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Shen YC, Wu JC, Lin TT, Chang KC, Su JJ, Juang JMJ. Case Report: Lacosamide unmasking SCN5A-associated Brugada syndrome in a young female with epilepsy. Front Cardiovasc Med 2024; 11:1406614. [PMID: 38883985 PMCID: PMC11176425 DOI: 10.3389/fcvm.2024.1406614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 05/20/2024] [Indexed: 06/18/2024] Open
Abstract
Background Lacosamide is frequently used as a mono- or adjunctive therapy for the treatment of adults with epilepsy. Although lacosamide is known to act on both neuronal and cardiac sodium channels, potentially leading to cardiac arrhythmias, including Brugada syndrome (BrS), its adverse effects in individuals with genetic susceptibility are less understood. Case We report a 33-year-old female with underlying epilepsy who presented to the emergency department with a four-day history of seizure clusters, and was initially treated with lacosamide therapy. During the intravenous lacosamide infusion, the patient developed sudden cardiac arrest caused by ventricular arrhythmias necessitating resuscitation. Of note, the patient had a family history of sudden cardiac death. Workup including routine laboratory results, 12-lead electrocardiogram (ECG), echocardiogram, and coronary angiogram was non-specific. However, a characteristic type 1 Brugada ECG pattern was identified by ajmaline provocation testing; thus, confirming the diagnosis of BrS. Subsequently, the genotypic diagnosis was confirmed by Sanger sequencing, which revealed a heterozygous mutation (c.2893C>T, p.Arg965Cys) in the SCN5A gene. Eventually, the patient underwent implantable cardioverter-defibrillator implantation and was discharged with full neurological recovery. Conclusion This case highlights a rare but lethal adverse event associated with lacosamide treatment in patients with genetic susceptibility. Further research is warranted to investigate the interactions between lacosamide and SCN5A variants.
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Affiliation(s)
- Ying-Chi Shen
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Jen-Chueh Wu
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Ting-Tse Lin
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Kai-Chung Chang
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Jen-Jen Su
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Jyh-Ming Jimmy Juang
- Cardiovascular Center, Center of Heart Failure and Center of Genetic Heart Diseases, Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
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Hung TY, Wu SN, Huang CW. Safinamide, an inhibitor of monoamine oxidase, modulates the magnitude, gating, and hysteresis of sodium ion current. BMC Pharmacol Toxicol 2024; 25:17. [PMID: 38331833 PMCID: PMC10851555 DOI: 10.1186/s40360-024-00739-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 01/30/2024] [Indexed: 02/10/2024] Open
Abstract
BACKGROUND Safinamide (SAF), an α-aminoamide derivative and a selective, reversible monoamine oxidase (MAO)-B inhibitor, has both dopaminergic and nondopaminergic (glutamatergic) properties. Several studies have explored the potential of SAF against various neurological disorders; however, to what extent SAF modulates the magnitude, gating, and voltage-dependent hysteresis [Hys(V)] of ionic currents remains unknown. METHODS With the aid of patch-clamp technology, we investigated the effects of SAF on voltage-gated sodium ion (NaV) channels in pituitary GH3 cells. RESULTS SAF concentration-dependently stimulated the transient (peak) and late (sustained) components of voltage-gated sodium ion current (INa) in pituitary GH3 cells. The conductance-voltage relationship of transient INa [INa(T)] was shifted to more negative potentials with the SAF presence; however, the steady-state inactivation curve of INa(T) was shifted in a rightward direction in its existence. SAF increased the decaying time constant of INa(T) induced by a train of depolarizing stimuli. Notably, subsequent addition of ranolazine or mirogabalin reversed the SAF-induced increase in the decaying time constant. SAF also increased the magnitude of window INa induced by an ascending ramp voltage Vramp. Furthermore, SAF enhanced the Hys(V) behavior of persistent INa induced by an upright isosceles-triangular Vramp. Single-channel cell-attached recordings indicated SAF effectively increased the open-state probability of NaV channels. Molecular docking revealed SAF interacts with both MAO and NaV channels. CONCLUSION SAF may interact directly with NaV channels in pituitary neuroendocrine cells, modulating membrane excitability.
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Affiliation(s)
- Te-Yu Hung
- Department of Pediatrics, Chi-Mei Medical Center, Tainan, Taiwan
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan.
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan.
- School of Medicine, National Sun Yat-sen University, Kaohsiung, Taiwan.
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
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Shiau AL, Lee KH, Cho HY, Chuang TH, Yu MC, Wu CL, Wu SN. Molnupiravir, a ribonucleoside antiviral prodrug against SARS-CoV-2, alters the voltage-gated sodium current and causes adverse events. Virology 2023; 587:109865. [PMID: 37572519 DOI: 10.1016/j.virol.2023.109865] [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: 03/09/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 08/14/2023]
Abstract
Molnupiravir (MOL) is a ribonucleoside prodrug for oral treatment of COVID-19. Common adverse effects of MOL are headache, diarrhea, and nausea, which may be associated with altered sodium channel function. Here, we investigated the effect of MOL on voltage-gated Na+ current (INa) in pituitary GH3 cells. We show that MOL had distinct effects on transient and late INa, in combination with decreased time constant in the slow component of INa inactivation. The 50% inhibitory concentration (IC50) values of MOL for suppressing transient and late INa were 26.1 and 6.3 μM, respectively. The overall steady-state current-voltage relationship of INa remained unchanged upon MOL exposure. MOL-induced alteration of INa may lead to changes in physiological function through sodium channels. Apart from its effect on inhibiting RNA virus replication, MOL exerts inhibitory effects on plasmalemma INa, which might constitute an additional yet crucial underlying mechanism of its pharmacological activity or adverse events.
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Affiliation(s)
- Ai-Li Shiau
- Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City, 60002, Taiwan; Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Kuan-Hsien Lee
- Department of Emergency Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City, 60002, Taiwan
| | - Hsin-Yen Cho
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Tzu-Hsien Chuang
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Meng-Cheng Yu
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Chao-Liang Wu
- Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City, 60002, Taiwan; Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan.
| | - Sheng-Nan Wu
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan; School of Medicine, College of Medicine, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan.
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Hung TY, Wu SN, Huang CW. Concerted suppressive effects of carisbamate, an anti-epileptic alkyl-carbamate drug, on voltage-gated Na + and hyperpolarization-activated cation currents. Front Cell Neurosci 2023; 17:1159067. [PMID: 37293624 PMCID: PMC10244622 DOI: 10.3389/fncel.2023.1159067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/02/2023] [Indexed: 06/10/2023] Open
Abstract
Carisbamate (CRS, RWJ-333369) is a new anti-seizure medication. It remains unclear whether and how CRS can perturb the magnitude and/or gating kinetics of membrane ionic currents, despite a few reports demonstrating its ability to suppress voltage-gated Na+ currents. In this study, we observed a set of whole-cell current recordings and found that CRS effectively suppressed the voltage-gated Na+ (INa) and hyperpolarization-activated cation currents (Ih) intrinsically in electrically excitable cells (GH3 cells). The effective IC50 values of CRS for the differential suppression of transient (INa(T)) and late INa (INa(L)) were 56.4 and 11.4 μM, respectively. However, CRS strongly decreased the strength (i.e., Δarea) of the nonlinear window component of INa (INa(W)), which was activated by a short ascending ramp voltage (Vramp); the subsequent addition of deltamethrin (DLT, 10 μM) counteracted the ability of CRS (100 μM, continuous exposure) to suppress INa(W). CRS strikingly decreased the decay time constant of INa(T) evoked during pulse train stimulation; however, the addition of telmisartan (10 μM) effectively attenuated the CRS (30 μM, continuous exposure)-mediated decrease in the decay time constant of the current. During continued exposure to deltamethrin (10 μM), known to be a pyrethroid insecticide, the addition of CRS resulted in differential suppression of the amplitudes of INa(T) and INa(L). The amplitude of Ih activated by a 2-s membrane hyperpolarization was diminished by CRS in a concentration-dependent manner, with an IC50 value of 38 μM. For Ih, CRS altered the steady-state I-V relationship and attenuated the strength of voltage-dependent hysteresis (Hys(V)) activated by an inverted isosceles-triangular Vramp. Moreover, the addition of oxaliplatin effectively reversed the CRS-mediated suppression of Hys(V). The predicted docking interaction between CRS and with a model of the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel or between CRS and the hNaV1.7 channel reflects the ability of CRS to bind to amino acid residues in HCN or hNaV1.7 channel via hydrogen bonds and hydrophobic interactions. These findings reveal the propensity of CRS to modify INa(T) and INa(L) differentially and to effectively suppress the magnitude of Ih. INa and Ih are thus potential targets of the actions of CRS in terms of modulating cellular excitability.
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Affiliation(s)
- Te-Yu Hung
- Department of Pediatrics, Chi Mei Medical Center, Tainan, Taiwan
| | - Sheng-Nan Wu
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- College of Medicine, Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
- School of Medicine, College of Medicine, National Sun Yat-sen University, Kaohsiung City, Taiwan
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Ting CY, Shih CL, Yu MC, Wu CL, Wu SN. Characterization of Stimulatory Action on Voltage-Gated Na + Currents Caused by Omecamtiv Mecarbil, Known to Be a Myosin Activator. Biomedicines 2023; 11:biomedicines11051351. [PMID: 37239022 DOI: 10.3390/biomedicines11051351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/26/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023] Open
Abstract
Omecamtiv mecarbil (OM, CK-1827452) is recognized as an activator of myosin and has been demonstrated to be beneficial for the treatment of systolic heart failure. However, the mechanisms by which this compound interacts with ionic currents in electrically excitable cells remain largely unknown. The objective of this study was to investigate the effects of OM on ionic currents in GH3 pituitary cells and Neuro-2a neuroblastoma cells. In GH3 cells, whole-cell current recordings showed that the addition of OM had different potencies in stimulating the transient (INa(T)) and late components (INa(L)) of the voltage-gated Na+ current (INa) with different potencies in GH3 cells. The EC50 value required to observe the stimulatory effect of this compound on INa(T) or INa(L) in GH3 cells was found to be 15.8 and 2.3 µM, respectively. Exposure to OM did not affect the current versus voltage relationship of INa(T). However, the steady-state inactivation curve of the current was observed to shift towards a depolarized potential of approximately 11 mV, with no changes in the slope factor of the curve. The addition of OM resulted in an increase in the decaying time constant during the cumulative inhibition of INa(T) in response to pulse-train depolarizing stimuli. Furthermore, the presence of OM led to a shortening of the recovery time constant in the slow inactivation of INa(T). Adding OM also resulted in an augmentation of the strength of the window Na+ current, which was evoked by a short ascending ramp voltage. However, the OM exposure had little to no effect on the magnitude of L-type Ca2+ currents in GH3 cells. On the other hand, the delayed-rectifier K+ currents in GH3 cells were observed to be mildly suppressed in its presence. Neuro-2a cells also showed a susceptibility to the differential stimulation of INa(T) or INa(L) upon the addition of OM. Molecular analysis revealed potential interactions between the OM molecule and hNaV1.7 channels. Overall, the direct stimulation of INa(T) and INa(L) by OM is assumed to not be mediated by an interaction with myosin, and this has potential implications for its pharmacological or therapeutic actions occurring in vivo.
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Affiliation(s)
- Chih-Yu Ting
- Department of Emergency Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan
| | - Chia-Lung Shih
- Clinical Research Center, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan
| | - Meng-Cheng Yu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
| | - Chao-Liang Wu
- Clinical Research Center, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- School of Medicine, National Sun Yat-Sen University College of Medicine, Kaohsiung 80424, Taiwan
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Chen YS, Lai MC, Chen TS, Tseng YH, Li YJ, Huang CW. Effectiveness and Safety of Lacosamide, A Third-generation Anti-seizure Medication, for Poststroke Seizure and Epilepsy: A Literature Review. Curr Neuropharmacol 2023; 21:2126-2133. [PMID: 37340744 PMCID: PMC10556369 DOI: 10.2174/1570159x21666230616114255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 12/07/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023] Open
Abstract
Advances in stroke treatment have resulted in a dramatic reduction in stroke mortality. Nevertheless, poststroke seizures and epilepsy are issues of clinical importance affecting survivors. Additionally, stroke is the most common cause of epilepsy in older adults. Although numerous antiseizure medications exist, studies are needed to provide robust evidence of the efficacy and tolerability of these medicines for treating poststroke seizures and epilepsy. Crucially, the newer generations of antiseizure medications require testing. Lacosamide, a third-generation antiseizure medication approved for treating localization-related epilepsy, has a novel mechanism of selectively enhancing the slow inactivation of sodium channels. This literature review evaluated whether lacosamide is effective and safe for the treatment of poststroke seizures and epilepsy. This review critically analyzed studies published in major academic databases (Pubmed, Embase, and Cochrane Library) from inception through June 2022 regarding the interaction of lacosamide with poststroke seizures and epilepsy. We included clinical prospective, retrospective, and case studies on patients with poststroke seizure and epilepsy, lacosamide as a treatment for seizures, neuroprotection in animal models of seizures, and the safety of lacosamide when coadministering anticoagulants. Clinical studies revealed lacosamide to be an effective antiseizure medication with high efficacy and tolerability in patients with poststroke seizures and epilepsy. In animal models, lacosamide proved effective at seizure reduction and neuroprotection. Pharmacokinetic studies demonstrated the safety of lacosamide when coadministering conventional and new anticoagulants. The literature suggests that Lacosamide is a promising candidate antiseizure medication for patients with poststroke seizures and epilepsy.
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Affiliation(s)
- Yu-Shiue Chen
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Ming-Chi Lai
- Department of Pediatrics, Chi-Mei Medical Center, Tainan, Taiwan
| | - Tsang-Shan Chen
- Department of Neurology, Tainan Sin-Lau Hospital, Tainan, Taiwan
| | - Yung-Hsin Tseng
- Department of Pharmacy, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Ya Jhen Li
- Kun-Yen Medical Library, National Cheng Kung University, Tainan, Taiwan
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Lin MH, Lin JF, Yu MC, Wu SN, Wu CL, Cho HY. Characterization in Potent Modulation on Voltage-Gated Na + Current Exerted by Deltamethrin, a Pyrethroid Insecticide. Int J Mol Sci 2022; 23:ijms232314733. [PMID: 36499059 PMCID: PMC9737322 DOI: 10.3390/ijms232314733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/20/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Deltamethrin (DLT) is a type-II pyrethroid ester insecticide used in agricultural and domestic applications as well as in public health. However, transmembrane ionic channels perturbed by this compound remain largely unclear, although the agent is thought to alter the gating characteristics of voltage-gated Na+ (NaV) channel current. In this study, we reappraised whether and how it and other related compounds can make any further modifications on voltage-gated Na+ current (INa) in pituitary tumor (GH3) cells. Cell exposure to DLT produced a differential and dose-dependent stimulation of peak (transient, INa(T)) or sustained (late, INa(L)) INa; consequently, the EC50 value required for DLT-stimulated INa(T) or INa(L) was determined to be 11.2 or 2.5 μM, respectively. However, neither the fast nor slow component in the inactivation time constant of INa(T) activated by short depolarizing pulse was changed with the DLT presence; conversely, tefluthrin (Tef), a type-I pyrethroid insecticide, can accentuate INa with a slowing in inactivation time course of the current. The INa(L) augmented by DLT was attenuated by further application of either dapagliflozin (Dapa) or amiloride, but not by chlorotoxin. During pulse train (PT) stimulation, with the Tef or DLT presence, the cumulative inhibition of INa(T) became slowed; moreover, following PT stimuli, a large tail current with a slowly recovering process was observed. Alternatively, during rapid depolarizing pulse, the amplitude of INa(L) and tail INa (INa(Tail)) for each depolarizing pulse became progressively increased by adding DLT, not by Tef. The recovery time constant following PT stimulation with continued presence of Tef or DLT was shortened by further addition of Dapa. The voltage-dependent hysteresis (Hys(V)) of persistent INa was differentially augmented by Tef or DLT. Taken together, the magnitude, gating, frequency dependence, as well as Hys(V) behavior of INa exerted by the presence of DLT or Tef might exert a synergistic impact on varying functional activities of excitable cells in culture or in vivo.
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Affiliation(s)
- Mao-Hsun Lin
- Division of Neurology, Department of Internal Medicine, Ditmanson Medical Foundation Chiayi Christian Hospital, Chiayi City 600, Taiwan
| | - Jen-Feng Lin
- Department of Emergency Medicine, Ditmanson Medical Foundation Chiayi Christian Hospital, Chiayi City 600, Taiwan
| | - Meng-Cheng Yu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 701, Taiwan
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 701, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 701, Taiwan
- Department of Post-Baccalaureate Medicine, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
- Correspondence: ; Tel.: +886-6-2353535-5334; Fax: 886-6-2362780
| | - Chao-Liang Wu
- Ditmanson Medical Foundation Chiayi Christian Hospital, Chiayi City 600, Taiwan
| | - Hsin-Yen Cho
- Department of Physiology, National Cheng Kung University Medical College, Tainan 701, Taiwan
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Shiau AL, Liao CS, Tu CW, Wu SN, Cho HY, Yu MC. Characterization in Effective Stimulation on the Magnitude, Gating, Frequency Dependence, and Hysteresis of INa Exerted by Picaridin (or Icaridin), a Known Insect Repellent. Int J Mol Sci 2022; 23:ijms23179696. [PMID: 36077093 PMCID: PMC9456182 DOI: 10.3390/ijms23179696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/21/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022] Open
Abstract
Picaridin (icaridin), a member of the piperidine chemical family, is a broad-spectrum arthropod repellent. Its actions have been largely thought to be due to its interaction with odorant receptor proteins. However, to our knowledge, to what extent the presence of picaridin can modify the magnitude, gating, and/or the strength of voltage-dependent hysteresis (Hys(V)) of plasmalemmal ionic currents, such as, voltage-gated Na+ current [INa], has not been entirely explored. In GH3 pituitary tumor cells, we demonstrated that with exposure to picaridin the transient (INa(T)) and late (INa(L)) components of voltage-gated Na+ current (INa) were differentially stimulated with effective EC50’s of 32.7 and 2.8 μM, respectively. Upon cell exposure to it, the steady-state current versus voltage relationship INa(T) was shifted to more hyperpolarized potentials. Moreover, its presence caused a rightward shift in the midpoint for the steady-state inactivate curve of the current. The cumulative inhibition of INa(T) induced during repetitive stimuli became retarded during its exposure. The recovery time course from the INa block elicited, following the conditioning pulse stimulation, was satisfactorily fitted by two exponential processes. Moreover, the fast and slow time constants of recovery from the INa block by the same conditioning protocol were noticeably increased in the presence of picaridin. However, the fraction in fast or slow component of recovery time course was, respectively, increased or decreased with an increase in picaridin concentrations. The Hys(V)’s strength of persistent INa (INa(P)), responding to triangular ramp voltage, was also enhanced during cell exposure to picaridin. The magnitude of resurgent INa (INa(R)) was raised in its presence. Picaritin-induced increases of INa(P) or INa(R) intrinsically in GH3 cells could be attenuated by further addition of ranolazine. The predictions of molecular docking also disclosed that there are possible interactions of the picaridin molecule with the hNaV1.7 channel. Taken literally, the stimulation of INa exerted by the exposure to picaridin is expected to exert impacts on the functional activities residing in electrically excitable cells.
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Affiliation(s)
- Ai-Li Shiau
- Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan
| | - Chih-Szu Liao
- Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan
| | - Chi-Wen Tu
- Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Correspondence: ; Tel.: +886-6-2353535-5334; Fax: +886-6-2362780
| | - Hsin-Yen Cho
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
| | - Meng-Cheng Yu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
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Evidence for Inhibitory Perturbations on the Amplitude, Gating, and Hysteresis of A-Type Potassium Current, Produced by Lacosamide, a Functionalized Amino Acid with Anticonvulsant Properties. Int J Mol Sci 2022; 23:ijms23031171. [PMID: 35163091 PMCID: PMC8835568 DOI: 10.3390/ijms23031171] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/11/2022] [Accepted: 01/19/2022] [Indexed: 02/05/2023] Open
Abstract
Lacosamide (Vimpat®, LCS) is widely known as a functionalized amino acid with promising anti-convulsant properties; however, adverse events during its use have gradually appeared. Despite its inhibitory effect on voltage-gated Na+ current (INa), the modifications on varying types of ionic currents caused by this drug remain largely unexplored. In pituitary tumor (GH3) cells, we found that the presence of LCS concentration-dependently decreased the amplitude of A-type K+ current (IK(A)) elicited in response to membrane depolarization. The IK(A) amplitude in these cells was sensitive to attenuation by the application of 4-aminopyridine, 4-aminopyridine-3-methanol, or capsaicin but not by that of tetraethylammonium chloride. The effective IC50 value required for its reduction in peak or sustained IK(A) was calculated to be 102 or 42 µM, respectively, while the value of the dissociation constant (KD) estimated from the slow component in IK(A) inactivation at varying LCS concentrations was 52 µM. By use of two-step voltage protocol, the presence of this drug resulted in a rightward shift in the steady-state inactivation curve of IK(A) as well as in a slowing in the recovery time course of the current block; however, no change in the gating charge of the inactivation curve was detected in its presence. Moreover, the LCS addition led to an attenuation in the degree of voltage-dependent hysteresis for IK(A) elicitation by long-duration triangular ramp voltage commands. Likewise, the IK(A) identified in mouse mHippoE-14 neurons was also sensitive to block by LCS, coincident with an elevation in the current inactivation rate. Collectively, apart from its canonical action on INa inhibition, LCS was effective at altering the amplitude, gating, and hysteresis of IK(A) in excitable cells. The modulatory actions on IK(A), caused by LCS, could interfere with the functional activities of electrically excitable cells (e.g., pituitary tumor cells or hippocampal neurons).
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10
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Lai MC, Wu SN, Huang CW. Telmisartan, an Antagonist of Angiotensin II Receptors, Accentuates Voltage-Gated Na + Currents and Hippocampal Neuronal Excitability. Front Neurosci 2020; 14:902. [PMID: 33013297 PMCID: PMC7499822 DOI: 10.3389/fnins.2020.00902] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 08/03/2020] [Indexed: 12/19/2022] Open
Abstract
Telmisartan (TEL), a non-peptide blocker of the angiotensin II type 1 receptor, is a widely used antihypertensive agent. Nevertheless, its neuronal ionic effects and how they potentially affect neuronal network excitability remain largely unclear. With the aid of patch-clamp technology, the effects of TEL on membrane ion currents present in hippocampal neurons (mHippoE-14 cells) were investigated. For additional characterization of the effects of TEL on hippocampal neuronal excitability, we undertook in vivo studies on Sprague Dawley (SD) rats using pilocarpine-induced seizure modeling, a hippocampal histopathological analysis, and inhibitory avoidance testing. In these hippocampal neurons, TEL increased the peak amplitude of INa, with a concomitant decline in the current inactivation rate. The TEL concentration dependently enhanced the peak amplitude of depolarization-elicited INa and lessened the inactivation rate of INa. By comparison, TEL was more efficacious in stimulating the peak INa and in prolonging the inactivation time course of this current than tefluthrin or (-)-epicatechin-3-gallate. In the continued presence of pioglitazone, the TEL-perturbed stimulation of INa remained effective. In addition, cell exposure to TEL shifted the steady-state inactivation INa curve to fewer negative potentials with no perturbations of the slope factor. Unlike chlorotoxin, either ranolazine, eugenol, or KMUP-1 reversed TEL-mediated increases in the strength of non-inactivating INa. In the cell-attached voltage-clamp recordings, TEL shortened the latency in the generation of action currents. Meanwhile, TEL increased the peak INa, with a concurrent decrease in current inactivation in HEKT293T cells expressing SCN5A. Furthermore, although TEL did not aggravate pilocarpine-induced chronic seizures and tended to preserve cognitive performance, it significantly accentuated hippocampal mossy fiber sprouting. Collectively, TEL stimulation of peak INa in combination with an apparent retardation in current inactivation could be an important mechanism through which hippocampal neuronal excitability is increased, and hippocampal network excitability is accentuated following status epilepticus, suggesting further attention to this finding.
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Affiliation(s)
- Ming-Chi Lai
- Department of Pediatrics, Chi-Mei Medical Center, Tainan, Taiwan
| | - Sheng-Nan Wu
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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11
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Electroencephalographic and Electrocardiographic Effect of Intravenous Lacosamide in Refractory Focal Epilepsy. J Clin Neurophysiol 2018; 35:365-369. [DOI: 10.1097/wnp.0000000000000479] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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12
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So EC, Wu SN, Lo YC, Su K. Differential regulation of tefluthrin and telmisartan on the gating charges of I Na activation and inactivation as well as on resurgent and persistent I Na in a pituitary cell line (GH 3). Toxicol Lett 2018; 285:104-112. [PMID: 29306026 DOI: 10.1016/j.toxlet.2018.01.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/23/2017] [Accepted: 01/02/2018] [Indexed: 12/19/2022]
Abstract
Voltage-gated Na+ currents (INa), known to contain many components (e.g., transient, resurgent and persistent INa) with unique gating properties, are involved in the generation and propagation of action potentials in excitable cells. In this study, how tefluthrin (Tef), a synthetic pyrethoid, and telmisartan (TEL), blocker of angiotensin II receptors can perturb those components of INa was investigated. The presence of either Tef or TEL increased the values of the gating charges of INa involved in the activation (za) and inactivation (zi). Tef also increased the amplitude of resurgent INa (INa(R)) or persistent INa (INa(P)) in a pituitary cell line (GH3), while TEL produced minimal effects on them. Subsequent addition of either ranolazine (a blocker of late INa) or d-limonene (a monoterpene), could reverse the changes by TEL or Tef on za or zi. In SCN5A-expressing HEK293T cells, addition of Tef or TEL also increased the peak amplitude and the inactivation time constant of INa which was accompanied by the increased za value of INa. Taken together, the results indicated that Tef- or TEL-mediated changes in the gating kinetics of INa are linked to their actions on functional activity of neurons, neuroendocrine or endocrine cells.
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Affiliation(s)
- Edmund Cheung So
- Department of Anesthesia, An Nan Hospital, China Medical University, 70965, Tainan City, Taiwan; Department of Anesthesia, China Medical University, 40447 Taichung City, Taiwan.
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, 70101 Tainan City, Taiwan.
| | - Yi-Ching Lo
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, 80756 Kaohsiung City, Taiwan.
| | - Kevin Su
- Department of Medicine, Shanghai Medical College, Fudan University, Shanghai City, China.
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Remen L, Bezençon O, Simons L, Gaston R, Downing D, Gatfield J, Roch C, Kessler M, Mosbacher J, Pfeifer T, Grisostomi C, Rey M, Ertel EA, Moon R. Preparation, Antiepileptic Activity, and Cardiovascular Safety of Dihydropyrazoles as Brain-Penetrant T-Type Calcium Channel Blockers. J Med Chem 2016; 59:8398-411. [DOI: 10.1021/acs.jmedchem.6b00756] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Lubos Remen
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Olivier Bezençon
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Lloyd Simons
- Kalexsyn, Inc., 4502 Campus Drive, Kalamazoo, Michigan 49008, United States
| | - Rick Gaston
- Kalexsyn, Inc., 4502 Campus Drive, Kalamazoo, Michigan 49008, United States
| | - Dennis Downing
- Kalexsyn, Inc., 4502 Campus Drive, Kalamazoo, Michigan 49008, United States
| | - John Gatfield
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Catherine Roch
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Melanie Kessler
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Johannes Mosbacher
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Thomas Pfeifer
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Corinna Grisostomi
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Markus Rey
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Eric A. Ertel
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Richard Moon
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
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