1
|
Raposo-Garcia S, Cao A, Costas C, Louzao MC, Vilariño N, Vale C, Botana LM. Mouse N2a Neuroblastoma Assay: Uncertainties and Comparison with Alternative Cell-Based Assays for Ciguatoxin Detection. Mar Drugs 2023; 21:590. [PMID: 37999414 PMCID: PMC10672529 DOI: 10.3390/md21110590] [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: 10/11/2023] [Revised: 10/25/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023] Open
Abstract
The growing concern about ciguatera fish poisoning (CF) due to the expansion of the microorganisms producing ciguatoxins (CTXs) increased the need to develop a reliable and fast method for ciguatoxin detection to guarantee food safety. Cytotoxicity assay on the N2a cells sensitized with ouabain (O) and veratridine (V) is routinely used in ciguatoxin detection; however, this method has not been standardized yet. This study demonstrated the low availability of sodium channels in the N2a cells, the great O/V damage to the cells and the cell detachment when the cell viability is evaluated by the classical cytotoxicity assay and confirmed the absence of toxic effects caused by CTXs alone when using the methods that do not require medium removal such as lactate dehydrogenase (LDH) and Alamar blue assays. Different cell lines were evaluated as alternatives, such as human neuroblastoma, which was not suitable for the CTX detection due to the greater sensitivity to O/V and low availability of sodium channels. However, the HEK293 Nav cell line expressing the α1.6 subunit of sodium channels was sensitive to the ciguatoxin without the sensitization with O/V due to its expression of sodium channels. In the case of sensitizing the cells with O/V, it was possible to detect the presence of the ciguatoxin by the classical cytotoxicity MTT method at concentrations as low as 0.0001 nM CTX3C, providing an alternative cell line for the detection of compounds that act on the sodium channels.
Collapse
Affiliation(s)
| | | | | | | | | | - Carmen Vale
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain; (S.R.-G.); (A.C.); (C.C.); (M.C.L.); (N.V.)
| | - Luis M. Botana
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain; (S.R.-G.); (A.C.); (C.C.); (M.C.L.); (N.V.)
| |
Collapse
|
2
|
König C, Ebersberger A, Eitner A, Wetzker R, Schaible HG. Prostaglandin EP3 receptor activation is antinociceptive in sensory neurons via PI3Kγ, AMPK and GRK2. Br J Pharmacol 2023; 180:441-458. [PMID: 36245399 DOI: 10.1111/bph.15971] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 07/22/2022] [Accepted: 09/29/2022] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE Prostaglandin E2 is considered a major mediator of inflammatory pain, by acting on neuronal Gs protein-coupled EP2 and EP4 receptors. However, the neuronal EP3 receptor, colocalized with EP2 and EP4 receptor, is Gi protein-coupled and antagonizes the pronociceptive prostaglandin E2 effect. Here, we investigated the cellular signalling mechanisms by which the EP3 receptor reduces EP2 and EP4 receptor-evoked pronociceptive effects in sensory neurons. EXPERIMENTAL APPROACH Experiments were performed on isolated and cultured dorsal root ganglion (DRG) neurons from wild type, phosphoinositide 3-kinase γ (PI3Kγ)-/- , and PI3Kγkinase dead (KD)/KD mice. For subtype-specific stimulations, we used specific EP2, EP3, and EP4 receptor agonists from ONO Pharmaceuticals. As a functional readout, we recorded TTX-resistant sodium currents in patch-clamp experiments. Western blots were used to investigate the activation of intracellular signalling pathways. EP4 receptor internalization was measured using immunocytochemistry. KEY RESULTS Different pathways mediate the inhibition of EP2 and EP4 receptor-dependent pronociceptive effects by EP3 receptor stimulation. Inhibition of EP2 receptor-evoked pronociceptive effect critically depends on the kinase-independent function of the signalling protein PI3Kγ, and adenosine monophosphate activated protein kinase (AMPK) is involved. By contrast, inhibition of EP4 receptor-evoked pronociceptive effect is independent on PI3Kγ and mediated through activation of G protein-coupled receptor kinase 2 (GRK2), which enhances the internalization of the EP4 receptor after ligand binding. CONCLUSION AND IMPLICATIONS Activation of neuronal PI3Kγ, AMPK, and GRK2 by EP3 receptor activation limits cAMP-dependent pain generation by prostaglandin E2 . These new insights hold the potential for a novel approach in pain therapy.
Collapse
Affiliation(s)
- Christian König
- Institute of Physiology 1/Neurophysiology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany
| | - Andrea Ebersberger
- Institute of Physiology 1/Neurophysiology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany
| | - Annett Eitner
- Institute of Physiology 1/Neurophysiology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany.,Department of Trauma, Hand and Reconstructive Surgery, Experimental Trauma Surgery, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany
| | - Reinhard Wetzker
- Clinic for Anesthesiology and Intensive Care, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany
| | - Hans-Georg Schaible
- Institute of Physiology 1/Neurophysiology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany
| |
Collapse
|
3
|
Röderer P, Belu A, Heidrich L, Siobal M, Isensee J, Prolingheuer J, Janocha E, Valdor M, Hagendorf S, Bahrenberg G, Opitz T, Segschneider M, Haupt S, Nitzsche A, Brüstle O, Hucho T. Emergence of nociceptive functionality and opioid signaling in human induced pluripotent stem cell-derived sensory neurons. Pain 2023:00006396-990000000-00249. [PMID: 36727909 DOI: 10.1097/j.pain.0000000000002860] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 11/15/2022] [Indexed: 02/03/2023]
Abstract
ABSTRACT Induced pluripotent stem cells (iPSCs) have enabled the generation of various difficult-to-access cell types such as human nociceptors. A key challenge associated with human iPSC-derived nociceptors (hiPSCdNs) is their prolonged functional maturation. While numerous studies have addressed the expression of classic neuronal markers and ion channels in hiPSCdNs, the temporal development of key signaling cascades regulating nociceptor activity has remained largely unexplored. In this study, we used an immunocytochemical high-content imaging approach alongside electrophysiological staging to assess metabotropic and ionotropic signaling of large scale-generated hiPSCdNs across 70 days of in vitro differentiation. During this period, the resting membrane potential became more hyperpolarized, while rheobase, action potential peak amplitude, and membrane capacitance increased. After 70 days, hiPSCdNs exhibited robust physiological responses induced by GABA, pH shift, ATP, and capsaicin. Direct activation of protein kinase A type II (PKA-II) through adenylyl cyclase stimulation with forskolin resulted in PKA-II activation at all time points. Depolarization-induced activation of PKA-II emerged after 35 days of differentiation. However, effective inhibition of forskolin-induced PKA-II activation by opioid receptor agonists required 70 days of in vitro differentiation. Our results identify a pronounced time difference between early expression of functionally important ion channels and emergence of regulatory metabotropic sensitizing and desensitizing signaling only at advanced stages of in vitro cultivation, suggesting an independent regulation of ionotropic and metabotropic signaling. These data are relevant for devising future studies into the development and regulation of human nociceptor function and for defining time windows suitable for hiPSCdN-based drug discovery.
Collapse
Affiliation(s)
- Pascal Röderer
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Andreea Belu
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Luzia Heidrich
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Maike Siobal
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Jörg Isensee
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Jonathan Prolingheuer
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | | | | | | | | | - Thoralf Opitz
- Institute of Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Michaela Segschneider
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
| | - Simone Haupt
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Anja Nitzsche
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Oliver Brüstle
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Tim Hucho
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| |
Collapse
|
4
|
Zhang XY, Wu X, Zhang P, Gan YH. Prolonged PGE 2 treatment increased TTX-sensitive but not TTX-resistant sodium current in trigeminal ganglionic neurons. Neuropharmacology 2022; 215:109156. [PMID: 35691365 DOI: 10.1016/j.neuropharm.2022.109156] [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: 01/04/2022] [Revised: 05/09/2022] [Accepted: 05/31/2022] [Indexed: 10/18/2022]
Abstract
Prostaglandin E2 (PGE2) is an important inflammatory mediator for the initiation and maintenance of inflammatory and neuropathic pain. The acute effect of PGE2 on sodium currents has been widely characterized in sensory neurons; however, the prolonged effect of PGE2 remains to be determined. Here, we performed patch clamp recordings to evaluate the acute and prolonged effects of PGE2 on sodium currents in trigeminal ganglionic (TG) neurons from male Sprague-Dawley rats. We found that 24-h treatment with PGE2 (10 μM) increased the peak sodium current density by approximately 31% in a voltage-dependent manner and shifted the activation curve in a hyperpolarized direction but did not affect steady-state inactivation. Furthermore, treatment with PGE2 for 24 h increased the current density of tetrodotoxin-sensitive (TTX-S) but not TTX-resistant (TTX-R) channels significantly. Interestingly, TTX-S current was increased mostly in medium-sized, but not in small-sized, neurons after 24 h of treatment with PGE2. Moreover, the mRNA level of TTX-S Nav1.1 but not TTX-R Nav1.8 or Nav1.9 was significantly increased after 24 h of treatment with PGE2. In contrast, 5-min treatment with PGE2 (10 μM) increased the peak sodium current density by approximately 29% and increased TTX-R sodium currents, but not TTX-S currents, in both small- and medium-sized TG neurons. Our results presented a differential regulation of subtypes of sodium channels by acute and prolonged treatments of PGE2, which may help to better understand the mechanism of PGE2-mediated orofacial pain development.
Collapse
Affiliation(s)
- Xiao-Yu Zhang
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
| | - Xi Wu
- Academy for Advanced Interdisciplinary Studies, College of Future Technology, Institute of Molecular Medicine, Peking University, Beijing, 100871, PR China
| | - Peng Zhang
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
| | - Ye-Hua Gan
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China.
| |
Collapse
|
5
|
PACAP-38 Induces Transcriptomic Changes in Rat Trigeminal Ganglion Cells Related to Neuroinflammation and Altered Mitochondrial Function Presumably via PAC1/VPAC2 Receptor-Independent Mechanism. Int J Mol Sci 2022; 23:ijms23042120. [PMID: 35216232 PMCID: PMC8874739 DOI: 10.3390/ijms23042120] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 11/17/2022] Open
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a broadly expressed neuropeptide which has diverse effects in both the peripheral and central nervous systems. While its neuroprotective effects have been shown in a variety of disease models, both animal and human data support the role of PACAP in migraine generation. Both PACAP and its truncated derivative PACAP(6-38) increased calcium influx in rat trigeminal ganglia (TG) primary sensory neurons in most experimental settings. PACAP(6-38), however, has been described as an antagonist for PACAP type I (known as PAC1), and Vasoactive Intestinal Polypeptide Receptor 2 (also known as VPAC2) receptors. Here, we aimed to compare the signaling pathways induced by the two peptides using transcriptomic analysis. Rat trigeminal ganglion cell cultures were incubated with 1 µM PACAP-38 or PACAP(6-38). Six hours later RNA was isolated, next-generation RNA sequencing was performed and transcriptomic changes were analyzed to identify differentially expressed genes. Functional analysis was performed for gene annotation using the Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome databases. We found 200 common differentially expressed (DE) genes for these two neuropeptides. Both PACAP-38 and PACAP(6-38) treatments caused significant downregulation of NADH: ubiquinone oxidoreductase subunit B6 and upregulation of transient receptor potential cation channel, subfamily M, member 8. The common signaling pathways induced by both peptides indicate that they act on the same target, suggesting that PACAP activates trigeminal primary sensory neurons via a mechanism independent of the identified and cloned PAC1/VPAC2 receptor, either via another target structure or a different splice variant of PAC1/VPAC2 receptors. Identification of the target could help to understand key mechanisms of migraine.
Collapse
|
6
|
Yang NJ, Isensee J, Neel DV, Quadros AU, Zhang HXB, Lauzadis J, Liu SM, Shiers S, Belu A, Palan S, Marlin S, Maignel J, Kennedy-Curran A, Tong VS, Moayeri M, Röderer P, Nitzsche A, Lu M, Pentelute BL, Brüstle O, Tripathi V, Foster KA, Price TJ, Collier RJ, Leppla SH, Puopolo M, Bean BP, Cunha TM, Hucho T, Chiu IM. Anthrax toxins regulate pain signaling and can deliver molecular cargoes into ANTXR2 + DRG sensory neurons. Nat Neurosci 2021; 25:168-179. [PMID: 34931070 DOI: 10.1038/s41593-021-00973-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 11/01/2021] [Indexed: 11/09/2022]
Abstract
Bacterial products can act on neurons to alter signaling and function. In the present study, we found that dorsal root ganglion (DRG) sensory neurons are enriched for ANTXR2, the high-affinity receptor for anthrax toxins. Anthrax toxins are composed of protective antigen (PA), which binds to ANTXR2, and the protein cargoes edema factor (EF) and lethal factor (LF). Intrathecal administration of edema toxin (ET (PA + EF)) targeted DRG neurons and induced analgesia in mice. ET inhibited mechanical and thermal sensation, and pain caused by formalin, carrageenan or nerve injury. Analgesia depended on ANTXR2 expressed by Nav1.8+ or Advillin+ neurons. ET modulated protein kinase A signaling in mouse sensory and human induced pluripotent stem cell-derived sensory neurons, and attenuated spinal cord neurotransmission. We further engineered anthrax toxins to introduce exogenous protein cargoes, including botulinum toxin, into DRG neurons to silence pain. Our study highlights interactions between a bacterial toxin and nociceptors, which may lead to the development of new pain therapeutics.
Collapse
Affiliation(s)
- Nicole J Yang
- Department of Immunology, Harvard Medical School, Boston, MA, USA
| | - Jörg Isensee
- Translational Pain Research, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Dylan V Neel
- Department of Immunology, Harvard Medical School, Boston, MA, USA
| | - Andreza U Quadros
- Center for Research in Inflammatory Diseases, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | | | - Justas Lauzadis
- Department of Anesthesiology, Stony Brook Medicine, Stony Brook, NY, USA
| | | | - Stephanie Shiers
- Department of Neuroscience, Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, USA
| | - Andreea Belu
- Translational Pain Research, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | | | | | | | | | - Victoria S Tong
- Department of Immunology, Harvard Medical School, Boston, MA, USA
| | - Mahtab Moayeri
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Pascal Röderer
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn, Germany.,Cellomics Unit, LIFE & BRAIN GmbH, Bonn, Germany
| | - Anja Nitzsche
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn, Germany.,Cellomics Unit, LIFE & BRAIN GmbH, Bonn, Germany
| | - Mike Lu
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Bradley L Pentelute
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA.,The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Oliver Brüstle
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn, Germany
| | | | | | - Theodore J Price
- Department of Neuroscience, Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, USA
| | - R John Collier
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Stephen H Leppla
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michelino Puopolo
- Department of Anesthesiology, Stony Brook Medicine, Stony Brook, NY, USA
| | - Bruce P Bean
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Thiago M Cunha
- Center for Research in Inflammatory Diseases, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Tim Hucho
- Translational Pain Research, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Isaac M Chiu
- Department of Immunology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
7
|
Roversi K, Callai-Silva N, Roversi K, Griffith M, Boutopoulos C, Prediger RD, Talbot S. Neuro-Immunity and Gut Dysbiosis Drive Parkinson's Disease-Induced Pain. Front Immunol 2021; 12:759679. [PMID: 34868000 PMCID: PMC8637106 DOI: 10.3389/fimmu.2021.759679] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/21/2021] [Indexed: 12/12/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder, affecting 1-2% of the population aged 65 and over. Additionally, non-motor symptoms such as pain and gastrointestinal dysregulation are also common in PD. These impairments might stem from a dysregulation within the gut-brain axis that alters immunity and the inflammatory state and subsequently drives neurodegeneration. There is increasing evidence linking gut dysbiosis to the severity of PD's motor symptoms as well as to somatosensory hypersensitivities. Altogether, these interdependent features highlight the urgency of reviewing the links between the onset of PD's non-motor symptoms and gut immunity and whether such interplays drive the progression of PD. This review will shed light on maladaptive neuro-immune crosstalk in the context of gut dysbiosis and will posit that such deleterious interplays lead to PD-induced pain hypersensitivity.
Collapse
Affiliation(s)
- Katiane Roversi
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, Canada.,Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada.,Département d'Ophtalmologie, Université de Montréal, Montréal, QC, Canada.,Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Natalia Callai-Silva
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, Canada.,Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada.,Département d'Ophtalmologie, Université de Montréal, Montréal, QC, Canada
| | - Karine Roversi
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, Canada
| | - May Griffith
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada.,Département d'Ophtalmologie, Université de Montréal, Montréal, QC, Canada
| | - Christos Boutopoulos
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada.,Département d'Ophtalmologie, Université de Montréal, Montréal, QC, Canada
| | - Rui Daniel Prediger
- Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Sébastien Talbot
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, Canada
| |
Collapse
|
8
|
Isensee J, van Cann M, Despang P, Araldi D, Moeller K, Petersen J, Schmidtko A, Matthes J, Levine JD, Hucho T. Depolarization induces nociceptor sensitization by CaV1.2-mediated PKA-II activation. J Cell Biol 2021; 220:212600. [PMID: 34431981 PMCID: PMC8404467 DOI: 10.1083/jcb.202002083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/14/2021] [Accepted: 08/05/2021] [Indexed: 01/20/2023] Open
Abstract
Depolarization drives neuronal plasticity. However, whether depolarization drives sensitization of peripheral nociceptive neurons remains elusive. By high-content screening (HCS) microscopy, we revealed that depolarization of cultured sensory neurons rapidly activates protein kinase A type II (PKA-II) in nociceptors by calcium influx through CaV1.2 channels. This effect was modulated by calpains but insensitive to inhibitors of cAMP formation, including opioids. In turn, PKA-II phosphorylated Ser1928 in the distal C terminus of CaV1.2, thereby increasing channel gating, whereas dephosphorylation of Ser1928 involved the phosphatase calcineurin. Patch-clamp and behavioral experiments confirmed that depolarization leads to calcium- and PKA-dependent sensitization of calcium currents ex vivo and local peripheral hyperalgesia in the skin in vivo. Our data suggest a local activity-driven feed-forward mechanism that selectively translates strong depolarization into further activity and thereby facilitates hypersensitivity of nociceptor terminals by a mechanism inaccessible to opioids.
Collapse
Affiliation(s)
- Jörg Isensee
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Marianne van Cann
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Patrick Despang
- Department of Pharmacology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Dioneia Araldi
- Division of Neuroscience, Departments of Medicine and Oral & Maxillofacial Surgery, University of California, San Francisco, San Francisco, CA
| | - Katharina Moeller
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Jonas Petersen
- Institute for Pharmacology and Clinical Pharmacy, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Achim Schmidtko
- Institute for Pharmacology and Clinical Pharmacy, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jan Matthes
- Department of Pharmacology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Jon D Levine
- Division of Neuroscience, Departments of Medicine and Oral & Maxillofacial Surgery, University of California, San Francisco, San Francisco, CA
| | - Tim Hucho
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| |
Collapse
|
9
|
Zybura A, Hudmon A, Cummins TR. Distinctive Properties and Powerful Neuromodulation of Na v1.6 Sodium Channels Regulates Neuronal Excitability. Cells 2021; 10:cells10071595. [PMID: 34202119 PMCID: PMC8307729 DOI: 10.3390/cells10071595] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 06/20/2021] [Accepted: 06/21/2021] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (Navs) are critical determinants of cellular excitability. These ion channels exist as large heteromultimeric structures and their activity is tightly controlled. In neurons, the isoform Nav1.6 is highly enriched at the axon initial segment and nodes, making it critical for the initiation and propagation of neuronal impulses. Changes in Nav1.6 expression and function profoundly impact the input-output properties of neurons in normal and pathological conditions. While mutations in Nav1.6 may cause channel dysfunction, aberrant changes may also be the result of complex modes of regulation, including various protein-protein interactions and post-translational modifications, which can alter membrane excitability and neuronal firing properties. Despite decades of research, the complexities of Nav1.6 modulation in health and disease are still being determined. While some modulatory mechanisms have similar effects on other Nav isoforms, others are isoform-specific. Additionally, considerable progress has been made toward understanding how individual protein interactions and/or modifications affect Nav1.6 function. However, there is still more to be learned about how these different modes of modulation interact. Here, we examine the role of Nav1.6 in neuronal function and provide a thorough review of this channel’s complex regulatory mechanisms and how they may contribute to neuromodulation.
Collapse
Affiliation(s)
- Agnes Zybura
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- Biology Department, School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Andy Hudmon
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA;
| | - Theodore R. Cummins
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- Biology Department, School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
- Correspondence:
| |
Collapse
|
10
|
Regulation of Mitochondrial Function by Epac2 Contributes to Acute Inflammatory Hyperalgesia. J Neurosci 2021; 41:2883-2898. [PMID: 33593853 DOI: 10.1523/jneurosci.2368-20.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 01/14/2021] [Accepted: 02/09/2021] [Indexed: 12/12/2022] Open
Abstract
Gαs-coupled receptors signaling through cAMP provide a key mechanism for the sensitization of nociceptive sensory neurons, and the cAMP effector Epac has been implicated in the transition from acute to chronic pain. Epac exerts its effects through Rap1 and protein kinase C (PKC). To identify targets of Epac-PKC signaling in sensory neurons of the mouse dorsal root ganglion (DRG), we profiled PKC substrate proteins phosphorylated in response to the activation of Epac with the proinflammatory prostaglandin E2 (PGE2). A prominent Epac-dependent phospho-protein band induced by PGE2 was identified by mass spectrometry as the mitochondrial enzyme pyruvate dehydrogenase (Pdha1). In dissociated DRG from both males and females, the recruitment of Pdha1 to phospho-protein fractions was rapidly induced by PGE2 and prevented by selective inhibition of Epac2. Epac activation increased mitochondrial respiration, consistent with an increase in Pdha1 function mediated by Epac2. Hindpaw injection of PGE2 induced heat hyperalgesia in males and females, but Pdha1 phosphorylation occurred only in males. Hyperalgesia was attenuated in males but not in females by systemic inhibition of Epac2, and also by a mitochondrial membrane potential uncoupler, dinitrophenol, supporting a role for mitochondrial regulation in acute hyperalgesia. These findings identify a mechanism for the regulation of mitochondrial function by Epac2 that contributes to acute inflammatory hyperalgesia in male mice. Systemic administration of the cyclooxygenase 2 inhibitor celecoxib suppressed both PGE2-induced heat hyperalgesia and Pdha1 phosphorylation in DRG of males but not females, suggesting that prostaglandin synthesis within the DRG mediates the phosphorylation of Pdha1 in response to hindpaw insult.SIGNIFICANCE STATEMENT There has been extensive investigation of mitochondrial dysfunction as a causative factor in neuropathic pain disorders. In contrast, results reported here implicate enhanced mitochondrial function as a contributing factor in the development of acute inflammatory hyperalgesia. We describe a mechanism in which Epac2 activation by prostaglandin receptors leads to phosphorylation of pyruvate dehydrogenase and an increase in mitochondrial respiration in peripheral sensory neurons. Although Epac2 activation leads to Pdha1 (pyruvate dehydrogenase) phosphorylation in dissociated neurons from mice of both sexes, induction of this pathway in vivo by hindpaw insult is restricted to males and appears to require intraganglionic prostaglandin synthesis. These findings support a model in which Gs-coupled receptor modulation of mitochondrial function promotes acute nociceptive signaling and inflammatory hyperalgesia.
Collapse
|
11
|
Nevin ST, Lawrence N, Nicke A, Lewis RJ, Adams DJ. Functional modulation of the human voltage-gated sodium channel Na V1.8 by auxiliary β subunits. Channels (Austin) 2020; 15:79-93. [PMID: 33315536 PMCID: PMC7781643 DOI: 10.1080/19336950.2020.1860399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The voltage-gated sodium channel Nav1.8 mediates the tetrodotoxin-resistant (TTX-R) Na+ current in nociceptive primary sensory neurons, which has an important role in the transmission of painful stimuli. Here, we describe the functional modulation of the human Nav1.8 α-subunit in Xenopus oocytes by auxiliary β subunits. We found that the β3 subunit down-regulated the maximal Na+ current amplitude and decelerated recovery from inactivation of hNav1.8, whereas the β1 and β2 subunits had no such effects. The specific regulation of Nav1.8 by the β3 subunit constitutes a potential novel regulatory mechanism of the TTX-R Na+ current in primary sensory neurons with potential implications in chronic pain states. In particular, neuropathic pain states are characterized by a down-regulation of Nav1.8 accompanied by increased expression of the β3 subunit. Our results suggest that these two phenomena may be correlated, and that increased levels of the β3 subunit may directly contribute to the down-regulation of Nav1.8. To determine which domain of the β3 subunit is responsible for the specific regulation of hNav1.8, we created chimeras of the β1 and β3 subunits and co-expressed them with the hNav1.8 α-subunit in Xenopus oocytes. The intracellular domain of the β3 subunit was shown to be responsible for the down-regulation of maximal Nav1.8 current amplitudes. In contrast, the extracellular domain mediated the effect of the β3 subunit on hNav1.8 recovery kinetics.
Collapse
Affiliation(s)
- S T Nevin
- School of Biomedical Sciences and the Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia
| | - N Lawrence
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia
| | - A Nicke
- School of Biomedical Sciences and the Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia.,Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia
| | - R J Lewis
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia
| | - D J Adams
- School of Biomedical Sciences and the Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia.,Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong , Wollongong, Australia
| |
Collapse
|
12
|
Mini-review - Sodium channels and beyond in peripheral nerve disease: Modulation by cytokines and their effector protein kinases. Neurosci Lett 2020; 741:135446. [PMID: 33166641 DOI: 10.1016/j.neulet.2020.135446] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/01/2020] [Accepted: 10/03/2020] [Indexed: 12/18/2022]
Abstract
Peripheral neuropathy is associated with enhanced activity of primary afferents which is often manifested as pain. Voltage-gated sodium channels (VGSCs) are critical for the initiation and propagation of action potentials and are thus essential for the transmission of the noxious stimuli from the periphery. Human peripheral sensory neurons express multiple VGSCs, including Nav1.7, Nav1.8, and Nav1.9 that are almost exclusively expressed in the peripheral nervous system. Distinct biophysical properties of Nav1.7, Nav1.8, and Nav1.9 underlie their differential contributions to finely tuned neuronal firing of nociceptors, and mutations in these channels have been associated with several inherited human pain disorders. Functional characterization of these mutations has provided additional insights into the role of these channels in electrogenesis in nociceptive neurons and pain sensation. Peripheral tissue damage activates an inflammatory response and triggers generation and release of inflammatory mediators, which can act through diverse signaling cascades to modulate expression and activity of ion channels including VGSCs, contributing to the development and maintenance of pathological pain conditions. In this review, we discuss signaling pathways that are activated by pro-nociceptive inflammatory mediators that regulate peripheral sodium channels, with a specific focus on direct phosphorylation of these channels by multiple protein kinases.
Collapse
|
13
|
Peigneur S, da Costa Oliveira C, de Sousa Fonseca FC, McMahon KL, Mueller A, Cheneval O, Cristina Nogueira Freitas A, Starobova H, Dimitri Gama Duarte I, Craik DJ, Vetter I, de Lima ME, Schroeder CI, Tytgat J. Small cyclic sodium channel inhibitors. Biochem Pharmacol 2020; 183:114291. [PMID: 33075312 DOI: 10.1016/j.bcp.2020.114291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/05/2020] [Accepted: 10/14/2020] [Indexed: 01/10/2023]
Abstract
Voltage-gated sodium (NaV) channels play crucial roles in a range of (patho)physiological processes. Much interest has arisen within the pharmaceutical industry to pursue these channels as analgesic targets following overwhelming evidence that NaV channel subtypes NaV1.7-NaV1.9 are involved in nociception. More recently, NaV1.1, NaV1.3 and NaV1.6 have also been identified to be involved in pain pathways. Venom-derived disulfide-rich peptide toxins, isolated from spiders and cone snails, have been used extensively as probes to investigate these channels and have attracted much interest as drug leads. However, few peptide-based leads have made it as drugs due to unfavourable physiochemical attributes including poor in vivo pharmacokinetics and limited oral bioavailability. The present work aims to bridge the gap in the development pipeline between drug leads and drug candidates by downsizing these larger venom-derived NaV inhibitors into smaller, more "drug-like" molecules. Here, we use molecular engineering of small cyclic peptides to aid in the determination of what drives subtype selectivity and molecular interactions of these downsized inhibitors across NaV subtypes. We designed a series of small, stable and novel NaV probes displaying NaV subtype selectivity and potency in vitro coupled with potent in vivo analgesic activity, involving yet to be elucidated analgesic pathways in addition to NaV subtype modulation.
Collapse
Affiliation(s)
- Steve Peigneur
- Toxicology and Pharmacology, Katholieke Universiteit (KU) Leuven, Campus Gasthuisberg, Leuven, Belgium; Department de Bioquímica e Imunologia, Laboratório de Venenos e Toxinas Animais, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo-Horizonte, Brazil
| | - Cristina da Costa Oliveira
- Department of Pharmacology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Flávia Cristina de Sousa Fonseca
- Department of Pharmacology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Kirsten L McMahon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Alexander Mueller
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Olivier Cheneval
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Ana Cristina Nogueira Freitas
- Department de Bioquímica e Imunologia, Laboratório de Venenos e Toxinas Animais, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo-Horizonte, Brazil
| | - Hana Starobova
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Igor Dimitri Gama Duarte
- Department of Pharmacology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld 4072, Australia; School of Pharmacy, The University of Queensland, Woolloongabba, Qld 4102, Australia
| | - Maria Elena de Lima
- Department de Bioquímica e Imunologia, Laboratório de Venenos e Toxinas Animais, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo-Horizonte, Brazil; Santa Casa de Belo Horizonte: Instituto de Ensino e Pesquisa, Brazil
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld 4072, Australia; National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA.
| | - Jan Tytgat
- Toxicology and Pharmacology, Katholieke Universiteit (KU) Leuven, Campus Gasthuisberg, Leuven, Belgium.
| |
Collapse
|
14
|
Zybura AS, Baucum AJ, Rush AM, Cummins TR, Hudmon A. CaMKII enhances voltage-gated sodium channel Nav1.6 activity and neuronal excitability. J Biol Chem 2020; 295:11845-11865. [PMID: 32611770 DOI: 10.1074/jbc.ra120.014062] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/30/2020] [Indexed: 11/06/2022] Open
Abstract
Nav1.6 is the primary voltage-gated sodium channel isoform expressed in mature axon initial segments and nodes, making it critical for initiation and propagation of neuronal impulses. Thus, Nav1.6 modulation and dysfunction may have profound effects on input-output properties of neurons in normal and pathological conditions. Phosphorylation is a powerful and reversible mechanism regulating ion channel function. Because Nav1.6 and the multifunctional Ca2+/CaM-dependent protein kinase II (CaMKII) are independently linked to excitability disorders, we sought to investigate modulation of Nav1.6 function by CaMKII signaling. We show that inhibition of CaMKII, a Ser/Thr protein kinase associated with excitability, synaptic plasticity, and excitability disorders, with the CaMKII-specific peptide inhibitor CN21 reduces transient and persistent currents in Nav1.6-expressing Purkinje neurons by 87%. Using whole-cell voltage clamp of Nav1.6, we show that CaMKII inhibition in ND7/23 and HEK293 cells significantly reduces transient and persistent currents by 72% and produces a 5.8-mV depolarizing shift in the voltage dependence of activation. Immobilized peptide arrays and nanoflow LC-electrospray ionization/MS of Nav1.6 reveal potential sites of CaMKII phosphorylation, specifically Ser-561 and Ser-641/Thr-642 within the first intracellular loop of the channel. Using site-directed mutagenesis to test multiple potential sites of phosphorylation, we show that Ala substitutions of Ser-561 and Ser-641/Thr-642 recapitulate the depolarizing shift in activation and reduction in current density. Computational simulations to model effects of CaMKII inhibition on Nav1.6 function demonstrate dramatic reductions in spontaneous and evoked action potentials in a Purkinje cell model, suggesting that CaMKII modulation of Nav1.6 may be a powerful mechanism to regulate neuronal excitability.
Collapse
Affiliation(s)
- Agnes S Zybura
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Anthony J Baucum
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Biology Department, Indiana University-Purdue University Indianapolis, School of Science, Indianapolis, Indiana, USA
| | | | - Theodore R Cummins
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Biology Department, Indiana University-Purdue University Indianapolis, School of Science, Indianapolis, Indiana, USA
| | - Andy Hudmon
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA .,Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, USA
| |
Collapse
|
15
|
Jang Y, Kim M, Hwang SW. Molecular mechanisms underlying the actions of arachidonic acid-derived prostaglandins on peripheral nociception. J Neuroinflammation 2020; 17:30. [PMID: 31969159 PMCID: PMC6975075 DOI: 10.1186/s12974-020-1703-1] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 01/06/2020] [Indexed: 12/30/2022] Open
Abstract
Arachidonic acid-derived prostaglandins not only contribute to the development of inflammation as intercellular pro-inflammatory mediators, but also promote the excitability of the peripheral somatosensory system, contributing to pain exacerbation. Peripheral tissues undergo many forms of diseases that are frequently accompanied by inflammation. The somatosensory nerves innervating the inflamed areas experience heightened excitability and generate and transmit pain signals. Extensive studies have been carried out to elucidate how prostaglandins play their roles for such signaling at the cellular and molecular levels. Here, we briefly summarize the roles of arachidonic acid-derived prostaglandins, focusing on four prostaglandins and one thromboxane, particularly in terms of their actions on afferent nociceptors. We discuss the biosynthesis of the prostaglandins, their specific action sites, the pathological alteration of the expression levels of related proteins, the neuronal outcomes of receptor stimulation, their correlation with behavioral nociception, and the pharmacological efficacy of their regulators. This overview will help to a better understanding of the pathological roles that prostaglandins play in the somatosensory system and to a finding of critical molecular contributors to normalizing pain.
Collapse
Affiliation(s)
- Yongwoo Jang
- Department of Psychiatry and Program in Neuroscience, McLean Hospital, Harvard Medical School, Belmont, MA, 02478, USA.,Department of Biomedical Engineering, Hanyang University, Seoul, 04763, South Korea
| | - Minseok Kim
- Department of Biomedical Sciences, Korea University, Seoul, 02841, South Korea
| | - Sun Wook Hwang
- Department of Biomedical Sciences, Korea University, Seoul, 02841, South Korea. .,Department of Physiology, College of Medicine, Korea University, Seoul, 02841, South Korea.
| |
Collapse
|
16
|
Cheng S, Rong Y, Ma M, Lin X, Liu X, Li C, Yang X, Chen S. Modulation on tetrodotoxin-resistant sodium current of loureirin B in rat dorsal root ganglion neurons via cyclic AMP-dependent protein kinase A. J Cell Biochem 2019; 121:1790-1800. [PMID: 31642099 DOI: 10.1002/jcb.29414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 10/08/2019] [Indexed: 12/23/2022]
Abstract
To search the modulation mechanism of loureirin B, a flavonoid is extracted from Dracaena cochinchinensis, on tetrodotoxin-resistant (TTX-R) sodium channel in dorsal root ganglion (DRG) neurons of rats. Experiments were carried out based on patch-clamp technique and molecular biological methods. We observed the time-dependent inhibition of loureirin B on TTX-R sodium currents in DRG neurons and found that neither occupancy theory nor rate theory could well explain the time-dependent inhibitory effect of loureirin B on TTX-R sodium currents. It suggested that a second messenger-mediated signaling pathway may be involved in the modulation mechanism. So the cyclin AMP (cAMP) level of the DRG neurons before and after incubation with loureirin B was tested by ELISA Kit. Results showed that loureirin B could increase the cAMP level and the increased cAMP was caused by the enhancement of adenylate cyclase (AC) induced by loureirin B. Immunolabelling experiments further confirmed that loureirin B can promote the production of PKA in DRG neurons. In the presence of the PKA inhibitor H-89, the inhibitory effect of loureirin B on TTX-R sodium currents was reversed. Forskolin, a tool in biochemistry to raise the levels of cAMP, also could reduce TTX-R sodium currents similar to that of loureirin B. These studies demonstrated that loureirin B can modulate the TTX-R sodium channel in DRG neurons via an AC/cAMP/PKA pathway involving the activation of AC and PKA, which also can be used to explain the other pharmacological effects of loureirin B.
Collapse
Affiliation(s)
- Song Cheng
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Wuhan, Hubei, China.,Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Wuhan, Hubei, China.,College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, Hubei, China
| | - Yi Rong
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Wuhan, Hubei, China.,Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Wuhan, Hubei, China.,College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, Hubei, China
| | - Minjie Ma
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Wuhan, Hubei, China.,Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Wuhan, Hubei, China.,College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, Hubei, China
| | - Xianguang Lin
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Wuhan, Hubei, China.,Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Wuhan, Hubei, China.,College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, Hubei, China
| | - Xiangming Liu
- Gong Qing Institute of Science and Technology, Jiujiang, Jiangxi, China
| | - Chenhong Li
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Wuhan, Hubei, China.,Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Wuhan, Hubei, China.,College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, Hubei, China
| | - Xiaofei Yang
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Wuhan, Hubei, China.,Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Wuhan, Hubei, China.,College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, Hubei, China
| | - Su Chen
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Wuhan, Hubei, China.,Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Wuhan, Hubei, China.,College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, Hubei, China
| |
Collapse
|
17
|
Crosson T, Roversi K, Balood M, Othman R, Ahmadi M, Wang JC, Seadi Pereira PJ, Tabatabaei M, Couture R, Eichwald T, Latini A, Prediger RD, Rangachari M, Seehus CR, Foster SL, Talbot S. Profiling of how nociceptor neurons detect danger - new and old foes. J Intern Med 2019; 286:268-289. [PMID: 31282104 DOI: 10.1111/joim.12957] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The host evolves redundant mechanisms to preserve physiological processing and homeostasis. These functions range from sensing internal and external threats, creating a memory of the insult and generating reflexes, which aim to resolve inflammation. Impairment in such functioning leads to chronic inflammatory diseases. By interacting through a common language of ligands and receptors, the immune and sensory nervous systems work in concert to accomplish such protective functions. Whilst this bidirectional communication helps to protect from danger, it can contribute to disease pathophysiology. Thus, the somatosensory nervous system is anatomically positioned within primary and secondary lymphoid tissues and mucosa to modulate immunity directly. Upstream of this interplay, neurons detect danger, which prompts the release of neuropeptides initiating (i) defensive reflexes (ranging from withdrawal response to coughing) and (ii) chemotaxis, adhesion and local infiltration of immune cells. The resulting outcome of such neuro-immune interplay is still ill-defined, but consensual findings start to emerge and support neuropeptides not only as blockers of TH 1-mediated immunity but also as drivers of TH 2 immune responses. However, the modalities detected by nociceptors revealed broader than mechanical pressure and temperature sensing and include signals as various as cytokines and pathogens to immunoglobulins and even microRNAs. Along these lines, we aggregated various dorsal root ganglion sensory neuron expression profiling datasets supporting such wide-ranging sensing capabilities to help identifying new danger detection modalities of these cells. Thus, revealing unexpected aspects of nociceptor neuron biology might prompt the identification of novel drivers of immunity, means to resolve inflammation and strategies to safeguard homeostasis.
Collapse
Affiliation(s)
- T Crosson
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - K Roversi
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.,Departamento de Farmacologia Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - M Balood
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.,Axe Neurosciences, Centre de recherche du CHU, Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - R Othman
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - M Ahmadi
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - J-C Wang
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.,Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | | | - M Tabatabaei
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - R Couture
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - T Eichwald
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - A Latini
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - R D Prediger
- Departamento de Farmacologia Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - M Rangachari
- Axe Neurosciences, Centre de recherche du CHU, Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - C R Seehus
- FM Kirby Neurobiology Center, Children's Hospital, Boston, MA, USA
| | - S L Foster
- Depression Clinical Research Program, Massachusetts General Hospital, Boston, MA, USA
| | - S Talbot
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| |
Collapse
|
18
|
Lee J, Kim S, Kim HM, Kim HJ, Yu FH. NaV1.6 and NaV1.7 channels are major endogenous voltage-gated sodium channels in ND7/23 cells. PLoS One 2019; 14:e0221156. [PMID: 31419255 PMCID: PMC6697327 DOI: 10.1371/journal.pone.0221156] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/31/2019] [Indexed: 01/02/2023] Open
Abstract
ND7/23 cells are gaining traction as a host model to express peripheral sodium channels such as NaV1.8 and NaV1.9 that have been difficult to express in widely utilized heterologous cells, like CHO and HEK293. Use of ND7/23 as a model cell to characterize the properties of sodium channels requires clear understanding of the endogenous ion channels. To define the nature of the background sodium currents in ND7/23 cells, we aimed to comprehensively profile the voltage-gated sodium channel subunits by endpoint and quantitative reverse transcription-PCR and by whole-cell patch clamp electrophysiology. We found that untransfected ND7/23 cells express endogenous peak sodium currents that average -2.12nA (n = 15) and with kinetics typical of fast sodium currents having activation and inactivation completed within few milliseconds. Furthermore, sodium currents were reduced to virtually nil upon exposure to 100nM tetrodotoxin, indicating that ND7/23 cells have essentially null background for tetrodotoxin-resistant (TTX-R) currents. qRT-PCR profiling indicated a major expression of TTX-sensitive (TTX-S) NaV1.6 and NaV1.7 at similar levels and very low expression of TTX-R NaV1.9 transcripts. There was no expression of TTX-R NaV1.8 in ND7/23 cells. There was low expression of NaV1.1, NaV1.2, NaV1.3 and no expression of cardiac or skeletal muscle sodium channels. As for the sodium channel auxiliary subunits, β1 and β3 subunits were expressed, but not the β2 and β4 subunits that covalently associate with the α-subunits. In addition, our results also showed that only the mouse forms of NaV1.6, NaV1.7 and NaV1.9 sodium channels were expressed in ND7/23 cells that was originally generated as a hybridoma of rat embryonic DRG and mouse neuroblastoma cell-line. By molecular profiling of auxiliary β- and principal α-subunits of the voltage gated sodium channel complex, our results define the background sodium channels expressed in ND7/23 cells, and confirm their utility for detailed functional studies of emerging pain channelopathies ascribed to mutations of the TTX-R sodium channels of sensory neurons.
Collapse
Affiliation(s)
- Jisoo Lee
- Department of Pharmacology and Dental Therapeutics, Program in Neurobiology, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - Shinae Kim
- Department of Pharmacology and Dental Therapeutics, Program in Neurobiology, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - Hye-mi Kim
- Department of Pharmacology and Dental Therapeutics, Program in Neurobiology, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - Hyun Jeong Kim
- Department of Dental Anesthesiology, Program in Neurobiology, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - Frank H. Yu
- Department of Pharmacology and Dental Therapeutics, Program in Neurobiology, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea
- * E-mail:
| |
Collapse
|
19
|
Bennett DL, Clark AJ, Huang J, Waxman SG, Dib-Hajj SD. The Role of Voltage-Gated Sodium Channels in Pain Signaling. Physiol Rev 2019; 99:1079-1151. [DOI: 10.1152/physrev.00052.2017] [Citation(s) in RCA: 256] [Impact Index Per Article: 51.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Acute pain signaling has a key protective role and is highly evolutionarily conserved. Chronic pain, however, is maladaptive, occurring as a consequence of injury and disease, and is associated with sensitization of the somatosensory nervous system. Primary sensory neurons are involved in both of these processes, and the recent advances in understanding sensory transduction and human genetics are the focus of this review. Voltage-gated sodium channels (VGSCs) are important determinants of sensory neuron excitability: they are essential for the initial transduction of sensory stimuli, the electrogenesis of the action potential, and neurotransmitter release from sensory neuron terminals. Nav1.1, Nav1.6, Nav1.7, Nav1.8, and Nav1.9 are all expressed by adult sensory neurons. The biophysical characteristics of these channels, as well as their unique expression patterns within subtypes of sensory neurons, define their functional role in pain signaling. Changes in the expression of VGSCs, as well as posttranslational modifications, contribute to the sensitization of sensory neurons in chronic pain states. Furthermore, gene variants in Nav1.7, Nav1.8, and Nav1.9 have now been linked to human Mendelian pain disorders and more recently to common pain disorders such as small-fiber neuropathy. Chronic pain affects one in five of the general population. Given the poor efficacy of current analgesics, the selective expression of particular VGSCs in sensory neurons makes these attractive targets for drug discovery. The increasing availability of gene sequencing, combined with structural modeling and electrophysiological analysis of gene variants, also provides the opportunity to better target existing therapies in a personalized manner.
Collapse
Affiliation(s)
- David L. Bennett
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Alex J. Clark
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Jianying Huang
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Stephen G. Waxman
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Sulayman D. Dib-Hajj
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| |
Collapse
|
20
|
Hameed S. Na v1.7 and Na v1.8: Role in the pathophysiology of pain. Mol Pain 2019; 15:1744806919858801. [PMID: 31172839 PMCID: PMC6589956 DOI: 10.1177/1744806919858801] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/25/2019] [Accepted: 05/30/2019] [Indexed: 01/25/2023] Open
Abstract
Chronic pain is a significant unmet medical problem. Current research regarding sodium channel function in pathological pain is advancing with the hope that it will enable the development of isoform-specific sodium channel blockers, a promising treatment for chronic pain. Before advancements in the pharmacological field, an elucidation of the roles of Nav1.7 and Nav1.8 in the pathophysiology of pain states is required. Thus, the aim of this report is to present what is currently known about the contributions of these sodium channel subtypes in the pathophysiology of neuropathic and inflammatory pain. The electrophysiological properties and localisation of sodium channel isoforms is discussed. Research concerning the genetic links of Nav1.7 and Nav1.8 in acquired neuropathic and inflammatory pain states from the scientific literature in this field is reported. The role of Nav1.7 and Nav1.8 in the generation and maintenance of abnormal neuronal electrogenesis and hyperexcitability highlights the importance of these channels in the development of pathological pain. However, further research in this area is required to fully elucidate the roles of Nav1.7 and Nav1.8 in the pathophysiology of pain for the development of subtype-specific sodium channel blockers.
Collapse
Affiliation(s)
- Shaila Hameed
- Department of Physiology, King’s College London, London, UK
| |
Collapse
|
21
|
Black BJ, Atmaramani R, Plagens S, Campbell ZT, Dussor G, Price TJ, Pancrazio JJ. Emerging neurotechnology for antinoceptive mechanisms and therapeutics discovery. Biosens Bioelectron 2018; 126:679-689. [PMID: 30544081 DOI: 10.1016/j.bios.2018.11.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 11/01/2018] [Accepted: 11/10/2018] [Indexed: 12/20/2022]
Abstract
The tolerance, abuse, and potential exacerbation associated with classical chronic pain medications such as opioids creates a need for alternative therapeutics. Phenotypic screening provides a complementary approach to traditional target-based drug discovery. Profiling cellular phenotypes enables quantification of physiologically relevant traits central to a disease pathology without prior identification of a specific drug target. For complex disorders such as chronic pain, which likely involves many molecular targets, this approach may identify novel treatments. Sensory neurons, termed nociceptors, are derived from dorsal root ganglia (DRG) and can undergo changes in membrane excitability during chronic pain. In this review, we describe phenotypic screening paradigms that make use of nociceptor electrophysiology. The purpose of this paper is to review the bioelectrical behavior of DRG neurons, signaling complexity in sensory neurons, various sensory neuron models, assays for bioelectrical behavior, and emerging efforts to leverage microfabrication and microfluidics for assay development. We discuss limitations and advantages of these various approaches and offer perspectives on opportunities for future development.
Collapse
Affiliation(s)
- Bryan J Black
- Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA.
| | - Rahul Atmaramani
- Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Sarah Plagens
- Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Zachary T Campbell
- Department of Biological Sciences, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Gregory Dussor
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Theodore J Price
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA
| | - Joseph J Pancrazio
- Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA
| |
Collapse
|
22
|
Cardoso FC, Lewis RJ. Sodium channels and pain: from toxins to therapies. Br J Pharmacol 2018; 175:2138-2157. [PMID: 28749537 PMCID: PMC5980290 DOI: 10.1111/bph.13962] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/11/2017] [Accepted: 07/17/2017] [Indexed: 12/16/2022] Open
Abstract
Voltage-gated sodium channels (NaV channels) are essential for the initiation and propagation of action potentials that critically influence our ability to respond to a diverse range of stimuli. Physiological and pharmacological studies have linked abnormal function of NaV channels to many human disorders, including chronic neuropathic pain. These findings, along with the description of the functional properties and expression pattern of NaV channel subtypes, are helping to uncover subtype specific roles in acute and chronic pain and revealing potential opportunities to target these with selective inhibitors. High-throughput screens and automated electrophysiology platforms have identified natural toxins as a promising group of molecules for the development of target-specific analgesics. In this review, the role of toxins in defining the contribution of NaV channels in acute and chronic pain states and their potential to be used as analgesic therapies are discussed. LINKED ARTICLES This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.
Collapse
Affiliation(s)
- Fernanda C Cardoso
- Department of Chemistry and Structural Biology, Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLDAustralia
| | - Richard J Lewis
- Department of Chemistry and Structural Biology, Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLDAustralia
| |
Collapse
|
23
|
Tsantoulas C, Laínez S, Wong S, Mehta I, Vilar B, McNaughton PA. Hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) ion channels drive pain in mouse models of diabetic neuropathy. Sci Transl Med 2018; 9:eaam6072. [PMID: 28954930 DOI: 10.1126/scitranslmed.aam6072] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/22/2017] [Accepted: 09/06/2017] [Indexed: 01/12/2023]
Abstract
Diabetic patients frequently suffer from continuous pain that is poorly treated by currently available analgesics. We used mouse models of type 1 and type 2 diabetes to investigate a possible role for the hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) ion channels as drivers of diabetic pain. Blocking or genetically deleting HCN2 channels in small nociceptive neurons suppressed diabetes-associated mechanical allodynia and prevented neuronal activation of second-order neurons in the spinal cord in mice. In addition, we found that intracellular cyclic adenosine monophosphate (cAMP), a positive HCN2 modulator, is increased in somatosensory neurons in an animal model of painful diabetes. We propose that the increased intracellular cAMP drives diabetes-associated pain by facilitating HCN2 activation and consequently promoting repetitive firing in primary nociceptive nerve fibers. Our results suggest that HCN2 may be an analgesic target in the treatment of painful diabetic neuropathy.
Collapse
Affiliation(s)
- Christoforos Tsantoulas
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London Bridge, London SE1 1UL, UK
| | - Sergio Laínez
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London Bridge, London SE1 1UL, UK
| | - Sara Wong
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London Bridge, London SE1 1UL, UK
| | - Ishita Mehta
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London Bridge, London SE1 1UL, UK
| | - Bruno Vilar
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London Bridge, London SE1 1UL, UK
| | - Peter A McNaughton
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London Bridge, London SE1 1UL, UK.
| |
Collapse
|
24
|
Protein kinase A regulates inflammatory pain sensitization by modulating HCN2 channel activity in nociceptive sensory neurons. Pain 2018; 158:2012-2024. [PMID: 28767511 DOI: 10.1097/j.pain.0000000000001005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Several studies implicated cyclic adenosine monophosphate (cAMP) as an important second messenger for regulating nociceptor sensitization, but downstream targets of this signaling pathway which contribute to neuronal plasticity are not well understood. We used a Cre/loxP-based strategy to disable the function of either HCN2 or PKA selectively in a subset of peripheral nociceptive neurons and analyzed the nociceptive responses in both transgenic lines. A near-complete lack of sensitization was observed in both mutant strains when peripheral inflammation was induced by an intradermal injection of 8br-cAMP. The lack of HCN2 as well as the inhibition of PKA eliminated the cAMP-mediated increase of calcium transients in dorsal root ganglion neurons. Facilitation of Ih via cAMP, a hallmark of the Ih current, was abolished in neurons without PKA activity. Collectively, these results show a significant contribution of both genes to inflammatory pain and suggest that PKA-dependent activation of HCN2 underlies cAMP-triggered neuronal sensitization.
Collapse
|
25
|
Gi-DREADD Expression in Peripheral Nerves Produces Ligand-Dependent Analgesia, as well as Ligand-Independent Functional Changes in Sensory Neurons. J Neurosci 2017; 36:10769-10781. [PMID: 27798132 DOI: 10.1523/jneurosci.3480-15.2016] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 08/23/2016] [Indexed: 12/22/2022] Open
Abstract
Designer receptors exclusively activated by designer drugs (DREADDs) are an advanced experimental tool that could potentially provide a novel approach to pain management. In particular, expression of an inhibitory (Gi-coupled) DREADD in nociceptors might enable ligand-dependent analgesia. To test this possibility, TRPV1-cre mice were used to restrict expression of Gi-DREADDs to predominantly C-fibers. Whereas baseline heat thresholds in both male and female mice expressing Gi-DREADD were normal, 1 mg/kg clozapine-N-oxide (CNO) produced a significant 3 h increase in heat threshold that returned to baseline by 5 h after injection. Consistent with these behavioral results, CNO decreased action potential firing in isolated sensory neurons from Gi-DREADD mice. Unexpectedly, however, the expression of Gi-DREADD in sensory neurons caused significant changes in voltage-gated Ca2+ and Na+ currents in the absence of CNO, as well as an increase in Na+ channel (NaV1.7) expression. Furthermore, CNO-independent excitatory and inhibitory second-messenger signaling was also altered in these mice, which was associated with a decrease in the analgesic effect of endogenous inhibitory G-protein-coupled receptor activation. These results highlight the potential of this exciting technology, but also its limitations, and that it is essential to identify the underlying mechanisms for any observed behavioral phenotypes. SIGNIFICANCE STATEMENT DREADD technology is a powerful tool enabling manipulation of activity and/or transmitter release from targeted cell populations. The purpose of this study was to determine whether inhibitory DREADDs in nociceptive afferents could be used to produce analgesia, and if so, how. DREADD activation produced a ligand-dependent analgesia to heat in vivo and a decrease in neuronal firing at the single-cell level. However, we observed that expression of Gi-DREADD also causes ligand-independent changes in ion channel activity and second-messenger signaling. These findings highlight both the potential and the limitations of this exciting technology as well as the necessity to identify the mechanisms underlying any observed phenotype.
Collapse
|
26
|
Isensee J, Schild C, Schwede F, Hucho T. Crosstalk from cAMP to ERK1/2 emerges during postnatal maturation of nociceptive neurons and is maintained during aging. J Cell Sci 2017; 130:2134-2146. [PMID: 28515230 DOI: 10.1242/jcs.197327] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 05/10/2017] [Indexed: 02/02/2023] Open
Abstract
Maturation of nociceptive neurons depends on changes in transcription factors, ion channels and neuropeptides. Mature nociceptors initiate pain in part by drastically reducing the activation threshold via intracellular sensitization signaling. Whether sensitization signaling also changes during development and aging remains so far unknown. Using a novel automated microscopy approach, we quantified changes in intracellular signaling protein expression and in their signaling dynamics, as well as changes in intracellular signaling cascade wiring, in sensory neurons from newborn to senescent (24 months of age) rats. We found that nociceptive subgroups defined by the signaling components protein kinase A (PKA)-RIIβ (also known as PRKAR2B) and CaMKIIα (also known as CAMK2A) developed at around postnatal day 10, the time of nociceptor maturation. The integrative nociceptor marker, PKA-RIIβ, allowed subgroup segregation earlier than could be achieved by assessing the classical markers TRPV1 and Nav1.8 (also known as SCN10A). Signaling kinetics remained constant over lifetime despite in part strong changes in the expression levels. Strikingly, we found a mechanism important for neuronal memory - i.e. the crosstalk from cAMP and PKA to ERK1 and ERK2 (ERK1/2, also known as MAPK3 and MAPK1, respectively) - to emerge postnatally. Thus, maturation of nociceptors is closely accompanied by altered expression, activation and connectivity of signaling pathways known to be central for pain sensitization and neuronal memory formation.
Collapse
Affiliation(s)
- Joerg Isensee
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, Cologne D-50931, Germany
| | - Cosimo Schild
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, Cologne D-50931, Germany
| | - Frank Schwede
- BIOLOG Life Science Institute, Flughafendamm 9A, Bremen D-28199, Germany
| | - Tim Hucho
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, Cologne D-50931, Germany
| |
Collapse
|
27
|
Isensee J, Krahé L, Moeller K, Pereira V, Sexton JE, Sun X, Emery E, Wood JN, Hucho T. Synergistic regulation of serotonin and opioid signaling contributes to pain insensitivity in Nav1.7 knockout mice. Sci Signal 2017; 10:10/461/eaah4874. [PMID: 28074005 DOI: 10.1126/scisignal.aah4874] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Genetic loss of the voltage-gated sodium channel Nav1.7 (Nav1.7-/-) results in lifelong insensitivity to pain in mice and humans. One underlying cause is an increase in the production of endogenous opioids in sensory neurons. We analyzed whether Nav1.7 deficiency altered nociceptive heterotrimeric guanine nucleotide-binding protein-coupled receptor (GPCR) signaling, such as initiated by GPCRs that respond to serotonin (pronociceptive) or opioids (antinociceptive), in sensory neurons. We found that the nociceptive neurons of Nav1.7 knockout (Nav1.7-/-) mice, but not those of Nav1.8 knockout (Nav1.8-/-) mice, exhibited decreased pronociceptive serotonergic signaling through the 5-HT4 receptors, which are Gαs-coupled GPCRs that stimulate the production of cyclic adenosine monophosphate resulting in protein kinase A (PKA) activity, as well as reduced abundance of the RIIβ regulatory subunit of PKA. Simultaneously, the efficacy of antinociceptive opioid signaling mediated by the Gαi-coupled mu opioid receptors was increased. Consequently, opioids inhibited more efficiently tetrodotoxin-resistant sodium currents, which are important for pain-initiating neuronal activity in nociceptive neurons. Thus, Nav1.7 controls the efficacy and balance of GPCR-mediated pro- and antinociceptive intracellular signaling, such that without Nav1.7, the balance is shifted toward antinociception, resulting in lifelong endogenous analgesia.
Collapse
Affiliation(s)
- Jörg Isensee
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, 50931 Cologne, Germany.
| | - Leonhardt Krahé
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, 50931 Cologne, Germany
| | - Katharina Moeller
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, 50931 Cologne, Germany
| | - Vanessa Pereira
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Jane E Sexton
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Xiaohui Sun
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Edward Emery
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Tim Hucho
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, 50931 Cologne, Germany.
| |
Collapse
|
28
|
Cornelison LE, Hawkins JL, Durham PL. Elevated levels of calcitonin gene-related peptide in upper spinal cord promotes sensitization of primary trigeminal nociceptive neurons. Neuroscience 2016; 339:491-501. [PMID: 27746346 DOI: 10.1016/j.neuroscience.2016.10.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 09/27/2016] [Accepted: 10/03/2016] [Indexed: 01/08/2023]
Abstract
Orofacial pain conditions including temporomandibular disorder (TMD) and migraine are characterized by peripheral and central sensitization of trigeminal nociceptive neurons. The goal of this study was to investigate the role of calcitonin gene-related peptide (CGRP) in promoting bidirectional signaling within the trigeminal system to mediate sensitization of primary nociceptive neurons. Adult male Sprague-Dawley rats were injected intercisternally with CGRP or co-injected with the receptor antagonist CGRP8-37 or KT 5720, a protein kinase A (PKA) inhibitor. Nocifensive head withdrawal response to mechanical stimulation was investigated using von Frey filaments. Expression of PKA, glial fibrillary acidic protein (GFAP), and ionized calcium-binding adapter molecule 1 (Iba1) in the spinal cord and phosphorylated extracellular signal-regulated kinase (P-ERK) in the ganglion was studied using immunohistochemistry. Some animals were co-injected with CGRP and Fast Blue dye and the ganglion was imaged using fluorescent microscopy. CGRP increased nocifensive responses to mechanical stimulation when compared to control. Co-injection of CGRP8-37 or KT 5720 with CGRP inhibited the nocifensive response. CGRP stimulated PKA and GFAP expression in the spinal cord, and P-ERK in ganglion neurons. Seven days post injection, Fast Blue was observed in ganglion neurons and satellite glial cells. Our results demonstrate that elevated levels of CGRP in the upper spinal cord promote sensitization of primary nociceptive neurons via a mechanism that involves activation of PKA centrally and P-ERK in ganglion neurons. Our findings provide evidence of bidirectional signaling within the trigeminal system that facilitate increased neuron-glia communication within the ganglion associated with trigeminal sensitization.
Collapse
Affiliation(s)
- Lauren E Cornelison
- Center for Biomedical and Life Sciences, Missouri State University, Springfield, MO, USA
| | - Jordan L Hawkins
- Center for Biomedical and Life Sciences, Missouri State University, Springfield, MO, USA
| | - Paul L Durham
- Center for Biomedical and Life Sciences, Missouri State University, Springfield, MO, USA.
| |
Collapse
|
29
|
Luiz AP, Wood JN. Sodium Channels in Pain and Cancer: New Therapeutic Opportunities. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 75:153-78. [PMID: 26920012 DOI: 10.1016/bs.apha.2015.12.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Voltage-gated sodium channels (VGSCs) underpin electrical activity in the nervous system through action potential propagation. First predicted by the modeling studies of Hodgkin and Huxley, they were subsequently identified at the molecular level by groups led by Catterall and Numa. VGSC dysfunction has long been linked to neuronal and cardiac disorders with some nonselective sodium channel blockers in current use in the clinic. The lack of selectivity means that side effect issues are a major impediment to the use of broad spectrum sodium channel blockers. Nine different sodium channels are known to exist, and selective blockers are now being developed. The potential utility of these drugs to target diseases ranging from migraine, multiple sclerosis, muscle, and immune system disorders, to cancer and pain is being explored. Four channels are potential targets for pain disorders. This conclusion comes from mouse knockout studies and human mutations that prove the involvement of Nav1.3, Nav1.7, Nav1.8, and Nav1.9 in the development and maintenance of acute and chronic pain. In this chapter, we present a short overview of the possible role of Nav1.3, Nav1.7, Nav1.8, and Nav1.9 in human pain and the emerging and unexpected role of sodium channels in cancer pathogenesis.
Collapse
Affiliation(s)
- Ana Paula Luiz
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom.
| |
Collapse
|
30
|
Laedermann CJ, Abriel H, Decosterd I. Post-translational modifications of voltage-gated sodium channels in chronic pain syndromes. Front Pharmacol 2015; 6:263. [PMID: 26594175 PMCID: PMC4633509 DOI: 10.3389/fphar.2015.00263] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/23/2015] [Indexed: 02/06/2023] Open
Abstract
In the peripheral sensory nervous system the neuronal expression of voltage-gated sodium channels (Navs) is very important for the transmission of nociceptive information since they give rise to the upstroke of the action potential (AP). Navs are composed of nine different isoforms with distinct biophysical properties. Studying the mutations associated with the increase or absence of pain sensitivity in humans, as well as other expression studies, have highlighted Nav1.7, Nav1.8, and Nav1.9 as being the most important contributors to the control of nociceptive neuronal electrogenesis. Modulating their expression and/or function can impact the shape of the AP and consequently modify nociceptive transmission, a process that is observed in persistent pain conditions. Post-translational modification (PTM) of Navs is a well-known process that modifies their expression and function. In chronic pain syndromes, the release of inflammatory molecules into the direct environment of dorsal root ganglia (DRG) sensory neurons leads to an abnormal activation of enzymes that induce Navs PTM. The addition of small molecules, i.e., peptides, phosphoryl groups, ubiquitin moieties and/or carbohydrates, can modify the function of Navs in two different ways: via direct physical interference with Nav gating, or via the control of Nav trafficking. Both mechanisms have a profound impact on neuronal excitability. In this review we will discuss the role of Protein Kinase A, B, and C, Mitogen Activated Protein Kinases and Ca++/Calmodulin-dependent Kinase II in peripheral chronic pain syndromes. We will also discuss more recent findings that the ubiquitination of Nav1.7 by Nedd4-2 and the effect of methylglyoxal on Nav1.8 are also implicated in the development of experimental neuropathic pain. We will address the potential roles of other PTMs in chronic pain and highlight the need for further investigation of PTMs of Navs in order to develop new pharmacological tools to alleviate pain.
Collapse
Affiliation(s)
- Cedric J. Laedermann
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Harvard Medical School, BostonMA, USA
| | - Hugues Abriel
- Department of Clinical Research, University of BernBern, Switzerland
| | - Isabelle Decosterd
- Pain Center, Department of Anesthesiology, Lausanne University Hospital (CHUV) and University of LausanneLausanne, Switzerland
- Department of Fundamental Neurosciences, University of LausanneLausanne, Switzerland
| |
Collapse
|
31
|
Schirmeyer J, Szafranski K, Leipold E, Mawrin C, Platzer M, Heinemann SH. Exon 11 skipping of SCN10A coding for voltage-gated sodium channels in dorsal root ganglia. Channels (Austin) 2015; 8:210-5. [PMID: 24763188 DOI: 10.4161/chan.28146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The voltage-gated sodium channel Na(V)1.8 (encoded by SCN10A) is predominantly expressed in dorsal root ganglia(DRG) and plays a critical role in pain perception. We analyzed SCN10A transcripts isolated from human DRGs using deep sequencing and found a novel splice variant lacking exon 11, which codes for 98 amino acids of the domain I/II linker. Quantitative PCR analysis revealed an abundance of this variant of up to 5–10% in human, while no such variants were detected in mouse or rat. Since no obvious functional differences between channels with and without the exon-11 sequence were detected, it is suggested that SCN10A exon 11 skipping in humans is a tolerated event.
Collapse
|
32
|
Huang WY, Dai SP, Chang YC, Sun WH. Acidosis Mediates the Switching of Gs-PKA and Gi-PKCε Dependence in Prolonged Hyperalgesia Induced by Inflammation. PLoS One 2015; 10:e0125022. [PMID: 25933021 PMCID: PMC4416776 DOI: 10.1371/journal.pone.0125022] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 03/19/2015] [Indexed: 12/27/2022] Open
Abstract
Chronic inflammatory pain, when not effectively treated, is a costly health problem and has a harmful effect on all aspects of health-related quality of life. Previous studies suggested that in male Sprague Dawley rats, prostaglandin E2 (PGE2)-induced short-term hyperalgesia depends on protein kinase A (PKA) activity, whereas long-lasting hyperalgesia induced by PGE2 with carrageenan pre-injection, requires protein kinase Cε (PKCε). However, the mechanism underlying the kinase switch with short- to long-term hyperalgesia remains unclear. In this study, we used the inflammatory agents carrageenan or complete Freund's adjuvant (CFA) to induce long-term hyperalgesia, and examined PKA and PKCε dependence and switching time. Hyperalgesia induced by both agents depended on PKA/PKCε and Gs/Gi-proteins, and the switching time from PKA to PKCε and from Gs to Gi was about 3 to 4 h after inflammation induction. Among the single inflammatory mediators tested, PGE2 and 5-HT induced transient hyperalgesia, which depended on PKA and PKCε, respectively. Only acidic solution-induced hyperalgesia required Gs-PKA and Gi-PKCε, and the switch time for kinase dependency matched inflammatory hyperalgesia, in approximately 2 to 4 h. Thus, acidosis in inflamed tissues may be a decisive factor to regulate switching of PKA and PKCε dependence via proton-sensing G-protein-coupled receptors.
Collapse
Affiliation(s)
- Wei-Yu Huang
- Department of Life Sciences, National Central University, Jhongli, Taiwan
| | - Shih-Ping Dai
- Department of Life Sciences, National Central University, Jhongli, Taiwan
| | - Yan-Ching Chang
- Department of Life Sciences, National Central University, Jhongli, Taiwan
| | - Wei-Hsin Sun
- Department of Life Sciences, National Central University, Jhongli, Taiwan
- Institute of Systems Biology & Bioinformatics, National Central University, Jhongli, Taiwan
- * E-mail:
| |
Collapse
|
33
|
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.
Collapse
Affiliation(s)
- Craig M Bullock
- University of Nottingham, Nottingham, UK, and University of Nottingham, Sutton Bonington Campus, Sutton Bonington, UK
| | | | | | | | | | | |
Collapse
|
34
|
The five “Ws” for bone pain due to the administration of granulocyte-colony stimulating factors (G-CSFs). Crit Rev Oncol Hematol 2014; 89:112-28. [DOI: 10.1016/j.critrevonc.2013.08.006] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 07/26/2013] [Accepted: 08/13/2013] [Indexed: 11/21/2022] Open
|
35
|
Abstract
The pseudounipolar sensory neurons of the dorsal root ganglia (DRG) give rise to peripheral branches that convert thermal, mechanical, and chemical stimuli into electrical signals that are transmitted via central branches to the spinal cord. These neurons express unique combinations of tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) Na(+) channels that contribute to the resting membrane potential, action potential threshold, and regulate neuronal firing frequency. The small-diameter neurons (<25 μm) isolated from the DRG represent the cell bodies of C-fiber nociceptors that express both TTX-S and TTX-R Na(+) currents. The large-diameter neurons (>35 μm) are typically low-threshold A-fibers that predominately express TTX-S Na(+) currents. Peripheral nerve damage, inflammation, and metabolic diseases alter the expression and function of these Na(+) channels leading to increases in neuronal excitability and pain. The Na(+) channels expressed in these neurons are the target of intracellular signaling cascades that regulate the trafficking, cell surface expression, and gating properties of these channels. Post-translational regulation of Na(+) channels by protein kinases (PKA, PKC, MAPK) alter the expression and function of the channels. Injury-induced changes in these signaling pathways have been linked to sensory neuron hyperexcitability and pain. This review examines the signaling pathways and regulatory mechanisms that modulate the voltage-gated Na(+) channels of sensory neurons.
Collapse
Affiliation(s)
- Mohamed Chahine
- Centre de recherche, Institut en santé mentale de Québec, Local F-6539, 2601, chemin de la Canardière, QC City, QC, Canada, G1J 2G3,
| | | |
Collapse
|
36
|
Galbavy W, Safaie E, Rebecchi MJ, Puopolo M. Inhibition of tetrodotoxin-resistant sodium current in dorsal root ganglia neurons mediated by D1/D5 dopamine receptors. Mol Pain 2013; 9:60. [PMID: 24283218 PMCID: PMC4220807 DOI: 10.1186/1744-8069-9-60] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 11/22/2013] [Indexed: 12/25/2022] Open
Abstract
Background Dopaminergic fibers originating from area A11 of the hypothalamus project to different levels of the spinal cord and represent the major source of dopamine. In addition, tyrosine hydroxylase, the rate-limiting enzyme for the synthesis of catecholamines, is expressed in 8-10% of dorsal root ganglia (DRG) neurons, suggesting that dopamine may be released in the dorsal root ganglia. Dopamine has been shown to modulate calcium current in DRG neurons, but the effects of dopamine on sodium current and on the firing properties of small DRG neurons are poorly understood. Results The effects of dopamine and dopamine receptor agonists were tested on the tetrodotoxin-resistant (TTX-R) sodium current recorded from acutely dissociated small (diameter ≤ 25 μm) DRG neurons. Dopamine (20 μM) and SKF 81297 (10 μM) caused inhibition of TTX-R sodium current in small DRG neurons by 23% and 37%, respectively. In contrast, quinpirole (20 μM) had no effects on the TTX-R sodium current. Inhibition by SKF 81297 of the TTX-R sodium current was not affected when the protein kinase A (PKA) activity was blocked with the PKA inhibitory peptide (6–22), but was greatly reduced when the protein kinase C (PKC) activity was blocked with the PKC inhibitory peptide (19–36), suggesting that activation of D1/D5 dopamine receptors is linked to PKC activity. Expression of D1and D5 dopamine receptors in small DRG neurons, but not D2 dopamine receptors, was confirmed by Western blotting and immunofluorescence analysis. In current clamp experiments, the number of action potentials elicited in small DRG neurons by current injection was reduced by ~ 30% by SKF 81297. Conclusions We conclude that activation of D1/D5 dopamine receptors inhibits TTX-R sodium current in unmyelinated nociceptive neurons and dampens their intrinsic excitability by reducing the number of action potentials in response to stimulus. Increasing or decreasing levels of dopamine in the dorsal root ganglia may serve to adjust the sensitivity of nociceptors to noxious stimuli.
Collapse
Affiliation(s)
| | | | | | - Michelino Puopolo
- Department of Anesthesiology, Stony Brook Medicine, Stony Brook, NY 11794, USA.
| |
Collapse
|
37
|
Isensee J, Diskar M, Waldherr S, Buschow R, Hasenauer J, Prinz A, Allgöwer F, Herberg FW, Hucho T. Pain modulators regulate the dynamics of PKA-RII phosphorylation in subgroups of sensory neurons. J Cell Sci 2013; 127:216-29. [PMID: 24190886 DOI: 10.1242/jcs.136580] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Knowledge about the molecular structure of protein kinase A (PKA) isoforms is substantial. In contrast, the dynamics of PKA isoform activity in living primary cells has not been investigated in detail. Using a high content screening microscopy approach, we identified the RIIβ subunit of PKA-II to be predominantly expressed in a subgroup of sensory neurons. The RIIβ-positive subgroup included most neurons expressing nociceptive markers (TRPV1, NaV1.8, CGRP, IB4) and responded to pain-eliciting capsaicin with calcium influx. Isoform-specific PKA reporters showed in sensory-neuron-derived F11 cells that the inflammatory mediator PGE₂ specifically activated PKA-II but not PKA-I. Accordingly, pain-sensitizing inflammatory mediators and activators of PKA increased the phosphorylation of RII subunits (pRII) in subgroups of primary sensory neurons. Detailed analyses revealed basal pRII to be regulated by the phosphatase PP2A. Increase of pRII was followed by phosphorylation of CREB in a PKA-dependent manner. Thus, we propose RII phosphorylation to represent an isoform-specific readout for endogenous PKA-II activity in vivo, suggest RIIβ as a novel nociceptive subgroup marker, and extend the current model of PKA-II activation by introducing a PP2A-dependent basal state.
Collapse
Affiliation(s)
- Joerg Isensee
- University Hospital Cologne, Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, Robert Koch Str. 10, 50931 Cologne, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Cady RJ, Denson JE, Durham PL. Inclusion of cocoa as a dietary supplement represses expression of inflammatory proteins in spinal trigeminal nucleus in response to chronic trigeminal nerve stimulation. Mol Nutr Food Res 2013; 57:996-1006. [PMID: 23576361 PMCID: PMC3777559 DOI: 10.1002/mnfr.201200630] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 01/14/2013] [Accepted: 01/15/2013] [Indexed: 12/19/2022]
Abstract
SCOPE Central sensitization is implicated in the pathology of temporomandibular joint disorder and other types of orofacial pain. We investigated the effects of dietary cocoa on expression of proteins involved in the development of central sensitization in the spinal trigeminal nucleus (STN) in response to inflammatory stimulation of trigeminal nerves. METHODS AND RESULTS Male Sprague-Dawley rats were fed either a control diet or an isocaloric diet consisting of 10% cocoa powder 14 days prior to bilateral injection of complete Freund's adjuvant (CFA) into the temporomandibular joint to promote prolonged activation of trigeminal ganglion neurons and glia. While dietary cocoa stimulated basal expression of glutamate-aspartate transporter and mitogen-activated protein kinase phosphatase-1 when compared to animals on a normal diet, cocoa suppressed basal calcitonin gene-related peptide levels in the STN. CFA-stimulated levels of protein kinase A, P2X3 , P-p38, glial fibrillary-associated protein, and OX-42, whose elevated levels in the STN are implicated in central sensitization, were repressed to near control levels in animals on a cocoa-enriched diet. Similarly, dietary cocoa repressed CFA-stimulated inflammatory cytokine expression. CONCLUSION Based on our findings, we speculate that cocoa-enriched diets could be beneficial as a natural therapeutic option for temporomandibular joint disorder and other chronic orofacial pain conditions.
Collapse
Affiliation(s)
- Ryan J Cady
- Center for Biomedical & Life Sciences, Missouri State University, Springfield, MO 65806, USA
| | | | | |
Collapse
|
39
|
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.
Collapse
Affiliation(s)
- Gábor Petho
- Pharmacodynamics Unit, Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Pécs, Pécs, Hungary
| | | |
Collapse
|
40
|
Qi F, Zhou Y, Xiao Y, Tao J, Gu J, Jiang X, Xu GY. Promoter demethylation of cystathionine-β-synthetase gene contributes to inflammatory pain in rats. Pain 2012; 154:34-45. [PMID: 23273102 DOI: 10.1016/j.pain.2012.07.031] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Revised: 07/27/2012] [Accepted: 07/30/2012] [Indexed: 12/28/2022]
Abstract
Hydrogen sulfide (H(2)S), an endogenous gas molecule synthesized by cystathionine-β-synthetase (CBS), is involved in inflammation and nociceptive signaling. However, the molecular and epigenetic mechanisms of CBS-H(2)S signaling in peripheral nociceptive processing remain unknown. We demonstrated that peripheral inflammation induced by intraplantar injection of complete Freund adjuvant significantly up-regulated expression of CBS at both protein and mRNA levels in rat dorsal root ganglia (DRG). The CBS inhibitors hydroxylamine and aminooxyacetic acid attenuated mechanical hyperalgesia in a dose-dependent manner and reversed hyperexcitability of DRG neurons in inflamed rats. Intraplantar administration of NaHS (its addition mimics CBS production of H(2)S) or l-cysteine in healthy rats elicited mechanical hyperalgesia. Application of NaHS in vitro enhanced excitability and tetrodotoxin (TTX)-resistant sodium current of DRG neurons from healthy rats, which was attenuated by pretreatment of protein kinase A inhibitor H89. Methylation-specific PCR and bisulfite sequencing demonstrated that promoter region of cbs gene was less methylated in DRG samples from inflamed rats than that from controls. Peripheral inflammation did not alter expression of DNA methyltransferase 3a and 3b, the 2 major enzymes for DNA methylation, but led to a significant up-regulation of methyl-binding domain protein 4 and growth arrest and DNA damage inducible protein 45α, the enzymes involved in active DNA demethylation. Our findings suggest that epigenetic regulation of CBS expression may contribute to inflammatory hyperalgesia. H(2)S seems to increase TTX-resistant sodium channel current, which may be mediated by protein kinase A pathway, thus identifying a potential therapeutic target for the treatment of chronic pain.
Collapse
Affiliation(s)
- Feihu Qi
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, PR China Institute of Neuroscience, Department of Neurobiology and Psychology, Key Laboratory of Pain Research and Therapy, Soochow University, Suzhou 215123, PR China Department of Anesthesiology and the Graduate Program in Neuroscience, University of Cincinnati College of Medicine, P.O. Box 670531, 231 Albert Sabin Way, Cincinnati, OH 45267-0531, USA
| | | | | | | | | | | | | |
Collapse
|
41
|
Pristerà A, Baker MD, Okuse K. Association between tetrodotoxin resistant channels and lipid rafts regulates sensory neuron excitability. PLoS One 2012; 7:e40079. [PMID: 22870192 PMCID: PMC3411591 DOI: 10.1371/journal.pone.0040079] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 06/05/2012] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) play a key role in the initiation and propagation of action potentials in neurons. NaV1.8 is a tetrodotoxin (TTX) resistant VGSC expressed in nociceptors, peripheral small-diameter neurons able to detect noxious stimuli. NaV1.8 underlies the vast majority of sodium currents during action potentials. Many studies have highlighted a key role for NaV1.8 in inflammatory and chronic pain models. Lipid rafts are microdomains of the plasma membrane highly enriched in cholesterol and sphingolipids. Lipid rafts tune the spatial and temporal organisation of proteins and lipids on the plasma membrane. They are thought to act as platforms on the membrane where proteins and lipids can be trafficked, compartmentalised and functionally clustered. In the present study we investigated NaV1.8 sub-cellular localisation and explored the idea that it is associated with lipid rafts in nociceptors. We found that NaV1.8 is distributed in clusters along the axons of DRG neurons in vitro and ex vivo. We also demonstrated, by biochemical and imaging studies, that NaV1.8 is associated with lipid rafts along the sciatic nerve ex vivo and in DRG neurons in vitro. Moreover, treatments with methyl-β-cyclodextrin (MβCD) and 7-ketocholesterol (7KC) led to the dissociation between rafts and NaV1.8. By calcium imaging we demonstrated that the lack of association between rafts and NaV1.8 correlated with impaired neuronal excitability, highlighted by a reduction in the number of neurons able to conduct mechanically- and chemically-evoked depolarisations. These findings reveal the sub-cellular localisation of NaV1.8 in nociceptors and highlight the importance of the association between NaV1.8 and lipid rafts in the control of nociceptor excitability.
Collapse
Affiliation(s)
- Alessandro Pristerà
- Division of Cell and Molecular Biology, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - Mark D. Baker
- Neuroscience and Trauma Centre, Blizard Institute, Queen Mary University of London, Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Kenji Okuse
- Division of Cell and Molecular Biology, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
- * E-mail:
| |
Collapse
|
42
|
Emery EC, Young GT, McNaughton PA. HCN2 ion channels: an emerging role as the pacemakers of pain. Trends Pharmacol Sci 2012; 33:456-63. [PMID: 22613784 DOI: 10.1016/j.tips.2012.04.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 04/07/2012] [Accepted: 04/13/2012] [Indexed: 02/08/2023]
Abstract
Acute nociceptive pain is caused by the direct action of a noxious stimulus on pain-sensitive nerve endings, whereas inflammatory pain (both acute and chronic) arises from the actions of a wide range of inflammatory mediators released following tissue injury. Neuropathic pain, which is triggered by nerve damage, is often considered to be very different in its origins, and is particularly difficult to treat effectively. Here we review recent evidence showing that members of the hyperpolarization-activated cyclic nucleotide-modulated (HCN) ion channel family - better known for their role in the pacemaker potential of the heart - play important roles in both inflammatory and neuropathic pain. Deletion of the HCN2 isoform from nociceptive neurons abolishes heat-evoked inflammatory pain and all aspects of neuropathic pain, but acute pain sensation is unaffected. This work shows that inflammatory and neuropathic pain have much in common, and suggests that selective blockers of HCN2 may have value as analgesics in the treatment of pain.
Collapse
Affiliation(s)
- Edward C Emery
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | | | | |
Collapse
|
43
|
Catterall WA. Voltage-gated sodium channels at 60: structure, function and pathophysiology. J Physiol 2012; 590:2577-89. [PMID: 22473783 DOI: 10.1113/jphysiol.2011.224204] [Citation(s) in RCA: 477] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Voltage-gated sodium channels initiate action potentials in nerve, muscle and other excitable cells. The sodium current that initiates the nerve action potential was discovered by Hodgkin and Huxley using the voltage clamp technique in their landmark series of papers in The Journal of Physiology in 1952. They described sodium selectivity, voltage-dependent activation and fast inactivation, and they developed a quantitative model for action potential generation that has endured for many decades. This article gives an overview of the legacy that has evolved from their work, including development of conceptual models of sodium channel function, discovery of the sodium channel protein, analysis of its structure and function, determination of its structure at high resolution, definition of the mechanism and structural basis for drug block, and exploration of the role of the sodium channel as a target for disease mutations. Structural models for sodium selectivity and conductance, voltage-dependent activation, fast inactivation and drug block are discussed. A perspective for the future envisions new advances in understanding the structural basis for sodium channel function, the role of sodium channels in disease and the opportunity for discovery of novel therapeutics.
Collapse
Affiliation(s)
- William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA.
| |
Collapse
|
44
|
Wu DF, Chandra D, McMahon T, Wang D, Dadgar J, Kharazia VN, Liang YJ, Waxman SG, Dib-Hajj SD, Messing RO. PKCε phosphorylation of the sodium channel NaV1.8 increases channel function and produces mechanical hyperalgesia in mice. J Clin Invest 2012; 122:1306-15. [PMID: 22426212 DOI: 10.1172/jci61934] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 02/08/2012] [Indexed: 12/19/2022] Open
Abstract
Mechanical hyperalgesia is a common and potentially disabling complication of many inflammatory and neuropathic conditions. Activation of the enzyme PKCε in primary afferent nociceptors is a major mechanism that underlies mechanical hyperalgesia, but the PKCε substrates involved downstream are not known. Here, we report that in a proteomic screen we identified the NaV1.8 sodium channel, which is selectively expressed in nociceptors, as a PKCε substrate. PKCε-mediated phosphorylation increased NaV1.8 currents, lowered the threshold voltage for activation, and produced a depolarizing shift in inactivation in wild-type - but not in PKCε-null - sensory neurons. PKCε phosphorylated NaV1.8 at S1452, and alanine substitution at this site blocked PKCε modulation of channel properties. Moreover, a specific PKCε activator peptide, ψεRACK, produced mechanical hyperalgesia in wild-type mice but not in Scn10a-/- mice, which lack NaV1.8 channels. These studies demonstrate that NaV1.8 is an important, direct substrate of PKCε that mediates PKCε-dependent mechanical hyperalgesia.
Collapse
Affiliation(s)
- Dai-Fei Wu
- Ernest Gallo Clinic and Research Center, Department of Neurology, UCSF, Emeryville, California 94608, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Jennings EA, Williams MC, Staikopoulos V, Ivanusic JJ. Neurobiology of Temporomandibular Joint Pain: Therapeutic Implications. Semin Orthod 2012. [DOI: 10.1053/j.sodo.2011.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
46
|
Abstract
The isolated sensory neuron in vitro is a powerful model with which to address a number of important neurobiological questions. Isolated neurons are relatively easy to prepare from both neonatal and adult animals and can be studied both acutely and after considerable time on culture. Intracellular recording is one of the most powerful ways to study these neurons. Methods are described for both the preparation of isolated sensory neurons in vitro as well as for recording major classes of ionic currents (Na(+), K(+), and Ca(2+)) from these neurons with whole cell voltage-clamp techniques. Methods are also provided for an initial characterization of active and passive electrophysiological properties of these neurons in current clamp as well as the use of perforated patch recording as a means to mitigate some of the limitations associated with conventional whole cell patch recording. The reader should be aware that the regulation of ion channels in sensory neurons may very subtle, requiring considerably more sophisticated protocols than have been provided here. The reader should also be aware that there is a tremendous heterogeneity among sensory neurons, which is both a curse and a blessing for those who wish to study them. Thus, the methods provided here should only be considered the starting point for a more detailed analysis of sensory neurons.
Collapse
Affiliation(s)
- Michael S Gold
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
47
|
Cady RJ, Glenn JR, Smith KM, Durham PL. Calcitonin gene-related peptide promotes cellular changes in trigeminal neurons and glia implicated in peripheral and central sensitization. Mol Pain 2011; 7:94. [PMID: 22145886 PMCID: PMC3267674 DOI: 10.1186/1744-8069-7-94] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 12/06/2011] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Calcitonin gene-related peptide (CGRP), a neuropeptide released from trigeminal nerves, is implicated in the underlying pathology of temporomandibular joint disorder (TMD). Elevated levels of CGRP in the joint capsule correlate with inflammation and pain. CGRP mediates neurogenic inflammation in peripheral tissues by increasing blood flow, recruiting immune cells, and activating sensory neurons. The goal of this study was to investigate the capability of CGRP to promote peripheral and central sensitization in a model of TMD. RESULTS Temporal changes in protein expression in trigeminal ganglia and spinal trigeminal nucleus were determined by immunohistochemistry following injection of CGRP in the temporomandibular joint (TMJ) capsule of male Sprague-Dawley rats. CGRP stimulated expression of the active forms of the MAP kinases p38 and ERK, and PKA in trigeminal ganglia at 2 and 24 hours. CGRP also caused a sustained increase in the expression of c-Fos neurons in the spinal trigeminal nucleus. In contrast, levels of P2X3 in spinal neurons were only significantly elevated at 2 hours in response to CGRP. In addition, CGRP stimulated expression of GFAP in astrocytes and OX-42 in microglia at 2 and 24 hours post injection. CONCLUSIONS Our results demonstrate that an elevated level of CGRP in the joint, which is associated with TMD, stimulate neuronal and glial expression of proteins implicated in the development of peripheral and central sensitization. Based on our findings, we propose that inhibition of CGRP-mediated activation of trigeminal neurons and glial cells with selective non-peptide CGRP receptor antagonists would be beneficial in the treatment of TMD.
Collapse
Affiliation(s)
- Ryan J Cady
- Center for Biomedical & Life Sciences, Missouri State University, Boonville, Springfield, MO, USA.
| | | | | | | |
Collapse
|
48
|
Swanwick RS, Pristerá A, Okuse K. The trafficking of Na(V)1.8. Neurosci Lett 2010; 486:78-83. [PMID: 20816723 PMCID: PMC2977848 DOI: 10.1016/j.neulet.2010.08.074] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 08/24/2010] [Accepted: 08/25/2010] [Indexed: 12/23/2022]
Abstract
The α-subunit of tetrodotoxin-resistant voltage-gated sodium channel Na(V)1.8 is selectively expressed in sensory neurons. It has been reported that Na(V)1.8 is involved in the transmission of nociceptive information from sensory neurons to the central nervous system in nociceptive [1] and neuropathic [24] pain conditions. Thus Na(V)1.8 has been a promising target to treat chronic pain. Here we discuss the recent advances in the study of trafficking mechanism of Na(V)1.8. These pieces of information are particularly important as such trafficking machinery could be new targets for painkillers.
Collapse
Affiliation(s)
| | | | - Kenji Okuse
- Division of Cell & Molecular Biology, Imperial College London, London SW7 2AZ, UK
| |
Collapse
|
49
|
Hematopoietic colony-stimulating factors: new players in tumor-nerve interactions. J Mol Med (Berl) 2010; 89:321-9. [PMID: 21079906 PMCID: PMC3055988 DOI: 10.1007/s00109-010-0697-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2010] [Revised: 10/02/2010] [Accepted: 10/28/2010] [Indexed: 12/30/2022]
Abstract
A variety of cancers are accompanied by debilitating pain, which constitutes the primary reason for poor quality of life in cancer patients. There is an urgent demand for the development of specific mechanism-based therapies against cancer pain. Recently, important advances have been made in mechanisms contributing to cancer pain. A notable finding was that the tumor-derived hematopoietic growth factors, granulocyte- and granulocyte-macrophage-colony-stimulating factors (G-CSF/GM-CSF), subserve important functions in the generation of pain hypersensitivity in tumor-affected regions. In this context, their receptors were unexpectedly found on pain-sensing nerves and were observed to be functionally linked to nociceptive sensitization and tumor-induced pain. Here, we review evidence supporting a role for G-/GM-CSF in sensitization of pain-sensing nerves, the underlying signaling pathways and the cross-talk with other pronociceptive cytokines, peptides and modulators derived from immune cells, osteoclasts and tumor cells. These findings hold implications in the therapy of pain in disease states, such as cancer and rheumatoid arthritis.
Collapse
|
50
|
Scheuer T. Regulation of sodium channel activity by phosphorylation. Semin Cell Dev Biol 2010; 22:160-5. [PMID: 20950703 DOI: 10.1016/j.semcdb.2010.10.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 10/04/2010] [Accepted: 10/05/2010] [Indexed: 12/24/2022]
Abstract
Voltage-gated sodium channels carry the major inward current responsible for action potential depolarization in excitable cells as well as providing additional inward current that modulates overall excitability. Both their expression and function is under tight control of protein phosphorylation by specific kinases and phosphatases and this control is particular to each type of sodium channel. This article examines the impact and mechanism of phosphorylation for isoforms where it has been studied in detail in an attempt to delineate common features as well as differences.
Collapse
Affiliation(s)
- Todd Scheuer
- Department of Pharmacology, University of Washington School of Medicine, Seattle, WA 98195-7280, United States.
| |
Collapse
|