1
|
Li T, Marashly Q, Kim JA, Li N, Chelu MG. Cardiac conduction diseases: understanding the molecular mechanisms to uncover targets for future treatments. Expert Opin Ther Targets 2024; 28:385-400. [PMID: 38700451 DOI: 10.1080/14728222.2024.2351501] [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: 11/18/2023] [Accepted: 05/01/2024] [Indexed: 05/05/2024]
Abstract
INTRODUCTION The cardiac conduction system (CCS) is crucial for maintaining adequate cardiac frequency at rest and modulation during exercise. Furthermore, the atrioventricular node and His-Purkinje system are essential for maintaining atrioventricular and interventricular synchrony and consequently maintaining an adequate cardiac output. AREAS COVERED In this review article, we examine the anatomy, physiology, and pathophysiology of the CCS. We then discuss in detail the most common genetic mutations and the molecular mechanisms of cardiac conduction disease (CCD) and provide our perspectives on future research and therapeutic opportunities in this field. EXPERT OPINION Significant advancement has been made in understanding the molecular mechanisms of CCD, including the recognition of the heterogeneous signaling at the subcellular levels of sinoatrial node, the involvement of inflammatory and autoimmune mechanisms, and the potential impact of epigenetic regulations on CCD. However, the current treatment of CCD manifested as bradycardia still relies primarily on cardiovascular implantable electronic devices (CIEDs). On the other hand, an If specific inhibitor was developed to treat inappropriate sinus tachycardia and sinus tachycardia in heart failure patients with reduced ejection fraction. More work is needed to translate current knowledge into pharmacologic or genetic interventions for the management of CCDs.
Collapse
Affiliation(s)
- Tingting Li
- Department of Medicine (Section of Cardiovascular Research), Baylor College of Medicine, Houston, TX, USA
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Qussay Marashly
- Department of Cardiology, Montefiore Medical Center, New York, NY, USA
| | - Jitae A Kim
- Division of CardiovasculMedicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Na Li
- Department of Medicine (Section of Cardiovascular Research), Baylor College of Medicine, Houston, TX, USA
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Mihail G Chelu
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
- Department of Medicine (Division of Cardiology), Baylor College of Medicine, Houston, TX, USA
- Division of Cardiology, Baylor St. Luke's Medical Center, Houston, TX, USA
- Division of Cardiology, Texas Heart Institute, Houston, TX, USA
| |
Collapse
|
2
|
Fan W, Sun X, Yang C, Wan J, Luo H, Liao B. Pacemaker activity and ion channels in the sinoatrial node cells: MicroRNAs and arrhythmia. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 177:151-167. [PMID: 36450332 DOI: 10.1016/j.pbiomolbio.2022.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/13/2022] [Accepted: 11/25/2022] [Indexed: 11/29/2022]
Abstract
The primary pacemaking activity of the heart is determined by a spontaneous action potential (AP) within sinoatrial node (SAN) cells. This unique AP generation relies on two mechanisms: membrane clocks and calcium clocks. Nonhomologous arrhythmias are caused by several functional and structural changes in the myocardium. MicroRNAs (miRNAs) are essential regulators of gene expression in cardiomyocytes. These miRNAs play a vital role in regulating the stability of cardiac conduction and in the remodeling process that leads to arrhythmias. Although it remains unclear how miRNAs regulate the expression and function of ion channels in the heart, these regulatory mechanisms may support the development of emerging therapies. This study discusses the spread and generation of AP in the SAN as well as the regulation of miRNAs and individual ion channels. Arrhythmogenicity studies on ion channels will provide a research basis for miRNA modulation as a new therapeutic target.
Collapse
Affiliation(s)
- Wei Fan
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China
| | - Xuemei Sun
- Department of Pharmacy, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China
| | - Chao Yang
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China
| | - Juyi Wan
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China.
| | - Hongli Luo
- Department of Pharmacy, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China.
| | - Bin Liao
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China.
| |
Collapse
|
3
|
Wang H, Wu T, Huang Z, Huang J, Geng Z, Cui B, Yan Y, Zhang Y, Wang Y. Channel HCN4 mutation R666Q associated with sporadic arrhythmia decreases channel electrophysiological function and increases protein degradation. J Biol Chem 2022; 298:102599. [PMID: 36244448 PMCID: PMC9663530 DOI: 10.1016/j.jbc.2022.102599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 10/06/2022] [Accepted: 10/10/2022] [Indexed: 11/07/2022] Open
Abstract
Mutations in the hyperpolarization-activated nucleotide-gated channel 4 (HCN4) are known to be associated with arrhythmias in which QT prolongation (delayed ventricular repolarization) is rare. Here, we identified a HCN4 mutation, HCN4-R666Q, in two sporadic arrhythmia patients with sinus bradycardia, QT prolongation, and short bursts of ventricular tachycardia. To determine the functional effect of the mutation, we conducted clinical, genetic, and functional analyses using whole-cell voltage-clamp, qPCR, Western blot, confocal microscopy, and co-immunoprecipitation. The mean current density of HEK293T cells transfected with HCN4-R666Q was lower in 24 to 36 h after transfection and was much lower in 36 to 48 h after transfection relative to cells transfected with wildtype HCN4. Additionally, we determined that the HCN4-R666Q mutant was more susceptible to ubiquitin-proteasome system–mediated protein degradation than wildtype HCN4. This decreased current density for HCN4-R666Q could be partly rescued by treatment with a proteasome inhibitor. Therefore, we conclude that HCN4-R666Q had an effect on HCN4 function in two aspects, including decreasing the current density of the channel as a biophysical effect and weakening its protein stability. Our findings provide new insights into the pathogenesis of the HCN4-R666Q mutation.
Collapse
|
4
|
Regulation of sinus node pacemaking and atrioventricular node conduction by HCN channels in health and disease. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 166:61-85. [PMID: 34197836 DOI: 10.1016/j.pbiomolbio.2021.06.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 06/02/2021] [Accepted: 06/14/2021] [Indexed: 12/19/2022]
Abstract
The funny current, If, was first recorded in the heart 40 or more years ago by Dario DiFrancesco and others. Since then, we have learnt that If plays an important role in pacemaking in the sinus node, the innate pacemaker of the heart, and more recently evidence has accumulated to show that If may play an important role in action potential conduction through the atrioventricular (AV) node. Evidence has also accumulated to show that regulation of the transcription and translation of the underlying Hcn genes plays an important role in the regulation of sinus node pacemaking and AV node conduction under normal physiological conditions - in athletes, during the circadian rhythm, in pregnancy, and during postnatal development - as well as pathological states - ageing, heart failure, pulmonary hypertension, diabetes and atrial fibrillation. There may be yet more pathological conditions involving changes in the expression of the Hcn genes. Here, we review the role of If and the underlying HCN channels in physiological and pathological changes of the sinus and AV nodes and we begin to explore the signalling pathways (microRNAs, transcription factors, GIRK4, the autonomic nervous system and inflammation) involved in this regulation. This review is dedicated to Dario DiFrancesco on his retirement.
Collapse
|
5
|
Mesirca P, Nakao S, Nissen SD, Forte G, Anderson C, Trussell T, Li J, Cox C, Zi M, Logantha S, Yaar S, Cartensen H, Bidaud I, Stuart L, Soattin L, Morris GM, da Costa Martins PA, Cartwright EJ, Oceandy D, Mangoni ME, Jespersen T, Buhl R, Dobrzynski H, Boyett MR, D'Souza A. Intrinsic Electrical Remodeling Underlies Atrioventricular Block in Athletes. Circ Res 2021; 129:e1-e20. [PMID: 33849278 DOI: 10.1161/circresaha.119.316386] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- Pietro Mesirca
- IGF, Université de Montpellier, CNRS, INSERM, France (P.M., I.B., M.E.M.)
| | - Shu Nakao
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
- Department of Biomedical Sciences, Ritsumeikan University, Japan (S.N.)
| | - Sarah Dalgas Nissen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences (S.D.N., H.C., R.B.), University of Copenhagen, Denmark
| | - Gabriella Forte
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Cali Anderson
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Tariq Trussell
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Jue Li
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Charlotte Cox
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Min Zi
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Sunil Logantha
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
- Liverpool Centre for Cardiovascular Sciences, University of Liverpool, United Kingdom (S.L.)
| | - Sana Yaar
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Helena Cartensen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences (S.D.N., H.C., R.B.), University of Copenhagen, Denmark
| | - Isabelle Bidaud
- IGF, Université de Montpellier, CNRS, INSERM, France (P.M., I.B., M.E.M.)
| | - Luke Stuart
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | | | - Gwilym M Morris
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | | | - Elizabeth J Cartwright
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Delvac Oceandy
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Matteo E Mangoni
- IGF, Université de Montpellier, CNRS, INSERM, France (P.M., I.B., M.E.M.)
| | - Thomas Jespersen
- Department of Biomedical Sciences (T.J., M.R.B.), University of Copenhagen, Denmark
| | - Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences (S.D.N., H.C., R.B.), University of Copenhagen, Denmark
| | - Halina Dobrzynski
- Department of Anatomy, Jagiellonian University Medical College, Poland (H.D.)
| | - Mark R Boyett
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
- Department of Biomedical Sciences (T.J., M.R.B.), University of Copenhagen, Denmark
| | - Alicia D'Souza
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| |
Collapse
|
6
|
Reevaluating the Mutation Classification in Genetic Studies of Bradycardia Using ACMG/AMP Variant Classification Framework. Int J Genomics 2020; 2020:2415850. [PMID: 32211440 PMCID: PMC7061116 DOI: 10.1155/2020/2415850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 02/08/2020] [Indexed: 11/17/2022] Open
Abstract
PURPOSE Next-generation sequencing (NGS) has become more accessible, leading to an increasing number of genetic studies of familial bradycardia being reported. However, most of the variants lack full evaluation. The relationship between genetic factors and bradycardia should be summarized and reevaluated. METHODS We summarized genetic studies published in the PubMed database from 2008/1/1 to 2019/9/1 and used the ACMG/AMP classification framework to analyze related sequence variants. RESULTS We identified 88 articles, 99 sequence variants, and 34 genes after searching the PubMed database and classified ABCC9, ACTN2, CACNA1C, DES, HCN4, KCNQ1, KCNH2, LMNA, MECP2, LAMP2, NPPA, SCN5A, and TRPM4 as high-priority genes causing familial bradycardia. Most mutated genes have been reported as having multiple clinical manifestations. CONCLUSIONS For patients with familial CCD, 13 high-priority genes are recommended for evaluation. For genetic studies, variants should be carefully evaluated using the ACMG/AMP variant classification framework before publication.
Collapse
|
7
|
Lussier Y, Fürst O, Fortea E, Leclerc M, Priolo D, Moeller L, Bichet DG, Blunck R, D'Avanzo N. Disease-linked mutations alter the stoichiometries of HCN-KCNE2 complexes. Sci Rep 2019; 9:9113. [PMID: 31235733 PMCID: PMC6591248 DOI: 10.1038/s41598-019-45592-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 06/11/2019] [Indexed: 12/21/2022] Open
Abstract
The four hyperpolarization-activated cylic-nucleotide gated (HCN) channel isoforms and their auxiliary subunit KCNE2 are important in the regulation of peripheral and central neuronal firing and the heartbeat. Disruption of their normal function has been implicated in cardiac arrhythmias, peripheral pain, and epilepsy. However, molecular details of the HCN-KCNE2 complexes are unknown. Using single-molecule subunit counting, we determined that the number of KCNE2 subunits in complex with the pore-forming subunits of human HCN channels differs with each HCN isoform and is dynamic with respect to concentration. These interactions can be altered by KCNE2 gene-variants with functional implications. The results provide an additional consideration necessary to understand heart rhythm, pain, and epileptic disorders.
Collapse
Affiliation(s)
- Yoann Lussier
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Oliver Fürst
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Eva Fortea
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Marc Leclerc
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Dimitri Priolo
- Department of Physics, Université de Montréal, Montréal, Canada
| | - Lena Moeller
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Canada
| | - Daniel G Bichet
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Rikard Blunck
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada.,Department of Physics, Université de Montréal, Montréal, Canada
| | - Nazzareno D'Avanzo
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada. .,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Canada.
| |
Collapse
|
8
|
Servatius H, Porro A, Pless SA, Schaller A, Asatryan B, Tanner H, de Marchi SF, Roten L, Seiler J, Haeberlin A, Baldinger SH, Noti F, Lam A, Fuhrer J, Moroni A, Medeiros-Domingo A. Phenotypic Spectrum of HCN4 Mutations: A Clinical Case. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2019; 11:e002033. [PMID: 29440115 DOI: 10.1161/circgen.117.002033] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Helge Servatius
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Alessandro Porro
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Stephan A Pless
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - André Schaller
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Babken Asatryan
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Hildegard Tanner
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Stefano F de Marchi
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Laurent Roten
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Jens Seiler
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Andreas Haeberlin
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Samuel H Baldinger
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Fabian Noti
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Anna Lam
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Juerg Fuhrer
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Anna Moroni
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.)
| | - Argelia Medeiros-Domingo
- From the Department of Cardiology (H.S., B.A., H.T., S.F.d.M., L.R., J.S., A.H., S.H.B., F.N., A.L., J.F., A.M.-D.) and Division of Human Genetics, Department of Pediatrics (A.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland; Artificial Organ Center for Biomedical Engineering Research, University of Bern, Switzerland (A.H.); Department of Biosciences, CNR IBF-Milano, Università degli Studi di Milano, Italy (A.P., A.M.); and Department of Drug Design and Pharmacology, Center for Biopharmaceuticals, University of Copenhagen, Denmark (S.A.P.).
| |
Collapse
|
9
|
Tanguay J, Callahan KM, D'Avanzo N. Characterization of drug binding within the HCN1 channel pore. Sci Rep 2019; 9:465. [PMID: 30679654 PMCID: PMC6345760 DOI: 10.1038/s41598-018-37116-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/29/2018] [Indexed: 11/09/2022] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels mediate rhythmic electrical activity of cardiac pacemaker cells, and in neurons play important roles in setting resting membrane potentials, dendritic integration, neuronal pacemaking, and establishing action potential threshold. Block of HCN channels slows the heart rate and is currently used to treat angina. However, HCN block also provides a promising approach to the treatment of neuronal disorders including epilepsy and neuropathic pain. While several molecules that block HCN channels have been identified, including clonidine and its derivative alinidine, lidocaine, mepivacaine, bupivacaine, ZD7288, ivabradine, zatebradine, and cilobradine, their low affinity and lack of specificity prevents wide-spread use. Different studies suggest that the binding sites of these inhibitors are located in the inner vestibule of HCN channels, but the molecular details of their binding remain unknown. We used computational docking experiments to assess the binding sites and mode of binding of these inhibitors against the recently solved atomic structure of human HCN1 channels, and a homology model of the open pore derived from a closely related CNG channel. We identify a possible hydrophobic groove in the pore cavity that plays an important role in conformationally restricting the location and orientation of drugs bound to the inner vestibule. Our results also help explain the molecular basis of the low-affinity binding of these inhibitors, paving the way for the development of higher affinity molecules.
Collapse
Affiliation(s)
- Jérémie Tanguay
- Department of Physics, Université de Montréal, Montréal, Canada
| | - Karen M Callahan
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Nazzareno D'Avanzo
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada.
| |
Collapse
|
10
|
Dong J, Subbotina E, Williams N, Sampson BA, Tang Y, Coetzee WA. Functional reclassification of variants of uncertain significance in the HCN4 gene identified in sudden unexpected death. Pacing Clin Electrophysiol 2019; 42:275-282. [PMID: 30578647 DOI: 10.1111/pace.13593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/07/2018] [Accepted: 12/18/2018] [Indexed: 11/28/2022]
Abstract
The HCN4 gene encodes a subunit of the hyperpolarization-activated cyclic nucleotide-gated channel, type 4 that is essential for the proper generation of pacemaker potentials in the sinoatrial node. The HCN4 gene is often present in targeted genetic testing panels for various cardiac conduction system disorders and there are several reports of HCN4 variants associated with conduction disorders. Here, we report the in vitro functional characterization of four rare variants of uncertain significance (VUS) in HCN4, identified through testing a cohort of 296 sudden unexpected natural deaths. The variants are all missense alterations, leading to single amino acid changes: p.E66Q in the N-terminus, p.D546N in the C-linker domain, and both p.S935Y and p.R1044Q in the C-terminus distal to the CNBD. We also identified a likely benign variant, p. P1063T, which has a high minor allele frequency in the gnomAD, which is utilized here as a negative control. Three of the HCN4 VUS (p.E66Q, p.S935Y, and p.R1044Q) had electrophysiological characteristics similar to the wild-type channel, suggesting that these variants are benign. In contrast, the p.D546N variant in the C-linker domain exhibited a larger current density, slower activation, and was unresponsive to cyclic adenosine monophosphate (cAMP) compared to wild-type. With functional assays, we reclassified three rare HCN4 VUS to likely benign variants, eliminating the necessity for costly and time-consuming further study. Our studies also provide a new lead to investigate how a VUS located in the C-linker connecting the pore to the cAMP binding domain may affect the channel open state probability and cAMP response.
Collapse
Affiliation(s)
- Jingyun Dong
- Departments of Pediatrics, NYU School of Medicine, New York, New York
| | | | - Nori Williams
- Molecular Genetics Laboratory, New York City Office of Chief Medical Examiner, New York, New York
| | - Barbara A Sampson
- Department of Forensic Pathology, New York City Office of Chief Medical Examiner, New York, New York
| | - Yingying Tang
- Molecular Genetics Laboratory, New York City Office of Chief Medical Examiner, New York, New York
| | - William A Coetzee
- Departments of Pediatrics, NYU School of Medicine, New York, New York.,Departments of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York.,Departments of Physiology and Neurosciences, NYU School of Medicine, New York, New York
| |
Collapse
|
11
|
|
12
|
Hategan L, Csányi B, Ördög B, Kákonyi K, Tringer A, Kiss O, Orosz A, Sághy L, Nagy I, Hegedűs Z, Rudas L, Széll M, Varró A, Forster T, Sepp R. A novel ‘splice site’ HCN4 Gene mutation, c.1737 + 1 G > T, causes familial bradycardia, reduced heart rate response, impaired chronotropic competence and increased short-term heart rate variability. Int J Cardiol 2017; 241:364-372. [DOI: 10.1016/j.ijcard.2017.04.058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/22/2017] [Accepted: 04/19/2017] [Indexed: 11/26/2022]
|
13
|
Raucci FJ, Shoemaker MB, Knollmann BC. Clinical phenotype of HCN4-related sick sinus syndrome. Heart Rhythm 2017; 14:725-726. [DOI: 10.1016/j.hrthm.2017.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Indexed: 10/20/2022]
|
14
|
Tse G, Liu T, Li KHC, Laxton V, Wong AOT, Chan YWF, Keung W, Chan CW, Li RA. Tachycardia-bradycardia syndrome: Electrophysiological mechanisms and future therapeutic approaches (Review). Int J Mol Med 2017; 39:519-526. [PMID: 28204831 PMCID: PMC5360359 DOI: 10.3892/ijmm.2017.2877] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/09/2017] [Indexed: 02/07/2023] Open
Abstract
Sick sinus syndrome (SSS) encompasses a group of disorders whereby the heart is unable to perform its pacemaker function, due to genetic and acquired causes. Tachycardia‑bradycardia syndrome (TBS) is a complication of SSS characterized by alternating tachycardia and bradycardia. Techniques such as genetic screening and molecular diagnostics together with the use of pre-clinical models have elucidated the electrophysiological mechanisms of this condition. Dysfunction of ion channels responsible for initiation or conduction of cardiac action potentials may underlie both bradycardia and tachycardia; bradycardia can also increase the risk of tachycardia, and vice versa. The mainstay treatment option for SSS is pacemaker implantation, an effective approach, but has disadvantages such as infection, limited battery life, dislodgement of leads and catheters to be permanently implanted in situ. Alternatives to electronic pacemakers are gene‑based bio‑artificial sinoatrial node and cell‑based bio‑artificial pacemakers, which are promising techniques whose long-term safety and efficacy need to be established. The aim of this article is to review the different ion channels involved in TBS, examine the three‑way relationship between ion channel dysfunction, tachycardia and bradycardia in TBS and to consider its current and future therapies.
Collapse
Affiliation(s)
- Gary Tse
- Department of Medicine and Therapeutics, Chinese University of Hong Kong
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, SAR
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, P.R. China
| | | | - Victoria Laxton
- Intensive Care Department, Royal Brompton and Harefield NHS Foundation Trust, London SW3 6NP, UK
| | - Andy On-Tik Wong
- Stem Cell and Regenerative Medicine Consortium, Li Ka Shing Faculty of Medicine, The University of Hong Kong
- Li Dak-Sum Research Centre-HKU-Karolinska Institutet Collaboration on Regenerative Medicine, University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Yin Wah Fiona Chan
- School of Biological Sciences, University of Cambridge, Cambridge CB2 1AG, UK
| | - Wendy Keung
- Stem Cell and Regenerative Medicine Consortium, Li Ka Shing Faculty of Medicine, The University of Hong Kong
- Li Dak-Sum Research Centre-HKU-Karolinska Institutet Collaboration on Regenerative Medicine, University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Camie W.Y. Chan
- Stem Cell and Regenerative Medicine Consortium, Li Ka Shing Faculty of Medicine, The University of Hong Kong
| | - Ronald A. Li
- Li Dak-Sum Research Centre-HKU-Karolinska Institutet Collaboration on Regenerative Medicine, University of Hong Kong, Hong Kong, SAR, P.R. China
- Ming Wai Lau Centre for Reparative Medicine, Karolinska Institutet, Hong Kong, SAR, P.R. China
| |
Collapse
|
15
|
Stallmeyer B, Kuß J, Kotthoff S, Zumhagen S, Vowinkel K, Rinné S, Matschke LA, Friedrich C, Schulze-Bahr E, Rust S, Seebohm G, Decher N, Schulze-Bahr E. A Mutation in the G-Protein Gene GNB2 Causes Familial Sinus Node and Atrioventricular Conduction Dysfunction. Circ Res 2017; 120:e33-e44. [PMID: 28219978 DOI: 10.1161/circresaha.116.310112] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/16/2017] [Accepted: 02/20/2017] [Indexed: 11/16/2022]
Abstract
RATIONALE Familial sinus node and atrioventricular conduction dysfunction is a rare disorder that leads to paroxysmal dizziness, fatigue, and syncope because of a temporarily or permanently reduced heart rate. To date, only a few genes for familial sinus and atrioventricular conduction dysfunction are known, and the majority of cases remain pathogenically unresolved. OBJECTIVE We aim to identify the disease gene in a large 3-generation family (n=25) with autosomal dominant sinus node dysfunction (SND) and atrioventricular block (AVB) and to characterize the mutation-related pathomechanisms in familial SND+AVB. METHODS AND RESULTS Genome-wide linkage analysis mapped the SND+AVB disease locus to chromosome 7q21.1-q31.1 (2-point logarithm of the odds score: 4.64; θ=0); in this region, targeted exome sequencing identified a novel heterozygous mutation (p.Arg52Leu) in the GNB2 gene that strictly cosegregated with the SND+AVB phenotype. GNB2 encodes the β2 subunit (Gβ2) of the heterotrimeric G-protein complex that is being released from G-protein-coupled receptors on vagal stimulation. In 2 heterologous expression systems (HEK-293T cells and Xenopus laevis oocytes), an enhanced activation of the G-protein-activated K+ channel (GIRK; Kir3.1/Kir3.4) was shown when mutant Gβ2 was coexpressed with Gγ2; this was in contrast to coexpression of mutant Gβ2-Gγ2 with other cardiac ion channels (HCN4, HCN2, and Cav1.2). Molecular dynamics simulations suggested a reduced binding property of mutant Gβ2 to cardiac GIRK channels when compared with native Gβ2. CONCLUSIONS A GNB2 gene mutation is associated with familial SND+AVB and leads to a sustained activation of cardiac GIRK channels, which is likely to hyperpolarize the myocellular membrane potential and thus reduces their spontaneous activity. Our findings describe for the first time a role of a mutant G-protein in the nonsyndromic pacemaker disease because of GIRK channel activation.
Collapse
Affiliation(s)
- Birgit Stallmeyer
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Johanna Kuß
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Stefan Kotthoff
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Sven Zumhagen
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Kirsty Vowinkel
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Susanne Rinné
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Lina A Matschke
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Corinna Friedrich
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Ellen Schulze-Bahr
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Stephan Rust
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Guiscard Seebohm
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Niels Decher
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Eric Schulze-Bahr
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.).
| |
Collapse
|
16
|
Vedantham V, Scheinman MM. Familial inappropriate sinus tachycardia: a new chapter in the story of HCN4 channelopathies. Eur Heart J 2017; 38:289-291. [PMID: 28182236 DOI: 10.1093/eurheartj/ehv635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Vasanth Vedantham
- Department of Medicine, Cardiac Electrophysiology Section, University of California-San Francisco, San Francisco, CA, USA
| | - Melvin M Scheinman
- Department of Medicine, Cardiac Electrophysiology Section, University of California-San Francisco, San Francisco, CA, USA
| |
Collapse
|
17
|
Biel S, Aquila M, Hertel B, Berthold A, Neumann T, DiFrancesco D, Moroni A, Thiel G, Kauferstein S. Mutation in S6 domain of HCN4 channel in patient with suspected Brugada syndrome modifies channel function. Pflugers Arch 2016; 468:1663-71. [PMID: 27553229 DOI: 10.1007/s00424-016-1870-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 07/21/2016] [Accepted: 08/11/2016] [Indexed: 12/17/2022]
Abstract
Diseases such as the sick sinus and the Brugada syndrome are cardiac abnormalities, which can be caused by a number of genetic aberrances. Among them are mutations in HCN4, a gene, which encodes the hyperpolarization-activated, cyclic nucleotide-gated ion channel 4; this pacemaker channel is responsible for the spontaneous activity of the sinoatrial node. The present genetic screening of patients with suspected or diagnosed Brugada or sick sinus syndrome identified in 1 out of 62 samples the novel mutation V492F. It is located in a highly conserved site of hyperpolarization-activated cyclic nucleotide-gated (HCN)4 channel downstream of the filter at the start of the last transmembrane domain S6. Functional expression of mutant channels in HEK293 cells uncovered a profoundly reduced channel function but no appreciable impact on channel synthesis and trafficking compared to the wild type. The inward rectifying HCN4 current could be partially rescued by an expression of heteromeric channels comprising wt and mutant monomers. These heteromeric channels were responsive to cAMP but they required a more negative voltage for activation and they exhibited a lower current density than the wt channel. This suggests a dominant negative effect of the mutation in patients, which carry this heterozygous mutation. Such a modulation of HCN4 activity could be the cause of the diagnosed cardiac abnormality.
Collapse
Affiliation(s)
- Stephanie Biel
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, 60596, Frankfurt am Main, Germany
| | - Marco Aquila
- Department of Biosciences and CNR IBF-Mi, University of Milano, Via Celoria 26, 20133, Milan, Italy
| | - Brigitte Hertel
- Department of Biology, Plant Membrane Biophysics, Technische Universität Darmstadt, Schnittspahnstrasse 3, 64287, Darmstadt, Germany
| | - Anne Berthold
- Department of Biology, Plant Membrane Biophysics, Technische Universität Darmstadt, Schnittspahnstrasse 3, 64287, Darmstadt, Germany
| | - Thomas Neumann
- Kerckhoff Heart and Thorax Center, University of Giessen, Benekestraße 2, 61231, Bad Nauheim, Germany
| | - Dario DiFrancesco
- The PaceLab, Department of Biosciences, University of Milano, via Celoria 26, 20133, Milan, Italy
| | - Anna Moroni
- Department of Biosciences and CNR IBF-Mi, University of Milano, Via Celoria 26, 20133, Milan, Italy
| | - Gerhard Thiel
- Department of Biology, Plant Membrane Biophysics, Technische Universität Darmstadt, Schnittspahnstrasse 3, 64287, Darmstadt, Germany.
| | - Silke Kauferstein
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, 60596, Frankfurt am Main, Germany
| |
Collapse
|
18
|
Mapping Breakpoints of Complex Chromosome Rearrangements Involving a Partial Trisomy 15q23.1-q26.2 Revealed by Next Generation Sequencing and Conventional Techniques. PLoS One 2016; 11:e0154574. [PMID: 27218255 PMCID: PMC4878739 DOI: 10.1371/journal.pone.0154574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/16/2016] [Indexed: 11/25/2022] Open
Abstract
Complex chromosome rearrangements (CCRs), which are rather rare in the whole population, may be associated with aberrant phenotypes. Next-generation sequencing (NGS) and conventional techniques, could be used to reveal specific CCRs for better genetic counseling. We report the CCRs of a girl and her mother, which were identified using a combination of NGS and conventional techniques including G-banding, fluorescence in situ hybridization (FISH) and PCR. The girl demonstrated CCRs involving chromosomes 3 and 8, while the CCRs of her mother involved chromosomes 3, 5, 8, 11 and 15. HumanCytoSNP-12 Chip analysis identified a 35.4 Mb duplication on chromosome 15q21.3-q26.2 in the proband and a 1.6 Mb microdeletion at chromosome 15q21.3 in her mother. The proband inherited the rearranged chromosomes 3 and 8 from her mother, and the duplicated region on chromosome 15 of the proband was inherited from the mother. Approximately one hundred genes were identified in the 15q21.3-q26.2 duplicated region of the proband. In particular, TPM1, SMAD6, SMAD3, and HCN4 may be associated with her heart defects, and HEXA, KIF7, and IDH2 are responsible for her developmental and mental retardation. In addition, we suggest that a microdeletion on the 15q21.3 region of the mother, which involved TCF2, TCF12, ADMA10 and AQP9, might be associated with mental retardation. We delineate the precise structures of the derivative chromosomes, chromosome duplication origin and possible molecular mechanisms for aberrant phenotypes by combining NGS data with conventional techniques.
Collapse
|
19
|
DiFrancesco D. HCN4, Sinus Bradycardia and Atrial Fibrillation. Arrhythm Electrophysiol Rev 2015; 4:9-13. [PMID: 26835093 DOI: 10.15420/aer.2015.4.1.9] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/29/2015] [Indexed: 01/01/2023] Open
Abstract
Based on their established role in the generation of spontaneous activity in pacemaker cells and control of cardiac rate, funny/ hyperpolarisation-activated, cyclic nucleotide gated 4 (HCN4) channels are natural candidates in the search for causes of sinus arrhythmias. Investigation of funny current-related inheritable arrhythmias has led to the identification of several mutations of the HCN4 gene associated with bradycardia and/or more complex arrhythmias. More recently, the search has been extended to include auxiliary proteins such as the minK-related peptide 1 (MiRP1) β-subunit. All mutations described so far are loss-of-function and in agreement with the role of funny channels, the predominant type of arrhythmia found is bradycardia. Funny channel-linked arrhythmias, however, also include atrioventricular (AV) block and atrial fibrillation, in agreement with an emerging new concept according to which defective funny channels have a still unexplored role in impairing AV conduction and triggering atrial fibrillation. Also, importantly, recent work shows that HCN4 mutations can be associated with cardiac structural abnormalities. In this short review I briefly address the current knowledge of funny/HCN4 channel mutations and associated sinus and more complex arrhythmias.
Collapse
Affiliation(s)
- Dario DiFrancesco
- PaceLab, University of Milan and Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata (CIMMBA), Milan, Italy
| |
Collapse
|
20
|
Verkerk AO, Wilders R. Pacemaker activity of the human sinoatrial node: an update on the effects of mutations in HCN4 on the hyperpolarization-activated current. Int J Mol Sci 2015; 16:3071-94. [PMID: 25642760 PMCID: PMC4346881 DOI: 10.3390/ijms16023071] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 01/22/2015] [Indexed: 11/22/2022] Open
Abstract
Since 2003, several loss-of-function mutations in the HCN4 gene, which encodes the HCN4 protein, have been associated with sinus node dysfunction. In human sinoatrial node (SAN), HCN4 is the most abundant of the four isoforms of the HCN family. Tetramers of HCN subunits constitute the ion channels that conduct the hyperpolarization-activated "funny" current (If), which plays an important modulating role in SAN pacemaker activity. Voltage-clamp experiments on HCN4 channels expressed in COS-7, CHO and HEK-293 cells, as well as in Xenopus oocytes have revealed changes in the expression and kinetics of mutant channels, but the extent to which especially the kinetic changes would affect If flowing during a human SAN action potential often remains unresolved. In our contribution to the Topical Collection on Human Single Nucleotide Polymorphisms and Disease Diagnostics, we provide an updated review of the mutation-induced changes in the expression and kinetics of HCN4 channels and provide an overview of their effects on If during the time course of a human SAN action potential, as assessed in simulated action potential clamp experiments. Future research may solve apparent inconsistencies between data from clinical studies and data from in vitro and in silico experiments.
Collapse
Affiliation(s)
- Arie O Verkerk
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
| | - Ronald Wilders
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
| |
Collapse
|