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Nav 1.7 blocker

Maxim V Sokolov, Petra Henrich-Noack, Carina Raynoschek, Bo Franzén, Olof Larsson, Martin Main, Michael Dabrowski
The voltage-gated sodium ion channel NaV 1.7 is crucial in pain signaling. We examined how auxiliary β2 and β3 subunits and the phosphorylation state of the channel influence its biophysical properties and pharmacology. The human NaV 1.7α subunit was co-expressed with either β2 or β3 subunits in HEK-293 cells. The β2 subunits and the NaV 1.7α, however, were barely associated as evidenced by immunoprecipitation. Therefore, the β2 subunits did not change the biophysical properties of the channel. In contrast, β3 subunit was clearly associated with NaV 1...
May 10, 2018: Journal of Molecular Neuroscience: MN
Tânia C Gonçalves, Rachid Boukaiba, Jordi Molgó, Muriel Amar, Michel Partiseti, Denis Servent, Evelyne Benoit
The Chinese bird spider huwentoxin-IV (HwTx-IV) is well-known to be a highly potent blocker of NaV 1.7 subtype of voltage-gated sodium (NaV ) channels, a genetically validated analgesic target, and thus promising as a potential lead molecule for the development of novel pain therapeutics. In the present study, the interaction between HwTx-IV and NaV 1.6 channel subtype was investigated using multiscale (from in vivo to individual cell) functional approaches. HwTx-IV was approximatively 2 times more efficient than tetrodotoxin (TTX) to inhibit the compound muscle action potential recorded from the mouse skeletal neuromuscular system in vivo, and 30 times more effective to inhibit nerve-evoked than directly-elicited muscle contractile force of isolated mouse hemidiaphragms...
May 1, 2018: Neuropharmacology
M Kollarik, H Sun, R A Herbstsomer, F Ru, M Kocmalova, S N Meeker, B J Undem
KEY POINTS: The action potential initiation in the nerve terminals and its subsequent conduction along the axons of afferent nerves are not necessarily dependent on the same voltage-gated sodium channel (NaV 1) subunits. The action potential initiation in jugular C-fibres within airway tissues is not blocked by TTX; nonetheless, conduction of action potentials along the vagal axons of these nerves is often dependent on TTX-sensitive channels. This is not the case for nodose airway Aδ-fibres and C-fibres, where both action potential initiation and conduction is abolished by TTX or selective NaV 1...
April 15, 2018: Journal of Physiology
Silmara R Sousa, Joshua S Wingerd, Andreas Brust, Christopher Bladen, Lotten Ragnarsson, Volker Herzig, Jennifer R Deuis, Sebastien Dutertre, Irina Vetter, Gerald W Zamponi, Glenn F King, Paul F Alewood, Richard J Lewis
Spider venoms are rich sources of peptidic ion channel modulators with important therapeutical potential. We screened a panel of 60 spider venoms to find modulators of ion channels involved in pain transmission. We isolated, synthesized and pharmacologically characterized Cd1a, a novel peptide from the venom of the spider Ceratogyrus darlingi. Cd1a reversibly paralysed sheep blowflies (PD50 of 1318 pmol/g) and inhibited human Cav2.2 (IC50 2.6 μM) but not Cav1.3 or Cav3.1 (IC50 > 30 μM) in fluorimetric assays...
2017: PloS One
Sassan Rahnama, Jennifer R Deuis, Fernanda C Cardoso, Venkatraman Ramanujam, Richard J Lewis, Lachlan D Rash, Glenn F King, Irina Vetter, Mehdi Mobli
Venom-derived peptides have attracted much attention as potential lead molecules for pharmaceutical development. A well-known example is Huwentoxin-IV (HwTx-IV), a peptide toxin isolated from the venom of the Chinese bird-eating spider Haplopelma schmitdi. HwTx-IV was identified as a potent blocker of a human voltage-gated sodium channel (hNaV1.7), which is a genetically validated analgesic target. The peptide was promising as it showed high potency at NaV1.7 (IC50 ~26 nM) and selectivity over the cardiac NaV subtype (NaV1...
2017: PloS One
Ying Wu, Beiyan Zou, Lingli Liang, Min Li, Yuan-Xiang Tao, Haibo Yu, Xiaoliang Wang, Min Li
Previous studies demonstrated that Loperamide, originally known as an anti-diarrheal drug, is a promising analgesic agent primarily targeting mu-opioid receptors. However some evidences suggested that non-opioid mechanisms may be contributing to its analgesic effect. In the present study, Loperamide was identified as a Nav1.7 blocker in a pilot screen. In HEK293 cells expressing Nav1.7 sodium channels, Loperamide blocked the resting state of Nav1.7 channels (IC50 = 1.86 ± 0.11 μM) dose-dependently and reversibly...
February 16, 2017: Neuropharmacology
Michaela Kocmalova, Marian Kollarik, Brendan J Canning, Fei Ru, R Adam Herbstsomer, Sonya Meeker, Silvia Fonquerna, Monica Aparici, Montserrat Miralpeix, Xian Xuan Chi, Baolin Li, Ben Wilenkin, Jeff McDermott, Eric Nisenbaum, Jeffrey L Krajewski, Bradley J Undem
Little is known about the neuronal voltage-gated sodium channels (NaVs) that control neurotransmission in the parasympathetic nervous system. We evaluated the expression of the α subunits of each of the nine NaVs in human, guinea pig, and mouse airway parasympathetic ganglia. We combined this information with a pharmacological analysis of selective NaV blockers on parasympathetic contractions of isolated airway smooth muscle. As would be expected from previous studies, tetrodotoxin potently blocked the parasympathetic responses in the airways of each species...
April 2017: Journal of Pharmacology and Experimental Therapeutics
Laura Guarina, David H F Vandael, Valentina Carabelli, Emilio Carbone
KEY POINTS: Mouse chromaffin cells (MCCs) generate spontaneous burst-firing that causes large increases of Ca(2+) -dependent catecholamine release, and is thus a key mechanism for regulating the functions of MCCs. With the aim to uncover a physiological role for burst-firing we investigated the effects of acidosis on MCC activity. Lowering the extracellular pH (pHo ) from 7.4 to 6.6 induces cell depolarizations of 10-15 mV that generate bursts of ∼330 ms at 1-2 Hz and a 7.4-fold increase of cumulative catecholamine-release...
April 15, 2017: Journal of Physiology
Fernanda C Cardoso, Zoltan Dekan, K Johan Rosengren, Andelain Erickson, Irina Vetter, Jennifer R Deuis, Volker Herzig, Paul F Alewood, Glenn F King, Richard J Lewis
Spider venoms are a rich source of ion channel modulators with therapeutic potential. Given the analgesic potential of subtype-selective inhibitors of voltage-gated sodium (NaV) channels, we screened spider venoms for inhibitors of human NaV1.7 (hNaV1.7) using a high-throughput fluorescent assay. Here, we describe the discovery of a novel NaV1.7 inhibitor, μ-TRTX-Tp1a (Tp1a), isolated from the venom of the Peruvian green-velvet tarantula Thrixopelma pruriens. Recombinant and synthetic forms of this 33-residue peptide preferentially inhibited hNaV1...
August 2015: Molecular Pharmacology
Niklas Telinius, Jens Majgaard, Sukhan Kim, Niels Katballe, Einar Pahle, Jørn Nielsen, Vibeke Hjortdal, Christian Aalkjaer, Donna Briggs Boedtkjer
Voltage-gated sodium channels (VGSC) play a key role for initiating action potentials (AP) in excitable cells. VGSC in human lymphatic vessels have not been investigated. In the present study, we report the electrical activity and APs of small human lymphatic collecting vessels, as well as mRNA expression and function of VGSC in small and large human lymphatic vessels. The VGSC blocker TTX inhibited spontaneous contractions in six of 10 spontaneously active vessels, whereas ranolazine, which has a narrower VGSC blocking profile, had no influence on spontaneous activity...
July 15, 2015: Journal of Physiology
Sudhish Mishra, Vitaliy Reznikov, Victor A Maltsev, Nidas A Undrovinas, Hani N Sabbah, Albertas Undrovinas
KEY POINTS: Late Na(+) current (INaL) contributes to action potential remodelling and Ca(2+)/Na(+) changes in heart failure. The molecular identity of INaL remains unclear. The contributions of different Na(+) channel isoforms, apart from the cardiac isoform, remain unknown. We discovered and characterized a substantial contribution of neuronal isoform Nav1.1 to INaL. This new component is physiologically relevant to the control of action potential shape and duration, as well as to cell Ca(2+) dynamics, especially in heart failure...
March 15, 2015: Journal of Physiology
Justin K Murray, Joseph Ligutti, Dong Liu, Anruo Zou, Leszek Poppe, Hongyan Li, Kristin L Andrews, Bryan D Moyer, Stefan I McDonough, Philippe Favreau, Reto Stöcklin, Les P Miranda
NaV1.7 is a voltage-gated sodium ion channel implicated by human genetic evidence as a therapeutic target for the treatment of pain. Screening fractionated venom from the tarantula Grammostola porteri led to the identification of a 34-residue peptide, termed GpTx-1, with potent activity on NaV1.7 (IC50 = 10 nM) and promising selectivity against key NaV subtypes (20× and 1000× over NaV1.4 and NaV1.5, respectively). NMR structural analysis of the chemically synthesized three disulfide peptide was consistent with an inhibitory cystine knot motif...
March 12, 2015: Journal of Medicinal Chemistry
Saad Javed, Ioannis N Petropoulos, Uazman Alam, Rayaz A Malik
Painful diabetic neuropathy (PDN) is a debilitating consequence of diabetes that may be present in as many as one in five patients with diabetes. The objective assessment of PDN is difficult, making it challenging to diagnose and assess in both clinical practice and clinical trials. No single treatment exists to prevent or reverse neuropathic changes or to provide total pain relief. Treatment of PDN is based on three major approaches: intensive glycaemic control and risk factor management, treatments based on pathogenetic mechanisms, and symptomatic pain management...
January 2015: Therapeutic Advances in Chronic Disease
Sudhish Mishra, Vitaliy Reznikov, Victor A Maltsev, Nidas A Undrovinas, Hani N Sabbah, Albertas Undrovinas
Late Na(+) current (INaL) contributes to action potential (AP) duration and Ca(2+) handling in cardiac cells. Augmented INaL was implicated in delayed repolarization and impaired Ca(2+) handling in heart failure (HF). We tested if Na(+) channel (Nav's) neuronal isoforms contribute to INaL and Ca(2+) cycling defects in HF in 17 dogs with HF achieved via sequential coronary artery embolizations. Six normal dogs served as control. Transient Na(+) current (INaT) and INaL in left ventricular cardiomyocytes (VCMs) were recorded by patch-clamp while Ca(2+) dynamics was monitored using fluo-4...
October 17, 2014: Journal of Physiology
Nikolaos Christidis, Isabell Kang, Brian E Cairns, Ujendra Kumar, Xudong Dong, Annika Rosén, Sigvard Kopp, Malin Ernberg
BACKGROUND: Previous studies have shown that 5-HT3-antagonists reduce muscle pain, but there are no studies that have investigated the expression of 5-HT3-receptors in human muscles. Also, tetrodotoxin resistant voltage gated sodium-channels (NaV) are involved in peripheral sensitization and found in trigeminal ganglion neurons innervating the rat masseter muscle. This study aimed to investigate the frequency of nerve fibers that express 5-HT3A-receptors alone and in combination with NaV1...
2014: Journal of Headache and Pain
R Cregg, J J Cox, D L H Bennett, J N Wood, R Werdehausen
BACKGROUND AND PURPOSE: The non-selective sodium channel inhibitor mexiletine has been found to be effective in several animal models of chronic pain and has become popular in the clinical setting as an orally available alternative to lidocaine. It remains unclear why patients with monogenic pain disorders secondary to gain-of-function SCN9a mutations benefit from a low systemic concentration of mexiletine, which does not usually induce adverse neurological side effects. The aim of this study was, therefore, to investigate the biophysical effects of mexiletine on the L858F primary erythromelalgia NaV 1...
October 2014: British Journal of Pharmacology
Nilufar Foadi, Christian Berger, Igor Pilawski, Carsten Stoetzer, Matthias Karst, Gertrud Haeseler, Florian Wegner, Andreas Leffler, Jörg Ahrens
BACKGROUND: The synthetic cannabinoid ajulemic acid has been demonstrated to alleviate pain in patients suffering from chronic neuropathic pain. Cannabinoids interact with several molecules within the pain circuit, including a potent inhibition of voltage-gated sodium channels. In this study, we closely characterized this property on neuronal and nonneuronal sodium channels. METHODS: The inhibition of sodium inward currents by ajulemic acid was studied in vitro...
June 2014: Anesthesia and Analgesia
Joanna Gajewiak, Layla Azam, Julita Imperial, Aleksandra Walewska, Brad R Green, Pradip K Bandyopadhyay, Shrinivasan Raghuraman, Beatrix Ueberheide, Marshall Bern, H Mimi Zhou, Natali A Minassian, Rebecca H Hagan, Mack Flinspach, Yi Liu, Grzegorz Bulaj, Alan D Wickenden, Baldomero M Olivera, Doju Yoshikami, Min-Min Zhang
A cone snail venom peptide, μO§-conotoxin GVIIJ from Conus geographus, has a unique posttranslational modification, S-cysteinylated cysteine, which makes possible formation of a covalent tether of peptide to its target Na channels at a distinct ligand-binding site. μO§-conotoxin GVIIJ is a 35-aa peptide, with 7 cysteine residues; six of the cysteines form 3 disulfide cross-links, and one (Cys24) is S-cysteinylated. Due to limited availability of native GVIIJ, we primarily used a synthetic analog whose Cys24 was S-glutathionylated (abbreviated GVIIJSSG)...
February 18, 2014: Proceedings of the National Academy of Sciences of the United States of America
Botond Borcsa, László Fodor, Dezső Csupor, Peter Forgo, Attila Molnár, Judit Hohmann
A new aconitane alkaloid, 1-O-demethylswatinine (1), was isolated from the root of Aconitum moldavicum together with the known compounds cammaconine (2), columbianine (3), swatinine (4), gigactonine (5), delcosine (6), lycoctonine (7), and ajacine (8). The structures were established by means of HRESIMS, 1D and 2D NMR spectroscopy, including 1H-1H COSY, NOESY, HSQC, and HMBC experiments, resulting in complete 1H-NMR chemical shift assignments for 1-4. The effects of the isolated compounds 4-8, together with eighteen other Aconitum diterpene and norditerpene alkaloids with different skeletal types and substitution patterns, were studied on Nav 1...
February 2014: Planta Medica
Yukiko Muroi, Bradley J Undem
Recent advances in our understanding of voltage-gated sodium channels (NaVs) lead to the rational hypothesis that drugs capable of selective blockade of NaV subtypes may be a safe and effective strategy for the treatment of unwanted cough. Among the nine NaV subtypes (NaV1.1-NaV1.9), the afferent nerves involved in initiating cough, in common with nociceptive neurons in the somatosensory system, express mainly NaV1.7, NaV1.8, and NaV1.9. Although knowledge about the effect of selectively blocking these channels on the cough reflex is limited, their biophysical properties indicate that each may contribute to the hypertussive and allotussive state that typifies subacute and chronic nonproductive cough...
February 2014: Lung
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