and western blotting analysis revealed that NR2B mRNA and protein levels were increased in the spinal dorsal horn, but not in dorsal root ganglion (DRG) in rats subjected to NaHS intraplantar injection. Collectively, these data suggest that peripheral injection of H2S donor causes hyperalgesia through increase in NR2B expression and production of H2S in the spinal cord.
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Affiliation(s)
- Shuang Zhao
- Department of Anesthesiology, The Third Hospital of HeBei Medical University, China
| | - Fei-Fei Liu
- Department of Anesthesiology, The Third Hospital of HeBei Medical University, China
| | - Yu-Ming Wu
- Department of Physiology, HeBei Medical University, Shijiazhuang, HeBei 050017, China
| | - Yu-Qing Jiang
- Department of Anesthesiology, The Third Hospital of HeBei Medical University, China
| | - Yue-Xian Guo
- Department of Anesthesiology, The Third Hospital of HeBei Medical University, China
| | - Xiu-Li Wang
- Department of Anesthesiology, The Third Hospital of HeBei Medical University, China.
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Carnosic acid attenuates neuropathic pain in rat through the activation of spinal sirtuin1 and down-regulation of p66shc expression. Neurochem Int 2016; 93:95-102. [DOI: 10.1016/j.neuint.2016.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 12/30/2015] [Accepted: 01/18/2016] [Indexed: 11/22/2022]
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Inducible Lentivirus-Mediated siRNA against TLR4 Reduces Nociception in a Rat Model of Bone Cancer Pain. Mediators Inflamm 2015; 2015:523896. [PMID: 26556957 PMCID: PMC4628653 DOI: 10.1155/2015/523896] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/26/2015] [Accepted: 08/10/2015] [Indexed: 01/28/2023] Open
Abstract
Although bone cancer pain is still not fully understood by scientists and clinicians alike, studies suggest that toll like receptor 4 (TLR4) plays an important role in the initiation and/or maintenance of pathological pain state in bone cancer pain. A promising treatment for bone cancer pain is the downregulation of TLR4 by RNA interference; however, naked siRNA (small interference RNA) is not effective in long-term treatments. In order to concoct a viable prolonged treatment for bone cancer pain, an inducible lentivirus LvOn-siTLR4 (tetracycline inducible lentivirus carrying siRNA targeting TLR4) was prepared and the antinociception effects were observed in bone cancer pain rats induced by Walker 256 cells injection in left leg. Results showed that LvOn-siTLR4 intrathecal injection with doxycycline (Dox) oral administration effectively reduced the nociception induced by Walker 256 cells while inhibiting the mRNA and protein expression of TLR4. Proinflammatory cytokines as TNF-α and IL-1β in spinal cord were also decreased. These findings suggest that TLR4 could be a target for bone cancer pain treatment and tetracycline inducible lentivirus LvOn-siTLR4 represents a new potential option for long-term treatment of bone cancer pain.
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Kim KT, Kim HJ, Cho DC, Bae JS, Park SW. Substance P stimulates proliferation of spinal neural stem cells in spinal cord injury via the mitogen-activated protein kinase signaling pathway. Spine J 2015; 15:2055-65. [PMID: 25921821 DOI: 10.1016/j.spinee.2015.04.032] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/20/2015] [Accepted: 04/20/2015] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Substance P (SP) is a neuropeptide that can influence neural stem/progenitor cell (NSPC) proliferation and neurogenesis in the brain. However, we could not find any experimental study that investigates SP action in the spinal cord. PURPOSE The aims of our study were to investigate the potential of the neuropeptide SP in promoting the proliferation of spinal cord-derived NSPCs (SC-NSPCs) after spinal cord injury (SCI) and to clarify the roles of the mitogen-activated protein (MAP) kinase signaling pathway in the process. STUDY DESIGN This is a randomized animal study. METHODS The SC-NSPCs were suspended in 100 μL of a neurobasal medium containing SP (binds neurokinin-1 receptor [NK1R]) or L-703,606 (NK1R antagonist) and cultured in a 96-well plate for 5 days. A cell proliferation assay was performed using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. A cord clipping method was used for the SCI model. Substance P and the NK1R antagonist (L-703,606) were infused intrathecally in SCI and sham models. Neural stem/progenitor cell proliferation was evaluated with immunostaining for bromodeoxyuridine (BrdU) and the immature neural marker nestin. An immunoblotting method was used for evaluating the MAP kinase signaling protein that contains extracellular signal-regulated kinases (ERKs and p38) and β-actin as the control group. RESULTS In vitro, SP (0.01-10 μmol/L) increased the proliferation of cultured SC-NSPCs, with a peak increase of 35±2% at the 0.1 μmol/L concentration. Substance P of 0.1 μmol/L continuously increased SC-NSPC proliferation from 6 hours to 5 days, whereas the proliferation decreased from 18% to 98% with L-703,606 (1-10 μM). Intrathecal infusion of SP (1 μmol/L) for 7 days significantly increased the number of proliferating NPSCs (cells positive for both BrdU and nestin) in the spinal cord (by 120±17%, p<.05) in adult rats, but infusion of L-703,606 (10 μmol/L) significantly decreased the post-SCI induction of NPSC proliferation in the spinal cord (by 87±4%). Also, SP stimulates proliferation of SC-NSPCs via the MAP kinase signaling pathway, especially the phosphorylated ERK and phosphorylated p38 proteins. The phosphorylated ERK and phosphorylated p38 protein levels increased with SP (0.1 μmol/L, p<.05). CONCLUSIONS These data indicate that SP can promote proliferation of SC-NSPCs in SCI and normal conditions and have important roles in neuronal regeneration after SCI. Also, ERKs and p38 MAP kinases are important signaling proteins in this process.
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Affiliation(s)
- Kyoung-Tae Kim
- Department of Neurosurgery, Kyungpook National University Hospital, 50 Samduk-2-ga, Jung-gu, Daegu 700-721, Republic of Korea.
| | - Hye-Jeong Kim
- Department of Neurosurgery, Kyungpook National University Hospital, 50 Samduk-2-ga, Jung-gu, Daegu 700-721, Republic of Korea
| | - Dae-Chul Cho
- Department of Neurosurgery, Kyungpook National University Hospital, 50 Samduk-2-ga, Jung-gu, Daegu 700-721, Republic of Korea
| | - Jae-Sung Bae
- Department of Physiology, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842, Republic of Korea
| | - Seung-Won Park
- Department of Neurosurgery, College of Medicine, Chung-Ang University Hospital, 224-1 Heukseok dong, Dongjak-gu, Seoul 156-755, Republic of Korea
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Selfridge BR, Wang X, Zhang Y, Yin H, Grace PM, Watkins LR, Jacobson AE, Rice KC. Structure-Activity Relationships of (+)-Naltrexone-Inspired Toll-like Receptor 4 (TLR4) Antagonists. J Med Chem 2015; 58:5038-52. [PMID: 26010811 DOI: 10.1021/acs.jmedchem.5b00426] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Activation of Toll-like receptors has been linked to neuropathic pain and opioid dependence. (+)-Naltrexone acts as a Toll-like receptor 4 (TLR4) antagonist and has been shown to reverse neuropathic pain in rat studies. We designed and synthesized compounds based on (+)-naltrexone and (+)-noroxymorphone and evaluated their TLR4 antagonist activities by their effects on inhibiting lipopolysaccharide (LPS) induced TLR4 downstream nitric oxide (NO) production in microglia BV-2 cells. Alteration of the N-substituent in (+)-noroxymorphone gave us a potent TLR4 antagonist. The most promising analog, (+)-N-phenethylnoroxymorphone ((4S,4aR,7aS,12bR)-4a,9-dihydroxy-3-phenethyl-2,3,4,4a,5,6-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-7(7aH)-one, 1j) showed ∼75 times better TLR-4 antagonist activity than (+)-naltrexone, and the ratio of its cell viability IC50, a measure of its toxicity, to TLR-4 antagonist activity (140 μM/1.4 μM) was among the best of the new analogs. This compound (1j) was active in vivo; it significantly increased and prolonged morphine analgesia.
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Affiliation(s)
- Brandon R Selfridge
- †Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, Maryland 20892-3373, United States
| | - Xiaohui Wang
- ‡Department of Psychology and Neuroscience, University of Colorado at Boulder, Boulder, Colorado 80309, United States.,§Department of Chemistry and Biochemistry the BioFrontiers Institute, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Yingning Zhang
- ‡Department of Psychology and Neuroscience, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Hang Yin
- §Department of Chemistry and Biochemistry the BioFrontiers Institute, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Peter M Grace
- ‡Department of Psychology and Neuroscience, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Linda R Watkins
- ‡Department of Psychology and Neuroscience, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Arthur E Jacobson
- †Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, Maryland 20892-3373, United States
| | - Kenner C Rice
- †Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, Maryland 20892-3373, United States
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Lewis SS, Hutchinson MR, Frick MM, Zhang Y, Maier SF, Sammakia T, Rice KC, Watkins LR. Select steroid hormone glucuronide metabolites can cause toll-like receptor 4 activation and enhanced pain. Brain Behav Immun 2015; 44:128-36. [PMID: 25218902 PMCID: PMC4275344 DOI: 10.1016/j.bbi.2014.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 08/01/2014] [Accepted: 09/02/2014] [Indexed: 12/18/2022] Open
Abstract
We have recently shown that several classes of glucuronide metabolites, including the morphine metabolite morphine-3-glucuronide and the ethanol metabolite ethyl glucuronide, cause toll like receptor 4 (TLR4)-dependent signaling in vitro and enhanced pain in vivo. Steroid hormones, including estrogens and corticosterone, are also metabolized through glucuronidation. Here we demonstrate that in silico docking predicts that corticosterone, corticosterone-21-glucuronide, estradiol, estradiol-3-glucuronide and estradiol-17-glucuronide all dock with the MD-2 component of the TLR4 receptor complex. In addition to each docking with MD-2, the docking of each was altered by pre-docking with (+)-naloxone, a TLR4 signaling inhibitor. As agonist versus antagonist activity cannot be determined from these in silico interactions, an in vitro study was undertaken to clarify which of these compounds can act in an agonist fashion. Studies using a cell line transfected with TLR4, necessary co-signaling molecules, and a reporter gene revealed that only estradiol-3-glucuronide and estradiol-17-glucuronide increased reporter gene product, indicative of TLR4 agonism. Finally, in in vivo studies, each of the 5 drugs was injected intrathecally at equimolar doses. In keeping with the in vitro results, only estradiol-3-glucuronide and estradiol-17-glucuronide caused enhanced pain. For both compounds, pain enhancement was blocked by the TLR4 antagonist lipopolysaccharide from Rhodobacter sphaeroides, evidence for the involvement in TLR4 in the resultant pain enhancement. These findings have implications for several chronic pain conditions, including migraine and temporomandibular joint disorder, in which pain episodes are more likely in cycling females when estradiol is decreasing and estradiol metabolites are at their highest.
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Affiliation(s)
- Susannah S. Lewis
- Department of Psychology & Neuroscience, University of Colorado at Boulder, Boulder, Colorado, USA,Corresponding author: Susannah S. Lewis, Department of Psychology, Campus Box 345, University of Colorado at Boulder, Boulder, Colorado, USA 80309-0345, , Fax: (303) 492-2967, Phone: (303) 492-3288
| | - Mark R. Hutchinson
- Discipline of Physiology, School of Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Morin M. Frick
- Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado, USA
| | - Yingning Zhang
- Department of Psychology & Neuroscience, University of Colorado at Boulder, Boulder, Colorado, USA
| | - Steven F. Maier
- Department of Psychology & Neuroscience, University of Colorado at Boulder, Boulder, Colorado, USA
| | - Tarek Sammakia
- Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado, USA
| | - Kenner C. Rice
- Chemical Biology Research Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism National Institutes of Health, Rockville, Maryland, USA
| | - Linda R. Watkins
- Department of Psychology & Neuroscience, University of Colorado at Boulder, Boulder, Colorado, USA
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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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Hou J, Xia Z, Xiao X, Wan X, Zhao B. Neurotoxicity of intrathecal injections of dexmedetomidine into the rat spinal dorsal horn. Neural Regen Res 2015; 7:1765-70. [PMID: 25624799 PMCID: PMC4302524 DOI: 10.3969/j.issn.1673-5374.2012.23.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 03/06/2012] [Indexed: 11/22/2022] Open
Abstract
To investigate the neurotoxicity of intrathecal injections of dexmedetomidine, Sprague-Dawley rats were intrathecally injected with dexmedetomidine at doses of 0.75, 1.50 and 3.00 μg/kg into the spinal dorsal horn. We found that c-Fos expression in the rat spinal dorsal horn peaked at 7 hours following the 3.00 μg/kg dexmedetomidine injection, while the levels of c-Fos expression following 0.75 and 1.50 μg/kg dexmedetomidine were similar to those in the spinal dorsal horn of normal rats. At 48 hours following administration, the level of c-Fos expression was similar to normal levels. In addition, the intrathecal injections of dexmedetomidine increased paw withdrawal mechanical thresholds and prolonged thermal tail flick latencies. These results indicate that dexmedetomidine has pronounced antinociceptive effects. However, dexmedetomidine appears to have neurotoxic effects in the spinal cord because it increased c-Fos expression in the spinal dorsal horn within 7 hours following administration.
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Affiliation(s)
- Jiabao Hou
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Zhongyuan Xia
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Xingpeng Xiao
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Xing Wan
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Bo Zhao
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
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Cowley KC, MacNeil BJ, Chopek JW, Sutherland S, Schmidt BJ. Neurochemical excitation of thoracic propriospinal neurons improves hindlimb stepping in adult rats with spinal cord lesions. Exp Neurol 2014; 264:174-87. [PMID: 25527257 DOI: 10.1016/j.expneurol.2014.12.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 12/01/2014] [Accepted: 12/07/2014] [Indexed: 01/07/2023]
Abstract
Using an in vitro neonatal rat brainstem-spinal cord preparation, we previously showed that cervicothoracic propriospinal neurons contribute to descending transmission of the bulbospinal locomotor command signal, and neurochemical excitation of these neurons facilitates signal propagation. The present study examined the relevance of these observations to adult rats in vivo. The first aim was to determine the extent to which rats are able to spontaneously recover hindlimb locomotor function in the presence of staggered contralateral hemisections (left T2-4 and right T9-11) designed to abolish all long direct bulbospinal projections. The second aim was to determine whether neurochemical excitation of thoracic propriospinal neurons in such animals facilitates hindlimb stepping. In the absence of intrathecal drug injection, all animals (n=24) displayed some degree of hindlimb recovery ranging from weak ankle movements to brief periods of unsupported hindlimb stepping on the treadmill. The effect of boluses of neurochemicals delivered via an intrathecal catheter (tip placed midway between the rostral and caudal thoracic hemisections) was examined at post-lesion weeks 3, 6 and 9. Quipazine was particularly effective facilitating hindlimb stepping. Subsequent complete transection above the rostral (n=3) or caudal (n=2) hemisections at week 9 had no consistent effect on drug-free locomotor performance, but the facilitatory effect of drug injection decreased in 4/5 animals. Two animals underwent complete transection at T3 as the first and only surgery and implantation of two intrathecal catheters targeted to the mid-thoracic and lumbar regions, respectively. A similar facilitatory effect on stepping was observed in response to drugs administered via either catheter. The results indicate that partial spontaneous recovery of stepping occurs in adult rats after abolishing all long direct bulbospinal connections, in contrast to previous studies suggesting that hindlimb stepping after dual hemisections either does not occur or is observed only if the second hemisection surgery is delayed relative to the first. The results support the hypothesis that artificial modulation of propriospinal neuron excitability may facilitate recovery of motor function after spinal cord injury. However, whether this facilitation is due to enhanced transmission of a descending locomotor signal or is the result of excitation of thoracolumbar circuits independent of supraspinal influence, requires further study.
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Affiliation(s)
- Kristine C Cowley
- Department of Physiology and Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, R3E 3J7, Canada
| | - Brian J MacNeil
- Department of Physical Therapy, College of Rehabilitation Sciences, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, R3E 3J7, Canada
| | - Jeremy W Chopek
- Department of Physiology and Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, R3E 3J7, Canada
| | - Scott Sutherland
- Department of Radiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, R3E 3J7, Canada
| | - Brian J Schmidt
- Department of Physiology and Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, R3E 3J7, Canada; Department of Internal Medicine, Section of Neurology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, R3E 3J7, Canada.
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Lentivirus mediated siRNA against GluN2B subunit of NMDA receptor reduces nociception in a rat model of neuropathic pain. BIOMED RESEARCH INTERNATIONAL 2014; 2014:871637. [PMID: 25243192 PMCID: PMC4163390 DOI: 10.1155/2014/871637] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/08/2014] [Accepted: 08/07/2014] [Indexed: 11/17/2022]
Abstract
Although neuropathic pain (NP) is still not fully understood by scientists and clinicians alike, studies suggest that N-methyl-D-aspartate (NMDA) receptors play an important role in the induction and maintenance of NP. A promising treatment for NP is through the downregulation of NMDA subunit GluN2B by RNA interference; however, naked siRNA (small interference RNA) is not effective in long-term treatments. In order to concoct a viable prolonged treatment for NP, Lv-siGluN2B (lentivirus carrying siRNA targeting GluN2B subunit) was prepared and the antinociception effects were observed in chronic constriction injury (CCI) rats in the present study. Results showed that Lv-siGluN2B was transduced into spinal cord cells after intrathecal injections and effectively reduced the nociception induced by sciatic nerve ligation while inhibiting the mRNA and protein expression of GluN2B. This antinociception effect lasted approximately 7 weeks. These findings suggest that GluN2B subunit could be a target for NP treatment and Lv-siGluN2B represents a new potential option for long-term treatment of NP.
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Cheng W, Zhao Y, Liu H, Fan Q, Lu FF, Li J, Yin Q, Yan CD. Resveratrol attenuates bone cancer pain through the inhibition of spinal glial activation and CX3CR1 upregulation. Fundam Clin Pharmacol 2014; 28:661-70. [PMID: 24872145 DOI: 10.1111/fcp.12084] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 05/11/2014] [Accepted: 05/22/2014] [Indexed: 02/04/2023]
Abstract
The present study examined the effects of intrathecal use of resveratrol on pain hypersensitivities, spinal glia activation, and CX3CR1 expression in the model of bone cancer pain (BCP). The BCP model was established through intrathecally injecting Walker 256 mammary gland carcinoma cells to Sprague-Dawley rats. We found that spinal CX3CR1 expression and glial activation aggravated after inoculation. Resveratrol (i.t.) attenuated bone cancer-induced pain hypersensitivities, decreased CX3CR1 expression and glial activation in the spine in a BCP model. Resveratrol (i.t.) also attenuated mechanical allodynia resulting from intrathecally injecting fractalkine in rats. Inhibition of spinal glial activation and CX3CR1 upregulation may involve in resveratrol's analgesic effects. These findings demonstrated that resveratrol attenuated pain facilitation through inhibiting spinal glial activation and CX3CR1 upregulation in a BCP model.
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Affiliation(s)
- Wei Cheng
- Affiliated Hospital of Xuzhou Medical College, 99 Huaihai West Road, Xuzhou, Jiangsu, 221002, China; Xuzhou medical College, Xuzhou, 221002, China; Jiangsu Province Key Laboratory of Anesthesiology and Center for Pain Research and Treatment, Xuzhou Medical College, Xuzhou, 221002, China
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Hou L, Zhang Y, Yang Y, Xiang K, Tan Q, Guo Q. Intrathecal siRNA Against GPNMB Attenuates Nociception in a Rat Model of Neuropathic Pain. J Mol Neurosci 2014; 55:533-40. [DOI: 10.1007/s12031-014-0379-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 07/07/2014] [Indexed: 01/08/2023]
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Itokazu T, Hayano Y, Takahashi R, Yamashita T. Involvement of Wnt/β-catenin signaling in the development of neuropathic pain. Neurosci Res 2014; 79:34-40. [DOI: 10.1016/j.neures.2013.12.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/10/2013] [Accepted: 12/10/2013] [Indexed: 02/08/2023]
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Lewis SS, Hutchinson MR, Zhang Y, Hund DK, Maier SF, Rice KC, Watkins LR. Glucuronic acid and the ethanol metabolite ethyl-glucuronide cause toll-like receptor 4 activation and enhanced pain. Brain Behav Immun 2013; 30:24-32. [PMID: 23348028 PMCID: PMC3641160 DOI: 10.1016/j.bbi.2013.01.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 01/09/2013] [Accepted: 01/10/2013] [Indexed: 12/19/2022] Open
Abstract
We have previously observed that the non-opioid morphine metabolite, morphine-3-glucuronide, enhances pain via a toll-like receptor 4 (TLR4) dependent mechanism. The present studies were undertaken to determine whether TLR4-dependent pain enhancement generalizes to other classes of glucuronide metabolites. In silico modeling predicted that glucuronic acid alone and ethyl glucuronide, a minor but long-lasting ethanol metabolite, would dock to the same MD-2 portion of the TLR4 receptor complex previously characterized as the docking site for morphine-3-glucuronide. Glucuronic acid, ethyl glucuronide and ethanol all caused an increase in TLR4-dependent reporter protein expression in a cell line transfected with TLR4 and associated co-signaling molecules. Glucuronic acid-, ethyl glucuronide-, and ethanol-induced increases in TLR4 signaling were blocked by the TLR4 antagonists LPS-RS and (+)-naloxone. Glucuronic acid and ethyl glucuronide both caused allodynia following intrathecal injection in rats, which was blocked by intrathecal co-administration of the TLR4 antagonist LPS-RS. The finding that ethyl glucuronide can cause TLR4-dependent pain could have implications for human conditions such as hangover headache and alcohol withdrawal hyperalgesia, as well as suggesting that other classes of glucuronide metabolites could have similar effects.
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Affiliation(s)
- Susannah S. Lewis
- Department of Psychology & Neuroscience, University of Colorado at Boulder, Boulder, Colorado, USA
| | - Mark R. Hutchinson
- Discipline of Pharmacology and Discipline of Physiology, School of Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Yingning Zhang
- Department of Psychology & Neuroscience, University of Colorado at Boulder, Boulder, Colorado, USA
| | - Dana K. Hund
- Department of Psychology & Neuroscience, University of Colorado at Boulder, Boulder, Colorado, USA
| | - Steven F. Maier
- Department of Psychology & Neuroscience, University of Colorado at Boulder, Boulder, Colorado, USA
| | - Kenner C. Rice
- Chemical Biology Research Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism National Institutes of Health, Rockville, Maryland, USA
| | - Linda R. Watkins
- Department of Psychology & Neuroscience, University of Colorado at Boulder, Boulder, Colorado, USA,Corresponding author: Linda R. Watkins, Department of Psychology, Campus Box 345, University of Colorado at Boulder, Boulder, Colorado, USA 80309-0345, , Fax: (303) 492-2967, Phone: (303) 492-7034
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Takahashi T, Okubo K, Kojima S, Nishikawa H, Takemura M, Tsubota-Matsunami M, Sekiguchi F, Kawabata A. Antihyperalgesic Effect of Buprenorphine Involves Nociceptin/Orphanin FQ Peptide–Receptor Activation in Rats With Spinal Nerve Injury–Induced Neuropathy. J Pharmacol Sci 2013; 122:51-4. [DOI: 10.1254/jphs.13029sc] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Resveratrol Facilitates Pain Attenuation in a Rat Model of Neuropathic Pain Through the Activation of Spinal Sirt1. Reg Anesth Pain Med 2013; 38:93-9. [DOI: 10.1097/aap.0b013e3182795b23] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Abstract
Opioid action was thought to exert reinforcing effects solely via the initial agonism of opioid receptors. Here, we present evidence for an additional novel contributor to opioid reward: the innate immune pattern-recognition receptor, toll-like receptor 4 (TLR4), and its MyD88-dependent signaling. Blockade of TLR4/MD2 by administration of the nonopioid, unnatural isomer of naloxone, (+)-naloxone (rats), or two independent genetic knock-outs of MyD88-TLR4-dependent signaling (mice), suppressed opioid-induced conditioned place preference. (+)-Naloxone also reduced opioid (remifentanil) self-administration (rats), another commonly used behavioral measure of drug reward. Moreover, pharmacological blockade of morphine-TLR4/MD2 activity potently reduced morphine-induced elevations of extracellular dopamine in rat nucleus accumbens, a region critical for opioid reinforcement. Importantly, opioid-TLR4 actions are not a unidirectional influence on opioid pharmacodynamics, since TLR4(-/-) mice had reduced oxycodone-induced p38 and JNK phosphorylation, while displaying potentiated analgesia. Similar to our recent reports of morphine-TLR4/MD2 binding, here we provide a combination of in silico and biophysical data to support (+)-naloxone and remifentanil binding to TLR4/MD2. Collectively, these data indicate that the actions of opioids at classical opioid receptors, together with their newly identified TLR4/MD2 actions, affect the mesolimbic dopamine system that amplifies opioid-induced elevations in extracellular dopamine levels, therefore possibly explaining altered opioid reward behaviors. Thus, the discovery of TLR4/MD2 recognition of opioids as foreign xenobiotic substances adds to the existing hypothesized neuronal reinforcement mechanisms, identifies a new drug target in TLR4/MD2 for the treatment of addictions, and provides further evidence supporting a role for central proinflammatory immune signaling in drug reward.
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Enhanced SCN7A/Nax expression contributes to bone cancer pain by increasing excitability of neurons in dorsal root ganglion. Neuroscience 2012; 227:80-9. [PMID: 23026072 DOI: 10.1016/j.neuroscience.2012.09.046] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 09/19/2012] [Accepted: 09/20/2012] [Indexed: 11/21/2022]
Abstract
Bone pain is one of the most common complications in cancer patients with bone metastases, and has the most significant impact on quality of life for patients. Patients with bone cancer pain may be difficult to treat due to the poor understanding of the mechanisms; therefore, the mechanisms of bone cancer pain required elucidation for developing new therapeutics. Recent studies show that SCN7A/Nax channel serves as a sodium-level sensor of the body fluid that controls the Na-intake behavior by changing the excitability of neurons. In the current study, the expression of SCN7A/Nax and the excitability of primary sensory neurons in bone cancer pain rats were examined. The analgesic effects of knockdown SCN7A/Nax channel using RNAi lentivirus intrathecal treatment were evaluated with a behavioral test. The results showed that implantation of sarcoma induced ongoing and movement-evoked pain behaviors, whereas SCN7A/Nax knockdown prevented the onset of these hyperalgesia. Immunohistochemistry showed that SCN7A/Nax was located in the medium- to large-sized neurons in dorsal root ganglions (DRGs). The proportion of SCN7A/Nax-positive cells was significantly increased in DRGs ipsilateral to sarcoma implantation. Immunostaining results were further confirmed by Western blot and real time-polymerase chain reaction (RT-PCR) analyses. Recording from primary sensory neurons in excised rat dorsal root ganglias, we found that most of SCN7A/Nax-positive neurons exhibited subthreshold oscillations, depolarized resting membrane potential and more negative threshold of action potential. These electrophysiological changes of neurons increased ectopic spike discharge which was thought to be an important generator of chronic pain, however, the hyperexcitability was completely reversed by SCN7A/Nax knockdown. These results demonstrate that enhanced expression of SCN7A/Nax channel within distinct subpopulation of DRG neurons contributes to bone cancer pain by increasing the excitability of these neurons. These findings may lead to novel strategies for the treatment of bone cancer pain.
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Wilkerson JL, Gentry KR, Dengler EC, Wallace JA, Kerwin AA, Armijo LM, Kuhn MN, Thakur GA, Makriyannis A, Milligan ED. Intrathecal cannabilactone CB(2)R agonist, AM1710, controls pathological pain and restores basal cytokine levels. Pain 2012; 153:1091-1106. [PMID: 22425445 DOI: 10.1016/j.pain.2012.02.015] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2011] [Revised: 12/19/2011] [Accepted: 02/14/2012] [Indexed: 12/30/2022]
Abstract
Spinal glial and proinflammatory cytokine actions are strongly implicated in pathological pain. Spinal administration of the anti-inflammatory cytokine interleukin (IL)-10 abolishes pathological pain and suppresses proinflammatory IL-1β and tumor necrosis factor alpha (TNF-α). Drugs that bind the cannabinoid type-2 receptor (CB(2)R) expressed on spinal glia reduce mechanical hypersensitivity. To better understand the CB(2)R-related anti-inflammatory profile of key anatomical nociceptive regions, we assessed mechanical hypersensitivity and protein profiles following intrathecal application of the cannabilactone CB(2)R agonist, AM1710, in 2 animal models; unilateral sciatic nerve chronic constriction injury (CCI), and spinal application of human immunodeficiency virus-1 glycoprotein 120 (gp120), a model of peri-spinal immune activation. In CCI animals, lumbar dorsal spinal cord and corresponding dorsal root ganglia (DRG) were evaluated by immunohistochemistry for expression of IL-10, IL-1β, phosphorylated p38-mitogen-activated-kinase (p-p38MAPK), a pathway associated with proinflammatory cytokine production, glial cell markers, and degradative endocannabinoid enzymes, including monoacylglycerol lipase (MAGL). AM1710 reversed bilateral mechanical hypersensitivity. CCI revealed decreased IL-10 expression in dorsal spinal cord and DRG, while AM1710 resulted in increased IL-10, comparable to controls. Adjacent DRG and spinal sections revealed increased IL-1β, p-p38MAPK, glial markers, and/or MAGL expression, while AM1710 suppressed all but spinal p-p38MAPK and microglial activation. In spinal gp120 animals, AM1710 prevented bilateral mechanical hypersensitivity. For comparison to immunohistochemistry, IL-1β and TNF-α protein quantification from lumbar spinal and DRG homogenates was determined, and revealed increased DRG IL-1β protein levels from gp120, that was robustly prevented by AM1710 pretreatment. Cannabilactone CB(2)R agonists are emerging as anti-inflammatory agents with pain therapeutic implications.
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Affiliation(s)
- Jenny L Wilkerson
- Department of Neurosciences, Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, NM 87131, USA Department of Anesthesiology and Critical Care Medicine, Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, NM 87131, USA Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, NM 87131, USA Center for Drug Discovery, Northeastern University, Boston, MA 02115, USA
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Changes in expression of mRNA for interleukin-8 and effects of interleukin-8 receptor inhibitor in the spinal dorsal horn in a rat model of lumbar disc herniation. Spine (Phila Pa 1976) 2011; 36:2139-46. [PMID: 21415806 DOI: 10.1097/brs.0b013e31821945a3] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Autologous nucleus pulposus obtained from coccygeal intervertebral discs was grafted on the proximal of L5 dorsal root ganglion. Pain behavior, mRNA expression of Interleukin-8 (IL-8), and immunohistochemical changes were assessed. OBJECTIVE The purpose of this study is to investigate temporal changes of IL-8 expression in the spinal cord and dorsal root ganglion and the pain-related behaviors with time course and to elucidate whether repertaxin (IL-8 receptor inhibitor) attenuates pain-related behaviors in a rat model of lumbar disc herniation. SUMMARY OF BACKGROUND DATA Inflammatory mediators like cytokines and chemokines have been implicated in radicular pain because of disc herniation. IL-8, known as CXCL8, is a chemokine, which has been reported to be associated with painful degenerative disc disorders and chronic inflammatory pain states. METHODS Lumbar disc herniated rat model was made by implantation of the autologous nucleus pulposus, harvested from the coccygeal vertebra of each tail, on the left L5 nerve root just proximal to the dorsal root ganglion. Rats were tested for mechanical allodynia and thermal hyperalgesia at 2 days before surgery, and on days 1, 5, 10, 20, 30, 40, 50, and 60 postoperatively. Experimental group was intrathecally injected with the IL-8 receptor inhibitor at L5 level on postoperative day 10. Mechanical allodynia of the plantar surface of both hindpaw was tested on 30 minutes, 1, 3 hours, 1, 3, 5, and 10 days after administration. For the staining of astrocytes and microglia, immunohistochemical study was done 20 days after surgery. RESULTS Mechanical allodynia in ipsilateral hindpaw developed 1 day after surgery and lasted until 60 days and thermal withdrawal latency decreased significantly on the ipsilateral side 10 days after surgery and gradually increased through day 60. The IL-8 receptor inhibitor attenuated the mechanical allodynia caused by nucleus pulposus when it was administered on postoperative day 10 and reduced microglial activation and phosphorylated form of mitogen-activated protein kinase (pERK) expression in the spinal dorsal horn. CONCLUSION IL-8 might be a potential therapeutic target in chronic radicular neuropathic pain because of disc herniation, CXCL8 inhibitor could be one of its promising therapeutic agents.
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Liu L, Ghosh N, Slivka PF, Fiorini Z, Hutchinson MR, Watkins LR, Yin H. An MD2 hot-spot-mimicking peptide that suppresses TLR4-mediated inflammatory response in vitro and in vivo. Chembiochem 2011; 12:1827-31. [PMID: 21678541 PMCID: PMC3374877 DOI: 10.1002/cbic.201100211] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Indexed: 01/11/2023]
Abstract
A truncated peptide was shown to retain the structure of the TLR4-binding hot-spot region of MD2, disrupting with the TLR4/MD2 interactions. The peptide not only demonstrated strong binding affinity in the fluorescence polarization assay, but also showed high specificity in macrophage cells. Furthermore, MD2-I was able to suppress neuropathic pain in animal models.
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Affiliation(s)
- Liping Liu
- Department of Chemistry and Biochemistry, 215 UCB, University of Colorado at Boulder Boulder, CO 80309-0215 (USA), Fax: (+1)303-492-5894
| | - Nilanjan Ghosh
- Department of Chemistry and Biochemistry, 215 UCB, University of Colorado at Boulder Boulder, CO 80309-0215 (USA), Fax: (+1)303-492-5894
| | - Peter F. Slivka
- Department of Chemistry and Biochemistry, 215 UCB, University of Colorado at Boulder Boulder, CO 80309-0215 (USA), Fax: (+1)303-492-5894
| | - Zeno Fiorini
- Department of Chemistry and Biochemistry, 215 UCB, University of Colorado at Boulder Boulder, CO 80309-0215 (USA), Fax: (+1)303-492-5894
| | - Mark R. Hutchinson
- Discipline of Physiology School of Medical Sciences, University of Adelaide, Adelaide, South Australia (Australia)
| | - Linda R. Watkins
- Department of Psychology and Neuroscience, University of Colorado at Boulder, Boulder, CO 80309-0345 (USA)
| | - Hang Yin
- Department of Chemistry and Biochemistry, 215 UCB, University of Colorado at Boulder Boulder, CO 80309-0215 (USA), Fax: (+1)303-492-5894
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Hains LE, Loram LC, Weiseler JL, Frank MG, Bloss EB, Sholar P, Taylor FR, Harrison JA, Martin TJ, Eisenach JC, Maier SF, Watkins LR. Pain intensity and duration can be enhanced by prior challenge: initial evidence suggestive of a role of microglial priming. THE JOURNAL OF PAIN 2011; 11:1004-14. [PMID: 20434956 DOI: 10.1016/j.jpain.2010.01.271] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2009] [Revised: 12/12/2009] [Accepted: 01/25/2010] [Indexed: 01/09/2023]
Abstract
UNLABELLED Activation of spinal microglia and consequent release of proinflammatory mediators facilitate pain. Under certain conditions, responses of activated microglia can become enhanced. Enhanced microglial production of proinflammatory products may result from priming (sensitization), similar to macrophage priming. We hypothesized that if spinal microglia were primed by an initial inflammatory challenge, subsequent challenges may create enhanced pain. Here, we used a "two-hit" paradigm using 2 successive challenges, which affect overlapping populations of spinal microglia, presented 2 weeks apart. Mechanical allodynia and/or activation of spinal glia were assessed. Initially, laparotomy preceded systemic lipopolysaccharide (LPS). Prior laparotomy caused prolonged microglial (not astrocyte) activation plus enhanced LPS-induced allodynia. In this "two-hit" paradigm, minocycline, a microglial activation inhibitor, significantly reduced later exaggerated pain induced by prior surgery when minocycline was administered intrathecally for 5 days starting either at the time of surgery or 5 days before LPS administration. To test generality of the priming effect, subcutaneous formalin preceded intrathecal HIV-1 gp120, which activates spinal microglia and causes robust allodynia. Prior formalin enhanced intrathecal gp120-induced allodynia, suggesting that microglial priming is not limited to laparotomy and again supporting a spinal site of action. Therefore, spinal microglial priming may increase vulnerability to pain enhancement. PERSPECTIVE Spinal microglia may become "primed" (sensitized) following their activation by disparate forms of peripheral trauma/inflammation. As a result, such primed microglia may overrespond to subsequent challenges, thereby enhancing pain intensity and duration.
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Affiliation(s)
- Leah E Hains
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado at Boulder, Boulder, Colorado 80309-0345, USA
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Jeon SM, Sung JK, Cho HJ. Expression of monocyte chemoattractant protein-1 and its induction by tumor necrosis factor receptor 1 in sensory neurons in the ventral rhizotomy model of neuropathic pain. Neuroscience 2011; 190:354-66. [PMID: 21712071 DOI: 10.1016/j.neuroscience.2011.06.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 06/07/2011] [Accepted: 06/11/2011] [Indexed: 12/16/2022]
Abstract
The expression and role of monocyte chemoattractant protein-1 (MCP-1) in the rat dorsal root ganglion (DRG) and spinal cord was evaluated in the lumbar 5 ventral rhizotomy (L5 VR) model of neuropathic pain. MCP-1 protein expression in the L4/L5 DRG neurons following L5 VR peaked after 3 days, and then declined. Immunohistochemistry showed that no MCP-1 immunoreactivity was observed in the spinal cord after L5 VR, while enzyme-linked immunosorbent assay (ELISA) revealed a small but significant increase in MCP-1 protein content. L5 VR resulted in robust and prolonged mechanical allodynia and thermal hyperalgesia. Administration of anti-MCP-1 neutralizing antibody before and at early time points after L5 VR resulted in a significant attenuation of mechanical allodynia and thermal hyperalgesia, while post-treatment had a weaker effect on established neuropathic pain. Extensive colocalization of tumor necrosis factor receptor 1 (TNFR1) and MCP-1 was observed in the L5 DRG following L5 VR, and treatment with TNFR1 antisense oligonucleotide reduced L5 VR-induced MCP-1 expression in L5 DRG neurons and neuropathic pain behaviors. MCP-1/chemokine (C-C motif) receptor 2 signaling has been proposed as a major regulator of macrophage trafficking. In contrast to the effect on pain behaviors, however, intrathecal administration of anti-MCP-1 neutralizing antibody had no effect on the L5 VR-induced increase in ED-1-immunoreactive macrophages in the L5 DRG and the distal stump of the transected L5 ventral root. These data indicate that increased MCP-1 in DRG neurons might participate in the initiation, rather than the maintenance, of neuropathic pain induced by L5 VR. Furthermore, increased MCP-1 in the DRG is induced by TNF-α/TNFR1 and has no effect on the infiltration of macrophages into the DRG following L5 VR.
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Affiliation(s)
- S-M Jeon
- Department of Anatomy, School of Medicine, Kyungpook National University, 2-101, Dongin Dong, Daegu 700-422, South Korea
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Intrathecal injection of anti-CX3CR1 neutralizing antibody delayed and attenuated pain facilitation in rat tibial bone cancer pain model. Behav Pharmacol 2010; 21:595-601. [DOI: 10.1097/fbp.0b013e32833e7e2a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Wu FX, Bian JJ, Miao XR, Huang SD, Xu XW, Gong DJ, Sun YM, Lu ZJ, Yu WF. Intrathecal siRNA against Toll-like receptor 4 reduces nociception in a rat model of neuropathic pain. Int J Med Sci 2010; 7:251-9. [PMID: 20714435 PMCID: PMC2920570 DOI: 10.7150/ijms.7.251] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 08/02/2010] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Neuropathic pain is characterized by hyperalgesia, allodynia and spontaneous pain. It often occurs as a result of injury to peripheral nerves, dorsal root ganglions (DRG), spinal cord, or brain. Recent studies have suggested that Toll-like receptor 4 (TLR4) might play a role in neuropathic pain. METHODOLOGY/PRINCIPAL FINDINGS In this study, we investigated the role of TLR4 in a rat chronic constriction injury (CCI) model and explored the feasibility of treating neuropathic pain by inhibiting TLR4. Our results demonstrated that intrathecal siRNA-mediated suppression of TLR4 attenuated CCI-induced mechanical allodynia and thermal hyperalgesia through inhibiting the activation of NF-kappaB p65 and production of proinflammatory cytokines (e.g., TNF-alpha and IL-1 beta). CONCLUSIONS/SIGNIFICANCE These findings suggest that suppression of TLR4 mediated by intrathecally administered siRNA may be a new strategy for the treatment of neuropathic pain.
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Affiliation(s)
- Fei-xiang Wu
- Department of Anesthesiology, Eastern Hepatobiliary Hospital, Second Military Medical University, Shanghai 200438, China
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A new metabotropic glutamate receptor agonist with in vivo anti-allodynic activity. Bioorg Med Chem 2010; 18:6089-98. [DOI: 10.1016/j.bmc.2010.06.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Revised: 06/16/2010] [Accepted: 06/17/2010] [Indexed: 11/19/2022]
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