1
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Wisedchaisri G, Gamal El-Din TM, Powell NM, Zheng N, Catterall WA. Structural basis for severe pain caused by mutations in the voltage sensors of sodium channel NaV1.7. J Gen Physiol 2023; 155:e202313450. [PMID: 37903281 PMCID: PMC10616507 DOI: 10.1085/jgp.202313450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/11/2023] [Accepted: 10/10/2023] [Indexed: 11/01/2023] Open
Abstract
Voltage-gated sodium channels in peripheral nerves conduct nociceptive signals from nerve endings to the spinal cord. Mutations in voltage-gated sodium channel NaV1.7 are responsible for a number of severe inherited pain syndromes, including inherited erythromelalgia (IEM). Here, we describe the negative shifts in the voltage dependence of activation in the bacterial sodium channel NaVAb as a result of the incorporation of four different IEM mutations in the voltage sensor, which recapitulate the gain-of-function effects observed with these mutations in human NaV1.7. Crystal structures of NaVAb with these IEM mutations revealed that a mutation in the S1 segment of the voltage sensor facilitated the outward movement of S4 gating charges by widening the pathway for gating charge translocation. In contrast, mutations in the S4 segments modified hydrophobic interactions with surrounding amino acid side chains or membrane phospholipids that would enhance the outward movement of the gating charges. These results provide key structural insights into the mechanisms by which these IEM mutations in the voltage sensors can facilitate outward movements of the gating charges in the S4 segment and cause hyperexcitability and severe pain in IEM. Our work gives new insights into IEM pathogenesis at the near-atomic level and provides a molecular model for mutation-specific therapy of this debilitating disease.
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Affiliation(s)
| | | | - Natasha M. Powell
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
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2
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Schroder RV, Cohen LS, Wang P, Arizala JD, Poget SF. Expression, Purification and Refolding of a Human Na V1.7 Voltage Sensing Domain with Native-like Toxin Binding Properties. Toxins (Basel) 2021; 13:toxins13100722. [PMID: 34679015 PMCID: PMC8541342 DOI: 10.3390/toxins13100722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 01/28/2023] Open
Abstract
The voltage-gated sodium channel NaV1.7 is an important target for drug development due to its role in pain perception. Recombinant expression of full-length channels and their use for biophysical characterization of interactions with potential drug candidates is challenging due to the protein size and complexity. To overcome this issue, we developed a protocol for the recombinant expression in E. coli and refolding into lipids of the isolated voltage sensing domain (VSD) of repeat II of NaV1.7, obtaining yields of about 2 mg of refolded VSD from 1 L bacterial cell culture. This VSD is known to be involved in the binding of a number of gating-modifier toxins, including the tarantula toxins ProTx-II and GpTx-I. Binding studies using microscale thermophoresis showed that recombinant refolded VSD binds both of these toxins with dissociation constants in the high nM range, and their relative binding affinities reflect the relative IC50 values of these toxins for full-channel inhibition. Additionally, we expressed mutant VSDs incorporating single amino acid substitutions that had previously been shown to affect the activity of ProTx-II on full channel. We found decreases in GpTx-I binding affinity for these mutants, consistent with a similar binding mechanism for GpTx-I as compared to that of ProTx-II. Therefore, this recombinant VSD captures many of the native interactions between NaV1.7 and tarantula gating-modifier toxins and represents a valuable tool for elucidating details of toxin binding and specificity that could help in the design of non-addictive pain medication acting through NaV1.7 inhibition.
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Affiliation(s)
- Ryan V. Schroder
- Department of Chemistry, College of Staten Island, University of New York, 2800 Victory Blvd., Staten Island, NY 10314, USA; (R.V.S.); (L.S.C.); (P.W.); (J.D.A.)
- The Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
| | - Leah S. Cohen
- Department of Chemistry, College of Staten Island, University of New York, 2800 Victory Blvd., Staten Island, NY 10314, USA; (R.V.S.); (L.S.C.); (P.W.); (J.D.A.)
| | - Ping Wang
- Department of Chemistry, College of Staten Island, University of New York, 2800 Victory Blvd., Staten Island, NY 10314, USA; (R.V.S.); (L.S.C.); (P.W.); (J.D.A.)
| | - Joekeem D. Arizala
- Department of Chemistry, College of Staten Island, University of New York, 2800 Victory Blvd., Staten Island, NY 10314, USA; (R.V.S.); (L.S.C.); (P.W.); (J.D.A.)
- The Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
| | - Sébastien F. Poget
- Department of Chemistry, College of Staten Island, University of New York, 2800 Victory Blvd., Staten Island, NY 10314, USA; (R.V.S.); (L.S.C.); (P.W.); (J.D.A.)
- The Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- The Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- Correspondence:
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3
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Punjani A, Fleet DJ. 3D variability analysis: Resolving continuous flexibility and discrete heterogeneity from single particle cryo-EM. J Struct Biol 2021; 213:107702. [PMID: 33582281 DOI: 10.1016/j.jsb.2021.107702] [Citation(s) in RCA: 405] [Impact Index Per Article: 135.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 01/12/2021] [Accepted: 01/26/2021] [Indexed: 01/06/2023]
Abstract
Single particle cryo-EM excels in determining static structures of protein molecules, but existing 3D reconstruction methods have been ineffective in modelling flexible proteins. We introduce 3D variability analysis (3DVA), an algorithm that fits a linear subspace model of conformational change to cryo-EM data at high resolution. 3DVA enables the resolution and visualization of detailed molecular motions of both large and small proteins, revealing new biological insight from single particle cryo-EM data. Experimental results demonstrate the ability of 3DVA to resolve multiple flexible motions of α-helices in the sub-50 kDa transmembrane domain of a GPCR complex, bending modes of a sodium ion channel, five types of symmetric and symmetry-breaking flexibility in a proteasome, large motions in a spliceosome complex, and discrete conformational states of a ribosome assembly. 3DVA is implemented in the cryoSPARC software package.
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Affiliation(s)
- Ali Punjani
- Department of Computer Sciences, University of Toronto M5S 3G4, Canada; Vector Institute, 710-661 University Ave., Toronto M5G 1M1, Canada; Structura Biotechnology Inc., 129-100 College Ave., Toronto M5G 1L5, Canada.
| | - David J Fleet
- Department of Computer Sciences, University of Toronto M5S 3G4, Canada; Vector Institute, 710-661 University Ave., Toronto M5G 1M1, Canada.
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4
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Wisedchaisri G, Tonggu L, Gamal El-Din TM, McCord E, Zheng N, Catterall WA. Structural Basis for High-Affinity Trapping of the Na V1.7 Channel in Its Resting State by Tarantula Toxin. Mol Cell 2021; 81:38-48.e4. [PMID: 33232657 PMCID: PMC8043720 DOI: 10.1016/j.molcel.2020.10.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/14/2020] [Accepted: 10/28/2020] [Indexed: 11/17/2022]
Abstract
Voltage-gated sodium channels initiate electrical signals and are frequently targeted by deadly gating-modifier neurotoxins, including tarantula toxins, which trap the voltage sensor in its resting state. The structural basis for tarantula-toxin action remains elusive because of the difficulty of capturing the functionally relevant form of the toxin-channel complex. Here, we engineered the model sodium channel NaVAb with voltage-shifting mutations and the toxin-binding site of human NaV1.7, an attractive pain target. This mutant chimera enabled us to determine the cryoelectron microscopy (cryo-EM) structure of the channel functionally arrested by tarantula toxin. Our structure reveals a high-affinity resting-state-specific toxin-channel interaction between a key lysine residue that serves as a "stinger" and penetrates a triad of carboxyl groups in the S3-S4 linker of the voltage sensor. By unveiling this high-affinity binding mode, our studies establish a high-resolution channel-docking and resting-state locking mechanism for huwentoxin-IV and provide guidance for developing future resting-state-targeted analgesic drugs.
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Affiliation(s)
| | - Lige Tonggu
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | | | - Eedann McCord
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
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5
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Kerth CM, Hautvast P, Körner J, Lampert A, Meents JE. Phosphorylation of a chronic pain mutation in the voltage-gated sodium channel Nav1.7 increases voltage sensitivity. J Biol Chem 2021; 296:100227. [PMID: 33361158 PMCID: PMC7948457 DOI: 10.1074/jbc.ra120.014288] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 12/17/2020] [Accepted: 12/22/2020] [Indexed: 12/19/2022] Open
Abstract
Mutations in voltage-gated sodium channels (Navs) can cause alterations in pain sensation, such as chronic pain diseases like inherited erythromelalgia. The mutation causing inherited erythromelalgia, Nav1.7 p.I848T, is known to induce a hyperpolarized shift in the voltage dependence of activation in Nav1.7. So far, however, the mechanism to explain this increase in voltage sensitivity remains unknown. In the present study, we show that phosphorylation of the newly introduced Thr residue explains the functional change. We expressed wildtype human Nav1.7, the I848T mutant, or other mutations in HEK293T cells and performed whole-cell patch-clamp electrophysiology. As the insertion of a Thr residue potentially creates a novel phosphorylation site for Ser/Thr kinases and because Nav1.7 had been shown in Xenopus oocytes to be affected by protein kinases C and A, we used different nonselective and selective kinase inhibitors and activators to test the effect of phosphorylation on Nav1.7 in a human system. We identify protein kinase C, but not protein kinase A, to be responsible for the phosphorylation of T848 and thereby for the shift in voltage sensitivity. Introducing a negatively charged amino acid instead of the putative phosphorylation site mimics the effect on voltage gating to a lesser extent. 3D modeling using the published cryo-EM structure of human Nav1.7 showed that introduction of this negatively charged site seems to alter the interaction of this residue with the surrounding amino acids and thus to influence channel function. These results could provide new opportunities for the development of novel treatment options for patients with chronic pain.
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Affiliation(s)
- Clara M Kerth
- Institute of Physiology, Uniklinik RWTH Aachen University, Aachen, Germany
| | - Petra Hautvast
- Institute of Physiology, Uniklinik RWTH Aachen University, Aachen, Germany
| | - Jannis Körner
- Institute of Physiology, Uniklinik RWTH Aachen University, Aachen, Germany; Department of Anesthesiology, Uniklinik RWTH Aachen University, Aachen, Germany
| | - Angelika Lampert
- Institute of Physiology, Uniklinik RWTH Aachen University, Aachen, Germany
| | - Jannis E Meents
- Institute of Physiology, Uniklinik RWTH Aachen University, Aachen, Germany.
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6
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Pajouhesh H, Beckley JT, Delwig A, Hajare HS, Luu G, Monteleone D, Zhou X, Ligutti J, Amagasu S, Moyer BD, Yeomans DC, Du Bois J, Mulcahy JV. Discovery of a selective, state-independent inhibitor of Na V1.7 by modification of guanidinium toxins. Sci Rep 2020; 10:14791. [PMID: 32908170 PMCID: PMC7481244 DOI: 10.1038/s41598-020-71135-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 08/06/2020] [Indexed: 12/15/2022] Open
Abstract
The voltage-gated sodium channel isoform NaV1.7 is highly expressed in dorsal root ganglion neurons and is obligatory for nociceptive signal transmission. Genetic gain-of-function and loss-of-function NaV1.7 mutations have been identified in select individuals, and are associated with episodic extreme pain disorders and insensitivity to pain, respectively. These findings implicate NaV1.7 as a key pharmacotherapeutic target for the treatment of pain. While several small molecules targeting NaV1.7 have been advanced to clinical development, no NaV1.7-selective compound has shown convincing efficacy in clinical pain applications. Here we describe the discovery and characterization of ST-2262, a NaV1.7 inhibitor that blocks the extracellular vestibule of the channel with an IC50 of 72 nM and greater than 200-fold selectivity over off-target sodium channel isoforms, NaV1.1-1.6 and NaV1.8. In contrast to other NaV1.7 inhibitors that preferentially inhibit the inactivated state of the channel, ST-2262 is equipotent in a protocol that favors the resting state of the channel, a protocol that favors the inactivated state, and a high frequency protocol. In a non-human primate study, animals treated with ST-2262 exhibited reduced sensitivity to noxious heat. These findings establish the extracellular vestibule of the sodium channel as a viable receptor site for the design of selective ligands targeting NaV1.7.
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Affiliation(s)
- H Pajouhesh
- SiteOne Therapeutics, South San Francisco, CA, 94080, USA
| | - J T Beckley
- SiteOne Therapeutics, Bozeman, MT, 59715, USA
| | - A Delwig
- SiteOne Therapeutics, South San Francisco, CA, 94080, USA
| | - H S Hajare
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - G Luu
- SiteOne Therapeutics, South San Francisco, CA, 94080, USA
| | - D Monteleone
- SiteOne Therapeutics, South San Francisco, CA, 94080, USA
| | - X Zhou
- SiteOne Therapeutics, South San Francisco, CA, 94080, USA
| | - J Ligutti
- Neuroscience Department, Amgen Research, Thousand Oaks, CA, 91320, USA
| | - S Amagasu
- Neuroscience Department, Amgen Research, Thousand Oaks, CA, 91320, USA
| | - B D Moyer
- Neuroscience Department, Amgen Research, Thousand Oaks, CA, 91320, USA
| | - D C Yeomans
- Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University, Stanford, CA, 94305, USA
| | - J Du Bois
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - J V Mulcahy
- SiteOne Therapeutics, South San Francisco, CA, 94080, USA.
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7
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Agwa AJ, Tran P, Mueller A, Tran HNT, Deuis JR, Israel MR, McMahon KL, Craik DJ, Vetter I, Schroeder CI. Manipulation of a spider peptide toxin alters its affinity for lipid bilayers and potency and selectivity for voltage-gated sodium channel subtype 1.7. J Biol Chem 2020; 295:5067-5080. [PMID: 32139508 PMCID: PMC7152767 DOI: 10.1074/jbc.ra119.012281] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/03/2020] [Indexed: 02/05/2023] Open
Abstract
Huwentoxin-IV (HwTx-IV) is a gating modifier peptide toxin from spiders that has weak affinity for the lipid bilayer. As some gating modifier toxins have affinity for model lipid bilayers, a tripartite relationship among gating modifier toxins, voltage-gated ion channels, and the lipid membrane surrounding the channels has been proposed. We previously designed an HwTx-IV analogue (gHwTx-IV) with reduced negative charge and increased hydrophobic surface profile, which displays increased lipid bilayer affinity and in vitro activity at the voltage-gated sodium channel subtype 1.7 (NaV1.7), a channel targeted in pain management. Here, we show that replacements of the positively-charged residues that contribute to the activity of the peptide can improve gHwTx-IV's potency and selectivity for NaV1.7. Using HwTx-IV, gHwTx-IV, [R26A]gHwTx-IV, [K27A]gHwTx-IV, and [R29A]gHwTx-IV variants, we examined their potency and selectivity at human NaV1.7 and their affinity for the lipid bilayer. [R26A]gHwTx-IV consistently displayed the most improved potency and selectivity for NaV1.7, examined alongside off-target NaVs, compared with HwTx-IV and gHwTx-IV. The lipid affinity of each of the three novel analogues was weaker than that of gHwTx-IV, but stronger than that of HwTx-IV, suggesting a possible relationship between in vitro potency at NaV1.7 and affinity for lipid bilayers. In a murine NaV1.7 engagement model, [R26A]gHwTx-IV exhibited an efficacy comparable with that of native HwTx-IV. In summary, this study reports the development of an HwTx-IV analogue with improved in vitro selectivity for the pain target NaV1.7 and with an in vivo efficacy similar to that of native HwTx-IV.
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Affiliation(s)
- Akello J Agwa
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Poanna Tran
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Alexander Mueller
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Hue N T Tran
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mathilde R Israel
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Kirsten L McMahon
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
- School of Pharmacy, The University of Queensland, Woolloongabba, Queensland 4103, Australia
| | - Christina I Schroeder
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
- National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, USA
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8
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Mulcahy JV, Pajouhesh H, Beckley JT, Delwig A, Bois JD, Hunter JC. Challenges and Opportunities for Therapeutics Targeting the Voltage-Gated Sodium Channel Isoform Na V1.7. J Med Chem 2019; 62:8695-8710. [PMID: 31012583 PMCID: PMC6786914 DOI: 10.1021/acs.jmedchem.8b01906] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Voltage-gated sodium ion channel subtype 1.7 (NaV1.7) is a high interest target for the discovery of non-opioid analgesics. Compelling evidence from human genetic data, particularly the finding that persons lacking functional NaV1.7 are insensitive to pain, has spurred considerable effort to develop selective inhibitors of this Na+ ion channel target as analgesic medicines. Recent clinical setbacks and disappointing performance of preclinical compounds in animal pain models, however, have led to skepticism around the potential of selective NaV1.7 inhibitors as human therapeutics. In this Perspective, we discuss the attributes and limitations of recently disclosed investigational drugs targeting NaV1.7 and review evidence that, by better understanding the requirements for selectivity and target engagement, the opportunity to deliver effective analgesic medicines targeting NaV1.7 endures.
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Affiliation(s)
- John V. Mulcahy
- SiteOne Therapeutics, 280 Utah Ave, Suite 250, South San Francisco, CA 94080
| | - Hassan Pajouhesh
- SiteOne Therapeutics, 280 Utah Ave, Suite 250, South San Francisco, CA 94080
| | - Jacob T. Beckley
- SiteOne Therapeutics, 351 Evergreen Drive, Suite B1, Bozeman, MT 59715
| | - Anton Delwig
- SiteOne Therapeutics, 280 Utah Ave, Suite 250, South San Francisco, CA 94080
| | - J. Du Bois
- Stanford University, Lokey Chemistry and Biology, 337 Campus Drive, Stanford, CA 94305
| | - John C. Hunter
- SiteOne Therapeutics, 280 Utah Ave, Suite 250, South San Francisco, CA 94080
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9
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Abstract
Chronic pain is a significant unmet medical problem. Current research regarding sodium channel function in pathological pain is advancing with the hope that it will enable the development of isoform-specific sodium channel blockers, a promising treatment for chronic pain. Before advancements in the pharmacological field, an elucidation of the roles of Nav1.7 and Nav1.8 in the pathophysiology of pain states is required. Thus, the aim of this report is to present what is currently known about the contributions of these sodium channel subtypes in the pathophysiology of neuropathic and inflammatory pain. The electrophysiological properties and localisation of sodium channel isoforms is discussed. Research concerning the genetic links of Nav1.7 and Nav1.8 in acquired neuropathic and inflammatory pain states from the scientific literature in this field is reported. The role of Nav1.7 and Nav1.8 in the generation and maintenance of abnormal neuronal electrogenesis and hyperexcitability highlights the importance of these channels in the development of pathological pain. However, further research in this area is required to fully elucidate the roles of Nav1.7 and Nav1.8 in the pathophysiology of pain for the development of subtype-specific sodium channel blockers.
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Affiliation(s)
- Shaila Hameed
- Department of Physiology, King’s College London, London, UK
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10
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Isbell HM, Kilpatrick AM, Lin Z, Mahling R, Shea MA. Backbone resonance assignments of complexes of apo human calmodulin bound to IQ motif peptides of voltage-dependent sodium channels Na V1.1, Na V1.4 and Na V1.7. Biomol NMR Assign 2018; 12:283-289. [PMID: 29728980 PMCID: PMC6274588 DOI: 10.1007/s12104-018-9824-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/29/2018] [Indexed: 06/08/2023]
Abstract
Human voltage-gated sodium (NaV) channels are critical for initiating and propagating action potentials in excitable cells. Nine isoforms have different roles but similar topologies, with a pore-forming α-subunit and auxiliary transmembrane β-subunits. NaV pathologies lead to debilitating conditions including epilepsy, chronic pain, cardiac arrhythmias, and skeletal muscle paralysis. The ubiquitous calcium sensor calmodulin (CaM) binds to an IQ motif in the C-terminal tail of the α-subunit of all NaV isoforms, and contributes to calcium-dependent pore-gating in some channels. Previous structural studies of calcium-free (apo) CaM bound to the IQ motifs of NaV1.2, NaV1.5, and NaV1.6 showed that CaM binding was mediated by the C-domain of CaM (CaMC), while the N-domain (CaMN) made no detectable contacts. To determine whether this domain-specific recognition mechanism is conserved in other NaV isoforms, we used solution NMR spectroscopy to assign the backbone resonances of complexes of apo CaM bound to peptides of IQ motifs of NaV1.1, NaV1.4, and NaV1.7. Analysis of chemical shift differences showed that peptide binding only perturbed resonances in CaMC; resonances of CaMN were identical to free CaM. Thus, CaMC residues contribute to the interface with the IQ motif, while CaMN is available to interact elsewhere on the channel.
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Affiliation(s)
- Holly M Isbell
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242-1109, USA
| | - Adina M Kilpatrick
- Department of Physics and Astronomy, Drake University, Des Moines, IA, 50311-4516, USA
| | - Zesen Lin
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242-1109, USA
| | - Ryan Mahling
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242-1109, USA
| | - Madeline A Shea
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242-1109, USA.
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11
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François-Moutal L, Scott DD, Perez-Miller S, Gokhale V, Khanna M, Khanna R. Chemical shift perturbation mapping of the Ubc9-CRMP2 interface identifies a pocket in CRMP2 amenable for allosteric modulation of Nav1.7 channels. Channels (Austin) 2018; 12:219-227. [PMID: 30081699 PMCID: PMC6104687 DOI: 10.1080/19336950.2018.1491244] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 06/06/2018] [Indexed: 02/08/2023] Open
Abstract
Drug discovery campaigns directly targeting the voltage-gated sodium channel NaV1.7, a highly prized target in chronic pain, have not yet been clinically successful. In a differentiated approach, we demonstrated allosteric control of trafficking and activity of NaV1.7 by prevention of SUMOylation of collapsin response mediator protein 2 (CRMP2). Spinal administration of a SUMOylation incompetent CRMP2 (CRMP2 K374A) significantly attenuated pain behavior in the spared nerve injury (SNI) model of neuropathic pain, underscoring the importance of SUMOylation of CRMP2 as a pathologic event in chronic pain. Using a rational design strategy, we identified a heptamer peptide harboring CRMP2's SUMO motif that disrupted the CRMP2-Ubc9 interaction, inhibited CRMP2 SUMOylation, inhibited NaV1.7 membrane trafficking, and specifically inhibited NaV1.7 sodium influx in sensory neurons. Importantly, this peptide reversed nerve injury-induced thermal and mechanical hypersensitivity in the SNI model, supporting the practicality of discovering pain drugs by indirectly targeting NaV1.7 via prevention of CRMP2 SUMOylation. Here, our goal was to map the unique interface between CRMP2 and Ubc9, the E2 SUMO conjugating enzyme. Using computational and biophysical approaches, we demonstrate the enzyme/substrate nature of Ubc9/CRMP2 binding and identify hot spots on CRMP2 that may form the basis of future drug discovery campaigns disrupting the CRMP2-Ubc9 interaction to recapitulate allosteric regulation of NaV1.7 for pain relief.
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Affiliation(s)
| | - David Donald Scott
- Departments of Pharmacology College of Medicine, University of Arizona, Tucson, Arizona USA
| | - Samantha Perez-Miller
- Departments of Pharmacology College of Medicine, University of Arizona, Tucson, Arizona USA
| | - Vijay Gokhale
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ
| | - May Khanna
- Departments of Pharmacology College of Medicine, University of Arizona, Tucson, Arizona USA
- Neuroscience Graduate Interdisciplinary Program, College of Medicine, University of Arizona, Tucson, Arizona USA
- The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, AZ, USA
| | - Rajesh Khanna
- Departments of Pharmacology College of Medicine, University of Arizona, Tucson, Arizona USA
- Neuroscience Graduate Interdisciplinary Program, College of Medicine, University of Arizona, Tucson, Arizona USA
- The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, AZ, USA
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12
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Körner J, Meents J, Machtens J, Lampert A. β1 subunit stabilises sodium channel Nav1.7 against mechanical stress. J Physiol 2018; 596:2433-2445. [PMID: 29659026 PMCID: PMC6002208 DOI: 10.1113/jp275905] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/06/2018] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS The voltage-gated sodium channel Nav1.7 is a key player in neuronal excitability and pain signalling. In addition to voltage sensing, the channel is also modulated by mechanical stress. Using whole-cell patch-clamp experiments, we discovered that the sodium channel subunit β1 is able to prevent the impact of mechanical stress on Nav1.7. An intramolecular disulfide bond of β1 was identified to be essential for stabilisation of inactivation, but not activation, against mechanical stress using molecular dynamics simulations, homology modelling and site-directed mutagenesis. Our results highlight the role of segment 6 of domain IV in fast inactivation. We present a candidate mechanism for sodium channel stabilisation against mechanical stress, ensuring reliable channel functionality in living systems. ABSTRACT Voltage-gated sodium channels are key players in neuronal excitability and pain signalling. Precise gating of these channels is crucial as even small functional alterations can lead to pathological phenotypes such as pain or heart failure. Mechanical stress has been shown to affect sodium channel activation and inactivation. This suggests that stabilising components are necessary to ensure precise channel gating in living organisms. Here, we show that mechanical shear stress affects voltage dependence of activation and fast inactivation of the Nav1.7 channel. Co-expression of the β1 subunit, however, protects both gating modes of Nav1.7 against mechanical shear stress. Using molecular dynamics simulation, homology modelling and site-directed mutagenesis, we identify an intramolecular disulfide bond of β1 (Cys21-Cys43) which is partially involved in this process: the β1-C43A mutant prevents mechanical modulation of voltage dependence of activation, but not of fast inactivation. Our data emphasise the unique role of segment 6 of domain IV for sodium channel fast inactivation and confirm previous reports that the intracellular process of fast inactivation can be modified by interfering with the extracellular end of segment 6 of domain IV. Thus, our data suggest that physiological gating of Nav1.7 may be protected against mechanical stress in a living organism by assembly with the β1 subunit.
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Affiliation(s)
- Jannis Körner
- Institute of PhysiologyRWTH Aachen UniversityPauwelsstrasse 30Aachen52074Germany
- Institute of Complex Systems, Zelluläre Biophysik (ICS‐4) and JARA‐HPCForschungszentrum JülichJülichGermany
| | - Jannis Meents
- Institute of PhysiologyRWTH Aachen UniversityPauwelsstrasse 30Aachen52074Germany
| | - Jan‐Philipp Machtens
- Institute of Complex Systems, Zelluläre Biophysik (ICS‐4) and JARA‐HPCForschungszentrum JülichJülichGermany
| | - Angelika Lampert
- Institute of PhysiologyRWTH Aachen UniversityPauwelsstrasse 30Aachen52074Germany
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Yang Y, Adi T, Effraim PR, Chen L, Dib‐Hajj SD, Waxman SG. Reverse pharmacogenomics: carbamazepine normalizes activation and attenuates thermal hyperexcitability of sensory neurons due to Na v 1.7 mutation I234T. Br J Pharmacol 2018; 175:2261-2271. [PMID: 28658526 PMCID: PMC5980548 DOI: 10.1111/bph.13935] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/17/2017] [Accepted: 06/05/2017] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND PURPOSE Pharmacotherapy for pain currently involves trial and error. A previous study on inherited erythromelalgia (a genetic model of neuropathic pain due to mutations in the sodium channel, Nav 1.7) used genomics, structural modelling and biophysical and pharmacological analyses to guide pharmacotherapy and showed that carbamazepine normalizes voltage dependence of activation of the Nav 1.7-S241T mutant channel, reducing pain in patients carrying this mutation. However, whether this approach is applicable to other Nav channel mutants is still unknown. EXPERIMENTAL APPROACH We used structural modelling, patch clamp and multi-electrode array (MEA) recording to assess the effects of carbamazepine on Nav 1.7-I234T mutant channels and on the firing of dorsal root ganglion (DRG) sensory neurons expressing these mutant channels. KEY RESULTS In a reverse engineering approach, structural modelling showed that the I234T mutation is located in atomic proximity to the carbamazepine-responsive S241T mutation and that activation of Nav 1.7-I234T mutant channels, from patients who are known to respond to carbamazepine, is partly normalized with a clinically relevant concentration (30 μM) of carbamazepine. There was significantly higher firing in intact sensory neurons expressing Nav 1.7-I234T channels, compared with neurons expressing the normal channels (Nav 1.7-WT). Pre-incubation with 30 μM carbamazepine also significantly reduced the firing of intact DRG sensory neurons expressing Nav 1.7-I234T channels. Although the expected use-dependent inhibition of Nav 1.7-WT channels by carbamazepine was confirmed, carbamazepine did not enhance use-dependent inhibition of Nav 1.7-I234T mutant channels. CONCLUSION AND IMPLICATIONS These results support the utility of a pharmacogenomic approach to treatment of pain in patients carrying sodium channel variants. 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)
- Yang Yang
- Department of NeurologyYale University School of MedicineNew HavenCTUSA
- Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenCTUSA
- Rehabilitation Research CenterVA Connecticut Healthcare SystemWest HavenCTUSA
| | - Talia Adi
- Department of NeurologyYale University School of MedicineNew HavenCTUSA
- Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenCTUSA
- Rehabilitation Research CenterVA Connecticut Healthcare SystemWest HavenCTUSA
| | - Philip R Effraim
- Department of NeurologyYale University School of MedicineNew HavenCTUSA
- Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenCTUSA
- Rehabilitation Research CenterVA Connecticut Healthcare SystemWest HavenCTUSA
- Department of AnesthesiologyYale University School of MedicineNew HavenCTUSA
| | - Lubin Chen
- Department of NeurologyYale University School of MedicineNew HavenCTUSA
- Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenCTUSA
- Rehabilitation Research CenterVA Connecticut Healthcare SystemWest HavenCTUSA
| | - Sulayman D Dib‐Hajj
- Department of NeurologyYale University School of MedicineNew HavenCTUSA
- Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenCTUSA
- Rehabilitation Research CenterVA Connecticut Healthcare SystemWest HavenCTUSA
| | - Stephen G Waxman
- Department of NeurologyYale University School of MedicineNew HavenCTUSA
- Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenCTUSA
- Rehabilitation Research CenterVA Connecticut Healthcare SystemWest HavenCTUSA
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Godazgar M, Zhang Q, Chibalina MV, Rorsman P. Biphasic voltage-dependent inactivation of human Na V 1.3, 1.6 and 1.7 Na + channels expressed in rodent insulin-secreting cells. J Physiol 2018; 596:1601-1626. [PMID: 29441586 PMCID: PMC5924821 DOI: 10.1113/jp275587] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/06/2018] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Na+ current inactivation is biphasic in insulin-secreting cells, proceeding with two voltage dependences that are half-maximal at ∼-100 mV and -60 mV. Inactivation of voltage-gated Na+ (NaV ) channels occurs at ∼30 mV more negative voltages in insulin-secreting Ins1 and primary β-cells than in HEK, CHO or glucagon-secreting αTC1-6 cells. The difference in inactivation between Ins1 and non-β-cells persists in the inside-out patch configuration, discounting an involvement of a diffusible factor. In Ins1 cells and primary β-cells, but not in HEK cells, inactivation of a single NaV subtype is biphasic and follows two voltage dependences separated by 30-40 mV. We propose that NaV channels adopt different inactivation behaviours depending on the local membrane environment. ABSTRACT Pancreatic β-cells are equipped with voltage-gated Na+ channels that undergo biphasic voltage-dependent steady-state inactivation. A small Na+ current component (10-15%) inactivates over physiological membrane potentials and contributes to action potential firing. However, the major Na+ channel component is completely inactivated at -90 to -80 mV and is therefore inactive in the β-cell. It has been proposed that the biphasic inactivation reflects the contribution of different NaV α-subunits. We tested this possibility by expression of TTX-resistant variants of the NaV subunits found in β-cells (NaV 1.3, NaV 1.6 and NaV 1.7) in insulin-secreting Ins1 cells and in non-β-cells (including HEK and CHO cells). We found that all NaV subunits inactivated at 20-30 mV more negative membrane potentials in Ins1 cells than in HEK or CHO cells. The more negative inactivation in Ins1 cells does not involve a diffusible intracellular factor because the difference between Ins1 and CHO persisted after excision of the membrane. NaV 1.7 inactivated at 15--20 mV more negative membrane potentials than NaV 1.3 and NaV 1.6 in Ins1 cells but this small difference is insufficient to solely explain the biphasic inactivation in Ins1 cells. In Ins1 cells, but never in the other cell types, widely different components of NaV inactivation (separated by 30 mV) were also observed following expression of a single type of NaV α-subunit. The more positive component exhibited a voltage dependence of inactivation similar to that found in HEK and CHO cells. We propose that biphasic NaV inactivation in insulin-secreting cells reflects insertion of channels in membrane domains that differ with regard to lipid and/or membrane protein composition.
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Affiliation(s)
- Mahdieh Godazgar
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineUniversity of OxfordChurchill HospitalOxfordOX3 7LEUK
| | - Quan Zhang
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineUniversity of OxfordChurchill HospitalOxfordOX3 7LEUK
| | - Margarita V. Chibalina
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineUniversity of OxfordChurchill HospitalOxfordOX3 7LEUK
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineUniversity of OxfordChurchill HospitalOxfordOX3 7LEUK
- Metabolic PhysiologyDepartment of Neuroscience and PhysiologyMedicinaregatan 11GothenburgS‐413 09Sweden
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Bang S, Yoo J, Gong X, Liu D, Han Q, Luo X, Chang W, Chen G, Im ST, Kim YH, Strong JA, Zhang MZ, Zhang JM, Lee SY, Ji RR. Differential Inhibition of Nav1.7 and Neuropathic Pain by Hybridoma-Produced and Recombinant Monoclonal Antibodies that Target Nav1.7 : Differential activities of Nav1.7-targeting monoclonal antibodies. Neurosci Bull 2018; 34:22-41. [PMID: 29333591 PMCID: PMC5799132 DOI: 10.1007/s12264-018-0203-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 12/18/2017] [Indexed: 12/21/2022] Open
Abstract
The voltage-gated Na+ channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na+ currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na+ currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na+ currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.
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Affiliation(s)
- Sangsu Bang
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Jiho Yoo
- Department of Biochemistry, Duke University Medical Center, 303 Research Drive, Durham, NC, 27710, USA
| | - Xingrui Gong
- Pain Research Center, Department of Anesthesiology, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267-0531, USA
- Department of Anesthesiology, Shanghai Children's Medical Center, Shanghai, 200127, China
| | - Di Liu
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Qingjian Han
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Xin Luo
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Wonseok Chang
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
- Department of Physiology and Biophysics, College of Medicine, Eulji University, 143-5 Yongdu-Dong, Jung-Gu, Daejeon, 34824, Korea
| | - Gang Chen
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
| | - Sang-Taek Im
- Department of Physiology, College of Medicine, Gachon University, Incheon, 21999, Korea
| | - Yong Ho Kim
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA
- Department of Physiology, College of Medicine, Gachon University, Incheon, 21999, Korea
| | - Judith A Strong
- Pain Research Center, Department of Anesthesiology, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267-0531, USA
| | - Ma-Zhong Zhang
- Department of Anesthesiology, Shanghai Children's Medical Center, Shanghai, 200127, China
| | - Jun-Ming Zhang
- Pain Research Center, Department of Anesthesiology, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267-0531, USA.
| | - Seok-Yong Lee
- Department of Biochemistry, Duke University Medical Center, 303 Research Drive, Durham, NC, 27710, USA.
| | - Ru-Rong Ji
- Department of Anesthesiology, Duke University Medical Center, 595 LaSalle St, Durham, NC, 27710, USA.
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Duque HM, Mourão CBF, Tibery DV, Barbosa EA, Campos LA, Schwartz EF. To4, the first Tityus obscurus β-toxin fully electrophysiologically characterized on human sodium channel isoforms. Peptides 2017; 95:106-115. [PMID: 28735770 DOI: 10.1016/j.peptides.2017.07.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 12/19/2022]
Abstract
Many scorpion toxins that act on sodium channels (NaScTxs) have been characterized till date. These toxins may act modulating the inactivation or the activation of sodium channels and are named α- or β-types, respectively. Some venom toxins from Tityus obscurus (Buthidae), a scorpion widely distributed in the Brazilian Amazon, have been partially characterized in previous studies; however, little information about their electrophysiological role on sodium ion channels has been published. In the present study, we describe the purification, identification and electrophysiological characterization of a NaScTx, which was first described as Tc54 and further fully sequenced and renamed To4. This toxin shows a marked β-type effect on different sodium channel subtypes (hNav1.1-hNav1.7) at low concentrations, and has more pronounced activity on hNav1.1, hNav1.2 and hNav1.4. By comparing To4 primary structure with other Tityus β-toxins which have already been electrophysiologically tested, it is possible to establish some key amino acid residues for the sodium channel activity. Thus, To4 is the first toxin from T. obscurus fully electrophysiologically characterized on different human sodium channel isoforms.
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Affiliation(s)
- Harry Morales Duque
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Instituto de Ciências Biológicas, Brasília, 70910-900, DF, Brazil
| | - Caroline Barbosa Farias Mourão
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Instituto de Ciências Biológicas, Brasília, 70910-900, DF, Brazil; Instituto Federal de Educação, Ciência e Tecnologia de Brasília, Campus Ceilândia, Brasília 72220-260, DF, Brazil
| | - Diogo Vieira Tibery
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Instituto de Ciências Biológicas, Brasília, 70910-900, DF, Brazil
| | - Eder Alves Barbosa
- LSAB - Laboratório de Síntese e Análise de Biomoléculas, Instituto de Química, Universidade de Brasília, Brasília 70910-900, DF, Brazil
| | - Leandro Ambrósio Campos
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Instituto de Ciências Biológicas, Brasília, 70910-900, DF, Brazil
| | - Elisabeth Ferroni Schwartz
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Instituto de Ciências Biológicas, Brasília, 70910-900, DF, Brazil.
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Kapetis D, Sassone J, Yang Y, Galbardi B, Xenakis MN, Westra RL, Szklarczyk R, Lindsey P, Faber CG, Gerrits M, Merkies ISJ, Dib-Hajj SD, Mantegazza M, Waxman SG, Lauria G. Network topology of NaV1.7 mutations in sodium channel-related painful disorders. BMC Syst Biol 2017; 11:28. [PMID: 28235406 PMCID: PMC5324268 DOI: 10.1186/s12918-016-0382-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 12/20/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Gain-of-function mutations in SCN9A gene that encodes the voltage-gated sodium channel NaV1.7 have been associated with a wide spectrum of painful syndromes in humans including inherited erythromelalgia, paroxysmal extreme pain disorder and small fibre neuropathy. These mutations change the biophysical properties of NaV1.7 channels leading to hyperexcitability of dorsal root ganglion nociceptors and pain symptoms. There is a need for better understanding of how gain-of-function mutations alter the atomic structure of Nav1.7. RESULTS We used homology modeling to build an atomic model of NaV1.7 and a network-based theoretical approach, which can predict interatomic interactions and connectivity arrangements, to investigate how pain-related NaV1.7 mutations may alter specific interatomic bonds and cause connectivity rearrangement, compared to benign variants and polymorphisms. For each amino acid substitution, we calculated the topological parameters betweenness centrality (B ct ), degree (D), clustering coefficient (CC ct ), closeness (C ct ), and eccentricity (E ct ), and calculated their variation (Δ value = mutant value -WT value ). Pathogenic NaV1.7 mutations showed significantly higher variation of |ΔB ct | compared to benign variants and polymorphisms. Using the cut-off value ±0.26 calculated by receiver operating curve analysis, we found that ΔB ct correctly differentiated pathogenic NaV1.7 mutations from variants not causing biophysical abnormalities (nABN) and homologous SNPs (hSNPs) with 76% sensitivity and 83% specificity. CONCLUSIONS Our in-silico analyses predict that pain-related pathogenic NaV1.7 mutations may affect the network topological properties of the protein and suggest |ΔB ct | value as a potential in-silico marker.
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Affiliation(s)
- Dimos Kapetis
- Bioinformatics Unit, IRCCS Foundation “Carlo Besta” Neurological Institute, Milan, Italy
- Neuroalgology Unit, IRCCS Foundation “Carlo Besta” Neurological Institute, Milan, Italy
| | - Jenny Sassone
- Neuroalgology Unit, IRCCS Foundation “Carlo Besta” Neurological Institute, Milan, Italy
- Present address: San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | - Yang Yang
- Department of Neurology, Yale University School of Medicine, New Haven, USA
- Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, USA
| | - Barbara Galbardi
- Bioinformatics Unit, IRCCS Foundation “Carlo Besta” Neurological Institute, Milan, Italy
| | - Markos N. Xenakis
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Knowledge Engineering, Maastricht University, Maastricht, The Netherlands
| | - Ronald L. Westra
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Knowledge Engineering, Maastricht University, Maastricht, The Netherlands
| | - Radek Szklarczyk
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Patrick Lindsey
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Catharina G. Faber
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Monique Gerrits
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ingemar S. J. Merkies
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Neurology, Spaarne Hospital, Hoofddorp, The Netherlands
| | - Sulayman D. Dib-Hajj
- Department of Neurology, Yale University School of Medicine, New Haven, USA
- Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, USA
| | - Massimo Mantegazza
- Laboratory of Excellence Ion Channel Science and Therapeutics, Institute of Molecular and Cellular Pharmacology, CNRS UMR7275 & University of Nice-Sophia Antipolis, Valbonne, France
| | - Stephen G. Waxman
- Department of Neurology, Yale University School of Medicine, New Haven, USA
- Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, USA
| | - Giuseppe Lauria
- Neuroalgology Unit, IRCCS Foundation “Carlo Besta” Neurological Institute, Milan, Italy
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18
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Wang Y, Mi J, Lu K, Lu Y, Wang K. Comparison of Gating Properties and Use-Dependent Block of Nav1.5 and Nav1.7 Channels by Anti-Arrhythmics Mexiletine and Lidocaine. PLoS One 2015; 10:e0128653. [PMID: 26068619 PMCID: PMC4465899 DOI: 10.1371/journal.pone.0128653] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/29/2015] [Indexed: 12/19/2022] Open
Abstract
Mexiletine and lidocaine are widely used class IB anti-arrhythmic drugs that are considered to act by blocking voltage-gated open sodium currents for treatment of ventricular arrhythmias and relief of pain. To gain mechanistic insights into action of anti-arrhythmics, we characterized biophysical properties of Nav1.5 and Nav1.7 channels stably expressed in HEK293 cells and compared their use-dependent block in response to mexiletine and lidocaine using whole-cell patch clamp recordings. While the voltage-dependent activation of Nav1.5 or Nav1.7 was not affected by mexiletine and lidocaine, the steady-state fast and slow inactivation of Nav1.5 and Nav1.7 were significantly shifted to hyperpolarized direction by either mexiletine or lidocaine in dose-dependent manner. Both mexiletine and lidocaine enhanced the slow component of closed-state inactivation, with mexiletine exerting stronger inhibition on either Nav1.5 or Nav1.7. The recovery from inactivation of Nav1.5 or Nav1.7 was significantly prolonged by mexiletine compared to lidocaine. Furthermore, mexiletine displayed a pronounced and prominent use-dependent inhibition of Nav1.5 than lidocaine, but not Nav1.7 channels. Taken together, our findings demonstrate differential responses to blockade by mexiletine and lidocaine that preferentially affect the gating of Nav1.5, as compared to Nav1.7; and mexiletine exhibits stronger use-dependent block of Nav1.5. The differential gating properties of Nav1.5 and Nav1.7 in response to mexiletine and lidocaine may help explain the drug effectiveness and advance in new designs of safe and specific sodium channel blockers for treatment of cardiac arrhythmia or pain.
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Affiliation(s)
- Ying Wang
- Biomedical Research Institute, Shenzhen Peking University-Hong Kong University of Science and Technology Medical Center, Shenzhen 518036, China
| | - Jianxun Mi
- Key Laboratory of Computational Intelligence, College of Computer Science and Technology, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Ka Lu
- Department of Molecular and Cellular Pharmacology, State Key Laboratory of Natural and Biomimetic Drugs, Peking University School of Pharmaceutical Sciences, Beijing 100191, China
| | - Yanxin Lu
- Biomedical Research Institute, Shenzhen Peking University-Hong Kong University of Science and Technology Medical Center, Shenzhen 518036, China
- Department of Molecular and Cellular Pharmacology, State Key Laboratory of Natural and Biomimetic Drugs, Peking University School of Pharmaceutical Sciences, Beijing 100191, China
| | - KeWei Wang
- Biomedical Research Institute, Shenzhen Peking University-Hong Kong University of Science and Technology Medical Center, Shenzhen 518036, China
- Department of Molecular and Cellular Pharmacology, State Key Laboratory of Natural and Biomimetic Drugs, Peking University School of Pharmaceutical Sciences, Beijing 100191, China
- Department of Pharmacology, Qingdao University School of Pharmacy, Qingdao 266021, China
- * E-mail:
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Koenig J, Werdehausen R, Linley JE, Habib AM, Vernon J, Lolignier S, Eijkelkamp N, Zhao J, Okorokov AL, Woods CG, Wood JN, Cox JJ. Regulation of Nav1.7: A Conserved SCN9A Natural Antisense Transcript Expressed in Dorsal Root Ganglia. PLoS One 2015; 10:e0128830. [PMID: 26035178 PMCID: PMC4452699 DOI: 10.1371/journal.pone.0128830] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 04/30/2015] [Indexed: 11/19/2022] Open
Abstract
The Nav1.7 voltage-gated sodium channel, encoded by SCN9A, is critical for human pain perception yet the transcriptional and post-transcriptional mechanisms that regulate this gene are still incompletely understood. Here, we describe a novel natural antisense transcript (NAT) for SCN9A that is conserved in humans and mice. The NAT has a similar tissue expression pattern to the sense gene and is alternatively spliced within dorsal root ganglia. The human and mouse NATs exist in cis with the sense gene in a tail-to-tail orientation and both share sequences that are complementary to the terminal exon of SCN9A/Scn9a. Overexpression analyses of the human NAT in human embryonic kidney (HEK293A) and human neuroblastoma (SH-SY5Y) cell lines show that it can function to downregulate Nav1.7 mRNA, protein levels and currents. The NAT may play an important role in regulating human pain thresholds and is a potential candidate gene for individuals with chronic pain disorders that map to the SCN9A locus, such as Inherited Primary Erythromelalgia, Paroxysmal Extreme Pain Disorder and Painful Small Fibre Neuropathy, but who do not contain mutations in the sense gene. Our results strongly suggest the SCN9A NAT as a prime candidate for new therapies based upon augmentation of existing antisense RNAs in the treatment of chronic pain conditions in man.
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Affiliation(s)
- Jennifer Koenig
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
| | - Robert Werdehausen
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
- Department of Anesthesiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Moorenstr. 5, Düsseldorf, Germany
| | - John E. Linley
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
| | - Abdella M. Habib
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
| | - Jeffrey Vernon
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
| | - Stephane Lolignier
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
| | - Niels Eijkelkamp
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
- Laboratory for Translational Immunology, UMC Utrecht, Utrecht, The Netherlands
| | - Jing Zhao
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
| | - Andrei L. Okorokov
- Wolfson Institute for Biomedical Research, University College London, Gower street, London, United Kingdom
| | - C. Geoffrey Woods
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge, United Kingdom
| | - John N. Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, College of Medicine, Seoul National University, Seoul, South Korea
| | - James J. Cox
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London, United Kingdom
- * E-mail:
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Cregg R, Laguda B, Werdehausen R, Cox JJ, Linley JE, Ramirez JD, Bodi I, Markiewicz M, Howell KJ, Chen YC, Agnew K, Houlden H, Lunn MP, Bennett DLH, Wood JN, Kinali M. Novel mutations mapping to the fourth sodium channel domain of Nav1.7 result in variable clinical manifestations of primary erythromelalgia. Neuromolecular Med 2013; 15:265-78. [PMID: 23292638 PMCID: PMC3650253 DOI: 10.1007/s12017-012-8216-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Accepted: 12/14/2012] [Indexed: 01/01/2023]
Abstract
We identified and clinically investigated two patients with primary erythromelalgia mutations (PEM), which are the first reported to map to the fourth domain of Nav1.7 (DIV). The identified mutations (A1746G and W1538R) were cloned and transfected to cell cultures followed by electrophysiological analysis in whole-cell configuration. The investigated patients presented with PEM, while age of onset was very different (3 vs. 61 years of age). Electrophysiological characterization revealed that the early onset A1746G mutation leads to a marked hyperpolarizing shift in voltage dependence of steady-state activation, larger window currents, faster activation kinetics (time-to-peak current) and recovery from steady-state inactivation compared to wild-type Nav1.7, indicating a pronounced gain-of-function. Furthermore, we found a hyperpolarizing shift in voltage dependence of slow inactivation, which is another feature commonly found in Nav1.7 mutations associated with PEM. In silico neuron simulation revealed reduced firing thresholds and increased repetitive firing, both indicating hyperexcitability. The late-onset W1538R mutation also revealed gain-of-function properties, although to a lesser extent. Our findings demonstrate that mutations encoding for DIV of Nav1.7 can not only be linked to congenital insensitivity to pain or paroxysmal extreme pain disorder but can also be causative of PEM, if voltage dependency of channel activation is affected. This supports the view that the degree of biophysical property changes caused by a mutation may have an impact on age of clinical manifestation of PEM. In summary, these findings extent the genotype-phenotype correlation profile for SCN9A and highlight a new region of Nav1.7 that is implicated in PEM.
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Affiliation(s)
- Roman Cregg
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, UCL, Gower Street, London, WC1E 6BT UK
- UCL Centre for Anaesthesia, Critical Care and Pain Medicine, London, UK
| | - Bisola Laguda
- Department of Paediatric Dermatology, Chelsea and Westminster Hospital, London, UK
| | - Robert Werdehausen
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, UCL, Gower Street, London, WC1E 6BT UK
- Department of Anesthesiology, Heinrich-Heine-University, Düsseldorf, Germany
| | - James J. Cox
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, UCL, Gower Street, London, WC1E 6BT UK
| | - John E. Linley
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, UCL, Gower Street, London, WC1E 6BT UK
| | - Juan D. Ramirez
- Neurorestoration Group, CARD, King’s College London, Guy’s Campus, London, UK
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Istvan Bodi
- Department of Clinical Neuropathology, King’s College Hospital, London, UK
| | | | - Kevin J. Howell
- Centre for Rheumatology and Connective Tissue Disease, UCL Division of Medicine, Royal Free Campus, London, UK
| | - Ya-Chun Chen
- Division of Cell and Molecular Biology, Faculty of Natural Sciences, Imperial College London, London, UK
| | - Karen Agnew
- Department of Paediatric Dermatology, Chelsea and Westminster Hospital, London, UK
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Michael P. Lunn
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - David L. H. Bennett
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - John N. Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, UCL, Gower Street, London, WC1E 6BT UK
| | - Maria Kinali
- Department of Paediatric Neurology, Chelsea and Westminster Hospital, London, UK
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