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Aldirawi M, Musa R, Hamdi M, Yavuz L. Congenital Long QT Syndrome (LQTS) in Infancy: A Challenging Case. Cureus 2024; 16:e51810. [PMID: 38322063 PMCID: PMC10844771 DOI: 10.7759/cureus.51810] [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] [Accepted: 01/07/2024] [Indexed: 02/08/2024] Open
Abstract
Long QT syndrome (LQTS), is an arrhythmia disorder, related to ventricular myocardial repolarization characterized by a prolonged QT interval on the electrocardiogram that can lead to symptomatic ventricular arrhythmias and increase the mortality rate. The prevalence of congenital LQTS is about 1 in 2000 live births. Here, we report the case of a two-month-old female, with a significant family history of early death, who was brought to our emergency with an episode of blueish discoloration. The initial workup was positive for COVID-19 in the respiratory panel, so she was admitted as a case of bronchiolitis. It was a challenge because of the overlapping presentation between a serious condition and other common pediatric illnesses. Furthermore, the paper aims to increase awareness of this condition among physicians and emphasizes the importance of obtaining a complete medical history, physical examination, and family screening in selected cases to facilitate early diagnosis and timely management.
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Affiliation(s)
| | - Rehab Musa
- Pediatrics, Al Jalila Children's Hospital, Dubai, ARE
| | - Moataz Hamdi
- Pediatrics, Al Jalila Children's Hospital, Dubai, ARE
| | - Lemis Yavuz
- Pediatrics, Al Jalila Children's Hospital, Dubai, ARE
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2
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Pandit M, Finn C, Tahir UA, Frishman WH. Congenital Long QT Syndrome: A Review of Genetic and Pathophysiologic Etiologies, Phenotypic Subtypes, and Clinical Management. Cardiol Rev 2023; 31:318-324. [PMID: 35576393 DOI: 10.1097/crd.0000000000000459] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Congenital Long QT Syndrome (CLQTS) is the most common inherited arrhythmia. The QT interval, which marks the duration of ventricular depolarization and repolarization in the myocardium, can be prolonged due to mutations in genes coding for the ion channel proteins that govern the cardiac action potential. The lengthening of the QT interval can lead to a wide range of clinical symptoms, including seizures, torsades de pointes, and fatal arrhythmias. There is a growing body of evidence that has revealed the genetic mutations responsible for the pathophysiology of CLQTS, and this has led to hypotheses regarding unique triggers and clinical features associated with specific gene mutations. Epidemiologic evidence has revealed a 1-year mortality rate of approximately 20% in untreated CLQTS patients, and a <1% of 1-year mortality rate in treated patients, underscoring the importance of timely diagnosis and effective clinical management. There are many phenotypic syndromes that constitute CLQTS, including but not limited to, Jervell and Lange-Nielsen syndrome, Romano and Ward syndrome, Andersen-Tawil syndrome, and Timothy syndrome. In this review, we aim to (1) summarize the genetic, epidemiologic, and pathophysiological basis of CLQTS and (2) outline the unique features of the phenotypic subtypes and their clinical management.
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Affiliation(s)
- Maya Pandit
- From the New York Medical College, Valhalla, NY
| | - Caitlin Finn
- Department of Medicine, Division of Cardiology, Harvard Medical School/Beth Israel Deaconess Medical Center, Boston, MA
| | - Usman A Tahir
- Department of Medicine, Division of Cardiology, Harvard Medical School/Beth Israel Deaconess Medical Center, Boston, MA
| | - William H Frishman
- Departments of Medicine and Cardiology, New York Medical College/Westchester Medical Center, Valhalla, NY
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3
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Lima B, Razmjouei S, Bajwa MT, Shahzad Z, Shoewu OA, Ijaz O, Mange P, Khanal S, Gebregiorgis T. Polypharmacy, Gender Disparities, and Ethnic and Racial Predispositions in Long QT Syndrome: An In-Depth Review. Cureus 2023; 15:e46009. [PMID: 37900391 PMCID: PMC10600617 DOI: 10.7759/cureus.46009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2023] [Indexed: 10/31/2023] Open
Abstract
Long QT syndrome (LQTS) is a complex disorder of cardiac electrophysiology. It is characterized by delayed myocardial polarization leading to QT prolongation and alterations on the ST segment and T wave visible on electrocardiogram (ECG). Syncope is a common manifestation, and torsade de pointes (TdP) can lead to sudden cardiac death. Three major LQTS genes (KCI31, KCNH2, and SCN5) lead to most of the cases of LQTS. Lifestyle modifications, beta blockers, and implantable cardioverter defibrillator (ICD) placement are the main treatments for LQTS. Polypharmacy, including QT-prolonging drugs, has been shown to worsen LQTS. The impact on potassium channels and the human ether-a-go-go-related gene (hERG) is the mechanism behind the QT interval prolongation caused by these medications. There is an increased incidence of LQTS among African-American men and women as compared to Caucasians. Women with LQTS tend to have a higher mortality rate from the condition, especially during menstruation and shortly after giving birth. Genetic testing is reserved to those patientswho exhibit either a strong clinical index of suspicion or experience persistent QT prolongation despite their lack of symptoms. Knowing the genetics, racial, and gender discrepancies can help improve patient management and a better comprehension on each case. Proper understanding of how ion channels function and their interaction with medications will lead to a better comprehension and to develop effective forms to treat those patients.
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Affiliation(s)
- Bruno Lima
- Medicine, University of Grande Rio, Rio Grande, USA
| | - Soha Razmjouei
- Anesthesiology, Case Western Reserve University School of Medicine, Cleveland, USA
| | | | - Zoha Shahzad
- Internal Medicine, Fatima Jinnah Medical University, Lahore, PAK
| | | | - Osama Ijaz
- Internal Medicine, Services Hospital Lahore, Lahore, PAK
| | - Pooja Mange
- Internal Medicine, K.J. Somaiya Hospital and Research Center, Mumbai, IND
| | | | - Tsion Gebregiorgis
- General Practice, Addis Ababa University Medical Faculty, Addis Ababa, ETH
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4
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Neumann B, Vink AS, Hermans BJM, Lieve KVV, Cömert D, Beckmann BM, Clur SAB, Blom NA, Delhaas T, Wilde AAM, Kääb S, Postema PG, Sinner MF. Manual vs. automatic assessment of the QT-interval and corrected QT. Europace 2023; 25:euad213. [PMID: 37470430 PMCID: PMC10469369 DOI: 10.1093/europace/euad213] [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: 04/10/2023] [Revised: 05/29/2023] [Accepted: 06/29/2023] [Indexed: 07/21/2023] Open
Abstract
AIMS Sudden cardiac death (SCD) is challenging to predict. Electrocardiogram (ECG)-derived heart rate-corrected QT-interval (QTc) is used for SCD-risk assessment. QTc is preferably determined manually, but vendor-provided automatic results from ECG recorders are convenient. Agreement between manual and automatic assessments is unclear for populations with aberrant QTc. We aimed to systematically assess pairwise agreement of automatic and manual QT-intervals and QTc. METHODS AND RESULTS A multi-centre cohort enriching aberrant QTc comprised ECGs of healthy controls and long-QT syndrome (LQTS) patients. Manual QT-intervals and QTc were determined by the tangent and threshold methods and compared to automatically generated, vendor-provided values. We assessed agreement globally by intra-class correlation coefficients and pairwise by Bland-Altman analyses and 95% limits of agreement (LoA). Further, manual results were compared to a novel automatic QT-interval algorithm. ECGs of 1263 participants (720 LQTS patients; 543 controls) were available [median age 34 (inter-quartile range 35) years, 55% women]. Comparing cohort means, automatic and manual QT-intervals and QTc were similar. However, pairwise Bland-Altman-based agreement was highly discrepant. For QT-interval, LoAs spanned 95 (tangent) and 92 ms (threshold), respectively. For QTc, the spread was 108 and 105 ms, respectively. LQTS patients exhibited more pronounced differences. For automatic QTc results from 440-540 ms (tangent) and 430-530 ms (threshold), misassessment risk was highest. Novel automatic QT-interval algorithms may narrow this range. CONCLUSION Pairwise vendor-provided automatic and manual QT-interval and QTc results can be highly discrepant. Novel automatic algorithms may improve agreement. Within the above ranges, automatic QT-interval and QTc results require manual confirmation, particularly if T-wave morphology is challenging.
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Affiliation(s)
- Benjamin Neumann
- Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany
- German Centre for Cardiovascular Research (DZHK), partner site: Munich Heart Alliance, Munich, Germany
| | - A Suzanne Vink
- Department of Clinical and Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Heart Center, Amsterdam, The Netherlands
- Department of Pediatric Cardiology, Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Ben J M Hermans
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Krystien V V Lieve
- Department of Clinical and Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Heart Center, Amsterdam, The Netherlands
| | - Didem Cömert
- Department of Clinical and Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Heart Center, Amsterdam, The Netherlands
| | - Britt-Maria Beckmann
- Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany
- Department of Legal Medicine, Goethe Univeristy, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Sally-Ann B Clur
- Department of Pediatric Cardiology, Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Nico A Blom
- Department of Pediatric Cardiology, Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Pediatric Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Tammo Delhaas
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Heart Center, Amsterdam, The Netherlands
- Department of Pediatric Cardiology, Leiden University Medical Center, Leiden, The Netherlands
- Princess Al-Jawhara Al-Brahim Center of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia
- European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart (ERN GUARD-Heart), Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Stefan Kääb
- Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany
- German Centre for Cardiovascular Research (DZHK), partner site: Munich Heart Alliance, Munich, Germany
| | - Pieter G Postema
- Department of Clinical and Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Heart Center, Amsterdam, The Netherlands
| | - Moritz F Sinner
- Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany
- German Centre for Cardiovascular Research (DZHK), partner site: Munich Heart Alliance, Munich, Germany
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Bhattacharyya S, Kollipara RK, Orquera-Tornakian G, Goetsch S, Zhang M, Perry C, Li B, Shelton JM, Bhakta M, Duan J, Xie Y, Xiao G, Evers BM, Hon GC, Kittler R, Munshi NV. Global chromatin landscapes identify candidate noncoding modifiers of cardiac rhythm. J Clin Invest 2023; 133:e153635. [PMID: 36454649 PMCID: PMC9888383 DOI: 10.1172/jci153635] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 11/30/2022] [Indexed: 12/03/2022] Open
Abstract
Comprehensive cis-regulatory landscapes are essential for accurate enhancer prediction and disease variant mapping. Although cis-regulatory element (CRE) resources exist for most tissues and organs, many rare - yet functionally important - cell types remain overlooked. Despite representing only a small fraction of the heart's cellular biomass, the cardiac conduction system (CCS) unfailingly coordinates every life-sustaining heartbeat. To globally profile the mouse CCS cis-regulatory landscape, we genetically tagged CCS component-specific nuclei for comprehensive assay for transposase-accessible chromatin-sequencing (ATAC-Seq) analysis. Thus, we established a global CCS-enriched CRE database, referred to as CCS-ATAC, as a key resource for studying CCS-wide and component-specific regulatory functions. Using transcription factor (TF) motifs to construct CCS component-specific gene regulatory networks (GRNs), we identified and independently confirmed several specific TF sub-networks. Highlighting the functional importance of CCS-ATAC, we also validated numerous CCS-enriched enhancer elements and suggested gene targets based on CCS single-cell RNA-Seq data. Furthermore, we leveraged CCS-ATAC to improve annotation of existing human variants related to cardiac rhythm and nominated a potential enhancer-target pair that was dysregulated by a specific SNP. Collectively, our results established a CCS-regulatory compendium, identified novel CCS enhancer elements, and illuminated potential functional associations between human genomic variants and CCS component-specific CREs.
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Affiliation(s)
| | | | | | - Sean Goetsch
- Department of Internal Medicine, Division of Cardiology
| | - Minzhe Zhang
- Quantitative Biomedical Research Center, Department of Population and Data Sciences
| | - Cameron Perry
- Department of Internal Medicine, Division of Cardiology
| | - Boxun Li
- Laboratory of Regulatory Genomics, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Reproductive Biology Research, Department of Obstetrics and Gynecology
| | | | - Minoti Bhakta
- Department of Internal Medicine, Division of Cardiology
| | - Jialei Duan
- Laboratory of Regulatory Genomics, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Reproductive Biology Research, Department of Obstetrics and Gynecology
| | - Yang Xie
- Quantitative Biomedical Research Center, Department of Population and Data Sciences
- Department of Bioinformatics
| | - Guanghua Xiao
- Quantitative Biomedical Research Center, Department of Population and Data Sciences
- Department of Bioinformatics
| | - Bret M. Evers
- Department of Internal Medicine, Division of Cardiology
| | - Gary C. Hon
- Laboratory of Regulatory Genomics, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Reproductive Biology Research, Department of Obstetrics and Gynecology
- Department of Bioinformatics
- Hamon Center for Regenerative Science and Medicine, and
| | - Ralf Kittler
- McDermott Center for Human Growth and Development
| | - Nikhil V. Munshi
- Department of Internal Medicine, Division of Cardiology
- McDermott Center for Human Growth and Development
- Hamon Center for Regenerative Science and Medicine, and
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, Texas, USA
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Vaiman EE, Shnayder NA, Zhuravlev NM, Petrova MM, Asadullin AR, Al-Zamil M, Garganeeva NP, Shipulin GA, Cumming P, Nasyrova RF. Genetic Biomarkers of Antipsychotic-Induced Prolongation of the QT Interval in Patients with Schizophrenia. Int J Mol Sci 2022; 23:ijms232415786. [PMID: 36555428 PMCID: PMC9785058 DOI: 10.3390/ijms232415786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/07/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Antipsychotics (AP) induced prolongation of the QT interval in patients with schizophrenia (Sch) is an actual interdisciplinary problem as it increases the risk of sudden death syndrome. Long QT syndrome (LQTS) as a cardiac adverse drug reaction is a multifactorial symptomatic disorder, the development of which is influenced by modifying factors (APs' dose, duration of APs therapy, APs polytherapy, and monotherapy, etc.) and non-modifying factors (genetic predisposition, gender, age, etc.). The genetic predisposition to AP-induced LQTS may be due to several causes, including causal mutations in the genes responsible for monoheme forms of LQTS, single nucleotide variants (SNVs) of the candidate genes encoding voltage-dependent ion channels expressed both in the brain and in the heart, and SNVs of candidate genes encoding key enzymes of APs metabolism. This narrative review summarizes the results of genetic studies on AP-induced LQTS and proposes a new personalized approach to assessing the risk of its development (low, moderate, high). We recommend implementation in protocols of primary diagnosis of AP-induced LQTS and medication dispensary additional observations of the risk category of patients receiving APs, deoxyribonucleic acid profiling, regular electrocardiogram monitoring, and regular therapeutic drug monitoring of the blood APs levels.
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Affiliation(s)
- Elena E. Vaiman
- Institute of Personalized Psychiatry and Neurology, V. M. Bekhterev National Medical Research Centre for Psychiatry and Neurology, 192019 Saint Petersburg, Russia
| | - Natalia A. Shnayder
- Institute of Personalized Psychiatry and Neurology, V. M. Bekhterev National Medical Research Centre for Psychiatry and Neurology, 192019 Saint Petersburg, Russia
- Shared Core Facilities “Molecular and Cell Technologies”, V. F. Voyno-Yasenetsky Krasnoyarsk State Medical University, 660022 Krasnoyarsk, Russia
- Correspondence: (N.A.S.); (R.F.N.); Tel.: +7-(812)-670-02-20 (N.A.S. & R.F.N.)
| | - Nikita M. Zhuravlev
- Institute of Personalized Psychiatry and Neurology, V. M. Bekhterev National Medical Research Centre for Psychiatry and Neurology, 192019 Saint Petersburg, Russia
| | - Marina M. Petrova
- Shared Core Facilities “Molecular and Cell Technologies”, V. F. Voyno-Yasenetsky Krasnoyarsk State Medical University, 660022 Krasnoyarsk, Russia
| | - Azat R. Asadullin
- Department of Psychiatry and Addiction, Bashkir State Medical University, 450008 Ufa, Russia
| | - Mustafa Al-Zamil
- Department of Physiotherapy, Faculty of Continuing Medical Education, Peoples’ Friendship University of Russia, 117198 Moscow, Russia
| | - Natalia P. Garganeeva
- Department of General Medical Practice and Outpatient Therapy, Siberian State Medical University, 634050 Tomsk, Russia
| | - German A. Shipulin
- Centre for Strategic Planning and Management of Biomedical Health Risks Management, 119121 Moscow, Russia
| | - Paul Cumming
- Department of Nuclear Medicine, Bern University Hospital, 3010 Bern, Switzerland
- School of Psychology and Counselling, Queensland University of Technology, Brisbane 4000, Australia
| | - Regina F. Nasyrova
- Institute of Personalized Psychiatry and Neurology, V. M. Bekhterev National Medical Research Centre for Psychiatry and Neurology, 192019 Saint Petersburg, Russia
- International Centre for Education and Research in Neuropsychiatry, Samara State Medical University, 443016 Samara, Russia
- Correspondence: (N.A.S.); (R.F.N.); Tel.: +7-(812)-670-02-20 (N.A.S. & R.F.N.)
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7
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Dyck JRB, Sossalla S, Hamdani N, Coronel R, Weber NC, Light PE, Zuurbier CJ. Cardiac mechanisms of the beneficial effects of SGLT2 inhibitors in heart failure: Evidence for potential off-target effects. J Mol Cell Cardiol 2022; 167:17-31. [PMID: 35331696 DOI: 10.1016/j.yjmcc.2022.03.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/02/2022] [Accepted: 03/17/2022] [Indexed: 02/07/2023]
Abstract
Sodium glucose cotransporter 2 inhibitors (SGLT2i) constitute a promising drug treatment for heart failure patients with either preserved or reduced ejection fraction. Whereas SGLT2i were originally developed to target SGLT2 in the kidney to facilitate glucosuria in diabetic patients, it is becoming increasingly clear that these drugs also have important effects outside of the kidney. In this review we summarize the literature on cardiac effects of SGLT2i, focussing on pro-inflammatory and oxidative stress processes, ion transport mechanisms controlling sodium and calcium homeostasis and metabolic/mitochondrial pathways. These mechanisms are particularly important as disturbances in these pathways result in endothelial dysfunction, diastolic dysfunction, cardiac stiffness, and cardiac arrhythmias that together contribute to heart failure. We review the findings that support the concept that SGLT2i directly and beneficially interfere with inflammation, oxidative stress, ionic homeostasis, and metabolism within the cardiac cell. However, given the very low levels of SGLT2 in cardiac cells, the evidence suggests that SGLT2-independent effects of this class of drugs likely occurs via off-target effects in the myocardium. Thus, while there is still much to be understood about the various factors which determine how SGLT2i affect cardiac cells, much of the research clearly demonstrates that direct cardiac effects of these SGLT2i exist, albeit mediated via SGLT2-independent pathways, and these pathways may play a role in explaining the beneficial effects of SGLT2 inhibitors in heart failure.
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Affiliation(s)
- Jason R B Dyck
- Cardiovascular Research Centre, Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Samuel Sossalla
- Department of Internal Medicine II, University Medical Center Regensburg, 93053 Regensburg, Germany; Klinik für Kardiologie und Pneumologie, Georg-August-Universität Goettingen, DZHK (German Centre for Cardiovascular Research), Robert-Koch Str. 40, D-37075 Goettingen, Germany
| | - Nazha Hamdani
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital Ruhr University Bochum, Bochum, Germany
| | - Ruben Coronel
- Department of Experimental Cardiology, Amsterdam University Medical Centers, Location AMC, Cardiovascular Science, Amsterdam, the Netherlands
| | - Nina C Weber
- Department of Anesthesiology - L.E.I.C.A, Amsterdam University Medical Centers, Location AMC, Cardiovascular Science, Amsterdam, the Netherlands
| | - Peter E Light
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Coert J Zuurbier
- Department of Anesthesiology - L.E.I.C.A, Amsterdam University Medical Centers, Location AMC, Cardiovascular Science, Amsterdam, the Netherlands.
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Proshlyakov AY, Chomakhidze PS, Novikova NA. Comparative Characteristics of Beta-Blockers in Patients with Congenital Long QT Syndrome. RATIONAL PHARMACOTHERAPY IN CARDIOLOGY 2021. [DOI: 10.20996/1819-6446-2021-06-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Congenital long QT syndrome is a pathology that requires special attention and knowledge about the safety and effectiveness of various medications. Prolongation of the QT interval due to congenital or acquired causes is an important factor in the development of an unfavorable life forecast with the formation of an elongated QT syndrome. With an unfavorable course, patients suffer from loss of consciousness, episodes of tachycardia. Often, stable polymorphic ventricular tachycardia develops. The risk of sudden cardiac death in this pathology can vary from 0.33% to 5%. In people who have suffered an episode of cardiac arrest, and do not have a permanent prescribed antiarrhythmic therapy, the mortality rate reaches 50% within 15 years. Preventive administration of antiarrhythmic drugs is not always effective. A positive result of treatment depends on the severity of long QT syndrome and its genotype. Beta-blockers are often prescribed to patients of different ages with various cardiac pathologies, including for the prevention of arrhythmia in long QT syndrome. Beta-blockers differ in various pharmacokinetic and pharmacodynamic parameters (lipophilicity/hydrophilicity, selectivity, presence/absence of internal sympathomimetic activity), which, along with the variant of the disease genotype, can affect their effectiveness and safety in the considered pathology. This review article presents the results of major studies on the safety and effectiveness of different groups of beta blockers in various variants of long QT syndrome. The preferred beta-blockers for various genotypes of the syndrome were determined, and a comparative characteristic of beta-blockers for their safety and preventive effectiveness was given.
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Affiliation(s)
- A. Yu. Proshlyakov
- I.M. Sechenov First Moscow State Medical University (Sechenov University)
| | - P. Sh. Chomakhidze
- I.M. Sechenov First Moscow State Medical University (Sechenov University)
| | - N. A. Novikova
- I.M. Sechenov First Moscow State Medical University (Sechenov University)
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9
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Philippaert K, Kalyaanamoorthy S, Fatehi M, Long W, Soni S, Byrne NJ, Barr A, Singh J, Wong J, Palechuk T, Schneider C, Darwesh AM, Maayah ZH, Seubert JM, Barakat K, Dyck JR, Light PE. Cardiac Late Sodium Channel Current Is a Molecular Target for the Sodium/Glucose Cotransporter 2 Inhibitor Empagliflozin. Circulation 2021; 143:2188-2204. [PMID: 33832341 PMCID: PMC8154177 DOI: 10.1161/circulationaha.121.053350] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/25/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND SGLT2 (sodium/glucose cotransporter 2) inhibitors exert robust cardioprotective effects against heart failure in patients with diabetes, and there is intense interest to identify the underlying molecular mechanisms that afford this protection. Because the induction of the late component of the cardiac sodium channel current (late-INa) is involved in the etiology of heart failure, we investigated whether these drugs inhibit late-INa. METHODS Electrophysiological, in silico molecular docking, molecular, calcium imaging, and whole heart perfusion techniques were used to address this question. RESULTS The SGLT2 inhibitor empagliflozin reduced late-INa in cardiomyocytes from mice with heart failure and in cardiac Nav1.5 sodium channels containing the long QT syndrome 3 mutations R1623Q or ΔKPQ. Empagliflozin, dapagliflozin, and canagliflozin are all potent and selective inhibitors of H2O2-induced late-INa (half maximal inhibitory concentration = 0.79, 0.58, and 1.26 µM, respectively) with little effect on peak sodium current. In mouse cardiomyocytes, empagliflozin reduced the incidence of spontaneous calcium transients induced by the late-INa activator veratridine in a similar manner to tetrodotoxin, ranolazine, and lidocaine. The putative binding sites for empagliflozin within Nav1.5 were investigated by simulations of empagliflozin docking to a three-dimensional homology model of human Nav1.5 and point mutagenic approaches. Our results indicate that empagliflozin binds to Nav1.5 in the same region as local anesthetics and ranolazine. In an acute model of myocardial injury, perfusion of isolated mouse hearts with empagliflozin or tetrodotoxin prevented activation of the cardiac NLRP3 (nuclear-binding domain-like receptor 3) inflammasome and improved functional recovery after ischemia. CONCLUSIONS Our results provide evidence that late-INa may be an important molecular target in the heart for the SGLT2 inhibitors, contributing to their unexpected cardioprotective effects.
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Affiliation(s)
- Koenraad Philippaert
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Subha Kalyaanamoorthy
- Faculty of Medicine and Dentistry (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
| | - Mohammad Fatehi
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Wentong Long
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Shubham Soni
- Department of Pediatrics (S.S., N.J.B., Z.H.M., J.R.B.D.), University of Alberta, Edmonton, Canada
| | - Nikole J. Byrne
- Department of Pediatrics (S.S., N.J.B., Z.H.M., J.R.B.D.), University of Alberta, Edmonton, Canada
| | - Amy Barr
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Jyoti Singh
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Jordan Wong
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Taylor Palechuk
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Chloe Schneider
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Ahmed M. Darwesh
- Faculty of Medicine and Dentistry (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
| | - Zaid H. Maayah
- Department of Pediatrics (S.S., N.J.B., Z.H.M., J.R.B.D.), University of Alberta, Edmonton, Canada
| | - John M. Seubert
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
- Faculty of Medicine and Dentistry (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
| | - Khaled Barakat
- Faculty of Medicine and Dentistry (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Li Ka Shing Institute of Virology (K.B.), University of Alberta, Edmonton, Canada
| | - Jason R.B. Dyck
- Department of Pediatrics (S.S., N.J.B., Z.H.M., J.R.B.D.), University of Alberta, Edmonton, Canada
| | - Peter E. Light
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
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10
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Marchiano S, Hsiang TY, Khanna A, Higashi T, Whitmore LS, Bargehr J, Davaapil H, Chang J, Smith E, Ong LP, Colzani M, Reinecke H, Yang X, Pabon L, Sinha S, Najafian B, Sniadecki NJ, Bertero A, Gale M, Murry CE. SARS-CoV-2 Infects Human Pluripotent Stem Cell-Derived Cardiomyocytes, Impairing Electrical and Mechanical Function. Stem Cell Reports 2021; 16:478-492. [PMID: 33657418 PMCID: PMC7881699 DOI: 10.1016/j.stemcr.2021.02.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 02/07/2023] Open
Abstract
COVID-19 patients often develop severe cardiovascular complications, but it remains unclear if these are caused directly by viral infection or are secondary to a systemic response. Here, we examine the cardiac tropism of SARS-CoV-2 in human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) and smooth muscle cells (hPSC-SMCs). We find that that SARS-CoV-2 selectively infects hPSC-CMs through the viral receptor ACE2, whereas in hPSC-SMCs there is minimal viral entry or replication. After entry into cardiomyocytes, SARS-CoV-2 is assembled in lysosome-like vesicles and egresses via bulk exocytosis. The viral transcripts become a large fraction of cellular mRNA while host gene expression shifts from oxidative to glycolytic metabolism and upregulates chromatin modification and RNA splicing pathways. Most importantly, viral infection of hPSC-CMs progressively impairs both their electrophysiological and contractile function, and causes widespread cell death. These data support the hypothesis that COVID-19-related cardiac symptoms can result from a direct cardiotoxic effect of SARS-CoV-2.
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Affiliation(s)
- Silvia Marchiano
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, 850 Republican Street, Brotman Building, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, Seattle, WA 98109, USA
| | - Tien-Ying Hsiang
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Akshita Khanna
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, 850 Republican Street, Brotman Building, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, Seattle, WA 98109, USA
| | - Ty Higashi
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, 850 Republican Street, Brotman Building, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, Seattle, WA 98109, USA; Department of Mechanical Engineering, University of Washington, 3720 15th Avenue NE, Seattle, WA 98105, USA
| | - Leanne S Whitmore
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Johannes Bargehr
- Wellcome - MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Puddicombe Way, CB2 0AW Cambridge, UK; Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, ACCI Level 6, Box 110, Hills Road, Cambridge CB2 0QQ, UK
| | - Hongorzul Davaapil
- Wellcome - MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Puddicombe Way, CB2 0AW Cambridge, UK; Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, ACCI Level 6, Box 110, Hills Road, Cambridge CB2 0QQ, UK
| | - Jean Chang
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Elise Smith
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Lay Ping Ong
- Wellcome - MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Puddicombe Way, CB2 0AW Cambridge, UK; Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, ACCI Level 6, Box 110, Hills Road, Cambridge CB2 0QQ, UK
| | - Maria Colzani
- Wellcome - MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Puddicombe Way, CB2 0AW Cambridge, UK; Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, ACCI Level 6, Box 110, Hills Road, Cambridge CB2 0QQ, UK
| | - Hans Reinecke
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, 850 Republican Street, Brotman Building, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, Seattle, WA 98109, USA
| | - Xiulan Yang
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, 850 Republican Street, Brotman Building, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, Seattle, WA 98109, USA
| | - Lil Pabon
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, 850 Republican Street, Brotman Building, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, Seattle, WA 98109, USA; Sana Biotechnology, 188 E Blaine Street, Seattle, WA 98102, USA
| | - Sanjay Sinha
- Wellcome - MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Puddicombe Way, CB2 0AW Cambridge, UK; Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, ACCI Level 6, Box 110, Hills Road, Cambridge CB2 0QQ, UK
| | - Behzad Najafian
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Nathan J Sniadecki
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, 850 Republican Street, Brotman Building, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, Seattle, WA 98109, USA; Department of Mechanical Engineering, University of Washington, 3720 15th Avenue NE, Seattle, WA 98105, USA; Department of Bioengineering, University of Washington, 3720 15th Avenue NE, Seattle, WA 98105, USA
| | - Alessandro Bertero
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, 850 Republican Street, Brotman Building, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, Seattle, WA 98109, USA
| | - Michael Gale
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington School of Medicine, Seattle, WA 98109, USA.
| | - Charles E Murry
- Department of Laboratory Medicine and Pathology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, 850 Republican Street, Brotman Building, Seattle, WA 98109, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, 850 Republican Street, Seattle, WA 98109, USA; Sana Biotechnology, 188 E Blaine Street, Seattle, WA 98102, USA; Department of Bioengineering, University of Washington, 3720 15th Avenue NE, Seattle, WA 98105, USA; Department of Medicine/Cardiology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA.
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11
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Tschirhart JN, Zhang S. Fentanyl-Induced Block of hERG Channels Is Exacerbated by Hypoxia, Hypokalemia, Alkalosis, and the Presence of hERG1b. Mol Pharmacol 2020; 98:508-517. [PMID: 32321735 DOI: 10.1124/mol.119.119271] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 04/08/2020] [Indexed: 01/19/2023] Open
Abstract
Human ether-a-go-go-related gene (hERG) encodes the pore-forming subunit of the rapidly activating delayed rectifier potassium current (IKr) important for repolarization of cardiac action potentials. Drug-induced disruption of hERG channel function is a main cause of acquired long QT syndrome, which can lead to ventricular arrhythmias and sudden death. Illicit fentanyl use is associated with sudden death. We have demonstrated that fentanyl blocks hERG current (IhERG) at concentrations that overlap with the upper range of postmortem blood concentrations in fentanyl-related deaths. Since fentanyl can cause respiratory depression and electrolyte imbalances, in the present study we investigated whether certain pathologic circumstances exacerbate fentanyl-induced block of IhERG Our results show that chronic hypoxia or hypokalemia additively reduced IhERG with fentanyl. As well, high pH potentiated the fentanyl-mediated block of hERG channels, with an IC50 at pH 8.4 being 7-fold lower than that at pH 7.4. Furthermore, although the full-length hERG variant, hERG1a, has been widely used to study hERG channels, coexpression with the short variant, hERG1b (which does not produce current when expressed alone), produces functional hERG1a/1b channels, which gate more closely resembling native IKr Our results showed that fentanyl blocked hERG1a/1b channels with a 3-fold greater potency than hERG1a channels. Thus, in addition to a greater susceptibility due to the presence of hERG1b in the human heart, hERG channel block by fentanyl can be exacerbated by certain conditions, such as hypoxia, hypokalemia, or alkalosis, which may increase the risk of fentanyl-induced ventricular arrhythmias and sudden death. SIGNIFICANCE STATEMENT: This work demonstrates that heterologously expressed human ether a-go-go-related gene (hERG) 1a/1b channels, which more closely resemble rapidly activating delayed rectifier potassium current in the human heart, are blocked by fentanyl with a 3-fold greater potency than the previously studied hERG1a expressed alone. Additionally, chronic hypoxia, hypokalemia, and alkalosis can increase the block of hERG current by fentanyl, potentially increasing the risk of cardiac arrhythmias and sudden death.
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Affiliation(s)
- Jared N Tschirhart
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Shetuan Zhang
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
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12
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Kurata Y, Tsumoto K, Hayashi K, Hisatome I, Kuda Y, Tanida M. Multiple Dynamical Mechanisms of Phase-2 Early Afterdepolarizations in a Human Ventricular Myocyte Model: Involvement of Spontaneous SR Ca 2+ Release. Front Physiol 2020; 10:1545. [PMID: 31998140 PMCID: PMC6965073 DOI: 10.3389/fphys.2019.01545] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 12/05/2019] [Indexed: 12/19/2022] Open
Abstract
Early afterdepolarization (EAD) is known to cause lethal ventricular arrhythmias in long QT syndrome (LQTS). In this study, dynamical mechanisms of EAD formation in human ventricular myocytes (HVMs) were investigated using the mathematical model developed by ten Tusscher and Panfilov (Am J Physiol Heart Circ Physiol 291, 2006). We explored how the rapid (IKr) and slow (IKs) components of delayed-rectifier K+ channel currents, L-type Ca2+ channel current (ICa L), Na+/Ca2+ exchanger current (INCX), and intracellular Ca2+ handling via the sarcoplasmic reticulum (SR) contribute to initiation, termination and modulation of phase-2 EADs during pacing in relation to bifurcation phenomena in non-paced model cells. Parameter-dependent dynamical behaviors of the non-paced model cell were determined by calculating stabilities of equilibrium points (EPs) and limit cycles, and bifurcation points to construct bifurcation diagrams. Action potentials (APs) and EADs during pacing were reproduced by numerical simulations for constructing phase diagrams of the paced model cell dynamics. Results are summarized as follows: (1) A modified version of the ten Tusscher-Panfilov model with accelerated ICaL inactivation could reproduce bradycardia-related EADs in LQTS type 2 and β-adrenergic stimulation-induced EADs in LQTS type 1. (2) Two types of EADs with different initiation mechanisms, ICaL reactivation-dependent and spontaneous SR Ca2+ release-mediated EADs, were detected. (3) Termination of EADs (AP repolarization) during pacing depended on the slow activation of IKs. (4) Spontaneous SR Ca2+ releases occurred at higher Ca2+ uptake rates, attributable to the instability of steady-state intracellular Ca2+ concentrations. Dynamical mechanisms of EAD formation and termination in the paced model cell are closely related to stability changes (bifurcations) in dynamical behaviors of the non-paced model cell, but they are model-dependent. Nevertheless, the modified ten Tusscher-Panfilov model would be useful for systematically investigating possible dynamical mechanisms of EAD-related arrhythmias in LQTS.
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Affiliation(s)
- Yasutaka Kurata
- Department of Physiology II, Kanazawa Medical University, Uchinada, Japan
| | - Kunichika Tsumoto
- Department of Physiology II, Kanazawa Medical University, Uchinada, Japan
| | - Kenshi Hayashi
- Department of Cardiovascular and Internal Medicine, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Ichiro Hisatome
- Department of Genetic Medicine and Regenerative Therapeutics, Graduate School of Medical Sciences, Tottori University, Yonago, Japan
| | - Yuhichi Kuda
- Department of Physiology II, Kanazawa Medical University, Uchinada, Japan
| | - Mamoru Tanida
- Department of Physiology II, Kanazawa Medical University, Uchinada, Japan
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13
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Benjamin EJ, Muntner P, Alonso A, Bittencourt MS, Callaway CW, Carson AP, Chamberlain AM, Chang AR, Cheng S, Das SR, Delling FN, Djousse L, Elkind MSV, Ferguson JF, Fornage M, Jordan LC, Khan SS, Kissela BM, Knutson KL, Kwan TW, Lackland DT, Lewis TT, Lichtman JH, Longenecker CT, Loop MS, Lutsey PL, Martin SS, Matsushita K, Moran AE, Mussolino ME, O'Flaherty M, Pandey A, Perak AM, Rosamond WD, Roth GA, Sampson UKA, Satou GM, Schroeder EB, Shah SH, Spartano NL, Stokes A, Tirschwell DL, Tsao CW, Turakhia MP, VanWagner LB, Wilkins JT, Wong SS, Virani SS. Heart Disease and Stroke Statistics-2019 Update: A Report From the American Heart Association. Circulation 2019; 139:e56-e528. [PMID: 30700139 DOI: 10.1161/cir.0000000000000659] [Citation(s) in RCA: 5219] [Impact Index Per Article: 1043.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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14
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Liu MB, Vandersickel N, Panfilov AV, Qu Z. R-From-T as a Common Mechanism of Arrhythmia Initiation in Long QT Syndromes. Circ Arrhythm Electrophysiol 2019; 12:e007571. [PMID: 31838916 PMCID: PMC6924944 DOI: 10.1161/circep.119.007571] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 09/24/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Long QT syndromes (LQTS) arise from many genetic and nongenetic causes with certain characteristic ECG features preceding polymorphic ventricular tachyarrhythmias (PVTs). However, how the many molecular causes result in these characteristic ECG patterns and how these patterns are mechanistically linked to the spontaneous initiation of PVT remain poorly understood. METHODS Anatomic human ventricle and simplified tissue models were used to investigate the mechanisms of spontaneous initiation of PVT in LQTS. RESULTS Spontaneous initiation of PVT was elicited by gradually ramping up ICa,L to simulate the initial phase of a sympathetic surge or by changing the heart rate, reproducing the different genotype-dependent clinical ECG features. In LQTS type 2 (LQT2) and LQTS type 3 (LQT3), T-wave alternans was observed followed by premature ventricular complexes (PVCs). Compensatory pauses occurred resulting in short-long-short sequences. As ICa,L increased further, PVT episodes occurred, always preceded by a short-long-short sequence. However, in LQTS type 1 (LQT1), once a PVC occurred, it always immediately led to an episode of PVT. Arrhythmias in LQT2 and LQT3 were bradycardia dependent, whereas those in LQT1 were not. In all 3 genotypes, PVCs always originated spontaneously from the steep repolarization gradient region and manifested on ECG as R-on-T. We call this mechanism R-from-T, to distinguish it from the classic explanation of R-on-T arrhythmogenesis in which an exogenous PVC coincidentally encounters a repolarizing region. In R-from-T, the PVC and the T wave are causally related, where steep repolarization gradients combined with enhanced ICa,L lead to PVCs emerging from the T wave. Since enhanced ICa,L was required for R-from-T to occur, suppressing window ICa,L effectively prevented arrhythmias in all 3 genotypes. CONCLUSIONS Despite the complex molecular causes, these results suggest that R-from-T is likely a common mechanism for PVT initiation in LQTS. Targeting ICa,L properties, such as suppressing window ICa,L or preventing excessive ICa,L increase, could be an effective unified therapy for arrhythmia prevention in LQTS.
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Affiliation(s)
- Michael B. Liu
- Department of Medicine (M.B.L., Z.Q.), University of California, Los Angeles
| | - Nele Vandersickel
- Department of Physics and Astronomy, Ghent University, Belgium (N.V., A.V.P.)
| | - Alexander V. Panfilov
- Department of Physics and Astronomy, Ghent University, Belgium (N.V., A.V.P.)
- Laboratory of Computational Biology and Medicine, Ural Federal University, Ekaterinburg, Russia (A.V.P.)
| | - Zhilin Qu
- Department of Medicine (M.B.L., Z.Q.), University of California, Los Angeles
- Department of Biomathematics (Z.Q.), University of California, Los Angeles
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15
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Puri K, Malek J, de la Uz CM, Lantos J, Cabrera AG, Frugé E. Allowing Adolescents to Weigh Benefits and Burdens of High-stakes Therapies. Pediatrics 2019; 144:peds.2018-3714. [PMID: 31167936 DOI: 10.1542/peds.2018-3714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/26/2018] [Indexed: 11/24/2022] Open
Abstract
We present the case of a girl aged 17 years and 10 months who has a strong family history of long QT syndrome and genetic testing confirming the diagnosis of long QT syndrome in the patient also. She was initially medically treated with β-blocker therapy; however, after suffering 1 episode of syncope during exertion, she underwent placement of an implantable cardioverter defibrillator. Since then, she has never had syncope. However, during the few months before this presentation, she experienced shocks on multiple occasions without any underlying arrhythmias. These shocks are disconcerting for her, and she is having significant anxiety about them. She requests the defibrillator to be inactivated. However, her mother, who also shares the diagnosis of long QT syndrome, disagrees and wants the defibrillator to remain active. The ethics team is consulted in this setting of disagreement between an adolescent, who is 2 months shy of the age of maturity and medical decision-making, and her mother, who is currently responsible for her medical decisions. The question for the consultation is whether it would be ethically permissible for the doctors to comply with the patient's request to turn off the defibrillator or whether the doctors should follow the mother's wishes until the patient is 18 years of age.
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Affiliation(s)
- Kriti Puri
- Lillie Frank Abercrombie Section of Cardiology, Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas;
| | - Janet Malek
- Center for Medical Ethics and Health Policy, Baylor College of Medicine, Houston, Texas
| | - Caridad Maylin de la Uz
- Lillie Frank Abercrombie Section of Cardiology, Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
| | - John Lantos
- Department of Pediatrics, School of Medicine, University of Missouri-Kansas City and Children's Mercy Hospital, Kansas City, Missouri; and
| | - Antonio Gabriel Cabrera
- Lillie Frank Abercrombie Section of Cardiology, Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
| | - Ernest Frugé
- Section of Hematology-Oncology, Department of Pediatrics, Center for Medical Ethics and Health Policy, Baylor College of Medicine and Texas Children's Cancer and Hematology Centers, Houston, Texas
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16
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Uchida S, Asai Y, Kariya Y, Tsumoto K, Hibino H, Honma M, Abe T, Nin F, Kurata Y, Furutani K, Suzuki H, Kitano H, Inoue R, Kurachi Y. Integrative and theoretical research on the architecture of a biological system and its disorder. J Physiol Sci 2019; 69:433-451. [PMID: 30868372 PMCID: PMC6456489 DOI: 10.1007/s12576-019-00667-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 02/08/2019] [Indexed: 11/28/2022]
Abstract
An organism stems from assemblies of a variety of cells and proteins. This complex system serves as a unit, and it exhibits highly sophisticated functions in response to exogenous stimuli that change over time. The complete sequencing of the entire human genome has allowed researchers to address the enigmas of life and disease at the gene- or molecular-based level. The consequence of such studies is the rapid accumulation of a multitude of data at multiple levels, ranging from molecules to the whole body, that has necessitated the development of entirely new concepts, tools, and methodologies to analyze and integrate these data. This necessity has given birth to systems biology, an advanced theoretical and practical research framework that has totally changed the directions of not only basic life science but also medicine. During the symposium of the 95th Annual Meeting of The Physiological Society of Japan 2018, five researchers reported on their respective studies on systems biology. The topics included reactions of drugs, ion-transport architecture in an epithelial system, multi-omics in renal disease, cardiac electrophysiological systems, and a software platform for computer simulation. In this review article these authors have summarized recent achievements in the field and discuss next-generation studies on health and disease.
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Affiliation(s)
- Shinichi Uchida
- Department of Nephrology, Graduate Schools of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Yoshiyuki Asai
- Department of Systems Bioinformatics, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Yoshiaki Kariya
- Department of Pharmacy, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Kunichika Tsumoto
- Division of Molecular and Cellular Pharmacology, Department of Pharmacology, Osaka University, Suita, Japan.,Center for Advanced Medical Engineering and Informatics, Osaka University, Suita, Japan.,Department of Physiology II, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Hiroshi Hibino
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Niigata, 951-8510, Japan. .,AMED-CREST, AMED, Niigata, Japan.
| | - Masashi Honma
- Department of Pharmacy, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Takeshi Abe
- Department of Systems Bioinformatics, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Fumiaki Nin
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Niigata, 951-8510, Japan.,AMED-CREST, AMED, Niigata, Japan
| | - Yasutaka Kurata
- Department of Physiology II, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Kazuharu Furutani
- Department of Physiology and Membrane Biology, University of California Davis, Davis, 95616, USA
| | - Hiroshi Suzuki
- Department of Pharmacy, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Hiroaki Kitano
- The Systems Biology Institute, Shinagawa-ku, Tokyo, 108-0071, Japan
| | - Ryuji Inoue
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan.
| | - Yoshihisa Kurachi
- Division of Molecular and Cellular Pharmacology, Department of Pharmacology, Osaka University, Suita, Japan. .,Center for Advanced Medical Engineering and Informatics, Osaka University, Suita, Japan.
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17
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Liang W, Gasparyan L, AlQarawi W, Davis DR. Disease modeling of cardiac arrhythmias using human induced pluripotent stem cells. Expert Opin Biol Ther 2019; 19:313-333. [PMID: 30682895 DOI: 10.1080/14712598.2019.1575359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
INTRODUCTION Inherited arrhythmias are an uncommon, but malignant family of cardiac diseases that result from genetic abnormalities in the ion channels and/or structural proteins within cardiomyocytes. Given the inherent differences between species and the limited reproducibility of in vitro heterologous cell models, progress in understanding the mechanisms underlying these malignant diseases has always languished far behind the clinical science and need. The ability to study human induced pluripotent stem cells (iPSCs) derived cardiomyocytes promises to change this paradigm as patient cells have the potential to become testing platforms for disease phenotyping or therapeutic discovery. AREAS COVERED This review will outline methods developed to genetically reprogram adult cells into iPSCs, differentiate iPSCs into ex vivo models of adult cardiac tissue and iPSCs-based progress in exploring the mechanisms underlying pro-arrhythmic disease phenotypes. EXPERT OPINION Despite being discovered less than 15 years ago, several studies have successfully leveraged iPSCs-derived cardiomyocytes to study malignant arrhythmogenic diseases. These models promise to increase our understanding of the pathophysiology underlying these complex diseases and may identify personalized approaches to treatment.
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Affiliation(s)
- Wenbin Liang
- a Division of Cardiology, Department of Medicine , University of Ottawa Heart Institute , Ottawa , Canada.,b Department of Cellular and Molecular Medicine , University of Ottawa , Ottawa , Canada
| | - Lilit Gasparyan
- a Division of Cardiology, Department of Medicine , University of Ottawa Heart Institute , Ottawa , Canada
| | - Wael AlQarawi
- a Division of Cardiology, Department of Medicine , University of Ottawa Heart Institute , Ottawa , Canada
| | - Darryl R Davis
- a Division of Cardiology, Department of Medicine , University of Ottawa Heart Institute , Ottawa , Canada.,b Department of Cellular and Molecular Medicine , University of Ottawa , Ottawa , Canada
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18
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Gray B, Behr ER. New Insights Into the Genetic Basis of Inherited Arrhythmia Syndromes. ACTA ACUST UNITED AC 2018; 9:569-577. [PMID: 27998945 DOI: 10.1161/circgenetics.116.001571] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Belinda Gray
- From the Department of Cardiology, Royal Prince Alfred Hospital, New South Wales, Australia (B.G.); Sydney Medical School, University of Sydney, Australia (B.G.), Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, New South Wales, Australia (B.G.); Cardiology Clinical Academic Group, St George's University of London, United Kingdom (E.R.B.); and St George's University Hospitals NHS Foundation Trust, London, United Kingdom (E.R.B.)
| | - Elijah R Behr
- From the Department of Cardiology, Royal Prince Alfred Hospital, New South Wales, Australia (B.G.); Sydney Medical School, University of Sydney, Australia (B.G.), Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, New South Wales, Australia (B.G.); Cardiology Clinical Academic Group, St George's University of London, United Kingdom (E.R.B.); and St George's University Hospitals NHS Foundation Trust, London, United Kingdom (E.R.B.).
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19
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Marino BS, Tabbutt S, MacLaren G, Hazinski MF, Adatia I, Atkins DL, Checchia PA, DeCaen A, Fink EL, Hoffman GM, Jefferies JL, Kleinman M, Krawczeski CD, Licht DJ, Macrae D, Ravishankar C, Samson RA, Thiagarajan RR, Toms R, Tweddell J, Laussen PC. Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association. Circulation 2018; 137:e691-e782. [PMID: 29685887 DOI: 10.1161/cir.0000000000000524] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.
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20
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Voros O, Szilagyi O, Balajthy A, Somodi S, Panyi G, Hajdu P. The C-terminal HRET sequence of Kv1.3 regulates gating rather than targeting of Kv1.3 to the plasma membrane. Sci Rep 2018; 8:5937. [PMID: 29650988 PMCID: PMC5897520 DOI: 10.1038/s41598-018-24159-8] [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: 08/10/2017] [Accepted: 03/08/2018] [Indexed: 12/13/2022] Open
Abstract
Kv1.3 channels are expressed in several cell types including immune cells, such as T lymphocytes. The targeting of Kv1.3 to the plasma membrane is essential for T cell clonal expansion and assumed to be guided by the C-terminus of the channel. Using two point mutants of Kv1.3 with remarkably different features compared to the wild-type Kv1.3 (A413V and H399K having fast inactivation kinetics and tetraethylammonium-insensitivity, respectively) we showed that both Kv1.3 channel variants target to the membrane when the C-terminus was truncated right after the conserved HRET sequence and produce currents identical to those with a full-length C-terminus. The truncation before the HRET sequence (NOHRET channels) resulted in reduced membrane-targeting but non-functional phenotypes. NOHRET channels did not display gating currents, and coexpression with wild-type Kv1.3 did not rescue the NOHRET-A413V phenotype, no heteromeric current was observed. Interestingly, mutants of wild-type Kv1.3 lacking HRET(E) (deletion) or substituted with five alanines for the HRET(E) motif expressed current indistinguishable from the wild-type. These results demonstrate that the C-terminal region of Kv1.3 immediately proximal to the S6 helix is required for the activation gating and conduction, whereas the presence of the distal region of the C-terminus is not exclusively required for trafficking of Kv1.3 to the plasma membrane.
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Affiliation(s)
- Orsolya Voros
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 400, 1 Egyetem sq., Debrecen, 4032, Hungary
| | - Orsolya Szilagyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 400, 1 Egyetem sq., Debrecen, 4032, Hungary
| | - András Balajthy
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, 400, 1 Egyetem sq., Debrecen, 4032, Hungary
| | - Sándor Somodi
- Department of Internal Medicine, Faculty of Medicine, University of Debrecen, 400, 1 Egyetem sq., Debrecen, 4032, Hungary
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 1 Egyetem sq., 4032, Hungary. MTA-DE-NAP B Ion Channel Structure-Function Research Group, RCMM, University of Debrecen, 400, Debrecen, Hungary
| | - Péter Hajdu
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 400, 1 Egyetem sq., Debrecen, 4032, Hungary. .,Department of Biophysics and Cell Biology, Faculty of Dentistry, University of Debrecen, 400, 1 Egyetem sq., Debrecen, 4032, Hungary.
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21
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Polavarapu KC, Patil A, Mistry R. Video-assisted thoracoscopic cardiac sympathetic denervation for prolonged QT syndrome—a case report. Indian J Thorac Cardiovasc Surg 2018. [DOI: 10.1007/s12055-017-0531-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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22
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Hysteretic Dynamics of Multi-Stable Early Afterdepolarisations with Repolarisation Reserve Attenuation: A Potential Dynamical Mechanism for Cardiac Arrhythmias. Sci Rep 2017; 7:10771. [PMID: 28883639 PMCID: PMC5589958 DOI: 10.1038/s41598-017-11355-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/23/2017] [Indexed: 02/08/2023] Open
Abstract
Some cardiovascular and non-cardiovascular drugs frequently cause excessive prolongation of the cardiac action potential (AP) and lead to the development of early afterdepolarisations (EADs), which trigger lethal ventricular arrhythmias. Combining computer simulations in APs with numerical calculations based on dynamical system theory, we investigated stability changes of APs observed in a paced human ventricular myocyte model by decreasing and/or increasing the rapid (IKr) and slow (IKs) components of delayed rectifying K+ current. Upon reducing IKr, the APs without EADs (no-EAD response) showed gradual prolongation of AP duration (APD), and were annihilated without AP configuration changes due to the occurrence of saddle-node bifurcations. This annihilation caused a transition to an AP with EADs as a new stable steady state. Furthermore, reducing repolarisation currents (repolarisation reserve attenuation) evoked multi-stable states consisting of APs with different APDs, and caused multiple hysteretic dynamics. Depending on initial ion circumstances within ventricular myocytes, these multi-stable AP states might increase the local/global heterogeneity of AP repolarisations in the ventricle. Thus, the EAD-induced arrhythmias with repolarisation reserve attenuation might be attributed to the APD variability caused by multi-stability in cardiac AP dynamics.
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KCNE1 and KCNE3 modulate KCNQ1 channels by affecting different gating transitions. Proc Natl Acad Sci U S A 2017; 114:E7367-E7376. [PMID: 28808020 DOI: 10.1073/pnas.1710335114] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
KCNE β-subunits assemble with and modulate the properties of voltage-gated K+ channels. In the heart, KCNE1 associates with the α-subunit KCNQ1 to generate the slowly activating, voltage-dependent potassium current (IKs) in the heart that controls the repolarization phase of cardiac action potentials. By contrast, in epithelial cells from the colon, stomach, and kidney, KCNE3 coassembles with KCNQ1 to form K+ channels that are voltage-independent K+ channels in the physiological voltage range and important for controlling water and salt secretion and absorption. How KCNE1 and KCNE3 subunits modify KCNQ1 channel gating so differently is largely unknown. Here, we use voltage clamp fluorometry to determine how KCNE1 and KCNE3 affect the voltage sensor and the gate of KCNQ1. By separating S4 movement and gate opening by mutations or phosphatidylinositol 4,5-bisphosphate depletion, we show that KCNE1 affects both the S4 movement and the gate, whereas KCNE3 affects the S4 movement and only affects the gate in KCNQ1 if an intact S4-to-gate coupling is present. Further, we show that a triple mutation in the middle of the transmembrane (TM) segment of KCNE3 introduces KCNE1-like effects on the second S4 movement and the gate. In addition, we show that differences in two residues at the external end of the KCNE TM segments underlie differences in the effects of the different KCNEs on the first S4 movement and the voltage sensor-to-gate coupling.
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24
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Hormones and sex differences: changes in cardiac electrophysiology with pregnancy. Clin Sci (Lond) 2017; 130:747-59. [PMID: 27128800 DOI: 10.1042/cs20150710] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/01/2016] [Indexed: 11/17/2022]
Abstract
Disruption of cardiac electrical activity resulting in palpitations and syncope is often an early symptom of pregnancy. Pregnancy is a time of dramatic and dynamic physiological and hormonal changes during which numerous demands are placed on the heart. These changes result in electrical remodelling which can be detected as changes in the electrocardiogram (ECG). This gestational remodelling is a very under-researched area. There are no systematic large studies powered to determine changes in the ECG from pre-pregnancy, through gestation, and into the postpartum period. The large variability between patients and the dynamic nature of pregnancy hampers interpretation of smaller studies, but some facts are consistent. Gestational cardiac hypertrophy and a physical shift of the heart contribute to changes in the ECG. There are also electrical changes such as an increased heart rate and lengthening of the QT interval. There is an increased susceptibility to arrhythmias during pregnancy and the postpartum period. Some changes in the ECG are clearly the result of changes in ion channel expression and behaviour, but little is known about the ionic basis for this electrical remodelling. Most information comes from animal models, and implicates changes in the delayed-rectifier channels. However, it is likely that there are additional roles for sodium channels as well as changes in calcium homoeostasis. The changes in the electrical profile of the heart during pregnancy and the postpartum period have clear implications for the safety of pregnant women, but the field remains relatively undeveloped.
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25
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Phenotype guided characterization and molecular analysis of Indian patients with long QT syndromes. Indian Pacing Electrophysiol J 2016; 16:8-18. [PMID: 27485560 PMCID: PMC4936664 DOI: 10.1016/j.ipej.2016.03.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 03/27/2016] [Accepted: 03/28/2016] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Long QT syndromes (LQTS) are characterized by prolonged QTc interval on electrocardiogram (ECG) and manifest with syncope, seizures or sudden cardiac death. Long QT 1-3 constitute about 75% of all inherited LQTS. We classified a cohort of Indian patients for the common LQTS based on T wave morphology and triggering factors to prioritize the gene to be tested. We sought to identify the causative mutations and mutation spectrum, perform genotype-phenotype correlation and screen family members. METHODS Thirty patients who fulfilled the criteria were enrolled. The most probable candidate gene among KCNQ1, KCNH2 and SCN5A were sequenced. RESULTS Of the 30 patients, 22 were classified at LQT1, two as LQT2 and six as LQT3. Mutations in KCNQ1 were identified in 17 (77%) of 22 LQT1 patients, KCNH2 mutation in one of two LQT2 and SCN5A mutations in two of six LQT3 patients. We correlated the presence of the specific ECG morphology in all mutation positive cases. Eight mutations in KCNQ1 and one in SCN5A were novel and predicted to be pathogenic by in-silico analysis. Of all parents with heterozygous mutations, 24 (92%) of 26 were asymptomatic. Ten available siblings of nine probands were screened and three were homozygous and symptomatic, five heterozygous and asymptomatic. CONCLUSIONS This study in a cohort of Asian Indian patients highlights the mutation spectrum of common Long QT syndromes. The clinical utility for prevention of unexplained sudden cardiac deaths is an important sequel to identification of the mutation in at-risk family members.
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26
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Malik M. Drug-Induced QT/QTc Interval Shortening: Lessons from Drug-Induced QT/QTc Prolongation. Drug Saf 2016; 39:647-59. [DOI: 10.1007/s40264-016-0411-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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27
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Czosek RJ, Kaltman JR, Cassedy AE, Shah MJ, Vetter VL, Tanel RE, Wernovksy G, Wray J, Marino BS. Quality of Life of Pediatric Patients With Long QT Syndrome. Am J Cardiol 2016; 117:605-610. [PMID: 26721659 DOI: 10.1016/j.amjcard.2015.11.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/18/2015] [Accepted: 11/18/2015] [Indexed: 11/24/2022]
Abstract
Children with long QT syndrome (LQTS) live with the risk of sudden death, activity restrictions, and the need for daily medications. We sought to evaluate the quality of life (QOL), self-perception, and behavior of patients with LQTS as perceived by both patients and their parents and identify predictors of lower QOL. QOL (Pediatric QOL Inventory [PedsQL] and Pediatric Cardiac Quality of Life Inventory [PCQLI]), self-perception, and behavioral inventories were completed by patients with LQTS and their parents. Comparison of PedsQL scores was made to published data for healthy children using t tests, and PCQLI scores were compared with those of patients with differing complexity of congenital heart disease. Mixed modeling was used for multivariable analysis. Sixty-one patients with LQTS were evaluated (age 13.6 ± 3.0 years; male 49%). Compared with healthy children, the PedsQL Total, Psychosocial, and Physical Health Summary scores were significantly lower for patients with LQTS and parent proxy reports (p ≤0.001). In general, PCQLI scores of patients with LQTS and parents were similar to those of patients with tetralogy of Fallot (p ≥0.2), lower than those of patients with bicuspid aortic valve (p ≤0.02), and higher than those of patients with single ventricle (p ≤0.03). Lower patient and parent PCQLI scores were associated with internalizing problems. For parents, the presence of a cardiac device and medication side effects were additionally associated with lower PCQLI scores. In conclusion, patients with LQTS and their parents report lower QOL than normal children secondary to physical and psychosocial factors. Increasing focus on the psychological well-being of these patients is needed in an effort to improve their QOL.
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28
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Qiu M, Dong YH, Han F, Qin JM, Zhang HN, Du JX, Hao XM, Yang YM. Influence of total flavonoids derived from Choerospondias axillaris folium on aconitine-induced antiarrhythmic action and hemodynamics in Wistar rats. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2016; 79:878-883. [PMID: 27599234 DOI: 10.1080/15287394.2016.1193117] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
It is well known that various traditional Chinese medicines produce antiarrhythmic actions. The aims of this study were to examine whether total flavones derived from Choerospondias axillaris folium (TFCF) also produced antiarrhythmic effects using a rat model of aconitine-induced arrhythmia and to compare these observations with the effects of total flavones of Choerospondias axillaris fructus (TFC). Wistar rats were orally administered TFC (0.2 g/kg) or TFCF (0.1, 0.2, or 0.4 g/kg) daily for 7 d. Subsequently, aconitine iv at 25 µg/kg was used to induce arrhythmia in these animals. Control (C) physiological saline and positive verapamil rats were also administered orally. The starting times of ventricular ectopic beats (VE), ventricular tachycardia (VT), ventricular fibrillation (VF), and heart arrest (HA) were recorded. In comparison to C, TFCF and TFC significantly prolonged the starting time of VE, VT, VF, and HA induced by aconitine. With respect to hemodynamics, TFC and high-dose TFCF were effective in reducing HR without associated changes in BP in all groups. TFC and TFCF decreased left ventricular systolic pressure (LVSP) and maximal velocity rate of ventricular pressure (+dp/dt max and -dp/dt min) with no marked effect on left ventricular end diastolic pressure (LVEDP) and -dp/dtmin. Data demonstrated that TFCF and TFC were equally effective in diminishing the aconitine-mediated arrhythmias. In addition, TFCF and TFC produced a similar reduction in HR with no accompanying change in BP. These findings indicate that the TFCF- and TFC-induced alterations may be attributed to inhibition of ventricular contraction without altering ventricular diastolic function.
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Affiliation(s)
- Min Qiu
- a Department of Pharmacy , Baotou Medical College , Baotou , Inner Mongolia , China
| | - Yong-He Dong
- a Department of Pharmacy , Baotou Medical College , Baotou , Inner Mongolia , China
| | - Feng Han
- a Department of Pharmacy , Baotou Medical College , Baotou , Inner Mongolia , China
| | - Jian-Min Qin
- a Department of Pharmacy , Baotou Medical College , Baotou , Inner Mongolia , China
| | - Hao-Nan Zhang
- a Department of Pharmacy , Baotou Medical College , Baotou , Inner Mongolia , China
| | - Jian-Xi Du
- b College of Science , Guangdong Ocean University , Zhanjiang , Guangdong , China
| | - Xin-Min Hao
- b College of Science , Guangdong Ocean University , Zhanjiang , Guangdong , China
| | - Yu-Mei Yang
- a Department of Pharmacy , Baotou Medical College , Baotou , Inner Mongolia , China
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A Possible Mechanistic Link Between the CYP2C19 Genotype, the Methadone Metabolite Ethylidene-1,5-Dimethyl-3,3-Diphenylpyrrolidene (EDDP), and Methadone-Induced Corrected QT Interval Prolongation in a Pilot Study. Mol Diagn Ther 2015; 19:131-8. [DOI: 10.1007/s40291-015-0137-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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30
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Prolonged QT Syndrome in a 27-Year-Old Female Presenting as a Cardiac Arrest after Elective Surgery. Case Rep Crit Care 2014; 2014:348274. [PMID: 25431685 PMCID: PMC4241282 DOI: 10.1155/2014/348274] [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: 08/22/2014] [Revised: 10/19/2014] [Accepted: 10/20/2014] [Indexed: 11/17/2022] Open
Abstract
Cardiac arrest is a true medical emergency and clinicians should base the management on American Heart Association advanced cardiac life support algorithm. The potential triggers of cardiac arrest should be sought. We present a case of a 27-year-old female who developed cardiac arrest and was later found to have congenital long QT syndrome. The patient's outcome was favorable. Discussion of the key management options will be discussed in the text.
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31
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Linder T, Saxena P, Timin E, Hering S, Stary-Weinzinger A. Structural Insights into Trapping and Dissociation of Small Molecules in K+ Channels. J Chem Inf Model 2014; 54:3218-28. [DOI: 10.1021/ci500353r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tobias Linder
- Department for Pharmacology and Toxicology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Priyanka Saxena
- Department for Pharmacology and Toxicology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Eugen Timin
- Department for Pharmacology and Toxicology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Steffen Hering
- Department for Pharmacology and Toxicology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Anna Stary-Weinzinger
- Department for Pharmacology and Toxicology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
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32
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Michishita R, Fukae C, Mihara R, Ikenaga M, Morimura K, Takeda N, Yamada Y, Higaki Y, Tanaka H, Kiyonaga A. Association between the physical activity and heart rate corrected-QT interval in older adults. Geriatr Gerontol Int 2014; 15:895-901. [PMID: 25243349 DOI: 10.1111/ggi.12365] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2014] [Indexed: 11/28/2022]
Abstract
AIM Increased physical activity can reduce the incidence of cardiovascular disease and the mortality rate. In contrast, a prolonged heart rate corrected-QT (QTc) interval is associated with an increased risk of arrhythmias, sudden cardiac death and coronary artery disease. The present cross-sectional study was designed to clarify the association between the physical activity level and the QTc interval in older adults. METHODS The participants included 586 older adults (267 men and 319 women, age 71.2 ± 4.7 years) without a history of cardiovascular disease, who were taking cardioactive drugs. Electrocardiography was recorded with a standard resting 12-lead electrocardiograph, while the QTc interval was calculated according to Hodges' formula. The physical activity level was assessed using a triaxial accelerometer. The participants were divided into four categories, which were defined equally quartile distributions of the QTc interval. RESULTS After adjusting for age, body mass index, waist circumference and the number of steps, the time spent in inactivity was higher and the time spent in light physical activity was significantly lower in the longest QTc interval group than in the shortest QTc interval group in both sexes (P < 0.05, respectively). However, there were no significant differences in the time spent in moderate and vigorous physical activities among the four groups in either sex. CONCLUSIONS These results suggest that a decreased physical activity level, especially inactivity and light intensity physical activity, were associated with QTc interval in older adults.
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Affiliation(s)
- Ryoma Michishita
- Laboratory of Exercise Physiology, Faculty of Health and Sports Science, Fukuoka University, Fukuoka, Japan
| | - Chika Fukae
- Laboratory of Exercise Physiology, Faculty of Health and Sports Science, Fukuoka University, Fukuoka, Japan
| | - Rikako Mihara
- Laboratory of Exercise Physiology, Faculty of Health and Sports Science, Fukuoka University, Fukuoka, Japan
| | - Masahiro Ikenaga
- Laboratory of Exercise Physiology, Faculty of Health and Sports Science, Fukuoka University, Fukuoka, Japan
| | - Kazuhiro Morimura
- Laboratory of Exercise Physiology, Faculty of Health and Sports Science, Fukuoka University, Fukuoka, Japan
| | - Noriko Takeda
- Japan Society for the Promotion of Science, Tokyo, Japan.,Faculty of Sport Sciences, Waseda University, Saitama, Japan
| | - Yosuke Yamada
- Fukuoka University Institute for Physical Activity, Fukuoka, Japan.,Department of Nutritional Science, National Institute of Health and Nutrition, Tokyo, Japan
| | - Yasuki Higaki
- Laboratory of Exercise Physiology, Faculty of Health and Sports Science, Fukuoka University, Fukuoka, Japan.,Fukuoka University Institute for Physical Activity, Fukuoka, Japan
| | - Hiroaki Tanaka
- Laboratory of Exercise Physiology, Faculty of Health and Sports Science, Fukuoka University, Fukuoka, Japan.,Fukuoka University Institute for Physical Activity, Fukuoka, Japan
| | - Akira Kiyonaga
- Laboratory of Exercise Physiology, Faculty of Health and Sports Science, Fukuoka University, Fukuoka, Japan.,Fukuoka University Institute for Physical Activity, Fukuoka, Japan
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Kinoshita K, Komatsu T, Nishide K, Hata Y, Hisajima N, Takahashi H, Kimoto K, Aonuma K, Tsushima E, Tabata T, Yoshida T, Mori H, Nishida K, Yamaguchi Y, Ichida F, Fukurotani K, Inoue H, Nishida N. A590T mutation in KCNQ1 C-terminal helix D decreases IKs channel trafficking and function but not Yotiao interaction. J Mol Cell Cardiol 2014; 72:273-80. [PMID: 24713462 DOI: 10.1016/j.yjmcc.2014.03.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 02/28/2014] [Accepted: 03/26/2014] [Indexed: 12/21/2022]
Abstract
KCNQ1 encodes the α subunit of the voltage-gated channel that mediates the cardiac slow delayed rectifier K(+) current (IKs). Here, we report a KCNQ1 allele encoding an A590T mutation [KCNQ1(A590T)] found in a 39-year-old female with a mild QT prolongation. A590 is located in the C-terminal α helical region of KCNQ1 that mediates subunit tetramerization, membrane trafficking, and interaction with Yotiao. This interaction is known to be required for the proper modulation of IKs by cAMP. Since previous studies reported that mutations in the vicinity of A590 impair IKs channel surface expression and function, we examined whether and how the A590T mutation affects the IKs channel. Electrophysiological measurements in HEK-293T cells showed that the A590T mutation caused a reduction in IKs density and a right-shift of the current-voltage relation of channel activation. Immunocytochemical and immunoblot analyses showed the reduced cell surface expression of KCNQ1(A590T) subunit and its rescue by coexpression of the wild-type KCNQ1 [KCNQ1(WT)] subunit. Moreover, KCNQ1(A590T) subunit interacted with Yotiao and had a cAMP-responsiveness comparable to that of KCNQ1(WT) subunit. These findings indicate that the A590 of KCNQ1 subunit plays important roles in the maintenance of channel surface expression and function via a novel mechanism independent of interaction with Yotiao.
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Affiliation(s)
- Koshi Kinoshita
- Department of Legal Medicine, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
| | - Takuto Komatsu
- Laboratory for Neural Information Technology, Graduate School of Sciences and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Kohki Nishide
- Laboratory for Neural Information Technology, Graduate School of Sciences and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Yukiko Hata
- Department of Legal Medicine, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
| | - Nozomi Hisajima
- Laboratory for Neural Information Technology, Graduate School of Sciences and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Hiroyuki Takahashi
- Laboratory for Neural Information Technology, Graduate School of Sciences and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Katsuya Kimoto
- Laboratory for Neural Information Technology, Graduate School of Sciences and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Kei Aonuma
- Laboratory for Neural Information Technology, Graduate School of Sciences and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Eikichi Tsushima
- Laboratory for Neural Information Technology, Graduate School of Sciences and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Toshihide Tabata
- Laboratory for Neural Information Technology, Graduate School of Sciences and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neurosciences, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
| | - Hisashi Mori
- Department of Molecular Neurosciences, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
| | - Kunihiro Nishida
- Second Department of Internal Medicine, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
| | - Yoshiaki Yamaguchi
- Second Department of Internal Medicine, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
| | - Fukiko Ichida
- Department of Pediatrics, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
| | - Kenkichi Fukurotani
- Laboratory for Neural Information Technology, Graduate School of Sciences and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Hiroshi Inoue
- Second Department of Internal Medicine, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
| | - Naoki Nishida
- Department of Legal Medicine, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan.
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SAKATA SHINJI, KURATA YASUTAKA, LI PEILI, NOTSU TOMOMI, MORIKAWA KUMI, MIAKE JUNICHIRO, HIGAKI KATSUMI, YAMAMOTO YASUTAKA, YOSHIDA AKIO, SHIRAYOSHI YASUAKI, YAMAMOTO KAZUHIRO, HORIE MINORU, NINOMIYA HARUAKI, KANZAKI SUSUMU, HISATOME ICHIRO. Instability of KCNE1-D85N that Causes Long QT Syndrome: Stabilization by Verapamil. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2014; 37:853-63. [DOI: 10.1111/pace.12360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 12/24/2013] [Accepted: 12/29/2013] [Indexed: 11/29/2022]
Affiliation(s)
- SHINJI SAKATA
- Department of Pediatrics; Faculty of Medicine; Tottori University; Yonago Japan
| | - YASUTAKA KURATA
- Department of Physiology; Kanazawa Medical University; Uchinada-machi Kahoku-gun Ishikawa Japan
| | - PEILI LI
- Division of Regenerative Medicine and Therapeutics; Department of Genetic Medicine and Regenerative Therapeutics; Institute of Regenerative Medicine and Biofunction; Tottori University Graduate School of Medical Science; Yonago Japan
| | - TOMOMI NOTSU
- Division of Regenerative Medicine and Therapeutics; Department of Genetic Medicine and Regenerative Therapeutics; Institute of Regenerative Medicine and Biofunction; Tottori University Graduate School of Medical Science; Yonago Japan
| | - KUMI MORIKAWA
- Division of Regenerative Medicine and Therapeutics; Department of Genetic Medicine and Regenerative Therapeutics; Institute of Regenerative Medicine and Biofunction; Tottori University Graduate School of Medical Science; Yonago Japan
| | - JUNICHIRO MIAKE
- Division of Cardiology; Tottori University Hospital; Yonago Japan
| | | | - YASUTAKA YAMAMOTO
- Division of Regenerative Medicine and Therapeutics; Department of Genetic Medicine and Regenerative Therapeutics; Institute of Regenerative Medicine and Biofunction; Tottori University Graduate School of Medical Science; Yonago Japan
| | - AKIO YOSHIDA
- Division of Regenerative Medicine and Therapeutics; Department of Genetic Medicine and Regenerative Therapeutics; Institute of Regenerative Medicine and Biofunction; Tottori University Graduate School of Medical Science; Yonago Japan
| | - YASUAKI SHIRAYOSHI
- Division of Regenerative Medicine and Therapeutics; Department of Genetic Medicine and Regenerative Therapeutics; Institute of Regenerative Medicine and Biofunction; Tottori University Graduate School of Medical Science; Yonago Japan
| | | | - MINORU HORIE
- Department of Cardiovascular and Respiratory Medicine; Shiga University of Medical Science; Shiga Japan
| | - HARUAKI NINOMIYA
- Department of Biological Regulation; Faculty of Medicine; Tottori University; Yonago Japan
| | - SUSUMU KANZAKI
- Department of Pediatrics; Faculty of Medicine; Tottori University; Yonago Japan
| | - ICHIRO HISATOME
- Division of Regenerative Medicine and Therapeutics; Department of Genetic Medicine and Regenerative Therapeutics; Institute of Regenerative Medicine and Biofunction; Tottori University Graduate School of Medical Science; Yonago Japan
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Shin DS, Park MJ, Lee HA, Lee JY, Chung HC, Yoo DS, Chae CH, Park SJ, Kim KS, Bae MA. A novel assessment of nefazodone-induced hERG inhibition by electrophysiological and stereochemical method. Toxicol Appl Pharmacol 2014; 274:361-71. [DOI: 10.1016/j.taap.2013.12.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 12/16/2013] [Accepted: 12/16/2013] [Indexed: 11/30/2022]
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Dërmaku-Sopjani M, Abazi S, Faggio C, Kolgeci J, Sopjani M. AMPK-sensitive cellular transport. J Biochem 2014; 155:147-58. [PMID: 24440827 DOI: 10.1093/jb/mvu002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The energy sensing AMP-activated protein kinase (AMPK) regulates cellular and whole-body energy balance through stimulating catabolic ATP-generating and suppressing anabolic ATP-consuming pathways thereby helping cells survive during energy depletion. The kinase has previously been reported to be either directly or indirectly involved in the regulation of several carriers, channels and pumps of high significance in cellular physiology. Thus AMPK provides a necessary link between cellular energy metabolism and cellular transport activity. Better understanding of the AMPK role in cellular transport offers a potential for improved therapies in various human diseases and disorders. In this review, we discuss recent advances in understanding the role and function of AMPK in transport regulation under physiological and pathological states.
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Affiliation(s)
- Miribane Dërmaku-Sopjani
- Faculty of Medicine, University of Prishtina, Str. Bulevardi i Dëshmorëve, p.n. 10 000 Prishtina, Kosova; Department of Chemistry, University of Prishtina, Str. 'Nëna Terezë' p.n. 10 000 Prishtina, Kosova; Department of Chemistry, University of Tirana, Tirana, Albania; and Department of Biological and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres, 31, 98166 S.Agata-Messina, Italy
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Mujtaba S, Romero J, Taub CC. Methadone, QTc prolongation and torsades de pointes: Current concepts, management and a hidden twist in the tale? J Cardiovasc Dis Res 2013; 4:229-35. [PMID: 24653586 PMCID: PMC3953689 DOI: 10.1016/j.jcdr.2013.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Accepted: 10/18/2013] [Indexed: 01/08/2023] Open
Abstract
Methadone is a drug that has found widespread utility in the management of opioid addiction and pain. Along with its popularity, methadone has also earned an infamous reputation for causing prolongation of the QT interval and an increased risk of torsades de pointes. In this article we will give a brief overview of the long QT syndromes, followed by an in-depth look at the current pathophysiologic mechanisms of methadone induced QT prolongation, a review of the existing literature and the current concepts regarding the prevention and management of methadone induced torsades de pointes. In addition, we explore the idea and implications of a genetic link between methadone induced prolongation of the QT interval and torsades de pointes.
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Affiliation(s)
- Sobia Mujtaba
- Department of Medicine, Jacobi Medical Center, Albert Einstein College of Medicine, Bronx, New York 10461-1138, USA
| | - Jorge Romero
- Division of Cardiology and Montefiore-Einstein Center for Heart and Vascular Care, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York 10467-2400, USA
| | - Cynthia C. Taub
- Division of Cardiology, Jack D. Weiler Hospital of the Albert Einstein College of Medicine, Bronx, New York 10461-2372, USA
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D'Argenio V, Frisso G, Precone V, Boccia A, Fienga A, Pacileo G, Limongelli G, Paolella G, Calabrò R, Salvatore F. DNA sequence capture and next-generation sequencing for the molecular diagnosis of genetic cardiomyopathies. J Mol Diagn 2013; 16:32-44. [PMID: 24183960 DOI: 10.1016/j.jmoldx.2013.07.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 07/03/2013] [Accepted: 07/30/2013] [Indexed: 12/15/2022] Open
Abstract
Hypertrophic cardiomyopathy is a relatively frequent disease with a prevalence of 0.2% worldwide and a remarkable genetic heterogeneity, with more than 30 causative genes reported to date. Current PCR-based strategies are inadequate for genomic investigations involving many candidate genes. Here, we report a next-generation sequencing procedure associated with DNA sequence capture that is able to sequence 202 cardiomyopathy-related genes simultaneously. We developed a complementary data analysis pipeline to select and prioritize genetic variants. The overall procedure can screen a large number of target genes simultaneously, thereby potentially revealing new disease-causing and modifier genes. By using this procedure, we analyzed hypertrophic cardiomyopathy patients in a shorter time and at a lower cost than with current procedures. The specificity of the next-generation sequencing-based procedure is at least as good as other techniques routinely used for mutation searching, and the sensitivity is much better. Analysis of the results showed some novel variants potentially involved in the pathogenesis of hypertrophic cardiomyopathy: a missense mutation in MYH7 and a nonsense variant in INS-IGF2 (patient 1), a splicing variant in MYBPC3 and an indel/frameshift variant in KCNQ1 (patient 2), and two concomitant variations in CACNA1C (patient 3). Sequencing of DNA from the three patients within a pool allowed detection of most variants identified in each individual patient, indicating that this approach is a feasible and cost-effective procedure.
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Affiliation(s)
- Valeria D'Argenio
- CEINGE-Biotecnologie Avanzate, Naples, Italy; Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Giulia Frisso
- CEINGE-Biotecnologie Avanzate, Naples, Italy; Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Vincenza Precone
- CEINGE-Biotecnologie Avanzate, Naples, Italy; Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy
| | | | - Antonella Fienga
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Giuseppe Pacileo
- Cardiomyopathy and Inherited Heart Disease Clinic, UOC Cardiology, Second University of Naples, Naples, Italy
| | - Giuseppe Limongelli
- Cardiomyopathy and Inherited Heart Disease Clinic, UOC Cardiology, Second University of Naples, Naples, Italy
| | - Giovanni Paolella
- CEINGE-Biotecnologie Avanzate, Naples, Italy; Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Raffaele Calabrò
- Cardiomyopathy and Inherited Heart Disease Clinic, UOC Cardiology, Second University of Naples, Naples, Italy
| | - Francesco Salvatore
- CEINGE-Biotecnologie Avanzate, Naples, Italy; IRCCS-Fondazione SDN, Naples, Italy.
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Iwai C, Li P, Kurata Y, Hoshikawa Y, Morikawa K, Maharani N, Higaki K, Sasano T, Notsu T, Ishido Y, Miake J, Yamamoto Y, Shirayoshi Y, Ninomiya H, Nakai A, Murata S, Yoshida A, Yamamoto K, Hiraoka M, Hisatome I. Hsp90 prevents interaction between CHIP and HERG proteins to facilitate maturation of wild-type and mutant HERG proteins. Cardiovasc Res 2013; 100:520-8. [PMID: 23963841 DOI: 10.1093/cvr/cvt200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIMS We examined the role of Hsp90 in expression and maturation of wild-type (WT) and mutant ether-a-go-go related gene (HERG) proteins by using Hsp90 inhibitors, geldanamycin (GA) and radicicol, and Hsp90 overexpression. METHODS AND RESULTS The proteins were expressed in HEK293 cells or collected from HL-1 mouse cardiomyocytes, and analysed by western blotting, immunoprecipitation, immunofluorescence, and whole-cell patch-clamp techniques. GA and radicicol suppressed maturation of HERG-FLAG proteins and increased their immature forms. Co-expression of Hsp90 counteracted the effects of Hsp90 inhibitors and suppressed ubiquitination of HERG proteins. Overexpressed Hsp90 also inhibited the binding of endogenous C-terminus of Hsp70-interacting protein (CHIP) to HERG-FLAG proteins. Hsp90-induced increase of functional HERG proteins was verified by their increased expression on the cell surface and enhanced HERG channel currents. CHIP overexpression decreased both mature and immature forms of HERG-FLAG proteins in cells treated with GA. Hsp90 facilitated maturation of endogenous ERG proteins, whereas CHIP decreased both forms of ERG proteins in HL-1 cells. Mutant HERG proteins harbouring disease-causing missense mutations were mainly in the immature form and had a higher binding capacity to CHIP than the WT; Hsp90 overexpression suppressed this association. Overexpressed Hsp90 increased the mature form of HERG(1122fs/147) proteins, reduced its ubiquitinated form, increased its immunoreactivity in the endoplasmic reticulum and on the plasma membrane, and increased the mutant-mediated membrane current. CHIP overexpression decreased the immature form of HERG(1122fs/147) proteins. CONCLUSION Enhancement of HERG protein expression through Hsp90 inhibition of CHIP binding might be a novel therapeutic strategy for long QT syndrome 2 caused by trafficking abnormalities of HERG proteins.
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Affiliation(s)
- Chisato Iwai
- Division of Regenerative Medicine and Therapeutics, Department of Genetic Medicine and Regenerative Therapeutics, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science. Nishichou 86, Yonago 683, Japan
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Mapping of interactions between the N- and C-termini and the channel core in HERG K+ channels. Biochem J 2013; 451:463-74. [PMID: 23418776 DOI: 10.1042/bj20121717] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The characteristic gating properties of the HERG [human eag (ether-a-go-go)-related gene] potassium channel determine its contribution to cardiac repolarization and in setting the electrical behaviour of a variety of cells. In the present study we analysed, using a site-directed cysteine and disulfide chemistry approach, whether the eag/PAS (Per/Arnt/Sim) and proximal domains at the HERG N-terminus exert a role in controlling the access of the N-terminal flexible tail to its binding site in the channel core for interaction with the gating machinery. Whereas the eag/PAS domain is necessary for disulfide bridging, plus the cysteine residues introduced at positions 3 and 542 of the HERG sequence, the presence of the proximal domain seems to be dispensable. The state-dependent formation of a disulfide bridge between Cys3 and an endogenous cysteine residue at position 723 in the C-terminal C-linker suggests that the N-terminal tail of HERG can also get into close proximity with the C-linker structures located at the bottom of helix S6. Therefore the intrinsic flexibility of the N-tail and its proximity to both the S4-S5 loop and the C-linker may dynamically contribute to the modulation of HERG channel gating.
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Moskovitz JB, Hayes BD, Martinez JP, Mattu A, Brady WJ. Electrocardiographic implications of the prolonged QT interval. Am J Emerg Med 2013; 31:866-71. [PMID: 23602761 DOI: 10.1016/j.ajem.2012.12.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 12/15/2012] [Accepted: 12/16/2012] [Indexed: 01/08/2023] Open
Abstract
The QT interval measures the time from the start of the QRS complex to the end of the T wave. Prolongation of the QT interval may lead to malignant ventricular tachydysrhythmias, including torsades de pointes. Causes of QT prolongation include congenital abnormalities of the sodium or potassium channel, electrolyte abnormalities, and medications; idiopathic causes have also been identified. Patients can be asymptomatic or present with syncope, palpitations, seizure-like activity, or sudden cardiac death. Management involves looking for and treating reversible causes. For patients with congenital or idiopathic QT interval prolongation, the use of beta-blockers can be considered. Certain subsets of patients benefit from implantation of a cardioverter-defibrillator. Clinicians must remain vigilant for QT interval prolongation when interpreting electrocardiograms, especially in patients presenting with syncope or ventricular arrhythmias.
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Affiliation(s)
- Joshua B Moskovitz
- Department of Emergency Medicine, Hofstra North Shore-Long Island Jewish School of Medicine, Hempstead, NY, USA
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Xiao L, Koopmann TT, Ördög B, Postema PG, Verkerk AO, Iyer V, Sampson KJ, Boink GJJ, Mamarbachi MA, Varro A, Jordaens L, Res J, Kass RS, Wilde AA, Bezzina CR, Nattel S. Unique cardiac Purkinje fiber transient outward current β-subunit composition: a potential molecular link to idiopathic ventricular fibrillation. Circ Res 2013; 112:1310-22. [PMID: 23532596 DOI: 10.1161/circresaha.112.300227] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
RATIONALE A chromosomal haplotype producing cardiac overexpression of dipeptidyl peptidase-like protein-6 (DPP6) causes familial idiopathic ventricular fibrillation. The molecular basis of transient outward current (I(to)) in Purkinje fibers (PFs) is poorly understood. We hypothesized that DPP6 contributes to PF I(to) and that its overexpression might specifically alter PF I(to) properties and repolarization. OBJECTIVE To assess the potential role of DPP6 in PF I(to). METHODS AND RESULTS Clinical data in 5 idiopathic ventricular fibrillation patients suggested arrhythmia origin in the PF-conducting system. PF and ventricular muscle I(to) had similar density, but PF I(to) differed from ventricular muscle in having tetraethylammonium sensitivity and slower recovery. DPP6 overexpression significantly increased, whereas DPP6 knockdown reduced, I(to) density and tetraethylammonium sensitivity in canine PF but not in ventricular muscle cells. The K(+)-channel interacting β-subunit K(+)-channel interacting protein type-2, essential for normal expression of I(to) in ventricular muscle, was weakly expressed in human PFs, whereas DPP6 and frequenin (neuronal calcium sensor-1) were enriched. Heterologous expression of Kv4.3 in Chinese hamster ovary cells produced small I(to); I(to) amplitude was greatly enhanced by coexpression with K(+)-channel interacting protein type-2 or DPP6. Coexpression of DPP6 with Kv4.3 and K(+)-channel interacting protein type-2 failed to alter I(to) compared with Kv4.3/K(+)-channel interacting protein type-2 alone, but DPP6 expression with Kv4.3 and neuronal calcium sensor-1 (to mimic PF I(to) composition) greatly enhanced I(to) compared with Kv4.3/neuronal calcium sensor-1 and recapitulated characteristic PF kinetic/pharmacological properties. A mathematical model of cardiac PF action potentials showed that I(to) enhancement can greatly accelerate PF repolarization. CONCLUSIONS These results point to a previously unknown central role of DPP6 in PF I(to), with DPP6 gain of function selectively enhancing PF current, and suggest that a DPP6-mediated PF early-repolarization syndrome might be a novel molecular paradigm for some forms of idiopathic ventricular fibrillation.
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Affiliation(s)
- Ling Xiao
- Department of Medicine, Montreal Heart Institute and Université de Montréal, Montreal, QC, Canada
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Mahida S, Hogarth AJ, Cowan C, Tayebjee MH, Graham LN, Pepper CB. Genetics of congenital and drug-induced long QT syndromes: current evidence and future research perspectives. J Interv Card Electrophysiol 2013; 37:9-19. [PMID: 23515882 DOI: 10.1007/s10840-013-9779-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 01/07/2013] [Indexed: 12/17/2022]
Abstract
The long QT syndrome (LQTS) is a condition characterized by abnormal prolongation of the QT interval with an associated risk of ventricular arrhythmias and sudden cardiac death. Congenital forms of LQTS arise due to rare and highly penetrant mutations that segregate in a Mendelian fashion. Over the years, multiple mutations in genes encoding ion channels and ion channel binding proteins have been reported to underlie congenital LQTS. Drugs are by far the most common cause of acquired forms of LQTS. Emerging evidence suggests that drug-induced LQTS also has a significant heritable component. However, the genetic substrate underlying drug-induced LQTS is presently largely unknown. In recent years, advances in next-generation sequencing technology and molecular biology techniques have significantly enhanced our ability to identify genetic variants underlying both monogenic diseases and more complex traits. In this review, we discuss the genetic basis of congenital and drug-induced LQTS and focus on future avenues of research in the field. Ultimately, a detailed characterization of the genetic substrate underlying congenital and drug-induced LQTS will enhance risk stratification and potentially result in the development of tailored genotype-based therapies.
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Affiliation(s)
- Saagar Mahida
- Leeds General Infirmary, Great George Street, Leeds, LS1 3EX, UK.
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Hihara T, Taniguchi T, Ueda M, Yoshinaga T, Miyamoto N, Sawada K. Probucol and the cholesterol synthesis inhibitors simvastatin and triparanol regulate I ks channel function differently. Hum Exp Toxicol 2013; 32:1028-37. [PMID: 23424208 DOI: 10.1177/0960327112474848] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Channels responsible for slowly activating delayed-rectifier potassium current (I(Ks)) are composed of KCNQ1 and KCNE1 subunits, and these channels play a role in the repolarization of cardiac action potentials. Recently, we showed that the antihyperlipidemic drug probucol, which induces QT prolongation, decreases the I(Ks) after 24-h treatment. In the present study, we investigated the effects of three cholesterol-lowering agents (probucol, an enhancer of cholesterol efflux; simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor; and triparanol, a 3β-hydroxysterol-▵24-reductase inhibitor) on cholesterol synthesis, the KCNQ1 current (I KCNQ1), and the I(Ks) to clarify the differences in the modes of action of these agents on the I(Ks). Probucol did not inhibit cholesterol synthesis and had no effect on I KCNQ1, while I(Ks) decreased after 24-h treatment. Simvastatin inhibited cholesterol synthesis and decreased I KCNQ1 and I(Ks). Additionally, the activation kinetics of I(Ks) became faster, compared with that of control I(Ks). Triparanol inhibited cholesterol synthesis but did not reduce I KCNQ1 and I(Ks). However, the activation kinetics of I(Ks) became faster. Our data indicated that the mechanism by which probucol inhibits I(Ks) was not mediated by the inhibition of cholesterol synthesis but depended on an interaction with the KCNQ1/KCNE1 complex. Meanwhile, the reduction in cholesterol induced by simvastatin and triparanol is one of the mechanisms that affects the kinetics of I(ks).
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Affiliation(s)
- Taro Hihara
- 1Department of Genomics-Based Drug Discovery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan
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McGorrian C, Constant O, Harper N, O'Donnell C, Codd M, Keelan E, Green A, O'Neill J, Galvin J, Mahon NG. Family-based cardiac screening in relatives of victims of sudden arrhythmic death syndrome. ACTA ACUST UNITED AC 2013; 15:1050-8. [DOI: 10.1093/europace/eus408] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Lariccia V, Moraca A, Marini M, Nasti AA, Battistoni I, Amoroso S, Perna GP. Unusual case of severe arrhythmia developed after acute intoxication with tosylchloramide. BMC Pharmacol Toxicol 2013; 14:8. [PMID: 23347670 PMCID: PMC3566980 DOI: 10.1186/2050-6511-14-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 01/21/2013] [Indexed: 01/09/2023] Open
Abstract
Background Drugs not commonly considered to be cardioactive agents may cause prolongation of the QT interval with resultant torsades de pointes and ventricular fibrillation. This form of drug toxicity often causes cardiac arrest or sudden death. Case presentation After accidental ingestion of tosylchloramide a caucasian 77-year-old woman, with a family history of cardiovascular disease and hypertension, was admitted to the intensive care unit following episodes of torsades de pointes with a prolonged QT/QTc interval (640/542 ms). The patient received an implantable cardioverter-defibrillator, was discharged from the hospital with normal QT/QTc interval and did not experience additional ventricular arrhythmias during one year of follow-up. Conclusion This is the first report concerning an unusual case of torsades de pointes after accidental intoxication by ingestion of tosylchloramide. The pronounced impact of the oxidyzing agent tosylchloramide on the activity of some of the ion channels regulating the QT interval was identified as a probable cause of the arrhythmia.
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Affiliation(s)
- Vincenzo Lariccia
- Department of Biomedical Sciences and Public Health, University Politecnica delle Marche, Ancona, Italy
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Identification of (R)-N-(4-(4-methoxyphenyl)thiazol-2-yl)-1-tosylpiperidine-2-carboxamide, ML277, as a novel, potent and selective K(v)7.1 (KCNQ1) potassium channel activator. Bioorg Med Chem Lett 2012; 22:5936-41. [PMID: 22910039 DOI: 10.1016/j.bmcl.2012.07.060] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 07/11/2012] [Accepted: 07/16/2012] [Indexed: 11/21/2022]
Abstract
A high-throughput screen utilizing a depolarization-triggered thallium influx through KCNQ1 channels was developed and used to screen the MLSMR collection of over 300,000 compounds. An iterative medicinal chemistry approach was initiated and from this effort, ML277 was identified as a potent activator of KCNQ1 channels (EC(50)=260 nM). ML277 was shown to be highly selective against other KCNQ channels (>100-fold selectivity versus KCNQ2 and KCNQ4) as well as against the distantly related hERG potassium channel.
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Valenzuela C. Female gender: risk factor for congenital long QT-related arrhythmias. Cardiovasc Res 2012; 95:263-4. [DOI: 10.1093/cvr/cvs203] [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: 11/13/2022] Open
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Obeyesekere MN, Leong-Sit P, Gula LJ, Yee R, Skanes AC, Klein GJ, Krahn AD. The Evaluation of a Borderline Long QT Interval in an Asymptomatic Patient. Card Electrophysiol Clin 2012; 4:227-238. [PMID: 26939820 DOI: 10.1016/j.ccep.2012.02.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
QT prolongation on resting electrocardiography (ECG) is common, and the clinician is often challenged by the dilemma of excluding acquired causes and recognizing potential congenital long QT syndrome (LQTS). The hallmark of LQTS is an abnormally long QT interval. However, a normal or borderline long QT interval may be observed in up to 50% of patients with LQTS because of the intermittent nature of QT prolongation. This review presents an approach to evaluating the asymptomatic patient with a borderline long QT interval, which incorporates a comprehensive clinical assessment, rest and provocative ECG testing, and genetic testing when appropriate.
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Affiliation(s)
- Manoj N Obeyesekere
- Division of Cardiology, The University of Western Ontario, 339 Windermere Road, London, Ontario N6A 5A5, Canada
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