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Servettini I, Talani G, Megaro A, Setzu MD, Biggio F, Briffa M, Guglielmi L, Savalli N, Binda F, Delicata F, Bru–Mercier G, Vassallo N, Maglione V, Cauchi RJ, Di Pardo A, Collu M, Imbrici P, Catacuzzeno L, D’Adamo MC, Olcese R, Pessia M. An activator of voltage-gated K + channels Kv1.1 as a therapeutic candidate for episodic ataxia type 1. Proc Natl Acad Sci U S A 2023; 120:e2207978120. [PMID: 37487086 PMCID: PMC10401004 DOI: 10.1073/pnas.2207978120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 06/23/2023] [Indexed: 07/26/2023] Open
Abstract
Loss-of-function mutations in the KCNA1(Kv1.1) gene cause episodic ataxia type 1 (EA1), a neurological disease characterized by cerebellar dysfunction, ataxic attacks, persistent myokymia with painful cramps in skeletal muscles, and epilepsy. Precision medicine for EA1 treatment is currently unfeasible, as no drug that can enhance the activity of Kv1.1-containing channels and offset the functional defects caused by KCNA1 mutations has been clinically approved. Here, we uncovered that niflumic acid (NFA), a currently prescribed analgesic and anti-inflammatory drug with an excellent safety profile in the clinic, potentiates the activity of Kv1.1 channels. NFA increased Kv1.1 current amplitudes by enhancing the channel open probability, causing a hyperpolarizing shift in the voltage dependence of both channel opening and gating charge movement, slowing the OFF-gating current decay. NFA exerted similar actions on both homomeric Kv1.2 and heteromeric Kv1.1/Kv1.2 channels, which are formed in most brain structures. We show that through its potentiating action, NFA mitigated the EA1 mutation-induced functional defects in Kv1.1 and restored cerebellar synaptic transmission, Purkinje cell availability, and precision of firing. In addition, NFA ameliorated the motor performance of a knock-in mouse model of EA1 and restored the neuromuscular transmission and climbing ability in Shaker (Kv1.1) mutant Drosophila melanogaster flies (Sh5). By virtue of its multiple actions, NFA has strong potential as an efficacious single-molecule-based therapeutic agent for EA1 and serves as a valuable model for drug discovery.
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Affiliation(s)
- Ilenio Servettini
- Section of Physiology, Department of Medicine, University of Perugia, Perugia06123, Italy
| | - Giuseppe Talani
- Institute of Neuroscience, National Research Council, Monserrato09042, Italy
| | - Alfredo Megaro
- Section of Physiology, Department of Medicine, University of Perugia, Perugia06123, Italy
| | - Maria Dolores Setzu
- Department of Biomedical Sciences, University of Cagliari, Monserrato09042, Italy
| | - Francesca Biggio
- Department of Life and Environmental Sciences, University of Cagliari, Monserrato09042, Italy
| | - Michelle Briffa
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MsidaMSD2080, Malta
| | - Luca Guglielmi
- Medical Research Council Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Nicoletta Savalli
- Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Francesca Binda
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne 1011, Switzerland
- Centre National de la Recherche Scientifique, Institut des Neurosciences Cellulaires et Intégratives, Université de Strasbourg, StrasbourgF-67000, France
| | - Francis Delicata
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MBR3E 0T5, Canada
| | - Gilles Bru–Mercier
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain17666, United Arab Emirates
| | - Neville Vassallo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MsidaMSD2080, Malta
| | - Vittorio Maglione
- Istituto di Ricovero e Cura a Carattere Scientifico Neuromed, Pozzilli86077, Italy
| | - Ruben J. Cauchi
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MsidaMSD2080, Malta
| | - Alba Di Pardo
- Istituto di Ricovero e Cura a Carattere Scientifico Neuromed, Pozzilli86077, Italy
| | - Maria Collu
- Department of Biomedical Sciences, University of Cagliari, Monserrato09042, Italy
| | - Paola Imbrici
- Department of Pharmacy–Drug Sciences, University of Bari ‘‘Aldo Moro”, 70125Bari, Italy
| | - Luigi Catacuzzeno
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia06123, Italy
| | - Maria Cristina D’Adamo
- Department of Medicine and Surgery, Libera Università Mediterranea ‘‘Giuseppe DEGENNARO”, Casamassima 70010, Italy
| | - Riccardo Olcese
- Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MsidaMSD2080, Malta
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain17666, United Arab Emirates
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Erro R, Magrinelli F, Bhatia KP. Paroxysmal movement disorders: Paroxysmal dyskinesia and episodic ataxia. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:347-365. [PMID: 37620078 DOI: 10.1016/b978-0-323-98817-9.00033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Paroxysmal movement disorders have traditionally been classified into paroxysmal dyskinesia (PxD), which consists in attacks of involuntary movements (mainly dystonia and/or chorea) without loss of consciousness, and episodic ataxia (EA), which features spells of cerebellar dysfunction with or without interictal neurological manifestations. In this chapter, PxD will be discussed first according to the trigger-based classification, thus reviewing clinical, genetic, and molecular features of paroxysmal kinesigenic dyskinesia, paroxysmal nonkinesigenic dyskinesia, and paroxysmal exercise-induced dyskinesia. EA will be presented thereafter according to their designated gene or genetic locus. Clinicogenetic similarities among paroxysmal movement disorders have progressively emerged, which are herein highlighted along with growing evidence that their pathomechanisms overlap those of epilepsy and migraine. Advances in our comprehension of the biological pathways underlying paroxysmal movement disorders, which involve ion channels as well as proteins associated with the vesical synaptic cycle or implicated in neuronal energy metabolism, may represent the cornerstone for defining a shared pathophysiologic framework and developing target-specific therapies.
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Affiliation(s)
- Roberto Erro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", Neuroscience Section, University of Salerno, Baronissi, Salerno, Italy
| | - Francesca Magrinelli
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom.
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Mehinovic E, Gray T, Campbell M, Ekholm J, Wenger A, Rowell W, Grudo A, Grimwood J, Korlach J, Gurnett C, Constantino JN, Turner TN. Germline mosaicism of a missense variant in KCNC2 in a multiplex family with autism and epilepsy characterized by long-read sequencing. Am J Med Genet A 2022; 188:2071-2081. [PMID: 35366058 PMCID: PMC9197999 DOI: 10.1002/ajmg.a.62743] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/04/2022] [Accepted: 02/18/2022] [Indexed: 02/06/2023]
Abstract
Currently, protein-coding de novo variants and large copy number variants have been identified as important for ~30% of individuals with autism. One approach to identify relevant variation in individuals who lack these types of events is by utilizing newer genomic technologies. In this study, highly accurate PacBio HiFi long-read sequencing was applied to a family with autism, epileptic encephalopathy, cognitive impairment, and mild dysmorphic features (two affected female siblings, unaffected parents, and one unaffected male sibling) with no known clinical variant. From our long-read sequencing data, a de novo missense variant in the KCNC2 gene (encodes Kv3.2) was identified in both affected children. This variant was phased to the paternal chromosome of origin and is likely a germline mosaic. In silico assessment revealed the variant was not in controls, highly conserved, and predicted damaging. This specific missense variant (Val473Ala) has been shown in both an ortholog and paralog of Kv3.2 to accelerate current decay, shift the voltage dependence of activation, and prevent the channel from entering a long-lasting open state. Seven additional missense variants have been identified in other individuals with neurodevelopmental disorders (p = 1.03 × 10-5 ). KCNC2 is most highly expressed in the brain; in particular, in the thalamus and is enriched in GABAergic neurons. Long-read sequencing was useful in discovering the relevant variant in this family with autism that had remained a mystery for several years and will potentially have great benefits in the clinic once it is widely available.
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Affiliation(s)
- Elvisa Mehinovic
- Department of GeneticsWashington University School of MedicineSt. LouisMissouriUSA
| | - Teddi Gray
- Department of PsychiatryWashington University School of MedicineSt. LouisMissouriUSA
| | - Meghan Campbell
- Department of PsychiatryWashington University School of MedicineSt. LouisMissouriUSA
| | | | | | | | - Ari Grudo
- Pacific BiosciencesMenlo ParkCaliforniaUSA
| | - Jane Grimwood
- HudsonAlpha Institute for BiotechnologyHuntsvilleAlabamaUSA
| | | | - Christina Gurnett
- Department of NeurologyWashington University School of MedicineSt. LouisMissouriUSA
| | - John N. Constantino
- Department of PsychiatryWashington University School of MedicineSt. LouisMissouriUSA
| | - Tychele N. Turner
- Department of GeneticsWashington University School of MedicineSt. LouisMissouriUSA
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Miceli F, Guerrini R, Nappi M, Soldovieri MV, Cellini E, Gurnett CA, Parmeggiani L, Mei D, Taglialatela M. Distinct epilepsy phenotypes and response to drugs in KCNA1 gain- and loss-of function variants. Epilepsia 2021; 63:e7-e14. [PMID: 34778950 PMCID: PMC9299230 DOI: 10.1111/epi.17118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/01/2021] [Accepted: 10/22/2021] [Indexed: 11/29/2022]
Abstract
A wide phenotypic spectrum of neurological diseases is associated with KCNA1 (Kv1.1) variants. To investigate the molecular basis of such a heterogeneous clinical presentation and identify the possible correlation with in vitro phenotypes, we compared the functional consequences of three heterozygous de novo variants (p.P403S, p.P405L, and p.P405S) in Kv1.1 pore region found in four patients with severe developmental and epileptic encephalopathy (DEE), with those of a de novo variant in the voltage sensor (p.A261T) identified in two patients with mild, carbamazepine-responsive, focal epilepsy. Patch-clamp electrophysiology was used to investigate the functional properties of mutant Kv1.1 subunits, both expressed as homomers and heteromers with wild-type Kv1.1 subunits. KCNA1 pore mutations markedly decreased (p. P405S) or fully suppressed (p. P403S, p. P405L) Kv1.1-mediated currents, exerting loss-of-function (LoF) effects. By contrast, channels carrying the p.A261T variant exhibited a hyperpolarizing shift of the activation process, consistent with a gain-of-function (GoF) effect. The present results unveil a novel correlation between in vitro phenotype (GoF vs LoF) and clinical course (mild vs severe) in KCNA1-related phenotypes. The excellent clinical response to carbamazepine observed in the patients carrying the A261T variant suggests an exquisite sensitivity of KCNA1 GoF to sodium channel inhibition that should be further explored.
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Affiliation(s)
- Francesco Miceli
- Department of Neuroscience, University of Naples "Federico II", Naples, Italy
| | - Renzo Guerrini
- Neuroscience Department, A. Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Mario Nappi
- Department of Neuroscience, University of Naples "Federico II", Naples, Italy
| | | | - Elena Cellini
- Neuroscience Department, A. Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Christina A Gurnett
- Department of Neurology, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Davide Mei
- Neuroscience Department, A. Meyer Children's Hospital, University of Florence, Florence, Italy
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Koźmiński W, Pera J. Involvement of the Peripheral Nervous System in Episodic Ataxias. Biomedicines 2020; 8:biomedicines8110448. [PMID: 33105744 PMCID: PMC7690566 DOI: 10.3390/biomedicines8110448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 12/04/2022] Open
Abstract
Episodic ataxias comprise a group of inherited disorders, which have a common hallmark—transient attacks of ataxia. The genetic background is heterogeneous and the causative genes are not always identified. Furthermore, the clinical presentation, including intraictal and interictal symptoms, as well as the retention and progression of neurological deficits, is heterogeneous. Spells of ataxia can be accompanied by other symptoms—mostly from the central nervous system. However, in some of episodic ataxias involvement of peripheral nervous system is a part of typical clinical picture. This review intends to provide an insight into involvement of peripheral nervous system in episodic ataxias.
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Affiliation(s)
- Wojciech Koźmiński
- Department of Neurology, University Hospital, ul. Jakubowskiego 2, 30-688 Krakow, Poland;
| | - Joanna Pera
- Department of Neurology, Jagiellonian University Medical College, ul. Botaniczna 3, 31-503 Krakow, Poland
- Correspondence:
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A Common Kinetic Property of Mutations Linked to Episodic Ataxia Type 1 Studied in the Shaker Kv Channel. Int J Mol Sci 2020; 21:ijms21207602. [PMID: 33066705 PMCID: PMC7589002 DOI: 10.3390/ijms21207602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 12/21/2022] Open
Abstract
(1) Background: Episodic ataxia type 1 is caused by mutations in the KCNA1 gene encoding for the voltage-gated potassium channel Kv1.1. There have been many mutations in Kv1.1 linked to episodic ataxia reported and typically investigated by themselves or in small groups. The aim of this article is to determine whether we can define a functional parameter common to all Kv1.1 mutants that have been linked to episodic ataxia. (2) Methods: We introduced the disease mutations linked to episodic ataxia in the drosophila analog of Kv1.1, the Shaker Kv channel, and expressed the channels in Xenopus oocytes. Using the cut-open oocyte technique, we characterized the gating and ionic currents. (3) Results: We found that the episodic ataxia mutations variably altered the different gating mechanisms described for Kv channels. The common characteristic was a conductance voltage relationship and inactivation shifted to less polarized potentials. (4) Conclusions: We suggest that a combination of a prolonged action potential and slowed and incomplete inactivation leads to development of ataxia when Kv channels cannot follow or adapt to high firing rates.
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7
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Orsucci D, Raglione LM, Mazzoni M, Vista M. Therapy of episodic ataxias: case report and review of the literature. Drugs Context 2019; 8:212576. [PMID: 30891074 PMCID: PMC6415777 DOI: 10.7573/dic.212576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 11/21/2022] Open
Abstract
Episodic ataxias (EAs) are characterized by recurrent, discrete episodes of vertigo and ataxia. EA1 and EA2 are the two most common forms. In the interictal interval, myokymia is typically present in EA1, whereas EA2 patients present with interictal nystagmus. Specific pharmacological therapies are available for EA1 and especially EA2. We briefly discuss the case of an Italian young man with EA2, with a novel de novo CACNA1A mutation, who in our opinion is particularly illustrative for introducing the therapeutic approach. Acetazolamide could fully suppress EA episodes in our patient. We also provide a perspective review of the topic. 4-Aminopyridine is another valid treatment option. For EA1 (and for rarer EAs), the therapeutic possibilities are more limited. Carbamazepine is probably the treatment of choice for EA1, but the optimal treatment plan is unknown. A better understanding of the molecular processes involved in the mediation of EAs will lead to more specific and efficacious therapies for this still elusive group of disorders.
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Affiliation(s)
| | | | | | - Marco Vista
- Unit of Neurology, San Luca Hospital, Lucca, Italy
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8
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Miceli F, Soldovieri MV, Ambrosino P, De Maria M, Manocchio L, Medoro A, Taglialatela M. Molecular pathophysiology and pharmacology of the voltage-sensing module of neuronal ion channels. Front Cell Neurosci 2015; 9:259. [PMID: 26236192 PMCID: PMC4502356 DOI: 10.3389/fncel.2015.00259] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 06/22/2015] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated ion channels (VGICs) are membrane proteins that switch from a closed to open state in response to changes in membrane potential, thus enabling ion fluxes across the cell membranes. The mechanism that regulate the structural rearrangements occurring in VGICs in response to changes in membrane potential still remains one of the most challenging topic of modern biophysics. Na+, Ca2+ and K+ voltage-gated channels are structurally formed by the assembly of four similar domains, each comprising six transmembrane segments. Each domain can be divided into two main regions: the Pore Module (PM) and the Voltage-Sensing Module (VSM). The PM (helices S5 and S6 and intervening linker) is responsible for gate opening and ion selectivity; by contrast, the VSM, comprising the first four transmembrane helices (S1–S4), undergoes the first conformational changes in response to membrane voltage variations. In particular, the S4 segment of each domain, which contains several positively charged residues interspersed with hydrophobic amino acids, is located within the membrane electric field and plays an essential role in voltage sensing. In neurons, specific gating properties of each channel subtype underlie a variety of biological events, ranging from the generation and propagation of electrical impulses, to the secretion of neurotransmitters and to the regulation of gene expression. Given the important functional role played by the VSM in neuronal VGICs, it is not surprising that various VSM mutations affecting the gating process of these channels are responsible for human diseases, and that compounds acting on the VSM have emerged as important investigational tools with great therapeutic potential. In the present review we will briefly describe the most recent discoveries concerning how the VSM exerts its function, how genetically inherited diseases caused by mutations occurring in the VSM affects gating in VGICs, and how several classes of drugs and toxins selectively target the VSM.
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Affiliation(s)
- Francesco Miceli
- Department of Neuroscience, University of Naples Federico II Naples, Italy
| | | | - Paolo Ambrosino
- Department of Medicine and Health Sciences, University of Molise Campobasso, Italy
| | - Michela De Maria
- Department of Medicine and Health Sciences, University of Molise Campobasso, Italy
| | - Laura Manocchio
- Department of Medicine and Health Sciences, University of Molise Campobasso, Italy
| | - Alessandro Medoro
- Department of Medicine and Health Sciences, University of Molise Campobasso, Italy
| | - Maurizio Taglialatela
- Department of Neuroscience, University of Naples Federico II Naples, Italy ; Department of Medicine and Health Sciences, University of Molise Campobasso, Italy
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Shaker IR T449 mutants separate C- from U-type inactivation. J Membr Biol 2014; 247:319-30. [PMID: 24487574 DOI: 10.1007/s00232-014-9634-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/13/2014] [Indexed: 10/25/2022]
Abstract
Previous studies demonstrated that slow inactivation of the Shaker potassium channel can be made ~100-fold faster or slower by point mutations at a site in the outer pore (T449). However, the discovery that two forms of slow inactivation coexist in Shaker raises the question of which inactivation process is affected by mutation. Equivalent mutations in K(V)2.1, a channel exhibiting only U-type inactivation, have minimal effects on inactivation, suggesting that mutation of Shaker T449 acts on C-type inactivation alone, a widely held yet untested hypothesis. This study reexamines mutations at Shaker T449, confirming that T449A speeds inactivation and T449Y/V slow it. T449Y and T449V exhibit U-type inactivation that is enhanced by high extracellular potassium, in contrast to C-type inactivation in T449A which is inhibited by high potassium. Automated parameter estimation for a 12-state Markov model suggests that U-type inactivation occurs mainly from closed states upon weak depolarization, but primarily from the open state at positive voltages. The model also suggests that WT channels, which in this study exhibit mostly C-type inactivation, recover from inactivation through closed-inactivated states, producing voltage-dependent recovery. This suggests that both C-type and U-type inactivation involve both open-inactivated and closed-inactivated states.
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Tian C, Zhu R, Zhu L, Qiu T, Cao Z, Kang T. Potassium Channels: Structures, Diseases, and Modulators. Chem Biol Drug Des 2013; 83:1-26. [DOI: 10.1111/cbdd.12237] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Chuan Tian
- School of Life Sciences and Technology; Tongji University; Shanghai 200092 China
- School of Pharmacy; Liaoning University of Traditional Chinese Medicine; Dalian Liaoning 116600 China
| | - Ruixin Zhu
- School of Life Sciences and Technology; Tongji University; Shanghai 200092 China
| | - Lixin Zhu
- Department of Pediatrics; Digestive Diseases and Nutrition Center; The State University of New York at Buffalo; Buffalo NY 14226 USA
| | - Tianyi Qiu
- School of Life Sciences and Technology; Tongji University; Shanghai 200092 China
| | - Zhiwei Cao
- School of Life Sciences and Technology; Tongji University; Shanghai 200092 China
| | - Tingguo Kang
- School of Pharmacy; Liaoning University of Traditional Chinese Medicine; Dalian Liaoning 116600 China
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Shah NH, Aizenman E. Voltage-gated potassium channels at the crossroads of neuronal function, ischemic tolerance, and neurodegeneration. Transl Stroke Res 2013; 5:38-58. [PMID: 24323720 DOI: 10.1007/s12975-013-0297-7] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/14/2013] [Accepted: 10/14/2013] [Indexed: 11/29/2022]
Abstract
Voltage-gated potassium (Kv) channels are widely expressed in the central and peripheral nervous system and are crucial mediators of neuronal excitability. Importantly, these channels also actively participate in cellular and molecular signaling pathways that regulate the life and death of neurons. Injury-mediated increased K(+) efflux through Kv2.1 channels promotes neuronal apoptosis, contributing to widespread neuronal loss in neurodegenerative disorders such as Alzheimer's disease and stroke. In contrast, some forms of neuronal activity can dramatically alter Kv2.1 channel phosphorylation levels and influence their localization. These changes are normally accompanied by modifications in channel voltage dependence, which may be neuroprotective within the context of ischemic injury. Kv1 and Kv7 channel dysfunction leads to neuronal hyperexcitability that critically contributes to the pathophysiology of human clinical disorders such as episodic ataxia and epilepsy. This review summarizes the neurotoxic, neuroprotective, and neuroregulatory roles of Kv channels and highlights the consequences of Kv channel dysfunction on neuronal physiology. The studies described in this review thus underscore the importance of normal Kv channel function in neurons and emphasize the therapeutic potential of targeting Kv channels in the treatment of a wide range of neurological diseases.
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Affiliation(s)
- Niyathi Hegde Shah
- Department of Neurobiology, University of Pittsburgh School of Medicine, 3500 Terrace Street, E1456 BST, Pittsburgh, PA, 15261, USA,
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