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Kimourtzis G, Rangwani N, Jenkins BJ, Jani S, McNaughton PA, Raouf R. Prostaglandin E2 depolarises sensory axons in vitro in an ANO1 and Nav1.8 dependent manner. Sci Rep 2024; 14:17360. [PMID: 39075089 PMCID: PMC11286870 DOI: 10.1038/s41598-024-67793-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 07/16/2024] [Indexed: 07/31/2024] Open
Abstract
Prostaglandin E2 (PGE2) is a major contributor to inflammatory pain hyperalgesia, however, the extent to which it modulates the activity of nociceptive axons is incompletely understood. We developed and characterized a microfluidic cell culture model to investigate sensitisation of the axons of dorsal root ganglia neurons. We show that application of PGE2 to fluidically isolated axons leads to sensitisation of their responses to depolarising stimuli. Interestingly the application of PGE2 to the DRG axons elicited a direct and persistent spiking activity propagated to the soma. Both the persistent activity and the membrane depolarisation in the axons are abolished by the EP4 receptor inhibitor and a blocker of cAMP synthesis. Further investigated into the mechanisms of the spiking activity showed that the PGE2 evoked depolarisation was inhibited by Nav1.8 sodium channel blockers but was refractory to the application of TTX or zatebradine. Interestingly, the depolarisation of axons was blocked by blocking ANO1 channels with T16Ainh-A01. We further show that PGE2-elicited axonal responses are altered by the changes in chloride gradient within the axons following treatment with bumetanide a Na-K-2Cl cotransporter NKCC1 inhibitor, but not by VU01240551 an inhibitor of potassium-chloride transporter KCC2. Our data demonstrate a novel role for PGE2/EP4/cAMP pathway which culminates in a sustained depolarisation of sensory axons mediated by a chloride current through ANO1 channels. Therefore, using a microfluidic culture model, we provide evidence for a potential dual function of PGE2 in inflammatory pain: it sensitises depolarisation-evoked responses in nociceptive axons and directly triggers action potentials by activating ANO1 and Nav1.8 channels.
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Affiliation(s)
- Georgios Kimourtzis
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE1 1UL, UK
| | - Natasha Rangwani
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE1 1UL, UK
| | - Bethan J Jenkins
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE1 1UL, UK
| | - Siddharth Jani
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE1 1UL, UK
| | - Peter A McNaughton
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE1 1UL, UK
| | - Ramin Raouf
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE1 1UL, UK.
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Bao C, Abraham SN. Mast cell-sensory neuron crosstalk in allergic diseases. J Allergy Clin Immunol 2024; 153:939-953. [PMID: 38373476 PMCID: PMC10999357 DOI: 10.1016/j.jaci.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 01/12/2024] [Accepted: 02/14/2024] [Indexed: 02/21/2024]
Abstract
Mast cells (MCs) are tissue-resident immune cells, well-positioned at the host-environment interface for detecting external antigens and playing a critical role in mobilizing innate and adaptive immune responses. Sensory neurons are afferent neurons innervating most areas of the body but especially in the periphery, where they sense external and internal signals and relay information to the brain. The significance of MC-sensory neuron communication is now increasingly becoming recognized, especially because both cell types are in close physical proximity at the host-environment interface and around major organs of the body and produce specific mediators that can activate each other. In this review, we explore the roles of MC-sensory neuron crosstalk in allergic diseases, shedding light on how activated MCs trigger sensory neurons to initiate signaling in pruritus, shock, and potentially abdominal pain in allergy, and how activated sensory neurons regulate MCs in homeostasis and atopic dermatitis associated with contact hypersensitivity and type 2 inflammation. Throughout the review, we also discuss how these 2 sentinel cell types signal each other, potentially resulting in a positive feedback loop that can sustain inflammation. Unraveling the mysteries of MC-sensory neuron crosstalk is likely to unveil their critical roles in various disease conditions and enable the development of new therapeutic approaches to combat these maladies.
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Affiliation(s)
- Chunjing Bao
- Department of Pathology, Duke University Medical Center, Durham, NC
| | - Soman N Abraham
- Department of Pathology, Duke University Medical Center, Durham, NC; Department of Immunology, Duke University Medical Center, Durham, NC; Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC; Department of Program in Emerging Infectious Diseases, Duke-National University of Singapore, Singapore, Singapore.
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Roy R, Roy J, Liya IJ, Basher MA, Miah MY. Antipyretic and antinociceptive effects of methanolic extract of C. iria L. tuber. JOURNAL OF ETHNOPHARMACOLOGY 2024; 318:116860. [PMID: 37419227 DOI: 10.1016/j.jep.2023.116860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 06/25/2023] [Accepted: 06/26/2023] [Indexed: 07/09/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Cyperus iria L. is a sedge belongs to Cyperaceae family. Tuber of this plant is traditionally used in fever. AIM OF THE STUDY This study aimed to verify the effectiveness of this plant part against fever. Additionally, antinociceptive effect of the plant was evaluated. MATERIALS AND METHODS Antipyretic effect was evaluated by yeast induced hyperthermia experiment. Antinociceptive effect was determined by acetic acid induced writhing test and hot plate test. Four different doses of plant extract were used in mice model. RESULTS Extract at dose of 400 mg/kg.bw produced greater effect than paracetamol; reduction of elevated mice body temperature was observed by 2.6 °F and 4.2 °F after 4 h by paracetamol and 400 mg/kg.bw extract respectively. In acetic acid writhing test, extract at 400 mg/kg.bw and diclofenac were found to have equivalent effects producing percentage inhibition of writhing of 67.68% and 68.29% respectively. In hot plat test, significant reduction in latency was also observed after administration of plant extracts. Mean percent maximal effect was 83.55% and 67.26% for ketorolac and extract (400 mg/kg.bw) respectively. CONCLUSION Our study endorsed the traditional use of C. iria tuber in fever with possible antinociceptive effects.
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Affiliation(s)
- Roni Roy
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - Jony Roy
- Department of Applied Chemistry and Chemical Engineering, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - Israt Jahan Liya
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - Mohammad Anwarul Basher
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - Muhammed Yusuf Miah
- Department of Applied Chemistry and Chemical Engineering, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
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Choi JG, Choi SR, Kang DW, Shin HJ, Lee M, Hwang J, Kim HW. Inhibition of angiotensin converting enzyme increases PKCβI isoform expression via activation of substance P and bradykinin receptors in cultured astrocytes of mice. J Vet Sci 2023; 24:e26. [PMID: 37012034 PMCID: PMC10071283 DOI: 10.4142/jvs.22275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/10/2023] [Accepted: 02/14/2023] [Indexed: 03/11/2023] Open
Abstract
BACKGROUND Angiotensin-converting enzyme inhibitor (ACEi) inhibits the catalysis of angiotensin I to angiotensin II and the degradation of substance P (SP) and bradykinin (BK). While the possible relationship between ACEi and SP in nociceptive mice was recently suggested, the effect of ACEi on signal transduction in astrocytes remains unclear. OBJECTIVES This study examined whether ACE inhibition with captopril or enalapril modulates the levels of SP and BK in primary cultured astrocytes and whether this change modulates PKC isoforms (PKCα, PKCβI, and PKCε) expression in cultured astrocytes. METHODS Immunocytochemistry and Western blot analysis were performed to examine the changes in the levels of SP and BK and the expression of the PKC isoforms in primary cultured astrocytes, respectively. RESULTS The treatment of captopril or enalapril increased the immunoreactivity of SP and BK significantly in glial fibrillary acidic protein-positive cultured astrocytes. These increases were suppressed by a pretreatment with an angiotensin-converting enzyme. In addition, treatment with captopril increased the expression of the PKCβI isoform in cultured astrocytes, while there were no changes in the expression of the PKCα and PKCε isoforms after the captopril treatment. The captopril-induced increased expression of the PKCβI isoform was inhibited by a pretreatment with the neurokinin-1 receptor antagonist, L-733,060, the BK B1 receptor antagonist, R 715, or the BK B2 receptor antagonist, HOE 140. CONCLUSIONS These results suggest that ACE inhibition with captopril or enalapril increases the levels of SP and BK in cultured astrocytes and that the activation of SP and BK receptors mediates the captopril-induced increase in the expression of the PKCβI isoform.
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Affiliation(s)
- Jae-Gyun Choi
- Department of Physiology and Medical Science, College of Medicine and Brain Research Institute, Chungnam National University, Daejeon 35015, Korea
| | - Sheu-Ran Choi
- Department of Pharmacology, Catholic Kwandong University College of Medicine, Gangneung 25601, Korea
| | - Dong-Wook Kang
- Department of Physiology and Medical Science, College of Medicine and Brain Research Institute, Chungnam National University, Daejeon 35015, Korea
| | - Hyun Jin Shin
- Department of Physiology and Medical Science, College of Medicine and Brain Research Institute, Chungnam National University, Daejeon 35015, Korea
| | - Miae Lee
- Department of Physiology and Medical Science, College of Medicine and Brain Research Institute, Chungnam National University, Daejeon 35015, Korea
| | - Jungmo Hwang
- Department of Orthopaedic Surgery, College of Medicine, Chungnam National University, Daejeon 35015, Korea.
| | - Hyun-Woo Kim
- Department of Physiology and Medical Science, College of Medicine and Brain Research Institute, Chungnam National University, Daejeon 35015, Korea.
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Vieira WF, Malange KF, de Magalhães SF, Lemes JBP, Dos Santos GG, Nishijima CM, de Oliveira ALR, da Cruz-Höfling MA, Tambeli CH, Parada CA. Anti-hyperalgesic effects of photobiomodulation therapy (904 nm) on streptozotocin-induced diabetic neuropathy imply MAPK pathway and calcium dynamics modulation. Sci Rep 2022; 12:16730. [PMID: 36202956 PMCID: PMC9537322 DOI: 10.1038/s41598-022-19947-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 09/06/2022] [Indexed: 11/23/2022] Open
Abstract
Several recent studies have established the efficacy of photobiomodulation therapy (PBMT) in painful clinical conditions. Diabetic neuropathy (DN) can be related to activating mitogen-activated protein kinases (MAPK), such as p38, in the peripheral nerve. MAPK pathway is activated in response to extracellular stimuli, including interleukins TNF-α and IL-1β. We verified the pain relief potential of PBMT in streptozotocin (STZ)-induced diabetic neuropathic rats and its influence on the MAPK pathway regulation and calcium (Ca2+) dynamics. We then observed that PBMT applied to the L4-L5 dorsal root ganglion (DRG) region reduced the intensity of hyperalgesia, decreased TNF-α and IL-1β levels, and p38-MAPK mRNA expression in DRG of diabetic neuropathic rats. DN induced the activation of phosphorylated p38 (p-38) MAPK co-localized with TRPV1+ neurons; PBMT partially prevented p-38 activation. DN was related to an increase of p38-MAPK expression due to proinflammatory interleukins, and the PBMT (904 nm) treatment counteracted this condition. Also, the sensitization of DRG neurons by the hyperglycemic condition demonstrated during the Ca2+ dynamics was reduced by PBMT, contributing to its anti-hyperalgesic effects.
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Affiliation(s)
- Willians Fernando Vieira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil
| | - Kauê Franco Malange
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil
| | - Silviane Fernandes de Magalhães
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil
| | - Júlia Borges Paes Lemes
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil
| | - Gilson Gonçalves Dos Santos
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil
| | - Catarine Massucato Nishijima
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil
| | - Alexandre Leite Rodrigues de Oliveira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil
| | - Maria Alice da Cruz-Höfling
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil
| | - Cláudia Herrera Tambeli
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil
| | - Carlos Amilcar Parada
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Carl von Linnaeus n/n, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-864, Brazil.
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Martinello K, Sucapane A, Fucile S. 5-HT3 Receptors in Rat Dorsal Root Ganglion Neurons: Ca 2+ Entry and Modulation of Neurotransmitter Release. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081178. [PMID: 36013357 PMCID: PMC9409985 DOI: 10.3390/life12081178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 07/29/2022] [Accepted: 07/31/2022] [Indexed: 11/16/2022]
Abstract
Rat dorsal root ganglion (DRG) neurons express 5-hydroxytryptamine receptors (5-HT3Rs). To elucidate their physiological role in the modulation of sensory signaling, we aimed to quantify their functional expression in newborn and adult rat DRG neurons, as well as their ability to modulate the Ca2+-dependent neurotransmitter release, by means of electrophysiological techniques combined with fluorescence-based Ca2+ imaging. The selective 5-HT3R agonist mCPBG (10 μM) elicited whole-cell currents in 92.5% of adult DRG neurons with a significantly higher density current than in responding newborn cells (52.2%), suggesting an increasing serotoninergic modulation on primary afferent cells during development. Briefly, 5-HT3Rs expressed by adult DRG neurons are permeable to Ca2+ ions, with a measured fractional Ca2+ current (i.e., the percentage of total current carried by Ca2+ ions, Pf) of 1.0%, similar to the value measured for the human heteromeric 5-HT3A/B receptor (Pf = 1.1%), but lower than that of the human homomeric 5-HT3A receptor (Pf = 3.5%). mCPBG applied to co-cultures of newborn DRG and spinal neurons significantly increased the miniature excitatory postsynaptic currents (mEPSCs) frequency in a subset of recorded spinal neurons, even in the presence of Cd2+, a voltage-activated Ca2+ channel blocker. Considered together, our findings indicate that the Ca2+ influx through heteromeric 5-HT3Rs is sufficient to increase the spontaneous neurotransmitter release from DRG to spinal neurons.
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Affiliation(s)
| | - Antonietta Sucapane
- Department of Physiology and Pharmacology, Sapienza University of Rome, P.le Aldo Moro, 5, 00185 Rome, Italy;
| | - Sergio Fucile
- IRCCS Neuromed, Via Atinense, 86077 Pozzilli, Italy;
- Department of Physiology and Pharmacology, Sapienza University of Rome, P.le Aldo Moro, 5, 00185 Rome, Italy;
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Jin Q, Zhao YL, Liu YP, Zhang RS, Zhu PF, Zhao LQ, Qin XJ, Luo XD. Anti-inflammatory and analgesic monoterpenoid indole alkaloids of Kopsia officinalis. JOURNAL OF ETHNOPHARMACOLOGY 2022; 285:114848. [PMID: 34798159 DOI: 10.1016/j.jep.2021.114848] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/05/2021] [Accepted: 11/15/2021] [Indexed: 06/13/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE "Ya gai", an important part of Dai medical theory, is traditionally recognized as an antidote. Kopsia officinalis Tsiang et P. T. Li is a "Ya gai" related medicine and has been widely used by Dai people for the treatment of pain and inflammation. Previous literature on title species suggested that monoterpenoid indole alkaloids (MIAs) could be its main bioactive components. However, the specific bioactive ingredients for inflammation-related treatment are still unrevealed, which inspired us to conduct a phytochemical and pharmacological investigation related to its traditional use. AIM OF THE STUDY To support the traditional use of K. officinalis by assessing the anti-inflammatory and analgesic effects of its purified MIAs. MATERIAL AND METHODS Compounds were isolated and purified from the barks and leaves of K. officinalis using diverse chromatographic methods. The structures were established by means of extensive spectroscopic analyses and quantum computational technique. The anti-inflammatory activities of the purified MIAs were evaluated in vitro based on the suppression of lipopolysaccharide-activated inflammatory mediators (COX-2, IL-1β, and TNF-α) in RAW 264.7 macrophage cells. Anti-inflammatory and analgesic activities in vivo were assessed with carrageenan-induced paw edema and acetic acid-stimulated writhing in mice models. RESULTS 23 MIAs including four new compounds were obtained and structurally established. Most of isolates showed significant anti-inflammatory effects in vitro by inhibiting inflammatory mediators (COX-2, IL-1β, and TNF-α). Further pharmacological evaluation in vivo revealed that 12-hydroxy-19(R)-hydroxy-ibophyllidine (1) and 11,12-methylenedioxykopsinaline N4-oxide (5) remarkably decreased the number of writhing, while kopsinic acid (8), (-)-kopsinilam (12), and normavacurine-21-one (20) significantly relieved paw edema, respectively, even better than the positive control aspirin. CONCLUSIONS The in vitro and in vivo findings supported the traditional use of K. officinalis with respect to its anti-inflammatory and analgesic effect, as well as provided potent bioactive MIAs for further chemical modification and pharmacological investigation.
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Affiliation(s)
- Qiong Jin
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China; University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Yun-Li Zhao
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Ya-Ping Liu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China
| | - Ruo-Song Zhang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China; University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Pei-Feng Zhu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China; University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Lan-Qin Zhao
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China; University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Xu-Jie Qin
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China; University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
| | - Xiao-Dong Luo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China; Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, People's Republic of China.
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Meng X, Li Y, Li Q, Yang J, An M, Fu X, Zhang S, Chen J. Involvement of bradykinin and bradykinin B1 receptor in patients with endometriosis. Exp Ther Med 2021; 22:1240. [PMID: 34539836 PMCID: PMC8438668 DOI: 10.3892/etm.2021.10675] [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] [Received: 05/30/2021] [Accepted: 08/06/2021] [Indexed: 11/30/2022] Open
Abstract
Endometriosis (EM), a benign aseptic inflammatory disease, is associated with the presence of endometrial foci. Pain, one of its typical symptoms, has been reported as a constant stressor, but the etiology and pathogenesis of EM-associated pain are unclear. In the present study, eutopic and ectopic endometrium samples from women with EM (n=50) and normal endometrium samples from control subjects (n=20) were collected. Serum levels of prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α) and bradykinin (BK) were measured using commercial ELISA kits. The expression of the BKB1 receptor (BKB1R) protein was evaluated by immunohistochemical staining and western blot assay. The mRNA expression of BKB1R was measured by reverse transcription-quantitative PCR. The results revealed that there was a substantial increase in the protein and mRNA expression of BKB1R, as well as the release of PGE2, PGF2α and BK in the blood, in the EM group compared with that in the control group. Moreover, PGE2, PGF2α and BK levels were significantly correlated with each other, as well as with the pain intensity of EM. The increased expression levels of BKB1R protein and mRNA were positively correlated with the pain degree of EM. Thus, these data indicated that BK and BKB1R were involved in the pathological onset of EM-associated pain and that they may play an important role in EM-related pain by inducing PGE2 and PGF2α. The data indicate a potential new therapeutic target for EM-related pain.
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Affiliation(s)
- Xin Meng
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Institute of Integrative Medicine, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
| | - Ying Li
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Institute of Integrative Medicine, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
| | - Qingxue Li
- Department of Gynecology, The Fourth Hospital of Shijiazhuang, Shijiazhuang, Hebei 050011, P.R. China
| | - Jian Yang
- Department of Rehabilitation, Special Care Hospital of Hebei, Shijiazhuang, Hebei 050051, P.R. China
| | - Mingli An
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Institute of Integrative Medicine, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
| | - Xinping Fu
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Institute of Integrative Medicine, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
| | - Shuancheng Zhang
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Institute of Integrative Medicine, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
| | - Jingwei Chen
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Institute of Integrative Medicine, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
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Alloxan as a better option than streptozotocin for studies involving painful diabetic neuropathy. J Pharmacol Toxicol Methods 2021; 112:107090. [PMID: 34175449 DOI: 10.1016/j.vascn.2021.107090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 05/26/2021] [Accepted: 06/18/2021] [Indexed: 11/21/2022]
Abstract
Previous data indicate that the diabetogenic substance streptozotocin might act in nociceptive neurons changing the sensory signal, regardless of hyperglycemia. In the present article the effects of streptozotocin were compared with another diabetogenic drug, alloxan, for diabetes induction in rats. A possible direct effect of these drugs was tested by means of in vivo experiments and in vitro assays using cultured primary nociceptive neurons. Streptozotocin (17.5 and 35 mg/kg), alloxan (15 and 30 mg/kg) or vehicle were injected in adult male rats and the animal groups were separated according to glycemic levels. Body mass, glycemia and paw mechanical sensitivity were evaluated for 5 weeks. Streptozotocin caused an increase in mechanical sensitivity in both hyperglycemic and normoglycemic rats, while alloxan induced mechanical sensitization only in hyperglycemic animals. Injection of both substances induced local inflammation at rat paws; however, only streptozotocin caused significant mechanical sensitization when injected near to sensory neurons at the dorsal root ganglia. Also, streptozotocin treatment induced a reduction in intracellular calcium levels and inhibited capsaicin induced calcium transients and membrane depolarization. Alloxan did not affect calcium levels or membrane potential in primary nociceptive neurons. These findings suggest that alloxan might be a better option for animal studies regarding painful diabetic neuropathy as streptozotocin directly affects nociceptive neurons, probably by modulating TRPV1 channel activation.
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DuBreuil DM, Chiang BM, Zhu K, Lai X, Flynn P, Sapir Y, Wainger BJ. A high-content platform for physiological profiling and unbiased classification of individual neurons. CELL REPORTS METHODS 2021; 1:100004. [PMID: 34318289 PMCID: PMC8312640 DOI: 10.1016/j.crmeth.2021.100004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/18/2021] [Accepted: 03/11/2021] [Indexed: 11/29/2022]
Abstract
High-throughput physiological assays lose single-cell resolution, precluding subtype-specific analyses of activation mechanism and drug effects. We demonstrate APPOINT (automated physiological phenotyping of individual neuronal types), a physiological assay platform combining calcium imaging, robotic liquid handling, and automated analysis to generate physiological activation profiles of single neurons at large scale. Using unbiased techniques, we quantify responses to sequential stimuli, enabling subgroup identification by physiology and probing of distinct mechanisms of neuronal activation within subgroups. Using APPOINT, we quantify primary sensory neuron activation by metabotropic receptor agonists and identify potential contributors to pain signaling. We expand the role of neuroimmune interactions by showing that human serum directly activates sensory neurons, elucidating a new potential pain mechanism. Finally, we apply APPOINT to develop a high-throughput, all-optical approach for quantification of activation threshold and pharmacologically validate contributions of ion channel families to optical activation.
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Affiliation(s)
- Daniel M. DuBreuil
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Brenda M. Chiang
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Kevin Zhu
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Xiaofan Lai
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Patrick Flynn
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Yechiam Sapir
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Brian J. Wainger
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Anesthesiology, Critical Care, & Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Harvard Stem Cell Institute, Cambridge, MA 02138, USA
- Broad Institute of Harvard University and MIT, Cambridge, MA 02142, USA
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11
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Lopez ER, Carbajal AG, Tian JB, Bavencoffe A, Zhu MX, Dessauer CW, Walters ET. Serotonin enhances depolarizing spontaneous fluctuations, excitability, and ongoing activity in isolated rat DRG neurons via 5-HT 4 receptors and cAMP-dependent mechanisms. Neuropharmacology 2020; 184:108408. [PMID: 33220305 DOI: 10.1016/j.neuropharm.2020.108408] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/10/2020] [Accepted: 11/16/2020] [Indexed: 12/18/2022]
Abstract
Ongoing activity in nociceptors, a driver of spontaneous pain, can be generated in dorsal root ganglion neurons in the absence of sensory generator potentials if one or more of three neurophysiological alterations occur - prolonged depolarization of resting membrane potential (RMP), hyperpolarization of action potential (AP) threshold, and/or increased amplitude of depolarizing spontaneous fluctuations of membrane potential (DSFs) to bridge the gap between RMP and AP threshold. Previous work showed that acute, sustained exposure to serotonin (5-HT) hyperpolarized AP threshold and potentiated DSFs, leading to ongoing activity if a separate source of maintained depolarization was present. Cellular signaling pathways that increase DSF amplitude and promote ongoing activity acutely in nociceptors are not known for any neuromodulator. Here, isolated DRG neurons from male rats were used to define the pathway by which low concentrations of 5-HT enhance DSFs, hyperpolarize AP threshold, and promote ongoing activity. A selective 5-HT4 receptor antagonist blocked these 5-HT-induced hyperexcitable effects, while a selective 5-HT4 agonist mimicked the effects of 5-HT. Inhibition of cAMP effectors, protein kinase A (PKA) and exchange protein activated by cAMP (EPAC), attenuated 5-HT's hyperexcitable effects, but a blocker of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels had no significant effect. 5-HT4-dependent PKA activation was specific to DRG neurons that bind isolectin B4 (a nonpeptidergic nociceptor marker). 5-HT's effects on AP threshold, DSFs, and ongoing activity were mimicked by a cAMP analog. Sustained exposure to 5-HT promotes ongoing activity in nonpeptidergic nociceptors through the Gs-coupled 5-HT4 receptor and downstream cAMP signaling involving both PKA and EPAC.
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Affiliation(s)
- Elia R Lopez
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UT Health, Houston, TX, 77030, USA.
| | - Anibal Garza Carbajal
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UT Health, Houston, TX, 77030, USA.
| | - Jin Bin Tian
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UT Health, Houston, TX, 77030, USA.
| | - Alexis Bavencoffe
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UT Health, Houston, TX, 77030, USA.
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UT Health, Houston, TX, 77030, USA.
| | - Carmen W Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UT Health, Houston, TX, 77030, USA.
| | - Edgar T Walters
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UT Health, Houston, TX, 77030, USA.
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12
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Barker PA, Mantyh P, Arendt-Nielsen L, Viktrup L, Tive L. Nerve Growth Factor Signaling and Its Contribution to Pain. J Pain Res 2020; 13:1223-1241. [PMID: 32547184 PMCID: PMC7266393 DOI: 10.2147/jpr.s247472] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Nerve growth factor (NGF) is a neurotrophic protein essential for the growth, differentiation, and survival of sympathetic and sensory afferent neurons during development. A substantial body of evidence, based on both animal and human studies, demonstrates that NGF plays a pivotal role in modulation of nociception in adulthood. This has spurred development of a variety of novel analgesics that target the NGF signaling pathway. Here, we present a narrative review designed to summarize how NGF receptor activation and downstream signaling alters nociception through direct sensitization of nociceptors at the site of injury and changes in gene expression in the dorsal root ganglion that collectively increase nociceptive signaling from the periphery to the central nervous system. This review illustrates that NGF has a well-known and multifunctional role in nociceptive processing, although the precise signaling pathways downstream of NGF receptor activation that mediate nociception are complex and not completely understood. Additionally, much of the existing knowledge derives from studies performed in animal models and may not accurately represent the human condition. However, available data establish a role for NGF in the modulation of nociception through effects on the release of inflammatory mediators, nociceptive ion channel/receptor activity, nociceptive gene expression, and local neuronal sprouting. The role of NGF in nociception and the generation and/or maintenance of chronic pain has led to it becoming a novel and attractive target of pain therapeutics for the treatment of chronic pain conditions.
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Affiliation(s)
- Philip A Barker
- Department of Biology, University of British Columbia, Kelowna, BC, Canada
| | - Patrick Mantyh
- Department of Pharmacology, University of Arizona, Tucson, AZ, USA
| | - Lars Arendt-Nielsen
- Department of Health Science and Technology and the Center for Sensory-Motor Interaction/Center for Neuroplasticity and Pain, Aalborg University, Aalborg, Denmark
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13
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Neves AF, Farias FH, de Magalhães SF, Araldi D, Pagliusi M, Tambeli CH, Sartori CR, Lotufo CMDC, Parada CA. Peripheral Inflammatory Hyperalgesia Depends on P2X7 Receptors in Satellite Glial Cells. Front Physiol 2020; 11:473. [PMID: 32523543 PMCID: PMC7261868 DOI: 10.3389/fphys.2020.00473] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/17/2020] [Indexed: 12/23/2022] Open
Abstract
Peripheral inflammatory hyperalgesia depends on the sensitization of primary nociceptive neurons. Inflammation drives molecular alterations not only locally but also in the dorsal root ganglion (DRG) where interleukin-1 beta (IL-1β) and purinoceptors are upregulated. Activation of the P2X7 purinoceptors by ATP is essential for IL-1β maturation and release. At the DRG, P2X7R are expressed by satellite glial cells (SGCs) surrounding sensory neurons soma. Although SGCs have no projections outside the sensory ganglia these cells affect pain signaling through intercellular communication. Therefore, here we investigated whether activation of P2X7R by ATP and the subsequent release of IL-1β in DRG participate in peripheral inflammatory hyperalgesia. Immunofluorescent images confirmed the expression of P2X7R and IL-1β in SGCs of the DRG. The function of P2X7R was then verified using a selective antagonist, A-740003, or antisense for P2X7R administered in the L5-DRG. Inflammation was induced by CFA, carrageenan, IL-1β, or PGE2 administered in rat's hind paw. Blockage of P2X7R at the DRG reduced the mechanical hyperalgesia induced by CFA, and prevented the mechanical hyperalgesia induced by carrageenan or IL-1β, but not PGE2. It was also found an increase in P2X7 mRNA expression at the DRG after peripheral inflammation. IL-1β production was also increased by inflammatory stimuli in vivo and in vitro, using SGC-enriched cultures stimulated with LPS. In LPS-stimulated cultures, activation of P2X7R by BzATP induced the release of IL-1β, which was blocked by A-740003. In summary, our data suggest that peripheral inflammation leads to the activation of P2X7R expressed by SGCs at the DRG. Then, ATP-induced activation of P2X7R mediates the release of IL-1β from SGC. This evidence places the SGC as an active player in the establishment of peripheral inflammatory hyperalgesia and highlights the importance of the events in DRG for the treatment of inflammatory diseases.
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Affiliation(s)
- Amanda Ferreira Neves
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Felipe Hertzing Farias
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | | | - Dionéia Araldi
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Marco Pagliusi
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Claudia Herrera Tambeli
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Cesar Renato Sartori
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | | | - Carlos Amílcar Parada
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Brazil
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14
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Roy R, Ud Daula AFMS, Akter A, Sultana S, Barek MA, Liya IJ, Basher MA. Antipyretic and anti-nociceptive effects of methanol extract of leaves of Fimbristylis miliacea in mice model. JOURNAL OF ETHNOPHARMACOLOGY 2019; 243:112080. [PMID: 31306693 DOI: 10.1016/j.jep.2019.112080] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Fimbristylis miliacea (L.) Vahl (Cyperaceae) is a grass like herb usually grows as a weed in rice fields and is mainly distributed in tropical or sub-tropical countries of south and south-east Asia, central America, northern Australia and west Africa. The plant has been traditionally used to treat fever as a form of poultice. AIM OF THE STUDY The present study aimed to investigate antipyretic and anti-nociceptive effects of methanol extract of leaves of Fimbristylis miliacea in mice model. MATERIALS AND METHODS Antipyretic effect of Fimbristylis miliacea was examined using Baker's yeast induced hyperthermia test. Anti-nociceptive effect was investigated using acetic acid induced writhing test, formalin induced hind paw licking test and hot plate test. RESULTS The extract at concentration of 400 mg/kg produced significant reduction in body temperature after 0.5 h of administration (4.12 °F, p ≤ 0.001) and continued to decrease (after 4 h, 5.92 °F, p ≤ 0.001). Extracts at 100 mg/kg and 200 mg/kg decreased the temperature by about 2.77 °F (from 99.47 °F to 96.7 °F) and 5.58 °F (98.2 °F-92.62 °F) respectively after 4 h whereas paracetamol dropped by about 7.2 °F (p ≤ 0.001). The extract showed significant decrease in number of writhes at all concentrations. Highest effect was found at 200 mg/kg having 35.7 writhes (p ≤ 0.001), much lower than control (89.2); standard drug diclofenac showed 23.2 writhes. Percent inhibition of writhing were 54.26 and 73.99 for 200 mg/kg and diclofenac respectively. The result of hind paw licking test also corroborated writhing test. Significant reduction in percent inhibition of licking was observed mainly in late phase. Percent inhibition of licking were 93.77 and 51.55 for 400 mg/kg extract and diclofenac respectively. In hot plate test, extract at 400 mg/kg showed significant increase in latency from 10.77 s to 13.59 s (p ≤ 0.05). Extract at this dose after 2 h demonstrated greater percent maximal effect (43.26%) compared to ketorolac (40.19%). CONCLUSION The experiment confirmed the traditional use of F. miliacea in the treatment of fever with possible anti-nociceptive effects.
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Affiliation(s)
- Roni Roy
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - A F M Shahid Ud Daula
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - Afroza Akter
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - Sharmin Sultana
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - Md Abdul Barek
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - Israt Jahan Liya
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
| | - Mohammad Anwarul Basher
- Department of Pharmacy, Noakhali Science and Technology University, Sonapur, Noakhali, 3814, Bangladesh.
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15
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Multiple Inhibitory Mechanisms of Lidocaine on Bradykinin Receptor Activity in Model Sensory Neurons. Reg Anesth Pain Med 2018; 43:605-612. [DOI: 10.1097/aap.0000000000000758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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Montilla-García Á, Perazzoli G, Tejada MÁ, González-Cano R, Sánchez-Fernández C, Cobos EJ, Baeyens JM. Modality-specific peripheral antinociceptive effects of μ-opioid agonists on heat and mechanical stimuli: Contribution of sigma-1 receptors. Neuropharmacology 2018; 135:328-342. [PMID: 29580951 DOI: 10.1016/j.neuropharm.2018.03.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/05/2018] [Accepted: 03/20/2018] [Indexed: 11/16/2022]
Abstract
Morphine induces peripherally μ-opioid-mediated antinociception to heat but not to mechanical stimulation. Peripheral sigma-1 receptors tonically inhibit μ-opioid antinociception to mechanical stimuli, but it is unknown whether they modulate μ-opioid heat antinociception. We hypothesized that sigma-1 receptors might play a role in the modality-specific peripheral antinociceptive effects of morphine and other clinically relevant μ-opioid agonists. Mechanical nociception was assessed in mice with the paw pressure test (450 g), and heat nociception with the unilateral hot plate (55 °C) test. Local peripheral (intraplantar) administration of morphine, buprenorphine or oxycodone did not induce antinociception to mechanical stimulation but had dose-dependent antinociceptive effects on heat stimuli. Local sigma-1 antagonism unmasked peripheral antinociception by μ-opioid agonists to mechanical stimuli, but did not modify their effects on heat stimulation. TRPV1+ and IB4+ cells are segregated populations of small neurons in the dorsal root ganglia (DRG) and the density of sigma-1 receptors was higher in IB4+ cells than in the rest of small nociceptive neurons. The in vivo ablation of TRPV1-expressing neurons with resiniferatoxin did not alter IB4+ neurons in the DRG, mechanical nociception, or the effects of sigma-1 antagonism on local morphine antinociception in this type of stimulus. However, it impaired the responses to heat stimuli and the effect of local morphine on heat nociception. In conclusion, peripheral opioid antinociception to mechanical stimuli is limited by sigma-1 tonic inhibitory actions, whereas peripheral opioid antinociception to heat stimuli (produced in TRPV1-expressing neurons) is not. Therefore, sigma-1 receptors contribute to the modality-specific peripheral effects of opioid analgesics.
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MESH Headings
- Analgesics, Opioid/pharmacology
- Animals
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/metabolism
- Ganglia, Spinal/pathology
- Hot Temperature
- Hyperalgesia/drug therapy
- Hyperalgesia/metabolism
- Hyperalgesia/pathology
- Mice, Knockout
- Nociceptors/drug effects
- Nociceptors/metabolism
- Nociceptors/pathology
- Random Allocation
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/metabolism
- Receptors, sigma/agonists
- Receptors, sigma/antagonists & inhibitors
- Receptors, sigma/genetics
- Receptors, sigma/metabolism
- TRPV Cation Channels/metabolism
- Touch
- Sigma-1 Receptor
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Affiliation(s)
- Ángeles Montilla-García
- Department of Pharmacology, Faculty of Medicine, University of Granada, 18071 Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Parque Tecnológico de Ciencias de la Salud, 18100 Armilla, Granada, Spain
| | - Gloria Perazzoli
- Department of Anatomy and Embryology, Faculty of Medicine, University of Granada, 18071 Granada, Spain; Institute of Biopathology and Regenerative Medicine (IBIMER), Biomedical Research Center, University of Granada, Parque Tecnológico de Ciencias de la Salud, 18100 Armilla, Granada, Spain
| | - Miguel Á Tejada
- Department of Pharmacology, Faculty of Medicine, University of Granada, 18071 Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Parque Tecnológico de Ciencias de la Salud, 18100 Armilla, Granada, Spain
| | - Rafael González-Cano
- Department of Pharmacology, Faculty of Medicine, University of Granada, 18071 Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Parque Tecnológico de Ciencias de la Salud, 18100 Armilla, Granada, Spain
| | - Cristina Sánchez-Fernández
- Department of Pharmacology, Faculty of Medicine, University of Granada, 18071 Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Parque Tecnológico de Ciencias de la Salud, 18100 Armilla, Granada, Spain
| | - Enrique J Cobos
- Department of Pharmacology, Faculty of Medicine, University of Granada, 18071 Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Parque Tecnológico de Ciencias de la Salud, 18100 Armilla, Granada, Spain; Biosanitary Research Institute, University Hospital Complex of Granada, 18012 Granada, Spain; Teófilo Hernando Institute for Drug Discovery, 28029 Madrid, Spain.
| | - José M Baeyens
- Department of Pharmacology, Faculty of Medicine, University of Granada, 18071 Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Parque Tecnológico de Ciencias de la Salud, 18100 Armilla, Granada, Spain; Biosanitary Research Institute, University Hospital Complex of Granada, 18012 Granada, Spain.
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17
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Yoshino O, Yamada-Nomoto K, Kobayashi M, Andoh T, Hongo M, Ono Y, Hasegawa-Idemitsu A, Sakai A, Osuga Y, Saito S. Bradykinin system is involved in endometriosis-related pain through endothelin-1 production. Eur J Pain 2017; 22:501-510. [PMID: 29034546 DOI: 10.1002/ejp.1133] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Endometriosis is a gynaecological disease exhibiting severe pelvic pain, but the mechanism of pain production remains unknown. Bradykinin (BK) is known as an inflammatory mediator, and shows elevated levels in inflammatory diseases such as rheumatoid arthritis. In the present study, we evaluated whether BK is involved in endometriosis-related pain. METHODS Endometriotic lesions were used for immunohistochemistry. Primary cultures of endometriotic stromal cells (ESC) were stimulated with IL-1β and/or BK. Quantitative RT-PCR was used to evaluate the mRNA expressions of BK receptors (BKR) and endothelin-1 in ESC. The concentration of endothelin-1 in cystic fluid of endometrioma or non-endometrioma was measured with ELISA. The conditioned medium of ESC stimulated with IL-1β and/or BK was injected intraplantarly in mice, and evaluated whether pain-related licking behaviour was elicited. RESULTS The expressions of BK and BKR in endometriotic lesions were observed by immunohistochemistry. In vitro experiments showed that IL-1β induced BKR-B1 and B2 on ESC. Activation of these receptors by BK significantly induced endothelin-1 expression in ESC, which was negated completely by HOE-140, a BKR-B2 antagonist. The cystic fluid of endometrioma contained higher amount of endothelin-1 compared to non-endometrioma. Intraplantar injection of the conditioned medium of ESC treated with IL-1β and BK significantly induced licking behaviour, which was suppressed with BQ-123, an endothelin type-A receptor antagonist. CONCLUSIONS The present study demonstrated the presence and the function of the BK axis in endometriosis, and established a potential new therapy target for endometriosis-related pain. SIGNIFICANCE The present study demonstrated (1) the presence and the function of the BK system in endometriosis, (2) activation of BKR induced endothelin-1 in endometriotic lesion and (3) blocking endothelin-1 was effective to decrease pain.
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Affiliation(s)
- O Yoshino
- Department of Obstetrics and Gynecology, University of Toyama, Japan
| | - K Yamada-Nomoto
- Department of Obstetrics and Gynecology, University of Toyama, Japan
| | - M Kobayashi
- Department of Obstetrics and Gynecology, University of Toyama, Japan
| | - T Andoh
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - M Hongo
- Department of Obstetrics and Gynecology, University of Toyama, Japan
| | - Y Ono
- Department of Obstetrics and Gynecology, University of Toyama, Japan
| | | | - A Sakai
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Y Osuga
- Department of Obstetrics and Gynecology, University of Tokyo, Japan
| | - S Saito
- Department of Obstetrics and Gynecology, University of Toyama, Japan
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18
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Lian YL, Cheng MJ, Zhang XX, Wang L. Elevated expression of transient receptor potential vanilloid type 1 in dorsal root ganglia of rats with endometriosis. Mol Med Rep 2017; 16:1920-1926. [PMID: 28627595 PMCID: PMC5561994 DOI: 10.3892/mmr.2017.6783] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 04/06/2017] [Indexed: 12/03/2022] Open
Abstract
Pain is the most pronounced complaint of women with endometriosis, however the underlying mechanism is still poorly understood. In the present study, the authors evaluate the effect of transient receptor potential vanilloid type 1 (TRPV1) of dorsal root ganglia (DRG) on endometriosis-associated pain. A total of 36 SD rats were randomly divided into a sham group (n=9) and a Model group (n=27), accepted auto‑transplanted pieces of fat or uterus to the pelvic cavity. At 4 weeks, the Model group was randomly subdivided into the following groups: ENDO group (no treatment, n=9), BCTC group (Model + BCTC, an antagonist of TRPV1, n=9), Vehicle group (Model + cyclodextrin, the vehicle of BCTC, n=9). Tail‑flick test was performed prior to surgery, 1 h prior to and following treatment of BCTC or cyclodextrin. The expression of TRPV1, substance P (SP), calcitonin gene‑related peptide (CGRP) in L1‑L6 DRG was measured via immunohistochemistry, western blotting and RT‑qPCR. The results indicated that the Model group exhibited a significant decrease in tail flick latency compared to pre‑surgical baseline, and the expression of TRPV1, SP, CGRP protein and mRNA in L1‑L6 DRG significantly increased compared to the sham group. BCTC significantly improved tail flick latency, and downregulated the expression of TRPV1, SP and CGRP protein and mRNA levels in L1‑L6 DRG compared to ENDO group. However, there were no significant differences of those in Vehicle group compared with the ENDO group. Taken together, the current study provides evidence that TRPV1 expressed in DRG may serve an important role in endometriosis-associated pain.
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Affiliation(s)
- Yu-Ling Lian
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, P.R. China
- Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, P.R. China
| | - Ming-Jun Cheng
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, P.R. China
- Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, P.R. China
| | - Xian-Xia Zhang
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, P.R. China
- Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, P.R. China
| | - Li Wang
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, P.R. China
- Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai 200011, P.R. China
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19
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Oliveira-Fusaro MCG, Zanoni CIS, Dos Santos GG, Manzo LP, Araldi D, Bonet IJM, Tambeli CH, Dias EV, Parada CA. Antihyperalgesic effect of CB 1 receptor activation involves the modulation of P2X 3 receptor in the primary afferent neuron. Eur J Pharmacol 2017; 798:113-121. [PMID: 28131783 DOI: 10.1016/j.ejphar.2017.01.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 01/18/2017] [Accepted: 01/24/2017] [Indexed: 12/18/2022]
Abstract
Cannabinoid system is a potential target for pain control. Cannabinoid receptor 1 (CB1) activation play a role in the analgesic effect of cannabinoids once it is expressed in primary afferent neurons. This study investigates whether the anti-hyperalgesic effect of CB1 receptor activation involves P2X3 receptor in primary afferent neurons. Mechanical hyperalgesia was evaluated by electronic von Frey test. Cannabinoid effect was evaluated using anandamide or ACEA, a non-selective or a selective CB1 receptor agonists, respectively; AM251, a CB1 receptor antagonist, and antisense ODN for CB1 receptor. Calcium imaging assay was performed to evaluated α,β-meATP-responsive cultured DRG neurons pretreated with ACEA. Anandamide or ACEA administered in peripheral tissue reduced the carrageenan-induced mechanical hyperalgesia. The reduction in the carrageenan-induced hyperalgesia induced by ACEA was completely reversed by administration of AM251 as well as by the intrathecal treatment with antisense ODN for CB1 receptor. Also, ACEA reduced the mechanical hyperalgesia induced by bradykinin and by α,β-meATP, a P2X3 receptor non-selective agonist, but not by tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and chemokine-induced chemoattractant-1 (CINC-1). Finally, CB1 receptors are co-localized with P2X3 receptors in DRG small-diameter neurons and the treatment with ACEA reduced the number of α,β-meATP-responsive cultured DRG neurons. Our data suggest that the analgesic effect of CB1 receptor activation is mediated by a negative modulation of the P2X3 receptor in the primary afferent neurons.
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MESH Headings
- Animals
- Bradykinin/pharmacology
- Carrageenan/pharmacology
- Cell Size
- Cytokines/metabolism
- Ganglia, Spinal/pathology
- Hyperalgesia/chemically induced
- Hyperalgesia/drug therapy
- Hyperalgesia/metabolism
- Hyperalgesia/pathology
- Male
- Neurons, Afferent/drug effects
- Neurons, Afferent/metabolism
- Neurons, Afferent/pathology
- Oligodeoxyribonucleotides, Antisense/genetics
- Rats
- Rats, Wistar
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptors, Purinergic P2X3/metabolism
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Affiliation(s)
| | - Cristiane Isabel Silva Zanoni
- Department of Pharmacology, Faculty of Medicine, Ribeirão Preto University of São Paulo, Ribeirão Preto, 14049-900 São Paulo, Brazil
| | - Gilson Gonçalves Dos Santos
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, 13083-862 São Paulo, Brazil
| | - Luis Paulo Manzo
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, 13083-862 São Paulo, Brazil
| | - Dionéia Araldi
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, 13083-862 São Paulo, Brazil
| | - Ivan José Magayewski Bonet
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, 13083-862 São Paulo, Brazil
| | - Cláudia Herrera Tambeli
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, 13083-862 São Paulo, Brazil
| | - Elayne Vieira Dias
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, 13083-862 São Paulo, Brazil.
| | - Carlos Amilcar Parada
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, 13083-862 São Paulo, Brazil
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20
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Aburawi S, Al-Tubuly R, Alghzewi E, Gorash Z. Effects of calcium channel blockers on antidepressant action of Alprazolam and Imipramine. Libyan J Med 2016. [DOI: 10.3402/ljm.v2i4.4727] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- S.M. Aburawi
- Dept of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, El-Fateh University, Libya
| | - R.A. Al-Tubuly
- Dept of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, El-Fateh University, Libya
| | - E.A. Alghzewi
- Dept of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, El-Fateh University, Libya
| | - Z.M. Gorash
- Dept of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, El-Fateh University, Libya
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21
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Abdulla MH, Duff M, Swanton H, Johns EJ. Bradykinin receptor blockade restores the baroreflex control of renal sympathetic nerve activity in cisplatin-induced renal failure rats. Acta Physiol (Oxf) 2016; 218:212-224. [PMID: 27614105 DOI: 10.1111/apha.12801] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 05/31/2016] [Accepted: 09/06/2016] [Indexed: 12/12/2022]
Abstract
AIM This study investigated the effect of renal bradykinin B1 and B2 receptor blockade on the high- and low-pressure baroreceptor reflex regulation of renal sympathetic nerve activity (RSNA) in rats with cisplatin-induced renal failure. METHODS Cisplatin (5 mg/kg) or saline was given intraperitoneally 4 days prior to study. Following chloralose/urethane anaesthesia, rats were prepared for measurement of mean arterial pressure (MAP), heart rate and RSNA and received intrarenal infusions of either Lys-[des-Arg9 , Leu8 ]-bradykinin (LBK), a bradykinin B1 receptor blocker, or bradyzide (BZ), a bradykinin B2 receptor blocker. RSNA baroreflex gain curves and renal sympatho-inhibitory responses to volume expansion (VE) were obtained. RESULTS In the control and renal failure groups, basal MAP (89 ± 3 vs. 80 ± 8 mmHg) and RSNA (2.0 ± 0.3 vs. 1.7 ± 0.6 μV.s) were similar but HR was lower in the latter group (331 ± 8 vs. 396 ± 9 beats/min). The baroreflex gain for RSNA in the renal failure rats was 39% (P < 0.05) lower than the control but was restored to normal values following intrarenal infusion of BZ, but not LBK. VE had no effect on MAP or HR but reduced RSNA by some 40% (P < 0.05) in control but not renal failure rats. Intrarenal LBK infusion in the renal failure rats normalized the VE induced renal sympatho-inhibition whereas BZ only partially restored the response. CONCLUSION These findings suggest that pro-inflammatory bradykinin acting at different receptors within the kidney generates afferent neural signals which impact differentially within the central nervous system on high- and low-pressure regulation of RSNA.
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Affiliation(s)
- M. H. Abdulla
- Department of Physiology; University College Cork; Cork Ireland
| | - M. Duff
- Department of Physiology; University College Cork; Cork Ireland
| | - H. Swanton
- Department of Physiology; University College Cork; Cork Ireland
| | - E. J. Johns
- Department of Physiology; University College Cork; Cork Ireland
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22
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Davidson S, Golden JP, Copits BA, Ray PR, Vogt SK, Valtcheva MV, Schmidt RE, Ghetti A, Price T, Gereau RW. Group II mGluRs suppress hyperexcitability in mouse and human nociceptors. Pain 2016; 157:2081-2088. [PMID: 27218869 PMCID: PMC4988887 DOI: 10.1097/j.pain.0000000000000621] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We introduce a strategy for preclinical research wherein promising targets for analgesia are tested in rodent and subsequently validated in human sensory neurons. We evaluate group II metabotropic glutamate receptors, the activation of which is efficacious in rodent models of pain. Immunohistochemical analysis showed positive immunoreactivity for mGlu2 in rodent dorsal root ganglia (DRG), peripheral fibers in skin, and central labeling in the spinal dorsal horn. We also found mGlu2-positive immunoreactivity in human neonatal and adult DRG. RNA-seq analysis of mouse and human DRG revealed a comparative expression profile between species for group II mGluRs and for opioid receptors. In rodent sensory neurons under basal conditions, activation of group II mGluRs with a selective group II agonist produced no changes to membrane excitability. However, membrane hyperexcitability in sensory neurons exposed to the inflammatory mediator prostaglandin E2 (PGE2) was prevented by (2R,4R)-4-aminopyrrolidine-2,4-dicarboxylate (APDC). In human sensory neurons from donors without a history of chronic pain, we show that PGE2 produced hyperexcitability that was similarly blocked by group II mGluR activation. These results reveal a mechanism for peripheral analgesia likely shared by mice and humans and demonstrate a translational research strategy to improve preclinical validation of novel analgesics using cultured human sensory neurons.
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Affiliation(s)
- Steve Davidson
- Washington University in St. Louis, School of Medicine, Pain Center and Department of Anesthesiology. St. Louis, MO. 63110
| | - Judith P. Golden
- Washington University in St. Louis, School of Medicine, Pain Center and Department of Anesthesiology. St. Louis, MO. 63110
| | - Bryan A. Copits
- Washington University in St. Louis, School of Medicine, Pain Center and Department of Anesthesiology. St. Louis, MO. 63110
| | - Pradipta R. Ray
- School of Brain and Behavioral Sciences, University of Texas at Dallas. 75080
| | - Sherri K. Vogt
- Washington University in St. Louis, School of Medicine, Pain Center and Department of Anesthesiology. St. Louis, MO. 63110
| | - Manouela V. Valtcheva
- Washington University in St. Louis, School of Medicine, Pain Center and Department of Anesthesiology. St. Louis, MO. 63110
| | - Robert E. Schmidt
- Washington University in St. Louis, School of Medicine Department of Neuropathology, St. Louis, MO. 63110
| | | | - Theodore Price
- School of Brain and Behavioral Sciences, University of Texas at Dallas. 75080
| | - Robert W. Gereau
- Washington University in St. Louis, School of Medicine, Pain Center and Department of Anesthesiology. St. Louis, MO. 63110
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23
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Inflammatory sensitization of nociceptors depends on activation of NMDA receptors in DRG satellite cells. Proc Natl Acad Sci U S A 2014; 111:18363-8. [PMID: 25489099 DOI: 10.1073/pnas.1420601111] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The present study evaluated the role of N-methyl-D-aspartate receptors (NMDARs) expressed in the dorsal root ganglia (DRG) in the inflammatory sensitization of peripheral nociceptor terminals to mechanical stimulation. Injection of NMDA into the fifth lumbar (L5)-DRG induced hyperalgesia in the rat hind paw with a profile similar to that of intraplantar injection of prostaglandin E2 (PGE2), which was significantly attenuated by injection of the NMDAR antagonist D(-)-2-amino-5-phosphonopentanoic acid (D-AP-5) in the L5-DRG. Moreover, blockade of DRG AMPA receptors by the antagonist 6,7-dinitroquinoxaline-2,3-dione had no effect in the PGE2-induced hyperalgesia in the paw, showing specific involvement of NMDARs in this modulatory effect and suggesting that activation of NMDAR in the DRG plays an important role in the peripheral inflammatory hyperalgesia. In following experiments we observed attenuation of PGE2-induced hyperalgesia in the paw by the knockdown of NMDAR subunits NR1, NR2B, NR2D, and NR3A with antisense-oligodeoxynucleotide treatment in the DRG. Also, in vitro experiments showed that the NMDA-induced sensitization of cultured DRG neurons depends on satellite cell activation and on those same NMDAR subunits, suggesting their importance for the PGE2-induced hyperalgesia. In addition, fluorescent calcium imaging experiments in cultures of DRG cells showed induction of calcium transients by glutamate or NMDA only in satellite cells, but not in neurons. Together, the present results suggest that the mechanical inflammatory nociceptor sensitization is dependent on glutamate release at the DRG and subsequent NMDAR activation in satellite glial cells, supporting the idea that the peripheral hyperalgesia is an event modulated by a glutamatergic system in the DRG.
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24
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Bullock CM, Wookey P, Bennett A, Mobasheri A, Dickerson I, Kelly S. Peripheral calcitonin gene-related peptide receptor activation and mechanical sensitization of the joint in rat models of osteoarthritis pain. Arthritis Rheumatol 2014; 66:2188-200. [PMID: 24719311 PMCID: PMC4314689 DOI: 10.1002/art.38656] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 04/01/2014] [Indexed: 12/11/2022]
Abstract
Objective To investigate the role of the sensory neuropeptide calcitonin gene-related peptide (CGRP) in peripheral sensitization in experimental models of osteoarthritis (OA) pain. Methods Experimental knee OA was induced in rats by intraarticular injection of monosodium iodoacetate (MIA) or by transection of the medial meniscus (MMT). Single-unit recordings of joint-innervating nociceptors were obtained in MIA- and saline-treated rats following administration of CGRP or the CGRP receptor antagonist CGRP 8–37. Effects of CGRP 8–37 were also examined in rats that underwent MMT and sham operations. Protein and messenger RNA (mRNA) levels of CGRP receptor components in the L3–L4 dorsal root ganglion (DRG) were investigated following MIA treatment. Results In both the MIA and MMT groups, the mechanical sensitivity of joint nociceptors was enhanced compared to that in the control groups. Exogenous CGRP increased mechanical sensitivity in a greater proportion of joint nociceptors in the MIA-treated rats than in the saline-treated rats. Local blockade of endogenous CGRP by CGRP 8–37 reversed both the MIA- and MMT-induced enhancement of joint nociceptor responses. Joint afferent cell bodies coexpressed the receptor for CGRP, called the calcitonin-like receptor (CLR), and the intracellular accessory CGRP receptor component protein. MIA treatment increased the levels of mRNA for CLR in the L3–L4 DRG and the levels of CLR protein in medium and large joint afferent neurons. Conclusion Our findings provide new and compelling evidence implicating a role of CGRP in peripheral sensitization in experimental OA. Our novel finding of CGRP-mediated control of joint nociceptor mechanosensitivity suggests that the CGRP receptor system may be an important target for the modulation of pain during OA. CGRP receptor antagonists recently developed for migraine pain should be investigated for their efficacy against pain in OA.
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Affiliation(s)
- Craig M Bullock
- University of Nottingham, Nottingham, UK, and University of Nottingham, Sutton Bonington Campus, Sutton Bonington, UK
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25
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Kim MS, Shutov LP, Gnanasekaran A, Lin Z, Rysted JE, Ulrich JD, Usachev YM. Nerve growth factor (NGF) regulates activity of nuclear factor of activated T-cells (NFAT) in neurons via the phosphatidylinositol 3-kinase (PI3K)-Akt-glycogen synthase kinase 3β (GSK3β) pathway. J Biol Chem 2014; 289:31349-60. [PMID: 25231981 DOI: 10.1074/jbc.m114.587188] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The Ca(2+)/calcineurin-dependent transcription factor nuclear factor of activated T-cells (NFAT) plays an important role in regulating many neuronal functions, including excitability, axonal growth, synaptogenesis, and neuronal survival. NFAT can be activated by action potential firing or depolarization that leads to Ca(2+)/calcineurin-dependent dephosphorylation of NFAT and its translocation to the nucleus. Recent data suggest that NFAT and NFAT-dependent functions in neurons can also be potently regulated by NGF and other neurotrophins. However, the mechanisms of NFAT regulation by neurotrophins are not well understood. Here, we show that in dorsal root ganglion sensory neurons, NGF markedly facilitates NFAT-mediated gene expression induced by mild depolarization. The effects of NGF were not associated with changes in [Ca(2+)]i and were independent of phospholipase C activity. Instead, the facilitatory effect of NGF depended on activation of the PI3K/Akt pathway downstream of the TrkA receptor and on inhibition of glycogen synthase kinase 3β (GSK3β), a protein kinase known to phosphorylate NFAT and promote its nuclear export. Knockdown or knockout of NFATc3 eliminated this facilitatory effect. Simultaneous monitoring of EGFP-NFATc3 nuclear translocation and [Ca(2+)]i changes in dorsal root ganglion neurons indicated that NGF slowed the rate of NFATc3 nuclear export but did not affect its nuclear import rate. Collectively, our data suggest that NGF facilitates depolarization-induced NFAT activation by stimulating PI3K/Akt signaling, inactivating GSK3β, and thereby slowing NFATc3 export from the nucleus. We propose that NFAT serves as an integrator of neurotrophin action and depolarization-driven calcium signaling to regulate neuronal gene expression.
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Affiliation(s)
- Man-Su Kim
- From the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242 and the College of Pharmacy, Inje University, Gimhae 621-749, Korea
| | - Leonid P Shutov
- From the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242 and
| | - Aswini Gnanasekaran
- From the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242 and
| | - Zhihong Lin
- From the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242 and
| | - Jacob E Rysted
- From the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242 and
| | - Jason D Ulrich
- From the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242 and
| | - Yuriy M Usachev
- From the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242 and
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26
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García G, Martínez-Rojas VA, Rocha-González HI, Granados-Soto V, Murbartián J. Evidence for the participation of Ca(2+)-activated chloride channels in formalin-induced acute and chronic nociception. Brain Res 2014; 1579:35-44. [PMID: 25036442 DOI: 10.1016/j.brainres.2014.07.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/23/2014] [Accepted: 07/07/2014] [Indexed: 01/03/2023]
Abstract
In this study we determined the role of Ca(2+)-activated chloride channels (CaCC) in acute and chronic nociceptive responses elicited by 1% formalin. Formalin injection produced a typical pattern of flinching behavior for about 1h. Moreover, it produced secondary allodynia and hyperalgesia in the ipsilateral and contralateral paws for at least 6 days. Local peripheral and intrathecal pre-treatment (-10 min) with the non-selective and selective CaCC blockers niflumic acid and CaCCinh-A01, respectively, prevented formalin-induced flinching behavior mainly during phase 2 of the formalin test. Furthermore, niflumic acid and CaCCinh-A01 also prevented in a dose-dependent manner the long-lasting evoked secondary mechanical allodynia and hyperalgesia in the ipsilateral and contralateral paws. Moreover, local peripheral and intrathecal post-treatment (on day 6) with both CaCC blockers decreased the established formalin-induced secondary mechanical allodynia and hyperalgesia behavior in both paws. CaCC anoctamin-1 and bestrophin-1 were detected in the dorsal root ganglia. Formalin injection increased anoctamin-1, but not bestrophin-1 protein levels at 6 days. Intrathecal injection of the CaCC inhibitor CaCCinh-A01 prevented formalin-induced anoctamin-1 increase. Data suggest that peripheral and spinal CaCC, and particularly anoctamin-1, participates in the acute nociception induced by formalin as well as in the development and maintenance of secondary mechanical allodynia and hyperalgesia. Thus, CaCC activity contributes to neuronal excitability in the process of nociception induced by formalin.
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Affiliation(s)
- Guadalupe García
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados (Cinvestav), Sede Sur. México, D.F., Mexico
| | - Vladimir A Martínez-Rojas
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados (Cinvestav), Sede Sur. México, D.F., Mexico
| | - Héctor I Rocha-González
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, México, D.F., Mexico
| | - Vinicio Granados-Soto
- Neurobiology of Pain Laboratory, Departamento de Farmacobiología, Cinvestav, Sede Sur, México, D.F., Mexico
| | - Janet Murbartián
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados (Cinvestav), Sede Sur. México, D.F., Mexico.
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Abstract
PURPOSE This review highlights the physiological mechanisms underlying the neural regulation of the kidney, normally to maintain cardiovascular homeostasis, and in pathophysiological states of hypertension and renal disease. It is relevant because of the demonstration that bilateral renal denervation in different hypertensive groups causes a sustained reduction in blood pressure. RECENT FINDINGS There are patients groups in whom their hypertension is resistant to antihypertensive drugs or with renal diseases in which they are contraindicated. Recently, medical devices have been developed to manipulate the sympathetic nervous system, for example, implantation of carotid sinus nerve stimulating electrodes and ablation of the renal innervation. These approaches have been relatively successful but there remains a lack of understanding of the neural mechanisms impinging on the kidney that regulate long-term control of blood pressure. SUMMARY The observation that bilateral renal nerve ablation can reduce blood pressure represents an important therapeutic milestone. Nonetheless, questions arise as to the underlying mechanisms, the long-term consequences, whether there may be re-innervation over a number of years, or whether some unknown consequence to the denervation may arise. This may point to the development of novel compounds targeted to the innervation of the kidney.
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Mohan S, Glushakov AV, Decurnou A, Narumiya S, Doré S. Contribution of PGE2 EP1 receptor in hemin-induced neurotoxicity. Front Mol Neurosci 2013; 6:31. [PMID: 24109429 PMCID: PMC3791386 DOI: 10.3389/fnmol.2013.00031] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 09/09/2013] [Indexed: 11/27/2022] Open
Abstract
Although hemin-mediated neurotoxicity has been linked to the production of free radicals and glutamate excitotoxicity, the role of the prostaglandin E2 (PGE2)-EP1 receptor remains unclear. Activation of the EP1 receptor in neurons results in increased intracellular calcium levels; therefore, we hypothesize that the blockade of the EP1 receptor reduces hemin neurotoxicity. Using postnatal primary cortical neurons cultured from wild-type (WT) and EP1−/− mice, we investigated the EP1 receptor role in hemin neurotoxicity measured by lactate dehydrogenase (LDH) cell survival assay. Hemin (75 μM) induced greater release of LDH in WT (34.7 ± 4.5%) than in EP1−/− (27.6 ± 3.3%) neurons. In the presence of the EP1 receptor antagonist SC-51089, the hemin-induced release of LDH decreased. To further investigate potential mechanisms of action, we measured changes in the intracellular calcium level [Ca2+]i following treatment with 17-phenyl trinor PGE2 (17-pt-PGE2) a selective EP1 agonist. In the WT neurons, 17-pt-PGE2 dose-dependently increased [Ca2+]i. However, in EP1−/− neurons, [Ca2+]i was significantly attenuated. We also revealed that hemin dose-dependently increased [Ca2+]i in WT neurons, with a significant decrease in EP1−/− neurons. Both 17-pt-PGE2 and hemin-induced [Ca2+]i were abolished by N-methyl-D-aspartic (NMDA) acid receptor and ryanodine receptor blockers. These results suggest that blockade of the EP1 receptor may be protective against hemin neurotoxicity in vitro. We speculate that the mechanism of hemin neuronal death involves [Ca2+]i mediated by NMDA acid receptor-mediated extracellular Ca2+ influx and EP1 receptor-mediated intracellular release from ryanodine receptor-operated Ca2+ stores. Therefore, blockade of the EP1 receptor could be used to minimize neuronal damage following exposure to supraphysiological levels of hemin.
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Affiliation(s)
- Shekher Mohan
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease, University of Florida Gainesville, FL, USA
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29
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Wang G, Sarkar P, Peterson JR, Anrather J, Pierce JP, Moore JM, Feng J, Zhou P, Milner TA, Pickel VM, Iadecola C, Davisson RL. COX-1-derived PGE2 and PGE2 type 1 receptors are vital for angiotensin II-induced formation of reactive oxygen species and Ca(2+) influx in the subfornical organ. Am J Physiol Heart Circ Physiol 2013; 305:H1451-61. [PMID: 24014678 DOI: 10.1152/ajpheart.00238.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Regulation of blood pressure by angiotensin II (ANG II) is a process that involves the reactive oxygen species (ROS) and calcium. We have shown that ANG-II type 1 receptor (AT1R) and prostaglandin E2 (PGE2) type 1 receptors (EP1R) are required in the subfornical organ (SFO) for ROS-mediated hypertension induced by slow-pressor ANG-II infusion. However, the signaling pathway associated with this process remains unclear. We sought to determine mechanisms underlying the ANG II-induced ROS and calcium influx in mouse SFO cells. Ultrastructural studies showed that cyclooxygenase 1 (COX-1) codistributes with AT1R in the SFO, indicating spatial proximity. Functional studies using SFO cells revealed that ANG II potentiated PGE2 release, an effect dependent on AT1R, phospholipase A2 (PLA2) and COX-1. Furthermore, both ANG II and PGE2 increased ROS formation. While the increase in ROS initiated by ANG II, but not PGE2, required the activation of the AT1R/PLA2/COX-1 pathway, both ANG II and PGE2 were dependent on EP1R and Nox2 as downstream effectors. Finally, ANG II potentiated voltage-gated L-type Ca(2+) currents in SFO neurons via the same signaling pathway required for PGE2 production. Blockade of EP1R and Nox2-derived ROS inhibited ANG II and PGE2-mediated Ca(2+) currents. We propose a mechanism whereby ANG II increases COX-1-derived PGE2 through the AT1R/PLA2 pathway, which promotes ROS production by EP1R/Nox2 signaling in the SFO. ANG II-induced ROS are coupled with Ca(2+) influx in SFO neurons, which may influence SFO-mediated sympathoexcitation. Our findings provide the first evidence of a spatial and functional framework that underlies ANG-II signaling in the SFO and reveal novel targets for antihypertensive therapies.
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Affiliation(s)
- Gang Wang
- The Brain and Mind Research Institute, Weill Cornell Medical College, New York, New York
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30
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Souza GR, Talbot J, Lotufo CM, Cunha FQ, Cunha TM, Ferreira SH. Fractalkine mediates inflammatory pain through activation of satellite glial cells. Proc Natl Acad Sci U S A 2013; 110:11193-8. [PMID: 23776243 PMCID: PMC3704031 DOI: 10.1073/pnas.1307445110] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The activation of the satellite glial cells (SGCs) surrounding the dorsal root ganglion (DRG) neurons appears to play a role in pathological pain. We tested the hypothesis that fractalkine, which is constitutively expressed by primary nociceptive neurons, is the link between peripheral inflammation and the activation of SGCs and is thus responsible for the genesis of the inflammatory pain. The injection of carrageenin into the rat hind paw induced a decrease in the mechanical nociceptive threshold (hypernociception), which was associated with an increase in mRNA and GFAP protein expression in the DRG. Both events were inhibited by anti-fractalkine antibody administered directly into the DRG (L5) [intraganglionar (i.gl.)]. The administration of fractalkine into the DRG (L5) produced mechanical hypernociception in a dose-, time-, and CX3C receptor-1 (CX3CR1)-dependent manner. Fractalkine's hypernociceptive effect appears to be indirect, as it was reduced by local treatment with anti-TNF-α antibody, IL-1-receptor antagonist, or indomethacin. Accordingly, the in vitro incubation of isolated and cultured SGC with fractalkine induced the production/release of TNF-α, IL-1β, and prostaglandin E2. Finally, treatment with i.gl. fluorocitrate blocked fractalkine (i.gl.)- and carrageenin (paw)-induced hypernociception. Overall, these results suggest that, during peripheral inflammation, fractalkine is released in the DRG and contributes to the genesis of inflammatory hypernociception. Fractalkine's effect appears to be dependent on the activation of the SGCs, leading to the production of TNFα, IL-1β, and prostanoids, which are likely responsible for the maintenance of inflammatory pain. Thus, these results indicate that the inhibition of fractalkine/CX3CR1 signaling in SGCs may serve as a target to control inflammatory pain.
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Affiliation(s)
- Guilherme R. Souza
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900, Sao Paulo, Brazil
| | - Jhimmy Talbot
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900, Sao Paulo, Brazil
| | | | - Fernando Q. Cunha
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900, Sao Paulo, Brazil
| | - Thiago M. Cunha
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900, Sao Paulo, Brazil
| | - Sérgio H. Ferreira
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900, Sao Paulo, Brazil
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31
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Sphingosine-1-phosphate-induced nociceptor excitation and ongoing pain behavior in mice and humans is largely mediated by S1P3 receptor. J Neurosci 2013; 33:2582-92. [PMID: 23392686 DOI: 10.1523/jneurosci.4479-12.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The biolipid sphingosine-1-phosphate (S1P) is an essential modulator of innate immunity, cell migration, and wound healing. It is released locally upon acute tissue injury from endothelial cells and activated thrombocytes and, therefore, may give rise to acute post-traumatic pain sensation via a yet elusive molecular mechanism. We have used an interdisciplinary approach to address this question, and we find that intradermal injection of S1P induced significant licking and flinching behavior in wild-type mice and a dose-dependent flare reaction in human skin as a sign of acute activation of nociceptive nerve terminals. Notably, S1P evoked a small excitatory ionic current that resulted in nociceptor depolarization and action potential firing. This ionic current was preserved in "cation-free" solution and blocked by the nonspecific Cl(-) channel inhibitor niflumic acid and by preincubation with the G-protein inhibitor GDP-β-S. Notably, S1P(3) receptor was detected in virtually all neurons in human and mouse DRG. In line with this finding, S1P-induced neuronal responses and spontaneous pain behavior in vivo were substantially reduced in S1P(3)(-/-) mice, whereas in control S1P(1) floxed (S1P(1)(fl/fl)) mice and mice with a nociceptor-specific deletion of S1P(1)(-/-) receptor (SNS-S1P(1)(-/-)), neither the S1P-induced responses in vitro nor the S1P-evoked pain-like behavior was altered. Therefore, these findings indicate that S1P evokes significant nociception via G-protein-dependent activation of an excitatory Cl(-) conductance that is largely mediated by S1P(3) receptors present in nociceptors, and point to these receptors as valuable therapeutic targets for post-traumatic pain.
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Petho G, Reeh PW. Sensory and signaling mechanisms of bradykinin, eicosanoids, platelet-activating factor, and nitric oxide in peripheral nociceptors. Physiol Rev 2013; 92:1699-775. [PMID: 23073630 DOI: 10.1152/physrev.00048.2010] [Citation(s) in RCA: 191] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Peripheral mediators can contribute to the development and maintenance of inflammatory and neuropathic pain and its concomitants (hyperalgesia and allodynia) via two mechanisms. Activation or excitation by these substances of nociceptive nerve endings or fibers implicates generation of action potentials which then travel to the central nervous system and may induce pain sensation. Sensitization of nociceptors refers to their increased responsiveness to either thermal, mechanical, or chemical stimuli that may be translated to corresponding hyperalgesias. This review aims to give an account of the excitatory and sensitizing actions of inflammatory mediators including bradykinin, prostaglandins, thromboxanes, leukotrienes, platelet-activating factor, and nitric oxide on nociceptive primary afferent neurons. Manifestations, receptor molecules, and intracellular signaling mechanisms of the effects of these mediators are discussed in detail. With regard to signaling, most data reported have been obtained from transfected nonneuronal cells and somata of cultured sensory neurons as these structures are more accessible to direct study of sensory and signal transduction. The peripheral processes of sensory neurons, where painful stimuli actually affect the nociceptors in vivo, show marked differences with respect to biophysics, ultrastructure, and equipment with receptors and ion channels compared with cellular models. Therefore, an effort was made to highlight signaling mechanisms for which supporting data from molecular, cellular, and behavioral models are consistent with findings that reflect properties of peripheral nociceptive nerve endings. Identified molecular elements of these signaling pathways may serve as validated targets for development of novel types of analgesic drugs.
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Affiliation(s)
- Gábor Petho
- Pharmacodynamics Unit, Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Pécs, Pécs, Hungary
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Lee S, Zhang J. Heterogeneity of macrophages in injured trigeminal nerves: cytokine/chemokine expressing vs. phagocytic macrophages. Brain Behav Immun 2012; 26:891-903. [PMID: 22469908 DOI: 10.1016/j.bbi.2012.03.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/14/2012] [Accepted: 03/15/2012] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Macrophages are important immune effector cells in both innate and adaptive immune responses. Injury to peripheral nerves triggers activation of resident macrophages and infiltration of haematogenous macrophages, which they play critical roles in Wallerian degeneration and neuropathic pain. As macrophages are able to change their phenotypes in response to environment cues, we attempt to identify distinct phenotypes of macrophages in injured nerves and to understand the potential contribution of each macrophage subpopulation to the genesis of neuropathic pain associated with nerve injury. METHODS Rat mental nerves (terminal branches of trigeminal nerve) were loosely ligated. Sensitivity to mechanical stimuli at the lower lip area was monitored using calibrated von Frey Hairs. We examined the expression pattern of Iba-1, MAC1 and ED1 which allow us to reveal the immunophenotypes of macrophages at different time points post-injury. Functional status of each macrophage subpopulation was further investigated by colocalization with cytokines/chemokines, myelin basic protein and MHC II antigen, which reflect respectively secretory, phagocytic and antigen presentation properties of activated macrophages. RESULTS Following nerve injury, a burst of Iba-1(+) macrophages was found in injured mental nerves. Among them, we detected two major immunophenotypes: MAC1(+) cytokines/chemokines secreting macrophages and ED1(+) phagocytic macrophages. Small, round shaped MAC1(+) macrophages were distributed essentially around the lesion site and existed only at early time points. Large, irregular and foamy ED1(+) macrophages were found among damaged nerve fibers and they persisted for at least 3 months post-injury. Although ED1(+) macrophages did not secrete inflammatory mediators, they were able to express neurotransmitter CGRP and MHC II at later time points. In parallel, we observed that mechanical allodynia developed after the nerve ligation was at its lowest level within 1 month. Although slightly increased afterwards, the head escape threshold maintained significantly lower than before injury until 3 months. We suggest that MAC1(+) macrophages contribute to the initiation of neuropathic pain by releasing cytokines/chemokines, and ED1(+) macrophages may contribute in maintaining the hypersensitivity under other mechanisms. CONCLUSION Our results highlighted the heterogeneity and the plasticity of macrophages in response to the injury and provided further information on their potential involvement in neuropathic pain. Exploring the full spectrum of macrophage phenotypes in injured nerve is necessary. Individual macrophage population may be selectively targeted by cell-specific intervention for an effective treatment of neuropathic pain.
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Affiliation(s)
- SeungHwan Lee
- The Alan Edwards Centre for Research on Pain, McGill University, 740, Dr. Penfield Ave., Montreal, Quebec, Canada H3A 0G1
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Role of peripheral and spinal 5-HT3 receptors in development and maintenance of formalin-induced long-term secondary allodynia and hyperalgesia. Pharmacol Biochem Behav 2012; 101:246-57. [DOI: 10.1016/j.pbb.2012.01.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 01/13/2012] [Accepted: 01/16/2012] [Indexed: 12/19/2022]
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Cunha TM, Souza GR, Domingues AC, Carreira EU, Lotufo CM, Funez MI, Verri WA, Cunha FQ, Ferreira SH. Stimulation of peripheral kappa opioid receptors inhibits inflammatory hyperalgesia via activation of the PI3Kγ/AKT/nNOS/NO signaling pathway. Mol Pain 2012; 8:10. [PMID: 22316281 PMCID: PMC3293001 DOI: 10.1186/1744-8069-8-10] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 02/08/2012] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND In addition to their central effects, opioids cause peripheral analgesia. There is evidence showing that peripheral activation of kappa opioid receptors (KORs) inhibits inflammatory pain. Moreover, peripheral μ-opioid receptor (MOR) activation are able to direct block PGE(2)-induced ongoing hyperalgesia However, this effect was not tested for KOR selective activation. In the present study, the effect of the peripheral activation of KORs on PGE(2)-induced ongoing hyperalgesia was investigated. The mechanisms involved were also evaluated. RESULTS Local (paw) administration of U50488 (a selective KOR agonist) directly blocked, PGE(2)-induced mechanical hyperalgesia in both rats and mice. This effect was reversed by treating animals with L-NMMA or N-propyl-L-arginine (a selective inhibitor of neuronal nitric oxide synthase, nNOS), suggesting involvement of the nNOS/NO pathway. U50488 peripheral effect was also dependent on stimulation of PI3Kγ/AKT because inhibitors of these kinases also reduced peripheral antinociception induced by U50488. Furthermore, U50488 lost its peripheral analgesic effect in PI3Kγ null mice. Observations made in vivo were confirmed after incubation of dorsal root ganglion cultured neurons with U50488 produced an increase in the activation of AKT as evaluated by western blot analyses of its phosphorylated form. Finally, immunofluorescence of DRG neurons revealed that KOR-expressing neurons also express PI3Kγ (≅ 43%). CONCLUSIONS The present study indicates that activation of peripheral KORs directly blocks inflammatory hyperalgesia through stimulation of the nNOS/NO signaling pathway which is probably stimulated by PI3Kγ/AKT signaling. This study extends a previously study of our group suggesting that PI3Kγ/AKT/nNOS/NO is an important analgesic pathway in primary nociceptive neurons.
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Affiliation(s)
- Thiago M Cunha
- Department of Pharmacology, School of Medicine of Ribeirão Preto University of São Paulo, Av, Bandeirantes, 3900, 14049-900, Ribeirão Preto SP, Brazil.
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Effects of simvastatin on pulmonary C-fiber sensitivity in rats with monocrotaline-induced pulmonary hypertension. J Heart Lung Transplant 2011; 30:332-40. [DOI: 10.1016/j.healun.2010.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 09/01/2010] [Accepted: 09/22/2010] [Indexed: 11/21/2022] Open
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Mair N, Benetti C, Andratsch M, Leitner MG, Constantin CE, Camprubí-Robles M, Quarta S, Biasio W, Kuner R, Gibbins IL, Kress M, Haberberger RV. Genetic evidence for involvement of neuronally expressed S1P₁ receptor in nociceptor sensitization and inflammatory pain. PLoS One 2011; 6:e17268. [PMID: 21359147 PMCID: PMC3040773 DOI: 10.1371/journal.pone.0017268] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 01/24/2011] [Indexed: 02/02/2023] Open
Abstract
Sphingosine-1-phosphate (S1P) is a key regulator of immune response. Immune cells, epithelia and blood cells generate high levels of S1P in inflamed tissue. However, it is not known if S1P acts on the endings of nociceptive neurons, thereby contributing to the generation of inflammatory pain. We found that the S1P1 receptor for S1P is expressed in subpopulations of sensory neurons including nociceptors. Both S1P and agonists at the S1P1 receptor induced hypersensitivity to noxious thermal stimulation in vitro and in vivo. S1P-induced hypersensitivity was strongly attenuated in mice lacking TRPV1 channels. S1P and inflammation-induced hypersensitivity was significantly reduced in mice with a conditional nociceptor-specific deletion of the S1P1 receptor. Our data show that neuronally expressed S1P1 receptors play a significant role in regulating nociceptor function and that S1P/S1P1 signaling may be a key player in the onset of thermal hypersensitivity and hyperalgesia associated with inflammation.
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Affiliation(s)
- Norbert Mair
- Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck, Austria.
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Analysis of cellular and behavioral responses to imiquimod reveals a unique itch pathway in transient receptor potential vanilloid 1 (TRPV1)-expressing neurons. Proc Natl Acad Sci U S A 2011; 108:3371-6. [PMID: 21300878 DOI: 10.1073/pnas.1019755108] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Despite its clinical importance, the mechanisms that mediate or generate itch are poorly defined. The identification of pruritic compounds offers insight into understanding the molecular and cellular basis of itch. Imiquimod (IQ) is an agonist of Toll-like receptor 7 (TLR7) used to treat various infectious skin diseases such as genital warts, keratosis, and basal cell carcinoma. Itch is reportedly one of the major side effects developed during IQ treatments. We found that IQ acts as a potent itch-evoking compound (pruritogen) in mice via direct excitation of sensory neurons. Combined studies of scratching behavior, patch-clamp recording, and Ca(2+) response revealed the existence of a unique intracellular mechanism, which is independent of TLR7 as well as different from the mechanisms exploited by other well-characterized pruritogens. Nevertheless, as for other pruritogens, IQ requires the presence of transient receptor potential vanilloid 1 (TRPV1)-expressing neurons for itch-associated responses. Our data provide evidence supporting the hypothesis that there is a specific subset of TRPV1-expressing neurons that is equipped with diverse intracellular mechanisms that respond to histamine, chloroquine, and IQ.
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Wijnvoord N, Albuquerque B, Häussler A, Myrczek T, Popp L, Tegeder I. Inter-strain differences of serotonergic inhibitory pain control in inbred mice. Mol Pain 2010; 6:70. [PMID: 20977736 PMCID: PMC2987995 DOI: 10.1186/1744-8069-6-70] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 10/26/2010] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Descending inhibitory pain control contributes to the endogenous defense against chronic pain and involves noradrenergic and serotonergic systems. The clinical efficacy of antidepressants suggests that serotonin may be particularly relevant for neuropathic pain conditions. Serotonergic signaling is regulated by synthesis, metabolisms, reuptake and receptors. RESULTS To address the complexity, we used inbred mouse strains, C57BL/6J, 129 Sv, DBA/2J and Balb/c, which differ in brain serotonin levels. Serotonin analysis after nerve injury revealed inter-strain differences in the adaptation of descending serotonergic fibers. Upregulation of spinal cord and midbrain serotonin was apparent only in 129 Sv mice and was associated with attenuated nerve injury evoked hyperalgesia and allodynia in this strain. The increase of dorsal horn serotonin was blocked by hemisectioning of descending fibers but not by rhizotomy of primary afferents indicating a midbrain source. Para-chlorophenylalanine-mediated serotonin depletion in spinal cord and midbrain intensified pain hypersensitivity in the nerve injury model. In contrast, chronic inflammation of the hindpaw did not evoke equivalent changes in serotonin levels in the spinal cord and midbrain and nociceptive thresholds dropped in a parallel manner in all strains. CONCLUSION The results suggest that chronic nerve injury evoked hypernociception may be contributed by genetic differences of descending serotonergic inhibitory control.
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Affiliation(s)
- Nina Wijnvoord
- Pharmazentrum frankfurt, ZAFES, Clinical Pharmacology, Goethe-University, Frankfurt, Germany
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Meves H. The action of prostaglandins on ion channels. Curr Neuropharmacol 2010; 4:41-57. [PMID: 18615137 DOI: 10.2174/157015906775203048] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Revised: 10/03/2005] [Accepted: 10/31/2005] [Indexed: 11/22/2022] Open
Abstract
Prostaglandins, in particular PGE(2) and prostacyclin PGI(2) have diverse biological effects. Most importantly, they are involved in inflammation and pain. Prostaglandins in nano- and micromolar concentrations sensitize nerve cells, i.e. make them more sensitive to electrical or chemical stimuli. Sensitization arises from the effect of prostaglandins on ion channels and occurs both at the peripheral terminal of nociceptors at the site of tissue injury (peripheral sensitization) and at the synapses in the spinal cord (central sensitization). The first step is the binding of prostaglandins to receptors in the cell membrane, mainly EP and IP receptors. The receptors couple via G proteins to enzymes such as adenylate cyclase and phospholipase C (PLC). Activation of adenylate cyclase leads to increase of cAMP and subsequent activation of protein kinase A (PKA) or PKA-independent effects of cAMP, e.g. mediated by Epac (=exchange protein activated by cAMP). Activation of PLC causes increase of inositol phosphates and increase of cytosolic calcium. This article summarizes the effects of PGE(2), PGE(1), PGI2 and its stable analogues on non-selective cation channels and sodium, potassium, calcium and chloride channels. It describes the mechanism responsible for the facilitatory or inhibitory prostaglandin effects on ion channels. Understanding these mechanisms is essential for the development of useful new analgesics.
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Affiliation(s)
- Hans Meves
- Physiologisches Institut, Universität des Saarlandes, D-66421 Homburg-Saar, Germany.
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Morphine peripheral analgesia depends on activation of the PI3Kgamma/AKT/nNOS/NO/KATP signaling pathway. Proc Natl Acad Sci U S A 2010; 107:4442-7. [PMID: 20147620 DOI: 10.1073/pnas.0914733107] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Morphine is one of the most prescribed and effective drugs used for the treatment of acute and chronic pain conditions. In addition to its central effects, morphine can also produce peripheral analgesia. However, the mechanisms underlying this peripheral action of morphine have not yet been fully elucidated. Here, we show that the peripheral antinociceptive effect of morphine is lost in neuronal nitric-oxide synthase null mice and that morphine induces the production of nitric oxide in primary nociceptive neurons. The activation of the nitric-oxide pathway by morphine was dependent on an initial stimulation of PI3Kgamma/AKT protein kinase B (AKT) and culminated in increased activation of K(ATP) channels. In the latter, this intracellular signaling pathway might cause a hyperpolarization of nociceptive neurons, and it is fundamental for the direct blockade of inflammatory pain by morphine. This understanding offers new targets for analgesic drug development.
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Grossmann L, Gorodetskaya N, Baron R, Jänig W. Enhancement of Ectopic Discharge in Regenerating A- and C-Fibers by Inflammatory Mediators. J Neurophysiol 2009; 101:2762-74. [DOI: 10.1152/jn.91091.2008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Afferent A- and C-fibers regenerating into a nerve following peripheral nerve injury are exposed to inflammatory mediators released by Schwann cells, resident and invading macrophages, and other inflammatory cells. Here we tested the hypothesis that ongoing and evoked activity in these afferent fibers are enhanced by a mixture of inflammatory mediators [inflammatory soup (IS)] applied to the injured nerve. Using in vivo electrophysiology, regenerating afferent nerve fibers were studied 7–14 days after sural nerve crush lesion. The ectopic activity was studied before and ≤1.5 h after topical application of IS to the nerve in 73 C-fibers and 22 A-fibers that were either ectopically active before application of IS (61 C-fibers, 17 A-fibers) or recruited by IS (12 C-fibers, 5 A-fibers). More than one half of the C-fibers were activated by IS for ≤90 min after its removal. The majority of mechano- (23/38) and heat-sensitive (29/35) C-fibers as well as mechano-sensitive A-fibers (12/17) decreased their activation thresholds and/or increased the response magnitude to mechanical and/or heat stimulation of the nerve. Noxious cold sensitivity, but not nonnoxious cold sensitivity, was weakly influenced by IS. Some initially nonresponsive C- and A-fibers developed new ectopic properties, i.e., were recruited, and exhibited ongoing activity and/or could be activated by physiological stimuli after application of IS. The results suggest that inflammatory mediators may be critical to enhance ectopic excitability of regenerating afferent nerve fibers. These peripheral mechanisms may be important triggering and maintaining neuropathic pain.
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Xu X, Wang P, Zou X, Li D, Fang L, Lin Q. Increases in transient receptor potential vanilloid-1 mRNA and protein in primary afferent neurons stimulated by protein kinase C and their possible role in neurogenic inflammation. J Neurosci Res 2009; 87:482-94. [PMID: 18752301 DOI: 10.1002/jnr.21844] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A recent study by our group demonstrates pharmacologically that the transient receptor potential vanilloid-1 (TRPV(1)) is activated by intradermal injection of capsaicin to initiate neurogenic inflammation by the release of neuropeptides in the periphery. In this study, expression of TRPV(1), phosphorylated protein kinase C (p-PKC), and calcitonin gene-related peptide (CGRP) in dorsal root ganglion (DRG) neurons was visualized by using immunofluorescence, real-time PCR, and Western blots to examine whether increases in TRPV(1) mRNA and protein levels evoked by capsaicin injection are subject to modulation by the activation of PKC and to analyze the role of this process in the pathogenesis of neurogenic inflammation. Capsaicin injection into the hindpaw skin of anesthetized rats evoked increases in the expression of TRPV(1), CGRP and p-PKC in mRNA and/or protein levels and in the number of single labeled TRPV(1), p-PKC, and CGRP neurons in ipsilateral L4-5 DRGs. Coexpressions of TRPV(1) with p-PKC and/or CGRP in DRG neurons were also significantly increased after CAP injection. These evoked expressions at both molecular and cellular levels were significantly inhibited after TRPV(1) receptors were blocked by 5'-iodoresiniferatoxin (5 microg) or PKC was inhibited by chelerythrine chloride (5 microg). Taken together, these results provide evidence that up-regulation of TRPV(1) mRNA and protein levels under inflammatory conditions evoked by capsaicin injection is subject to modulation by the PKC cascade in which increased CGRP level in DRG neurons may be related to the initiation of neurogenic inflammation. Thus, up-regulation of TRPV(1) receptors in DRG neurons seems critical for initiating acute neurogenic inflammation.
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Affiliation(s)
- Xijin Xu
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555-1069, USA
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Molecular Mechanisms of TRPV1-Mediated Pain. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s1567-7443(08)10404-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Pethő G, Reeh PW. Effects of Bradykinin on Nociceptors. NEUROGENIC INFLAMMATION IN HEALTH AND DISEASE 2009. [DOI: 10.1016/s1567-7443(08)10407-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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Lynn PA, Chen BN, Zagorodnyuk VP, Costa M, Brookes SJH. TNBS-induced inflammation modulates the function of one class of low-threshold rectal mechanoreceptors in the guinea pig. Am J Physiol Gastrointest Liver Physiol 2008; 295:G862-71. [PMID: 18755810 PMCID: PMC2575914 DOI: 10.1152/ajpgi.00585.2007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The effects of trinitrobenzene sulfonic acid (TNBS)-induced inflammation on specialized, low-threshold, slowly adapting rectal mechanoreceptors were investigated in the guinea pig. Under isoflurane anesthesia, 300 microl saline or TNBS (15 mg/ml) in 30% ethanol was instilled 7 cm from the anal sphincter. Six or 30 days later, single unit extracellular recordings were made from rectal nerve trunks in flat-sheet in vitro preparations attached to a mechanical tissue stretcher. TNBS treatment caused macroscopic ulceration of the rectal mucosa at 6 days, which fully resolved by 30 days. Muscle contractility was unaffected by TNBS treatment. At 6 days posttreatment, responses of low-threshold rectal mechanoreceptors to circumferential stretch were increased, and the proportion of afferents responding with von Frey hair thresholds <or=0.1 mN and mechanoreceptor excitability in response to electrical stimulation were increased in TNBS-treated tissue, suggesting increased sensitivity of the mechanotransducer. Mechanoreceptor function at 30 days posttreatment was in most cases unchanged. The inflammatory mediator prostaglandin E(2) (1 microM) activated mechanoreceptors (6 days) in conjunction with contractile activity, but capsaicin (1 microM) failed to activate mechanoreceptors. Bradykinin (1 microM) activated mechanoreceptors independently of contractile activity and responses to stretch were increased in the presence of bradykinin. Both capsaicin and bradykinin activated unidentified stretch-insensitive afferents independently of contractile activity. Mechanoreceptor function is modulated at 6 days posttreatment but not at 30 days, suggesting a moderate increase in mechanoreceptor sensitivity in inflamed tissue but not after recovery. Other unclassified stretch-insensitive afferents are responsive to inflammatory mediators and capsaicin and may be involved in aspects of visceral sensation.
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Affiliation(s)
- P. A. Lynn
- Department of Human Physiology and Centre for Neuroscience Flinders University, Bedford Park, Australia
| | - B. N. Chen
- Department of Human Physiology and Centre for Neuroscience Flinders University, Bedford Park, Australia
| | - V. P. Zagorodnyuk
- Department of Human Physiology and Centre for Neuroscience Flinders University, Bedford Park, Australia
| | - M. Costa
- Department of Human Physiology and Centre for Neuroscience Flinders University, Bedford Park, Australia
| | - S. J. H. Brookes
- Department of Human Physiology and Centre for Neuroscience Flinders University, Bedford Park, Australia
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Katanosaka K, Banik RK, Giron R, Higashi T, Tominaga M, Mizumura K. Contribution of TRPV1 to the bradykinin-evoked nociceptive behavior and excitation of cutaneous sensory neurons. Neurosci Res 2008; 62:168-75. [PMID: 18789982 DOI: 10.1016/j.neures.2008.08.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 08/04/2008] [Accepted: 08/05/2008] [Indexed: 12/28/2022]
Abstract
Bradykinin (BK), a major inflammatory mediator, excites and sensitizes nociceptor neurons/fibers, thus evoking pain and hyperalgesia. The cellular signaling mechanisms underlying these actions have remained unsolved, especially in regard to the identity of channels that mediate acute excitation. Here, to clarify the contribution of transient receptor potential vanilloid 1 (TRPV1), a heat-sensitive ion channel, to the BK-evoked nociceptor excitation and pain, we examined the behavioral and physiological BK-responses in TRPV1-deficient (KO) mice. A nocifencive behavior after BK injection (100 pmol/site) into mouse sole was reduced in TRPV1-KO mice compared with wild-type (WT). A higher dose of BK (1 nmol/site), however, induced the response in TRPV1-KO mice indistinguishable from that in the WT. BK-evoked excitation of cutaneous C-fibers in TRPV1-KO mice was comparable to that in WT. BK clearly increased intracellular calcium in cultured dorsal root ganglion (DRG) neurons of TRPV1-KO mice, although the incidence of BK-sensitive neurons was reduced. BK has been reported to activate TRPA1 indirectly, yet a considerable part of BK-sensitive DRG neurons did not respond to a TRPA1 agonist, mustard oil. These results suggest that BK-evoked nociception/nociceptor response would not be simply explained by activation of TRPV1 and A1, and that BK-evoked nociceptor excitation would be mediated by several ionic mechanisms.
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Affiliation(s)
- Kimiaki Katanosaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
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Li D, Ren Y, Xu X, Zou X, Fang L, Lin Q. Sensitization of primary afferent nociceptors induced by intradermal capsaicin involves the peripheral release of calcitonin gene-related Peptide driven by dorsal root reflexes. THE JOURNAL OF PAIN 2008; 9:1155-68. [PMID: 18701354 DOI: 10.1016/j.jpain.2008.06.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 06/12/2008] [Accepted: 06/18/2008] [Indexed: 10/21/2022]
Abstract
UNLABELLED Neuropeptides released from axons of primary afferent nociceptive neurons are the key elements for the incidence of neurogenic inflammation and their release is associated with dorsal root reflexes (DRRs). However, whether the release is due to the triggering of DRRs and plays a role in inflammation-induced pain still remain to be determined. The present study assessed the role of calcitonin gene-related peptide (CGRP) in sensitization of primary afferent nociceptors induced by activation of transient receptor potential vanilloid-1 (TRPV(1)) after intradermal injection of capsaicin and determined if this release is due to activation of primary afferent neurons antidromically by triggering of DRRs. Under dorsal root intact conditions, primary afferent nociceptive fibers recorded in anesthetized rats could be sensitized by capsaicin injection, as shown by an increase in afferent responses and lowering of the response threshold to mechanical stimuli. After DRRs were removed by dorsal rhizotomy, the capsaicin-evoked sensitization was significantly reduced. In dorsal root intact rats, peripheral pretreatment with a CGRP receptor antagonist could dose-dependently reduce the capsaicin-induced sensitization. Peripheral post-treatment with CGRP could dose-dependently restore the capsaicin-induced sensitization under dorsal rhizotomized conditions. Capsaicin injection evoked increases in numbers of single and double labeled TRPV(1) and CGRP neurons in ipsilateral dorsal root ganglia (DRG). After dorsal rhizotomy, these evoked expressions were significantly inhibited. PERSPECTIVE These data indicate that the DRR-mediated neurogenic inflammation enhances sensitization of primary afferent nociceptors induced by capsaicin injection. The underlying mechanism involves antidromic activation of DRG neurons via upregulation of TRPV(1) receptors whereby CGRP is released peripherally.
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Affiliation(s)
- Dingge Li
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555-1069, USA
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TRPC channels and diacylglycerol dependent calcium signaling in rat sensory neurons. Histochem Cell Biol 2008; 130:655-67. [DOI: 10.1007/s00418-008-0477-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2008] [Indexed: 10/21/2022]
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Kuo YL, Lai CJ. Ovalbumin sensitizes vagal pulmonary C-fiber afferents in Brown Norway rats. J Appl Physiol (1985) 2008; 105:611-20. [PMID: 18535139 DOI: 10.1152/japplphysiol.01099.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Sensitization of vagal lung C fibers has been postulated to contribute to the development of asthma, but support for this notion is still lacking. We investigated the characteristics and function of pulmonary C fibers (PCFs) in ovalbumin (OVA)-sensitized Brown Norway rats, an established animal model of asthma. Rats were sensitized with intraperitoneal injection of OVA or were treated with saline (control). In study 1, with the use of open-chest and artificially ventilated rats, inhalation of 5% OVA aerosol evoked an augmented increase in total lung resistance in the OVA-sensitized rats, compared with the control rats. Bilateral vagotomy or subcutaneous pretreatment with a high-dose of capsaicin for blocking of C-fiber function equally attenuated this augmented total lung resistance response, suggesting the involvement of PCFs. In study 2, with the use of anesthetized, spontaneously breathing rats, right atrial injection of capsaicin (1 microg/kg; a PCF stimulant) evoked an augmented apneic response in the OVA-sensitized rats, compared with the control rats. In study 3, with the use of open-chest, paralyzed, and artificially ventilated rats, the afferent PCF responses to right atrial injection of capsaicin (0.5 and 1.0 microg/kg), phenylbiguanide (8 microg/kg; a PCF stimulant), or adenosine (0.2 mg/kg; a PCF stimulant) were enhanced in the OVA-sensitized rats, compared with the control rats. However, the baseline activities of PCFs and their afferent responses to mechanical stimulation by lung hyperinflation in the OVA-sensitized and control rats were comparable. Our results suggested that OVA-sensitized Brown Norway rats possess sensitized vagal PCFs, which may participate in the development of the airway hyperreactivity observed in these animals.
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Affiliation(s)
- Y L Kuo
- Institute of Neuroscience, Department of Physiology, Tzu Chi University, No. 701, Sec. 3, Chung-Yang Rd., Hualien 97004, Taiwan
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