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Zhang H, Fu T, Sun J, Zou S, Qiu S, Zhang J, Su S, Shi C, Li DP, Xu Y. Pharmacological suppression of Nedd4-2 rescues the reduction of Kv11.1 channels in pathological cardiac hypertrophy. Front Pharmacol 2022; 13:942769. [PMID: 36059970 PMCID: PMC9428276 DOI: 10.3389/fphar.2022.942769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/12/2022] [Indexed: 11/13/2022] Open
Abstract
The human ether-á-go-go-related gene (hERG) encodes the pore-forming subunit (Kv11.1), conducting a rapidly delayed rectifier K+ current (IKr). Reduction of IKr in pathological cardiac hypertrophy (pCH) contributes to increased susceptibility to arrhythmias. However, practical approaches to prevent IKr deficiency are lacking. Our study investigated the involvement of ubiquitin ligase Nedd4-2-dependent ubiquitination in IKr reduction and sought an intervening approach in pCH. Angiotensin II (Ang II) induced a pCH phenotype in guinea pig, accompanied by increased incidences of sudden death and higher susceptibility to arrhythmias. Patch-clamp recordings revealed a significant IKr reduction in pCH cardiomyocytes. Kv11.1 protein expression was decreased whereas its mRNA level did not change. In addition, Nedd4-2 protein expression was increased in pCH, accompanied by an enhanced Nedd4-2 and Kv11.1 binding detected by immunoprecipitation analysis. Cardiac-specific overexpression of inactive form of Nedd4-2 shortened the prolonged QT interval, reversed IKr reduction, and decreased susceptibility to arrhythmias. A synthesized peptide containing the PY motif in Kv11.1 C-terminus binding to Nedd4-2 and a cell-penetrating sequence antagonized Nedd4-2-dependent degradation of the channel and increased the surface abundance and function of hERG channel in HEK cells. In addition, in vivo administration of the PY peptide shortened QT interval and action potential duration, and enhanced IKr in pCH. We conclude that Nedd4-2-dependent ubiquitination is critically involved in IKr deficiency in pCH. Pharmacological suppression of Nedd4-2 represents a novel approach for antiarrhythmic therapy in pCH.
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Affiliation(s)
- Hua Zhang
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Tian Fu
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Jinglei Sun
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Sihao Zou
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Suhua Qiu
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Jiali Zhang
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Shi Su
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Chenxia Shi
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - De-Pei Li
- Center for Precision Medicine, Department of Medicine, School of Medicine University of Missouri, Columbia, MO, United States
- *Correspondence: Yanfang Xu, ; De-Pei Li,
| | - Yanfang Xu
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei Province, China
- *Correspondence: Yanfang Xu, ; De-Pei Li,
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Egly CL, Blackwell DJ, Schmeckpeper J, Delisle BP, Weaver CD, Knollmann BC. A High-Throughput Screening Assay to Identify Drugs that Can Treat Long QT Syndrome Caused by Trafficking-Deficient K V11.1 (hERG) Variants. Mol Pharmacol 2022; 101:236-245. [PMID: 35125346 PMCID: PMC9638947 DOI: 10.1124/molpharm.121.000421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 01/01/2022] [Indexed: 11/22/2022] Open
Abstract
Loss-of-function (LOF) variants in the KV11.1 potassium channel cause long QT syndrome (LQTS). Most variants disrupt intracellular channel transport (trafficking) to the cell membrane. Since some channel inhibitors improve trafficking of KV11.1 variants, a high-throughput screening (HTS) assay to detect trafficking enhancement would be valuable to the identification of drug candidates. The thallium (Tl+) flux assay technique, widely used for drug screening, was optimized using human embryonic kidney (HEK-293) cells expressing a trafficking-deficient KV11.1 variant in 384-well plates. Assay quality was assessed using Z prime (Z') scores comparing vehicle to E-4031, a drug that increases KV11.1 membrane trafficking. The optimized assay was validated by immunoblot, electrophysiology experiments, and a pilot drug screen. The combination of: 1) truncating the trafficking-deficient variant KV11.1-G601S (KV11.1-G601S-G965*X) with the addition of 2) KV11.1 channel activator (VU0405601) and 3) cesium (Cs+) to the Tl+ flux assay buffer resulted in an outstanding Z' of 0.83. To validate the optimized trafficking assay, we carried out a pilot screen that identified three drugs (ibutilide, azaperone, and azelastine) that increase KV11.1 trafficking. The new assay exhibited 100% sensitivity and specificity. Immunoblot and voltage-clamp experiments confirmed that all three drugs identified by the new assay improved membrane trafficking of two additional LQTS KV11.1 variants. We report two new ways to increase target-specific activity in trafficking assays-genetic modification and channel activation-that yielded a novel HTS assay for identifying drugs that improve membrane expression of pathogenic KV11.1 variants. SIGNIFICANCE STATEMENT: This manuscript reports the development of a high-throughput assay (thallium flux) to identify drugs that can increase function in KV11.1 variants that are trafficking-deficient. Two key aspects that improved the resolving power of the assay and could be transferable to other ion channel trafficking-related assays include genetic modification and channel activation.
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Affiliation(s)
- Christian L Egly
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee (C.L.E., D.J.B., J.S., B.C.K.); Department of Physiology, University of Kentucky, Lexington, Kentucky (B.P.D.); and Department of Pharmacology, Vanderbilt University, Nashville, Tennessee (C.D.W.)
| | - Daniel J Blackwell
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee (C.L.E., D.J.B., J.S., B.C.K.); Department of Physiology, University of Kentucky, Lexington, Kentucky (B.P.D.); and Department of Pharmacology, Vanderbilt University, Nashville, Tennessee (C.D.W.)
| | - Jeffrey Schmeckpeper
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee (C.L.E., D.J.B., J.S., B.C.K.); Department of Physiology, University of Kentucky, Lexington, Kentucky (B.P.D.); and Department of Pharmacology, Vanderbilt University, Nashville, Tennessee (C.D.W.)
| | - Brian P Delisle
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee (C.L.E., D.J.B., J.S., B.C.K.); Department of Physiology, University of Kentucky, Lexington, Kentucky (B.P.D.); and Department of Pharmacology, Vanderbilt University, Nashville, Tennessee (C.D.W.)
| | - C David Weaver
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee (C.L.E., D.J.B., J.S., B.C.K.); Department of Physiology, University of Kentucky, Lexington, Kentucky (B.P.D.); and Department of Pharmacology, Vanderbilt University, Nashville, Tennessee (C.D.W.)
| | - Björn C Knollmann
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee (C.L.E., D.J.B., J.S., B.C.K.); Department of Physiology, University of Kentucky, Lexington, Kentucky (B.P.D.); and Department of Pharmacology, Vanderbilt University, Nashville, Tennessee (C.D.W.)
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3
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Dave N, Cetiner U, Arroyo D, Fonbuena J, Tiwari M, Barrera P, Lander N, Anishkin A, Sukharev S, Jimenez V. A novel mechanosensitive channel controls osmoregulation, differentiation, and infectivity in Trypanosoma cruzi. eLife 2021; 10:67449. [PMID: 34212856 PMCID: PMC8282336 DOI: 10.7554/elife.67449] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/01/2021] [Indexed: 12/19/2022] Open
Abstract
The causative agent of Chagas disease undergoes drastic morphological and biochemical modifications as it passes between hosts and transitions from extracellular to intracellular stages. The osmotic and mechanical aspects of these cellular transformations are not understood. Here we identify and characterize a novel mechanosensitive channel in Trypanosoma cruzi (TcMscS) belonging to the superfamily of small-conductance mechanosensitive channels (MscS). TcMscS is activated by membrane tension and forms a large pore permeable to anions, cations, and small osmolytes. The channel changes its location from the contractile vacuole complex in epimastigotes to the plasma membrane as the parasites develop into intracellular amastigotes. TcMscS knockout parasites show significant fitness defects, including increased cell volume, calcium dysregulation, impaired differentiation, and a dramatic decrease in infectivity. Our work provides mechanistic insights into components supporting pathogen adaptation inside the host, thus opening the exploration of mechanosensation as a prerequisite for protozoan infectivity.
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Affiliation(s)
- Noopur Dave
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
| | - Ugur Cetiner
- Department of Biology, University of Maryland, College Park, United States
| | - Daniel Arroyo
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
| | - Joshua Fonbuena
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
| | - Megna Tiwari
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
| | - Patricia Barrera
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Noelia Lander
- Department of Biological Sciences, University of Cincinnati, Cincinnati, United States
| | - Andriy Anishkin
- Department of Biology, University of Maryland, College Park, United States
| | - Sergei Sukharev
- Department of Biology, University of Maryland, College Park, United States
| | - Veronica Jimenez
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
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Xu Parks X, Qudsi H, Braun C, Lopes CMB. The auxiliary subunit KCNE1 regulates KCNQ1 channel response to sustained calcium-dependent PKC activation. PLoS One 2020; 15:e0237591. [PMID: 32833978 PMCID: PMC7446858 DOI: 10.1371/journal.pone.0237591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/29/2020] [Indexed: 11/18/2022] Open
Abstract
The slow cardiac delayed rectifier current (IKs) is formed by KCNQ1 and KCNE1 subunits and is one of the major repolarizing currents in the heart. Decrease of IKs currents either due to inherited mutations or pathological remodeling is associated with increased risk for cardiac arrhythmias and sudden death. Ca2+-dependent PKC isoforms (cPKC) are chronically activated in heart disease and diabetes. Recently, we found that sustained stimulation of the calcium-dependent PKCβII isoform leads to decrease in KCNQ1 subunit membrane localization and KCNQ1/KCNE1 channel activity, although the role of KCNE1 in this regulation was not explored. Here, we show that the auxiliary KCNE1 subunit expression is necessary for channel internalization. A mutation in a KCNE1 phosphorylation site (KCNE1(S102A)) abolished channel internalization in both heterologous expression systems and cardiomyocytes. Altogether, our results suggest that KCNE1(S102) phosphorylation by PKCβII leads to KCNQ1/KCNE1 channel internalization in response to sustained PKC stimulus, while leaving KCNQ1 homomeric channels in the membrane. This preferential internalization is expected to have strong impact on cardiac repolarization. Our results suggest that KCNE1(S102) is an important anti-arrhythmic drug target to prevent IKs pathological remodeling leading to cardiac arrhythmias.
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Affiliation(s)
- Xiaorong Xu Parks
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States of America
| | - Haani Qudsi
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States of America
| | - Chen Braun
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States of America
| | - Coeli M. B. Lopes
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States of America
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van der Horst J, Greenwood IA, Jepps TA. Cyclic AMP-Dependent Regulation of Kv7 Voltage-Gated Potassium Channels. Front Physiol 2020; 11:727. [PMID: 32695022 PMCID: PMC7338754 DOI: 10.3389/fphys.2020.00727] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/04/2020] [Indexed: 01/08/2023] Open
Abstract
Voltage-gated Kv7 potassium channels, encoded by KCNQ genes, have major physiological impacts cardiac myocytes, neurons, epithelial cells, and smooth muscle cells. Cyclic adenosine monophosphate (cAMP), a well-known intracellular secondary messenger, can activate numerous downstream effector proteins, generating downstream signaling pathways that regulate many functions in cells. A role for cAMP in ion channel regulation has been established, and recent findings show that cAMP signaling plays a role in Kv7 channel regulation. Although cAMP signaling is recognized to regulate Kv7 channels, the precise molecular mechanism behind the cAMP-dependent regulation of Kv7 channels is complex. This review will summarize recent research findings that support the mechanisms of cAMP-dependent regulation of Kv7 channels.
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Affiliation(s)
- Jennifer van der Horst
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Iain A Greenwood
- Molecular and Clinical Sciences Institute, St. George's University of London, London, United Kingdom
| | - Thomas A Jepps
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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Andersen MN, Skibsbye L, Saljic A, Larsen MZ, Rasmussen HB, Jespersen T. Regulation of Kv1.4 potassium channels by PKC and AMPK kinases. Channels (Austin) 2017; 12:34-44. [PMID: 29168928 PMCID: PMC5972802 DOI: 10.1080/19336950.2017.1405196] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Over the last years extensive kinase-mediated regulation of a number of voltage-gated potassium (Kv) channels important in cardiac electrophysiology has been reported. This includes regulation of Kv1.5, Kv7.1 and Kv11.1 cell surface expression, where the kinase-mediated regulation appears to center around the ubiquitin ligase Nedd4-2. In the present study we examined whether Kv1.4, constituting the cardiac Ito,s current, is subject to similar regulation. In the epithelial Madin-Darby Canine Kidney (MDCK) cell line, which constitutes a highly reproducible model system for addressing membrane targeting, we find, by confocal microscopy, that Kv1.4 cell surface expression is downregulated by activation of protein kinase C (PKC) and AMP-activated protein kinase (AMPK). In contrast, manipulating the activities of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and serum and glucocorticoid-regulated kinase 1 (SGK1) were without effect on channel localization. The PKC and AMPK-mediated downregulation of Kv1.4 membrane surface localization was confirmed by two-electrode voltage clamp in Xenopus laevis oocytes, where pharmacological activation of PKC and AMPK reduced Kv1.4 current levels. We further demonstrate that unlike related Kv channels, Kv1.4 current levels in Xenopus laevis oocytes are not reduced by co-expression of Nedd4-2, or the related Nedd4-1 ubiquitin ligase. In conclusion, we demonstrate that the surface expression of Kv1.4 is downregulated by the two kinases AMPK and PKC, but is unaffected by PI3K-SGK1 signaling, as well as Nedd4-1/Nedd4-2 activity. In the light of previous reports, our results demonstrate an impressive heterogeneity in the molecular pathways controlling the surface expression of highly related potassium channel subunits.
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Affiliation(s)
- Martin Nybo Andersen
- a Dept. of Biomedical Sciences , Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Lasse Skibsbye
- a Dept. of Biomedical Sciences , Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Arnela Saljic
- a Dept. of Biomedical Sciences , Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Martin Zahle Larsen
- a Dept. of Biomedical Sciences , Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Hanne Borger Rasmussen
- a Dept. of Biomedical Sciences , Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Thomas Jespersen
- a Dept. of Biomedical Sciences , Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
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7
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Piccini I, Fehrmann E, Frank S, Müller FU, Greber B, Seebohm G. Adrenergic Stress Protection of Human iPS Cell-Derived Cardiomyocytes by Fast K v7.1 Recycling. Front Physiol 2017; 8:705. [PMID: 28959214 PMCID: PMC5603700 DOI: 10.3389/fphys.2017.00705] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 08/31/2017] [Indexed: 01/09/2023] Open
Abstract
The fight-or-flight response (FFR), a physiological acute stress reaction, involves positive chronotropic and inotropic effects on heart muscle cells mediated through β-adrenoceptor activation. Increased systolic calcium is required to enable stronger heart contractions whereas elevated potassium currents are to limit the duration of the action potentials and prevent arrhythmia. The latter effect is accomplished by an increased functional activity of the Kv7.1 channel encoded by KCNQ1. Current knowledge, however, does not sufficiently explain the full extent of rapid Kv7.1 activation and may hence be incomplete. Using inducible genetic KCNQ1 complementation in KCNQ1-deficient human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), we here reinvestigate the functional role of Kv7.1 in adapting human CMs to adrenergic stress. Under baseline conditions, Kv7.1 was barely detectable at the plasma membrane of hiPSC-CMs, yet it fully protected these from adrenergic stress-induced beat-to-beat variability of repolarization and torsade des pointes-like arrhythmia. Furthermore, isoprenaline treatment increased field potential durations specifically in KCNQ1-deficient CMs to cause these adverse macroscopic effects. Mechanistically, we find that the protective action by Kv7.1 resides in a rapid translocation of channel proteins from intracellular stores to the plasma membrane, induced by adrenergic signaling. Gene silencing experiments targeting RAB GTPases, mediators of intracellular vesicle trafficking, showed that fast Kv7.1 recycling under acute stress conditions is RAB4A-dependent.Our data reveal a key mechanism underlying the rapid adaptation of human cardiomyocytes to adrenergic stress. These findings moreover aid to the understanding of disease pathology in long QT syndrome and bear important implications for safety pharmacological screening.
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Affiliation(s)
- Ilaria Piccini
- Department of Cardiovascular Medicine, Institute of Genetics of Heart Diseases, University of Münster Medical SchoolMünster, Germany.,Human Stem Cell Pluripotency Laboratory, Max Planck Institute for Molecular BiomedicineMünster, Germany
| | - Edda Fehrmann
- Institute of Pharmacology and Toxicology, University of MünsterMünster, Germany
| | - Stefan Frank
- Human Stem Cell Pluripotency Laboratory, Max Planck Institute for Molecular BiomedicineMünster, Germany.,Chemical Genomics Centre of the Max Planck SocietyDortmund, Germany
| | - Frank U Müller
- Institute of Pharmacology and Toxicology, University of MünsterMünster, Germany
| | - Boris Greber
- Human Stem Cell Pluripotency Laboratory, Max Planck Institute for Molecular BiomedicineMünster, Germany.,Chemical Genomics Centre of the Max Planck SocietyDortmund, Germany
| | - Guiscard Seebohm
- Department of Cardiovascular Medicine, Institute of Genetics of Heart Diseases, University of Münster Medical SchoolMünster, Germany
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