1
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Mendez-Otalvaro E, Kopec W, de Groot BL. Effect of two activators on the gating of a K 2P channel. Biophys J 2024; 123:3408-3420. [PMID: 39161093 DOI: 10.1016/j.bpj.2024.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 06/27/2024] [Accepted: 08/09/2024] [Indexed: 08/21/2024] Open
Abstract
TWIK-related potassium channel 1 (TREK1), a two-pore-domain mammalian potassium (K+) channel, regulates the resting potential across cell membranes, presenting a promising therapeutic target for neuropathy treatment. The gating of this channel converges in the conformation of the narrowest part of the pore: the selectivity filter (SF). Various hypotheses explain TREK1 gating modulation, including the dynamics of loops connecting the SF with transmembrane helices and the stability of hydrogen bond (HB) networks adjacent to the SF. Recently, two small molecules (Q6F and Q5F) were reported as activators that affect TREK1 by increasing its open probability in single-channel current measurements. Here, using molecular dynamics simulations, we investigate the effect of these ligands on the previously proposed modulation mechanisms of TREK1 gating compared to the apo channel. Our findings reveal that loop dynamics at the upper region of the SF exhibit only a weak correlation with permeation events/nonpermeation periods, whereas the HB network behind the SF appears more correlated. These nonpermeation periods arise from both distinct mechanisms: a C-type inactivation (resulting from dilation at the top of the SF), which has been described previously, and a carbonyl flipping in an SF binding site. We find that, besides the prevention of C-type inactivation in the channel, the ligands increase the probability of permeation by modulating the dynamics of the carbonyl flipping, influenced by a threonine residue at the bottom of the SF. These results offer insights for rational ligand design to optimize the gating modulation of TREK1 and related K+ channels.
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Affiliation(s)
- Edward Mendez-Otalvaro
- Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Wojciech Kopec
- Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Department of Chemistry, Queen Mary University of London, London, United Kingdom.
| | - Bert L de Groot
- Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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2
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Neelsen LC, Riel EB, Rinné S, Schmid FR, Jürs BC, Bedoya M, Langer JP, Eymsh B, Kiper AK, Cordeiro S, Decher N, Baukrowitz T, Schewe M. Ion occupancy of the selectivity filter controls opening of a cytoplasmic gate in the K 2P channel TALK-2. Nat Commun 2024; 15:7545. [PMID: 39215031 PMCID: PMC11364775 DOI: 10.1038/s41467-024-51812-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 08/16/2024] [Indexed: 09/04/2024] Open
Abstract
Two-pore domain K+ (K2P) channel activity was previously thought to be controlled primarily via a selectivity filter (SF) gate. However, recent crystal structures of TASK-1 and TASK-2 revealed a lower gate at the cytoplasmic pore entrance. Here, we report functional evidence of such a lower gate in the K2P channel K2P17.1 (TALK-2, TASK-4). We identified compounds (drugs and lipids) and mutations that opened the lower gate allowing the fast modification of pore cysteine residues. Surprisingly, stimuli that directly target the SF gate (i.e., pHe., Rb+ permeation, membrane depolarization) also opened the cytoplasmic gate. Reciprocally, opening of the lower gate reduced the electric work to open the SF via voltage driven ion binding. Therefore, it appears that the SF is so rigidly locked into the TALK-2 protein structure that changes in ion occupancy can pry open a distant lower gate and, vice versa, opening of the lower gate concurrently promote SF gate opening. This concept might extent to other K+ channels that contain two gates (e.g., voltage-gated K+ channels) for which such a positive gate coupling has been suggested, but so far not directly demonstrated.
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Affiliation(s)
- Lea C Neelsen
- Institute of Physiology, Christian-Albrechts University of Kiel, Kiel, Germany
| | - Elena B Riel
- Institute of Physiology, Christian-Albrechts University of Kiel, Kiel, Germany
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, USA
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Philipps-University of Marburg, Marburg, Germany
| | | | - Björn C Jürs
- Institute of Physiology, Christian-Albrechts University of Kiel, Kiel, Germany
- MSH Medical School Hamburg, University of Applied Sciences and Medical University, Hamburg, Germany
| | - Mauricio Bedoya
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca, Chile
- Laboratorio de Bioinformática y Química Computacional (LBQC), Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca, Chile
| | - Jan P Langer
- Institute of Physiology, Christian-Albrechts University of Kiel, Kiel, Germany
| | - Bisher Eymsh
- Institute of Physiology, Christian-Albrechts University of Kiel, Kiel, Germany
| | - Aytug K Kiper
- Institute of Physiology and Pathophysiology, Philipps-University of Marburg, Marburg, Germany
| | - Sönke Cordeiro
- Institute of Physiology, Christian-Albrechts University of Kiel, Kiel, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Philipps-University of Marburg, Marburg, Germany.
| | - Thomas Baukrowitz
- Institute of Physiology, Christian-Albrechts University of Kiel, Kiel, Germany.
| | - Marcus Schewe
- Institute of Physiology, Christian-Albrechts University of Kiel, Kiel, Germany.
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3
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Park SJ, Silic MR, Staab PL, Chen J, Zackschewski EL, Zhang G. Evolution of two-pore domain potassium channels and their gene expression in zebrafish embryos. Dev Dyn 2024; 253:722-749. [PMID: 38270285 PMCID: PMC11269526 DOI: 10.1002/dvdy.690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/10/2023] [Accepted: 01/03/2024] [Indexed: 01/26/2024] Open
Abstract
BACKGROUND The two-pore domain potassium (K2P) channels are a major type of potassium channels that maintain the cell membrane potential by conducting passive potassium leak currents independent of voltage change. They play prominent roles in multiple physiological processes, including neuromodulation, perception of pain, breathing and mood control, and response to volatile anesthetics. Mutations in K2P channels have been linked to many human diseases, such as neuronal and cardiovascular disorders and cancers. Significant progress has been made to understand their protein structures, physiological functions, and pharmacological modifiers. However, their expression and function during embryonic development remain largely unknown. RESULTS We employed the zebrafish model and identified 23 k2p genes using BLAST search and gene cloning. We first analyzed vertebrate K2P channel evolution by phylogenetic and syntenic analyses. Our data revealed that the six subtypes of the K2P genes have already evolved in invertebrates long before the emergence of vertebrates. Moreover, the vertebrate K2P gene number increased, most likely due to two whole-genome duplications. Furthermore, we examined zebrafish k2p gene expression during early embryogenesis by in situ hybridization. Each subgroup's genes showed similar but distinct gene expression domains with some exceptions. Most of them were expressed in neural tissues consistent with their known function of neural excitability regulation. However, a few k2p genes were expressed temporarily in specific tissues or organs, suggesting that these K2P channels may be needed for embryonic development. CONCLUSIONS Our phylogenetic and developmental analyses of K2P channels shed light on their evolutionary history and potential roles during embryogenesis related to their physiological functions and human channelopathies.
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Affiliation(s)
- Sung Jun Park
- Department of Comparative Pathobiology, Purdue University, 625 Harrison Street, West Lafayette, Indiana. 47906. USA
| | - Martin R. Silic
- Department of Comparative Pathobiology, Purdue University, 625 Harrison Street, West Lafayette, Indiana. 47906. USA
| | - Peyton L. Staab
- Department of Comparative Pathobiology, Purdue University, 625 Harrison Street, West Lafayette, Indiana. 47906. USA
| | - Jiapei Chen
- Department of Comparative Pathobiology, Purdue University, 625 Harrison Street, West Lafayette, Indiana. 47906. USA
| | - Ethan L. Zackschewski
- Department of Comparative Pathobiology, Purdue University, 625 Harrison Street, West Lafayette, Indiana. 47906. USA
| | - GuangJun Zhang
- Department of Comparative Pathobiology, Purdue University, 625 Harrison Street, West Lafayette, Indiana. 47906. USA
- Purdue University Center for Cancer Research, Purdue University, 625 Harrison Street, West Lafayette, Indiana. 47906. USA
- Purdue Institute for Inflammation, Immunology and Infectious Diseases (PI4D), Purdue University, 625 Harrison Street, West Lafayette, Indiana. 47906. USA
- Purdue Institute for Integrative Neuroscience, Purdue University, 625 Harrison Street, West Lafayette, Indiana. 47906. USA
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4
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de Souza JGV, de Souza DP, da Silva CAA, Martins Sá RW, Paton JFR, da Silva MP, Moraes DJA. Electrophysiological Properties and Morphology of Cardiac and Pulmonary Motoneurons within the Dorsal Motor Nucleus of the Vagus of Rats. Neuroscience 2024; 551:153-165. [PMID: 38821242 DOI: 10.1016/j.neuroscience.2024.05.038] [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: 02/16/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/02/2024]
Abstract
The dorsal motor nucleus of the vagus (DMV) contains parasympathetic motoneurons that project to the heart and lungs. These motoneurons control ventricular excitability/contractility and airways secretions/blood flow, respectively. However, their electrophysiological properties, morphology and synaptic input activity remain unknown. One important ionic current described in DMV motoneurons controlling their electrophysiological behaviour is the A-type mediated by voltage-dependent K+ (Kv) channels. Thus, we compared the electrophysiological properties, synaptic activity, morphology, A-type current density, and single cell expression of Kv subunits, that contribute to macroscopic A-type currents, between DMV motoneurons projecting to either the heart or lungs of adult male rats. Using retrograde labelling, we visualized distinct DMV motoneurons projecting to the heart or lungs in acutely prepared medullary slices. Subsequently, whole cell recordings, morphological reconstruction and single motoneuron qRT-PCR studies were performed. DMV pulmonary motoneurons were more depolarized, electrically excitable, presented higher membrane resistance, broader action potentials and received greater excitatory synaptic inputs compared to cardiac DMV motoneurons. These differences were in part due to highly branched dendritic complexity and lower magnitude of A-type K+ currents. By evaluating expression of channels that mediate A-type currents from single motoneurons, we demonstrated a lower level of Kv4.2 in pulmonary versus cardiac motoneurons, whereas Kv4.3 and Kv1.4 levels were similar. Thus, with the distinct electrical, morphological, and molecular properties of DMV cardiac and pulmonary motoneurons, we surmise that these cells offer a new vista of opportunities for genetic manipulation providing improvement of parasympathetic function in cardiorespiratory diseases such heart failure and asthma.
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Affiliation(s)
- Júlia G V de Souza
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Daniel P de Souza
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Carlos A A da Silva
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Renato W Martins Sá
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Julian F R Paton
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Melina P da Silva
- Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP, Brazil.
| | - Davi J A Moraes
- Department of Physiology and Biophysics, Biomedical Science Institute, University of São Paulo, São Paulo, SP, Brazil.
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5
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Barzó P, Szöts I, Tóth M, Csajbók ÉA, Molnár G, Tamás G. Electrophysiology and Morphology of Human Cortical Supragranular Pyramidal Cells in a Wide Age Range. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.13.598792. [PMID: 38915496 PMCID: PMC11195274 DOI: 10.1101/2024.06.13.598792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
The basic excitatory neurons of the cerebral cortex, the pyramidal cells, are the most important signal integrators for the local circuit. They have quite characteristic morphological and electrophysiological properties that are known to be largely constant with age in the young and adult cortex. However, the brain undergoes several dynamic changes throughout life, such as in the phases of early development and cognitive decline in the aging brain. We set out to search for intrinsic cellular changes in supragranular pyramidal cells across a broad age range: from birth to 85 years of age and we found differences in several biophysical properties between defined age groups. During the first year of life, subthreshold and suprathreshold electrophysiological properties changed in a way that shows that pyramidal cells become less excitable with maturation, but also become temporarily more precise. According to our findings, the morphological features of the three-dimensional reconstructions from different life stages showed consistent morphological properties and systematic dendritic spine analysis of an infantile and an old pyramidal cell showed clear significant differences in the distribution of spine shapes. Overall, the changes that occur during development and aging may have lasting effects on the properties of pyramidal cells in the cerebral cortex. Understanding these changes is important to unravel the complex mechanisms underlying brain development, cognition and age-related neurodegenerative diseases.
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Affiliation(s)
- Pál Barzó
- Department of Neurosurgery, University of Szeged, Szeged, Hungary
| | - Ildikó Szöts
- ELKH-SZTE Research Group for Cortical Microcircuits, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Martin Tóth
- ELKH-SZTE Research Group for Cortical Microcircuits, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Éva Adrienn Csajbók
- ELKH-SZTE Research Group for Cortical Microcircuits, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Gábor Molnár
- ELKH-SZTE Research Group for Cortical Microcircuits, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Gábor Tamás
- ELKH-SZTE Research Group for Cortical Microcircuits, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
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6
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Ricardo PC, Arias MC, de Souza Araujo N. Decoding bee cleptoparasitism through comparative transcriptomics of Coelioxoides waltheriae and its host Tetrapedia diversipes. Sci Rep 2024; 14:12361. [PMID: 38811580 PMCID: PMC11137135 DOI: 10.1038/s41598-024-56261-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 03/04/2024] [Indexed: 05/31/2024] Open
Abstract
Cleptoparasitism, also known as brood parasitism, is a widespread strategy among bee species in which the parasite lays eggs into the nests of the host species. Even though this behavior has significant ecological implications for the dynamics of several species, little is known about the molecular pathways associated with cleptoparasitism. To shed some light on this issue, we used gene expression data to perform a comparative analysis between two solitary neotropical bees: Coelioxoides waltheriae, an obligate parasite, and their specific host Tetrapedia diversipes. We found that ortholog genes involved in signal transduction, sensory perception, learning, and memory formation were differentially expressed between the cleptoparasite and the host. We hypothesize that these genes and their associated molecular pathways are engaged in cleptoparasitism-related processes and, hence, are appealing subjects for further investigation into functional and evolutionary aspects of cleptoparasitism in bees.
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Affiliation(s)
- Paulo Cseri Ricardo
- Departamento de Genética e Biologia Evolutiva - Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
| | - Maria Cristina Arias
- Departamento de Genética e Biologia Evolutiva - Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
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7
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Liu Y, Zhang J, Jiang Z, Qin M, Xu M, Zhang S, Ma G. Organization of corticocortical and thalamocortical top-down inputs in the primary visual cortex. Nat Commun 2024; 15:4495. [PMID: 38802410 PMCID: PMC11130321 DOI: 10.1038/s41467-024-48924-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 05/16/2024] [Indexed: 05/29/2024] Open
Abstract
Unified visual perception requires integration of bottom-up and top-down inputs in the primary visual cortex (V1), yet the organization of top-down inputs in V1 remains unclear. Here, we used optogenetics-assisted circuit mapping to identify how multiple top-down inputs from higher-order cortical and thalamic areas engage V1 excitatory and inhibitory neurons. Top-down inputs overlap in superficial layers yet segregate in deep layers. Inputs from the medial secondary visual cortex (V2M) and anterior cingulate cortex (ACA) converge on L6 Pyrs, whereas ventrolateral orbitofrontal cortex (ORBvl) and lateral posterior thalamic nucleus (LP) inputs are processed in parallel in Pyr-type-specific subnetworks (Pyr←ORBvl and Pyr←LP) and drive mutual inhibition between them via local interneurons. Our study deepens understanding of the top-down modulation mechanisms of visual processing and establishes that V2M and ACA inputs in L6 employ integrated processing distinct from the parallel processing of LP and ORBvl inputs in L5.
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Affiliation(s)
- Yanmei Liu
- Songjiang Hospital and Songjiang Research Institute, Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai, 201600, China
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jiahe Zhang
- Songjiang Hospital and Songjiang Research Institute, Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai, 201600, China
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Zhishan Jiang
- Songjiang Hospital and Songjiang Research Institute, Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai, 201600, China
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Meiling Qin
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Min Xu
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Siyu Zhang
- Songjiang Hospital and Songjiang Research Institute, Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai, 201600, China.
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Guofen Ma
- Songjiang Hospital and Songjiang Research Institute, Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai, 201600, China.
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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8
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Kaliya-Perumal AK, Celik C, Carney TJ, Harris MP, Ingham PW. Genetic regulation of injury-induced heterotopic ossification in adult zebrafish. Dis Model Mech 2024; 17:dmm050724. [PMID: 38736327 DOI: 10.1242/dmm.050724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 04/05/2024] [Indexed: 05/14/2024] Open
Abstract
Heterotopic ossification is the inappropriate formation of bone in soft tissues of the body. It can manifest spontaneously in rare genetic conditions or as a response to injury, known as acquired heterotopic ossification. There are several experimental models for studying acquired heterotopic ossification from different sources of damage. However, their tenuous mechanistic relevance to the human condition, invasive and laborious nature and/or lack of amenability to chemical and genetic screens, limit their utility. To address these limitations, we developed a simple zebrafish injury model that manifests heterotopic ossification with high penetrance in response to clinically emulating injuries, as observed in human myositis ossificans traumatica. Using this model, we defined the transcriptional response to trauma, identifying differentially regulated genes. Mutant analyses revealed that an increase in the activity of the potassium channel Kcnk5b potentiates injury response, whereas loss of function of the interleukin 11 receptor paralogue (Il11ra) resulted in a drastically reduced ossification response. Based on these findings, we postulate that enhanced ionic signalling, specifically through Kcnk5b, regulates the intensity of the skeletogenic injury response, which, in part, requires immune response regulated by Il11ra.
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Affiliation(s)
- Arun-Kumar Kaliya-Perumal
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive 636921, Singapore
| | - Cenk Celik
- Department of Genetics, Evolution and Environment, Genetics Institute, University College London, London WC1E 6BT, UK
| | - Tom J Carney
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive 636921, Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos 138673, Singapore
| | - Matthew P Harris
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Department of Orthopedic Research, Boston Children's Hospital, Boston, MA 02115, USA
| | - Philip W Ingham
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive 636921, Singapore
- Department of Life Sciences, University of Bath, Bath BA2 7AY, UK
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9
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Han X, Xu S, Wang L, Bi Z, Wang D, Bu H, Da J, Liu Y, Tan W. Artificial DNA Framework Channel Modulates Antiapoptotic Behavior in Ischemia-Stressed Cells via Destabilizing Promoter G-Quadruplex. ACS NANO 2024; 18:6147-6161. [PMID: 38372229 DOI: 10.1021/acsnano.3c06563] [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: 02/20/2024]
Abstract
Regulating folding/unfolding of gene promoter G-quadruplexes (G4s) is important for understanding the topological changes in genomic DNAs and the biological effects of such changes on important cellular events. Although many G4-stabilizing ligands have been screened out, effective G4-destabilizing ligands are extremely rare, posing a great challenge for illustrating how G4 destabilization affects gene function in living cells under stress, a long-standing question in neuroscience. Herein, we report a distinct methodology able to destabilize gene promoter G4s in ischemia-stressed neural cells by mitigating the ischemia-induced accumulation of intracellular K+ with an artificial membrane-spanning DNA framework channel (DFC). We also show that ischemia-triggered K+ influx is positively correlated to anomalous stabilization of promoter G4s and downregulation of Bcl-2, an antiapoptotic gene with neuroprotective effects against ischemic injury. Intriguingly, the DFC enables rapid transmembrane transport of excessive K+ mediated by the internal G4 filter, leading to the destabilization of endogenous promoter G4 in Bcl-2 and subsequent turnover of gene expression at both transcription and translation levels under ischemia. Consequently, this work enriches our understanding of the biological roles of endogenous G4s and may offer important clues to study the cellular behaviors in response to stress.
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Affiliation(s)
- Xiaoyan Han
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Shujuan Xu
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Linlin Wang
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Zhengyan Bi
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Dan Wang
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Huitong Bu
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Jun Da
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Yanlan Liu
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Weihong Tan
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
- The Key Laboratory of Zhejiang Province for Aptamers and Theranostics, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, China
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, and College of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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10
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Stengl M, Schneider AC. Contribution of membrane-associated oscillators to biological timing at different timescales. Front Physiol 2024; 14:1243455. [PMID: 38264332 PMCID: PMC10803594 DOI: 10.3389/fphys.2023.1243455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 12/12/2023] [Indexed: 01/25/2024] Open
Abstract
Environmental rhythms such as the daily light-dark cycle selected for endogenous clocks. These clocks predict regular environmental changes and provide the basis for well-timed adaptive homeostasis in physiology and behavior of organisms. Endogenous clocks are oscillators that are based on positive feedforward and negative feedback loops. They generate stable rhythms even under constant conditions. Since even weak interactions between oscillators allow for autonomous synchronization, coupling/synchronization of oscillators provides the basis of self-organized physiological timing. Amongst the most thoroughly researched clocks are the endogenous circadian clock neurons in mammals and insects. They comprise nuclear clockworks of transcriptional/translational feedback loops (TTFL) that generate ∼24 h rhythms in clock gene expression entrained to the environmental day-night cycle. It is generally assumed that this TTFL clockwork drives all circadian oscillations within and between clock cells, being the basis of any circadian rhythm in physiology and behavior of organisms. Instead of the current gene-based hierarchical clock model we provide here a systems view of timing. We suggest that a coupled system of autonomous TTFL and posttranslational feedback loop (PTFL) oscillators/clocks that run at multiple timescales governs adaptive, dynamic homeostasis of physiology and behavior. We focus on mammalian and insect neurons as endogenous oscillators at multiple timescales. We suggest that neuronal plasma membrane-associated signalosomes constitute specific autonomous PTFL clocks that generate localized but interlinked oscillations of membrane potential and intracellular messengers with specific endogenous frequencies. In each clock neuron multiscale interactions of TTFL and PTFL oscillators/clocks form a temporally structured oscillatory network with a common complex frequency-band comprising superimposed multiscale oscillations. Coupling between oscillator/clock neurons provides the next level of complexity of an oscillatory network. This systemic dynamic network of molecular and cellular oscillators/clocks is suggested to form the basis of any physiological homeostasis that cycles through dynamic homeostatic setpoints with a characteristic frequency-band as hallmark. We propose that mechanisms of homeostatic plasticity maintain the stability of these dynamic setpoints, whereas Hebbian plasticity enables switching between setpoints via coupling factors, like biogenic amines and/or neuropeptides. They reprogram the network to a new common frequency, a new dynamic setpoint. Our novel hypothesis is up for experimental challenge.
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Affiliation(s)
- Monika Stengl
- Department of Biology, Animal Physiology/Neuroethology, University of Kassel, Kassel, Germany
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Wiedmann F, Paasche A, Nietfeld J, Kraft M, Meyer AL, Warnecke G, Karck M, Frey N, Schmidt C. Activation of neurokinin-III receptors modulates human atrial TASK-1 currents. J Mol Cell Cardiol 2023; 184:26-36. [PMID: 37793594 DOI: 10.1016/j.yjmcc.2023.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 09/26/2023] [Accepted: 09/30/2023] [Indexed: 10/06/2023]
Abstract
RATIONALE The neurokinin-III receptor was recently shown to regulate atrial cardiomyocyte excitability by inhibiting atrial background potassium currents. TASK-1 (hK2P3.1) two-pore-domain potassium channels, which are expressed atrial-specifically in the human heart, contribute significantly to atrial background potassium currents. As TASK-1 channels are regulated by a variety of intracellular signalling cascades, they represent a promising candidate for mediating the electrophysiological effects of the Gq-coupled neurokinin-III receptor. OBJECTIVE To investigate whether TASK-1 channels mediate the neurokinin-III receptor activation induced effects on atrial electrophysiology. METHODS AND RESULTS In Xenopus laevis oocytes, heterologously expressing neurokinin-III receptor and TASK-1, administration of the endogenous neurokinin-III receptor ligands substance P or neurokinin B resulted in a strong TASK-1 current inhibition. This could be reproduced by application of the high affinity neurokinin-III receptor agonist senktide. Moreover, preincubation with the neurokinin-III receptor antagonist osanetant blunted the effect of senktide. Mutagenesis studies employing TASK-1 channel constructs which lack either protein kinase C (PKC) phosphorylation sites or the domain which is regulating the diacyl glycerol (DAG) sensitivity domain of TASK-1 revealed a protein kinase C independent mechanism of TASK-1 current inhibition: upon neurokinin-III receptor activation TASK-1 channels are blocked in a DAG-dependent fashion. Finally, effects of senktide on atrial TASK-1 currents could be reproduced in patch-clamp measurements, performed on isolated human atrial cardiomyocytes. CONCLUSIONS Heterologously expressed human TASK-1 channels are inhibited by neurokinin-III receptor activation in a DAG dependent fashion. Patch-clamp measurements, performed on human atrial cardiomyocytes suggest that the atrial-specific effects of neurokinin-III receptor activation on cardiac excitability are predominantly mediated via TASK-1 currents.
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Affiliation(s)
- Felix Wiedmann
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg /Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany
| | - Amelie Paasche
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg /Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany
| | - Jendrik Nietfeld
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Manuel Kraft
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg /Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany
| | - Anna L Meyer
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Gregor Warnecke
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Matthias Karck
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Norbert Frey
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg /Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg /Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany.
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Perger E, Bertoli S, Lombardi C. Pharmacotherapy for obstructive sleep apnea: targeting specific pathophysiological traits. Expert Rev Respir Med 2023; 17:663-673. [PMID: 37646222 DOI: 10.1080/17476348.2023.2241353] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 07/24/2023] [Indexed: 09/01/2023]
Abstract
INTRODUCTION The pathophysiology of obstructive sleep apnea (OSA) is multi-factorial and complex. Varying OSA's pathophysiological traits have been identified, including pharyngeal collapsibility, upper airway muscle reactivity, arousal threshold, and regulation of the ventilatory drive. Being CPAP of difficult tolerance and other interventions reserved to specific subpopulations new pharmacological treatments for OSA might be resolutive. AREAS COVERED Several existing and newly developed pharmacological drugs can impact one or more endotypes and could therefore be proposed as treatment options for sleep disordered breathing. With this review we will explore different pathophysiological traits as new targets for OSA therapy. This review will summarize the most promising pharmacological treatment for OSA accordingly with their mechanisms of action on upper airway collapsibility, muscle responsiveness, arousal threshold, and loop gain. EXPERT OPINION Only understanding the pathophysiological traits causing OSA in each patient and placing the disease in the framework of patient comorbidities, we will be able to evolve interventions toward OSA. The development of new drug's combinations will permit different approaches and different choices beside conventional treatments. In the next future, we hope that sleep specialists will select the treatment for a specific patient on the base of its pathophysiology, defining a precision medicine for OSA.
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Affiliation(s)
- Elisa Perger
- Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, Milan, Italy
| | - Simona Bertoli
- Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, Milan, Italy
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy
- Lab of Nutrition and Obesity Research, Istituto Auxologico Italiano, IRCCS, Milan, Carolina
| | - Carolina Lombardi
- Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, Milan, Italy
- Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
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Cai D, Zheng Z, Jin X, Fu Y, Cen L, Ye J, Song Y, Lian J. The Advantages, Challenges, and Future of Human-Induced Pluripotent Stem Cell Lines in Type 2 Long QT Syndrome. J Cardiovasc Transl Res 2023; 16:209-220. [PMID: 35976484 DOI: 10.1007/s12265-022-10298-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 07/23/2022] [Indexed: 02/05/2023]
Abstract
Type 2 long QT syndrome (LQT2) is the second most common subtype of long QT syndrome and is caused by mutations in KCHN2 encoding the rapidly activating delayed rectifier potassium channel vital for ventricular repolarization. Sudden cardiac death is a sentinel event of LQT2. Preclinical diagnosis by genetic testing is potentially life-saving.Traditional LQT2 models cannot wholly recapitulate genetic and phenotypic features; therefore, there is a demand for a reliable experimental model. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) meet this challenge. This review introduces the advantages of the hiPSC-CM model over the traditional model and discusses how hiPSC-CM and gene editing are used to decipher mechanisms of LQT2, screen for cardiotoxicity, and identify therapeutic strategies, thus promoting the realization of precision medicine for LQT2 patients.
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Affiliation(s)
- Dihui Cai
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo University, Zhejiang Province, Ningbo, China
| | - Zequn Zheng
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo University, Zhejiang Province, Ningbo, China
- Department of Cardiovascular, First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Xiaojun Jin
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo University, Zhejiang Province, Ningbo, China
| | - Yin Fu
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo University, Zhejiang Province, Ningbo, China
| | - Lichao Cen
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo University, Zhejiang Province, Ningbo, China
| | - Jiachun Ye
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo University, Zhejiang Province, Ningbo, China
| | - Yongfei Song
- Department of Cardiovascular, Ningbo Institute of Innovation for Combined Medicine and Engineering, Ningbo, China
| | - Jiangfang Lian
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo University, Zhejiang Province, Ningbo, China.
- Department of Cardiovascular, Ningbo Institute of Innovation for Combined Medicine and Engineering, Ningbo, China.
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14
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Xing C, Bao L, Li W, Fan H. Progress on role of ion channels of cardiac fibroblasts in fibrosis. Front Physiol 2023; 14:1138306. [PMID: 36969589 PMCID: PMC10033868 DOI: 10.3389/fphys.2023.1138306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/27/2023] [Indexed: 03/29/2023] Open
Abstract
Cardiac fibrosis is defined as excessive deposition of extracellular matrix (ECM) in pathological conditions. Cardiac fibroblasts (CFs) activated by injury or inflammation differentiate into myofibroblasts (MFs) with secretory and contractile functions. In the fibrotic heart, MFs produce ECM which is composed mainly of collagen and is initially involved in maintaining tissue integrity. However, persistent fibrosis disrupts the coordination of excitatory contractile coupling, leading to systolic and diastolic dysfunction, and ultimately heart failure. Numerous studies have demonstrated that both voltage- and non-voltage-gated ion channels alter intracellular ion levels and cellular activity, contributing to myofibroblast proliferation, contraction, and secretory function. However, an effective treatment strategy for myocardial fibrosis has not been established. Therefore, this review describes the progress made in research related to transient receptor potential (TRP) channels, Piezo1, Ca2+ release-activated Ca2+ (CRAC) channels, voltage-gated Ca2+ channels (VGCCs), sodium channels, and potassium channels in myocardial fibroblasts with the aim of providing new ideas for treating myocardial fibrosis.
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15
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Wang Z, Zhao X, Bu L, Liu K, Li Z, Zhang H, Zhang X, Yuan F, Wang S, Guo Z, Shi L. Low sodium intake ameliorates hypertension and left ventricular hypertrophy in mice with primary aldosteronism. Front Physiol 2023; 14:1136574. [PMID: 36875038 PMCID: PMC9974669 DOI: 10.3389/fphys.2023.1136574] [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: 01/03/2023] [Accepted: 02/01/2023] [Indexed: 02/17/2023] Open
Abstract
The goal of this paper is to elucidate the effects of sodium restriction on hypertension and left ventricular (LV) hypertrophy in a mouse model with primary aldosteronism (PA). Mice with genetic deletion of TWIK-related acid-sensitive K (TASK)-1 and TASK-3 channels (TASK-/-) were used as the animal model of PA. Parameters of the LV were assessed using echocardiography and histomorphology analysis. Untargeted metabolomics analysis was conducted to reveal the mechanisms underlying the hypertrophic changes in the TASK-/- mice. The TASK-/- adult male mice exhibited the hallmarks of PA, including hypertension, hyperaldosteronism, hypernatremia, hypokalemia, and mild acid-base balance disorders. Two weeks of low sodium intake significantly reduced the 24-h average systolic and diastolic BP in TASK-/- but not TASK+/+ mice. In addition, TASK-/- mice showed increasing LV hypertrophy with age, and 2 weeks of the low-sodium diet significantly reversed the increased BP and LV wall thickness in adult TASK-/- mice. Furthermore, a low-sodium diet beginning at 4 weeks of age protected TASK-/- mice from LV hypertrophy at 8-12 weeks of age. Untargeted metabolomics demonstrated that the disturbances in heart metabolism in the TASK-/- mice (e.g., Glutathione metabolism; biosynthesis of unsaturated fatty acids; amino sugar and nucleotide sugar metabolism; pantothenate and CoA biosynthesis; D-glutamine and D-glutamate metabolism), some of which were reversed after sodium restriction, might be involved in the development of LV hypertrophy. In conclusion, adult male TASK-/- mice exhibit spontaneous hypertension and LV hypertrophy, which are ameliorated by a low-sodium intake.
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Affiliation(s)
- Zitian Wang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xue Zhao
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Lifang Bu
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Kun Liu
- Department of Laboratory Medicine, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Ziping Li
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Huaxing Zhang
- Core Facilities and Centers, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xiaoguang Zhang
- Core Facilities and Centers, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Fang Yuan
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China.,Hebei Key Laboratory of Neurophysiology, Shijiazhuang, Hebei, China
| | - Sheng Wang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China.,Hebei Key Laboratory of Neurophysiology, Shijiazhuang, Hebei, China
| | - Zan Guo
- Core Facilities and Centers, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Luo Shi
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China.,Hebei Key Laboratory of Neurophysiology, Shijiazhuang, Hebei, China
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Boron-containing compounds on neurons: Actions and potential applications for treating neurodegenerative diseases. J Inorg Biochem 2023; 238:112027. [PMID: 36345068 DOI: 10.1016/j.jinorgbio.2022.112027] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/27/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022]
Abstract
Boron-containing compounds (BCC) exert effects on neurons. After the expanding of both the identification and synthesis of new BCC, novel effects in living systems have been reported, many of these involving neuronal action. In this review, the actions of BCC on neurons are described; the effects have been inferred by boron deprivation or addition. Also, the effects can be related to those mediated by interaction on ionic channels, G-protein coupled receptors, or other receptors exerting modification on neuronal behavior. Additionally, BCC have exhibited effects by the modulation of inflammation or oxidative processes. BCC are expanding as drugs. Deprivation of boron sources from the diet shows the role of some natural BCC. However, the observations of several new synthesized compounds suggest their ability to act with attractive potency, efficacy, and long-term action on neuronal receptors or processes related with the origin and evolution of neurodegenerative processes. The details of BCC-target interactions are currently being elucidated in progress, as those observed from BCC-protein crystal complexes. Taking all of the above into account, the expansion is presumably near to having studies on the application of BCC as drugs on specific targets for treating neurodegenerative diseases.
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Fan X, Lu Y, Du G, Liu J. Advances in the Understanding of Two-Pore Domain TASK Potassium Channels and Their Potential as Therapeutic Targets. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238296. [PMID: 36500386 PMCID: PMC9736439 DOI: 10.3390/molecules27238296] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/09/2022] [Accepted: 11/15/2022] [Indexed: 11/29/2022]
Abstract
TWIK-related acid-sensitive K+ (TASK) channels, including TASK-1, TASK-3, and TASK-5, are important members of the two-pore domain potassium (K2P) channel family. TASK-5 is not functionally expressed in the recombinant system. TASK channels are very sensitive to changes in extracellular pH and are active during all membrane potential periods. They are similar to other K2P channels in that they can create and use background-leaked potassium currents to stabilize resting membrane conductance and repolarize the action potential of excitable cells. TASK channels are expressed in both the nervous system and peripheral tissues, including excitable and non-excitable cells, and are widely engaged in pathophysiological phenomena, such as respiratory stimulation, pulmonary hypertension, arrhythmia, aldosterone secretion, cancers, anesthesia, neurological disorders, glucose homeostasis, and visual sensitivity. Therefore, they are important targets for innovative drug development. In this review, we emphasized the recent advances in our understanding of the biophysical properties, gating profiles, and biological roles of TASK channels. Given the different localization ranges and biologically relevant functions of TASK-1 and TASK-3 channels, the development of compounds that selectively target TASK-1 and TASK-3 channels is also summarized based on data reported in the literature.
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Affiliation(s)
- Xueming Fan
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Department of Anesthesiology, Guizhou Provincial People’s Hospital, Guiyang 550002, China
| | - Yongzhi Lu
- Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Guizhi Du
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Correspondence: (G.D.); (J.L.)
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Correspondence: (G.D.); (J.L.)
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Arévalo B, Bedoya M, Kiper AK, Vergara F, Ramírez D, Mazola Y, Bustos D, Zúñiga R, Cikutovic R, Cayo A, Rinné S, Ramirez-Apan MT, Sepúlveda FV, Cerda O, López-Collazo E, Decher N, Zúñiga L, Gutierrez M, González W. Selective TASK-1 Inhibitor with a Defined Structure–Activity Relationship Reduces Cancer Cell Proliferation and Viability. J Med Chem 2022; 65:15014-15027. [DOI: 10.1021/acs.jmedchem.1c00378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Bárbara Arévalo
- Centro de Estudios en Alimentos Procesados−CEAP, Conicyt, Programa Regional R19A10001, Gore Maule, 3460000 Talca, Chile
| | - Mauricio Bedoya
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, 3460000 Talca, Chile
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, 3480094 Talca, Chile
| | - Aytug K. Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037 Marburg, Germany
| | - Fernando Vergara
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
| | - David Ramírez
- Departamento de Farmacología, Facultad de Ciencias Biológicas, Universidad de Concepción, 4030000 Concepción, Chile
| | - Yuliet Mazola
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
| | - Daniel Bustos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, 3460000 Talca, Chile
- Laboratorio de Bioinformática y Química Computacional (LBQC), Escuela de Química y Farmacia, Facultad de Medicina, Universidad Católica del Maule, 3460000 Talca, Chile
| | - Rafael Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
- Instituto de Investigación Interdisciplinaria, Vicerrectoría Académica, Universidad de Talca, 3460000 Talca, Chile
| | - Rocio Cikutovic
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
| | - Angel Cayo
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037 Marburg, Germany
| | - M. Teresa Ramirez-Apan
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, 04510 México, DF, México
| | - Francisco V. Sepúlveda
- Centro de Estudios Científicos (CECs), 5110466 Valdivia, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, 5110466 Valdivia, Chile
| | - Oscar Cerda
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile
| | - Eduardo López-Collazo
- The Innate Immune Response Group and Tumor Immunology Laboratory, IdiPAZ, La Paz University Hospital, 8046 Madrid, Spain
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037 Marburg, Germany
- Marburg Center for Mind, Brain and Behavior−MCMBB, Philipps-University Marburg, 35037 Marburg, Germany
| | - Leandro Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
| | - Margarita Gutierrez
- Laboratorio de Síntesis y Actividad Biológica, Instituto de Química de Recursos Naturales, Universidad de Talca, 1 poniente No. 1141, 3460000 Talca, Chile
| | - Wendy González
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
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Kolesnikova TO, Demin KA, Costa FV, Zabegalov KN, de Abreu MS, Gerasimova EV, Kalueff AV. Towards Zebrafish Models of CNS Channelopathies. Int J Mol Sci 2022; 23:ijms232213979. [PMID: 36430455 PMCID: PMC9693542 DOI: 10.3390/ijms232213979] [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: 09/14/2022] [Revised: 11/06/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Channelopathies are a large group of systemic disorders whose pathogenesis is associated with dysfunctional ion channels. Aberrant transmembrane transport of K+, Na+, Ca2+ and Cl- by these channels in the brain induces central nervous system (CNS) channelopathies, most commonly including epilepsy, but also migraine, as well as various movement and psychiatric disorders. Animal models are a useful tool for studying pathogenesis of a wide range of brain disorders, including channelopathies. Complementing multiple well-established rodent models, the zebrafish (Danio rerio) has become a popular translational model organism for neurobiology, psychopharmacology and toxicology research, and for probing mechanisms underlying CNS pathogenesis. Here, we discuss current prospects and challenges of developing genetic, pharmacological and other experimental models of major CNS channelopathies based on zebrafish.
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Affiliation(s)
| | - Konstantin A. Demin
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 197341 St. Petersburg, Russia
| | - Fabiano V. Costa
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
| | | | - Murilo S. de Abreu
- Moscow Institute of Physics and Technology, 141701 Moscow, Russia
- Correspondence: (M.S.d.A.); (A.V.K.); Tel.: +55-54-99605-9807 (M.S.d.A.); +1-240-899-9571 (A.V.K.); Fax: +1-240-899-9571 (A.V.K.)
| | - Elena V. Gerasimova
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
| | - Allan V. Kalueff
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 197341 St. Petersburg, Russia
- Moscow Institute of Physics and Technology, 141701 Moscow, Russia
- Laboratory of Preclinical Bioscreening, Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of Russian Federation, 197758 St. Petersburg, Russia
- Ural Federal University, 620002 Yekaterinburg, Russia
- Scientific Research Institute of Neurosciences and Medicine, 630117 Novosibirsk, Russia
- Correspondence: (M.S.d.A.); (A.V.K.); Tel.: +55-54-99605-9807 (M.S.d.A.); +1-240-899-9571 (A.V.K.); Fax: +1-240-899-9571 (A.V.K.)
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20
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Sinha AS, Wang T, Watanabe M, Hosoi Y, Sohara E, Akita T, Uchida S, Fukuda A. WNK3 kinase maintains neuronal excitability by reducing inwardly rectifying K+ conductance in layer V pyramidal neurons of mouse medial prefrontal cortex. Front Mol Neurosci 2022; 15:856262. [PMID: 36311015 PMCID: PMC9613442 DOI: 10.3389/fnmol.2022.856262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 09/22/2022] [Indexed: 11/13/2022] Open
Abstract
The with-no-lysine (WNK) family of serine-threonine kinases and its downstream kinases of STE20/SPS1-related proline/alanine-rich kinase (SPAK) and oxidative stress-responsive kinase-1 (OSR1) may regulate intracellular Cl− homeostasis through phosphorylation of cation-Cl− co-transporters. WNK3 is expressed in fetal and postnatal brains, and its expression level increases during development. Its roles in neurons, however, remain uncertain. Using WNK3 knockout (KO) mice, we investigated the role of WNK3 in the regulation of the intracellular Cl− concentration ([Cl−]i) and the excitability of layer V pyramidal neurons in the medial prefrontal cortex (mPFC). Gramicidin-perforated patch-clamp recordings in neurons from acute slice preparation at the postnatal day 21 indicated a significantly depolarized reversal potential for GABAA receptor-mediated currents by 6 mV, corresponding to the higher [Cl−]i level by ~4 mM in KO mice than in wild-type littermates. However, phosphorylation levels of SPAK and OSR1 and those of neuronal Na+-K+-2Cl− co-transporter NKCC1 and K+-Cl− co-transporter KCC2 did not significantly differ between KO and wild-type mice. Meanwhile, the resting membrane potential of neurons was more hyperpolarized by 7 mV, and the minimum stimulus current necessary for firing induction was increased in KO mice. These were due to an increased inwardly rectifying K+ (IRK) conductance, mediated by classical inwardly rectifying (Kir) channels, in KO neurons. The introduction of an active form of WNK3 into the recording neurons reversed these changes. The potential role of KCC2 function in the observed changes of KO neurons was investigated by applying a selective KCC2 activator, CLP290. This reversed the enhanced IRK conductance in KO neurons, indicating that both WNK3 and KCC2 are intimately linked in the regulation of resting K+ conductance. Evaluation of synaptic properties revealed that the frequency of miniature excitatory postsynaptic currents (mEPSCs) was reduced, whereas that of inhibitory currents (mIPSCs) was slightly increased in KO neurons. Together, the impact of these developmental changes on the membrane and synaptic properties was manifested as behavioral deficits in pre-pulse inhibition, a measure of sensorimotor gating involving multiple brain regions including the mPFC, in KO mice. Thus, the basal function of WNK3 would be the maintenance and/or development of both intrinsic and synaptic excitabilities.
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Affiliation(s)
- Adya Saran Sinha
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Tianying Wang
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Miho Watanabe
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yasushi Hosoi
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Tenpei Akita
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
- *Correspondence: Atsuo Fukuda
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21
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Griego E, Segura-Villalobos D, Lamas M, Galván EJ. Maternal immune activation increases excitability via downregulation of A-type potassium channels and reduces dendritic complexity of hippocampal neurons of the offspring. Brain Behav Immun 2022; 105:67-81. [PMID: 35803480 DOI: 10.1016/j.bbi.2022.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/29/2022] [Accepted: 07/03/2022] [Indexed: 11/29/2022] Open
Abstract
The epidemiological association between bacterial or viral maternal infections during pregnancy and increased risk for developing psychiatric disorders in offspring is well documented. Numerous rodent and non-human primate studies of viral- or, to a lesser extent, bacterial-induced maternal immune activation (MIA) have documented a series of neurological alterations that may contribute to understanding the pathophysiology of schizophrenia and autism spectrum disorders. Long-term neuronal and behavioral alterations are now ascribed to the effect of maternal proinflammatory cytokines rather than the infection itself. However, detailed electrophysiological alterations in brain areas relevant to psychiatric disorders, such as the dorsal hippocampus, are lacking in response to bacterial-induced MIA. This study determined if electrophysiological and morphological alterations converge in CA1 pyramidal cells (CA1 PC) from the dorsal hippocampus in bacterial-induced MIA offspring. A series of changes in the functional expression of K+ and Na+ ion channels altered the passive and active membrane properties and triggered hyperexcitability of CA1 PC. Contributing to the hyperexcitability, the somatic A-type potassium current (IA) was decreased in MIA CA1 PC. Likewise, the spontaneous glutamatergic and GABAergic inputs were dysregulated and biased toward increased excitation, thereby reshaping the excitation-inhibition balance. Consistent with these findings, the dendritic branching complexity of MIA CA1 PC was reduced. Together, these morphophysiological alterations modify CA1 PC computational capabilities and contribute to explaining cellular alterations that may underlie the cognitive symptoms of MIA-associated psychiatric disorders.
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Affiliation(s)
- Ernesto Griego
- Departamento de Farmacobiología, CINVESTAV Unidad Sur, Ciudad de México, Mexico
| | | | - Mónica Lamas
- Departamento de Farmacobiología, CINVESTAV Unidad Sur, Ciudad de México, Mexico
| | - Emilio J Galván
- Departamento de Farmacobiología, CINVESTAV Unidad Sur, Ciudad de México, Mexico.
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22
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Benarroch E. What Is the Role of 2-Pore Domain Potassium Channels (K2P) in Pain? Neurology 2022; 99:516-521. [PMID: 36123135 DOI: 10.1212/wnl.0000000000201197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 07/15/2022] [Indexed: 11/15/2022] Open
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23
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Zúñiga L, Cayo A, González W, Vilos C, Zúñiga R. Potassium Channels as a Target for Cancer Therapy: Current Perspectives. Onco Targets Ther 2022; 15:783-797. [PMID: 35899081 PMCID: PMC9309325 DOI: 10.2147/ott.s326614] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 07/08/2022] [Indexed: 12/18/2022] Open
Abstract
Potassium (K+) channels are highly regulated membrane proteins that control the potassium ion flux and respond to different cellular stimuli. These ion channels are grouped into three major families, Kv (voltage-gated K+ channel), Kir (inwardly rectifying K+ channel) and K2P (two-pore K+ channels), according to the structure, to mediate the K+ currents. In cancer, alterations in K+ channel function can promote the acquisition of the so-called hallmarks of cancer – cell proliferation, resistance to apoptosis, metabolic changes, angiogenesis, and migratory capabilities – emerging as targets for the development of new therapeutic drugs. In this review, we focus our attention on the different K+ channels associated with the most relevant and prevalent cancer types. We summarize our knowledge about the potassium channels structure and function, their cancer dysregulated expression and discuss the K+ channels modulator and the strategies for designing new drugs.
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Affiliation(s)
- Leandro Zúñiga
- Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile.,Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Escuela de Medicina, Universidad de Talca, Talca, Chile
| | - Angel Cayo
- Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile.,Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Escuela de Medicina, Universidad de Talca, Talca, Chile
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca, Chile.,Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca, Chile
| | - Cristian Vilos
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Escuela de Medicina, Universidad de Talca, Talca, Chile.,Laboratory of Nanomedicine and Targeted Delivery, School of Medicine, Universidad de Talca, Talca, 3460000, Chile.,Center for The Development of Nanoscience & Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago, 8350709, Chile
| | - Rafael Zúñiga
- Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile.,Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Escuela de Medicina, Universidad de Talca, Talca, Chile
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24
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A Direct Interaction between Cyclodextrins and TASK Channels Decreases the Leak Current in Cerebellar Granule Neurons. BIOLOGY 2022; 11:biology11081097. [PMID: 35892953 PMCID: PMC9331813 DOI: 10.3390/biology11081097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 07/14/2022] [Accepted: 07/18/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary Cyclodextrins are cyclic oligosaccharides used to deplete cholesterol from cellular membranes. The effects of methyl-β-cyclodextrin (MβCD) on cellular functions originate principally from reductions in cholesterol levels. In this study, using immunocytochemistry, heterologous expression of K2P channels, and cholesterol-depleting maneuvers, we provide evidence of expression in cultured rat cerebellar granule neurons (CGNs) of TWIK-1 (K2P1), TASK-1 (K2P3), TASK-3 (K2P9), and TRESK (K2P18) channels and their association with lipid rafts using the specific lipids raft markers. In addition, we show a direct blocking with MβCD of TASK-1 and TASK-3 channels as well as for the covalently concatenated heterodimer TASK-1/TASK-3. Abstract Two pore domain potassium channels (K2P) are strongly expressed in the nervous system (CNS), where they play a central role in excitability. These channels give rise to background K+ currents, also known as IKSO (standing-outward potassium current). We detected the expression in primary cultured cerebellar granule neurons (CGNs) of TWIK-1 (K2P1), TASK-1 (K2P3), TASK-3 (K2P9), and TRESK (K2P18) channels by immunocytochemistry and their association with lipid rafts using the specific lipids raft markers flotillin-2 and caveolin-1. At the functional level, methyl-β-cyclodextrin (MβCD, 5 mM) reduced IKSO currents by ~40% in CGN cells. To dissect out this effect, we heterologously expressed the human TWIK-1, TASK-1, TASK-3, and TRESK channels in HEK-293 cells. MβCD directly blocked TASK-1 and TASK-3 channels and the covalently concatenated heterodimer TASK-1/TASK-3 currents. Conversely, MβCD did not affect TWIK-1- and TRESK-mediated K+ currents. On the other hand, the cholesterol-depleting agent filipin III did not affect TASK-1/TASK-3 channels. Together, the results suggest that neuronal background K+ channels are associated to lipid raft environments whilst the functional activity is independent of the cholesterol membrane organization.
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25
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Blum K, Brodie MS, Pandey SC, Cadet JL, Gupta A, Elman I, Thanos PK, Gondre-Lewis MC, Baron D, Kazmi S, Bowirrat A, Febo M, Badgaiyan RD, Braverman ER, Dennen CA, Gold MS. Researching Mitigation of Alcohol Binge Drinking in Polydrug Abuse: KCNK13 and RASGRF2 Gene(s) Risk Polymorphisms Coupled with Genetic Addiction Risk Severity (GARS) Guiding Precision Pro-Dopamine Regulation. J Pers Med 2022; 12:jpm12061009. [PMID: 35743793 PMCID: PMC9224860 DOI: 10.3390/jpm12061009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/12/2022] [Accepted: 06/16/2022] [Indexed: 11/22/2022] Open
Abstract
Excessive alcohol intake, e.g., binge drinking, is a serious and mounting public health problem in the United States and throughout the world. Hence the need for novel insights into the underlying neurobiology that may help improve prevention and therapeutic strategies. Therefore, our group employed a darkness-induced alcohol intake protocol to define the reward deficiency domains of alcohol and other substance use disorders in terms of reward pathways' reduced dopamine signaling and its restoration via specifically-designed therapeutic compounds. It has been determined that KCNK13 and RASGRF2 genes, respectively, code for potassium two pore domain channel subfamily K member 13 and Ras-specific guanine nucleotide-releasing factor 2, and both genes have important dopamine-related functions pertaining to alcohol binge drinking. We present a hypothesis that identification of KCNK13 and RASGRF2 genes' risk polymorphism, coupled with genetic addiction risk score (GARS)-guided precision pro-dopamine regulation, will mitigate binge alcohol drinking. Accordingly, we review published reports on the benefits of this unique approach and provide data on favorable outcomes for both binge-drinking animals and drunk drivers, including reductions in alcohol intake and prevention of relapse to drinking behavior. Since driving under the influence of alcohol often leads to incarceration rather than rehabilitation, there is converging evidence to support the utilization of GARS with or without KCNK13 and RASGRF2 risk polymorphism in the legal arena, whereby the argument that "determinism" overrides the "free will" account may be a plausible defense strategy. Obviously, this type of research is tantamount to helping resolve a major problem related to polydrug abuse.
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Affiliation(s)
- Kenneth Blum
- The Kenneth Blum Behavioral & Neurogenetic Institute, Austin, TX 78701, USA; (E.R.B.); (C.A.D.)
- Division of Addiction Research & Education, Center for Psychiatry, Medicine & Primary Care (Office of Provost), Western University Health Sciences, Pomona, CA 91766, USA; (D.B.); (M.F.)
- Institute of Psychology, ELTE Eötvös Loránd University, Egyetem tér 1-3, 1053 Budapest, Hungary
- Department of Psychiatry, School of Medicine, University of Vermont, Burlington, VT 05405, USA
- Department of Psychiatry, Wright State University Boonshoft School of Medicine and Dayton VA Medical Centre, Dayton, OH 45324, USA
- Correspondence:
| | - Mark S. Brodie
- Center for Alcohol Research in Epigenetics, Departments of Physiology and Biophysics, and Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA; (M.S.B.); (S.C.P.)
| | - Subhash C. Pandey
- Center for Alcohol Research in Epigenetics, Departments of Physiology and Biophysics, and Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA; (M.S.B.); (S.C.P.)
| | - Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Ashim Gupta
- Future Biologics, Lawrenceville, GA 30043, USA;
| | - Igor Elman
- Center for Pain and the Brain (P.A.I.N Group), Department of Anesthesiology, Critical Care & Pain Medicine, Boston Children’s Hospital, Boston, MA 02115, USA;
| | - Panayotis K. Thanos
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Clinical Research Institute on Addictions, Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biosciences, State University of New York at Buffalo, Buffalo, NY 14203, USA;
- Department of Psychology, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Marjorie C. Gondre-Lewis
- Neuropsychopharmacology Laboratory, Department of Anatomy, Howard University College of Medicine, Washington, DC 20059, USA;
| | - David Baron
- Division of Addiction Research & Education, Center for Psychiatry, Medicine & Primary Care (Office of Provost), Western University Health Sciences, Pomona, CA 91766, USA; (D.B.); (M.F.)
| | - Shan Kazmi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA;
| | - Abdalla Bowirrat
- Department of Molecular Biology and Adelson School of Medicine, Ariel University, Ariel 40700, Israel;
| | - Marcelo Febo
- Division of Addiction Research & Education, Center for Psychiatry, Medicine & Primary Care (Office of Provost), Western University Health Sciences, Pomona, CA 91766, USA; (D.B.); (M.F.)
| | - Rajendra D. Badgaiyan
- Department of Psychiatry, South Texas Veteran Health Care System, Audie L. Murphy Memorial VA Hospital, Long School of Medicine, University of Texas Medical Center, San Antonio, TX 78229, USA;
| | - Eric R. Braverman
- The Kenneth Blum Behavioral & Neurogenetic Institute, Austin, TX 78701, USA; (E.R.B.); (C.A.D.)
| | - Catherine A. Dennen
- The Kenneth Blum Behavioral & Neurogenetic Institute, Austin, TX 78701, USA; (E.R.B.); (C.A.D.)
| | - Mark S. Gold
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA;
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26
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Shvetsova AA, Lazarenko VS, Gaynullina DK, Tarasova OS, Schubert R. TWIK-Related Acid-Sensitive Potassium Channels (TASK-1) Emerge as Contributors to Tone Regulation in Renal Arteries at Alkaline pH. Front Physiol 2022; 13:895863. [PMID: 35669582 PMCID: PMC9163564 DOI: 10.3389/fphys.2022.895863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/29/2022] [Indexed: 12/19/2022] Open
Abstract
Aim: TASK-1 channels are established regulators of pulmonary artery tone but their contribution to the regulation of vascular tone in systemic arteries is poorly understood. We tested the hypothesis that TASK-1 channel functional impact differs among systemic vascular beds, that this is associated with differences in their expression and may increase with alkalization of the extracellular environment. Therefore, we evaluated the expression level of TASK-1 channels and their vasomotor role in mesenteric and renal arteries.Methods: Pulmonary, mesenteric and renal arteries from male Wistar rats were used for TASK-1 channel mRNA (qPCR) and protein content (Western blotting) measurements. The functional role of TASK-1 channels was studied by wire myography using the TASK-1 channel blocker AVE1231. In some experiments, the endothelium was removed with a rat whisker.Results: Expression levels of both mRNA and protein of the TASK-1 channel pore-forming subunit were highest in pulmonary arteries, lowest in mesenteric arteries and had an intermediate value in renal arteries. Blockade of TASK-1 channels by 1 µM AVE1231 increased U46619-induced contractile responses of pulmonary arteries but did not affect basal tone and contractile responses to methoxamine of mesenteric and renal arteries at physiological extracellular pH (pHo = 7.41). At alkaline extracellular pH = 7.75 (increase of NaHCO3 to 52 mM) AVE1231 evoked the development of basal tone and increased contractile responses to low concentrations of methoxamine in renal but not mesenteric arteries. This effect was independent of the endothelium.Conclusion: In the rat systemic circulation, TASK-1 channels are abundant in renal arteries and have an anticontractile function under conditions of extracellular alkalosis.
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Affiliation(s)
| | | | - Dina K. Gaynullina
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Olga S. Tarasova
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Rudolf Schubert
- Physiology, Institute of Theoretical Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
- *Correspondence: Rudolf Schubert,
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27
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Country MW, Haase K, Blank K, Canez CR, Roberts JA, Campbell BFN, Smith JC, Pelling AE, Jonz MG. Seasonal changes in membrane structure and excitability in retinal neurons of goldfish (Carassius auratus) under constant environmental conditions. J Exp Biol 2022; 225:275230. [PMID: 35485205 DOI: 10.1242/jeb.244238] [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: 03/04/2022] [Accepted: 04/25/2022] [Indexed: 11/20/2022]
Abstract
Seasonal modifications in the structure of cellular membranes occur as an adaptive measure to withstand exposure to prolonged environmental change. Little is known about whether such changes may occur independently of external cues, such as photoperiod or temperature, or how they may impact the central nervous system. We compared membrane properties of neurons isolated from the retina of goldfish (Carassius auratus), an organism well-adapted to extreme environmental change, during the summer and winter months. Goldfish were maintained in a facility under constant environmental conditions throughout the year. Analysis of whole-retina phospholipid composition using mass spectrometry-based lipidomics revealed a two-fold increase in phosphatidylethanolamine species during the winter, suggesting an increase in cell membrane fluidity. Atomic force microscopy was used to produce localized, nanoscale-force deformation of neuronal membranes. Measurement of Young's modulus indicated increased membrane-cortical stiffness (or decreased elasticity) in neurons isolated during the winter. Voltage-clamp electrophysiology was used to assess physiological changes in neurons between seasons. Winter neurons displayed a hyperpolarized reversal potential (Vrev) and a significantly lower input resistance (Rin) compared to summer neurons. This was indicative of a decrease in membrane excitability during the winter. Subsequent measurement of intracellular Ca2+ activity using Fura-2 microspectrofluorometry confirmed a reduction in action potential activity, including duration and action potential profile, in neurons isolated during the winter. These studies demonstrate chemical and biophysical changes that occur in retinal neurons of goldfish throughout the year without exposure to seasonal cues, and suggest a novel mechanism of seasonal regulation of retinal activity.
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Affiliation(s)
| | | | - Katrin Blank
- Department of Chemistry, Carleton University, Canada
| | | | | | | | | | | | - Michael G Jonz
- Department of Biology, University of Ottawa, Canada.,Brain and Mind Research Institute, University of Ottawa, Canada
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28
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Zhang Q, Fu J, Zhang S, Guo P, Liu S, Shen J, Guo J, Yang H. 'C-type' closed state and gating mechanisms of K2P channels revealed by conformational changes of the TREK-1 channel. J Mol Cell Biol 2022; 14:6504012. [PMID: 35022758 PMCID: PMC9021975 DOI: 10.1093/jmcb/mjac002] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/04/2022] [Accepted: 01/07/2022] [Indexed: 01/10/2023] Open
Abstract
Two-pore domain potassium (K2P) channels gate primarily within the selectivity filter, termed ‘C-type’ gating. Due to the lack of structural insights into the nonconductive (closed) state, ‘C-type’ gating mechanisms remain elusive. Here, molecular dynamics (MD) simulations on TREK-1, a K2P channel, revealed that M4 helix movements induce filter closing in a novel ‘deeper-down’ structure that represents a ‘C-type’ closed state. The ‘down’ structure does not represent the closed state as previously proposed and instead acts as an intermediate state in gating. The study identified the allosteric ‘seesaw’ mechanism of M4 helix movements in modulating filter closing. Finally, guided by this recognition of K2P gating mechanisms, MD simulations revealed that gain-of-function mutations and small-molecule activators activate TREK-1 by perturbing state transitions from open to closed states. Together, we reveal a ‘C-type’ closed state and provide mechanical insights into gating procedures and allosteric regulations for K2P channels.
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Affiliation(s)
- Qiansen Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Jie Fu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Shaoying Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Peipei Guo
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Shijie Liu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Juwen Shen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Jiangtao Guo
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Huaiyu Yang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
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29
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Wrzosek A, Gałecka S, Żochowska M, Olszewska A, Kulawiak B. Alternative Targets for Modulators of Mitochondrial Potassium Channels. Molecules 2022; 27:299. [PMID: 35011530 PMCID: PMC8746388 DOI: 10.3390/molecules27010299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial potassium channels control potassium influx into the mitochondrial matrix and thus regulate mitochondrial membrane potential, volume, respiration, and synthesis of reactive oxygen species (ROS). It has been found that pharmacological activation of mitochondrial potassium channels during ischemia/reperfusion (I/R) injury activates cytoprotective mechanisms resulting in increased cell survival. In cancer cells, the inhibition of these channels leads to increased cell death. Therefore, mitochondrial potassium channels are intriguing targets for the development of new pharmacological strategies. In most cases, however, the substances that modulate the mitochondrial potassium channels have a few alternative targets in the cell. This may result in unexpected or unwanted effects induced by these compounds. In our review, we briefly present the various classes of mitochondrial potassium (mitoK) channels and describe the chemical compounds that modulate their activity. We also describe examples of the multidirectional activity of the activators and inhibitors of mitochondrial potassium channels.
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Affiliation(s)
- Antoni Wrzosek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Shur Gałecka
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Monika Żochowska
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Anna Olszewska
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland;
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
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30
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Biophysical and synaptic properties of regular spiking interneurons in hippocampal area CA3 of aged rats. Neurobiol Aging 2021; 112:27-38. [PMID: 35041997 DOI: 10.1016/j.neurobiolaging.2021.12.007] [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: 07/01/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 12/11/2022]
Abstract
Neuronal processing from the dentate gyrus to the hippocampus is critical for storage and recovery of new memory traces. In area CA3, GABAergic interneurons form a strong barrage of inhibition that modulates pyramidal cells. A well-established feature of aging is decreased GABAergic inhibition, a phenomenon that contributes to the exacerbated excitability of aged pyramidal cells. In hippocampal slices of aged rats (22-28 months old) we examined the properties of regular spiking CA3 interneurons with patch-clamp whole-cell recordings. We found enhanced firing discharge without altering the maximal firing rate of aged regular spiking interneurons. In the mossy fibers (MF) to interneurons synapse, a switch in the AMPA receptor subunit composition was found in aged interneurons. Young regular spiking interneurons predominantly express CP AMPA receptors and MF LTD. By contrast, aged regular spiking interneurons contain a higher proportion of CI AMPA receptors and respond with MF LTP. We show for the first time that the specialized MF terminals contacting interneurons, retain synaptic capabilities and provide a novel insight of the interneuron's function during aging.
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Abstract
Sour taste, the taste of acids, is one of the most enigmatic of the five basic taste qualities; its function is unclear and its receptor was until recently unknown. Sour tastes are transduced in taste buds on the tongue and palate epithelium by a subset of taste receptor cells, known as type III cells. Type III cells express a number of unique markers, including the PKD2L1 gene, which allow for their identification and manipulation. These cells respond to acid stimuli with action potentials and release neurotransmitters onto afferent nerve fibers, with cell bodies in geniculate and petrosal ganglia. Here, we review classical studies of sour taste leading up to the identification of the sour receptor as the proton channel, OTOP1. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Heather N Turner
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, California, USA; ,
| | - Emily R Liman
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, California, USA; ,
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Activity of TREK-2-like Channels in the Pyramidal Neurons of Rat Medial Prefrontal Cortex Depends on Cytoplasmic Calcium. BIOLOGY 2021; 10:biology10111119. [PMID: 34827112 PMCID: PMC8614805 DOI: 10.3390/biology10111119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/26/2021] [Accepted: 10/28/2021] [Indexed: 11/22/2022]
Abstract
Simple Summary The pyramidal neurons of rat prefrontal cortex express potassium channels identified as a non-canonical splice variant of the TREK-2 channel. The main function of TREK channels is to regulate the resting membrane potential. We showed that cytoplasmic Ca2+ upregulates the activity of TREK-2-like channels. Previous studies have indicated that the activation of TREK-2 channels is mediated by PI(4,5)P2, a polyanionic lipid in the inner leaflet of the plasma membrane. While TREK channels are believed to not be regulated by calcium, our work shows otherwise. We propose a model in which calcium ions enable the formation of PI(4,5)P2 nanoclusters, which stabilize active conformation of the channel. Abstract TREK-2-like channels in the pyramidal neurons of rat prefrontal cortex are characterized by a wide range of spontaneous activity—from very low to very high—independent of the membrane potential and the stimuli that are known to activate TREK-2 channels, such as temperature or membrane stretching. The aim of this study was to discover what factors are involved in high levels of TREK-2-like channel activity in these cells. Our research focused on the PI(4,5)P2-dependent mechanism of channel activity. Single-channel patch clamp recordings were performed on freshly dissociated pyramidal neurons of rat prefrontal cortexes in both the cell-attached and inside-out configurations. To evaluate the role of endogenous stimulants, the activity of the channels was recorded in the presence of a PI(4,5)P2 analogue (PI(4,5)P2DiC8) and Ca2+. Our research revealed that calcium ions are an important factor affecting TREK-2-like channel activity and kinetics. The observation that calcium participates in the activation of TREK-2-like channels is a new finding. We showed that PI(4,5)P2-dependent TREK-2 activity occurs when the conditions for PI(4,5)P2/Ca2+ nanocluster formation are met. We present a possible model explaining the mechanism of calcium action.
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Zhang M, Cui Y, Cheng Y, Wang Q, Sun H. The neuroprotective effect and possible therapeutic application of xenon in neurological diseases. J Neurosci Res 2021; 99:3274-3283. [PMID: 34716615 DOI: 10.1002/jnr.24958] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 07/19/2021] [Accepted: 08/20/2021] [Indexed: 11/09/2022]
Abstract
Xenon is an inert gas with stable chemical properties which is used as an anesthetic. Recent in vitro and in vivo findings indicate that xenon also elicits an excellent neuroprotective effect in subanesthetic concentrations. The mechanisms underlying this primarily involve the attenuation of excitotoxicity and the inhibition of N-methyl-d-aspartic acid (NMDA) receptors and NMDA receptor-related effects, such as antioxidative effects, reduced activation of microglia, and Ca2+ -dependent mechanisms, as well as the interaction with certain ion channels and glial cells. Based on this strong neuroprotective role, a large number of experimental and clinical studies have confirmed the significant therapeutic effect of xenon in the treatment of neurological diseases. This review summarizes the reported neuroprotective mechanisms of xenon and discusses its possible therapeutic application in the treatment of various neurological diseases.
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Affiliation(s)
- Mengdi Zhang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Yaru Cui
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Yao Cheng
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Qiaoyun Wang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Hongliu Sun
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
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Mishra P, Narayanan R. Ion-channel degeneracy: Multiple ion channels heterogeneously regulate intrinsic physiology of rat hippocampal granule cells. Physiol Rep 2021; 9:e14963. [PMID: 34342171 PMCID: PMC8329439 DOI: 10.14814/phy2.14963] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 06/13/2021] [Accepted: 06/21/2021] [Indexed: 01/09/2023] Open
Abstract
Degeneracy, the ability of multiple structural components to elicit the same characteristic functional properties, constitutes an elegant mechanism for achieving biological robustness. In this study, we sought electrophysiological signatures for the expression of ion-channel degeneracy in the emergence of intrinsic properties of rat hippocampal granule cells. We measured the impact of four different ion-channel subtypes-hyperpolarization-activated cyclic-nucleotide-gated (HCN), barium-sensitive inward rectifier potassium (Kir ), tertiapin-Q-sensitive inward rectifier potassium, and persistent sodium (NaP) channels-on 21 functional measurements employing pharmacological agents, and report electrophysiological data on two characteristic signatures for the expression of ion-channel degeneracy in granule cells. First, the blockade of a specific ion-channel subtype altered several, but not all, functional measurements. Furthermore, any given functional measurement was altered by the blockade of many, but not all, ion-channel subtypes. Second, the impact of blocking each ion-channel subtype manifested neuron-to-neuron variability in the quantum of changes in the electrophysiological measurements. Specifically, we found that blocking HCN or Ba-sensitive Kir channels enhanced action potential firing rate, but blockade of NaP channels reduced firing rate of granule cells. Subthreshold measures of granule cell intrinsic excitability (input resistance, temporal summation, and impedance amplitude) were enhanced by blockade of HCN or Ba-sensitive Kir channels, but were not significantly altered by NaP channel blockade. We confirmed that the HCN and Ba-sensitive Kir channels independently altered sub- and suprathreshold properties of granule cells through sequential application of pharmacological agents that blocked these channels. Finally, we found that none of the sub- or suprathreshold measurements of granule cells were significantly altered upon treatment with tertiapin-Q. Together, the heterogeneous many-to-many mapping between ion channels and single-neuron intrinsic properties emphasizes the need to account for ion-channel degeneracy in cellular- and network-scale physiology.
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Affiliation(s)
- Poonam Mishra
- Cellular Neurophysiology LaboratoryMolecular Biophysics UnitIndian Institute of ScienceBangaloreIndia
| | - Rishikesh Narayanan
- Cellular Neurophysiology LaboratoryMolecular Biophysics UnitIndian Institute of ScienceBangaloreIndia
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35
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Nawreen N, Baccei ML, Herman JP. Single Prolonged Stress Reduces Intrinsic Excitability and Excitatory Synaptic Drive Onto Pyramidal Neurons in the Infralimbic Prefrontal Cortex of Adult Male Rats. Front Cell Neurosci 2021; 15:705660. [PMID: 34366790 PMCID: PMC8342808 DOI: 10.3389/fncel.2021.705660] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/02/2021] [Indexed: 02/05/2023] Open
Abstract
Post-traumatic stress disorder (PTSD) is a chronic, debilitating mental illness marked by abnormal fear responses and deficits in extinction of fear memories. The pathophysiology of PTSD is linked to decreased activation of the ventromedial prefrontal cortex (vmPFC). This study aims to investigate underlying functional changes in synaptic drive and intrinsic excitability of pyramidal neurons in the rodent homolog of the vmPFC, the infralimbic cortex (IL), following exposure to single prolonged stress (SPS), a paradigm that mimics core symptoms of PTSD in rats. Rats were exposed to SPS and allowed 1 week of recovery, following which brain slices containing the PFC were prepared for whole-cell patch clamp recordings from layer V pyramidal neurons in the IL. Our results indicate that SPS reduces spontaneous excitatory synaptic drive to pyramidal neurons. In addition, SPS decreases the intrinsic membrane excitability of IL PFC pyramidal cells, as indicated by an increase in rheobase, decrease in input resistance, hyperpolarization of resting membrane potential, and a reduction in repetitive firing rate. Our results suggest that SPS causes a lasting reduction in PFC activity, supporting a body of evidence linking traumatic stress with prefrontal hypoactivity.
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Affiliation(s)
- Nawshaba Nawreen
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, OH, United States
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH, United States
- Cincinnati Veterans Affairs Medical Center, Cincinnati, OH, United States
| | - Mark L Baccei
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH, United States
- Department of Anesthesiology, Pain Research Center, University of Cincinnati Medical Center, Cincinnati, OH, United States
| | - James P Herman
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, OH, United States
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH, United States
- Cincinnati Veterans Affairs Medical Center, Cincinnati, OH, United States
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36
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Abstract
K+ channels enable potassium to flow across the membrane with great selectivity. There are four K+ channel families: voltage-gated K (Kv), calcium-activated (KCa), inwardly rectifying K (Kir), and two-pore domain potassium (K2P) channels. All four K+ channels are formed by subunits assembling into a classic tetrameric (4x1P = 4P for the Kv, KCa, and Kir channels) or tetramer-like (2x2P = 4P for the K2P channels) architecture. These subunits can either be the same (homomers) or different (heteromers), conferring great diversity to these channels. They share a highly conserved selectivity filter within the pore but show different gating mechanisms adapted for their function. K+ channels play essential roles in controlling neuronal excitability by shaping action potentials, influencing the resting membrane potential, and responding to diverse physicochemical stimuli, such as a voltage change (Kv), intracellular calcium oscillations (KCa), cellular mediators (Kir), or temperature (K2P).
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37
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Control of Biophysical and Pharmacological Properties of Potassium Channels by Ancillary Subunits. Handb Exp Pharmacol 2021; 267:445-480. [PMID: 34247280 DOI: 10.1007/164_2021_512] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Potassium channels facilitate and regulate physiological processes as diverse as electrical signaling, ion, solute and hormone secretion, fluid homeostasis, hearing, pain sensation, muscular contraction, and the heartbeat. Potassium channels are each formed by either a tetramer or dimer of pore-forming α subunits that co-assemble to create a multimer with a K+-selective pore that in most cases is capable of functioning as a discrete unit to pass K+ ions across the cell membrane. The reality in vivo, however, is that the potassium channel α subunit multimers co-assemble with ancillary subunits to serve specific physiological functions. The ancillary subunits impart specific physiological properties that are often required for a particular activity in vivo; in addition, ancillary subunit interaction often alters the pharmacology of the resultant complex. In this chapter the modes of action of ancillary subunits on K+ channel physiology and pharmacology are described and categorized into various mechanistic classes.
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38
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Ramírez D, Mejia-Gutierrez M, Insuasty B, Rinné S, Kiper AK, Platzk M, Müller T, Decher N, Quiroga J, De-la-Torre P, González W. 5-(Indol-2-yl)pyrazolo[3,4- b]pyridines as a New Family of TASK-3 Channel Blockers: A Pharmacophore-Based Regioselective Synthesis. Molecules 2021; 26:molecules26133897. [PMID: 34202296 PMCID: PMC8271858 DOI: 10.3390/molecules26133897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 11/16/2022] Open
Abstract
TASK channels belong to the two-pore-domain potassium (K2P) channels subfamily. These channels modulate cellular excitability, input resistance, and response to synaptic stimulation. TASK-channel inhibition led to membrane depolarization. TASK-3 is expressed in different cancer cell types and neurons. Thus, the discovery of novel TASK-3 inhibitors makes these bioactive compounds very appealing to explore new cancer and neurological therapies. TASK-3 channel blockers are very limited to date, and only a few heterofused compounds have been reported in the literature. In this article, we combined a pharmacophore hypothesis with molecular docking to address for the first time the rational design, synthesis, and evaluation of 5-(indol-2-yl)pyrazolo[3,4-b]pyridines as a novel family of human TASK-3 channel blockers. Representative compounds of the synthesized library were assessed against TASK-3 using Fluorometric imaging plate reader-Membrane Potential assay (FMP). Inhibitory properties were validated using two-electrode voltage-clamp (TEVC) methods. We identified one active hit compound (MM-3b) with our systematic pipeline, exhibiting an IC50 ≈ 30 μM. Molecular docking models suggest that compound MM-3b binds to TASK-3 at the bottom of the selectivity filter in the central cavity, similar to other described TASK-3 blockers such as A1899 and PK-THPP. Our in silico and experimental studies provide a new tool to predict and design novel TASK-3 channel blockers.
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Affiliation(s)
- David Ramírez
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Llano Subercaseaux 2801-Piso 5, Santiago 8900000, Chile
- Correspondence: (D.R.); (P.D.-l.-T.); (W.G.)
| | - Melissa Mejia-Gutierrez
- Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, A.A, Cali 760031, Colombia; (M.M.-G.); (B.I.); (J.Q.)
| | - Braulio Insuasty
- Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, A.A, Cali 760031, Colombia; (M.M.-G.); (B.I.); (J.Q.)
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Center for Mind, Brain and Behavior (CMBB), Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany; (S.R.); (A.K.K.); (N.D.)
| | - Aytug K. Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Center for Mind, Brain and Behavior (CMBB), Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany; (S.R.); (A.K.K.); (N.D.)
| | - Magdalena Platzk
- Joint Pulmonary Drug Discovery Lab Bayer-MGH, Boston, MA 02114, USA;
| | - Thomas Müller
- Bayer AG, Research & Development, Pharmaceuticals, D-42096 Wuppertal, Germany;
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Center for Mind, Brain and Behavior (CMBB), Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany; (S.R.); (A.K.K.); (N.D.)
| | - Jairo Quiroga
- Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, A.A, Cali 760031, Colombia; (M.M.-G.); (B.I.); (J.Q.)
| | - Pedro De-la-Torre
- Department of Otolaryngology, Harvard Medical School and Massachusetts Eye and Ear, 243 Charles St, Boston, MA 02114, USA
- Caribe Therapeutics, Vía 40 No. 69-111, Oficina 804 A, Barranquilla 080002, Colombia
- Correspondence: (D.R.); (P.D.-l.-T.); (W.G.)
| | - Wendy González
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Poniente No. 1141, Talca 3460000, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3460000, Chile
- Correspondence: (D.R.); (P.D.-l.-T.); (W.G.)
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Vera J, Lippmann K. Post-stroke epileptogenesis is associated with altered intrinsic properties of hippocampal pyramidal neurons leading to increased theta resonance. Neurobiol Dis 2021; 156:105425. [PMID: 34119635 DOI: 10.1016/j.nbd.2021.105425] [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: 03/25/2021] [Revised: 06/01/2021] [Accepted: 06/08/2021] [Indexed: 01/23/2023] Open
Abstract
Brain insults like stroke, trauma or infections often lead to blood-brain barrier-dysfunction (BBBd) frequently resulting into epileptogenesis. Affected patients suffer from seizures and cognitive comorbidities that are potentially linked to altered network oscillations. It has been shown that a hippocampal BBBd in rats leads to in vivo seizures and increased power at theta (3-8 Hz), an important type of network oscillations. However, the underlying cellular mechanisms remain poorly understood. At membrane potentials close to the threshold for action potentials (APs) a subpopulation of CA1 pyramidal cells (PCs) displays intrinsic resonant properties due to an interplay of the muscarine-sensitive K+-current (IM) and the persistent Na+-current (INaP). Such resonant neurons are more excitable and generate more APs when stimulated at theta frequencies, being strong candidates for contributing to hippocampal theta oscillations during epileptogenesis. We tested this hypothesis by characterizing changes in intrinsic properties of hippocampal PCs one week after post-stroke epileptogenesis, a model associated with BBBd, using slice electrophysiology and computer modeling. We find a higher proportion of resonant neurons in BBBd compared to sham animals (47 vs. 29%), accompanied by an increase in their excitability. In contrast, BBBd non-resonant neurons showed a reduced excitability, presented with lower impedance and more positive AP threshold. We identify an increase in IM combined with either a reduction in INaP or an increase in ILeak as possible mechanisms underlying the observed changes. Our results support the hypothesis that a higher proportion of more excitable resonant neurons in the hippocampus contributes to increased theta oscillations and an increased likelihood of seizures in a model of post-stroke epileptogenesis.
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Affiliation(s)
- Jorge Vera
- Grass Laboratory, Marine Biological Laboratory, Woods Hole, MA 02543, USA; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kristina Lippmann
- Grass Laboratory, Marine Biological Laboratory, Woods Hole, MA 02543, USA; Carl-Ludwig-Institute for Physiology, Medical Faculty, University of Leipzig, D-04103 Leipzig, Germany.
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40
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You C, Vandegrift BJ, Brodie MS. KCNK13 potassium channels in the ventral tegmental area of rats are important for excitation of ventral tegmental area neurons by ethanol. Alcohol Clin Exp Res 2021; 45:1348-1358. [PMID: 33960499 DOI: 10.1111/acer.14630] [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: 12/10/2020] [Revised: 04/23/2021] [Accepted: 04/27/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Alcohol excites neurons of the ventral tegmental area (VTA) and the release of dopamine from these neurons is a key event in ethanol (EtOH)-induced reward and reinforcement. Many mechanisms have been proposed to explain EtOH's actions on neurons of the VTA, but antagonists generally do not eliminate the EtOH-induced excitation of VTA neurons. We have previously demonstrated that the ion channel KCNK13 plays an important role in the EtOH-related excitation of mouse VTA neurons. Here, we elaborate on that finding and further assess the importance of KCNK13 in rats. METHODS Rats (Sprague-Dawley and Fisher 344) were used in these studies. In addition to single-unit electrophysiology in brain slices, we used quantitative PCR and immunohistochemistry to discern the effects of EtOH and the brain slice preparation method on the expression levels of the Kcnk13 gene and KCNK13 protein. RESULTS Immunohistochemistry demonstrated that the levels of KCNK13 were significantly reduced during procedures normally used to prepare brain slices for electrophysiology, with a reduction of about 75% in KCNK13 protein at the time that electrophysiological recordings would normally be made. Extracellular recordings demonstrated that EtOH-induced excitation of VTA neurons was reduced after knockdown of Kcnk13 using a small interfering RNA (siRNA) delivered via the recording micropipette. Real-time PCR demonstrated that the expression of Kcnk13 was altered in a time-dependent manner after alcohol withdrawal. CONCLUSIONS KCNK13 plays an important role in EtOH-induced stimulation of rat VTA neurons and is dynamically regulated by cell damage and EtOH exposure, and during withdrawal. KCNK13 is a novel alcohol-sensitive protein, and further investigation of this channel may offer new avenues for the development of agents useful in altering the rewarding effect of alcohol.
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Affiliation(s)
- Chang You
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA.,Department of Psychiatry, Center for Alcohol Research in Epigenetics, University of Illinois at Chicago, Chicago, IL, USA
| | - Bertha J Vandegrift
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA.,Department of Psychiatry, Center for Alcohol Research in Epigenetics, University of Illinois at Chicago, Chicago, IL, USA
| | - Mark S Brodie
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA.,Department of Psychiatry, Center for Alcohol Research in Epigenetics, University of Illinois at Chicago, Chicago, IL, USA
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41
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Wiedmann F, Beyersdorf C, Zhou XB, Kraft M, Paasche A, Jávorszky N, Rinné S, Sutanto H, Büscher A, Foerster KI, Blank A, El-Battrawy I, Li X, Lang S, Tochtermann U, Kremer J, Arif R, Karck M, Decher N, van Loon G, Akin I, Borggrefe M, Kallenberger S, Heijman J, Haefeli WE, Katus HA, Schmidt C. Treatment of atrial fibrillation with doxapram: TASK-1 potassium channel inhibition as a novel pharmacological strategy. Cardiovasc Res 2021; 118:1728-1741. [PMID: 34028533 DOI: 10.1093/cvr/cvab177] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Indexed: 12/20/2022] Open
Abstract
AIMS TASK-1 (K2P3.1) two-pore domain potassium channels are atrial-specific and significantly upregulated in atrial fibrillation (AF) patients, contributing to AF-related electrical remodelling. Inhibition of TASK-1 in cardiomyocytes of AF patients was shown to counteract AF-related action potential duration shortening. Doxapram was identified as a potent inhibitor of the TASK-1 channel. In the present study, we investigated the antiarrhythmic efficacy of doxapram in a porcine model of AF. METHODS AND RESULTS Doxapram successfully cardioverted pigs with artificially induced episodes of AF. We established a porcine model of persistent AF in domestic pigs via intermittent atrial burst stimulation using implanted pacemakers. All pigs underwent catheter-based electrophysiological investigations prior to and after 14 d of doxapram treatment. Pigs in the treatment group received intravenous administration of doxapram once per day. In doxapram-treated AF pigs, the AF burden was significantly reduced. After 14 d of treatment with doxapram, TASK-1 currents were still similar to values of sinus rhythm animals. Doxapram significantly suppressed AF episodes and normalized cellular electrophysiology by inhibition of the TASK-1 channel. Patch-clamp experiments on human atrial cardiomyocytes, isolated from patients with and without AF could reproduce the TASK-1 inhibitory effect of doxapram. CONCLUSIONS Repurposing doxapram might yield a promising new antiarrhythmic drug to treat AF in patients. TRANSLATIONAL PERSPECTIVE Pharmacological suppression of atrial TASK 1 potassium currents prolongs atrial refractoriness with no effects on ventricular repolarization, resulting in atrial-specific class III antiarrhythmic effects. In our preclinical pilot study the respiratory stimulant doxapram was successfully administered for cardioversion of acute AF as well as rhythm control of persistent AF in a clinically relevant porcine animal model.
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Affiliation(s)
- Felix Wiedmann
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Christoph Beyersdorf
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Xiao-Bo Zhou
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Manuel Kraft
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Amelie Paasche
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Natasa Jávorszky
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior MCMBB, University of Marburg, Marburg, Germany
| | - Henry Sutanto
- Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Antonius Büscher
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Kathrin I Foerster
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Antje Blank
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Ibrahim El-Battrawy
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Xin Li
- First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Siegfried Lang
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Ursula Tochtermann
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Jamila Kremer
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Rawa Arif
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Matthias Karck
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior MCMBB, University of Marburg, Marburg, Germany
| | - Gunther van Loon
- Department of Large Animal Internal Medicine, Equine Cardioteam, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Ibrahim Akin
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Martin Borggrefe
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Stefan Kallenberger
- Digital Health Center, Berlin Institute of Health (BIH) and Charité, Berlin, Germany and Health Data Science Unit, University Hospital Heidelberg, Heidelberg, Germany
| | - Jordi Heijman
- Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Walter E Haefeli
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
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Shvetsova AA, Gaynullina DK, Tarasova OS, Schubert R. Remodeling of Arterial Tone Regulation in Postnatal Development: Focus on Smooth Muscle Cell Potassium Channels. Int J Mol Sci 2021; 22:ijms22115413. [PMID: 34063769 PMCID: PMC8196626 DOI: 10.3390/ijms22115413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/15/2021] [Accepted: 05/18/2021] [Indexed: 11/30/2022] Open
Abstract
Maturation of the cardiovascular system is associated with crucial structural and functional remodeling. Thickening of the arterial wall, maturation of the sympathetic innervation, and switching of the mechanisms of arterial contraction from calcium-independent to calcium-dependent occur during postnatal development. All these processes promote an almost doubling of blood pressure from the moment of birth to reaching adulthood. This review focuses on the developmental alterations of potassium channels functioning as key smooth muscle membrane potential determinants and, consequently, vascular tone regulators. We present evidence that the pattern of potassium channel contribution to vascular control changes from Kir2, Kv1, Kv7 and TASK-1 channels to BKCa channels with maturation. The differences in the contribution of potassium channels to vasomotor tone at different stages of postnatal life should be considered in treatment strategies of cardiovascular diseases associated with potassium channel malfunction.
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Affiliation(s)
- Anastasia A. Shvetsova
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia; (D.K.G.); (O.S.T.)
- Correspondence:
| | - Dina K. Gaynullina
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia; (D.K.G.); (O.S.T.)
- Department of Physiology, Russian National Research Medical University, 117997 Moscow, Russia
| | - Olga S. Tarasova
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia; (D.K.G.); (O.S.T.)
- Laboratory of Exercise Physiology, State Research Center of the Russian Federation-Institute for Biomedical Problems, Russian Academy of Sciences, 123007 Moscow, Russia
| | - Rudolf Schubert
- Physiology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, 86159 Augsburg, Germany;
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Wong CO, Karagas NE, Jung J, Wang Q, Rousseau MA, Chao Y, Insolera R, Soppina P, Collins CA, Zhou Y, Hancock JF, Zhu MX, Venkatachalam K. Regulation of longevity by depolarization-induced activation of PLC-β-IP 3R signaling in neurons. Proc Natl Acad Sci U S A 2021; 118:e2004253118. [PMID: 33859040 PMCID: PMC8072327 DOI: 10.1073/pnas.2004253118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial ATP production is a well-known regulator of neuronal excitability. The reciprocal influence of plasma-membrane potential on ATP production, however, remains poorly understood. Here, we describe a mechanism by which depolarized neurons elevate the somatic ATP/ADP ratio in Drosophila glutamatergic neurons. We show that depolarization increased phospholipase-Cβ (PLC-β) activity by promoting the association of the enzyme with its phosphoinositide substrate. Augmented PLC-β activity led to greater release of endoplasmic reticulum Ca2+ via the inositol trisphosphate receptor (IP3R), increased mitochondrial Ca2+ uptake, and promoted ATP synthesis. Perturbations that decoupled membrane potential from this mode of ATP synthesis led to untrammeled PLC-β-IP3R activation and a dramatic shortening of Drosophila lifespan. Upon investigating the underlying mechanisms, we found that increased sequestration of Ca2+ into endolysosomes was an intermediary in the regulation of lifespan by IP3Rs. Manipulations that either lowered PLC-β/IP3R abundance or attenuated endolysosomal Ca2+ overload restored animal longevity. Collectively, our findings demonstrate that depolarization-dependent regulation of PLC-β-IP3R signaling is required for modulation of the ATP/ADP ratio in healthy glutamatergic neurons, whereas hyperactivation of this axis in chronically depolarized glutamatergic neurons shortens animal lifespan by promoting endolysosomal Ca2+ overload.
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Affiliation(s)
- Ching-On Wong
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102
| | - Nicholas E Karagas
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
- Graduate Program in Biochemistry and Cell Biology, MD Anderson Cancer Center and UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Jewon Jung
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
| | - Qiaochu Wang
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
| | - Morgan A Rousseau
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
| | - Yufang Chao
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
| | - Ryan Insolera
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Pushpanjali Soppina
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Catherine A Collins
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
- Graduate Program in Biochemistry and Cell Biology, MD Anderson Cancer Center and UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
- Graduate Program in Biochemistry and Cell Biology, MD Anderson Cancer Center and UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
- Graduate Program in Biochemistry and Cell Biology, MD Anderson Cancer Center and UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Kartik Venkatachalam
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030;
- Graduate Program in Biochemistry and Cell Biology, MD Anderson Cancer Center and UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030
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44
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Yi C, Spitters TWGM, Al-Far EADA, Wang S, Xiong T, Cai S, Yan X, Guan K, Wagner M, El-Armouche A, Antos CL. A calcineurin-mediated scaling mechanism that controls a K +-leak channel to regulate morphogen and growth factor transcription. eLife 2021; 10:e60691. [PMID: 33830014 PMCID: PMC8110307 DOI: 10.7554/elife.60691] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 04/07/2021] [Indexed: 01/10/2023] Open
Abstract
The increase in activity of the two-pore potassium-leak channel Kcnk5b maintains allometric juvenile growth of adult zebrafish appendages. However, it remains unknown how this channel maintains allometric growth and how its bioelectric activity is regulated to scale these anatomical structures. We show the activation of Kcnk5b is sufficient to activate several genes that are part of important development programs. We provide in vivo transplantation evidence that the activation of gene transcription is cell autonomous. We also show that Kcnk5b will induce the expression of different subsets of the tested developmental genes in different cultured mammalian cell lines, which may explain how one electrophysiological stimulus can coordinately regulate the allometric growth of diverse populations of cells in the fin that use different developmental signals. We also provide evidence that the post-translational modification of serine 345 in Kcnk5b by calcineurin regulates channel activity to scale the fin. Thus, we show how an endogenous bioelectric mechanism can be regulated to promote coordinated developmental signaling to generate and scale a vertebrate appendage.
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Affiliation(s)
- Chao Yi
- School of Life Sciences and Technology, ShanghaiTech UniversityShanghaiChina
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of SciencesShanghaiChina
| | - Tim WGM Spitters
- School of Life Sciences and Technology, ShanghaiTech UniversityShanghaiChina
| | | | - Sen Wang
- School of Life Sciences and Technology, ShanghaiTech UniversityShanghaiChina
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of SciencesShanghaiChina
| | - TianLong Xiong
- School of Life Sciences and Technology, ShanghaiTech UniversityShanghaiChina
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of SciencesShanghaiChina
| | - Simian Cai
- School of Life Sciences and Technology, ShanghaiTech UniversityShanghaiChina
| | - Xin Yan
- School of Life Sciences and Technology, ShanghaiTech UniversityShanghaiChina
| | - Kaomei Guan
- Institut für Pharmakologie und Toxikologie, Technische Universität DresdenDresdenGermany
| | - Michael Wagner
- Institut für Pharmakologie und Toxikologie, Technische Universität DresdenDresdenGermany
- Klinik für Innere Medizin und Kardiologie, Herzzentrum Dresden, Technische Universität DresdenDresdenGermany
| | - Ali El-Armouche
- Institut für Pharmakologie und Toxikologie, Technische Universität DresdenDresdenGermany
| | - Christopher L Antos
- School of Life Sciences and Technology, ShanghaiTech UniversityShanghaiChina
- Institut für Pharmakologie und Toxikologie, Technische Universität DresdenDresdenGermany
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45
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Kraft M, Büscher A, Wiedmann F, L’hoste Y, Haefeli WE, Frey N, Katus HA, Schmidt C. Current Drug Treatment Strategies for Atrial Fibrillation and TASK-1 Inhibition as an Emerging Novel Therapy Option. Front Pharmacol 2021; 12:638445. [PMID: 33897427 PMCID: PMC8058608 DOI: 10.3389/fphar.2021.638445] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 01/21/2021] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia with a prevalence of up to 4% and an upwards trend due to demographic changes. It is associated with an increase in mortality and stroke incidences. While stroke risk can be significantly reduced through anticoagulant therapy, adequate treatment of other AF related symptoms remains an unmet medical need in many cases. Two main treatment strategies are available: rate control that modulates ventricular heart rate and prevents tachymyopathy as well as rhythm control that aims to restore and sustain sinus rhythm. Rate control can be achieved through drugs or ablation of the atrioventricular node, rendering the patient pacemaker-dependent. For rhythm control electrical cardioversion and pharmacological cardioversion can be used. While electrical cardioversion requires fasting and sedation of the patient, antiarrhythmic drugs have other limitations. Most antiarrhythmic drugs carry a risk for pro-arrhythmic effects and are contraindicated in patients with structural heart diseases. Furthermore, catheter ablation of pulmonary veins can be performed with its risk of intraprocedural complications and varying success. In recent years TASK-1 has been introduced as a new target for AF therapy. Upregulation of TASK-1 in AF patients contributes to prolongation of the action potential duration. In a porcine model of AF, TASK-1 inhibition by gene therapy or pharmacological compounds induced cardioversion to sinus rhythm. The DOxapram Conversion TO Sinus rhythm (DOCTOS)-Trial will reveal whether doxapram, a potent TASK-1 inhibitor, can be used for acute cardioversion of persistent and paroxysmal AF in patients, potentially leading to a new treatment option for AF.
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Affiliation(s)
- Manuel Kraft
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Antonius Büscher
- Clinic for Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
| | - Felix Wiedmann
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Yannick L’hoste
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Walter E. Haefeli
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | - Norbert Frey
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Hugo A. Katus
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
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Abstract
Ion exchange between intracellular and extracellular spaces is the basic mechanism for controlling cell metabolism and signal transduction. This process is mediated by ion channels and transporters on the plasma membrane, or intracellular membranes that surround various organelles, in response to environmental stimuli. Macroautophagy (hereafter referred to as autophagy) is one of the lysosomal-dependent degradation pathways that maintains homeostasis through the degradation and recycling of cellular components (e.g., dysfunctional proteins and damaged organelles). Although autophagy-related (ATG) proteins play a central role in regulating the formation of autophagy-related member structures (e.g., phagophores, autophagosomes, and autolysosomes), the autophagic process also involves changes in expression and function of ion channels and transporters. Here we discuss current knowledge of the mechanisms that regulate autophagy in mammalian cells, with special attention to the ion channels and transporters. We also highlight prospects for the development of drugs targeting ion channels and transporters in autophagy.
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Affiliation(s)
- Ruoxi Zhang
- Department of Surgery, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Rui Kang
- Department of Surgery, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Daniel J Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Daolin Tang
- Department of Surgery, UT Southwestern Medical Center, Dallas, Texas, USA
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47
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Chronic sleep fragmentation enhances habenula cholinergic neural activity. Mol Psychiatry 2021; 26:941-954. [PMID: 30980042 PMCID: PMC6790161 DOI: 10.1038/s41380-019-0419-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 02/21/2019] [Accepted: 03/26/2019] [Indexed: 01/25/2023]
Abstract
Sleep is essential to emotional health. Sleep disturbance, particularly REM sleep disturbance, profoundly impacts emotion regulation, but the underlying neural mechanisms remain elusive. Here we show that chronic REM sleep disturbance, achieved in mice by chronic sleep fragmentation (SF), enhanced neural activity in the medial habenula (mHb), a brain region increasingly implicated in negative affect. Specifically, after a 5-day SF procedure that selectively fragmented REM sleep, cholinergic output neurons (ChNs) in the mHb exhibited increased spontaneous firing rate and enhanced firing regularity in brain slices. The SF-induced firing changes remained intact upon inhibition of glutamate, GABA, acetylcholine, and histamine receptors, suggesting cell-autonomous mechanisms independent of synaptic transmissions. Moreover, the SF-induced hyperactivity was not because of enhanced intrinsic membrane excitability, but was accompanied by depolarized resting membrane potential in mHb ChNs. Furthermore, inhibition of TASK-3 (KCNK9) channels, a subtype of two-pore domain K+ channels, mimicked the SF effects by increasing the firing rate and regularity, as well as depolarizing the resting membrane potential in mHb ChNs in control-sleep mice. These effects of TASK-3 inhibition were absent in SF mice, suggesting reduced TASK-3 activity following SF. By contrast, inhibition of small-conductance Ca2+-activated K+ (SK) channels did not produce similar effects. Thus, SF compromised TASK-3 function in mHb ChNs, which likely led to depolarized resting membrane potential and increased spontaneous firing. These results not only demonstrate that selective REM sleep disturbance leads to hyperactivity of mHb ChNs, but also identify a key molecular substrate through which REM sleep disturbance may alter affect regulation.
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48
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da Silva MP, Magalhães KS, de Souza DP, Moraes DJA. Chronic intermittent hypoxia increases excitability and synaptic excitation of protrudor and retractor hypoglossal motoneurones. J Physiol 2021; 599:1917-1932. [PMID: 33507557 DOI: 10.1113/jp280788] [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: 09/15/2020] [Accepted: 01/11/2021] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Dysfunctions in the hypoglossal control of tongue extrinsic muscles are implicated in obstructive sleep apnoea (OSA) syndrome. Chronic intermittent hypoxia (CIH), an important feature of OSA syndrome, produces deleterious effects on the motor control of oropharyngeal resistance, but whether the hypoglossal motoneurones innervating the tongue extrinsic muscles are affected by CIH is unknown. We show that CIH enhanced the respiratory-related activity of rat hypoglossal nerve innervating the protrudor and retractor tongue extrinsic muscles. Intracellular recordings revealed increases in respiratory-related firing frequency and synaptic excitation of inspiratory protrudor and retractor hypoglossal motoneurones after CIH. CIH also increased their intrinsic excitability, depolarised resting membrane potential and reduced K+ -dominated leak conductance. CIH affected the breathing-related synaptic control and intrinsic electrophysiological properties of protrudor and retractor hypoglossal motoneurones to optimise the neural control of oropharyngeal function. ABSTRACT Inspiratory-related tongue movements and oropharyngeal motor actions are controlled mainly by the protrudor and retractor extrinsic tongue muscles, which are innervated by the hypoglossal motoneurones. Chronic intermittent hypoxia (CIH), an important feature of obstructive sleep apnoea syndrome, produces detrimental effects on the contractile function of the tongue extrinsic muscles and the medullary inspiratory network of rodents. However, the impact of the CIH on the electrophysiological properties of protrudor and retractor hypoglossal motoneurones has not been described before. Using nerves and intracellular recordings in in situ preparation of rats (5 weeks old), we tested the hypothesis that CIH (FiO2 of 0.06, SaO2 74%, during 30-40 s, every 9 min, 8 h/day for 10 days) increases the intrinsic excitability of protrudor and retractor motoneurones from the hypoglossal motor nucleus of rats. Recordings of hypoglossal nerve, before its bifurcation to innervate the tongue protrudor and retractor muscles, revealed that CIH enhances its pre-inspiratory, simultaneously with the presence of active expiration, and inspiratory activities. These changes were mediated by increases in the respiratory-related firing frequency and synaptic excitation of inspiratory protrudor and retractor hypoglossal motoneurones. Besides, CIH increases their intrinsic excitability and depolarises resting membrane potential by reducing a K+ -dominated leak conductance. In conclusion, CIH enhances the respiratory-related neural control of oropharyngeal function of rats by increasing the synaptic excitation, intrinsic excitability, and reducing leak conductance in both protrudor and retractor hypoglossal motoneurones. We propose that these network and cellular changes are important to optimise the oropharyngeal resistance in conditions related to intermittent hypoxia.
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Affiliation(s)
- Melina P da Silva
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Karolyne S Magalhães
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Daniel P de Souza
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Davi J A Moraes
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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Kohanski MA, Brown L, Orr M, Tan LH, Adappa ND, Palmer JN, Rubenstein RC, Cohen NA. Bitter taste receptor agonists regulate epithelial two-pore potassium channels via cAMP signaling. Respir Res 2021; 22:31. [PMID: 33509163 PMCID: PMC7844973 DOI: 10.1186/s12931-021-01631-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/20/2021] [Indexed: 11/20/2022] Open
Abstract
Background Epithelial solitary chemosensory cell (tuft cell) bitter taste signal transduction occurs through G protein coupled receptors and calcium-dependent signaling pathways. Type II taste cells, which utilize the same bitter taste signal transduction pathways, may also utilize cyclic adenosine monophosphate (cAMP) as an independent signaling messenger in addition to calcium. Methods In this work we utilized specific pharmacologic inhibitors to interrogate the short circuit current (Isc) of polarized nasal epithelial cells mounted in Ussing chambers to assess the electrophysiologic changes associated with bitter agonist (denatonium) treatment. We also assessed release of human β-defensin-2 from polarized nasal epithelial cultures following treatment with denatonium benzoate and/or potassium channel inhibitors. Results We demonstrate that the bitter taste receptor agonist, denatonium, decreases human respiratory epithelial two-pore potassium (K2P) current in polarized nasal epithelial cells mounted in Ussing chambers. Our data further suggest that this occurs via a cAMP-dependent signaling pathway. We also demonstrate that this decrease in potassium current lowers the threshold for denatonium to stimulate human β-defensin-2 release. Conclusions These data thus demonstrate that, in addition to taste transducing calcium-dependent signaling, bitter taste receptor agonists can also activate cAMP-dependent respiratory epithelial signaling pathways to modulate K2P currents. Bitter-agonist regulation of potassium currents may therefore serve as a means of rapid regional epithelial signaling, and further study of these pathways may provide new insights into regulation of mucosal ionic composition and innate mechanisms of epithelial defense.
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Affiliation(s)
- Michael A Kohanski
- Department of Otorhinolaryngology-Head and Neck Surgery, Division of Rhinology, University of Pennsylvania Medical Center, Perelman School of Medicine, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA, USA.
| | - Lauren Brown
- Cystic Fibrosis Center, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Melissa Orr
- Cystic Fibrosis Center, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Li Hui Tan
- Department of Otorhinolaryngology-Head and Neck Surgery, Division of Rhinology, University of Pennsylvania Medical Center, Perelman School of Medicine, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA, USA
| | - Nithin D Adappa
- Department of Otorhinolaryngology-Head and Neck Surgery, Division of Rhinology, University of Pennsylvania Medical Center, Perelman School of Medicine, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA, USA
| | - James N Palmer
- Department of Otorhinolaryngology-Head and Neck Surgery, Division of Rhinology, University of Pennsylvania Medical Center, Perelman School of Medicine, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA, USA
| | - Ronald C Rubenstein
- Cystic Fibrosis Center, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Pediatrics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA.,Division of Allergy and Pulmonary Medicine, Department of Pediatrics, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Noam A Cohen
- Department of Otorhinolaryngology-Head and Neck Surgery, Division of Rhinology, University of Pennsylvania Medical Center, Perelman School of Medicine, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA, USA.,Corporal Michael J. Crescenz Veterans Administration Medical Center, Philadelphia, PA, USA.,Monell Chemical Senses Institute, Philadelphia, PA, USA
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50
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Wiedmann F, Beyersdorf C, Zhou XB, Kraft M, Foerster KI, El-Battrawy I, Lang S, Borggrefe M, Haefeli WE, Frey N, Schmidt C. The Experimental TASK-1 Potassium Channel Inhibitor A293 Can Be Employed for Rhythm Control of Persistent Atrial Fibrillation in a Translational Large Animal Model. Front Physiol 2021; 11:629421. [PMID: 33551849 PMCID: PMC7858671 DOI: 10.3389/fphys.2020.629421] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 12/30/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Upregulation of the two-pore-domain potassium channel TASK-1 (hK2 P 3.1) was recently described in patients suffering from atrial fibrillation (AF) and resulted in shortening of the atrial action potential. In the human heart, TASK-1 channels facilitate repolarization and are specifically expressed in the atria. In the present study, we tested the antiarrhythmic effects of the experimental ion channel inhibitor A293 that is highly affine for TASK-1 in a porcine large animal model of persistent AF. METHODS Persistent AF was induced in German landrace pigs by right atrial burst stimulation via implanted pacemakers using a biofeedback algorithm over 14 days. Electrophysiological and echocardiographic investigations were performed before and after the pharmacological treatment period. A293 was intravenously administered once per day. After a treatment period of 14 days, atrial cardiomyocytes were isolated for patch clamp measurements of currents and atrial action potentials. Hemodynamic consequences of TASK-1 inhibition were measured upon acute A293 treatment. RESULTS In animals with persistent AF, the A293 treatment significantly reduced the AF burden (6.5% vs. 95%; P < 0.001). Intracardiac electrophysiological investigations showed that the atrial effective refractory period was prolonged in A293 treated study animals, whereas, the QRS width, QT interval, and ventricular effective refractory periods remained unchanged. A293 treatment reduced the upregulation of the TASK-1 current as well as the shortening of the action potential duration caused by AF. No central nervous side effects were observed. A mild but significant increase in pulmonary artery pressure was observed upon acute TASK-1 inhibition. CONCLUSION Pharmacological inhibition of atrial TASK-1 currents exerts in vivo antiarrhythmic effects that can be employed for rhythm control in a porcine model of persistent AF. Care has to be taken as TASK-1 inhibition may increase pulmonary artery pressure levels.
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Affiliation(s)
- Felix Wiedmann
- Department of Cardiology, Heidelberg University, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, Heidelberg University, Heidelberg, Germany
| | - Christoph Beyersdorf
- Department of Cardiology, Heidelberg University, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, Heidelberg University, Heidelberg, Germany
| | - Xiao-Bo Zhou
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Heidelberg, Germany
- First Department of Medicine, University Medical Center, Mannheim University, Mannheim, Germany
| | - Manuel Kraft
- Department of Cardiology, Heidelberg University, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, Heidelberg University, Heidelberg, Germany
| | - Kathrin I. Foerster
- Department of Clinical Pharmacology and Pharmacoepidemiology, Heidelberg University, Heidelberg, Germany
| | - Ibrahim El-Battrawy
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Heidelberg, Germany
- First Department of Medicine, University Medical Center, Mannheim University, Mannheim, Germany
| | - Siegfried Lang
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Heidelberg, Germany
- First Department of Medicine, University Medical Center, Mannheim University, Mannheim, Germany
| | - Martin Borggrefe
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Heidelberg, Germany
- First Department of Medicine, University Medical Center, Mannheim University, Mannheim, Germany
| | - Walter E. Haefeli
- Department of Clinical Pharmacology and Pharmacoepidemiology, Heidelberg University, Heidelberg, Germany
| | - Norbert Frey
- Department of Cardiology, Heidelberg University, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, Heidelberg University, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, Heidelberg University, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, Heidelberg University, Heidelberg, Germany
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