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Messina DN, Peralta ED, Acosta CG. Complex alterations in inflammatory pain and analgesic sensitivity in young and ageing female rats: involvement of ASIC3 and Nav1.8 in primary sensory neurons. Inflamm Res 2024; 73:669-691. [PMID: 38483556 DOI: 10.1007/s00011-024-01862-z] [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: 02/05/2024] [Accepted: 02/12/2024] [Indexed: 04/10/2024] Open
Abstract
OBJECTIVE AND DESIGN Our aim was to determine an age-dependent role of Nav1.8 and ASIC3 in dorsal root ganglion (DRG) neurons in a rat pre-clinical model of long-term inflammatory pain. METHODS We compared 6 and 24 months-old female Wistar rats after cutaneous inflammation. We used behavioral pain assessments over time, qPCR, quantitative immunohistochemistry, selective pharmacological manipulation, ELISA and in vitro treatment with cytokines. RESULTS Older rats exhibited delayed recovery from mechanical allodynia and earlier onset of spontaneous pain than younger rats after inflammation. Moreover, the expression patterns of Nav1.8 and ASIC3 were time and age-dependent and ASIC3 levels remained elevated only in aged rats. In vivo, selective blockade of Nav1.8 with A803467 or of ASIC3 with APETx2 alleviated mechanical and cold allodynia and also spontaneous pain in both age groups with slightly different potency. Furthermore, in vitro IL-1β up-regulated Nav1.8 expression in DRG neurons cultured from young but not old rats. We also found that while TNF-α up-regulated ASIC3 expression in both age groups, IL-6 and IL-1β had this effect only on young and aged neurons, respectively. CONCLUSION Inflammation-associated mechanical allodynia and spontaneous pain in the elderly can be more effectively treated by inhibiting ASIC3 than Nav1.8.
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Affiliation(s)
- Diego N Messina
- Laboratory of Neurobiology of Pain, Faculty of Medical Sciences, IHEM (Instituto de Histologia y Embriologia Mendoza, Dr. Mario H Burgos), Cuyo National University, Av. Del Libertador 80, 5500, Mendoza, Argentina
| | - Emanuel D Peralta
- Laboratory of Neurobiology of Pain, Faculty of Medical Sciences, IHEM (Instituto de Histologia y Embriologia Mendoza, Dr. Mario H Burgos), Cuyo National University, Av. Del Libertador 80, 5500, Mendoza, Argentina
| | - Cristian G Acosta
- Laboratory of Neurobiology of Pain, Faculty of Medical Sciences, IHEM (Instituto de Histologia y Embriologia Mendoza, Dr. Mario H Burgos), Cuyo National University, Av. Del Libertador 80, 5500, Mendoza, Argentina.
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2
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Brackx W, de Cássia Collaço R, Theys M, Cruyssen JV, Bosmans F. Understanding the physiological role of Na V1.9: Challenges and opportunities for pain modulation. Pharmacol Ther 2023; 245:108416. [PMID: 37061202 DOI: 10.1016/j.pharmthera.2023.108416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/31/2023] [Accepted: 04/12/2023] [Indexed: 04/17/2023]
Abstract
Voltage-activated Na+ (NaV) channels are crucial contributors to rapid electrical signaling in the human body. As such, they are among the most targeted membrane proteins by clinical therapeutics and natural toxins. Several of the nine mammalian NaV channel subtypes play a documented role in pain or other sensory processes such as itch, touch, and smell. While causal relationships between these subtypes and biological function have been extensively described, the physiological role of NaV1.9 is less understood. Yet, mutations in NaV1.9 can cause striking disease phenotypes related to sensory perception such as loss or gain of pain and chronic itch. Here, we explore our current knowledge of the mechanisms by which NaV1.9 may contribute to pain and elaborate on the challenges associated with establishing links between experimental conditions and human disease. This review also discusses the lack of comprehensive insights into NaV1.9-specific pharmacology, an unfortunate situation since modulatory compounds may have tremendous potential in the clinic to treat pain or as precision tools to examine the extent of NaV1.9 participation in sensory perception processes.
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Affiliation(s)
- Wayra Brackx
- Molecular Physiology and Neurophysics Group, Department of Basic and Applied Medical Sciences, University of Ghent, Ghent, Belgium
| | - Rita de Cássia Collaço
- Molecular Physiology and Neurophysics Group, Department of Basic and Applied Medical Sciences, University of Ghent, Ghent, Belgium
| | - Margaux Theys
- Molecular Physiology and Neurophysics Group, Department of Basic and Applied Medical Sciences, University of Ghent, Ghent, Belgium
| | - Jolien Vander Cruyssen
- Molecular Physiology and Neurophysics Group, Department of Basic and Applied Medical Sciences, University of Ghent, Ghent, Belgium
| | - Frank Bosmans
- Molecular Physiology and Neurophysics Group, Department of Basic and Applied Medical Sciences, University of Ghent, Ghent, Belgium.
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3
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Glial-derived neurotrophic factor regulates the expression of TREK2 in rat primary sensory neurons leading to attenuation of axotomy-induced neuropathic pain. Exp Neurol 2022; 357:114190. [PMID: 35907583 DOI: 10.1016/j.expneurol.2022.114190] [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: 06/14/2022] [Revised: 07/12/2022] [Accepted: 07/24/2022] [Indexed: 11/24/2022]
Abstract
TREK2 is a member of the 2-pore domain family of K+ channels (K2P) preferentially expressed by unmyelinated, slow-conducting and non-peptidergic isolectin B4-binding (IB4+) primary sensory neurons of the dorsal root ganglia (DRG). IB4+ neurons depend on the glial-derived neurotrophic factor (GDNF) family of ligands (GFL's) to maintain their phenotype. In our previous work, we demonstrated that 7 days after spinal nerve axotomy (SNA) of the L5 DRG, TREK2 moves away from the cell membrane resulting in a more depolarised resting membrane potential (Em). Given that axotomy deprives DRG neurons from peripherally-derived GFL's, we hypothesized that they might control the expression of TREK2. Using a combination of immunohistochemistry, immunocytochemistry, western blotting, in vivo pharmacological manipulation and behavioral tests we examined the ability of the GFL's (GDNF, neurturin and artemin) and their selective receptors (GFRα1, GFRα2 and GFRα3) to regulate the expression and function of TREK2 in the DRG. We found that TREK2 correlated strongly with the three receptors normally and ipsilaterally for all GFR's after SNA. GDNF, but not NGF, neurturin or artemin up-regulated the expression of TREK2 in cultured DRG neurons. In vivo continuous, subcutaneous administration of GDNF restored the subcellular distribution of TREK2 ipsilaterally and reversed mechanical and cold allodynia 7 days after SNA. This is the first demonstration that GDNF controls the expression of a K2P channel in nociceptors. As TREK2 controls the Em of C-nociceptors affecting their excitability, our finding has therapeutic potential in the treatment of chronic pain.
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Alles SRA, Smith PA. Peripheral Voltage-Gated Cation Channels in Neuropathic Pain and Their Potential as Therapeutic Targets. FRONTIERS IN PAIN RESEARCH 2021; 2:750583. [PMID: 35295464 PMCID: PMC8915663 DOI: 10.3389/fpain.2021.750583] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022] Open
Abstract
The persistence of increased excitability and spontaneous activity in injured peripheral neurons is imperative for the development and persistence of many forms of neuropathic pain. This aberrant activity involves increased activity and/or expression of voltage-gated Na+ and Ca2+ channels and hyperpolarization activated cyclic nucleotide gated (HCN) channels as well as decreased function of K+ channels. Because they display limited central side effects, peripherally restricted Na+ and Ca2+ channel blockers and K+ channel activators offer potential therapeutic approaches to pain management. This review outlines the current status and future therapeutic promise of peripherally acting channel modulators. Selective blockers of Nav1.3, Nav1.7, Nav1.8, Cav3.2, and HCN2 and activators of Kv7.2 abrogate signs of neuropathic pain in animal models. Unfortunately, their performance in the clinic has been disappointing; some substances fail to meet therapeutic end points whereas others produce dose-limiting side effects. Despite this, peripheral voltage-gated cation channels retain their promise as therapeutic targets. The way forward may include (i) further structural refinement of K+ channel activators such as retigabine and ASP0819 to improve selectivity and limit toxicity; use or modification of Na+ channel blockers such as vixotrigine, PF-05089771, A803467, PF-01247324, VX-150 or arachnid toxins such as Tap1a; the use of Ca2+ channel blockers such as TTA-P2, TTA-A2, Z 944, ACT709478, and CNCB-2; (ii) improving methods for assessing "pain" as opposed to nociception in rodent models; (iii) recognizing sex differences in pain etiology; (iv) tailoring of therapeutic approaches to meet the symptoms and etiology of pain in individual patients via quantitative sensory testing and other personalized medicine approaches; (v) targeting genetic and biochemical mechanisms controlling channel expression using anti-NGF antibodies such as tanezumab or re-purposed drugs such as vorinostat, a histone methyltransferase inhibitor used in the management of T-cell lymphoma, or cercosporamide a MNK 1/2 inhibitor used in treatment of rheumatoid arthritis; (vi) combination therapy using drugs that are selective for different channel types or regulatory processes; (vii) directing preclinical validation work toward the use of human or human-derived tissue samples; and (viii) application of molecular biological approaches such as clustered regularly interspaced short palindromic repeats (CRISPR) technology.
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Affiliation(s)
- Sascha R A Alles
- Department of Anesthesiology and Critical Care Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Peter A Smith
- Department of Pharmacology, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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5
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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) 2021; 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] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 11/30/2020] [Accepted: 11/30/2020] [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.
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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
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Smith PA. K + Channels in Primary Afferents and Their Role in Nerve Injury-Induced Pain. Front Cell Neurosci 2020; 14:566418. [PMID: 33093824 PMCID: PMC7528628 DOI: 10.3389/fncel.2020.566418] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/21/2020] [Indexed: 12/12/2022] Open
Abstract
Sensory abnormalities generated by nerve injury, peripheral neuropathy or disease are often expressed as neuropathic pain. This type of pain is frequently resistant to therapeutic intervention and may be intractable. Numerous studies have revealed the importance of enduring increases in primary afferent excitability and persistent spontaneous activity in the onset and maintenance of peripherally induced neuropathic pain. Some of this activity results from modulation, increased activity and /or expression of voltage-gated Na+ channels and hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. K+ channels expressed in dorsal root ganglia (DRG) include delayed rectifiers (Kv1.1, 1.2), A-channels (Kv1.4, 3.3, 3.4, 4.1, 4.2, and 4.3), KCNQ or M-channels (Kv7.2, 7.3, 7.4, and 7.5), ATP-sensitive channels (KIR6.2), Ca2+-activated K+ channels (KCa1.1, 2.1, 2.2, 2.3, and 3.1), Na+-activated K+ channels (KCa4.1 and 4.2) and two pore domain leak channels (K2p; TWIK related channels). Function of all K+ channel types is reduced via a multiplicity of processes leading to altered expression and/or post-translational modification. This also increases excitability of DRG cell bodies and nociceptive free nerve endings, alters axonal conduction and increases neurotransmitter release from primary afferent terminals in the spinal dorsal horn. Correlation of these cellular changes with behavioral studies provides almost indisputable evidence for K+ channel dysfunction in the onset and maintenance of neuropathic pain. This idea is underlined by the observation that selective impairment of just one subtype of DRG K+ channel can produce signs of pain in vivo. Whilst it is established that various mediators, including cytokines and growth factors bring about injury-induced changes in DRG function and excitability, evidence presently available points to a seminal role for interleukin 1β (IL-1β) in control of K+ channel function. Despite the current state of knowledge, attempts to target K+ channels for therapeutic pain management have met with limited success. This situation may change with the advent of personalized medicine. Identification of specific sensory abnormalities and genetic profiling of individual patients may predict therapeutic benefit of K+ channel activators.
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Affiliation(s)
- Peter A. Smith
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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7
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Kim D, Kim KR, Kwon Y, Kim M, Kim MJ, Sim Y, Ji H, Park JJ, Cho JH, Choi H, Kim S. AAV-Mediated Combination Gene Therapy for Neuropathic Pain: GAD65, GDNF, and IL-10. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 18:473-483. [PMID: 32728596 PMCID: PMC7378317 DOI: 10.1016/j.omtm.2020.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 06/22/2020] [Indexed: 12/26/2022]
Abstract
Neuropathic pain is a chronic pain state characterized by nerve damage, inflammation, and nociceptive neuron hyperactivity. As the underlying pathophysiology is complex, a more effective therapy for neuropathic pain would be one that targets multiple elements. Here, we generated recombinant adeno-associated viruses (AAVs) encoding three therapeutic genes, namely, glutamate decarboxylase 65, glial cell-derived neurotrophic factor, and interleukin-10, with various combinations. The efficacy for pain relief was evaluated in a rat spared nerve injury model of neuropathic pain. The maximal analgesic effect was achieved when the AAVs expressing all three genes were administered to rats with neuropathic pain. The combination of two virus constructs expressing the three genes was named KLS-2031 and evaluated as a potential novel therapeutic for neuropathic pain. Single transforaminal epidural injections of KLS-2031 into the intervertebral foramen to target the appropriate dorsal root ganglion produced notable long-term analgesic effects in female and male rats. Furthermore, KLS-2031 mitigated the neuroinflammation, neuronal cell death, and dorsal root ganglion hyperexcitability induced by the spared nerve injury. These results suggest that KLS-2031 represents a promising therapeutic option for refractory neuropathic pain.
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Affiliation(s)
- Daewook Kim
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Kyung-Ran Kim
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Yejin Kwon
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Minjung Kim
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Min-Ju Kim
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Yeomoon Sim
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Hyelin Ji
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Jang-Joon Park
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Jong-Ho Cho
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Heonsik Choi
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
| | - Sujeong Kim
- Institute of BioInnovation Research, Kolon Life Science, 110 Magokdong-ro, Gangseo-gu, Seoul 07793, Republic of Korea
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Atmaramani RR, Black BJ, de la Peña JB, Campbell ZT, Pancrazio JJ. Conserved Expression of Nav1.7 and Nav1.8 Contribute to the Spontaneous and Thermally Evoked Excitability in IL-6 and NGF-Sensitized Adult Dorsal Root Ganglion Neurons In Vitro. Bioengineering (Basel) 2020; 7:bioengineering7020044. [PMID: 32429423 PMCID: PMC7356605 DOI: 10.3390/bioengineering7020044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 05/08/2020] [Accepted: 05/12/2020] [Indexed: 02/06/2023] Open
Abstract
Sensory neurons respond to noxious stimuli by relaying information from the periphery to the central nervous system via action potentials driven by voltage-gated sodium channels, specifically Nav1.7 and Nav1.8. These channels play a key role in the manifestation of inflammatory pain. The ability to screen compounds that modulate voltage-gated sodium channels using cell-based assays assumes that key channels present in vivo is maintained in vitro. Prior electrophysiological work in vitro utilized acutely dissociated tissues, however, maintaining this preparation for long periods is difficult. A potential alternative involves multi-electrode arrays which permit long-term measurements of neural spike activity and are well suited for assessing persistent sensitization consistent with chronic pain. Here, we demonstrate that the addition of two inflammatory mediators associated with chronic inflammatory pain, nerve growth factor (NGF) and interleukin-6 (IL-6), to adult DRG neurons increases their firing rates on multi-electrode arrays in vitro. Nav1.7 and Nav1.8 proteins are readily detected in cultured neurons and contribute to evoked activity. The blockade of both Nav1.7 and Nav1.8, has a profound impact on thermally evoked firing after treatment with IL-6 and NGF. This work underscores the utility of multi-electrode arrays for pharmacological studies of sensory neurons and may facilitate the discovery and mechanistic analyses of anti-nociceptive compounds.
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Affiliation(s)
- Rahul R. Atmaramani
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA; (R.R.A.); (B.J.B.)
- Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA; (J.B.d.l.P.); (Z.T.C.)
| | - Bryan J. Black
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA; (R.R.A.); (B.J.B.)
- Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA; (J.B.d.l.P.); (Z.T.C.)
| | - June Bryan de la Peña
- Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA; (J.B.d.l.P.); (Z.T.C.)
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Zachary T. Campbell
- Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA; (J.B.d.l.P.); (Z.T.C.)
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Joseph J. Pancrazio
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA; (R.R.A.); (B.J.B.)
- Correspondence: ; Tel.: +1-972-883-2138
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9
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Johansson JK, Karema-Jokinen VI, Hakanen S, Jylhä A, Uusitalo H, Vihinen-Ranta M, Skottman H, Ihalainen TO, Nymark S. Sodium channels enable fast electrical signaling and regulate phagocytosis in the retinal pigment epithelium. BMC Biol 2019; 17:63. [PMID: 31412898 PMCID: PMC6694495 DOI: 10.1186/s12915-019-0681-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 07/11/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Voltage-gated sodium (Nav) channels have traditionally been considered a trademark of excitable cells. However, recent studies have shown the presence of Nav channels in several non-excitable cells, such as astrocytes and macrophages, demonstrating that the roles of these channels are more diverse than was previously thought. Despite the earlier discoveries, the presence of Nav channel-mediated currents in the cells of retinal pigment epithelium (RPE) has been dismissed as a cell culture artifact. We challenge this notion by investigating the presence and possible role of Nav channels in RPE both ex vivo and in vitro. RESULTS Our work demonstrates that several subtypes of Nav channels are found in human embryonic stem cell (hESC)-derived and mouse RPE, most prominently subtypes Nav1.4, Nav1.6, and Nav1.8. Whole cell patch clamp recordings from the hESC-derived RPE monolayers showed that the current was inhibited by TTX and QX-314 and was sensitive to the selective blockers of the main Nav subtypes. Importantly, we show that the Nav channels are involved in photoreceptor outer segment phagocytosis since blocking their activity significantly reduces the efficiency of particle internalization. Consistent with this role, our electron microscopy results and immunocytochemical analysis show that Nav1.4 and Nav1.8 accumulate on phagosomes and that pharmacological inhibition of Nav channels as well as silencing the expression of Nav1.4 with shRNA impairs the phagocytosis process. CONCLUSIONS Taken together, our study shows that Nav channels are present in RPE, giving this tissue the capacity of fast electrical signaling. The channels are critical for the physiology of RPE with an important role in photoreceptor outer segment phagocytosis.
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Affiliation(s)
- Julia K Johansson
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Viivi I Karema-Jokinen
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Satu Hakanen
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Antti Jylhä
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Hannu Uusitalo
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
- Tays Eye Centre, Tampere University Hospital, Tampere, Finland
| | - Maija Vihinen-Ranta
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Heli Skottman
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Teemu O Ihalainen
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Soile Nymark
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
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10
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Wu B, McDermott JS, Krajewski JL, Knopp KL, Nisenbaum ES, Cummins TR, Tan ZY. Extracellular signal-regulated kinases mediate the enhancing effects of inflammatory mediators on resurgent currents in dorsal root ganglion neurons. Mol Pain 2019; 15:1744806919837104. [PMID: 30803321 PMCID: PMC6452589 DOI: 10.1177/1744806919837104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Previously we reported that a group of inflammatory mediators significantly enhanced resurgent currents in dorsal root ganglion neurons. To understand the underlying intracellular signaling mechanism, we investigated the effects of inhibition of extracellular signal-regulated kinases and protein kinase C on the enhancing effects of inflammatory mediators on resurgent currents in rat dorsal root ganglion neurons. We found that the extracellular signal-regulated kinases inhibitor U0126 completely prevented the enhancing effects of the inflammatory mediators on both Tetrodotoxin-sensitive and Tetrodotoxin-resistant resurgent currents in both small and medium dorsal root ganglion neurons. U0126 substantially reduced repetitive firing in small dorsal root ganglion neurons exposed to inflammatory mediators, consistent with prevention of resurgent current amplitude increases. The protein kinase C inhibitor Bisindolylmaleimide I also showed attenuating effects on resurgent currents, although to a lesser extent compared to extracellular signal-regulated kinases inhibition. These results indicate a critical role of extracellular signal-regulated kinases signaling in modulating resurgent currents and membrane excitability in dorsal root ganglion neurons treated with inflammatory mediators. It is also suggested that targeting extracellular signal-regulated kinases-resurgent currents might be a useful strategy to reduce inflammatory pain.
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Affiliation(s)
- Bin Wu
- 1 Department of Pharmacology and Toxicology, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | | | - Kelly L Knopp
- 2 Lilly Research Laboratories, Indianapolis, IN, USA
| | | | - Theodore R Cummins
- 1 Department of Pharmacology and Toxicology, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.,3 Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Zhi-Yong Tan
- 1 Department of Pharmacology and Toxicology, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
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11
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Noh MC, Stemkowski PL, Smith PA. Long-term actions of interleukin-1β on K +, Na + and Ca 2+ channel currents in small, IB 4-positive dorsal root ganglion neurons; possible relevance to the etiology of neuropathic pain. J Neuroimmunol 2019; 332:198-211. [PMID: 31077855 DOI: 10.1016/j.jneuroim.2019.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 04/18/2019] [Accepted: 05/01/2019] [Indexed: 12/25/2022]
Abstract
Excitation of dorsal root ganglion (DRG) neurons by interleukin 1β (IL-1β) is implicated in the onset of neuropathic pain. To understand its mechanism of action, isolectin B4 positive (IB4+) DRG neurons were exposed to 100pM IL-1β for 5-6d. A reversible increase in action potential (AP) amplitude reflected increased TTX-sensitive sodium current (TTX-S INa). An irreversible increase in AP duration reflected decreased Ca2+- sensitive K+ conductance (BK(Ca) channels). Different processes thus underlie regulation of the two channel types. Since changes in AP shape facilitated Ca2+ influx, this explains how IL-1β facilitates synaptic transmission in the dorsal horn; thereby provoking pain.
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Affiliation(s)
- Myung-Chul Noh
- Department of Pharmacology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Patrick L Stemkowski
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Peter A Smith
- Department of Pharmacology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada; Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
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12
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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.
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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
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13
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Network-Based Drug Discovery: Coupling Network Pharmacology with Phenotypic Screening for Neuronal Excitability. J Mol Biol 2018; 430:3005-3015. [DOI: 10.1016/j.jmb.2018.07.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/05/2018] [Accepted: 07/10/2018] [Indexed: 01/02/2023]
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14
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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.
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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
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Wu Y, Ma H, Zhang F, Zhang C, Zou X, Cao Z. Selective Voltage-Gated Sodium Channel Peptide Toxins from Animal Venom: Pharmacological Probes and Analgesic Drug Development. ACS Chem Neurosci 2018; 9:187-197. [PMID: 29161016 DOI: 10.1021/acschemneuro.7b00406] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (Navs) play critical roles in action potential generation and propagation. Nav channelopathy as well as pathological sensitization contribute to allodynia and hyperalgesia. Recent evidence has demonstrated the significant roles of Nav subtypes (Nav1.3, 1.7, 1.8, and 1.9) in nociceptive transduction, and therefore these Navs may represent attractive targets for analgesic drug discovery. Animal toxins are structurally diverse peptides that are highly potent yet selective on ion channel subtypes and therefore represent valuable probes to elucidate the structures, gating properties, and cellular functions of ion channels. In this review, we summarize recent advances on peptide toxins from animal venom that selectively target Nav1.3, 1.7, 1.8, and 1.9, along with their potential in analgesic drug discovery.
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Affiliation(s)
- Ying Wu
- Jiangsu Provincial Key Laboratory for TCM Evaluation
and Translational Development, China Pharmaceutical University, Nanjing 211198, China
| | - Hui Ma
- Jiangsu Provincial Key Laboratory for TCM Evaluation
and Translational Development, China Pharmaceutical University, Nanjing 211198, China
| | - Fan Zhang
- Jiangsu Provincial Key Laboratory for TCM Evaluation
and Translational Development, China Pharmaceutical University, Nanjing 211198, China
| | - Chunlei Zhang
- Jiangsu Provincial Key Laboratory for TCM Evaluation
and Translational Development, China Pharmaceutical University, Nanjing 211198, China
| | - Xiaohan Zou
- Jiangsu Provincial Key Laboratory for TCM Evaluation
and Translational Development, China Pharmaceutical University, Nanjing 211198, China
| | - Zhengyu Cao
- Jiangsu Provincial Key Laboratory for TCM Evaluation
and Translational Development, China Pharmaceutical University, Nanjing 211198, China
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16
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Yasko JR, Mains RE. Chronic pain following spinal cord injury: Current approaches to cellular and molecular mechanisms. TRENDS IN CELL & MOLECULAR BIOLOGY 2018; 13:67-84. [PMID: 33564218 PMCID: PMC7869846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Traumatic spinal cord injury (SCI) has devastating implications for patients, including a high prevalence of chronic pain. Despite advancements in our understanding of the mechanisms involved post-SCI, there are no effective treatments for chronic pain following injury. The development of new treatment interventions for pain is needed, but this requires improved models to assess injury-related cellular, neurophysiological and molecular changes in the spinal cord. Here, we will discuss recent animal models for SCI, molecular screening for altered patterns of gene expression, and the importance of injury severity and timing after SCI.
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Affiliation(s)
- Jessica R. Yasko
- Department of Neuroscience, University of Connecticut Health Center, Farmington CT 06030-3401, USA
| | - Richard E. Mains
- Department of Neuroscience, University of Connecticut Health Center, Farmington CT 06030-3401, USA
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Cortés D, Carballo-Molina OA, Castellanos-Montiel MJ, Velasco I. The Non-Survival Effects of Glial Cell Line-Derived Neurotrophic Factor on Neural Cells. Front Mol Neurosci 2017; 10:258. [PMID: 28878618 PMCID: PMC5572274 DOI: 10.3389/fnmol.2017.00258] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Accepted: 07/31/2017] [Indexed: 01/23/2023] Open
Abstract
Glial cell line-derived neurotrophic factor (GDNF) was first characterized as a survival-promoting molecule for dopaminergic neurons (DANs). Afterwards, other cells were also discovered to respond to GDNF not only as a survival factor but also as a protein supporting other cellular functions, such as proliferation, differentiation, maturation, neurite outgrowth and other phenomena that have been less studied than survival and are now more extendedly described here in this review article. During development, GDNF favors the commitment of neural precursors towards dopaminergic, motor, enteric and adrenal neurons; in addition, it enhances the axonal growth of some of these neurons. GDNF also induces the acquisition of a dopaminergic phenotype by increasing the expression of Tyrosine Hydroxylase (TH), Nurr1 and other proteins that confer this identity and promote further dendritic and electrical maturation. In motor neurons (MNs), GDNF not only promotes proliferation and maturation but also participates in regenerating damaged axons and modulates the neuromuscular junction (NMJ) at both presynaptic and postsynaptic levels. Moreover, GDNF modulates the rate of neuroblastoma (NB) and glioblastoma cancer cell proliferation. Additionally, the presence or absence of GDNF has been correlated with conditions such as depression, pain, muscular soreness, etc. Although, the precise role of GDNF is unknown, it extends beyond a survival effect. The understanding of the complete range of properties of this trophic molecule will allow us to investigate its broad mechanisms of action to accelerate and/or improve therapies for the aforementioned pathological conditions.
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Affiliation(s)
- Daniel Cortés
- Instituto de Fisiología Celular—Neurociencias, Universidad Nacional Autónoma de MéxicoMéxico City, Mexico
- Laboratorio de Reprogramación Celular del IFC-UNAM, Instituto Nacional de Neurología y NeurologíaMéxico City, Mexico
| | - Oscar A. Carballo-Molina
- Instituto de Fisiología Celular—Neurociencias, Universidad Nacional Autónoma de MéxicoMéxico City, Mexico
- Laboratorio de Reprogramación Celular del IFC-UNAM, Instituto Nacional de Neurología y NeurologíaMéxico City, Mexico
| | - María José Castellanos-Montiel
- Instituto de Fisiología Celular—Neurociencias, Universidad Nacional Autónoma de MéxicoMéxico City, Mexico
- Laboratorio de Reprogramación Celular del IFC-UNAM, Instituto Nacional de Neurología y NeurologíaMéxico City, Mexico
| | - Iván Velasco
- Instituto de Fisiología Celular—Neurociencias, Universidad Nacional Autónoma de MéxicoMéxico City, Mexico
- Laboratorio de Reprogramación Celular del IFC-UNAM, Instituto Nacional de Neurología y NeurologíaMéxico City, Mexico
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18
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Reduced excitability and impaired nociception in peripheral unmyelinated fibers from Nav1.9-null mice. Pain 2016; 158:58-67. [DOI: 10.1097/j.pain.0000000000000723] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Cortés D, Robledo-Arratia Y, Hernández-Martínez R, Escobedo-Ávila I, Bargas J, Velasco I. Transgenic GDNF Positively Influences Proliferation, Differentiation, Maturation and Survival of Motor Neurons Produced from Mouse Embryonic Stem Cells. Front Cell Neurosci 2016; 10:217. [PMID: 27672361 PMCID: PMC5018488 DOI: 10.3389/fncel.2016.00217] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/30/2016] [Indexed: 11/13/2022] Open
Abstract
Embryonic stem cells (ESC) are pluripotent and thus can differentiate into every cell type present in the body. Directed differentiation into motor neurons (MNs) has been described for pluripotent cells. Although neurotrophic factors promote neuronal survival, their role in neuronal commitment is elusive. Here, we developed double-transgenic lines of mouse ESC (mESC) that constitutively produce glial cell line-derived neurotrophic factor (GDNF) and also contain a GFP reporter, driven by HB9, which is expressed only by postmitotic MNs. After lentiviral transduction, ESC lines integrated and expressed the human GDNF (hGDNF) gene without altering pluripotency markers before differentiation. Further, GDNF-ESC showed significantly higher spontaneous release of this neurotrophin to the medium, when compared to controls. To study MN induction, control and GDNF cell lines were grown as embryoid bodies and stimulated with retinoic acid and Sonic Hedgehog. In GDNF-overexpressing cells, a significant increase of proliferative Olig2+ precursors, which are specified as spinal MNs, was found. Accordingly, GDNF increases the yield of cells with the pan motor neuronal markers HB9, monitored by GFP expression, and Isl1. At terminal differentiation, almost all differentiated neurons express phenotypic markers of MNs in GDNF cultures, with lower proportions in control cells. To test if the effects of GDNF were present at early differentiation stages, exogenous recombinant hGDNF was added to control ESC, also resulting in enhanced MN differentiation. This effect was abolished by the co-addition of neutralizing anti-GDNF antibodies, strongly suggesting that differentiating ESC are responsive to GDNF. Using the HB9::GFP reporter, MNs were selected for electrophysiological recordings. MNs differentiated from GDNF-ESC, compared to control MNs, showed greater electrophysiological maturation, characterized by increased numbers of evoked action potentials (APs), as well as by the appearance of rebound APs, sag inward rectification, spike frequency adaptation and spontaneous synaptic potentials. Upon challenge with kainate, GDNF-overexpressing cells are more resistant to excitotoxicity than control MNs. Together these data indicate that GDNF promotes proliferation of MN-committed precursors, promotes neuronal differentiation, enhances maturation, and confers neuroprotection. GDNF-expressing ESC can be useful in studies of development and disease.
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Affiliation(s)
- Daniel Cortés
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de MéxicoMexico City, Mexico; Laboratorio de Reprogramación Celular del Instituto de Fisiología Celular, Universidad Nacional Autónoma de México en el Instituto Nacional de Neurología y Neurología "Manuel Velasco Suárez"Mexico City, Mexico
| | - Yolanda Robledo-Arratia
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - Ricardo Hernández-Martínez
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - Itzel Escobedo-Ávila
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - José Bargas
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - Iván Velasco
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de MéxicoMexico City, Mexico; Laboratorio de Reprogramación Celular del Instituto de Fisiología Celular, Universidad Nacional Autónoma de México en el Instituto Nacional de Neurología y Neurología "Manuel Velasco Suárez"Mexico City, Mexico
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20
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Lin Z, Santos S, Padilla K, Printzenhoff D, Castle NA. Biophysical and Pharmacological Characterization of Nav1.9 Voltage Dependent Sodium Channels Stably Expressed in HEK-293 Cells. PLoS One 2016; 11:e0161450. [PMID: 27556810 PMCID: PMC4996523 DOI: 10.1371/journal.pone.0161450] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 08/07/2016] [Indexed: 11/19/2022] Open
Abstract
The voltage dependent sodium channel Nav1.9, is expressed preferentially in peripheral sensory neurons and has been linked to human genetic pain disorders, which makes it target of interest for the development of new pain therapeutics. However, characterization of Nav1.9 pharmacology has been limited due in part to the historical difficulty of functionally expressing recombinant channels. Here we report the successful generation and characterization of human, mouse and rat Nav1.9 stably expressed in human HEK-293 cells. These cells exhibit slowly activating and inactivating inward sodium channel currents that have characteristics of native Nav1.9. Optimal functional expression was achieved by coexpression of Nav1.9 with β1/β2 subunits. While recombinantly expressed Nav1.9 was found to be sensitive to sodium channel inhibitors TC-N 1752 and tetracaine, potency was up to 100-fold less than reported for other Nav channel subtypes despite evidence to support an interaction with the canonical local anesthetic (LA) binding region on Domain 4 S6. Nav1.9 Domain 2 S6 pore domain contains a unique lysine residue (K799) which is predicted to be spatially near the local anesthetic interaction site. Mutation of this residue to the consensus asparagine (K799N) resulted in an increase in potency for tetracaine, but a decrease for TC-N 1752, suggesting that this residue can influence interaction of inhibitors with the Nav1.9 pore. In summary, we have shown that stable functional expression of Nav1.9 in the widely used HEK-293 cells is possible, which opens up opportunities to better understand channel properties and may potentially aid identification of novel Nav1.9 based pharmacotherapies.
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Affiliation(s)
- Zhixin Lin
- Neuroscience and Pain Research Unit, Pfizer Inc., Durham, North Carolina, United States of America
- * E-mail:
| | - Sonia Santos
- Neuroscience and Pain Research Unit, Pfizer Inc., Durham, North Carolina, United States of America
| | - Karen Padilla
- Neuroscience and Pain Research Unit, Pfizer Inc., Durham, North Carolina, United States of America
| | - David Printzenhoff
- Neuroscience and Pain Research Unit, Pfizer Inc., Durham, North Carolina, United States of America
| | - Neil A. Castle
- Neuroscience and Pain Research Unit, Pfizer Inc., Durham, North Carolina, United States of America
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An oral NaV1.8 blocker improves motor function in mice completely deficient of myelin protein P0. Neurosci Lett 2016; 632:33-8. [PMID: 27530546 DOI: 10.1016/j.neulet.2016.08.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/11/2016] [Accepted: 08/12/2016] [Indexed: 01/06/2023]
Abstract
Mice deficient of myelin protein P0 are established models of demyelinating Charcot-Marie-Tooth (CMT) disease. Dysmyelination in these mice is associated with an ectopic expression of the sensory neuron specific sodium channel isoform NaV1.8 on motor axons. We reported that in P0+/-, a model of CMT1B, the membrane dysfunction could be acutely improved by a novel oral NaV1.8 blocker referred to as Compound 31 (C31, Bioorg. Med. Chem. Lett. 2010, 20, 6812; AbbVie Inc.). The aim of this study was to investigate the extent to which C31 treatment could also improve the motor axon function in P0-/-, a CMT model with a much more severe neuropathy. We found that the progressive impairment of motor performance from 1 to 4 months of age in P0-/- could be acutely reversed by C31 treatment. The effect was associated with an improvement of the amplitude of the plantar CMAP evoked by tibial nerve stimulation. The corresponding motor nerve excitability studies by "threshold tracking" showed changes after C31 consistent with attenuation of a resting membrane depolarization. Our data suggest that the depolarizing motor conduction failure in P0-/- could be acutely improved by C31. This provides proof-of-concept that treatment with oral subtype-selective NaV1.8 blockers could be used to improve the motor function in severe forms of demyelinating CMT.
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Luiz AP, Kopach O, Santana-Varela S, Wood JN. The role of Nav1.9 channel in the development of neuropathic orofacial pain associated with trigeminal neuralgia. Mol Pain 2015; 11:72. [PMID: 26607325 PMCID: PMC4658751 DOI: 10.1186/s12990-015-0076-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 11/12/2015] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Trigeminal neuralgia is accompanied by severe mechanical, thermal and chemical hypersensitivity of the orofacial area innervated by neurons of trigeminal ganglion (TG). We examined the role of the voltage-gated sodium channel subtype Nav1.9 in the development of trigeminal neuralgia. RESULTS We found that Nav1.9 is required for the development of both thermal and mechanical hypersensitivity induced by constriction of the infraorbital nerve (CION). The CION model does not induce change on Nav1.9 mRNA expression in the ipsilateral TG neurons when evaluated 9 days after surgery. CONCLUSIONS These results demonstrate that Nav1.9 channels play a critical role in the development of orofacial neuropathic pain. New routes for the treatment of orofacial neuropathic pain focussing on regulation of the voltage-gated Nav1.9 sodium channel activity should be investigated.
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Affiliation(s)
- Ana Paula Luiz
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower St, London, WC1E 6BT, UK.
| | - Olga Kopach
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower St, London, WC1E 6BT, UK.
| | - Sonia Santana-Varela
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower St, London, WC1E 6BT, UK.
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower St, London, WC1E 6BT, UK. .,Department of Molecular Medicine and Biopharmaceutical Sciences, College of Medicine, Seoul National University, Seoul, South Korea.
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Bonetti S, Pistone A, Brucale M, Karges S, Favaretto L, Zambianchi M, Posati T, Sagnella A, Caprini M, Toffanin S, Zamboni R, Camaioni N, Muccini M, Melucci M, Benfenati V. A lysinated thiophene-based semiconductor as a multifunctional neural bioorganic interface. Adv Healthc Mater 2015; 4:1190-202. [PMID: 25721438 DOI: 10.1002/adhm.201400786] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 01/28/2015] [Indexed: 11/08/2022]
Abstract
Lysinated molecular organic semiconductors are introduced as valuable multifunctional platforms for neural cells growth and interfacing. Cast films of quaterthiophene (T4) semiconductor covalently modified with lysine-end moieties (T4Lys) are fabricated and their stability, morphology, optical/electrical, and biocompatibility properties are characterized. T4Lys films exhibit fluorescence and electronic transport as generally observed for unsubstituted oligothiophenes combined to humidity-activated ionic conduction promoted by the charged lysine-end moieties. The Lys insertion in T4 enables adhesion of primary culture of rat dorsal root ganglion (DRG), which is not achievable by plating cells on T4. Notably, on T4Lys, the number on adhering neurons/area is higher and displays a twofold longer neurite length than neurons plated on glass coated with poly-l-lysine. Finally, by whole-cell patch-clamp, it is shown that the biofunctionality of neurons cultured on T4Lys is preserved. The present study introduces an innovative concept for organic material neural interface that combines optical and iono-electronic functionalities with improved biocompatibility and neuron affinity promoted by Lys linkage and the softness of organic semiconductors. Lysinated organic semiconductors could set the scene for the fabrication of simplified bioorganic devices geometry for cells bidirectional communication or optoelectronic control of neural cells biofunctionality.
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Affiliation(s)
- Simone Bonetti
- Consiglio Nazionale delle Ricerche (CNR); Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); via Gobetti, 101 40129 Bologna Italy
| | - Assunta Pistone
- Consiglio Nazionale delle Ricerche (CNR); Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); via Gobetti, 101 40129 Bologna Italy
- Consiglio Nazionale delle Ricerche (CNR); Istituto per la Sintesi Organica e la Fotoreattività (ISOF); via Gobetti, 101 40129 Bologna Italy
| | - Marco Brucale
- Consiglio Nazionale delle Ricerche (CNR); Istituto per lo studio dei Materiali Nanostrutturati (ISMN); Area della Ricerca Roma1; Via Salaria km 29.3 00015 Monterotondo, Roma Italy
| | - Saskia Karges
- Consiglio Nazionale delle Ricerche (CNR); Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); via Gobetti, 101 40129 Bologna Italy
| | - Laura Favaretto
- Consiglio Nazionale delle Ricerche (CNR); Istituto per la Sintesi Organica e la Fotoreattività (ISOF); via Gobetti, 101 40129 Bologna Italy
| | - Massimo Zambianchi
- Consiglio Nazionale delle Ricerche (CNR); Istituto per la Sintesi Organica e la Fotoreattività (ISOF); via Gobetti, 101 40129 Bologna Italy
| | - Tamara Posati
- Laboratory MIST E-R; Via Gobetti 101 40129 Bologna Italy
| | - Anna Sagnella
- Consiglio Nazionale delle Ricerche (CNR); Istituto per la Sintesi Organica e la Fotoreattività (ISOF); via Gobetti, 101 40129 Bologna Italy
- Laboratory MIST E-R; Via Gobetti 101 40129 Bologna Italy
| | - Marco Caprini
- Consiglio Nazionale delle Ricerche (CNR); Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); via Gobetti, 101 40129 Bologna Italy
- Department of Pharmacy and BioTechnology; University of Bologna; Via S. Donato 19/2 40127 Bologna Italy
| | - Stefano Toffanin
- Consiglio Nazionale delle Ricerche (CNR); Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); via Gobetti, 101 40129 Bologna Italy
| | - Roberto Zamboni
- Consiglio Nazionale delle Ricerche (CNR); Istituto per la Sintesi Organica e la Fotoreattività (ISOF); via Gobetti, 101 40129 Bologna Italy
| | - Nadia Camaioni
- Consiglio Nazionale delle Ricerche (CNR); Istituto per la Sintesi Organica e la Fotoreattività (ISOF); via Gobetti, 101 40129 Bologna Italy
| | - Michele Muccini
- Consiglio Nazionale delle Ricerche (CNR); Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); via Gobetti, 101 40129 Bologna Italy
| | - Manuela Melucci
- Consiglio Nazionale delle Ricerche (CNR); Istituto per la Sintesi Organica e la Fotoreattività (ISOF); via Gobetti, 101 40129 Bologna Italy
| | - Valentina Benfenati
- Consiglio Nazionale delle Ricerche (CNR); Istituto per la Sintesi Organica e la Fotoreattività (ISOF); via Gobetti, 101 40129 Bologna Italy
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Han C, Estacion M, Huang J, Vasylyev D, Zhao P, Dib-Hajj SD, Waxman SG. Human Na(v)1.8: enhanced persistent and ramp currents contribute to distinct firing properties of human DRG neurons. J Neurophysiol 2015; 113:3172-85. [PMID: 25787950 DOI: 10.1152/jn.00113.2015] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/13/2015] [Indexed: 12/19/2022] Open
Abstract
Although species-specific differences in ion channel properties are well-documented, little has been known about the properties of the human Nav1.8 channel, an important contributor to pain signaling. Here we show, using techniques that include voltage clamp, current clamp, and dynamic clamp in dorsal root ganglion (DRG) neurons, that human Na(v)1.8 channels display slower inactivation kinetics and produce larger persistent current and ramp current than previously reported in other species. DRG neurons expressing human Na(v)1.8 channels unexpectedly produce significantly longer-lasting action potentials, including action potentials with half-widths in some cells >10 ms, and increased firing frequency compared with the narrower and usually single action potentials generated by DRG neurons expressing rat Na(v)1.8 channels. We also show that native human DRG neurons recapitulate these properties of Na(v)1.8 current and the long-lasting action potentials. Together, our results demonstrate strikingly distinct properties of human Na(v)1.8, which contribute to the firing properties of human DRG neurons.
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Affiliation(s)
- Chongyang Han
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and Center for Neuroscience and Regeneration Research, Veterans Affairs Medical Center, West Haven, Connecticut
| | - Mark Estacion
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and Center for Neuroscience and Regeneration Research, Veterans Affairs Medical Center, West Haven, Connecticut
| | - Jianying Huang
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and Center for Neuroscience and Regeneration Research, Veterans Affairs Medical Center, West Haven, Connecticut
| | - Dymtro Vasylyev
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and Center for Neuroscience and Regeneration Research, Veterans Affairs Medical Center, West Haven, Connecticut
| | - Peng Zhao
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and Center for Neuroscience and Regeneration Research, Veterans Affairs Medical Center, West Haven, Connecticut
| | - Sulayman D Dib-Hajj
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and Center for Neuroscience and Regeneration Research, Veterans Affairs Medical Center, West Haven, Connecticut
| | - Stephen G Waxman
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and Center for Neuroscience and Regeneration Research, Veterans Affairs Medical Center, West Haven, Connecticut
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Valtcheva MV, Samineni VK, Golden JP, Gereau RW, Davidson S. Enhanced nonpeptidergic intraepidermal fiber density and an expanded subset of chloroquine-responsive trigeminal neurons in a mouse model of dry skin itch. THE JOURNAL OF PAIN 2015; 16:346-56. [PMID: 25640289 DOI: 10.1016/j.jpain.2015.01.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 01/08/2015] [Accepted: 01/16/2015] [Indexed: 12/13/2022]
Abstract
UNLABELLED Chronic pruritic conditions are often associated with dry skin and loss of epidermal barrier integrity. In this study, repeated application of acetone and ether followed by water (AEW) to the cheek skin of mice produced persistent scratching behavior with no increase in pain-related forelimb wiping, indicating the generation of itch without pain. Cheek skin immunohistochemistry showed a 64.5% increase in total epidermal innervation in AEW-treated mice compared to water-treated controls. This increase was independent of scratching, because mice prevented from scratching by Elizabethan collars showed similar hyperinnervation. To determine the effects of dry skin treatment on specific subsets of peripheral fibers, we examined Ret-positive, calcitonin gene-related peptide (CGRP)-positive, and glial cell line-derived neurotrophic factor family receptor α3 (GFRα3)-positive intraepidermal fiber density. AEW treatment increased Ret-positive fibers but not CGRP-positive or GFRα3-positive fibers, suggesting that a specific subset of nonpeptidergic fibers could contribute to dry skin itch. To test whether trigeminal ganglion neurons innervating the cheek exhibited altered excitability after AEW treatment, primary cultures of retrogradely labeled neurons were examined using whole-cell patch clamp electrophysiology. AEW treatment produced no differences in measures of excitability compared to water-treated controls. In contrast, a significantly higher proportion of trigeminal ganglion neurons was responsive to the nonhistaminergic pruritogen chloroquine after AEW treatment. We conclude that nonpeptidergic, Ret-positive fibers and chloroquine-sensitive neurons may contribute to dry skin pruritus. PERSPECTIVE This study examines the underlying neurobiological mechanisms of persistent dry skin itch. Our results indicate that nonpeptidergic epidermal hyperinnervation and nonhistaminergic pruritic receptors are potential targets for chronic pruritus.
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Affiliation(s)
- Manouela V Valtcheva
- Washington University Pain Center and Department of Anesthesiology, Washington University in St. Louis, St. Louis, Missouri; Medical Scientist Training Program, Washington University in St. Louis, St. Louis, Missouri
| | - Vijay K Samineni
- Washington University Pain Center and Department of Anesthesiology, Washington University in St. Louis, St. Louis, Missouri
| | - Judith P Golden
- Washington University Pain Center and Department of Anesthesiology, Washington University in St. Louis, St. Louis, Missouri
| | - Robert W Gereau
- Washington University Pain Center and Department of Anesthesiology, Washington University in St. Louis, St. Louis, Missouri
| | - Steve Davidson
- Washington University Pain Center and Department of Anesthesiology, Washington University in St. Louis, St. Louis, Missouri.
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Gudes S, Barkai O, Caspi Y, Katz B, Lev S, Binshtok AM. The role of slow and persistent TTX-resistant sodium currents in acute tumor necrosis factor-α-mediated increase in nociceptors excitability. J Neurophysiol 2015; 113:601-19. [PMID: 25355965 PMCID: PMC4297796 DOI: 10.1152/jn.00652.2014] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 10/26/2014] [Indexed: 12/12/2022] Open
Abstract
Tetrodotoxin-resistant (TTX-r) sodium channels are key players in determining the input-output properties of peripheral nociceptive neurons. Changes in gating kinetics or in expression levels of these channels by proinflammatory mediators are likely to cause the hyperexcitability of nociceptive neurons and pain hypersensitivity observed during inflammation. Proinflammatory mediator, tumor necrosis factor-α (TNF-α), is secreted during inflammation and is associated with the early onset, as well as long-lasting, inflammation-mediated increase in excitability of peripheral nociceptive neurons. Here we studied the underlying mechanisms of the rapid component of TNF-α-mediated nociceptive hyperexcitability and acute pain hypersensitivity. We showed that TNF-α leads to rapid onset, cyclooxygenase-independent pain hypersensitivity in adult rats. Furthermore, TNF-α rapidly and substantially increases nociceptive excitability in vitro, by decreasing action potential threshold, increasing neuronal gain and decreasing accommodation. We extended on previous studies entailing p38 MAPK-dependent increase in TTX-r sodium currents by showing that TNF-α via p38 MAPK leads to increased availability of TTX-r sodium channels by partial relief of voltage dependence of their slow inactivation, thereby contributing to increase in neuronal gain. Moreover, we showed that TNF-α also in a p38 MAPK-dependent manner increases persistent TTX-r current by shifting the voltage dependence of activation to a hyperpolarized direction, thus producing an increase in inward current at functionally critical subthreshold voltages. Our results suggest that rapid modulation of the gating of TTX-r sodium channels plays a major role in the mediated nociceptive hyperexcitability of TNF-α during acute inflammation and may lead to development of effective treatments for inflammatory pain, without modulating the inflammation-induced healing processes.
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Affiliation(s)
- Sagi Gudes
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University Faculty of Medicine, Jerusalem, Israel; and The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University, Jerusalem, Israel
| | - Omer Barkai
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University Faculty of Medicine, Jerusalem, Israel; and The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University, Jerusalem, Israel
| | - Yaki Caspi
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University Faculty of Medicine, Jerusalem, Israel; and The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University, Jerusalem, Israel
| | - Ben Katz
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University Faculty of Medicine, Jerusalem, Israel; and The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University, Jerusalem, Israel
| | - Shaya Lev
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University Faculty of Medicine, Jerusalem, Israel; and The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University, Jerusalem, Israel
| | - Alexander M Binshtok
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University Faculty of Medicine, Jerusalem, Israel; and The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University, Jerusalem, Israel
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Persistent modification of Nav1.9 following chronic exposure to insecticides and pyridostigmine bromide. Toxicol Appl Pharmacol 2014; 277:298-309. [DOI: 10.1016/j.taap.2014.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 03/14/2014] [Accepted: 04/03/2014] [Indexed: 12/21/2022]
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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.
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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,
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Common biological pathways underlying the psychoneurological symptom cluster in cancer patients. Cancer Nurs 2013; 35:E1-E20. [PMID: 22228391 DOI: 10.1097/ncc.0b013e318233a811] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND A symptom cluster is a group of symptoms that occur together and are interrelated. The clinical implication of symptom cluster research is to use the clustering patterns of symptoms to understand the mechanisms for these symptoms and develop management strategies targeted at multiple symptoms. OBJECTIVE The purposes of this review were to summarize the evidence for a psychoneurological symptom cluster in cancer patients, to provide information regarding the underlying biological mechanisms for each of the psychoneurological symptoms within the cluster, and to propose possible common biological pathways that may underlie this cluster. METHODS A systematic review of the literature was conducted. RESULTS Empirical evidence exists to support a cluster of psychoneurological symptoms (ie, depressive symptoms, cognitive disturbance, fatigue, sleep disturbance, pain). At a molecular level, common biological pathways (ie, proinflammatory cytokines, hypothalamic-pituitary-adrenal axis, and monoamine neurotransmission system) may underlie the development of symptoms within this cluster. Activation of proinflammatory cytokines is proposed as a first stage of mechanistic pathway. However, other biological factors, such as lowered estrogen or hemoglobin levels, may influence psychoneurological cluster. CONCLUSION Additional studies are needed to confirm the roles of cytokines as well as other biological factors in the development of the psychoneurological cluster and to determine the biomarkers to identify the subgroups of cancer patients who are at greatest risk for this cluster. IMPLICATIONS FOR PRACTICE This information can be used by researchers and clinicians to guide the selection of symptom management strategies that are ideally targeted to the biological mechanisms that underlie this symptom cluster.
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Liang J, Liu X, Zheng J, Yu S. Effect of amitriptyline on tetrodotoxin-resistant Nav1.9 currents in nociceptive trigeminal neurons. Mol Pain 2013; 9:31. [PMID: 24228717 PMCID: PMC3691845 DOI: 10.1186/1744-8069-9-31] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 06/14/2013] [Indexed: 12/19/2022] Open
Abstract
Background Amitriptyline (AMI) is tricyclic antidepressant that has been widely used to manage various chronic pains such as migraines. Its efficacy is attributed to its blockade of voltage-gated sodium channels (VGSCs). However, the effects of AMI on the tetrodotoxin-resistant (TTX-r) sodium channel Nav1.9 currents have been unclear to present. Results Using a whole-cell patch clamp technique, this study showed that AMI efficiently inhibited Nav1.9 currents in a concentration-dependent manner and had an IC50 of 15.16 μM in acute isolated trigeminal ganglion (TG) neurons of the rats. 10 μM AMI significantly shifted the steady-state inactivation of Nav1.9 channels in the hyperpolarizing direction without affecting voltage-dependent activation. Surprisingly, neither 10 nor 50 μM AMI caused a use-dependent blockade of Nav1.9 currents elicited by 60 pulses at 1 Hz. Conclusion These data suggest that AMI is a state-selective blocker of Nav1.9 channels in rat nociceptive trigeminal neurons, which likely contributes to the efficacy of AMI in treating various pains, including migraines.
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Affiliation(s)
- Jingyao Liang
- Department of Neurology, Chinese PLA General Hospital, Beijing 100853, PR China.
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Takeda M, Takahashi M, Hara N, Matsumoto S. Glial cell line-derived neurotrophic factor modulates the excitability of nociceptive trigeminal ganglion neurons via a paracrine mechanism following inflammation. Brain Behav Immun 2013; 28:100-7. [PMID: 23131757 DOI: 10.1016/j.bbi.2012.10.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 10/29/2012] [Indexed: 01/05/2023] Open
Abstract
Previous our report indicated that acute application of glial cell line-derived neurotrophic factor (GDNF) enhances the neuronal excitability of adult rat small-diameter trigeminal ganglion (TRG) neurons, which innervate the facial skin in the absence of neuropathic and inflammatory conditions. This study investigated whether under in vivo conditions, GDNF modulates the excitability of nociceptive Aδ-TRG neurons innervating the facial skin via a paracrine mechanism following inflammation. We used extracellular electrophysiological recording with multibarrel-electrodes in this study. Spontaneous Aδ-TRG neuronal activity was induced in control rats after iontophoretic application of GDNF into the trigeminal ganglia (TRGs). Noxious and non-noxious mechanical stimuli evoked Aδ-TRG neuronal firing rate were significantly increased by iontophoretic application of GDNF. The mean mechanical threshold of nociceptive TRG neurons was significantly decreased by GDNF application. The increased discharge frequency and decreased mechanical threshold induced by GDNF were antagonized by application of the protein tyrosine kinase inhibitor, K252b. The number of Aδ-TRG neurons with spontaneous firings and their firing rates in rats with inflammation induced by Complete Freund's Adjuvant were significantly higher than control rats. The firing rates of Aδ-TRG spontaneous neuronal activity were significantly decreased by iontophoretic application of K252b in inflamed rats. K252b also inhibited Aδ-TRG neuron activity evoked by mechanical stimulation in inflamed rats. These results suggest that in vivo GDNF enhances the excitability of nociceptive Aδ-TRG neurons via a paracrine mechanism within TRGs following inflammation. GDNF paracrine mechanism could be important as a therapeutic target for trigeminal inflammatory hyperalgesia.
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Affiliation(s)
- Mamoru Takeda
- Department of Physiology, School of Life Dentistry at Tokyo, Nippon Dental University, 1-9-20, Fujimi-cho, Chiyoda-ku, Tokyo 102-8159, Japan.
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Gilchrist J, Bosmans F. Animal toxins can alter the function of Nav1.8 and Nav1.9. Toxins (Basel) 2012; 4:620-32. [PMID: 23012651 PMCID: PMC3446747 DOI: 10.3390/toxins4080620] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 07/24/2012] [Accepted: 07/27/2012] [Indexed: 12/19/2022] Open
Abstract
Human voltage-activated sodium (Nav) channels are adept at rapidly transmitting electrical signals across long distances in various excitable tissues. As such, they are amongst the most widely targeted ion channels by drugs and animal toxins. Of the nine isoforms, Nav1.8 and Nav1.9 are preferentially expressed in DRG neurons where they are thought to play an important role in pain signaling. Although the functional properties of Nav1.8 have been relatively well characterized, difficulties with expressing Nav1.9 in established heterologous systems limit our understanding of the gating properties and toxin pharmacology of this particular isoform. This review summarizes our current knowledge of the role of Nav1.8 and Nav1.9 in pain perception and elaborates on the approaches used to identify molecules capable of influencing their function.
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Affiliation(s)
- John Gilchrist
- Department of Physiology, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA;
| | - Frank Bosmans
- Department of Physiology, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA;
- Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
- Author to whom correspondence should be addressed; ; Tel.: +1-410-955-4428
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Hoeijmakers JGJ, Merkies ISJ, Gerrits MM, Waxman SG, Faber CG. Genetic aspects of sodium channelopathy in small fiber neuropathy. Clin Genet 2012; 82:351-8. [PMID: 22803682 DOI: 10.1111/j.1399-0004.2012.01937.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 07/11/2012] [Accepted: 07/11/2012] [Indexed: 12/12/2022]
Abstract
Small fiber neuropathy (SFN) is a disorder typically dominated by neuropathic pain and autonomic dysfunction, in which the thinly myelinated Aδ-fibers and unmyelinated C-fibers are selectively injured. The diagnosis SFN is based on a reduced intraepidermal nerve fiber density and/or abnormal thermal thresholds in quantitative sensory testing. The etiologies of SFN are diverse, although no apparent cause is frequently seen. Recently, SCN9A-gene variants (single amino acid substitutions) have been found in ∼30% of a cohort of idiopathic SFN patients, producing gain-of-function changes in sodium channel Na(V)1.7, which is preferentially expressed in small diameter peripheral axons. Functional testing showed that these variants altered fast inactivation, slow inactivation or resurgent current and rendered dorsal root ganglion neurons hyperexcitable. In this review, we discuss the role of Na(V)1.7 in pain and highlight the molecular genetics and pathophysiology of SCN9A-gene variants in SFN. With increasing knowledge regarding the underlying pathophysiology in SFN, the development of specific treatment in these patients seems a logical target for future studies.
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Affiliation(s)
- J G J Hoeijmakers
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
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Ramachandra R, McGrew SY, Baxter JC, Kiveric E, Elmslie KS. Tetrodotoxin-resistant voltage-dependent sodium channels in identified muscle afferent neurons. J Neurophysiol 2012; 108:2230-41. [PMID: 22855776 DOI: 10.1152/jn.00219.2012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Muscle afferents are critical regulators of motor function (Group I and II) and cardiovascular responses to exercise (Group III and IV). However, little is known regarding the expressed voltage-dependent ion channels. We identified muscle afferent neurons in dorsal root ganglia (DRGs), using retrograde labeling to examine voltage-dependent sodium (Na(V)) channels. In patch-clamp recordings, we found that the dominant Na(V) current in the majority of identified neurons was insensitive to tetrodotoxin (TTX-R), with Na(V) current in only a few (14%) neurons showing substantial (>50%) TTX sensitivity (TTX-S). The TTX-R current was sensitive to a Na(V)1.8 channel blocker, A803467. Immunocytochemistry demonstrated labeling of muscle afferent neurons by a Na(V)1.8 antibody, which further supported expression of these channels. A portion of the TTX-R Na(V) current appeared to be noninactivating during our 25-ms voltage steps, which suggested activity of Na(V)1.9 channels. The majority of the noninactivating current was insensitive to A803467 but sensitive to extracellular sodium. Immunocytochemistry showed labeling of muscle afferent neurons by a Na(V)1.9 channel antibody, which supports expression of these channels. Further examination of the muscle afferent neurons showed that functional TTX-S channels were expressed, but were largely inactivated at physiological membrane potentials. Immunocytochemistry showed expression of the TTX-S channels Na(V)1.6 and Na(V)1.7 but not Na(V)1.1. Na(V)1.8 and Na(V)1.9 appear to be the dominant functional sodium channels in small- to medium-diameter muscle afferent neurons. The expression of these channels is consistent with the identification of these neurons as Group III and IV, which mediate the exercise pressor reflex.
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Affiliation(s)
- Renuka Ramachandra
- The Baker Laboratory of Pharmacology, Department of Pharmacology, Kirksville College of Osteopathic Medicine, AT Still University of Health Sciences, Kirksville, MO 63501, USA
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Increased expression of tetrodotoxin-resistant sodium channels Nav1.8 and Nav1.9 within dorsal root ganglia in a rat model of bone cancer pain. Neurosci Lett 2012; 512:61-6. [DOI: 10.1016/j.neulet.2012.01.069] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 01/27/2012] [Accepted: 01/28/2012] [Indexed: 11/22/2022]
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Ren YS, Qian NS, Tang Y, Liao YH, Yang YL, Dou KF, Toi M. Sodium channel Nav1.6 is up-regulated in the dorsal root ganglia in a mouse model of type 2 diabetes. Brain Res Bull 2012; 87:244-9. [DOI: 10.1016/j.brainresbull.2011.10.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Revised: 10/02/2011] [Accepted: 10/24/2011] [Indexed: 10/15/2022]
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Tetrodotoxin (TTX) as a therapeutic agent for pain. Mar Drugs 2012; 10:281-305. [PMID: 22412801 PMCID: PMC3296997 DOI: 10.3390/md10020281] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 01/19/2012] [Accepted: 01/19/2012] [Indexed: 12/19/2022] Open
Abstract
Tetrodotoxin (TTX) is a potent neurotoxin that blocks voltage-gated sodium channels (VGSCs). VGSCs play a critical role in neuronal function under both physiological and pathological conditions. TTX has been extensively used to functionally characterize VGSCs, which can be classified as TTX-sensitive or TTX-resistant channels according to their sensitivity to this toxin. Alterations in the expression and/or function of some specific TTX-sensitive VGSCs have been implicated in a number of chronic pain conditions. The administration of TTX at doses below those that interfere with the generation and conduction of action potentials in normal (non-injured) nerves has been used in humans and experimental animals under different pain conditions. These data indicate a role for TTX as a potential therapeutic agent for pain. This review focuses on the preclinical and clinical evidence supporting a potential analgesic role for TTX. In addition, the contribution of specific TTX-sensitive VGSCs to pain is reviewed.
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Shi JY, Liu GS, Liu LF, Kuo SM, Ton CH, Wen ZH, Tee R, Chen CH, Huang HT, Chen CL, Chao D, Tai MH. Glial cell line-derived neurotrophic factor gene transfer exerts protective effect on axons in sciatic nerve following constriction-induced peripheral nerve injury. Hum Gene Ther 2011; 22:721-31. [PMID: 21604994 DOI: 10.1089/hum.2010.036] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Damage to peripheral nerves following trauma or neurodegenerative diseases often results in various sensory and motor abnormalities and chronic neuropathic pain. The loss of neurotrophic factor support has been proposed to contribute to the development of peripheral neuropathy. The main objective of this study was to investigate the protective effect of glial cell line-derived neurotrophic factor (GDNF) using peripheral gene delivery in a rat model of constriction-induced peripheral nerve injury. In this study, it was shown that mechanical and thermal hypersensitivity increased on the injured limb at day 7 after chronic constrictive injury (CCI) was induced. The neurological changes were correlated with the structural changes and loss of GDNF/Akt signaling, particularly in the distal stump of the injured sciatic nerve. Subsequently, recombinant adenovirus was employed to evaluate the potential of intramuscular GDNF gene delivery to alleviate the CCI-induced nerve degeneration ad neuropathic pain. After CCI for 3 days, intramuscular injection of adenovirus encoding GDNF (Ad-GDNF) restored the protein level and activity of GDNF/Akt signaling pathway in the sciatic nerve. This was associated with an improved myelination profile and behavioral outcomes in animals with CCI. In conclusion, the present study demonstrates the involvement of GDNF loss in the pathogenesis of CCI-induced neuropathic pain and the therapeutic potential of intramuscular GDNF gene delivery for the treatment of peripheral nerve degeneration.
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Affiliation(s)
- Jhih-Yin Shi
- Institute of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
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Wang W, Gu J, Li YQ, Tao YX. Are voltage-gated sodium channels on the dorsal root ganglion involved in the development of neuropathic pain? Mol Pain 2011; 7:16. [PMID: 21345196 PMCID: PMC3052185 DOI: 10.1186/1744-8069-7-16] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 02/23/2011] [Indexed: 12/17/2022] Open
Abstract
Neuropathic pain is a common clinical condition. Current treatments are often inadequate, ineffective, or produce potentially severe adverse effects. Understanding the mechanisms that underlie the development and maintenance of neuropathic pain will be helpful in identifying new therapeutic targets and developing effective strategies for the prevention and/or treatment of this disorder. The genesis of neuropathic pain is reliant, at least in part, on abnormal spontaneous activity within sensory neurons. Therefore, voltage-gated sodium channels, which are essential for the generation and conduction of action potentials, are potential targets for treating neuropathic pain. However, preclinical studies have shown unexpected results because most pain-associated voltage-gated channels in the dorsal root ganglion are down-regulated after peripheral nerve injury. The role of dorsal root ganglion voltage-gated channels in neuropathic pain is still unclear. In this report, we describe the expression and distribution of voltage-gated sodium channels in the dorsal root ganglion. We also review evidence regarding changes in their expression under neuropathic pain conditions and their roles in behavioral responses in a variety of neuropathic pain models. We finally discuss their potential involvement in neuropathic pain.
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Affiliation(s)
- Wei Wang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Lee JH, Yu HS, Lee GS, Ji A, Hyun JK, Kim HW. Collagen gel three-dimensional matrices combined with adhesive proteins stimulate neuronal differentiation of mesenchymal stem cells. J R Soc Interface 2011; 8:998-1010. [PMID: 21247946 DOI: 10.1098/rsif.2010.0613] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Three-dimensional gel matrices provide specialized microenvironments that mimic native tissues and enable stem cells to grow and differentiate into specific cell types. Here, we show that collagen three-dimensional gel matrices prepared in combination with adhesive proteins, such as fibronectin (FN) and laminin (LN), provide significant cues to the differentiation into neuronal lineage of mesenchymal stem cells (MSCs) derived from rat bone marrow. When cultured within either a three-dimensional collagen gel alone or one containing either FN or LN, and free of nerve growth factor (NGF), the MSCs showed the development of numerous neurite outgrowths. These were, however, not readily observed in two-dimensional culture without the use of NGF. Immunofluorescence staining, western blot and fluorescence-activated cell sorting analyses demonstrated that a large population of cells was positive for NeuN and glial fibrillary acidic protein, which are specific to neuronal cells, when cultured in the three-dimensional collagen gel. The dependence of the neuronal differentiation of MSCs on the adhesive proteins containing three-dimensional gel matrices is considered to be closely related to focal adhesion kinase (FAK) activation through integrin receptor binding, as revealed by an experiment showing no neuronal outgrowth in the FAK-knockdown cells and stimulation of integrin β1 gene. The results provided herein suggest the potential role of three-dimensional collagen-based gel matrices combined with adhesive proteins in the neuronal differentiation of MSCs, even without the use of chemical differentiation factors. Furthermore, these findings suggest that three-dimensional gel matrices might be useful as nerve-regenerative scaffolds.
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Affiliation(s)
- Jae Ho Lee
- Institute of Tissue Regeneration Engineering (ITREN), Dankook University, , South Korea
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Gallaher ZR, Larios RM, Ryu V, Sprunger LK, Czaja K. Recovery of viscerosensory innervation from the dorsal root ganglia of the adult rat following capsaicin-induced injury. J Comp Neurol 2010; 518:3529-40. [DOI: 10.1002/cne.22412] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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42
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Abstract
Nociception is essential for survival whereas pathological pain is maladaptive and often unresponsive to pharmacotherapy. Voltage-gated sodium channels, Na(v)1.1-Na(v)1.9, are essential for generation and conduction of electrical impulses in excitable cells. Human and animal studies have identified several channels as pivotal for signal transmission along the pain axis, including Na(v)1.3, Na(v)1.7, Na(v)1.8, and Na(v)1.9, with the latter three preferentially expressed in peripheral sensory neurons and Na(v)1.3 being upregulated along pain-signaling pathways after nervous system injuries. Na(v)1.7 is of special interest because it has been linked to a spectrum of inherited human pain disorders. Here we review the contribution of these sodium channel isoforms to pain.
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Affiliation(s)
- Sulayman D Dib-Hajj
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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43
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Kistner K, Zimmermann K, Ehnert C, Reeh PW, Leffler A. The tetrodotoxin-resistant Na+ channel Nav1.8 reduces the potency of local anesthetics in blocking C-fiber nociceptors. Pflugers Arch 2010; 459:751-63. [DOI: 10.1007/s00424-010-0785-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 01/03/2010] [Accepted: 01/07/2010] [Indexed: 10/19/2022]
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Linley JE, Rose K, Ooi L, Gamper N. Understanding inflammatory pain: ion channels contributing to acute and chronic nociception. Pflugers Arch 2010; 459:657-69. [DOI: 10.1007/s00424-010-0784-6] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 01/04/2010] [Accepted: 01/06/2010] [Indexed: 02/06/2023]
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Undem BJ, Carr MJ. Targeting primary afferent nerves for novel antitussive therapy. Chest 2010; 137:177-84. [PMID: 20051402 DOI: 10.1378/chest.09-1960] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The best available data support the hypothesis that there are at least two types of vagal nerves responsible for initiating coughing reflexes. One type of nerve conducts action potentials in the A-range and is characterized by rapidly adapting responses to mechanical probing or acidification of the large airway epithelium. Stimulation of these nerves can evoke cough in unconscious experimental animals and humans. These nerves are important in immediate cough evoked by aspiration and as such perform a critical role in airway defense. The other type of primary afferent nerve involved in cough is the vagal C-fiber. Inhalation of selective C-fiber stimulants leads to cough only in conscious animals. In clinical studies, inhalation of a low concentration of a C-fiber stimulant causes an irritating, itchy urge-to-cough sensation that mimics the urge-to-cough sensations associated with respiratory tract infection, post-infection, gastroesophageal reflux disorders, and inflammatory airway diseases. Here we discuss the recent advances in sensory neurobiology that allow for the targeting of vagal C-fibers for novel antitussive therapy. No attempts are made to be all-inclusive with respect to the numerous possible molecular targets being considered to accomplish this goal. Rather, two general strategies are discussed: decreasing generator potential amplitude and decreasing the efficiency by which a generator potential evokes action-potential discharge. For the first category we focus on two targets, transient receptor potential vanilloid 1 and transient receptor potential A1. For the latter category we focus on recent advances in voltage-gated sodium (Na(V)) channel biology.
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Affiliation(s)
- Bradley J Undem
- Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA.
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46
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Takeda M, Kitagawa J, Nasu M, Takahashi M, Iwata K, Matsumoto S. Glial cell line-derived neurotrophic factor acutely modulates the excitability of rat small-diameter trigeminal ganglion neurons innervating facial skin. Brain Behav Immun 2010; 24:72-82. [PMID: 19679180 DOI: 10.1016/j.bbi.2009.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 07/14/2009] [Accepted: 08/05/2009] [Indexed: 12/31/2022] Open
Abstract
Glial cell line-derived neurotrophic factor (GDNF) plays an important role in adult sensory neuron function. However, the acute effects of GDNF on primary sensory neuron excitability remain to be elucidated. The aim of the present study was to investigate whether GDNF acutely modulates the excitability of adult rat trigeminal ganglion (TRG) neurons that innervate the facial skin by using perforated-patch clamping, retrograde-labeling and immunohistochemistry techniques. Fluorogold (FG) retrograde labeling was used to identify the TRG neurons innervating the facial skin. The FG-labeled small- and medium-diameter GDNF immunoreactive TRG neurons, and most of these neurons also expressed the GDNF family receptor alpha-1 (GFRalpha-1). In whole-cell voltage-clamp mode, GDNF application significantly inhibited voltage-gated K(+) transient (I(A)) and sustained (I(K)) currents in most dissociated FG-labeled small-diameter TRG neurons. This effect was concentration-dependent and was abolished by co-application of the protein tyrosine kinase inhibitor, K252b. Under current-clamp conditions, the repetitive firing during a depolarizing pulse were significantly increased by GDNF application. GDNF application also increased the duration of the repolarization phase and decreased the duration of the depolarization phase of the action potential, and these characteristic effects were also abolished by co-application of K252b. These results suggest that acute application of GDNF enhances the neuronal excitability of adult rat small-diameter TRG neurons innervating the facial skin, via activation of GDNF-induced intracellular signaling pathway. We therefore conclude that a local release of GDNF from TRG neuronal soma and/or nerve terminals may regulate normal sensory function, including nociception.
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Affiliation(s)
- Mamoru Takeda
- Department of Physiology, School of Life Dentistry at Tokyo, Nippon Dental University, 1-9-20, Fujimi-cho, Chiyoda-ku, Tokyo 102-8159, Japan.
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Dib-Hajj SD, Black JA, Waxman SG. Voltage-Gated Sodium Channels: Therapeutic Targets for Pain. PAIN MEDICINE 2009; 10:1260-9. [DOI: 10.1111/j.1526-4637.2009.00719.x] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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McAlexander MA, Carr MJ. Peripheral mechanisms I: plasticity of peripheral pathways. Handb Exp Pharmacol 2008:129-54. [PMID: 18825339 DOI: 10.1007/978-3-540-79842-2_7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cough plays a vital role in protecting the lower airways from inhaled irritants, pollutants, and infectious agents. The cough reflex exhibits remarkable plasticity, such that in the context of infectious or inflammatory respiratory diseases such as asthma, chronic bronchitis, and idiopathic pulmonary fibrosis the cough reflex can become dysregulated, leading to a chronic cough. A chronic, nonproductive (dry) cough can rob sufferers of quality of life. Plasticity of the cough reflex likely involves multiple intersecting pathways within the airways, the peripheral nerves that supply them, and the central nervous system. While further studies are needed to determine the presence and relevance of many of these specific pathways in cough associated with chronic respiratory disease, the last decade has yielded unprecedented insight into the molecular identity of the ion channels and associated proteins that initiate and conduct action potentials in the primary sensory nerves involved in reflexes such as cough. We now know, for instance, that members of the transient receptor potential superfamily of nonselective cation channels function as transducers that convert specific external stimuli into neuronal activation. We also know that certain Na+ and K+ channels play specialized roles in regulating action potential discharge in irritant-sensing afferent nerves. In this chapter, we summarize the available information regarding factors that may modulate afferent neuron function acutely, via posttranslational modifications and over the longer term through neurotrophin-dependent alterations of the transcriptional programs of adult sensory neurons.
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Affiliation(s)
- M A McAlexander
- GlaxoSmithKline, 709 Swedeland Rd, King of Prussia, PA 19406, USA
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Fukuoka T, Kobayashi K, Yamanaka H, Obata K, Dai Y, Noguchi K. Comparative study of the distribution of the alpha-subunits of voltage-gated sodium channels in normal and axotomized rat dorsal root ganglion neurons. J Comp Neurol 2008; 510:188-206. [PMID: 18615542 DOI: 10.1002/cne.21786] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We compared the distribution of the alpha-subunit mRNAs of voltage-gated sodium channels Nav1.1-1.3 and Nav1.6-1.9 and a related channel, Nax, in histochemically identified neuronal subpopulations of the rat dorsal root ganglia (DRG). In the naïve DRG, the expression of Nav1.1 and Nav1.6 was restricted to A-fiber neurons, and they were preferentially expressed by TrkC neurons, suggesting that proprioceptive neurons possess these channels. Nav1.7, -1.8, and -1.9 mRNAs were more abundant in C-fiber neurons compared with A-fiber ones. Nax was evenly expressed in both populations. Although Nav1.8 and -1.9 were preferentially expressed by TrkA neurons, other alpha-subunits were expressed independently of TrkA expression. Actually, all IB4(+) neurons expressed both Nav1.8 and -1.9, and relatively limited subpopulations of IB4(+) neurons (3% and 12%, respectively) expressed Nav1.1 and/or Nav1.6. These findings provide useful information in interpreting the electrophysiological characteristics of some neuronal subpopulations of naïve DRG. After L5 spinal nerve ligation, Nav1.3 mRNA was up-regulated mainly in A-fiber neurons in the ipsilateral L5 DRG. Although previous studies demonstrated that nerve growth factor (NGF) and glial cell-derived neurotrophic factor (GDNF) reversed this up-regulation, the Nav1.3 induction was independent of either TrkA or GFRalpha1 expression, suggesting that the induction of Nav1.3 may be one of the common responses of axotomized DRG neurons without a direct relationship to NGF/GDNF supply.
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Affiliation(s)
- Tetsuo Fukuoka
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan.
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