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The BDNF-TrkB signaling pathway in the rostral anterior cingulate cortex is involved in the development of pain aversion in rats with bone cancer via NR2B and ERK-CREB signaling. Brain Res Bull 2022; 185:18-27. [DOI: 10.1016/j.brainresbull.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 03/15/2022] [Accepted: 04/05/2022] [Indexed: 11/19/2022]
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2
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Lu ZY, Fan J, Yu LH, Ma B, Cheng LM. The Up-regulation of TNF-α Maintains Trigeminal Neuralgia by Modulating MAPKs Phosphorylation and BKCa Channels in Trigeminal Nucleus Caudalis. Front Cell Neurosci 2021; 15:764141. [PMID: 34899191 PMCID: PMC8657151 DOI: 10.3389/fncel.2021.764141] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/18/2021] [Indexed: 12/30/2022] Open
Abstract
Trigeminal neuralgia (TN) is a severe chronic neuropathic pain. Despite numerous available medical interventions, the therapeutic effects are not ideal. To control the pain attacks, the need for more contemporary drugs continues to be a real challenge. Our previous study reported that Ca2+-activated K+ channels (BKCa) channels modulated by mitogen-activated protein kinases (MAPKs) in the trigeminal ganglia (TG) neurons play crucial roles in regulating TN, and some research studies demonstrated that inflammatory cytokine tumor necrosis factor alpha (TNF-α) could promote neuropathic pain. Meanwhile, the trigeminal nucleus caudalis (TNC), the first central site of the trigeminal nociceptive pathway, is responsible for processing sensory and pain signals from the peripheral orofacial area. Thus, this study is aimed to further investigate whether TNF-α and MAPKs phosphorylation in the TNC could mediate the pathogenesis of TN by modulating BKCa channels. The results showed that TNF-α of the TNC region is upregulated significantly in the chronic constriction injury of infraorbital nerve (ION-CCI) rats model, which displayed persistent facial mechanical allodynia. The normal rats with target injection of exogenous TNF-α to the fourth brain ventricle behaved just like the ION-CCI model rats, the orofacial mechanical pain threshold decreased clearly. Meanwhile, the exogenous TNF-α increased the action potential frequency and reduced the BKCa currents of TNC neurons significantly, which could be reversed by U0126 and SB203580, the inhibitors of MAPK. In addition, U0126, SB203580, and another MAPK inhibitor SP600125 could relieve the facial mechanical allodynia by being injected into the fourth brain ventricle of ION-CCI model rats, respectively. Taken together, our work suggests that the upregulation of TNF-α in the TNC region would cause the increase of MAPKs phosphorylation and then the negative regulation of BKCa channels, resulting in the TN.
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Affiliation(s)
- Zhan-Ying Lu
- Experimental Training Center of Basic Medical Science, Naval Medical University, Shanghai, China
| | - Juan Fan
- Experimental Training Center of Basic Medical Science, Naval Medical University, Shanghai, China
| | - Li-Hua Yu
- Experimental Training Center of Basic Medical Science, Naval Medical University, Shanghai, China
| | - Bei Ma
- Experimental Training Center of Basic Medical Science, Naval Medical University, Shanghai, China.,Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of the Ministry of Education, Division of Spine Surgery, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Li-Ming Cheng
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of the Ministry of Education, Division of Spine Surgery, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
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Ruan J, Chen L, Ma Z. Activation of spinal Extacellular Signal‐Regulated Kinases and c‐jun N‐terminal kinase signaling pathways contributes to morphine‐induced acute and chronic hyperalgesia in mice. J Cell Biochem 2019; 120:15045-15056. [PMID: 31016764 DOI: 10.1002/jcb.28766] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/27/2019] [Accepted: 01/30/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Jia‐Ping Ruan
- Department of Anesthesiology Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University Nanjing Jiangsu China
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine Nanjing University of Chinese Medicine Nanjing Jiangsu China
| | - Ling Chen
- Laboratory of Reproductive Medicine Nanjing Medical University Nanjing Jiangsu China
| | - Zheng‐liang Ma
- Department of Anesthesiology Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University Nanjing Jiangsu China
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Nam Y, Kim JH, Kim JH, Jha MK, Jung JY, Lee MG, Choi IS, Jang IS, Lim DG, Hwang SH, Cho HJ, Suk K. Reversible Induction of Pain Hypersensitivity following Optogenetic Stimulation of Spinal Astrocytes. Cell Rep 2017; 17:3049-3061. [PMID: 27974216 DOI: 10.1016/j.celrep.2016.11.043] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 10/17/2016] [Accepted: 11/12/2016] [Indexed: 12/30/2022] Open
Abstract
While glial activation is an integral part of pain pathogenesis, the existence of a causal relationship between glia and pain processing has yet to be demonstrated in vivo. Here, we have investigated whether the activation of spinal astrocytes could directly evoke pain hypersensitivity in vivo via the use of optogenetic techniques. Optogenetic stimulation of channelrhopdopsin-2 (ChR)-expressing spinal astrocytes induced pain hypersensitivity in a reversible and time-dependent manner, which was accompanied by glial activation, NR1 phosphorylation, ATP release, and the production of proalgesic mediators. Photostimulation of ChR2-expressing astrocytes in culture and spinal slices recapitulated in vivo findings, demonstrating the release of proalgesic mediators and electrophysiological disinhibition of spinal projection neurons. These findings deepen our understanding of the role of astrocytes in pain pathogenesis and provide the scientific basis for an astrocyte-oriented pain treatment.
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Affiliation(s)
- Youngpyo Nam
- Department of Pharmacology, Brain Science & Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea
| | - Jae-Hong Kim
- Department of Pharmacology, Brain Science & Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea
| | - Jong-Heon Kim
- Department of Pharmacology, Brain Science & Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea
| | - Mithilesh Kumar Jha
- Department of Pharmacology, Brain Science & Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea
| | - Ji Young Jung
- Department of Pharmacology, Brain Science & Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea
| | - Maan-Gee Lee
- Department of Pharmacology, Brain Science & Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea
| | - In-Sun Choi
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 41940, Republic of Korea
| | - Il-Sung Jang
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 41940, Republic of Korea
| | - Dong Gun Lim
- Department of Anesthesiology and Pain Medicine, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea
| | - Sung-Hun Hwang
- Department of Anatomy, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea
| | - Hee-Jung Cho
- Department of Anatomy, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea
| | - Kyoungho Suk
- Department of Pharmacology, Brain Science & Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41944, Republic of Korea.
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The NA v1.7 blocker protoxin II reduces burn injury-induced spinal nociceptive processing. J Mol Med (Berl) 2017; 96:75-84. [PMID: 29063143 PMCID: PMC5750333 DOI: 10.1007/s00109-017-1599-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/07/2017] [Accepted: 10/02/2017] [Indexed: 12/19/2022]
Abstract
Controlling pain in burn-injured patients poses a major clinical challenge. Recent findings suggest that reducing the activity of the voltage-gated sodium channel Nav1.7 in primary sensory neurons could provide improved pain control in burn-injured patients. Here, we report that partial thickness scalding-type burn injury on the rat paw upregulates Nav1.7 expression in primary sensory neurons 3 h following injury. The injury also induces upregulation in phosphorylated cyclic adenosine monophosphate response element-binding protein (p-CREB), a marker for nociceptive activation in primary sensory neurons. The upregulation in p-CREB occurs mainly in Nav1.7-immunopositive neurons and exhibits a peak at 5 min and, following a decline at 30 min, a gradual increase from 1 h post-injury. The Nav1.7 blocker protoxin II (ProTxII) or morphine injected intraperitoneally 15 min before or after the injury significantly reduces burn injury-induced spinal upregulation in phosphorylated serine 10 in histone H3 and phosphorylated extracellular signal-regulated kinase 1/2, which are both markers for spinal nociceptive processing. Further, ProTxII significantly reduces the frequency of spontaneous excitatory post-synaptic currents in spinal dorsal horn neurons following burn injury. Together, these findings indicate that using Nav1.7 blockers should be considered to control pain in burn injury. KEY MESSAGES • Burn injury upregulates Nav1.7 expression in primary sensory neurons. • Burn injury results in increased activity of Nav1.7-expressing primary sensory neurons. • Inhibiting Nav1.7 by protoxin II reduces spinal nociceptive processing. • Nav1.7 represents a potential target to reduce pain in burn injury.
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The analgesic activities of Stauntonia brachyanthera and YM 11 through regulating inflammatory mediators and directly controlling the sodium channel prompt. Sci Rep 2017; 7:7574. [PMID: 28790377 PMCID: PMC5548894 DOI: 10.1038/s41598-017-07095-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/22/2017] [Indexed: 12/30/2022] Open
Abstract
The analgesic studies on Stauntonia brachyanthera, a traditional Chinese folk medicine used to treat headache, pains and inflammatory diseases in local areas, showed that the EtOH extracts (EESB) and the characteristic ingredient YM11 could significantly inhibit the acetic acid-induced writhing responses by 43.1% and 78.95%, and decrease the xylene-induced ear edemas by 48.9% and 21.4%, respectively. EESB could significantly increase pain threshold of mice in hot-plate test, but the effect of YM11 was not obviously. Further study in formalin test showed the inhibitory effect of YM11 in 2nd phase was more significant than that in 1st phase, revealed the peripheral analgesic activity of YM11. The ELISA and Western Blot analysis suggested that the analgesic mechanisms of YM11 were related to the inhibitions of the expressions of TNF-α, IL-1β and IL-6, and down-regulations of Nav1.8 protein in the left side of L4–6 DRG regulated by MAPKs, in which the levels of p-ERK, p-JNK and p-p38 were all decreased. In addition, the electrophysiological experiments indicated YM11 could reduce the Nav1.8 currents by 46.01% in small-diameter DRG neurons. Therefore, the analgesic activity of S. brachyanthera might be based on the regulation of inflammatory mediators and the directly control of the sodium channel prompt.
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Jones MG, Andreou AP, McMahon SB, Spanswick D. Pharmacology of reflex blinks in the rat: a novel model for headache research. J Headache Pain 2016; 17:96. [PMID: 27770405 PMCID: PMC5074984 DOI: 10.1186/s10194-016-0686-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 09/29/2016] [Indexed: 11/10/2022] Open
Abstract
Background Migraineurs are highly sensitive to the nitric oxide donor glyceryl trinitrate which triggers attacks in many sufferers. In animal studies, glyceryl trinitrate increases neuronal activity in the trigeminovascular pathway and elevates neurotransmitter levels in the brainstem. Many migraineurs also display alterations in blink reflexes, known to involve brainstem circuits. We investigated the effect of GTN on evoked blinks in the anaesthetised rat to determine whether such reflexes may prove useful as the basis for a novel animal model to evaluate potential anti-migraine therapeutic agents. Method In anaesthetised rats the electromyogram associated with the reflex blink evoked by corneal airpuff was recorded. Rats were infused with glyceryl trinitrate, sumatriptan plus glyceryl trinitrate or vehicle control. Changes in the magnitude of the reflex blink-associated electromyogram following these treatments were measured. Results Glyceryl trinitrate potentiated the evoked reflex blink-associated EMG response from 2 h after infusion. That effect was abolished by simultaneous infusion of sumatriptan with glyceryl trinitrate. Conclusions These results show that simple skin surface measurements of evoked electromyographic activity in the rat can reliably detect the evoked blink reflex that can be potentiated by nitric oxide donors. This novel model may be an effective tool for evaluating putative anti-migraine therapeutic agents.
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Affiliation(s)
- M G Jones
- Neurorestoration Group, Wolfson Centre for Age-Related Disease, Kings College London, London, UK. .,Zenith NeuroTech, Wolfson Centre for Age-Related Disease, Kings College London, London, UK.
| | - A P Andreou
- Academic Headache Centre, Wolfson Centre for Age-Related Disease, Kings College London, London, UK.,London and Pain Management and Neuromodulation Centre, St Thomas's Hospital, London, UK
| | - S B McMahon
- Neurorestoration Group, Wolfson Centre for Age-Related Disease, Kings College London, London, UK
| | - D Spanswick
- Neurosolutions Ltd., University of Warwick, Coventry, UK
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9
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Sanna MD, Ghelardini C, Galeotti N. Regionally selective activation of ERK and JNK in morphine paradoxical hyperalgesia: A step toward improving opioid pain therapy. Neuropharmacology 2014; 86:67-77. [DOI: 10.1016/j.neuropharm.2014.06.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 06/03/2014] [Accepted: 06/05/2014] [Indexed: 12/30/2022]
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Activation of CB1 inhibits NGF-induced sensitization of TRPV1 in adult mouse afferent neurons. Neuroscience 2014; 277:679-89. [PMID: 25088915 DOI: 10.1016/j.neuroscience.2014.07.041] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 06/12/2014] [Accepted: 07/02/2014] [Indexed: 01/02/2023]
Abstract
Transient receptor potential vanilloid 1 (TRPV1)-containing afferent neurons convey nociceptive signals and play an essential role in pain sensation. Exposure to nerve growth factor (NGF) rapidly increases TRPV1 activity (sensitization). In the present study, we investigated whether treatment with the selective cannabinoid receptor 1 (CB1) agonist arachidonyl-2'-chloroethylamide (ACEA) affects NGF-induced sensitization of TRPV1 in adult mouse dorsal root ganglion (DRG) afferent neurons. We found that CB1, NGF receptor tyrosine kinase A (trkA), and TRPV1 are present in cultured adult mouse small- to medium-sized afferent neurons and treatment with NGF (100ng/ml) for 30 min significantly increased the number of neurons that responded to capsaicin (as indicated by increased intracellular Ca(2 +) concentration). Pretreatment with the CB1 agonist ACEA (10nM) inhibited the NGF-induced response, and this effect of ACEA was reversed by a selective CB1 antagonist. Further, pretreatment with ACEA inhibited NGF-induced phosphorylation of AKT. Blocking PI3 kinase activity also attenuated the NGF-induced increase in the number of neurons that responded to capsaicin. Our results indicate that the analgesic effect of CB1 activation may in part be due to inhibition of NGF-induced sensitization of TRPV1 and also that the effect of CB1 activation is at least partly mediated by attenuation of NGF-induced increased PI3 signaling.
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11
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Liu CY, Lu ZY, Li N, Yu LH, Zhao YF, Ma B. The role of large-conductance, calcium-activated potassium channels in a rat model of trigeminal neuropathic pain. Cephalalgia 2014; 35:16-35. [PMID: 24820887 DOI: 10.1177/0333102414534083] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Trigeminal neuralgia is a disorder of paroxysmal and severely disabling facial pain and continues to be a real therapeutic challenge. At present there are few effective drugs. Here the aim of this study was to investigate the role of BKCa channels in trigeminal neuropathic pain. METHODS Rats were divided into two groups: a sham and a chronic constriction injury of infraorbital branch of trigeminal nerve (ION-CCI) group. Nociceptive behavior testing, immunohistochemistry, RT-PCR, Western blotting and whole-cell patch clamp recording were used. RESULTS Relative to the sham group, rats with ION-CCI consistently displayed lower mechanical pain thresholds in the vibrissal pad region from day 6 to 42 after ION-CCI operation. ION-CCI induced a significant down-regulation of BKCa channels both in mRNA and protein levels in the ipsilateral trigeminal ganglion (TG), a lower threshold intensity of action potential, and decreased total BKCa currents in cultured TG neurons. TG target injection of NS1619 (20-100 µg), an opener of BKCa channels, dose-dependently increased the mechanical pain threshold, which was blocked by the BKCa channel inhibitor iberiotoxin (IbTX, 20 µg). NS1619 (10 µM) significantly increased the mean threshold intensities of action potentials in ION-CCI rats, while failing to affect those in the sham rats. The levels of phosphorylated extracellular signal-regulated kinase (ERK), p38 and c-Jun N-terminal kinases (JNK) in TG were significantly increased after ION-CCI operation. The ERK1/2 antagonist U0126, p38 antagonist SB203580 and JNK antagonist SP600125 significantly reversed the facial mechanical allodynia in ION-CCI rats. However, the ERK1/2 antagonist U0126, p38 antagonist SB203580 but not JNK antagonist SP600125 significantly increased BKCa currents in ION-CCI TG neurons. CONCLUSIONS Our results indicate the important involvement of mainly ERK and p38 MAPK pathways in modulating BKCa channels in ION-CCI TG neurons. BKCa channels represent a new therapeutic target for the clinical treatment of trigeminal neuropathic pain.
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Affiliation(s)
- Cai-Yue Liu
- Department of Physiology and Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, PR China Department of Stomatology, Changzheng Hospital, Second Military Medical University, PR China
| | - Zhan-Ying Lu
- Department of Physiology and Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, PR China
| | - Na Li
- Department of Physiology and Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, PR China Department of Anesthesia, Changhai Hospital, Second Military Medical University, PR China
| | - Li-Hua Yu
- Department of Physiology and Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, PR China
| | - Yun-Fu Zhao
- Department of Stomatology, Changzheng Hospital, Second Military Medical University, PR China
| | - Bei Ma
- Department of Physiology and Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, PR China
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12
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Astrocytes--multitaskers in chronic pain. Eur J Pharmacol 2013; 716:120-8. [PMID: 23528354 DOI: 10.1016/j.ejphar.2013.03.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 02/20/2013] [Accepted: 03/04/2013] [Indexed: 12/31/2022]
Abstract
Treatment of chronic pain remains a clinical challenge and sufficient pharmacological management is difficult to achieve without concurrent adverse drug effects. Recently the concept of chronic pain as a solely neuron-mediated phenomenon has evolved and it is now appreciated that also glial cells are of critical importance in pain generation and modulation. Astrocytes are macroglial cells that have close structural relationships with neurons; they contact neuronal somata and dendrites and enwrap synapses, where small astrocytic processes have been shown to be highly motile. This organization allows astrocytes to directly influence and coordinate neurons located within their structural domains. Moreover, astrocytes form astroglial networks and calcium wave propagations can spread through neighbouring astrocytes. ATP, which is released from astrocytes in response to elevated intracellular calcium concentrations, can contribute to the central mechanisms in chronic pain via purinergic receptors. In this review we highlight the structural organization and the functionalities of astrocytes that allow them to undertake critical roles in pain processing and we stress the possibility that astrocytes contribute to chronic pain not via a single pathway, but by undertaking various roles depending on the pain condition.
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Wang ZY, Wang P, Bjorling DE. Activation of cannabinoid receptor 2 inhibits experimental cystitis. Am J Physiol Regul Integr Comp Physiol 2013; 304:R846-53. [PMID: 23515618 DOI: 10.1152/ajpregu.00585.2012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cannabinoids have been shown to exert analgesic and anti-inflammatory effects, and the effects of cannabinoids are mediated primarily by cannabinoid receptors 1 and 2 (CB1and CB2). Both CB1 and CB2 are present in bladders of various species, including human, monkey, and rodents, and it appears that CB2 is highly expressed in urothelial cells. We investigated whether treatment with the CB2 agonist GP1a alters severity of experimental cystitis induced by acrolein and referred mechanical hyperalgesia associated with cystitis. We also investigated whether the mitogen-activated protein kinases (MAPK), ERK1/2, p38, and JNK are involved in the functions of CB2. We found that treatment with the selective CB2 agonist GP1a (1-10 mg/kg, ip) inhibited the severity of bladder inflammation 3 h after intravesical instillation of acrolein in a dose-dependent manner, and inhibition reached significance at a dose of 10 mg/kg (P < 0.05). Treatment with GP1a (10 mg/kg) inhibited referred mechanical hyperalgesia associated with cystitis (P < 0.05). The inhibitory effects of the CB2 agonist were prevented by the selective CB2 antagonist AM630 (10 mg/kg, sc). We further demonstrated the inhibitory effects of CB2 appear to be at least partly mediated by reducing bladder inflammation-induced activation of ERK1/2 MAPK pathway. The results of the current study indicate that CB2 is a potential therapeutic target for treatment of bladder inflammation and pain in patients.
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Affiliation(s)
- Zun-Yi Wang
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA.
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Keay KA. pERK-ing up the brainstem after injury. Eur J Pain 2012; 17:1-2. [PMID: 23233315 DOI: 10.1002/j.1532-2149.2012.00222.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2012] [Indexed: 11/12/2022]
Affiliation(s)
- K A Keay
- School of Medical Sciences (Anatomy and Histology), University of Sydney, Australia.
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Wilkerson JL, Milligan ED. The Central Role of Glia in Pathological Pain and the Potential of Targeting the Cannabinoid 2 Receptor for Pain Relief. ACTA ACUST UNITED AC 2011; 2011. [PMID: 22442754 DOI: 10.5402/2011/593894] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Under normal conditions, acute pain processing consists of well-characterized neuronal signaling events. When dysfunctional pain signaling occurs, pathological pain ensues. Glial activation and their released factors participate in the mediation of pathological pain. The use of cannabinoid compounds for pain relief is currently an area of great interest for both basic scientists and physicians. These compounds, bind mainly either the cannabinoid receptor subtype 1 (CB(1)R) or cannabinoid receptor subtype 2 (CB(2)R) and are able to modulate pain. Although cannabinoids were initially only thought to modulate pain via neuronal mechanisms within the central nervous system, strong evidence now supports that CB(2)R cannabinoid compounds are capable of modulating glia, (e.g. astrocytes and microglia) for pain relief. However, the mechanisms underlying cannabinoid receptor-mediated pain relief remain largely unknown. An emerging body of evidence supports that CB(2)R agonist compounds may prove to be powerful novel therapeutic candidates for the treatment of chronic pain.
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Affiliation(s)
- Jenny L Wilkerson
- Department of Neurosciences, School of Medicine, University of New Mexico, HSC, MSC08-4740, Albuquerque, NM 87131, USA
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White JPM, Ko CW, Fidalgo AR, Cibelli M, Paule CC, Anderson PJ, Cruz C, Gomba S, Matesz K, Veress G, Avelino A, Nagy I. Severe burn injury induces a characteristic activation of extracellular signal-regulated kinase 1/2 in spinal dorsal horn neurons. Eur J Pain 2011; 15:683-90. [PMID: 21371920 DOI: 10.1016/j.ejpain.2010.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 12/02/2010] [Accepted: 12/21/2010] [Indexed: 01/18/2023]
Abstract
We have studied scalding-type burn injury-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2) in the spinal dorsal horn, which is a recognised marker for spinal nociceptive processing. At 5min after severe scalding injury to mouse hind-paw, a substantial number of phosphorylated ERK1/2 (pERK1/2) immunopositive neurons were found in the ipsilateral dorsal horn. At 1h post-injury, the number of pERK1/2-labelled neurons remained substantially the same. However, at 3h post-injury, a further increase in the number of labelled neurons was found on the ipsilateral side, while a remarkable increase in the number of labelled neurons on the contralateral side resulted in there being no significant difference between the extent of the labelling on both sides. By 6h post-injury, the number of labelled neurons was reduced on both sides without there being significant difference between the two sides. A similar pattern of severe scalding injury-induced activation of ERK1/2 in spinal dorsal horn neurons over the same time-course was found in mice which lacked the transient receptor potential type 1 receptor (TRPV1) except that the extent to which ERK1/2 was activated in the ipsilateral dorsal horn at 5 min post-injury was significantly greater in wild-type animals when compared to TRPV1 null animals. This difference in activation of ERK1/2 in spinal dorsal horn neurons was abolished within 1h after injury, demonstrating that TRPV1 is not essential for the maintenance of ongoing spinal nociceptive processing in inflammatory pain conditions in mouse resulting from at least certain types of severe burn injury.
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Affiliation(s)
- John P M White
- Section of Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, 369, Fulham Road, London SW10 9NH, United Kingdom
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