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Rönnelid O, Elinder F. Carboxyl-group compounds activate voltage-gated potassium channels via a distinct mechanism. J Gen Physiol 2024; 156:e202313516. [PMID: 38832889 PMCID: PMC11148469 DOI: 10.1085/jgp.202313516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/14/2024] [Accepted: 05/21/2024] [Indexed: 06/06/2024] Open
Abstract
Voltage-gated ion channels are responsible for the electrical excitability of neurons and cardiomyocytes. Thus, they are obvious targets for pharmaceuticals aimed to modulate excitability. Compounds activating voltage-gated potassium (KV) channels are expected to reduce excitability. To search for new KV-channel activators, we performed a high-throughput screen of 10,000 compounds on a specially designed Shaker KV channel. Here, we report on a large family of channel-activating compounds with a carboxyl (COOH) group as the common motif. The most potent COOH activators are lipophilic (4 < LogP <7) and are suggested to bind at the interface between the lipid bilayer and the channel's positively charged voltage sensor. The negatively charged form of the COOH-group compounds is suggested to open the channel by electrostatically pulling the voltage sensor to an activated state. Several of the COOH-group compounds also activate the therapeutically important KV7.2/7.3 channel and can thus potentially be developed into antiseizure drugs. The COOH-group compounds identified in this study are suggested to act via the same site and mechanism of action as previously studied COOH-group compounds, such as polyunsaturated fatty acids and resin acids, but distinct from sites for several other types of potassium channel-activating compounds.
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Affiliation(s)
- Olle Rönnelid
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Fredrik Elinder
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
- Science for Life Laboratory, Linköping University, Linköping, Sweden
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2
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Urrutia J, Arrizabalaga-Iriondo A, Sanchez-del-Rey A, Martinez-Ibargüen A, Gallego M, Casis O, Revuelta M. Therapeutic role of voltage-gated potassium channels in age-related neurodegenerative diseases. Front Cell Neurosci 2024; 18:1406709. [PMID: 38827782 PMCID: PMC11140135 DOI: 10.3389/fncel.2024.1406709] [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: 05/02/2024] [Indexed: 06/05/2024] Open
Abstract
Voltage-gated ion channels are essential for membrane potential maintenance, homeostasis, electrical signal production and controlling the Ca2+ flow through the membrane. Among all ion channels, the key regulators of neuronal excitability are the voltage-gated potassium channels (KV), the largest family of K+ channels. Due to the ROS high levels in the aging brain, K+ channels might be affected by oxidative agents and be key in aging and neurodegeneration processes. This review provides new insight about channelopathies in the most studied neurodegenerative disorders, such as Alzheimer Disease, Parkinson's Disease, Huntington Disease or Spinocerebellar Ataxia. The main affected KV channels in these neurodegenerative diseases are the KV1, KV2.1, KV3, KV4 and KV7. Moreover, in order to prevent or repair the development of these neurodegenerative diseases, previous KV channel modulators have been proposed as therapeutic targets.
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Affiliation(s)
- Janire Urrutia
- Department of Physiology, Faculty of Medicine and Nursery, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Ane Arrizabalaga-Iriondo
- Department of Physiology, Faculty of Medicine and Nursery, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Ana Sanchez-del-Rey
- Department of Otorhinolaryngology, Faculty of Medicine, University of the Basque Country, Bilbao, Spain
| | - Agustín Martinez-Ibargüen
- Department of Otorhinolaryngology, Faculty of Medicine, University of the Basque Country, Bilbao, Spain
| | - Mónica Gallego
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain
| | - Oscar Casis
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain
| | - Miren Revuelta
- Department of Physiology, Faculty of Medicine and Nursery, University of the Basque Country (UPV/EHU), Bilbao, Spain
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3
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Zhao C, Hong L, Riahi S, Lim VT, Tobias DJ, Tombola F. A novel Hv1 inhibitor reveals a new mechanism of inhibition of a voltage-sensing domain. J Gen Physiol 2021; 153:212452. [PMID: 34228045 PMCID: PMC8263925 DOI: 10.1085/jgp.202012833] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 06/14/2021] [Indexed: 12/16/2022] Open
Abstract
Voltage-gated sodium, potassium, and calcium channels consist of four voltage-sensing domains (VSDs) that surround a central pore domain and transition from a down state to an up state in response to membrane depolarization. While many types of drugs bind pore domains, the number of organic molecules known to bind VSDs is limited. The Hv1 voltage-gated proton channel is made of two VSDs and does not contain a pore domain, providing a simplified model for studying how small ligands interact with VSDs. Here, we describe a ligand, named HIF, that interacts with the Hv1 VSD in the up and down states. We find that HIF rapidly inhibits proton conduction in the up state by blocking the open channel, as previously described for 2-guanidinobenzimidazole and its derivatives. HIF, however, interacts with a site slowly accessible in the down state. Functional studies and MD simulations suggest that this interaction traps the compound in a narrow pocket lined with charged residues within the VSD intracellular vestibule, which results in slow recovery from inhibition. Our findings point to a “wrench in gears” mechanism whereby side chains within the binding pocket trap the compound as the teeth of interlocking gears. We propose that the use of screening strategies designed to target binding sites with slow accessibility, similar to the one identified here, could lead to the discovery of new ligands capable of interacting with VSDs of other voltage-gated ion channels in the down state.
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Affiliation(s)
- Chang Zhao
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA.,Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA
| | - Liang Hong
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA
| | - Saleh Riahi
- Department of Chemistry, University of California, Irvine, Irvine, CA
| | - Victoria T Lim
- Department of Chemistry, University of California, Irvine, Irvine, CA
| | - Douglas J Tobias
- Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA.,Department of Chemistry, University of California, Irvine, Irvine, CA
| | - Francesco Tombola
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA.,Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA
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4
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Bohannon BM, Wu X, Wu X, Perez ME, Liin SI, Larsson HP. Polyunsaturated fatty acids produce a range of activators for heterogeneous IKs channel dysfunction. J Gen Physiol 2021; 152:133474. [PMID: 31865382 PMCID: PMC7062506 DOI: 10.1085/jgp.201912396] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 09/05/2019] [Accepted: 11/27/2019] [Indexed: 01/28/2023] Open
Abstract
Repolarization and termination of the ventricular cardiac action potential is highly dependent on the activation of the slow delayed-rectifier potassium IKs channel. Disruption of the IKs current leads to the most common form of congenital long QT syndrome (LQTS), a disease that predisposes patients to ventricular arrhythmias and sudden cardiac death. We previously demonstrated that polyunsaturated fatty acid (PUFA) analogues increase outward K+ current in wild type and LQTS-causing mutant IKs channels. Our group has also demonstrated the necessity of a negatively charged PUFA head group for potent activation of the IKs channel through electrostatic interactions with the voltage-sensing and pore domains. Here, we test whether the efficacy of the PUFAs can be tuned by the presence of different functional groups in the PUFA head, thereby altering the electrostatic interactions of the PUFA head group with the voltage sensor or the pore. We show that PUFA analogues with taurine and cysteic head groups produced the most potent activation of IKs channels, largely by shifting the voltage dependence of activation. In comparison, the effect on voltage dependence of PUFA analogues with glycine and aspartate head groups was half that of the taurine and cysteic head groups, whereas the effect on maximal conductance was similar. Increasing the number of potentially negatively charged moieties did not enhance the effects of the PUFA on the IKs channel. Our results show that one can tune the efficacy of PUFAs on IKs channels by altering the pKa of the PUFA head group. Different PUFAs with different efficacy on IKs channels could be developed into more personalized treatments for LQTS patients with a varying degree of IKs channel dysfunction.
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Affiliation(s)
- Briana M Bohannon
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL
| | - Xiaoan Wu
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL
| | - Xiongyu Wu
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Marta E Perez
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL
| | - Sara I Liin
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - H Peter Larsson
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL
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5
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Ottosson NE, Silverå Ejneby M, Wu X, Estrada-Mondragón A, Nilsson M, Karlsson U, Schupp M, Rognant S, Jepps TA, Konradsson P, Elinder F. Synthetic resin acid derivatives selectively open the hK V 7.2/7.3 channel and prevent epileptic seizures. Epilepsia 2021; 62:1744-1758. [PMID: 34085706 DOI: 10.1111/epi.16932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/19/2021] [Accepted: 05/03/2021] [Indexed: 01/10/2023]
Abstract
OBJECTIVE About one third of all patients with epilepsy have pharmacoresistant seizures. Thus there is a need for better pharmacological treatments. The human voltage-gated potassium (hKV ) channel hKV 7.2/7.3 is a validated antiseizure target for compounds that activate this channel. In a previous study we have shown that resin acid derivatives can activate the hKV 7.2/7.3 channel. In this study we investigated if these channel activators have the potential to be developed into a new type of antiseizure drug. Thus we examined their structure-activity relationships and the site of action on the hKV 7.2/7.3 channel, if they have unwanted cardiac and cardiovascular effects, and their potential antiseizure effect. METHODS Ion channels were expressed in Xenopus oocytes or mammalian cell lines and explored with two-electrode voltage-clamp or automated patch-clamp techniques. Unwanted vascular side effects were investigated with isometric tension recordings. Antiseizure activity was studied in an electrophysiological zebrafish-larvae model. RESULTS Fourteen resin acid derivatives were tested on hKV 7.2/7.3. The most efficient channel activators were halogenated and had a permanently negatively charged sulfonyl group. The compounds did not bind to the sites of other hKV 7.2/7.3 channel activators, retigabine, or ICA-069673. Instead, they interacted with the most extracellular gating charge of the S4 voltage-sensing helix, and the effects are consistent with an electrostatic mechanism. The compounds altered the voltage dependence of hKV 7.4, but in contrast to retigabine, there were no effects on the maximum conductance. Consistent with these data, the compounds had less smooth muscle-relaxing effect than retigabine. The compounds had almost no effect on the voltage dependence of hKV 11.1, hNaV 1.5, or hCaV 1.2, or on the amplitude of hKV 11.1. Finally, several resin acid derivatives had clear antiseizure effects in a zebrafish-larvae model. SIGNIFICANCE The described resin acid derivatives hold promise for new antiseizure medications, with reduced risk for adverse effects compared with retigabine.
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Affiliation(s)
- Nina E Ottosson
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Malin Silverå Ejneby
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Xiongyu Wu
- Department of Physics, Chemistry, and Biology, Linköping University, Linköping, Sweden
| | | | - Michelle Nilsson
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Urban Karlsson
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | | | - Salomé Rognant
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Andrew Jepps
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Konradsson
- Department of Physics, Chemistry, and Biology, Linköping University, Linköping, Sweden
| | - Fredrik Elinder
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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6
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Kaur J, Famta P, Famta M, Mehta M, Satija S, Sharma N, Vyas M, Khatik GL, Chellappan DK, Dua K, Khurana N. Potential anti-epileptic phytoconstituents: An updated review. JOURNAL OF ETHNOPHARMACOLOGY 2021; 268:113565. [PMID: 33166627 DOI: 10.1016/j.jep.2020.113565] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 10/12/2020] [Accepted: 11/05/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Epilepsy is one of the most commonly occurring non-communicable neurological disorder that affects people of all age groups. Around 50 million people globally are epileptic, with 80% cases in developing countries due to lack of access to treatments determined by high cost and poor availability or it can be defined by the fraction of active epileptic patients who are not appropriately being treated. The availability of antiepileptic drugs and their adjuvant therapy in such countries is less than 50% and these are highly susceptible to drug interactions and severe adverse effects. As a result, the use of herbal medicine is increasingly becoming popular. AIM OF THE STUDY To provide pharmacological information on the active constituents evaluated in the preclinical study to treat epilepsy with potential to be used as an alternative therapeutic option in future. It also provides affirmation for the development of novel antiepileptic drugs derived from medicinal plants. MATERIALS AND METHODS Relevant information on the antiepileptic potential of phytoconstituents in the preclinical study (in-vitro, in-vivo) is provided based on their effect on screening parameters. Besides, relevant information on pharmacology of phytoconstituents, the traditional use of their medicinal plants related to epilepsy and status of phytoconstituents in the clinical study were derived from online databases, including PubMed, Clinicaltrial. gov, The Plant List (TPL, www.theplantlist.org), Science Direct. Articles identified using preset searching syntax and inclusion criteria are presented. RESULTS More than 70% of the phytoconstituents reviewed in this paper justified the traditional use of their medicinal plant related to epilepsy by primarily acting on the GABAergic system. Amongst the phytoconstituents, only cannabidiol and tetrahydrocannabinol have been explored for clinical application in epilepsy. CONCLUSION The preclinical and clinical data of the phytoconstituents to treat epilepsy and its associated comorbidities provides evidence for the discovery and development of novel antiepileptic drugs from medicinal plants. In terms of efficacy and safety, further randomized and controlled clinical studies are required to understand the complete pharmacodynamic and pharmacokinetic picture of phytoconstituents. Also, specific botanical source evaluation is needed.
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Affiliation(s)
- Jaskiran Kaur
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, 144411, India
| | - Paras Famta
- Institute of Nano Science and Technology, Phase-10, Sector-64, Mohali, Punjab, 160062, India
| | - Mani Famta
- Department of Pharmacy, Birla Institute of Technology and Sciences (BITS), Vidya Vihar Campus, Street Number 41, Pilani, Rajasthan, 333031, India
| | - Meenu Mehta
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, 144411, India; Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Saurabh Satija
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, 144411, India; Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Neha Sharma
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, 144411, India
| | - Manish Vyas
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, 144411, India
| | - Gopal Lal Khatik
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, 144411, India
| | - Dinesh Kumar Chellappan
- Department of Life Sciences, School of Pharmacy, International Medical University (IMU), Bukit Jalil, 57000, Kuala Lumpur, Malaysia
| | - Kamal Dua
- Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, NSW, 2007, Australia; Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute (HMRI) & School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Navneet Khurana
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, 144411, India.
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7
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Silverå Ejneby M, Gromova A, Ottosson NE, Borg S, Estrada-Mondragón A, Yazdi S, Apostolakis P, Elinder F, Delemotte L. Resin-acid derivatives bind to multiple sites on the voltage-sensor domain of the Shaker potassium channel. J Gen Physiol 2021; 153:211862. [PMID: 33683319 PMCID: PMC7944402 DOI: 10.1085/jgp.202012676] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 11/30/2020] [Accepted: 01/27/2021] [Indexed: 01/10/2023] Open
Abstract
Voltage-gated potassium (KV) channels can be opened by negatively charged resin acids and their derivatives. These resin acids have been proposed to attract the positively charged voltage-sensor helix (S4) toward the extracellular side of the membrane by binding to a pocket located between the lipid-facing extracellular ends of the transmembrane segments S3 and S4. By contrast to this proposed mechanism, neutralization of the top gating charge of the Shaker KV channel increased resin-acid-induced opening, suggesting other mechanisms and sites of action. Here, we explore the binding of two resin-acid derivatives, Wu50 and Wu161, to the activated/open state of the Shaker KV channel by a combination of in silico docking, molecular dynamics simulations, and electrophysiology of mutated channels. We identified three potential resin-acid-binding sites around S4: (1) the S3/S4 site previously suggested, in which positively charged residues introduced at the top of S4 are critical to keep the compound bound, (2) a site in the cleft between S4 and the pore domain (S4/pore site), in which a tryptophan at the top of S6 and the top gating charge of S4 keeps the compound bound, and (3) a site located on the extracellular side of the voltage-sensor domain, in a cleft formed by S1-S4 (the top-VSD site). The multiple binding sites around S4 and the anticipated helical-screw motion of the helix during activation make the effect of resin-acid derivatives on channel function intricate. The propensity of a specific resin acid to activate and open a voltage-gated channel likely depends on its exact binding dynamics and the types of interactions it can form with the protein in a state-specific manner.
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Affiliation(s)
- Malin Silverå Ejneby
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Arina Gromova
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Nina E Ottosson
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Stina Borg
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, Sweden
| | | | - Samira Yazdi
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Panagiotis Apostolakis
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Fredrik Elinder
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Lucie Delemotte
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, Sweden
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Abstract
The opening and closing of voltage-gated ion channels are regulated by voltage sensors coupled to a gate that controls the ion flux across the cellular membrane. Modulation of any part of gating constitutes an entry point for pharmacologically regulating channel function. Here, we report on the discovery of a large family of warfarin-like compounds that open the two voltage-gated type 1 potassium (KV1) channels KV1.5 and Shaker, but not the related KV2-, KV4-, or KV7-type channels. These negatively charged compounds bind in the open state to positively charged arginines and lysines between the intracellular ends of the voltage-sensor domains and the pore domain. This mechanism of action resembles that of endogenous channel-opening lipids and opens up an avenue for the development of ion-channel modulators.
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D’Adamo MC, Liantonio A, Rolland JF, Pessia M, Imbrici P. Kv1.1 Channelopathies: Pathophysiological Mechanisms and Therapeutic Approaches. Int J Mol Sci 2020; 21:ijms21082935. [PMID: 32331416 PMCID: PMC7215777 DOI: 10.3390/ijms21082935] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 04/19/2020] [Accepted: 04/20/2020] [Indexed: 12/27/2022] Open
Abstract
Kv1.1 belongs to the Shaker subfamily of voltage-gated potassium channels and acts as a critical regulator of neuronal excitability in the central and peripheral nervous systems. KCNA1 is the only gene that has been associated with episodic ataxia type 1 (EA1), an autosomal dominant disorder characterized by ataxia and myokymia and for which different and variable phenotypes have now been reported. The iterative characterization of channel defects at the molecular, network, and organismal levels contributed to elucidating the functional consequences of KCNA1 mutations and to demonstrate that ataxic attacks and neuromyotonia result from cerebellum and motor nerve alterations. Dysfunctions of the Kv1.1 channel have been also associated with epilepsy and kcna1 knock-out mouse is considered a model of sudden unexpected death in epilepsy. The tissue-specific association of Kv1.1 with other Kv1 members, auxiliary and interacting subunits amplifies Kv1.1 physiological roles and expands the pathogenesis of Kv1.1-associated diseases. In line with the current knowledge, Kv1.1 has been proposed as a novel and promising target for the treatment of brain disorders characterized by hyperexcitability, in the attempt to overcome limited response and side effects of available therapies. This review recounts past and current studies clarifying the roles of Kv1.1 in and beyond the nervous system and its contribution to EA1 and seizure susceptibility as well as its wide pharmacological potential.
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Affiliation(s)
- Maria Cristina D’Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MDS-2080, Malta; (M.C.D.); (M.P.)
| | - Antonella Liantonio
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy;
| | | | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MDS-2080, Malta; (M.C.D.); (M.P.)
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain Po Box 17666, UAE
| | - Paola Imbrici
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy;
- Correspondence:
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Jakešová M, Silverå Ejneby M, Đerek V, Schmidt T, Gryszel M, Brask J, Schindl R, Simon DT, Berggren M, Elinder F, Głowacki ED. Optoelectronic control of single cells using organic photocapacitors. SCIENCE ADVANCES 2019; 5:eaav5265. [PMID: 30972364 PMCID: PMC6450690 DOI: 10.1126/sciadv.aav5265] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 02/12/2019] [Indexed: 05/23/2023]
Abstract
Optical control of the electrophysiology of single cells can be a powerful tool for biomedical research and technology. Here, we report organic electrolytic photocapacitors (OEPCs), devices that function as extracellular capacitive electrodes for stimulating cells. OEPCs consist of transparent conductor layers covered with a donor-acceptor bilayer of organic photoconductors. This device produces an open-circuit voltage in a physiological solution of 330 mV upon illumination using light in a tissue transparency window of 630 to 660 nm. We have performed electrophysiological recordings on Xenopus laevis oocytes, finding rapid (time constants, 50 μs to 5 ms) photoinduced transient changes in the range of 20 to 110 mV. We measure photoinduced opening of potassium channels, conclusively proving that the OEPC effectively depolarizes the cell membrane. Our results demonstrate that the OEPC can be a versatile nongenetic technique for optical manipulation of electrophysiology and currently represents one of the simplest and most stable and efficient optical stimulation solutions.
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Affiliation(s)
- Marie Jakešová
- Laboratory of Organic Electronics, ITN Campus Norrköping, Linköping University, SE-60221 Norrköping, Sweden
| | - Malin Silverå Ejneby
- Department of Clinical and Experimental Medicine, Linköping University, SE-58185 Linköping, Sweden
| | - Vedran Đerek
- Laboratory of Organic Electronics, ITN Campus Norrköping, Linköping University, SE-60221 Norrköping, Sweden
- Wallenberg Centre for Molecular Medicine, Linköping University, SE-58185 Linköping, Sweden
| | - Tony Schmidt
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Maciej Gryszel
- Laboratory of Organic Electronics, ITN Campus Norrköping, Linköping University, SE-60221 Norrköping, Sweden
- Wallenberg Centre for Molecular Medicine, Linköping University, SE-58185 Linköping, Sweden
| | - Johan Brask
- Department of Clinical and Experimental Medicine, Linköping University, SE-58185 Linköping, Sweden
| | - Rainer Schindl
- Gottfried Schatz Research Center, Medical University of Graz, A-8010 Graz, Austria
| | - Daniel T. Simon
- Laboratory of Organic Electronics, ITN Campus Norrköping, Linköping University, SE-60221 Norrköping, Sweden
| | - Magnus Berggren
- Laboratory of Organic Electronics, ITN Campus Norrköping, Linköping University, SE-60221 Norrköping, Sweden
| | - Fredrik Elinder
- Department of Clinical and Experimental Medicine, Linköping University, SE-58185 Linköping, Sweden
| | - Eric Daniel Głowacki
- Laboratory of Organic Electronics, ITN Campus Norrköping, Linköping University, SE-60221 Norrköping, Sweden
- Wallenberg Centre for Molecular Medicine, Linköping University, SE-58185 Linköping, Sweden
- Corresponding author.
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11
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Liin SI, Lund PE, Larsson JE, Brask J, Wallner B, Elinder F. Biaryl sulfonamide motifs up- or down-regulate ion channel activity by activating voltage sensors. J Gen Physiol 2018; 150:1215-1230. [PMID: 30002162 PMCID: PMC6080886 DOI: 10.1085/jgp.201711942] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 04/20/2018] [Accepted: 06/11/2018] [Indexed: 11/20/2022] Open
Abstract
Voltage-gated ion channels are key molecules for the generation of cellular electrical excitability. Many pharmaceutical drugs target these channels by blocking their ion-conducting pore, but in many cases, channel-opening compounds would be more beneficial. Here, to search for new channel-opening compounds, we screen 18,000 compounds with high-throughput patch-clamp technology and find several potassium-channel openers that share a distinct biaryl-sulfonamide motif. Our data suggest that the negatively charged variants of these compounds bind to the top of the voltage-sensor domain, between transmembrane segments 3 and 4, to open the channel. Although we show here that biaryl-sulfonamide compounds open a potassium channel, they have also been reported to block sodium and calcium channels. However, because they inactivate voltage-gated sodium channels by promoting activation of one voltage sensor, we suggest that, despite different effects on the channel gates, the biaryl-sulfonamide motif is a general ion-channel activator motif. Because these compounds block action potential-generating sodium and calcium channels and open an action potential-dampening potassium channel, they should have a high propensity to reduce excitability. This opens up the possibility to build new excitability-reducing pharmaceutical drugs from the biaryl-sulfonamide scaffold.
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Affiliation(s)
- Sara I Liin
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Per-Eric Lund
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Johan E Larsson
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Johan Brask
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Björn Wallner
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Fredrik Elinder
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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12
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Wu X, Silverå Ejneby M, Ottosson NE, Elinder F, Konradsson P. A Suzuki-Miyaura Coupling of ortho
-Hydroxyaryl Bromide with Isopropenylboronic Pinacol Ester: Synthesis of the Potassium-Channel Opener (+)-Callitrisic Acid. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Xiongyu Wu
- Department of Physics, Chemistry and Biology; Linköping University; Linköping Sweden
| | - Malin Silverå Ejneby
- Department of Clinical and Experimental Medicine; Linköping University; Linköping Sweden
| | - Nina E Ottosson
- Department of Clinical and Experimental Medicine; Linköping University; Linköping Sweden
| | - Fredrik Elinder
- Department of Clinical and Experimental Medicine; Linköping University; Linköping Sweden
| | - Peter Konradsson
- Department of Physics, Chemistry and Biology; Linköping University; Linköping Sweden
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13
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Silverå Ejneby M, Wu X, Ottosson NE, Münger EP, Lundström I, Konradsson P, Elinder F. Atom-by-atom tuning of the electrostatic potassium-channel modulator dehydroabietic acid. J Gen Physiol 2018; 150:731-750. [PMID: 29626041 PMCID: PMC5940250 DOI: 10.1085/jgp.201711965] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/12/2018] [Indexed: 11/25/2022] Open
Abstract
Dehydroabietic acid was recently shown to open voltage-gated potassium channels. Silverå Ejneby et al. show that its effect peaks when the carboxyl-group charge and hydrophobic anchor are separated by three atoms and use this rule to design molecules that open the human Kv7.2/7.3 potassium channel. Dehydroabietic acid (DHAA) is a naturally occurring component of pine resin that was recently shown to open voltage-gated potassium (KV) channels. The hydrophobic part of DHAA anchors the compound near the channel’s positively charged voltage sensor in a pocket between the channel and the lipid membrane. The negatively charged carboxyl group exerts an electrostatic effect on the channel’s voltage sensor, leading to the channel opening. In this study, we show that the channel-opening effect increases as the length of the carboxyl-group stalk is extended until a critical length of three atoms is reached. Longer stalks render the compounds noneffective. This critical distance is consistent with a simple electrostatic model in which the charge location depends on the stalk length. By combining an effective anchor with the optimal stalk length, we create a compound that opens the human KV7.2/7.3 (M type) potassium channel at a concentration of 1 µM. These results suggest that a stalk between the anchor and the effector group is a powerful way of increasing the potency of a channel-opening drug.
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Affiliation(s)
- Malin Silverå Ejneby
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Xiongyu Wu
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Nina E Ottosson
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - E Peter Münger
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Ingemar Lundström
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Peter Konradsson
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Fredrik Elinder
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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14
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Ni H, Narsingani K, Zhang H, Giles WR. Can principles of the surface potential be combined with knowledge of natural products to reduce atrial rhythm disturbances? Acta Physiol (Oxf) 2018; 222. [PMID: 28719150 DOI: 10.1111/apha.12918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- H. Ni
- Biological Physics Group; School of Physics & Astronomy; The University of Manchester; Manchester UK
| | - K. Narsingani
- Faculties of Kinesiology & Medicine; University of Calgary; Calgary AB Canada
| | - H. Zhang
- Biological Physics Group; School of Physics & Astronomy; The University of Manchester; Manchester UK
| | - W. R. Giles
- Faculties of Kinesiology & Medicine; University of Calgary; Calgary AB Canada
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15
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Salari S, Silverå Ejneby M, Brask J, Elinder F. Isopimaric acid - a multi-targeting ion channel modulator reducing excitability and arrhythmicity in a spontaneously beating mouse atrial cell line. Acta Physiol (Oxf) 2018; 222. [PMID: 28514017 DOI: 10.1111/apha.12895] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 03/08/2017] [Accepted: 05/12/2017] [Indexed: 11/28/2022]
Abstract
AIM Atrial fibrillation is the most common persistent cardiac arrhythmia, and it is not well controlled by present drugs. Because some resin acids open voltage-gated potassium channels and reduce neuronal excitability, we explored the effects of the resin acid isopimaric acid (IPA) on action potentials and ion currents in cardiomyocytes. METHODS Spontaneously beating mouse atrial HL-1 cells were investigated with the whole-cell patch-clamp technique. RESULTS 1-25 μmol L-1 IPA reduced the action potential frequency by up to 50%. The effect of IPA on six different voltage-gated ion channels was investigated; most voltage-dependent parameters of ion channel gating were shifted in the negative direction along the voltage axis, consistent with a hypothesis that a lipophilic and negatively charged compound binds to the lipid membrane close to the positively charged voltage sensor of the ion channels. The major finding was that IPA inactivated sodium channels and L- and T-type calcium channels and activated the rapidly activating potassium channel and the transient outward potassium channel. Computer simulations of IPA effects on all of the ion currents were consistent with a reduced excitability, and they also showed that effects on the Na channel played the largest role to reduce the action potential frequency. Finally, induced arrhythmia in the HL-1 cells was reversed by IPA. CONCLUSION Low concentrations of IPA reduced the action potential frequency and restored regular firing by altering the voltage dependencies of several voltage-gated ion channels. These findings can form the basis for a new pharmacological strategy to treat atrial fibrillation.
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Affiliation(s)
- S. Salari
- Department of Clinical and Experimental Medicine; Linköping University; Linköping Sweden
| | - M. Silverå Ejneby
- Department of Clinical and Experimental Medicine; Linköping University; Linköping Sweden
| | - J. Brask
- Department of Clinical and Experimental Medicine; Linköping University; Linköping Sweden
| | - F. Elinder
- Department of Clinical and Experimental Medicine; Linköping University; Linköping Sweden
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16
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Ottosson NE, Silverå Ejneby M, Wu X, Yazdi S, Konradsson P, Lindahl E, Elinder F. A drug pocket at the lipid bilayer-potassium channel interface. SCIENCE ADVANCES 2017; 3:e1701099. [PMID: 29075666 PMCID: PMC5656419 DOI: 10.1126/sciadv.1701099] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 09/27/2017] [Indexed: 06/07/2023]
Abstract
Many pharmaceutical drugs against neurological and cardiovascular disorders exert their therapeutic effects by binding to specific sites on voltage-gated ion channels of neurons or cardiomyocytes. To date, all molecules targeting known ion channel sites bind to protein pockets that are mainly surrounded by water. We describe a lipid-protein drug-binding pocket of a potassium channel. We synthesized and electrophysiologically tested 125 derivatives, analogs, and related compounds to dehydroabietic acid. Functional data in combination with docking and molecular dynamics simulations mapped a binding site for small-molecule compounds at the interface between the lipid bilayer and the transmembrane segments S3 and S4 of the voltage-sensor domain. This fundamentally new binding site for small-molecule compounds paves the way for the design of new types of drugs against diseases caused by altered excitability.
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Affiliation(s)
- Nina E. Ottosson
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Malin Silverå Ejneby
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Xiongyu Wu
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Samira Yazdi
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Peter Konradsson
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Erik Lindahl
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- Department of Physics, Swedish e-Science Research Centre, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Fredrik Elinder
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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17
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Ahuja S, Mukund S, Deng L, Khakh K, Chang E, Ho H, Shriver S, Young C, Lin S, Johnson JP, Wu P, Li J, Coons M, Tam C, Brillantes B, Sampang H, Mortara K, Bowman KK, Clark KR, Estevez A, Xie Z, Verschoof H, Grimwood M, Dehnhardt C, Andrez JC, Focken T, Sutherlin DP, Safina BS, Starovasnik MA, Ortwine DF, Franke Y, Cohen CJ, Hackos DH, Koth CM, Payandeh J. Structural basis of Nav1.7 inhibition by an isoform-selective small-molecule antagonist. Science 2015; 350:aac5464. [DOI: 10.1126/science.aac5464] [Citation(s) in RCA: 218] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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