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Deshar G, Christensen NM, Novak I. Pantoprazole and riluzole target H +/K +-ATPases and pH-sensitive K + channels in pancreatic cancer cells. Int J Cancer 2024. [PMID: 38975879 DOI: 10.1002/ijc.35076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/28/2024] [Accepted: 06/10/2024] [Indexed: 07/09/2024]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) remains the most lethal cancer type. PDAC is characterized by fibrotic, hypoxic, and presumably acidic tumor microenvironment (TME). Acidic TME is an important player in tumor development, progression, aggressiveness, and chemoresistance. The dysregulation of ductal ion transporters/channels might contribute to extracellular pH (pHe) acidification and PDAC progression. Our aim was to test whether H+/K+-ATPases and pH-sensitive K+ channels contribute to these processes and could be targeted by clinically approved drugs. We used human pancreatic cancer cells adapted to various pHe conditions and grown in monolayers and spheroids. First, we created cells expressing pHoran4 at the outer plasma membrane and showed that pantoprazole, the H+/K+-ATPase inhibitor, alkalinized pHe. Second, we used FluoVolt to monitor the membrane voltage (Vm) and showed that riluzole hyperpolarized Vm, most likely by opening of pH-sensitive K+ channels such as TREK-1. Third, we show that pantoprazole and riluzole inhibited cell proliferation and viability of monolayers and spheroids of cancer cells adapted to various pHe conditions. Most importantly, combination of the two drugs had significantly larger inhibitory effects on PDAC cell survival. We propose that co-targeting H+/K+-ATPases and pH-sensitive K+ channels by re-purposing of pantoprazole and riluzole could provide novel acidosis-targeted therapies of PDAC.
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Affiliation(s)
- Ganga Deshar
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Ivana Novak
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
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2
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Bechard E, Arel E, Bride J, Louradour J, Bussy X, Elloumi A, Vigor C, Soule P, Oger C, Galano JM, Durand T, Le Guennec JY, Moha-Ou-Maati H, Demion M. Activation of hTREK-1 by polyunsaturated fatty acids involves direct interaction. Sci Rep 2024; 14:15244. [PMID: 38956407 PMCID: PMC11220079 DOI: 10.1038/s41598-024-66192-w] [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: 12/21/2023] [Accepted: 06/28/2024] [Indexed: 07/04/2024] Open
Abstract
TREK-1 is a mechanosensitive channel activated by polyunsaturated fatty acids (PUFAs). Its activation is supposed to be linked to changes in membrane tension following PUFAs insertion. Here, we compared the effect of 11 fatty acids and ML402 on TREK-1 channel activation using the whole cell and the inside-out configurations of the patch-clamp technique. Firstly, TREK-1 activation by PUFAs is variable and related to the variable constitutive activity of TREK-1. We observed no correlation between TREK-1 activation and acyl chain length or number of double bonds suggesting that the bilayer-couple hypothesis cannot explain by itself the activation of TREK-1 by PUFAs. The membrane fluidity measurement is not modified by PUFAs at 10 µM. The spectral shift analysis in TREK-1-enriched microsomes indicates a KD,TREK1 at 44 µM of C22:6 n-3. PUFAs display the same activation and reversible kinetics than the direct activator ML402 and activate TREK-1 in both whole-cell and inside-out configurations of patch-clamp suggesting that the binding site of PUFAs is accessible from both sides of the membrane, as for ML402. Finally, we proposed a two steps mechanism: first, insertion into the membrane, with no fluidity or curvature modifications at 10 µM, and then interaction with TREK-1 channel to open it.
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Affiliation(s)
- Emilie Bechard
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Elodie Arel
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Jamie Bride
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Julien Louradour
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Xavier Bussy
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Anis Elloumi
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | - Claire Vigor
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | | | - Camille Oger
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | - Jean-Marie Galano
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | - Thierry Durand
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | - Jean-Yves Le Guennec
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Hamid Moha-Ou-Maati
- IGF, Université de Montpellier, UMR CNRS 5203, Inserm 1191, Montpellier, France
- INM, Inserm U1298, Montpellier, France
| | - Marie Demion
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France.
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Sun W, Yang F, Wang Y, Yang Y, Du R, Wang X, Luo Z, Wu J, Chen J. Sortilin-Mediated Inhibition of TREK1/2 Channels in Primary Sensory Neurons Promotes Prediabetic Neuropathic Pain. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2310295. [PMID: 38626370 PMCID: PMC11187941 DOI: 10.1002/advs.202310295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 03/29/2024] [Indexed: 04/18/2024]
Abstract
Neuropathic pain can occur during the prediabetic stage, even in the absence of hyperglycemia. The presence of prediabetic neuropathic pain (PDNP) poses challenges to the management of individuals with prediabetes. However, the mechanisms underlying this pain remain unclear. This study aims to investigate the underlying mechanism and identify potential therapeutic targets of PDNP. A prediabetic animal model induced by a high-energy diet exhibits both mechanical allodynia and thermal hyperalgesia. Furthermore, hyperexcitability and decreased potassium currents are observed in the dorsal root ganglion (DRG) neurons of these rats. TREK1 and TREK2 channels, which belong to the two-pore-domain K+ channel (K2P) family and play an important role in controlling cellular excitability, are downregulated in DRG neurons. Moreover, this alteration is modulated by Sortilin, a molecular partner that modulates the expression of TREK1. The overexpression of Sortilin negatively affects the expression of TREK1 and TREK2, leading to increased neuronal excitability in the DRG and enhanced peripheral pain sensitivity in rats. Moreover, the downregulation of Sortilin or activation of TREK1 and TREK2 channels by genetic or pharmacological approaches can alleviate PDNP. Therefore, targeting the Sortilin-mediated TREK1/2 pathway may provide a therapeutic approach for ameliorating PDNP.
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Affiliation(s)
- Wei Sun
- Institute for Biomedical Sciences of PainTangdu HospitalThe Fourth Military Medical UniversityXi'anShaanxi Province710038P. R. China
| | - Fan Yang
- Institute for Biomedical Sciences of PainTangdu HospitalThe Fourth Military Medical UniversityXi'anShaanxi Province710038P. R. China
| | - Yan Wang
- Institute for Biomedical Sciences of PainTangdu HospitalThe Fourth Military Medical UniversityXi'anShaanxi Province710038P. R. China
| | - Yan Yang
- Institute for Biomedical Sciences of PainTangdu HospitalThe Fourth Military Medical UniversityXi'anShaanxi Province710038P. R. China
| | - Rui Du
- Institute for Biomedical Sciences of PainTangdu HospitalThe Fourth Military Medical UniversityXi'anShaanxi Province710038P. R. China
| | - Xiao‐Liang Wang
- Institute for Biomedical Sciences of PainTangdu HospitalThe Fourth Military Medical UniversityXi'anShaanxi Province710038P. R. China
| | - Zhi‐Xin Luo
- Institute for Biomedical Sciences of PainTangdu HospitalThe Fourth Military Medical UniversityXi'anShaanxi Province710038P. R. China
| | - Jun‐Jie Wu
- State Key Laboratory of Oral & Maxillofacial Reconstruction and RegenerationNational Clinical Research Center for Oral DiseasesShaanxi Key Laboratory of StomatologyDepartment of Orthodontics, School of StomatologyThe Fourth Military Medical UniversityXi'anShaanxi Province710032P. R. China
| | - Jun Chen
- Institute for Biomedical Sciences of PainTangdu HospitalThe Fourth Military Medical UniversityXi'anShaanxi Province710038P. R. China
- Present address:
Sanhang Institute for Brain Science and Technology (SiBST)School of Medical Research, Northwestern Polytechnical University (NPU)Xi'an Shaanxi710129P. R. China
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Türkaydin B, Schewe M, Riel EB, Schulz F, Biedermann J, Baukrowitz T, Sun H. Atomistic mechanism of coupling between cytosolic sensor domain and selectivity filter in TREK K2P channels. Nat Commun 2024; 15:4628. [PMID: 38821927 PMCID: PMC11143257 DOI: 10.1038/s41467-024-48823-y] [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: 10/13/2023] [Accepted: 05/15/2024] [Indexed: 06/02/2024] Open
Abstract
The two-pore domain potassium (K2P) channels TREK-1 and TREK-2 link neuronal excitability to a variety of stimuli including mechanical force, lipids, temperature and phosphorylation. This regulation involves the C-terminus as a polymodal stimulus sensor and the selectivity filter (SF) as channel gate. Using crystallographic up- and down-state structures of TREK-2 as a template for full atomistic molecular dynamics (MD) simulations, we reveal that the SF in down-state undergoes inactivation via conformational changes, while the up-state structure maintains a stable and conductive SF. This suggests an atomistic mechanism for the low channel activity previously assigned to the down state, but not evident from the crystal structure. Furthermore, experimentally by using (de-)phosphorylation mimics and chemically attaching lipid tethers to the proximal C-terminus (pCt), we confirm the hypothesis that moving the pCt towards the membrane induces the up-state. Based on MD simulations, we propose two gating pathways by which movement of the pCt controls the stability (i.e., conductivity) of the filter gate. Together, these findings provide atomistic insights into the SF gating mechanism and the physiological regulation of TREK channels by phosphorylation.
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Affiliation(s)
- Berke Türkaydin
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
- Insitute of Chemistry, Technical University of Berlin, Berlin, Germany
| | - Marcus Schewe
- Institute of Physiology, Kiel University, Kiel, Germany.
| | - Elena Barbara Riel
- Institute of Physiology, Kiel University, Kiel, Germany
- Department of Anesthesiology, Weill Cornell Medical College, New York, USA
| | | | - Johann Biedermann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | | | - Han Sun
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany.
- Insitute of Chemistry, Technical University of Berlin, Berlin, Germany.
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Woods CB, Predoi B, Howe M, Reczek CR, Kayser EB, Ramirez JM, Morgan PG, Sedensky MM. Potassium Leak Channels and Mitochondrial Complex I Interact in Glutamatergic Interneurons of the Mouse Spinal Cord. Anesthesiology 2024; 140:715-728. [PMID: 38147628 PMCID: PMC10939847 DOI: 10.1097/aln.0000000000004891] [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] [Indexed: 12/28/2023]
Abstract
BACKGROUND Volatile anesthetics induce hyperpolarizing potassium currents in spinal cord neurons that may contribute to their mechanism of action. They are induced at lower concentrations of isoflurane in noncholinergic neurons from mice carrying a loss-of-function mutation of the Ndufs4 gene, required for mitochondrial complex I function. The yeast NADH dehydrogenase enzyme, NDi1, can restore mitochondrial function in the absence of normal complex I activity, and gain-of-function Ndi1 transgenic mice are resistant to volatile anesthetics. The authors tested whether NDi1 would reduce the hyperpolarization caused by isoflurane in neurons from Ndufs4 and wild-type mice. Since volatile anesthetic behavioral hypersensitivity in Ndufs4 is transduced uniquely by glutamatergic neurons, it was also tested whether these currents were also unique to glutamatergic neurons in the Ndufs4 spinal cord. METHODS Spinal cord neurons from wild-type, NDi1, and Ndufs4 mice were patch clamped to characterize isoflurane sensitive currents. Neuron types were marked using fluorescent markers for cholinergic, glutamatergic, and γ-aminobutyric acid-mediated (GABAergic) neurons. Norfluoxetine was used to identify potassium channel type. Neuron type-specific Ndufs4 knockout animals were generated using type-specific Cre-recombinase with floxed Ndufs4. RESULTS Resting membrane potentials (RMPs) of neurons from NDi1;Ndufs4, unlike those from Ndufs4, were not hyperpolarized by 0.6% isoflurane (Ndufs4, ΔRMP -8.2 mV [-10 to -6.6]; P = 1.3e-07; Ndi1;Ndufs4, ΔRMP -2.1 mV [-7.6 to +1.4]; P = 1). Neurons from NDi1 animals in a wild-type background were not hyperpolarized by 1.8% isoflurane (wild-type, ΔRMP, -5.2 mV [-7.3 to -3.2]; P = 0.00057; Ndi1, ΔRMP, 0.6 mV [-1.7 to 3.2]; P = 0.68). In spinal cord slices from global Ndufs4 animals, holding currents (HC) were induced by 0.6% isoflurane in both GABAergic (ΔHC, 81.3 pA [61.7 to 101.4]; P = 2.6e-05) and glutamatergic (ΔHC, 101.2 pA [63.0 to 146.2]; P = 0.0076) neurons. In neuron type-specific Ndufs4 knockouts, HCs were increased in cholinergic (ΔHC, 119.5 pA [82.3 to 156.7]; P = 0.00019) and trended toward increase in glutamatergic (ΔHC, 85.5 pA [49 to 126.9]; P = 0.064) neurons but not in GABAergic neurons. CONCLUSIONS Bypassing complex I by overexpression of NDi1 eliminates increases in potassium currents induced by isoflurane in the spinal cord. The isoflurane-induced potassium currents in glutamatergic neurons represent a potential downstream mechanism of complex I inhibition in determining minimum alveolar concentration. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Christian B Woods
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
| | - Beatrice Predoi
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
| | - Miranda Howe
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
| | - Colleen R Reczek
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Ernst-Bernhard Kayser
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
| | - Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Neurological Surgery, University of Washington, Seattle, WA, 98105, USA
| | - Philip G Morgan
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle WA, 98105, USA
| | - Margaret M Sedensky
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle WA, 98105, USA
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6
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Lim XR, Harraz OF. Mechanosensing by Vascular Endothelium. Annu Rev Physiol 2024; 86:71-97. [PMID: 37863105 PMCID: PMC10922104 DOI: 10.1146/annurev-physiol-042022-030946] [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] [Indexed: 10/22/2023]
Abstract
Mechanical forces influence different cell types in our bodies. Among the earliest forces experienced in mammals is blood movement in the vascular system. Blood flow starts at the embryonic stage and ceases when the heart stops. Blood flow exposes endothelial cells (ECs) that line all blood vessels to hemodynamic forces. ECs detect these mechanical forces (mechanosensing) through mechanosensors, thus triggering physiological responses such as changes in vascular diameter. In this review, we focus on endothelial mechanosensing and on how different ion channels, receptors, and membrane structures detect forces and mediate intricate mechanotransduction responses. We further highlight that these responses often reflect collaborative efforts involving several mechanosensors and mechanotransducers. We close with a consideration of current knowledge regarding the dysregulation of endothelial mechanosensing during disease. Because hemodynamic disruptions are hallmarks of cardiovascular disease, studying endothelial mechanosensing holds great promise for advancing our understanding of vascular physiology and pathophysiology.
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Affiliation(s)
- Xin Rui Lim
- Department of Pharmacology, Larner College of Medicine and Vermont Center for Cardiovascular and Brain Health, University of Vermont, Burlington, Vermont, USA;
| | - Osama F Harraz
- Department of Pharmacology, Larner College of Medicine and Vermont Center for Cardiovascular and Brain Health, University of Vermont, Burlington, Vermont, USA;
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Nakamura F. The Role of Mechanotransduction in Contact Inhibition of Locomotion and Proliferation. Int J Mol Sci 2024; 25:2135. [PMID: 38396812 PMCID: PMC10889191 DOI: 10.3390/ijms25042135] [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: 12/19/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/25/2024] Open
Abstract
Contact inhibition (CI) represents a crucial tumor-suppressive mechanism responsible for controlling the unbridled growth of cells, thus preventing the formation of cancerous tissues. CI can be further categorized into two distinct yet interrelated components: CI of locomotion (CIL) and CI of proliferation (CIP). These two components of CI have historically been viewed as separate processes, but emerging research suggests that they may be regulated by both distinct and shared pathways. Specifically, recent studies have indicated that both CIP and CIL utilize mechanotransduction pathways, a process that involves cells sensing and responding to mechanical forces. This review article describes the role of mechanotransduction in CI, shedding light on how mechanical forces regulate CIL and CIP. Emphasis is placed on filamin A (FLNA)-mediated mechanotransduction, elucidating how FLNA senses mechanical forces and translates them into crucial biochemical signals that regulate cell locomotion and proliferation. In addition to FLNA, trans-acting factors (TAFs), which are proteins or regulatory RNAs capable of directly or indirectly binding to specific DNA sequences in distant genes to regulate gene expression, emerge as sensitive players in both the mechanotransduction and signaling pathways of CI. This article presents methods for identifying these TAF proteins and profiling the associated changes in chromatin structure, offering valuable insights into CI and other biological functions mediated by mechanotransduction. Finally, it addresses unanswered research questions in these fields and delineates their possible future directions.
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Affiliation(s)
- Fumihiko Nakamura
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
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8
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Spencer KA, Woods CB, Worstman HM, Johnson SC, Ramirez JM, Morgan PG, Sedensky MM. TREK-1 and TREK-2 Knockout Mice Are Not Resistant to Halothane or Isoflurane. Anesthesiology 2023; 139:63-76. [PMID: 37027798 PMCID: PMC10247454 DOI: 10.1097/aln.0000000000004577] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
BACKGROUND A variety of molecular targets for volatile anesthetics have been suggested, including the anesthetic-sensitive potassium leak channel, TREK-1. Knockout of TREK-1 is reported to render mice resistant to volatile anesthetics, making TREK-1 channels compelling targets for anesthetic action. Spinal cord slices from mice, either wild type or an anesthetic- hypersensitive mutant, Ndufs4, display an isoflurane-induced outward potassium leak that correlates with their minimum alveolar concentrations and is blocked by norfluoxetine. The hypothesis was that TREK-1 channels conveyed this current and contribute to the anesthetic hypersensitivity of Ndufs4. The results led to evaluation of a second TREK channel, TREK-2, in control of anesthetic sensitivity. METHODS The anesthetic sensitivities of mice carrying knockout alleles of Trek-1 and Trek-2, the double knockout Trek-1;Trek-2, and Ndufs4;Trek-1 were measured. Neurons from spinal cord slices from each mutant were patch clamped to characterize isoflurane-sensitive currents. Norfluoxetine was used to identify TREK-dependent currents. RESULTS The mean values for minimum alveolar concentrations (± SD) between wild type and two Trek-1 knockout alleles in mice (P values, Trek-1 compared to wild type) were compared. For wild type, minimum alveolar concentration of halothane was 1.30% (0.10), and minimum alveolar concentration of isoflurane was 1.40% (0.11); for Trek-1tm1Lex, minimum alveolar concentration of halothane was 1.27% (0.11; P = 0.387), and minimum alveolar concentration of isoflurane was 1.38% (0.09; P = 0.268); and for Trek-1tm1Lzd, minimum alveolar concentration of halothane was 1.27% (0.11; P = 0.482), and minimum alveolar concentration of isoflurane was 1.41% (0.12; P = 0.188). Neither allele was resistant for loss of righting reflex. The EC50 values of Ndufs4;Trek-1tm1Lex did not differ from Ndufs4 (for Ndufs4, EC50 of halothane, 0.65% [0.05]; EC50 of isoflurane, 0.63% [0.05]; and for Ndufs4;Trek-1tm1Lex, EC50 of halothane, 0.58% [0.07; P = 0.004]; and EC50 of isoflurane, 0.61% [0.06; P = 0.442]). Loss of TREK-2 did not alter anesthetic sensitivity in a wild-type or Trek-1 genetic background. Loss of TREK-1, TREK-2, or both did not alter the isoflurane-induced currents in wild-type cells but did cause them to be norfluoxetine insensitive. CONCLUSIONS Loss of TREK channels did not alter anesthetic sensitivity in mice, nor did it eliminate isoflurane-induced transmembrane currents. However, the isoflurane-induced currents are norfluoxetine-resistant in Trek mutants, indicating that other channels may function in this role when TREK channels are deleted. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Kira A Spencer
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle WA, 98105, USA
| | - Christian B Woods
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
| | - Hailey M Worstman
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
| | - Simon C Johnson
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Applied Sciences, Translational Biosciences, Northumbria University, Ellison A521A, UK (current)
| | - Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Neurological Surgery, University of Washington, Seattle, WA, 98105, USA
| | - Philip G Morgan
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle WA, 98105, USA
| | - Margaret M Sedensky
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle WA, 98105, USA
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9
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Darkow E, Yusuf D, Rajamani S, Backofen R, Kohl P, Ravens U, Peyronnet R. Meta-Analysis of Mechano-Sensitive Ion Channels in Human Hearts: Chamber- and Disease-Preferential mRNA Expression. Int J Mol Sci 2023; 24:10961. [PMID: 37446137 DOI: 10.3390/ijms241310961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
The cardiac cell mechanical environment changes on a beat-by-beat basis as well as in the course of various cardiac diseases. Cells sense and respond to mechanical cues via specialized mechano-sensors initiating adaptive signaling cascades. With the aim of revealing new candidates underlying mechano-transduction relevant to cardiac diseases, we investigated mechano-sensitive ion channels (MSC) in human hearts for their chamber- and disease-preferential mRNA expression. Based on a meta-analysis of RNA sequencing studies, we compared the mRNA expression levels of MSC in human atrial and ventricular tissue samples from transplant donor hearts (no cardiac disease), and from patients in sinus rhythm (underlying diseases: heart failure, coronary artery disease, heart valve disease) or with atrial fibrillation. Our results suggest that a number of MSC genes are expressed chamber preferentially, e.g., CHRNE in the atria (compared to the ventricles), TRPV4 in the right atrium (compared to the left atrium), CACNA1B and KCNMB1 in the left atrium (compared to the right atrium), as well as KCNK2 and KCNJ2 in ventricles (compared to the atria). Furthermore, 15 MSC genes are differentially expressed in cardiac disease, out of which SCN9A (lower expressed in heart failure compared to donor tissue) and KCNQ5 (lower expressed in atrial fibrillation compared to sinus rhythm) show a more than twofold difference, indicative of possible functional relevance. Thus, we provide an overview of cardiac MSC mRNA expression in the four cardiac chambers from patients with different cardiac diseases. We suggest that the observed differences in MSC mRNA expression may identify candidates involved in altered mechano-transduction in the respective diseases.
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Affiliation(s)
- Elisa Darkow
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg∙Bad Krozingen, 79110 Freiburg im Breisgau, Germany
- Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Dilmurat Yusuf
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Sridharan Rajamani
- Translational Safety and Bioanalytical Sciences, Amgen Research, Amgen Inc., South San Francisco, CA 91320, USA
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Centre for Integrative Biological Signalling Studies (CIBSS), University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg∙Bad Krozingen, 79110 Freiburg im Breisgau, Germany
- Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Centre for Integrative Biological Signalling Studies (CIBSS), University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Ursula Ravens
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg∙Bad Krozingen, 79110 Freiburg im Breisgau, Germany
- Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Rémi Peyronnet
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg∙Bad Krozingen, 79110 Freiburg im Breisgau, Germany
- Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
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10
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Kim SS, Park J, Kim E, Hwang EM, Park JY. β-COP Suppresses the Surface Expression of the TREK2. Cells 2023; 12:1500. [PMID: 37296621 PMCID: PMC10252889 DOI: 10.3390/cells12111500] [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: 04/14/2023] [Revised: 05/18/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
K2P channels, also known as two-pore domain K+ channels, play a crucial role in maintaining the cell membrane potential and contributing to potassium homeostasis due to their leaky nature. The TREK, or tandem of pore domains in a weak inward rectifying K+ channel (TWIK)-related K+ channel, subfamily within the K2P family consists of mechanical channels regulated by various stimuli and binding proteins. Although TREK1 and TREK2 within the TREK subfamily share many similarities, β-COP, which was previously known to bind to TREK1, exhibits a distinct binding pattern to other members of the TREK subfamily, including TREK2 and the TRAAK (TWIK-related acid-arachidonic activated K+ channel). In contrast to TREK1, β-COP binds to the C-terminus of TREK2 and reduces its cell surface expression but does not bind to TRAAK. Furthermore, β-COP cannot bind to TREK2 mutants with deletions or point mutations in the C-terminus and does not affect the surface expression of these TREK2 mutants. These results emphasize the unique role of β-COP in regulating the surface expression of the TREK family.
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Affiliation(s)
- Seong-Seop Kim
- School of Biosystems and Biomedical Sciences, College of Health Sciences, Korea University, Seoul 02841, Republic of Korea; (S.-S.K.); (J.P.)
| | - Jimin Park
- School of Biosystems and Biomedical Sciences, College of Health Sciences, Korea University, Seoul 02841, Republic of Korea; (S.-S.K.); (J.P.)
- BK21FOUR R&E Center for Learning Health Systems, Korea University, Seoul 02841, Republic of Korea
| | - Eunju Kim
- Brain Science Institute (BSI), Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea;
| | - Eun Mi Hwang
- Brain Science Institute (BSI), Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea;
| | - Jae-Yong Park
- School of Biosystems and Biomedical Sciences, College of Health Sciences, Korea University, Seoul 02841, Republic of Korea; (S.-S.K.); (J.P.)
- BK21FOUR R&E Center for Learning Health Systems, Korea University, Seoul 02841, Republic of Korea
- ASTRION, Inc., Seoul 02842, Republic of Korea
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11
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Herrera-Pérez S, Lamas JA. TREK channels in Mechanotransduction: a Focus on the Cardiovascular System. Front Cardiovasc Med 2023; 10:1180242. [PMID: 37288256 PMCID: PMC10242076 DOI: 10.3389/fcvm.2023.1180242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/26/2023] [Indexed: 06/09/2023] Open
Abstract
Mechano-electric feedback is one of the most important subsystems operating in the cardiovascular system, but the underlying molecular mechanism remains rather unknown. Several proteins have been proposed to explain the molecular mechanism of mechano-transduction. Transient receptor potential (TRP) and Piezo channels appear to be the most important candidates to constitute the molecular mechanism behind of the inward current in response to a mechanical stimulus. However, the inhibitory/regulatory processes involving potassium channels that operate on the cardiac system are less well known. TWIK-Related potassium (TREK) channels have emerged as strong candidates due to their capacity for the regulation of the flow of potassium in response to mechanical stimuli. Current data strongly suggest that TREK channels play a role as mechano-transducers in different components of the cardiovascular system, not only at central (heart) but also at peripheral (vascular) level. In this context, this review summarizes and highlights the main existing evidence connecting this important subfamily of potassium channels with the cardiac mechano-transduction process, discussing molecular and biophysical aspects of such a connection.
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Affiliation(s)
- Salvador Herrera-Pérez
- Laboratory of Neuroscience, CINBIO, University of Vigo, Vigo, Spain
- Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
| | - José Antonio Lamas
- Laboratory of Neuroscience, CINBIO, University of Vigo, Vigo, Spain
- Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
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12
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Ullrich J, Ohlhoff C, Dondapati SK, Zemella A, Kubick S. Evaluation of the Ion Channel Assembly in a Eukaryotic Cell-Free System Focusing on Two-Pore Domain Potassium Channels K2P. Int J Mol Sci 2023; 24:ijms24076299. [PMID: 37047271 PMCID: PMC10094441 DOI: 10.3390/ijms24076299] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
Oligomeric ion channels are abundant in nature. However, the recombinant expression in cell culture-based systems remains tedious and challenging due to negative side effects, limiting the understanding of their role in health and disease. Accordingly, in this work, we demonstrate the cell-free synthesis (CFS) as an alternative platform to study the assembly of two-pore domain potassium channels (K2P) within endogenous endoplasmic reticulum-derived microsomes. Exploiting the open nature of CFS, we investigate the cotranslational translocation of TREK-2 into the microsomes and suggest a cotranslational assembly with typical single-channel behavior in planar lipid-bilayer electrophysiology. The heteromeric assembly of K2P channels is a contentious matter, accordingly we prove the successful assembly of TREK-2 with TWIK-1 using a biomolecular fluorescence complementation assay, Western blot analysis and autoradiography. The results demonstrate that TREK-2 homodimer assembly is the initial step, followed by heterodimer formation with the nascent TWIK-1, providing evidence of the intergroup heterodimerization of TREK-2 and TWIK-1 in eukaryotic CFS. Since K2P channels are involved in various pathophysiological conditions, including pain and nociception, CFS paves the way for in-depth functional studies and related pharmacological interventions. This study highlights the versatility of the eukaryotic CFS platform for investigating ion channel assembly in a native-like environment.
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Affiliation(s)
- Jessica Ullrich
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476 Potsdam, Germany
- Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Carsten Ohlhoff
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476 Potsdam, Germany
- Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Srujan Kumar Dondapati
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476 Potsdam, Germany
- Correspondence:
| | - Anne Zemella
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476 Potsdam, Germany
| | - Stefan Kubick
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476 Potsdam, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
- Faculty of Health Sciences, Joint Faculty of the Brandenburg University of Technology Cottbus-Senftenberg, the Brandenburg Medical School Theodor Fontane and the University of Potsdam, 14476 Potsdam, Germany
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13
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Buijs TJ, Vilar B, Tan C, McNaughton PA. STIM1 and ORAI1 form a novel cold transduction mechanism in sensory and sympathetic neurons. EMBO J 2023; 42:e111348. [PMID: 36524441 PMCID: PMC9890232 DOI: 10.15252/embj.2022111348] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 10/25/2022] [Accepted: 11/10/2022] [Indexed: 12/23/2022] Open
Abstract
Moderate coolness is sensed by TRPM8 ion channels in peripheral sensory nerves, but the mechanism by which noxious cold is detected remains elusive. Here, we show that somatosensory and sympathetic neurons express two distinct mechanisms to detect noxious cold. In the first, inhibition by cold of a background outward current causes membrane depolarization that activates an inward current through voltage-dependent calcium (CaV ) channels. A second cold-activated mechanism is independent of membrane voltage, is inhibited by blockers of ORAI ion channels and by downregulation of STIM1, and is recapitulated in HEK293 cells by co-expression of ORAI1 and STIM1. Using total internal reflection fluorescence microscopy we found that cold causes STIM1 to aggregate with and activate ORAI1 ion channels, in a mechanism similar to that underlying store-operated calcium entry (SOCE), but directly activated by cold and not by emptying of calcium stores. This novel mechanism may explain the phenomenon of cold-induced vasodilation (CIVD), in which extreme cold increases blood flow in order to preserve the integrity of peripheral tissues.
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Affiliation(s)
- Tamara J Buijs
- Wolfson Centre for Age‐Related DiseasesKing's College LondonLondonUK
- Present address:
Department of Synapse and Network DevelopmentNetherlands Institute for NeuroscienceAmsterdamThe Netherlands
| | - Bruno Vilar
- Wolfson Centre for Age‐Related DiseasesKing's College LondonLondonUK
| | - Chun‐Hsiang Tan
- Department of PharmacologyUniversity of CambridgeCambridgeUK
- Present address:
Department of NeurologyKaohsiung Medical University HospitalKaohsiungTaiwan
- Present address:
Graduate Institute of Clinical Medicine, College of MedicineKaohsiung Medical UniversityKaohsiungTaiwan
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14
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Synergistic effects of agonists and two-pore-domain potassium channels on secretory responses of human pancreatic duct cells Capan-1. Pflugers Arch 2023; 475:361-379. [PMID: 36534232 PMCID: PMC9908661 DOI: 10.1007/s00424-022-02782-9] [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: 10/12/2022] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022]
Abstract
Mechanisms of synergistic agonist stimulation and modulation of the electrochemical driving force for anion secretion are still not fully explored in human pancreatic duct epithelial cells. The first objective of this study was therefore to test whether combined agonist stimulation augments anion transport responses in the Capan-1 monolayer model of human pancreatic duct epithelium. The second objective was to test the influence of H+,K+-ATPase inhibition on anion transport in Capan-1 monolayers. The third objective was to analyze the expression and function of K+ channels in Capan-1, which could support anion secretion and cooperate with H+,K+-ATPases in pH and potassium homeostasis. The human pancreatic adenocarcinoma cell line Capan-1 was cultured conventionally or as polarized monolayers that were analyzed by Ussing chamber electrophysiological recordings. Single-cell intracellular calcium was assayed with Fura-2. mRNA isolated from Capan-1 was analyzed by use of the nCounter assay or RT-PCR. Protein expression was assessed by immunofluorescence and western blot analyses. Combined stimulation with different physiological agonists enhanced anion transport responses compared to single agonist stimulation. The responsiveness of Capan-1 cells to histamine was also revealed in these experiments. The H+,K+-ATPase inhibitor omeprazole reduced carbachol- and riluzole-induced anion transport responses. Transcript analyses revealed abundant TASK-2, TWIK-1, TWIK-2, TASK-5, KCa3.1, and KCNQ1 mRNA expression. KCNE1 mRNA and TREK-1, TREK-2, TASK-2, and KCNQ1 protein expression were also shown. This study shows that the Capan-1 model recapitulates key physiological aspects of a bicarbonate-secreting epithelium and constitutes a valuable model for functional studies on human pancreatic duct epithelium.
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15
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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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16
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Scarpa GB, Starrett JR, Li GL, Brooks C, Morohashi Y, Yazaki-Sugiyama Y, Remage-Healey L. Estrogens rapidly shape synaptic and intrinsic properties to regulate the temporal precision of songbird auditory neurons. Cereb Cortex 2022; 33:3401-3420. [PMID: 35849820 PMCID: PMC10068288 DOI: 10.1093/cercor/bhac280] [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: 06/08/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 01/14/2023] Open
Abstract
Sensory neurons parse millisecond-variant sound streams like birdsong and speech with exquisite precision. The auditory pallial cortex of vocal learners like humans and songbirds contains an unconventional neuromodulatory system: neuronal expression of the estrogen synthesis enzyme aromatase. Local forebrain neuroestrogens fluctuate when songbirds hear a song, and subsequently modulate bursting, gain, and temporal coding properties of auditory neurons. However, the way neuroestrogens shape intrinsic and synaptic properties of sensory neurons remains unknown. Here, using a combination of whole-cell patch clamp electrophysiology and calcium imaging, we investigate estrogenic neuromodulation of auditory neurons in a region resembling mammalian auditory association cortex. We found that estradiol rapidly enhances the temporal precision of neuronal firing via a membrane-bound G-protein coupled receptor and that estradiol rapidly suppresses inhibitory synaptic currents while sparing excitation. Notably, the rapid suppression of intrinsic excitability by estradiol was predicted by membrane input resistance and was observed in both males and females. These findings were corroborated by analysis of in vivo electrophysiology recordings, in which local estrogen synthesis blockade caused acute disruption of the temporal correlation of song-evoked firing patterns. Therefore, on a modulatory timescale, neuroestrogens alter intrinsic cellular properties and inhibitory neurotransmitter release to regulate the temporal precision of higher-order sensory neurons.
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Affiliation(s)
- Garrett B Scarpa
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, 639 N. Pleasant St., Amherst, MA 01003, United States
| | - Joseph R Starrett
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, 639 N. Pleasant St., Amherst, MA 01003, United States
| | - Geng-Lin Li
- Department of Otorhinolaryngology, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd, Xuhui District, Shanghai 200031, China
| | - Colin Brooks
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, 639 N. Pleasant St., Amherst, MA 01003, United States
| | - Yuichi Morohashi
- Okinawa Institute of Science and Technology (OIST) Graduate University, 1919-1 Tancha, Onna, Kunigami District, Okinawa, Japan
| | - Yoko Yazaki-Sugiyama
- Okinawa Institute of Science and Technology (OIST) Graduate University, 1919-1 Tancha, Onna, Kunigami District, Okinawa, Japan
| | - Luke Remage-Healey
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, 639 N. Pleasant St., Amherst, MA 01003, United States
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17
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Pope L, Minor DL. The Polysite Pharmacology of TREK K 2P Channels. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1349:51-65. [PMID: 35138610 DOI: 10.1007/978-981-16-4254-8_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
K2P (KCNK) potassium channels form "background" or "leak" currents that have critical roles in cell excitability control in the brain, cardiovascular system, and somatosensory neurons. Similar to many ion channel families, studies of K2Ps have been limited by poor pharmacology. Of six K2P subfamilies, the thermo- and mechanosensitive TREK subfamily comprising K2P2.1 (TREK-1), K2P4.1 (TRAAK), and K2P10.1 (TREK-2) are the first to have structures determined for each subfamily member. These structural studies have revealed key architectural features that underlie K2P function and have uncovered sites residing at every level of the channel structure with respect to the membrane where small molecules or lipids can control channel function. This polysite pharmacology within a relatively small (~70 kDa) ion channel comprises four structurally defined modulator binding sites that occur above (Keystone inhibitor site), at the level of (K2P modulator pocket), and below (Fenestration and Modulatory lipid sites) the C-type selectivity filter gate that is at the heart of K2P function. Uncovering this rich structural landscape provides the framework for understanding and developing subtype-selective modulators to probe K2P function that may provide leads for drugs for anesthesia, pain, arrhythmia, ischemia, and migraine.
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Affiliation(s)
- Lianne Pope
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, US
| | - Daniel L Minor
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, US. .,Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA. .,California Institute for Quantitative Biomedical Research, University of California, San Francisco, CA, USA. .,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA, USA. .,Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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18
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Regulation of Two-Pore-Domain Potassium TREK Channels and their Involvement in Pain Perception and Migraine. Neurosci Lett 2022; 773:136494. [DOI: 10.1016/j.neulet.2022.136494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 02/07/2023]
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19
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García-Fernández MD, Chatelain FC, Nury H, Moroni A, Moreau CJ. Distinct classes of potassium channels fused to GPCRs as electrical signaling biosensors. CELL REPORTS METHODS 2021; 1:None. [PMID: 34977850 PMCID: PMC8688152 DOI: 10.1016/j.crmeth.2021.100119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 08/05/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022]
Abstract
Ligand-gated ion channels (LGICs) are natural biosensors generating electrical signals in response to the binding of specific ligands. Creating de novo LGICs for biosensing applications is technically challenging. We have previously designed modified LGICs by linking G protein-coupled receptors (GPCRs) to the Kir6.2 channel. In this article, we extrapolate these design concepts to other channels with different structures and oligomeric states, namely a tetrameric viral Kcv channel and the dimeric mouse TREK-1 channel. After precise engineering of the linker regions, the two ion channels were successfully regulated by a GPCR fused to their N-terminal domain. Two-electrode voltage-clamp recordings showed that Kcv and mTREK-1 fusions were inhibited and activated by GPCR agonists, respectively, and antagonists abolished both effects. Thus, dissimilar ion channels can be allosterically regulated through their N-terminal domains, suggesting that this is a generalizable approach for ion channel engineering.
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Affiliation(s)
| | - Franck C. Chatelain
- Université Côte d’Azur, IPMC CNRS UMR7275, Laboratory of Excellence ICST, 660 route des Lucioles, 06650 Valbonne, France
| | - Hugues Nury
- Université Grenoble Alpes, CNRS, CEA, IBS, 71, av. Martyrs, CS10090, 38044 Grenoble Cedex9, France
| | - Anna Moroni
- University of Milan, Department of Biosciences, Via Celoria 26, 20133 Milano, Italy
| | - Christophe J. Moreau
- Université Grenoble Alpes, CNRS, CEA, IBS, 71, av. Martyrs, CS10090, 38044 Grenoble Cedex9, France
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20
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Lewis KJ. Osteocyte calcium signaling - A potential translator of mechanical load to mechanobiology. Bone 2021; 153:116136. [PMID: 34339908 DOI: 10.1016/j.bone.2021.116136] [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: 02/18/2021] [Revised: 06/25/2021] [Accepted: 07/27/2021] [Indexed: 10/20/2022]
Abstract
Osteocytes are embedded dendritic bone cells; by virtue of their position in bone tissue, ability to coordinate bone building osteoblasts and resorbing osteoclasts, and sensitivity to tissue level mechanical loading, they serve as the resident bone mechanosensor. The mechanisms osteocytes use to change mechanical loading into biological signals that drive tissue level changes has been well studied over the last 30 years, however the ways loading parameters are encoded at the cellular level are still not fully understood. Calcium signaling is a first messenger signal exhibited by osteocytes in response to mechanical forces. A body of work interrogating the mechanisms of osteocyte calcium signaling exists and is presently expanding, presenting the opportunity to better understand the relationship between calcium signaling characteristics and tuned osteocyte responses to tissue level strain features (e.g. magnitude, duration, frequency). This review covers the history of osteocyte load induced calcium signaling and highlights potential cellular mechanisms used by osteocytes to turn details about loading parameters into biological events.
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Affiliation(s)
- Karl J Lewis
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States of America.
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21
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Mini-Review: Two Brothers in Crime - The Interplay of TRESK and TREK in Human Diseases. Neurosci Lett 2021; 769:136376. [PMID: 34852287 DOI: 10.1016/j.neulet.2021.136376] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/17/2021] [Accepted: 11/25/2021] [Indexed: 02/07/2023]
Abstract
TWIK-related spinal cord potassium (TRESK) and TWIK-related potassium (TREK) channels are both subfamilies of the two-pore domain potassium (K2P) channel group. Despite major structural, pharmacological, as well as biophysical differences, emerging data suggest that channels of these two subfamilies are functionally more closely related than previously assumed. Recent studies, for instance, indicate an assembling of TRESK and TREK subunits, leading to the formation of heterodimeric channels with different functional properties compared to homodimeric ones. Formation of tandems consisting of TRESK and TREK subunits might thus multiply the functional diversity of both TRESK and TREK activity. Based on the involvement of these channels in the pathophysiology of migraine, we here highlight the role as well as the impact of the interplay of TRESK and TREK subunits in the context of different disease settings. In this regard, we focus on their involvement in migraine and pain syndromes, as well as on their influence on (neuro-)inflammatory processes. Furthermore, we describe the potential implications for innovative therapeutic strategies that take advantage of TRESK and TREK modulation as well as obstacles encountered in the development of therapies related to the aforementioned diseases.
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22
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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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23
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Rueda-Ruzafa L, Herrera-Pérez S, Campos-Ríos A, Lamas JA. Are TREK Channels Temperature Sensors? Front Cell Neurosci 2021; 15:744702. [PMID: 34690704 PMCID: PMC8526543 DOI: 10.3389/fncel.2021.744702] [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: 07/20/2021] [Accepted: 09/08/2021] [Indexed: 11/17/2022] Open
Abstract
Internal human body normal temperature fluctuates between 36.5 and 37.5°C and it is generally measured in the oral cavity. Interestingly, most electrophysiological studies on the functioning of ion channels and their role in neuronal behavior are carried out at room temperature, which usually oscillates between 22 and 24°C, even when thermosensitive channels are studied. We very often forget that if the core of the body reached that temperature, the probability of death from cardiorespiratory arrest would be extremely high. Does this mean that we are studying ion channels in dying neurons? Thousands of electrophysiological experiments carried out at these low temperatures suggest that most neurons tolerate this aggression quite well, at least for the duration of the experiments. This also seems to happen with ion channels, although studies at different temperatures indicate large changes in both, neuron and channel behavior. It is known that many chemical, physical and therefore physiological processes, depend to a great extent on body temperature. Temperature clearly affects the kinetics of numerous events such as chemical reactions or conformational changes in proteins but, what if these proteins constitute ion channels and these channels are specifically designed to detect changes in temperature? In this review, we discuss the importance of the potassium channels of the TREK subfamily, belonging to the recently discovered family of two-pore domain channels, in the transduction of thermal sensitivity in different cell types.
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Affiliation(s)
- Lola Rueda-Ruzafa
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
| | - Salvador Herrera-Pérez
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Grupo de Neurofisiología Experimental y Circuitos Neuronales, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain
| | - Ana Campos-Ríos
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
| | - J A Lamas
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
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24
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Conrad LJ, Proks P, Tucker SJ. Effects of ionic strength on gating and permeation of TREK-2 K2P channels. PLoS One 2021; 16:e0258275. [PMID: 34618865 PMCID: PMC8496810 DOI: 10.1371/journal.pone.0258275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/22/2021] [Indexed: 11/26/2022] Open
Abstract
In addition to the classical voltage-dependent behavior mediated by the voltage-sensing-domains (VSD) of ion channels, a growing number of voltage-dependent gating behaviors are being described in channels that lack canonical VSDs. A common thread in their mechanism of action is the contribution of the permeating ion to this voltage sensing process. The polymodal K2P K+ channel, TREK2 responds to membrane voltage through a gating process mediated by the interaction of K+ with its selectivity filter. Recently, we found that this action can be modulated by small molecule agonists (e.g. BL1249) which appear to have an electrostatic influence on K+ binding within the inner cavity and produce an increase in the single-channel conductance of TREK-2 channels. Here, we directly probed this K+-dependent gating process by recording both macroscopic and single-channel currents of TREK-2 in the presence of high concentrations of internal K+. Surprisingly we found TREK-2 is inhibited by high internal K+ concentrations and that this is mediated by the concomitant increase in ionic-strength. However, we were still able to determine that the increase in single channel conductance in the presence of BL1249 was blunted in high ionic-strength, whilst its activatory effect (on channel open probability) persisted. These effects are consistent with an electrostatic mechanism of action of negatively charged activators such as BL1249 on permeation, but also suggest that their influence on channel gating is complex.
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Affiliation(s)
- Linus J. Conrad
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, United Kingdom
- OXION Initiative in Ion Channels and Disease, University of Oxford, Oxford, United Kingdom
| | - Peter Proks
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, United Kingdom
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, United Kingdom
| | - Stephen J. Tucker
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, United Kingdom
- OXION Initiative in Ion Channels and Disease, University of Oxford, Oxford, United Kingdom
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, United Kingdom
- * E-mail:
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25
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Translocation of TMEM175 Lysosomal Potassium Channel to the Plasma Membrane by Dynasore Compounds. Int J Mol Sci 2021; 22:ijms221910515. [PMID: 34638858 PMCID: PMC8508992 DOI: 10.3390/ijms221910515] [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: 08/03/2021] [Revised: 09/21/2021] [Accepted: 09/25/2021] [Indexed: 12/15/2022] Open
Abstract
TMEM175 (transmembrane protein 175) coding sequence variants are associated with increased risk of Parkinson’s disease. TMEM175 is the ubiquitous lysosomal K+ channel regulated by growth factor receptor signaling and direct interaction with protein kinase B (PKB/Akt). In the present study, we show that the expression of mouse TMEM175 results in very small K+ currents through the plasma membrane in Xenopus laevis oocytes, in good accordance with the previously reported intracellular localization of the channel. However, the application of the dynamin inhibitor compounds, dynasore or dyngo-4a, substantially increased TMEM175 currents measured by the two-electrode voltage clamp method. TMEM175 was more permeable to cesium than potassium ions, voltage-dependently blocked by 4-aminopyridine (4-AP), and slightly inhibited by extracellular acidification. Immunocytochemistry experiments indicated that dyngo-4a increased the amount of epitope-tagged TMEM175 channel on the cell surface. The coexpression of dominant-negative dynamin, and the inhibition of clathrin- or caveolin-dependent endocytosis increased TMEM175 current much less than dynasore. Therefore, dynamin-independent pharmacological effects of dynasore may also contribute to the action on the channel. TMEM175 current rapidly decays after the withdrawal of dynasore, raising the possibility that an efficient internalization mechanism removes the channel from the plasma membrane. Dyngo-4a induced about 20-fold larger TMEM175 currents than the PKB activator SC79, or the coexpression of a constitutively active mutant PKB with the channel. In contrast, the allosteric PKB inhibitor MK2206 diminished the TMEM175 current in the presence of dyngo-4a. These data suggest that, in addition to the lysosomes, PKB-dependent regulation also influences TMEM175 current in the plasma membrane.
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26
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Roy Choudhury A, Großhans J, Kong D. Ion Channels in Epithelial Dynamics and Morphogenesis. Cells 2021; 10:cells10092280. [PMID: 34571929 PMCID: PMC8465836 DOI: 10.3390/cells10092280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/22/2021] [Accepted: 08/30/2021] [Indexed: 01/21/2023] Open
Abstract
Mechanosensitive ion channels mediate the neuronal sensation of mechanical signals such as sound, touch, and pain. Recent studies point to a function of these channel proteins in cell types and tissues in addition to the nervous system, such as epithelia, where they have been little studied, and their role has remained elusive. Dynamic epithelia are intrinsically exposed to mechanical forces. A response to pull and push is assumed to constitute an essential part of morphogenetic movements of epithelial tissues, for example. Mechano-gated channels may participate in sensing and responding to such forces. In this review, focusing on Drosophila, we highlight recent results that will guide further investigations concerned with the mechanistic role of these ion channels in epithelial cells.
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27
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Pang JJ, Gao F, Wu SM. Generators of Pressure-Evoked Currents in Vertebrate Outer Retinal Neurons. Cells 2021; 10:cells10061288. [PMID: 34067375 PMCID: PMC8224636 DOI: 10.3390/cells10061288] [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: 04/21/2021] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 12/19/2022] Open
Abstract
(1) Background: High-tension glaucoma damages the peripheral vision dominated by rods. How mechanosensitive channels (MSCs) in the outer retina mediate pressure responses is unclear. (2) Methods: Immunocytochemistry, patch clamp, and channel fluorescence were used to study MSCs in salamander photoreceptors. (3) Results: Immunoreactivity of transient receptor potential channel vanilloid 4 (TRPV4) was revealed in the outer plexiform layer, K+ channel TRAAK in the photoreceptor outer segment (OS), and TRPV2 in some rod OS disks. Pressure on the rod inner segment evoked sustained currents of three components: (A) the inward current at <-50 mV (Ipi), sensitive to Co2+; (B) leak outward current at ≥-80 mV (Ipo), sensitive to intracellular Cs+ and ruthenium red; and (C) cation current reversed at ~10 mV (Ipc). Hypotonicity induced slow currents like Ipc. Environmental pressure and light increased the FM 1-43-identified open MSCs in the OS membrane, while pressure on the OS with internal Cs+ closed a Ca2+-dependent current reversed at ~0 mV. Rod photocurrents were thermosensitive and affected by MSC blockers. (4) Conclusions: Rods possess depolarizing (TRPV) and hyperpolarizing (K+) MSCs, which mediate mutually compensating currents between -50 mV and 10 mV, serve as an electrical cushion to minimize the impact of ocular mechanical stress.
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28
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Huang L, Xu G, Jiang R, Luo Y, Zuo Y, Liu J. Development of Non-opioid Analgesics Targeting Two-pore Domain Potassium Channels. Curr Neuropharmacol 2021; 20:16-26. [PMID: 33827408 PMCID: PMC9199554 DOI: 10.2174/1570159x19666210407152528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/14/2021] [Accepted: 03/24/2021] [Indexed: 02/08/2023] Open
Abstract
Two-pore domain potassium (K2P) channels are a diverse family of potassium channels. K2P channels generate background leak potassium currents to regulate cellular excitability and are thereby involved in a wide range of neurological disorders. K2P channels are modulated by a variety of physicochemical factors such as mechanical stretch, temperature, and pH. In the the peripheral nervous system (PNS), K2P channels are widely expressed in nociceptive neurons and play a critical roles in pain perception. In this review, we summarize the recent advances in the pharmacological properties of K2P channels, with a focus on the exogenous small-molecule activators targeting K2P channels. We emphasize the subtype-selectivity, cellular and in vivo pharmacological properties of all the reported small-molecule activators. The key underlying analgesic mechanisms mediated by K2P are also summarized based on the data in the literature from studies using small-molecule activators and genetic knock-out animals. We discuss advantages and limitations of the translational perspectives of K2P in pain medicine and provide outstanding questions for future studies in the end.
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Affiliation(s)
- Lu Huang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Guangyin Xu
- Department of Physiology and Neurobiology, Institute of Neuroscience, Medical College of Soochow University, Suzhou, 215123, Jiangsu. China
| | - Ruotian Jiang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Yuncheng Luo
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Yunxia Zuo
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
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29
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Lee H, Lolicato M, Arrigoni C, Minor DL. Production of K 2P2.1 (TREK-1) for structural studies. Methods Enzymol 2021; 653:151-188. [PMID: 34099170 DOI: 10.1016/bs.mie.2021.02.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
K2P (KCNK) potassium channels form 'background' or 'leak' currents that are important for controlling cell excitability in the brain, cardiovascular system, and somatosensory neurons. K2P2.1 (TREK-1) is one of the founding members of this family and one of the first well-characterized polymodal ion channels capable of responding to a variety of physical and chemical gating cues. Of the six K2P subfamilies, the thermo-and mechano-sensitive TREK subfamily comprising K2P2.1 (TREK-1), K2P4.1 (TRAAK), and K2P10.1 (TREK-2) is the first to have structures determined for each subfamily member. These structural studies have revealed key architectural features that provide a framework for understanding how gating cues sensed by different channel elements converge on the K2P selectivity filter C-type gate. TREK family structural studies have also revealed numerous sites where small molecules or lipids bind and affect channel function. This rich structural landscape provides the framework for probing K2P function and for the development of new K2P-directed agents. Such molecules may be useful for affecting processes where TREK channels are important such as anesthesia, pain, arrythmia, ischemia, migraine, intraocular pressure, and lung injury. Production of high quality protein samples is key to addressing new questions about K2P function and pharmacology. Here, we present methods for producing pure K2P2.1 (TREK-1) suitable for advancing towards these goals through structural and biochemical studies.
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Affiliation(s)
- Haerim Lee
- Cardiovascular Research Institute, University of California, San Francisco, CA, United States
| | - Marco Lolicato
- Cardiovascular Research Institute, University of California, San Francisco, CA, United States
| | - Cristina Arrigoni
- Cardiovascular Research Institute, University of California, San Francisco, CA, United States
| | - Daniel L Minor
- Cardiovascular Research Institute, University of California, San Francisco, CA, United States; Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, CA, United States; California Institute for Quantitative Biomedical Research, University of California, San Francisco, CA, United States; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA, United States; Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
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30
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Momin A, Bahrampour S, Min HK, Chen X, Wang X, Sun Y, Huang X. Channeling Force in the Brain: Mechanosensitive Ion Channels Choreograph Mechanics and Malignancies. Trends Pharmacol Sci 2021; 42:367-384. [PMID: 33752907 DOI: 10.1016/j.tips.2021.02.006] [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: 11/04/2020] [Revised: 02/15/2021] [Accepted: 02/26/2021] [Indexed: 12/15/2022]
Abstract
Force is everywhere. Through cell-intrinsic activities and interactions with the microenvironment, cells generate, transmit, and sense mechanical forces, such as compression, tension, and shear stress. These forces shape the mechanical properties of cells and tissues. Akin to how balanced biochemical signaling safeguards physiological processes, a mechanical optimum is required for homeostasis. The brain constructs a mechanical optimum from its cellular and extracellular constituents. However, in brain cancer, the mechanical properties are disrupted: tumor and nontumoral cells experience dysregulated solid and fluid stress, while tumor tissue develops altered stiffness. Mechanosensitive (MS) ion channels perceive mechanical cues to govern ion flux and cellular signaling. In this review, we describe the mechanical properties of the brain in healthy and cancer states and illustrate MS ion channels as sensors of mechanical cues to regulate malignant growth. Targeting MS ion channels offers disease insights at the interface of cancer, neuroscience, and mechanobiology to reveal therapeutic opportunities in brain tumors.
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Affiliation(s)
- Ali Momin
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ONT, M5S 3E1, Canada.
| | - Shahrzad Bahrampour
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Hyun-Kee Min
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ONT, M5S 3E1, Canada
| | - Xin Chen
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada
| | - Xian Wang
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ONT, M5S 3G8, Canada
| | - Xi Huang
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ONT, M5S 3E1, Canada.
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31
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Choi SW, Woo J, Park KS, Ko J, Jeon YK, Choi SW, Yoo HY, Kho I, Kim TJ, Kim SJ. Higher expression of KCNK10 (TREK-2) K + channels and their functional upregulation by lipopolysaccharide treatment in mouse peritoneal B1a cells. Pflugers Arch 2021; 473:659-671. [PMID: 33586023 DOI: 10.1007/s00424-021-02526-1] [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: 07/14/2020] [Revised: 01/10/2021] [Accepted: 01/28/2021] [Indexed: 11/24/2022]
Abstract
Innate-like CD5+ B1a cells localized in serous cavities are activated by innate stimuli, such as lipopolysaccharide (LPS), leading to T cell-independent antibody responses. Although ion channels play crucial roles in the homeostasis and activation of immune cells, the electrophysiological properties of B1a cells have not been investigated to date. Previously, in the mouse B cell lymphoma cells, we found that the voltage-independent two-pore-domain potassium (K2P) channels generate a negative membrane potential and drive Ca2+ influx. Here, we newly compared the expression and activities of K2P channels in mouse splenic follicular B (FoB), marginal zone B (MZB), and peritoneal B1a cells. Next-generation sequencing analysis showed higher levels of transcripts for TREK-2 and TWIK-2 in B1a cells than those in FoB or MZB cells. Electrophysiological analysis, using patch clamp technique, revealed higher activity of TREK-2 with the characteristic large unitary conductance (~ 250 pS) in B1a than that in FoB or MZB cells. TREK-2 activity was further increased by LPS treatment (>2 h), which was more prominent in B1a than that in MZB or FoB cells. The cytosolic Ca2+ concentration of B cells was decreased by high-K+-induced depolarization (ΔRKCl (%)), suggesting the basal Ca2+ influx to be driven by negative membrane potential. The LPS treatment significantly increased the ΔRKCl (%) in B1a, though not in FoB and MZB cells. Our study was the first to compare the K2P channels in mouse primary B cell subsets, elucidating the functional upregulation of TREK-2 and augmentation of Ca2+ influx by the stimulation of Toll-like receptor 4 in B1a cells.
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Affiliation(s)
- Si Won Choi
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Joohan Woo
- Department of Physiology and Ion Channel Disease Research Center, Dongguk University College of Medicine, Seoul, Republic of Korea
| | - Kyung Sun Park
- Wide River Institute of Immunology, Seoul National University College of Medicine, Hongcheon, Republic of Korea
| | - Juyeon Ko
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Young Keul Jeon
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Seong Woo Choi
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Physiology and Ion Channel Disease Research Center, Dongguk University College of Medicine, Seoul, Republic of Korea.,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hae Young Yoo
- Department of Nursing, Chung-Ang University, Seoul, Republic of Korea
| | - Inseong Kho
- Department of Immunology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Tae Jin Kim
- Department of Immunology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea. .,Wide River Institute of Immunology, Seoul National University College of Medicine, Hongcheon, Republic of Korea. .,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
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32
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Abstract
Two-pore domain potassium channels are formed by subunits that each contain two pore-loops moieties. Whether the channels are expressed in yeast or the human central nervous system, two subunits come together to form a single potassium selective pore. TOK1, the first two-domain channel was cloned from Saccharomyces cerevisiae in 1995 and soon thereafter, 15 distinct K2P subunits were identified in the human genome. The human K2P channels are stratified into six K2P subfamilies based on sequence as well as physiological or pharmacological similarities. Functional K2P channels pass background (or "leak") K+ currents that shape the membrane potential and excitability of cells in a broad range of tissues. In the years since they were first described, classical functional assays, latterly coupled with state-of-the-art structural and computational studies have revealed the mechanistic basis of K2P channel gating in response to specific physicochemical or pharmacological stimuli. The growing appreciation that K2P channels can play a pivotal role in the pathophysiology of a growing spectrum of diseases makes a compelling case for K2P channels as targets for drug discovery. Here, we summarize recent advances in unraveling the structure, function, and pharmacology of the K2P channels.
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Affiliation(s)
- Jordie M Kamuene
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Yu Xu
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Leigh D Plant
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA.
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33
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Gregory KJ, Goudet C. International Union of Basic and Clinical Pharmacology. CXI. Pharmacology, Signaling, and Physiology of Metabotropic Glutamate Receptors. Pharmacol Rev 2020; 73:521-569. [PMID: 33361406 DOI: 10.1124/pr.119.019133] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Metabotropic glutamate (mGlu) receptors respond to glutamate, the major excitatory neurotransmitter in the mammalian brain, mediating a modulatory role that is critical for higher-order brain functions such as learning and memory. Since the first mGlu receptor was cloned in 1992, eight subtypes have been identified along with many isoforms and splice variants. The mGlu receptors are transmembrane-spanning proteins belonging to the class C G protein-coupled receptor family and represent attractive targets for a multitude of central nervous system disorders. Concerted drug discovery efforts over the past three decades have yielded a wealth of pharmacological tools including subtype-selective agents that competitively block or mimic the actions of glutamate or act allosterically via distinct sites to enhance or inhibit receptor activity. Herein, we review the physiologic and pathophysiological roles for individual mGlu receptor subtypes including the pleiotropic nature of intracellular signal transduction arising from each. We provide a comprehensive analysis of the in vitro and in vivo pharmacological properties of prototypical and commercially available orthosteric agonists and antagonists as well as allosteric modulators, including ligands that have entered clinical trials. Finally, we highlight emerging areas of research that hold promise to facilitate rational design of highly selective mGlu receptor-targeting therapeutics in the future. SIGNIFICANCE STATEMENT: The metabotropic glutamate receptors are attractive therapeutic targets for a range of psychiatric and neurological disorders. Over the past three decades, intense discovery efforts have yielded diverse pharmacological tools acting either competitively or allosterically, which have enabled dissection of fundamental biological process modulated by metabotropic glutamate receptors and established proof of concept for many therapeutic indications. We review metabotropic glutamate receptor molecular pharmacology and highlight emerging areas that are offering new avenues to selectively modulate neurotransmission.
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Affiliation(s)
- Karen J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.) and Institut de Génomique Fonctionnelle (IGF), University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Sante et de la Recherche Medicale (INSERM), Montpellier, France (C.G.)
| | - Cyril Goudet
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.) and Institut de Génomique Fonctionnelle (IGF), University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Sante et de la Recherche Medicale (INSERM), Montpellier, France (C.G.)
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34
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Kim SE, Kim MH, Woo J, Kim SJ. Dual regulatory effects of PI(4,5)P 2 on TREK-2 K + channel through antagonizing interaction between the alkaline residues (K 330 and R 355-357) in the cytosolic C-terminal helix. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2020; 24:555-561. [PMID: 33093276 PMCID: PMC7585596 DOI: 10.4196/kjpp.2020.24.6.555] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/08/2020] [Accepted: 10/08/2020] [Indexed: 11/15/2022]
Abstract
TWIK-related two-pore domain K+ channel-2 (TREK-2) has voltageindependent activity and shows additional activation by acidic intracellular pH (pHi) via neutralizing the E332 in the cytoplasmic C terminal (Ct). We reported opposite regulations of TREK-2 by phosphatidylinositol 4,5-bisphosphate (PIP2) via the alkaline K330 and triple Arg residues (R355-357); inhibition and activation, respectively. The G334 between them appeared critical because its mutation (G334A) endowed hTREK-2 with tonic activity, similar to the mutation of the inhibitory K330 (K330A). To further elucidate the role of putative bent conformation at G334, we compared the dual mutation forms, K330A/G334A and G334A/R355-7A, showing higher and lower basal activity, respectively. The results suggested that the tonic activity of G334A owes to a dominant influence from R355-7. Since there are additional triple Arg residues (R377-9) distal to R355-7, we also examined the triple mutant (G334A/R355-7A/R377-9A) that showed tonic inhibition same with G334A/R355-7A. Despite the state of tonic inhibition, the activation by acidic pHi was preserved in both G334A/R355-7A and G334A/R355-7A/R377-9A, similar to the R355-7A. Also, the inhibitory effect of ATP could be commonly demonstrated under the activation by acidic pHi in R355-7A, G334A/R355-7A, and G334A/R355-7A/R377-9A. These results suggest that the putative bent conformation at G334 is important to set the tug-of-war between K330 and R355-7 in the PIP2-dependent regulation of TREK-2.
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Affiliation(s)
- Sung Eun Kim
- Department of Physiology, Seoul National University College of Medicine, Gyeongju 38066, Korea
| | - Myoung-Hwan Kim
- Department of Physiology, Seoul National University College of Medicine, Gyeongju 38066, Korea
| | - Joohan Woo
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Korea.,Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Gyeongju 38066, Korea.,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 03080, Korea
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35
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Diz-Chaves Y, Herrera-Pérez S, González-Matías LC, Lamas JA, Mallo F. Glucagon-Like Peptide-1 (GLP-1) in the Integration of Neural and Endocrine Responses to Stress. Nutrients 2020; 12:nu12113304. [PMID: 33126672 PMCID: PMC7692797 DOI: 10.3390/nu12113304] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/14/2020] [Accepted: 10/27/2020] [Indexed: 12/20/2022] Open
Abstract
Glucagon like-peptide 1 (GLP-1) within the brain is produced by a population of preproglucagon neurons located in the caudal nucleus of the solitary tract. These neurons project to the hypothalamus and another forebrain, hindbrain, and mesolimbic brain areas control the autonomic function, feeding, and the motivation to feed or regulate the stress response and the hypothalamic-pituitary-adrenal axis. GLP-1 receptor (GLP-1R) controls both food intake and feeding behavior (hunger-driven feeding, the hedonic value of food, and food motivation). The activation of GLP-1 receptors involves second messenger pathways and ionic events in the autonomic nervous system, which are very relevant to explain the essential central actions of GLP-1 as neuromodulator coordinating food intake in response to a physiological and stress-related stimulus to maintain homeostasis. Alterations in GLP-1 signaling associated with obesity or chronic stress induce the dysregulation of eating behavior. This review summarized the experimental shreds of evidence from studies using GLP-1R agonists to describe the neural and endocrine integration of stress responses and feeding behavior.
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Affiliation(s)
- Yolanda Diz-Chaves
- CINBIO, Universidade de Vigo, Grupo FB3A, Laboratorio de Endocrinología, 36310 Vigo, Spain;
- Correspondence: (Y.D.-C.); (F.M.); Tel.: +34-(986)-130226 (Y.D.-C.); +34-(986)-812393 (F.M.)
| | - Salvador Herrera-Pérez
- CINBIO, Universidade de Vigo, Grupo FB3B, Laboratorio de Neurociencia, 36310 Vigo, Spain; (S.H.-P.); (J.A.L.)
| | | | - José Antonio Lamas
- CINBIO, Universidade de Vigo, Grupo FB3B, Laboratorio de Neurociencia, 36310 Vigo, Spain; (S.H.-P.); (J.A.L.)
| | - Federico Mallo
- CINBIO, Universidade de Vigo, Grupo FB3A, Laboratorio de Endocrinología, 36310 Vigo, Spain;
- Correspondence: (Y.D.-C.); (F.M.); Tel.: +34-(986)-130226 (Y.D.-C.); +34-(986)-812393 (F.M.)
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García G, Méndez-Reséndiz KA, Oviedo N, Murbartián J. PKC- and PKA-dependent phosphorylation modulates TREK-1 function in naïve and neuropathic rats. J Neurochem 2020; 157:2039-2054. [PMID: 33006141 DOI: 10.1111/jnc.15204] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 02/07/2023]
Abstract
PKC and PKA phosphorylation inhibit TREK-1 channels downstream of Gs protein-coupled receptor activation in vitro. However, the role of phosphorylation of TREK-1 in neuropathic pain is unknown. The purpose of this study was to investigate whether altered TREK-1 channel function by PKA and PKC modulators contributes to antiallodynia in neuropathic rats. Furthermore, we investigated if the in vitro described sites for PKC and PKA phosphorylation (S300 and S333, respectively) participate in the modulation of TREK-1 in naïve and neuropathic rats. L5/L6 spinal nerve ligation (SNL) induced tactile allodynia. Intrathecal injection of BL-1249 (TREK-1 activator) reversed nerve injury-induced tactile allodynia, whereas spadin (TREK-1 blocker) produced tactile allodynia in naïve rats and reversed the antiallodynic effect induced by BL-1249 in neuropathic rats. Intrathecal administration of rottlerin or Rp-cAMPs (PKC and PKA inhibitors, respectively) enhanced the antiallodynia observed with BL-1249 in neuropathic rats. In contrast, pretreatment with PdBu or forskolin (PKC and PKA activators, respectively) reduced the BL-1249-induced antiallodynia. Intrathecal injection of two high-activity TREK-1 recombinant channels, using a in vivo transfection method with lipofectamine, with mutations at PKC/PKA phosphosites (S300A and S333A) reversed tactile allodynia in neuropathic rats, with no effect in naïve rats. In contrast, transfection of two low-activity TREK-1 recombinant channels with phosphomimetic mutations at those sites (S300D and S333D) produced tactile allodynia in naïve rats and interfered with antiallodynic effects of rottlerin/BL-1249 or Rp-cAMPs/BL-1249. Data suggest that TREK-1 channel activity can be dynamically tuned in vivo by PKC/PKA to provoke allodynia and modulate its antiallodynic role in neuropathic pain.
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Affiliation(s)
- Guadalupe García
- Departamento de Farmacobiología, Cinvestav, Sede Sur., Mexico City, Mexico
| | | | - Norma Oviedo
- Unidad de Investigación Médica en Inmunología e Infectología, Centro Médico Nacional, La Raza, Instituto Mexicano del Seguro Social., Mexico City, Mexico
| | - Janet Murbartián
- Departamento de Farmacobiología, Cinvestav, Sede Sur., Mexico City, Mexico
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Early Stimulation of TREK Channel Transcription and Activity Induced by Oxaliplatin-Dependent Cytosolic Acidification. Int J Mol Sci 2020; 21:ijms21197164. [PMID: 32998392 PMCID: PMC7584002 DOI: 10.3390/ijms21197164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 09/27/2020] [Indexed: 11/16/2022] Open
Abstract
Oxaliplatin-induced peripheral neuropathy is characterized by an acute hyperexcitability syndrome triggered/exacerbated by cold. The mechanisms underlying oxaliplatin-induced peripheral neuropathy are unclear, but the alteration of ion channel expression and activity plays a well-recognized central role. Recently, we found that oxaliplatin leads to cytosolic acidification in dorsal root ganglion (DRG) neurons. Here, we investigated the early impact of oxaliplatin on the proton-sensitive TREK potassium channels. Following a 6-h oxaliplatin treatment, both channels underwent a transcription upregulation that returned to control levels after 42 h. The overexpression of TREK channels was also observed after in vivo treatment in DRG cells from mice exposed to acute treatment with oxaliplatin. Moreover, both intracellular pH and TREK channel transcription were similarly regulated after incubation with amiloride, an inhibitor of the Na+/H+ exchanger. In addition, we studied the role of oxaliplatin-induced acidification on channel behavior, and, as expected, we observed a robust positive modulation of TREK channel activity. Finally, we focused on the impact of this complex modulation on capsaicin-evoked neuronal activity finding a transient decrease in the average firing rate following 6 h of oxaliplatin treatment. In conclusion, the early activation of TREK genes may represent a mechanism of protection against the oxaliplatin-related perturbation of neuronal excitability.
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Serova OV, Gantsova EA, Deyev IE, Petrenko AG. The Value of pH Sensors in Maintaining Homeostasis of the Nervous System. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2020. [DOI: 10.1134/s1068162020040196] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Busserolles J, Ben Soussia I, Pouchol L, Marie N, Meleine M, Devilliers M, Judon C, Schopp J, Clémenceau L, Poupon L, Chapuy E, Richard S, Noble F, Lesage F, Ducki S, Eschalier A, Lolignier S. TREK1 channel activation as a new analgesic strategy devoid of opioid adverse effects. Br J Pharmacol 2020; 177:4782-4795. [PMID: 32851651 DOI: 10.1111/bph.15243] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 07/06/2020] [Accepted: 08/03/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND AND PURPOSE Opioids are effective painkillers. However, their risk-benefit ratio is dampened by numerous adverse effects and opioid misuse has led to a public health crisis. Safer alternatives are required, but isolating the antinociceptive effect of opioids from their adverse effects is a pharmacological challenge because activation of the μ opioid receptor triggers both the antinociceptive and adverse effects of opioids. EXPERIMENTAL APPROACH The TREK1 potassium channel is activated downstream of μ receptor and involved in the antinociceptive activity of morphine but not in its adverse effects. Bypassing the μ opioid receptor to directly activate TREK1 could therefore be a safer analgesic strategy. KEY RESULTS We developed a selective TREK1 activator, RNE28, with antinociceptive activity in naive rodents and in models of inflammatory and neuropathic pain. This activity was lost in TREK1 knockout mice or wild-type mice treated with the TREK1 blocker spadin, showing that TREK1 is required for the antinociceptive activity of RNE28. RNE28 did not induce respiratory depression, constipation, rewarding effects, or sedation at the analgesic doses tested. CONCLUSION AND IMPLICATIONS This proof-of-concept study shows that TREK1 activators could constitute a novel class of painkillers, inspired by the mechanism of action of opioids but devoid of their adverse effects.
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Affiliation(s)
- Jérôme Busserolles
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
| | - Ismail Ben Soussia
- Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Labex ICST, Université Côte d'Azur, INSERM, Valbonne, France
| | - Laetitia Pouchol
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
| | - Nicolas Marie
- Neuroplasticité et thérapie des addictions, Université Paris Descartes, CNRS, Inserm, Paris, France
| | - Mathieu Meleine
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
| | - Maïly Devilliers
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
| | - Céline Judon
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
| | - Julien Schopp
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
| | - Loïc Clémenceau
- Neuroplasticité et thérapie des addictions, Université Paris Descartes, CNRS, Inserm, Paris, France
| | - Laura Poupon
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
| | - Eric Chapuy
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
| | - Serge Richard
- Centre de Recherches Biologiques, CERB, Baugy, France
| | - Florence Noble
- Neuroplasticité et thérapie des addictions, Université Paris Descartes, CNRS, Inserm, Paris, France
| | - Florian Lesage
- Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Labex ICST, Université Côte d'Azur, INSERM, Valbonne, France
| | - Sylvie Ducki
- ICCF, SIGMA Clermont, Université Clermont Auvergne, CNRS, Clermont-Ferrand, France
| | - Alain Eschalier
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
| | - Stéphane Lolignier
- Université Clermont Auvergne, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.,Faculté de Médecine, Institut Analgesia, Clermont-Ferrand, France
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Buijs TJ, McNaughton PA. The Role of Cold-Sensitive Ion Channels in Peripheral Thermosensation. Front Cell Neurosci 2020; 14:262. [PMID: 32973456 PMCID: PMC7468449 DOI: 10.3389/fncel.2020.00262] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/27/2020] [Indexed: 11/13/2022] Open
Abstract
The detection of ambient cold is critical for mammals, who use this information to avoid tissue damage by cold and to maintain stable body temperature. The transduction of information about the environmental cold is mediated by cold-sensitive ion channels expressed in peripheral sensory nerve endings in the skin. Most transduction mechanisms for detecting temperature changes identified to date depend on transient receptor potential (TRP) ion channels. Mild cooling is detected by the menthol-sensitive TRPM8 ion channel, but how painful cold is detected remains unclear. The TRPA1 ion channel, which is activated by cold in expression systems, seemed to provide an answer to this question, but whether TRPA1 is activated by cold in neurons and contributes to the sensation of cold pain continues to be a matter of debate. Recent advances have been made in this area of investigation with the identification of several potential cold-sensitive ion channels in thermosensory neurons, including two-pore domain potassium channels (K2P), GluK2 glutamate receptors, and CNGA3 cyclic nucleotide-gated ion channels. This mini-review gives a brief overview of the way by which ion channels contribute to cold sensation, discusses the controversy around the cold-sensitivity of TRPA1, and provides an assessment of some recently-proposed novel cold-transduction mechanisms. Evidence for another unidentified cold-transduction mechanism is also presented.
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Affiliation(s)
- Tamara Joëlle Buijs
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
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41
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Rivas-Ramírez P, Reboreda A, Rueda-Ruzafa L, Herrera-Pérez S, Lamas JA. Contribution of KCNQ and TREK Channels to the Resting Membrane Potential in Sympathetic Neurons at Physiological Temperature. Int J Mol Sci 2020; 21:E5796. [PMID: 32806753 PMCID: PMC7461115 DOI: 10.3390/ijms21165796] [Citation(s) in RCA: 4] [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: 07/07/2020] [Revised: 07/31/2020] [Accepted: 08/10/2020] [Indexed: 12/19/2022] Open
Abstract
The ionic mechanisms controlling the resting membrane potential (RMP) in superior cervical ganglion (SCG) neurons have been widely studied and the M-current (IM, KCNQ) is one of the key players. Recently, with the discovery of the presence of functional TREK-2 (TWIK-related K+ channel 2) channels in SCG neurons, another potential main contributor for setting the value of the resting membrane potential has appeared. In the present work, we quantified the contribution of TREK-2 channels to the resting membrane potential at physiological temperature and studied its role in excitability using patch-clamp techniques. In the process we have discovered that TREK-2 channels are sensitive to the classic M-current blockers linopirdine and XE991 (IC50 = 0.310 ± 0.06 µM and 0.044 ± 0.013 µM, respectively). An increase from room temperature (23 °C) to physiological temperature (37 °C) enhanced both IM and TREK-2 currents. Likewise, inhibition of IM by tetraethylammonium (TEA) and TREK-2 current by XE991 depolarized the RMP at room and physiological temperatures. Temperature rise also enhanced adaptation in SCG neurons which was reduced due to TREK-2 and IM inhibition by XE991 application. In summary, TREK-2 and M currents contribute to the resting membrane potential and excitability at room and physiological temperature in the primary culture of mouse SCG neurons.
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Affiliation(s)
- Paula Rivas-Ramírez
- Department of Functional Biology and Health Sciences, Faculty of Biology-CINBIO-IBIV, University of Vigo, Campus Lagoas-Marcosende, 36310 Vigo, Spain; (P.R.-R.); (L.R.-R.); (S.H.-P.)
| | - Antonio Reboreda
- Department of Functional Biology and Health Sciences, Faculty of Biology-CINBIO-IBIV, University of Vigo, Campus Lagoas-Marcosende, 36310 Vigo, Spain; (P.R.-R.); (L.R.-R.); (S.H.-P.)
- Functional Architecture of Memory Department, Leibniz-Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Lola Rueda-Ruzafa
- Department of Functional Biology and Health Sciences, Faculty of Biology-CINBIO-IBIV, University of Vigo, Campus Lagoas-Marcosende, 36310 Vigo, Spain; (P.R.-R.); (L.R.-R.); (S.H.-P.)
| | - Salvador Herrera-Pérez
- Department of Functional Biology and Health Sciences, Faculty of Biology-CINBIO-IBIV, University of Vigo, Campus Lagoas-Marcosende, 36310 Vigo, Spain; (P.R.-R.); (L.R.-R.); (S.H.-P.)
| | - Jose Antonio Lamas
- Department of Functional Biology and Health Sciences, Faculty of Biology-CINBIO-IBIV, University of Vigo, Campus Lagoas-Marcosende, 36310 Vigo, Spain; (P.R.-R.); (L.R.-R.); (S.H.-P.)
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Le Ribeuz H, Courboulin A, Ghigna MR, Lambert M, Hautefort A, Humbert M, Montani D, Cohen-Kaminsky S, Perros F, Antigny F. In vivo miR-138-5p inhibition alleviates monocrotaline-induced pulmonary hypertension and normalizes pulmonary KCNK3 and SLC45A3 expression. Respir Res 2020; 21:186. [PMID: 32678044 PMCID: PMC7364627 DOI: 10.1186/s12931-020-01444-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/06/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The pathogenesis of pulmonary arterial hypertension (PAH) involves many signalling pathways. MicroRNAs are potential candidates involved in simultaneously coordinating multiple genes under such multifactorial conditions. METHODS AND RESULTS MiR-138-5p is overexpressed in pulmonary arterial smooth muscle cells (PASMCs) from PAH patients and in lungs from rats with monocrotaline-induced pulmonary hypertension (MCT-PH). MiR-138-5p is predicted to regulate the expression of the potassium channel KCNK3, whose loss is associated with the development and progression of PAH. We hypothesized that, in vivo, miR-138-5p inhibition would restore KCNK3 lung expression and subsequently alleviate PAH. Nebulization-based delivery of anti-miR-138-5p to rats with established MCT-PH significantly reduced the right ventricular systolic pressure and significantly improved the pulmonary arterial acceleration time (PAAT). These haemodynamic improvements were related to decrease pulmonary vascular remodelling, lung inflammation and pulmonary vascular cell proliferation in situ. In vivo inhibition of miR-138-5p restored KCNK3 mRNA expression and SLC45A3 protein expression in the lungs. CONCLUSIONS We confirmed that in vivo inhibition of miR-138-5p reduces the development of PH in experimental MCT-PH. The possible curative mechanisms involve at least the normalization of lung KCNK3 as well as SLC45A3 expression.
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Affiliation(s)
- Hélène Le Ribeuz
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Audrey Courboulin
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Maria-Rosa Ghigna
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Mélanie Lambert
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Aurélie Hautefort
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Marc Humbert
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - David Montani
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Sylvia Cohen-Kaminsky
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Frédéric Perros
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Fabrice Antigny
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France.
- INSERM UMR_S 999 « Hypertension pulmonaire : Physiopathologie et Innovation Thérapeutique », Hôpital Marie Lannelongue, Le Plessis-Robinson, France.
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France.
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Arazi E, Blecher G, Zilberberg N. A regulatory domain in the K 2P2.1 (TREK-1) carboxyl-terminal allows for channel activation by monoterpenes. Mol Cell Neurosci 2020; 105:103496. [PMID: 32320829 DOI: 10.1016/j.mcn.2020.103496] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 04/12/2020] [Accepted: 04/15/2020] [Indexed: 11/30/2022] Open
Abstract
Potassium K2P ('leak') channels conduct current across the entire physiological voltage range and carry leak or 'background' currents that are, in part, time- and voltage-independent. K2P2.1 channels (i.e., TREK-1, KCNK2) are highly expressed in excitable tissues, where they play a key role in the cellular mechanisms of neuroprotection, anesthesia, pain perception, and depression. Here, we report for the first time that human K2P2.1 channel activity is regulated by monoterpenes (MTs). We found that cyclic, aromatic monoterpenes containing a phenol moiety, such as carvacrol, thymol and 4-IPP had the most profound effect on current flowing through the channel (up to a 6-fold increase). By performing sequential truncation of the carboxyl-terminal domain of the channel and testing the activity of several channel regulators, we identified two distinct regulatory domains within this portion of the protein. One domain, as previously reported, was needed for regulation by arachidonic acid, anionic phospholipids, and temperature changes. Within a second domain, a triple arginine residue motif (R344-346), an apparent PIP2-binding site, was found to be essential for regulation by holding potential changes and important for regulation by monoterpenes.
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Affiliation(s)
- Eden Arazi
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 8410501, Israel
| | - Galit Blecher
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 8410501, Israel
| | - Noam Zilberberg
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 8410501, Israel; Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 8410501, Israel.
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Ma R, Lewis A. Spadin Selectively Antagonizes Arachidonic Acid Activation of TREK-1 Channels. Front Pharmacol 2020; 11:434. [PMID: 32317978 PMCID: PMC7154116 DOI: 10.3389/fphar.2020.00434] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/20/2020] [Indexed: 12/13/2022] Open
Abstract
TREK-1 channel activity is a critical regulator of neuronal, cardiac, and smooth muscle physiology and pathology. The antidepressant peptide, spadin, has been proposed to be a TREK-1-specific blocker. Here we sought to examine the mechanism of action underlying spadin inhibition of TREK-1 channels. Heterologous expression in Xenopus laevis oocytes and electrophysiological analysis using two-electrode voltage clamp in standard bath solutions was used to characterize the pharmacological profile of wild-type and mutant murine TREK-1 and TREK-2 channels using previously established human K2P activators; arachidonic acid (AA), cis-4,7,10,13,16,19-docosahexaenoic acid (DHA), BL-1249, and cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC) and inhibitors; spadin and barium (Ba2+). Mouse TREK-1 and TREK-2 channel currents were both significantly increased by AA, BL-1249, and CDC, similar to their human homologs. Under basal conditions, both TREK-1 and TREK-2 currents were insensitive to application of spadin, but could be blocked by Ba2+. Spadin did not significantly inhibit either TREK-1 or TREK-2 currents either chemically activated by AA, BL-1249, or CDC, or structurally activated via a gating mutation. However, pre-exposure to spadin significantly perturbed the subsequent activation of TREK-1 currents by AA, but not TREK-2. Furthermore, spadin was unable to prevent activation of TREK-1 by BL-1249, CDC, or the related bioactive lipid, DHA. Spadin specifically antagonizes the activation of TREK-1 channels by AA, likely via an allosteric mechanism. Lack of intrinsic activity may explain the absence of clinical side effects during antidepressant therapy.
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Affiliation(s)
- Ruolin Ma
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Anthony Lewis
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, United Kingdom
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Fernández-Fernández D, Lamas JA. Metabotropic Modulation of Potassium Channels During Synaptic Plasticity. Neuroscience 2020; 456:4-16. [PMID: 32114098 DOI: 10.1016/j.neuroscience.2020.02.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/14/2020] [Accepted: 02/18/2020] [Indexed: 01/06/2023]
Abstract
Besides their primary function mediating the repolarization phase of action potentials, potassium channels exquisitely and ubiquitously regulate the resting membrane potential of neurons and therefore have a key role establishing their intrinsic excitability. This group of proteins is composed of a very diverse collection of voltage-dependent and -independent ion channels, whose specific distribution is finely tuned at the level of the synapse. Both at the presynaptic and postsynaptic membranes, different types of potassium channels are subjected to modulation by second messenger signaling cascades triggered by metabotropic receptors, which in this way serve as a link between neurotransmitter actions and changes in the neuron membrane excitability. On the one hand, by regulating the resting membrane potential of the postsynaptic membrane, potassium channels appear to be critical towards setting the threshold for the induction of long-term potentiation and depression. On the other hand, these channels maintain the presynaptic membrane potential under control, therefore influencing the probability of neurotransmitter release underlying different forms of short-term plasticity. In the present review, we examine in detail the role of metabotropic receptors translating their activation by different neurotransmitters into a final effect modulating several types of potassium channels. Furthermore, we evaluate the consequences that this interplay has on the induction and maintenance of different forms of synaptic plasticity.
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Affiliation(s)
- D Fernández-Fernández
- Laboratory of Neuroscience, Biomedical Research Center (CINBIO), University of Vigo, Vigo, Galicia, Spain.
| | - J A Lamas
- Laboratory of Neuroscience, Biomedical Research Center (CINBIO), University of Vigo, Vigo, Galicia, Spain
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Paschou M, Maier L, Papazafiri P, Selescu T, Dedos SG, Babes A, Doxakis E. Neuronal microRNAs modulate TREK two-pore domain K + channel expression and current density. RNA Biol 2020; 17:651-662. [PMID: 31994436 DOI: 10.1080/15476286.2020.1722450] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The TREK family of leak potassium channels has been found to play critical roles in nociception, sensitivity to general anaesthetics, neuroprotection, and memory. The three members of the family, TREK1, TREK2 and TRAAK establish the resting potential and modify the duration, frequency and amplitude of action potentials. Despite their apparent importance, the repertoire of regulatory interactions utilized by cells to control their expression is poorly understood. Herein, the contribution of miRNAs in the regulation of their post-transcriptional gene expression has been examined. Using different assays, miR-124 and to a lesser extent miR-128 and miR-183 were found to reduce TREK1 and TREK2 levels through specific binding to their 3'UTRs. In contrast, miR-9 which was predicted to bind to TRAAK 3'UTR, did not alter its expression. Expression of miR-124, miR-128 and miR-183 was found to mirror that of Trek1 and Trek2 mRNAs during brain development. Moreover, application of proinflammatory mediators in dorsal root ganglion (DRG) neurons revealed an inverse correlation between miR-124 and Trek1 and Trek2 mRNA expression. Voltage clamp recordings of TREK2-mediated currents showed that miR-124 reduced the sensitivity of TREK2-expressing cells to non-aversive warmth stimulation. Overall, these findings reveal a significant regulatory mechanism by which TREK1 and TREK2 expression and hence activity are controlled in neurons and uncover new druggable targets for analgesia and neuroprotection.Abbreviations: microRNA: miRNA; UTR: untranslated region; K2p channels: two-pore domain K+channels; DRG: dorsal root ganglion; CNS: central nervous system; FBS: fetal bovine serum; TuD: Tough Decoy; TREK: tandem P-domain weak inward rectifying K+ (TWIK)-related K+ channel 1; TRAAK: TWIK-related arachidonic acid K+.
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Affiliation(s)
- Maria Paschou
- Center for Basic Research, Biomedical Research Foundation, Academy of Athens, Athens, Greece.,Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Larisa Maier
- Department of Anatomy, Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Panagiota Papazafiri
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Tudor Selescu
- Department of Anatomy, Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Skarlatos G Dedos
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Alexandru Babes
- Department of Anatomy, Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Epaminondas Doxakis
- Center for Basic Research, Biomedical Research Foundation, Academy of Athens, Athens, Greece
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Bustos D, Bedoya M, Ramírez D, Concha G, Zúñiga L, Decher N, Hernández-Rodríguez EW, Sepúlveda FV, Martínez L, González W. Elucidating the Structural Basis of the Intracellular pH Sensing Mechanism of TASK-2 K 2P Channels. Int J Mol Sci 2020; 21:ijms21020532. [PMID: 31947679 PMCID: PMC7013731 DOI: 10.3390/ijms21020532] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/25/2019] [Accepted: 01/08/2020] [Indexed: 11/23/2022] Open
Abstract
Two-pore domain potassium (K2P) channels maintain the cell’s background conductance by stabilizing the resting membrane potential. They assemble as dimers possessing four transmembrane helices in each subunit. K2P channels were crystallized in “up” and “down” states. The movements of the pore-lining transmembrane TM4 helix produce the aperture or closure of side fenestrations that connect the lipid membrane with the central cavity. When the TM4 helix is in the up-state, the fenestrations are closed, while they are open in the down-state. It is thought that the fenestration states are related to the activity of K2P channels and the opening of the channels preferentially occurs from the up-state. TASK-2, a member of the TALK subfamily of K2P channels, is opened by intracellular alkalization leading the deprotonation of the K245 residue at the end of the TM4 helix. This charge neutralization of K245 could be sensitive or coupled to the fenestration state. Here, we describe the relationship between the states of the intramembrane fenestrations and K245 residue in TASK-2 channel. By using molecular modeling and simulations, we show that the protonated state of K245 (K245+) favors the open fenestration state and, symmetrically, that the open fenestration state favors the protonated state of the lysine residue. We show that the channel can be completely blocked by Prozac, which is known to induce fenestration opening in TREK-2. K245 protonation and fenestration aperture have an additive effect on the conductance of the channel. The opening of the fenestrations with K245+ increases the entrance of lipids into the selectivity filter, blocking the channel. At the same time, the protonation of K245 introduces electrostatic potential energy barriers to ion entrance. We computed the free energy profiles of ion penetration into the channel in different fenestration and K245 protonation states, to show that the effects of the two transformations are summed up, leading to maximum channel blocking. Estimated rates of ion transport are in qualitative agreement with experimental results and support the hypothesis that the most important barrier for ion transport under K245+ and open fenestration conditions is the entrance of the ions into the channel.
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Affiliation(s)
- Daniel Bustos
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca 3460000, Chile; (D.B.); (M.B.)
- Departamento de Computación e Industrias, Facultad de Ciencias de la Ingeniería, Universidad Católica del Maule, Talca 3460000, Chile
| | - Mauricio Bedoya
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca 3460000, Chile; (D.B.); (M.B.)
| | - David Ramírez
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago 8380453, Chile;
| | - Guierdy Concha
- Centro de Investigaciones Médicas, Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile; (G.C.); (L.Z.)
- Magíster en Gestión de Operaciones, Facultad de Ingeniería (Campus Los Niches), Universidad de Talca, Talca 3460000, Chile
| | - Leandro Zúñiga
- Centro de Investigaciones Médicas, Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile; (G.C.); (L.Z.)
- Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Universidad de Talca, Talca 3460000, Chile
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, D-35037 Marburg, Germany;
| | | | - Francisco V. Sepúlveda
- Centro de Estudios Científicos (CECs), Avenida Arturo Prat 514, Valdivia 5110466, Chile
- Correspondence: (F.V.S.); (L.M.); (W.G.)
| | - Leandro Martínez
- Institute of Chemistry and Center for Computing in Engineering & Science, University of Campinas, Campinas 13083-861 SP, Brazil
- Correspondence: (F.V.S.); (L.M.); (W.G.)
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca 3460000, Chile; (D.B.); (M.B.)
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3460000, Chile
- Correspondence: (F.V.S.); (L.M.); (W.G.)
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Rivas-Ramírez P, Reboreda A, Rueda-Ruzafa L, Herrera-Pérez S, Lamas JA. PIP 2 Mediated Inhibition of TREK Potassium Currents by Bradykinin in Mouse Sympathetic Neurons. Int J Mol Sci 2020; 21:ijms21020389. [PMID: 31936257 PMCID: PMC7014146 DOI: 10.3390/ijms21020389] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 12/17/2022] Open
Abstract
Bradykinin (BK), a hormone inducing pain and inflammation, is known to inhibit potassium M-currents (IM) and to increase the excitability of the superior cervical ganglion (SCG) neurons by activating the Ca2+-calmodulin pathway. M-current is also reduced by muscarinic agonists through the depletion of membrane phosphatidylinositol 4,5-biphosphate (PIP2). Similarly, the activation of muscarinic receptors inhibits the current through two-pore domain potassium channels (K2P) of the “Tandem of pore-domains in a Weakly Inward rectifying K+ channel (TWIK)-related channels” (TREK) subfamily by reducing PIP2 in mouse SCG neurons (mSCG). The aim of this work was to test and characterize the modulation of TREK channels by bradykinin. We used the perforated-patch technique to investigate riluzole (RIL) activated currents in voltage- and current-clamp experiments. RIL is a drug used in the palliative treatment of amyotrophic lateral sclerosis and, in addition to blocking voltage-dependent sodium channels, it also selectively activates the K2P channels of the TREK subfamily. A cell-attached patch-clamp was also used to investigate TREK-2 single channel currents. We report here that BK reduces spike frequency adaptation (SFA), inhibits the riluzole-activated current (IRIL), which flows mainly through TREK-2 channels, by about 45%, and reduces the open probability of identified single TREK-2 channels in cultured mSCG cells. The effect of BK on IRIL was precluded by the bradykinin receptor (B2R) antagonist HOE-140 (d-Arg-[Hyp3, Thi5, d-Tic7, Oic8]BK) but also by diC8PIP2 which prevents PIP2 depletion when phospholipase C (PLC) is activated. On the contrary, antagonizing inositol triphosphate receptors (IP3R) using 2-aminoethoxydiphenylborane (2-APB) or inhibiting protein kinase C (PKC) with bisindolylmaleimide did not affect the inhibition of IRIL by BK. In conclusion, bradykinin inhibits TREK-2 channels through the activation of B2Rs resulting in PIP2 depletion, much like we have demonstrated for muscarinic agonists. This mechanism implies that TREK channels must be relevant for the capture of information about pain and visceral inflammation.
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Wright PD, McCoull D, Walsh Y, Large JM, Hadrys BW, Gaurilcikaite E, Byrom L, Veale EL, Jerman J, Mathie A. Pranlukast is a novel small molecule activator of the two-pore domain potassium channel TREK2. Biochem Biophys Res Commun 2019; 520:35-40. [DOI: 10.1016/j.bbrc.2019.09.093] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 09/21/2019] [Indexed: 11/29/2022]
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Moehring F, Halder P, Seal RP, Stucky CL. Uncovering the Cells and Circuits of Touch in Normal and Pathological Settings. Neuron 2019; 100:349-360. [PMID: 30359601 DOI: 10.1016/j.neuron.2018.10.019] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 01/18/2023]
Abstract
The sense of touch is fundamental as it provides vital, moment-to-moment information about the nature of our physical environment. Primary sensory neurons provide the basis for this sensation in the periphery; however, recent work demonstrates that touch transduction mechanisms also occur upstream of the sensory neurons via non-neuronal cells such as Merkel cells and keratinocytes. Within the spinal cord, deep dorsal horn circuits transmit innocuous touch centrally and also transform touch into pain in the setting of injury. Here non-neuronal cells play a key role in the induction and maintenance of persistent mechanical pain. This review highlights recent advances in our understanding of mechanosensation, including a growing appreciation for the role of non-neuronal cells in both touch and pain.
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Affiliation(s)
- Francie Moehring
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Priyabrata Halder
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Center for the Neural Basis of Cognition, Pittsburgh, PA 15213, USA
| | - Rebecca P Seal
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Center for the Neural Basis of Cognition, Pittsburgh, PA 15213, USA; Pittsburgh Center for Pain Research, Pittsburgh, PA 15213, USA
| | - Cheryl L Stucky
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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